• 제어로봇시스템학회논문지
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• 제11권8호
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• pp.704-708
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• 2005

In this paper, a simple idea is proposed to change the compliance center of the Remote Center Compliance (RCC) by adjusting the elasticity of the Elastomer Shear Pad (ESP). To vary the elasticity of the ESP, a hole is made in the ESP along its stiffness axis, and a stiffness adjusting rod (SAR) is inserted into the hole. By adjusting the insertion depth of the rod, lateral stiffness of the ESP can be varied, and the compliance center of the VRCC can be controlled accordingly. To verify the effectiveness of the proposed idea, a prototype VRCC is designed and, the position of the compliance center with various lengths of the inserted rod are measured.

• 대한토목학회논문집
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• 제14권3호
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• pp.487-493
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• 1994

강절(剛節) 뼈대 구조물(構造物)의 해석(解析)에 적용하는 모멘트 분배법은 총조정(總調整) 모멘트라는 개념을 이용하여 연립방정식(聯立方程式)으로 간단히 표현된다. 이 방정식(方程式)은 간단한 손계산기(hand calculator)로 직접 작성되고 쉽게 풀어질 수 있다. 이 방정식(조정방정식(調整方程式))은 무한번의 분배 과정을 완료한 상태를 나타내며 그 해는 소거법(消去法)으로 풀 수도 있으나 일종의 이완방정식(弛緩方程式)으로써 되풀이 산법을 사용하면 간단히 풀어진다. 이 방법이 연속량(連續梁)의 휨 모멘트 계산이나 영향선(影響線) 해석(解析)에 어떻게 이용될 수 있는 지를 두개의 예제로서 설명하였다. 특히 영향선의 해법은 전산에 편리하도록 행렬(行列)로 표현하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.772-775
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• 2006

Muilti-dimensional feature vector matching algorithm uses multiple features such as intensity, gradient, variance, first or second derivative of a pixel to find correspondence pixels in stereo images. In this paper, we proposed a new method for adjusting automatically the weight of feature in multi-dimensional feature vector matching considering sharpeness of a pixel in feature vector distance curve. The sharpeness consists of minimum and maximum vector distances of a small window mask. In the experiment we used IKONOS satellite stereo imagery and obtained accurate matching results comparable to the manual weight-adjusting method.

• Journal of Advanced Marine Engineering and Technology
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• 제24권4호
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• pp.470-477
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• 2000

The states of control loops in existing actual systems are changed according to time varying conditions of controllest process and other system components. Adjusting control parameters properly at site which is performed generally by Ziegler & Nichols mthod is important for safe and efficient operation, but the method may require much time to adjust and not easy to inexperienced engineers. This study is aimed to propose more handy method to adjust control parameters by plotting operating conditions on the space of adjusting parameters. One loop of model control system without perturbation condition has been adopted and its stability limit was plotted on the coordinates of Gain and Integral time which was acquired after analyzing Nyquist diagrams and time domain responses. The result showed that the sets of adjusting parameters according to critical stability and proper stability could be acquired reasonably through both responses and the curves on parameter space revealed available patterns for the purpose of easy maintenance of control characteristics.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.203.2-203.2
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• 2005

• 콘크리트학회논문집
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• 제25권4호
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• pp.429-438
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• 2013

콘크리트 장기변형이 합성단면과 부재의 경계조건에 의해 내 외부 구속된 구조물에 단계별계산법(SSM)을 적용하 기위해 축-휨 요소가 적용된 객체지향 전산구조해석 프로그램이 개발되었다. 단순 및 연속 지지된 PS 콘크리트 박스 및 합성거더, 연속 강합성거더의 조립식 바닥판, 단순 프리플렉스 합성거더에 대한 SSM의 전산구조해석 결과 구속정도가 클수록 수정계수는 감소하였다. 수정계수의 감소에 대해 선인장의 손실률에는 큰 변화가 없으나, 선압축의 손실률은 급격히 증가하였다. 연속보의 내부지점에서 선압축의 손실률은 더욱 증가하였다. 이는 선인장의 손실에 기초한 설계는 내 외부 구속 정도가 큰 구조물에 대한 선압축의 손실을 과소평가할 수 있음을 보여준다. 전산구조해석을 만족하는 크리프의 수정계수는 0.35~0.95의 값이었으며, 수정 계수는 콘크리트 장기변형의 내 외부 구속의 정도를 나타내는 지표로 사용될 수 있다. 도로교설계기준의 수정계수 0.5는 긴장력이 도입된 강합성단면의 조립식 바닥판에 대해서는 부적절하며, 2007년 도입된 AASHTO LRFD 도로교설계기준(2008)과 한계상태에 대한 도로교설계기준의 긴장력 손실에 적용된 수정계수 0.7과 0.8은 PS 콘크리트 합성거더의 연속화에 대한 손실률을 과소평가한다. 복합구조 합성단면의 수정계수는 0.4 이하의 값이 적절하다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제9권3호
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• pp.292-304
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• 2017

High-speed vessels are prone to the surf-riding in adverse quartering seas. The possibility of mitigating the surf-riding of the ITTC A2 fishing vessel in the design stage is investigated using the 6-DOF weakly non-linear model developed for surf-riding simulations in quartering seas. The longitudinal position of the ship's center of buoyancy (LCB) is chosen as the design parameter. The adjusting of LCB is achieved by changing frame area curves, and hull surfaces are reconstructed accordingly using the Radial Basis Function (RBF). Surf-riding motions in regular following seas for cases with different LCBs and Froude numbers are simulated using the numerical model. Results show that the surf-riding cannot be prevented by the adjusting of LCB. However, it occurs with a higher threshold speed when ship's center of buoyancy (COB) is moved towards stem compared to moving towards stern, which is mainly due to the differences on wave resistance caused by the adjusting of LCB.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.467-470
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• 2002

The offects of a small control rod (d=3mm) located near a main circular cylinder on the drag reduction and wake structure modification were investigated. The location of the small control rod mounted on a rod-like spring is self-adjusting according to the wake structure far optimal control of the flow around the main cylinder. The experiments were carried out at the Reynolds numbers based on the cylinder diameter (D=50mm) in the range $Re_{D}=1{\times}10^4{\~}6{\times}10^4$. Mean velocity and turbulent statistics were measured with varying the angle along the cylinder circumference ${\Theta}=15^{\circ},\;30^{\circ},\;45^{\circ}$ and the distance between the main and control rods L =0.7, 1. Compared with the bare cylinder, the main circular cylinder with the fixed and self-adjusting rods reduced drag coefficient by $10{\%}$ at the angle of ${\Theta}=45^{\circ}$. For the main cylinder with self-adjusting rot as the Reynolds numbers increase, the streamwise mean velocity is increased, however, the turbulence intensity is decreased. In addition, the control rods tested in this study are effective at higher Reynolds number than at lower Reynolds number.

• 정보교육학회논문지
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• 제8권3호
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• pp.307-317
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• 2004

웹 기반 교육 환경에서 학습자 특성에 따른 개별 적응적인 피드백 제공의 필요성에도 불구하고 학습자 특성의 변인 도출의 어려움과 이를 위한 체계적인 전략과 실천 도구 개발이 미흡한 실정이다. 본 연구에서는 웹 기반 교수 학습 환경에서 중요시되고 있는 학습자 특성 변인 중에서 학습자의 학습 패턴을 Apriori 알고리즘을 이용하여 분석하고, 유사한 학습 패턴을 갖는 학습자들로 그룹화 하였다. 이를 기반으로 학습자 개인에게 학습 콘텐츠, 학습 경로, 학습 상황 등을 제공하기 위한 e-SRM 피드백 시스템을 설계하고 개발하였다. 개발된 시스템은 학습자 특성에 맞는 최적의 학습 환경을 제공해 줄 수 있는 기반을 조성할 수 있을 것으로 기대된다.

• Wind and Structures
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• 제36권4호
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• pp.249-261
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• 2023

Aerodynamic force coefficients are generally prescribed by an ensemble average of ten and/or twenty 10-minute samples. However, this makes it difficult to identify the exact probability distribution and exceedance probability of the prescribed values. In this study, 12,600 10-minute samples on three tall buildings were measured, and the probability distributions were first identified and the aerodynamic force coefficients corresponding to the specific non-exceedance probabilities (cumulative probabilities) of wind load were then evaluated. It was found that the probability distributions of the mean and fluctuating aerodynamic force coefficients followed a normal distribution. The ratios of aerodynamic force coefficients corresponding to the specific non-exceedance probabilities (C_f,Non) to the ensemble average of 12,600 samples (C_f,Ens), which was defined as an adjusting factor (C_f,Non/C_f,Ens), were less than 2%. The effect of coefficient of variation of wind speed on the adjusting factor is larger than that of the annual non-exceedance probability of wind load. The non-exceedance probabilities of the aerodynamic force coefficient is between P_C,nonex = 50% and 60% regardless of force components and aspect ratios. The adjusting factors from the Gumbel distribution were larger than those from the normal distribution.