• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.10
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• pp.992-1000
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• 1991

At present, using different method, in the view of point of that factory to the rising of the productivity, they try to rise productivity by factory automation. First, it is the automation of each unit process. In out country, in the case of a few developed factory. they are realized by line automation. The majority factories are established by automation device of unit process. But, as the established devices, it must be connect between unit processes or mutual assistance and offical automation in order to raise up productivity highly. In this paper, process inspection control system is installed by each unit process automation and connect main computer with them. So, we try to rise high productivity using stochastic process and supervision function.

• Journal of the Korean Statistical Society
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• v.22 no.2
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• pp.271-282
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• 1993

Unit root test for temporally aggregated first order autoregressive process is considered. The temporal aggregate of fist order autoregression is an autoregressive moving average of order (1,1) with moving average parameter being function of the autoregressive parameter. One-step Gauss-Newton estimators are proposed and are shown to have the same limiting distribution as the ordinary least squares estimator for unit root when complete observations are available. A Monte-Carlo simulation shows that the temporal aggregation have no effect on the size. The power of the suggested test are nearly the same as the powers of the test based on complete observations.

• Transactions of Materials Processing
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• v.15 no.1 s.82
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• pp.21-26
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• 2006

A optical head unit for nano optical probe array was developed. The optical probe array is generated by Talbot effect. The shape and thickness of microlens array(MLA) were designed to minimize the spot size at the foci of MLA. To increase the optical efficiency of the system and obtain the large tolerance for fabrication, aperture size was theoretically optimized. Then microlens illuminated aperture array(MLIAA) as an optical head unit was fabricated using a ultra violet(UV) molding process on aluminum aperture array. In this process, Al aperture array was fabricated separately using the photolithography and reactive ion etching(RIE) process. Optical properties of the generated optical probes were measured and compared at Talbot distance from the aperture array having a diameter of $1{\mu}m$ and MLIAA.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.09a
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• pp.29-34
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• 2005

A optical head unit for nano optical probe away was developed. The optical probe array is generated by Talbot effect. The shape and thickness of microlens array(MLA) were designed to minimize the spot size at the foci of MLA. To increase the optical efficiency of the system and obtain the large tolerance for fabrication, aperture size was theoretically optimized. Then microlens illuminated aperture array(MLIAA) as an optical head unit was fabricated using a ultra violet(UV) molding process on aluminum aperture array. In this process, Al aperture array was fabricated separately using the photolithography and reactive ion etching(RIE) process. Optical properties of the generated optical probes were measured and compared at Talbot distance from the aperture array having a diameter of $1{\mu}m$ and MLIAA.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.2
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• pp.45-51
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• 2008

The objective of this study is to develop an automatic object changer unit to improve processing problems existed in the conventional horizontal machining center. In order to perform this objective, a upward and downward traverse unit in which a unit that consists of a motor and reducer, chain and sprocket wheel, and upper and lower base employed in an automatic object changer unit performs sliding contact motion in a frame was designed. To achieve this design, constraint conditions for the upward and downward traverse unit first designed. Then, an operation mechanism was designed and that was introduced as a sum of kinetic energy for the sprocket wheel and upper and lower base based on the moment of inertia, which is the kinetic energy of the converted upward and downward traverse unit in the side of the reducer. In addition, The work required to rotate the converted upward and downward traverse unit in the side of the reducer by one revolution can be calculated using the sum of work that is required in the sprocket wheel and upper and lower base that is a part of the upward and downward traverse unit. Furthermore, the converted equation of motion in the side of the motor can be introduced using the equation of motion using the converted upward and downward traverse unit in the side of the motor. Then, Then, a proper motor can be determined using predetermined specifications employed in the motor and several parameters in the upward and downward traverse unit in order to verify such predetermined specifications. Also, a design of a horizontal traverse unit that performs sliding motion on a upward and downward traverse unit and simulation that verifies the results of this design are required as a future study.

• Journal of computational fluids engineering
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• v.15 no.4
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• pp.92-98
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• 2010

In a modern high speed drawing process of optical fibers, it is necessary to use helium as a cooling gas in a glass fiber cooling unit in order to sufficiently cool down the fast moving glass fiber freshly drawn from the heated silica preform in the furnace. Since the air is entrained unavoidably when the glass fiber passes through the cooling unit, the helium is needed to be injected constantly into the cooling unit. The present numerical study investigates and analyzes the air entrainment using an axisymmetric geometry of glass fiber cooling unit. The effects of helium injection rate and direction on the air entrainment rate are discussed in terms of helium purity of cooling gas inside the cooling unit. For a given rate of helium injection, it is found that there exists a certain drawing speed that results in sudden increase in the air entrainment rate, which leads to the decreasing helium purity and therefore the cooling performance of the glass fiber cooling unit. Also, the helium injection in aiding direction is found to be more advantageous than the injection in opposing direction.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.183-184
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• 2008

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.32-33
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• 2006

현재 변전소 자동화의 국제 표준으로 대두되고 있는 IEC61850은 스테이션 버스뿐만 아니라 프로세서 버스까지도 표준화된 통신기술을 채용하였고 자동화에 필요한 모델을 제시하였다. 본 연구에서는 프로세서 버스의 대표적인 장비인 Merging Unit의 특성과 구현에 필요한 기술을 고찰하였다. 특히 정밀한 시간동기에 필요한 GPS(Global Positioning System)를 이용한 동기화 기술에 대하여 고찰하였다. 이와 더불어 IEC61850-9-2 SV(Sampled Value) 서비스를 분석하고 실제로 마이크로프로세서를 이용하여 Merging Unit에 대한 설계를 수행하였다. 제안된 Merging Unit의 성능을 검증하기 위해서 전송된 SV 데이터를 시간 정보를 기준으로 재구성할 수 있는 오실로그래피(Oscillography)를 위한 플레이백(Playback) 프로그램을 제작하였다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2004.05a
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• pp.197-200
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• 2004

Compared to conventional flame combustion, catalytic combustion had the advantage of oxidation of V.O.C. gas which was high voluminous, low caloric mixture flow. However, the temperature of mixture gas should be over the one of catalytic reaction start and the control of reaction on the catalytic surface tends to be vulnerable. To overcome these obstacles, composition of both catalytic combustor and heat exchanger was devised and named the sequential catalytic combustion system. In this system, only trigger unit needed preheating process for transient starting time. Once trigger unit was ignited, the next unit w3s supplied heat to ignite from that and same process was performed to the last one sequentially. When it come to steady state, whole mixture gas was oxidated at each unit simultaneously and preheating for trigger unit was not needed any more. System of 100 kcalh/hr capacity was devised and operated successfully.

• IEMEK Journal of Embedded Systems and Applications
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• v.4 no.1
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• pp.1-8
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• 2009

This paper proposes a 24-bit floating point multiply and accumulate(MAC) unit that can be used in geometry transformation process in 3D graphics. The MAC unit is composed of floating point multiplier and floating point accumulator. When separate multiplier and accumulator are used, matrix calculation, used in the transformation process, can't use continuous accumulation values. In the proposed MAC unit the accumulator can get continuous input from the multiplier and the calculation time is reduced. The MAC unit uses about 4,300 gates and can be operated at 150 MHz frequency.