• Journal of the Korea Society for Simulation
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• v.18 no.2
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• pp.65-75
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• 2009

The semiconductor manufacturing process normally includes a great number of complex sequential steps those are related with various types of equipment. Such equipments are installed with the mixed patterns of serial or parallel structures while considering a number of engineering or environmental factors at the same time. It is thus extremely difficult to change the layout after installation due to expensive costs and other related factors. Because of these reasons, a new investment or layout change, which is usually caused by the production policy such as product mix or production quantity, must be carefully considered. This case study introduces a simulation conducted in a semiconductor parts production company which produces the Board on Chip (BOC)-type of packaging substrate and has plans to change the facility layout. For this study, we used $QUEST^{(R)}$ for simulation modeling and evaluated various strategies which may cause layout changes. Further, the Analytic Hierarchy Process (AHP) is applied to select the best strategy from several alternatives with multiple decision criteria.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.8
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• pp.961-966
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• 2013

A coupled governing equation of thermoelectric materials can be converted into an uncoupled form to predict the effective Seebeck coefficient of thermoelectric composites, where modified Eshelby model is adopted. The predicted results by the present approach for serial- and parallel-connected composites and composite with spherical inclusions are compared with theoretical and experimental results from literatures to be justified. It is shown that the predictions by the theoretical approaches coincide exactly and show in good agreement with the experiments.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.273-273
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• 2009

고체산화물 연료전지 (Solid Oxide Fuel Cell, 이하 SOFC)는 제조형태에 따라 크게 평판형과 원통형으로 구분할 수 있다. 단위면적당 출력 효율이 높은 평판형의 장점과 원통형의 밀봉이 용이한 장점을 동시에 가지는 평관형 형태로 지지체를 제작하였으며, 셀의 배치를 평면상 직렬로 연결하는 다전지식으로 구성함으로 전극의 길이나, 셀 간격을 기존 평판형이나 원통형에 비해 대폭 감소시켜 단위면적당 전압 및 출력효율을 높이고자 하였다. Segmented 평관형 지지체의 소재로는 연료전지의 성능 특성에 관여하지 않으며 열사이클 저항성과 기계적 강도가 우수한 spinel구조를 가지는 $MgAl_2O_4$를 선정하였다. 연료가스의 원활한 공급이 가능하도록 carbon을 기공 전구체로 사용하여 압출성형하였으며 건조과정에서 crack이 생기지 않는 공정을 확립한 후 $1400^{\circ}C$ 에서 소결하였다. 제조된 지지체는 수은침투법과 3점 굽힘 강도법으로 기공율과 기계적 강도를 각각 측정하였다. Anode를 스크린 프린팅법으로 지지체 위에 적층한 후 미세구조를 확인하였고 이를 바탕으로 다공성이며 기계적 강도를 가지고 음극과의 반응이 없는 우수한 지지체를 제조할 수 있었다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.2
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• pp.41-51
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• 1983

An efficient method for the desist of active filters from doubly terminated lossless ladder type passive filters is presented. This technique is based on the linear transformation of network variables from the voltage-current domain to a new domain for the active realization of the passive networks. The method developed herein applies the linear transformation to a ladder building block which contains both a shunt and a series reactive arm, resulting in the minimization of the number of operational amplifiers required for the active realization. The validity and efficiency of this method are verified by the design of the 8th-order Chebyshev low-pass filter followed by the measurement of its frequency characteristics which fairly agree with the theoretic ones.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.6
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• pp.603-611
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• 2008

In this paper, we introduce a multi-coil antenna which is useful for reducing the effects of radio frequency noise in an inductively coupled RFID system. A multi-coil antenna is composed of a central coil and four subsidiary coils that are connected in series. A multi-coil antenna is designed so that the total noise disappear when the induced voltages of a central coil and subsidiary coils are added. The noise in a multi-coil antenna was about 30 dB lower than that in a single coil antenna. The multi-coil antenna is very effective in noise reduction even in an environment that the spatial distribution of RF noise is changed abruptly, and the induced noise was about 16 dB lower than that in a dual coil antenna.

• Journal of KIISE:Software and Applications
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• v.37 no.11
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• pp.826-836
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• 2010

This paper proposes a hybrid machine translation system which integrates SMT, RBMT, and PBMT in serial manner. SMT in our project has been implemented as a Quasi-syntax-based system where monotone search is done, given a preprocessed string of foreign language. Preprocessing includes rule-based reordering, NE recognition, clausal splitting, and attaching pattern translation information at the end of the input text. For lengthy & complex sentences, clausal splitting turned out to generate better translation than normal input.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.3
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• pp.211-218
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• 1996

Theorectical and experimental studies of On-Glass antenna in the 1.9GHz bandare performed. In this paper, the structure of designed On-Glass antenna consists of a 5/8-wavelength upper segment and quarter-wavelength lower segment separated by phasing coil. On-Glass antenna may be resonated by the use of suitably spaced phasing coil in series with the antenna wire. This tuning structure leads to an improvement in antenna efficiency. And then, this can be very useful for installation where limited space like automobil is available. The analytical method is based on collocation method with pulse function. The results obtained from numerical method are presented and compared with an experimental evaluation. From this, the VSWR, gain, radiation pattern, and bandwidth of the On-Glass antenna are analyzed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2584-2589
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• 2015

In this paper, we want to able to reduce the time effectively about the analysis of protocol and development of protocol converter in industrial network. For this purpose, we developed the user protocol converter that can be to analysing the communication protocol in the industrial network. and also that is able to converting to user protocol and transmitting to another network. The developed user protocol converter was consist of S/W and H/W, and is supporting the Modbus, the NMEA0183 and the ethernet. The hardware main processor was used the AVR128, and placed the serial communication part and the ethernet part in converter board. The experiment results, we acquired very high transmission rate and conversion rate.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.81-86
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• 2019

This paper is concerned with a system design that enables a the plurality of switching mode power supplies to be supplied with larger power through a parallel connection. For this purpose, a shunt resistor is placed in series at the output of the constant voltage regulator and the output voltage is sensed and controlled using an arduino. In this paper, two constant-voltage regulators were used for the experiment, but it is possible to generalize for more boards. By using the method that controls the system, the sum of the currents delivered by the two systems to the load was found to be 96% of the current drawn from each board. In case of efficiency, 92.4% efficiency is achieved in the unit board and the efficiency in parallel connection is about 90%.

• The Korean Journal of Archival Studies
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• no.21
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• pp.323-353
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• 2009

This study examines current states of Professionals of records management after "Records Management of public instituition Act(공공기관의 기록물 관리에 관한 법률)" was enacted in 1999. The law forced to arrange records manager in Records Center. However the hire of Professionals of records management became in earnest in 2005. Records Manager among the research officials was established in 2005 February in the Participatory Government. Because of this regulation, in 2005 July, Professionals of records management were arranged in each of 45 central department for the first time. Going through many trial and error, Professionals of records management contributed to systemizing record management of center department and office. According to "Public Records Management Act(공공기록물 관리에 관한 법률)" totally revised in 2007, sixteen major cities and its public office of education decided to employ Professionals of records management until the end of 2007. In addition, minor cities which consists of people over 150,000 and public office of education which consist of the number of students over 70,000 are supposed to have Professionals of records management until 2008, but it is not accomplished yet. Furthermore, when recruiting professionalists of records management, it is necessary to employ not as a contract or a part-time employee or but as a regular or a full-time worker. Especially, if the specialists of record management were employed as a part-time employee, they would not concentrate on their work because of their unstable social positions. It means that changes from a contract worker to a regular employee are needed without further delay. At first, records managers who were recruited at the Central Department in May 2007 had various kinds of difficulties and experienced trial and error. These days, however, they show their expertise with finding their own works. Someday in Korea, the records manager is expected to be a professional career with their know-hows and active movements.