• 연구논문집
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• 통권28호
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• pp.5-12
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• 1998

Test Results and Status of development of the urban transit maglev system (UTM-0l) are reported. Maglev Project Team in KIMM, in cooperation with Hyundai Precision Company and the Korea Electrotechnology Research Institute (KERI). has successfully finished the second stage development project (1995.5-1998.8) and demonstrated a prototype two vehicle consisted urban maglev train operating in the speed range of 50 km/h. In this paper, we report various test results of the UTM-01 system. present status of quo and future prospect, and what have been done so far to improve the performance of the maglev system overall.

• 한국군사과학기술학회지
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• 제14권3호
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• pp.353-358
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• 2011

In this paper, we have introduced a Missile In the Loop Simulation(MILS) Software developed for the missile ground test, which is based on a commercial hard real-time operating system(OS) on Windows platform called as Real-Time eXtension(RTX). MILS software makes it possible to test overall system functions of a integrated missile on the ground in the flight conditions by real-time imitating its inertial data. By means of MILS, we have performed missiles ground tests, which result in successful real flight tests.

• International Journal of Control, Automation, and Systems
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• 제5권5호
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• pp.515-525
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• 2007

In this paper, we develop a co-design methodology of stochastic optimal controllers and network parameters that optimizes the overall quality of control (QoC) in networked control systems (NCSs). A new dynamic model for NCSs is provided. The relationship between the system stability and performance and the sampling frequency is investigated, and the analysis of co-design of control and network parameters is presented to determine the working range of the sampling frequency in an NCS. This optimal sampling frequency range is derived based on the system dynamics and the network characteristics such as data rate, time-delay upper bound, data-packet size, and device processing time. With the optimal sampling frequency, stochastic optimal controllers are designed to improve the overall QoC in an NCS. This co-design methodology is a useful rule of thumb to choose the network and control parameters for NCS implementation. The feasibility and effectiveness of this co-design methodology is verified experimentally by our NCS test bed, a ball magnetic-levitation (maglev) system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1480-1483
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• 2009

The KNR wayside and onboard subsystem has completed commissioning tests applicable to the Pilot Line section by BOMBARDIER. Andreas Hardt/Assessor and Rod Muttram/VP, Quality & safety approved the Automatic Train Protection(ATP) System. However additional evidences are necessary to come to a Specific Application, which is mandatory to approve the Generic Applications included for commercial running on the overall main line railway with ATP. According to Factory Acceptance Test plan, CBC, CBF, LEU(Line Electronic Unit) made by domestic factory is tested by official recognition test Standards-Setting Agency. It is important to verify quality which form checklist during Factory Acceptance Test. In this paper, review the process, test item, norm and checklist for the CBC, CBF, LEU.

• Journal of Biosystems Engineering
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• 제26권2호
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• pp.105-114
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• 2001

Modulus of elasticity, modulus of rigidity, damping ratio, and natural frequency of three varieties of boxthorn (Lycium chinense Mill) (Cheongyang #2, Cheongyang gugija, and Cheongyang native) branches were analyzed. Modulus of elasticity and modulus of elasticity and modulus of rigidity of the boxthorn branch was determined using standard formula after simple beam bending and torsion test, respectively, using an universal testing machine. Damping ratio and natural frequency of branches were determined using a system consisted of an accelerometer, a PC equipped with A/D converter, and a software for data analysis. Relationship between the elastic modulus and branch diameter in overall varieties and branch types showed a good correlation (r -0.81). There was, however, no correlation between torsional rigidity and branch diameter. The internal damping results were highly variable and the overall range of the damping ratio of the boxthorn branch was 0.014-0.087, which indicated that the branch was a lightly damped structure. The natural frequency of the boxthorn branch was in the range of 89-363 rad/s for the overall varieties and branch types. A good correlation (r 0.82) existed between the natural frequency and branch diameter in overall varieties and branch type.

• Journal of Electrical Engineering and information Science
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• 제2권5호
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• pp.45-50
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• 1997

This paper present an advanced fault diagnosis expert system to assist the operators at local control center. The system utilizes all th information available in a local control center for the better diagnostic performance. The major feature of the system is dealing with multiple faults diagnosis based on the certainty factor method for the reasoning process. the overall performance and the generality are also enhanced by utilizing the general topological knowledge. ASCADA simulator is also developed for he test and demonstration.

• 대한기계학회논문집
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• 제19권4호
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• pp.1125-1133
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• 1995

Experiments were performed to investigate the condensing heat transfer characteristics of non-azeotropic mixtures of R-22 and R-114 in a heat pump system with a horizontal smooth tube as a condenser. The ranges of parameters, such as heating capacity, mass flow rate of refrigerant and quality were 780-3,480W, 24-71kg/h, and 0-1, respectively. The overall compositions of R-22 in a R-22/114 mixture were 25, 50, 75 and 100 per cent by wight. The results show that the overall condensing heat transfer coefficients for the mixtures were lower than the pure R-22 values. Local heat transfer coefficient of the pure R-22 was hghest at the top of the test tube. The local heat transfer coefficient of R-22/114 (50/50 wt%) at side and bottom of the test tube was higher than that at the top. From the obtained data, a prediction for the condensing heat transfer coefficients of the mixture was done based on the method of Fujii.

• 동력기계공학회지
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• 제9권2호
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• pp.88-92
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• 2005

The experiment of thermal performance about closed-wet cooling tower was conducted in this study. A closed cooling tower is a device similar to a general cooling tower, but with cooling tower replaced by a heat exchanger. The test section for this experiment has the process that the cooling water flows from the top of the heat exchanger to the bottom side in the inner part of the tube, and spray water flows in the gravitational direction in the outer side. Air comes in direct contact with the spray water at the outer side of the tube while passing from the lower the upper part having a counterflow to the spray water. The heat transfer pipe used in this experiment is a bare-type tube having an outer diameter of 15.88mm. The heat exchanger is consisted of seven rows and fifteen columns. In this experiment, thermal performance of the cooling tower is derived from overall heat transfer coefficients between the process fluid and sprayed water and volumetric overall mass transfer coefficient between sprayed water and air.

• 정보과학회 논문지
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• 제41권11호
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• pp.911-920
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• 2014

본 논문은 기계학습을 기반으로 하는 중등수준의 단문형 영어작문 자동채점시스템에 대해 제안한다. 본 논문에서는 기계학습을 이용한 영어 자동채점의 전반적인 수행 방법과 시스템의 구성 및 동작방식, 채점자질의 고려사항에 대해 논한다. 학생 답안의 내용 완성도를 평가하기 위하여 문서의 내용을 요약한 "개념답안"을 제안하여 사용하였다. 본 연구에서는 여러 개의 기계학습 알고리즘을 사용하여 자동평가를 수행한다. 자동평가의 성능을 향상시키기 위해 여러 개의 기계학습 알고리즘의 결과를 최적으로 결합하여 하나의 최종 결과를 도출할 수 있는 "최적조합" 결정과정을 제안한다. 실제 학생들의 작문 데이터를 이용하여 시스템을 구축하고 자동채점 시스템의 성능 평가를 수행하였다.

• 한국철도학회논문집
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• 제9권6호
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• pp.671-676
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• 2006

A measurement system was developed in this study. It conducts on-line testing and evaluation of tilting train express(TTX). The measurement system is installed in each train for the performance measurement during the test run. It is composed of software part, hardware part and can measure various signals such as vehicle velocity, catenary voltage, motor temperature. The software controls the hardware of the measurement system, performs the analysis and calculation of measurement data and acts as interface between users and the system hardware. The hardware is consisted of 7 DAMs(Data Acquisition Modules) and 6 monitoring modules.