• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.11a
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• pp.327-331
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• 2006

This paper considers an integrated inventory-distribution system with a fleet of heterogeneous vehicles employed where a single warehouse distributes a single type of products to many spatially distributed retailers to satisfy their dynamic demands and the product is provided to the warehouse via procurement ordering from any manufacturing plant or market The Problem is formulated as an Mixed Integer Programming with the objective function of minimizing the sum of inventory holding cost (at the warehouse and retailers), and transportation cost and procurement ordering cost at the warehouse, subject to inventory-balancing constraints, ordering constraints, vehicle capacity constraints and transportation time constraints. The problem is Proven to be NP-hard. Accordingly, a Lagrangean heuristic procedure is derived and tested for its effectiveness through computational experiments with some numerical instances.

• YAKHAK HOEJI
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• v.46 no.1
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• pp.52-57
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• 2002

Effects of the butanl fraction of Astragali Radix (BFAR) on the cellular and nonspecific immune responses were investigated in ICR mice. Mice were divided into 4 groups and BFAR at doses of 5, 25 and 125 mg/kg u ere administered orally to mice daily for 3 weeks, and the normal animals were given vehicle. The results of this study are summarized as follows; the relative weight of thymus was greatly increased by BFAR treatment, compared with that in mormal mice. However, the body weight gain was not affected. Delayed-type hypersensitivity (DTH) reaction to sheep red blood cells (SRBC) for cellular immunity was significantly enhanced by BFAR treatment, compared with those in normal mice. In these mice, BFAR also dose-dependently increased activities of phagocyte and natural killer (NK) cells as well as the number of leukocyte resulted from nonspecific immunity Thus, these results demonstrate that BFAF treatment results in a significant increase in both cellular and nonspecific immune responses to antigen in concentrations that enhance humoral immune function.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2477-2479
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• 2004

본 논문에서는 차선관련 정보의 변이도함수(DLI, Disparity of Lane-related Information)를 기반으로 하는 선행차량 인식 알고리즘을 제안한다. 본 논문에서 제안하는 알고리즘을 이용하여, 주행차선내에 있는 선행차량의 유무 검출과 위치 유추 및 선행차량 인식을 수행한다. DLI를 이용하는 방법은 특징점의 탐색공간을 현저히 줄여 실시간 처리문제를 해결한 수 있는 장점을 가지고 있다. 본 논문에서는 제안된 선행차량 인식알고리즘의 성능을 검증하기 위하여 다양한 환경의 도로영상에 알고리즘을 적용하여, 제안된 선행차량 인식기법의 우수함을 확인하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.2
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• pp.175-181
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• 2014

Location awareness is one of the key functions to build an U-city. Recently, many of works for the location-aware systems are emerging to be applied to on-going large-scale apartment complex. For example, when dwellers or cars with active tags are move in the apartment complex, the active tags broadcast their own identifiers periodically and receivers such that routers use this information to calculate the location of the active tags. Since the active tags can actually move between routers and coordinators, it requires a hand-off mechanism. In this paper, we investigate the hand-off problem occurred in location awareness system based on ZigBee active tags. We propose and analyze a new approach for handling the hand-off problem. Through a mathematical analysis, we show that our approach diminishes the quantity of packet transfer than ZigBee's approach.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1303-1308
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• 2006

지금까지 제조업체는 생산 및 물류 시스템의 효율성 증대를 통한 제품판매 증가에만 주의를 기울여왔다. 그러나 환경에 대한 관심이 높아지고, 관련 법규가 엄격해지면서 폐기물 처리와 재활용이 기업의 생존을 위한 중요한 과제로 떠오르고 있다. 자동차 제조업계에서 역시 폐자동차 재사용 및 재활용에 대한 연구가 진행되고 있으나, 한국에서는 자동차 산업의 외형적 성장과는 달리 이에 대한 시스템 구축이 미비한 상태이다. 본 연구에서는 폐자동차의 재활용에 관한 외국의 사례를 조사하고, 폐자동차의 회수 및 해체 촉진을 위한 바람직한 정부 정책 모델을 제시하려 한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.323-327
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• 2001

Electrorheological(ER) and magnetorheological(MR) fluids have a unique ability to increase the dynamic yield stress of the fluid substantially when electric or magnetic field is applied. Controllable fluids such as ER and MR fluids have received considerable attention as several components of engineering devices. One of them is a smart impact damper using ER/MR fluids. Impact damper system can be used in the joint mechanism of railroad vehicle, protection equipment of elevator's drop, and launch equipment of aircraft. This paper presents the results of an analytical study of the performance of a smart impact damper to suppress vibration during impact excitation. The damping capabilities of MR impact damper for variable applied current are analyzed using Bingham model under sudden impact load.

• IEMEK Journal of Embedded Systems and Applications
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• v.5 no.2
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• pp.103-110
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• 2010

Due to the increasing amount of electronic control system in a vehicle, the automotive software is increasingly sophisticated and complicated. Therefore it may be faced a time critical problem caused by its complexity. In order to solve such problems, the automotive electronic system can use a real-time scheduling mechanism based on predictability. We first consider the standard specification of the AUTOSAR OS and uC/OS-II such as its scheduling theory with time determinism. In this paper, we propose the scheduling algorithm to be conformable to a conformance class of OSEK/VDX specification. Algorithm analysis shows that our scheduling algorithm outperforms an existing Trampoline OS by intuition.

• 연구논문집
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• s.26
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• pp.15-24
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• 1996

In this study, we performed the static analysis of a cord-reinforced rubber airspring and generated the three-dimensional half-symmetry model which use the finite-strain shell elements to model the airbag. the three-dimensional hydrostatic fluid elements to model the air-filled cavity, and the rebar elements to model the multi-ply nylon reinforcement of airbag. In addition, a three-dimensional rigid surface is used to define the contact between the airspring and metal bead. The air inside the airspring cavity has been modeled as a compressible fluid satisfying the ideal gas law. The conclusions of this study are as follows. 1) In the pressurization step of analysis, we could predict the change of vertical reaction force, cavity volume and pressure within the airspring. 2) In the second step of analyzing vertical static stiffness, the increase of the vertical load increases the vertical stiffness. 3) In case of changing the angle of nylon cord, the increase the angle of nylon cord increases the vertical stiffness.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.355-356
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• 2010

일반도로에서 자유주행이 가능한 온라인 전기자동차(On-Line Electric Vehicle, OLEV)에 적용하기 위해 전류원 급전방식의 직렬-직렬 공진형 자기유도 전력전달시스템(Inductive Power Transfer System, IPTS)을 개발하였다. OLEV용 IPTS에서는 급전선로의 누설 인덕턴스가 크고 집전픽업의 유무에 따라 입력측에 유기되는 전압변동이 심한 특성을 반영하여 급전측에 공진형 전류원을 사용한다. 또한 자화 인덕턴스와 집전픽업의 누설 인덕턴스를 포함하여 변압기를 완전 공진시킨다. 본 논문에서는 이러한 방식의 IPTS에서 최대출력을 전달하기 위한 조건을 찾고, 이로써 최대 출력전류 및 출력전력을 제한하는 요인을 찾아 최적설계를 할 수 있도록 하였다. 또한 실험을 통해 그 타당성을 검증하였다.

• Transactions of Materials Processing
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• v.26 no.5
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• pp.277-285
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• 2017

Vehicle weight reduction is a known strategy to improve fuel efficiency and strengthen exhaust gas regulation. The use of high strength steel can satisfy safety, efficiency, emission, manufacturability, durability, and cost requirements. However, springback of high strength steel results in undesired shape defects. Springback is one of the most important issues of high strength steel for many applications in an automobile. Servo press has various capabilities to improve defects, process conditions, and productivity problems when forming a high strength steel. Especially, servo press can be set to function with variable slide motion in a single operation. In this study, the effect of servo press slide motion on 980MPa high strength steel was investigated through U-bending test.