<p>With so many software-related failures happening these days, there is an increasing demand for software quality. Rigorous development approaches, which apply mathematical techniques to the design and implementation, should be getting more consideration as one of the solutions to software reliability.</p> <p>Pre/postcondition approaches and relational approaches are two groups of influential rigorous techniques. Both of them use classical mathematical concepts to describe and simplify programming objects. To further propel the application of these approaches, their relative strengths and limitations in terms of practicability and accessibility need to be identified and elaborated.</p> <p>In this thesis, we conduct a comparative study between the pre/postcondition approaches, proposed by Floyd, Hoare, Dijkstra and Baber, and the relational approaches, proposed by Mills and Parnas. We investigate aspects related to their mathematical models. Their abilities of specifying different termination behaviours, dealing with non-determinism, distinguishing between specifications and descriptions, etc. are discussed. Some practical issues, such as considerations on common programming constructs, side effects, verification procedures, etc. are reviewed. The comparison criteria are grouped into two categories - theory and practice. Under each criterion, we illustrate and evaluate the strength or weakness of each approach. Suggestions regarding the applications of these approaches are also presented.</p> / Master of Science (MS)

Att tillhandahålla vuxenutbildning är en skyldighet som Sveriges kommuner åläggs enligt Skollagen. I samma lag anges att inriktningen på det systematiska kvalitetsarbete ska vara att de nationella målen (som uttrycks i Läroplan för Vuxenutbildningen) uppfylls. Denna översiktliga formulering gör att det i stor utsträckning blir upp till varje enskild kommun att utveckla egna rutiner för arbetet med kvalitet inom vuxenutbildningen. I Västerås genomförs varje år en kvalitetsgranskning av de skolor som verkar inom den kommunala vuxenutbildningen. Granskningen omfattar bland annat strukturella förutsättningar, uppnådda resultat och efterlevnad till lag- och förordningskrav. Västerås kommun skapar och skickar ut en kvalitetsmall som fylls i av respektive skola. Detta material utgör sedan en grund (av flera) för den granskning av tjänstekvalitet som varje skola årligen genomgår. Syftet med denna uppsats är att undersöka hur tjänstekvalitet inom vuxenutbildningen i Västerås har operationaliserats till mätbara indikatorer inför kvalitetsgranskningen 2021.Utifrån teorin om mellanbegrepp analyseras vilka aspekter kommunen har bestämt ska ligga till grund för tjänstekvalitet inom Vux Västerås och också vilka följder det får om en skola inte lever upp till det kommunen betraktar som tillräcklig kvalitet.

In this study three commonly used computer programs for influence diagram evaluation are compared: Netica, Hugin Expert and PrecisionTree. The programs are analysed with respect to three main issues: how they comply with semantic rules for influence diagrams, how the issue of asymmetric decision problems is handled in each tool, and if and in what way they implement the arc reversal functionality. The results show that i) none of the tools fully complies with the semantic rules for influence diagrams, ii) the tools based on Bayesian nets (Netica, Hugin Expert) handle asymmetric decision problems in a similar way, whereas PrecisionTree implements a unique, efficient way of handling the issue, and iii) two of the three tools, Netica and Hugin Expert,support arc reversal.

Integrating technology into schools is a complex issue. Educators do not just use a single technology in their classroom, but they plan and design their instructional activities so that the use of one technology can be combined with other instructional activities relevant to the topic at hand. This research was conducted as part of a master's thesis that aimed to investigate and understand the integration of technology and its challenges in Swedish elementary school. The framework in which educational technologies are to be introduced, accepted, and successfully used in the classroom needs to be right. To achieve this goal, the study posed three research questions. These questions are, "What educational technologies are used in elementary schools? How do teachers use or integrate educational technologies when planning and implementing activities to achieve learning objectives? What are the factors/challenges that influence the integration of technology in elementary classrooms from the teachers' perspective?"  The researcher explored these research questions through a thematic analysis of five semi-structured interviews, one face-to-face interview, and four Microsoft forms interviews, as well as three classroom observations.  The results of this study indicate that teachers have a positive view of the use or integration of technology in the classroom, with the exception of one teacher who expressed reservations about the use of ICT in grades 4 and 5. Furthermore, the results show that there is a lack of both knowledge and competence regarding the use and integration of educational technology in the classroom.

<p>Optical coatings have been applied to the facets of semiconductor diode lasers using the electron cyclotron resonance plasma enhanced chemical vapour deposition technique. Processes have been developed for the fabrication of optical interference filters from silicon oxynitride thin films using both tris dimethylaminosilane and silane as the silicon precursor. An important component for the fabrication of filters with a controlled reflectance index by ellipsometry. Using the ellipsometer, it is shown that, after correcting for systematic errors, an accurate measurement of the film index of refraction can be made during a deposition. Three separate applications of these optical coatings are discussed. The fabrication of anti-reflection coatings, the fabrication of narrow band reflectance coatings which could potentially have beneficial effects on the spectral properties of the laser and the use of silicon nitride layers, in conjunction with a sulphur based passivation, to improve the reliability of high power AlGaAs based lasers. Single and double layer anti-reflection coatings have been designed for specific laser waveguide structures. An existing theoretical model of the spectral output of a semiconductor laser has been modified to include the effect of an optical filter with a highly wavelength dependent reflectance, in order to understand the limitations of this technique. Finally, improvements in the surface properties of passivated and encapsulated AlGaAs material have been observed through an increase in the yield of photoluminescence after the passivation process was applied.</p> / Doctor of Philosophy (PhD)

<p>Electric field induced changes in the excitonic band-edge absorption spectra of Multiple Quantum-Well (MQW) structures were investigated theoretically and experimentally. Three In(x)Ga(1-x)-GaAs quantum-well p-i-n waveguide structures were designed, and were then grown by the National Research Council of Canada. Band edge absorption changes with field were then investigated using light incident perpendicular to the sample surface. Theoretically, a comparison was made of three different exactly solvable methods for calculating quantum-well energies in an electric field, both with and without conduction-band non-parabolicity. An exactly solvable method was used to calculate the hole dispersion and thereby determine the heavy-hole parallel effective mass. By using calculated wavefunctions, and these mass values, a numerical method was used (Wu, 1989) to solve for the exciton binding energies. After determining broadening factors, the absorption edge was calculated at low and moderate fields for three In(x)Ga(1-x)As-GaAs structures for various fields. At high fields, a different Franz-Keldysh type of absorption calculation was developed. Comparisons vs. experiment were favourable, but some discrepancy was noted. Slab and rib waveguide modulators, with operating wavelengths from about 970nm to 1035nm, were processed from the three material growths. Waveguiding transmission spectra again agreed favourably with theory, although some differences were seen. The modulators typically exhibited greater than 20 dB of switching over a 40nm range with less than 2 dB of low-bias absorption loss. Switching speed was not examined. Theoretical analysis of different structures revealed many trade-offs, in design, with 3% to 17% indium, and 6.5nm to 13nm well-widths being acceptable.</p> / Doctor of Philosophy (PhD)

<p>The decoupled seismic analysis of Multi-Degree-Of-Freedom (MDOF) secondary system subjected to multiple-support excitations overestimates its response. It is recognized that the analysis overestimates the secondary system response because the dynamic characteristics of the combined Primary-Secondary (P-S) system are neglected. The problem that is addressed in this thesis is how to include the effects of these dynamic characteristics in decoupled seismic analyses of multiply-supported MDOF secondary systems. The objective is to estimate the secondary system response using a decoupled seismic analysis such that it approximates the response that would have been obtained using a coupled analysis. Three approaches are considered in addressing the problem. These are the conventional deterministic approach, the recently developed Cross-Cross-Floor-Spectrum (CCFS) approach, and the stochastic approach. Three major contributions are achieved. First, the complexity associated with the seismic analysis of multiply-supported MDOF secondary systems is highlighted. Second, an improved CCFS approach, that avoids the shortcomings of the original CCFS approach, is proposed. Third, a new stochastic approach, that accounts for the dynamic characteristics of the combined P-S system, is developed.</p> / Doctor of Philosophy (PhD)

<p dir="ltr">There are 150 fatal occupational injuries on average per year due to exposure to electricity in the United States (U.S.) [1]. Power utility workers are exposed to electrical hazards when restoring power service to utility customers, who experience an average of 2 hours of power outages per year in the U.S. [2]. Utility companies struggle to keep qualified workers from quitting during the highest ever-recorded voluntary turnover in the U.S. with 55 million people quitting their jobs in 2022, raising the risk of safety incidents [3].</p><p dir="ltr">This research studies the department responsible for the operations in the power distribution system, Distribution Dispatch Center (DDC), based on a case study of a power company called Ohm-Sweet-Ohm (OSO) Inc. This thesis proposes a 12-step methodology and approach to assess the efficiency of OSO DDC by using a variation of the Collective System Design methodology for the design of enterprises [4].</p><p dir="ltr">The methodology consists of developing a system design decomposition that defines the functions and improvements to existing solutions of OSO DDC. The decomposition addresses the inconsistencies of the functions identified without a solution in the current state of OSO DDC.</p><p dir="ltr">The proposed methodology's impact is safety improvements in power distribution operations and the potential cost benefit for OSO Inc. of almost four million dollars a year. The measurements to evaluate the success of the proposed solutions are the number of safety incidents per year, the time taken to restore utility customers after power outages, and the voluntary turnover rate in the OSO DDC.</p>

Risk är ett mångfacetterat begrepp som kan definieras på många sätt. Denna studie fokuserar på att se hur begreppet risk kan kategoriseras i svensk statlig styrning med utgångspunkt i 2022 års regleringsbrev. Begreppet risk ingår en eller flera gånger i 46 av 163 regleringsbrev (28%). I studien har begreppet risk delats in i fem olika kategorier: K1-risk som kombination av sannolikhet och konsekvens; K2- risk somsannolikhet/möjlighet; K3-risk som påverkan/konsekvens; K4- risk som händelse/osäkerhetsmoment, och K5-risk som hot/riskkälla. Studien visar att begreppet risk i svensk statlig styrning via regleringsbrev kan tolkas och kategoriseras på flera sätt. I 35% av de gånger risk nämns i regleringsbrev kan samtliga kategorier K1-5 anses vara möjliga alternativ för begreppet risk. Den kategori som är vanligast förekommande och som tydligast kan särskiljas från övriga är kategorin K2- risk somsannolikhet/möjlighet. Effekter av olika tolkningar av betydelsen av risk diskuteras i arbetet och till exempel skulle olika tolkningar av begreppet risk kunna medföra påverkan på riskhanteringen hos myndigheterna.

No description available.