A test coverage analyzer speeds up the software testing process and minimizes the cost. The development steps for most of the test coverage analyzers are similar for any block structured language. This indicates the p...
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ISBN:
(纸本)0889863946
A test coverage analyzer speeds up the software testing process and minimizes the cost. The development steps for most of the test coverage analyzers are similar for any block structured language. This indicates the potential for a generic technique for test coverage analyzer development. Most of the commonly used coverage like path coverage, branch coverage, block coverage, function coverage, loop coverage, deal with the control structure representation of the program. We can generate report for these coverages with the help of block trace and the control structure representation. The processing done on control structure remains same for generating a coverage report for all block structured language. Control structure representation of programs can easily be generated from the grammar of the language inst.umented for block coverage. Using the control structure representation and the block trace generated from the block coverage analysis, our technique can be used to generate report for coverage like path coverage, block coverage, branch coverage, loop coverage, function coverage, etc.. We have implemented our technique to generate the report for path coverage. The results had shown a great reduction in development time for path coverage analyzer for a block structured language. After developing the reporting mechanism for all other coverage also (using our technique), one need not develop all these coverage analyzers for a new block structured language. Thus, only the block coverage analyzer and control structure generator are to be developed for a new block structured language.
In this paper, we describe a framework that facilitates automatic generation of optimizers. The framework consists of a specification language to describe optimizations and a tool to generate optimizers from these spe...
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ISBN:
(纸本)0889863490
In this paper, we describe a framework that facilitates automatic generation of optimizers. The framework consists of a specification language to describe optimizations and a tool to generate optimizers from these specifications. The framework provides a test-bed for verifying correctness of various optimizations and studying the interactions between them, and thus deciding the order in which they shall be applied to achieve maximum benefit.
Existing multicast routing protocols for Mobile Ad hoc Networks can be broadly classified into two categories, tree based protocols and mesh based protocols. Mesh based protocols have high packet delivery ratio comp.r...
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Existing multicast routing protocols for Mobile Ad hoc Networks can be broadly classified into two categories, tree based protocols and mesh based protocols. Mesh based protocols have high packet delivery ratio comp.red to tree based protocols, but incur more control overhead. The packet delivery ratio of tree based protocols decreases with increasing mobility. This is due to the occurrence of frequent tree breaks and lack of proper tree maintenance mechanisms. These tree breaks result in frequent flooding of JoinQuery packets by the multicast group member nodes which try to get re-connected to the tree. These broadcast packets collide with data packets and reduce the efficiency of the protocol. We propose an efficient protocol which we call as Preferred Link Based Multicast protocol (PLBM). PLBM uses a preferred link approach for forwarding JoinQuery packets. A subset of neighbors of a node are selected using a preferred link based algorithm. These nodes, termed as preferred nodes, are only eligible for further forwarding of JoinQuery packets. We also propose a quick link break detection mechanism that locally repairs broken links. Simulation results show that our protocol performs better than other existing multicast protocols in terms of packet delivery ratio and control overhead.
Consider a synchronous network of n players, each with a local input. The goal of distributed consensus is to globally agree on one of the valid inputs even if some non-trivial sub-set of the players are faulty. By va...
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ISBN:
(纸本)9781581137088
Consider a synchronous network of n players, each with a local input. The goal of distributed consensus is to globally agree on one of the valid inputs even if some non-trivial sub-set of the players are faulty. By valid input, we mean the input of any non-faulty player. Extant results in Byzantine agreement literature capture the behaviour of faulty players in an "all-or-nothing" fashion, For inst.nce, a (Byzantine) faulty player is comp.etely unconstrained and could behave differently with different players. This leads to a gross underestimation of the achievable fault-tolerance. In this work, we propose a fault-model that considerably improves the estimation of fault-tolerance and helps capture real-life scenarios better. For inst.nce, if two (honest) players were part of the same LAN (which is essentially a broadcast network), it is impossible for a external faulty player to behave differently with these two players (though the faulty player may behave with "equal" malice with both these players!). Among our results, we introduce the sectional fault-model that is more general and can capture practical scenarios not captured by any extant model. We provide a comp.ete characterization of the tolerable faults and present efficient protocols to achieve consensus. We remark that the results of this paper strictly generalize the extant characterizations of fault-tolerance. For example, consider a network of four players P1,P1,P3 and P 4, under the corrupting influence of a Byzantine adversary given by the adversary structure A = {(P1,P2),(P2,P 3),(P4)}. Agreement is impossible in such a scenario, since the three sets from A cover the player set. However, it would be evident from our results that consensus in the above scenario was indeed possible if (and only if) the players P1, P3 and P4 belonged to a single LAN in the network!
We present a novel vector quantization method for pattern, classification tasks. The input space is quantized into volume regions by code-vectors formed by weights of neurons. During training, the volume regions are m...
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We present a novel vector quantization method for pattern, classification tasks. The input space is quantized into volume regions by code-vectors formed by weights of neurons. During training, the volume regions are merged and split, depending upon the ambiguity in classification, measured using Kullback-Leibler divergence. The heuristic followed is to split ambiguous regions, and merge two volume regions if they contain predominant populations of the same class. The neural network forms a generalized Delaunay graph, whose topology changes dynamically with the merging and splitting. The simulation results indicate the utility of the proposed method.
In this paper, we evaluate the Erlang capacity of CDMA systems according to two sector operation methods: optimized sectoring and fixed-angle sectoring. For the performance analysis, a multidimensional Markov channel ...
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In this paper, we evaluate the Erlang capacity of CDMA systems according to two sector operation methods: optimized sectoring and fixed-angle sectoring. For the performance analysis, a multidimensional Markov channel model is developed. The improved Erlang capacity through optimized sectoring is quantified over fixed-angle sectoring. As a result, we can get about 20% capacity improvement for optimized sectoring over fixed-angle sectoring under the uniform traffic distribution among sectors. In addition, optimized sectoring provides a constant Erlang capacity improvement (about 3.6 times) over an omnidirectional case, even when traffic loads among sectors are nonuniformly distributed. On the other hand, fixed-angle sectoring results in the actual capacity improvement 1.8-3 times over an omnidirectional case, depending on the traffic distribution among sectors.
M2S1 is a Java application for creating virtual worlds based on road maps. A user scans an ordinary road map with a color scanner. M2S analyzes the image and produces a virtual world which is in accordance with the ma...
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ISBN:
(纸本)158113861X
M2S1 is a Java application for creating virtual worlds based on road maps. A user scans an ordinary road map with a color scanner. M2S analyzes the image and produces a virtual world which is in accordance with the map. A rich user-interface lets the user edit and comp.ete the generated 3D-model. A large number of properties can be set: from the background-image via the level of detail up to the algorithm to be used for a specific task. An included fly-through serves to explore and evaluate the result. The exporter tool of M2S currently supports VRML97 and Microsoft's X file format.
Using the multiresolution technique is one way to archive the real-time rendering for the large-scale environment visualization;however, most multiresolution techniques did not consider the appearance of the environme...
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Using the multiresolution technique is one way to archive the real-time rendering for the large-scale environment visualization;however, most multiresolution techniques did not consider the appearance of the environment, then the shapes of the models and environment are degraded during lower-resolution rendering. We here presented a multiresolution modeling algorithm using quadric error metrics and provide the error metrics with the appearance attributes of a model such as color, normal and texture coordinates to rapidly obtain multiresolution models with high qualities. The view-dependent technique is one way to further improve the rendering performance of multiresolution models. We here also provide the view-dependent technique for automatically deciding the proper resolution and model structure based on the view parameters to archive a real-time visualization.
Approaches of image enhancement, edge extraction, and line-based matching for remote sensing images are proposed. In the image enhancement, we propose a wavelet shrinkage technique to blur the urban regions (i.e., the...
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Approaches of image enhancement, edge extraction, and line-based matching for remote sensing images are proposed. In the image enhancement, we propose a wavelet shrinkage technique to blur the urban regions (i.e., the small-scale texture regions) while preserving the sharpness of large-scale edges (such as, highways and rivers) based on a Teager energy criterion. The edge extraction contains wavelet-based edge detection and tracking. The contextual-filter edge detector generates multiresolution gradient images, and then the multiscale edge tracker refines the results as well as reduces the influence of fragment edges and the broken edges. Each extracted edge segment is represented by the coordinates of its mid-point, the logarithm of its length, and its orientation. Then, the matching algorithm based on the Hausdorff distance is applied twice on the two sets of feature vectors for invariant matching.
Messaging is one of the most important issues in information technology. Programmers have to build messaging systems in application, in operating systems, in comp.nent frameworks, etc. There are plenty of algorithms t...
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ISBN:
(纸本)1892512416
Messaging is one of the most important issues in information technology. Programmers have to build messaging systems in application, in operating systems, in comp.nent frameworks, etc. There are plenty of algorithms to make messaging efficient and reliable. Thus, programmers can apply those algorithms on their messaging system to save some work. However, to build a messaging system from scratch is still a tedious work since there are many issues such as connection, message storage, and etc. to concern. Here, we present a framework to reduce such work. In this paper, we identify the building blocks of a messaging system and analyze the relationship among them. The building blocks mentioned in this paper are: &bull Connection service provider &bull Connection operator &bull Message storage operator &bull Gateway service provider.
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