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This research addresses sourcing decisions and how those decisions can affect the management of a company's assets. The study begins with a single-plant problem, in which one facility chooses, from a list of parts, which parts to bring in-house. The selection is based on maximizing the value of the selected parts, while remaining within the plant's capacity. This problem is defined as the insourcing problem and modeled as a multidimensional knapsack problem (MKP). The insourcing model is extended to address outsourcing and multiple plants. This multi-plant model, also modeled as an MKP, enables the movement of parts from one plant to another and consideration of a company-wide objective function (as opposed to a single-plant objective function as in the insourcing model). The sourcing problem possesses characteristics that distinguish it from the standard MKP. One such characteristic is what we define as multiple attributes. To understand the multiple attribute characteristic, we compare the various dimensions in the multidimensional knapsack problem. A classification is given for an MKP as either having a single attribute (SA) or multiple attributes (MA). Mathematically, the problems of each attribute classification can be modeled in the same way with simply a different interpretation of the knapsack constraints. However, experimentation indicates that the MA-MKP is more difficult to solve than the SA-MKP. For small problems, with 100 variables and 5 constraints, the CPU time required to find the optimal solution for MA-MKP to SA-MKP problems has a ratio of 32:1. To determine effective methods for addressing the MA-MKP, standard mixed integer programming techniques are tested. The results of this testing are that the exact approaches are not successful in dramatically reducing the solution time to the level of the SA problems. However, a simple heuristic that performs very well on the MA-MKP is presented. The heuristic utilizes variations on the benefit-to-cost ratio and strongest surrogate constraints. The results from experimentation for MA-MKP problem sets, generated using the methods for standard MKP test data sets in the literature, are presented and indicate that the heuristic performs well and improves with larger problems. The average gap between the heuristic solution and the optimal solution is 1.39% for 200-part problems and is reduced to 0.69% when the size of the problem is increased to 298 parts. Although the MA characteristic reflects the sourcing problem, the actual data used in the eperimentation is generated with techniques presented in the literature for standard MKP test problems. Therefore, to more accurately represent the sourcing problem, industry data from a manufacturing facility is studied to identify further sourcing problem characteristics. As a result, industry-motivated data sets are generated that reflect the characteristics of industry data, yet maintain the structure of literature data sets to allow for easy comparison. It is found that both industry and industry-motivated data sets, although possessing the MA characteristic, are much easier to solve than SA problems. Indicators of difficulty appear to be the constraint tightness and a measure of the matrix sparsity. The sparsity is a significant factor because industry data tends to be very sparse, while data sets generated in the literature are completely dense. Another interesting result from the industry-motivated data sets with the single-plant problem is the tendency for a facility to prefer currently produced parts over insourcing new parts from outside the facility. It is not uncommon for a company to have more than one facility with a particular capability. Therefore, the sourcing model is extended to include multiple facilities. With multiple-facilities, effectively all the parts are removed to form one list, and then each part is assigned to one of the facilities or outsourced externally. The multi-facility model is similar to the single-facility model with the addition of assignment constraints enforcing that each part can be assigned to only one facility. Experimentation is performed for the two-, three-, and four-facility models. The problem gets easier to solve as the number of facilities increases. With a greater number of facilities, it is likely that for each part one of facilities will dominate as the best option. Therefore, other solutions can quickly be eliminated and the problem solved more quickly. The two-facility problem is the most difficult; however, the heuristic performs well with an average gap of 0.06% between the heuristic and optimal solutions. We conclude with a summary on experiences with modeling and solving the sourcing problem for a sheet metal fabrication facility. The model solved for this problem had over 1857 parts with 19 machines, which translates to over 70,000 variables and 38 constraints. Although extremely large compared to problems solved in the literature, this problem was solvable because of the unique structure of industry data. Our work with the facility saved the parent organization up to $4.16M per year and provided a tool that encourages a systematic and quantitative process for evaluating decisions related to sheet metal fabrication capacity. / Ph. D.

published_or_final_version / Psychology / Master / Master of Philosophy

In this article we explore the semantic space spanned by self-reported statements of Republican voters. Our semantic structure analysis uses multidimensional scaling and social network analysis to extract, explore, and visualize word patterns and word associations in response to the stimulus statement "I'm a Republican, because ..." which were collected from the official website of the Republican Party. With psychological value theory as our backdrop, we examine the association of specific keywords within and across the statements, compute clusters of statements based on these associations, and explore common word sequences Republican voters use to characterize their political association with the Party. (authors' abstract)

The study explored maternal and paternal attachment, taking a multidimensional approach, in relation to adolescent self-harm. Based on adolescents’ perception of their mothers and fathers availability, anger, and empathy, we examined what contribution of attachment was most predictive of self-harm separately and simultaneously. The sample included 564 Canadian high school students in grade 8 to 12. The quantitative survey was conducted on computers, and was from a three year longitudinal study, using the second and third annual assessments. Cross-sectionally, the results suggested low parental availability, anger toward mothers, and low empathy toward fathers to be related to self-harm. Longitudinal analysis did not support the hypotheses. In sum, attachment to mothers and fathers both contributed to the understanding of adolescent self-harm.

Li Chi Yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 78-80). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Multidimensional Scaling (MDS) --- p.1 / Chapter 1.2 --- Unidimensional Scaling (UDS) --- p.15 / Chapter 1.3 --- Circular Unidimensional Scaling (CDS) --- p.17 / Chapter 1.4 --- The Goodness of fit of models --- p.24 / Chapter 1.5 --- The admissible transformations of the MDS configuration --- p.26 / Chapter 2 --- "Computational Methods on MDS, UDS and CDS" --- p.29 / Chapter 2.1 --- Classical Scaling --- p.29 / Chapter 2.2 --- Guttman's updating algorithm and Pliner's smoothing algorithm --- p.36 / Chapter 2.3 --- Circular Unidimensional Scaling/Circumplex Model --- p.43 / Chapter 3 --- A new algorithm for CDS --- p.45 / Chapter 3.1 --- Method of choosing a good starting value in Guttman's updating algorithm and Pliner's smoothing algorithm --- p.46 / Chapter 3.2 --- A new approach for circular unidimensional scaling --- p.54 / Chapter 3.3 --- Examples --- p.62 / Chapter 3.3.1 --- Comparison of the new approach to existing method --- p.62 / Chapter 3.3.2 --- Illustrations of application to political data --- p.64 / Chapter 4 --- Conclusion and Extensions --- p.67 / Chapter A --- Figures and Tables --- p.70 / Chapter B --- References --- p.78

A Experiência de Verô ou Janela para Vera(cidade) aborda a multiplicidade de dimensões espaço-temporais que permeia a vida social a partir do avanço exponencial da tecnologia. A metodologia adotada no trabalho poético, a que este texto corresponde, segue a orientação da pesquisa da sensação, que propõe problematizar a experiência sensorial, considerando-a como fonte de problemas sensíveis. Foi construída uma videoinstalação composta por projeção em vídeo e cenário para funcionar como ambiente propício à experimentação polifônica de sensações oriundas de diversos dispositivos tecnológicos. A convergência dos elementos existentes no ambiente cenográfico está expressa nas janelas/telas que se multiplicam e caracterizam as diversas manifestações em vídeo de acontecimentos sincrônicos e diacrônicos. Janela para Vera(cidade) cria, a partir de operações poéticas audiovisuais, a possibilidade de uma experiência singular do corpo no espaço e no tempo, em que as interpenetrações multidimensionais simultâneas são uma constante. / A Experiência de Verô ou Janela para Vera(cidade) addresses the multiple dimensions of space-time that permeates the social life from the exponential advance of technology. The methodology adopted in the poetic work follows the guidance of \"search of sensation,\" which aims to discuss the sensory experience, considering it as a source of sensitive issues. The video installation project consists in a video projection and a scenario. This environment conducts to a polyphonic sensations experiment, which comes from different technological devices. The convergence of elements in the environment is expressed in the scenic windows / screens that multiply and characterize the different kinds of events in video synchronic and diachronic. Experiência de Verô ou Janela para Vera(cidade) creates, from poetic audiovisual operations, the possibility of a singular experience of the body in space and time, where simultaneous multidimensional interrelationships are constant.

A Experiência de Verô ou Janela para Vera(cidade) aborda a multiplicidade de dimensões espaço-temporais que permeia a vida social a partir do avanço exponencial da tecnologia. A metodologia adotada no trabalho poético, a que este texto corresponde, segue a orientação da pesquisa da sensação, que propõe problematizar a experiência sensorial, considerando-a como fonte de problemas sensíveis. Foi construída uma videoinstalação composta por projeção em vídeo e cenário para funcionar como ambiente propício à experimentação polifônica de sensações oriundas de diversos dispositivos tecnológicos. A convergência dos elementos existentes no ambiente cenográfico está expressa nas janelas/telas que se multiplicam e caracterizam as diversas manifestações em vídeo de acontecimentos sincrônicos e diacrônicos. Janela para Vera(cidade) cria, a partir de operações poéticas audiovisuais, a possibilidade de uma experiência singular do corpo no espaço e no tempo, em que as interpenetrações multidimensionais simultâneas são uma constante. / A Experiência de Verô ou Janela para Vera(cidade) addresses the multiple dimensions of space-time that permeates the social life from the exponential advance of technology. The methodology adopted in the poetic work follows the guidance of \"search of sensation,\" which aims to discuss the sensory experience, considering it as a source of sensitive issues. The video installation project consists in a video projection and a scenario. This environment conducts to a polyphonic sensations experiment, which comes from different technological devices. The convergence of elements in the environment is expressed in the scenic windows / screens that multiply and characterize the different kinds of events in video synchronic and diachronic. Experiência de Verô ou Janela para Vera(cidade) creates, from poetic audiovisual operations, the possibility of a singular experience of the body in space and time, where simultaneous multidimensional interrelationships are constant.

For equating tests that measure several distinct proficiencies, procedures that reflect the multidimensional structure of the data are needed. Although there exist a few equating procedures developed under the multidimensional item response theory (MIRT) framework, there is a need for further research in this area. Therefore, the primary objectives of this dissertation are to consolidate and expand MIRT observed score equating research with a specific focus on the common-item nonequivalent groups (CINEG) design, which requires scale linking. Content areas and item types are two focal points of dimensionality. This dissertation uses two studies with different data types and comparison criteria to address the research objectives. In general, a comparison between unidimensional item response theory (UIRT) and MIRT methods suggested a better performance of the MIRT methods over UIRT. The simple structure (SS) and full MIRT methods showed more accurate equating results compared to UIRT. In terms of calibration methods, concurrent calibration outperformed separate calibration for all equating methods under most of the studied conditions.

The equity properties can be used to assess the quality of an equating. The degree to which expected scores conditional on ability are similar between test forms is referred to as first-order equity. Second-order equity is the degree to which conditional standard errors of measurement are similar between test forms after equating. The purpose of this dissertation was to investigate the use of a multidimensional IRT framework for assessing first- and second-order equity of mixed format tests. Both real and simulated data were used for assessing the equity properties for mixed-format tests. Using real data from three Advanced Placement (AP) exams, five different equating methods were compared in their preservation of first- and second-order equity. Frequency estimation, chained equipercentile, unidimensional IRT true score, unidimensional IRT observed score, and multidimensional IRT observed score equating methods were used. Both a unidimensional IRT framework and a multidimensional IRT framework were used to assess the equity properties. Two simulation studies were also conducted. The first investigated the accuracy of expected scores and conditional standard errors of measurement as tests became increasingly multidimensional using both a unidimensional IRT framework and multidimensional IRT framework. In the second simulation study, the five different equating methods were compared in their ability to preserve first- and second-order equity as tests became more multidimensional and as differences in group ability increased. Results from the real data analyses indicated that the performance of the equating methods based on first- and second-order equity varied depending on which framework was used to assess equity and which test was used. Some tests showed similar preservation of equity for both frameworks while others differed greatly in their assessment of equity. Results from the first simulation study showed that estimates of expected scores had lower mean squared error values when the unidimensional framework was used compared to when the multidimensional framework was used when the correlation between abilities was high. The multidimensional IRT framework had lower mean squared error values for conditional standard errors of measurement when the correlation between abilities was less than .95. In the second simulation study, chained equating performed better than frequency estimation for first-order equity. Frequency estimation better preserved second-order equity compared to the chained method. As tests became more multidimensional or as group differences increased, the multidimensional IRT observed score equating method tended to perform better than the other methods.