• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.344-347
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• 2011

This paper presents qualification process of the T700/701K turbo-shaft engine for Korean Utility Helicopter(KUH). The T700/701K is the rear-drive variant of the GE's T700-701C/D engine which was qualified for military applications in the world. The main scope of the development is the modification from a front-drive engine to a rear-drive one, the performance enhancement of the power turbine and the incorporation of two channel FADEC(Full Authority Digital Engine Control) system for more reliable operation. Therefore, T700/701K engine must be qualified by Korean government in order to perform a flight in the country. Reflecting the influence of developing scope, the main requirements including performance and control are verified by test and analysis, while the requirement for module or component that is same to that of T700-701C/D are verified by similarity.

• Journal of KIISE:Information Networking
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• v.28 no.4
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• pp.611-620
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• 2001

To meet the requirements of reliable service for various applications, a Reliable Multicast Transport Protocol should be implemented over IP Multicast where currently best-effort service is provided. Among the current researches, hierarchical tree-based mechanism has been proposed and actively studied. This mechanism is known to provide high scalability as well as reliability, but needs an additional tree configuring mechanism for building an efficient logical tree in transport layer. Bottom-up approach has been used for creating such a tree. This method has benefits from parallel tree construction for receivers, while it has some drawbacks such that it does not guarantee a loop-free tree and brings heavy message overhead during tree creation process. Therefore, this paper proposes a top-down based mechanism for constructing a control tree, which can guarantee loop-freeness by step-wise mannered tree building. From experimental simulations, it shows that the proposed mechanism has less message overhead. It is recommended that the bottom-up and the proposed top-down will be selectively used in real networks, according to the requirements of the concerned multicast applications.

• The Transactions of the Korea Information Processing Society
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• v.5 no.1
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• pp.161-171
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• 1998

In this paper, we shows the implementation of Web based performance manager which analyze the traffic of a Web server to support the diagnostics of it. The manager monitors the HTIP traffic by polling and measures and presents is performance on demand. To enhance the adaptability of management interface Web based interfaces with JAVA is used. Recently, the need of traffic management on s Web has grown, because of increasing Web traffic. Therefore, the traffic management of Web service and the effective management of a Web server's performance are needed. We have designed interfaces with which is comprised of Collection-Request, Analysis-Request, Realtime-Monitoring, Comparison-Analysis on a client with Web Browser on a network, and implemented the server system that can analyze these requests. Also we have introduced some perfonnance indicator by referring a Web related MIB. Also, we have designed and developed a message format for communication between the Web client and the server system.

• Clean Technology
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• v.3 no.1
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• pp.9-26
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• 1997

The recent movement toward the better environment urges the shift of pollution prevention strategy from traditional "command/control" and "end-of-pipe" technologies to clean technologies. Development of Clean Technology, which makes products without creating pollutions, is a way to solve Environmental problems fundamentally. The main objective of this study is to define the long-term strategy to develope "Innovative Clean Technology". "Innovative Clean Technology" is an active way of solving the environmental problems arising from industrial activities. It aims to find ways either to make products without creating pollution, to produce environmentally benign end-products, or else to recover and re-use the materials which have hitherto considered waste.

• 한국정보교육학회:학술대회논문집
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• 2011.01a
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• pp.211-217
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• 2011

Recent IT (information technology) environmental changes, such as emerging social network services or increasing user participation in multimedia environment, have made it necessary for e-learning systems to undergo changes in various ways. Metadata is an agreement for interoperability between different systems. The standardization of metadata for e-learning system has been driven by some domestic and international organizations, but applying diverse environmental changes into the design of e-learning metadata is in dire need. In this paper, we present a methodology for the analysis and design of modeling e-learning metadata and elicit the design requirements, on the basis of the metadata standard KEM 3.0, about the elements that are expected to be needed in future e-learning systems. Based on the requirements from the analysis, we present the three-layer model for classifying the requirements by the importance of metadata elements per Kana Model. An intelligent e-learning system is to be developed based on the proposed modeling design, which we hope to influence the development of an international standard in the future.

• Convergence Security Journal
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• v.14 no.7
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• pp.45-51
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• 2014

The most important point in the QoS management system to ensure the quality of the IoT system design goal is quality measurement system and the quality evaluation system. This research study is a matrix model for the IoT based on key quality measures by diagnosis system structure and function. Developing for the quality metrics measured Internet of Things environment will provide the foundation for the Internet of Things quality measurement/analysis. IoT matrix system for quality evaluation is a method to describe the functional requirements and the quality requirements in a single unified table for quality estimation performed. Comprehensive functional requirements and quality requirements by assessing the association can improve the reliability and usability evaluation. When applying the proposed method IoT quality can be improved while reducing the QoS signaling, the processing, the basis for more efficient quality assurances as a whole.

• Magazine of the Korea Concrete Institute
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• v.6 no.3
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• pp.173-179
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• 1994

Test results to evaluate the rr~echanical properties of epoxy-coated reinforcing bars are described. Tests include adhesion, impact, bend, and abrasion test of epoxy coating to reinforcing steel, specified in relevant KS and ASTM standards. Three nomnal thicknesses of epoxy coating, $120{\mu}m$, $220{\mu}m$, $300{\mu}m$ are used. The results show good adhesion and abrasion resistance satisfying the requirements. The results also show faily good bendability. However, the thicker the coating, the weaker the adhesion is. Impact resistance is in the tolerable range, but it is recorrmerided that careful treatments are required during handling of epoxy-coated bars. From the results, epoxy-coated bars, with a coating thickness ranging from $150{\mu}m$ to $300{\mu}m$, should well perform for fabrication in field construction.

• Journal of Advanced Navigation Technology
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• v.21 no.3
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• pp.279-286
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• 2017

The international maritime organization(IMO) has defined performance requirements for future maritime navigation through IMO resolution A.915(22) in 2001. Many DGPS systems currently providing DGPS services do not meet the performance requirements specified in IMO resolution A.915(22). The use of SBAS is considered as one of the DGPS replacement and supplementary system for coping with the increase in demand performance and providing safe positioning service. In particular, since a large amount of budget is required to rearrange the existing DGPS reference stations, a method which transmits differential corrections generated by using SBAS message has been proposed. In this paper, we compare and analyze the performance of NDGPS which is operated by the National Maritime PNT Office of the ministry of oceans and fisheries(MOF) in Korea and MSAS in Japan. Also, we verify that SBAS, as alternative and complementary system, meets the performance requirement specified in IMO resolution A.915(22).

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.584-587
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• 2006

Quality assessment of the building is strongly dependent upon satisfying owner's requirements. To develop indicators for the assessment of design quality, survey on current situation of design process and analysis of Design Quality Indicator(DQI) is performed. The survey revealed that the main cause of frequent design changes is variability feature of owner's requirements. DQI, an indicator developed in UK, questionnaire encompasses questions which are relevant throughout the development stages of a building, and can be used at every key stage of the process. Further research will focus on the development of indicators for the assessment of design quality applicable to Korean market. In addition, research on the visualization method to present assessment results and supporting tools to facilitate assessment will be considered.

• Journal of KIISE:Information Networking
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• v.31 no.2
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• pp.123-130
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• 2004

Routing and wavelength assignment(RWA) problem is an important issue in optical transport networks based on wavelength division multiplexing(WDM) technique. It is typically solved using a combination of linear programming and graph coloring, or path selection based graph algorithms. Such methods are either complex or make extensive use of heuristics. In this paper we propose a novel and efficient approach which basically obtains the maximum edge disjoint paths (EDPs) for each source-destination demand pair. And those EDPs obtained are stored in Lookup Table and used for the update of weight matrix. Routes are determined in order by the weight matrix for the demand set. The comprehensive computer simulation shows that the Proposed algorithm uses similar or fewer wavelengths with significantly less execution time than bounded greedy approach (BGA) for EDP which is currently known to be effective in practice.