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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Evolvability and Excess Capability as a Response to Uncertain and Future Requirements

Allen, Jeffrey Douglas 01 December 2016 (has links)
Product and system designers face many challenges in the modern world. Designing products that will be subject to emerging or uncertain requirements can be one of the most significant of these challenges. A major risk associated with emerging or uncertain requirements is premature obsolescence. Large-scale, complex engineered systems, such as, aircraft, spacecraft, large seagoing vessels, communication and power systems are especially susceptible to this issue. However, this challenge is not limited to only large-scale complex systems. Even relatively simple products can suffer from premature obsolescence and even failure to be initially accepted, due to inadequately understood or changing requirements. One approach to mitigating this challenge is to increase the product's flexibility and adaptability, thus enabling it to evolve or adapt to meet unforeseen requirements. The flexibility of a product to adapt to new or changing requirements has been shown to increase acceptance rates and reduce the risk of premature obsolescence. Methodologies to accomplish this include product family platform design, transformable product design, reconfigurable product design and modular product design. The literature presents several techniques to aid designers, such as design structure matrices (DSM), change propagation analysis, change modes and effects analysis (CMEA), metrics and guides. These techniques address the challenge by seeking to understand and manage the relationships and interfaces between functions or components within the design. While these are excellent techniques, they do not provide quantifiable functions or models for the design alternatives. Quantifiable functions and models are of value to designers, because they enable numerical design aids. Numerical optimization techniques have been shown to aid designers in efficiently determining appropriate design parameters. This dissertation identifies, analyzes and presents new techniques, which are based on designed-in excess capabilities and to which numerical optimization can be directly applied. There are four parts to the dissertation. In the first part, a technique is presented for determining the relative value of a product, which has been over-designed (excess capabilities) to address future requirements versus redesigning the product once the future requirements emerge. It is shown that in many cases the over-design approach provides greater benefit. In the second part, a numerical metric for the evolvability of a product based on excess capability is presented. An important result of this metric is that the evolvability of a product and the usability of each excess capability can be numerically determined. The third part presents a technique to design products for increased adaptability, based on optimally designed-in excess. Deterministic, and non-deterministic conditions are included in this optimization. Once a numerical model of the design is available the issue of uncertain requirements can be mitigated by directly focusing on the uncertainties. In the fourth part, a technique employing optimization and sensitivity analysis is used to systematically and efficiently guide the designer toward minimizing or eliminating the most critical uncertainties.
2

Audionarratologi Inom Spel

Normell, Lukas, Larsson, Marcus January 2020 (has links)
I dagens samhälle blir underhållningen mer digital, det blir allt mer vanligt att lyssna på en ljudbok istället för att läsa själv. Eftersom spelindustrin är en av de populäraste formerna av underhållning idag ville vi undersöka hur man kan använda sig av audionarrotologi inom spel. Audionarratologi är läran och studien om ljudets funktion inom ett narrativ. Termen är ett paraplybegrepp från narratologi vilket är läran och studien om narrativ. Vi har använt oss audionarratologi för att se hur ljudet kan samverka med ett textbaserat solo-äventyrsspel, eftersom ljudeffekter vanligtvis inte är ett fokus i spel av denna genre. Vi har utvecklat ett textbaserat spel utan en visuell bild med fokus på text och ljud för att kunna utföra vår undersökning om ljudets roll i ett textbaserat spel. Vi har utfört en kvalitativ studie för att ta reda på vad som är det mest optimala sättet att använda sig av ljud för att förstärka narrativet i ett spel. Programmet som användes för utvecklandet av spelet var Twine. I vårt spel får spelare göra olika val för att kunna fortsätta berättelsen, undersökningen utfördes genom att respondenterna fick fylla i ett frågeformulär och svara på vad de tyckte om ljudet i spelet och hur det påverkade narrativet. Med hjälp av svaren har vi sedan dragit slutsatsen att en bra ljudmix och jämna mellanrum mellan ljud och röster stärker narrativet / In today's society where entertainment is becoming more digital, and it is becoming more common to listen to an audiobook instead of reading one yourself. The game media is one of the most popular forms of entertainment in today's society, we want to see how to make use of audionarrotolgy in video games. Audionarratology is the doctrine and study of the function of sound within a story and a narrative, the term is an umbrella concept from narratology which is the doctrine and study of narration. We've used audionarrotolgy to see how the sound can cooperate with a text-based solo adventure story game, because sound effects are usually not a focus in games of this genre. We have developed a text-based game without visual imagery and with a focus on text and sound, in order to perform research on the role of sound in a text-based game. We conducted a qualitative study to find out what the most optimal way to use sound to reinforce the story in a game. The program that was used to develop the game was Twine. The survey was conducted by respondents filling out a questionnaire and answering what they liked about the sound of the game and how it affected the story. With the help of the answers we have then made our own conclusions for how the sound can interact with the story. We came to the conclusion that having a good sound mix and even intervals for sounds and voices, would make the sound reinforce the narrative.
3

交叉實驗設計之探討及分析 / A Study on Cross-over Design

呂怡瑱, Lu, Yi Jenn Unknown Date (has links)
在本文中,分別就四種不同參數組合(包括六個模式)的二維交叉實驗設計,採用一般線性模式法及二樣本t檢定法予以分析,並探討模式間與分析方法間的異同。此外,在二維重覆測量交叉實驗設計方面,我們也分別以單變量分裂區集變異數分析法及多變量變異數分析法進行探討。 / Four possible parametrizations ( including six models ) are considered in this study to clearify some ambigous issues related to a 2*2 cross-over design. Each model is analyzed using both the GLM procedure and two-sample t test. In addition, we also discuss issues related to the 2*2 repeated measurements cross-over design by using the univariate split-plot and multivariate analysis of variance techniques.
4

Nichtparametrische Cross-Over-Verfahren / Nonparametric applications for the cross-over-design

Kulle, Bettina 30 January 2002 (has links)
No description available.
5

Confidence Intervals for a Ratio of Binomial Proportions Based on Paired Data

Bonett, Douglas, Price, Robert M. 15 September 2006 (has links)
Four interval estimation methods for the ratio of marginal binomial proportions are compared in terms of expected interval width and exact coverage probability. Two new methods are proposed that are based on combining two Wilson score intervals. The new methods are easy to compute and perform as well or better than the method recently proposed by Nam and Blackwelder. Two sample size formulas are proposed to approximate the sample size required to achieve an interval estimate with desired confidence level and width.
6

BOM removal by biofiltration- Developing a quantitative basis for comparison

Shen,Dinghua (David) 14 June 2010 (has links)
Biological filtration (Biofiltration) processes have been used first in Europe and then in North America for decades, however currently there is not a good overall parameter to guide biofiltration design and operation except adopting parameters from traditional particle- removal filtration process. On the basis of the biofilm model developed by Rittmann and McCarty (1980a) and the pseudo-analytical solution for the model, Zhang and Huck (1996a) obtained an analytical solution for PF (plug flow) reactors (which can be used for biofilters approximately) after demonstrating that axial dispersion could be reasonably ignored and developed a new parameter, X*, which incorporates considerations of physical contact time, filter media particle size, kinetics, etc. A small-scale application on peers’ engineering/research data by Huck (1999) demonstrated it was a better indicator than other parameters for biofiltration performance. By collecting, screening and investigating literature on AOC, BDOC and odorous compounds removal by biofiltration process, this thesis applied the X* concept to the collected investigations to assess process performances among different target parameters, different filters and different investigations. To the author’s knowledge, this is the first such attempted comprehensive comparison of literature studies, interpreted in terms of a common parameter (X*). The wide ranges of particle sizes, EBCTs, temperatures and high diversity of pre-treatment and operation conditions for the collected cases were considered to be able to well represent biofiltration practices for studied removal targets. No significant relationship between EBCTs and removal percentages were found, indicating that EBCT alone is not able to guide biofiltration design and operation. Based on kinetics parameter comparison, BDOC removal-X* relationship was established. A new parameter, θα, was developed in this thesis to refer to estimated X* values only considering EBCT and particle size. θα parameter values were estimated by comparison of ratios of θα products ((θα)’) based on the properly chosen calculation bases. Distribution of the θα values for temperature-favored (i.e. temperature ≥15°C) AOC and BDOC removal biofiltration processes matched the established removal-X* relationship reasonably. Given the exploratory nature of this research and the complexity of attempting quantitations, fits were assessed based on visual comparison. With the assistance of supporting information and by adopting available temperature activity coefficients, temperature-adjustment coefficients for θα values were determined for the different temperature ranges. Temperature-adjusted AOC and BDOC removal-θα relationships were developed and temperature-adjusted θα parameter values for AOC and BDOC removal were also estimated. Comparisons were conducted, showing fair matches based on visual examinations, for most of the temperature ranges. No relationships were found between ozone dosages and AOC/BDOC removal percentages and the statistical analysis indicated there was significant difference of removal efficiencies between ozonated and non-ozonated influents for biofilters, suggesting ozonation may not only increase the amount of BOM for following biofilter and increase the biodegradability of bulk water; it may also increase the biodegradability of AOC and BDOC themselves. It may not be realistic to obtain the estimated θα values for MIB and geosmin removal by biofiltration. However, plotting θα product vs. removal percentage for the collected MIB and geosmin removal cases shows more positive co-relationships than EBCT-removal percentage relationships visually. A utilization factor η was proposed to guide biofilter design and operation and to assess “over-design” and “under-operated”. Biofilter over-design or under-operated is common for the collected cases. In general, examining X* (or θα, a parameter incorporating the physical components of X*) provided useful information in terms of evaluation and prediction of biodegradable organic compounds removal by biofiltration, which confirms that X* is a better parameter for biofiltration design and operation than other parameters, such as EBCT.
7

BOM removal by biofiltration- Developing a quantitative basis for comparison

Shen,Dinghua (David) 14 June 2010 (has links)
Biological filtration (Biofiltration) processes have been used first in Europe and then in North America for decades, however currently there is not a good overall parameter to guide biofiltration design and operation except adopting parameters from traditional particle- removal filtration process. On the basis of the biofilm model developed by Rittmann and McCarty (1980a) and the pseudo-analytical solution for the model, Zhang and Huck (1996a) obtained an analytical solution for PF (plug flow) reactors (which can be used for biofilters approximately) after demonstrating that axial dispersion could be reasonably ignored and developed a new parameter, X*, which incorporates considerations of physical contact time, filter media particle size, kinetics, etc. A small-scale application on peers’ engineering/research data by Huck (1999) demonstrated it was a better indicator than other parameters for biofiltration performance. By collecting, screening and investigating literature on AOC, BDOC and odorous compounds removal by biofiltration process, this thesis applied the X* concept to the collected investigations to assess process performances among different target parameters, different filters and different investigations. To the author’s knowledge, this is the first such attempted comprehensive comparison of literature studies, interpreted in terms of a common parameter (X*). The wide ranges of particle sizes, EBCTs, temperatures and high diversity of pre-treatment and operation conditions for the collected cases were considered to be able to well represent biofiltration practices for studied removal targets. No significant relationship between EBCTs and removal percentages were found, indicating that EBCT alone is not able to guide biofiltration design and operation. Based on kinetics parameter comparison, BDOC removal-X* relationship was established. A new parameter, θα, was developed in this thesis to refer to estimated X* values only considering EBCT and particle size. θα parameter values were estimated by comparison of ratios of θα products ((θα)’) based on the properly chosen calculation bases. Distribution of the θα values for temperature-favored (i.e. temperature ≥15°C) AOC and BDOC removal biofiltration processes matched the established removal-X* relationship reasonably. Given the exploratory nature of this research and the complexity of attempting quantitations, fits were assessed based on visual comparison. With the assistance of supporting information and by adopting available temperature activity coefficients, temperature-adjustment coefficients for θα values were determined for the different temperature ranges. Temperature-adjusted AOC and BDOC removal-θα relationships were developed and temperature-adjusted θα parameter values for AOC and BDOC removal were also estimated. Comparisons were conducted, showing fair matches based on visual examinations, for most of the temperature ranges. No relationships were found between ozone dosages and AOC/BDOC removal percentages and the statistical analysis indicated there was significant difference of removal efficiencies between ozonated and non-ozonated influents for biofilters, suggesting ozonation may not only increase the amount of BOM for following biofilter and increase the biodegradability of bulk water; it may also increase the biodegradability of AOC and BDOC themselves. It may not be realistic to obtain the estimated θα values for MIB and geosmin removal by biofiltration. However, plotting θα product vs. removal percentage for the collected MIB and geosmin removal cases shows more positive co-relationships than EBCT-removal percentage relationships visually. A utilization factor η was proposed to guide biofilter design and operation and to assess “over-design” and “under-operated”. Biofilter over-design or under-operated is common for the collected cases. In general, examining X* (or θα, a parameter incorporating the physical components of X*) provided useful information in terms of evaluation and prediction of biodegradable organic compounds removal by biofiltration, which confirms that X* is a better parameter for biofiltration design and operation than other parameters, such as EBCT.

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