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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Internet Computing and Services
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Korean Society for Internet Information
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Volume & Issues
Volume 12, Issue 6 - Dec 2011
Volume 12, Issue 5 - Oct 2011
Volume 12, Issue 4 - Aug 2011
Volume 12, Issue 3 - Jun 2011
Volume 12, Issue 2 - Apr 2011
Volume 12, Issue 1 - Feb 2011
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Performance Analysis on Coexistence of Contention-based Heterogeneous Wireless Networks
Park, Eun-Chan ; Rim, Min-Joong ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 1~14
This paper analyzes the fairness and efficiency of channel sharing when heterogeneous wireless networks that have different transmission power and/or coverage coexist with the contention-based channel access protocol. First, we show that the existing CSMA (carrier sensing multiple access) protocol, that is a prevailing contention-based mechanism, results in significant unfairness of channel access because of (1) the asymmetric capability of carrier sensing and (2) the blindness of binary exponential backoff and link adaptation mechanisms to the interference-driven transmission failures. Next, we derive the feasible region of carrier sensing thresholds that assures spatial reuse and fair channel sharing simultaneously. Moreover, we establish an analytical model for per-system throughput and investigate the effect of contention window size and transmission rate on the fairness and efficiency of channel sharing. Finally, we compare the performance of several approaches for fair channel sharing via simulations under various network configurations.
An Efficient Hierarchical Authentication Scheme through Brokers in Mobile IPv6 Networks
Jung, Ha-Gwon ; Jeong, Jong-Pil ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 15~26
As quick and secure mobility service is becoming a critical issue in the ubiquitous environment. Internet Engineering Task Force (IETF) has done a lot of meaningful work in order to cope with the critical issues, which is a key technology of guaranteeing the legally and safely using of network resources, they has proposed Hierarchical Mobile IPv6 (HMIPv6) to complement for such problems as handover latency and signaling overhead in existing MIPv6. Most of the current research about HMIPv6 focuses on how to optimize the interactive processes between the HMIPv6 and AAA (Authentication, Authorization, Accounting) protocol. This paper describes a cost-effective hierarchical authentication scheme, which makes its focus on minimizing the authentication latency in AAA processing. In this scheme, a hierarchical AAA architecture is proposed, in which the AAA servers are deployed on the Mobility Anchor Point (MAP), the Root AAA server manages several Leaf AAA servers and the Brokers on behalf of the AAA server in home domain. The simulation results shows that the proposed scheme reduces the handoff and authentication latency evidently compared to the previous traditional authentication combination modeling.
Decision Feedback Equalizer Algorithms based on Error Entropy Criterion
Kim, Nam-Yong ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 27~33
For compensation of channel distortion from multipath fading and impulsive noise, a decision feedback equalizer (DFE) algorithm based on minimization of Error entropy (MEE) is proposed. The MEE criterion has not been studied for DFE structures and impulsive noise environments either. By minimizing the error entropy with respect to equalizer weight based on decision feedback structures, the proposed decision feedback algorithm has shown to have superior capability of residual intersymbol interference cancellation in simulation environments with severe multipath and impulsive noise.
An contention-aware ordered sequential collaborative spectrum sensing scheme for CRAHN
Nguyen-Thanh, Nhan ; Koo, In-Soo ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 35~43
Cognitive Radio (CR) ad hoc network is highly considered as one of promising future ad hoc networks, which enables opportunistic access to under-utilized licensed spectrum. Similarly to other CR networks, the spectrum sensing is a prerequisite in CR ad hoc network. Collaborative spectrum sensing can help increasing sensing performance. For such an infrastructureless network, however the coordination for the sensing collaboration is really complicated due to the lack of a central controller. In this paper, we propose a novel collaborative spectrum sensing scheme in which the final decision is made by the node with the highest data reliability based on a sequential Dempster Shafer theory. The collaboration of sensing data is also executed by the proposed contention-aware reporting mechanism which utilizes the sensing data reliability order for broadcasting spectrum sensing result. The proposed method reduces the collecting time and the overhead of the control channel due to the efficiency of the ordered sequential combination while keeping the same sensing performance in comparison with the conventional cooperative centralized spectrum sensing scheme.
Design of MJPEG Encoder for FH/TDD Multiple Transmissions
Kang, Min-Goo ; Sonh, Seung-Il ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 45~50
In this paper, the encoding time delay of FH/TDD(Frequency Hopping/Time Division Duplex) based Motion JPEG image compression CODEC is analyzed for radio video transmissions of multi-camera systems in a vehicle. And, Synchronized connection of minimum channel collision is designed with synchronized shift and access according to channel status for Motion JPEG based FH/TDD multiple access.
Analyzing the Relationship between Market Concentration and Performance in Global Pay TV Markets for the Media Industry Regulation and Policy
Lee, Chi-Hyung ; Lee, Bong-Gyou ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 51~59
The purpose of this study is to provide relevant directions of media industry regulation and policy by analyzing the relationship between market concentration and performance in global pay TV markets. The market concentration has long been regulated in the media industry under the belief that it harms market efficiency and cultural diversity. As the global media market is undergoing significant chance accelerated by the advance of technology, it is necessary to examine the feasibility of this long myth. The data are collected from global 17 pay TV markets and analyzed to see whether the highly concentrated markets by a single player result in higher price and slower service penetration. The result indicates that the price is not escalated and the penetration is not limited even in the markets where a dominant player takes high market share. It implies that more diverse factors other than the market concentration affect the market performance and that maintaining strict regulation of the market concentration is likely to have negative effect on technology innovation.
An Analysis of the Economic Effects on the Project to Construct Smart Network
Jeong, Woo-Soo ; Kim, Sa-Hyuk ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 61~71
The Smart Network Project is planned for achieving the Internet advanced country by adjusting the Government Future Internet Development as a national agenda. The future Internet is defined as diverse alternative technology and services that can provide optimal services for individual characteristic and situation in anywhere, anytime throughout convergence of communication, broadcasting, and computing to solve the current limitation of the Internet. This paper is to analyze the economic effects of the smart network build-up. For the economic effect analysis, we reclassified the smart network industry classification system and re-drew up 2011 Inter-industry Relations Table by using the Inter-industry Relations Table issued by the Bank of Korea and the RAS techniques. And we analyzed the economic effects that can be drawn from the investment of the smart network industry. As a result, the gross production inductive effect which appears with the economic effect of the smart network establishment project from 2011 to 2015 came out to be about 72 trillion 808.2 billion KW, added value inductive effect of 44 trillion 192.9 billion KW and the employment inductive effect of the job creation of about 412 thousands people. Afterward, it is anticipated that the smart network build-up project to contribute to the improvement of Koreans' daily life. Moreover, this research will be used as a valued basic material in the pursuit of the future network projects.
A Study on the Suitability for Acceptance of Tablet Media in the u-Learning Environment: Based on Kano's Model and IPA Methodology
Seo, Hyun-Sik ; Song, In-Kuk ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 73~91
This research aims to compare the features and environments for media acceptance of tablet against laptop computer in the u-Learning environment. While it is need to accept suitable media for u-Learning learner, most of existing research has focused on finding factors which can affect perceived usefulness and perceived ease of use on extended technology acceptance model and how to fulfill those factors. Thus this research drew four categories need to use media in the u-Learning environment, then adopts Kano's model and IPA methodology. The results by Kano's model identify exciting and basic attributes which do not match overall satisfaction of learners. Moreover the research analyses by IPA methodology illustrate whether the factors considered important by learners are fulfilled. The research also emphasis the significance of enhancing relative importance as well as satisfaction of the properties for media acceptance in the u-Learning environment.
Remaking Mobile Ecosystem Policies for New Mobile Market
Kwak, Jeong-Ho ; Cho, Ji-Yeon ; Lee, Yong-Seok ; Lee, Bong-Gyou ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 93~106
The Korean mobile telecom market has undergone a sea change since Apple created a new mobile ecosystem with Appstore and iPhone. Many non-telecom operators have been trying hard to come up with new business strategies to gain a competitive edge. The shifting competition landscape requires a new communications policy that can further stimulate the evolving market. This is why countries around the world are upgrading their communications policies: to renew the market foundation and better respond to the ever-changing industry environment. Using the ANP(Analytic Network Process) model, this study identifies policy variables and performs quantitative analysis on their priorities. The analysis results will help prioritize policy variables under the limited amount of resources, and serve as useful guidelines for making mobile ecosystem policies.
An EFASIT model considering the emotion criteria in Knowledge Monitoring System
Ryu, Kyung-Hyun ; Pi, Su-Young ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 107~117
The appearance of Web has brought an substantial revolution to all fields of society such knowledge management and business transaction as well as traditional information retrieval. In this paper, we propose an EFASIT(Extended Fuzzy AHP and SImilarity Technology) model considering the emotion analysis. And we combine the Extended Fuzzy AHP Method(EFAM) with SImilarity Technology(SIT) based on the domain corpus information in order to efficiently retrieve the document on the Web. The proposed the EFASIT model can generate the more definite rule according to integration of fuzzy knowledge of various decision-maker, and can give a help to decision-making, and confirms through the experiment.
Clustering and Pattern Analysis for Building Semantic Ontologies in RESTful Web Services
Lee, Yong-Ju ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 119~133
With the advent of Web 2.0, the use of RESTful web services is expected to overtake that of the traditional SOAP-based web services. Recently, the growing number of RESTful web services available on the web raises the challenging issue of how to locate the desired web services. However, the existing keyword searching method is insufficient for the bad recall and the bad precision. In this paper, we propose a novel building semantic ontology method which employs both the clustering technique based on association rules and the semantic analysis technique based on patterns. From this method, we can generate ontologies automatically, reduce the burden of semantic annotations, and support more efficient web services search. We ran our experiments on the subset of 168 RESTful web services downloaded from the PregrammableWeb site. The experimental results show that our method achieves up to 35% improvement for recall performance, and up to 18% for precision performance compared to the existing keyword searching method.
A Study on Design of K-12 e-Learning System for Utilization Smartphone
Kim, Yong ; Shon, Jin-Gon ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 135~143
The smartphone allows learners to be involved in learning environments in which students actively study from anywhere and at anytime. Because learners can keep engaged in the environment where they can access to the internet, they can efficiently study in transit using various features and functions of smartphone. Smart learning is a unique learning based on mobility and functions of mobile digital devices including searching and sharing information and using various applications. For the effective use of smartphones in e-learning systems, the contents and learning management systems should be designed to meet effective teaching and learning principles, such as interactivity and collaborations. In smart learning, learning contents for effective learning need to be integrated with typical functions of smartphones and to develop small pieces of learning contents according to learning topics. In the case of learning management systems, it should reflect understanding of learners' environment using a PA agent program and provide personalized learning services.
Analysis on a Structural Equation Model of e-Piracy Causes
Yoo, Sang-Mi ; Kim, Mi-Ryang ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 145~156
The purpose of the study is to analyze the factors which cause the deviations of e-piracy. For this, empirical data were collected by conducing a field survey with a total of 531 collegians, and a Structural Equation Model was used for the purpose of analyzing the data acquired by that. A Structural Equation Model was designed and constructed by such factors as Anonymous Environment, Norm-Consciousness, and Recognition on Penalty, which are considered as the direct variables. In addition, the factor of Anonymous Environment was set as a variable for the factors of both Norm-Consciouness and Recoginition on Penalty. These are the results of the analysis; it is found that Anonymous Environment is the direct cause of e-piracy, but the other two factors are not statistically significant. And it is also found that Anonymous Environment gives a direct influence on the other factors of Norm-Consciousness and Recognition on Penalty and it also gives indirect influence on the factor of Recognition on Penalty by means of the factor of Norm-Consciousness. Therefore, in order to prevent e-piracy, it is required to provide the proper opportunity to be trained to observe norms under the environment of anonymity. For this, diverse and effectual teaching methods for information ethic education should be sought.
Cloud P2P OLAP: Query Processing Method and Index structure for Peer-to-Peer OLAP on Cloud Computing
Joo, Kil-Hong ; Kim, Hun-Dong ; Lee, Won-Suk ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 157~172
The latest active studies on distributed OLAP to adopt a distributed environment are mainly focused on DHT P2P OLAP and Grid OLAP. However, these approaches have its weak points, the P2P OLAP has limitations to multidimensional range queries in the cloud computing environment due to the nature of structured P2P. On the other hand, the Grid OLAP has no regard for adjacency and time series. It focused on its own sub set lookup algorithm. To overcome the above limits, this paper proposes an efficient central managed P2P approach for a cloud computing environment. When a multi-level hybrid P2P method is combined with an index load distribution scheme, the performance of a multi-dimensional range query is enhanced. The proposed scheme makes the OLAP query results of a user to be able to reused by other users' volatile cube search. For this purpose, this paper examines the combination of an aggregation cube hierarchy tree, a quad-tree, and an interval-tree as an efficient index structure. As a result, the proposed cloud P2P OLAP scheme can manage the adjacency and time series factor of an OLAP query. The performance of the proposed scheme is analyzed by a series of experiments to identify its various characteristics.
Developing Advanced Location-Based Route-Search Service for Smart-phones
Pak, Woo-Guil ; Lim, Sung-Man ; Oh, Han-Joon ; Yu, Kwang-Hyun ; Kwon, Min-Young ; Lee, Hee-Seung ; Choi, Young-June ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 173~180
Various smart-phone applications for location-based service are enabled through mobile communications such as 3G and WiFi. We have developed MARS, an advanced location-based route-search application based on the Android platform. It provides three functions: route-registration, route-search, and route-evaluation. These functions are dynamically maintained by a web server, a database server, and user mobile terminals. As users can update location information using their smart-phone devices, servers provide the information and allow users to add, modify, and remove their own information as well as adding comments to others, while existing map services do not support direct inputs from users. We show our implementation process and demonstration of its operations. We also show the comparison results with existing services. Through these results, we can confirm that MARS can achieve better performance.
Design and Implementation of Event Based Message Exchange Architecture between Servers for Server Push
Cho, Dong-Il ; Rhew, Sung-Yul ;
Journal of Internet Computing and Services, volume 12, issue 4, 2011, Pages 181~194
Server push which is technology of sending contents from servers to browsers in real time using long polling requests enables real time bidirectional communications between servers and browsers in HTTP environment. Recently, thanks to the rapid supply of mobile devices having ability of full browsing, server push is being applied to various applications. However, because servers providing services should offer distributed contents to a large number of users simultaneously in various user environments, they have a burden that offers contents quickly distinguishing much more concurrent users than before. The method of message exchange so far achieved in distributed server environment has difficulties in the performance of simultaneous user request process, the identification of users and the contents delivery. In this paper, We proposed message exchange architecture between servers for offering server push in the distributed server environment. The proposed architecture enables message exchange in the method of push between servers based on event driven architecture. In addition, the proposed architecture enables flexible identification of a event agent and event processing under the connected environment of a lot of users. In this paper, we designed and implemented the proposed architecture and compared performance with the previous way through a performance test. In addition, function is confirmed through the case realization. As a result of the performance test, the proposed architecture can lessen the use of server Thread and response time of users and increase simultaneous throughput.