• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.12
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• pp.5231-5248
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• 2016

As a service-oriented paradigm, web service composition has obtained great attention from both academia and industry, especially in the area of cloud service. Nowadays more and more web services providing the same function but different in QoS are available in cloud, so an important mission of service composition strategy is to select the optimal composition solution according to QoS. Furthermore, the selected composition solution should satisfy the service level agreement (SLA) which defines users' request for the performance of composite service, such as price and response time. A composite service is feasible only if its QoS satisfies user's request. In order to obtain composite service with the optimal QoS and avoid SLA violations simultaneously, in this paper we first propose a QoS evaluation method which takes the SLA satisfaction into account. Then we design a service selection algorithm based on our QoS evaluation method. At last, we put forward a parallel running strategy for the proposed selection algorithm. The simulation results show that our approach outperforms existing approaches in terms of solutions' optimality and feasibility. Through our running strategy, the computation time can be reduced to a large extent.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.7
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• pp.1597-1603
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• 2004

Recently many corporations are introducing web services which supports mutual smooth information exchange without depending on platform or programming language and new distributed computing environment based on U standard technology and internet standard protocol such as HTTP. However they are suffering difficulty in interoperability because of the problem of version inconsistency of standards supported by platforms that each vender offers. To solve these interoperability problem, although WS-I is progressing a consecutive standardization work by method of that offer Basic Profile and Usage Scenario, it is in the state that the domestic research connected with this is not sufficient yet. Accordingly, this treatise constructed interoperability Test framework by developing web services on the basis of different platform from books information retrieval services that can easily be come with and simulated and verified the interoperability by applying WS-I Basic Profile.

• Convergence Security Journal
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• v.23 no.5
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• pp.45-55
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• 2023

With the widespread use of digital devices, anonymous communication technologies such as the dark web and deep web are becoming increasingly popular for criminal activity. Because these technologies leave little local data on the device, they are difficult to track using conventional crime investigation techniques. The United States and the United Kingdom have enacted laws and developed systems to address this issue, but South Korea has not yet taken any significant steps. This paper proposes a new blockchain-based crime investigation method that uses physical memory data analysis to track the behavior of anonymous network users. The proposed method minimizes infringement of basic rights by only collecting physical memory data from the device of the suspected user and storing the tracking information on a blockchain, which is tamper-proof and transparent. The paper evaluates the effectiveness of the proposed method using a simulation environment and finds that it can track the behavior of dark website users with a residual rate of 77.2%.

• Journal of KIISE
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• v.41 no.10
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• pp.838-846
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• 2014

Three-dimensional (3D) object retrieval from user-drawn sketch queries is one of the important research issues in the areas of pattern recognition and computer graphics for simulation, visualization, and Computer Aided Design. The performance of content-based 3D object retrieval system depends on the availability of effective descriptors and similarity measures for this kind of data. In this paper, we present a sketch-based 3D object retrieval system by extracting a hybrid edge descriptor which is robust against rotation and translation. The experimental results which are based on HTML5 and WebGL show that proposed sketch-based 3D object retrieval method is very efficient to search and order the 3D objects according to user's intention.

• The KIPS Transactions:PartC
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• v.12C no.6 s.102
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• pp.773-780
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• 2005

Recently, the telecommunication network is in a transition toward the BcN (Broadband convergence Networks) that integrates the Internet, the telecommunication and the broadcasting. The BcN makes it possible to provide of 4he third-party application by using the Open API The Parlay X API is an example of the Open API and the Parlay X API is grafted in the Web Service and is abstracted from the Parlay API. So, the Parlay X API does not only have advantages of a Web Service, but also disadvantages of the Web Service. The main disadvantage of the Web Service is that it does not support the any QoS mechanism. In this paper, we propose the architecture that solves the reliability among the QoS issues for the Web Service. The proposed mechanism adopts the Asynchronous architecture for the reliable Web Service and improves the performance of the retransmission between the client and the server using the expected response time. We perform the performance evaluation through the simulation in older to compare with the existing mechanism. Consequently, we can confirm that the performance of the proposed mechanism performs better than the existing mechanism.

• Journal of the Korea Society of Computer and Information
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• v.11 no.3
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• pp.21-30
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• 2006

This study applies the cognitive apprenticeship theory a representative learning theory of constructivism. to design and create a web courseware for data device operator license. to enable research that begins with peripheral participation in Problem solving and ends with full participation and initiative, to act as a medium for assisting students in learning, to enable adaptation to actual situations through simulation studies, to allow aggressive interaction, and to help reinforce the level of data processing with regard to learning. The student was made to evaluate learning materials at real time for feedback on insufficient areas, to enable effective learning. The study was done by offering a web courseware without applying the cognitive apprenticeship theory and a web courseware with the cognitive apprenticeship theory, which was followed by an evaluation on study achievement level and learning behavior and then a survey was done after the evaluations. The results of this study were first, the learning group with web courseware applying cognitive apprenticeship theory showed more effect in improving learning achievement than the group with web courseware without the cognitive apprenticeship theory. Secondly, learning with web courseware applying cognitive apprenticeship theory was more effective for improving learning behavior.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.9
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• pp.816-821
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• 2005

The remote operation of $4\~5$ cranes for container loading/unloading at a port by one operator will dramatically improve loading/unloading efficiency through productivity increase, cost reduction, and so on. This study develops a remote crane control system for container loading/unloading yard cranes. First, a wireless video and audio system to transmit views and sounds of the working field is designed by using 3 web cameras and a microphone. Next, a RSVP-based multi-path reservation method is presented with a view to improving the quality of service in the communication network for remote control. Simulation results show that a RSVP-based multi-path reservation can enhance the reservation success rate in the TCP/IP network.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.1
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• pp.14-24
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• 2013

The marine leisure industry in Korea has been the focus of the power of economic growth and the creation of jobs in recent years. In this regard, many studies concerning marine leisure are on-going in various fields. In this paper, developed a layout system and algorithm can resolve the factory and facility layout problem. For a layout design of leisure-boat factories, the leisure-boat production process is analyzed in order to derive standard production space elements for the layout of the factory. Based on the results, a draft design of the factory layout is carried out based on the manpower planning data, as well as the characteristics and relationships of each process data. A layout design of this paper can be verified through a factory simulation solution and we suggest the verification method using a SBD(simulation based design) methodology. The layout system takes into account the user's accessibility and extendibility, so it is web-oriented and uses RIA (rich Internet Application) technology. Furthermore, the system and layout algorithm of this paper are verified with samples data that show the efficient factory arrangement and practical application method.

• The Journal of Korean Association of Computer Education
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• v.4 no.1
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• pp.43-52
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• 2001

The aim of this paper is to develop a network-based collaborative learning system based on cooperative learning, computer simulation, role playing, and web-based instruction, which is called NetClass. It is an educational system of hybrid-type, and supports three learning modes as a distributed network, a stand-alone system, or a web browser. To accomplish the purpose of this paper, we have studied on the following topics. First, we selected appropriate learning contents among dilemmas on information ethics. Second, a Collaborative Dilemma-solving Learning Model (CDLM) was designed, and this model means systematic procedures that leaners can notice others' feeling and thinking and predict the results of his actions by introducing interactions among learners on computer networks. Third, Collaborative Learning System Model based on standard architecture of an educational system was proposed. Fourth, we developed many components such as network components, database components, and interface components.

• Journal of Digital Contents Society
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• v.18 no.2
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• pp.411-422
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• 2017

Current policies for sharing bandwidth increase average throughput and improve utilization of the bandwidth in the local network. However, with these policies, a central administer, which is responsible for allocating bandwidth to each network flow, cannot allocate resources based on user characteristics. Thus, it leads to unfair bandwidth allocation because it does not guarantee services based on user characteristics. Therefore, we propose a novel negotiation method to share the bandwidth in a limited bandwidth network, in which, a user negotiates with other users to gain more resource. Ideally, we use a fuzzy system to infer and determine whether a device will request bandwidth or not based on the current usage of the given device. We conduct two experiments consisting of a video streaming simulation in OPNET and a real-time video streaming in WebRTC. The results of the experiment indicate that the proposed method can flexibly share the bandwidth utilization based on user's requirement in the network.