• Journal of Power System Engineering
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• v.5 no.2
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• pp.43-49
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• 2001

For machining auto-mobile cam, the developed biarcs-fitting method eliminates the ridge problems in conventional straight-line fitting approximation or single-arc fitting of curve tool path where it leaves ridges of tool marks on the machined surface of the workpiece. The powerful advantage of this biarc method is demonstrated by applying it to the numerically controlled machining of a curved cam profile, also verified by using a CNC simulating program for auto-mobile cam profile. As a result, this algorithm may be used in CNC milling and turning for cam profile machining with short block line.

• Transactions of Materials Processing
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• v.12 no.8
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• pp.738-743
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• 2003

The major problems of a plastic injection mould can be devided into two kinds, one is in mould another in injected parts. Most of defects of the former comes from mould design, such as, structure and working. The latter are weld line, warpage, sink mark, burning, flow mark, scratching, shading, black hole and so on. Most of problems in injection molding are difficult to find the reason because of complexity. The purpose of this paper is to improve the quality of plastic injection mould and parts with inquiring the counter plan and analizing troubles of the part of Flat TV Front Cover by flow control method and gas-assisted injection moulding. For minimizing defects of the injection moulded parts, computer aided simulation method for injection mould filling was used. Based on these numerical results, the guidelines of mould design and injection processing condition were established. As a result, the improvement of quality, such as minimizing surface defects of injection moulding parts and troubles in mould was achieved.

• Journal of the Korean Society of Clothing and Textiles
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• v.20 no.3
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• pp.452-466
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• 1996

The purpose of this study is to proviede basic data for designing sports-brassiere by a questionnaire survey about sports-brassieres preferences and physiological wearing test. The results of the survey and the physiological wearing tests on sports-brassieres are as follow; 1. According to the survey, dissatisfied factors on the sports-brassiere are "drooping and vibrating of the breasts". Preferable factors are supporting breasts by stretch and seldom changing its position by motion. The bigger cup-size and more hemispherical-type causes more discontent than flat-type. 2. The shape of breasts is oval, on what ground, horizontal line is longer than vertical. For the cross section of bust line, shirts type.brassiere is more gently curved than cup-brassiere. 3. The feeling of wearing comfort is correlated with bust.up, shield, close adhesion. The vibration of breasts is correlated with covering urea and close adhesion, and the changing band's position by movement, close adhesion. Too much covering area or strain are in inverse correlation of the comfort. 4. The rate of prevention of vibration is 75~80% on superior sports-brassieres, which has broad covering area and excellent close adhesion. adhesion.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1550-1556
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• 2009

The sophisticated technologies, ensuring both stability and curving performance, are required for the medium high speed train running on conventional railway line where tangent and curved section mixed together. We can hardly meet the both requirements conflicting each other with the conventional type of bogie. Effective solution is to apply stabilizing mechanism for the bogie design, which increase hunting stability or dynamically critical speed while maintaining curving performance. In this research the numerical analysis by means of multi-body dynamic simulation S/W, experiments by using roller test rig and main line running test have been comprehensively performed for the 200km/h Korean Tilting Train with newly developed stabilizer. The paper proposes the effectiveness of stabilizer and its usefulness based on the results of analyses.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.215-219
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• 2009

For the effective manufacture of doubly curved metal plates, a line array roll set (LARS) process is proposed. The suggested process utilizes a pair of upper and lower symmetric roll assemblies. In the process, the initial plate is progressed into the final shape in a stepwise or pathwise manner according to the basic principle of the incremental forming process. In this work, the intermediate shape which is closest to a final shape is proposed to fabricate the desired shape effectively in design of forming schedule. The intermediate shape has homogeneous curvature in a longitudinal and transverse direction so that it can be fabricated easily without complicated controls of rolls in the roll set. The method of approximation using genetic algorithm is proposed and applied to some actual ship hulls to evaluate the efficiency of the algorithm.

• Journal of Korea Society of Industrial Information Systems
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• v.8 no.2
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• pp.21-29
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• 2003

The thinning algorithms using 8-neighbors connection value can extract the skeleton of a character almost similar to the original pattern by using the connection value representing connectivity of each pixel. This paper considers the erosion phenomenon which appears in the thinning algorithm using 8-neighbors connection value without skeleton disappearance phenomenon. The experimental results show that the proposed thinning algorithm can be applied to the application of both a straight line segment and a curved line segment.

• Proceeding of KASS Symposium
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• 2006.05a
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• pp.205-213
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• 2006

Membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The design procedure of membrane structures are needed to do shape finding, stress-deformation analysis and cutting pattern generation, because the material property has strong axial stiffness, but little bending stiffness. The problem of cutting pattern is highly varied in their size, curvature and material stiffness. So, the approximation inherent in cooing pattern generation methods is quite different. Therefore the ordinary computer software of structural analysis & design is not suitable for membrane structures. In this study, we develop the program for cutting pattern generation using geodesic line, and investigate the result of example's cutting pattern in detail.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6B
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• pp.993-1001
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• 2000

This research features a method that quantitatively evaluates the performance of edge detection algorithms. Contrary to conventional methods that evaluate the performance of edge detection as a function of the amount of noise added to he input image, the proposed method is capable of assessing the performance of edge detection algorithms based on chosen parameters that influence the performance of edge detection. We have proposed a quantitative measure, called average performance index, that compares the average performance of different edge detection algorithms. We have applied the method to the commonly used edge detectors, Sobel, LOG(Laplacian of Gaussian), and Canny edge detectors for noisy images that contain straight line edges and curved line edges. Two kinds of noises i.e, Gaussian and impulse noises, are used. Experimental results show that our method of quantitatively evaluating the performance of edge detection algorithms can facilitate the selection of the optimal dge detection algorithm for a given task.

• The Journal of Korean Physical Therapy
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• v.26 no.6
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• pp.398-402
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• 2014

Purpose: This study was carried out in order to verify actual applicability of mental practice in the clinical field by applying it to Parkinson disease patients. Methods: : The number of subjects was three and they were aged between 65 and 69. One year or longer period has passed since they were diagnosed with Parkinson disease. The baseline A consisted of three sessions. After the baseline period, the researcher applied mental practice to the subjects once per day, for 20 minutes per each time, for 10 sessions. The no-intervention withdrawal phase was composed of three sessions. Outcome measures 10 meter walking test(10MWT), timed up and go (TUG) test, 8-figure walk test (8FWT). Results: All results indicated that 10 MWT, TUG, F8WT was improved when compared mental practice(B) to pre base line(A). base line(A) after mental practice intervention(B) was also sustained. Conclusion: As a result of the mental practice, we can know that it helps straight gait, dynamic balance, curved gait to improve.

• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.119-124
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• 2019

Radiation therapy using flattening filter free beam can prevent beam attenuation caused by flattening filter and can improve treatment efficiency. However, accurate dose control is not established for nonuniform iso dose distributions. In this study, curved dosimeter based on photoconductive material $HgI_2$ was fabricated and its reproducibility and linearity were evaluated at 6 MV photon energy to verify its performance. In order to show the usefulness of the curved measurement, the signals measured on the flat substrate and the curved substrate were compared in the flattening filter free beam using the acrylic filter. As a result, the reproducibility of the unit cell dosimeter was evaluated as SE 0.613%, and the linearity was evaluated as R-sq 0.9999. The usability evaluation of the array curve dosimeter demonstrated its usefulness by indicating a curvature error rate of 11.073%p and a reduced error rate.