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  • 1.
    Abdalla, Suliman A
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Architecture and circuit design of photon counting readout for X-ray imaging sensors2007Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Hybrid pixel array detectors for X-ray imaging are based on different technologies for sensor and readout electronics. The readout electronics are based on standard CMOS technologies that are experiencing continuously rapid improvements by means of down-scaling the feature sizes, which in turn lead to higher transistor densities, lower power consumption, and faster circuits. For pixel-array imaging sensors the improvements in CMOS technology opens up new possibilities of integrating more functionality in the pixels for local processing of the sensor data. However, new issues related to the tight integration of both analog and digital processing circuits within the small area of a pixel must also be evaluated.

    The advantages of down-scaling the CMOS technology can be utilized to increase the spatial resolution by reducing the pixel sizes. Recent research indicates however that the bottleneck in reaching further spatial resolution in X-ray imaging sensors may not be limited by the circuit area occupied by the functions necessary in the pixels, but are instead related to problems associated with charge-sharing of charges generated by the sensor which are distributed over a neighbourhood of pixels and will limit the spatial resolution and lead to a distortion of the energy spectrum. In this thesis a mechanism to be implemented in the readout circuits is proposed in order to suppress the charge-sharing effects. The proposed architecture and its circuit implementation are evaluated with respect to circuit complexity (area) and power consumption. For a photon-counting pixel it is demonstrated that the complete pixel, with charge-sharing suppression mechanism, can be implemented using 300 transistors with an idle power consumption of 2.7μW in a 120nm CMOS technology operating with a 1.2V power supply.

    The improvements in CMOS technology can also be used for increasing the range of applications for X-ray imaging sensors. In this thesis, an architecture is proposed for multiple energy discrimination, called color X-ray imaging. The proposed solution is the result of balancing the circuit complexity and the image quality. The method is based on color sub-sampling with intensity biasing. For three-level energy discrimination, that corresponds to color imaging systems for visible light with R, G, and B color components, the increase in circuit complexity will be only 20% higher than that for the Bayer method but results in significantly better image quality.

    As the circuit complexity in the digital processing within each pixel is increased, the digitally induced noise may play an increasingly important role for the signal-to-noise ratio in the measurements. In this thesis an initial study is conducted regarding how the digital switching noise affects the analog amplifiers in the photon-counting pixel.

  • 2.
    Ahlin, Karin
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för data- och systemvetenskap.
    Approaching the intangible benefits of a boundary object2014Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Today´s information society is constantly increasing the quantity of digital information that organisations have access to and depend on. Despite this dependency, few descriptions exist of the benefits which this digital information can provide the organisation with. Examples of what the organisation can use the information for include business intelligence or in a business process. The absence of such benefit descriptions results in missed opportunities in organisational management and a failure to cultivate the artefact. In terms of a practical operational work role, this means that the artefact just exists and that there are no decisions, communication and discussions connected to it. Earlier research about benefits in the Information Systems field is focused on describing the process of finding benefit factors from different IT investments and how these investments can be measured financially. The result of this was that it was only the measurable benefits that were taken into consideration. Later benefit management research has shown interest in the intangible benefit factors as well and added this as an activity in the evaluation process. Today´s view is that the benefit consists both of tangible and intangible benefit factors. This thesis emphasises benefit factors found by means of qualitative research in organisations producing Technical Information (TI). TI isinformation connected to goods and services and is a part of a product. The intangible benefit factors found which are connected to TI are semantic interoperability and knowledge. Semantic interoperability is beneficial both for the organisation and the individuals – in the first case exemplified by a uniform working process and in the second as efficiency in the internal communication. Knowledge also provides benefit both to the organisation and the individuals – the organisation can operate without depending on certain individuals and information gives the individuals mobility in their profession.The next part in the thesis discusses information management´simpact on benefit factors. In the case of an autocratic approach, it is the organisation that benefits most, whereas a decentralised management style provides the individual co-workers with a greater number of benefit factors. This proves that information management is an important and decisive ingredient, and that it affects benefit factors.One step in the direction of converting the intangible benefit factors into tangible ones is to visualise them. In this work the theoreticallens provided by a boundary object has been used. This lens adds a qualitative view on cross-boundary information and has efficiency approaches. These approaches are the syntactical, semantic andpragmatic. Via interpretations from the thesis´s two empirical cases, those approaches are "measured" by interpretations and visualised by the three leaves of a clover. This gives the opportunity to describewhat information efficiency, in this case connected to a positiveexpectation, can contribute to the organisation or the individuals. By this procedure, different cases or time aspects can be compared,thereby providing a basis for decision-making, communication and discussion. Future research in this area can be made in different directions – one is to investigate whether the intangible benefit factors can be turned into measurable ones. In this way, the internal organisation can be provided with better knowledge of the digital information's impact. Another research direction is to investigate how the passage of time affects the benefit factors that digital information gives the organisation.

  • 3.
    Ahmad, Jawad
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för elektronikkonstruktion.
    Screen Printed Large Area Sensors for Pressure Distribution Monitoring in Wheelchairs2019Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    A sedentary lifestyle can induce health related problems including pressure ulcers. Pro­longed sitting inadequacies constitute a risk for pressure ulcer to many individuals, in particular people with disabilities and re­duced mobility. The measurement of distributed pressure and detection of irregular sitting postures are essential in prevention of the risk of developing pres­sure ulcers.

    In this thesis, a screen-printed pressure sensor for a large area is presented, with the objective of measuring the distributed pressure of a seated per­son in a wheelchair. The conductors and interdigital patterns are printed with silver-based ink. A blend of a non-conductive and a low resis­tive ink is used for customized resistance for an optimal sensing range of the pressure sensor. The effect of moisture and temper­ature are realized in an environment chamber. For characterization, other key performance tests such as repeatability, drift and flexibility are carried out. The surface morphology is carried out for structural analysis of printed samples. The sensor data is acquired and processed using an 8-bit ATmega-2560 micro­controller and wirelessly transmitted to a PC for post-processing, storage and analysis. For real-time data presentation of dis­tributed pressure points, a GUI has been developed to display the values ob­tained from the large area sensor. The detection of four sit­ting pos­tures; forward leaning, backward leaning, left leaning and right leaning along with a normal sitting posture is attained. An analysis for stretchable printed tracks has been conducted to investigate the changes in electrical resistance using elon­ga­tion tests, surface morphology and EDS. The optimal curing time and tem­per­ature were investigated to manufacture stretchable conductive tracks.

    In summary, the contributions in this thesis provides an effective approach regarding pressure distribution measurement and recognizing irregular sitting postures for wheelchair users.

  • 4.
    Ahmad, Naeem
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Modelling and optimization of sky surveillance visual sensor network2012Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    A Visual Sensor Network (VSN) is a distributed system of a largenumber of camera sensor nodes. The main components of a camera sensornode are image sensor, embedded processor, wireless transceiver and energysupply. The major difference between a VSN and an ordinary sensor networkis that a VSN generates two dimensional data in the form of an image, whichcan be exploited in many useful applications. Some of the potentialapplication examples of VSNs include environment monitoring, surveillance,structural monitoring, traffic monitoring, and industrial automation.However, the VSNs also raise new challenges. They generate large amount ofdata which require higher processing powers, large bandwidth requirementsand more energy resources but the main constraint is that the VSN nodes arelimited in these resources.This research focuses on the development of a VSN model to track thelarge birds such as Golden Eagle in the sky. The model explores a number ofcamera sensors along with optics such as lens of suitable focal length whichensures a minimum required resolution of a bird, flying at the highestaltitude. The combination of a camera sensor and a lens formulate amonitoring node. The camera node model is used to optimize the placementof the nodes for full coverage of a given area above a required lower altitude.The model also presents the solution to minimize the cost (number of sensornodes) to fully cover a given area between the two required extremes, higherand lower altitudes, in terms of camera sensor, lens focal length, camera nodeplacement and actual number of nodes for sky surveillance.The area covered by a VSN can be increased by increasing the highermonitoring altitude and/or decreasing the lower monitoring altitude.However, it also increases the cost of the VSN. The desirable objective is toincrease the covered area but decrease the cost. This objective is achieved byusing optimization techniques to design a heterogeneous VSN. The core ideais to divide a given monitoring range of altitudes into a number of sub-rangesof altitudes. The sub-ranges of monitoring altitudes are covered by individualsub VSNs, the VSN1 covers the lower sub-range of altitudes, the VSN2 coversthe next higher sub-range of altitudes and so on, such that a minimum cost isused to monitor a given area.To verify the concepts, developed to design the VSN model, and theoptimization techniques to decrease the VSN cost, the measurements areperformed with actual cameras and optics. The laptop machines are used withthe camera nodes as data storage and analysis platforms. The area coverage ismeasured at the desired lower altitude limits of homogeneous as well asheterogeneous VSNs and verified for 100% coverage. Similarly, the minimumresolution is measured at the desired higher altitude limits of homogeneous aswell as heterogeneous VSNs to ensure that the models are able to track thebird at these highest altitudes.

  • 5.
    Ainegren, Mats
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik och hållbar utveckling.
    Ainegren, Mats
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för hälsovetenskap.
    The rolling resistances of roller skis and their effects on human performance during treadmill roller skiing2010Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Modern ski-treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical performance in a laboratory environment using classical and freestyle techniques on roller skis. For elite athletes the differences in performance between test occasions are quite small, thus emphasising the importance of knowing the roller skis’ rolling resistance coefficient, µR, in order to allow correct comparisons between the results, as well as providing the opportunity to study work economy between different athletes, test occasions and core techniques.

    Thus, one of the aims of this thesis was to evaluate how roller skis’ µR is related to warm-up, mass, velocity and inclination of the treadmill. It was also necessary to investigate the methodological variability of the rolling resistance measurement system, RRMS, specially produced for the experiments, with a reproducibility study in order to indicate the validity and reliability of the results.

    The aim was also to study physiological responses to different µR during roller skiing with freestyle and classical roller skis and techniques on the treadmill as a case in which all measurements were carried out in stationary and comparable conditions.

    Finally, the aim was also to investigate the work economy of amateurs and female and male junior and senior cross-country skiers during treadmill roller skiing, i.e. as a function of skill, age and gender, including whether differences in body mass causes significant differences in external power per kg due to differences in the roller skis’ µR.

    The experiments showed that during a warm-up period of 30 minutes, µR decreased to about 60-65% and 70-75% of its initial value for freestyle and classical roller skis respectively. For another 30 minutes of rolling no significant change was found. Simultaneous measurements of roller ski temperature and mR showed that stabilized mR corresponds to a certain running temperature for a given normal force on the roller ski. The study of the influence on mR of normal force, velocity and inclination produced a significant influence of normal force on mR, while different velocities and inclinations of the treadmill only resulted in small changes in mR. The reproducibility study of the RRMS showed no significant differences between paired measurements with either classical or the freestyle roller skis.

    The study of the effects on physiological variables of ~50% change in µR,showed that during submaximal steady state exercise, external power, oxygen uptake, heart rate and blood lactate were significantly changed, while there were non significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests showed that time to exhaustion was significantly changed and this occurred without a significantly changed maximal power, maximal oxygen uptake, maximal heart rate and blood lactate, and that the influence on ratings of perceived exertion was non significant or small.

    The final part of the thesis, which focused on work economy, found no significant difference between the four groups of elite competitors, i.e. between the two genders and between the junior and senior elite athletes. It was only the male amateurs who significantly differed among the five studied groups. The study also showed that the external power per kg was significantly different between the two genders due to differences in body mass and mR, i.e. the lighter female testing groups were roller skiing with a relatively heavier rolling resistance coefficient compared to the heavier testing groups of male participants.

  • 6.
    Alam, Mohammad Anzar
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Online Surface Topography Characterization Technique for Paper and Paperboard using Line of Light Triangulation2012Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 7.
    Alfredsson, Jon
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Performance of Digital Floating-Gate Circuits Operating at Subthreshold Power Supply Voltages2007Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    All who is involved in electronic design knows that one of the critical issues

    in today’s electronic is the power consumption. Designers are always looking for

    new approaches in order to reduce currents while still retain performance.

    Floating-gate (FGMOS) circuits have previously been shown to be a promising

    technique to improve speed and still keep the power consumption low when

    power supply is reduced below subthreshold voltage for the transistors.

    In this thesis, the goal is to determine how good floating-gate circuits can be

    compared to conventional static CMOS when the circuits are working in

    subthreshold. The most interesting performance parameters are speed and power

    consumption and specifically the Energy-Delay Product (EDP) that is a

    combination of those two. To get a view over how the performance varies and how

    good the FGMOS circuits are at their best case, the circuits have been designed and

    simulated for best case performance.

    The investigation also includes trade-offs with speed and power

    consumption for better performance, how to select floating-gate capacitances, how

    a large circuit fan-in will affect performance and also the influence of different

    kinds of refresh circuits.

    The first simulations of the FGMOS circuits in a 0.13 μm process have

    several interesting results. First of all, in the best case it is shown that FGMOS has

    potential to achieve up to 260 times in better EDP-performance compared to CMOS

    at 150 mV power supply. Continuing with simulations of FGMOS capacitances

    shows that minimum floating-gate capacitance can be as small as 400 fF and more

    realistic performance shows that EDP is 37 times better for FGMOS (with parasitic

    capacitances included). Other aspects of FGMOS design have been to look at how

    refresh circuits will affect performance (semi-floating-gate circuits) and how a

    larger fan-in will change noise margin and EDP. It turns out that refresh circuits

    with the same transistor size does not give a noticeable change in performance

    while an increase of 8 times in size will give between 5 and 10 times wors EDP.

    When it comes to fan-in the simulations shows that a maximum fan-in of 5 is

    possible at 250 mV supply and it decrease to 3 when supply voltage is reduced to

    150 mV.

    Finally, it should be kept in mind that tuning the performance of FGMOS

    circuits with trade-offs and by changing the floating-gate voltages to achieve

    results like the ones stated above will also always affect the noise margins, NM, of

    the circuits. As a consequence of this, the NM will sometimes be so close to 1 that a

    fabricated circuit with that NM may not be as functional as simulations suggests.

    The probability to design functional FGMOS circuits in subthreshold does not

    seem to be a problem though.

  • 8.
    Ambatipudi, Radhika
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Multilayered Coreless Printed Circuit Board (PCB) Step-down Transformers for High Frequency Switch Mode Power Supplies (SMPS)2011Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The Power Supply Unit (PSU) plays a vital role in almost all electronic equipment. The continuous efforts applied to the improvement of semiconductor devices such as MOSFETS, diodes, controllers and MOSFET drivers have led to the increased switching speeds of power supplies. By increasing the switching frequency of the converter, the size of passive elements such as inductors, transformers and capacitors can be reduced. Hence, the high frequency transformer has become the backbone in isolated AC/DC and DC/DC converters. The main features of transformers are to provide isolation for safety purpose, multiple outputs such as in telecom applications, to build step down/step up converters and so on. The core based transformers, when operated at higher frequencies, do have limitations such as core losses which are proportional to the operating frequency. Even though the core materials are available in a few MHz frequency regions, because of the copper losses in the windings of the transformers those which are commercially available were limited from a few hundred kHz to 1MHz. The skin and proximity effects because of induced eddy currents act as major drawbacks while operating these transformers at higher frequencies. Therefore, it is necessary to mitigate these core losses, skin and proximity effects while operating the transformers at very high frequencies. This can be achieved by eliminating the magnetic cores of transformers and by introducing a proper winding structure.

    A new multi-layered coreless printed circuit board (PCB) step down transformer for power transfer applications has been designed and this maintains the advantages offered by existing core based transformers such as, high voltage gain, high coupling coefficient, sufficient input impedance and high energy efficiency with the assistance of a resonant technique. In addition, different winding structures have been studied and analysed for higher step down ratios in order to reduce copper losses in the windings and to achieve a higher coupling coefficient. The advantage of increasing the layer for the given power transfer application in terms of the coupling coefficient, resistance and energy efficiency has been reported. The maximum energy efficiency of the designed three layered transformers was found to be within the range of 90%-97% for power transfer applications operated in a few MHz frequency regions. The designed multi-layered coreless PCB transformers for given power applications of 8, 15 and 30W show that the volume reduction of approximately 40-90% is possible when compared to its existing core based counterparts. The estimation of EMI emissions from the designed transformers proves that the amount of radiated EMI from a three layered transformer is less than that of the two layered transformer because of the decreased radius for the same amount of inductance.

    Multi-layered coreless PCB gate drive transformers were designed for signal transfer applications and have successfully driven the double ended topologies such as the half bridge, the two switch flyback converter and resonant converters with low gate drive power consumption of about half a watt. The performance characteristics of these transformers have also been evaluated using the high frequency magnetic material made up of NiZn and operated in the 2-4MHz frequency region.

    These multi-layered coreless PCB power and signal transformers together with the latest semiconductor switching devices such as SiC and GaN MOSFETs and the SiC schottky diode are an excellent choice for the next generation compact SMPS.

  • 9.
    Andersson, Henrik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Development of Process Technology for Photon Radiation Measurement Applications2007Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis presents work related to new types of photo detectors and their applications. The focus has been on the development of process technology and methods by means of experimentation and measurements. The overall aim has been to develop and improve photon radiation measurement applications which are possible to manufacture using standard Si processing technology.

    A new type of position sensitive detector that has switching possibilities based on the MOS principle has been fabricated and characterized. The influence of mechanical stress on the linearity of position sensitive detectors has been investigated. The results show that mechanical stress arising, for example, by the mounting of detectors in capsules can have an impact on device performance. Under normal circumstances these effects are rather small, but are considered to be worthwhile taking into account.

    Electroless deposition of Nickel including various dopants in porous silicon was performed to manufacture electrical contacts for this interesting material. After heat treatment it was confirmed by X-ray diffraction that Nickel silicide had been formed and I-V measurements show that different contacts exhibit Ohmic and rectifying behaviour.

    Spectrometers are used extensively in the process and food industry to measure both the chemical content and the amount of substances used during manufacturing. These instruments are often rather bulky and costly, though the trend is towards smaller and more portable equipment. A spectrometer based on an array of Fabry-Perot interferometers mounted close to an array detector is shown to be a viable option for the manufacture of a very compact device. Such a device has minimal intermediate optics and it may be possible, in the future, for it to be developed and completely integrated with a detector array into a single unit.

  • 10.
    Andersson, Johanna
    et al.
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för hälsovetenskap.
    Lundin, Marie
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för hälsovetenskap.
    Sjuksköterskans upplevelser och attityder i omvårdnaden av personer med självskadebeteende.2009Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Bakgrund: Den vanligaste formen av självskadebeteende kallas för ytligt självskadande. Det innebär att personen skär eller rispar sig själv med ett vasst föremål. Sjuksköterskor och annan vårdpersonal bör uppmanas att tänka över sina egna värderingar och sedan införliva det i arbetet med personer som skadar sig själva. Syfte: Syftet var att belysa sjuksköterskans upplevelser och attityder i omvårdnaden av personer med självskadebeteende. Metod: En litteraturstudie utfördes där 13 vetenskapliga artiklar inkluderades. Artiklarna granskades och bearbetades och sammanställdes till ett resultat. Resultat: Resultatet presenterades i två huvudkategorier och dessa var; upplevelser och attityder hos sjuksköterskan och behov av stöd. Sjuksköterskor bar på många känslor, så som frustration, rädsla, ångest och stress. Utbildning gav sjuksköterskorna nya färdigheter i omvårdnaden av personer med självskadebeteende. Diskussion: Den mest genomgripande känslan hos sjuksköterskorna i arbetet med personer som skadar sig själva var frustration. Den känslomässiga motviljan hos sjuksköterskorna gentemot dessa personer reducerades efter utbildningen. Slutsats: Brist på kunskap hos sjuksköterskorna kunde leda till en försämrad förståelse av självskadebeteende som i sin tur kunde leda till ett sämre bemötande. Behoven som sjuksköterskorna hade i omvårdnaden av personer med självskadebeteende var utbildning och en god arbetsmiljö.

     

  • 11.
    Andersson, Kerstin
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap, teknik och matematik.
    Lignin in wastewater generated by mechalical pulping: Chemical characterisation and removal by adsorption2010Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 12.
    Andersson, Stefan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap, teknik och matematik.
    Low consistency refining of mechanical pulp: process conditions and energy efficiency2011Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The thesis is focussed on low consistency (LC) refining of mechanical pulp. Theresearch included evaluations of energy efficiency, development of pulpproperties, the influence of fibre concentration on LC refining and effects of rotorposition in a two-zoned LC refiner.

    Trials were made in mill scale in a modern TMP line equipped with an MSDImpressafiner for chip pre-treatment, double disc (DD) first stage refining and aprototype 72-inch TwinFlo LC refiner in the second stage. Tensile index increasedby 8 Nm/g and fibre length was reduced by 10 % in LC refining at 140 kWh/adtgross specific refining energy and specific edge load 1.0 J/m. Specific lightscattering coefficient did not develop significantly over the LC refiner.

    The above mentioned TMP line was compared with a two stage single disc highconsistency Twin 60 refiner line. The purpose was to evaluate specific energyconsumption and pulp properties. The two different process solutions were testedin mill scale, running similar Norway spruce wood supply. At the same tensileindex and freeness, the specific energy consumption was 400 kWh/adt lower in theDD-LC concept compared with the SD-SD system. Pulp characteristics of the tworefining concepts were compared at tensile index 47 Nm/g. Fibre length was lowerafter DD-LC refining than after SD-SD refining. Specific light scattering coefficientwas higher and shive content much lower for DD-LC pulp.

    The effects of sulphite chip pre-treatment on second stage LC refining were alsoevaluated. No apparent differences in fibre properties after LC refining werenoticed between treated and untreated pulps. Sulphite chip pre-treatment iniiicombination with LC refining in second stage, yielded a pulp without screeningand reject refining with tensile index and shives content that were similar to nonpre-treated final pulp after screening and reject refining.

    A pilot scale study was performed to investigate the influence of fibreconcentration on pulp properties in LC refining of mechanical pulps. MarketCTMP was utilised in all trials and fibre concentrations were controlled by meansof adjustments of the pulp consistency and by screen fractionation of the pulp. Inaddition, various refiner parameters were studied, such as no-load, gap and baredge length. Pulp with the highest fibre concentration supported a larger refinergap than pulp with low fibre concentration at a given gross power input. Fibreshortening was lower and tensile index increase was higher for long fibre enrichedpulp. The results from this study support the interesting concept of combiningmain line LC refining and screening, where screen reject is recycled to the LCrefiner inlet.

    It has been observed that the rotor in two-zoned refiners is not always centred,even though pulp flow rate is equal in both refining zones. This leads to unequalplate gaps, which renders unevenly refined pulp. Trials were performed in millscale, using the 72-inch TwinFlo, to investigate differences in pulp properties androtor positions by means of altering the pressure difference between the refiningzones. In order to produce homogenous pulp, it was found that uneven plate gapscan be compensated for in LC refiners with dual refining zones. Results from thedifferent flow rate adjustments indicated that the control setting with similar plategap gave the most homogenous pulp.

  • 13.
    Andres, Britta
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Paper-based Supercapacitors2014Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The growing market of mobile electronic devices, renewable off-grid energy sources and electric vehicles requires high-performance energy storage devices. Rechargeable batteries are usually the first choice due to their high energy density. However, supercapacitors have a higher power density and longer life-time compared to batteries. For some applications supercapacitors are more suitable than batteries. They can also be used to complement batteries in order to extend a battery's life-time. The use of supercapacitors is, however, still limited due to their high costs. Most commercially available supercapacitors contain expensive electrolytes and costly electrode materials.

    In this thesis I will present the concept of cost efficient, paper-based supercapacitors. The idea is to produce supercapacitors with low-cost, green materials and inexpensive production processes. We show that supercapacitor electrodes can be produced by coating graphite on paper. Roll-to-roll techniques known from the paper industry can be employed to facilitate an economic large-scale production. We investigated the influence of paper on the supercapacitor's performance and discussed its role as passive component. Furthermore, we used chemically reduced graphite oxide (CRGO) and a CRGO-gold nanoparticle composite to produce electrodes for supercapacitors. The highest specific capacitance was achieved with the CRGO-gold nanoparticle electrodes. However, materials produced by chemical synthesis and intercalation of nanoparticles are too costly for a large-scale production of inexpensive supercapacitor electrodes. Therefore, we introduced the idea of producing graphene and similar nano-sized materials in a high-pressure homogenizer. Layered materials like graphite can be exfoliated when subjected to high shear forces. In order to form mechanical stable electrodes, binders need to be added. Nanofibrillated cellulose (NFC) can be used as binder to improve the mechanical stability of the porous electrodes. Furthermore, NFC can be prepared in a high-pressure homogenizer and we aim to produce both NFC and graphene simultaneously to obtain a NFC-graphene composite. The addition of 10% NFC in ratio to the amount of graphite, increased the supercapacitor's capacitance, enhanced the dispersion stability of homogenized graphite and improved the mechanical stability of graphite electrodes in both dry and wet conditions. Scanning electron microscope images of the electrode's cross section revealed that NFC changed the internal structure of graphite electrodes depending on the type of graphite used. Thus, we discussed the influence of NFC and the electrode structure on the capacitance of supercapacitors.

  • 14.
    Appelberg, Jonas
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för medie- och kommunikationsvetenskap.
    Gilla oss!: En studie av fyra svenska medieföretags arbete med sociala medier2018Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    This dissertation contains an exploratory study of how four Swedish media companies has decided to use social media in their daily work, and also how they in fact use them. What are the goals with implementing social media, how do they differ between different companies and do the goals transfer into the newsrooms?

    The four companies studied are Sveriges Radio, Aftonbladet, Dalarnas Tidningar and Gotlands Media. Media companies that differ from one another both in size, geographical coverage and economy. They range from small local newspapers to national public service radio and the biggest tabloid on the Swedish market. The methods used are qualitative research interviews and field studies as well as quantitative data analysis. The theoretical chapter helps define traditional journalism and journalistic practice. The concepts of boundaries, participatory cultures and normalizing of work methods are also discussed and helps build a context for the analysis of the empirical data.

    Some key findings from the study are that there are more similarities than differences between the various companies in both how they aim to use social media and how they in fact use them. That the digital development in the surrounding society are much faster than the implementation of new technologies in the newsrooms. Also, that there are differences between how the companies aim to use social media and the actual usage. For instance, all companies strive for a more active dialog with the audience in their visionary work, but has a hard time turning this into reality.

    There is also notable that social media in this study do not change the journalistic fundamental routines and traditions. The studied journalists are still in control of their own content and they aim to meet the same standard in journalistic quality when working in social media. It is also evident that Facebook is invaluable for all the studied companies, which gives Facebook an interesting indirect power over the journalistic work process and product. Finally, the study finds that it is hard to engage the audience in an active collaboration even when working with social media.

  • 15.
    Ashraf, Shakeel
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Design and Integration of Infrared Absorber Structures into Polymer Membranes based Thermal Detectors2015Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 16. Backlund, Hans-Olof
    Measurement of shear force, temperature profiles and fibre development in mill-scale TMP refiners2004Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Två typer av kraftgivare har utvecklats för att mäta tangentiella krafter i

    kommersiella TMP raffinörer, den ena baserad på piezoelektriska sensorer och den

    andra på trådtöjningsgivare. Tekniken har använts för att lära mer om de mekanismer

    som är verksamma vid raffinering i både plandiskraffinörer och i koniska raffinörer.

    Trots extremt svåra förhållanden med stora variationer i både temperatur och

    ångtryck har kraftfördelningen bestämts i malzonen.

    Resultaten från plandiskförsöken visar att den tangentiella kraften i malzonen

    antar ett maximum nära periferin. Kraftprofilen i planzonen på CD raffinören visar

    en likartad profil som den som uppmätts i plandiskraffinören. I båda fallen ökar den

    tangentiella kraften med radien och visar på större variationer i amplitud vid små

    radier. Viktigt att notera är att temperaturprofilen och kraftprofilen antog sina

    maxvärden vid olika radier.

    En studie av fiberkarakteristiken i en enstegs CD-82 har genomförts där

    massaprover har tagits både efter plan- och CD zonen. Försöken visade att

    planzonsspalten har stor inverkan på långfiberandelen och fiberfraktionerna.

  • 17.
    Bader, Sebastian
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Enabling autonomous envionmental measurement systems with low-power wireless sensor networks2011Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Wireless Sensor Networks appear as a technology, which provides the basisfor a broad field of applications, drawing interest in various areas. On theone hand, they appear to allow the next step in computer networks, buildinglarge collections of simple objects, exchanging information with respect totheir environment or their own state. On the other hand, their ability tosense and communicate without a fixed physical infrastructure makes theman attractive technology to be used for measurement systems.Although the interest inWireless Sensor Network research is increasing,and new concepts and applications are being demonstrated, several fundamentalissues remain unsolved. While many of these issues do not requireto be solved for proof-of-concept designs, they are important issues to beaddressed when referring to the long-term operation of these systems. Oneof these issues is the system’s lifetime, which relates to the lifetime of thenodes, upon which the system is composed.This thesis focuses on node lifetime extension based on energy management.While some constraints and results might hold true from a moregeneral perspective, the main application target involves environmental measurementsystems based onWireless Sensor Networks. Lifetime extensionpossibilities, which are the result of application characteristics, by (i) reducingenergy consumption and (ii) utilizing energy harvesting are to be presented.For energy consumption, we show howprecise task scheduling due to nodesynchronization, combined with methods such as duty cycling and powerdomains, can optimize the overall energy use. With reference to the energysupply, the focus lies on solar-based solutions with special attentionplaced on their feasibility at locations with limited solar radiation. Furtherdimensioning of these systems is addressed.It will be shown, that for the presented application scenarios, near-perpetualnode lifetime can be obtained. This is achieved by focusing on efficient resourceusage and by means of a carefully designed energy supply.

  • 18.
    Bakar, Muhammad Abu
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Design and optimization of soft switched power converters for low and medium power applications2016Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 19.
    Bellman, Lina
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för samhällsvetenskap.
    Auktoriserade fastighetsvärderares syn på värdering: tankemönster om kommersiella fastigheter2012Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [sv]

    Värdering av kommersiella fastigheter handlar om att samla in, analysera och bedöma information. Förutom att fastigheternas marknadsvärden har betydelse för samhället i stort är de av vikt för dem som fattar beslut som grundas på värdeutlåtanden. Syftet med denna licentiatavhandling är a) att kartlägga hur svenska auktoriserade fastighetsvärderare ser på de faktorer som avgör värdet på kommersiella fastigheter när värderingen görs inför upprättandet av årsredovisning samt b) att jämföra och dra slutsatser om fastighetsvärderarnas tanke­mönster vad gäller innehåll, komplexitet och homogenitet samt i vilken omfattning tankemönstren skiljer sig åt mellan olika grupper av fastighets­värderare.

    För att kartlägga fastighetsvärderarnas tankemönster använder jag mig av Kellys (1955) gridteknik och kompletterande semistrukturerade intervjuer. Jag har intervjuat nära hälften (67) av Sveriges auktoriserade fastighetsvärderare. Resultatet visar tre tolkningsbara dimensioner som kan anses centrala i fastighetsvärderarnas tankemönster. Den första dimensionen avser värderingens fokus. Den handlar om att fastighetsvärderare uppfattar att olika sorters information och bedömning har olika påverkan på fastighetsvärdering på mikro- respektive makronivå. Med mikronivå menas då fastigheter i relation till deras fastighets­ägare och makronivå avser fastigheter i relation till marknaden i stort. Den andra dimensionen ger uttryck för att fastighetsvärderare uppfattar att viss information är mer eller mindre verifierbar utifrån informationens karaktär. Den tredje dimensionen avser bedömningens komplexitet. Fastighetsvärderare uppfattar att olika typer av information är komplexare respektive enklare att bedöma.

    Resultaten tyder på att fastighetsvärderare har ett flerdimentionellt tankemönster. När de auktoriserade fastighetsvärderarna delas upp i grupper utifrån olika bakgrunds­variabler återkommer de tre dimensionerna i samtliga gruppers tankemönster. Detta tyder även på att auktoriserade fastighetsvärderare har relativt homogena tankestrukturer. Vissa skillnader i komplexitet och homogenitet framkommer dock. Dessa skillnader visar sig främst utifrån de auktoriserade fastighets­­värderarnas verksamhetsorter och vid vilka lärosäten de studerat.

  • 20.
    Bergström, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Modelling Mechanics of Fibre Network using Discrete Element Method2018Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Low-density fibre networks are a fundamental structural framework of everyday hygiene products, such as baby diapers, incontinence and feminine care products, bathroom tissue and kitchen towels. These networks are a random assembly of fibres, loosely bonded and oriented in the plane direction.

    Designing such a complex network structure for better performance, better use of materials and lower cost is a constant challenge for product designers, requiring in-depth knowledge and understanding of the structure and properties on the particle (fibre) level.

    This thesis concerns the development of a computational design platform that will generate low-density fibre networks and test their properties, seamlessly, with the aim to deepening the fundamental understanding of the micromechanics of this class of fibre networks.

    To achieve this goal, we have used a particle-based method, the Discrete Element Method (DEM), to model the fibres and fibre networks. A fibre is modelled as a series of linked beads, so that one can consider both its axial properties (stretching and bending) and transverse properties (shearing,twisting and transverse compression). For manufacturing simulations, we developed the models for depositing fibres to form a fibre network, consolidating the fibre network, compressing to make a 3D-structured network, and creating creping. For testing the end-use performance, we have developed two models and investigated the micromechanics of the fibre network in uniaxial compression in the thickness direction (ZD) and in uniaxial tension in the in-plane direction.

    In the ZD-uniaxial compression of entangled (unbonded) fibrenetworks, the compression stress exhibits a power-law relationship with density, with a threshold density. During compression, the fibre deformation mode changed from fibre bending to the transverse compression of fibre. Accordingly, the transverse properties of the fibreshad a large impact on the constitutive relation. By considering a realistic value for the transverse fibre property, we were able to predict the valuesof the exponent widely observed in the experimental literature. We havefound that the deviation of the experimental values from those predictions by the earlier theoretical studies is due to the neglect of the transverse fibre property.

    For tensile properties of bonded networks, we have investigated scaling of network strength with density and fibre–fibre bond strength. The network strength showed beautiful scaling behaviour with both density and bond strength, with exponents 1.88 and 1.08 respectively. The elastic modulus of the network, on the other hand, showed a changing exponent(from 2.16 to 1.69) with density in accordance with previous results in the literature. We have also reconfirmed that, with increasing density, the deformation mode changes from bending to stretching. The predicted results for both elastic modulus and strength agreed very well with experimental data of fibre networks of varying densities reported in the literature.

    We have developed a computational platform, based on DEM, for accurately modelling a fibre network from its manufacturing process to product properties. This is a tool that allows a versatile design of materials and products used for hygiene products, providing a promising venue for exploring the parameter space of new material and process design.

  • 21.
    Blomquist, Nicklas
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Large-Scale Nanographite Exfoliation for Low-Cost Metal-Free Supercapacitors2016Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 22.
    Bogren, Maria
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för samhällsvetenskap.
    EN UTOPISK IDÉ?: Medverkan på (o)lika villkor i utvecklingspartnerskap2010Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [sv]

    A utopian idea?

    Participation Under (Dis)Similar Conditions inDevelopment Partnerships

    Maria Bogren

     

    Department of Social Sciences

    Mid Sweden University, SE-831 25 Östersund, Sweden

    ISSN 1652-8948, Mid Sweden University Licentiate Thesis 53;

    ISBN 978-91-86694-12-8

     

     

    Abstract

    Important societal issues nowadays do not get resolved through the care of the state; it is rather the case that solutions involve multiple actors.  Such cooperation can be organized in partnership where actors from the public sector, private companies and non-profit organizations, for example, attempt to find solutions to a current societal issue. The target group affected by the problems can also be involved in the partnership. The aim of this study is to contribute to an increased understanding regarding cooperation in partnerships and especially the target group’s participation in partnerships. An idea regarding the target group’s participation stems from the European level to the national level and finally to the local level in a development partnership. I follow the local development partner-ship for two years with a view to examining the translation process of the idea regarding the target group’s participation. Data was collected through interviews, relevant documents and observation. What is more, the significance of the institutional surroundings regarding what happens in the partnership is discussed. The idea regarding the target group’s participation manifests itself on: a) how the target group should be represented; b) how it gains influence and c) how the role of the target group’s representatives should be shaped. The study shows that ideas change and adjust over time and also that the target group participates under different conditions compared to the rest of the representatives in the partnership. A way to strengthen the target group’s participation in the partnership can be through further organizing, thus increasing the legitimization level of the target group.

     

    Keywords: translation, target group, participation, public-private partnerships

    SAMMANFATTNING

     

    Angelägna samhällsproblem får numera inte alltid sin lösning genom statens försorg utan istället involveras flera aktörer. Ett sådant samarbete kan organiseras i partner­skap där aktörer från exempelvis offentlig sektor, företag och ideella organisationer tillsammans försöker hitta lösningar på något aktuellt samhällsproblem. I partner­ska­pet kan även den målgrupp som berörs av problematiken involveras. Syftet med denna studie är att bidra till ökad förståelse när det gäller samverkan i partnerskap och speciellt när det gäller målgruppens medverkan i partnerskap. En idé om målgruppens medverkan följs från europeisk nivå, till nationell nivå och slutligen till lokal nivå i ett utvecklingspartnerskap. Jag följer det lokala utvecklings­partnerskapet under två års tid och använder dokumentstudier, intervjuer och obser­vationer för att studera översättningsprocessen av idén om målgruppens medverkan. Dessutom diskuteras den institutionella omgivningens betydelse för det som händer i partnerskapet. Idén om målgruppens medverkan tar sig uttryck i idéer om hur målgruppen ska finnas repre­sen­terad och hur den ska få inflytande samt hur rollen som målgrupps­rep­resen­tant ska utformas. Studien visar att idéerna förändras och anpassas över tid samt att målgruppen medverkar på olika villkor jämfört med övriga representanter i partnerskapet. Ett sätt att stärka målgruppens medverkan i partnerskapet kan vara genom ytterligare organisering för att på så sätt ge ökad legitimitet för målgruppen.

     

    Nyckelord: översättning, målgrupp, medverkan, privatoffentliga partnerskap

  • 23.
    Boija, Susanne
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    On metal ion chelates and conditional stability constant determination: Method development and selective ion flotation of chelating surfactants2014Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 24.
    Bois, Lisa
    Mittuniversitetet, Fakulteten för humanvetenskap, Avdelningen för ekonomivetenskap och juridik.
    Företagares agerande för hembygdens utveckling2017Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [sv]

    Denna licentiatavhandling handlar om vardagligt samhällsentreprenörskap iform av landsbygdsaktivering och inspiration med exempel frånbefolkningsmässigt små byar belägna i Jämtlands län. Syftet med denna heltkvalitativa ansats är att beskriva lokala företagares roll och engagemang förutvecklingen i deras hembygder. Resultatet är en beskrivande modell medgemensamma parametrar som funnits med i byarnas utveckling och en modellöver vilka olika roller en entreprenör kan.Landsbygden står inför många utmaningar, inte minst har utglesning avbefolkningen aldrig gått snabbare än nu (SWECO, 2014).Samhällsentreprenörskapet som beskrivs handlar om att invånare tar tag ihembyns egen framtid och skapar aktiviteter som känns meningsfulla för demsjälva och uppskattade lokalt på landsbygden. Tillsammans har gemensammaansträngningar gjort att de undersökta byarna skapat något exceptionellt inom sinegen nisch. Denna utgångspunkt leder vidare till kopplingen mellan lokalaföretagare, vardagligt entreprenörskap och dess direkta påverkan på lokalutveckling.De teoretiska bidragen i licentiatavhandlingen är en beskrivning av fenomenetvardagligt samhällsentreprenörskap och dess koppling till lokal utveckling.Beskrivningen fördjupas med fokus på vardagliga aktiviteter med framtagnamodeller. Licentiatavhandlingen beskriver vardagligt samhällsentreprenörskap iform av aktiviteter för lokal utveckling. Här är det exempel på vardagliga utbytenoch aktiviteter med många timmars engagemang som har gett resultat. De trebyarna har lyckats aktivera familjer och grannar, de som själv har velat delta.Tillsammans har de skapat något som gett mervärden och som de själva tyckt harvarit till det bättre. Detta har byarna även uppmärksammats för på olika vis. Dehar i sin tur spridit sitt engagemang och inspirerat andra byars invånare till attockså ta initiativ och agera för egen lokalutveckling. Utifrån arbetet i de olikabyarna gjordes en gemensam modell av påverkande utvecklingsfaktorer.Det andra teoretiska bidraget är beskrivningen av vilka drivkrafter som lågbakom valet att agera och dess koppling till den lokala utvecklingen. Oavsettvilken drivkraft som låg till grund för entreprenören blev utfallet snarlikt för denlokala utvecklingen. Även om det fanns en drivkraft att tjäna pengar i vissa fallblev resultatet en typ av samhällsnytta direkt i byn i alla fall. Ett vardagligtentreprenörskap inspirerade till ökad aktivitet för utveckling och blev på så vis tillett vardagligt samhällsentreprenörskap.

  • 25.
    Borglund, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    A predictive model for attaining quality in recordkeeping2006Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Records are a subset of information and recordkeeping requirements demand that a record is managed with maintained authenticity and reliability, i.e. with high quality. Records are evidence of transactions and are used and managed in daily work processes. Records may be preserved for anything from milliseconds to eternity. With computer based information systems the electronic record was born: a record that is born digital. With electronic records problems regarding maintenance of authenticity and reliability have been identified. Electronic records are no longer physical entities as traditional records were. An electronic record is a logical entity that can be spread over different locations in a computer based information system. In this research the aim is to improve the possibility of reaching high quality in recordkeeping systems, i.e. to maintain reliability and authenticity of electronic records, which is necessary if electronic records are to be usable as evidence of transactions. Based on case studies and literature studies, a recordkeeping quality model is presented: a predictive model for attaining quality in recordkeeping. The recordkeeping quality model consists of four major concepts which are interrelated with each other: Electronic records, Records use, Electronic record quality, and Multidimensional perspective. The model is proposed for use when designing and developing computer based information systems which are required to be recordkeeping, systems which manage electronic records. In this research two results beside the recordkeeping quality model are emphasized. The first is that quality in recordkeeping must be seen in a multidimensional perspective, and the second is that recordkeeping systems are information systems with a partially unknown purpose.

  • 26.
    Brodin, Kerstin
    Mittuniversitetet, Fakulteten för humanvetenskap, Avdelningen för omvårdnad.
    Den vakna patienten: En kvalitativ studie om intraoperativ omvårdnad2018Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Inledning: Som ett resultat av utvecklingen inom anestesi och kirurgi kan allt mer komplexa operationer utföras i lokala eller regionala anestesier. Detta innebär att den kirurgiska patienten kan förbli mer eller mindre vaken genom hela den intraoperativa fasen.

    Syfte: Syftet med denna avhandling var att få en djupare förståelse för den intraoperativa omvårdnaden när patienten är vaken. Avhandlingen består av två delstudier [I-II] vilka har, beroende på delstudiens syfte, utgått från operationssjuksköterskans perspektiv [I] och patientens perspektiv [II].

    Metod: Utifrån syftet valdes kvalitativa metoder för båda delstudierna. Data samlades in genom fokusgruppintervjuer [I] och individuella intervjuer [I,II]. Insamlad data analyserades i enlighet med Grundad teori [I] och kvalitativ innehållsanalys [II].

    Resultat: Studie I visade att det som ansågs vara operationssjuksköterskans huvudangelägenhet var att ta den vakna patienten i beaktande vilket de försökte åstadkomma genom att uppnå och bibehålla en hög moral på sal genom hela processen. För att uppnå hög moral var det tre aspekter som operationssjuksköterskan tog hänsyn till; patienten, teamet och den professionella yrkesrollen. För att uppnå hög moral på sal var operationssjuksköterskorna vaksamma och flexibla. De balanserade mellan patientens behov, teamets behov de behov som var förknippade med säker kirurgi. Moralen beskrevs vara en helhet med målet att ge patienten en positiv upplevelse. Resultatet i studie II visade att patienterna upplevde att de var i en situation de inte hade kontroll över och de var uppmärksamma och reflekterande för att skapa mening och trygghet åt situationen. Det övergripande temat ”att söka efter förtroende i en utsatt och beroende situation” illustrerar hur patienterna tenderade att i första hand tolka det som skedde omkring dem på så sätt att det bringade känslan av att vara trygga. De fyra kategorierna; att erfara stämningen på sal, att möta[o]väntade känselförnimmelser, att uppfatta bevis på säkerhet och att använda individuella strategier, beskriver patienternas upplevelser om vad som påverkade förtroendet samt hur de hanterade dessa upplevelser. Huvudfynden berörde de intraoperativa behoven samt hanteringen och balanseringen mellan dess.

    Slutsats: Operationssjuksköterskans intraoperativa omvårdnad kan bidra till positiva upplevelser för patienten som är vaken under ett kirurgiskt ingrepp. Operationssjuksköterskans förmåga att tolka och agera på olika intraoperativa behov samt patientens personlighet och egna förmåga att hantera situationen är av stor betydelse för upplevelsen av den intraoperativa fasen.

  • 27.
    Bäck, Lena
    Mittuniversitetet, Fakulteten för humanvetenskap, Avdelningen för omvårdnad.
    Confidence in Midwifery: Midwifery students and midwives’ perspectives2018Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    En trygg barnmorska har en positiv inverkan för förlossningsutfall samt förlossningsupplevelse. Kunskap, kompetens och trygghet är ett livslångt lärande och har stor betydelse för att utveckla och forma personliga färdigheter, att låta de personliga egenskaperna växa och mogna. Tidigare internationella studier har påvisat att barnmorskestudenter känner sig otrygga inom områden där förväntas vara självständiga. Syftet med denna avhandling var att undersöka graden av trygghet hos svenska barnmorskstudenter strax innan de var färdigutbildade. Ett annat syfte var att utforska hur kliniskt verksamma barnmorskor reflekterar över lärande och vilka faktorer som bidrar till att utveckla yrkesmässig kompetens och trygghet.

    Studie I var en tvärsnittsundersökning med svenska barnmorskestudenter (n = 238). De bedömde egen trygghet inom alla kompetenser som en barnmorska förväntas kunna samt utföra självständigt. Resultaten av studie I bekräftade att svenska barnmorskestudenter känner sig trygga att hantera de vanligaste rutinerna vid normal graviditet, förlossning, eftervård samt nyföddhets vård. De känner sig emellertid inte fullt så trygga när något avviker från det normala samt vid obstetriska nödsituationer. Vid jämförelse mellan yngre och äldre barnmorskestudenter samt grad av trygghet, var det den yngre gruppen av barnmorskestudenter som kände sig tryggare i allmänhet jämfört med den äldre gruppen. Studenter vid ett universitet med en medicinsk fakultet var också mer trygga än studenterna vid ett universitet utan en medicinsk fakultet.

    I studie II hölls fokusgrupper med 14 barnmorskor, de diskuterade och reflekterade över hur barnmorskor utvecklar kompetens. Metod för att analysera var innehållsanalys, i resultatet framkom fyra kategorier 1.) känslor av professionell trygghet utvecklas över tid ; 2.) Personliga kvaliteter påverkar yrkesutveckling. 3.) metoder för kunskap och kompetensutveckling; och 4.) Kompetens som utveckling och krävande.

    Slutsatsen av denna avhandling är att mer klinisk träning under utbildning är önskvärt. Barnmorskestudenter behöver tillgång och möjlighet att öva obstetriska nödsituationer tillsammans i team bestående av förlossningspersonal och barnläkare. Det tar tid att lära samt att känna trygghet, en möjlighet att underlätta för studenter vore att utöka samt förlänga barnmorskeutbildningen, att inkludera mer klinisk träning. Detta skulle innebära att stärka studenters möjligheter till en utökad klinisk trygghet. Kliniska barnmorskor hävdar att det tar tid att känna sig trygg och att det ett finns behov av att utveckla professionalism.

  • 28.
    Bång, Åsa
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Go with the flow?: Filipendula ulmaria, a common riparian plant species2006Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 29.
    Cao, Cao
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Automatic synthesis of partitioned FSMs based on mixed synchronous/asynchronous state memory2005Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 30.
    Carnerud, Daniel
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    Exploring Trends, Patterns and Characteristics of Quality Management Through Text Mining2016Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Regelbundet publiceras det nya rapporter och artiklar där vikten av hög kvalitet liksom kvalitetsförbättrande åtgärder inom offentlig och privat sektor lyfts fram som oumbärliga för att Sverige ska överleva som välfärds- och näringslivsnation. Situationen tycks inte vara unik för Sverige, likande tongångar hörs även i andra delar av världen. På 2000-talet ska konsumenter och medborgare tillhandahållas ständigt förbättrad kvalitet till lägre kostnad, annars går företag i konkurs och politiska företrädare förlorar folkets förtroende. Kvalitet är alltså ett ord som används flitigt av dagens makthavare och samhällsdebattörer. Utifrån detta perspektiv kan det anses angeläget att kvalitet, kvalitetsutveckling, kvalitetsarbete och andra närbesläktade ord är väl definierade för att möjliggöra konstruktiv dialog som mynnar ut i verkningsfulla insatser. Så är dock ofta inte fallet - varför visioner, kampanjer och andra kvalitetsförbättrande initiativ riskerar att faller till korta innan de ens hunnit lanseras. Med denna bakgrund, är syftet med avhandlingen att underlätta givande diskussioner genom att närmare belysa forskningsfältet kvalitetsteknik, eller Quality Management (QM), och hur trender, termer och forskningsfokus har växlat över tid. Genom att öka förståelsen för forskningens utveckling över tid kan även en sammanhängande översikt skapas, vilka tillsammans förhoppningsvis kan bidra till att minska den förvirring och polarisering som råder både inom akademi liksom praktik. Därigenom kanske det är möjligt att öka mängden lyckade kvalitetssatsningar liksom att lägga grunden för ett långsiktigt hållbart och systemövergripande kvalitetsarbete i samhället i överlag.

    Avhandlingen baseras på tre studier, varav den första har tittat närmare på konferensbidrag från en av världens idag ledande forskningskonferenser om kvalitet – QMOD-ICQSS konferensen. De två senare studierna behandlar sammanfattningar från tre av de högst rankade forskningstidskrifterna med fokus på kvalitet – International Journal of Quality and Reliability Management, Total Quality Management Journal och Total Quality Management & Business Excellence. Samtliga studier har utformats enligt text-mining metodik, vilket medför att statistiska hjälpmedel i form av hård och mjukvara har använts för datainsamling, modellering och analys. Angreppssättet är explorativt och tidigare ej beprövat i ovanstående syfte varför de tre studierna erbjuder unika perspektiv på forskningsområdet samtidigt som nya metodologiska verktyg och arbetssätt utforskats och utvärderats.

    Genom studierna går det att påvisa förekomsten av trender i forskningsinriktningar liksom i publikationernas utformning och popularitet. Studierna identifierar även centrala, återkommande teman kring vilka forskningen koncentrerats. Dessa teman indikerar att forskningsområdet, trots tillfälliga trender och moden, vilar på en stadigvarande grund gällande problemformuleringar och ansatser att lösa dessa. Slutligen presenteras en modell som sammanfattar de perspektiv och utgångspunkter som utmärker kvalitetstekniken (QM) och som gör det till ett forskningsområde i sin egen rätt.

  • 31.
    Casales Morici, Belén
    Mittuniversitetet, Fakulteten för humanvetenskap, Avdelningen för ekonomivetenskap och juridik.
    Corporate Entrepreneurship: A Comprehensive Field Review and Assessment of the Internal Organizational Environment Supportive of Strategic Entrepreneurship2018Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The aim of this thesis is to expand current knowledge on the development of corporate entrepreneurship and to contribute new theoretical and empirical insights into strategic entrepreneurship. To those ends, the thesis attempts to answer two research questions. First, how has the field of corporate entrepreneurship research evolved in terms of main themes, applied methods and theory, and what do these developments reveal about the future trajectories of the field? Second, what is the relationship between internal organizational factors and strategic entrepreneurship in the form of sustained regeneration, organizational rejuvenation, and strategic renewal? To answer the first question, a systematic and comprehensive review of 344 articles addressing the development of research on corporate entrepreneurship during 1969–2017 was conducted. To answer the second question, a survey was administered at a major financial services company to examine the relationship among four internal organizational factors and three forms of strategic entrepreneurship. The overall conclusion of the literature review is that corporate entrepreneurship is a growing and, in several respects, maturing field of research. Signs of its maturity are undermined, however, by the lack of commonly applied theories and theoretical frameworks. Those findings take support from the overall conclusion of the second study, which highlights the need to develop and further test empirically existing frameworks, constructs, and theoretical connections within literature on strategic entrepreneurship.

    Taken together, the findings of the thesis suggest that corporate entrepreneurship faces the difficult challenge of developing a set of more distinct, unifying theories and conceptual frameworks. Concerning strategic entrepreneurship, it is concluded that research on this topic should consider specific organizational structures and conditions of the company and, at the same time, it should also develop greater sensitivity to the effects of industry and institutional settings. The findings also highlight that internal organizational factors could have differentiated effects on the main forms of strategic entrepreneurship.

  • 32.
    Chekalina, Tatiana
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för samhällsvetenskap.
    A value co-creation perspective on the customer-based brand equity model for tourism destinations2012Licentiatavhandling, monografi (Övrigt vetenskapligt)
  • 33.
    Cheng, Xin
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Hardware centric machine vision for high precision measurement of reference structures in optical navigation2012Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 34.
    Cronskär, Marie
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik och hållbar utveckling.
    The use of additive manufacturing in the custom design of orthopedic implants2011Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 35.
    Daghighi, Abtin
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för tillämpad naturvetenskap och design.
    The Maximum Principle for Cauchy-Riemann Functions and Hypocomplexity2012Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Uppsatsen innehåller resultat om maximumprincipen för kontinuerligaCauchy–Riemann funktioner (CR-funktioner) på svagt 1-konkava CRmångfalder,samt hypokomplexitet för lokalt integrerbara strukturer.Maximumprincipen gäller inte generellt för släta CR funktioner ochmotexempel kan konstrueras givet strängt pseudokonvexa punkter.Vi bevisar en maximumprincip för kontinuerliga CR-funktioner påsläta inbäddade svagt 1-konkava CR-mångfalder. Eftersom svagt 1-konkavitet också är nödvändigt får vi som konsekvens att för slätageneriska inbäddade CR-mångfalder i Cn gäller att maximum-principenför kontinuerliga CR-funktioner håller om och endast om CR-mångfaldenär svagt 1-konkav. Vi generaliserar satsen till svagt p-konkava CRmångfalderi p-kompletta mångfalder. Den andra delen behandlarhypokomplexitet och hypoanalytiska strukturer. Vi generaliserar enkänd sats om automatisk släthet för lösningar till de tangentiella CRekvationerna,givet existensen av lokal holomorf utvidgning. Generaliseringenger att en lokalt integrerbar struktur är hypokomplex iorigo om och endast om den inte tillåter lösningar nära origo som inteär släta nära origo.

  • 36.
    Damghanian, Mitra
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informations- och kommunikationssystem.
    The Sampling Pattern Cube: A Framework for Representation and Evaluation of Plenoptic Capturing Systems2013Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    Digital cameras have already entered our everyday life. Rapid technological advances have made it easier and cheaper to develop new cameras with unconventional structures. The plenoptic camera is one of the new devices which can capture the light information which is then able to be processed for applications such as focus adjustments. The high level camera properties, such as the spatial or angular resolution are required to evaluate and compare plenoptic cameras. With complex camera structures that introduce trade-offs between various high level camera properties, it is no longer straightforward to describe and extract these properties. Proper models, methods and metrics with the desired level of details are beneficial to describe and evaluate plenoptic camera properties.

    This thesis attempts to describe and evaluate camera properties using a model based representation of plenoptic capturing systems in favour of a unified language. The SPC model is proposed and it describes which light samples from the scene are captured by the camera system. Light samples in the SPC model carry the ray and focus information of the capturing setup. To demonstrate the capabilities of the introduced model, property extractors for lateral resolution are defined and evaluated. The lateral resolution values obtained from the introduced model are compared with the results from the ray-based model and the ground truth data. The knowledge about how to generate and visualize the proposed model and how to extract the camera properties from the model based representation of the capturing system is collated to form the SPC framework.

    The main outcomes of the thesis can be summarized in the following points: A model based representation of the light sampling behaviour of the plenoptic capturing system is introduced, which incorporates the focus information as well as the ray information. A framework is developed to generate the SPC model and to extract high level properties of the plenoptic capturing system. Results confirm that the SPC model is capable of describing the light sampling behaviour of the capturing system, and that the SPC framework is capable of extracting high level camera properties with a higher descriptive level as compared to the ray-based model. The results from the proposed model compete with those from the more elaborate wave optics model in the ranges that wave nature of the light is not dominant. The outcome of the thesis can benefit design, evaluation and comparison of the complex capturing systems.

  • 37.
    Danielski, Itai
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för ekoteknik och hållbart byggande.
    Energy efficiency of new residential buildings in sweden: Design and Modelling Aspects2014Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Energy security and climate change mitigation have been discussed in Sweden since the oil crisis in the 1970s. Sweden has since then increased its share of renewable energy resources to reach the highest level among the EU member states, but is still among the countries with the highest primary energy use per capita. Not least because of that, increasing energy efficiency is important and it is part of the Swedish long term environmental objectives. Large potential for improving energy efficiency can be found in the building sector, mainly in the existing building stock but also in newly constructed buildings

    In this thesis, criteria for energy efficiency in new residential buildings are studied, several design aspects of residential buildings are examined, and possible further analysis from an energy system perspective discussed. Three case studies of existing residential buildings were analysed, including one detached house and multi-storey apartment buildings. The analysis was based on both energy simulations and measurements in residential buildings.

    The results show that the calculated specific final energy demand of residential buildings, before they are built, is too rough an indicator to explicitly steer society toward lower final energy use in the building sector. One of the reasons is assumptions made during calculation before the buildings is built. Another reason is the interior building design. A design that includes relatively large areas of heated corridors, service and storage rooms will lower the specific final energy demand without improving the building energy efficiency, which might increase both the total final energy demand and the use of construction materials in the building sector.

    Efficient thermal envelopes are essential in construction of energy efficient buildings, which include the thermal resistance and also the shape of the building. The shape factor of buildings was found to be an important variable for heat demand in buildings located in temperate and colder climates, particularly if they are exposed to strong winds.

    From a system perspective, energy efficiency measures and the performance of the end use heating technology in buildings should be evaluated together with the energy supply system, including the dynamic interaction between them.

  • 38.
    de Bruijn, Robert
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Cardiovascular and hematological responses to voluntary apnea in humans2007Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis deals with cardiovascular and hematological responses to voluntary apnea in

    humans, with a special focus on O2 usage and storage. Humans, and many other air‐breathing

    animals, respond to apnea (breath holding) with a collection of interacting cardiovascular

    reflexes, which are collectively called the diving response. In humans, the main characteristics of

    the diving response are a reduction in heart rate (bradycardia), decreased cardiac output,

    peripheral vasoconstriction and increased arterial blood pressure. Another response during

    apnea in mammals, more recently also observed in man, is a transient increase in hemoglobin

    concentration across a series of apneas, probably due a reduction in spleen size. There may also

    be long‐term effects on erythropoiesis in the apneic diver, as suggested by high hemoglobin

    levels observed in divers. The focus of the included studies are the short transient diving

    response (I), the more slowly occurring transient hematological changes to apnea, most likely

    related to a reduction in spleen size (II), and the possible effects of repeated apnea on serum

    erythropoietin concentration (III).

    I) The aim was to study the effects of body immersion on the O2‐conserving effect of the

    human diving response. The results showed that, regardless of body immersion, apnea with face

    immersion causes a stronger cardiovascular diving response compared to during apnea alone,

    leading to a smaller reduction in arterial oxygen saturation levels. Thus the diving response is

    triggered and conserves O2 even during whole‐body immersion, which has previously only been

    observed during apnea without whole‐body immersion.

    II) The aim was to study hematological responses to voluntary repeated maximal‐duration

    apneas in divers and non‐divers. Increases in hemoglobin concentration were found across a

    series of 3 apneas in elite breath‐hold divers, elite cross‐country skiers and untrained subjects.

    However a larger increase in hemoglobin was found in divers compared to non‐divers, which

    suggests a possible training effect of their extensive apnea‐specific training. In contrast, physical

    endurance training does not appear to affect the hematological response to apnea.

    III) The aim was to study the effects of serial voluntary apnea on the serum erythropoietin

    concentration. In a comparison between elite breath‐hold divers and subjects untrained in apnea,

    divers were found to have a 5% higher resting hemoglobin concentration. An average maximum

    increase in erythropoietin of 24 % was found in untrained subjects after 15 maximal duration

    apneas, preceded by 1 min of hyperventilation. This suggests a possible erythropoietic effect of

    apnea‐induced hypoxia, which may connect the increased resting hemoglobin found in divers to

    their apnea‐specific training.

    It was concluded from these studies that man responds to apnea with a series of different

    adjustments in order to limit O2 usage and increase O2 storage: The classical diving response is

    effectively restricting O2‐consumption also during full immersion, the spleen related hemoglobin

    increase occurs in both divers and non‐divers with different levels of physiological training, but

    is more prominent in divers, and finally, the observed high levels of hemoglobin concentration in

    divers may be related to enhanced erythropoiesis during dive training.

  • 39.
    Dima, Elijs
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informationssystem och -teknologi.
    Multi-Camera Light Field Capture: Synchronization, Calibration, Depth Uncertainty, and System Design2018Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The digital camera is the technological counterpart to the human eye, enabling the observation and recording of events in the natural world. Since modern life increasingly depends on digital systems, cameras and especially multiple-camera systems are being widely used in applications that affect our society, ranging from multimedia production and surveillance to self-driving robot localization. The rising interest in multi-camera systems is mirrored by the rising activity in Light Field research, where multi-camera systems are used to capture Light Fields - the angular and spatial information about light rays within a 3D space. 

    The purpose of this work is to gain a more comprehensive understanding of how cameras collaborate and produce consistent data as a multi-camera system, and to build a multi-camera Light Field evaluation system. This work addresses three problems related to the process of multi-camera capture: first, whether multi-camera calibration methods can reliably estimate the true camera parameters; second, what are the consequences of synchronization errors in a multi-camera system; and third, how to ensure data consistency in a multi-camera system that records data with synchronization errors. Furthermore, this work addresses the problem of designing a flexible multi-camera system that can serve as a Light Field capture testbed.

    The first problem is solved by conducting a comparative assessment of widely available multi-camera calibration methods. A special dataset is recorded, giving known constraints on camera ground-truth parameters to use as reference for calibration estimates. The second problem is addressed by introducing a depth uncertainty model that links the pinhole camera model and synchronization error to the geometric error in the 3D projections of recorded data. The third problem is solved for the color-and-depth multi-camera scenario, by using a proposed estimation of the depth camera synchronization error and correction of the recorded depth maps via tensor-based interpolation. The problem of designing a Light Field capture testbed is addressed empirically, by constructing and presenting a multi-camera system based on off-the-shelf hardware and a modular software framework.

    The calibration assessment reveals that target-based and certain target-less calibration methods are relatively similar at estimating the true camera parameters. The results imply that for general-purpose multi-camera systems, target-less calibration is an acceptable choice. For high-accuracy scenarios, even commonly used target-based calibration approaches are insufficiently accurate. The proposed depth uncertainty model is used to show that converged multi-camera arrays are less sensitive to synchronization errors. The mean depth uncertainty of a camera system correlates to the rendered result in depth-based reprojection, as long as the camera calibration matrices are accurate. The proposed depthmap synchronization method is used to produce a consistent, synchronized color-and-depth dataset for unsynchronized recordings without altering the depthmap properties. Therefore, the method serves as a compatibility layer between unsynchronized multi-camera systems and applications that require synchronized color-and-depth data. Finally, the presented multi-camera system demonstrates a flexible, de-centralized framework where data processing is possible in the camera, in the cloud, and on the data consumer's side. The multi-camera system is able to act as a Light Field capture testbed and as a component in Light Field communication systems, because of the general-purpose computing and network connectivity support for each sensor, small sensor size, flexible mounts, hardware and software synchronization, and a segmented software framework. 

  • 40.
    Ding, Xiasong
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Fast local optimization in decision analytic software2004Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    In decision analysis, significant recognition has been given to the fact that requiring numerically precise information seems unrealistic for real-life decision situations, Despite the emergence of many modern apporaches, which attempt to handle imprecise estimates, concentration has focused more on representation and less on evaluation. Methods such as the DELTA method  challenged this issue by its evaluation framework that can accommodate both precision an imprecision, and thus pushes forward the disign of advanced dicision analysis systems. However, computationally, DELTA may incur time-consuming calculations due to the introduction of imprecise information into the probability space as well as the value space. Although two fast linear programming based bilinear optimazation algorithms were suggested, which were supporsed to satisfy certain presumed conditions, they are found to be too restrictive.

    This thesis presents a fast potimization approach that can be viewed as a generalized version of the two fast algorithms. The motivation stems from the attempts to discard those presumed conditions. This approach combines ideas from both matrix computations and linear programming, and is, in fact, an iterative method. Since the DELTA method inteds to compute the difference of two expected utilities, this bilinear optimization issue is non-convex, and thus will certainly touch upon the global optimization area. As previously suggested, actually all methods for global optimization consist of two phases: a global phose to thoroughly explore subsets of the feasible region where it is known the blobal optimum will be found, an a local phase to improve the approximation to some local optima, Basically, this fast algorithm is devoted to the local optimization phase.

  • 41.
    Dobslaw, Felix
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Automatic Instance-based Tailoring of Parameter Settings for Metaheuristics2011Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Many industrial problems in various fields, such as logistics, process management, orproduct design, can be formalized and expressed as optimization problems in order tomake them solvable by optimization algorithms. However, solvers that guarantee thefinding of optimal solutions (complete) can in practice be unacceptably slow. Thisis one of the reasons why approximative (incomplete) algorithms, producing near-optimal solutions under restrictions (most dominant time), are of vital importance.

    Those approximative algorithms go under the umbrella term metaheuristics, each of which is more or less suitable for particular optimization problems. These algorithmsare flexible solvers that only require a representation for solutions and an evaluation function when searching the solution space for optimality.What all metaheuristics have in common is that their search is guided by certain control parameters. These parameters have to be manually set by the user andare generally problem and interdependent: A setting producing near-optimal resultsfor one problem is likely to perform worse for another. Automating the parameter setting process in a sophisticated, computationally cheap, and statistically reliable way is challenging and a significant amount of attention in the artificial intelligence and operational research communities. This activity has not yet produced any major breakthroughs concerning the utilization of problem instance knowledge or the employment of dynamic algorithm configuration.

    The thesis promotes automated parameter optimization with reference to the inverse impact of problem instance diversity on the quality of parameter settings with respect to instance-algorithm pairs. It further emphasizes the similarities between static and dynamic algorithm configuration and related problems in order to show how they relate to each other. It further proposes two frameworks for instance-based algorithm configuration and evaluates the experimental results. The first is a recommender system for static configurations, combining experimental design and machine learning. The second framework can be used for static or dynamic configuration,taking advantage of the iterative nature of population-based algorithms, which is a very important sub-class of metaheuristics.

    A straightforward implementation of framework one did not result in the expected improvements, supposedly because of pre-stabilization issues. The second approach shows competitive results in the scenario when compared to a state-of-the-art model-free configurator, reducing the training time by in excess of two orders of magnitude.

  • 42.
    Duan, Ran
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    On Shaping Mechanical Properties of Lignocellulosic Materials by Benign Chemical Processing2016Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 43.
    Dumoulin, Etienne
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för samhällsvetenskap.
    The current financial crisis and its effects on the French economy2010Självständigt arbete på grundnivå (kandidatexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [en]

    AbstractIn this paper, we will be interested by the current financial crisis and how it did affect on the French economy. After setting the global French point of view and an overview of other crises, the discussion will be focused on the subprime crisis and how it turned into a worldwide financial crisis to reach the state of France. The data of the French statistic institute (INSEE) will be used as an analytic tool to show how France has been hit.To discuss this topic, we start from a chronology of the last crises to an overview of the French point of view in economy to correlate the current financial crisis to the French economy shrink. To set the subprime principles permit to explain the spread of the toxic mortgages in the worldwide finance and the collapse of economies. In more details, that explains the French economy collapse. The shrinking French economy started with the GDP and as a snowball effect, foreign trade, and companies followed. In the same time, the rise of unemployment and the change of the consumer behaviour can be notice. All of those are correlated with the current financial crisis.Going through this paper, we learnt that the subprime crisis is the cause of the current financial crisis. Indeed, the spread of the toxic loan into the whole financial market provided its collapse and finally reached to a fall of the world wide economy. In this study, we were focused on the effects of the current financial crisis on the French economy. This paper showed in the conclusion that the economy are recovering after a period of depression.

  • 44.
    Duplain, Laurianne
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för samhällsvetenskap.
    France within the European Union and the Eurozone : a survey study2010Självständigt arbete på grundnivå (kandidatexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [en]

    In this paper, we are going to study the relations between France, the European Unionand the Eurozone. The involvements of France in the European Union and the Eurozone aswell as the effects of the European evolutions in France. As France has played many roles indifferent areas for the European Union, the relations are social, political, juridical andobviously economic. We cannot analyse these relations without interest in the historicalpart, which shows the chronological involvements of France in the EU, from the firstagreement in 1951 to the Treaty of Lisbon in December 2009. Beside this, our analyse needsalso to focus on the European Union as several institutions; as well as the Eurozone and itseconomic consequences in Europe and in France. To do so, we are going to raise monetaryand institutional questions and develop the most important European stakes as theenlargements, the European budget, the common policies and the European institutions.France can be considered as a founding father of the European Union, and in spite ofsome difficulties; both France and the European Union have had positive influences on eachother and the European Union could not have grown in this way without France.

  • 45.
    Edström, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik, fysik och matematik.
    Mathematical Modelling of Light Scattering in Paper and Print2004Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    A problem formulation and a solution method are outlined for the radiative transfer problem in vertically inhomogeneous scattering and absorbing media, using discrete ordinate model geometry. The treatment spans from the physical problem via a continuous formulation, a discretization and a numerical analysis, to an implementation with performance evaluation and application to real-world problems. The thesis clearly illustrates how considerations in one step affect other steps, and thus provides an example of an overall treatment of mathematical modeling of a large applied problem. A selection of different steps is brought together. First all the steps necessary to get a numerically stable solution procedure are treated, and then methods are introduced to increase the speed by a factor of several thousand. The solution procedure is implemented in MATLAB under the name of DORT2002, and is adapted primarily to light scattering simulations in paper and print. A confined presentation is given of the effect of the steps that are needed, or possible, to make any discrete ordinate radiative transfer solution method numerically efficient. This is done through studies of the numerical performance of DORT2002. Performance tests show that the steps that are included to improve stability and speed of DORT2002 are very successful. Together they give an unconditionally stable solution method to a problem previously considered numerically intractable, and decrease computation time compared to a naive implementation with a factor of 1 000 � 10 000 in typical cases and with a factor up to and beyond 10 000 000 in extreme cases. It is also shown that the speed increasing steps are not introduced at the cost of reduced accuracy, and that DORT2002 converges to the true value as the discretization is made finer. It is shown by the use of DORT2002 that when a medium has a finite thickness, the light distribution deviates from the perfectly diffuse even under the theoretically ideal conditions for which the Kubelka-Munk model was created. This effect, which is in opposition to what one would intuitively expect, is caused by light escaping through the lower boundary of the medium, and causes errors in Kubelka-Munk reflectance calculations that can be up to 20% and more, even for a grammage of 80 g/m2. The magnitude of the error shows a strong dependence on the degree of absorption, with higher absorption giving greater error. This confirms previously reported problems with Kubelka-Munk for strongly absorbing media, and DORT2002 offers a partial explanation of these problems, as it can describe this effect and quantify the Kubelka-Munk errors. It is argued that DORT2002 could well be considered for increased understanding in cases where the level of accuracy of Kubelka-Munk reflectance calculations is not acceptable. A comprehensive list of advantages for the applied user of a model with higher dimensionality is supplied.

  • 46.
    Erdegren, Mikael
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för tillämpad naturvetenskap och design.
    Understanding surface defects on direct chill cast 6xxx aluminium billets2012Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 47.
    Eriksson, Maria
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik och hållbar utveckling.
    Creating customer value in commercial experiences2009Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Det är en ny industri på växande frammarsch som får allt större uppmärksamhet i massmedia både utifrån erbjudandet och genom allt mer betydande ekonomiska resultat. En industri som erbjuder kunden något extra, någonting att minnas, en kommersiell upplevelse. Det finns de som hävdar att den kommersiella upplevelsen skiljer sig från traditionell industri med massproduktion och att den till och med är skild från varor och tjänster. Att kunna erbjuda sina kunder någonting extraordinärt för att nå en ökad vinstmarginal är av allt större intresse bland företag idag. Allt fler kunder letar efter en upplevelse som tar dig till en högre nivå av personlig utveckling, en upplevelse som skapar en personlig identitet och leder till minnen för livet. Detta fenomen är något som allt fler människor är villiga att betala pengar för, en kommersiell upplevelsemarknad.

    Det övergripande syftet med licentiatuppsatsen är att bidra med kunskap och skapa en djupare förståelse för kommersiella upplevelser, både på ett generellt plan men även med avseende på hur kundvärde skapas. Ett ytterligare fokus för forskningen är att stärka de organisationer som erbjuder sina kunder en upplevelse. För att uppnå syftet har två fallstudier med olika fokus genomförts. Den första fallstudien innebar att leta efter ett föredöme och belysa goda exempel på arbetssätt som kan användas för att skapa en kommersiell upplevelse. Den andra studien syftade till att identifiera behov för att utveckla och stärka de organisationer som erbjuder sina kunder en kommersiell upplevelse.

    Utifrån mina observationer i fallstudie 1 så verkar det finnas flera saker som skiljer en kommersiell upplevelse från varor och tjänster, som t.ex. prisnivå, kundens spenderade tid, kundens emotionella beröring och kanske mest betydande att den kommersiella upplevelsen når en högre nivå av skapat kundvärde än vad varor och tjänster gör. Allt detta bidrar till att klassificera kommersiella upplevelser som ett eget fenomen, ett erbjudande med ett förädlat kundvärde. Eftersom kommersiella upplevelser påstås beröra kunder på ett minnesvärt sätt, uppnås också en högre nivå av skapat kundvärde än för varor och tjänster. Detta är en kritisk faktor för den kommersiella upplevelsen. Att förstå kundens behov, och vad det är som skapar kundvärde, blir därmed av extra vikt för att lyckas för de organisationer som erbjuder en kommersiell upplevelse.

    Vid studien av en framgångsrik organisation hittades flera likheter i de arbetssätt som användes för att på ett framgångsrikt sätt skapa en upplevelse med de värderingar som beskrivs inom TQM. Ytterligare arbetssätt som utpekas som framgångsfaktorer är storytelling, tematisering och att skapa kreativa arbetsmiljöer. Utöver arbetssätten belystes också vikten av att bygga en organisationskultur baserad på värderingar som fokuserar på att skapa kundvärde. Att rekrytera sin personal baserat i huvudsak på värderingar i stället för enbart på kompetens anses vara ytterligare en framgångsfaktor, detta eftersom medarbetaren ofta skapar upplevelsen i ett möte tillsammans med kunden. Att skapa en organisationskultur som bygger på gemensamma värderingar är viktigt för att nå framgång inom upplevelseindustrin. Det är inte begränsat till en specifik typ av organisation att erbjuda kommersiella upplevelser, det är i stället vikten av att lägga till det extra kundvärdet för att uppnå attraktiv kvalitet som är essentiellt för framgång.

    Den kommersiella upplevelsen beskrivs som något djupt berör kundens känslor och dess sinnen med ett resultat i nya värdefulla minnesbilder. Det är ett minnesvärt ögonblick som kunden är beredd att betala för. De ingredienser som används för att beskriva en kommersiell upplevelse är engagemang, personlig betydelse, nyhetsvärde, överraskning och lärande. Egenskaperna är inte begränsade till att enbart gälla för en viss typ av organisation eller bransch. Det faktum att intresset för att erbjuda kommersiella upplevelser är växande, och att området är relativt outforskat indikerar att det finns flera behov av utveckling, framförallt i att hitta bra arbetssätt och metoder för att identifiera kundens förväntningar och mäta kundnöjdhet. Varmt välkommen att här vidareutforska upplevelseindustrin, där nya minnen värderas så högt att människor är beredda att betala för dem.

  • 48.
    Esebamen, Omeime Xerviar
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Simulation, Measurement and Analysis of the Response of Electron- and Position Sensitive Detector2012Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Different methods exist in relation to probing and investigating thephysical and structural composition of materials especially detectors whoseusage have become an integral part of radiation detection. The use of thescanning electron microscopy is just one of such exploratory methods. Thistechnique uses a focused beam of high-energy electrons to generate a varietyof signals at the surface of the device under investigationThis thesis presents the results derived from signals from electron beamsampleinteractions, revealing information about the different cleanroomfabricated electron detectors used. This information includes the detector’sexternal morphology and texture, surface recombination, fixed oxide chargeand the behavioral characteristic in the form of its position detection accuracyand linearity.An electron detector with a high ionization factor and which has a 10nmSilicon Oxide passivating layer was fabricated. Results from using the scanningelectron microscopy showed that its maximum responsivity wasapproximately 0.25 A/W from a possible 0.27 A/W. In conjunction withsimulations, results also showed the significance of the effect of the minoritycarrier's surface recombination velocity on the responsivity of the detectors.In addition, measurements were conducted to ascertain the performancevariance of these electron detectors with respect to their surfacerecombination velocity and fixed oxide charge when the doping profile isaltered.By incorporating special features on a fabricated duo-lateral positionsensitive detector (PSD), a position sensing resolution of the PSD using theelectron microscopic method was also evaluated. The evaluation showed avery high linearity over two-dimensions for 77% of the PSD’s active area.The results in this thesis offer a significant improvement in electrondetectors for applications such as gas chromatography detection of traceamounts of chemical compounds in a sample as well as applications involvingposition sensitive detection.

  • 49.
    Farag, Hossam
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationssystem och –teknologi.
    Enabling Time- and Mission-Critical Applications in Industrial Wireless Sensor Networks2019Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Nowadays, Wireless Sensor Networks (WSNs) have gained importance as aflexible, easier deployment/maintenance and cost-effective alternative to wired networks,e.g., Fieldbus and Wired-HART, in a wide-range of applications. Initially,WSNs were mostly designed for military and environmental monitoringapplications where energy efficiency is the main design goal. The nodes in the network were expected to have a long lifetime with minimum maintenance while providing best-effort data delivery which is acceptable in such scenarios. With recent advances in the industrial domain, WSNs have been subsequently extended to support industrial automation applications such as process automation and control scenarios. However, these emerging applications are characterized by stringent requirements regarding reliability and real-time communications that impose challenges in the design of Industrial Wireless Sensor Networks (IWSNs) to effectively support time- and mission-critical applications.

    Typically, time- and mission-critical applications support different traffic categories ranging from relaxed requirements, such as monitoring traffic to firm requirements, such as critical safety and emergency traffic. The critical traffic is mostly acyclic in nature and occasionally occurs at unpredictable time instants. Once it is generated, it must be delivered within strict deadlines. Exceeding the delay bound could lead to system instability, economic loss, or even endanger human life in the working area. The situation becomes even more challenging when an emergency event triggers multiple sensor nodes to transmit critical traffic to the controller simultaneously. The unpredictability of the arrival of such a type of traffic introduces difficulties with regard to making a suitable scheduling that guarantees data delivery within deadline bounds. Existing industrial standards and related research work have thus far not presented a satisfactory solution to the issue. Therefore, providing deterministic and timely delivery for critical traffic and its prioritization over regular traffic is a vital research topic.

    Motivated by the aforementioned challenges, this work aims to enable real-timecommunication for time- and mission-critical applications in IWSNs. In this context, improved Medium Access Control (MAC) protocols are proposed to enablea priority-based channel access that provides a timely delivery for acyclic critical traffic. The proposed framework starts with a stochastic modelling of the network delay performance under a priority-oriented transmission scheme, followed by two MAC approaches. The first approach proposes a random Clear Channel Assessment (CCA) mechanism to improve the transmission efficiency of acyclic control traffic that is generated occasionally as a result of observations of an established tendency, such as closed-loop supervisory traffic. A Discrete-Time Markov Chain (DTMC) model is provided to evaluate the performance of the proposed protocol analytically in terms of the expected delay and throughput. Numerical results show that the proposed random CCA mechanism improves the shared slots approach in WirelessHART in terms of delay and throughput along with better transmission reliability.

    The second approach introduces a slot-stealing MAC protocol based on a dynamic deadline-aware scheduling to provide deterministic channel access in emergency and event-based situations, where multiple sensor nodes are triggered simultaneously to transmit time-critical data to the controller. The proposed protocol is evaluated mathematically to provide the worst-case delay bound for the time-critical traffic and the numerical results show that the proposed approach outperforms TDMA-based WSNs in terms of delay and channel utilization.

  • 50.
    Fjellström, Helena
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    The Photostabilising Effect of Coating Layers on CTMP‐based Papers2006Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
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