15452882
On Cellular Capacity with Base Station Cooperation
This paper is concerned with cellular systems with rate constraints in fading environments. We consider a simple but asymptotically optimal matched filtering/successive interference cancellation (MF-SIC) scheme. We derive several concise and closed-form bounds for the power and spectral efficiencies of various base station cooperation strategies, which provide some useful insights into cellular systems.
1622406
Structure Analysis and SNR-Variance Evolution for Parallel Concatenated Coded IDMA Systems
This paper is concerned with parallel concatenated coded interleave-division multiple-access (IDMA) systems. We briefly present the transmitter/receiver structure of these systems and propose an efficient SNR-variance evolution scheme for bit-error-rate (BER) performance evaluation. The proposed evolution scheme is also useful for system performance optimization. Numerical results show that the BER performance curves obtained by simulation and evolution are quite close when the data length is long enough.
15663663
Kernel based articulated object tracking with scale adaptation and model update
Kernel based object tracking (KBOT) is one of the most popular and effective techniques for tracking task. However the constancy of the target model and unsound scale adaptation method are two main limitations. In this paper, we present a kernel based approach incorporated with scale estimation and target model update for articulated object tracking task. After predicating the object center with scale fixed KBOT, we extend scale selection theory to estimate the local optimal object scale. Once the object scale has been estimated, a kernel density estimation based strategy is developed to update the target model. Experimental results show that our approach is superior to traditional KBOT in the following two aspects: 1) it is less affected by the object scale change; 2) it is less prone to appearance variation.
39099940
Efficient error recovery techniques in a novel multimedia streaming framework with peer-paired collaboration
Recently, active research has gone to application-level multicast that tries to bring all the merits of unicast and IP multicast together while avoiding their drawbacks. How to efficiently recover from errors in such a system is a difficult question yet to be answered. The current research focus is primarily on developing local error recovery techniques, but these techniques would not work in case of shared losses, which often occur in application-level multicast. In this paper, a novel multimedia streaming framework called peer-paired pyramid streaming (P/sup 3/S) is proposed. It is basically a hybrid client/server and peer-to-peer structure. In P/sup 3/S, clients are hierarchically organized and those at the same level are coupled and peer-pairs are then formed. Based on P/sup 3/S, we introduce some controlled delay between packets that are vulnerable to shared losses to combat with the shared losses. The proposed technique is supported by both theoretical and experimental results presented in this paper.
37867207
A Low-Latency Peer-to-Peer Approach for Massively Multiplayer Games
This paper focuses on the latency reduction problem in massively multiplayer games (MMGs). As the client-server (CS) architecture in use today in most commercial MMGs applications are exposing its weakness in scalability as the number of players increases, researchers start to consider the peer-to-peer (P2P) model that has inherent high scalability for MMGs. However, existing P2P models generally lead to high latency that significantly detracts from the playing experience. To improve this, we present a novel communication model intended to reduce the latency of network communication on game states. The model, based on DHT protocol, can select the best candidate node to perform server's role for a game zone. In contrast, existing P2P models designate 'peer servers' randomly without considering latency effects. The simulation shows that our approach obtains much lower latency than existing P2P models. The performance of our approach is shown to be even better than that of CS models.
14004456
Enhancing multimedia streaming performance through peer-paired collaboration
In this paper, a novel multimedia streaming framework called peer-paired pyramid streaming (P/sup 3/S) is proposed. The philosophy of P/sup 3/S is to enable collaboration between clients so as to bring in better performance. The structure of P/sup 3/S is basically a hybrid client/server and peer-to-peer structure and exhibits a triangle-cell based hierarchy. Based on P/sup 3/S, performance enhancement techniques are designed to increase the aggregated bandwidth of all participants. We present an optimal data allocation algorithm, which maximizes the overall throughput of the whole streaming session. We also present a greedy data allocation algorithm that is slightly suboptimal but much simpler. Extensive simulations were performed to demonstrate the effectiveness of proposed techniques.
28870218
An algorithm for optimal difference systems of sets
Abstract
Difference Systems of Sets (DSS) are combinatorial structures that generalize cyclic difference sets and are used in code synchronization. A DSS is optimal if the associated code has minimum redundancy for the given block length n, alphabet size q, and error-correcting capacity ρ. An algorithm for finding optimal DSS is presented together with tables of optimal solutions found by this algorithm.

3219653
Key Elements Tracing Method for Parallel XML Parsing in Multi-Core System
Though XML is applied intensively in a lot of applications, XML parsing is not practical in many fields because of its poor performance. Parallel XML parsing on multi-core is a promising choice. Previous methods all adopt data parallel approach on XML parsing. As the semi-structured nature of XML, they were obliged to divide the data into well-formed XML chunks and then parse these chunks parallel. The division process is named as preparsing. As the preparsing is serial, it becomes the bottleneck of parallel XML parsing. Related work Simultaneous Finite Transducer (SFTXP) parallelized the preparsing stage. It maintained multiple preparser results for each equal sized chunk according to enumerated all possible parsing states. In spite of finite states for each XML, the overhead by SFTXP is tremendous, including CPU time and memory for multiple results generating and storing, respectively. In this work, we address parallel XML parsing by Key Element Parse Tracing (KEPT) method which parallelizes the preparsing and parsing at element level. It remolds the preparsing as a key element extracting process and schedules the processing of key elements in the framework of KEPT. Then parsing process is parallelized as a whole. To demonstrate the effectiveness, we implement it on libxml2 and obtain good scalability on both an 8-core Linux machine and an 8-core 24 SMT Sun machine running Solaris.
6984424
Ontology-based security assessment for software products
This paper proposes an ontology-based approach to analyzing and assessing the security posture for software products. It provides measurements of trust for a software product based on its security requirements and evidence of assurance, which are retrieved from an ontology built for vulnerability management. Our approach differentiates with the previous work in the following aspects: (1) It is a holistic approach emphasizing that the system assurance cannot be determined or explained by its component assurance alone. Instead, the software system as a whole determines its assurance level. (2) Our approach is based on widely accepted standards such as CVSS, CVE, CWE, CPE, and CAPEC. Our ontology integrated these standards seamlessly thus provides a solid foundation for security assessment. (3) Automated tools have been built to support our approach, delivering the environmental scores for software products.
24555513
Semantic Annotation for CSSCI Academic Resources Based on Ontology
The paper emphatically elaborates the process and method of realizing semantic annotation for domain data based on the CSSCI conceptualization which constructed before. The essence is that extracting the academic resource instances from CSSCI data under the guidance of the object-oriented knowledge organization model, setting values for properties of the instances by methods of directly extracting based on relational data model, directly statistic calculating assisted by TF-IDF algorithm, synthesis algorithm combined criterion weighting with formal concept analysis and so on, discovering and analyzing semantic association between instances, so as to integrate all CSSCI academic resources into a huge knowledge map based on ontology and to support the knowledge retrieval and citation analysis.
17568245
Security metrics for software systems
Security metrics for software products provide quantitative measurement for the degree of trustworthiness for software systems. This paper proposes a new approach to define software security metrics based on vulnerabilities included in the software systems and their impacts on software quality. We use the Common Vulnerabilities and Exposures (CVE), an industry standard for vulnerability and exposure names, and the Common Vulnerability Scoring System (CVSS), a vulnerability scoring system designed to provide an open and standardized method for rating software vulnerabilities, in our metric definition and calculation. Examples are provided in the paper, which show that our definition of security metrics is consistent with the common practice and real-world experience about software quality in trustworthiness.