Supporting various top-k queries over uncertain datasets

There have been many researches and semantics in answering top-k queries on uncertain data in various applications. However, most of these semantics must consume much of their time in computing position probability. Our approach to support various top-k queries is based on position probability distribution （PPD） sharing. In this paper, a PPD-tree structure and several basic operations on it are proposed to support various top-k queries. In addition, we proposed an approximation method to improve the efficiency of PPD generation. We also verify the effectiveness and efficiency of our approach by both theoretical analysis and experiments.     

Power law and small world properties in a comparison of traffic city networks

We analyze the statistical properties of the urban public bus networks of two cities (Beijing and Chengdu) in China. To this end, we present a comprehensive survey of the degree distribution, average path length, and clustering of both networks. It is shown that both networks exhibit small world behavior and are hierarchically organized. We also discuss the differences between the statistical properties displayed by the two networks. In addition, we propose a weight distribution approach to study the passenger flow through the public bus networks we considered. A hierarchical structure is observed here also.     

Power law and small world properties in a comparison of traffic city networks

We analyze the statistical properties of the urban public bus networks of two cities (Beijing and Chengdu) in China. To this end, we present a comprehensive survey of the degree distribution, average path length, and clustering of both networks. It is shown that both networks exhibit small world behavior and are hierarchically organized. We also discuss the differences between the statistical properties displayed by the two networks. In addition, we propose a weight distribution approach to study ...     

一个面向服务的教学计划框架体系

The science of services constitutes a breakthrough in the traditional way of thinking of the place of informatics in the economic development of a State,a Region,an enterprise and consequently in the teaching programs.The question is no more only a question of computer science.We are in front of a more complex situation,which requires not only a multidisciplinary approach,but an interoperable approach at the intellectual level.This paper is an introduction to this complexity and it is also an attempt to propose crucial questions about the new bachelor programs and master programs.     

Implementing Operating System Support for Extended Trusted Path in TPM-Capable Environments

Trusted path is one of the crucial features that operating systems must provide for fundamental security support. In order to explore the possibility of implementing a trusted path mechanism with the support of trusted platform module （TPM） technologies, and to support TPM capabilities in operating systems, the paper extended the scope of the conventional trusted path to cover the situation in which a user communicates with software residing on a remote host. The paper combined the concept of operating system support for trusted path with that for TPM platforms, and proposed the architecture of an extended trusted path mechanism in operating system with considerations on TPM-capable platforms support. As part of the author＇s research in secure operating systems, the work of the paper was carried out with Linux as an experimental prototype system. The research result shows that TPM capabilities can strengthen extended trusted path mechanisms of operating systems.     

A Peer-to-Peer resource sharing scheme using trusted computing technology

Facing the increasing security issues in P2P networks, a scheme for resource sharing using trusted computing technologies is proposed in this paper. We advance a RS-UCON model with decision continuity and attribute mutability to control the usage process and an architecture to illustrate how TC technologies support policy enforcement with bidirectional attestation. The properties required for attestation should include not only integrity measurement value of platform and related application, but also reputation of users and access history, in order to avoid the limitation of the existing approaches. To make a permission, it is required to evaluate both the authorization and conditions of the subject and the object in resource usage to ensure trustable resources to be transferred to trusted users and platform.     

A shortest path algorithm for moving objects in spatial network databases

One of the most important kinds of queries in Spatial Network Databases （SNDB） to support location-based services （LBS） is the shortest path query. Given an object in a network, e.g. a location of a car on a road network, and a set of objects of interests, e.g. hotels, gas station, and car, the shortest path query returns the shortest path from the query object to interested objects. The studies of shortest path query have two kinds of ways, online processing and preprocessing. The studies of preprocessing suppose that the interest objects are static. This paper proposes a shortest path algorithm with a set of index structures to support the situation of moving objects. This algorithm can transform a dynamic problem to a static problem. In this paper we focus on road networks. However, our algorithms do not use any domain specific information, and therefore can be applied to any network, This algorithm＇s complexity is O（klog2i）, and traditional Diikstra＇s comolexitv is O（（i ＋ k）^2）.     

Context-aware recommendation in mobile environments: An approach based on interest resonance

The recommendation system can efficiently solve the information overload in mobile Internet. Thus, how to effectively utilize context information to improve the accuracy of recommendation becomes the research focus in the field. This article puts forward a novel approach to realize the context-aware recommendation in mobile environments. It first gets users’ interest resonance with a hash-based interest resonance mining algorithm. Then, it calculates the association degree between the user and the item and then predicts the user’s rating on the item. Finally, it comprehensively figures out the recommending index. Moreover, this article also designs a personal recommendation model for the users and provides relevant decision-making coefficients. Experiments have demonstrated that our approach is superior to the traditional ones (RMP, RSTE, MD and BBBs) in both performance and efficiency.     

Web database sampling approach based on attribute correlation

In this paper,we present a novel approach utilizing attributes correlation for the sampling task on nonuniform hidden databases. We propose the method of calculating the attributes dependency and construct the sampling template according to the attributes dependency. Then,we use the sampling template to gen-erate initial sampling queries and propose a bottom-up algorithm to search the sampling template. We also conduct extensive ex-periments over real deep Web sites and controlled databases to illustrate that our sampling method has good performance both on the quality and efficiency.     

Analysis of the Role and Technique of Feedback in the Development of Students’Writing Skills

Feedback on writing can be defined as comments, corrections, questions and suggestions, that a reader gives to a writer with the aim to steer him through the process of writing on to the product, according to Keh (1990:294). This paper discusses the role of feedback in a process-focused approach to writing. The use of both peer feedback and teacher feedback could improve students’writing skills effectively in the long run. This paper also looks at the different techniques that a teacher can use in the writing classroom.     

Pedigree transmission disequilibrium test for quantitative traits in farm animals

General pedigrees are very common in farm animals,and the recent availability of large panels of SNPs in domestic species has given new momentum to the search for the mutations underlying variation in quantitative traits.In this paper,we proposed a new transmission disequilibrium test approach,called the pedigree transmission disequilibrium test,which deals with general pedigrees and quantitative traits in farm animals.Compared with the existing pedigree disequilibrium test (PDT) and general linear model-based method QTDT,our approach performed better with higher power and lower type I error,especially in scenarios where the quantitative trait locus (QTL) effect was small.We also investigated the application of our approach in selective genotyping design.Our simulation studies indicated that it was plausible to implement a selective genotyping strategy in the proposed pedigree transmission disequilibrium test.We found that our approach performed equally well or better when only some proportion of the individuals in the two tails were genotyped compared with its performance when all the individuals in the pedigree were genotyped.     

A Method of Characterizing Radio Signal Space for Wireless Device Localization

In this work we present a novel approach for describing radio signal spaces for localization algorithms.We first introduce a new metric, the Discretely Distributed Log-H ¨older Metric(DDLHM). The DDLHM is designed to characterize the type and degree of signal distortion relative to lognormal signal-to-distance path models. We first show how the DDLHM can describe and discriminate distortions in an exhaustive set of synthetic signal spaces.We then determine a reduced set of maximally diagnostic distortion parameters. Using only 4% of the maximal set of DDLHMs, we found the reduced set matches with an acceptable degree of error 95% of the time. Using the synthetic reduced set, we characterized a variety of wireless localization algorithms' behaviors to attenuation, bias,and multipath. We found algorithms made much different tradeoffs between best case and average case error. We then use the DDLHM to identify distortion types in three different physical environments using measured 802.11 signal strengths, and predict the positioning performance of several localization algorithms. Our approach predicts average localization error to within 2 meters of the observed average error.     

Distributed Dynamic Navigation for Sensor Networks

Navigation with sensor networks has shown many advantages and great potential in many scenarios.Previous works have mainly focused on selecting the shortest path to navigate an internal user out of an emergency field.However,they did not consider variations of the dangerous areas which usually occur in practical applications.This paper presents an efficient dynamic routing algorithm to successfully guide users to the destination exit.The navigation goal is looking for a safe and short path to enable the user to escape from a dangerous area as fast as possible.Without knowing the locations of the nodes,the user is guided by a sequence of sensor nodes to pass through the dangerous areas.The algorithm ensures the navigation path security by predicting the dynamic changes affecting the navigation path.The performance of this approach is evaluated using extensive simulations to validate its effectiveness.Simulations show that the approach is scalable and performs well in various settings.     

A New Framework for Focused Web Crawling

Focused crawlers are important tools to support applications such as specialized Web portals, online searching, and Web search engines. A topic driven crawler chooses the best URLs and relevant pages to pursue during Web crawling. It is difficult to deal with irrelevant pages. This paper presents a novel focused crawler framework. In our focused crawler, we propose a method to overcome some of the limitations of dealing with the irrelevant pages. We also introduce the implementation of our focused crawler and present some important metrics and an evaluation function for ranking pages relevance. The experimental result shows that our crawler can obtain more ＂important＂ pages and has a high precision and recall value.     

SELF-LEARNING FUZZY CONTROL RULES USING GENETIC ALGORITHMS

This papcr presents a new genetic algorithms(GAs)-based method for self-learniag fuzzy control rules. An improved GA is used to learn to optimally select the fuzzy membership functions of the linguistic labels in the condition portion of each rule, and to automatically generate fuzzy control actions under each condition. The dynamics of the controlled system is unknown to the GA. The only information for evaluating performance is a failure signal indicating that the controlled system is out of control. We compare its performance with that of other learning methods for the same problem. We also examine the ability of the algorithm to adapt to changing conditions. Simulation results show that such an approach for self-learning fuzzy control rules is both effective and robust.     

Summarization based on physical features and logical structure of multi documents

With the rapid development of the Internet, multi documents summarization is becoming a very hot research topic. In order to generate a summarization that can effectively characterize the original information from documents, this paper proposes a multi documents summarization approach based on the physical features and logical structure of the document set. This method firstly clusters similar sentences iuto several Logical Topics (LTs), and then orders these topics according to their physical features of multi documents. After that, sentences used for the summarization are extracted from these LTs, and fiually the summarization is generated via certain sorting algoritluns. Our experiments show that the information coverage rate of our method is 8.83 % higher than those methods based solely on logical structures, and 14.31% higher than Top-N method.     

Spatial-temporal spectrum hole discovery: a hybrid spectrum sensing and geolocation database framework

A hybrid spectrum sensing and geolocation database framework is proposed to tackle the discovery of spatial-temporal spectrum hole in cognitive radio networks. We first analyze the advantages and disadvantages of spectrum sensing-based and geolocation database-based approaches respectively, which motivate us to further propose a hybrid protocol framework by effectively inte-grating the benefits of both spectrum sensing and geolo-cation database. Specifically, in the proposed hybrid approach, the goal is to maximize the utilization of spatial-temporal spectrum hole while satisfying the protection constraints for the primary users. Analytical and numerical results demonstrate the superior performance of the pro-posed hybrid approach over the existing spectrum sensing only and geolocation database only approaches, in terms of interference-free throughput. This article serves as a fun-damental framework for advancing the design of hybrid approaches for spatial-temporal spectrum hole discovery.     

Data Hiding and Security for XML Database： A TRBAC-Based Approach

In order to cope with varying protection granularity levels of XML (eXtensible Markup Language) documents, we propose a TXAC (Two-level XML Access Control) framework, in which an extended TRBAC (Temporal Role-Based Access Control) approach is proposed to deal with the dynamic XML data. With different system components,TXAC algorithm evaluates access requests efficiently by appropriate access control policy in dynamic web environment. The method is a flexible and powerful security system offering a multi-level access control solution.     

Molecular ecology studies of marine Synechococcus

Cyanobacteria of the genus Synechococcus is a dominant component of microbial community in the world's oceans, and is a major contributor to marine primary productivity and thus plays an important role in carbon cycling in the oceans. Besides the ecological importance, the cultivability also made Synechococcus a very special group of marine microorganisms, which has attracted great attention from oceanographers and biologists. Great progress in the physiology, biochemistry and phylogeny of Synechococcus has been made since its discovery. We here review the current status of molecular ecology of marine Synechococcus and give a perspective into the future based on our understanding of the literature and our own work.