• Journal of the Korean Society for Precision Engineering
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• v.30 no.12
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• pp.1321-1325
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• 2013

In this paper, we proposed an air bearing stage with active magnetic preloads in vertical directions compensating motion errors and attenuating vibrations to improve dynamic characteristics. This preloaded design gives simpler configuration of the stage, and active control of preload can be used for compensating motion errors by feedforward method. To improve dynamic characteristics, vibration of the table is monitored by an accelerometer, and controlled by a DSP based digital controller with integrator and band pass filters for suppressing roll and pitch vibration modes. The modes were evaluated by measuring frequency response functions, and compared with compensated responses. This showed effective results for suppressing poorly damped regenerative vibration of air bearings.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.3
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• pp.22-28
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• 2000

제조업의 경쟁력 제고를 위하여 시작된 선도 기술개발 사업의 하나인 '첨단생산시스템기술개발' 사업은 제 1 단계에서 FMS 핵심 기술 개발을, 제 2 단계에서는 CIM 기술 개발을 수행하였다. 1,2단계 기술 개발의 연속성 위에서 제 3 단계에서는 지능형 생산시스템(IMS: Intelligent Manufacturing System)을 구현하기 위하여 1999년 11월부터 연구가 시작되었다.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.1
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• pp.11-16
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• 2009

• Journal of Korean Society of Industrial and Systems Engineering
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• v.16 no.28
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• pp.129-135
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• 1993

Quality is become not only the most critical component of manufacturing strategy but also the most critical measure of performance and justification of advanced manufacturing system. The objective of this paper is to offer classification & optimum concept of quality-cost and to illustrate a method of evaluation quality-cost then a case example is presented to illustrate the result of quantifying the suggested formula and these values are given to justify of management.

• IE interfaces
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• v.9 no.3
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• pp.306-316
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• 1996

The easily use of WWW and Web browser of INTERNET makes the world our stage. But when we search for the information and resource that we want, the information supplied by search engine (e.g., Yahoo, Lycos, WebCrawler, Alta Vista) is inadequate to acquire the necessary and related information of research issues. This paper surveys AMT(Advanced Manufacturing Technology) which is the research topics recently on the WWW(WorLd Wide Web) and provides searching methods and information for academic research, technical report, proceedings, software, etc. It also briefly surveys WWW-VL(Virtual Library) and reviews the major three technology, CALS (Commerce At Light Speed), AMS(Agile Manufacturing System), CE(Concurrent Engineering), that is recently the focus of the research issue of Industrial Engineer.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.87-94
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• 2002

Most of Rapid Prototyping (RP) process adopt a solid Computer Aided Design (CAD) model, slicing into thin layers of uniform, but not necessarily constant, thickness in the building direction. Each cross-sectional layer is successive1y deposited and at the same time, bonded onto the previous layers; the stacked layers form a physical part of the model. The objective of this study is to develop a method for calculating the rotation angle ($$\theta$_x, $\theta$_y$) of hotwire of the cutting system in the three-dimensional space for the Variable Lamination Manufacturing process using expandable polystyrene foam sheet (VLM-S). In order to examine the applicability of the developed method to VLM-S, various three-dimensional shapes. such as a screw, an extruded cross, and free surface bodies such as miniatures of the monkey(a figure of Sonokong), were made using the data obtained form the method.

• The KSFM Journal of Fluid Machinery
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• v.16 no.3
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• pp.18-25
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• 2013

Recently the requirement of long-term mobile energy source for mobile robot or small-sized unmanned vehicle is highly increased, and the micro turbine generator(MTG) which is known to have high energy and power density is under development. MTG is designed to have air foil bearing and high speed rotor of which operating speed is 400,000rpm. In the development stage of high speed rotor and bearing, stability analysis for the full operational speed range is essential and the dynamic coefficients such as stiffness and damping coefficients of bearing depending on the rotational speed are required for that. Although perturbation method is usually used to identify the dynamic coefficients, it's not easy to give the perturbation to the high speed rotating rotor. In this study, we present the dynamic coefficients measurement system for air foil bearing which consists of electromagnets, gap sensors, high speed motor and controller. This measurement system can exert the sine sweep force to the rotor-bearing, measure the displacement of rotor and get FRF(Frequency response function) of rotor-bearing. The least square estimation method is applied to identify the dynamic coefficients of bearing from the measured frequency response at the different rpm and the identified dynamic coefficients for the wide rotational speed range are presented.

• Journal of Engineering Education Research
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• v.15 no.4
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• pp.53-57
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• 2012

Modern manufacturing needs a great number of advanced engineers. China has the world's second largest equipment manufacturing and electronic information industry, and in 2020, the shortage of talented personnel in key industries will be more than 5 million in China. Universities and colleges are the main places to cultivate engineering talents. In this paper, we will introduce a multi-level engineering talents cultivating system we have applied in Dali University, China for more than 4 years. Under this training system, we have achieved some gratifying results.

• IE interfaces
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• v.9 no.2
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• pp.203-218
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• 1996

This paper deals with a Direct-Input-Output Manufacturing System (DIOMS) which has a number of machine centers placed along a built-in automated storage/retrieval system (AS/RS). During its operations, the storage/retrieval(S/R) machine picks up a pallet from the pickup/deposit port of a machine center and then moves it either to an empty rack opening of the AS/RS for temporary storage or to place it on the port of another machine center for subsequent operation. The machine layout problem in DIOMS is formulated as an integer mathematical programming whose objective is to minimize the total expected distance of the loaded S/R machine during a production period. Recognizing the limit of the exact solution procedure(the Branch and Bound method), two improvement-type heuristics are proposed. One is based on the simulated annealing method and the other the pairwise interchange method. The validity of the heuristics is examined with example problems.

• Journal of Industrial Technology
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• v.27 no.A
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• pp.69-76
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• 2007

The body of an excavator, one sort of the construction equipment, consists of mainframe part, track frame part, boom part and arm part. The all parts are manufactured in the body welding operation. The scheduling in the body welding operation of a construction equipment manufacturing is to take all the various constraints into consideration. The offset time, due date, daily capacity of operations, daily jig's capacity, precedence relation, outsourcing, alternative resource and all of the shop floor environment should be considered. An APS(Advanced Planning & Scheduling) system is a proper and efficient system in such circumstance. In this paper, we present an APS system, the optimal scheduling system for the construction equipment manufacturing specifically for the body welding operation, using ILOG Solver/Scheduler. ILOG Solver/Scheduler is a general purposed commercial software which supports to find a feasible or optimal solution using object oriented technique and constraints satisfaction programming, given constraints and objectives.