• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1995.04a
• /
• pp.787-796
• /
• 1995

A man model is a useful design tool for the evaluation of man machine systems and products. An arm reach trajectory prediction for such a model will be specifically useful to present human activities and, consequently, could increase the accuracy and reality of the evaluation. In this study, a three-dimensional reach trajectory prediction model was developed using an inverse kinematics technique. The upper body was modeled as a four link open kinematic chain with seven degrees of freedom. The Resolved Motion Method used for the robot kinematics problem was used to predict the joint movements. The cost function of the perceived discomfort developed using the central composite design was also used as a performance function. This model predicts the posture by moving the joints to minimize the discomfort on the constraint of the end effector velocity directed to a target point. The results of the pairwise t-test showed that all the joint coordinates except the shoulder joint's showed statistically no differences at .alpha. = 0.01. The reach trajectory prediction model developed in this study was found to accurately simulate human arm reach trajectory and the model will help understand the human arm reach movement.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.1148-1154
• /
• 2006

Composite discharge capacity tests and smear effect tests are carried out to estimate the parameters for the reliability-based design of vertical drain method. Also the probabilistic and deterministic solutions of radial consolidation theory are presented. It compared to the result of reliability-based design and that of deterministic design using the tested and estimated parameters. The results indicated that the drain spacing is larger the deterministic method than the probabilistic method because the former is not considered the uncertainties in the properties of soil. The divergence of methods is dependent on the probability of achieving target degree of consolidation by a given time and the coefficient of variation(COV) of the coefficient of horizontal consolidation$(c_h)$.

• 제어로봇시스템학회:학술대회논문집
• /
• 1991.10a
• /
• pp.872-877
• /
• 1991

This paper presents the composite control method using fuzzy and neural network theory. Fuzzy theory is applied to make control rules and neural net is used to learn them and to generate proper control signals. The electric furnace is controlled to maintain the desired temperature and to minimize the fluctuation of the temperatures in various locations inside the furnace. This controller consists of three neural nets which deal with the average of the temperatures, variances of them and the temperature stabilizing mechanism. Experiments are performed with the target temperatures of 70.deg. C and 80.deg. C. Test results show that this simple method is very effective.

• Steel and Composite Structures
• /
• v.25 no.4
• /
• pp.473-484
• /
• 2017

In this study a seismic retrofit scheme for a building structure was presented using steel plate slit dampers. The energy dissipation capacity of the slit damper used in the retrofit was verified by cyclic loading test. Genetic algorithm was applied to find out the optimum locations of the slit dampers satisfying the target displacement. The seismic retrofit of the model structure using the slit dampers was compared with the retrofit with enlarging shear walls. A simple damper distribution method was proposed using the capacity spectrum method along with the damper distribution pattern proportional to the inter-story drifts. The validity of the simple story-wise damper distribution procedure was verified by comparing the results of genetic algorithm. It was observed that the capacity-spectrum method combined with the simple damper distribution pattern leaded to satisfactory story-wise distribution of dampers compatible with the optimum solution obtained from genetic algorithm.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.04a
• /
• pp.451-454
• /
• 2003

Nonpoint source pollution of groundwater and subsurface water from irrigated agriculture is a major concern in many areas. In this study we aimed to investigate the effect of the water applied by irrigation in agricultural area on the transport of nitrogen and phosphorus originated from fertilizers applied to the surface of soil in agricultural activities. We first conducted investigation on the resdual concentrations of soil N and P in a selected agricultural area. And simulating the target area by column studies in the laboratory leaching extent of various components from the composite and urea fertilizers applied on the soil surface during irrigation was studied. Infiltration of water enhanced the leaching of nitrogen and phosphorus in both the rice paddy field soil and the patch soil. The downward N and P transport with infiltrating water was more pronounced in the patch soil column and the increased residual concentrations of N and P in the lower sections in the patch soil column was found with time.

• Progress in Superconductivity and Cryogenics
• /
• v.16 no.4
• /
• pp.53-56
• /
• 2014

A numerical method of magnetic field calculation for the air-core solenoid is presented in this paper. In application of the Biot-Savart law, the magnetic field induced from the source current can be obtained by a double integration ormula. The numerical method named composite Simpson's rule for the integration is applied to the program and the adaptive quadrature method is used to adjust the step size in the calculation according to the precision we need. When the target point is in the solenoid and the intergrand's denominator may be zeroin the process of calculation, the method sill can provide an appropriate result. We have developed a program which calculates the magnetic field with at least 1ppm precision and named it as rzBI() to implement this method. The method has been used in the design of an MRI magnet, and the result show it is very flexible and convenient.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.04a
• /
• pp.328-330
• /
• 2004

현재 CC는 하나의 제품으로 이루어진 단일 TOE(Target of Evaluation)를 기준으로 작성된 것이며, 여러 제품으로 이루어진 시스템에 대해서는 다루고 있지 않다. 또한 국ㆍ내외적으로 정보보호제품 분류체계가 서로 달라 표준화가 이루어져야 한다. 이에 본 논문에서는 CC기반 통합제품의 산출 모델 및 평가업무량 알고리즘을 제시하고, 환경에 따른 표준화된 정보보호제품 분류체계를 제시한다.

• Journal of the Korean Vacuum Society
• /
• v.7 no.s1
• /
• pp.25-29
• /
• 1998

$SiO_2$ thin films embedded with Ge microcrystallites (Ge-$SiO_2$) were prepared by use of r.f. co-sputtering technique from a Ge, $SiO_2$ composite target. The size of Ge crystallites can been modulated by the experiment parameters. The optical absorption and non-linear optical properties of Ge-$SiO_2$ films were measured. The blue shift of the optical absorption edge, the saturated absorption and two-photon absorption under the condition of resonant absorption have been observed, and are discussed according to the quantum confinement effect.

• Journal of the Korean Vacuum Society
• /
• v.7 no.s1
• /
• pp.197-201
• /
• 1998

Ge quantum dots in $SiO_2$ thin films were prepared by r.f. magnetron co-sputtering using a Ge, $SiO_2$ composite target. The size of quantum dots was modulated by controlling of substrate temperature during depositing and annealing of samples deposited at certain substrate temperature. A series of work was done on the influence of preparing parameters on the growth of quantum dots, and a discussion on the formation and growth of quantum dots under different preparation parameters is given.

• Steel and Composite Structures
• /
• v.25 no.1
• /
• pp.45-55
• /
• 2017

Stainless steel exhibits high ductility and strain hardening capacity in comparison with carbon steel widely used in constructions. To analyze the particular behaviour of stainless steel cover-plate joints, an experimental study was conducted. It showed large ductility and complex failure modes of the joints. A non-linear finite element model was developed to predict the main parameters influencing the behaviour of these joints. The results of this deterministic model allow us to built a meta-model by using the quadratic response surface method, in order to allow for efficient reliability analysis. This analysis is then applied to the assessment of design formulae in the currently used codes of practice. The reliability analysis has shown that the stainless steel joint design according to Eurocodes leads to much lower failure probabilities than the Eurocodes target reliability for carbon steel, which incites revising the resisting model evaluation and consequently reducing stainless steel joint costs. This approach can be used as a basis to evaluate a wide range of steel joints involving complex failure modes, particularly bearing failure.