• Title/Summary/Keyword: Adjusting

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Development of a Variable Remote Center Compliance (VRCC) with Stiffness Adjusting Rods. (탄성 조절 막대를 이용한 가변형 원격 순응 중심 장치 개발에 관한 연구)

  • Lee, Sang-Cheo
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.8
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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.

Adjusting Equation Method (or Relaxation Equation Method) and its Application to the Influence Line Analysis of Continuous Beams (조정방정식법(調整方程式法)(혹은 이완방정식법(弛緩方程式法))과 연속량(連續梁)에의 응용(應用))

  • Cho, Hyun Yung;Kim, Mi Ock
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.3
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    • pp.487-493
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    • 1994
  • Moment distribution procedure in the elastic analysis of rigid frames can be easily expressed with the adjusting moment equations(or relaxation equations) by using the concept of total adjusting moment at each joint after infinite cycles of moment distribution. Adjusting moment equations are a set of simultaneous equations from which the total adjusting moments at each joints after infinite cycles of physical relaxation can be determined. The form of simultaneous equations is a kind of relaxation equations and can be easily solved by the hand calculators. A unique and simplified procedure for the influence line analysis of a continuous beam is presented as an application of the method.

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A METHOD FOR ADJUSTING ADAPTIVELY THE WEIGHT OF FEATURE IN MULTI-DIMENSIONAL FEATURE VECTOR MATCHING

  • Ye, Chul-Soo
    • Proceedings of the KSRS Conference
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    • v.2
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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.

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STUDY ON THE OPERATING CONDITION AND STABILITY OF CONTROL SYSTEM IN THE SPACE OF ADJUSTING PARAMETERS (조정파라미터 공간에서의 제어계 동작점과 안정성에 관한 연구)

  • 최순만
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.4
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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.

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Numerical Evaluation of Stress Loss Rates and Adjusting Coefficients due to Internal and External Constraints of Concrete Long-Term Deformation (콘크리트 장기변형의 내·외부 구속에 의한 응력 손실률 및 수정계수 평가의 전산구조해석)

  • Yon, Jung-Heum;Kim, Hyun-Jin
    • Journal of the Korea Concrete Institute
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    • v.25 no.4
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    • pp.429-438
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    • 2013
  • An object oriented numerical analysis program of axial-flexural elements and the step-by-step method (SSM) has been developed to analyze concrete long-term behaviors of structures constrained internally and externally. The results of the numerical analysis for simple and continuous prestressed (PS) concrete box and composite girders, pre-cast slab of continuous steel composite girder, and simple preflex composite girder show that the adjusting coefficient decreases by increasing constraint. The loss rates of pre-tension force were not sensitive but those of pre-compression force were increased rapidly by decreasing adjusting coefficient. This indicates that the design based on the loss rate of pre-tension can over-estimate the pre-compression force in a concrete section constrained internally and externally. The adjusting coefficients which satisfy results of the numerical analysis are 0.35~0.95, and it can be used as an index of constraint of concrete long-term deformation. The adjusting coefficient 0.5 of Bridge Design Specifications can under-estimate residual stress of PS concrete slab, and the coefficient 0.7 or 0.8 of LRFD Bridge Designing Specifications can under-estimate the loss rates of continuous PS concrete girders. The adjusting coefficient of hybrid structures should be less then 0.4.

On the mitigation of surf-riding by adjusting center of buoyancy in design stage

  • Yu, Liwei;Ma, Ning;Gu, Xiechong
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.9 no.3
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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.

Flow Control of Turbulent Wake Behind a Circular Cylinder Using a Self-adjusting Rod (자율 제어봉을 이용한 실린더 후류의 유동제어에 관한 연구)

  • Lim Hee Chang;Kam Dong Hyuk;Lee Sang Joon
    • Proceedings of the KSME Conference
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    • 2002.08a
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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.

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Design and Implementation of e-SRM System Supporting Individual Adjusting Feedback in Web-based Learning Environment (웹 기반 학습 환경에서 개별 적응적 피드백을 지원하는 e-SRM 시스템의 설계 및 구현)

  • Baek, Jang-Hyeon;Kim, Yung-Sik
    • Journal of The Korean Association of Information Education
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    • v.8 no.3
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    • pp.307-317
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    • 2004
  • In web-based education environment, it is necessary to provide individually adjusting feedback according to learner's characteristic. Despite this necessity, it is a current state that there are difficulties in deriving the variables of learners' characteristics and lack in developing the systematic strategies and practical tools for providing individually adjusting feedback. This study analyzed the learners' learning patterns, one of learner's characteristic variables regarded as important in web-based teaching and learning environment by employing Apriori algorithm, and also grouped the learners by learning pattern. Under this framework, the e-SRM feedback system was designed and developed to provide learning content, learning channel, and learning situation, etc. for individual learners. The proposed system in this study is expected to provide an optimal learning environment complying with learner's characteristic.

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Application of probabilistic method to determination of aerodynamic force coefficients on tall buildings

  • Yong Chul Kim;Shuyang Cao
    • Wind and Structures
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    • v.36 no.4
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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 (Cf,Non) to the ensemble average of 12,600 samples (Cf,Ens), which was defined as an adjusting factor (Cf,Non/Cf,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 PC,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.