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Kwok, YuKwong; Ahmad, Ishfaq; Wu, MinYou; Shu, Wei
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2 Citations
In this paper, we introduce an experimental software tool called CASCH (Computer Aided SCHeduling) for automatic parallelization and scheduling of applications to parallel processors. CASCH transforms a sequential program to a parallel program through automatic task graph generation, scheduling, mapping, communication, and synchronization primitives insertion. The major strength of CASCH is its extensive library of stateoftheart scheduling and mapping algorithms reported in the recent literature. Using these algorithms, a practitioner can choose the most suitable one for generating the shortest schedule for the application at hand. Furthermore, the scheduling algorithms can be interactively analyzed, tested and compared using real data on a common platform with various performance objectives. CASCH with its graphical interface is useful for both novice and expert programmers of parallel machines, and can serve as a teaching and learning aid for understanding scheduling and mapping algorithms.
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By
Panzirsch, Michael; Hulin, Thomas; Artigas, Jordi; Ott, Christian; Ferre, Manuel
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1 Citations
In teleoperation systems, the master robot receives force feedback from the remote slave side. Thus, the human operator can perceive the contact between the slave robot and its environment. Application of a force sensor at the slave robot improves the performance of the telepresence system in terms of transparency. Still, so far no approach allowing measured force feedback in time delayed multilateral systems that allow the interaction of multiple agents can be found in literature. To this end, this paper presents a multilateral setup with passive measured force feedback based on the time domain passivity approach. Besides this solution to measured force feedback in multilateral systems, the presented approach promises improvements compared to other time invariant and model based approaches for measured force feedback also when applied to bilateral systems. Experiments are presented to allow for a performance analysis of the proposed system design.
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By
Shi, Qiaoshuo; Shan, Jinsong; Yan, Wenjie; Wu, Youxi ; Wu, Xindong
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Pattern matching (PM) with gap constraints (or flexible wildcards) is one of the essential tasks in repetitive sequential pattern mining (or sequence pattern mining), since it can compute the support of a pattern in a sequence. Nonoverlapping PM (or PM under nonoverlapping condition) which is a kind of PM with gap constraints methods allows the same position character in the sequence to be reused at different locations in the pattern, but is not allowed to be reused in the same position of the pattern. The researches on nonoverlapping are under nonnegative gaps which are more restrictive on the order of each character occurring in the sequence. As we know that it is easy to obtain valuable patterns under the nonoverlapping condition in sequence pattern mining. This paper addresses a nonoverlapping PM problem with general gaps which means that the gap can be a negative value. We proposes an effective algorithm which employs Nettree structure to convert the problem into a general gap Nettree at first. In order to find the nonoverlapping occurrences, the algorithm employs a backtracking strategy to find the leftmost full path in each iteration. This paper also analyzes the time and space complexities of the proposed algorithm. Experimental results verify the proposed algorithm has better performance and demonstrate that the general gap is more flexible than the nonnegative gap.
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By
Luan, Feng; Nygård, Mads
Migration is the most often used preservation approach in longterm preservation systems. To design a migration plan, custodians need to know about technical infrastructure about a preservation system, characteristics and provenance about digital materials, restrictions about preservation activities, and policies about retention rules. However, current tools cannot provide all these information. They just can output information about formats and characteristics for several given formats. Hence, in this paper, we design a migration metadata extraction tool. This tool uses the stored metadata to retrieve the above information for the custodians. The test results show that due to the limitation on the stored metadata, our solution still cannot get the sufficient information. However, it outputs more migration metadata and has better performance than current tools.
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By
Lingas, Andrzej; Sledneu, Dzmitry
1 Citations
We consider the problem of computing allpairs shortest paths in a directed graph with nonnegative real weights assigned to vertices.
For an n×n 0 − 1 matrix C, let K_{C} be the complete weighted graph on the rows of C where the weight of an edge between two rows is equal to their Hamming distance. Let MWT(C) be the weight of a minimum weight spanning tree of K_{C}.
We show that the allpairs shortest path problem for a directed graph G on n vertices with nonnegative real weights and adjacency matrix A_{G} can be solved by a combinatorial randomized algorithm in time
$$\widetilde{O}(n^{2}\sqrt{n + \min\{MWT(A_G), MWT(A_G^t)\}})$$
As a corollary, we conclude that the transitive closure of a directed graph G can be computed by a combinatorial randomized algorithm in the aforementioned time.
We also conclude that the allpairs shortest path problem for vertexweighted uniform disk graphs induced by point sets of bounded density within a unit square can be solved in time
$\widetilde{O}(n^{2.75})$
.
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By
Cahill, Vinny; Lafferty, Donal
This chapter:
introduces the objectoriented approach to computer programming
describes how objectoriented programs are made up of collections of interacting objects
describes how objects are defined by the class to which they belong
describes how to define a new class of objects in C#…
… and how to write a C# program that uses this class
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By
Hamana, Makoto
4 Citations
Abstract syntax with variable binding is known to be characterised as an initial algebra in a presheaf category. This paper extends it to the case of polymorphic typed abstract syntax with binding. We consider two variations, secondorder and higherorder polymorphic syntax. The central idea is to apply Fiore’s initial algebra characterisation of typed abstract syntax with binding repeatedly, i.e. first to the type structure and secondly to the term structure of polymorphic system. In this process, we use the Grothendieck construction to combine differently staged categories of polymorphic contexts.
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By
Xu, Shuo ; Liu, Junwan; Zhai, Dongsheng; An, Xin; Wang, Zheng; Pang, Hongshen
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4 Citations
It is increasing important to identify automatically thematic structures from massive scientific literature. The interdisciplinarity enables thematic structures without natural boundaries. In this work, the identification of thematic structures is regarded as an overlapping community detection problem from the largescale citationlink network. A mixedmembership stochastic blockmodel, armed with stochastic variational inference algorithm, is utilized to detect the overlapping thematic structures. In the meanwhile, in order to enhance readability, each theme is labeled with soft mutual information based method by several topical terms. Extensive experimental results on the astro dataset indicate that mixedmembership stochastic blockmodel primarily uses the local information and allows for the pervasive overlaps, but it favors similar sized themes, which disqualifies this approach from being used to extract the thematic structures from scientific literature. In addition, the thematic structures from the bibliographic coupling network is similar to those from the cocitation network.
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By
Agussalim; Tsuru, Masato
1 Citations
This paper proposes a framework for message transmission scheduling on a simple tandem multihop transmission model with lossy unreliable wireless links, where each of N nodes periodically generates a message every T timeslots. Such a model is of practical importance, e.g., in lowcost seriallyarranged sensor networks in the wild. Each message can be transmitted to an adjacent in a single timeslot, and should be relayed in a storewaitandforward manner from its source node to one of gateways at the edges of the tandem within T timeslots. Our framework consists of: (i) a static global timeslot assignment over all links analytically derived by a central server; and (ii) a local message selection for transmission with a simple XOR network codingbased proactive recovery over assigned timeslots on each link. Simulation results show the probability that all messages are successfully delivered to the server (via gateways) by the proposed framework is comparable to or even better than that by ACKbased reactive recovery schemes.
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