JaamSim is a free, open-source simulation package written in the java programming language. A modern graphical user interface is provided that is comparable to commercial software, including drag-and-drop model buildi...
详细信息
ISBN:
(纸本)9781479939503;9781479920778
JaamSim is a free, open-source simulation package written in the java programming language. A modern graphical user interface is provided that is comparable to commercial software, including drag-and-drop model building, an Input Editor, Output Viewer, and 3D graphics. Users are able to create their own palettes of high-level objects using standard java and modern programming tools such as Eclipse. If you are writing hundreds or thousands of lines of code in the proprietary programminglanguage provided with your commercial software, you would be far better off to write your code in java and use JaamSim.
With the rise of social networks, large-scale graph analysis becomes increasingly important. Because SQL lacks the expressiveness and performance needed for graph algorithms, lower-level, general-purpose languages are...
详细信息
ISBN:
(纸本)9781467349093;9781467349086
With the rise of social networks, large-scale graph analysis becomes increasingly important. Because SQL lacks the expressiveness and performance needed for graph algorithms, lower-level, general-purpose languages are often used instead. For greater ease of use and efficiency, we propose SociaLite, a high-level graph query language based on Datalog. As a logic programminglanguage, Datalog allows many graph algorithms to be expressed succinctly. However, its performance has not been competitive when compared to low-level languages. With SociaLite, users can provide high-level hints on the data layout and evaluation order;they can also define recursive aggregate functions which, as long as they are meet operations, can be evaluated incrementally and efficiently. We evaluated SociaLite by running eight graph algorithms (shortest paths, PageRank, hubs and authorities, mutual neighbors, connected components, triangles, clustering coefficients, and betweenness centrality) on two real-life social graphs, Live-Journal and Last. fm. The optimizations proposed in this paper speed up almost all the algorithms by 3 to 22 times. SociaLite even outperforms typical java implementations by an average of 50% for the graph algorithms tested. When compared to highly optimized java implementations, SociaLite programs are an order of magnitude more succinct and easier to write. Its performance is competitive, giving up only 16% for the largest benchmark. Most importantly, being a query language, SociaLite enables many more users who are not proficient in software engineering to make social network queries easily and efficiently.
Data races are one of the major causes of concurrency bugs in multithreaded programs, but they are hard to find due to nondeterministic thread scheduling. Data race detectors are essential tools that help long-sufferi...
详细信息
ISBN:
(纸本)9781479924189
Data races are one of the major causes of concurrency bugs in multithreaded programs, but they are hard to find due to nondeterministic thread scheduling. Data race detectors are essential tools that help long-suffering programmers to locate data races in multithreaded programs. One type of detectors precisely detects data races but is sensitive to thread scheduling, whereas another type is less sensitive to thread scheduling but reports a considerable number of false positives. In this paper, we propose a new dynamic data race detector called SimpleLock that accurately detects data races in a scheduling insensitive manner with low execution overhead. We reduce execution overhead by using two assumptions. The first is that most data races are caused by the accessing of shared variables without locks. The second is that two accesses that cause a data race have not a long distance between them in an execution trace. The results of experiments conducted on the RoadRunner framework confirm that these assumptions are valid and that our SimpleLock detector can efficiently and accurately detect real and potential data races in one execution trace. The results also indicate that the execution overhead of SimpleLock is not much higher than that of FastTrack, the fastest happens-before race detector.
To effectively cope with correctness issues of concurrent and timed systems, the use of formal tools is mandatory. This paper proposes an original approach to modeling and exhaustive verification of java-based concurr...
详细信息
ISBN:
(纸本)9781467344715
To effectively cope with correctness issues of concurrent and timed systems, the use of formal tools is mandatory. This paper proposes an original approach to modeling and exhaustive verification of java-based concurrent systems which relies on the popular UPPAAL model checker. More precisely, a library of UPPAAL timed automata (TA) reproducing the semantics of major java concurrent and synchronization mechanisms was developed, which fosters a smooth transition from specification down to implementation. The library includes such common control structures like semaphores and monitors, both classic and java specific. The paper describes the developed TA library and shows its practical use by means of examples. Finally, an indication of on-going and future work directions is drawn in the conclusion.
In this paper we present PCJ - a new library for parallel computations in java. The PCJ library implements partitioned global address space approach. It hides communication details and therefore it is easy to use and ...
详细信息
ISBN:
(纸本)9783642368035
In this paper we present PCJ - a new library for parallel computations in java. The PCJ library implements partitioned global address space approach. It hides communication details and therefore it is easy to use and allows for fast development of parallel programs. With the PCJ user can focus on implementation of the algorithm rather than on thread or network programming. The design details with examples of usage for basic operations are described. We also present evaluation of the performance of the PCJ communication on the state of art hardware such as cluster with gigabit interconnect. The results show good performance and scalability when compared to native MPI implementations.
FPGAs enable NoC architecture experimentation, although to be effective they need to be supported by tools and frameworks for construction of the NoC and effective software programming of the NoC. In this paper, we fo...
详细信息
ISBN:
(纸本)9781479920785
FPGAs enable NoC architecture experimentation, although to be effective they need to be supported by tools and frameworks for construction of the NoC and effective software programming of the NoC. In this paper, we focus upon effective programming of the NoC using java, complementing previous work which proposes the Blueshell framework for NoC generation for FPGAs. The approach taken is called Network-Chi, providing a number of key extensions to the Chi java compiler. This includes provision of a networking API within java giving a mesh based abstraction for network communication, allowing the programmer to send java objects to other nodes without consideration for the underlying hardware topology or protocols;and a region-based memory management API that enables the definition of transient allocation contexts that discard all objects allocated within them when they reach the end of execution. Results show the approach taken to be efficient and effective.
To promote reliability, the adoption of deferred error coding within computer science curricula is advocated. It is both a sound development strategy and aligned well pedagogically. By deferring specific error handlin...
详细信息
ISBN:
(纸本)9781450320788
To promote reliability, the adoption of deferred error coding within computer science curricula is advocated. It is both a sound development strategy and aligned well pedagogically. By deferring specific error handling (first, doing no harm) the student better appreciates error handling's subtleties and its importance as an independent topic. The presentation will also include taxonomies of exceptions and exception handlers, and the relationships between them. Much of the discussion is language independent, but specific attention is given to the java checked exception controversy.
This paper introduces JT2FIS, a java Class Library for Interval Type-2 Fuzzy Inference Systems that can be used to build intelligent object-oriented applications. The architecture of the system is presented and its ob...
详细信息
This paper presents an analysis of data of the most widely used integrated environments of application development on java. A set of different criteria is proposed to allow estimating with high credibility the propert...
详细信息
暂无评论