• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.133-138
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• 2001

The high-speed data service is on the increase and on the development because of using the coaxial cable which hold the most part of subscriber's loop, the transmission rate in a subscriber line has influenced by an external-electromagnetic factor such as the falling of a thunderbolt and the electromagnetic induction on transmission line. this external environment gets the noise of a communications line and then has an influence to the transmission speed and quality for the high-speed data service. this paper makes an analysis of noise characteristic appeared a subscriber communications line, measures a transmission speed per each cable-distance and resolves these relationship by putting the noise, which has affected extensively the transmission quality of ADSL service, into a subscriber line.

• Tunnel and Underground Space
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• v.27 no.4
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• pp.185-194
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• 2017

This technical paper is a study on the unique displacements of Shotcrete Lining at the mined tunnel during excavation period through deep consideration with real time data from monitoring instrumentations correlation with the numerical analysis to identify the rock stresses and the rock spring points at the working face of the Conventional tunnelling by the Drill and Blast, based on the geological face mapping results of the project NS2, Transmission cable tunnel project in Singapore. The created geometry of numerical model was prepared to the real mined tunnel construction site including, vertical shaft, construction adit, tunnel junction area, and 2 enlargement caverns. The convergence measurements by the monitoring instrumentation were performed during the tunnel excavation and shaft sinking construction stages to guarantee the safety of complicated underground structures.

• Journal of Ocean Engineering and Technology
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• v.30 no.6
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• pp.458-467
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• 2016

In this paper, a strongly coupled method for investigating the interaction between a cable and tow-fish is presented. The nodal position finite element method was utilized to analyze the nonlinear cable dynamics, and 6DOF equations of motion were employed to describe the 3D rigid body motion of the tow-fish. Combining cable and tow-fish systems into a single formulation allowed the two nonlinear systems to be strongly coupled into a unified nonlinear system. This strongly coupled system was numerically integrated in the time domain using a predictor/multi-corrector Newmark algorithm. To demonstrate the validity, efficacy, and applicability of the current approach, two different scenarios (virtual and sea trial) were simulated, and the simulation results were validated using the physical plausibility and the sea trial test.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.367-370
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• 2001

This paper proposes a new deterioration diagnostic technique for power facilities by analyzing the pulse-height analysis of leakage current. Until now, various deterioration diagnostic techniques to prevent power system failures by deterioration of power facilities are suggested, and most of which measures leakage current amplitude only as a estimation parameter. In this experiment, it is known that the pulse heights of the leakage current are increased according to deterioration progress as well as there comes remarkable changes in pulse height distribution thereto. Therefore, the use of pulse height distribution in deterioration diagnostic technique makes more accurate diagnosis than the conventional method by using only leakage current value. From the application test, it is confirmed that the proposed technique has sufficient performance to diagnose deterioration of power facilities.

• Journal of IKEEE
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• v.23 no.1
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• pp.159-163
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• 2019

The food service industry has been grown due to improvement of living standards. In addition, the demand for frozen food delivery is increasing day by day at online/offline and the refrigerated vehicles are used in most of these food distributions. One of the most important factors in a refrigerated car is to measure the temperature accurately. Conventional temperature recording systems are generally connected directly to temperature sensor modules. Since the temperature data are transmitted to the temperature recorder by using the electric wire, there is a disadvantage that the resistance error must be compensated according to the cable length. In this paper, we propose a method to correct errors due to cable resistance using digital processing and CAN (Controller Area Network) communication. We use PT-1000 platinum sensor to increase the accuracy of the temperature measurement.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.6
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• pp.609-616
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• 2011

In the study, we analyzed the collision characteristics of a so-called arch-type submarine cable protector by considering the changes in drop heights of a stock anchor and material models for concrete and steel reinforcing bars. We considered plastic kinematics model and Johnson-Holmquist Concrete model for the concrete and linear elastic model and plastic kinematics model for the reinforcing bars. The drop heights of 2-ton stock anchor were selected as 3, 5, and 8.83m, respectively. ANSYS, a finite element analysis program, was used for the collision analysis. To save computational time, we converted those drop heights into initial velocities by the principle of energy conservation. From the sensitivity of the material models on the drop height changes, it is shown that the collision response of the reinforcing bars is sensitive firstly on the steel models and secondly on the concrete models, while the collision response of the concrete is sensitive only on the concrete models.

• Journal of KIISE:Information Networking
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• v.36 no.5
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• pp.376-382
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• 2009

The recent growth of cable broadcast technology such as Tru2Way enables the cable service operator to provide more enhanced experiences to cable TV audience. As a result, various applications have been produced and user can easily access cable network to receive multimedia content as well as interactive application in cable environment. In order for current cable technology to be accepted as a web extended technology, a process of web based applications having a web document and multimedia resources, proper web service definition and middleware architecture for existing cable environment should be established. In this paper, we define a web application for cable environment and propose a middIeware architecture which can process web application based on Tru2Way technology

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.1
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• pp.55-63
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• 1993

Finite element analyses are conducted with stochastic elastic moduli when truss structures are subjected to static loads of a deterministic nature. Stochastic stiffness matrix is derived from stochastic shape functions and numerical analyses are performed within the framework of the Monte Carlo method. Analysis methods are verified for the space truss and applied to cable stayed bridge for determining the cable force.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.4
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• pp.53-62
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• 1996

작물의 최대 수확을 위한 관개계획은 작물의 수분장력 스트래스와 삼투스트래스를 최소화 시킬 수 있도록 언제 얼마의 물을 어떤 속도로 공급해 줄 것인가를 결정하는 것이다. 이는 토양, 작물 및 대기의 여러 가지 요소를 측정하여 결정할 수 있다. 관개속도는 주로 토양의 투수계수에 의하여 결정되지만 관개시간과 양은 토양함수량과 경우에 따라서는 토양염도에 의하여 결정된다. Time Domain Reflectometry (TDR)는 한 개의 탐침으로 토양 함수량과 토양염도를 동시에 측정하는 새로운 기법이다. TDR의 측정원리와 상업용 TDR장비에 대하여 자세히 설명하였다. TDR 탐침의 간격, 직경 및 길이의 제한요소를 토양함수량과 전기전도도의 함수로 나타내었다. 토양 columm 및 현장에서의 TDR 전극 삽입과 케이블테스터의 신속한 분리기법과 토양층에 TDR 탐침을 영구히 설치하는 기법에 대하여 자세히 설명하였다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.12a
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• pp.691-700
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• 2003

어디서나 접속할 수 있는 인터넷의 광역성과 최근 들어 인터넷을 통한 전자상거래의 급진전, 네트웍을 통한 다양한 형태의 원격 접속 확대 등으로 이제 많은 기업들이 통신비가 상대적으로 저렴하면 서도 기밀성이 보장되는 인터넷을 기반으로 하는 Internet Protocol Virtual Private Network(IP VPN) 도입을 서두르고 있다 VPN은 공중망 인프라를 공유하여 구축된 가상 사설망을 의미한다. IP VPN으로 기업은 본사와 지사를 연결하는 Intranet, 협력사와 연결되는 Extranet 그리고 최근 들어 급증하고 있는 이동 근무자와 재택 근무자를 회사에 안전하게 연결시킬 수 있는 원격 접속 등을 경제적으로 구축할 수 있다. 또한 광케이블과 동축케이블이 혼합된 Hybrid Fiber & Coaxial(HFC)망이 초고속인터넷, 디지털방송, 주문형비디오(VOD) 등의 멀티미디어 서비스를 수용하기에 가장 좋은 방안으로 최근 각광을 받고 있다. HFC망은 기존의 CATV망을 기반으로 하므로 신규 투자비가 적게 들면서도 다양한 형태의 고속 데이터 통신이 가능하다. 이에 본 논문에서는 HFC망에서의 IP VPN의 성능을 전송 프로토콜과 암호화 알고리즘을 달리 하면서 어떤 요소가 성능에 얼마나 영향을 주는지와 요소간 상호작용이 어떻게 일어나는지, 또한 어떤 조합으로 VPN 통신을 할 때 가장 좋은 성능을 보이는지를 비교 분석한다.