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Residual-Based Isotropic and Anisotropic Mesh Adaptation for Computational Fluid DynamicsBaserinia, Amir Reza January 2008 (has links)
The accuracy of a fluid flow simulation depends not only on the numerical method used for discretizing the governing equations, but also on the distribution and topology of the mesh elements. Mesh adaptation is a technique for automatically modifying the mesh in order to improve the simulation accuracy in an attempt to reduce the manual work required for mesh generation. The conventional approach to mesh adaptation is based on a feature-based criterion that identifies the distinctive features in the flow field such as shock waves and boundary layers. Although this approach has proved to be simple and effective in many CFD applications, its implementation may require a lot of trial and error for determining the appropriate criterion in certain applications. An alternative approach to mesh adaptation is the residual-based approach in which the discretization error of the fluid flow quantities across the mesh faces is used to construct an adaptation criterion. Although this approach provides a general framework for developing robust mesh adaptation criteria, its incorporation leads to significant computational overhead.
The main objective of the thesis is to present a methodology for developing an appropriate mesh adaptation criterion for fluid flow problems that offers the simplicity of a feature-based criterion and the robustness of a residual-based criterion. This methodology is demonstrated in the context of a second-order accurate cell-centred finite volume method for simulating laminar steady incompressible flows of constant property fluids. In this methodology, the error of mass and momentum flows across the faces of each control volume are estimated with a Taylor series analysis. Then these face flow errors are used to construct the desired adaptation criteria for triangular isotropic meshes and quadrilateral anisotropic meshes. The adaptation results for the lid-driven cavity flow show that the solution error on the resulting adapted meshes is 80 to 90 percent lower than that of a uniform mesh with the same number of control volumes.
The advantage of the proposed mesh adaptation method is the capability to produce meshes that lead to more accurate solutions compared to those of the conventional methods with approximately the same amount of computational effort.
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Residual-Based Isotropic and Anisotropic Mesh Adaptation for Computational Fluid DynamicsBaserinia, Amir Reza January 2008 (has links)
The accuracy of a fluid flow simulation depends not only on the numerical method used for discretizing the governing equations, but also on the distribution and topology of the mesh elements. Mesh adaptation is a technique for automatically modifying the mesh in order to improve the simulation accuracy in an attempt to reduce the manual work required for mesh generation. The conventional approach to mesh adaptation is based on a feature-based criterion that identifies the distinctive features in the flow field such as shock waves and boundary layers. Although this approach has proved to be simple and effective in many CFD applications, its implementation may require a lot of trial and error for determining the appropriate criterion in certain applications. An alternative approach to mesh adaptation is the residual-based approach in which the discretization error of the fluid flow quantities across the mesh faces is used to construct an adaptation criterion. Although this approach provides a general framework for developing robust mesh adaptation criteria, its incorporation leads to significant computational overhead.
The main objective of the thesis is to present a methodology for developing an appropriate mesh adaptation criterion for fluid flow problems that offers the simplicity of a feature-based criterion and the robustness of a residual-based criterion. This methodology is demonstrated in the context of a second-order accurate cell-centred finite volume method for simulating laminar steady incompressible flows of constant property fluids. In this methodology, the error of mass and momentum flows across the faces of each control volume are estimated with a Taylor series analysis. Then these face flow errors are used to construct the desired adaptation criteria for triangular isotropic meshes and quadrilateral anisotropic meshes. The adaptation results for the lid-driven cavity flow show that the solution error on the resulting adapted meshes is 80 to 90 percent lower than that of a uniform mesh with the same number of control volumes.
The advantage of the proposed mesh adaptation method is the capability to produce meshes that lead to more accurate solutions compared to those of the conventional methods with approximately the same amount of computational effort.
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Slip point of subcutaneous adipose tissue as an indicator of beef carcass qualityWard, Lindsay Paige 15 May 2009 (has links)
We hypothesized that slip point of subcutaneous (s.c.) adipose tissue lipids would
predict beef carcass quality. To address our hypothesis, 79 M. longissimus dorsi (LD)
steaks from cattle of unknown background were used to provide information on slip
points, percentage intramuscular lipid, fatty acid composition, and MUFA:SFA ratios.
Overlying s.c. adipose tissue was separated from the muscle lean, which contained
intramuscular (i.m.) adipose tissue. Lipids were extracted from s.c. adipose tissue and
muscle lean by a modified chloroform:methanol procedure and subjected to various
analyses. The hypothesis was tested by developing regression equations to determine
which fatty acid variables were most useful in predicting carcass composition. There
was a high correlation between s.c. MUFA:SFA ratio and s.c. slip points (P < 0.001)
with an R2 of 0.557. Also, the MUFA:SFA fatty acid ratios of s.c. and i.m. adipose
tissue were significantly correlated and an R2 of 0.440 was observed (P < 0.001) when
regressed against each other. The current data set observed s.c. MUFA:SFA ratios
(0.73) lower than previous studies, which suggests a population of young or unfinished
cattle. This study demonstrated that it is possible to predict the intramuscular lipid
(IML) MUFA:SFA ratio by measuring s.c. slip point (R2 of 0.097; P < 0.01). However, our hypothesis of predicting amount of marbling, hence quality grade, from the melting
temperature of s.c. adipose tissue lipids proved incorrect (R2 = 0.001). Nonetheless,
these data indicate that LD fatty acid composition can be estimated by measuring s.c.
adipose tissue slip point.
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Making sense of divergent career test scoresRodriguez, Steven 15 May 2009 (has links)
The purposes of this study were to discover patterns in test scores when both the Myers-Briggs Type Indicator and the Strong Interest Inventory are used simultaneously and to offer career counselors practical ways to interpret the scores when counseling their clients. To do this, the researcher conducted one study using canonical correlation to study the relationships and interrelationships between scores on the MBTI dichotomies and the SII GOTs. A second study utilized MANOVA to increase our understanding of age and gender differences in scores on these two instruments. Another study sought to use case examples of clients who had completed both tests to explain practical ways that career counselors can help their clients understand and apply results of both tests in ways that most benefit the clients’ career decision making.
From the results of these studies, it would appear that the most common scores to occur simultaneously on both tests at once are MBTI Intuition, and SII Artistic. One could conclude from this that the personality characteristic of enjoying working in settings that allow for creative endeavor is particularly strong relative to other personality characteristics measured by these tests. We could also conclude that as individuals age, they are more likely to prefer working in settings that allow them to pursue creative endeavors. Another conclusion supported by this data indicates that men are more comfortable with career fields that are unstable and entrepreneurial than women throughout the lifespan.
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An Investigation of Factors Influencing District Hospitals¡¦ Participation in Taiwan Healthcare Indicator Series (THIS)Ma, Su-Mei 10 September 2004 (has links)
Due to rapid change of healthcare environment and the awakening consciousness of health service consumers, healthcare quality becomes a major concern of hospital administrators. In 1999, Taiwan Joint Commission on Hospital Accreditation cooperated with Maryland Hospital Association and then implemented Taiwan Quality Indicator Project (TQIP). On the other hand, within the years 1998~ 2000, Taiwan College of Healthcare Executives developed a localized healthcare indicator series (referred to as Taiwan Healthcare Indicator Series, THIS, afterwards) aiming at providing a better system for monitoring medical care quality for the long run. Nevertheless, relevant reports show that so far not many hospitals actively participate in the THIS.
The main purpose of this study is to explore those factors which might influence a district hospital¡¦s decision of whether participating in the THIS no not. Hospital administrators were the subjects of this study. Mailing survey was adopted to collect the data. In May, 2004, a total of 436 questionnaires were mailed out. 147 hospitals responded (i.e. a response rate of 33.72%).
The key variables of interest may be classified into three groups-- hospital characteristics, perception of THIS, and professional technique related to THIS. Descriptive analyses showed that more than 60% district hospitals did not participate in the THIS; the reasons are listed in order as follows: lack of budget, lack of quality assurance specialists, indicator unable to meet hospital¡¦s requirement, human resource shortage, annual fee too expensive. As for those hospitals participating in THIS, their considerations are showed in order as follows: better reimbersencement, meeting the requirement of assessment, complying with regulation of the authority, and meeting the requirement of hospital policy and patient needs. Besides, a logistic regression analysis indicated that the most important factor influencing hospitals¡¦ participation in THIS is ¡§whether any medical quality related activity is implemented within the hospital.¡¨
With a response rate of 33.72% and with responding hospitals relatively restricted to Kaohsiung-Pingtung area, a careful generalization of results is needed. Further, it is suggested that a qualitative study design along with a higher response rate of quantitative analysis might help enhance the generalization for future study.
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The Development of a Mathematics Achievement Test For the Seventh Graders in Tainan City Based on the Grade 1-9 CurriculumHuang, Guo-chin 07 December 2004 (has links)
The purposes of this study were to develop a mathematics achievement test for the seventh graders in Tainan based on the Grade 1-9 Curriculum, and to explore the difference in performance for variables of gender, tutoring, scale of school, public-private school and textbook version.
The population of this study consisted of the eight graders in Tainan City. Three samples were drawn for this study: the first tryout sample¡]n=402¡^, the second tryout sample¡]n=455¡^and the norm sample¡]n=870¡^. The Mathematics Achievement Test for Seventh Graders developed by the researcher was used. The data were analyzed in two dimensions: 1. items and test with methods of CTT and IRT; and 2. the difference in performance for variables of gender, tutoring, scale of school, public-private school and textbook version with statistical testing methods.
The results of this study were listed below:
I. Item and Test Analysis:
1.Regarding the difficulty and discrimination of CTT, the average difficulty of interval scale¡]¡µ¡^of items was 12.14, the mean of percentage passing and discrimination were 0.58 and 0.52, respectively.
2.According to the result of the reliability examination, the Cronbach value of internal consistency was 0.85, the test-retest reliability indicated 0.86, the split-half reliability showed 0.86.
3.The evidences of validity about this test were well content-related, criterion-related, construct-related. As for the result of the validity examination, the content validity of this test was through experts¡¦ review and judgment. The criterion validity was based on significantly positive correlation of the monthly test scores for each school. The construct validity had established in two ways of the internal consistency and the different groups analysis.
4.Analyzing items with IRT, 3PL model, the mean of discrimination (a), difficulty (b) and guessing(c) are 1.23, 0.14 and 0.21, respectively.
5. DIF was present for the item 17 between gender groups.
6. The correlations of item difficulty values between IRT and CTT were 0.97¡ã1.00, the correlations of item discrimination were 0.21¡ã0.95. The correlation between ability parameters of IRT model and total score of CTT ranged from 0.98 to 1.00. The result of indices between IRT and CTT revealed high correlations.
7. This test established a percentile rank and T-score norms.
II. Testing of the performance differences with significance level£\=0.01:
1.The student¡¦s performances were significantly different between gender groups, and the female exceeded male.
2.The performances of the students who accepted tutoring after school hours were better than the others¡¦ performances significantly.
3. The student¡¦s performances in the public and private school were significantly different, and the private school outperformed the public school.
4.The performances of the students in private school were better than the performances of the students¡]both accepting tutoring and not ¡^in public school. And in public school, the performances of the students accepting tutoring were better than the students not accepting tutoring.
5.As for the school scale, the large is better than the small, and the middle is better than the small at statistical significant level.
6.In the textbook version, this test found that the performance of student using the version Nani surpassed the performance of student using the version Hanlin, and the version Jenlin outshined the version Hanlin.
Finally, based on the results and findings of this study, numerous suggestions for the practical use of the test and future researches were provided.
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Constructing Performance Evaluation Criteria with AHP for Production Supervisors - A Case Study on Taiwan Paper IndustryWang, Hsin-Ju 17 June 2005 (has links)
Paper industry in Taiwan is mainly focused on domestic demand. Its production and sales not only are related to economic growth but also serve as an index of a nation¡¦s economic situation. Due to the business model of this industry, production line workers compose the majority of employees of the enterprise. So production supervisors play a very important role in the effectiveness of first-line worker management and improvement of operation procedures. Therefore, production supervisors in Taiwan paper industry are focused as the subject of this research. The purpose of this study is to propose, by applying Analytic Hierarchy Process (AHP), an approach to construct Performance Evaluation Indicators and weights. Specific suggestions for the construction and modification of Performance Appraisal system for paper industry in Taiwan will also be made.
The research method includes literature review and references made to industrial practice, by which performance appraisal criteria for production supervisors were drafted. Further, expert survey on the evaluation system in use was carried out among members of Taiwan Paper Industry Association. Based on the data gathered from the questionnaire survey, analysis of importance and the AHP approach were applied to construct the structure and weights of the Performance Appraisal Criteria for production supervisors. Also, validation was made in a manufacture of the paper industry. Empirical examination supports the practicality and fitness of the structure of this Performance Evaluation System. Finally, analysis results were concluded into suggestions for administrative practice and future studies. Findings of this research are as follows:
I. Performance Appraisal Criteria and weights
The Performance Appraisal Criteria includes the following three constructs: 1. Work achievement (Weight : 0.4092) ; 2. Professional capacity (Weight : 0.3383); 3. Work behavior and attitude (Weight : 0.2525).
II. Secondary Performance Appraisal Criteria and weights
1. ¡§Work achievement¡¨ construct includes the following 6 items: (1) Occupational safety (Weight: 0.1598); (2) Product quality (Weight: 0.0739); (3) Cost control (Weight: 0.0536); (4) Discipline (Weight: 0.0409); (5) Production capacity (Weight: 0.0408); (6) Equipment utilization efficiency (Weight: 0.0400).
¡@2. ¡§Professional capacity¡¨ construct includes 6 items: (1) Executive skills (Weight : 0.0549); (2) Leadership (Weight : 0.0512); (3) Resourcefulness (Weight : 0.0423); (4) Professional knowledge and skills (Weight : 0.0404); (5) Interpersonal relationship skills (Weight : 0.0323); (6) Strategy-making (Weight : 0.0314).
¡@3. ¡§Work behavior and attitude¡¨ construct has 7 sub-items: (1) Teamwork and cooperation (Weight 0.0676); (2) Integrity (Weight 0.0577); (3) Responsibility (Weight 0.0545); (4) Proactivity (Weight 0.0439); (5) Cost-consciousness (Weight 0.0434); (6) Professional attitude (Weight 0.0403); (7) Self-control (Weight 0.0309).
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The Change of Economic Structure and the Quality of Life in TaiwanCHU, HUI-TAI 12 July 2005 (has links)
ABSTRACT
Most of the countries in the world take increasing national income and improving living standard as their economic development goals. Due to the change of economic structure, the nation¡¦s average national income per year has exceeded USD.10,000, and the people are enjoying the material life brought forth from the high economic growth. However, the increasing of wealth doesn¡¦t guarantee the increasing of happiness and well-being. Therefore, the idea of ¡§Quality of Life¡¨ in the advanced country is to remind us that pursuing living standard is only a tool, pursuing quality of life is the real goal of economic development. Looking back at 50 years¡¦ change of economic structure and the quality of life in Taiwan, the result of the transformation of the economic structure shows on the high multiple increasing of income and the notable improvement of quality of life in each aspect of people¡¦s life, such as education, medical insurance etc. However, pursuing the rapid economic development also brings about the negative effects on the quality of life, causing the impact of environmental pollution and the over development of resource, city densely populated, thus the quality of public security, social order, and nature-ecology environment cannot reach the people¡¦s expectation but even worsen. There is a tendency towards slow rising of the general quality of life index, just as the American economic historian W. W. Rostow said, people begin to improve their quality of life when the economic development comes into the mature stage. As a result, when Taiwan is pursuing the high economic growth and wealth, the improvement of ¡§quality¡¨ is much more important than that of ¡§quantity¡¨. The expense for improving the quality of life today is the investment in the payoff tomorrow. To improve the quality of life, we have to understand the external effect in the change of economic structure, and to estimate and deal with the external cost properly.
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Transformation of the Competence Indicators into Teaching Objectives for Elementary School For the First, Second, and Third Learning Stage in the Area of ¡§Person-Space¡¨Chen, Chien-Lee 07 August 2005 (has links)
The goal of this research is to investigate the common properties of the transformation of the social studies area competence indicator into teaching objectives for elementary school. The competence indicators for the first, second, and third learning stage in the area of ¡§person-space¡¨ were considered in this research. The method of content analysis was used to compare the corresponding teaching objectives amongst a collection of textbook for these competence indicators. A number of surveys were conducted using a Delphi based questionnaire to gather the opinions of elementary school curriculum developers, textbook publishers and reviewers, and the field teachers on the transformation of the competence indicators for the first, second, and third learning stage in the area of ¡§person-space¡¨ into the corresponding teaching objectives contained in these textbook.
The main findings of this research are following:
1.The transformation are usually made by first analyzing the level of competence and the core concept aspects of the competence indicator and then followed by the actual construction of the feasible teaching objectives derived based on the results of such analysis.
2.For the elementary school social studies area of ¡§person-space¡¨, the transformations of the competence indicator for the area subject axis made by the various editor groups of these textbook were different not only in the number but also in the feasibility and concept of the resulting teaching objectives. The different might be resulted from the various approaches took by the editor groups to analyze and interpret the indicators.
3. Three survey, each using a Delphi based questionnaire, were conducted to gather opinions on the transformations made for the social studies area of ¡§person-space¡¨ from the curriculum expert and scholars, textbook editors and publishers, textbook reviewers, and elementary school field teachers. The result indicated that the four groups gradually gained the consensus on the transformations made for a total of 20 competence indicators and the resulting teaching objectives. For the analysis of competence indicators, all four groups achieved the agreement in the aspect of competence; and in the aspect of core concept, all four groups achieve the mutual agreement in all but three core concepts. As for the analysis of teaching objectives, all four groups obtained the consensus in all but eight of the objectives.
4. Additional analyses using the ANOVA method were performed for those core concepts and teaching objectives that the agreement was not reached. The results of comparison indicated that the group of curriculum experts and scholars and the group of elementary school field teachers were significantly different in the approval degree aspect. The group of curriculum experts and scholars and the elementary school field teachers were significantly different in the teaching objectives aspect.
Finally, based on the findings of this research, some suggestions on the transformation of the competence indicators for the first, second, and third learning stage in the elementary school social studies area of ¡§person-space¡¨ will be proposed and made available to the field teachers, curriculum developers, textbook publishers and the reviewers, and the later researchers for their reference.
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Performance appraisal indicators study for restaurant employee in hotel industryTsai, Ching-I 31 August 2005 (has links)
To assist hotel manager better human-resources practices implement and enhance organization performance, the purpose of this study is to identify the key factors of performance appraisal for restaurant employee in the hotel industry. Starting from reviewing related references and interviewing industry experts to collect information both in theory & actual practice, an indicators list has developed in consensus as result of the first phase. Main factors and sub-factors have identified through AHP process and the weightings as well.
Analysis is based on expert questionnaire, which 100 delivered to managers or supervisors of restaurant in hotel, and 26 are valid.
The conclusions of the study are listed as below,
1. Established indicators list by reviewing related references, theories and experts interview which consisting 21 key indicators as most suitable indicators for restaurant employee in hotel industry.
2. Personal characteristic indicator is the main factor of performance appraisal in hotel industry identified by the study, followed are result oriented factor and behavioral factor.
3. Established assessment weighting system for the main and sub-indicators by using AHP.
4. Developed a new performance appraisal form for hotel management as a reference, which each indicator consist different weighting of assessment.
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