Thinking Across Borders. 13th Annual Research Week: Event Proceedings

Poster and podium presentations of research by students and faculty of University of the Incarnate Word

12th Annual Research Week--Event Proceedings

12th Annual Research Week A Celebration of Student Researc

Excellence Summit 2024

In it\u27s 17th year, the University of the Incarnate Word, welcome all to read and review the proceedings of the annual research week. The 2024 Excellence Summit highlighted academic excellence across all schools featuring topics from nutrition studies to soil amendments, artificial intelligence, medical case studies, and music composition studies. The rich mixture of humanities, health sciences, physical sciences, education, and business can be found in this booklet. We thank all that contributed to these works and hope the community enjoys learning from today\u27s and tomorrow\u27s leaders in research, inquiry, and scholarship

Resource allocation in stochastic processing networks : performance and scaling

Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, Operations Research Center, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 189-193).This thesis addresses the design and analysis of resource allocation policies in largescale stochastic systems, motivated by examples such as the Internet, cloud facilities, wireless networks, etc. A canonical framework for modeling many such systems is provided by "stochastic processing networks" (SPN) (Harrison [28, 29]). In this context, the key operational challenge is efficient and timely resource allocation. We consider two important classes of SPNs: switched networks and bandwidth-sharing networks. Switched networks are constrained queueing models that have been used successfully to describe the detailed packet-level dynamics in systems such as input-queued switches and wireless networks. Bandwidth-sharing networks have primarily been used to capture the long-term behavior of the flow-level dynamics in the Internet. In this thesis, we develop novel methods to analyze the performance of existing resource allocation policies, and we design new policies that achieve provably good performance. First, we study performance properties of so-called Maximum-Weight-[alpha] (MW-[alpha]) policies in switched networks, and of a-fair policies in bandwidth-sharing networks, both of which are well-known families of resource allocation policies, parametrized by a positive parameter [alpha] > 0. We study both their transient properties as well as their steady-state behavior. In switched networks, under a MW-a policy with a 2 1, we obtain bounds on the maximum queue size over a given time horizon, by means of a maximal inequality derived from the standard Lyapunov drift condition. As a corollary, we establish the full state space collapse property when [alpha] > 1. In the steady-state regime, for any [alpha] >/= 0, we obtain explicit exponential tail bounds on the queue sizes, by relying on a norm-like Lyapunov function, different from the standard Lyapunov function used in the literature. Methods and results are largely parallel for bandwidth-sharing networks. Under an a-fair policy with [alpha] >/= 1, we obtain bounds on the maximum number of flows in the network over a given time horizon, and hence establish the full state space collapse property when [alpha] >/= 1. In the steady-state regime, using again a norm-like Lyapunov function, we obtain explicit exponential tail bounds on the number of flows, for any a > 0. As a corollary, we establish the validity of the diffusion approximation developed by Kang et al. [32], in steady state, for the case [alpha] = 1. Second, we consider the design of resource allocation policies in switched networks. At a high level, the central performance questions of interest are: what is the optimal scaling behavior of policies in large-scale systems, and how can we achieve it? More specifically, in the context of general switched networks, we provide a new class of online policies, inspired by the classical insensitivity theory for product-form queueing networks, which admits explicit performance bounds. These policies achieve optimal queue-size scaling, in the conventional heavy-traffic regime, for a class of switched networks, thus settling a conjecture (documented in [51]) on queue-size scaling in input-queued switches. In the particular context of input-queued switches, we consider the scaling behavior of queue sizes, as a function of the port number n and the load factor [rho]. In particular, we consider the special case of uniform arrival rates, and we focus on the regime where [rho] = 1 - 1/f(n), with f(n) >/= n. We provide a new class of policies under which the long-run average total queue size scales as O(n1.5 -f(n) log f(n)). As a corollary, when f(n) = n, the long-run average total queue size scales as O(n2.5 log n). This is a substantial improvement upon prior works [44], [52], [48], [39], where the same quantity scales as O(n3 ) (ignoring logarithmic dependence on n).by Yuan Zhong.Ph.D

Online optimization problems

Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, Operations Research Center, 2013.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 149-153).In this thesis, we study online optimization problems in routing and allocation applications. Online problems are problems where information is revealed incrementally, and decisions must be made before all information is available. We design and analyze algorithms for a variety of online problems, including traveling salesman problems with rejection options, generalized assignment problems, stochastic matching problems, and resource allocation problems. We use worst case competitive ratios to analyze the performance of proposed algorithms. We begin our study with online traveling salesman problems with rejection options where acceptance/rejection decisions are not required to be explicitly made. We propose an online algorithm in arbitrary metric spaces, and show that it is the best possible. We then consider problems where acceptance/rejection decisions must be made at the time when requests arrive. For dierent metric spaces, we propose dierent online algorithms, some of which are asymptotically optimal. We then consider generalized online assignment problems with budget constraints and resource constraints. We first prove that all online algorithms are arbitrarily bad for general cases. Then, under some assumptions, we propose, analyze, and empirically compare two online algorithms, a greedy algorithm and a primal dual algorithm. We study online stochastic matching problems. Instances with a fixed number of arrivals are studied first. A novel algorithm based on discretization is proposed and analyzed for unweighted problems. The same algorithm is modified to accommodate vertex-weighted cases. Finally, we consider cases where arrivals follow a Poisson Process. Finally, we consider online resource allocation problems. We first consider the problems with free but fixed inventory under certain assumptions, and present near optimal algorithms. We then relax some unrealistic assumptions. Finally, we generalize the technique to problems with flexible inventory with non-decreasing marginal costs.by Xin Lu.Ph.D

Operational Evaluation Test Report on Beaver Micro-Vegetation Cutter

The Micro-Vegetation Cutter (MVC) system was tested in the late summer and early fall of 2004 at a U.S. Army Countermine development site in central Virginia. The MVC project was funded by the U.S. Army’s Night Vision and Electronic Sensors Directorate (NVESD), Countermine Division, Humanitarian Demining (HD) Research and Development Office located at Ft. Belvoir, Virginia. The MVC system, consisting of a remote-controlled vegetation cutter vehicle and a command vehicle, is the product of the project engineer, Mr. J. Michael Collins. Mr. Collins was responsible for the concept, its design, and directed the MVC’s fabrication. All work was performed in the Modeling and Mechanical Fabrication Shop located at Ft. Belvoir, Virginia. During the annual Department of Defense Humanitarian Demining Requirements Workshop, sponsored by the U.S. Army’s Humanitarian Demining Program Office, located at Ft. Belvoir, and attended by representatives of demining organizations throughout the world, one of the more frequently requested equipment needs was for systems that can be used to prepare areas for demining operations. While there are many commercial off-the-shelf (COTS) pieces of equipment available, most are large and expensive. Thus, there was still a need for a small, affordable, robust system having cross-country mobility and the capability to clear light to moderately heavy vegetation and remove surface ferrous metal scrap in preparation for demining activities. With this objective, the Humanitarian Demining Program Office funded the design and fabrication of a concept developed by Mr. J. Michael Collins, a mechanical systems engineer in the Program Office. The concept, consisting of a multiattachment, remotely controlled, boom and stick work vehicle, named the Beaver, and an armored control vehicle, named the Duck, comprise the Micro-Vegetation Cutter (MVC) System. Fabrication was completed in the summer of 2004. A pre-evaluation test was conducted in March 2004 at Ft. Belvoir to insure that all systems functioned as intended. The results of the MVC system pretest are included as this report’s Appendix. After completing the system assembly and addressing some of the issues raised during the pretest, an operational evaluation test was scheduled for late summer 2004

Report on the Mine Clearing Rake Test

The purpose of the operational evaluation test was to assess the ability of the mine clearing rake (MCR) to enhance the effectiveness of a humanitarian demining mission. To this end, the HD PM purchased an MCR and initiated the testing process. Operational Demining Tasks Considered for the MCR: Based on the claims made regarding the MCR\u27s performance, three distinct HD phases were considered for assessing the MCR\u27s capabilities. These were the area preparation, demining, and quality assurance phases. Of the three, the area preparation and demining phases were considered poor choices for the MCR since it required driving the primary power source for the MCR, in this case a tractor, over potentially mined ground, creating a significant safety risk for the driver and vehicle. The quality assurance task, while still posing some risk was considered an acceptable risk. Based on the performance of the Mine Clearing Rake during this operational evaluation test, it should not be considered for use in Humanitarian Demining operations

2010 results of the advanced placement (AP) examinations and the international baccalaureate (IB) examinations

Since 1984, each school district in South Carolina has been required to provide Advanced Placement (AP) courses in all secondary schools that include grades 11 or 12. These classes prepare students for the national AP examinations. Students who score 3, 4, or 5 on an AP exam are generally considered qualified to receive credit for the equivalent course(s) at colleges and universities that give credit for AP exams. The data are presented for high school students who participated in AP courses in public schools and took at least one AP exam during the 2009-10 school year