시뮬레이션과 메타모델을 이용한 자동물류센터 설계 최적화

강정윤,이홍철,엄인섭,Kang, Jeong-Yun,Lee, Hong-Chul,Um, In-Sup 한국시뮬레이션학회 2006 한국시뮬레이션학회 논문지 Vol.15 No.3

Now distribution centers include an ASRS (Automated Storage and Retrieving System) and automated transfer systems such as conveyors and AGV (Automated Guided Vehicle). These automated distribution centers have lots of parameters to be considered fur operating performance. The general basic parameters in the distribution centers are specifications of storage equipment, system operating rules, configuration of storage area and unit load features. In this paper, an approach using simulation and metamodeling with response Surface method to optimize the design parameters of an automated distribution center model is presented. The simulation based metamodel will constitute an efficient approximation of the system function, and the approximate function will be used to design rapid optimal parameters of the distribution center model. This paper provides a comprehensive framework for economical material flow system design using the simulation and metamodeling. 최근의 자동물류센터는 자동창고(ASRS)와 자동주행대차(AGV)를 중심으로 각종 컨베이어시스템과 운반장치 등으로 구성되면서 매우 복잡한 시스템 형태를 갖게 되었다. 이러한 시스템의 복잡성에 기인하여 시스템 설계과정에서의 정확한 운영 수행도 파악을 위해서는 많은 종류의 설계변수들이 고려되어야 한다. 물류센터 설계에서 고려해야할 일반적인 설계 변수로는 보관설비 및 운반설비의 사양과 여러 가지 시스템 운영 규칙, 보관영역이나 보관물의 형태 등이 있다. 이 논문에서는 자동화물류센터에 대하여 시뮬레이션 실험과 반응표면모델을 이용하여 메타모델을 만들고 이를 통하여 설계변수들을 최적화하는 효율적인 방법에 대하여 소개 하고자 한다. 정확하게 정의된 시뮬레이션 기반의 메타모델은 시스템 함수의 근사적 표현으로서 수리적 계산을 통해 신속한 설계변수 최적화를 가능하게 한다. 이 논문에서 제시한 접근 방법은 자동물류센터와 같은 복잡한 물류 시스템의 설계 단계에서 시뮬레이션의 설계 참여도를 극대화시키고 최종 설계의 정확도를 향상시키는데 기여 할 것이다.

새로운 셀렌화 방법으로 제작된 고효율 Cu(In,Ga)Se₂ 태양 전지

강정윤(Jeong-yun Kang),전찬욱(Chan-Wook Jeon) 한국신재생에너지학회 2015 한국신재생에너지학회 학술대회논문집 Vol.2015 No.6

CoAP 프로토콜을 이용한 다중대역 웨어러블 디바이스 제어 시스템

강정윤(Jeong-Yun Kang),정창수(Chang-Su Jung),서지훈(Ji-Hun Seo),윤용탁(Yong-Tak Yoon),한기준(Ki-Jun Han) 한국컴퓨터정보학회 2017 한국컴퓨터정보학회 학술발표논문집 Vol.25 No.2

WBAN (Wearable Body Area Network)는 옷이나 몸에 이식된 디바이스들이 몸을 중심으로 결합이나 통신하는 네트워크를 뜻한다. 여기서 사람이 몸에 착용하는 장치인 웨어러블 디바이스는 가벼운 형태의 배터리를 요구한다. 그로 인해, 다른 기기들과는 달리 짧은 배터리 수명을 가질 뿐만 아니라 통신에 관한 제약을 발생시킨다. 따라서 본 논문에서는 저전력 프로토콜을 지원하는 다중대역 웨어러블 디바이스 제어 시스템을 제안한다. 이를 위해 BLE (Bluetooth Low Energy) 기반의 프로토콜 스택으로 BLE, 6LoWPAN (IPv6 over Low power WPAN), CoAP (Constrained Application Protocol)을 적용해 데이터 패킷 크기를 감소 시키고 BLE/Wi-Fi 선택 기능을 통해 통신 제약을 완화하고 전체적인 WBAN 에서의 소비 전력을 감소하고자한다.

진화전략과 DEA를 이용한 통합 물류 시스템 분석 방법

엄인섭,이홍철,강정윤,Um In-Sup,Lee Hong-Chul,Kang Jeong-Yun 한국시뮬레이션학회 2004 한국시뮬레이션학회 논문지 Vol.13 No.4

The focus of this study is to represent a methodology of analysis for integrated logistic system by means of the Evolution Strategies and Data Envelopment Analysis(DEA). The integrated logistic system is composed of AS/RS (Automated Storages and Retrieval System), AGVs(Automated Guided Vehicle System) and Conveyor System. We design the simulation alternatives with choosing the qualitative critical factors for the each subsystem. Evolution Strategies is used to optimize the quantitative critical factors and responses of each alternative. DEA is applied to measure the efficiency of the alternatives in order to select the optimal operation efficiency scheme. The method of analysis which combines Evolution Strategies with DEA can be used to analyze the qualitative and quantitative critical factors in the integrated logistic systems.

실링재 및 실링방법이 HVOF 용사된 CrC-NiCr 코팅의 내식성에 미치는 영향

정영훈(Younghun Jeong),남욱희(Uk-Hee Nam),변응선(Eungsun Byon),강태일(Tae-il Kang),강정윤(Chung-Yun Kang) 한국표면공학회 2014 한국표면공학회지 Vol.47 No.6

Effects of sealant and sealing procedure on corrosion resistance of high velocity oxy-fuel (HVOF) sprayed coatings were studied. HVOF-sprayed CrC-20NiCr coatings were sealed using three commercial sealants based on phenolics and epoxy. Penetration depth of sealants, measured by fluorescent microscope technique, was between 19 μm and 340 μm depending on sealant, sealing condition or sealing procedure. It was found that sealing on rotation status was more effective than that on stationary specimen due to the Coriolis effect of fluid in pores of the coating. From the CASS results, corrosion resistance of properly sealed CrC-20NiCr coatings was equal to that of hexa-valent chromium plating.

주성분 분석을 활용한 우리나라 치과위생사 인력의 수급 지수 제안

정태양(Taeyang Jeong),김주희(Juhee Kim),김규석(Kyuseok Kim),강정윤(Jung Yun Kang) 한국산업기술융합학회(구. 산업기술교육훈련학회) 2024 산업기술연구논문지 (JITR) Vol.29 No.1

우리나라 치과 보조인력의 수급 불균형으로 치과의원에서 치과위생사의 인력난이 심화하고 있다. 매년 5천여 명의 치과위생사가 배출되고 2019년 기준 면허등록 치과위생사는 83,817명에 이르지만 현직에서 활동하는 치과위생사는 전체의 절반 수준에 불과하다. 이와 관련해서 본 연구에서는 치과위생사 수급과 관련하여 문제점을 짚어보고 지역별 치과위생사 수급지수를 개발하고자 한다. 연구 데이터는 취업 포털 사이트의 치과위생사 구인 공고 수와 치위생학과 졸업생 수, 치과 병의원 수를 활용한다. 연구방법론으로 상관있는 요인들로부터 특징이 되는 본질을 합성하여 데이 터를 분석하는 통계적 기법인 비지도학습 머신러닝 기반의 주성분 분석을 사용한다. 주성분 분석을 활용한 치과위생사 수급 지수를 개발한 결과, 치과위생사의 수급 지수는 치위생학과 졸업생 수와 상관성이 낮고, 치과 병의원의 수와 상관성이 가장 크게 나타났다. 본 연구에서 활용한 데이터를 누적하여 추후 더 정확도가 높은 지수 개발을 할 수있을 것으로 기대한다. An imbalance in Korea between the supply and demand for auxiliary dental personnel has led to a growing shortage of dental hygienists in clinics. Despite the annual graduation of approximately 5,000 dental hygienists, the number of registered dental hygienists stands at 83,817 as of 2019, and the number of active practitioners account for only half of this total. This study aimed to address issues related to the supply and demand of dental hygienists and develop a regional dental hygienist supply-and-demand index. The research data included the number of dental clinics, graduates from dental hygiene departments, and job openings for dental hygienists on employment websites. Unsupervised machine learning-based principal component analysis, a statistical technique that synthesizes the essence of features from correlated factors, was used for data analysis. The results of developing a dental hygienist supply-and-demand index using principal component analysis revealed a low correlation of the index with the number of graduates from dental hygiene departments, and the highest correlation with the number of dental clinics. The data used and delivered in this study are expected to support the accumulation of knowledge for and the future development of a more accurate index.

MBF-30을 사용한 Inconel-625/Ni-201 브레이징 접합부의 인장성질에 미치는 접합조건의 영향

유정우,박상현,김창수,강정윤,Yu, Jeong-Woo,Park, Sang-Hyun,Kim, Chang-Su,Kang, Chung-Yun 대한용접접합학회 2012 대한용접·접합학회지 Vol.30 No.6

This study was carried out to investigate the effect of bonding temperature and holding time on microstructure and mechanical properties in brazing joints of Ni-base superalloy using MBF-30 (Ni-4.5Si-3.2B [wt.%]). The heating rate was $20^{\circ}C$/min to the bonding temperatures $1050^{\circ}C$, $1070^{\circ}C$, $1090^{\circ}C$ under high vacuum condition. The holding times were 100s, 400s, 900s and 1600s. $Ni_3B$ phases and proeutectic Ni were observed in the interlayer of Ni-201. Then, Ni3B and Ni3Si were found in the middle region of brazing joint. Cr-boride phase appeared in the interlayer of Inconel-625. Tensile strength and elongation were decreased at $1050^{\circ}C$-1600s, $1070^{\circ}C$-900s and $1090^{\circ}C$-400s. After observation the fracture specimens, There was Ni3B which is very brittle phase in the grain boundary of Ni201.

STS304 콤팩트 열교환기 고상확산접합부의 접합부 변형과 인장성질에 미치는 접합온도 및 접합압력의 영향

전애정,윤태진,김상호,김현준,강정윤,Jeon, Ae-Jeong,Yoon, Tae-Jin,Kim, Sang-Ho,Kim, Hyeon-Jun,Kang, Chung-Yun 대한용접접합학회 2014 대한용접·접합학회지 Vol.32 No.4

In this study, the effect of bonding temperature and bonding pressure on deformation and tensile properties of diffusion bonded joint of STS304 compact heat exchanger was investigated. The diffusion bonds were prepared at 700, 800 and $900^{\circ}C$ for 30, 60 and 90 min in pressure of 3, 5, and 7 MPa under high vacuum condition. The height deformation of joint decreased and the width deformation of joint increased with increasing bonding pressure at $900^{\circ}C$. The ratio of non-bonded layer and void observed in the joint decreased with increasing bonding temperature and bonding pressure. Three types of the fracture surface were observed after tensile test. The non-bonded layer was observed in diffusion bonded joint preformed at $700^{\circ}C$, the non-bonded layer and void were observed at $800^{\circ}C$. On the other hand, the ductile fracture occurred in diffusion bonded joint preformed at $900^{\circ}C$. Tensile load of joint bonded at $800^{\circ}C$ was proportional to length of bonded layer and tensile load of joint bonded at $900^{\circ}C$ was proportional to minimum width of pattern. The tensile strength of joint was same as base metal.

고상확산접합된 Haynes230의 인장성질에 미치는 접합조건의 영향

강길모,전애정,김홍규,홍성석,강정윤,Kang, Gil-Mo,Jeon, Ae-Jeong,Kim, Hong-Kyu,Hong, Sung-Suk,Kang, Chung-Yun 대한용접접합학회 2013 대한용접·접합학회지 Vol.31 No.3

This study investigated the effect of bonding temperature and holding time on microstructures and mechanical properties of diffusion bonded joint of Haynes230. The diffusion bonds were performed at the temperature of 950, 1050, and $1150^{\circ}C$ for holding times of 30, 60, 120 and 240 minutes at a pressure of 4MPa under high vacuum condition. The amount of non-bonded area and void observed in the bonded interface decreased with increasing bonding temperature and holding time. Cr-rich precipitates at the linear interface region restrained grain migration at $950^{\circ}C$ and $1050^{\circ}C$. However, the grain migration was observed in spite of short holding time due to the dissolution of precipitates to base metal in the interface region at $1150^{\circ}C$. Three types of the fracture surface were observed after tensile test. The region where the coalesce and migration of grain occurred much showed high fracture load because of base metal fracture whereas the region where those did less due to the precipitates demonstrated low fracture load because of interface fracture. The expected fracture load could be derived with the value of fracture area of base metal ($A_{BF}$) and interface ($A_{IF}$), $Load=201A_{BF}+153A_{IF}$. Based on this equation, strength of base metal and interface fracture were calculated as 201MPa and 153MPa, respectively.

Al-Si 용융도금된 11%Cr 페라이트 스테인리스강, STS409L GTA 용접부의 미세조직과 경도

박태준,공종판,나혜성,강정윤,엄상호,김정길,우인수,이종섭,Park, Tae-Jun,Kong, Jong-Pan,Na, Hye-Sung,Kang, Chung-Yun,Uhm, Sang-Ho,Kim, Jeong-Kil,Woo, In-Su,Lee, Jong-Sub 대한용접접합학회 2010 대한용접·접합학회지 Vol.28 No.3

Ferritic stainless steels, which have relatively small thermal expansion coefficient and excellent corrosion resistance, are increasingly being used in vehicle manufacturing, in order to increase the lifetime of exhaust manifold parts. But, there are limits on use because of the problem related to cosmetic resistance, corrosions of condensation and high temperature salt etc. So, Aluminum-coated stainless steel instead of ferritic stainless steel are utilized in these parts due to the improved properties. In this investigation, Al-8wt% Si alloy coated 409L ferritic stainless steel was used as the base metal during Gas Tungsten Arc(GTA) welding. The effects of coated layer on the microstructure and hardness were investigated. Full penetration was obtained, when the welding current was higher than 90A and the welding speed was lower than 0.52m/min. Grain size was the largest in fusion zone and decreased from near HAZ to base metal. As welding speed increased, grain size of fusion zone decreased, and there was no big change in HAZ. Hardness had a peak value in the fusion zone and decreased from the bond line to the base metal. The highest hardness in the fusion zone resulted from the fine re-precipitation of the coarse TiN and Ti(C, N) existed in the base metal during melting and solidification process and the presence of fine $Al_2O_3$ and $SiO_2$ formed by the migration of the elements, Al and Si, from the melted coating layer into the fusion zone.