• 한국정보처리학회논문지
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• 제4권5호
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• pp.1349-1357
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• 1997

정보통신의 발달과 더불어 새로이 제안되는 프로토콜의 크기가 커지고 복잡해짐에 따라 프로토콜 을 개발하는데 자동화 도구들이 필요하게 되었다. 따라서 이들 프로토콜의 개발을 지원하는 자동화 도구를 개발하기 위한 활발하게 진행중이다. 그러나 현재 까지 여러 가지 도구들이 개발되었으나, 이들 도구들은 실험적으로 사용되고 있을 분 이론적 연구성과에 비해 실제 활용도가 낮은 편이다. 또한 지금까지 제안된 도구들은 대부분 개별적으로 개발되어 프로토콜을 개발하는 일련의 과정을 수행하는데 제약이 따른다. 본 논문 에서는 이러한 제약을 해결키 위하여 기존에 개발된 도구들을 효과적으로 통합하여 프로토콜 개발을 위한 각종 도구들의 통합환경을 설계하고 구축하였다. 구축된 통합환경은 프도토콜 개발 과정의 전 사이클을 제공하므로서 자동화를 통한 프로토콜 개발 기간을 단축하고 프로토콜의 신뢰성을 향상시킬 수 있다.

• Journal of Advanced Marine Engineering and Technology
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• 제33권7호
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• pp.1003-1011
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• 2009

This study aims at precise control of oil outlet temperature in the oil cooler system of machine tools for enhancement of working speed and processing accuracy. PID control logic is adopted to obtain desired oil outlet temperature of the oil cooler system with hot-gas bypass method. We showed that the gains of PID controller could be easily determined by using gain tuning methods to get the gain of PID controller without any mathematical model. We also investigated various gain tuning methods to design the gains of PID and compared each control performance for selecting the optimal tuning method on the hot gas bypass method through experiments. Moreover, we confirmed excellent control performance with proposed PI controller gain even though disturbances were abruptly added to the experimental system.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권1호
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• pp.33-43
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• 2012

In this paper, a prototype of ship basic planning system is implemented for the small and medium sized shipyards based on the internet technology and concurrent engineering concept. The system is designed from the user requirements. Consequently, standardized development environment and tools are selected. These tools are used for the system development to define and evaluate core application technologies. The system will contribute to increasing competitiveness of small and medium sized shipyards in the 21st century industrial en-vironment.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.792-795
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• 2005

The guide-ways of precision machine tools are one of important element of machine tools. It has usually a pair of surfaces for constraint of one direction with bearing. In the case of precision machine tools, non-contact bearing such as hydrostatic bearing and aerostatic bearing is adopted usually. In this case, profiles of rails has effect on straightness and the clearance of bearing has effect on stiffness of guide way, which changes to higher if clearance changes to smaller. The clearance is varied along moving table according to relative distance of pair of rails. The relative distance of pair of rail can be divided by three properties. First and second properties are straightness of each pair of rail and bearing pad. And, third is parallelism about pair of rails and pairs of bearing pad. There are several methods for measuring straightness of each surface such as reversal method, sequential two point method, and way straightness. These straightness measuring methods are always acquiring deviation of profile from eliminating linear fitted inclined line and don't have the information of parallelism. Therefore, to get the small clearance for high stiffness, the straightness of rail and bearing pad and parallelism about pair of rails and pair of bearing pads are measured for correction such as regrinding, reassembling and lapping. In this research, new and easy method for measuring parallelism of pair of rails is suggested. Two displacement probe and sensor stage, which is carry on the displacement sensor, are needed. The simulation and experiment was accomplished about pair of horizontal guide way to confirm the measurement of parallelism. And, the third probe is added to measure the straightness of each rails by sequential two point method. From the estimation of combined these two methods, it is confirmed that the profiles of a pairs of rails can be measured.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.158-161
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• 2003

Recently, the evolution in production techniques (e.g. high-speed milling), the complex shapes involved in modem production design, and the ever increasing pressure for higher productivity demand a drastic improvement of the dynamic behavior of the machine tool axes used in production machinery. And also machine tools of multi functional and minimized parts are increasingly required as demand of higher accurate in some fields such as electronic and optical components etc. The accuracy and the productivity of machined parts are natural to depend on the linear system of machine tools. The complex workpiece surfaces encountered in present-day products and generated by CAD systems are to be transformed into tool paths for machine tools. The more complex these tool paths and the higher the speed requirements, the higher the acceleration requirements are needed to the machine tool axes and the motion control system, and the more difficult it is to meet the requirements. The traditional indirect drive design for high speed machine tools, which consists of a rotary motor with a ball-screw transmission to the slide, is limited in speed, acceleration, and accuracy. The direct drive design of machine tool axes. which is based on linear motors and which recently appeared on the market. is a viable candidate to meet the ever increasing demands, because of these advantages such as no backlash, less friction, no mechanical limitations on acceleration and velocity and mechanical simplicity. Therefore performance tests were carried out to machine tool axes based on linear motor. Especially, dynamic characteristics were investigated through circular test.

• 한국기계가공학회지
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• 제12권1호
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• pp.9-14
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• 2013

In recent years, high hardness steel is used for most of the material in many areas including aircraft, nuclear power, space exploration and automotive parts. Low CBN tools are widely used in industrial field which can effectively process high hardness steel of HRC 45 or harder. The results of this study demonstrated, when high hardness steel, SCM440 is turned with Low CBN tools coated with TiN and TiAlN coatings respectively, that both the thrust force and cutting force tends to increase with more increase in cutting force than thrust force, as the feed rate increases at constant cutting speed. In addition, the size of the cutting force and thrust force does not change with the increased cutting speed at the same feed rate, but the tool life is reduced if the cutting speed is increased to shorten the machining time. Therefore, it is recommended to limit the cutting speed at 250 m/min maximum or less. Furthermore, comparing the cutting force of the three tools at the same cutting condition, Tin coating tool showed the smallest cutting force and Low CBN was the next, and the TiAlN coating tools showed the largest cutting force.

• 공학교육연구
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• 제19권1호
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• pp.3-10
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• 2016

This study was conducted to identify Korea's TRIZ research trends and to propose implications for setting a direction for future TRIZ research by analyzing TRIZ-related research over the past 15 years, or from 1998 to 2013. The subjects in this study were 256 published studies, including 149 studies in academic journals, 97 master theses, and 10 doctorate theses. This study reached the following conclusion. First, academic journals were the most frequent form of publication of TRIZ-related studies, followed by master's degree theses, and doctorate theses. Second, two or more TRIZ tools were used to solve problems and the most frequently used topic was technical contradiction as the result of frequency analysis for TRIZ research topics. This signified that it was easier to solve problems when various TRIZ tools were used, rather than applying a single TRIZ tool while technical contradiction was considered to be actively used as it allowed the relatively easy understanding of TRIZ. Third, the use of TRIZ research topics had increased and diversified each year. This could be interpreted to be based on the increased understanding of TRIZ. Fourth, case studies and experimental research were the most frequently used methods in TRIZ-related research. This was because various TRIZ tools were applied on problem solving situations, which were directly proposed as the research result. Fifth, the use of TRIZ was increasing in the educational field. Specifically, it was noted that TRIZ was used in creativity education with the use of 40 invention principles in elementary, middle, and high schools.

• 한국정밀공학회지
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• 제30권5호
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• pp.480-485
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• 2013

Enhancing energy efficiency of machine tools causes substantial impacts on the manufacturing industries, to cope with the competitive introduction of the total energy management strategies. Real-time energy monitoring is essential to identify energy consumption patterns of the machine tools and correlate them with the energy management strategy. Integrated analysis of machine tool's operation status and the corresponding energy usage is most important to accurately evaluate the energy efficiency under the various machining process environments. This paper proposes a system architecture to realize the online energy monitoring system and the embedded energy monitoring approach interconnected with the CNC kernel. The shop-floor operation management system is presented to integrate the proposed online energy monitoring approach.

• International Journal of Precision Engineering and Manufacturing
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• 제4권2호
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• pp.64-70
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• 2003

A new method using a transfer function is introduced in the present paper for analyzing the motion errors of hydrostatic bearing tables. The relationship between film reaction force in a single-side hydrostatic pad and the form error of guide rail is derived at various spatial frequencies by finite element analysis, and it is expressed as a transfer function. This transfer function clarifies so called 'the averaging effect of an oil film' quantitively. It is found that the amplitude of film force is reduced as the spatial frequency increases or the relative width of the pocket is reduced. The motion errors of a multi pad type table are estimated using a transfer function, the form errors of a guide rail and the geometric relationship between the pads. The method is named as the Transfer Function Method (TFM). The motion errors calculated by the TFM show good agreement with the motion errors calculated by the Multi Pad Method considering the entire table as an analysis object. From the results, it is confirmed that the proposed TFM is very effective to analyze the motion errors of hydrostatic tables.

• International Journal of Precision Engineering and Manufacturing
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• 제4권2호
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• pp.57-63
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• 2003

A new method using a transfer function was proposed in the previous paper for analyzing motion errors of hydrostatic tables. The calculated motion errors by the new method, named as the transfer (unction method (TFM), were compared with the results by the conventional multi pad method, and the validity of the proposed method was theoretically verified. In this paper, the relationship between rail form error and motion errors of a hydrostatic table is examined theoretically in order to comprehand so-called 'the averaging effect of an oil film', and the characteristics of the motion errors in a hydrostatic table is tested. The tested hydrostatic table has three single-side pads in the vertical direction and three pairs of double-sides pads in the horizontal direction. The motion errors are tested for three rails which have different form errors. The experimental results are compared with the theoretical results calculated by the TFM, and both results show good agreement. From the results, it is shown that the TFM is very effective to analyze the motion errors of hydrostatic tables.