Vehicle routing problem is one of the traveling salesman problems with various conditions such as vehicle capacity limits, delivery time windows, as well as time dependent speeds in metropolitan area. In this research hourly vehicle moving speeds informat

This study focuses on the problem of scheduling wafer lots of several recipe(operation condition) types in the photolithography workstation in a semiconductor wafer fabrication facility, and sequence-dependent recipe set up times may be required at the ph

The objective of this study was to investigate the effectiveness of cryopreservation methods for the effect of various vitrification containers, such as EM-grid, OPS, or cryo-loop on the survival and developmental rate of vitrified mouse pronuclear embryos, and mouse cleavage embryo, at 21, 24, 27 and 30 hr after hCG injection. Post-thaw cleavage was similar among treatments, while the developmental rates of mouse blastocyst and hatched blastocyst were higher ( <0.05) in 27 hr and 30 hr than 21 hr. The developmental rate of hatched blastocyst at vitrified cleavage mouse embryos in cryo-loop was significantly higher than vitrified pronuclear embryos of control group as well as EM-grid and OPS ( <0.05). The developmental rate using cryo-loop was higher than EM-grid, but in case of OPS at vitrified cleavage and mouse pronuclear embryos, no significant difference was noticed. These results of our study show that the developmental rates of mouse embryos were unaffected by various vitrification containers, but in case of mouse embryos and hatched blastocysts at late vitrified pronuclear embryos the developmental rates were higher than early vitrified pronuclear embryos. Moreover, the developmental rate of hatched blastocyst at vitrified cleavage mouse embryos was significantly higher than vitrified pronuclear embryos. For better execution of this study, it will be mandatory to include improvement of vitrification containers, cryopreservation methods and conditions, higher survival rate, safe preservation, contamination and embryo loss.

교통사고 발생시점부터 사고처리가 완료된 시점까지를 돌발상황 지속시간(Incident Duration Time)이라고 정의하는데, 이를 단축시켜야만 교통사고 피해를 최소화할 수 있다. 본 연구는 고속도로 교통사고를 대상으로 돌발상황 지속시간에 영향을 주는 요인들을 찾아내기 위한 모형을 개발하였다. 모형은 모든 사고자료에 포함한 통합 모형(모형1)과 일반구간, 교량, 터널 등 교통사고 장소별로 구분하여 분석한 세부 모형(모형 2, 3, 4) 등 모두 4개의 모형을 구축하였다. 분석 결과, 교통사고가 발생한 장소에 따라 돌발상황 지속시간에 다른 영향을 주는 것으로 나타났으며, 현장 처리를 위한 작업차량 도착시간이 가장 민감한 요인으로 분석되었다. 또한 차-차 사고, 화물차에 의한 사고, 야간 사고, 주말 사고 등의 시사점 있는 요인들을 찾아냈다. 이러한 연구결과는 향후 교통사고 관리대책을 수립하는 데 있어 중요한 판단지표로 활용이 가능할 것으로 판단된다.

Avian influenza (AI) and Newcastle disease (ND) distress a variety of avian species, especially domestic poultry. Severe syndromes are caused by highly virulent specific virus strains termed highly pathogenic AI and velogenic ND viruses, which are potential agrobioterrorism agents. This outbreak emphasizes the need for continuing cooperation between public health and veterinary medical communities in controlling AI and ND when it has a zoonotic potential. Up to date, the stamping out and burying system were applied for controlling methods against these highly infectious diseases in the ordinary way, however these methods had many environmental problems, including leachat and effluvium. Thus, we assessed that sterilization effect of AI and ND virus dependent on several treatment conditions, such as autoclaving time and cutting types of chicken. As a result, we found that the cutting type of chicken meat revealed a reduced HA titer (20) against both of AI and ND virus after 10 min of autoclaving, while whole chicken showed same titer after 30 and 60 min. Therefore, we propose that the conditions of treatment on infected chicken should be developed for convenient, affordable, and effective prevention methods against for AI and ND.

본 연구에서는 EFDC모델과 입자추적모델을 이용하여 마산만의 담수유입에 의한 폐쇄성 내만의 물질체류시간을 산정하였다. 마산만의 해수유동을 재현하고 이를 바탕으로 평균체류시간을 계산하였다. 마산만의 조석에 의한 평균물질체류시간은 만 북측과 돝섬 부근까지가 약 110일이내, 모도 주변 해역이 약 40일, 부도에서 외해까지 약 20일 정도로 산정되었다. 담수유입에 따른 마산만의 4개 소해역별 평균물질체류시간은 I과 II영역에서 약 81일로 감소하였으나, 마산만의 외해측에 위치한 III과 IV영역은 각각 58일과 17일로 증가하였다.

Customers are generally requiring a variety of products, earlier due date, and lower price. A manufacturing process needs the efficient scheduling to meet those customer's requirements. This study proposes the novel algorithm named MJA(Minimum Job completion time and AGV time) that increases the performance of machines and AGV(Automated Guided Vehicles) in many kinds of job types. MJA optimizes the bottleneck of machines and efficiency of AGV with considering two types of dispatching at the same time. Suggested algorithm was compared with existing heuristic methods by several simulations, it performed better for reducing the time of tardiness.

A typical job sequencing problem is studied in this research to improve productivities in manufacturing companies. The problem consists of two-stage parts and assembly processes. Two parts are provided independently each other and then two sequential asse

이 연구에서는 동적 애니메이션 지도 제작을 위해 HTML5 Canvas와 OGC의 WMS 시간 차원 정보를 활용하였다. 동적 애니메이션 지도는 플러그인 없이 구동이 가능하기 때문에 플랫폼에 독립적인 특징을 가진다. WMS 시간 차원 정보는 사용자가 연속적인 지도 정보를 전송 받을 수 있는 기능을 제공한다. HTML5 Canvas로는 애니메이션 지도를 표출하고, 지속시간, 시점, 순서와 같은 동적 변수를 조정할 수 있는 컨트롤 구현이 가능하였다. HTML5 Canvas와 WMS는 모바일 웹 기반의 동적 애니메이션 지도 제작을 위한 기능적 요구 사항을 충분히 지원하는 것으로 평가된다.

This paper addresses the analysis of the travel distance and order picking time of the vehicle in a aisle when items are picked by the batch in a warehouse system. Batching is to combine several orders in a single tour of the storage/retrieval machine. An

MAO(Micro-Arc Oxidation) method was used to make surface on 6063 Al specimen. This study was focused on an influence of voltage, density of electrolyte and a period of treatment on the change of surface microstructure by using SEM(Scanning Electron Microscope), EDS(Energy Dispersive X-ray Spectroscopy). The microstructure shows higher roughness and thicker oxidized layer with increase of voltage and maintaining period of treatment. The density of electrolyte affected a formation of more dense surface and increase of a oxidized layer.

In this study, the effect of milling time on the microstructure and phase transformation behaviors of Ni-12 wt.%B powders was investigated using vibratory ball milling process. X-ray diffraction patterns showed that the phase transformation of mixed Ni-B elemental powder occurred after 50 hours of milling, with a formation of nickel boride phases. Through the study of microstructures in mechanical alloying process, it was considered that ball milling strongly accelerates solid-state diffusions of the Ni and B atoms during mechanical alloying process. The results of X-ray photoelectron spectroscopy showed that most of B atoms in the powder were linked to Ni with a formation of nickel boride phases after 200 hours of milling. It was finally concluded that mechanical alloying using ball milling process is feasible to synthesize fine and uniform nickel boride powders.

This research is to sequence flow shop with two parallel parts production and two assembly machines in sequence. Two different objective functions are studied. One is to minimize total completion time and the other is to minimize the difference of 1 job completion time and total completion time. A heuristic is designed to solve the sequencing problem. Initial solution is developed in the first stage and then the initial solution is improved in the second stage. Experimental 5 job problems are used to evaluate the performance of the suggested heuristic. The optimum solutions obtained by enumeration are used to comparisons. Also 20 job problems are generated for evaluations. 100 randomly generated sequences are evaluated and proved that the distributions are normal. And then presented how good the solutions obtained by suggested method. The initial solution stage is different for the minimization of completion time differences.

고정반복법에 의한 암시적 HHT 시간적분법을 이용하여 3층 3경간 철근콘크리트 골조구조물을 수치해석모형과 물리적 분구조모형으로 나누어 실시간 하이브리드실험을 실시하였다. 물리적 부분구조모형으로는 1층 내부 비연성기둥 1개소가 선택되었고, 수치해석모형에 일축 방향의 지진하중을 시편이 심한 손상에 의하여 파괴에 이를 때까지 작용시켰다. 비선형 유한요소해석 프로그램인 Mercury가 실시간 하이브리드실험을 위하여 새로이 개발 및 적용되었다. 실험결과는 물리적 부분구조모형의 상부 수평방향 층간변위비를 OpenSees에 의한 수치해석시뮬레이션과 진동대실험의 그것과 비교하였다. 본 실험은 가장 복잡한 실시간 하이브리드실험 중의 하나이고, 하드웨어, 알고리즘 그리고 모형에 대한 기술적인 내용을 본 논문에 자세히 설명하였다. 수치해석모형의 개선, 물리적 부분구조 모형 접선강성행렬의 유한요소해석 프로그램에서의 평가 그리고 하중기반 보-요소의 요소상태결정의 연산시간을 줄이기 위한 소프트웨어의 개선이 이루어진다면 실시간 하이브리드실험과 진동대실험결과의 비교는 권장할 만하다. 그리고 "지진과 같은 동적하중하의 복잡한 구조물의 수치해석시뮬레이션"이라는 목적을 위하여 실시간 하이브리드실험은 동적하중에 대한 실험적 검증을 점진적으로 수치해석모형으로 대체하기 위한 저비용-고효율 실험법으로서의 가치를 충분히 가지고 있다고 할 수 있다.

This study focuses on the problem of scheduling wafer lots of several recipe(operation condition) types in the photolithography workstation in a semiconductor wafer fabrication facility. and sequence-dependent recipe set up times may be required at the photolithography machines. In addition. a lot is able to be operated at a machine when the reticle(mask) corresponding to the recipe type is set up in the photolithography machine. We suggest various heuristic algorithms. in which developed machine selection rules and lot selection rules are used to generate reasonable schedules to minimizing the total weighted flowtime. Results of computational tests on randomly generated test problems show that the suggested algorithms outperform a scheduling method used in a real manufacturing system in terms of the total weighted flowtime of the wafer lots with ready times.