• 한국정밀공학회지
• /
• 제16권6호
• /
• pp.197-208
• /
• 1999

This paper presents an operation sequence-based approach for determining machine cell layout in a cellular manufacturing environment. The proposed model considers the sequence of operations in evaluating the intercell and intracell movements. In this paper, design of cellular layout has an objective of minimization of total material flow among facilities, where the total material flow is defined as a weighted sum of both intercell and intracell part movements. The proposed algorithm is developed by using genetic algorithm and can be used to design an optimal cellular layout which can cope with changes of shop floor situation by considering constraints such as the number of machine cells and the number of machines in a machine cell.

• 산업경영시스템학회지
• /
• 제42권2호
• /
• pp.94-103
• /
• 2019

Self Organizing Map (SOM) is a neural network that is effective in classifying patterns that form the feature map by extracting characteristics of the input data. In this study, we propose an algorithm to determine the cell formation and the machine layout within the cell for the cell formation problem with operation sequence using the SOM. In the proposed algorithm, the output layer of the SOM is a one-dimensional structure, and the SOM is applied to the parts and the machine in two steps. The initial cell is formed when the formed clusters is grouped largely by the utilization of the machine within the cell. At this stage, machine cell are formed. The next step is to create a flow matrix of the all machine that calculates the frequency of consecutive forward movement for the machine. The machine layout order in each machine cell is determined based on this flow matrix so that the machine operation sequence is most reflected. The final step is to optimize the overall machine and parts to increase machine layout efficiency. As a result, the final cell is formed and the machine layout within the cell is determined. The proposed algorithm was tested on well-known cell formation problems with operation sequence shown in previous papers. The proposed algorithm has better performance than the other algorithms.

• 대한산업공학회지
• /
• 제27권1호
• /
• pp.54-60
• /
• 2001

In this paper, a shape-based block layout (SBL) approach is presented to solve the facility layout problem with unequal-area and fixed shapes. The SBL approach employs hybrid genetic algorithm (Hybrid-GA) to find a good solution and the concept of bay structure is used. In the typical facility layout problem with unequal area and fixed shapes, the given geometric constraints of unequal-area and fixed shapes are mostly approximated to original shape by aspect ratio. Thus, the layout results require extensive manual revision to create practical layouts and it produces irregular building shapes and too much unusable spaces. Experimental results show that a SBL model is able to produce better solution and to create more practical layouts than those of existing approaches.

• 한국생산제조학회지
• /
• 제24권1호
• /
• pp.63-68
• /
• 2015

Pattern layout design is very important to the automation of apparel industry. Until now, the genetic algorithm and Tabu search method have been applied to layout design automation. With the genetic algorithm and Tabu search method, the obtained values are not always consistent depending on the initial conditions, number of iterations, and scheduling. In addition, the selection of various parameters for these methods is not easy. This paper presents a hybrid search method that uses a neural network and simulated annealing to solve these problems. The layout of pattern elements was optimized to verify the potential application of the suggested method to apparel pattern layout design.

• 산업공학
• /
• 제20권2호
• /
• pp.121-132
• /
• 2007

The facility layout problem (FLP) involves the positioning of facilities within a given workplace in order to minimize the material flow distance between facilities. In this paper, we focus on the FLP in which the each facility has a rectangular shape and an input and output points. We develop a heuristic algorithm in which the facilities are arranged according to the layout algorithm using center of gravity and then simulated annealing algorithm is applied to improve the solution. A comparison of the computational results with exiting algorithms shows that the proposed algorithm provides better solutions in reasonable range of computational time.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2001년도 하계종합학술대회 논문집(2)
• /
• pp.113-116
• /
• 2001

In this paper we present a new hierarchical layout object extraction algorithm, which is based on rectangles rather than edges. The original layout data is modeled as instances connected by wires. Each polygon shape is divided into a set of rectangles and the instances and wires are extracted and recognized from those rectangles together with their connection and size information. We have applied the algorithm to actual layouts. Experiments on several standard cell library demonstrate the effectiveness of the algorithm.

• 대한기계학회논문집
• /
• 제18권12호
• /
• pp.3236-3245
• /
• 1994

The nesting of two-dimensional patterns onto a given raw sheet has applications in a number industries. It is a common problem often faced by designers in the shipbuilding, garment making, blanking die design, glass and wood industries. This paper presents a multi-stage layout approach for nesting two-dimensional patterns by using artificial intelligence techniques with a relatively short computation time. The raw material with irregular boundaries and internal defects which must be considered in various cases of nesting was also investigated in this study. The proposed nesting approach consists of two stages : initial layout stage and layout improvement stage. The initial layout configuration is achieved by the self-organizing assisted layout(SOAL) algorithm while in the layout improvement stage, the simulated annealing(SA) is adopted for a finer optimization.

• 산업경영시스템학회지
• /
• 제22권49호
• /
• pp.89-98
• /
• 1999

The objective of this study is to develop an improved algorithm for layout problems. Computerized facility layout program was also applied to solve the layout problem in locomotive maintenance workshop. The current facility layout is structured in the large space without considerations of many variable factors. For this reason, effectiveness of layout results in loss on effective space utility. This study is to develop an algorithm in the consideration of importance weight and desirable shape of specific department in the computerized layout planning and quantitative relationship rating between each department was used. Standard process duration of locomotive maintenance workshop was used to select the main activities of locomotive maintenance work. This study could generate more efficient facility layout design to reduce the number of movement frequency and travel distance in maintenance workshop.

• 한국산업정보학회논문지
• /
• 제13권5호
• /
• pp.142-148
• /
• 2008

Facility Layout Planning is concerned with how to arrange facilities necessary for production in a given space. Its objective is often to minimize the total sum of all material flows multiplied by the distance among facilities. FLP belongs to NP complete problem; i.e., the number of possible layout solutions increases with the increase of the number of facilities. Thus, meta heuristics such as Genetic Algorithm (GA) and Simulated Annealing have been investigated to solve the FLP problems. However, one of the biggest problems which lie in the existing meta heuristics including GA is hard to find an appropriate combinations of parameters which result in optimal solutions for the specific problem. The Ant System algorithm with elitist and ranking strategies is used to solve the FLP problem as an another good alternative. Experimental results show that the AS algorithm is able to produce the same level of solution quality with less sensitive parameters selection comparing to the ones obtained by applying other existing meta heuristic algorithms.

• 한국컴퓨터정보학회논문지
• /
• 제18권5호
• /
• pp.95-102
• /
• 2013

생명체 내에서 나타나는 네트워크 중 하나인 대사 경로는 화합물의 상호 관계를 그래프를 통해 표현된다. 대사 경로는 본질적인 복잡성 때문에 대사 경로 내의 흐름을 한 눈에 알 수 있도록 가시화하여 보여 주는 도구가 반드시 필요하다. 이러한 가시화 도구의 경우 노드수가 증가할수록 에지 교차가 기하급수적으로 증가하는 문제가 있다. 따라서 유전체 수준의 대사 경로를 연구하기 위해서는 대사 경로 그래프 레이아웃 상에 나타나는 에지 교차를 줄이는 것이 시각화의 매우 중요한 부분이다. 본 논문은 생물학에서의 대사 경로에 대한 시각화를 위한 2-계층을 이용한 대사 경로 레이아웃 알고리즘을 제안한다. 대사 경로의 구조적 특징을 고려하여 대사 경로 그래프에 존재하는 주요 컴포넌트인 환형 컴포넌트 또는 연결성 높은 노드를 찾아 상위 계층에 레이아웃 하고 나머지 부분그래프는 하위 계층에 레이아웃 한다. 제안한 대사 경로 레이아웃 알고리즘은 유연성 있는 대사 경로 분석의 기초가 된다.