The starting point of this paper is the observation that methods based on the direct match of keywords are inadequate because they do not consider the cognitive ability of concept formation and abstraction. We argue that keyword evaluation needs to be based on a semantic model of language capturing the semantic relatedness of words to satisfy the claim of the human-like ability of concept formation and abstraction and achieve better evaluation results. Evaluation of keywords is difficult since semantic informedness is required for this purpose. This model must be capable of identifying semantic relationships such as synonymy, hypernymy, hyponymy, and location-based abstraction. For example, when gathering texts from online sources, one usually finds a few keywords with each text. Still, these keyword sets are neither complete for the text nor are they in themselves closed, i.e., in most cases, the keywords are a random subset of all possible keywords and not that informative w.r.t. the complete keyword set. Therefore all algorithms based on this cannot achieve good evaluation results and provide good/better keywords or even a complete keyword set for a text. As a solution, we propose a word graph that captures all these semantic relationships for a given language. The problem with the hyponym/hyperonym relationship is that, unlike synonyms, it is not bidirectional. Thus the space of keyword sets requires a metric that is non-symmetric, in other words, a quasi-metric. We sketch such a metric that works on our graph. Since it is nearly impossible to obtain such a complete word graph for a language, we propose for the keyword task a simpler graph based on the base text upon which the keyword sets should be evaluated. This reduction is usually sufficient for evaluating keyword sets.

<p>The goal of this thesis is to establish generalized isoperimetric inequalities on first exit time distributions as well as expectations of L\'evy processes.</p> <p>Firstly, we prove inequalities on first exit time distributions in the case that the L\'evy process is an $\alpha$-stable symmetric process $A_t$ on $\R^d$, $\alpha\in(0,2]$. Given $A_t$ and a bounded domain $D\subset\R^d$, we present a proof, based on the classical Brascamp-Lieb-Luttinger inequalities for multiple integrals, that the distribution of the first exit time of $A_t$ from $D$ increases under Steiner symmetrization. Further, it is shown that when a sequence of domains $\{D_m\}$ each contained in a ball $B\subset\R^d$ and satisfying the $\varepsilon$-cone property converges to a domain $D'$ with respect to the Hausdorff metric, the sequence of distributions of first exit times for Brownian motion from  $D_m$  converges to the distribution of the exit time of Brownian motion from $D'$. The second set of results in this thesis extends the theorems from \cite{BanMen} by proving generalized isoperimetric inequalities on expectations of L\'evy processes in the case of Steiner symmetrization.% using the Brascamp-Lieb-Luttinger inequalities used above. </p> <p>These results will then be used to establish inequalities involving distributions of first exit times of $\alpha$-stable symmetric processes $A_t$ from triangles and quadrilaterals. The primary application of these inequalities is verifying a conjecture from Ba\~nuelos for these planar domains. This extends a classical result of P\'olya and Szeg\"o to the fractional Laplacian with Dirichlet boundary conditions.</p>

No description available.

We have two main results. Our first main result is a sharp bound for the number of vertices in a minimal forbidden subgraph for the graphs having minimum rank at most 3 over the finite field of order 2. We also list all 62 such minimal forbidden subgraphs and show that many of these are minimal forbidden subgraphs for any field. Our second main result is a structural characterization of all graphs having minimum rank at most k for any k over any finite field. This characterization leads to a very strong connection to projective geometry and we apply projective geometry results to the minimum rank problem.

Let F be a field, let G be an undirected graph on n vertices, and let SF(G) be the set of all F-valued symmetric n x n matrices whose nonzero off-diagonal entries occur in exactly the positions corresponding to the edges of G. Let MRF(G) be defined as the set of matrices in SF(G) whose rank achieves the minimum of the ranks of matrices in SF(G). We develop techniques involving Z-hat, a process termed nil forcing, and induced subgraphs, that can determine when diagonal entries corresponding to specific vertices of G must be zero or nonzero for all matrices in MRF(G). We call these vertices nil or nonzero vertices, respectively. If a vertex is not a nil or nonzero vertex, we call it a neutral vertex. In addition, we completely classify the vertices of trees in terms of the classifications: nil, nonzero and neutral. Next we give an example of how nil vertices can help solve the inverse inertia problem. Lastly we give results about the inverse eigenvalue problem and solve a more complex variation of the problem (the λ, µ problem) for the path on 4 vertices. We also obtain a general result for the λ, µ problem concerning the number of λ’s and µ’s that can be equal.

The semiconductor industry has been driven by Moore's law for almost half a century. Miniaturization of device size has allowed more transistors to be packed into a smaller area while the improved transistor performance has resulted in a significant increase in frequency. Increased density of devices and rising frequency led, unfortunately, to a power density problem which became an obstacle to further integration. The processor industry responded to this problem by lowering processor frequency and integrating multiple processor cores on a die, choosing to focus on Thread Level Parallelism (TLP) for performance instead of traditional Instruction Level Parallelism (ILP). While continued scaling of devices have provided unprecedented integration, it has also unfortunately led to a few serious problems: The first problem is that of increasing rates of system failures due to soft errors and aging defects. Soft errors are caused by ionizing radiations that originate from radioactive contaminants or secondary release of charged particles from cosmic neutrons. Ionizing radiations may charge/discharge a storage node causing bit flips which may result in a system failure. In this dissertation, we propose solutions for online detection of such errors in microprocessors. A small and functionally limited core called the Sentry Core (SC) is added to the multicore. It monitors operation of the functional cores in the multicore and whenever deemed necessary, it opportunistically initiates Dual Modular redundancy (DMR) to test the operation of the cores in the multicore. This scheme thus allows detection of potential core failure and comes at a small hardware overhead. In addition to detection of soft errors, this solution is also capable of detecting errors introduced by device aging that results in failure of operation. The solution is further extended to verify cache coherence transactions. A second problem we address in this dissertation relate to power concerns. While the multicore solution addresses the power density problem, overall power dissipation is still limited by packaging and cooling technologies. This limits the number of cores that can be integrated for a given package specification. One way to improve performance within this constraint is to reduce power dissipation of individual cores without sacrificing system performance. There have been prior solutions to achieve this objective that involve Dynamic Voltage and Frequency Scaling (DVFS) and the use of sleep states. DVFS and sleep states take advantage of coarse grain variation in demand for computation. In this dissertation, we propose techniques to maximize performance-per-power of multicores at a fine grained time scale. We propose multiple alternative architectures to attain this goal. One of such architectures we explore is Asymmetric Multicore Processors (AMPs). AMPs have been shown to outperform the symmetric ones in terms of performance and Performance-per-Watt for a fixed resource and power budget. However, effectiveness of these architectures depends on accurate thread-to-core scheduling. To address this problem, we propose online thread scheduling solutions responding to changing computational requirements of the threads. Another solution we consider is for Symmetric Multicore processors (SMPs). Here we target sharing of the large and underutilized resources between pairs of cores. While such architectures have been explored in the past, the evaluations were incomplete. Due to sharing, sometimes the shared resource is a bottleneck resulting in significant performance loss. To mitigate such loss, we propose the Dynamic Voltage and Frequency Boosting (DVFB) of the shared resources. This solution is found to significantly mitigate performance loss in times of contention. We also explore in this dissertation, performance-per-Watt improvement of individual cores in a multicore. This is based on dynamic reconfiguration of individual cores to run them alternately in out-of-order (OOO) and in-order (InO) modes adapting dynamically to workload characteristics. This solution is found to significantly improve power efficiency without compromising overall performance. Thus, in this dissertation we propose solutions for several important problems to facilitate continued scaling of processors. Specifically, we address challenges in the area of reliability of computation and propose low power design solutions to address power constraints.

Previous cross-cultural research in nonverbal immediacy indicates that nonverbal immediacy behavior varies across cultures, and some researchers have suggested that power distance might serve as a moderating variable, however no research has systematically set out to determine whether that is the case. This study assessed the perceived use of nonverbal immediacy under symmetric and asymmetric power conditions, as well as gender, in three cultures: Brazil, Kenya, and the United States. Quantitative data was collected from 527 participants who completed a nonverbal immediacy measure and an individual power distance measure under either a symmetric or an asymmetric power condition. Results related to power distance partially supported the idea that cultural power distance may act as a moderating variable with regard to the use of nonverbal immediacy behaviors. Related to gender, results revealed that: (a) female participants perceived more nonverbal immediacy behaviors than males, (b) under symmetric power conditions females were perceived to use more nonverbal immediacy than males, and (c) under asymmetric power conditions there was no statistically significant difference between use of nonverbal immediacy behaviors between females and males. Implications of results, limitations, and suggestions for future research are presented.

No description available.

This research work is focused on the balanced and partially balanced incomplete block designs when observations within blocks are correlated. The topic for this dissertation was motivated by a problem in pharmaceutical research, when several treatments are allocated to individuals, and repeated measurements are taken on each individual. In that case, there is correlation among the observations taken on the same individual. Typically, it is reasonable to assume that the observations within individual close to each other are highly correlated than observations that are far away from each other. It is also reasonable to assume that the correlation between any two observations within each individual is same. We have characterized balanced and partially balanced incomplete block designs when observations within blocks are autocorrelated. In Chapter 3, we have provided an explicit expression for the average variance of estimated elementary treatment contrasts for designs obtained by Type I and II series of orthogonal arrays, under autocorrelated errors, and compared them with the corresponding balanced incomplete block designs with uncorrelated errors. The relative efficiency of balanced incomplete block design compared to the corresponding balanced incomplete block design obtained by Types I and II series of orthogonal array under autocorrelated errors does not depend on the number of treatments (v) and is an increasing function of the block size (k). When orthogonal arrays of Type I or Type II do not exist for a given number of treatments, we provided alternative partially balanced designs with autocorrelated errors. In Chapter 4, we rearranged the treatments in each block of symmetric balanced incomplete block designs and used them with autocorrelated error structure of the plots in a block. The C-matrix of estimated treatment effects under autocorrelation was given and the relative efficiency of symmetric balanced incomplete block designs with independent errors compared to the autocorrelated designs is given. In Chapter 5, we discussed the compound symmetry correlation structure within blocks. An explicit expression of the average variance of designs obtained by Type I and II series of orthogonal arrays and symmetric balanced incomplete block designs under compound symmetric errors has been provided and compared them with the corresponding balanced incomplete block designs with uncorrelated errors. Finally, the relative efficiencies of these designs with autocorrelated errors vs. compound symmetric error structure are given / Statistics

yes / The present article proposes to re-examine the parity-of-reasoning or double-standard fallacy argument, which favours a time-symmetric Gold universe model over a cosmological arrow of time. There are two reasons for this re-examination. One is empirical: 1) the recent discovery of an expanding and accelerating universe questions the symmetry assumption of the Gold universe on empirical grounds; 2) the other is theoretical: the argument from t-symmetry fails to take into account some important aspects of the topology of phase space and recently developed typicality arguments. If the parity-of-reasoning argument, which depends on the t-symmetry of probability, is reconsidered in terms of the topology of phase space and typicality arguments, the double-standard fallacy argument loses much of its appeal. The Gold universe model itself suffers from unexplained dynamic asymmetries. The upshot of this paper is that the Gold universe model is implausible or far less plausible than asymmetric models.