In this paper, a unified fixed-coefficient recursive structure for computing the general length discrete transforms is proposed. After the regular data preprocessing, the general discrete transforms are simplified and...
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In this paper, a unified fixed-coefficient recursive structure for computing the general length discrete transforms is proposed. After the regular data preprocessing, the general discrete transforms are simplified and converted into the simpler DCT, which is realized in a second-order infinite-impulse response (IIR) filter. The proposed recursive structure only requires half the recursive cycles and also achieves more accurate results than the existing ones. Furthermore, the proposed algorithm can be applied to many popular transforms, such as subband synthesis filtering, inverse modified discrete cosine transform (IMDCT) and all discrete cosine transform (DCT) types. The proposed structure is extremely regular and more suitable for VLSI implementation.
The proceedings contain 46 papers from the ISSAC 2004 - proceedings of the 2004 International symposium on Symbolic and Algebraic Computation. The topics discussed include: sums of squares of polynomials and their app...
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The proceedings contain 46 papers from the ISSAC 2004 - proceedings of the 2004 International symposium on Symbolic and Algebraic Computation. The topics discussed include: sums of squares of polynomials and their applications;numerical parametrization of affine varieties using ODEs;optimal descriptions of orbit spaces and strata of finite groups;the characteristic ideal of a finite, connected, regular graph;inversion of parameterized hypersurfaces by means of subresultants;absolute polynomial factorization in two variables and the knapsack problem;rational general solutions of algebraic ordinary differential equations;and computing irredundant irreducible decompositions of large scale monomial ideals.
Women in the first systems course in Stanford's CS core find themselves in a divided culture in which they are a minority. For these women, establishing an identity of competence becomes critical to defining a pla...
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ISBN:
(纸本)1581137982
Women in the first systems course in Stanford's CS core find themselves in a divided culture in which they are a minority. For these women, establishing an identity of competence becomes critical to defining a place in the CS culture and establishing legitimacy. Social factors such as gendered self-presentation and communication, rather than objective measures of ability, plays a large role in developing confidence. Only by understanding the role of such social factors can we develop strategies for creating a more inclusive CS culture in which women may thrive. Findings are drawn from surveys, interviews, and five years of enrollment data. Copyright 2004acm.
The proceedings contain 56 papers from the conference proceedings OF THE TWENTIETH ANNUAL symposium ON COMPUTATIONAL GEOMETRY (SCG'04). The topics discussed include: geodesic ham-sandwich cuts;separating point set...
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The proceedings contain 56 papers from the conference proceedings OF THE TWENTIETH ANNUAL symposium ON COMPUTATIONAL GEOMETRY (SCG'04). The topics discussed include: geodesic ham-sandwich cuts;separating point sets in polygonal environments;computing the visibility graph of points within a polygon;on lines avoiding unit balls in three dimensions;the numbers of line tangent to arbitrary convex polyhedra inthree dimensional (3D) and random monotone paths on polyhedra.
In this paper, we survey the models and approaches applied to the middleware services of pervasive computing environments. Architectural styles and patterns introduced in the domain of mobile and wireless computing ar...
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ISBN:
(纸本)0769521061
In this paper, we survey the models and approaches applied to the middleware services of pervasive computing environments. Architectural styles and patterns introduced in the domain of mobile and wireless computing are also appropriate in pervasive computing. However, the development of pervasive middleware requires more emphasis on interoperability, adaptability and scalability of software services and components. To this aim, we introduce interoperability layers, separation of concerns and ontology-orientation as key enabling technologies to design and maintain agile middleware of pervasive computing environments.
For a system of polynomial equations over Qp we present an efficient construction of a single polynomial of quite small degree whose zero set over Qp coincides with, the zero set over Qp of the original system. We als...
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ISBN:
(纸本)9781581138276
For a system of polynomial equations over Qp we present an efficient construction of a single polynomial of quite small degree whose zero set over Qp coincides with, the zero set over Qp of the original system. We also show that the polynomial has some other attractive features such as low additive and straight-line complexity. The proof is based on a link established here between the above problem and some recent number theoretic result about zeros of p-adic forms. Copyright 2004acm.
Mobile Ad Hoc Networks (MANETs) provide rapidly deployable and self-configuring network capacity required in many critical applications, e.g., battlefields, disaster relief and wide area sensing. In this paper we stud...
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ISBN:
(纸本)9781581138498
Mobile Ad Hoc Networks (MANETs) provide rapidly deployable and self-configuring network capacity required in many critical applications, e.g., battlefields, disaster relief and wide area sensing. In this paper we study the problem of efficient data delivery in sparse MANETs where network partitions can last for a significant period. Previous approaches rely on the use of either long range communication which leads to rapid draining of nodes' limited batteries, or existing node mobility which results in low data delivery rates and large delays. In this paper, we describe a Message Ferrying (MF) approach to address the problem. MF is a mobility-assisted approach which utilizes a set of special mobile nodes called message ferries (or ferries for short) to provide communication service for nodes in the deployment area. The main idea behind the MF approach is to introduce non-randomness in the movement of nodes and exploit such non-randomness to help deliver data. We study two variations of MF, depending on whether ferries or nodes initiate proactive movement. The MF design exploits mobility to improve data delivery performance and reduce energy consumption in nodes. We evaluate the performance of MF via extensive ns simulations which confirm the MF approach is efficient in both data delivery and energy consumption under a variety of network conditions.
We present a new method, based on a form of dependent typing, to verify the correct usage of resources in a program. Our approach allows complex resources to be specified, whose properties are captured by annotated ty...
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ISBN:
(纸本)9781581138351
We present a new method, based on a form of dependent typing, to verify the correct usage of resources in a program. Our approach allows complex resources to be specified, whose properties are captured by annotated types and conditions on invariance and final states. The protocol itself is specified through a set of pre-defined methods, whose pre-condition and post-condition together, enforce the correct temporal usage of each resource type. We design a simple language together with a type system that shows how resource protocol verification can be achieved. We formalise an operational semantics for the language and provide a correctness proof which confirms that well-typed programs conform to the specified protocol of each resource type.
Generic programming is an attractive paradigm for developing libraries for high-performance computing because of the simultaneous emphases placed on generality and efficiency. In this approach, interfaces are based on...
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ISBN:
(纸本)0769521320
Generic programming is an attractive paradigm for developing libraries for high-performance computing because of the simultaneous emphases placed on generality and efficiency. In this approach, interfaces are based on sets of specified requirements on types, rather than on any particular type, allowing algorithms to inter-operate with any data type meeting the necessary requirements. These sets of requirements, known as concepts, can specify syntactic as well as semantic requirements. Although concepts are fundamental to generic programming, they are not supported as first-class entities in mainstream programming languages, thus limiting the degree to which generic programming can be effectively applied. In this paper we advocate better syntactic and semantic support for concepts and describe some straightforward language features that could better support them. We also briefly discuss uses for concepts beyond their use in constraining polymorphism.
In this paper we propose a novel visibility-culling technique for optimizing the computation and rendering of opaque isosurfaces. Given a continuous scalar field f(x) over a domain D and an isovalue w, our technique e...
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