به نام خدا
Title: Inductive Data Flow Graphs
Authors: Azadeh Farzan Zachary Kincaid, Andreas Podelski
Abstract: The correctness of a sequential program can be shown by the annotation of its control flow graph with inductive assertions. We pro-pose inductive data flow graphs, data flow graphs with incorporated inductive assertions, as the basis of an approach to verifying concurrent programs. An inductive data flow graph accounts for a set of dependencies between program actions in interleaved thread executions, and therefore stands as a representation for the set of concurrent program traces which give rise to these dependencies. The approach first constructs an inductive data flow graph and then checks whether all program traces are represented. The size of the inductive data flow graph is polynomial in the number of data dependencies (in a sense that can be made formal); it does not grow exponentially in the number of threads unless the data dependencies do. The approach shifts the burden of the exponential explosion towards the check whether all program traces are represented, i.e., to a combinatorial problem (over finite graphs).
Publish Year: 2013
Published in: ACM-SIGPLAN-SIGACT
Number of Pages: 14
موضوع: نظریه گراف (Graph Theory)
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به نام خدا
Title: Minimizing Transmit Power for Cooperative Multicell System with Massive MIMO
Authors: Jinkyu Kang and Joonhyuk Kang
Abstract: We consider the problem of designing transmit beam former and power for downlink cooperative base-station(BS) system with a large antenna arrays. Since the design of the beam forming vector at the transmitter requires high computational complexity, in a large antenna arrays, we utilize the zero-forcing transmit beamformer, which is the simplest form and the optimal performance in a large antenna arrays. Therefore, this paper focuses on the design of power allocation with n¼üxed transmit beam former for minimizing the transmit power while meeting target signal-to-interference-and-noise-ratio(SINR) of each user and power constraints. We consider two scenarios according to the power constraints of cooperative BSs.One scenario is the sum power constraint on the cooperative base-stations. In this case, the cooperative BSs share the total available transmit power. However, each BS exists a maximum availabletransmit power in practical implementations. Thus, we consider amore realistic per BS power constraints. We proposed the solution strategies for both scenarios: For the sum power constraint case,a simple intuitive solution, where the power is allocated withoutregard to the power constraint until the SINR constraints issatisn¼üed, is presented. For the per BS power constraints case, weuse the properties of a large antenna arrays to n¼ünd the solution ofclosed form. We also demonstrate, via numerical simulation, the performance of proposed strategy is convergent to the optimal performance which is achieved by using the iterative algorithm.
Publish Year: 2013
Published in: CCNC - IEEE
Number of Pages: 5
موضوع: الکترونیک
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به نام خدا
Title: Slender-Set Differential Cryptanalysis
Authors: Julia Borghoff, Lars R Knudsen, Gregor Leander, and Sren S Thomsen
Abstract: This paper considers PRESENT-like ciphers with key-dependent S-boxes. We focus on the setting where the same selection of S-boxes is used in every round. One particular variant with 16 rounds, proposed in 2009, is broken in practice in a chosen plaintext/chosen cipher text scenario. Extrapolating these results suggests that up to 28 rounds of such ciphers can be broken. Furthermore, we outline how our attack strategy can be applied to an extreme case where the S-boxes are chosen uniformly at random for each round, and where the bit permutation is key-dependent as well.
Publish Year: 2013
Published in: Journal of Cryptography - Journal of Springer
Number of Pages: 28
موضوع: رمزنگاری (Cryptography)
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به نام خدا
Title: Visualizing Uncertainty in Multi-resolution Volumetric Data Using Marching Cubes
Authors: J Ma,D Murphy,M Hayes,G Provan
Abstract: Data sets acquired from complex scientific simulation, high precision engineering experiment and high-speed computer network have been exponentially increased, and visualization and analysis of such large-scale of data sets have been identified as a significant challenge to the visualization com-munity. Over the past years many scientists have made at-tempt to address this problem by proposing various data reduction techniques. Consequently the size of data can be reduced and issues associated to the visualization can be improved (e.g. real-time interaction and visual overload).However, during the process of data reduction, the information of original data sets was approximated and potential errors were introduced. It leads to a new problem with regard to the integrity of the data and might mislead users for incorrect decision making. Therefore in this paper we aim to solve the problem by introducing three novel uncertainty visualization methods, which depict both the multi-resolution(MR) approximations of the original data set and the errors associated with each of its low resolution representations. As a result we faithfully represent the MR data sets and allow users to make suitable decisions from the visual output. We applied our techniques on a data set from medical domain to demonstrate their effectiveness and usability.
Publish Year: 2012
Published in: AVI - ACM
Number of Pages: 8
موضوع: مصورسازی داده ها (Data Visualization)
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به نام خدا
Title: Thermal phenomena associated with water transport across a fuel cell membrane: Soret and Dufour effects
Authors: K Glavatskiy a,n , JG Pharoah b , S Kjelstrup
Abstract: We present calculations of the coupling effects that take place when heat and water are transported across a membrane relevant to fuel cells, using the theory of non-equilibrium thermodynamics. Numerical results are given for the Nafeon membrane bounded by surfaces of molecular thickness in contact with water vapor of varying relative humidity. Analytical expressions for thermal effects of water transport are given. We show how reversible heat transport (Dufour effects) can be understood in terms of coupling coefficients (heats of transfers). The sign of the enthalpy of adsorption of water in the membrane determines the sign of the coupling coefficient, the Dufour and Soret effect as well as thermal osmosis effects meaning that the effect can be large at interfaces. Weshow how data presented in the literature can be understood in terms of the presented theory. Using common estimates for transport properties in the membrane and its surface, we ?nd that the more detailed equations predict a 10 30% variation in the heat and mass fluxes as the membrane thickness drops below 1 mm. Analysis of experiments on thermal osmosis suggests that more accurate measurements on the water content as a function of activity are required.
Publish Year: 2013
Published in: Journal of Membrane Science - Science Direct
Number of Pages: 9
موضوع: ترمودینامیک
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