Reproduction de : Thèse de doctorat : Informatique : Grenoble 1 : 1990. / Titre provenant de l'écran-titre. Bibliogr. p. 176-186.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: self-powered; universal hashing; ultra-low-power; message authentication codes; provable security. Includes bibliographical references (p. 55-61).

Neighborhood design has a significant impact on environmental and human health and is largely regulated by the codes developed by various professional organizations. While the sustainability movement as a whole has embraced the mutually beneficial goals of improving environmental and human health, the work of professionals in the environmental and public health fields has remained largely segregated over the past century. The purpose of my thesis is to compare the approach of each field in fostering sustainable neighborhoods through the development and implementation of codes and to quantify both the existing degree of collaboration and the latent potential for further collaboration within these codes. For comparison, I selected LEED for Neighborhood Development and the Healthy Development Measurement Tool to be representative of neighborhood codes generated by the environmental and public health movements, respectively, because they are the most fully developed and widely implemented evaluation systems presently available in each field. In order to investigate how the codes generated in each field compare in their approach, structure, and organization, I first performed a comparative analysis between them. I then performed a content analysis on both codes to quantify the overlap in goals between them. My hypothesis was that each field would exhibit a bias towards goals which explicitly support their own field, but that a significant portion of their goals would simultaneously support the other field. This hypothesis proved to be correct, but most interesting was the significant percentage of shared goals that were left unexpressed. Ultimately, 94% of recommended actions in LEED-ND were related to human health, though it was only explicitly referenced in 25% of the code. Similarly, 74% of recommended actions in the HDMT were related to environmental health, though it was only explicitly mentioned in 33% of the code. My thesis demonstrates that, while both fields already recognize that a small portion of their goals are shared, it is actually likely that nearly all of their goals are shared. By actively acknowledging these shared goals, both fields can potentially benefit from the greater amount of support, resources, and expertise that would become available to them through collaboration. / text

This report is an exploration of theoretical and applied aspects of form-based coding. First, it presents an in-depth look at conventional zoning, conditions surrounding its origins around the turn of the twentieth century, the system of legal precedents that supports zoning, the evolution of the zoning “toolkit”, and the scope of zoning policies which are prevalent today. Second, form-based codes are defined and differentiated from conventional codes as well as design guidelines. The organizing principles on which FBCs are based are explained and the components of FBCs are described. Issues and controversy surrounding FBCs are discussed. Third, diverse case studies from around the country are carried out in order to examine how form-based codes are developed and applied in various real-world contexts. Case studies are presented in two different tiers, primary and secondary. Primary case studies involve in-depth research, whereas secondary case studies receive a brief, overview-style treatment. Primary case studies are: St. Lucie County, Florida and Sarasota County, Florida. Secondary case studies are: Leander, Texas; Peoria, Illinois; Montgomery, Alabama; Arlington County, Virginia; Hercules, California; and Miami, Florida. Fourth, conclusions are drawn from the research and point towards best practices in form-based coding. The report concludes that form-based codes are not a cure-all, should be developed in the context of a visioning process, and should strike a balance in terms of regulation. Additionally, market factors play a major role. The high cost of coding is a major concern. Furthermore, code writers should be prepared to educate the public as part of their profession. / text

This thesis makes progress towards the fundamental understanding of heterogeneous and dynamic information systems and the way that we store and process massive data-sets. Reliable large-scale data storage: Distributed storage systems for large clusters typically use replication to provide reliability. Recently, erasure codes have been used to reduce the large storage overhead of three-replicated systems. However, traditional erasure codes are associated with high repair cost that is often considered an unavoidable price to pay. In this thesis, we show how to overcome these limitations. We construct novel families of erasure codes that are optimal under various repair cost metrics, while achieving the best possible reliability. We show how these modern storage codes significantly outperform traditional erasure codes. Low-rank approximations for large-scale data processing: A central goal in data analytics is extracting useful and interpretable information from massive data-sets. A challenge that arises from the distributed and large-scale nature of the data at hand, is having algorithms that are good in theory but can also scale up gracefully to large problem sizes. Using ideas from prior work, we develop a scalable lowrank optimization framework with provable guarantees for problems like the densest k-subgraph (DkS) and sparse PCA. Our experimental findings indicate that this low-rank framework can outperform the state-of-the art, by offering higher quality and more interpretable solutions, and by scaling up to problem inputs with billions of entries. / text

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In mid- to late-1960s America and Britain, against the backdrop of escalating socio-political disappointment, countercultural ideologies and fantasies of a musical youth dovetailed with improvements in recording technologies to generate new sonic languages of limning in sound utopian pastoral spaces to which recordists and listeners could escape, virtually. Seeking alternative spaces that their alternative identities could more comfortably inhabit became a central project of many progressive groups and individuals, often, but not always, hailing from middle-class white society. The cultural and musical trends did eventually have a global sway. Coeval advances in sound recording and reproduction technologies made musical recordings a major avenue through which the sought spaces were limned and even materialized sonically, but other media, especially album cover art and film in conjunction with musical soundtracks, provided additional avenues for pastoral spatial projects of this generation and afford us ancillary resources for better understanding these projects. While the specific utopian spatial projects and the underlying ideologies of musicians working in various branches of country rock, soft rock, progressive country, progressive bluegrass, art rock, Afrocentric avant-garde jazz, and proto-New Age music were not always exactly the same, there were considerable overlaps in the societal sources of their disaffections, the wellsprings of their inspiration, and in the textural sonic languages they developed in the recording studio. Unlike music with overtly spatial projects, the sonic aspects of music that subtly captures a hyper-real sense of the natural have remained underconsidered and their contribution to the aesthetic and psychological impact of music has slipped by under the radar of most listeners' conscious attention. This dissertation, then, is an attempt to analyze the subtle acoustic and musical communicative codes devised by musicians and recordists that do inform later music. Through close listening and textual analysis, this dissertation identifies the different levels at which spatial allusions are encoded into a musical product. Ethnographic interviews help distinguish between deliberate manipulations of studio technology and responses based in tacit understandings thereof. An overall cross disciplinary approach, borrowing especially from acoustics and psychoacoustics, aided me substantially with the analyses. / text

We study fundamental properties of Locally Decodable Codes (LDCs). LDCs are motivated by the intuition that traditional codes do not have a good tradeoff between resistance to arbitrary error and probe complexity. For example, if you apply a traditional code on a database, the resulting codeword can be resistant to error even if a constant fraction of it was corrupted; however, to accomplish this, the decoding procedure would typically have to analyze the entire codeword. For large data sizes, this is considered computationally expensive. This may be necessary even if you are only trying to recover a single bit of the database! This motivates the concept of LDCs, which encode data in such a way that up to a constant fraction of the result could be corrupted; while the decoding procedures only need to read a sublinear, ideally constant, number of codeword bits to retrieve any bit of the input with high probability. Our most exciting contribution is an exponential lower bound on the length of three query LDCs (binary or linear) with high correctness. This is the first strong length lower bound for any kind of LDC allowing more than two queries. For LDCs allowing three or more queries, the previous best lower bound, given by Woodruff, is below [omega](n2). Currently, the best upper bound is sub-exponential, but still very large. If polynomial length constructions exist, LDCs might be useful in practice. If polynomial length constructions do not exist, LDCs are much less likely to find adoption -- the resources required to implement them for large database sizes would be prohibitive. We prove that in order to achieve just slightly higher correctness than the current best constructions, three query LDCs (binary or linear) require exponential size. We also prove several impossibility results for LDCs. It has been observed that for an LDC that withstands up to a delta fraction of error, the probability of correctness cannot be arbitrarily close to 1. However, we are the first to estimate the largest correctness probability obtainable for a given delta. We prove close to tight bounds for arbitrary numbers of queries. / text

In 1997, Drs. G. R. Blakley and I. Borosh published two papers whose stated purpose was to present a general formulation of the notion of a code that depends only upon a code's structure and not its functionality. In doing so, they created a further generalization--the idea of a precode. Recently, Drs. Blakley, Borosh, and A. Klappenecker have worked on interpreting the structures and results in these pioneering papers within the framework of category theory. The purpose of this dissertation is to further the above work. In particular, we seek to accomplish the following tasks within the ``general theory of codes.' 1. Rewrite the original two papers in terms of the alternate representations of precodes as bipartite digraphs and Boolean matrices. 2. Count various types of bipartite graphs up to isomorphism, and count various classes of codes and precodes up to isomorphism. 3. Identify many of the classical objects and morphisms from category theory within the categories of codes and precodes. 4. Describe the various ways of constructing a code from a precode by ``splitting' the precode. Identify important properties of these constructions and their interrelationship. Discuss the properties of the constructed codes with regard to the factorization of homomorphisms through them, and discuss their relationship to the code constructed from the precode by ``smashing.' 5. Define a parametrization of a precode and give constructions of various parametrizations of a given precode, including a ``minimal' parametrization. 6. Use the computer algebra system, Maple, to represent and display a precode and its companion, opposite, smash, split, bald-split, and various parametrizations. Implement the formulae developed for counting bipartite graphs and precodes up to isomorphism.

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