• Journal of Institute of Control, Robotics and Systems
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• v.6 no.6
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• pp.500-505
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• 2000

This paper deals with wafer temperature uniformity control essential in rapid thermal processing (RTP). One of the important control objectives of RTP is to keep the temperature over the wafer surface as uniformly as possible. For this, a discrete time state equation around the operating point is first identified by using the subspace fitting method, and a multivariable LQG(Linear Quadratic Gaussian) controller is designed based on the identified model. Simulation and experimental results show improvement in temperature uniformity over the conventional PID method.

• Bulletin of the Korean Mathematical Society
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• v.42 no.1
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• pp.179-188
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• 2005

We give a method to derive partial differential equations for the product of any two classical orthogonal polynomials in one variable and thus find several new differential equations. We also explain with an example that our method can be extended to a more general case such as product of two sets of orthogonal functions.

• Journal of Biomedical Engineering Research
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• v.3 no.2
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• pp.65-70
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• 1982

This paper presents a new method of solving the electric potential distribution using the finite element method. The thoracic region surrounded by the body surface and the heart is discretized into finite elements and the Continuous Laplace-equation is transformed into one of the finite degrees of freedom. The current source density, the conductivity, and the excitable range is obtained by the references. From the result of simulation, it was revealed that the potential pattern of in homogeneity was much different from that of homogeneity.

• Asian Journal of Turfgrass Science
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• v.9 no.2
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• pp.131-136
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• 1995

The herb, shrub, understory and canopy strata, which arbitrarily delineated by size classes, were sampled separately. The former one were sampled by the pin-point quadrat method. And remaining three by size quadrats, diversity (H= =$\Sigma$ Pi log Pi) of of each stratum was estimated for each set of census data. Species diversity within a stratum was independent of sample plot size above a minimum cumulative area. Diversity based on plotless and plot samples could he determined by the same equation, and by pooling the data needed to estimate diversity of each stratum.

• Journal of applied mathematics & informatics
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• v.23 no.1_2
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• pp.311-319
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• 2007

This article studies a modified BFGS algorithm for solving smooth unconstrained strongly convex minimization problem. The modified BFGS method is based on the new quasi-Newton equation $B_k+1{^s}_k=yk\;where\;y_k^*=yk+A_ks_k\;and\;A_k$ is a matrix. Wei, Li and Qi [WLQ] have proven that the average performance of two of those algorithms is better than that of the classical one. In this paper, we prove the global convergence of these algorithms associated to a general line search rule.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.05a
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• pp.215-221
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• 2005

In this paper, we propose a method to a synchronization of chaotic UAVs that have unstable limit cycles in a chaos trajectory surface. We assume all obstacles in the chaos trajectory surface have a Van der Pol equation with an unstable limit cycle. The proposed methods are assumed that if one of two chaotic UAVs receives the synchronization command, the other UAV also follows the same trajectory during chaotic UAVs search on the arbitrary surface.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.7
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• pp.52-61
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• 1992

An iterative scheme for computing the three-dimensional position and the surface orientation of an opaque object from a singel shaded image is proposed. This method demonstrates that calculating the depth(distance) between the camera and the object from one shaded video image is possible. Most previous research works on $'Shape from Shading$' problem, even in the $'Photometric Stereo Method$', invoved the determination of surface orientation only. To measure the depth of an object, depth of the object, and the reflectance properties of the surface. Assuming that the object surface is uniform Lambertian the measured intensity level at a given image pixel*x,y0becomes a function of surface orientation and depth component of the object. Derived Image Irradiance Equation can`t be solved without further informations since three unknown variables(p,q and D) are in one nonlinear equation. As an additional constraints we assume that surface satisfy smoothness conditions. Then equation can be solved relaxatively using standard methods of TEX>$'Calculus of VariationTEX>$'. After checking the sensitivity of the algorithm to the errors ininput parameters, the theoretical results is tested by experiments. Three objects (plane, cylinder, and sphere)are used. Thees initial results are very encouraging since they match the theoretical calculations within 20$\%$ error in simple experiments.> error in simple experiments.

• Spatial Information Research
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• v.11 no.3
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• pp.241-249
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• 2003

The purpose of this paper is to provide the basic data to select the most proper site, which is essential for the economic activation of North Korea by means of the GIS tool. In this purpose, firstly, Nampo area is sampled as model case, classifying the factors into the natural environmental one and socio- cultural one. Secondly, to analyze the land use status and topographic status which is essential for natural environment factor. Besides USLE(Universal Soil Loss Equation), which is one of the disaster effect assessments, is being applied to suggest the selection method for minimizing the environment change by way of assuming the land effluence amount. The started could advance to prove the ideal model in selecting the most suitable site while minimizing the environmental change by means of the composite tool of GIS and USLE.

• Journal of Biosystems Engineering
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• v.32 no.4
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• pp.256-262
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• 2007

Image processing systems have been used to measure the plant parameters such as size, shape and structure of plants. There are yet some limited applications for evaluating plant colors due to illumination conditions. This study was focused to present adaptive methods to analyze plant leaf color regardless of illumination conditions. Color patches attached on the calibration bars were selected to represent leaf colors of lettuces and to test a possibility of health monitoring of lettuces. Repeatability of assigning leaf colors to color patches was investigated by two-tailed t-test for paired comparison. It resulted that there were no differences of assignment histogram between two images of one lettuce that were acquired at different light conditions. It supported that use of the calibration bars proposed for leaf color analysis provided color constancy, which was one of the most important issues in a video color analysis. A health discrimination equation was developed to classify lettuces into one of two classes, SOUND group and POOR group, using the machine vision. The classification accuracy of the developed health discrimination equation was 80.8%, compared to farmers' decision. This study could provide a feasible method to develop a standard color chart for evaluating leaf colors of plants and plant health monitoring system using the machine vision.

• Journal of the Korean Society of Mechanical Technology
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• v.20 no.6
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• pp.844-851
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• 2018

In this study, the regression equation was suggested to predict of the shot ball velocity according to blade shapes based on discrete element (DE) analysis. First, the flat type blade DE model was used in the analysis, the validity of the DE model was verified by giving that the velocity of the shot ball almost equal to the theoretical one. Next, the DE analyses for curved and combined blade models was accomplished, and their analytical velocities of shot ball were compared with the theoretical one. The velocity of combined blade model was greatest. From this, the regression equation for velocity of shot ball according to the blade shape based on the DE analysis was derived. Additionally, the wind speed measurement experiment was carried out, and the experimental result and analytical one were the same. Ultimately, it was confirmed that the prediction method of the velocity of shot ball based on DE analysis was effective.