• Analytical Science and Technology
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• v.10 no.2
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• pp.146-152
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• 1997

A rapid BOD measurement system using a microbial membrane electrode has been developed. Culture of microorganism and the preparation of microbial membrane, the effect of sample flow rate on the BOD measurement, the effect of solution pH and response characteristics of the microbial membrane electrode were investigated. The rapid BOD measurement system developed by us was connected to a personal computer and the whole BOD measurement procedures were carried out automatically. The best results were obtained when the solution flow rate was 7.8mL/min and the data were obtained 5 minutes after sample injection.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.167-179
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• 1998

Todays in the field of lens makers, the technology machinery equipment and investment is shrunken by many factors. But much more decisive investment is wanted to strengthen competitiveness. Most of all, the technology of management and quality examination is important in the confidence of lens. So external and internal examination must be accomplished scientifically not by macrography but by the microscope and the computer. As the hardness examination of glass in the automobile, that of spectacle lens must not be harmful to the human body. All the raw material of spectacle lens is being imported for the lack of technology. To overcome these circumstances. We must establish the research institute that can develop the technology and must train a technical expert.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.68-74
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• 2001

This system is composed of fine and coarse apparatus, measurement system and control system. Piezoelectric actuator is designed for fine positioning. We make a study of precision apparatus that is used in the various industrial machine. The study was carried out to develope a precision positioning apparatus, consisting of servo motor and piezoelectric actuator. Coarse positioning using lead screw is drived by servo motor. Control system output a signal from laser interferometer to amplifier of servo motor and piezoelectric actuator after digital signal processing(DSP). Resolution of this apparatus measure with laser interferometer. In this study, design method and control system with ultra precision position apparatus are researched. As the first step, we have estimated for control performance and system stability before an actual apparatus is manufactured by MATLAB with SIMULINK including various functions those are composed of pre-design and system modeling.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.1
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• pp.17-25
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• 2002

This system is composed of fine and coarse apparatus, measurement system and control system. Piezoelectric actuator is designed far fee positioning. We make a study of precision apparatus that is used in the various industrial machine. The study was carried out to develope a precision positioning apparatus, consisting of servo motor and piezoelectric actuator Coarse positioning using lead screw is thrived by servo motor. Control system output a signal from laser interferometer to amplifier of servo motor and piezoelectric actuator after digital signal processing (DSP). Resolution of this apparatus measure with laser interferometer. In this study, design method and control system with ultra precision position apparatus are researched. As the first step, we have estimated for control performance and system stability before an actual apparatus is manufactured by MATLAB with SIMUUNK including various frictions those are composed of pre-design and system modeling.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.211-217
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• 2007

A nano-imprinting stage has been widely used in various fields of nanotechnology. In this study, an analysis method of a nano-imprinting stage machine using FEM and flexible multi-body kinematics and dynamics has been presented. We have developed a virtual imprinting machine to evaluate the prototype design in the early design stage. The simulation using CAE for the imprinting machine is not only to analyze static and dynamic characteristics of the machine but also to determine design parameters of the components for the imprinting machine, such as dimensions and specifications of actuators and sensors. Structural components as the upper plate, the rotator, the shaft and the translator have been modeled with finite elements to analyze flexibility effects during the precision stage motion. In this paper flexible multi-body dynamic simulation is executed to support robust design of the precision stage mechanism. In addition, we made the 4-axis stage model to compare the dynamic behavior with that of 3-axis stage model.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.6
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• pp.264-269
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• 2019

The design for household sterilizer applying UV LED was studied. Based on UV LED sterilization distance and time data, the concept of home disinfectioner design was presented. Using technologies such as computer aided design software, 3D printing and laser cutting, etc., three different UV LED operating method models were produced. The final design was derived by conducting an analysis of the product's merits and demerits on the three plans from the result of each model.

• Journal of Energy Engineering
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• v.6 no.1
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• pp.87-95
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• 1997

A chemical heat pump based on the reversible reactions between metal chlorides and ammonia gas is attractive alternative to compression system and liquid absorption systems in cooling and refrigerating fields. The advantages of chemical heat pump are no regulatory constants due to CFC refrigerants, utilization of gas, industrial waste heat, electricity, fuel oil etc. as heat sources and wide applications to energy storage system, large-scale energy managements for industrial process. The scale-up of chemical heat pump from laboratory prototype to pilot plants necessitates the interpretation of system performance and evaluation of dynamic behavior in the chemical reactor. This study contains the prediction of performance of chemical refrigerator according to operating condition, the dynamic simulations through reactor modelling, which is used for the calculation of reactive medium temperature and the conversion variation with reactor cooling temperature, and the effect survey of block parameters on the power of refrigerator.

• Electronics and Telecommunications Trends
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• v.3 no.2
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• pp.116-133
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• 1988

ASIC (Application Specific Integrated Circuit)은 직역하면 응용특정 IC, 혹은 특정용도 IC로서 LSI시장의 조사회사인 Dataquest사가 '84년경부터 사용하기 시작한 말이다. ASIC이 최근 크게 주목을 끌고있는 것은, 반도체 사용자가 자신의 제품에 개성을 불어넣기 위해서는 범용IC를 사용해온 것으로는 기술적 우위성이 확보되지 않는다고 판단했기 때문에 주문형 LSI를 강하게 추진해 왔다는 것과 반도체 메이커도 메모리IC를 중심으로 한 범용IC시장의 부진, 더우기 날로 더해가는 반도체 시장의 시장쟁탈 및 무역마찰로 인해 ASIC 시장에로의 참여가 강화되어 왔다는 점 등을 들수있다. 집적화 기술은 매년 진보하여 지금은 100만개 이상의 트랜지스터를 집적할 수 있게 되었다. 따라서 지금까지 SSI/MSI를 사용해서 회로설계한 기능단위의 칩을 프린터 기판위에 조합시켜 시스팀을 구축해 왔으나, 앞으로는 하나의 칩위에 시스팀을 구성하는 시대로 변하고 있다. ASIC은 그 요청에 따라서 one-chip화의 개념에 따라서 만들어진 것으로서, 시장환경에 대단히 유익한 디바이스로 생각할 수 있다. 시스팀의 one-chip화의 실현결과 압도적으로 소형화, 경량화, 성자원화가 달성됨과 동시에 신뢰성 및 동작성능도 우수하게 되었다. ASIC기술은 현재 주류로 되어있는 게이트 어레이를 볼때, 개발비용은 크게 감소하여 개발기간도 논리회로가 완성된다면 3~4주 정도로 단축시킬수 있다. ASIC 설계에는 각 공정에 있어서 고도의 컴퓨터 지원설계가 채용되고 제조공정에서는 첨단의 프로세서 기술 등이 이용되므로 ASIC기술은 종합적인 첨단기술의 집약이라고 불러도 좋을것이다. 이러한 기술추세에 맞추어 전자통신 동향분석지 제3권 제1호(1988.3.)에 발표된 최신 ASIC기술동향의 후속편으로 ASIC에 관련된 중요용어 50개를 선정, 알파벳 순으로 나열하여 설명하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.3
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• pp.15-19
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• 2002

It is a quite quality concerming to the temperature of single cystalline growth as it does when we get most of heat treating products. It is also important factor to control the temperature when we make the A1203(single crystalline) used to artificial jewels, glass af watches, and heat resistant transparent glasses. Thus, it is a major interest to get the proper temperature in accordance with the time process while we are making mixture of oxygen and hydrogen to have the right tempearture. In this paper, we will study of electrical valve positioning system with DC-Motor for the gas mixture to improve the quality of products.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.5
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• pp.805-810
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• 2019

Recently, a majority of 4G mobile telecommunication manufacturers prefer repeaters with good adaptability. In this paper, we propose a new LMF(: Least Means Fourth) algorithm for LTE(: Long Term Evolution) RF(: Radio Frequency) Repeater. The proposed algorithm is a modification of the LMF, which appropriately adjusts the step size and improves performance according to the Sign function. The steady state MSE(: Mean Square Error) performance of the proposed LMF algorithm with step size of 0.009 is low level at about -25dB, and the proposed LMF algorithm requires 500 less iterations than the conventional algorithms at MSE of -25dB.