• Proceedings of the KIEE Conference
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• 2005.10a
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• pp.197-201
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• 2005

In this paper, an automatic welding carriage is developed by wireless communication. In the developed system, a data transmission of a automatic welding line tracking is adopted by RF communication. Additional, a welding condition of the automatic welding carriage IS displayed by microprocessor. Therefore, the developed system can overcome the restriction of an operating distance and perform an accurate transmission of the control signal.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.784-786
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• 1995

Variable Structure Control(VSC) scheme with sliding mode is widely used to keep a control system insensitive to parameter variations and disturbances. However, the conventional sliding mode control has the undesired phenomenon of chattering which may become a serious problem. Also the restriction of the sliding mode regime cannot guarantee the insensitivity throughout an entire response. In this paper, the sliding surfaces, which are composed of three-line segments, are used to remove the reaching phase. Also, the concept of fuzzy logic is incorporated with the sliding mode control in order to control the unknown or partially known systems effectively. The proposed method is applied to a Double-Sided MM Type LDM to show its usefulness.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.5
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• pp.1011-1018
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• 1992

A series of experiment has been performed on the spray characteristics in a cylindrical confined space with the injection pressure taken as a parameter. By using a single-hole patternator and the Malvern particle sizer, the spray mass flux, drop size and volume concentration distributions along the radial and axial directions were obtained ; the line-of- sight data by Malvern particle sizer have been converted to the ring-of-sight data by using the tomographical transformation techniqe. The experimental results show that, due to the restriction on the ambient gas entrainment by the wall boundary, the effective spray angle is increasing. The spray drops were measured to be smaller in the confined space because of a large number of floating small drops by recirculation of the gas phase and the breakup of large drops by the wall collision. Also the details on the flow behavior of the confined spray are discussed.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.633-635
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• 2007

To cope with increasing power demand in metropolitan area, the power system in Korea has equipped with unit generator of large capacity, high density and uneven distribution, and transmission line of long distance, large capacity and high voltage. As the power system growing up enormous, it has become difficult to maintain the standard voltage in case of radical fluctuation of load or severe change of voltage by power system fault for its weakness of responsive characteristics although the power condenser has been installed to solve the unstability by lack of reactive power. Consequently, we review harmonic wave production and control characteristics to solve unstability problem of voltage in northern metropolitan, to reduce transmission restriction cost and to minimize load shedding by relocation of SVC (Static Var Compensator), which is highly effective for improvement of responsive characteristics for radical voltage fluctuation.

• Structural Engineering and Mechanics
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• v.17 no.6
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• pp.829-862
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• 2004

This paper presents a method for the nonlinear analysis of beam elements subjected to the cyclical combined actions of torsion, biaxial flexure and axial forces based on an extension of the disturbed compression field (DSFM). The theoretical model is based on a hybrid formulation between the full rotation of the cracks model and the fixed direction of the cracking model. The described formulation, which treats cracked concrete as an orthotropic material, includes a new approach for the evaluation of the re-orientation of both the compression field and the deformation field by removing the restriction of their coincidence. A new equation of congruence permits evaluating the deformation of the middle line. The problem consists in the solution of coupled nonlinear simultaneous equations expressing equilibrium, congruence and the constitutive laws. The proposed method makes it possible to determine the deformations of the beam element according to the external stresses applied.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.39
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• pp.255-264
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• 1996

This Paper presents a heuristic algorithm for machine-part group formation considering part production information (Production volume, roution sequence, unit operation time, facility size) in cellular manufacturing logistics system. In general, factory space is restricted within limited size when cells are located. A twofold heuristic algorithm is developed for considering factory space restrictions of located cells. The first phase is a aggregation procedure to minimize inter cell movement for satisfactoring space restriction. The second phase is a rearrangement procedure to maximize line balancing efficiency between machines within the cell and non assigned machine during first phase. Numerical example is presented to verify the efficiency of proposed algorithm.

• International Journal of Advanced Culture Technology
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• v.9 no.3
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• pp.142-151
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• 2021

The content industry was greatly affected by the pandemic that hit the world in 2020. The release and production of major Hollywood films were postponed. Performances, festivals, and mega-events such as tourism and the Olympic Games were also canceled or postponed. The innovation of the content industry became inevitable in line with these rapid environmental changes, and the industry had to undergo internal changes according to these external environmental changes. Representative examples are talent fostering and job creation for young people. This study conducts both SWOT analysis and PEST analysis on the South Korean content industry, thereby analyzing cases of talent fostering and job creation suitable for the new environment.

• Brain Tumor Research and Treatment
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• v.6 no.2
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• pp.92-96
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• 2018

A 59-year-old patient with a history of hepatocellular carcinoma presented with decreased consciousness and left hemiparesis. A rim-enhanced mass lesion without diffusion restriction was observed in contrast-enhanced MRI including diffusion-weighted imaging. Based on these findings, metastatic brain tumor was suspected. However, brain abscess (BA) was diagnosed after multiple bacterial colonies were observed in aspiration biopsy. Initial conventional antibiotic treatment including vancomycin had failed, so linezolid was used as second-line therapy. As a result, infection signs and clinical symptoms were resolved. We report a case with atypical imaging features and antibiotic susceptibility of a BA in an immunocompromised patient undergoing chemotherapy.

• Clinical and Experimental Reproductive Medicine
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• v.43 no.2
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• pp.82-89
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• 2016

Objective: The long interspersed elements (LINE-1, L1s) are a group of genetic elements found in large numbers in the human genome that can translate into phenotype by controlling genes. Growing evidence supports the role of epigenetic in polycystic ovary syndrome (PCOS). The purpose of this study is to evaluate the DNA methylation levels in LINE-1 in a tissue-specific manner using cumulus cells from patients with PCOS compared with normal controls. Methods: The study included 19 patients with PCOS and 22 control patients who were undergoing controlled ovarian hyperstimulation. After oocyte retrieval, cumulus cells were extracted. LINE-1 DNA methylation levels were analysed by bisulfite treatment, polymerase chain reaction, and restriction enzyme digestion. The Connection Up- and Down-Regulation Expression Analysis of Microarrays software package was used to compare the gene regulatory functions of intragenic LINE-1. Results: The results showed higher LINE-1 DNA methylation levels in the cumulus cells of mature oocytes in PCOS patients, 79.14 (${\pm}2.66$) vs. 75.40 (${\pm}4.92$); p=0.004, but no difference in the methylation of cumulus cells in immature oocytes between PCOS and control patients, 70.33 (${\pm}4.79$) vs. 67.79 (${\pm}5.17$); p=0.155. However, LINE-1 DNA methylation levels were found to be higher in the cumulus cells of mature oocytes than in those of immature oocytes in both PCOS and control patients. Conclusion: These findings suggest that the epigenetic modification of LINE-1 DNA may play a role in regulating multiple gene expression that affects the pathophysiology and development of mature oocytes in PCOS.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.11
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• pp.1535-1541
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• 2005

Five broiler chicken lines, namely HC, BPB2, CPB2, PB2 and UM1, involving in a selection program and differing in selection intensity and genetic background, were screened for randomly amplified polymorphic DNA (RAPD) polymorphism using 10 selected decamer primers. Nine primers amplified the genomic DNA, generating 200 to 2,500 bp and all detected polymorphism between lines. Out of 74 bands scored using these primers, 34 (50.0%) were found to be polymorphic. The number of polymorphic loci ranged from 3 to 6 with an average of 4.33. Lines differed considerably for within-population genetic similarity estimated by band frequency (WS = 93.55 to 99.25). Between-line genetic similarity estimates based on band sharing as well as on band frequency ranged from 71.35 to 86.45 and from 73.38 to 87.68, respectively. Lines HC and PB2 were the most closely related to the other, while BPB2 and CPB2 appeared to be more distant from each other. The between-line genetic distance based on both band sharing and band frequency revealed the similar trends as for Between-line genetic similarity. Based on BS and BF criteria, BPB2 and CPB2 as well as PB2 and UM1 lines can be merged to launch a new genetic group for further progress in biometrical objectives. A phylogenetic tree, derived using Nei's coefficient of similarity revealed the different pattern of genetic distance between lines.