• Journal of Advanced Navigation Technology
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• v.21 no.4
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• pp.339-346
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• 2017

We propose the design of an INS simulated equipment to evaluate the enhanced jamming resistance of an INS-aided GPS receiver with INS, when a jamming signal is injected into a simulated high dynamic platform. We propose the design of a relative cheap INS simulated equipment, instead of an expensive INS simulator connected to GPS simulators. Based on the design, we implement the equipment and setup high dynamic test environment using the equipment to evaluate an INS-aided GPS receiver. In the GPS L1 C/A and L2C simulations that inject jamming signals of the narrow and wide bandwidth into the GPS receiver with and without INS-aided algorithm, we obtain increased jamming resistance performance as +5 dB compared with the GPS receiver without INS-aided algorithm in all kinds of jamming bandwidth. Based on the simulations, we verified that the INS simulated equipment can be used to evaluate the enhanced jamming resistance of INS-aided GPS receivers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9B
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• pp.795-801
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• 2008

Wireless Mesh Networks (WMNs) are popular due to their low cost and rapid deployment. Currently, many WMN researchers often considers the use of ad-hoc routing protocols because WMNs are similar to the ad-hoc networks. Some of currently deployed WMNs consider to use on-demand routing protocols such as Ad-hoc On-demand Distance Vector (AODV) and Dynamic Source Routing (DSR). But, AODV are not appropriate for Wireless Mesh Networks (WMNs), because flooding-based route discovery is both redundant and expensive in terms of control message overhead. In this paper, we propose a directional AODV (D-AODV) routing protocol based on hop count to a gateway. We implement the D-AODV routing protocol and evaluate the performance of the D-AODV on the testbed. The measurement results show that the D-AODV can enhance the network throughput by reducing the routing overhead.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2001.06a
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• pp.1-2
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• 2001

1. 연구목적 : 현재 한반도 내에서 관측을 수행하고 있거나 계획중인 지표 플럭스 관련 연구자들간의 관측 시스템의 상호 비교, 경계층 동시관측, 이산화탄소를 포함한 다양한 미량기체 플럭스 관측 및 지면과정 모형의 운용과 검정을 위한 실측 자료 확보, 분석 및 활용 2. 논의 : 하리 HIFE 집중실험에 참여한 연구팀들의 관측 시스템 및 연구 목적을 간략히 소개하고 이들간의 국내 공동 연구 및 네트워크 구축의 필요성에 대하여 소개한다.(중략)

• The KIPS Transactions:PartD
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• v.9D no.6
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• pp.1105-1112
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• 2002

Nowadays the information exchange based on XML such as B2B electronic commerce is spreading. Therefore a systematic and stable management mechanism for storing the exchanged information is needed. For this goal there are many research activities for concerning the connection between XML application and relational databases. But because XML data has hierarchical structure and relational databases can store only flat-structured data, we need to make a conversion rule which changes the hierarchical architecture to a 2-dimensional format. Accordingly the modeling methodology for storing such structured information in relational databases is needed. In order to build good quality application systems, modeling is an important first step. In 1997, the OMG adopted the UML as its standard modeling language. Since industry has warmly embraced UML, its popularity should become more important in the future. So a design methodology based on UML is needed to develop efficient XML applications. In this paper, we propose a unified design methodology for XML applications based on relational database using UML. To reach these goals, first we introduce a XML modeling methodology to design W3C XML schema using UML and second we propose data modeling methodology for relational database schema to store XML data efficiently in relational databases.

• Journal of Animal Environmental Science
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• v.17 no.sup
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• pp.61-68
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• 2011

To assess the total cost with all stages of facilities, the feasibility of Life Cycle Cost (LCC) analysis was examined in this study to estimate the livestock manure treatment system and optimal decision making process. For the economic evaluation, the plant/equipment investment and annual operation cost of four Public Livestock Recycling Facilities, whose treatment capacity is 100 ton piggery manure per day, was compared. The initial cost was in the range of 2,699 million won to 3,202 million won, where T and E methods were highest and lowest, respectively. The annual operation cost was in the level of 378 million to 498 million won, which decreased in the following order : T method > J method > E method > B method. For the LCC analysis, 4.7% of interest rate, 3.13% of inflation rate, and 1.52% of net discount rate was considered by the data received from Bank of Korea and Statics Korea in the period of 2000 to 2009. Also, for the calculation of present value factor, the durable years of civil engineering & construction, machinery and electric instrument was 30 years, 10 years and 15 years, respectively. Based on these consideration, operation cost was in the range of 17,570 won/ton to 20,661 won/ton, and E method (17,570 won/ton) was economical and B method (20,661 won/ton) was non-economical. Though initial cost of T method was higher than that of B method, LCC analysis of T method was lower than that of T method due to the lower operation cost. Therefore, LCC analysis, which considers both initial cost and operation cost, is more reasonable evaluation method than either initial cost or annual operation cost. For the change of LCC analysis according to the uncertainty, the sensitivity analysis was carried out using fluctuation magnitude of discount rate in the period of 2000 to 2009. As a result, LCC analysis evaluated by discount rate was stable for the uncertain factors since the cost leadership did not change even though the sensitivity analysis varied. In summary, the economic evaluation using LCC analysis could be an efficient reference to choose the suitable livestock manure treatment plants. Furthermore, standardization of statement calculation for the actual cost analysis should be conducted and more detailed study is necessary to validate this summary. Therefore, the application of comprehensive technology evaluation, which considers LCC analysis, should contribute in obtaining objectivity and enhancing reliability for the 'Evaluation of Livestock Manure Treatment System and its Technology'.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.359-360
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• 2009

홈 네트워크 구축의 핵심 부품인 전력선 통신용 블로킹 필터를 제조하였으며, 신호 감쇄 특성을 측정하고 적용가능성을 평가 하였다. 전자장 모의 해석을 통하여 자심재료에 대한 포화자속밀도 특성을 분석 하였으며, 최소의 크기를 갖는 I 형상의 자심재료에 $3.2\Phi$의 나동선을 10.5턴 권선하여 대용량 인덕터를 제조하고, $4.3\;{\mu}H$의 인덕턴스를 구현하였다. 설계된 대용량 인덕터를 적용하여 30A급의 블로킹 필터를 제조하였고, 1.7 MHz ~ 30 MHz 대역에서의 -60 dB의 신호감쇄 특성을 얻었다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.354-358
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• 2004

There was not the evident analysis about the cutting process of CNC machining, and wouldn't be difficult to estimate the result of machining for the various cutting conditions. Therefore they were not founded the systemic technology about the optimum cutting conditions and selection of cutting tools. So this study have investigated the common facts for needs through the end-mill cutting machining by Machining-Centers or High-speed cutting machines, and developed the user-centered intelligent decision system to selection of the methodology about cutting conditions to improve the machining efficiency of end-mill cutting process.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.3
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• pp.1-8
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• 2009

There are several ways to solve parking problem in the downtown. One of them is to manage parking efficiently, that is, to raise use-efficiency of parking place and to help in the block efficiently, it can prevent disproportion that some parking space is over capacity and the other parking one is under. It causes not only the disproportion of economic efficiency but also the congestion of local road. The precondition to manage parking efficiently is to analyse the parking characteristics. In this paper we build up total D/B by collecting every information about parking space. We developed the Parking Management System by using RFID and Sensor. The efficient Parking Management System is for convenience of drivers and efficient usage of parking space. And this system is also the basic study to be developed as the total Parking Management System by upgrading every information.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.478-482
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• 2006

하천에서의 수질예측은 하천 환경의 관리 및 운영 측면에서 매우 중요하다. 그러나 현재의 수질에 관련된 물관리 운영 체제는 물관련 기관을 대상으로 산재되어 있는 물 정보를 정리하여 D/B로 활용하는 수준에 머무르고 있어 실질적인 정보의 활용과 해석 및 실시간적인 예측기능을 수행할 수 있는 예측시스템의 개발이 요구된다. 따라서 본 연구에서는 수질예측을 위한 시스템의 개발을 위해 신경망 기법을 활용하여 한강유역의 지류인 달천지점의 수질을 예측할 수 있는 지능형 모형을 구축하고 그 적용성을 검증하였다. 개발된 수질예측 시스템은 수자원의 효과적인 활용 및 하천의 중 장기 수질보존 대책 수립에 활용될 수 있을 것으로 기대된다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.3
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• pp.199-205
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• 2011

This paper proposes a framework to predict the mechanical fault of hot rolling mill system (HRMS). The optimum process of HRMS is usually identified by the rotating velocity of working roll. Therefore, observing the velocity of working roll is relevant to early know the HRMS condition. In this paper, we propose the framework which consists of two methods namely spectrum matrix which related to case-based fast Fourier transform(FFT) analysis, and three dimensional condition monitoring based on novel visualization. Validation of the proposed method has been conducted using vibration data acquired from HRMS by accelerometer sensors. The acquired data was also tested by developed software referred as hot rolling mill facility analysis module. The result is plausible and promising, and the developed software will be enhanced to be capable in prediction of remaining useful life of HRMS.