• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.4
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• pp.341-346
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• 2011

In the development of high-speed trains, ride comfort is an important factor that determines the quality of the train. In this study, the ride comforts of high-speed trains with rigid and flexible car bodies were evaluated. The rail irregularity is used as an exciting source of the car-body bounce motion. The complex extruded structures of the car-body are modeled as shell structures using the calculated equivalent stiffness of the flexible model. The numerical results show that the ride of the rigid-body model improves as the speed increases, which is unreasonable. In contrast, the relationship between ride comfort and speed in the case of flexible-body model is reasonable. Thus, it is confirmed that the flexibility of the car body needs to be taken into consideration while fabricating a high-speed train.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.2
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• pp.141-147
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• 2016

NHPP software reliability models for failure analysis can have, in the literature, exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, infinite failures NHPP models that repairing software failure point in time reflects the situation, was presented for comparing property. Commonly used in the field of software reliability based on Flexible Weibull extension distribution software reliability of infinite failures was presented for comparison problem. The result is that a relatively small shaping parameter was effectively. The parameters estimation using maximum likelihood estimation was conducted and model selection was performed using the mean square error and the coefficient of determination.. In this research, software developers to identify software failure property follows shape parameter, some extent be able to help is considered.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.2
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• pp.51-57
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• 2010

The shape of the register mark for the image processing becomes very important, because the printing quality is determined by the error correction between the register marks for the image processing. In this paper, printing marks are developed using the image process for the gravure printing method which is commonly being used in roll to roll, high resolution printing. The marks which can be cited to the flexible display print are developed The developed register marks which satisfies 10[${\mu}m$] error tolerance are tested under 70[mpm] printing conditions and confirmed through the experiments.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.7
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• pp.562-567
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• 2016

Morphing wing which has a configuration optimized to flight speed and condition is faced to a lot of barriers to be overcome such as actuator technique, structural mechanization technique, flexible skin material, control law, and so on. As the first step for developing a morphing wing with rapid response, we designed and fabricated the morphing airfoil using a SMA(shape memory alloy) wire actuator and torsional bias springs. The design concept of the morphing airfoil was verified through operation test. The measured results show that the flap deflects smoothly and fast.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.12 no.3
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• pp.139-148
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• 2000

In this paper, the interaction of oblique incident waves with a bottom-mounted and fluid-filled flexible membrane structure is investigated in the frame of linear hydro-elastic theory. The static shape of a membrane structure containing the fluid of a specific density is initially unknown and must be calculated before the hydrodynamic analysis. To solve hydrodynamic problem, the fluid domain is divided into the inner and outer region. The inner solution based on discrete membrane dynamic model and simple-source distribution over the entire fluid boundaries is matched to the outer solution ba~ed on an eigenfunction expansion method. The numerical results were compared to a series of Ohyama's experimental results. The measured reflection and tran¬smission coefficients reasonably follow the trend of predicted values. Using the computer program developed, the performance of a bottom-mounted and fluid-filled flexible membrane strocture is tested with various system parameters (membrane shape, internal pressure, density ratio) and wave characteristics (wave frequencies, incident wave angle). It is found that a bottom-mounted and fluid-filled flexible membrane structure can be an effel;tive wave barrier if properly designed.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.688-690
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• 2003

본 논문에서는 다해상도 2차원 실루엣 영상들을 이용하여 3차원 모델간의 형상 유사성을 비교하기 위한 방법을 제안한다. 제안 시스템은 포즈 정규화 모듈, 유사성 계산 모듈, 3차원 시각화 모듈로 구성된다. 형상 비교를 위해서 먼저, 3차원 인체 장기 모델을 입력으로 받아서 정규화를 수행하고, 다해상도 깊이맵을 획득한다. 이어서 유사성 비교를 위해 실루엣 영상을 추출한 후, 유사도 측정을 위해 시그니쳐를 측도로 사용한다. 최종적으로 계산된 결과들은 3차원 글리프 및 컬러 코딩을 이용하여 시각화된다. 본 논문에서 제시한 3차원 형상 비교 시스템은 전처리 단계에서의 정규화 수행을 통하여 스케일 및 회전 변환에 불변하는 특성을 보인다. 그리고 다양한 레벨의 깊이맵을 형상 비교에 사용하여 다해상도 기반의 유사성 평가를 지원하며, 평가 계산 속도와 정확성간의 유연성을 제공한다. 또한 3차원 히스토그램. 3차윈 글리프. 컬러 코딩 시각화 기법들과 2차원 실루엣 피킹 인터페이스를 통하여 인체 장기 모델간의 정량적 형상 차이를 사용자가 직관적으로 평가할 수 있도록 한다. 본 시스템은 차후 데이터베이스를 이용한 원격 진료 시스템에서의 질병 진단, 추적 관찰. 치료계획 등에 활용될 수 있을 것이다.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1135-1139
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• 2007

청계천 복원의 효과가 하천의 형상, 종 조성, 종 다양성 변화의 유연성 및 환경 개선 효과 측면에서 검토되었다. 복원된 청계천은 하천의 종단 및 횡단 형상에서 모두 낮은 자연성을 나타내었다. 종 조성은 부분적으로 자연하천과 유사한 조성을 보였으나 전반적으로 낮은 자연성을 보였다. 종 다양성은 비교적 낮았지만 복원의 역사를 고려할 때 양호한 것으로 평가되었다. 하류와 수변에서는 홍수 후 많은 변화를 가져와 자연으로 회귀할 가능성도 보였지만 상류와 홍수터 이상에서는 변화의 유연성이 낮아 자연으로 회귀하는데 많은 시간이 소요될 것으로 평가되었다. 인공위성 영상 분석 결과, 복원된 청계천은 기온 완화 효과를 나타내었다. 그 밖에 복원된 청계천은 그 주변의 분산된 녹지를 연결하여 그린네트워크를 구축하고자 할 때 핵심적 역할을 할 것으로 기대되어 경관생태적 측면에서의 환경개선효과도 기대되었다.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.90-92
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• 2005

Magnetic Fluid Linear Pump(MFLP)는 자성유체의 자기적 성질과 유체의 성질을 이용하여 일반적인 펌프의 기어 대신 자성유체를 이용하여 기계적 진동이나 소음을 최소화한 시스템이다. MFLP는 구조가 간단하고 동작전류에 의해 쉽게 조절할 수 있다. MFLP의 동작전류에 의해 발생한 자기장의 정도에 따라 유연하면서 펌핑력이 높은 동작이 가능하다. 따라서 MFLP를 운전하는데 있어 동작전류의 패턴과 크기, 중첩정도에 따른 펌핑력이 변하게 되며, 이에 따른 자기장과 관내의 자성유체의 형상을 해석하여 유연하고 펌핑력이 높은 MFLP의 운전방식을 개발하고자 하였다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.6
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• pp.681-689
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• 2009

Disk grinding was often applied to deburring process in order to enhance the final product quality. Inherent chamfering capability of the flexible disk grinding process in the early stage was analyzed with respect to various process parameters including workpiece length, wheel speed, depth of cut and feed. Initial chamfered edge defined as arc zone was characterized with local radius of curvature. Averaged radius and arc zone ratio was well evaluated using neural network system. Additional neural network analysis adding workpiece length showed enhance performance in predicting arc zone ratio and curvature radius with reduced error rate. A process condition design parameter was estimated using remaining input and output parameters with the prediction error rate lower than 2.0% depending on the relevant input parameter combination and neural network structure composition.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.8
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• pp.114-121
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• 1995

This paper describes a method which uses rail curves for blending surfaces. Blending surface between the free form surfaces which have the flexible shapes and are widely used today is investigated. The rail curves give blending surface continuty through Pointwise interpola- tion. It is the point in this paper that the blending surfaces give a good flexibility to modeling of base free form surfaces. Using rail curves for simple base surfaces, complicated models can be designed. Also this blending surfaces can be used for path generation in compoud surfaces.