• Journal of the Korean GEO-environmental Society
• /
• v.18 no.3
• /
• pp.25-30
• /
• 2017

This paper introduces a novel method to quantify the morphological evolution of the strain response envelope. The strain response envelope is defined as an image in strain increment space corresponding to the unit stress input in stress space. Based on the shape of strain response envelopes, the deformation characteristics of soils can be described using the framework of elastic-plastic theory. Fourier descriptor analysis was used to investigate the morphological characteristics of strain response envelopes. The numerical results show that when the stress input remains in the initial yield surface the Fourier descriptors remain constant. Once the stress input crosses the initial yield surface, every descriptors deals in this study change. Numerical and experimental results of this study show that clear yielding response is only found in natural block samples. Among the Fourier descriptors, the descriptor called as asymmetry is the best for detecting the yield and is minimally sensitive to the number of input stress paths.

• Journal of the Korean Society for Railway
• /
• v.15 no.5
• /
• pp.447-453
• /
• 2012

It is studied that the structure of the contact plane geometry of the contact wire would be changed when the contact wire tension is increased in the existing overhead contact lines for the purpose of improving the operation speed temporarily. In this paper, the dropper length formula which could be well applied to the pre-sagged catenary is reviewed first. Second, the changing amount of the pre-sag if the contact wire tension change from 20kN to 23kN or from 20kN to 25kN for the Gyeongbu HSL(high speed line) 49.5m catenary is evaluated by using of the self-written program in accordance with the dropper length formula. Moreover, the increasing tension and measuring the pre-sag change experiment in the Gyeongbu 2 HSL was conducted. The calculated data are compared with the measured data. As a result, it is found that the geometry change is very little and will not make the current collection performance deteriorated.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2007.05a
• /
• pp.1737-1741
• /
• 2007

Using kinematic wave equation, the influence of moving rainstorms to runoff was analysised with a focus on watershed shapes and rainfall distribution types. Watershed shapes used are the oblong, square and elongated shape, and the distribution types of moving storms used are uniform, advanced and intermediate type. The runoff hydrographs according to the rainfall distribution types were simulated and the characteristics were explored for the storms moving down, up and cross the watershed with various velocity. And the hydrographs were compared in the case of varing the rainstorm intensity and varing the rainstorm length in order to make the same total runoff volume. When the rainstorm intensity was varied the shape, peak time and peak runoff of a runoff hydrograph are significantly influenced by spatial and temporal variability in rainfall and watershed shapes. The peak time of down and upstream moving strorms appeared latest in the case of the elongated shape basin, meanwhile at cross stream moving storms, the peak time of elongated shape basin is earlier than the others. For storms moving downstream peak time was more delayed than for other storm direction in the case of elongated watershed. The runoff volume and time base of the hydrograph decreased with the increasing storm speed.

• Journal of the Microelectronics and Packaging Society
• /
• v.14 no.3
• /
• pp.51-55
• /
• 2007

Nickel iron (Ni-Fe) alloy coating was investigated. The effects of the current density, current type, pulse duration and bath compositions on the morphologies and surface hardness of nickeliron deposits as well as the chemical compositions were investigated. The morphologies, surface hardness and chemical compositions of nickel-iron deposits were varied with current density, current type and bath compositions. The surface hardness was increased up to $550{\sim}600Hv$ when PC plating was employed. Crackless coating was obtained when saccharin was added. The change of composition with thickness was analyzed with EDS and FESEM.

• KIPS Transactions on Software and Data Engineering
• /
• v.7 no.2
• /
• pp.63-68
• /
• 2018

Interests in face recognition area have been increasing due to diverse emerging applications. Face recognition algorithm from a two-dimensional source could be challenging in dealing with some circumstances such as face orientation, illuminance degree, face details such as with/without glasses and various expressions, like, smiling or crying. Hopfield Network capabilities have been used specially within the areas of recalling patterns, generalizations, familiarity recognitions and error corrections. Based on those abilities, a specific experimentation is conducted in this paper to apply the Redundant Parallel Hopfield Network on a face recognition problem. This new design has been experimentally confirmed and tested to be robust in any kind of practical situations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1995.10a
• /
• pp.25-31
• /
• 1995

본 연구는 방음벽의 성능예측을 위해 BEM의 접근 방법을 시도하였으며 범용 음향 소프트웨어인 Sys-noise 5.2의 direct collocation bem을 사용하여 반무한 평면 방음벽에 대한 해석을 수행하였으며, 그 결과를 검증하기 위해 Maekawa에 의한 근사해와 해석적 점근해에 비교하였다. 또한, 수음점이 방음벽으로부터 떨어진 거리, 방음벽의 폭, 방음벽의 높이에 따른 삽입손실을 계산하였고, 방음벽에 흡음처리를 한 경우와 방음벽상단의 형상변화에 따른 삽입손실의 변화를 계산하였다.

• The Journal of the Acoustical Society of Korea
• /
• v.17 no.3
• /
• pp.37-46
• /
• 1998

본 연구에서는 압전 세라믹인 PZT를 이용하여 두께 진동모드의 다중모드 필터를 설계, 제작하였다. 다중모드 세라믹필터의 등가회로를 설계하였고, 이를 이용하여 설계변수 인 물성변수와 형상변수에 따른 필터전달특성의 경향을 분석하였다. 이를 바탕으로 10.7MHz의 중심주파수를 가지는 세라믹필터를 제작하였고, 설계변수 중에서 압전세라믹 기 판과 전극형상의 변화에 따른 필터의 전달특성의 변화를 실험적으로 검증하였다. 본 연구를 통한 경향분석결과는 다양한 진동모드와 다양한 주파수대를 가지는 다중모드 필터를 설계하 는데 있어서 유용한 도구로 사용될 수 있을 것이다.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2001.10a
• /
• pp.31-32
• /
• 2001

어구의 형상과 움직임은 어구를 구성하는 부품의 물리적인 특성 및 어구의 디자인과 예망속력 및 끌줄 길이의 변화와 같은 어구 조작방법에 따라 달라지며, 이러한 변화는 어획량에 매우 큰 영향을 미친다. 따라서 어구의 디자인과 어구 조작방법에 따라 달라지는 어구의 형상과 거동을 예측할 수 있다면 성능이 우수한 어구를 개발할 수 있으며, 어구를 운용하는데 있어서도 중요한 정보를 얻을 수 있다. (중략)

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2013.05a
• /
• pp.145-145
• /
• 2013

저가 공정으로 진행되는 전기 방사 기법을 이용하여 태양전지용 구리 섬유를 제작하였다. 전기 방사 용액은 PVP, 에탄올, 염화 구리의 혼합액을 사용하였고, 금속염의 농도와 인가전압 변화에 따라 다양한 직경의 섬유가 제작되었다. 또한, 무질서 하게 방사되는 섬유의 배열 제어를 위해 컬렉터 형상을 변화하였다. 컬렉터에 형성된 고분자-구리 복합섬유를 채취한 후 열처리와 환원 처리를 통하여 구리 섬유를 얻었다. 환원된 금속 섬유는 scanning electron scope(SEM)을 통해 형상을 관찰하였으며, 4단자법으로 섬유의 전기적 특성에 관하여 알아보았다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2005.11a
• /
• pp.301-304
• /
• 2005

본 논문은 개폐기의 접점 형상에 따른 전계 분포 특성을 2차계 전자계 해석 program인 Flux-2D를 통해 살펴보았다. 2개의 모델을 선정하여 전극간 이격거리를 115[mm], 120[mm], 125[mm]로 변화를 주었을 때 최고 전계 강도의 변화를 살펴보았다. 1000[V] 인가시 최고 전계 강도는 (a)모델에서 115[mm]일 때 61.84[V/m], (b)모델에서 115[mm]일 때 66.90[V/m]로 나타났다.