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You searched for +publisher:"Virginia Tech" +contributor:("Slonim, Anthony D."). Showing records 1 – 3 of 3 total matches.

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Virginia Tech

1. Xie, Xiaojin. Variation in Computerized Tomography Scan Utilization.

Degree: MS, Industrial and Systems Engineering, 2010, Virginia Tech

The U.S. health care system is one of the most expensive health care systems in the world, yet it is not as efficient as it is expected. Studies have shown that the use of expensive imaging procedures, such as CT scans, was significantly increasing for the past few years. However, the increased number of CT scans may not help to improve quality of care. No studies are conducted on investigate geographic variation on CT scan usage rate. This research is the first one to examine CT scan usage rate among counties and to examine variation caused by patient and hospital characteristics. We used the 2007 HCUP-SID database provided data for the research. GIS graph was used to illustrate geographic variation on CT scan usage in New York State. Contingency tables were developed to evaluate to what extent patient and hospital characteristics contribute to the variation. A logistic regression model was built to control the variation caused by patient and hospital characteristics in order to find variation contributed by other potential factors such as availability of CT scanners and radiologists. Significant geographic variation of CT scan usage rate in the county level of New York State was found. Patient demographics, insurance status and medical conditions as well as hospital bed size and teaching status were contributing factors to the variation. After controlling these factors, significant geographic variation was still found. It indicates that other potential reasons would influence the technology use. Advisors/Committee Members: Wernz, Christian (committeechair), Slonim, Anthony D. (committee member), Koelling, Charles Patrick (committee member).

Subjects/Keywords: utilization rate; geographic variation; CT scan; logistic regression

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APA (6th Edition):

Xie, X. (2010). Variation in Computerized Tomography Scan Utilization. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/44723

Chicago Manual of Style (16th Edition):

Xie, Xiaojin. “Variation in Computerized Tomography Scan Utilization.” 2010. Masters Thesis, Virginia Tech. Accessed September 26, 2020. http://hdl.handle.net/10919/44723.

MLA Handbook (7th Edition):

Xie, Xiaojin. “Variation in Computerized Tomography Scan Utilization.” 2010. Web. 26 Sep 2020.

Vancouver:

Xie X. Variation in Computerized Tomography Scan Utilization. [Internet] [Masters thesis]. Virginia Tech; 2010. [cited 2020 Sep 26]. Available from: http://hdl.handle.net/10919/44723.

Council of Science Editors:

Xie X. Variation in Computerized Tomography Scan Utilization. [Masters Thesis]. Virginia Tech; 2010. Available from: http://hdl.handle.net/10919/44723


Virginia Tech

2. Xie, Shiguang. Optimal Allocation of Resources for Screening of Donated Blood.

Degree: PhD, Industrial and Systems Engineering, 2011, Virginia Tech

Blood products, either whole blood or its components, are vital healthcare commodities for patients across all age groups, multiple diagnoses, and in a variety of settings. Meanwhile, blood shortages are common, and are projected to significantly increase in the near future in both developing and developed countries due to a limited supply of and increasing demand for blood, lack of resources, infrastructure. Unfortunately, today there remains a definable risk associated with the transfusion of blood and blood products. We explored, in depth, the resource allocation problem in reducing the risks of transfusion-transmitted infections (TTI). We developed models and algorithms to study the problem of selecting a set of blood screening tests for risk reduction, which we show to be very efficient in numerical studies with realistic-sized problems. This analysis also motivates the development of effective lower bounds with co-infection; our analysis indicates that these algorithms are very efficient and effective for the general problem. We also incorporate other objective functions and constraints (i.e., waste) into the analysis. Waste, defined as the fraction of disposed blood in the ``infection-free" blood, is incorporated into the risk-based model as a constraint. As an important extension, we compared our results of the blood screening problem in risk model with that of weighted risk objectives, which allows for different weights for each TTI. We further explored efficient algorithms to study this extension of the model and analyze how the test composition changes with the different objectives. Finally, in the context of blood screening, the last extension we investigated is to include a ``differential" testing policy, in which an optimal solution is allowed to contain multiple test sets, each applied to a fraction of the total blood units. In particular, the decision-maker faces the problem of selecting a collection of test sets as well as determining the proportion (or fraction) of blood units each test set will be administered to. We proposed the solution methodology and determined how the test sets under differential policy relate to those under the "same-for-all" policy; and how these changes impact the risk, and allow for better budget utilization. Advisors/Committee Members: Pasupathy, Raghu (committee member), Slonim, Anthony D. (committeecochair), Bish, Douglas R. (committeecochair), Bish, Ebru K. (committeecochair).

Subjects/Keywords: Probabilistic Risk Assessment; Blood screening; Resource allocation; Joint Replacement; Risk Reduction

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Xie, S. (2011). Optimal Allocation of Resources for Screening of Donated Blood. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/39259

Chicago Manual of Style (16th Edition):

Xie, Shiguang. “Optimal Allocation of Resources for Screening of Donated Blood.” 2011. Doctoral Dissertation, Virginia Tech. Accessed September 26, 2020. http://hdl.handle.net/10919/39259.

MLA Handbook (7th Edition):

Xie, Shiguang. “Optimal Allocation of Resources for Screening of Donated Blood.” 2011. Web. 26 Sep 2020.

Vancouver:

Xie S. Optimal Allocation of Resources for Screening of Donated Blood. [Internet] [Doctoral dissertation]. Virginia Tech; 2011. [cited 2020 Sep 26]. Available from: http://hdl.handle.net/10919/39259.

Council of Science Editors:

Xie S. Optimal Allocation of Resources for Screening of Donated Blood. [Doctoral Dissertation]. Virginia Tech; 2011. Available from: http://hdl.handle.net/10919/39259


Virginia Tech

3. Zeng, Xin. Comparative Statics Analysis of Some Operations Management Problems.

Degree: PhD, Industrial and Systems Engineering, 2012, Virginia Tech

We propose a novel analytic approach for the comparative statics analysis of operations management problems on the capacity investment decision and the influenza (flu) vaccine composition decision. Our approach involves exploiting the properties of the underlying mathematical models, and linking those properties to the concept of stochastic orders relationship. The use of stochastic orders allows us to establish our main results without restriction to a specific distribution. A major strength of our approach is that it is "scalable," i.e., it applies to capacity investment decision problem with any number of â non-independentâ (i.e., demand or resource sharing) products and resources, and to the influenza vaccine composition problem with any number of candidate strains, without a corresponding increase in computational effort. This is unlike the current approaches commonly used in the operations management literature, which typically involve a parametric analysis followed by the use of the implicit function theorem. Providing a rigorous framework for comparative statics analysis, which can be applied to other problems that are not amenable to traditional parametric analysis, is our main contribution. We demonstrate this approach on two problems: (1) Capacity investment decision, and (2) influenza vaccine composition decision. A comparative statics analysis is integral to the study of these problems, as it allows answers to important questions such as, "does the firm acquire more or less of the different resources available as demand uncertainty increases? does the firm benefit from an increase in demand uncertainty? how does the vaccine composition change as the yield uncertainty increases?" Using our proposed approach, we establish comparative statics results on how the newsvendor's expected profit and optimal capacity decision change with demand risk and demand dependence in multi-product multi-resource newsvendor networks; and how the societal vaccination benefit, the manufacturer's profit, and the vaccine output change with the risk of random yield of strains. Advisors/Committee Members: Bish, Ebru K. (committeechair), Bish, Douglas R. (committee member), Haller, Hans H. (committee member), Slonim, Anthony D. (committee member), Wernz, Christian (committee member).

Subjects/Keywords: Comparative Statics Analysis; Capacity Planning; Influenza Vaccine; Yield Uncertainty; Stochastic Programming; Game-theoretic Model; Stochastic Orders

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Zeng, X. (2012). Comparative Statics Analysis of Some Operations Management Problems. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/39178

Chicago Manual of Style (16th Edition):

Zeng, Xin. “Comparative Statics Analysis of Some Operations Management Problems.” 2012. Doctoral Dissertation, Virginia Tech. Accessed September 26, 2020. http://hdl.handle.net/10919/39178.

MLA Handbook (7th Edition):

Zeng, Xin. “Comparative Statics Analysis of Some Operations Management Problems.” 2012. Web. 26 Sep 2020.

Vancouver:

Zeng X. Comparative Statics Analysis of Some Operations Management Problems. [Internet] [Doctoral dissertation]. Virginia Tech; 2012. [cited 2020 Sep 26]. Available from: http://hdl.handle.net/10919/39178.

Council of Science Editors:

Zeng X. Comparative Statics Analysis of Some Operations Management Problems. [Doctoral Dissertation]. Virginia Tech; 2012. Available from: http://hdl.handle.net/10919/39178

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