Journal of Computer and System Sciences (J Comput Syst Sci )

Description

The Journal of Computer and System Sciences publishes original research papers in computer science and related subjects in system science, with attention to the relevant mathematical theory. Applications-oriented papers may also be accepted. Research Areas Include: Traditional Subjects such as: Theory of algorithms and computability; Formal languages; Automata theory; Contemporary Subjects such as Complexity theory Algorithmic; Complexity; Parallel and distributed computing; Computer networks; Neural networks; Computational learning theory; Database theory and practice Computer modeling of complex systems.

  • Impact factor
    1.00
  • 5-year impact
    1.11
  • Cited half-life
    0.00
  • Immediacy index
    0.29
  • Eigenfactor
    0.01
  • Article influence
    0.97
  • Website
    Journal of Computer and System Sciences website
  • Other titles
    Journal of computer and system sciences (Online), Journal of computer and system sciences
  • ISSN
    1090-2724
  • OCLC
    36943413
  • Material type
    Document, Periodical, Internet resource
  • Document type
    Internet Resource, Computer File, Journal / Magazine / Newspaper

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: Accurate simulation is vital for the proper design and evaluation of any computing architecture. Researchers seek unified simulation frameworks that can model heterogeneous architectures like CPU and GPU devices and their interactions as computing patterns move toward heterogeneous era. In this paper, we introduce MCMG (Multi-CPU Multi-GPU) simulator, a cycle accurate, modular and open-source toolset that enables simulating x86 CPUs and Nvidia G80 like GPUs simultaneously. Targeting heterogeneous architectural exploration, MCMG supports fully configuration of multiple CPUs, GPUs and their memory sub-system. Not only CPUs, relative running frequency of each GPU can be also defined conveniently. Simulation validation is demonstrated with a preliminary architectural exploration study. Then we present shared LLC access results of heterogeneous cores and show reasonable explanation. Finally, we conclude the job.
    Journal of Computer and System Sciences 02/2015; 81(1):57–71.
  • Journal of Computer and System Sciences 02/2015; 81(1):1–2.
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    ABSTRACT: Functional correctness of low-level operating-system (OS) code is an indispensable requirement. However, many applications rely also on quantitative aspects such as speed, energy efficiency, resilience with regards to errors and other cost factors. We report on our experiences of applying probabilistic model-checking techniques for analysing the quantitative long-run behaviour of low-level OS-code. Our approach, illustrated in a case study analysing a simple test-and-test-and-set (TTS) spinlock protocol, combines measure-based simulation with probabilistic model-checking to obtain high-level models of the performance of realistic systems and to tune the models to predict future system behaviour. We report how we obtained a nearly perfect match of analytic results and measurements and how we tackled the state-explosion problem to obtain model-checking results for a large number of processes where measurements are no longer feasible. These results gave us valuable insights in the delicate interplay between lock load, average spinning times and other performance measures.
    Journal of Computer and System Sciences 02/2015; 81(1):258–287.
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    ABSTRACT: Due to the serious information overload problem on the Internet, recommender systems have emerged as an important tool for recommending more useful information to users by providing personalized services for individual users. However, in the “big data” era, recommender systems face significant challenges, such as how to process massive data efficiently and accurately. In this paper we propose an incremental algorithm based on singular value decomposition (SVD) with good scalability, which combines the Incremental SVD algorithm with the Approximating the Singular Value Decomposition (ApproSVD) algorithm, called the Incremental ApproSVD. Furthermore, strict error analysis demonstrates the effectiveness of the performance of our Incremental ApproSVD algorithm. We then present an empirical study to compare the prediction accuracy and running time between our Incremental ApproSVD algorithm and the Incremental SVD algorithm on the MovieLens dataset and Flixster dataset. The experimental results demonstrate that our proposed method outperforms its counterparts.
    Journal of Computer and System Sciences 12/2014;
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    ABSTRACT: It is well known that processing big graph data can be costly on Cloud. Processing big graph data introduces complex and multiple iterations that raise challenges such as parallel memory bottlenecks, deadlocks, and inefficiency. To tackle the challenges, we propose a novel technique for effectively processing big graph data on Cloud. Specifically, the big data will be compressed with its spatiotemporal features on Cloud. By exploring spatial data correlation, we partition a graph data set into clusters. In a cluster, the workload can be shared by the inference based on time series similarity. By exploiting temporal correlation, in each time series or a single graph edge, temporal data compression is conducted. A novel data driven scheduling is also developed for data processing optimization. The experiment results demonstrate that the spatiotemporal compression and scheduling achieve significant performance gains in terms of data size and data fidelity loss.
    Journal of Computer and System Sciences 12/2014;
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    ABSTRACT: To secure multimedia communications, existing encryption techniques usually encrypt the whole data stream using the same session key during a session. The use of the session key confronts with tradeoff problem between session key creation latency and security for the real-time multimedia stream. The main feature of our proposed scheme is to selectively encrypt RTP packets using different one-time packet keys in the same session for real-time multimedia applications. The packet key, which has already been used, will never be reused throughout the same session. The use of the one-time packet key enables to improve security strength of real-time multimedia. To solve the issue of the real-time packet key exchanges related to the timely use of the one-time packet keys, this paper suggests the one-time packet key exchange method that does not need to occur on a packet-by-packet basis.
    Journal of Computer and System Sciences 12/2014;
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    ABSTRACT: Cloud systems provide significant benefits by allowing users to store massive amount of data on demand in a cost-effective manner. Role-based access control (RBAC) is a well-known access control model which can be used to protect the security of cloud data storage. Although cryptographic RBAC schemes have been developed recently to secure data outsourcing, these schemes assume the existence of a trusted administrator managing all the users and roles, which is not realistic in large-scale systems. In this paper, we introduce a cryptographic administrative model AdC-RBAC for managing and enforcing access policies for cryptographic RBAC schemes. The AdC-RBAC model uses cryptographic techniques to ensure that the administrative tasks are performed only by authorised administrative roles. Then we propose a role-based encryption (RBE) scheme and show how the AdC-RBAC model decentralises the administrative tasks in the RBE scheme thereby making it practical for security policy management in large-scale cloud systems.
    Journal of Computer and System Sciences 12/2014;
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    ABSTRACT: The concept of cloud computing has emerged as the next generation of computing infrastructure to reduce the costs associated with the management of hardware and software resources. It is vital to its success that cloud computing is featured efficient, flexible and secure characteristics. In this paper, we propose an efficient and anonymous data sharing protocol with flexible sharing style, named EFADS, for outsourcing data onto the cloud. Through formal security analysis, we demonstrate that EFADS provides data confidentiality and data sharer's anonymity without requiring any fully-trusted party. From experimental results, we show that EFADS is more efficient than existing competing approaches. Furthermore, the proxy re-encryption scheme we propose in this paper may be independent of interests, i.e., compared to those previously reported proxy re-encryption schemes, the proposed scheme is the first pairing-free, anonymous and unidirectional proxy re-encryption scheme in the standard model.
    Journal of Computer and System Sciences 12/2014;
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    ABSTRACT: Modern software systems are frequently required to be adaptive in order to cope with constant changes. Unfortunately, service-oriented systems built with WS-BPEL are still too rigid. In this paper, we propose a novel model-driven approach to supporting the development of dynamically adaptive WS-BPEL based systems. We model the system functionality with two distinct but highly correlated parts: a stable part called the base model describing the flow logic aspect and a volatile part called the variable model describing the decision logic aspect. We develop an aspect-oriented method to weave the base model and the variable model together so that runtime changes can be applied to the variable model without affecting the base model. A model-driven platform has been implemented to support the development of adaptive WS-BPEL processes. In-lab experiments show that our approach has low performance overhead. A real-life case study also validates the applicability of our approach.
    Journal of Computer and System Sciences 11/2014;
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    ABSTRACT: Control in elections models situations in which an external actor tries to change the outcome of an election by restructuring the election itself. The corresponding decision problems have been shown NP-hard for a variety of voting systems. In particular, in our companion paper [16], we have shown that fallback and Bucklin voting are resistant (in terms of NP-hardness) to almost all of the common types of control. While NP-hardness results for manipulation (another way of tampering with the outcomes of elections) have been challenged experimentally (see, e.g., the work of Walsh and ), such an experimental approach is sorely missing for control. We for the first time tackle NP-hard control problems in an experimental setting. Our experiments allow a more fine-grained analysis and comparison—across various control scenarios, vote distribution models, and voting systems—than merely stating NP-hardness for all these control problems.
    Journal of Computer and System Sciences 11/2014;
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    ABSTRACT: Carpooling for commuting can save cost and helps in reducing pollution. An automatic Web based Global CarPooling Matching Service (GCPMS) for matching commuting trips has been designed. The service supports carpooling candidates by supplying advice during their exploration for potential partners. Such services collect data about the candidates, and base their advice for each pair of trips to be combined, on an estimate of the probability for successful negotiation between the candidates to carpool. The probability values are calculated by a learning mechanism using, on one hand, the registered person and trip characteristics, and on the other hand, the negotiation feedback. The problem of maximizing the expected value of carpooling negotiation success was formulated and was proved to be NP-hard. In addition, the network characteristics for a realistic case have been analyzed. The carpooling network was established using results predicted by the operational FEATHERS activity based model for Flanders (Belgium).
    Journal of Computer and System Sciences 11/2014;
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    ABSTRACT: Accurate peak power evaluation of query processing is fundamental to a power-aware DBMS running in large data centers. To estimate the peak power of the core operator join in query processing, the concept of CPU-boundedness was introduced, i.e., the ratio of CPU-intensive operations in unit time. The power prediction models were constructed with the piecewise and continuous fitting methods; and the multivariate model was further developed by incorporating both CPU-boundedness and CPU-frequency into the model via surface fitting. A non-runtime peak power estimation method is proposed for four most commonly used join algorithms in DBMS. To the best of our knowledge, our work is the first attempt towards modeling and estimating the peak power of query processing. Extensive experiments have demonstrated the effectiveness of our proposed methods with acceptable mean relative errors.
    Journal of Computer and System Sciences 11/2014;
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    ABSTRACT: Electoral control models ways of changing the outcome of an election via such actions as adding, deleting, or partitioning either candidates or voters. To protect elections from such control attempts, computational complexity has been used to establish so-called resistance results. We show that fallback voting, an election system proposed by Brams and Sanver [12] to combine Bucklin with approval voting, displays the broadest control resistance currently known to hold among natural election systems with a polynomial-time winner problem. We also study the control complexity of Bucklin voting and show that it performs almost as well as fallback voting in terms of control resistance. Furthermore, we investigate the parameterized control complexity of Bucklin and fallback voting, according to several parameters that are often likely to be small for typical instances. In a companion paper [28], we challenge our worst-case complexity results from an experimental point of view.
    Journal of Computer and System Sciences 11/2014;
  • Journal of Computer and System Sciences 11/2014;
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    ABSTRACT: The aim of a routing protocol is to compute routes between every couple of nodes. When the topology evolves over time, routing decisions should be constantly reconsidered to ensure continuous valid routing. Conventional proactive routing protocols periodically re-compute their routing-tables. However, due to their inherent nature based on shortest-paths, they select longer links (victims of rapid breakages as nodes move). Increasing the updates' frequency certainly allows a better tracking of the topology changes; however, it induces higher signaling overhead. An adequate trade-off between the period size and the control overhead should be found. In this paper, we propose a new mechanism that keeps sensing the mobility-level to properly-adjust the routing period size. It relies on a distributed algorithm collecting the network cartography to self-regulate the routing period size. Simulation results show that our proposal (SARP) correctly tracks topology changes and properly adjusts the current period size leading to better performances.
    Journal of Computer and System Sciences 11/2014;
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    ABSTRACT: Interactive tables are more frequently being suggested to support collaborative and co-localized applications. They can be tactile, tangible or mixed. New sensory entries enable users to manipulate different types of tangible objects. The purpose of this article is to propose a global interaction model that associates multiagent system concepts with interactive table entities. The model incorporates simultaneously usable entities: virtual and tangible entities. The virtual entities can be seen through video projection or the use of a screen integrated into the interactive table. The tangible entities are physical objects that can be manipulated by one or more users around the table. These objects are detected through dedicated sensors. A case study illustrates the proposal. The study incorporates the management of a road traffic simulator using the TangiSense interactive table; this table is equipped with RFID technology. The illustrations mainly show communication between the different agents involved in the simulation.
    Journal of Computer and System Sciences 11/2014;
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    ABSTRACT: Wireless Sensor Network (WSN) enables pervasive, ubiquitous, and seamless communication with the physical world. This paper investigates an optimal cross-layer optimization for WSN with periodic application. A joint energy efficient routing with minimum delay scheduling optimization model is proposed in this paper. The problem is formulated as an Integer Linear Program (ILP) model. The proposed ILP model has multi objectives cost function. The main objective of the proposed model is to maximize network lifetime and to minimize delay. The proposed ILP model represents the operation of Energy-Efficient Distributed Schedule-Based (EEDS) protocol. The ILP model is solved for different network configurations. The solution obtained by solving the proposed ILP model is compared with EEDS simulation results. Although the two solutions show similar behavior, the ILP solution outperforms the solution obtained by EEDS simulation by 28.3%. Moreover, the optimal solutions assuming different objectives are compared together.
    Journal of Computer and System Sciences 11/2014;
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    ABSTRACT: This paper addresses the issue of autonomous fair signature exchange in emerging ubiquitous (u-) commerce systems, which require that the exchange task be delegated to authorised devices for its autonomous and secure execution. Relevant existing work is either inefficient or ineffective in dealing with such delegated exchange. To rectify this situation, this paper aims to propose an effective, efficient and secure solution to the delegated exchange to support the important autonomy feature offered by u-commerce systems. The proposed work includes a novel approach to symmetric-key based verifiable proxy encryption to make the exchange delegation flexible, efficient and simple to implement on resource-limited devices commonly used in u-commerce systems. This approach is then applied to design a new exchange protocol. An analysis of the protocol is also provided to confirm its security and fairness. Moreover, a comparison with related work is presented to demonstrate its much better efficiency and simplicity.
    Journal of Computer and System Sciences 11/2014;
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    ABSTRACT: Minimum Fill-in is a fundamental and classical problem arising in sparse matrix computations. In terms of graphs it can be formulated as a problem of finding a triangulation of a given graph with the minimum number of edges. In this paper, we study the parameterized complexity of local search for the Minimum Fill-in problem in the following form: Given a triangulation H of a graph G , is there a better triangulation, i.e. triangulation with less edges than H , within a given distance from H ? We prove that this problem is fixed-parameter tractable (FPT) being parameterized by the distance from the initial triangulation, by providing an algorithm that in time f(k)|G|O(1)f(k)|G|O(1) decides if a better triangulation of G can be obtained by swapping at most k edges of H. Our result adds Minimum Fill-in to the list of very few problems for which local search is known to be FPT.
    Journal of Computer and System Sciences 11/2014;
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    ABSTRACT: We show how to represent recursively enumerable sets of matrices by products of matrices.•We give a version of Rice's theorem for products of matrices.•The proof is based on the Diophantine representation of recursively enumerable sets.
    Journal of Computer and System Sciences 11/2014;