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Method of drifting user's interests based on hybrid model

Jisuanji Gongcheng/computer engineering 2006年第1期32卷 4-6+89页

作者： Song, Lizhe Niu, Zhendong Yu, Zhengtao Song, Hantao Dong, Xiangjun Department of Computer Science and Engineering Beijing Institute of Technology Beijing 100081 China School of Software Engineering Beijing Institute of Technology Beijing 100081 China National Library Digital Technology Corp. Ltd. Beijing 100083 China

This paper aims at the problem of combination of user's interests and previous interests. It proposes a hybrid model based on concept correlations. In this hybrid model, user's interests consist of long-term model and short-term model, and these two models adopt different algorithms to deal with the interest's changes. Short-term model uses sliding window algorithm to deal with the sequence of the user's interest samples. Long-term model uses gradual forgetting algorithm based on concepts correlations to calculate the interests' weight. Experiment shows that this method is more efficient;it can not only trace the interest change of the user exactly, but also predict the interest of the users.

关键词： Concept correlations Concept drift Gradual forgetting Sliding window

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Classification of brain glioma by using SVMs bagging with feature selection

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PAKDD 2006 Workshop on Data Mining for Biomedical Applications, BioDM 2006

作者： Li, Guo-Zheng Liu, Tian-Yu Cheng, Victor S. State Key Laboratory for Novel Software Technology Nanjing University Nanjing 210093 China School of Computer Engineering and Science Shanghai University Shanghai 200072 China Institute of Biomedical Instrument Shanghai Jiao Tong University Shanghai 200030 China

ISBN: (纸本)3540331042

The degree of malignancy in brain glioma needs to be assessed by MRI findings and clinical data before operations. There have been previous attempts to solve this problem by using fuzzy max-min neural networks and support vector machines (SVMs), while in this paper, a novel algorithm named PRIFEB is proposed by combining bagging of SVMs with embedded feature selection for its individuals. PRIFEB is compared with the general case of bagging on UCI data sets, experimental results show PRIFEB can obtain better performance than the general case of bagging. Then, PRIFEB is used to predict the degree of malignancy in brain glioma, computation results show that PRIFEB obtains better accuracy than other several methods like bagging of SVMs and single SVMs does. © Springer-Verlag Berlin Heidelberg 2006.

关键词： Diseases

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An Efficient Secure Real-Time Concurrency Control Protocol

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Wuhan University Journal of Natural Sciences 2006年第6期11卷 1899-1902页

作者： XIAO Yingyuan LIU Yunsheng CHEN Xiangyang Department of Computer Science and Engineering Tianjin University of Technology Tianjin 300191 China School of Software Huazhong University of Science and Technology Wuhan 430074 Hubei China School of Computer Science and Engineering Wuhan Institute of Technology Wuhan 430073 Hubei China

Secure real-time databases must simultaneously satisfy two requirements in guaranteeing data security and minimizing the missing deadlines ratio of transactions. However, these two requirements can conflict with each other and achieve one requirement is to sacrifice the other. This paper presents a secure real-time concurrency control protocol based on optimistic method. The concurrency control protocol incorporates security constraints in a real-time optimistic concurrency control protocol and makes a suitable tradeoff between security and real-time requirements by introducing secure influence factor and real-time influence factor. The experimental results show the concurrency control protocol achieves data security without degrading real-time perform ance significantly.

关键词： real-time databases concurrency control security covert channel

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Eliciting better quality architecture evaluation scenarios: A controlled experiment on top-down vs. bottom-up

Eliciting better quality architecture evaluation scenarios: ...

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ISCE'06 - 5th ACM-IEEE International Symposium on Empirical software engineering

作者： Babar, Muhammed Ali Biffl, Stefan National ICT Australia Ltd. Sydney NSW 1466 Australia School of Computer Science and Engineering University of New South Wales Sydney NSW 2052 Australia Institute for Software Technology and Interactive Systems Vienna Technical University Austria

ISBN: (纸本)1595932186

Scenarios are extensively used in software architecture evaluation. These scenarios are elicited from stakeholders using either a topdown or bottom-up approach. The former approach uses categorization schemes to focus stakeholders on developing scenarios for each required category. The latter approach uses brainstorming without any explicit categories of scenarios. It is claimed that top-down approach can result in improved quality of scenarios. However, there has been no empirical evidence on the relative effectiveness of the scenario elicitation techniques. In this paper we report on a controlled experiment with 24 subjects (postgraduate and final year undergraduate students with industry experience) in an academic context with the goal to assess the relative effectiveness of the two scenario elicitation approaches. Two groups developed scenarios to characterize quality attributes: the treatment group was given software change categories, the control group was not. The outcome variable was the quality of the scenarios produced by each participant. The average quality score for individual scenario profiles in the treatment group was significantly greater than the control group. All participants using the change categories reported that the knowledge of change categories helped them develop better quality scenarios. Our results support the claim that the provision of domainspecific software change categories helps generate better quality scenarios. Copyright 2006 ACM.

关键词： software architecture

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Evaluation Models for the Effect of Sample Imbalance on Gene Selection

Evaluation Models for the Effect of Sample Imbalance on Gene...

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International Multi-Symposiums on computer and Computational Sciences (IMSCCS)

作者： Kun Yang Jianzhong Li Chaokun Wang Hong Gao Department of Computer Science and Engineering Harbin Institute of Technology Harbin China School of Software Tsinghua University Beijing China

In this paper, we considered the problem of sample imbalance in the context of gene selection. Based on simple random sampling, two evaluation models were proposed to investigate the effect of sample imbalance on gene selection. Under the proposed evaluation models, the performances of five famous gene selection methods on the unbalanced data were compared. The experimental results indicated that the proposed evaluation models are effective and the sample imbalance has a great influence on gene selection. Our findings provide some guidelines in the design of microarray experiments and the following data analysis, and two evaluation models are suitable for selecting feasible gene selection method to identify differential expression genes

关键词： Sampling methods Gene expression Chaos Data analysis Cancer Statistical analysis computer science Performance evaluation Guidelines Biological system modeling

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New approach to complexity reduction of intra prediction in advanced multimedia compression

New approach to complexity reduction of intra prediction in ...

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ICCSA 2006: International Conference on Computational Science and Its Applications

作者： Yu, Mei Jiang, Gangyi Li, Shiping Li, Fucui Choi, Tae-Young Faculty of Information Science and Engineering Ningbo University Ningbo 315211 China State Key Lab. for Novel Software Technology Nanjing University Nanjing 210093 China Institute of Computer Technology Graduate School Chinese Academy of Sciences Beijing 100871 China Division of Electronics Engineering Ajou University Suwon 442-749 Korea Republic of

ISBN: (纸本)354034070X

H.264 is the new multimedia compression standard developed by VCEG and MPEG. In order to maximize the compression performance, H.264 adopts RDO mode decision techniques at the cost of very remarkable computational complexity. To reduce encoder complexity associated with the intra-prediction mode selection, in this paper, a fast intra prediction mode selection scheme is proposed. It is based on three improvement parts, including improvement of the intra prediction algorithm structure, fast selection between intra 4×4 block mode and intra 16×16 block mode, and the fast 4×4 luma block mode selection based on the luma similarity between reference pixels. Experimental results show that the proposed scheme outperforms Pan's method, and compared with the test model JM8.6 provided by JVT, the proposed scheme reduces 83.10% coding time for intra frames and 50.94% coding time for all the frames while maintaining the PSNR and bit rate. © Springer-Verlag Berlin Heidelberg 2006.

关键词： Large scale systems

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On Control Gain Selection in PI-RED

On Control Gain Selection in PI-RED

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IEEE International Conference on Networking, Sensing and Control

作者： Naixue Xiong X. Defago Yan Yang Yanxiang He Jing He Key Laboratory of Software Engineering Computer School of Wuhan University China School of Information Science Institute of Science and Technology Japan School of Computer Science and Technology Wuhan University of Science and Technology Hubei China State Key Laboratory of Software Engineering Computer School Wuhan University of China Hubei China Department of Computer Science Utah State University Logan UT USA

Active queue management (AQM) is an effective method used in Internet routers to enhance congestion control, and to achieve a trade off between link utilization and delay. The de facto standard, the random early detection (RED) AQM scheme, and most of its variants use queue length as a congestion indicator to trigger packet dropping. Random early detection (RED) is a widely studied active queue management (AQM) scheme implemented in routers for Internet congestion control. Although certain stability conditions for various RED controllers are discussed, no efficient method for dynamically adapting control gains or result on control gain optimization has been proposed so far. Therefore based on control theory, this paper proposes proportional and integral RED (PI-RED) algorithm, that not only considers the average queue length at the current time slot, but also takes into consideration the past average queue lengths within a round trip time. We provide guidelines for the selection of the feedback gains (the proportional parameter and the integral parameter) for TCP/RED system to stabilize the dynamics, make the congested queue converge at a certain target and hence to improve network performance. Simulations demonstrate that indeed satisfactory performance can be achieved if the control gains are selected based on the guidelines. Based on the stability condition and control gains selection method, extensive simulations with ns2 demonstrate that indeed satisfactory performance can be achieved in terms of robustness, drop probability and stability if the control gains are selected based on the guidelines

关键词： Performance gain Guidelines Robust stability Internet Queueing analysis Delay effects Optimization methods Control theory Feedback Robust control

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On the quality of service of failure detectors based on control theory

On the quality of service of failure detectors based on cont...

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International Conference on Advanced Information Networking and Applications (AINA)

作者： N. Xiong Yan Yang Jianxun Chen Yanxiang He The State Key Lab of Software Engineering Computer School of Wuhan University China Japan Advanced Institute of Science and Technology School of Information Science Japan Computer Science and Technology School Wuhan University of Science and Technology China

The detection of failures is a fundamental issue for fault tolerance in distributed systems. Recently, many people have come to realize that failure detection ought to be provided as some form of generic service, similar to IP address lookup. However, this has not been successful so far; one of the reasons being the fact that classical failure detectors were not designed to satisfy several application requirements simultaneously. More specifically, traditional implementations of failure detectors are often tuned for running over local networks and fail to address some important problems found in wide-area distributed systems with a large number of monitored components. In this paper, we study the quality of service (QoS) of failure detectors. We first present a novel failure detector scheme combined with control theory that can help in solving or optimizing some problems. Furthermore, this paper discusses the design and analysis of implementing a scalable failure detection service for such large wide-area distributed systems considering dynamically adjusting the heartbeat streams, so that it satisfies the bottleneck router requirements. We further show how the online failure detector control algorithm can be used to design a controller, analyze the theoretical aspects of the proposed algorithm and verify its agreement. Simulation results show the efficiency of our scheme in terms of high utilization of the bottleneck link, fast response and good stability of the bottleneck router buffer occupancy as well as of the controlled sending rates. In conclusion, the new failure detector algorithm provides a better QoS.

关键词： Quality of service Detectors Control theory Failure analysis Algorithm design and analysis Fault detection Fault tolerant systems Condition monitoring Heart beat Stability

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Hybrid context modeling: a location-based scheme using ontologies

Hybrid context modeling: a location-based scheme using ontol...

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IEEE Annual Conference on Pervasive Computing and Communications Workshops (PerCom)

作者： I. Roussaki M. Strimpakou N. Kalatzis M. Anagnostou C. Pils School of Electrical & Computer Engineering National and Technical University of Athens Greece Telecommunications Software & Systems Group Waterford Institute of Technology Ireland

Context awareness is an inherent feature of pervasive computing. It enhances the proactiveness of the system thus requiring less user attention and fewer human-machine interactions, it supports intelligent personalization features, and it can assist the system to address the user requirements considering the current conditions. Nevertheless, in such environments, various types of context information are involved and need to be efficiently managed and maintained, soundly interpreted, rapidly processed, and securely disseminated by the system. Thus, an interoperable and flexible context representation scheme is necessary that will support efficient context interpretation and reasoning and will perform well in distributed large-scale context-aware systems. This paper is concerned with the development of a hybrid context representation scheme that aims to combine the maintenance, distribution and administrative facilities of a location-based context model and the semantic advantages of context ontologies

关键词： Context modeling Ontologies Pervasive computing Context awareness Information management Telecommunication computing software systems Man machine systems Environmental management Large-scale systems

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Privacy-Aware Modelling and Distribution of Context Information in Pervasive Service Provision

Privacy-Aware Modelling and Distribution of Context Informat...

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IEEE/ACS International Conference on Pervasive Services (ICPS)

作者： Roussaki Strimpakou Pils Kalatzis Neubauer Hauser Anagnostou School of Electrical and Computer Engineering National and Technical University of Athens Greece Telecommunications Software & Systems Group Waterford Institute of Technology Ireland Institute of Communication Networks and Computer Engineering (IKR) University of Stuttgart Germany

Context awareness is an essential cornerstone in future pervasive computing systems. It has the potential to greatly reduce the user attention and interaction bottlenecks, to give humans the impression that services fade into the background, and to support intelligent personalization features. Nevertheless, in order to create such an environment, a growing amount of personal information has to be provided to the system, either manually or automatically. Hence the digital trace and representation users have in the system is getting dangerously detailed, thus stressing the need for privacy protection. DAIDALOS (Satyanarayanan, 2001) is a European research project in the area of 3G and beyond, which aims to combine heterogeneous networks in a transparent and seamless way, and develop on top of this a pervasive environment for applications and end-users. This paper describes the main models and mechanisms that have been established to provide federated context-aware services and protect the privacy of their users

关键词： Context modeling Context-aware services Pervasive computing Telecommunication computing Context awareness Privacy computer networks Protection Communication system software software systems

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