• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.11
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• pp.108-114
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• 2021

In this study, a multivariate function was applied to the genetic algorithm for D-type lugs currently used in shipyards to closely analyze the behavioral form of weight loss without double plates. An optimal lifting lug structure design without attachments is proposed. MATLAB R2016a was used to design features by applying multivariate functions to genetic algorithms. Furthermore, the design was achieved by deriving the optimal shapes of lugs using genetic algorithms. The shapes of the designed lugs were validated for structural bonding using the structural analysis program ANSYS 2020 R2, and a robust design of lugs with no appendages was developed.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.4
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• pp.342-348
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• 1999

This paper describes a low-cost single-phase active power filter, which consists of a half-bridge P\A미1 inverter with a s simple control circuit. In order to verify the performance of proposed active power filter, many computer simulations w with EMTP codes and experimental works with a hardware prototype were done. Both results confirm that the p proposed active power filter shows excellent performance to eliminate the harmonics generated in the single-phase non l linear‘ load. The active power filter has advantage of low implementation cost and compact size. using a half-bridge i inverter and a simple control circuit with only one current sensor. So. it can be fabricated as a plug-in type.

• The Journal of Fisheries Business Administration
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• v.37 no.1 s.70
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• pp.111-120
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• 2006

식품관련 시장조사 기관인 Food marketing Instittue에 따르면, 미국전체의 식료품체인 가운데 25%가 최소한 온라인 쇼핑을 운영하고 있다. Safeway, Albertsons 등 대형 수퍼마켓 체인들이 연이어 온라인 시장에 참가했고, Melon Seed, FreshDirect.com 등 신규업체도 참가했다. 2002년 5월 Safeway.cm을 설립한 Safeway는 동년 7월에 8번째 점포를 시애틀에 오픈하는 등, 온라인 비즈니스를 확대했다. 최근 할인매장, 드러그 스토어 둥에 일부 시장을 잠식당하고 있는 이들 전통적인 수퍼마켓 체인들은 고객의 이탈을 막기 위해 비록 소수이기는 하지만 고객의 온라인 수요에 대응할 필요성이 있다고 생각하기 때문이다. 본고의 목적은 미국의 식료품 온라인 쇼핑에서 발생하고 있는 여러 문제점을 지적하는 것이다. Webvan이 Dot Com의 실패를 예증하는데 사용되는 주요한 전자상거래 비즈니스이다. 오늘날 온라인 쇼핑 비즈니스의 도전을 보여주고 이익을 낳기 위해 취해야 할 조치를 논의하기 위해 온라인 쇼핑 밴더가 참조되고 있다. 또한 본고는 미국의 Vons.com, Peapod.com 그리고 Safeway.com과 같은 온라인 식료품 쇼핑 비즈니스에서 나타나고 있는 추세, 신규 영업자 및 잔존 영업자들의 특성과 온라인 식료품 쇼핑업자들의 성장에 필요한 요인들에 관해서도 논하였다.

• Journal of Sensor Science and Technology
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• v.29 no.2
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• pp.118-122
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• 2020

This paper proposes a specific sensor-design strategy and the possibility of improving the sensing performance, which can be obtained by replacing part of the existing plasmonic sensor based on the Kretschmann configuration method with an effective refractive-index layer. By replacing the metal layer with an effective refractive-index layer composed of gold and the material to be sensed, an improvement in the detection performance, accompanied by an increase in the sensed incident angle, is observed, and the gold-composition ratio that demonstrates the best result is presented. Subsequently, an increase in the sensed incident angle generated in the previous step can be suppressed by randomly etching a portion of the prism adjacent to the metal layer in a sub-wavelength scale. Finally, this study analyzes the optimization of the metal-layer thickness in a given sensor structure. An effective refractive thin-film surface plasmon resonance sensor design that can achieve optimal sensing performance is then proposed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.12
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• pp.1107-1114
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• 2011

In this paper, the fatigue life of a laser peened structure was predicted. In order to calculate residual stress induced by laser peening finite element simulation was carried out. Modified Goodman equation was used to consider the effect of compressive residual stress induced by laser peening in fatigue analysis. In addition, additive adjustment factor approach was applied to consider S-N curve model uncertainty. Consequently, the reliable bounds of the predicted fatigue life of the laser peened structure was determined.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.47-50
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• 2003

JA2 Propellants, made by non-solvent process, are of great interest for the tank gun propellant. This is due to high energy. The grain geometries of JA2 and modified JA2 propellant were designed for application to 105mm APFSDS projectile. The combustion, thermochemical, and interior ballistic properties of the propellant were tested and calculated. The performances of the propellant were evaluated out using 105mm slug T2 projectiles and 105mm tank gun. The muzzle velocity of the propellants was higher than that of the KM30 for K274 projectile.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.1
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• pp.29-35
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• 2020

Car inspection systems are regularly carried out by the state to ensure the safety and emission status of cars, thereby improving the safety and quality of life by reducing fine dust and greenhouse gases that are the main culprits of vehicle defects and air pollution. These automobile inspections are largely divided into either regular or comprehensive inspections. This study analyzed the smoke measuring probes used in the lug - down 3 mode. In the previously issued paper "Improvement of Soot Probe Efficiency for Automotive Emission Measurement," an improved smoke measurement probe(B) improved on the problems that arise from the current smoke measurement probe (A). In this study, a technique that can improve the probe's inhalation efficiency over the improved (B) probes was applied to probes (C). Probe (C) involves a structure designed close to the center of the circumference of the exhaust pipe, and the suction efficiency was improved by adding a variable center unit.

• Journal of The Korean Association of Information Education
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• v.19 no.4
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• pp.489-498
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• 2015

In this study, we suggested the contents, teaching and learning method, and assessment types of algorithm education in elementary schools. First, we suggested the algorithm education contents; the expression, understanding, flowcharts, structure, results, correction, and improvement of algorithm. Second, we showed the algorithm teaching and learning methods; algorithm in our daily life, the unplugged activity, block programming and tangible programming. Finally, we analyzed all missions of 'Hour of Code' in Code.org, and suggested the algorithm assessment 4 types, which includes selecting, filling, correcting, predicting of appropriate algorithm.

• Journal of Welding and Joining
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• v.25 no.6
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• pp.44-52
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• 2007

A welding process of a lifting lug for lifting heavy objects is one of the important welding processes directly related to the safety in shipbuilding. Welding a lifting lug is done in the manually and takes about forty minutes. Working environment for the lifting lug welding is very poor due to an radiant heat and a harmful fume. The purpose of this study is to develop methods of multi-pass welding using the lifting lug welding robot system. This study shows robot welding methods to achieve proper corner, straight and connection welding and an effectiveness of application.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.4
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• pp.77-84
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• 2011

Tire manufactures have dealt with noise problem by varying the pitch of the tread. The various formulas for the variations are generally determined differently, however. Often these variations are based on a combination of trial and error, intuition, and economics. Some manufactures have models and analogs to test tread patterns and their variations. These efforts, however practical, do not determine the best variation beforehand or guarantee the best results. For this reason it was felt that a general mathematical approach for determining the best variation was needed. Moreover, the method should be completely general, easy to use, and sufficiently accurate. This paper discusses a mathematical method called Mechanical Frequency Modulation(MFM) which meets the above requirements. Thus, MFM pertains to computing an irregular time sequence of events so that the resulting excitation spectrum is shaped to a preferred form. The first part of this paper treats the theoretical basis for computing an optimum variation ; the second part discusses experimental results and simulation program which corroborate the theory.