bluuebunny/crossref_metadata_2025 huggingface dataset:
SVM Based Classification Mapping for User Navigation
Authors: Yuan Jing-Ling , Yu Yang , Xiao Xuan , Li Xiao-Yan
Published: January 2009

In order to implement active service, a kind of user navigation based on Support Vector Machine (SVM) classification was proposed which solved many traditional problems such as lack of rules and adaptability and so on. Especially, this paper completed a dual classified coordination between user attribute classification and SVM user classification using mapping matrix.

In our SVM based user navigation, we first regard User interest Set as input, then apply the SVM classifier to sort out users on the basis of their interests or attributes, and what is more, combine the merit that user attributes classification promise better service being offered to users whose using frequency is not high, a dual-classified collaborating navigation between user attribute classification, and SVM user classification by using mapping matrix is being proposed.

We use the mapping method to mix their advantages of common classification methods which lead them to collaborate and to provide the new and old custom with navigation. Using Classification T to statistic the latest and the most frequently used demands of each user type, then applying a mapping from user attribute class (A) to user interest class (T) with the purpose to judge what kind of user type in Classification T has the most possibility the user might belong, to and then to provide the user with the latest services according to their interests. From the experiments, the fitting degree of A and T classification and the true personality of users are derived by tracking the demand of 50 users. We can see that with the increase of frequency in use, the matching degree between Users Attribute Classification (A) and real types of user are essentially the same, and User Personalized Classification (T) is gradually reaching saturation. Regarding the certain point as a dividing line, after using classification mapping, the user's true extent of matching has a broader applicability.

SVM have excellent generalization performance and minimum structural risk, which is a good machine learning method that elicits objective regulation from complex statistical dates. So we have improved the user model of active service navigation system and user navigation combined with User Attribute Classification A and SVM User Interest Classification T by mapping matrix. Classification A and T using mapping matrix to bounding them can satisfy the requirement of a different user. The records in the Classified Statistic Library can provide feedback date and research information for further study between a personalized user and user attribute.
Routing Algorithms Based on Partial Deployment of SAVA Nodes in Trustworthy Internet
Authors: Guo Lei , Wang Xingwei , Wang Dong , Hou Weigang
Published: January 2009

Although the fundamental principles of best-effort and destination address based packet forwarding in today's Internet have brought tremendous convenience, the trustworthy issue in Internet is a hot problem since the lack of source IP address checking in most cases makes it easy for the attackers to spoof the source address. Therefore, one challenge in trustworthy Internet is to build a feasible mechanism to verify the source address. Recently, a feasible mechanism called Source Address Validation Architecture (SAVA) has been proposed to specify standardization of methods for building effective source-address validation to ensure that packets forwarded hold authentic source addresses. In SAVA mechanism, if a packet has been recognized as a spoofed source address, it will be dropped by the SAVA router and not be transmitted to the next hop. In our work, we study the routing algorithms based on partial deployment of SAVA nodes in Internet and propose three kinds of routing algorithms, i.e., Shortest-Path Algorithm (SPA), SAVA based Shortest-Path Algorithm (SSPA), and SAVA based Shortest-Path Algorithm with Load Balancing (SSPALB). To the best of our best knowledge, this is the first investigation for SAVA mechanism from the point of routing method. In SPA, the packet will be routed on the shortest path that may not traverse the SAVA node, and then the SAVA requirement may not be ensured. In SSPA, the packet will be routed on the shortest path that must traverse one SAVA node such that the SAVA requirement can be ensured. In SSPALB, the packet will be routed on the shortest path that must traverse one SAVA node at the same time this SAVA node must be the least-load such that the SAVA requirement can be ensured and the load can be more balancing. We simulate an incremental traffic model for the three kinds of routing algorithms to compare the performances of SAVA Satisfactory Degree (SSD) and Load Balancing (LB). Simulation results show that: the SSDs of SSPA and SSPALB can reach 100% while the SSD of SPA is only 20%-30%, which means that SSPA and SSPALB are completely satisfactory for SAVA requirements but SPA cannot; the LB of SSPALB can reach 100% while the LBs of SPA and SSPA are only 70%-80%, which means that SSPALB is more favorable for the load balancing.
A New Replica Placement Algorithm for Improving the Performance in CDNs
Authors: Zhang Lei , Tian Hui , Steglich Stephan
Published: January 2009

With the advent of services and applications over the Internet, speed and reliability have become critical issues for clients, and the Internet currently is not well suited for the purpose of the emerging new service delivery contemplated by today's applications. In response to these challenges, commercial Content Distribution Network (CDN) deploys a set of proxy servers called replicas and improves the content delivery performance by replicating the content to multiple replicas in the Internet.

These issues motivate us to do research in how to efficiently place replicas in the network, and then propose a cost-based replica placement algorithm which selects replica locations using a greedy fashion iteratively. We evaluated that it can yield close to optimal performance at low management and computation cost among several replica placement strategies.

The key contributions of this paper are threefold: A practical cost function from the game theoretic perspective is designed, and is limited by various parameters and constraints. It can minimize either its clients' latency or its total bandwidth consumption. A cost-based replica placement integrating a greedy algorithm is proposed, which can provide CDNs with the performance close to optimal. The performance of the diversified replica placement algorithms is evaluated by simulating their behavior on synthetic and real network topologies. To the best of our knowledge, there are few studies on this subject.

In summary, we study the online problem of placing web replicas in CDNs to minimize the cost for clients to access data replicated from the original web servers. The novel cost-based replica placement is designed combining with the minimum k-median heuristic greedy algorithm. We evaluate the performance of the different replica placement algorithms by simulating their behavior on both synthetic and real network topologies. Based upon simulation results, we conclude that our cost-based greedy algorithm for web server replica placement can provide CDNs with performance that is close to optimal. Although the greedy algorithm depends upon estimation, we find it is a viable and practical algorithm to use in the general Internet environment. As for future work, we are interested in exploring incremental versions of the placement algorithms that also take into account the cost of changing the set of replica sites. Ideally, for placement strategies with similar performance, we prefer the one that incurs the least amount of perturbation to the system.
Research on the Algorithms for Registration in Sensor Network for Target Tracking
Authors: Wu Ling , Lu Fa-Xing
Published: January 2009

To gain benefit from netted sensors, it is essential to correctly integrate each sensor into a global frame of reference. The process is termed sensor registration. It involves minimizing the effects of the errors from the imprecisely known relative positions or orientations of the various sensors, the biased sensor measurements, the offset sensor clocks, and so on. In the paper, a model of a typical sensor registration problem in a 2-sensor scenario is presented for illustration. Four kinds of registration errors, i.e., calibration errors (offsets), attitude (orientation) errors, position errors, and timing errors are mainly discussed in literatures, and literatures are categorized in the paper by its purpose that which one of the four kinds of errors, or which combination of the decoupled errors among them is aimed to solve. The registration errors can be viewed as constant and they can also vary or drift slowly. To address them, different kinds of algorithms have been developed. The algorithms for sensor registration can be divided into three types referred to as Type 1, Type 2, and Type 3 respectively. Algorithms of Type 1, mainly including batch processing methods and meta-heuristic optimization ones, are applied to cases that the registration errors are constant over time. Algorithms of Type 2 provide online estimation of sensor biases, but it is decoupled from the target estimation. The assumption for constant errors is relaxed, and the approaches are extended to cope with both constant and varying errors. The algorithms of Type 3 attempt to simultaneously solve for target variables and sensor systematic biases, and most of them achieve this via augmented state Kalman filter with the augmented state vector combining the target states and sensor uncertainty. References are accordingly organized by type, discussed, and annotated. Related issues of sensor registration are concerned including the non-unique detection probability, the asynchronous sensor measurements, the observability of registration problem, the relative registration and absolute registration, and the performance bounds of the estimator of the registration errors. The developed techniques for solving the problems are summarized respectively. The paper is concluded with a brief summary and some thoughts on the future trends and research directions.
A Novel Group Management Protocol for IP Multicast (LW-IGMPv3)
Authors: Jiwen Liu , Wendong Wang , Xiangyang Gong , Hui Liu , Wei Cao , Xuesong Gao
Published: January 2009

With the deployment of multicast service, people gradually find that hardly any practical application uses Exclude filter mode to block sources. For this reason it is generally unnecessary to support the filtering function to block sources. In addition, the newly proposed SSM service model has defined several modifications to IGMPv3; therefore certain modifications to IGMPv3 must be performed before it can be deployed in the SSM model.

On the basis of the above analysis, LW-IGMPv3 is designed as a simplified version of IGMPv3 by Huawei Technology Co., which has been accepted by the IETF Mboned working group as a new draft. LW-IGMPv3 follows the query/response model adopted by all the previous IGMP versions. Therefore the network overhead of LW-IGMPv3 is basically the same with IGMPv3.

The major difference between IGMP and LW-IGMPv3 is below. First, the reception state for each attached network maintained by the multicast router is simplified as: (multicast address, group timer, (source records)); second, most record types have the same operation rule in both ASM and Include state, and only the TO_IN record type need to vary its operation according to the value of its group timer; third, the forwarding suggestion rule no longer needs to take the filter mode into consideration.

Functional research is performed, in which protocol states and message operation procedures are analyzed and compared to those of IGMPv3.

A simulation is conducted with our developed C++ simulator to generate network traffic and LW-IGMPv3 and IGMPv3 protocols deployed on the open source router platform XORP in order to compare router performance of LW-IGMPv3 and IGMPv3. During the simulation, the performance, which was measured by CPU processing time and Memory occupancy, of the device running LW-IGMPv3 is improved substantially compared to the one running IGMPv3 and the value of all the parameters of both IGMP protocol and multicast routing protocol are the same. Also, a simulation environment is established and a series of test cases is designed to verify the compatibility of LW-IGMPv3.

The result shows that LW-IGMPv3 is not only compatible with old versions of IGMP, but also shows great improvements in router performance and scalability.
Some Issues of the Paradigm of Multi-Learning Machine - Modular Neural Networks
Authors: Wang Pan , Feng Shuai , Fan Zhun
Published: January 2009

This paper addresses some issues on the weighted linear integration of modular neural networks (MNN: a paradigm of hybrid multi-learning machines).

First, from the general meaning of variable weights and variable elements synthesis, three basic kinds of integrated models are discussed that are intrinsic-factors-determined, extrinsic-factors-determined, and hybrid-factors-determined. The authors point out: integrations dominated by both of the internal and external elements are highly correlative with not only the historical quality of the sub-networks, but also with the environment in which the information is processed.

In the sense of the mean of square error (MSE), several sufficient conditions to improve the whole system's performance are given while deleting one/some sub-networks in all the networks population. Meanwhile, when the whole performance of the current MNN system possesses is unsatisfactory, a corresponding improved strategy which need add one/some sub-networks is presented.

For the optimal weights vector under the framework of the weighted sum of the sub-networks' outputs, we point out some constraints forms of the sub-networks' integrated weights are unreasonable and present a general form while the corresponding computational algorithms are described briefly.

The authors present a new training algorithm of sub-networks named “‘Expert in one thing and good at many’ (EOGM).” In this algorithm, every sub-network is trained on a primary dataset with some of its near neighbors as the accessorial datasets. Simulated results with a kind of dynamic integration methods show the effectiveness of these algorithms, where the performance of the algorithm with EOGM is better than that of the algorithm with a common training method.
Definition of the Constraint with Spatial Characters
Authors: Ju Shiguang , Gu Yi , Tang Zhu , Chen Weihe
Published: January 2009

With the development of the RBAC applications, the spatial characters of those protected data objects have to be considered in many fields. In most cases, the permissions of the same user's access will be changed when the users' location changed. The roles played by the same user may be different since their spatial location is changing and then this user would have the different access authorizations in different spatial locations. Generally speaking, the permissions assigned to users depend on their position in a reference space: users often belong to well-defined categories; objects to which permissions must be granted are located in that space; access control policies must grant some privileges based on the positions of objects/users. Some considerable efforts have been recently devoted to the research of secure spatial database systems which guarantee high security and privacy. Especially the integration of the spatial dimension into RBAC-based models has been the hot topic as a consequence of the growing relevance of geo-spatial information in advanced GIS and mobile applications. In the context of mobile applications, spatial constraints are very important for supporting the definition and maintenance of access control policy. Constraint is an important matter of role-based access control policy. It is enforced on special roles in order to maintain the system security. There is only one constraint specified in the traditional RBAC, which is used to enforce the Separation of Duty (SoD) constraint. In this paper, according to the analysis of the spatial features of those protected spatial data object, combining the necessity of spatial constraints and the non-conflict conditions of spatial constraints with the satisfiability of spatial constraints sets and relevance between the different classes of constraints, the constraints with spatial characters are divided into three different classes: the constraints on spatial region, spatial separation of duty constraint, and constraints on cardinality of spatial role activation. We also present the relationship between the different constraints.
Resource Allocation Model Based on Non-Cooperative Bidding Game in P2P Network
Authors: Tao Jun
Published: January 2009

Game theory is applied to studying the P2P resource allocation technologies further in this paper. The mechanism of P2P resource pricing, which shows the relation of supply and demand, was presented based on bidding. Subsequently, we designed the utility function of end system and proved the existence and uniqueness of Nash Equilibrium in P2P resource allocation game. At last, we present a P2P resource allocation algorithm (PRANG) based on the resource allocation game model. The results of the experiment and the simulation show that PRANG algorithm can provide references for the quantity of resource that users demand and regularize the users' bids. Consequently, the allocation of the whole P2P resource tends to be more reasonable.
Linear Clustering Algorithm by Competitive Learning Suitable for Coal Mine in Wireless Sensor Networks
Authors: Feng Tian , Chuan-Yun Wang , Wei Guo , Qian Gao
Published: January 2009

Because of the complex environment of coal mines, there are many accidents like communication link fault caused by mobile equipment and sliding stones. Therefore, fast rebuilding of remaining nodes and dynamic adding of nodes toted by the rescuer are required after the disaster. Furthermore, the sensor nodes used for localization of the miner and his equipment can only be deployed redundantly along the straight laneway to form a linear wireless sensor network, which proposes a new requirement of topology control strategy. Combining with the self-organizing learning theory of the artificial neural networks, LCACL is presented, a linear clustering algorithm by competitive learning, in which sensor nodes are divided into mobile nodes which add or leave the network dynamically and fixed nodes which could act as sleep nodes, followers, cluster-bridges, or cluster-heads self-adaptively. On the comprehensive consideration of the remaining energy of the sensor node and the number of neighboring nodes, the competition vector, the base for competition, and evaluation vector, the evaluation standard, are formed, which correspond to the input vector and weight vector of artificial neural networks respectively. A similarity comparison using the Euclidean distance is made between them after normalization, and the competitive selection of roles and conversion are achieved using the Euclidean distance. Only the winner node will be entitled to make a learning adjustment, and then broadcasts the adjusted competition vector, which is the evaluation vector in the next competition. According to the rule of cluster-head selection from odd hops and cluster-bridge selection from even hops, the network is initialized as that nodes are divided into clusters of scale-uniform and low overlap ratio. The cluster-head initiates the competitive selection of the sleep node if there are too many followers, and its followers compete to sleep. Along with the energy consumption of the node, the cluster-head or cluster-bridge initiates a new election if it detects its energy consumption exceeding a certain threshold, and all the nodes in the cluster participate in competition by means of competitive learning to achieve role conversion. The simulation results show that the network organized by LCACL has balanced energy consumption, stronger ability to resist destruction, better expansibility, and longer lifetime of network, and the ratio of overlap could be 14% if the communication radius is 70 meters.
A Novel Location Management Scheme for Wireless Mesh Networks
Authors: Hu Weiqi , Zou Shihong , Cheng Shiduan
Published: January 2009

Conventional location management schemes are not designed for Wireless mesh networks and result in considerable signaling cost if used directly in the circumstance. In this paper, a Cluster-based location management scheme is introduced, which takes adequately into account the characteristic of the mesh structure. Numerical result reveals that the proposed scheme enables to significantly lessen the signaling cost.
The Hyper-Kautz Network: A New Scalable Product Network
Authors: Wei Wenhong , Xiao Wenjun , Qin Yong
Published: January 2009

In this paper, we propose a new product network using a Cartesian product of hypercube and Kautz network, named as hyper-Kautz network. The proposed network possesses the properties of both hypercube and the Kautz network including logarithmic diameter, optimal connectivity, and simple routing algorithms.
One-Dimensional Localization Algorithm Based on Signal Strength Ratio
Authors: Yang Xinyu , Kong Qingru , Xie Xiaoyang
Published: January 2009

Localization algorithm in wireless sensor networks has attracted significant interest in recent years. The RSSI approach is considered as the cheapest solution allowing coarse-grain, yet effective for many applications in outdoor environments. However, when environments change, there exists a big localization error using RSSI without a reconstructing data set.

In order to solve the problem of reestablishing the data set when the environments change, a novel one-dimensional localization algorithm based on received signal strength ratio (1-DIM-RSSR) is proposed for the one-dimensional wireless sensor network applications, such as road surveillance and pipeline transmission. While synthetically considering accuracy, power consumption, localization time, and device costs, we can only use coordinate x to locate the nodes by defining y as 0.

Our algorithm is based on the theory as follows: the values of Signal Strength vary from one environment to another. When environments change, even the distance between the transmitter and the receiver remains unchanged, but there is still at least 10dBm's difference. On the contrary, the ratio of the received signal strength from two base stations varies little in the condition of the unchanged distance, and thus it avoids reconstructing the dataset when environments change.

1-DIM-RSSR comprises of two phases: the data set construction phase and the localization phase. In the first phase, N reference nodes are uniformly distributed between the two base stations BS1 and BS2. We collect the signal strength RRi1 and RRi1 from BS1 and BS2 respectively and get signal strength ratio Ri = RRi1/RRi2 at each point, where i ϵ [1, N] corresponding to the N references nodes. In the localization phase, we record the signal strength ratio Rʹ of mobile nodes and pick the one that best matches the observed signal strength ratio. Our idea is to compute the distance | Ri - Rʹ| at a fixed set of locations, and then pick the location that minimizes the distance. Simulation and experiment results show that localization precision of the proposed algorithm compared with the RSSI algorithm is improved when the environments change.

The proposed method is easy to operate, and need not reconstruct the dataset when the environments change. So this method holds the promise for many applications such as monitoring product lines, road surveillance, and pipeline transmission. Meanwhile, since our algorithm is based on 1-D localization, how to extend this conception to 2-D or even 3-D localization will be our ongoing work.
Bayesian Network-Based Service Context Recognition Model
Authors: Qiao Xiuquan , Li Xiaofeng
Published: January 2009

Service context refers to the environmental information which influences the service execution. The processing of service context information is the foundation of the future intelligent telecommunication services in the ubiquitous convergent network. As the complexity and variability of the real world, there exists a large number of uncertain service context information, such as the imprecise information collected by sensors, data noise, and inaccurate location by different location technologies. Hence, it is crucial to recognize the correct service context environment based on unreliable context information.

In recent years, context computing and context-awareness have become a major topic of research in an ubiquitous computing field. Ontology technology is often used to support context modeling and reasoning. And the probability theory, especially the Bayesian network, is adopted to deal with uncertainty. However, much of the existing relevant research work mainly concentrated on the modeling and reasoning of context information. But the way to construct and evolve the service context recognition model supporting uncertain reasoning effectively and systematically has not involved. In addition, most of the relative work is only the qualitative analysis, and lacks the quantitative performance analysis and experimental verification. What is more, the research on how to apply context-awareness technology to the telecommunication field and support the intelligence and individualization of the service is scarce.

In this article, we combine context-awareness technology with telecommunication service network, and discuss the mechanism of service intelligence in ubiquitous convergent network environment. Then a construction method of the service context recognition model based on the Bayesian Network is put forward. The process of constructing the Bayesian network-based service context recognition model is mainly divided into the following steps: First, according to different service requirements and scenarios, the specific context problem domain should be specified; second, constructing the service context recognition model, which includes the determination of the topology structure and the node probability distribution of Bayesian network; third, when the preliminary Bayesian network-based service context recognition model is constructed, it could be initially applied to the practical system to do the clustering or causality analysis; and last, when the model cannot satisfy the need, the model update should be performed based on the feedback information of the evaluation step and the newly-generated plentiful sample data.

This approach has been applied to intelligent access adaptation processing of call service in the office environment. The experimental results show that this approach can strengthen the intelligence of service and compensate for restrictions of certain reasoning.
The Reuse Policy in Developing Multi-Agent System
Authors: Xiao Xue , Lina Yao , Junwei Luo
Published: January 2009

The agent-oriented (AO) methodology is an effective means for constructing distributed systems. Despite a great deal of research, a number of challenges still exist before making agent-based computing a widely accepted paradigm in software engineering practice. The problem of “difficult to implement agent-based system” originates from the gap between design models and system implementation to a high degree. Developers often feel that those characteristics depicted in agent design models are too abstract and difficult to implement.

In order to solve this problem, the paper presents a hierarchical development architecture (HDA) approach to facilitate building up a new agent system. The HDA consists of two parts (analysis and design part, and the system implementation part), covering the entire development lifecycle. Each phase of the HDA is further categorized into a layered model structure. Based on the goal and the task of each layer, the user can fill different method fragments into the appropriate layers to handle different kinds of quality attributes. Instead of creating incompatible techniques, models and CASE tools for each methodology, modular and reusable models can be created once, and shared within different methodologies. It represents significant savings in the development cost and the learning cost.

As the supporting tool, the method engineering process and design patterns play the key role in the HDA. In order to build a new method based on the reuse policy, we adopted (and extended) the method engineering paradigm. According to this approach, a new method is built by assembling pieces of method fragments from a method repository, which is a structural representation of the method fragments that compose the actual AO method with their composing relationships. In this way we could obtain the best method for our specific needs.

In our view, the excellent design patterns will be a good choice for developers to customize their own infra-structure, which is flexible and pluggable. Therefore, a layered-structure is presented, aimed at giving an explicit guide about how to apply those patterns and an order of examination of pattern application. Through applying the HDA-based design patterns, developers can build applications from third party off-the-shelf solution components conveniently.

To exemplify its feasibility and effectiveness, the construction of the C4I system is presented as a case study. An agent-oriented new approach derived from HDA is applied and the experimental result is satisfactory.
Improved Cross Authentication Model Based on Threshold Method in Wireless Network
Authors: Yang Yatao , Pan Shaoming
Published: January 2009

A novel cross authentication model is proposed based on (t, n) threshold method in Layered and Grouped Structure (LGS) wireless multi-hop network, the issues of cross authentication and secure communication between nodes in different trusted domains are settled. With no CA, new scheme of cross certificate being issued and validated is designed, by which, the node identification can be authenticated in different trusted domains.
A Global Reputation Model for Grid Computing
Authors: Mei Yiduo , Guan Shangyuan , Gao Zhixing , Ma Siyuan , Dong Xiaoshe
Published: January 2009

Trust and reputation are important decision-making factors in large-scale distributed systems. The Constellation Model is one of our previous works about grid resource management. Since local feedback plays an important role in aggregating global reputation, a new local feedback metric is introduced to reflect the dynamic feature of trust. This paper introduces our recent effort of combining reputation into the Constelltaion Model. We propose a novel global reputation model for grid systems such as Constellation Model.

We model the relationship between global reputation and the nodes' feedback credibility. A node's feedback credibility which is calculated by similarity measurement will impact on its reputation in a direct way. In our model, to promote a node's reputation, there exist two possible ways: the first one is to provide high-quality services to others. The second way is to provide authentic feedbacks towards others. In addition, to evaluate a node's local feedback trustiness, approach based on similarity measurement is employed. If local feedback trustiness is too low, compensation calculated by exponential smoothing is applied. This design is employed to combat malicious collectives and slandering in large-scale communities. The computational framework of EigenTrust which is proposed by S. D. Kamvar at Stanford University is used to compute global reputations of all the nodes in the Constellation Model.

In the Constellation Model, nodes (stars) in a solar system can be organized using a Peer-to-Peer way. Distributed Hash Table protocol such as Chord which is proposed by I. Stoica, et al. at University of California, Berkeley can be used to implement the distributed ranking mechanism.

We have implemented a prototype of Constellation Model. Experimental results show that, our model can reflect dynamic characteristics of trust better. Our model can also improve the evaluation accuracy of global reputation by leveraging feedback credibility. In Comparison with EigenTrust, our model shows an improved robustness with the presence of malicious behaviors in the Constellation Model.
A Scheme of Restricted Flooding and Greedy Forwarding Routing for Object Tracking Sensor Networks
Authors: Cheng Yuanguo , Li Guohui
Published: January 2009

A protocol named RFGFR (Restricted Flooding and Greedy Forwarding Routing) is presented in this paper. RFGFR propagates query packets from the sink to the centroid of a target region, it employs a scheme of restricted flooding and greedy forwarding results in fewer nodes to forward packets, which means less energy consumption. Greedy forwarding decision can reduce transmission delay by reducing communication hops. Simulations show RFGFR exhibits better performances for object tracking in sensor networks.
An Autonomic Multimedia and Information Service Gateway for Mobile Devices
Authors: Li Yuhong , Pan Shuwen , He Na , Zhao Yi , Su Huichun , Yu Kuifei , Ma Jian
Published: January 2009

With the increase of the networking functions of the mobile handheld devices, today there is a strong need for receiving multimedia through mobile handheld devices. However, the current streaming technologies cannot well satisfy the users' need due to the large network bandwidth requirement and high price. And the infrastructure of broadcasting oriented for a mobile handheld device, such as DVB-H, are not yet popular in the daily life.

Based on these considerations, a new multimedia and information service gateway is proposed, where novel multimedia and information services can be well provided to users with mobile devices. The gateway can connect DVB network, Internet, IPTV etc. media and content provisioning networks with the local area networks such as WLAN and LAN, as well as 3G cellular networks and WiMax which provide access to mobile and portable devices. The gateway aggregates media and Internet information and then distributes them via different access networks to mobile users. The most important feature of the gateway is that it has introduced the idea of the autonomic communications to solve the key problems for providing multimedia services like the video quality and the heterogeneity of mobile devices. Two control loops are designed in the gateway, based on which the autonomic source media transcoding and the dual-driven autonomic channel transcoding techniques are realized. Hence, the gateway system can adapt itself to the varying environments and can therefore provide better multimedia services to users.

In general, the gateway can realize the following functions: sending multimedia to individual mobile devices with suitable format, size, and resolution multicasting multimedia to a group of mobile devices broadcasting multimedia to the mobile devices in the local area providing various information services to users through “push” or “pull”

Especially, the gateway has the following three autonomic features: autonomic user management: i.e., it can obtain the users context information automatically and deal with users' subscription of the services autonomic source media transcoding: i.e., it can adapt the format of the multimedia data received from the media provisioning network according to the capability of the receivers' devices autonomic channel coding: i.e., it can adapt the coding parameters for the video transmission within WLAN by monitoring the status of the network and the receivers

Simulation and test results show that the proposed service gateway can provide a new solution for multimedia and information service provisioning.
Analysis of Instant Messaging Group Worms
Authors: Wang Wei , Xie Ming , Luo Daisheng , Fang Yong
Published: January 2009

Instant Messaging group is the new feature added into the IM system. In the IM group network, two IM users are considered connecting if they are in the same group, which is the essential difference from previous topology. We study worms under IM group topology for the first time. After analyzing the real data, we propose some new propagation approaches of worms and prove their efficiency. To prevent IM group worms, we propose some new defense methods and define some new items. Results can be greatly helpful to administrators of the IM service.
Commercial Quality Influence on Perceptions of Television News
Authors: Perry Stephen D. , Trunnell Dana , Ellis Cori , Kazoleas Dean
Published: January 2009

The impact of high and low-quality commercials on perception of local television newscasts was examined to determine if contrast effects research or affective priming would provide a better explanation of the commercial/newscast interaction. This study showed the strongest support for contrast effects among males and affective priming among females. Men's and women's perceptions were affected differently by ad quality and ad presence on several measures. Results also suggested an interaction between news quality and the presence of commercials within newscasts in producing an emotional response. In addition, when commercials were present within the news program, participants were able to recall fewer of the news stories.
A Healthy Mix of Faculty Members
Authors: Cole Richard
Published: January 2009

The debate about whether to hire faculty members with PhDs or those with significant professional experience has been ongoing for years. It's the old “green eye shades vs. chi-square” argument.
Clinical Practice Guidelines for the Management Candidiasis: 2009 Update by the Infectious Diseases Society of America
Authors: Pappas Peter G. , Kauffman Carol A. , Andes David , Benjamin Daniel K. , Calandra Thierry F. , Edwards John E. , Filler Scott G. , Fisher John F. , Kullberg Bart-Jan , Zeichner Luis Ostrosky , Reboli Annette C. , Rex John H. , Walsh Thomas J. , Sobe Jack D.
Published: January 2009

Guidelines for the management of patients with invasive candidiasis and mucosal candidiasis were prepared by an Expert Panel of the Infectious Diseases Society of America. These updated guidelines replace the previous guidelines published in the 15 January 2004 issue of Clinical Infectious Diseases and are intended for use by health care providers who care for patients who either have or are at risk of these infections. Since 2004, several new antifungal agents have become available, and several new studies have been published relating to the treatment of candidemia, other forms of invasive candidiasis, and mucosal disease, including oropharyngeal and esophageal candidiasis. There are also recent prospective data on the prevention of invasive candidiasis in high-risk neonates and adults and on the empiric treatment of suspected invasive candidiasis in adults. This new information is incorporated into this revised document.
Genome-wide association analysis by lasso penalized logistic regression
Authors: Wu Tong Tong , Chen Yi Fang , Hastie Trevor , Sobel Eric , Lange Kenneth
Published: January 2009

Motivation: In ordinary regression, imposition of a lasso penalty makes continuous model selection straightforward. Lasso penalized regression is particularly advantageous when the number of predictors far exceeds the number of observations.

Method: The present article evaluates the performance of lasso penalized logistic regression in case–control disease gene mapping with a large number of SNPs (single nucleotide polymorphisms) predictors. The strength of the lasso penalty can be tuned to select a predetermined number of the most relevant SNPs and other predictors. For a given value of the tuning constant, the penalized likelihood is quickly maximized by cyclic coordinate ascent. Once the most potent marginal predictors are identified, their two-way and higher order interactions can also be examined by lasso penalized logistic regression.

Results: This strategy is tested on both simulated and real data. Our findings on coeliac disease replicate the previous SNP results and shed light on possible interactions among the SNPs.

Availability: The software discussed is available in Mendel 9.0 at the UCLA Human Genetics web site.

Contact:  klange@ucla.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
QMSim: a large-scale genome simulator for livestock
Authors: Sargolzaei Mehdi , Schenkel Flavio S
Published: January 2009

Summary: QMSim was designed to simulate large-scale genotyping data in multiple and complex livestock pedigrees. The simulation is basically carried out in two steps. In the first step, a historical population is simulated to establish mutation-drift equilibrium, and in the second step, recent population structures are generated, which can be very complex. A wide variety of genome architectures, ranging from infinitesimal model to single-locus model, can be simulated. The program is efficient in terms of computing time and memory requirements.

Availability: Executable versions of QMSim for Windows and Linux are freely available at http://www.aps.uoguelph.ca/~msargol/qmsim/.

Contact:  msargol@uoguelph.ca
Retention time alignment algorithms for LC/MS data must consider non-linear shifts
Authors: Podwojski Katharina , Fritsch Arno , Chamrad Daniel C. , Paul Wolfgang , Sitek Barbara , Stühler Kai , Mutzel Petra , Stephan Christian , Meyer Helmut E. , Urfer Wolfgang , Ickstadt Katja , Rahnenführer Jörg
Published: January 2009

Motivation: Proteomics has particularly evolved to become of high interest for the field of biomarker discovery and drug development. Especially the combination of liquid chromatography and mass spectrometry (LC/MS) has proven to be a powerful technique for analyzing protein mixtures. Clinically orientated proteomic studies will have to compare hundreds of LC/MS runs at a time. In order to compare different runs, sophisticated preprocessing steps have to be performed. An important step is the retention time (rt) alignment of LC/MS runs. Especially non-linear shifts in the rt between pairs of LC/MS runs make this a crucial and non-trivial problem.

Results: For the purpose of demonstrating the particular importance of correcting non-linear rt shifts, we evaluate and compare different alignment algorithms. We present and analyze two versions of a new algorithm that is based on regression techniques, once assuming and estimating only linear shifts and once also allowing for the estimation of non-linear shifts. As an example for another type of alignment method we use an established alignment algorithm based on shifting vectors that we adapted to allow for correcting non-linear shifts also. In a simulation study, we show that rt alignment procedures that can estimate non-linear shifts yield clearly better alignments. This is even true under mild non-linear deviations.

Availability: R code for the regression-based alignment methods and simulated datasets are available at http://www.statistik.tu-dortmund.de/genetik-publikationen-alignment.html

Contact:  katharina.podwojski@tu-dortmund.de

Supplementary information:  Supplementary data are available at Bioinformatics online.
Testing significance relative to a fold-change threshold is a TREAT
Authors: McCarthy Davis J. , Smyth Gordon K.
Published: January 2009

Motivation: Statistical methods are used to test for the differential expression of genes in microarray experiments. The most widely used methods successfully test whether the true differential expression is different from zero, but give no assurance that the differences found are large enough to be biologically meaningful.

Results: We present a method, t-tests relative to a threshold (TREAT), that allows researchers to test formally the hypothesis (with associated p-values) that the differential expression in a microarray experiment is greater than a given (biologically meaningful) threshold. We have evaluated the method using simulated data, a dataset from a quality control experiment for microarrays and data from a biological experiment investigating histone deacetylase inhibitors. When the magnitude of differential expression is taken into account, TREAT improves upon the false discovery rate of existing methods and identifies more biologically relevant genes.

Availability: R code implementing our methods is contributed to the software package limma available at http://www.bioconductor.org.

Contact:  smyth@wehi.edu.au
Fast computation of neighbor seeds
Authors: Ilie Lucian , Ilie Silvana
Published: January 2009

Motivation: Alignment of biological sequences is one of the most frequently performed computer tasks. The current state of the art involves the use of (multiple) spaced seeds for producing high quality alignments. A particular important class is that of neighbor seeds which combine high sensitivity with reduced space requirements. Current algorithms for computing good neighbor seeds are very slow (exponential).

Results: We give a polynomial-time heuristic algorithm that computes better neighbor seeds than previous ones while being several orders of magnitude faster.

Contact:  ilie@csd.uwo.ca
Automated procedure for candidate compound selection in GC-MS metabolomics based on prediction of Kovats retention index
Authors: Mihaleva V. V. , Verhoeven H. A. , de Vos R. C. H. , Hall R. D. , van Ham R. C. H. J.
Published: January 2009

Motivation: Matching both the retention index (RI) and the mass spectrum of an unknown compound against a mass spectral reference library provides strong evidence for a correct identification of that compound. Data on retention indices are, however, available for only a small fraction of the compounds in such libraries. We propose a quantitative structure-RI model that enables the ranking and filtering of putative identifications of compounds for which the predicted RI falls outside a predefined window.

Results: We constructed multiple linear regression and support vector regression (SVR) models using a set of descriptors obtained with a genetic algorithm as variable selection method. The SVR model is a significant improvement over previous models built for structurally diverse compounds as it covers a large range (360–4100) of RI values and gives better prediction of isomer compounds. The hit list reduction varied from 41% to 60% and depended on the size of the original hit list. Large hit lists were reduced to a greater extend compared with small hit lists.

Availability:  http://appliedbioinformatics.wur.nl/GC-MS

Contact:  roeland.vanham@wur.nl

Supplementary information:  Supplementary data are available at Bioinformatics online.
A novel comprehensive wave-form MS data processing method
Authors: Chen Shuo , Li Ming , Hong Don , Billheimer Dean , Li Huiming , Xu Baogang J. , Shyr Yu
Published: January 2009

Motivation: Mass spectrometry (MS) can generate high-throughput protein profiles for biomedical research to discover biologically related protein patterns/biomarkers. The noisy functional MS data collected by current technologies, however, require consistent, sensitive and robust data-processing techniques for successful biomedical application. Therefore, it is important to detect features precisely for each spectrum, quantify them well and assign a unique label to features from the same protein/peptide across spectra.

Results: In this article, we propose a new comprehensive MS data preprocessing package, Wave-spec, which includes several novel algorithms. It can overcome several conventional difficulties. Wave-spec can be applied to multiple types of MS data generated with different MS technologies. Results from this new package were evaluated and compared to several existing approaches based on a MALDI-TOF MS dataset.

Availability: An example of MATLAB scripts used to implement the methods described in this article, along with Supplementary Figures, can be found at http://www.vicc.org/biostatistics/supp.php.

Contact:  yu.shyr@vanderbilt.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.