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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Computing Science and Engineering
Journal Basic Information
Journal DOI :
Korean Institute of Information Scientists and Engineers
Editor in Chief :
In-Sup Lee / Il-Yeol Song / Jong C. Park / Tae-Whan Kim
Volume & Issues
Volume 9, Issue 4 - Dec 2015
Volume 9, Issue 3 - Sep 2015
Volume 9, Issue 2 - Jun 2015
Volume 9, Issue 1 - Mar 2015
Selecting the target year
An Optimization Algorithm with Novel Flexible Grid: Applications to Parameter Decision in LS-SVM
Gao, Weishang ; Shao, Cheng ; Gao, Qin ;
Journal of Computing Science and Engineering, volume 9, issue 2, 2015, Pages 39~50
DOI : 10.5626/JCSE.2015.9.2.39
Genetic algorithm (GA) and particle swarm optimization (PSO) are two excellent approaches to multimodal optimization problems. However, slow convergence or premature convergence readily occurs because of inappropriate and inflexible evolution. In this paper, a novel optimization algorithm with a flexible grid optimization (FGO) is suggested to provide adaptive trade-off between exploration and exploitation according to the specific objective function. Meanwhile, a uniform agents array with adaptive scale is distributed on the gird to speed up the calculation. In addition, a dominance centroid and a fitness center are proposed to efficiently determine the potential guides when the population size varies dynamically. Two types of subregion division strategies are designed to enhance evolutionary diversity and convergence, respectively. By examining the performance on four benchmark functions, FGO is found to be competitive with or even superior to several other popular algorithms in terms of both effectiveness and efficiency, tending to reach the global optimum earlier. Moreover, FGO is evaluated by applying it to a parameter decision in a least squares support vector machine (LS-SVM) to verify its practical competence.
Scratchpad Memory Architectures and Allocation Algorithms for Hard Real-Time Multicore Processors
Liu, Yu ; Zhang, Wei ;
Journal of Computing Science and Engineering, volume 9, issue 2, 2015, Pages 51~72
DOI : 10.5626/JCSE.2015.9.2.51
Time predictability is crucial in hard real-time and safety-critical systems. Cache memories, while useful for improving the average-case memory performance, are not time predictable, especially when they are shared in multicore processors. To achieve time predictability while minimizing the impact on performance, this paper explores several time-predictable scratch-pad memory (SPM) based architectures for multicore processors. To support these architectures, we propose the dynamic memory objects allocation based partition, the static allocation based partition, and the static allocation based priority L2 SPM strategy to retain the characteristic of time predictability while attempting to maximize the performance and energy efficiency. The SPM based multicore architectural design and the related allocation methods thus form a comprehensive solution to hard real-time multicore based computing. Our experimental results indicate the strengths and weaknesses of each proposed architecture and the allocation method, which offers interesting on-chip memory design options to enable multicore platforms for hard real-time systems.
A Semantic Aspect-Based Vector Space Model to Identify the Event Evolution Relationship within Topics
Xi, Yaoyi ; Li, Bicheng ; Liu, Yang ;
Journal of Computing Science and Engineering, volume 9, issue 2, 2015, Pages 73~82
DOI : 10.5626/JCSE.2015.9.2.73
Understanding how the topic evolves is an important and challenging task. A topic usually consists of multiple related events, and the accurate identification of event evolution relationship plays an important role in topic evolution analysis. Existing research has used the traditional vector space model to represent the event, which cannot be used to accurately compute the semantic similarity between events. This has led to poor performance in identifying event evolution relationship. This paper suggests constructing a semantic aspect-based vector space model to represent the event: First, use hierarchical Dirichlet process to mine the semantic aspects. Then, construct a semantic aspect-based vector space model according to these aspects. Finally, represent each event as a point and measure the semantic relatedness between events in the space. According to our evaluation experiments, the performance of our proposed technique is promising and significantly outperforms the baseline methods.
A Holistic Approach to Optimizing the Lifetime of IEEE 802.15.4/ZigBee Networks with a Deterministic Guarantee of Real-Time Flows
Kim, Kang-Wook ; Park, Myung-Gon ; Han, Junghee ; Lee, Chang-Gun ;
Journal of Computing Science and Engineering, volume 9, issue 2, 2015, Pages 83~97
DOI : 10.5626/JCSE.2015.9.2.83
IEEE 802.15.4 is a global standard designed for emerging applications in low-rate wireless personal area networks (LR-WPANs). The standard provides beneficial features, such as a beacon-enabled mode and guaranteed time slots for realtime data delivery. However, how to optimally operate those features is still an open issue. For the optimal operation of the features, this paper proposes a holistic optimization method that jointly optimizes three cross-related problems: cluster-tree construction, nodes' power configuration, and duty-cycle scheduling. Our holistic optimization method provides a solution for those problems so that all the real-time packets can be delivered within their deadlines in the most energy-efficient way. Our simulation study shows that compared to existing methods, our holistic optimization can guarantee the on-time delivery of all real-time packets while significantly saving energy, consequently, significantly increasing the lifetime of the network. Furthermore, we show that our holistic optimization can be extended to take advantage of the spatial reuse of a radio frequency resource among long distance nodes and, hence, significantly increase the entire network capacity.
A Conflict Detection Method Based on Constraint Satisfaction in Collaborative Design
Yang, Kangkang ; Wu, Shijing ; Zhao, Wenqiang ; Zhou, Lu ;
Journal of Computing Science and Engineering, volume 9, issue 2, 2015, Pages 98~107
DOI : 10.5626/JCSE.2015.9.2.98
Hierarchical constraints and constraint satisfaction were analyzed in order to solve the problem of conflict detection in collaborative design. The constraints were divided into two sets: one set consisted of known constraints and the other of unknown constraints. The constraints of the two sets were detected with corresponding methods. The set of the known constraints was detected using an interval propagation algorithm, a back propagation (BP) neural network was proposed to detect the set with the unknown constraints. An immune algorithm (IA) was utilized to optimize the weights and the thresholds of the BP neural network, and the steps were designed for the optimization process. The results of the simulation indicated that the BP neural network that was optimized by IA has a better performance in terms of convergent speed and global searching ability than a genetic algorithm. The constraints were described using the eXtensible Markup Language (XML) for computers to be able to automatically recognize and establish the constraint network. The implementation of the conflict detection system was designed based on constraint satisfaction. A wind planetary gear train is taken as an example of collaborative design with a conflict detection system.
Priority-Based Network Interrupt Scheduling for Predictable Real-Time Support
Lee, Minsub ; Kim, Hyosu ; Shin, Insik ;
Journal of Computing Science and Engineering, volume 9, issue 2, 2015, Pages 108~117
DOI : 10.5626/JCSE.2015.9.2.108
Interrupt handling is generally separated from process scheduling. This can lead to a scheduling anomaly and priority inversion. The processor can interrupt a higher priority process that is currently executing, in order to handle a network packet reception interruption on behalf of its intended lower priority receiver process. We propose a new network interrupt handling scheme that combines interrupt handling with process scheduling and the priority of the process. The proposed scheme employs techniques to identify the intended receiver process of an incoming packet at an earlier phase. We implement a prototype system of the proposed scheme on Linux 2.6, and our experiment results show that the prototype system supports the predictable real-time behavior of higher priority processes even when excessive traffic is sent to lower priority processes.