물류 동선 최소화를 위한 혼합형 배치설계 모델 연구

채준재 ( Jun Jae Chae ) 한국로지스틱스학회 2014 로지스틱스연구 Vol.22 No.3

배치설계(또는 설비배치)는 생산 및 물류 에서 많은 연구가 되어온 분야이고 지금도 많은 연구자들이 새로운 방법론을 찾기 위해 지속적으로 연구가 되고 있는 분야이다. 하지만 오랜 연구에도 불구하고 배치를 위한 모델링 작업을 위해 개체를 사각형으로 단순화하였고 이 사각형의 특성 또한 배치하고자 하는 모든 영역에 있어서 같은 특성을 갖는다는 조건을 갖도록 하였다. 즉 모든 개체가 가로 세로 길이가 미리 주어진 특성을 갖거나 또는 면적과 범위를 주어진 형태로 나타내도록 하는 두 가지의 형태로 나누어 모델을 구성하는 연구를 하였다. 본 연구에서는 이러한 두 가지 형태의 개체가 한 모델에 함께 다루어져야 할 경우 최적배치를 위한 모델을 제안하고 이 모델에 대한 제한성을 제시한다. 배치설계에 대한 모델은 혼합정수모델(MIP: Mixed Integer Programming)로 최적해를 찾을 때 그 개체수가 늘어나면서 제한적으로 해를 찾을 수밖에 없다고 알려져 있다. 따라서 본 연구에서는 혼합형 개체의 배치 설계를 위한 모델로 인해 난이도가 증가하면서 찾을 수 있는 개체의 수에 대한 제한성 또한 언급하게 된다. Layout design problem is a fundamental optimization problem in manufacturing and service industries. The problem is defined as finding most efficient arrangement of departments with unequal area requirements within given space. The department area can be expressed as product of width and length of rectangular representation, or the width and length could be given in advance. This study is about modeling the layout design problem with these two types of departments. The model can generate the optimal layout for the departments with given area and the one with fixed length and width. Since the basic model for layout design is MIP (Mixed Integer Programing) and is known to be NP-Hard category, the model coping with these two types of departments is harder than the basic model. However, the model proposed by this study gives basic notion for mixing type in a single model and would be valuable for many related applications.

항공사 비정상 운항 복구를 위한 리-타이밍 전략과 개미군집최적화 알고리즘 적용

김국화(Guk hwa Kim),채준재(Jun jae Chae) 한국산업경영시스템학회 2017 한국산업경영시스템학회지 Vol.40 No.2

Airline schedules are highly dependent on various factors of uncertainties such as unfavorable weather conditions, mechanical problems, natural disaster, airport congestion, and strikes. If the schedules are not properly managed to cope with such disturbances, the operational cost and performance are severely affected by the delays, cancelations, and so forth. This is described as a disruption. When the disruption occurs, the airline requires the feasible recovery plan returning to the normal operations in a timely manner so as to minimize the cost and impact of disruptions. In this research, an Ant Colony Optimization (ACO) algorithm with re-timing strategy is developed to solve the recovery problem for both aircraft and passenger. The problem consists of creating new aircraft routes and passenger itineraries to produce a feasible schedule during a recovery period. The suggested algorithm is based on an existing ACO algorithm that aims to reflect all the downstream effects by considering the passenger recovery cost as a part of the objective function value. This algorithm is complemented by re-timing strategy to effectively manage the disrupted passengers by allowing delays even on some of undisrupted flights. The delays no more than 15 minutes are accepted, which does not influence on the on-time performance of the airlines. The suggested method is tested on the real data sets from 2009 ROADEF Challenge, and the computational results are compared with the existing ones on the same data sets. The method generates the solution for most of problem set in 10 minutes, and the result generated by re-timing strategy is discussed for its impact.

창고에서의 이송장비 운영정책에 관한 연구

이후언(Hue-On Lee),채준재(Jun-Jae Chae),이문수(Moon-Su Lee) 한국산업경영시스템학회 2011 한국산업경영시스템학회지 Vol.34 No.1

Controlling industrial vehicle operated by human in warehouse was not simple since the information transfer for controlling the vehicle was not easy. However, as the technology for the WMS (Warehouse Management System) has been advanced and the PDA (Personal Digital Assistant) has come into wide use in a workplace, the control of man-operated vehicle became less difficult as do to AGVS (Automated Guided Vehicle System). This study examines the ways to improve the efficiency of warehouse operation through introducing rule of task assignment for the vehicles, particularly forklift. This study, basically, refer to AGV operation policy because a great number of studies for AGV dispatching rule have been done and the mechanism for the controlling vehicles is very similar. The workers in field prefer to simple dispatching rules such as Shortest Retrieval Time First (SRTF), Shortest Travel Time First (STTF), and Longest Waiting Time First (LWTF). However, these rules have potential disadvantage. Thus, several rules made up by combining rules mentioned above are introduced and these new rules use threshold value or evaluation formula. The effectiveness of these new rules are tested by simulation and the results are compared. This study proposes favorable dispatching rules for forklift in warehouse for the efficiency of the vehicle operation and stability of service level.

AGV 기반 제조물류시스템의 성능평가를 위한 해석적 모형에 관한 연구 -반도체 Tandem 레이아웃 시스템을 중심으로-

이문수 ( Moon Su Lee ),채준재 ( Jun Jae Chae ) 한국로지스틱스학회 2010 로지스틱스연구 Vol.18 No.2

본 논문에서는 AGV(Automated Guided Vehicle)기반의 Tandem 레이아웃 내 구역(zone)의 물류 시스템 성능을 분석하기위해 대기행렬이론을 이용한 새로운 개념의 해석적 모형을 개발하고 이를 제시하였다. 일반적으로 해석적 모형이 가지는 간편함과 편리함에도 불구하고 AGV기반의 제조물류시스템의 분석을 위해서는 시뮬레이션기법이 주로 사용되어 왔었다. 이러한 현상의 가장 큰 이유 중 하나는 해석적 모형 자체의 부정확성 때문이었다. 따라서 본 논문에서는 AGV 기반의 제조물류시스템이 가지는 특성을 감안한 정확한 해석적 모형 개발 방법론을 제시하고 여기에 AGV 배차규칙을 어떻게 반영할 수 있는지에 대한 기본적인 접근방법에 대해 논하고자 한다. 이를 위해 우선 AGV기반의 제조물류시스템이 가지는 특성인 상태의존성(state-dependency)을 감안한 모형을 개발하고 해당 모형을 바탕으로 기본적인 2가지 AGV 배차규칙(Shortest Distance Rule: SDR; Time Limit/Shortest Distance Rule: TL/SDR)들을 어떻게 반영할 수 있는지에 대한 방법론을 제시하고 예제를 통해 그 정확성을 분석하였고, 각각의 경우 시뮬레이션 모델을 통해 해석적 모형의 정확성을 비교 검토하였다. This study presents a new analytical model with bases of queueing theory for analyzing the performance of material handling system of zone in AGV-based Tandem layout. Generally, the simulation method is preferred to analyze the AGV-based material handling system since the inaccuracies of analytical model though the analytical model is simple and convenient to apply. Thus, this paper introduces the methodology for developing analytical model which is well representing the characteristics of AGV-based material handling system. This paper also discusses the basic approaches for how the AGV dispatching rules are applied to the model. We developed the model taking one of the characteristics of AGV based material handling system, the state-dependency, into consideration. With this model, we suggest the methodology for how the two AGV dispatching rules, shortest distance rule (SDR) and time limit/shortest distance rule (TL/SDR), can be applied to the model. The accuracy of the model was investigated through the example problem and result of simulation model.

M/G/1시스템 물류시스템 상에서의 최적의 AGV 운영룰에 대한 해석적 연구

이문수 ( Moon Su Lee ),채준재 ( Jun Jae Chae ) 한국로지스틱스학회 2007 로지스틱스연구 Vol.15 No.2

제조물류시스템 내의 효율적인 복적재 차량할당을 위한 발견적 기법

이문수 ( Moon Su Lee ),채준재 ( Jun Jae Chae ) 한국로지스틱스학회 2007 로지스틱스연구 Vol.15 No.1

혼합형 배치설계를 위한 화음 탐색 기반 알고리듬

강수민 ( Su Min Kang ),채준재 ( Jun Jae Chae ) 한국로지스틱스학회 2015 로지스틱스연구 Vol.23 No.4

혼합형 배치설계 모델은 실제로 산업체에서 요구되는 배치설계로서 면적이 주어지는 형태의 개체와 가로 세로의 길이가 주어지는 형태의 개체를 모두 고려하여 각 개체간의 총 물류이동을 최소화 하는 배치를 찾는 것을 목표로 한다. 배치설계 분야에서 오랜 연구에도 불구하고 혼합형 배치설계 모델은 많은 연구가 진행되지 않았다. 본 연구는 혼합형 배치설계를 해결하기 위해 화음 탐색과 유동적-베이 방법을 조합한 기법을 제안하였다. 이 기법은 혼합형 배치설계의 해를 표현하기 위해 유동적-베이 방법을 이용하였으며 해를 찾는 발견적인 기법인 화음 탐색 알고리즘을 적용하였다. 화음 탐색 기반 혼합형 배치설계 기법은 잘 알려진 비혼합형 문제를 실험하여 기존의 기법들과 성능을 비교하여 제안하는 방법론에 대해 안정적인 해를 도출하는 것을 확인하였고 이후 이러한 실험을 바탕으로 혼합형 문제를 실험하여 비교적 크기가 큰 문제의 해도 비교적 빠르게 찾을 수 있음을 확인하였다. Facility layout problem(FLP) with mixed type departments is more concerned than the problem with a single type department. The FLP with mixed departments is the designing problem finding favorable layout for the department with unequal area requirements and the one with fixed size to minimize the total weighted distance of material flow in the facility. In this study, we develop Harmony Search based heuristic to generate the layout for the FLP with mixed type departments. The flexible bay structure is used to represent the layout and proposed search algorithm finds the best layout in the structure. We test several well known layout problem with non-mixed departments to evaluate search performance. The harmony search based algorithm, modified harmony search, found favorable solution for the problem and we extends our experiment to the layout problem with mixed type department. The modified Harmony search generates the layout solution in desirable time.

탄소 배출량 최소화를 위한 차량 경로 탐색 기법

박영환 ( Young Hwan Park ),우재헌 ( Jae Heon Woo ),채준재 ( Jun Jae Chae ) 한국로지스틱스학회 2013 로지스틱스연구 Vol.21 No.3

본 연구에서는 탄소 배출량을 최소로 하는 차량 경로 탐색 기법을 제안하였다. 차량의 이동과정에서 발생되는 탄소 배출량은 경로를 형성하는 노드의 순서와 이때 차량에 탑재하는 화물의 무게따라 배출량이 달리 산정된다. 본 연구에서 제안하는 기법은 각 노드에서의 탑재되는 무게와 순서를 동시에 고려하도록 saving 알고리듬의 개념을 기본으로 C-Saving 알고리즘을 적용하였다. C-Saving 알고리즘은 기존의 saving 알고리즘과 비교 분석을 통하여 탄소 배출량을 줄일 수 있는 경로를 제공함으로서 효과적인 경로의 의사결정을 할 수 있도록 돕는다. This study introduces a vehicle routing method to minimize CO2 emission. The total CO2 emission of traveling truck is rely on its weight of loads the truck delivering. The route scheduling can be reduced the emission with keeping the weight of truck as low as possible when it visits the designated location. This study presents C-Saving algorithm which is bit similar to well-known Saving algorithm to generate the route for lower CO2 emission and it showed that the algorithm performs as it is expected.

수하물시스템의 사전할당지점을 이용한 병합제어

김민희(Min hee Kim),신현우(Hyun woo Shin),채준재(Jun jae Chae) 한국산업경영시스템학회 2017 한국산업경영시스템학회지 Vol.40 No.2

A baggage handling system (BHS) in airport is an unified system for moving the passengers’ baggage in designated time. Input baggage from the check-in counter travels to the baggage claim area or cargo handling terminal through this system. In particular, entryway BHS consists of conveyors, X-ray and sorters such as tilt-tray to send the baggage to departing airplane and it could have various problems for handling certain amount of baggage in restricted time such as baggage jamming at certain merge point. This causes systemic error such as delay of the time, omissions of the baggage and even breakdown of the equipment and inefficiency. Also the increasing maximum time of the baggage passing through the BHS could delay the flight schedule and finally decrease the service level. Thus, the algorithm for controlling the flow of the merge is essential to the system. The window reservation algorithm is the one of the most frequently used methods to control the merge configuration. Above all, the reserve location, so called reserve ahead point, that allocates the window is important for the performance of the algorithm. We propose the modified window reservation algorithm and the best reserve locations by changing the reserve ahead point in the induction conveyors. The effect of various reserve ahead points such as the capacity and utility of the system were analyzed and the most effective reserve ahead point combination was found. The total baggage processing time and the utilization of the tilt-tray are properly considered when choosing the optimal Reserve ahead point combination. In the layout of this study, the configuration of four conveyors merged into one tilt-tray is studied and simulation analysis is done by AutoMod??, 3D simulation software. Through the simulation, the window reservation algorithm is effectively operated with the best combination of reserve ahead point which reduces the maximum baggage travel time.

국내 무인항공기의 경로계획 연구

김진우(Jin woo Kim),김진욱(Jin wook Kim),채준재(Jun jae Chae) 한국산업경영시스템학회 2015 한국산업경영시스템학회지 Vol.38 No.4

UAV (Unmanned Aerial Vehicle), the pilotless plane or drone, draws researchers' attention at these days for its extended use to various area. The research was initiated for military use of the UAV, but the area of applicable field is extended to surveillance, communication, and even delivery for commercial use. As increasing the interest in UAV, the needs of research for operating the flying object which is not directly visible when it conducts a certain mission to remote place is obviously grown as much as developing high performance pilotless plane is required. One of the project supported by government is related to the use of UAV for logistics fields and controlling UAV to deliver the certain items to isolated or not-easy-to-access place is one of the important issues. At the initial stage of the project, the previous researches for controlling UAV need to be organized to understand current state of art in local researches. Thus, this study is one of the steps to develop the unmanned system for using in military or commercial. Specifically, we focused on reviewing the approaches of controlling UAV from origination to destination in previous in-country researches because the delivery involves the routing planning and the efficient and effective routing plan is critical to success to delivery mission using UAV. This routing plan includes the method to avoid the obstacles and reach the final destination without a crash. This research also present the classification and categorization of the papers and it could guide the researchers, who conduct researches and explore in comparable fields, to catch the current address of the research.