• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.533-544
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• 1992

한 제품의 구성 부품 수가 증가함에 따라 조립/분해 순서의 방법수는 기하급수적으로 증가한다. 또한 이 순서의 선택에 의하여 조립/분해의 효율성이 결정된다. 본 논문에서는 조립제품의 조립순서(Assembly Sequence)와 특정부품의 효율적 교체(Part Replacement)를 위한 분해순서(Disassembly sequence)에 관한 새로운 Algorithm들을 다음 3가지 경우를 통하여 소개한다 : 1) Full Assembly/Disassembly, 2) Part Replacement by Individual Disassembly, 그리고 3) Part Replacement by Group Disassembly. 이들 Algorithm들은 'Freedom and Interference Space'라는 새로운 개념으로부터 유도되며, Group Disassembly는 Carpenter's Approach를 통하여 실현된다. 이 논문에서 소개되는 Algorithm들은 조립/분해순서와 함께 조립/분해 방향도 제시하는데 비교적 복잡한 예를 통하여 이들을 실현함으로써 실제 제품 Design에의 활용 가능성을 보여준다.

• Journal of Korean Institute of Industrial Engineers
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• v.35 no.2
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• pp.129-140
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• 2009

This paper introduces the planar storage location assignment problem (PSLAP) that no research has attempted to mathematically solve. The PSLAP can be defined as the assignment of the inbound and outbound objects to the storage yard with aim of minimizing the number of obstructive object moves. The storage yard allows only planar moves of objects. The PSLAP usually occurs in the assembly block stockyard operations at a shipyard. This paper formulates the PSLAP using a mathematical programming model, but which belongs to the NP-hard problems category. Thus this paper utilizes an efficient genetic algorithm (GA) to solve the PSLAP for real-sized instances. The performance of the proposed mathematical programming model and developed GA is verified by a number of numerical experiments.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.1
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• pp.63-71
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• 2006

In this paper, we consider a planning problem arising from printed circuit board manufacturing industries. Given a set of several types of PCBs, component feeders and surface mounting machines in series in a PCB assembly line, the problem is to define the feeder allocation and job sequence with the objective of minimizing the total operation time of the line. We formulate the problem as a mathematical model. And, the problem is proven to be NP-hard, so a genetic algorithm is developed. Finally, we give test results to evaluate the performance of the genetic algorithm.

• Journal of the Korea Society of Computer and Information
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• v.21 no.2
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• pp.97-103
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• 2016

This paper deals with the cycle time minimization problem that determines the productivity in printed circuit board (PCB) with n components using the m placement machines. This is known as production cycle time determination problem (PCTDP). The polynomial time algorithm to be obtain the optimal solution has been unknown yet, therefore this hard problem classified by NP-complete. This paper gets the initial assignment result with the machine has minimum unit placement time per each component firstly. Then, the balancing process with reallocation from overhead machine to underhead machine. Finally, we perform the swap optimization and get the optimal solution of cycle time $T^*$ within O(mn) computational complexity. For experimental data, the proposed algorithm can be obtain the same result as integer programming+branch-and-bound (IP+B&B) and B&B.

• Proceedings of the Safety Management and Science Conference
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• 2005.05a
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• pp.523-534
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• 2005

This paper is concerned with the integrated problem of line balancing and model sequencing in mixed model assembly lines(MMALBS), which is important to efficient utilization of the lines. In the problem, we deal with the objective of minimizing the overall line length To apply the GAs to MMALBS problems, we suggest a GA representation which suitable for its problems, an efficient decoding technique for the objective, and genetic operators which produce feasible offsprings. Extensive experiments are carried out to analyze the performance of the proposed algorithm. The computational results show that our algorithm is promising in solution quality.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.117-118
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• 2023

Estimating the construction period at the initial stage of the project and determining whether it is appropriate is very important for the developer's decision-making and the success of the construction company's business. Existing researchers have conducted various studies to calculate the appropriate construction period, but there is no study on the influencing factors and methodology for the construction period of beam-column PC apartment building frame construction. The purpose of this study is to calculate the PC member assembly time using the mathematical algorithm of PC member assembly. The results of this study can be used as basic data to calculate the construction date of the standard floor of PC construction.

• Steel and Composite Structures
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• v.50 no.3
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• pp.337-345
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• 2024

This research proposed a particle swarm optimization (PSO) based seismic retrofit design of moment frame structures using a steel frame assembly. Two full scale specimens of the steel frame assembly with different corner details were attached to one-story RC frames for seismic retrofit, and the lateral load resisting capacities of the retrofitted frames subjected to cyclic loads were compared with those of a bare RC frame. The open source software framework Opensees was used to develop an analytical model for validating the experimental results. The developed analytical model and the optimization scheme were applied to a case study structure for economic seismic retrofit design, and its seismic performance was assessed before and after the retrofit. The results show that the developed steel frame assembly was effective in increasing seismic load resisting capability of the structure, and the PSO algorithm could be applied as convenient optimization tool for seismic retrofit design of structures.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.72-72
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• 1995

• Journal of the Society of Naval Architects of Korea
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• v.38 no.2
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• pp.79-86
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• 2001

This study shows an attempt to generate an assembly sequence and its model for a ship block assembly using the graph theory and graph algorithms. To generate the ship block assembly, we propose four levels of the ship block assembly model such as "geometry mode1", "relational model", "sequential mode1", and "hierarchical model". To obtain the relational model, we used surface and surface intersection algorithm. The sequential model that represents a possible assembly sequence is made by using several graph algorithms from the relational model. The hierarchical model will be constructed from the sequential model in order to represent the block assembly tree and so forth. The purpose of the hierarchical model is to define an assembly tree and to generate the Bill Of Material(BOM). Lastly, the validity of the method proposed in this study is examined with application to ship block assembly models of a single type and double type according to four models mentioned above.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.5
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• pp.552-560
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• 2013

In this paper, an optimization algorithm for the block assembly accuracy control assessment is proposed with consideration for the current block assembly process and accuracy control procedure used in the shipbuilding site. The objective function of the proposed algorithm consists of root mean square error of the distances between design and measured data of the other control points with respect to a specific point of the whole control points. The control points are divided into two groups: points on the control line and the other points. The grouped data are used as criteria for determining the combination of 6 degrees of freedom in the registration process when constituting constraints and calculating objective function. The optimization algorithm is developed by using combination of the sampling method and the point to point relation based modified ICP algorithm which has an allowable error check procedure that makes sure that error between design and measured point is under allowable error. According to the results from the application of the proposed algorithm with the design and measured data of two blocks data which are verified and validated by an expert in the shipbuilding site, it implies that the choice of whole control points as target points for the accuracy calculation shows better results than that of the control points on the control line as target points for the accuracy of the calculation and the best optimized result can be acquired from the accuracy calculation with a fixed point on the control line as the reference point of the registration.