• Smart Structures and Systems
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• 제13권6호
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• pp.959-974
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• 2014

Hand-Arm Vibration Syndrome (HAVS) is a group of diseases caused by exposure of the hands to vibration while operating the hand held power tools such as road breaker, drilling machine, demolition hammer in construction works. In this paper, area-changed capacitive micro-accelerometer is designed to measure the vibration exposure on worker's hand when operating a drilling machine on various blocks such as clay block, paver block and solid cement block. The design process includes mathematical modelling of micro-accelerometer and simulations are done using INTELLISUITE 8.6. Experimental results are taken for various blocks surfaces using conventional and micro-accelerometer. Comparisons show that usage of area-changed micro-accelerometer for Hand-arm vibration monitoring provides better sensitivity, which in turn reduces the risk of HAVS in workers.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.277-282
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• 2010

Imported vane type air motor and-piece is used widely in the domestic dental services. The imported hand-pieces are more than 90 percent in the domestic market. The air-motor unit of the hand-piece had not been developed inside of the country yet. Therefore it needs some research works. Purpose of this study is to design the air motor of the hand-piece for better performance. The geometry of the air-motor is based on product of NSK Company. The airflow of the air motor unit is simulated by Computational Fluid Dynamics. The performance analysis of the air motor units is investigated. ANSYS 12.0 CFX is used to analysis of the flowfield. Torque changes depends on spin calculated by the immersed solid method.

• 대한기계학회논문집
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• 제14권2호
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• pp.367-375
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• 1990

A data structure representing 3-D objects was designed for the personal computer. It is very simple to be used in the personal computers which have small memory and low speed. A homogeneous transformation for developing 3-D objects was derived. Each developing procedure consists of five transformations : one translational-three rotational-one translational. Developing a solid is a creative work. So the results of developing vary with the order of surfaces to be developed. One method to reduce the length of seam was considered. The programs used in this study were written in Pascal and Assembly and a modeller that generates 3-D primitives was included. This program is an interactive dual-screen system. While all the menus in Korean are displayed at the monochrome monitor, the development figures with projective views are drawn at the color monitor. The program has wide applications for plate works.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.426-431
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• 1997

Features are well recognized to play an important role for the integration of ACD and CAPP. Majority of pervious works for the feature recognition for prismatic part is based on 3D solid model. But in real factories, 2D drawing are used more than 3D drawings. In this paper, we develope an algorithm of the feature recognition on prismatic parts in 2D drawings, using by the graph method and the heuristic algorithm. Previous algorithms have some conflicts at feature interaction. In this paper, elements are grouped into connection by the graph method. Then features are recognized by using these grouped elements and their relationships of front and side-view. For resolving the problem of feature interaction, the element graphs are modified by an deloped algorithm. This algorithm is applied to a CAPP system for milling process planning.

• 한국정밀공학회지
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• 제22권11호
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• pp.104-110
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• 2005

GIS(Gas Insulated Switchgear) is used in electric power system, to insure non conductivity, breaking capacity and operating reliability. The commercial dynamic analysis code COSMOS MOTION and 3-D modeling program SOLID WORKS were used to simulate dynamic analysis of the closing resistors of the GIS in this paper. To reduce chatter vibration of closing resistors, the motion of moving and fixed parts of closing resistors were simulated by varying the spring constant, the damping coefficient and the mass of moving and fixed parts. The simulated results were compared with experimental results. As a result, chatter vibration of closing resistors of the GIS could be reduced by using the results. These data can be used to determine the spring constant, the damping coefficient and mass of a moving part to reduce chatter vibration when the next model is developed.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1997년도 춘계학술대회논문집
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• pp.273-280
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• 1997

Rotary swaging is a process for reducing the cross-sectional area or changing the shape of bar, tube or wires by repeated radial blows with one or more parirs of opposed dies. The present study is concerned with investigation the effect of process parameters upon product quality(hardness, roughness, precision of dimension). To enhance the product quality, experimental works are carried out for some process parameters such as forming speed, billet shape, lubrication, reduction of area and ratio of t/D. Rod shift formed by RSM25 under cold conditions has good surface quality, hardness and precision of dimension. The recommendable process conditions are suggested for solid and tubular products.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.529-534
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• 2011

The air-motor unit of the hand-piece had not been developed inside of the country yet. Therefore it needs some research works. The objective of this study is to investigate the effect of the many mini holes at the outle of the air-motort. The flow fields analysis has been conducted by the immersed solid method using ANSYS 12.0 CFX.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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• pp.172-180
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• 2006

A novel pyrolysis-melting incineration system of reduced scale (30 kg/hr) is and constructed in Korea Institute of Industrial Technology. The incineration process is composed of three parts: pyrolysis, gas combustion and ash melting processes. For each unit process, experimental and numerical approaches including reduced-scale cold/hot flow tests have been conducted to find optimal design and operating conditions. This paper presents major results of these approaches with brief descriptions on the pilot-scale incinerator (200 kg/hr) under construction and future research works.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.175-180
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• 2000

This paper describes the method and the process for impeller machining on 5-axis CNC machining center. Also, The CAD/CAM software for the impeller post processing is developed. The software can be interfaced with Solid-works software for confirmation of the impeller shapes. In this study, blades on impeller is described from Ruled-surfaces between two Ferguson curves. In this study, using 5-axis NC part program obtained from the developed software, a sample impeller was machined on 5-axis CNC machining center. The machined impeller was very agreeable to the designed impeller. Thus, theories proposed in this study can be very useful for the 5-axis machining of impeller blades with Ruled-surfaces.

• Asia pacific journal of information systems
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• 제11권3호
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• pp.23-42
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• 2001

Recently, knowledge management becomes a core management tool for efficient and effective organizations. However, there are little known researches on measuring knowledge management level. The objective of this paper is to develop a process capability model for knowledge management of an organization. We developed 5 stage process capability model for knowledge management. The 1st stage is the initial stage where no significant knowledge management activity is performed. The 2nd stage is the performed stage where planning and tracking activities are performed on organization level. The 3rd stage is the established, and the 4th stage is the predictable stage where processes and results of knowledge management can be predictable. Final stage is the optimizing stage where knowledge management process is continuously improved at an organizational level. We surveyed 37 korean companies to test the validity of the proposed stage model. Statistical tests show that the developed stage model of knowledge management is valid and sound in general conditions. The result of this study on process capability model can be a solid stepping stone for future works in this area.