It is well known that the average case deterministic communication complexity is bounded below by an entropic quantity, which one would now call deterministic information complexity. In this paper we show a correspond...
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It is well known that the average case deterministic communication complexity is bounded below by an entropic quantity, which one would now call deterministic information complexity. In this paper we show a corresponding upper bound. We also improve known lower bounds for the public coin Las Vegas communication complexity by a constant factor. (c) 2006 Elsevier B.V. All rights reserved.
The Media Accelerating Peer Services system extends P2P infrastructures to improve multimedia services across heterogeneous computing platforms. In this article, we present an architecture and resource management and ...
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The Media Accelerating Peer Services system extends P2P infrastructures to improve multimedia services across heterogeneous computing platforms. In this article, we present an architecture and resource management and adaptation framework that transcends existing infrastructures to accommodate and accelerate multimedia peer applications and services. We also propose key technology components that support seamless adaptation of resources to enhance quality of service and the building of better tools and applications that utilize the peer-computing network's underlying power
Modern scientific data mainly consist of huge data sets gathered by a very large number of techniques and stored in much diversified and often incompatible data repositories. More in general, in the e-science environm...
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Modern scientific data mainly consist of huge data sets gathered by a very large number of techniques and stored in much diversified and often incompatible data repositories. More in general, in the e-science environment, it is considered as a critical and urgent requirement to integrate services across distributed, heterogeneous, dynamic "virtual organizations" formed by different resources within a single enterprise. In the last decade, Astronomy has become an immensely data-rich field due to the evolution of detectors (plates to digital to mosaics), telescopes and space instruments. The Virtual Observatory approach consists of the federation under common standards of all astronomical archives available worldwide, as well as data analysis, data mining and data exploration applications. The main drive behind such an effort is that once the infrastructure is complete, it will allow a new type of multi-wavelength, multi-epoch science, which can only be barely imagined. Data mining, or knowledge discovery in databases, while being the main methodology to extract the scientific information contained in such Massive Data Sets (MDS), poses crucial problems since it has to orchestrate complex problems posed by transparent access to different computing environments, scalability of algorithms, reusability of resources, etc. In the present paper we summarize the present status of the MDS in the Virtual Observatory and what is currently done and planned to bring advanced data mining methodologies in the case of the DAME (DAta Mining and Exploration) project. (C) 2010 Elsevier B.V. All rights reserved.
For the case of infinitely large apertures the followiug probability distributions are derived in this paper: the probability of finding a ray at the nth lens at a distance r from the axis, the probability of finding ...
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For the case of infinitely large apertures the followiug probability distributions are derived in this paper: the probability of finding a ray at the nth lens at a distance r from the axis, the probability of finding a ray with an amplitude A at lens n, the cumulative probability of finding a ray with a displacement less than r and the cumulative probability of finding a ray with an amplitude less than A. The case of lenses with finite apertures was explored with the help of computer simulated experiments whose results are given. These experiments show that the probability distributions for the ray amplitudes which were derived for infinite apertures are still useful even in the case of lenses with finite apertures as long as the probability of losing the ray is less than 20 percent.
We present private secure coded computation that ensures both the master's privacy and data security against the workers, where the master aims to compute a function of its private data and a specific data in a li...
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We present private secure coded computation that ensures both the master's privacy and data security against the workers, where the master aims to compute a function of its private data and a specific data in a library exclusively owned by the external workers. For privacy, the master should conceal the index of the specific data in the library against the workers. For security, the master should encrypt its private data. As an achievable scheme, we propose private secure polynomial codes and compare the proposed scheme with private polynomial codes in private coded computation and the optimal scheme of robust private information retrieval (RPIR).
Ultrahigh Q, X-band resonators, used in a frequency discriminator for stabilization of a low-noise signal generator, can provide a means of obtaining significant reduction in phase noise levels. Resonator unloaded Qs ...
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Ultrahigh Q, X-band resonators, used in a frequency discriminator for stabilization of a low-noise signal generator, can provide a means of obtaining significant reduction in phase noise levels. Resonator unloaded Qs on the order of 500 K can be obtained in a sapphire dielectric resonator (DR) operating on a low-order (i.e., TE01) mode at 77 K and employing high-temperature superconducting (HTS) films installed in the DR enclosure covers. Rigorous analysis for the determination of resonator frequency, modes, and unloaded Q have been carried out using mode matching techniques. Trade-off studies have been performed to select resonator dimensions for the optimum mode yielding highest unloaded Q and widest spurious mode separation. Field distributions within the resonator have been computed to enable practical excitation of the required mode. The results of both analysis and prototype device evaluation experiments are compared for resonators fabricated using enclosures consisting of conventional, metal sidewalls and covers employing high-temperature superconducting films as a function of cover (i.e., HTS film) conductivity.
The National Fusion Collaboratory (NFC) project was created to advance scientific understanding and innovation in magnetic fusion research by enabling more efficient use of existing experimental facilities through mor...
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The National Fusion Collaboratory (NFC) project was created to advance scientific understanding and innovation in magnetic fusion research by enabling more efficient use of existing experimental facilities through more effective integration of experiment, theory, and modeling. To achieve this objective, NFC introduced the concept of "network services", which build on top of computational Grids, and provide Fusion codes, together with their maintenance and hardware resources as a service to the community. This mode of operation requires the development of new authorization and enforcement capabilities. In addition, the nature of Fusion experiments places strident quality of service requirements on codes run during the experimental cycle. In this paper, we describe Grid computing requirements of the Fusion community, and present our first experiments in meeting those requirements. Published by Elsevier Science B.V.
Coded computation has attracted great interests as a promising technique to cope with straggling computing nodes in mobile edge computing (MEC) networks. Contrary to the existing coded computation schemes developed wi...
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Coded computation has attracted great interests as a promising technique to cope with straggling computing nodes in mobile edge computing (MEC) networks. Contrary to the existing coded computation schemes developed with a fixed network topology, this paper studies a MDS coded computation for random networks. Specifically, we put forth maximum distance separable (MDS) coded task offloading and investigate its MDS coded computing gain by deriving the average successful retrieval probability with stochastic geometry in random wireless edge computing networks, where it encodes the original task into multiple equal and small sized MDS coded sub-tasks and offloads their subset to edge computing nodes for computation. We also identify a tradeoff between the latency in processing a sub-task at an edge node and the minimal number of edge nodes required to retrieve the original task output, according to the size of MDS coded sub-tasks. To efficiently control the tradeoff, we determine the desirable size of MDS coded sub-tasks in a semi-closed form to maximize the average successful retrieval probability for regime 1 and regime 2 networks, which correspond to the cases that communication latency is negligible compared to computation latency and that computation latency is negligible compared to communication latency, respectively, and develop an efficient algorithm with low search complexity for a general environment. Our numerical results reveal that the proposed scheme outperforms the other conventional task offloading schemes such as partial task offloading and replication task offloading in terms of average successful retrieval probability.
Given a set of nodes in a distributed system, a coterie is a collection of subsets of the set of nodes such that any two subsets have a nonempty intersection and are not properly contained in one another. A subset of ...
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Given a set of nodes in a distributed system, a coterie is a collection of subsets of the set of nodes such that any two subsets have a nonempty intersection and are not properly contained in one another. A subset of nodes in a coterie is called a quorum. Coteries may be used to implement a distributed mutual exclusion algorithm which gracefully tolerates node and communication line failures. Two types of coteries exist: dominated and nondominated. In this paper, we introduce an algorithm, called the join algorithm, which takes nonempty coteries, as input, and returns a new, larger coterie. The new coterie is called a composite coterie. We prove that a composite coterie is nondominated if and only if the input coteries are nondominated. Using the algorithm, dominated or nondominated coteries may be easily constructed for a large number of nodes. Then, we present an efficient method for determining whether a given set of nodes contains a quorum of a composite coterie. The test does not require that the quorums of a composite coterie be computed in advance. As an example, we generalize tree coteries, using the join algorithm, and prove that tree coteries are nondominated. Finally, we show that the join algorithm may be used to generate read and write quorums which may be used by a replica control protocol.
This note reports an interesting kind of partition, called an s-partition, for a natural number n. Each cell in an s-partition has an element of the form 2(r) - 1. We give a recurrence relation to enumerate all s-part...
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This note reports an interesting kind of partition, called an s-partition, for a natural number n. Each cell in an s-partition has an element of the form 2(r) - 1. We give a recurrence relation to enumerate all s-partitions of it and also derive an upper bound on the number of possible s-partitions. We define a relation of domination to get a lexical order on s-partitions and show that a unique partition, called d-partition, dominates all other s-partitions of n. A d-partition has the smallest cardinality of O(log n) and can be generated in O(log n) steps. A d-partition may have a potential application in cryptography as we demonstrate its use in a distributed algorithm to compute a(n) mod m, a key computation intensive step in many cryptographic algorithms. (C) 1999 Elsevier Science B.V. All rights reserved.
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