• 한국IT서비스학회지
• /
• 제12권4호
• /
• pp.175-186
• /
• 2013

Among many automotive manufacturing processes, an assembly process has the smallest automatization percentage. As the correct assembly of the supplied components according to its specification is directly related with the quality of the final product, it is of the utmost importance to reduce the possible human errors in the assembly line. However, due to the lack of an effective verification system for an assembly line, currently, there is huge cost loss caused by the errors in seat assembly every year. Therefore, in this paper, to overcome the limit of the current verification method and to prevent the occurrence of assembly errors caused by mismatching assembling components or its specifications, a verification system and its method is proposed employing the RFID technology. The system is for automatic detection of the assembly errors, so that it can reduce the time and effort needed for verification and maximize the work efficiency. Also, by preventing the assembly errors in advance, the productivity can be increased through a quality innovation.

• 한국마이크로전자및패키징학회:학술대회논문집
• /
• 한국마이크로전자및패키징학회 2001년도 3rd Korea-Japan Advanced Semiconductor Packaging Technology Seminar
• /
• pp.51-69
• /
• 2001

Japan Jisso Technology Roadmap 2001 (JJTR2001) was published by JEITA in April 2001. Future electronic products request further higher assembly technology (ex. Finer pitch packages & components, 3D assembly, etc.) to reduce size and improve performance of the electric products. For LSI Packages, finer ball pitch technology and finer chip connection technology will be developed. For electric components, further size reduction will be developed. For Jisso (assembly) machine, finer pitch assembly and short tact time technology will be developed. Mr. Utsunomiya will present PCB roadmap next.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2006년도 춘계학술대회 논문집
• /
• pp.625-626
• /
• 2006

Nowadays, the increasing global competition forces manufacturing enterprises to apply new technologies method of their products. To save time and cost in assembly process and to increase the quality of products, it is very important to choose an optimal assembly system. We propose a methodology that generates an optimal assembly system by using the Digital manufacturing.

• 한국경영과학회지
• /
• 제19권2호
• /
• pp.217-228
• /
• 1994

This paper presents a new integer formulation (Type III ALB) for a single model assembly line balancing problem. The objective of the formulation is to minimize the total idle time, which is defined as the product of the number of work stations and the cycle times minus the total work content. This formulation considers currently existing Type I (minimizing the number of work stations for a given cycle time) and type II (minimizing the cycle time for a given number of work stations) formulations as its special cases and provides the global minimum solutions of the cycle time and the number of work stations. This information would be of great value to line designers involved in designing new assembly lines and rebalancing old lines under flexible conditions. Solution methods based on combination of Type I and Type II approaches are also suggested and compared.

• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회 1996년도 추계학술대회발표논문집; 고려대학교, 서울; 26 Oct. 1996
• /
• pp.307-309
• /
• 1996

This paper analyses a deterministic scheduling problem concerned with manufacturing two types of components at a pre-assembly stage which consists of two independent feeding machines each producing its own type of component. Each type represents a unique component which may have variations in its size or quality. Therefore, the completion time of each component depends on both its type and quality (size) variations. Such manufactured components are subsequently assembled into various component dependent products. The problem has the objective measure of minimizing the total weighted completion time of a finite number of jobs(products) where the completion time of each job is measured by the latest completion time of its two components at the pre-assembly stage. The problem is shown to be NP-complete in the strong sense. A WSPT rule coupled with a machine-aggregation idea is developed for good heuristics which show the error bound of 2.

• Industrial Engineering and Management Systems
• /
• 제15권1호
• /
• pp.1-10
• /
• 2016

This paper presents a fast sequencing algorithm for a mixed model assembly line with multiple workstations which minimize the total utility work and idle time. We compare the proposed algorithms with another heuristic, the Tsai-based heuristic, for a sequencing problem that minimizes the total utility works. Numerical experiments are used to evaluate the performance and effectiveness of the proposed algorithm. The Tsai-based heuristic performs best in terms of utility work, but the fast sequencing algorithm performs well for both utility work and idle time. However, the computational complexity of the fast sequencing algorithm is O (KN) while the Tsai-based algorithm is O (KNlogN). Actual computational time of the fast sequencing heuristic is 2-6 times faster than that of the Tsai-based heuristic.

• Nuclear Engineering and Technology
• /
• 제56권6호
• /
• pp.2120-2130
• /
• 2024

This study significantly reduced the seismic analysis time of PCSG assembly by introducing a reduced model using homogenization and sub-structuring methods. The homogenization method was applied to the primary and secondary micro-channel sheets, and the sub-structuring method was applied to the PCSG module sets. Modal analysis and frequency response analysis were then performed to validate the accuracy of the reduced model. The analysis results were compared with the full model and it was confirmed that the reduced model provided almost the same analysis results as the full model. To verify the computational efficiency of the reduced model, the computational time was then compared with the full model, and it was confirmed that the modal analysis time was reduced by 3.42 times and the frequency response analysis time was reduced by 4.59 times.

• ETRI Journal
• /
• 제40권3호
• /
• pp.347-354
• /
• 2018

Using various offset times to separate differential services is the most common form of service differentiation in optical burst switching networks. In this approach, a larger offset time is given to a higher priority burst, but it causes this burst to have a longer delay. One solution to this problem is to adjust the burst assembly time so that the buffering delay of the higher priority burst is always shorter than that of the lower priority burst. However, this adjustment causes another problem, called delay unfairness, for bursts with differential priorities that share the same path to their destination. This article proposes a new solution for delay fairness using the burst assembly.

• 산업경영시스템학회지
• /
• 제21권48호
• /
• pp.299-310
• /
• 1998

Actually mixed assembly line is mixed with open and close type workstation. This workstation is called hybridworkstation. The propose of this paper is to determine the sequencing of model that minimize line length for actual(hybridworkstation) mixed model assembly line. we developed three mathematical formulation of the problem to minimize the overall length of a line with hybrid station. Mathematical formulation classified model by operato schedule. Mixed model assembly line is combination program and NP-hard program. Thus computation time is often a critical factor in choosing a method of determining the sequence. This study suggests a tabu search technique which can provide a near optimal solution in real time and use the hill climbing heuristic method for selecting initial solution. Modified tabu search method is compared with MIP(Mixed Integer Program). Numerical results are reported to demonstrate the efficiency of the method.

• 제어로봇시스템학회논문지
• /
• 제8권6호
• /
• pp.514-523
• /
• 2002

Feeder arrangement is an important element of process planning for printed circuit board assembly systems. This paper newly proposes a feeder arrangement method for multihead-gantry chip mounters. The multihead-gantry chip mounters are very popular in printed circuit board assembly system, but the research has been mainly focused on single-head-gantry chip mounters. We present an integer programming formulation for optimization problem of multihead-gantry chip mounters, and propose a heuristic method to solve the large NP-complete problem in reasonable time. Dynamic programming method is then applied to feeder arrangement optimization to reduce the overall assembly time. Comparative simulation results are finally presented to verify the usefulness of the proposed method.