• 산업경영시스템학회지
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• 제20권41호
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• pp.167-175
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• 1997

This study is concerned with Quality Maintenance System in Total Productive Maintenance. The important factor in manufacturing process is to attain the uniformity of quality Also quality assurance system is defined such as manufacturing process and products. In this paper, the design of quality maintenance system is considered to manufacturing process elements. Especially the manufacturing process is oriented to machinery equipments, repair and maintenance system is wide principal factor. And quality in manufacturing field is influenced by equipment maintenance system. So in the article, maintenance system for quality is given in a view of quality assurance. And the analysis of Physical Mechanism is explored in real field example.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1081-1087
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• 2009

An automatic construction system in Korea is now at the stage of the full automation like in Japan, and an actual pilot project is going to be built in 2009. However, in developing a new construction system that has never been implemented before, there is a need to assess the performance and to consider the uncertainty of the system. The program evaluation and review technique (PERT) allows dealing with this uncertainty. Thus, this paper implements an analysis of the process of steel fabrication and makes suggestions for time-related problems arising from the analysis. The time required for steel erection by the automatic system was compared with that in the traditional method. In the result, finding out another construction process and improving robot performance were proposed to resolve the problems. The results will contribute to promoting the development of an efficient system for the new automatic construction system.

• 한국해양공학회지
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• 제32권5호
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• pp.372-379
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• 2018

High-pressure gas injection engines (HPGI) took center stage in LNG carrier propulsion systems after their advent. The HPGI engine system can be easily modified to include a re-liquefaction system by adding several devices, which can significantly increase the economic feasibility of the total system. This paper suggests the optimal operating conditions and capacity for a re-liquefaction system for an LNG carrier, which can minimize increases in the total annualized cost. The installation of a re-liquefaction system can save 0.23 million USD per year when the cost of LNG is 5 USD/Mscf. A sensitivity analysis with different LNG costs showed that the re-liquefaction system is profitable when the LNG cost is higher than 3.5 USD/Mscf.

• 한국군사과학기술학회지
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• 제2권2호
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• pp.13-23
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• 1999

This paper deals with manufacturing process design of a simplified gun tube applying CE principle. A concept and characteristics of CE, mathematical model for understanding interaction between design and manufacturing, basic elements and related equations for process planning and cost estimating are introduced. A Knowledge-based Computer-Aided Process Planning System(KCAPPS) is constructed, yielding optimal production cost/time for the shape input and selection of appropriate machines and tools.

• 한국정밀공학회지
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• 제23권4호
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• pp.183-190
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• 2006

Digital 3D Real Object Duplication System (RODS) consists of 3D Scanner and Solid Freeform Fabrication System (SFFS). It is a device to make three-dimensional objects directly from the drawing or the scanning data. In this research, we developed an office type SFFS based on Three Dimensional Printing Process and an industrial SFFS using Dual Laser. An office type SFFS applied sliding mode control with sliding perturbation observer (SMCSPO) algorithm for control of this system. And we measured process variables about droplet diameter measurement and powder bed formation etc. through experiments. In case of industrial type SFFS, in order to develop more elaborate and speedy system for large objects than existing SLS process, this study applies a new Selective Dual-Laser Sintering (SDLS) process and 3-axis Dynamic Focusing Scanner for scanning large area instead of the existing f lens. In this process, the temperature has a great influence on sintering of the polymer. Also the laser parameters are considered like that laser beam power, scan speed, and scan spacing. Now, this study is in progress to evaluate the effect of experimental parameters on the sintering process.

• 한국기계가공학회지
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• 제3권2호
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• pp.53-59
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• 2004

In this paper, we propose a new multi-purpose Scanning Force Microscope (SFM) system. The system can be used for nano/micro-scratching, in-process profile measurement, and observation of potential surface defects which occur during the scratching in air or liquid. Experimental results of nano/micro-scratching show that the smallest scratching depth can be controlled to be 10nm, which corresponds to the stability of the SFM system. Profile measurements of nano/micro-scratching surfaces have also been performed by the method of on-machine measurement and in-process measurement. Two measurement results were in good agreement with each other. The maximum difference was approximately 10 nm, which was mainly caused by the sampling repeatability error that influences the measurement accuracy Also, micro-defects on the micro-scratching surface were successfully detected by the SFM system. It was confirmed that the number of micro-defects increases when the surface is subjected to a cyclic bending load. The maximum depth was less than 100nm.

• 한국멀티미디어학회:학술대회논문집
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• 한국멀티미디어학회 2004년도 춘계학술발표대회논문집
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• pp.709-713
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• 2004

This Paper Presents an Internet-based Java self-learning educational system which consists of a management system named Java Web Player (JWP) and creative multimedia contents fer Java language. The JWP Is a Java application program free from security problems by the Java Web Start technologies that supports an Integrated learning environment including three Important learning Procedures: Java concept learning Process, Programming practice process and assessment process. This JWP enables the learners to achieve efficient and Interesting self-learning since the learning process is designed to enhance the multimedia capabilities on the basis of various educational technologies. On-line voice presentation and its related texts together with moving images are synchronized for efficiently conveying creative contents to learners. Furthermore, a simple and useful compiler is included in the JWP fur providing user-friendly language practice environment enabling such as coding, editing, executing and debugging Java source files on the Web. The assessment process with various items helps the learners not only to increase their academic capability but also to appreciate their current degree of understanding. Finally, simple multiple choices are given suddenly to the learners while they are studying through the JWP and the test results are displayed on the message box. The proposed system can be used for an efficient tool for learning system on the Web.

• 한국기계가공학회지
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• 제18권11호
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• pp.1-8
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• 2019

In this study, we design the feed system and process conditions for a lamp garnish lens of an automobile. For this purpose, four design alternatives are presented and injection molding simulation analyses are performed. The optimal feed system is selected by considering the formability of the product and the cost of mold manufacture. The product formability is assessed by the weld line, warpage, sink mark and the maximum injection pressure, whereas the mold-making cost is estimated by the number of valve gates in the hot runner system. To improve the product formability, process conditions are optimized using an experimental design approach named one-factor-at-a-time. No weld line is generated as a result of the optimization. In addition, it is found the warpage and sink mark are reduced while the maximum injection pressure is increased, compared with those before the optimization.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권4호
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• pp.91-97
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• 2012

In this study, cost analysis of electrokinetic (EK) restoration process for desalination of saline agricultural land was performed for field application based on a pilot scale field application. For reasonable cost analysis, EK process was classified into three major parts: system design, installation and operation. Cost of system installation consists of materials and installation for electrode/electric wire, power supply and data monitoring, drainage system, etc. Operation cost was calculated based on electrical consumption and water charges for EK process. Total cost for EK process was 2,943,013 won for $1000m^2$ in greenhouse area. Cost for system installation was 2,553,786 won, that is, 87% of total cost, while cost for system operation was 389,229 won, that is, 13% of total cost.

• 한국정밀공학회지
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• 제16권10호
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• pp.68-79
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• 1999

This paper describes an approach to collaborative design which focuses on the effects of individual activities on the overall design process. We utilize a new process modeling tool to define the process and then analyze and refine the process based on critical paths. This information is then shared over the Internet with all participants. The goal of this system is to detect critical errors at initial design stage and guide the designers to make better decisions based on the knowledge of the overall process. This system enables participating designers to publish his local process through an Internet bulletin board. Other members of the team can then provide feedback based on how the proposed process impacts their activities. The system provides a context-rich, persistent forum for collecting, preserving, and refining corporate expertise of the team. For example, designers can select any process from the bulletin board and use it as a template for his current project and then use it to maintain his own design history. This paper is based on the process modeling concepts of Design Roadamap and describe several key extensions in the area of CPM calculations and collaborative interfaces.