• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.2
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• pp.339-350
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• 1994

This paper presents a method for automatic generation of line balanced assembly sequences based on disassemblability and proposes a method of evaluating an assembly work time using neural networks. Since a line balancing problem in flexible assembly system requires a sophisticated planning method, reasoning about line balanced assembly sequences is an important field of concern for planning assembly lay-out. For the efficient inference of line balanced assembly sequences, many works have been reported on how to evaluate an assembly work time at each work station. However, most of them have some limitations in that they use cumbersome user query or approximated assembly work time data without considering assembly conditions. To overcome such criticism, this paper proposes a new approach to mathematically verify assembly conditions based on disassemblability. Based upon the results, we present a method of evaluating assembly work time using neural networks. The proposed method provides an effective means of solving the line balancing problem and gives a design guidance of planning assembly lay-out in flexible assembly application. An example study is given to illustrate the concepts and procedure of the proposed scheme.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.3
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• pp.355-363
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• 2007

This paper presents a method of an automatic work time evaluation based on the verification of a disassemblability and assembly configuration. Even though a work time evaluation is an important field of concern for planning assembly lay-out, there are some limitations using cumbersome user query or approximated work time data without considering assembly condition. To overcome such restriction, this paper presents a method to mathematically verify assembly conditions based on the disassemblability, which is defined by the separability and stability cost. The separability cost represents a facility of the part disassembly operation, and the stability cost which represents a degree of the stability for the base assembly motion. Based upon the results, we propose a new approach of evaluating work time using neural networks. The proposed method provides an effective means of solving the work time evaluation problem and gives a design guidance of planning assembly lay-out in flexible manufacturing application. Example study is given to illustrate the concepts and procedure of the proposed schemes.

• Industrial Engineering and Management Systems
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• v.11 no.2
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• pp.188-195
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• 2012

This paper presents a new mode of expressing a 3D assembly work for creating a 3D CG animation without judgment by human from minimal required information. In the field of manufacturing, there are favorable movements in the utilization of 3D CAD for 3D simulation to shorten lead time for product development and pre-production. But simulating an assembly work has troubles to need huge quantity of manually input data. This paper discusses what minimal necessary information for creating 3D CG animations of assembly works is, focusing on the features of assembly works. Furthermore, a new mode of expressing a 3D assembly work is proposed as "state/change transition diagrams" (SCTD), which express arbitrary scenes in an assembly work as "state" and describe a sequential assembly work with "state" and "change", and the outline of its stepwise generation algorithm is also described. SCTD can be converted to a 3D CG animation of an assembly work without judgment by human. This paper focuses on the creating 3D CG animation of assembly works which workers use only their both hands.

• Journal of Nutrition and Health
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• v.34 no.6
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• pp.701-714
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• 2001

The purpose of this study was to apply a PERT-type system, a combination of the project evaluation and review technique(PERT) and critical path method(CPM) on the employees' work time management of flood preparation, assembly, transportation and cleaning in home-delivered meals program for elderly The resources allotment heuristic program was developed by considering the number of employees and cooking utilities, being limited resources of home- delivered meals program. This program could assign the employees to perform the works included in flood preparation, assembly, transportation ind cleaning. Critical path and activities ware identified by PERT-type system on the basic of work time investigation in five senior centers. Work sheets were invented to perform the work by the shortest path with flexible employees'maximum flow As a result of the work time investigation, the most prevalent activities were ones of preparation in center C and E. Besides, the preparation(over fifty percent) was the most proportion among flood preparation, assembly, transportation and cleaning in center C and E. Critical path and activities of 'C'center were cucumber in sauce preparation path and assembly, wrapping in assembly path and case delivery in transportation path. Critical path and activities of 'E'center were Pan-fried Potato Preparation Path and assembly, case covering, wrapping in assembly Path. The work sheet invented by the heuristic program and PERT-type system reduced the work completion time and man hours in both centers.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.7 s.196
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• pp.39-48
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• 2007

This paper presents a method of a line balanced assembly sequence generation based on the verification of a disassemblability and a work time. To derive the disassemblability for a part to be disassembled, first we inference collision free assembly directions by extracting separable directions fur the part. And we determine the disassemblability defined by the separability and stability cost. The separability cost represents a facility of the part disassembly operation, and the stability cost which represents a degree of the stability for the base assembly motion. Based upon the results, we propose a new approach of evaluating work time using neural networks. The proposed assembly sequence generation provides an effective means of solving the line balancing problem and gives a design guidance of planning assembly lay-out in flexible manufacturing application. Example study is given to illustrate the concepts and procedure of the proposed schemes.

• Journal of the Ergonomics Society of Korea
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• v.25 no.3
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• pp.61-66
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• 2006

Awkward work postures in workshop highly affect on work-related musculoskeletal disorders(WMSDs). Especially, in automobiles assembly process, these awkward work postures of workers may cause serious injury and illness. This study is to compare the performance among the evaluation tools which can measure the work-loads caused by the awkward work postures in automobiles assemble process. RULA, REBA and TVAL(Toyota Verification of Assembly Line) are used as the evaluation tools. The 85 jobs selected in the automobiles assembly process are applied to the three tools and their performances are analyzed after the evaluation of the work-load in each job. Through various measures of performance such as statistical test, DUNCAN test, regression test etc., the tendencies and characteristics among them are analyzed in detail.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.9-13
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• 2009

Recently, construction in downtown is often done closely at the adjacent building. In this case, underground construction need to Basement Composite Wall(BCW) construction. However, generally, during the construction process of BCW form works have many problems that are narrow working space and inefficient time consuming. Despite of these problems, there was no quantitative research for the work time of BCM assembly. Therefore, in this study, work time of CBW form assembly in underground construction is identified by the work analysis. The results of this study reveal that buttress work of basement form take lots of time in the entire work process of Basement Composite Wall form assembly.

• Industrial Engineering and Management Systems
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• v.12 no.4
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• pp.368-379
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• 2013

Efficiency in work training is a perennial issue due to high-diversity low-volume production, particularly for manufacturers producing office machines which are manually assembled by workers. To reduce the training cost, parts used in training are usually reused; a trainer disassembles a product assembled by a worker in training. This paper proposes a training method that employs disassembly usually performed by a trainer. This method assigns both assembly and disassembly to a worker in training, in contrast to the conventional method. The effectiveness of the proposed method is experimentally discussed in terms of learning assembly motions and work procedure at each learning stage, namely, "undergoing learning," "immediately after learning," and "seven days after learning." The effectiveness of the training method is confirmed. The method improves the stability of work procedure recollection immediately after training. Furthermore, at seven days after training, it improves retention of the assembly motions and work procedure, and also promotes and maintains memory related to product structure.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.5
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• pp.87-92
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• 2005

In this study, an automation assembly jig for the automation assembly process for the ventilation grille that is used in the interior of a car Is developed. As the method that can do the automation assembly for the ventilation grille, a simple jig and air cylinder have been applied. And a solenoid valve, a filter regulator, and on-off switch have been used in controlling the system. Moreover, the timer is attached to the equipment so that a worker may control the assembly time, as fitting the quantity on demand of production. Actually with executing the assembly test productivity and performance of assembly have been verified. In case of the automation assembly work for a ventilation grille is compared to the manual work. The optimum working speed has been identified to make the process twice or three times better.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.77-82
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• 2000

In this study, an automation assembly jig for the automation assembly process for the ventilation grille that is used in the interior of a car is developed. As the method that can do the automation assembly for the ventilation grille, a simple jig and air cylinder have been applied. And a solenoid valve, a filter regulator, and on-off switch have been used in controlling the system. Moreover, the timer is attached to the equipment so that a worker may control the assembly time, as fitting the quantity on demand of production. Actually with executing the assembly test productivity and performance of assembly have been verified. In case of the automation assembly work for a ventilation grille is compared to the manual work. The optimum working speed has been identified to make the process twice or three times better.