We present the results of a community detection analysis of the Wikipedia graph. Distinct communities in Wikipedia contain semantically closely related articles. The central topic of a community can be identified usin...
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ISBN:
(纸本)9781605584874
We present the results of a community detection analysis of the Wikipedia graph. Distinct communities in Wikipedia contain semantically closely related articles. The central topic of a community can be identified using PageRank. Extracted communities can be organized hierarchically similar to manually created Wikipedia category structure. Copyright is held by the author/owner(s).
The calculation of "Probability of Failure on Demand" (PFH) according to IEC 61508 shows for a 1oo1 and a 1oo2 system using the same initial values that - as expected - a 1oo2 system is a better safety integ...
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The calculation of "Probability of Failure on Demand" (PFH) according to IEC 61508 shows for a 1oo1 and a 1oo2 system using the same initial values that - as expected - a 1oo2 system is a better safety integrity system than a 1oo1 system. This means, that a 1oo2 system has a lower probability of failure than a 1oo1 system. Comparing the same systems operating in a high demand or continuous mode of operation, there will be some cases, especially for systems with high diagnostics, where a 1oo1 system has a lower ¿Probability of Failure per Hour¿ (PFH) value than a 1oo2 system, using the PFH formulas according to IEC 61508. Using the equation according to IEC 61508, it is also possible that the PFH value is apparently better the longer the system runs either in the high mode or continuous mode of operation. Both results are irreproducible in industrial reality. Therefore, this paper will analyze first what conditions are necessary to get a hazard event when using a PFH system. Only those cases are considered in the modified PFH calculation, in which indeed a hazard event occurs. In a second step, it presents a new approach with the help of plausible arguments in order to calculate the PFH value of a PFH system considering a high diagnostic and a very low failure rate. The presented approach can also be correctly verified with mathematics using the advanced Markov model also described in this paper.
Multithreaded Object-Oriented programming in concurrency environment using object-oriented technology is a complex activity. Programmers need to be aware of issues unrelated to their domain of problem, and are often u...
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Multithreaded Object-Oriented programming in concurrency environment using object-oriented technology is a complex activity. Programmers need to be aware of issues unrelated to their domain of problem, and are often unprepared for the challenges of the concurrent object-oriented programming brings. The interaction of their components becomes more complex, and makes it difficult to validate the design and correctness of the implemented program. Supporting separation of concerns in the design and implementation of the multithreaded object-oriented programming can provide a number of benefits such as comprehension, reusability, extensibility and adaptability in both design and implementation. We have tackled this problem by adopting the technique of separation of concerns in multithreaded object-oriented programming. In this paper we demonstrate an aspect-oriented approach that can be used for multithreaded object-oriented programming. We also show how better the separation of concerns in components. Readers/Writers problem is demonstrated using an aspect-oriented approach. Our methodology, which is based on aspect-oriented techniques as well as language and architecture independence, is an aspect-oriented framework.
Maintainability, extendibility and reusability of components in the design of robot control architectures is a major challenge. Parallel kinematic robots feature a wide variety of structures and applications. They are...
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This paper presents a novel method on coloring the grayscale images. For this purpose, a combination of artificial neural networks and some image processing algorithms was developed to transfer colors from a user-sele...
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This paper presents a novel method on coloring the grayscale images. For this purpose, a combination of artificial neural networks and some image processing algorithms was developed to transfer colors from a user-selected source image to a target grayscale image. According to the results of this combining method, a survey where volunteers were asked to rate the plausibility of the colorings generated automatically was performed for individual images. In most cases automatically-colored images were rated either as totally or mostly acceptable.
The SecureMDD approach aims to generate both, a formal specification for verification and executable code, from UML diagrams. The UML models define the static as well as dynamic components of the system under developm...
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ISBN:
(纸本)9781424437252
The SecureMDD approach aims to generate both, a formal specification for verification and executable code, from UML diagrams. The UML models define the static as well as dynamic components of the system under development. This model-driven approach is focused on security-critical applications that are based on cryptographic protocols, especially Java Card applications. In this paper we describe the generation of the formal specification from the UML model which is then used as input for our interactive verification system KIV. The formal specification is based on abstract state machines and algebraic specifications. It allows to formulate and to prove application-specific security properties.
Efficiently using the computational power made available through desktop grids based distributed systems is a complicated and many-sided problem, caused by the intermittent resource availability. In this paper a novel...
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ISBN:
(纸本)9781424435692
Efficiently using the computational power made available through desktop grids based distributed systems is a complicated and many-sided problem, caused by the intermittent resource availability. In this paper a novel solution is presented for predicting the runtimes of parameter sweep jobs. These jobs are characterized by their lack of inter-dependence and suitability for runtime prediction by modeling. This makes them ideal candidates for deployment on volatile grid configurations using prediction based techniques. The parameter sweep prediction framework used to make the predictions is referred to as GIPSy (grid information prediction system). Previous research involving GIPSy has focused on results obtained during simulation were it is necessary to make some basic assumptions. By combining GIPSy with PGS (prediction based grid scheduling), an actual grid implementation, real results can be obtained. A detailed comparison between the expected results, based on simulation analysis, and the final results is given. Discrepancies are highlighted and possible causes are identified, solutions are proposed and implemented. By comparing the results for different model building configurations an optimal configuration is found that produces reliable result independent of the chosen job type. Results are presented for a quantum physics problem and two simulated workloads represented by sleep jobs.
Partial Differential Equations (PDE) are the heart of most simulations in many scientific fields, from Fluid Mechanics to Astrophysics. One the most popular mathematical schemes to solve a PDE is Finite Difference (FD...
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Partial Differential Equations (PDE) are the heart of most simulations in many scientific fields, from Fluid Mechanics to Astrophysics. One the most popular mathematical schemes to solve a PDE is Finite Difference (FD). In this work we map a PDE-FD algorithm called Reverse Time Migration to a GPU using CUDA. This seismic imaging (Geophysics) algorithm is widely used in the oil industry. GPUs are natural contenders in the aftermath of the clock race, in particular for High-performance Computing (HPC). Due to GPU characteristics, the parallelism paradigm shifts from the classical threads plus SIMD to Single Program Multiple Data (SPMD). The NVIDIA GTX 280 implementation outperforms homogeneous CPUs up to 9x (Intel Harpertown E5420) and up to 14x (IBM PPC 970). These preliminary results confirm that GPUs are a real option for HPC, from performance to programmability.
For understanding the performance differences caused by different computer architectures and optimization technologies, the paper characterizes performance of SPEC CPU2006 benchmarks both on Intel and AMD platform. Us...
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For understanding the performance differences caused by different computer architectures and optimization technologies, the paper characterizes performance of SPEC CPU2006 benchmarks both on Intel and AMD platform. Using the performance events collected by Performance Monitor Unit, we compare their performance differences and analyze the causes from the features of architectures and the optimization technologies. Our results and analysis help the programmers better understand the memory performance and branch prediction performance which are caused by architectures and guide them in the optimization. The analysis also help the processor architects better balance among the key architecture factors such as memory disambiguation and hardware prefetch when doing architecture design decision.
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