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The market for Insulated Gate Bipolar Transistor (IGBT) is growing and there is a need for techniques to improve the design, modeling and simulation of IGBT. In this thesis, we first developed a new method to optimize the layout and dimensions of IGBT circuits based on device simulation and combinatorial optimization. Our method leads to the optimal IGBT layout consisting of hexagons, which is 6 % more efficient in terms of performance (current per unit area) over that of squares, and up to 80 % more efficient than rectangles. We also explored several techniques to reduce the time used for device simulation. In particular, we developed an accurate Verilog-A description based on the Hefner model. For transient simulation, the time used by SPICE on the Verilog-A model is only 1/10000 of that used by device simulation on the device structure. The SPICE results, though contain some inaccuracies in the details, match device simulation in the general trend. Due to the effectiveness and efficiency of our methods, we propose their application in designing better power electronic circuits and shorter turn-around time.

Lean Manufacturing has proven to be a very successful strategy for achieving production efficiencies. The basic elements of lean manufacturing are flow and pull. The traditional methods for establishing flow and pull do not fit well in the realm of high variety low volume manufacturing systems. This thesis provides a general framework for establishing flow and pull in high variety low volume manufacturing systems, through the concept of hybrid flow layouts. The existing analytical procedure for forming hybrid flow layouts is described and a new heuristic procedure, that overcomes some of the limitations of the existing procedure, is proposed. The performance of the new procedure in comparison to the existing procedure is illustrated using a real world case study. Finally, certain practical implementation issues that affect the formation of hybrid flow layouts are provided.

Syftet med studien var att granska en befintlig kallelse till hjulskifte för att se var kommunikationen eventuellt brister. Frågeställningarna var följande: Vilket läsbarhetsindex har kallelsen? Hur är språket i kallelsen utformat, dvs. är språket lätt- eller svårbegripligt? Innehåller kallelsen den information som kunderna behöver? Hur ser kallelsens layout ut? Är den mottagaranpassad? Därefter granskades textens språk, innehåll samt layout. Metoderna som användes var Hellspongs läsbarhetsanalys, ett frågeformulär samt Björkvalls teori om visuell framskjutenhet samt typografi. Materialet som användes var kallelsen samt ett frågeformulär. Resultatet visade att kallelsen uppfyller sin funktion med att informera företagets kunder om att det är dags för hjulskifte. Samtidigt som många saknade datum, tid och plats utskrivet på kallelsen, så var detta en lösning Bilia gjort för att öka kundnöjdheten genom att kunderna får bestämma själva. Slutsatsen blev att kallelsen håller måttet som lättläst, hade ett lättbegripligt språk samt ger kunderna den information de behöver.

In order to create a machining line layout that supports the principles of lean a systematic approach is needed to ensure that a wide range of factors are taken into consideration. Despite this, many companies today design new layouts mainly considering delivery times of machines and equipment, and available space in the factory. A combined literature and case study has aimed to identify the most important factors in a lean line layout and a supporting structure to apply these in the design or redesign of automated machining lines. Highly automated machining environments mainly distinguish themselves from the more thoroughly studied area of assembly line layouts in two ways. Primarily, automated machining lines separate the operator from the actual processing, making line balancing and productivity less dependent on the workstation design around the operator. Secondly, automated machining lines often involve a higher level of complexity, leading to a more comprehensive work load, requiring longer training times but also offering less repetitive assignments. Automation offers improved productivity, quality and ergonomics, but if the acquisition and allocation of automation is not substantiated by a well-developed strategy, automation risks contradicting lean principles by creating a more complex, rigid layout that places the machines in the center instead of the workers. Factors that are important in the design of the typically less automated assembly lines, such as minimizing the walking distance of the operator and rotating stations to provide meaningful work assignments, must in an automated machining environment give way to factors like visualization, material flow and maintenance. Visualizing a factory helps operators and managers learn and understand the factory better. Problems can be detected and corrected faster and disturbances in production can thus be reduced. A good material flow is straight with no intersecting flows, triggered by downstream demand and reduces unnecessary buffers and WIP that bind up capital and consume space. Finally, since the machines rather than the operators produce, a good maintenance is required to avoid unplanned stops. The value of teamwork and humans in production which are strongly advocated within lean remain important also in automated machining lines but acquires a new content compared to assembly lines. Teamwork in automated machining environments occur within a group of lines rather than in a single line and it is a major factor when it comes to competence development, production planning and worker satisfaction. While teamwork in assembly lines works to balance the production flow within the line, teamwork in automated machining lines has little or no effect on the line balancing. However, joint efforts in setups and in case of machine failures or worker absence help increasing productivity, and potentially smooth the production at the plant in its entirety. The empirical studies showed that there is no standardized way of working with machining line layout design and redesign, and factors considered were often coincidental and dependent on the functions and priorities of the participants at different layout meeting. To ensure that all factors are taken into consideration a supporting tool where the most important factors were divided into ten categories was developed. Layouts are evaluated and rated on one category at a time to support a systematic way of working. Ongoing discussions, adjustments and improvements to better comply with the factors are encouraged.

Newspapers have increased their emphasis on page design and presentation due to modern design styles, competition, and changes in technology. While newspaper designers have taken on increasingly important roles in newsrooms, professional and academic literature points to a divide between "word" journalists and "visual" journalists. This researcher examined current attitudes toward this divide using Q methodology.Forty-one journalists at four Midwestern newspapers comprised the sample. The journalists sorted 50 Q statements concerning attitudes about the responsibilities of designers and the value of design to the newspaper and its readers.Upon analysis of results, respondents were divided into three factor groups: the Collaborators, the Progressives, and the Traditionalists. Respondents in all three factors agreed that design elements serve readers and cooperation between designers and other journalists benefits readers. Collaborators had the most advanced point of view on the ability of designers and other journalists to effectively work together. Progressives were highly correlated with Collaborators, but placed a heavier emphasis on the product rather than the process, expressing positive attitudes toward the ability of design elements to aid readers and add to the quality of the newspaper. Traditionalists represented a less-advanced point of view, expressing negative feelings toward collaboration and the ability of designers to contribute as journalists. Newspaper policies and philosophies appeared to dictate attitudes toward the role of design, rather than demographic characteristics or job responsibilities. / Department of Journalism

This thesis was a descriptive study of the process of designing a newspaper front page by three journalists. The newspaper industry has placed increased importance on journalistic design. However, little research had been completed on the mental processes of designers.This study was concerned with the processes that occur as professional journalists designed a front page of a newspaper as determined by protocol analysis. Three Indiana newspapers,The Evansville Courier, The South Bend Tribune and The Times from Munster, Ind., were selected. The individual who designed the front page on a regular basis participated in the protocol sessions.The conclusions showed that these designers spent the majority of the design process planning and analyzing materials to be used. The majority of all decisions made by the designers were based on past design knowledge. The journalists applied their skills in a rapid and confident way as they designed separate portions of the page until all elements were used and the page was complete. / Department of Journalism

With contemporary research focusing its attention primarily on benchmark-driven performance evaluation, studying fundamental memory characteristics has gone by the way-side. This thesis presents a systematic study of the expected performance characteristics for contemporary multi-core CPUs. These characteristics are the primary influence on benchmarking variability and need to be quantified if more accurate benchmark results are desired. With the aid of a new, highly customizable, micro-benchmark suite, these CPU-specific attributes are evaluated and contrasted. The benchmark tool provides the framework for accurately measuring instruction throughput and integrates hardware performance counters to gain insight into machine-level caching performance. Additionally, the Linux operating system's impact on cache utilization is evaluated. With careful virtual memory management, cache-misses may be reduced, significantly contributing to benchmark result stability. Finally, a popular cache performance model, stack distance profile, is evaluated with respect to contemporary CPU architectures. While particularly popular in multi-core contention-aware scheduling projects, modern incarnations of the model fail to account for trends in CPU cache hardware, leading to measurable degrees of inaccuracy.

An integrative model of effects of office characteristics and individual differences on workspace satisfaction and work behaviour was developed and tested using survey data from 139 office employees working for four organisations. Workspace experiences, role stress, environmental stressors, and interpersonal interaction were treated as intermediary variables. The variables employed in this study were derived from previous research as well as self-developed, and were divided into seven group variables. The group labels and their respective variables are: (1) office characteristics: office openness, shared office, and number of people sharing; (2) individual differences: job level, organisation tenure, and Type-A behaviour pattern; (3) workspace experience: privacy and distraction; (4) role stress and environmental stressors: role ambiguity, role conflict, superior stressor, co-worker stressor, and physical stressor; (5) interpersonal interaction: attention, social relation, and listening; (6) workspace satisfaction; (7) work behaviour: task performance and friendliness.