• 한국정밀공학회지
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• 제19권9호
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• pp.82-89
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• 2002

There is an intensifying demand fur linear motors in vast range of industry applications such as in factory automation and semi-conductor manufacturing equipment due to their high positioning accuracy, high static stiffness, high thrust and excellent dynamic characteristics. This paper presents an iron core type linear motor for machine tool whose rated thrust is up to 6000N. For electromagnetic field and dynamic analysis, finite element method (FEM) is implemented to predict motor performance. Various design parameters are considered to reduce thrust ripple and to improve dynamic performance with the least sacrifice of effective thrust. Experimental results on thrust and static stiffness are also followed to confirmed the validity of the analysis.

• 한국정밀공학회지
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• 제16권4호통권97호
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• pp.85-94
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• 1999

Reconfiguration, expansion, or new establishment of FMS requires the availability of a shop floor control (SFC) system relevant to the FMS since it is closely related with the hardware component of FMS. Due to the expensive cost of its development, significant research efforts have been made to develop an SFC system that is reusable. This paper presents Abstract Machine Tool (AMT) approach applied to develop an SFC sytem that is reusable without additional programming. The AMT model enables us to design the SFC system independently of the hardware-dependent attributes of euqipment; an AMT models a workstation by abstraction and presents an equipment-independent interface to machining cell controller. Specifically, we describe how we formalize the interfaces among equipment in order to build an AMT and how we design the machining cell control software based on AMT models. We also present MACHINIST the machining cell control system for IAE-FMS plant as an implementation example.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.283-286
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• 2002

This paper presents the straightness compensation system which is a device for improving the machining accuracy of ultra-precision machines by synchronizing the position of diamond tool tip with machine error motion. Sine it is actuated by piezoelectric actuator with highly nonlinear hysteresis characteristics, the feedback control schemes such as Proportional Integral(PI), are required and realized by measuring the displacements of diamond tool tip. for the better tracking performance, the controller was implemented using TMS320C32 32bit floating-point DSP which is fast so that the real-time control is possible. In addition, stand alone type DSP board was chosen fur the easy assembly into the ultra-precision machines. The experimental results show good command tracking performance and the motion error of the machine is satisfactorily compensated during the machining process.

• 한국정밀공학회지
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• 제15권3호
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• pp.75-81
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• 1998

In the machining process, variation in cutting forces results in relative displacements between the tool and the workpiece leading to tool vibration. Also there is a demand to change the depth of cut very frequently. One solution for the both cases is to develop a system which has the ability to reposition a cutting tool to a very small level, i.e., micron. This paper presents the development of a micropositioner using a magnetostrictive material. The developed micropositioner is implemented to a lathe and subjected to various tests. The results show that the micropositioner with a magnetostrictive actuator has good potential for machining application.

• 대한전자공학회논문지
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• 제27권4호
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• pp.620-627
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• 1990

A software tool implementing cascaded SCF (Switched Capacitor Filter) is developed. A comprehensive procedure is described for the design of cascaded SCF, and some design considerations are discussed. In program several user-selectable filter approximation techniques, and two optimising methods which reduce the total capacitance are included. Analysis of the partial positive feedback and the effect of clock frequency to total capacitance are presented in detail. Two pratical examples are given to prove its validity in reducing the total capacitance. Developed tool can be used for general SCF generator.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.2044-2049
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• 2009

Recent advances in computer technology have brought more dependence on software to railway signaling systems. Hence, the safety assurance of the vital software running on the railway signaling system is very critical task and yet, not many works have been done. While much efforts have been reported to improve electronic hardware's safety, not so much systematic approaches to evaluate software's safety. In this paper, we suggested an automated analysis tool for S/W change impact in railway signaling system, and presented its result of implementation. The analysis items in the implemented tool had referred to the international standards in relation to the software for railway signaling system, such as IEC 61508 and IEC 62279. In these international standards, 'change impact analysis' for railway signaling system S/W has to be required mandatorily. The proposed tool can be utilized at the assessment stage and also the software development stage.

• 한국CDE학회논문집
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• 제6권4호
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• pp.244-253
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• 2001

For more complete process planning, machining sequence determination is critical to attain machining economics. Although many studies have been conducted in recent years, most of them suggests the non-unique machining sequences. When the tool approach directions(TAD) are considered fur a feature, both machining time and number of setups can be reduced. Then, the unique machining sequence can be extracted from alternate(non-unique) sequences by minimizing the idle time between operations within a sequence. This study develops an algorithm to generate the best machining sequence for composite prismatic features in a vertical milling operation. The algorithm contains five steps to produce an unique sequence: a precedence relation matrix(PRM) development, tool approach direction determination, machining time calculation, alternate machining sequence generation, and finally, best machining sequence generation with idle times. As a result, the study shows that the algorithm is effective for a given composite feature and can be applicable fur other prismatic parts.

• Journal of Information Technology Applications and Management
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• 제16권1호
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• pp.77-96
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• 2009

The balanced scorecard has drawn attention from many researchers in various fields since its appearance in 1992. It became a norm for performance evaluation framework in many areas, such as marketing, information system evaluation, strategic planning, etc. Centered in the large companies in Korea, the balanced scorecard has been popularly used as a performance evaluation tool for human resource management. Now we Question its applicability to performance evaluation tool even in small business. This study tried to apply the balanced scorecard in developing an information system for performance evaluation in a small business. The study showed that the balanced scorecard can be nicely used in small business as a performance evaluation tool. The process of developing an information system is described in detail. The practitioners are to obtain a lot of insights in designing their human resource management systems from the study results.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2002년도 춘계학술대회 논문집
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• pp.115-122
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• 2002

O-R 매핑툴을 이용하면 업체별로 상이하며 가변적인 요소를 포함하는 전자 상거래 시스템을 효과적으로 구현할 수 있다. 본 논문에서는 전자상거래 시스템을 위한 범용적 O-R Mapping Tool인 Object $Organizer{\;}^{TM}$를 소개하고, 이를 설계하고 구현하기 위해 이용된 접근법에 대해 설명한다. 기존의 0-R 매핑툴에 대한 분석을 통해 사용 편의성과 수행 성능을 개선할 수 있도록 설계하였으며 전자 상거래 시스템의 구현 방법에서 일반화될 수 있는 부분을 추출하기 위하여 개발 프로세스와 구현 방식을 분석하였다. 또한 전자 상거래 시스템의 요구 사항을 충분히 반영할 수 있는 애플리케이션도메인을 선정하여 현업의 구체적인 요구 사항을 효과적으로 처리 가능하도록 설계하였다. 본 논문은 전자 상거래 시스템에 범용적으로 사용될 수 있는 O-R 매핑툴의 구현 방향을 제시했으며 Object $Organizer{\;}^{TM}$를 통해 이를 구현하였다. O-R 매핑툴의 범용성을 확보하기 위해 기존의 제품을 분석하고 전자상거래 시스템의 구현 방법을 분석하고 일반화하였으며 실제 전자 상거래 애플리케이션을 구현해 봄으로써 Object $Organizer{\;}^{TM}$의 개발 효율성을 평가하였다.

• 산업공학
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• 제12권1호
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• pp.49-55
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• 1999

There are many types of holes to be machined on dies manufactured in the car industry. In this paper we introduce a CAM software developed for hole machining of press dies. The CAM software automatically generates NC files for machining holes from CAD data modeled in the CATIA system. A procedure generating NC files consists of three steps. First, the geometric information such as types of holes, hole positions, hole diameters, and hole depths is extracted from CATIA models. And then tools to be used and operation orders are standardized to establish a data base. Finally, NC files are generated by considering the machining conditions such as feedrate and rpm. It is efficient that holes with the same type and the same size should be grouped and machined by a tool to reduce the tool change time. The optimal tool path for machining the holes in a group can be determined by applying an algorithm solving the traveling salesman problem.