• 한국생산제조학회지
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• 제26권1호
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• pp.66-73
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• 2017

This study attempted to design lights with Type II distribution suitable for LED street lights based on the regulations of street light distribution developed by the Illuminating Engineering Society of North America (IESNA). The shape of an asymmetric lens, different from that of a rotationally symmetric lens, cannot be generated using a simple mathematical formula. In the first trial, the outline of the lens was fixed and simulated to confirm the distribution type. Following ISENA regulations, some problems that occurred during simulations and repeating was be modified that process is how we detected errors. Through optical research and simulations, a lens conforming to the regulations of Type II very short, Type II short, and Type II medium distributions was developed. A prototype was developed using simulation data and it was subjected to distribution tests. The results show that it can compare with property of Type II distribution.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제21권11호
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• pp.739-744
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• 2015

본 논문에서는 물류 중소 IT기업과 학부 프로젝트 교과목을 연계하여 기업 실무 주제인 로컬 푸드 재고관리시스템을 공동개발하고 솔루션화하는 프로젝트 중심 교육사례를 연구하였다. 기존 이론 및 텀 프로젝트 진행방식에 탈피하여 기업의 실무 프로젝트를 대상으로 기업의 실무자가 멘토로 참여하여 프로젝트 주제를 제시하고 학생들이 그 주제의 시스템을 개발하였고 기업 실무자와 토의하는 과정에서 실무적인 지식을 습득하게 유도하였다. 이러한 방식을 통하여 상호 최신기술을 공유하고 물류 비즈니스 도메인을 이해하는 기회가 되었으며 프로젝트 수행을 위해 필요한 비용, 품질, 납기에 대하여 학생 스스로 이해하고 해결해 가는 경험을 하였으며 자신감을 얻을 수 있었다. 기업은 시제품 개발을 위한 비용절감과 우수인력을 교류할 수 있는 기회가 되었다.

• 한국대기환경학회지
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• 제1권1호
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• pp.93-98
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• 1985

Mass size distribution of atmospheric particulates were measured using an Andersen using an Andersen sampler in urban air. The atmospheric particulates were fractionated in eight stages of an Andersen sampler operating at 28.4$\ell/min$ and collected on polyester sheets. A quartz filter was placed behind the last stage collect permeated partculates. The size distribution of atmospheric particulates were divided around 1-2 $\mu$m into two groups, coarse and fine particulates regardless of sampling times. The variation of course particulates concentration was higher than fine particulates among sampling times. Different meterorological conditions and natural phenomena brought high variation of course particulates' concentration. The rain caused removal of coarse particulates seriously and the yellow and may take part in a increase of the course particulates in spring. The average concentration of atmospheric particulates to be collected by Andersen sampler was 170.8 $\mug/m^3$ during 3 times of sampling. Among them the average concentration of atmospheric particulates which could penetrated under a bronchi and alveoli were 70.4$\mug/m^3$ and 36.6$\mug/m^3$ respectively.

• 한국생산제조학회지
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• 제26권4호
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• pp.371-377
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• 2017

In this study, the heat dissipation performances of metal printed circuit boards (MPCBs) and flexible printed circuit boards (FPCBs) used in light-emitting diode (LED) lights were compared and analyzed by performing a heat dissipation simulation using a thermal flow analysis program. The results were summarized graphically. The temperature distribution of the MPCB was found to be better than that of the FPCB, indicating the better heat dissipation performance of the MPCB. For the two FPCB structures studied, we confirmed the LED temperature and temperature distribution by thermal flow analysis and found that for better overall heat dissipation performance, PCBs should preferably have an asymmetric structure. We confirmed the possibility of using FPCBs, which are characterized by a flexible structure, for LED lighting.

• 한국생산제조학회지
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• 제24권4호
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• pp.448-454
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• 2015

In this paper, the band structural design that is typically in a line was arranged in a ring shape, so as to configure the high power LED lighting in such a way as to form a concentrated light distribution angle of less than 15 degrees. The parabolic aluminized reflector PAR38 that facilitates design using area and the area of the optical system to the same extent, applied a multiple light-source condenser lens optical system for the control of integration. The LED used here implemented a single linear light source using ans LED module with ans LED, flip-chip chip-scale package. The optical system was designed based on the energy star standard.

• 한국조리학회지
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• 제6권1호
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• pp.253-274
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• 2000

This report deals with what the distribution industry is and the actual condition and keynote of the domestic distribution industry. Now, it is difficult compare with the domestic distribution industryand other advanced nation. because of inferior enviroment and given circumstance such as. Open market pressure. We will study about realities and weakness of the domestic distribution industry, also check how to cope with, especially the Government and enterprise, these difficulties for the development of the domestic distribution industry.

• 한국생산제조학회지
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• 제23권6호
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• pp.609-617
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• 2014

We have studied a chip-on-board LED lighting optical system for various luminous-intensity-distribution angles of the LED. An optical system that can accept different LEDs was made to reduce the systems's weight and size as we selected the chip-on-board LED, which is easy to apply to optical systems, unlike existing package-on-board LEDs. The luminous-intensity-distribution angles were $45^{\circ}$, $60^{\circ}$, $90^{\circ}$, and $120^{\circ}$. We researched these four types of optical systems. The $45^{\circ}$ and $60^{\circ}$ units were developed into reflectors, and the $90^{\circ}$ and $120^{\circ}$ units, into lenses. We checked the performance of the designed optical system through simulation and made a mock-up. Then we made a prototype of the chip-on-board LED high bay for use with the mock-up. After measuring its performance, we tested the luminous-intensity-distribution angles and compared them with simulation data. The resulting prototype was developed considering brightness, light uniformity, age, and economics which are suitable for a factory environment.

• 해양환경안전학회지
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• 제19권2호
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• pp.193-199
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• 2013

파랑 중 선박의 직진성능을 시뮬레이션을 통하여 비교 검토하였다. 시뮬레이션을 구성하기위해 선박의 3자유도 조종운동방정식을 사용했으며, 선박에 가해지는 파랑강제력은 3차원 특이점 분포법을 사용하여 계산하였다. 시뮬레이션의 외란으로서 규칙파와 불규칙파를 사용하였고 최대사용타각과 제어시간지연을 제어기의 제한조건으로 설정하였다. 조종성능에 따른 직진성능을 검토하기 위해 유체력 미계수를 인위적으로 변화시킴으로서 조종성능이 다른 선박의 시뮬레이션을 구성하였다. Autopilot제어기를 사용한 일정시간의 선박의 직진 시뮬레이션을 수행하고 해당시간동안의 직진거리를 비교하여 선박의 직진성능을 검토하였다.

• 유통과학연구
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• 제18권4호
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• pp.73-78
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• 2020

Purpose: This study was to examine public access defibrillator (PAD) deployment on some golf courses and to analyze automatic external defibrillators (AEDs) demand by appropriate distance. Research design, data, and methodology: We conducted telephone interview on 124 golf courses in Gyeonggi and Gangwon province in South Korea. The area within 3 minutes by 3 minutes for retrieval and 1 minute for shock and 1.5 minutes by the American Heart Association (AHA)recommendation for community AED placement were calculated as 3.14×162㎡ and 3.14×100㎡. Results: The average area was 1,811,481.8㎡, and 29 (42.7%) in below 999,999㎡, 75 (60.5%) in 1,000,000 to 1,999,999㎡, 12 (9.7%) in 2,000,000 to 2,999,999㎡ took up. The average retrieval time was 161.8 seconds, and 5 (4.1%) in below 90 seconds, 10 (8.0%) in 91 to 180 seconds took up a small part. AED demands according to 3 and 1.5 retrieval minutes were 2,602 and 6,986 respectively. Average AED demands per golf course were 21.0 and 56.3 respectively on 124 golf courses. Conclusions: The numbers of AED needed in South Korean golf course were 5,880 to 15,764. To ensure defibrillation on the golf courses, the supply and distribution of AEDs should be strengthened.

• 공학교육연구
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• 제10권1호
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• pp.5-19
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• 2007

공과대학은 다른 인문, 사회 계열과는 달리 교양교육과정이 전공과정과 뚜렷하게 구분되기 때문에 어떤 형태와 내용으로 구성되어 있느냐에 따라 학생의 학습 성과(outcomes)에 많은 영향을 미칠 수 있다. 또한 한국의 공과대학에서는 공학교육인증(ABEEK) 시행에 따라 그 기준에 부합하는 교양교육과정을 구성하는 방법상의 문제에 많은 혼란이 있어 왔다. 따라서 본 연구에서는 미국의 우수한 공과대학으로 꼽히고 있는 스탠포드대학교(Stanford University), 메사추세스공과대학(Massachusetts Institute of Technology), 로즈헐맨공과대학(Rose-hulman Institute of technology)과 프린스턴대학교(Princeton University)와 미시간대학교(Michigan University-Ann Arbor) 그리고 펜실베이니아 주립대학교(Pennsylvania State University)와 캔자스주립대학교(kansas state University)의 교양교육과정을 비교하여 한국 공과대학 교양교육과정 구성에 시사점을 찾기 위해 구현방식과 학문적 영역상의 특성을 분석하여 제시하였다.