• KIPS Transactions on Software and Data Engineering
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• v.3 no.11
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• pp.503-510
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• 2014

With the development of electronic communication technology, the ship's navigational equipment is being digitized, and it has being studied touch-screen-based navigation user interface. However, due to the influence of environmental factors such as waves, it has a potential problem hazardous marine accident occurs due to incorrect operation, the systematic research in consideration of this be done do not. In this paper, we provide a user interface experimental model to verify the stability that takes into account the external environment of the touch-screen input on. Further, we simulated to verify that the interface of the touch screen, the effect of applying the input delay time and the size of the button is obtained through the experimental model proposed. It will be able to greatly contribute to studies of the interface robust touch screen user errors that can be analyzed by the experimental model is proposed to improve the ship, the overall system stability.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.945-946
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• 2009

현재의 컴퓨터 설문 시스템은 설문의 규칙이나 처리절차들을 하드코딩하는 방식으로 구현하기 때문에 설문이 변경되면 처리엔진을 수정해야 한다. 이것은 설문 처리엔진이 설문에 종속되어 있음을 의미한다. 본 논문에서는 이러한 약점을 해결하고자 능동문서 모델을 이용하여 설문으로부터 처리엔진을 독립시키는 방법을 고안하였다. 능동문서 기반의 설문지는 컨텐츠, 로직, 지식베이스(사용자 응답), 질의로 구성된다. 이 중에서 로직은 다양한 질문유형에 대한 처리 방법을 기술하는 것으로서 어떤 설문 설계자도 정의할 수 있어야 한다. 또한 로직은 직관적으로 서술할 수 있고 실행가능 하도록 XML 형식의 규칙 마크업 언어인 ERML로 표현하였다. ERML로 작성된 로직은 Prolog로 변환된 후 추론기에 등록되며, 사용자 응답에 따라 설문을 제어하고 처리한다. 마지막으로 몇 가지 질문유형을 ERML로 구현하고 설문 시스템(WINAD: The Web Interview System with Active Documents)에 적용한 실험 결과 설문으로부터 처리엔진을 독립시킬 수 있음을 확인했다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.8
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• pp.735-743
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• 2011

In this study, the distribution of surface pressure was measured in a steady state on a turbine blade which was moved the injected region and receded the stagnation region using a linear cascade apparatus. Axial-type blades were used and the blade chord was 200mm. The rectangular nozzle was applied and its size was $200mm{\times}200mm$. The experiment was done at $3{\times}10^5$ of Reynolds number based on the chord. The surface pressures on the blade were measured at three different nozzle angles of $58^{\circ}$, $65^{\circ}$ and $72^{\circ}$ for off-design performance test. In addition, three different solidities of 1.25, 1.38 and 1.67 were applied. From the results, the low solidity caused the low pressure on the blade suction surface at entering region and the reverse rotating force was generated at the low nozzle angle. The positive incidence also made the pressure lower on the suction surface at entering region.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.73-73
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• 2023

전 세계적으로 기후변화의 영향이 심화되면서, 예상치 못한 가뭄 지속에 따른 물부족 문제 역시 심각해지고 있으며, 국제사회 및 국내외 기업들은 기후변화 심화에 따른 물 리스크를 관리하기 위한 Water Positive 시스템의 도입, ESG 경영, 환경공시 강화 등을 추진하고 있다. 우리나라의 경우 최근 광주·전라남도 지역에서 가뭄이 발생하여, 기업과 지역주민들이 물절약 캠페인을 벌이고, 공장 정비 일정을 변경하는 등의 대응을 하고 있으며, 중앙 정부 및 지방 정부 역시 물 부족대응을 위한 다양한 정책을 추진하고 있다. 본 연구는 이와 같이 기후변화로 인해 심화되는 가뭄대응에 대한 경제적 가치를 추정하는 것을 목적으로 수행되었다. 특히 최근 지속되는 가뭄으로 물부족이 심각한 광주 및 전라남도 지역 주민을 대상으로 물부족 문제 대응에 대한 경제적 가치를 산정해보았다. 다양한 시나리오 하에서 분석이 가능하도록 단위 가치를 추정할 수 있는 선택실험법을 적용하였으며, 광주 및 전라남도 지역의 소득이 있는 1,000가구를 대상으로 지역별·연령별 표본설계를 하였다. 조사된 결과를 바탕으로 추정된 경제적 가치는 다양한 물부족 대응 프로젝트, 정책 등의 평가시 기초자료로 활용될 수 있을 것이다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.5
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• pp.383-390
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• 2013

The reduction of the maximum acceleration which causes shock for a missile is very important to prevent abnormal operation of a missile and decrease size and cost of missile components. Because the maximum acceleration created by operation of an ejection gas generator occurs in the initial ejection stage, the design parameters which affect initial ejection stage were examined. The igniter and the nozzle closure were selected as design parameters of a gas generator. The maximum acceleration created by the gas generator was examined experimentally by changing of the design parameters. Finally the reduction effect of the maximum acceleration was compared quantitatively by static fire test of a gas generator. The maximum acceleration of the best model which was applied to each optimal design parameter was about 68% reduced than that of the reference model.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.1097-1103
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• 2010

Injection pressure, an important factor in the filling procedure, should be minimized to enhance injection molding quality. In addition, warping deformation and weld lines, which are representative failures, should be avoided to enhance injection molding quality. To improve injection molding quality, the design procedure for an automotive fog blank cover is divided into two stages. In the first stage, we optimally obtain injection molding process variables that minimize injection pressure and warping deformation by using design of experiments, approximation and optimization techniques equipped in PIAnO (Process Integration, Automation and Optimization), a commercial PIDO (Process Integration and Design Optimization) tool. Then, we determine the thickness of the automotive fog blank cover that enables us to avoid generating weld lines. The design results we obtain in this study are found far better than those of the initial design, which demonstrates the effectiveness of our design method.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.35-38
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• 2005

인버터는 전기적으로 DC(직류)를 AC(교류)로 변환하는 역 변환 장치이며, 상용전원(AC 22V/440V)으로부터 공급된 전력을 입력받아 전압과 주파수를 가변시켜 전동기에 공급함으로써 전동기의 속도를 고효율로 이용하게 제어하는 장치이다. 본 논문에서는 550kW급 IGBT, DIODE의 발열에 의한 인버터 내부의 열 및 온도분포를 ICEPAK 상용코드를 통하여 수치적 해석을 수행하였다. 인버터의 발열은 캐패시터의 수명과 소자들의 오작동 등 많은 열적 문제를 가지고 있으며 Heat-sink, Fan, Duck등을 통하여 전도와 대류가 이루어지는 시스템이다. 인버터은 많은 파라미터들에 의해 온도가 결정되기 때문에 실험을 통한 해석은 제한적 일수 밖에 없다. 따라서 수치해석을 통하여 빠른 시간에 효율적인 열 설계를 할 수 있으며, 인버터의 크기는 최종적으로 Heat-sink의 형상에 따라 달라지므로 이를 최적화 하고 소형화 하는 작업이 필요하다. 인버터의 복잡한 내부구조상 하단부(발열원, Heat-sink, Fan등)만 수치해석을 수행하였을 때와 Full Model과는 $15^{\circ}C$ 온도 차이를 보였다. 최종적으로 인버터의 최적 열 설계를 위하여 Frame위치 변경, Heat-Sink 형상변화등 많은 수치해석을 통하여 만족할 만한 결과를 얻었다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.1
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• pp.86-94
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• 1984

In order to improve the rotational performances of NC lathe spindle system in high speed range, a new type(Floating-type driven by V-belt)spindle system was optimally designed and experimented. Through the results of the experiments, the rotational performances of the new type spindle system was discussed and compared with the three equivalent conventional lathe spindle systems. The spindle rotational accuracy( radial error motion of spindle axis), the accelation and the temperature rise of the front spindle bearings for the non-cutting operation were considered as the spindle rotational performances. The radial error motion of the spindle axis was measured by applying the modified L.R.L. method. Compared with the equivalent conventional spindle systems, the following results were obtained. (1) The new type spindle system reduces the radial error motion of the spindle axis in high speed range(1800rpm-2000rpm). (2) The new type spindle system reduces the acceleration and the temperature rise of the spindle bearings considerably with increasing the spindle speed. It is also confirmed that, by this new type spindle system, the max. allowable speed can be increased with satisfying the spindle rotational performances.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.18 no.1
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• pp.21-28
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• 2005

This study tries to analyzes the torque and engaging time generated in a micro-electromagnetic clutch by using FEM. For the purpose of design change and optimization of the micro-electromagnetic clutch, the torque prediction is very important. We employ a mathematical approach based on the electromagnetic principle. For torque prediction, real material properties are substituted to the constructed axi-symmetric FEM model to obtain the analytical torque and engaging time. The predicted torque and engaging time are compared with those obtained by experiments to discuss the validity of torque and engaging time analysis. The analytical results agrees well with experimental data, therefore explaining the validity of the torque and engaging time prediction method.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.4
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• pp.463-468
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• 2007

Some network equipments made in Korea were exposed to severe earthquake in Japan several years ago. More than a hundred slim base transfer network stations had been seized with the severe earthquake at Nigata and it was reported that less than fifteen sets showed blackout by interruption of electricity, not by the structural failure. The purpose of this paper is to check the structural safety of the network equipments by performing table test, and the static and dynamic finite element analysis. For the dynamic test, the station weighing 200 kg was subjected to the Zone 3 earthquake loading of GR-63-CORE on the shaking table to obtain the dynamic responses to compare with the analysis results. It is shown that the FE analysis results are a little bit larger than that of the experimental values. And the sensitivity analysis and optimization for the natural frequency is performed and it is found that the first natural frequency is sensitive to small design change as shown in the results. And the dynamic response of optimized design is less than the original design.