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  • Thesis

  • Authors: He, Changhua (2005)

  • Security is a serious concern in wireless networks. In order to eliminate the vulnerabilities in previous Standards, the IEEE 802.11i Standard is designed to provide security enhancements in MAC layer. The authentication process consists of several components, including an 802.1X authentication phase using TLS over EAP, a 4-Way Handshake to establish a fresh session key, and an optional Group Key Handshake for group communications. The objective of this work is to analyze IEEE 802.11i with respect to data confidentiality, integrity, mutual authentication, and availability. Under our threat model, 802.111 appears to provide effective data confidentiality and integrity when CCMP is used. 802.111 may also provide satisfactory mutual authentication and key management, although there ar...

  • Thesis

  • Authors: Liu, Yi-Wen (2005)

  • "Digital Watermarking" refers to the hiding of binary information in signals such as audio record¬ings, images, or video clips. While the dominating technologies utilize small masked changes in the amplitude to hide information in audio, in an alternate approach, this thesis presents a scheme based on frequency modulation. From an input signal, salient sinusoids are identified in its short-time spectra and parametrized by slowly time-varying frequency envelopes. To bear a watermark, the frequency envelopes are modified by quantization index modulation (QIM), a technique that rounds values to signaling grids. Frequency shifts due to QIM are intended to be not objectionable, if noticeable. To this end, the sensitivity of human ears to pitch changes is carefully considered in the desig...

  • Thesis

  • Authors: Yang, Danny Bon-Ray (2005)

  • Advances in CMOS fabrication have enabled low-cost camera nodes with limited communication and computation capabilities. By combining these capabilities within a small form-factor device, multi-camera networks can readily be built. However, cameras are high-data-rate devices, and many computer vision algorithms are computationally expensive, while these camera nodes are communication and computation constrained. In this dissertation, we present lightweight techniques for distributed scene analysis in such resource-constrained camera networks. We show that in this setting we can compute global aggregates from distributed local measurements. In particular we use the camera network to count and localize targets. Counting and localizing are useful in many applications in surveillance, ...

  • Thesis

  • Authors: Lin, Li (2005)

  • Curcumin is the major yellow pigment isolated from the rhizome of Curcuma longa, known as turmeric. Over a long period of study, curcumin has been found to possess a wide range of bioactivities including anti-prostate cancer activity in vitro and in vivo. Based on these observations, our laboratory has been using curcumin as the lead compound to develop various analogs as potential anti-prostate cancer agents. Two curcumin analogs, dimethyl curcumin (DMC, 4) and 4-ethoxycarbonylethyl curcumin (ECECur, 5) developed previously were found to be active anti-androgen receptor agents, which showed greater potency than hydroxyflutamide, an anti-androgen currently used clinically. However, the tautomerism of ECECur, which causes it to exist in both enol-keto and di-keto forms, may hinder it...

  • Thesis

  • Authors: Chen, Wei (2005)

  • Well coordinated behaviors greatly improve intelligent entities overall performance, while inappropriate coordination results in reduced system efficiency, unfinished core tasks, misuse of key resources, and even system crashes. Thus, coordination is a central research task in Distributed Artificial Intelligence (DAI). This dissertation discusses our way of approaching the coordination problem, which is to develop an extended set of coordination mechanisms to manage the inter-dependencies between the activities among multiple agents. This dissertation presents four steps to tackle this problem. First, formal representation: articulating a domain-independent approach for specifying a set of coordination mechanisms and representing the characteristics of the agents’ tasks and action...

  • Thesis

  • Authors: Nudelman, Eugene (2005)

  • Traditionally, computer scientists have considered computational problems and al¬gorithms as artificial formal objects that can be studied theoretically. In this work we propose a different view of algorithms as natural phenomena that can be studied using empirical methods. In the first part, we propose a methodology for using ma-chine learning techniques to create accurate statistical models of running times of a given algorithm on particular problem instances. Rather than focus on the traditional aggregate notions of hardness, such as worst-case or average-case complexity, these models provide a much more comprehensive picture of algorithms' performance. We demonstrate that such models can indeed be constructed for two notoriously hard domains: winner determination problem for com...

  • Thesis

  • Authors: Park, Woo-Tae (2005)

  • Micromachined accelerometers have been introduced in the late 1970s and have been used in various applications. The applications range from inertial navigation and data logging in wells to body activity monitoring for pacemakers. Although the size of the accelerometers was sufficient for their applications, there were not many efforts in pushing the limits of accelerometer miniaturization. In this study, we utilized film deposition packaging technology and other modern microfabrication techniques to miniaturize the size and mass of the packaged accelerometers, two orders of magnitude smaller than any accelerometers ever reported. We used these ultra miniature accelerometers to offer sensing capabilities for biomedical applications which was not possible with any other means. A nove...

  • Thesis

  • Authors: Yoon, Sungroh (2005)

  • Today, more and more large-scale genomic data sets are being produced by various high-throughput technologies, and genomic data mining has never been more impor¬tant. Clustering is an unsupervised learning technique that has been popular in data analysis. Although there is mature statistical literature on clustering, new types of genomic data such as gene expression data have sparked development of multiple new methods. Specifically, the technique of biclustering refers to a method that performs simultaneous clustering of rows and columns in a data matrix identifying patterns that appear in the form of (possibly overlapping) submatrices. Although this method has some clear advantages over conventional clustering techniques, it has been chal¬lenging to develop an efficient biclusteri...

  • Thesis

  • Authors: Ghosh, Ronojoy (2005)

  • Recent advances in quantitative biology have created a tremendous opportunity to apply dynamical systems modeling to biological phenomena, and to validate these models using experimental data. Using simulation and analysis, there is immense scope to discover non-intuitive design principles behind biological processes, and successfully predict the effects of changing key variables. Systems biology, defined as the integration of mathematical analysis with experimental biology, has the potential to revolutionize the way biology is done. Cellular protein signaling networks exhibit complex combinations of both discrete and continuous behaviors. The dynamics that govern the spatial and temporal in-crease or decrease of protein concentrations inside cells are continuous differential equat...

  • Thesis

  • Authors: Shacham, Hovav (2005)

  • Digital signatures provide authenticity and nonrepudiation. They are a standard crypto¬graphic primitive with many applications in higher-level protocols. Groups featuring a com¬putable bilinear map are particularly well suited for signature-related primitives. For some signature variants the only construction known uses bilinear maps. Where constructions based on, e.g., RSA are known.. bilinear-map-based constructions are simpler, more efficient. and yield shorter signatures. We describe several constructions that support this claim. First, we present the Boneh-Lynn-Shacham (BLS) short signature scheme. BLS signa¬tures with 1024-bit security are 160 bits long, the shortest of any scheme based on standard assumptions. Second, we present Boneh-Gentry-Lynn-Shacham (BGLS) aggregate s...