• 한국미생물·생명공학회지
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• 제20권4호
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• pp.451-458
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• 1992

에탄올발효에서 에탄올은 세포의 성장 및 에탄올생합성에 저해작용을 하는 것으로 알려져 있다. 이러한 저해작용을 감소시켜주기 위하여 에탄올을 선택적으로 분리하는 투과증발법을 이용하였다. 실리콘폴리슬폰 복합막을 제조하여 사용하였는데, 이 막은 유입액의 에탄올 농도가 25g/l, 온도가 30'C, 막하부의 압력이 10mmHg일 때 에탄올의 선택도가 약 4 이었으며, 총 투과유속은 300g/m2h이었다. 에탄올 발효는 Saccharomyces cerevisiae를 Ca-alginate에 고정화시켜 유동층 생물반응기에 접종하여 수행하였고, 이 반응기를 투과증발장치와 연결한 혼합공정을 구성하였는데, 혼합공정의 경우 발효배지의 에탄올농도는 막을 연결하지 않았을 때보다 감소하여 저해작용을 감소시키고 생산성을 향상시켰다.

• 한국멀티미디어학회논문지
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• 제6권2호
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• pp.216-223
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• 2003

본 논문에서는 음성과 온라인 문자를 단일시스템으로 인식할 수 있는 음성 문자 공용인식 시스템을 제안한다. 일반적으로 CHMM(Continuous Hidden Markov Model)은 음성인식과 온라인 문자인식을 위해 매우 유용한 도구로 잘 알려져 있으나, 인식을 위해서는 각각을 독립 시스템으로 구현하고 있어 추가적인 메모리와 계산량을 요구한다. 제안한 공용인식 시스템은 음성인식과 문자인식을 결합하기 위하여 이들을 동일한 CHMM모델로 구성한 후 상태단위로 지속정보를 제어하는 OPDP(One Pass Dynamic Programming) 알고리즘을 통하여 음성과 문자를 인식할 수 있는 확률 통계적 시스템을 구현하였다. 음성은 MFCC(Mel Frequency Cepstrum Coefficient) 파라미터, 문자는 위치 변화량 파라미터와 비트맵 파라미터를 사용하였으며, MLE(Maximum Likelihood Estimation) 추정법을 이용하여 음소와 자소를 결합한 115개의 3상태 9천이 CHMM모델을 구성하였다. 공용인식기의 실험결과 음소 인식률 51.65%, 음성 단어 인식률 88.6%, 자소 인식률 85.3%, 필기체 단어인식률 85.6%를 나타내어 공용인식의 유효함을 확인할 수 있었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.211-225
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• 2011

Railroad signalling systems are to control intervals and routes of trains. There are ATS(Automatic Train Stop), ATP(Automatic Train Protection), ATO(Automatic Train Operation) and ATC(Automatic Train Control) system. Trains are operated in the section which is met on the signalling system because various signalling systems are used in Korea. On the other words, trains are not operated in the section which is used in the other signalling system. To solve this problem, recently combined on-board system has been developed. The combined on-board system is designed by doubling the ATS, ATP and ATC system. Information signal is received by magnetic sensors in the ATC system and is received by antennas in the ATS and ATP system. Therefore, it is possible to arise transmission problems by magnetic coupling. In this paper, electric model of the ATS and ATP antenna is suggested and interference frequency by the magnetic coupling between the ATS and ATP antenna is estimated numerically. As a results of the magnetic coupling, the value of the magnetic coupling is presented without magnetic induction.

• 동력기계공학회지
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• 제12권2호
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• pp.55-61
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• 2008

This paper discusses the advantages of using Fourier-based periodic excitation and of combining internal and external models in dynamic robot parameter identification. Internal models relate the joint torques or forces with the motion of the robot; external models relate the reaction forces and torques on the bedplate with the motion data. This combined model allows to combine joint torque/force and reaction torque/force measurements in one parameter estimation scheme. This combined model estimation will yield more accurate parameter estimates, and consequently better predictions of actuator torque, which is shown by means of a simulated experiment on a CRS A465 industrial robot.

• 전기학회논문지
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• 제62권11호
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• pp.1610-1616
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• 2013

Recently, district heating and cooling (DHC) systems based on combined cycle generation (CCG) providers are increasing in Korea. Since characteristics of combined heat and power (CHP) generators and heat demands of providers, heat trading between DHC providers based on the economic viewpoint is required; the heat trading has been doing. In this paper, a mathematical model for optimal operation based on heat trading between DHC providers is proposed. Especially, start-up characteristic of CCG is included. The operation model is established by mixed integer linear programming (MILP).

• Journal of Positioning, Navigation, and Timing
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• 제3권1호
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• pp.31-36
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• 2014

Precise Point Positioning (PPP) is a stand-alone precise positioning approach. As the quality of satellite orbit and clock products from analysis centers has been improved, PPP can provide more precise positioning accuracy and reliability. A combined use of Global Positioning System (GPS) and Global Orbiting Navigation Satellite System (GLONASS) in PPP is now available. In this paper, we explained about an approach for combined GPS and GLONASS PPP measurement processing, and validated the performance through the comparison with GPS-only PPP results. We also used the measurement obtained from the GRAS reference station for the performance validation. As a result, we found that the combined GPS/GLONASS PPP can yield a more precise positioning than the GPS-only PPP.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.686-687
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• 2011

In this paper, the method on calculating benefits of combined heat and power is introduced for standard evaluation in electrical power system. This paper calculates benefits about new national viewpoint and viewpoint of independent power producers and assesses benefits of combined heat and power in Korea and In Seoul national capital area. Benefit costs are composed of avoid cost of centralized generation, line upgrading adjustment, loss adjustment and electrical power trade cost per year in earlier study, in addition trade cost of CO2, construction cost of combined heat and power for accurate calculation. Benefit of combined heat and power is calculated by simulation results of real electrical power system.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 춘계학술대회
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• pp.87-91
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• 1995

Combined models, specified by two or more modeling formalisms, can represent a wide variety of complex systems. This paper describes a methodology for the development of combined models in two model types of discrete events and continuous process. The methodology is based on transformation of continuous state space into discrete one to homomorphically represent dynamics of continuous processes in discrete events. As an example, a combined model of human heart is developed which Incorporates conventional differential equation formalism with Zeigler's DEVS(Discrete Event Specification System) [4]formalism.

• Journal of Positioning, Navigation, and Timing
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• 제10권2호
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• pp.131-137
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• 2021

The Angle-of-Arrival (AOA) estimation in real time is one of core technologies for the real-time tracking system, such as a radar or a satellite. Although AOA estimation algorithms for various antenna types have been studied, most of them are for the single-shaped array antenna suitable to the specific frequency. In this paper, we propose the cascade AOA estimation algorithm for the combined array antenna with Uniform Rectangular Frame Array (URFA) and Uniform Circular Array (UCA), with the excellent performance for various frequencies. The proposed technique is consisted of Capon for roughly finding AOA groups with multiple signal AOAs and Beamspace Multiple Signal Classification (MUSIC) for estimating the detailed signal AOA in the AOA group, for the combined array antenna. In addition, we provide computer simulation results for verifying the estimation performance of the proposed algorithm.

• 한국물환경학회지
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• 제22권6호
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• pp.982-990
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• 2006

Generally CSOs (Combined Sewer Overflows) are regarded as one of the most serious nonpoint pollution source in the urban watershed, Particularly, the water quality of the Oncheon stream is seriously affected by CSOs because the capacity of interception sewer system connected to the Suyoung wastewater treatment plant is too small to intercept most storm water discharges. The objective of this study is to evaluate the effect of nonpoint source on an urban stream with regards to combined sewer system and separate sewer system using GIS (Geographic Information System) and SWMM (Storm Water Management Model), and to provide an insight for the management of urban stream water quality. In order to consider the effect of CSOs on the receiving water quality, the flow divider element in SWMM was applied. The model calibration and verification were performed by the measured data of quantity and quality on the Oncheon stream. The quantity data acquired from the Suyoung wastewater treatment plant were also used for this procedure. In case of separate sewer system, the modeling results showed the increased tendency in streamflow compared with the combined system in dry weather, In addition, the water quality is remarkably improved in rainfall events at the separate condition. The results imply that the construction of separate sewer system should be taken into first consideration to restore the quality and quantity of water in urban streams.