• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.41-44
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• 1999

The main purpose of the UPS is to supply independent and stable power to connected equipment. In installing and operating the UPS system, songle module, three phase UPS in more benefit than multi module, songle phase UPS in the point of volume and cost. However, when supplying Rectifier with output power form three phase UPS, by connecting auto-transformer, occurred harmonic and ripple current makes output filter damaged and leads to nonlinear current coasted by unbalance load. Therefor, in this paper the aim of concentring compound-wound transformer and harmonic filter is supplying liner current by reducing harmonic and ripple current and improving unbalance in voltage and distortion in current wave.

• Journal of Power Electronics
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• v.17 no.1
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• pp.127-135
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• 2017

Recently the researches on modular multi-level converter (MMC) are being highlighted because high quality and efficient power transmission have become key issues in high voltage direct current (HVDC) systems. This paper proposes an improved pre-charging method for the sub-module (SM) capacitor of MMC-based HVDC systems, which operates in the nearest level control (NLC) modulation and does not need additional circuits or pulse width modulation (PWM) techniques. The feasibility of the proposed method was verified through computer simulations for a scaled 3-phase 10kVA MMC with 12 SMs per each arm. Hardware experiments with a scaled prototype have also been performed in the lab to confirm the simulation results.

• Journal of the Korean Institute of Educational Facilities
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• v.16 no.5
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• pp.19-26
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• 2009

This study attempts to find out the spatial characteristics of the converging technology laboratory. For this, the understanding of the nature of converging technology and its necessary system requirements are crucial. The foremost concern lies in the 'flexibility' of the laboratory space, i.e. 'open-lab system', because of the multi-disciplinary spatial arrangement which is supposed to be open to a number of different research fields in the same building cluster. From the case analysis, this study reveals that in order to maximize the adjustability, the module based space unit plan should be considered at the earliest stage. In addition, it is also found from the analysis that the linkage of the communication spaces such as seminar room, auditorium, lounge, rest room, dining room, and corridors should be dealt with a higher degree of sophistication, since these facilitate the interaction of information at the behavioral level.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.113.3-113
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• 2001

In this paper, we have designed the VHDL module of DS/SS QPSK wireless modem processor for digital data communication. The spread spectrum method is used for modern processor, because this method guarantees good frequency efficiency and higher security. Also, it guarantees good performance in digital communication system under multi-path interferences. The differential encoder and decoder are used for simple circuit composition in the signal detection. For the synchronization of receiver, matched filter and power detector are used. And the IF modulation/demodulation of QPSK method is used in the digital level. The transmitter of VHDL modem processor consists of differential encoder, PN code generator, and QPSK ...

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.1153-1156
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• 2003

In this paper, we present a reducing power consumption of a scheduling for module selection under the time constraint. Traditional high-level synthesis do not allow reuse of complex, realistic datapath component during the task of scheduling. On the other hand, the proposed scheduling of reducing power consumption is able to approach a productivity of the design the low power to reuse which given a library of user-defined datapath component and to share of resource sharing on the switching activity in a shared resource. Also, we are obtainable the optimal the scheduling result in experimental results of our approach various HLS benchmark environment using chaining and multi-cycling in the scheduling techniques..

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.307-310
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• 2001

In this paper, development of TIM Module for constructing PDM will be introduced. Technical information relevant product data influences cost, quality, precision and productivity. One of the very important feature of product data is organizing not by oneself but very closed to many technical information such as document, file, image and analysis sheet. To manage various technical information, several kinds of management system are used in multi level of production system. PDM and TIM systems are being developed for suitable purpose and are in need of Network technology, Information Technology, Database, sharing and distributing information. Developed TIM system is based on Web environment. By using this system, we can manage systematic technical information and reduce cost for constructing PDM system. And also we will put to practical use another technical information management system for mold plant.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1717-1722
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• 2003

In this paper we developed flip-chip bonder using XY stage, liner-rotary actuator and vision system. We depicted the major parts of the developed flip-chip bonder. Then we discussed several problems and their solutions such as vision and motion control, pick-up module position accuracy, separation of chip from the blue taped hoop, etc. We used a post guide to improve the horizontal positional accuracy against the long arm. Also, we used an ejector module and synchronization technique for easy chip separation from the blue tape.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.8 s.197
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• pp.97-107
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• 2007

The present CNC machining system if without any CAM software has been limited to 2D or 2.5D plane cut using lines, arcs and curves. If the CNC is equipped with a surface interpolation module and a surface reorganizing module inside it, we can easily try 3D surface machining without aid of CAM software. The existing NURBS surface interpolator is simple and direct to use for a unit surface. However, it enables only machining of each reference surface individually even when machining a simple composite surface. In this paper, we propose a method which can unify and reorganize various reference surfaces with a newly defined NURBS surface cycle command: a multi-repetitive cycle command such as in a CNC turning center. We also introduce a reorganizing rule for reference surfaces using NURBS properties. The usefulness of the proposed method is verified through computer simulation.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.3
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• pp.25-33
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• 1997

In the design of microwave multi-stage amplifiers composed of N amplifier modules, the variation of performances of amplifier as various connection length between modules has been studied. In addition, the methods, equations and conditions for the maximum gain or the most flat gain are presented. The results of sensitivity analysis for the connection length showed that the small change in phase of input, output reflection coefficients(S$_{11}$, S$_{22}$) of module itself is the most important in determination of connection length for the most flat gain. Th egain flatness of 2-module amplifier of which connection length between modules had been determined by presented methods was the best one out of performances with various arbitrary connectio lengths.s.

• International Journal of Contents
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• v.4 no.1
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• pp.1-6
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• 2008

Existing improvement measures for resource management are merely concentrating on the document automation only. In addition, such improvements rarely benefit metal millwork management. Following the trend of constructing high rise and multi-complex buildings, the importance of resource management from the aspect of construction project management is being emphasized. Metal work resources are critical most of construction projects, it became a target for special management. Therefore, the study has determined work process of metal work resource management, for the metal millwork is one of the most important construction materials most of construction projects, and proposed a web based module for improving the management task.