• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.3
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• pp.673-681
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• 2007

The integration of Quality Circles and Six-Sigma has gained attentions for the attainment of enhanced customer satisfaction, costs reduction, and improved business performance. The purpose of this paper is to verify the benefit from the integration of Quality Circles and Six-Sigma by applying the integrated process for an alcohol manufacturing line. In the integrated process, we used the first three steps of Six-Sigma of Define, Measure, and Analyze(D-M-A) and then applied the concept of Quality Circle, which has good performance in the Improvement and Control(I-C) process. For the selection of the theme of quality circles, Analytic Hierarch Process(AHP) is used, and we also employed the experimental design, which is designed to find an optimal operating condition. Furthermore, the results of the economic analysis confirm that the integration process would be successful in reducing the incidence of defects and the quality cost.

• School Mathematics
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• v.16 no.1
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• pp.57-81
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• 2014

This study was to investigate how the underachievers of mathematics in a non-leveling excellent high school would overcome the errors through the lessons based on the inductive thinking model in the equation of a circle. The results showed that when there were many stages to solve the problem, the students gave it up or forgot the stage they reached. In this case, if they had a revisit-opportunity to review their thinking process by planning ahead the stage to solve the problem and recording it, the omission error of the solving process and the error of wrong conclusions would be dramatically decreased. Moreover, they understood the mathematical concept, principle, and formula and remembered the learning contents extremely well through thinking by themselves in exploration-based activities and by using visualization for the problem and could solve the problem through these pictures besides algebraic expressions.

• Proceeding of KASS Symposium
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• 2006.05a
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• pp.91-101
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• 2006

We have conducted the study about the shelter effect against the wind by using the wind fence with various porosities and the measured distance from the wind fence, in three different types of it ; (Circle wind fence, Vertical wind fence, Horizontal wind fence) The shelter effect and turbulence characteristics of the selected wind barrier is throughly investigated by wind tunnel test. flow characteristics of velocities and turbulences behind wind fence were measured using hot-wire anemometer. we characterize the turbulence behind the wind fence by varying the porosity of 0 %, 20 %, 40%, and 60%, and the distances from the wind fence from 1 H to 9 H with maintaining the uniform flow velocity of 6 m/s. In addition, we investigated the overall characterization of the wind fence by measuring total of twenty eight points on the wind fence, which forms the lattice structure on it with seven points in lateral direction and four points in vertical direction. The results of analysis from the circle wind fence indicate that the degree of the turbulence is lowered and the velocity of the wind is decreased when the porosity of 40 % are used at the distance from 3 H to 9 H. On the other hand, the vertical, horizontal wind fence with the porosity of 20% is more advantageous at the distance of 2 H to 9 H. For the effectiveness of the wind fence depending on the position, the center part is the greatest and it decreases at the edges with 10 % to 30 % less than that of at the center.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.8
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• pp.845-852
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• 2012

The diaphragm-type stylus probe was developed for ultra-precision on-machine measurement (OMM) application. This probe is equipped with two diaphragms which are parallel and one capacitive sensor is used for detecting the vertical motion of end tip in the stylus when it is contacted to the optical freeform surface. For better performance of proposed probes, several design parameters such as axial stiffness and the lateral deformations were investigated with finite element analysis techniques. To verify the feasibility, the profiles of the master sphere ball were measured on the ultra-precision milling machine. The measurement results show that the proposed probe can calculate the radius of the circle within the accuracy of 0.1 ${\mu}m$ for the ultraprecision optical surface.

• ETRI Journal
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• v.32 no.6
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• pp.871-880
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• 2010

Many applications dealing with image management need a technique for removing duplicate images or for grouping related (near-duplicate) images in a database. This paper proposes a concentric circle-based image signature which makes it possible to detect near-duplicates rapidly and accurately. An image is partitioned by radius and angle levels from the center of the image. Feature values are calculated using the average or variation between the partitioned sub-regions. The feature values distributed in sequence are formed into an image signature by hash generation. The hashing facilitates storage space reduction and fast matching. The performance was evaluated through discriminability and robustness tests. Using these tests, the particularity among the different images and the invariability among the modified images are verified, respectively. In addition, we also measured the discriminability and robustness by the distribution analysis of the hashed bits. The proposed method is robust to various modifications, as shown by its average detection rate of 98.99%. The experimental results showed that the proposed method is suitable for near-duplicate detection in large databases.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.1
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• pp.1-10
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• 2020

In the previous study, a shooting trajectory assuming that the purse seine shooting trajectory is a circle was proposed based on the speed and direction of the movement of the fish school. However, in practice, a trajectory that is closer to an elliptical shape than a circular one is often formed. In this study, the existing circular trajectory and the elliptical trajectory methods were compared under the same conditions to confirm the effectiveness of elliptical shooting trajectory. In addition, changes in the eccentricity of ellipses were derived to assess which type of ellipse was appropriate as a shooting trajectory. When a high-speed fish school moves in a straight line, an elliptical shooting trajectory with the eccentricity of 0.7 to 0.9 will be reasonable, and for middle-low speed fish school, an elliptical shooting trajectory with the eccentricity of 0.4 to 0.6 will be more useful than a circle shooting trajectory.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.5
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• pp.971-976
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• 2000

The main objective of this paper is to present the rain cell size distribution observed during squall line episodes in the Sudano-Sahelian region. The used data were collected during the EPSAT Program [Etude des Precipitation par SATellite (Satellites Study of Precipitation)] which has been developed since 1958, on an experimental area located near Niamey, Niger (2 10′32"E, 13 28′38"N). The data were obtained with a C-band radar and a network composed of approximately 100 raingages over a 10,000 $\textrm{km}^2$. In this work a culling of the squall line episodes was made for the 1992 rainy season. After radar data calibration using the raingage network a number of PPI (Plan Position Indicator) images were generated. Each image was then treated in order to obtain a series of radar reflectivity (Z) maps. To describe the cell distribution, a contouring program was used to analyze the areas with rain rate greater than or equal to the contour threshold (R$\geq$$\tau$). 24700 contours were generated, where each iso-pleth belongs to a predefined threshold. Computing each cell surface and relating its area to an equi-circle (a circle having the same area as the cell), a statistical analysis was made. The results show that the number of rain cells having a given size is an inverse exponential function of the equivalent radius. The average and median equivalent radii ate 1.4 and 0.69 In respectively. Implications of these results for the precipitation estimation using threshold methods are discussed.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.146-149
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• 1997

Computerized densitometry was developed or the quantitative measurement of diffuse retinal nerve fiber layer (RNFL) atrophy and intra- and inter-operator reliability and clinical validity of this system were evaluated. Vertical diameter, center of the optic disc, and peripapillary circles which had radii of 1.5 and 2.5 times that of the optic disc were user-interactively determined in digitized RNFL photograph and density profile along each circle was measured and normalized. The areas under the normalized density profiles of the superior and the inferior segments in both circle were used or the study of RNFL. To determine the variability and correspondence in the measurements of density variations, 21 RNFL photographs of glaucoma patients which showed varying degrees of atrophy underwent computerized densitometry by two operators on two separate occasions. Coefficient of variation in the densitometric measurements was $1.2{\sim}5.4%$. Intra- and inter-operator reliabilities were excellent. The correlations between the densitometric values and mean deviations of Humphrey C30-2 visual field showed statistical significance. Computerized densitometry of RNFL photographs was useful in the objective and quantitative assessment of diffuse RNFL atrophy.

• Geomechanics and Engineering
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• v.9 no.1
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• pp.115-124
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• 2015

Determination of mobilized shear strength parameters (that identify stresses on the failure plane) is required for analyzing the stability by limit equilibrium method. Generalized Hoek-Brown (GHB) and Mohr-Coulomb (MC) failure criteria are usually used for obtaining stresses on the plane of failure. In the present paper, the applicability of these criteria for determining the stresses on failure plane is investigated. The comparison is based on stresses on the real failure plane which are obtained from the Mohr stress circle. To do so, 18 sets of data (consist of principal stresses and angle of failure plane) presented in the literature are used. In addition, the values account for (VAF) and the root mean square error (RMSE) indices were calculated to check the determination performance of the obtained results. Values of VAF and RMSE for the normal stresses on the failure plane evaluated from MC are 49% and 31.5 where for GHB are 55% and 30.5, respectively. Also, for the shear stresses on failure plane, they are 74% and 36 for MC, 76% and 34.5 for GHB. Results show that the obtained stresses and angles of failure plane for each criterion differ from real ones, but GHB results are closer to the empirical results. Also, it is inferred that results are affected by the failure envelope not real failure plane. Therefore, obtained shear strength parameters are not mobilized. Finally, a multivariable regressed relation is presented for determining the stresses on the failure plane.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.11
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• pp.61-68
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• 2004

Recently, there has been an increasing demand for computer-vision based inspection and/or measurement system as a part of factory automation equipment. Existing manual inspection method can inspect only specific samples and has low measuring accuracy as well as it increases working time. Thus, in order to improve the objectivity and reproducibility, computer-aided analysis method is needed. In this paper, front and side profile inspection and/or data transfer system are developed using computer-vision during the inspection process on three kinds of pipes coming from a forming line. Straight line and circle are extracted from profiles obtained from vision using Laplace operator. To reduce inspection time, Hough Transform is used with clustering method for straight line detection and the center points and diameters of inner and outer circle are found to determine eccentricity and whether good or bad. Also, an inspection system has been built that each pipe's data and images of good/bad test are stored as files and transferred to the server so that the center can manage them.