Enhancing North Texas' built environment : improvements to design review in Dallas and Fort Worth

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2007.Includes bibliographical references (p. 121-125).Design review is a government-supported process through which individuals representing the public interest critique, commend and advise proposed development projects' potential impacts on the built environment. These independent public interest representatives come together in a number of forms, including design review boards, planning commissions, and citizen' advisory committees, and they receive various levels of guidance from government in terms of the design criteria upon which they base their judgments and recommendations. This thesis asks what has caused the differences in design review between two cities in Texas, Dallas and Fort Worth, and it suggests adjustments that could improve the process in both of them. The analysis that follows focuses on five key features of the design review - the authority of the design review board, the credibility of the board, the role of the design review board staff, the triggers necessary for project review to take place, and the nature of the design guidelines/standards utilized by board members as they make their decisions.(cont.) Through the exploration of these five features as they exist in each city, I examine the strengths and weaknesses of design review in Dallas and Fort Worth. Once I have clarified the differences, I consider a number of rival explanations in attempt to describe why the disparity in design review occurs, and I work to narrow down the number of reasonable ones. Then, I offer short term and long term proposals for potential improvement to design review in both cities. These forecasts remain grounded in the political realities of Dallas and Fort Worth but also attempt to assume an optimistic outlook for the future of design review in North Texas.by Belton Allen Cullum.M.C.P

Cooperative diversity in wireless networks : algorithms and architectures

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.Includes bibliographical references (p. 179-187).To effectively combat multipath fading across multiple protocol layers in wireless networks, this dissertation develops energy-efficient algorithms that employ certain kinds of cooperation among terminals, and illustrates how one might incorporate these algorithms into various network architectures. In these techniques, sets of terminals relay signals for each other to create a virtual antenna array, trading off the costs-in power, bandwidth, and complexity-for the greater benefits gained by exploiting spatial diversity in the channel. By contrast, classical network architectures only employ point-to-point transmission and thus forego these benefits. After summarizing a model for the wireless channel, we present various practical cooperative diversity algorithms based upon different types of relay processing and re-encoding, both with and without limited feedback from the ultimate receivers. Using information theoretic tools, we show that all these algorithms can achieve full spatial diversity, as if each terminal had as many transmit antennas as the entire set of cooperating terminals. Such diversity gains translate into greatly improved robustness to fading for the same transmit power, or substantially reduced transmit power for the same level of performance. For example, with two cooperating terminals, power savings as much as 12 dB (a factor of sixteen) are possible for outage probabilities around one in a thousand. Finally, we discuss how the required level of complexity in the terminals makes different algorithms suitable for particular network architectures that arise in, for example, current cellular and ad-hoc networks.by J. Nicholas Laneman.Ph.D

Exploring the Plasmodium falciparum Transcriptome Using Hypergeometric Analysis of Time Series (HATS)

Malaria poses a significant public health and economic threat in many regions of the world, disproportionately affecting children in sub-Saharan Africa under the age of five. Though success has been celebrated in lowering infection rates, it remains a serious challenge, causing at least 200 million infections and 655,000 deaths per year, with deleterious effects on economic growth and development. Investigation of the malaria parasite Plasmodium falciparum has entered the post-genomics age, with several strains sequenced and many microarray gene expression studies performed. Gene expression studies allow a full sampling of the genomic repertoire of a parasite, and their detailed analysis will prove invaluable in deciphering novel parasite biology as well as the modes of action of antimalarial drug resistance. We have developed a computational pipeline that converts a series of fluorescence readings from a DNA microarray into a meaningful set of biological hypotheses based on the comparison of two lines, generally one that is drug sensitive and one that is drug resistant. Each step of the computational pipeline is described in detail in this thesis, beginning with data normalization and alignment, followed by visualization through dimensionality reduction, and finally a direct analysis of the differences and similarities between the two lines. Comparisons and analyses were performed at both the individual gene and gene set level. An important component of the analytical methods we have developed is a suite of visualization tools that help to easily identify outliers and experimental flaws, measure the significance of predictions, show how lines relate and how well they can be aligned, and demonstrate the results of an analysis. These visualization tools should be used as a starting point for further biological study to test the resulting hypotheses. We also developed a software tool, Gene Attribute and Set Enrichment Ranking (GASER), which combines a wealth of genomic data from the TDR Targets web site along with expression data from a variety of sources, and allows researchers to create sophisticated weighted queries to undercover potential drug targets. Queries in our system can be updated in real time, along with their accompanying gene and gene set lists. We analyzed all possible pair-wise combinations of 11 parasite lines to create baseline distributions for gene and gene set enrichment. Using the baseline as a comparison, we identified and discarded spurious results and recognized stochastic genes and gene sets. We analyzed three major sets of parasite lines: those involving manipulation of the multidrug resistance-1 (PfMDR1) transporter, a key resistance determinant; those involving manipulation of the P. falciparum chloroquine resistance transporter (PfCRT), another important resistance determinant; and finally a set of parasites that had varying sensitivity to artemisinins. This analysis resulted in a rich library of high scoring genes that may merit further exploration as potential modes of action of resistance. More specifically, we found that manipulation of pfcrt expression resulted in an up-regulation of tRNA synthetases, which might serve to increase protein production in response to reduced amino acid availability from degraded hemoglobin. We observed that a copy number increase in pfmdr1 resulted in increases in glycerophospholipid metabolism and up-regulation of a number of ABC transporters. Finally, when comparing artemisinin sensitive to artemisinin tolerant lines, we found an increased abundance of redox metabolites and the transcripts involved in redox regulation, and significant reduction in transcription and altered expression of transcripts encoding for core histone proteins. These alterations could help confer an increased tolerance to drug induced redox perturbation by lowering endogenous redox stress. We also offer a robust computational tool, Hypergeometric Analysis of Time Series (HATS), to handle challenging biological questions related to comparison of time series experiments. Our pipeline provides a rigorous method for aligning expression experiments and then determining which genes and gene sets differ most between them. The changes in gene expression level between drug-sensitive and drug-resistant lines offer important clues in our quest for understanding mechanisms of resistance and identifying new drug targets. Our pipeline allows for comparison of future lines with our base set and holds potential for other organisms, especially those similar to Plasmodium with a strong time-dependent component. The full excel files of all the analyses performed in this thesis can be found at: (http://www.fidock.org/dan)

Colonial mutations of caste in Tamil Nadu : an essay on space and untouchability, with special reference to Madurai district, c.1500-1990

After the lengthy war of conquest, the British installed the Permanent Settlement on much of the dry zone of south India. This was part of an original pacification plan designed to be temporary; however, colonial interests later decided that it was politically convenient to maintain some of the "native rank" in the country. These zamindari estates became precisely the area where caste-inducing pseudo-jajmani systems enjoyed a colonized efflorescence. These changes occurred in the nineteenth century; not all of the peculiar traditions of the south Indian social world pre-date the colonial kali yuga

Reviving and adapting a vernacular architectural element to promote low carbon homes using genetic algorithms: the case of Rawshan

When reviving vernacular architectural elements in developed countries, evaluations using computational intelligence techniques, as well as the corresponding cultural and environmental aspects, are important areas of consideration. A Rawshan is one such vernacular architectural element that embodies Arab-Islamic values and was a prominent feature in Saudi Arabia’s architectural history. This study aims to facilitate the revival of the Rawshan vernacular architectural element, utilizing Genetic Algorithms and establishing an optimized Rawshan design framework that takes into account the local climatic conditions, context, and socio-cultural challenges. As the biggest country in the Middle East, Saudi Arabia is characterized by a variety of climates and topographies, making it an ideal case study for this research. To address the study objectives, a comprehensive, five stage study is conducted. This investigation attempts to: (a) identify factors resulting in a revival of vernacular architecture in general, and for the Rawshans in Saudi Arabia in particular; (b) determine the values (criteria) of the Rawshan that constitute its identity; (c) evaluate the Rawshan's ability to reduce energy consumption; (d) establish and develop an energy-efficient Rawshan framework that supports architects, designers, and building professionals to reviving Rawshan in the Saudi Arabian climate, context and, cultural requirements; and (e) propose six different optimized Rawshans for six different climates. Living room prototypes that face different directions are input into the established framework, thereby validating it through the identification of various energy consumption levels. Each stage of this research utilizes a specific methodology: secondary data; public survey analysis, using the SPSS software; site visits and a modelling analysis, using Rhinoceros 3D and its plug-in, Grasshopper; decision-maker expert interviews, using NVivo analysis software; computational intelligent techniques, using Grasshopper and its components for simulations and optimizations; and a validation analysis. This study contributes to the body of knowledge within this field by offering a framework for reviving the Rawshan vernacular architectural element to reduce energy consumption,while also providing adequate daylight for Saudi Arabian homes. Consequently, two methods of optimization algorithms were used: (a) a single-objective optimization method (SOO) that used energy and UDLI as its objectives; and (b) a multi-objective optimization method (MOO). These findings are broadly applicable to other regions with similar climatic conditions and cultural requirements, such as those in the Middle East and GCC countries. The findings of the SOO revealed that the Rawshan reduced energy consumption by 1–3% in the east, west, and south directions of a virtual living room located in Jeddah. Moreover, by comparing the methods that were utilized with the simulation of the living room without a Rawshan, it was found that there was less energy efficiency for cities located at the sea level, for example, Jeddah, Dammam, and Jizan. However, for all the cities analyzed, the MOO methods effectively decreased energy consumption in living rooms with a Rawshan

Routing Strategies for Capacity Enhancement in Multi-hop Wireless Ad Hoc Networks

This thesis examines a Distributed Interference Impact Probing (DIIP) strategy for Wireless Ad hoc Networks (WANETs), using a novel cross-layer Minimum Impact Routing (MIR) protocol. Perfonnance is judged in tenns of interference reduction ratio, efficiency, and system and user capacity, which are calculated based on the measurement of Disturbed Nodes (DN). A large number of routing algorithms have been proposed with distinctive features aimed to overcome WANET's fundamental challenges, such as routing over a dynamic topology, scheduling broadcast signals using dynamic Media Access Control (MAC), and constraints on network scalability. However, the scalability problem ofWANET cannot simply adapt the frequency reuse mechanism designed for traditional stationary cellular networks due to the relay burden, and there is no single comprehensive algorithm proposed for it. DIIP enhances system and user capacity using a cross layer routing algorithm, MIR, using feedback from DIIP to balance transmit power in order to control hop length, which consequently changes the number of relays along the path. This maximizes the number of simultaneous transmitting nodes, and minimizes the interference impact, i.e. measured in tenns of 'disturbed nodes'. The perfonnance of MIR is examined compared with simple shortest-path routing. A WANET simulation model is configured to simulate both routing algorithms under multiple scenarios. The analysis has shown that once the transmitting range of a node changes, the total number of disturbed nodes along a path changes accordingly, hence the system and user capacity varies with interference impact variation. By carefully selecting a suitable link length, the neighbouring node density can be adjusted to reduce the total number of DN, and thereby allowing a higher spatial reuse ratio. In this case the system capacity can increase significantly as the number of nodes increases. In contrast, if the link length is chosen regardless ofthe negative impact of interference, capacity decreases. In addition, MIR diverts traffic from congested areas, such as the central part of a network or bottleneck points

Multiple-antenna systems in ad-hoc wireless networks

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (leaves 223-229).The increasing demand for wireless communication services has resulted in crowding of the electromagnetic spectrum. The "spectral-commons" model, where a portion of the electromagnetic spectrum is public and used on an ad-hoc basis, has been proposed to free up spectrum that has been allocated but underutilized. Ad-hoc wireless networks (networks with no central control) are also interesting in their own right as they do not require costly infrastructure, are robust to single-node failures, and can be deployed in environments where it is difficult to deploy infrastructure. The main contributions of this thesis are expressions for the mean and in some cases the variance of the spectral efficiency (bits/second/Hz) of single-hop links in random wireless networks as a function of the number of antennas per node, link-length, interferer density, and path-loss-exponent (an environmental parameter that determines signal decay with distance), under assumptions chosen for realistic implementability in the near future. These results improve our understanding of such systems as they indicate the data rates achievable as a function of tangible parameters like user density and environmental characteristics, and are useful for designers of wireless networks to trade-off hardware costs, data-rates, and user densities. We found that constant mean spectral efficiencies can be maintained in wireless networks with increasing user density by linearly increasing the number of antenna elements per user, or by maintaining a constant fraction of nodes connected to high capacity infrastructure like optical fiber, equipped with antenna arrays. These are promising ways to serve an increasing density of users without increasing bandwidth. Additionally, several interesting features of such networks have been highlighted.(cont.) For instance we found that the mean and variance of spectral efficiencies can be characterized in terms of a parameter called the link rank, which on average equals the number of interferers whose signal power is stronger at a representative receiver than its target transmitter. Rank thus combines the effects of node density and link lengths. Another interesting finding is that mean spectral efficiency in networks with rank-1 links, and equal numbers of antennas at transmit and receive sides can be improved if nodes turn off two thirds of their transmit antennas. These results were derived using infinite random matrix theory and validated using Monte Carlo simulations which were also used to characterize the distribution of spectral efficiencies in such networks.by Siddhartan Govindasamy.Ph.D

Is business performance of further education colleges improved by entrepreneurial leadership and the adoption of a positive market orientation?: an empirical study of English FE colleges

The political role of English further education colleges has been ambiguous for some 20 years, being a nationally funded service administered by local government. In 1993 this role ambiguity was challenged with the incorporation of colleges, accompanied by a shift in the locus of power to national government. Significant cultural change was driven through by an expansionary yet punitive funding regime based on the principles of the free market. In common with other parts of the public sector, this change in orientation has had mixed results. This thesis explores the issues that face the leaders of the modern FE college, approaching the subject from the perspectives of entrepreneurial leadership and market orientation. The sector was dominated by financial instability during the first five years, with the next three being characterised by improving financial health for some colleges and the failure of others. The sector has lost 25 colleges since incorporation through mergers and takeovers. The removal of barriers to competition and the development of rising standards underpinned by audit and inspection have required colleges to adapt to a hostile and turbulent operating environment. A new management paradigm and approach to client orientation has been required to compete and survive in the post incorporation era. The roles of entrepreneurial leadership and market orientation and their impact on business performance have not been widely studied in the UK public sector and the further education sector in particular. The thesis is based on an empirical study of a sample of 250 colleges, representing 60% of English FE colleges. Using quantitative analysis tools, the direction and strength of causal relationships are explored. The financial performance measurement problems typical of public sector are explored using data envelopment analysis and linear structural equations. The thesis concludes with a review of the managerial implications of the study by way of three qualitative case studies and elite interviewing, reconciling theory with the results of the study. The thesis ends with a summary of issues for future research direction