Vol. 7, No. 2, Apr. 2011
Ai Hua Ho, Yao H. Ho, Kien A. Hua, Roy Villafane, Han-Chieh Chao
Vol. 7, No. 2, pp. 221-240, Apr. 2011
Keywords: V2V Communication Protocols, Vehicular Network, Ad Hoc Network, Broadcast, Broadcasting Storm, Routing
Show / Hide AbstractVehicular networks are a promising application of mobile ad hoc networks. In this paper, we introduce an efficient broadcast technique, called CB-S (Cell Broadcast for Streets), for vehicular networks with occlusions such as skyscrapers. In this environment, the road network is fragmented into cells such that nodes in a cell can communicate with any node within a two cell distance. Each mobile node is equipped with a GPS (Global Positioning System) unit and a map of the cells. The cell map has information about the cells including their identifier and the coordinates of the upper-right and lower-left corner of each cell. CB-S has the following desirable property. Broadcast of a message is performed by rebroadcasting the message from every other cell in the terrain. This characteristic allows CB-S to achieve an efficient performance. Our simulation results indicate that messages always reach all nodes in the wireless network. This perfect coverage is achieved with minimal overhead. That is, CB-S uses a low number of nodes to disseminate the data packets as quickly as probabilistically possible. This efficiency gives it the advantage of low delay. To show these benefits, we give simulations results to compare CB-S with four other broadcast techniques. In practice, CB-S can be used for information dissemination, or to reduce the high cost of destination discovery in routing protocols. By also specify the radius of affected zone, CB-S is also more efficient when broadcast to a subset of the nodes is desirable.
Mohammad S. Obaidat, Sanjay K. Dhur, her, Khushboo Diwakar
Vol. 7, No. 2, pp. 241-260, Apr. 2011
Keywords: routing, Multimedia Networks, Congestion-aware Selection, MANET, CASPER, Performance Evaluation
Show / Hide AbstractIn earlier days, most of the data carried on communication networks was textual data requiring limited bandwidth. With the rise of multimedia and network technologies, the bandwidth requirements of data have increased considerably. If a network link at any time is not able to meet the minimum bandwidth requirement of data, data transmission at that path becomes difficult, which leads to network congestion. This causes delay in data transmission and might also lead to packet drops in the network. The retransmission of these lost packets would aggravate the situation and jam the network. In this paper, we aim at providing a solution to the problem of network congestion in mobile ad hoc networks [1, 2] by designing a protocol that performs routing intelligently and minimizes the delay in data transmission. Our Objective is to move the traffic away from the shortest path obtained by a suitable shortest path calculation algorithm to a less congested path so as to minimize the number of packet drops during data transmission and to avoid unnecessary delay. For this we have proposed a protocol named as Congestion Aware Selection Of Path With Efficient Routing (CASPER). Here, a router runs the shortest path algorithm after pruning those links that violate a given set of constraints. The proposed protocol has been compared with two link state protocols namely, OSPF [3, 4] and OLSR [5, 6, 7, 8].The results achieved show that our protocol performs better in terms of network throughput and transmission delay in case of bulky data transmission.
Wei Nie, Houjun Wang, Jong Hyuk Park
Vol. 7, No. 2, pp. 261-270, Apr. 2011
Keywords: IEEE.802.16, Scheduling, Round Robin, Weighted Proportional, Fairness
Show / Hide AbstractThe IEEE 802.16 standard is supposed to provide a wide-range broadband wireless service, but it leaves the implementation of the wireless resource scheduler as an open issue. We have studied the scheduling problem and propose a two level scheduling (TLS) scheme with support for quality of service and fairness guarantees for downlink traffic in a WiMAX network. A central controller Base Station has a number of users, and each mobile subscriber station has different channel conditions. The same mobile subscriber station may have different service requirements at different times in the WiMAX network. Based on OPNET simulation, the results show our scheduling algorithm can increase the network throughput, maintain relative fairness, and lower delay over the round robin and weighted round robin algorithms.
Yamin Li, Shietung Peng, Wanming Chu
Vol. 7, No. 2, pp. 271-286, Apr. 2011
Keywords: Interconnection Networks, Algorithm, Parallel Prefix Computation, Sorting
Show / Hide AbstractIn this paper, we propose efficient algorithms for parallel prefix computation and sorting on a recursive dual-net. The recursive dual-net RDNk(B) for k > 0 has (2no)2K/2 nodes and d0 + k links per node, where n0 and d0 are the number of nod es and the node-degree of the base-network B, respectively. Assume that each node holds one data item, the communication and computation time complexities of the algorithm for parallel prefix computation on RDNk(B), k > 0, are 2k+1-2+2kTcomm(0) and 2 k+1-2+2kTcomp(0), respectively, where Tcomm(0) and Tcomp(0) are the communication and computation time complexities of the algorithm for parallel prefix computation on the base-network B, respectively. The algorithm for parallel sorting on RDNk(B) is restricted on B = Qm where Qm is an m-cube. Assume that each node holds a single data item, the sorting algorithm runs in O((m2k)2) computation steps and O((km2k)2) communication steps, respectively.
Meeyeon Lee, Jung-Won Lee, Kyung-Ah Kim, Seung Soo Park
Vol. 7, No. 2, pp. 287-298, Apr. 2011
Keywords: Quality model, Quality Metric, Dynamic Service Composition, U-service (Ubiquitous-Service) Ontology, U-service Description Specification
Show / Hide AbstractEfficient service description and modeling methodologies are essential for dynamic service composition to provide autonomous services for users in ubiquitous computing environments. In our previous research, we proposed a ¡®u-service¡¯ ontology which is an abstract and structured concept for device operations in ubiquitous environments. One of the problems that we faced during the design process was that there are not enough standards to analyze the effectiveness of a u-service ontology. In this paper, we propose a quality evaluation model to facilitate the design process of a uservice ontology. We extract modeling goals and evaluation indicators based on the uservice description specification. We also present quality metrics to quantify each of the design properties. The experiment result of the proposed quality model shows that we can use it to analyze the design of u-service ontology from various angles. Also, it shows that the model can provide a guideline, and offer appropriate recommendations for improvements.
Nithiapidary Muthuvelu, Ian Chai, Eswaran Chikkannan, Rajkumar Buyya
Vol. 7, No. 2, pp. 299-320, Apr. 2011
Keywords: Batch Resizing, Task Granularity, Global Grid, Application Turnaround Time
Show / Hide AbstractThe overhead of processing fine-grain tasks on a grid induces the need for batch processing or task group deployment in order to minimise overall application turnaround time. When deciding the granularity of a batch, the processing requirements of each task should be considered as well as the utilisation constraints of the interconnecting network and the designated resources. However, the dynamic nature of a grid requires the batch size to be adaptable to the latest grid status. In this paper, we describe the policies and the specific techniques involved in the batch resizing process. We explain the nuts and bolts of these techniques in order to maximise the resulting benefits of batch processing. We conduct experiments to determine the nature of the policies and techniques in response to a real grid environment. The techniques are further investigated to highlight the important parameters for obtaining the appropriate task granularity for a grid resource.
Vu Van Tan, Myeong-Jae Yi
Vol. 7, No. 2, pp. 321-340, Apr. 2011
Keywords: OPC, OPC UA SDK, Monitoring and Control, Redundancy, Unified Architecture
Show / Hide AbstractIn this article, the current technological state of OPC (Openness, Productivity, and Collaboration; formerly ¡°OLE for Process Control¡±) standards and the problem statement of these OPC standards are discussed. The development of an OPC clientserver framework for monitoring and control systems is introduced by using the new OPC Unified Architecture (UA) specifications, Service Oriented Architecture (SOA), web services, XML, etc. The developed framework in turn minimizes the efforts of developers in learning new techniques and allows system architects and designers to perform dependency analysis on the development of monitoring and control applications. The potential areas of the proposed framework and the redundancy strategies to increase the efficiency and reliability of the system are also represented according to the initial results from the system that was developed by the Visual Studio 2008 and OPC UA SDK.
Ash Mohammad Abbas
Vol. 7, No. 2, pp. 341-354, Apr. 2011
Keywords: information systems, Quality of Research, Impact factor, h-index, g-index
Show / Hide AbstractAnalyzing the relationships among the parameters for quantifying the quality of research published in journals is a challenging task. In this paper, we analyze the relationships between the impact factor, h-index, and g-index of a journal. To keep our analysis simple and easy to understand, we consider a generalized version of the impact factor where there is no time window. In the absence of the time window, the impact factor converges to the number of citations received per paper. This is not only justified for the impact factor, it also simplifies the analysis of the h-index and g-index as well because addition of a time window in the form of years complicates the computation of indices too. We derive the expressions for the relationships among impact factor, h index, and g-index and validate them using a given set of publication-citation data.
Jaehee Byeon, Ju-Hong Song, Nammee Moon
Vol. 7, No. 2, pp. 355-362, Apr. 2011
Keywords: Mobile IPTV, UI(User Interface), Contents Browser, EPG, Personalized Content, Interactive Service
Show / Hide AbstractSince two-way interactive broadcasting service began, remote controls have been fitted with 4 color buttons, which enables interaction and convenience to increase between users and content. Currently, diverse studies on IPTV are in progress. Particularly, as the mobile market rapidly grows, studies on mobile IPTV and on linkage with other media are constantly increasing. However, mobile IPTV has never been studied until now. In that sense, this present study attempted to design a mobile-based IPTV UI that could use a multi-dimensional search method based on consistent criteria for content search. As a result, the proposed IPTV UI is fitted with more usability and functionality for 4 color buttons. The UI designed in this study was compared to the IMDb Android Application, which uses GOMS-KLM. The results showed that the performance process was reduced by three stages, and that the performance time was reduced by more than 17.9%. Therefore, the conclusion can be reached that the proposed UI is effective for a fast search of contents.
Ruchika Malhotra, Mohit Garg
Vol. 7, No. 2, pp. 363-384, Apr. 2011
Keywords: Software Testing, Adequacy Based Testing Criteria, Reliability Based Testing Criteria, Genetic Algorithms, Mutation Analysis
Show / Hide AbstractAs the complexity of software is increasing, generating an effective test data has become a necessity. This necessity has increased the demand for techniques that can generate test data effectively. This paper proposes a test data generation technique based on adequacy based testing criteria. Adequacy based testing criteria uses the concept of mutation analysis to check the adequacy of test data. In general, mutation analysis is applied after the test data is generated. But, in this work, we propose a technique that applies mutation analysis at the time of test data generation only, rather than applying it after the test data has been generated. This saves significant amount of time (required to generate adequate test cases) as compared to the latter case as the total time in the latter case is the sum of the time to generate test data and the time to apply mutation analysis to the generated test data. We also use genetic algorithms that explore the complete domain of the program to provide near-global optimum solution. In this paper, we first define and explain the proposed technique. Then we validate the proposed technique using ten real time programs. The proposed technique is compared with path testing technique (that use reliability based testing criteria) for these ten programs. The results show that the adequacy based proposed technique is better than the reliability based path testing technique and there is a significant reduce in number of generated test cases and time taken to generate test cases.
Hong Joo Lee
Vol. 7, No. 2, pp. 385-396, Apr. 2011
Keywords: Business Attributes, Information Technology, Value Chain, Business System
Show / Hide AbstractInformation technology is changing the business value chain and business systems. This situation is due to the business value chain and the value creation factors in business. Technology companies and researchers are developing new businesses, but many companies and researchers cannot find successful ways to analyze and develop a business in a specific way. In this paper, the following will be explored. First, the value creation motive in business is analyzed through a literary review. Second, business attributes are analyzed while considering the value creation motive and business factors in management. Finally, the business attributes of information technology are studied through a review of previous research that has been conducted on this topic.