• Journal of the Korean Society of Systems Engineering
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• v.5 no.2
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• pp.63-69
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• 2009

For the effective and efficient system development, it is provided of complex and diverse disciplines, analysis and design, points of views for decisions making, technical information management, assurance of products, and so on to be integrated and ensured. Systems engineering is conducted through a process and is implemented by tools based on relevant methodologies. Systems engineering environment should be provided to support the systems engineering process, method, and tools used on the project. In this paper, the essential environment in performing works in a organization applying systems engineering on the basis of system life cycle was reviewed. The present states on establishment of the systems engineering in Korea Railroad Research Institute were also examined with some reviews of other cases.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.1
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• pp.1-8
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• 2012

Recently, the needs of system performances such as working speed and processing accuracy in machine tools have been increased. Especially, the speed increment generates harmful heat at both moving part of the machine tools and handicrafts. The heat is a main drawback to progress accuracy of the processing. Hence, a cooler system to control temperature is inevitable for the machine tools. In general, two representative control schemes, hot-gas bypass and variable speed control of a compressor, have been adopted in the water cooler system. In this paper, comparisons of system performances according to the control schemes in a cooler for machine tools were conducted in detail. Each proportional-integral feedback controller for the two different control systems is designed. The system performances, especially the temperature control accuracy and coefficient of performance which is a criterion of energy saving, were mainly analyzed through various experiments using 1RT water cooler system with different two types of control scheme. These evaluations will provide useful information to choose suitable water cooler system for the engineers who design controllers of the cooler system for machine tools.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.4
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• pp.7-15
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• 2009

• Journal of Aerospace System Engineering
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• v.18 no.2
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• pp.79-86
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• 2024

We have developed software for the SMFD that utilizes a range of graphic design tools. These tools enable us to effortlessly create graphic elements by defining their attributes, such as position and motion. Subsequently, we can convert these designs into source code and execute the resulting software on the target system, leveraging the graphic engines provided by the tools. However, when it comes to developing the displaying software for the SMFD using multiple graphic design tools on a single system, we face various challenges. In this paper, we will delve into these challenges and propose solutions for developing the displaying software for SMFD based on heterogeneous display design tools.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.1
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• pp.104-111
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• 1995

The needs of ultraprecision machine tools, which manufacture and machine the high precision parts used in computers, semiconductors and othe rprecise machines, have been increased recentrly. So it is important to design the driving parts of the ultraprecision machine tools which affect significantly on the performance of them. In this paper, the dynamic analyses on the belt-drive system were studied. The correlational equations between the acoustic natural frequency and the tension of belt were derived by experiments. The dynamic delections while the dynamic loads on the motor system changed were analyzed by the finite element analysis. The nonlinear characteristics of the bearings on the dynamic performance was studied and the belt connecting the motor to the spindle of a machine tool was modeled by the truss element and the beam element.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.915-916
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• 2008

• Journal of Korean Society of Industrial and Systems Engineering
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• v.27 no.1
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• pp.9-14
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• 2004

More than three years have passed since Korean companies introduced Six-Sigma. Each company used a lot of quality improvement tools for years. However, the tools have been taught to the companies with a little understanding of Six sigma tools. Therefore, it is difficult to use the tools correctly at appropriate time. This survey paper was conducted on MBBs and BBs of the manufacturing companies that introduced Six-Sigma. It is intended, in this paper, to provide the companies that will be introduce Six-Sigma a guideline of training course and tools by understanding the importance of each DMAIC stage of Six-Sigma, examining the frequently used tools in each process and their performances, and selecting the key tools for each stage based on the result of this survey.

• Journal of the Ergonomics Society of Korea
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• v.30 no.4
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• pp.491-494
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• 2011

Objective: to improve agricultural working environment using tools and equipments. Background: most existing tools currently used, in fact, are discrepant from human factor guidelines so that they are still exposed to the musculoskeletal disease. Method: the provided tools and equipments are mostly designed considering human factor engineering or usability engineering in a way to avoid musculoskeletal disease. Results: propose the top-down procedure and usability engineering steps to evaluate them for the system design suitability. Conclusion: apply them conveniently into rural environment to help farmers working environment.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.1
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• pp.111-117
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• 2000

One of the major limitations of productivity and quality in metal cutting is the machining accuracy of machine tools. The machining accuracy is affected by geometric errors, thermally-induced errors, and the deterioration of the machine tools. Geometric and thermal errors of machine tools should be measured and compensated to manufacture high quality products. In metal cutting, the machining accuracy is more affected by thermal errors than by geometric errors. This paper models the thermal errors for error analysis and develops an on-the-machine measurement system by which the volumetric errors are measured and compensated. The thermal error is modeled by means of angularity errors of a column and thermal drift error of the spindle unit which are measured by the touch probe unit with a star type styluses and a designed spherical ball artifact (SBA). Experiments show that the developed system provides a high measuring accuracy, with repeatability of $\pm$2$\mu\textrm{m}$ in X, Y and Z directions. It is believed that the developed measurement system can be also applied to the machine tools with CNC controller. In addition, machining accuracy and product quality can be also improved by using the developed measurement system when the spherical ball artifact is mounted on a modular fixture.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.778-783
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• 1994

In operating automated manufacturing system, the long term stability and reliability of NC machine tools become most critical issues. Especially the machining accuracy is dominated by the thermal deformation of machine tools which remains still unsolved and causes troubles in manufacturing operations. Although researches have been carried out on the thermal behavior of a machine tools to minimize or control the thermal deformation of machine tools, the computer models for an analysis of the thermal behacior in machine tools has yet to appear in the open literature. The object of the paper is to present a method of modeling the thermal behavior of a machine tool. The method will make use of finite elements ad be capable of modeling whole machine structures as well as of heat generation processes in the kinematic system components. And temperature distributions and thermal deformations of a CNC lathe are analyzed using the finite element method and are compared with those measured in practice.