Resource allocation optimization problems in the public sector

This dissertation consists of three distinct, although conceptually related, public sector topics: the Transportation Security Agency (TSA), U.S. Customs and Border Patrol (CBP), and the Georgia Trauma Care Network Commission (GTCNC). The topics are unified in their mathematical modeling and mixed-integer programming solution strategies. In Chapter 2, we discuss strategies for solving large-scale integer programs to include column generation and the known heuristic of particle swarm optimization (PSO). In order to solve problems with an exponential number of decision variables, we employ Dantzig-Wolfe decomposition to take advantage of the special subproblem structures encountered in resource allocation problems. In each of the resource allocation problems presented, we concentrate on selecting an optimal portfolio of improvement measures. In most cases, the number of potential portfolios of investment is too large to be expressed explicitly or stored on a computer. We use column generation to effectively solve these problems to optimality, but are hindered by the solution time and large CPU requirement. We explore utilizing multi-swarm particle swarm optimization to solve the decomposition heuristically. We also explore integrating multi-swarm PSO into the column generation framework to solve the pricing problem for entering columns of negative reduced cost. In Chapter 3, we present a TSA problem to allocate security measures across all federally funded airports nationwide. This project establishes a quantitative construct for enterprise risk assessment and optimal resource allocation to achieve the best aviation security. We first analyze and model the various aviation transportation risks and establish their interdependencies. The mixed-integer program determines how best to invest any additional security measures for the best overall risk protection and return on investment. Our analysis involves cascading and inter-dependency modeling of the multi-tier risk taxonomy and overlaying security measurements. The model selects optimal security measure allocations for each airport with the objectives to minimize the probability of false clears, maximize the probability of threat detection, and maximize the risk posture (ability to mitigate risks) in aviation security. The risk assessment and optimal resource allocation construct are generalizable and are applied to the CBP problem. In Chapter 4, we optimize security measure investments to achieve the most cost-effective deterrence and detection capabilities for the CBP. A large-scale resource allocation integer program was successfully modeled that rapidly returns good Pareto optimal results. The model incorporates the utility of each measure, the probability of success, along with multiple objectives. To the best of our knowledge, our work presents the first mathematical model that optimizes security strategies for the CBP and is the first to introduce a utility factor to emphasize deterrence and detection impact. The model accommodates different resources, constraints, and various types of objectives. In Chapter 5, we analyze the emergency trauma network problem first by simulation. The simulation offers a framework of resource allocation for trauma systems and possible ways to evaluate the impact of the investments on the overall performance of the trauma system. The simulation works as an effective proof of concept to demonstrate that improvements to patient well-being can be measured and that alternative solutions can be analyzed. We then explore three different formulations to model the Emergency Trauma Network as a mixed-integer programming model. The first model is a Multi-Region, Multi-Depot, Multi-Trip Vehicle Routing Problem with Time Windows. This is a known expansion of the vehicle routing problem that has been extended to model the Georgia trauma network. We then adapt an Ambulance Routing Problem (ARP) to the previously mentioned VRP. There are no known ARPs of this magnitude/extension of a VRP. One of the primary differences is many ARPs are constructed for disaster scenarios versus day-to-day emergency trauma operations. The new ARP also implements more constraints based on trauma level limitations for patients and hospitals. Lastly, the Resource Allocation ARP is constructed to reflect the investment decisions presented in the simulation.Ph.D

Low-Power Human-Machine Interfaces: Analysis And Design

Human-Machine Interaction (HMI) systems, once used for clinical applications, have recently reached a broader set of scenarios, such as industrial, gaming, learning, and health tracking thanks to advancements in Digital Signal Processing (DSP) and Machine Learning (ML) techniques. A growing trend is to integrate computational capabilities into wearable devices to reduce power consumption associated with wireless data transfer while providing a natural and unobtrusive way of interaction. However, current platforms can barely cope with the computational complexity introduced by the required feature extraction and classification algorithms without compromising the battery life and the overall intrusiveness of the system. Thus, highly-wearable and real-time HMIs are yet to be introduced. Designing and implementing highly energy-efficient biosignal devices demands a fine-tuning to meet the constraints typically required in everyday scenarios. This thesis work tackles these challenges in specific case studies, devising solutions based on bioelectrical signals, namely EEG and EMG, for advanced hand gesture recognition. The implementation of these systems followed a complete analysis to reduce the overall intrusiveness of the system through sensor design and miniaturization of the hardware implementation. Several solutions have been studied to cope with the computational complexity of the DSP algorithms, including commercial single-core and open-source Parallel Ultra Low Power architectures, that have been selected accordingly also to reduce the overall system power consumption. By further adding energy harvesting techniques combined with the firmware and hardware optimization, the systems achieved self-sustainable operation or a significant boost in battery life. The HMI platforms presented are entirely programmable and provide computational power to satisfy the requirements of the studies applications while employing only a fraction of the CPU resources, giving the perspective of further application more advanced paradigms for the next generation of real-time embedded biosignal processing

A synthesis of good design practices for stand alone "Global e-learning" for global organisations

Global organizations spend millions of dollars designing stand alone Global e-learning. The shortage of research in stand alone Global e-learning and a consequent lack of empirically validated guidelines presents a challenge for global organizations in their efforts to design and deliver e-learning courses that are suitable for a diverse range of learners (World Bank, 1999). Guidelines proposed by Henderson (1996), Edmundson (1996), and Gunawardena and Sanchez (1996) are often used in the design of global courses. However, it is difficult to find under what conditions a particular guideline or educational strategy is effective. This study aims to reduce this lacuna in the knowledge about the design of stand alone e-learning courses. The current work is an exploratory study of four Global e-learning courses. Using Reeve's (1997) e-learning dimensions, the study focused on exploring Global e-learning from the learner's point of view. This analysis of e-learning design is important because it can identify the important considerations as perceived by the learner. Personalizing the learning content, opportunities for learner interaction, flexible design, and the use of multiple epistemologies emerged as important design considerations. Using recommendations from learners, a set of ten design guidelines emerged. In the strategic planning process these guidelines can provide useful tools for evaluating existing Global e-learning initiatives or determining critical success for future Global e-learning initiatives. The discussion focuses on essential elements to be considered for the development of stand alone Global e-learning in global organizations

Aeronautical engineering: A cumulative index to a continuing bibliography

This bibliography is a cumulative index to the abstracts contained in NASA SP-7037 (197) through NASA SP-7037 (208) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, foreign technology, contract, report number, and accession number indexes

Synthetic bacterial communities for plant growth promotion

PhD ThesisIncreasing food demands have driven the adoption of new global strategies to intensify productivity without relying on heavy chemical treatments. In the last decades, plant-growth promoting rhizobacteria (PGPR) have emerged as potential biofertilisers and biopesticides in agriculture. The overall aim of this study was to research and develop approaches to genetically engineer PGPR to improve their beneficial activities toward the plant partner. A simplified PGPR community, a Bacillus consortium of three strains, was adopted to study the complexity of the interactions occurring within the consortium and the plant microbiome. Firstly, the comparative genomic analysis of the consortium highlighted the unique and shared features responsible for plant promotion, microbial interaction and cooperation among the strains (niche partitioning, organisation in biofilms with cooperative mechanisms of quorum sensing, cell density control and antibiotic detoxification). Flux balance analysis identified cross-feeding interactions among the strains and the metabolic capability of the consortium to provide nitrogen to the plant, transforming it into forms available for plant utilisation. The consortium PGP potential was then investigated in vitro (LEAP mesocosm assay) and in vivo (pot experiment) on the vegetable crop Brassica rapa. These tests show increased plant growth when the strains were inoculated together rather than individually and when the consortium was used as a supplement of the natural bulk soil microbiome. The in silico study and the plant experiments highlighted areas for genetic improvement of the consortium genomes. Lastly, this work describes the development of a conjugation system that could be used to efficiently engineer non-domesticated bacteria and bacterial communities, such as rhizobacteria and plant microbiomes. The system, based on the plasmid pLS20, was developed in Bacillus subtilis 168 and successfully tested on twenty-three wild type Bacillus strains and three rhizobacillus communities. The research presented here provides tools and approaches for the genetic manipulation of rhizobacterial communities, with the ultimate aim of generating sustainable agricultural bioformulations and sheds light on the complex interactions that can occur in a model microbial PGPR consortia

A study of cultural content in the British ELT GLobal Coursebook : a cultural studies approach

This thesis investigates cultural content in a sample of British ELT global\ud coursebooks published over the past three decades from a cultural studies perspective.\ud Using a constructionist epistemology, the study aims to identify the nature of cultural\ud content, to account for the form it takes and to examine what a group of Barcelonabased\ud teachers think about such content and the role of culture in ELT. The research\ud design is based on a modified version of the `circuit of culture' proposed by Du Gay,\ud Hall et al. (1997) for the investigation of the construction of meanings associated with\ud cultural artefacts.\ud A descriptive framework, combining elements of content analysis and social semiotics,\ud is applied to four best-selling coursebooks. Their `representational repertoires' are\ud shown to be typified by a pervasive `native speakerism', and the deployment of\ud discourses of feminism, multiculturalism, individualism and consumerism, alongside\ud the ongoing globalizing of content. This content is partly explained by referring to\ud publishers' guidelines and interviews with publishers, in which a discourse analysis\ud approach is used. However, it is only by turning to the literatures on visual\ud communication, consumerism and the concept of promotional culture that a fuller\ud explanation can be provided.\ud What emerges is a picture of a carefully constructed artefact, only some of whose\ud meanings resonate with those of the teachers. Interviews reveal that they construe\ud their practice in terms of teaching English as an international language for\ud predominantly lingua franca purposes. Broad approval for the representational\ud practices associated with gender and race does not extend to the pervasive `native\ud speakerism' or content which is seen as irrelevant to the context of instruction. The\ud thesis suggests that the form cultural content takes is best decided by locals for whom\ud English may have a range of meanings other than those determined for them by\ud British ELT publishers