• 항공우주시스템공학회지
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• 제18권1호
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• pp.46-52
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• 2024

엔진 시운전실은 엔진의 성능 및 운용 특성 요구도를 적절하게 검증할 수 있도록 통제된 시험 환경을 제공해야 한다. 하지만 시운전 설비마다 구조 및 특성이 완전히 같을 수는 없기 때문에, 신규 시운전실은 기준 시운전실과의 Correlation 시험을 통해 시험 결과의 신뢰성을 검증하고 차이점을 보정하는 과정이 필요하다. 본 논문에서는 터보팬과 터보샤프트 엔진의 공통점과 차이점을 바탕으로 Correlation 시험을 수행할 때 고려사항들을 연구하였으며, 경험에 따른 Correlation 시험 절차의 예시를 제시하였다. 향후 본 연구가 엔진 종류에 따른 시험 설비의 인증 표준을 설정하는 것에 도움을 줄 것으로 기대한다.

• 조명전기설비학회논문지
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• 제24권7호
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• pp.9-19
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• 2010

Fuel cell (FC) distributed generation (DG) is gradually becoming more attractive to mainstream electricity users as capacity improves and costs decrease. New technologies including inverters are becoming available to provide a uniform standard interconnection of DGs with an electric power system. Some of the operating conflicts and the effect of DG on power quality are addressed and investigated through simulations on a real distribution network with an FC power plant. The results of these simulations have proved load tracking capability following the real and reactive power change of the load and have shown the flow of overcurrent from an FC power plant during the ground fault of a distribution line.

• KSBB Journal
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• 제6권3호
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• pp.299-307
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• 1991

In this paper the effect of light on non-aerated Baker's Yeast(Saccharomyces cereuisiae) production and the protein excretion to the extracellular fluid is studied. Previous results in our laboratory indicate that at pH=5 and T-32$^{\circ}C$ yeast may be affected by light, but those differences seem to be within statistical variation of the data. In this paper, cell and extracellular protein concentrations along with redox potential are monitored for batch fermentations in the presence and absence of light at pH levels of 3 and 5 and at 31$^{\circ}C$, in order to explore whether possible light effects can be more readily discerned at lower pH values. Yeast particle size distributions are also determined over the course of fermentation using a particle counter in order to add one more measuring tool to our usual cell and total protein measurements. An apparently noticeable difference in the redox potential is observed between the light and the dark runs for early times for the pH=3 runs. The particle size distributions show differences in the particle diameters between light and dark runs at pH=3, but those differences fall within one standard deviation of the mean particle diameters.

• 대한의용생체공학회:의공학회지
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• 제28권2호
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• pp.205-211
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• 2007

A novel envelope extraction algorithm for speech processor of cochlear implants, called adaptation algorithm, was developed which is based on a adaptation effect of the inner hair cell(IHC)/auditory nerve(AN) synapse. We achieved acoustic simulation and hearing experiments with 12 normal hearing persons to compare this adaptation algorithm with existent standard envelope extraction method. The results shows that speech processing strategy using adaptation algorithm showed significant improvements in speech recognition rate under most channel/noise condition, compared to conventional strategy We verified that the proposed adaptation algorithm may yield better speech perception under considerable amount of noise, compared to the conventional speech processing strategy.

• Journal of information and communication convergence engineering
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• 제7권1호
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• pp.66-71
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• 2009

A novel sensing scheme using resistive characteristics of the finger is proposed. ESD problem is more harmful than a capacitive fingerprint sensor in a resistive fingerprint sensor, because the sensor plate is directly connected to the sensing cell. The proposed circuit is more robust than conventional circuit for ESD. The sensor plate and sensing cell are isolated by capacitor. The pixel level simple detection circuit is fully digital operation unlike that of the capacitive sensing cell. The sensor circuit blocks are designed and simulated in a standard CMOS $0.35{\mu}m$ process. The proposed circuit is more stable and effective than a typical circuit.

• 한국전기전자재료학회논문지
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• 제21권1호
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• pp.53-56
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• 2008

The commercial parallel plate electrodes system with guard-ring electrode have been widely used for measurement of dielectric constants of solid materials. And the specification of the electrodes system is about 1 % of measurement uncertainty. This measurement uncertainty is only estimated the error come from mechanical measurements such as the area of the electrodes and the gap between the electrodes except the error come from the air gap between the electrodes and dielectric specimen. Because it is impossible to measure the air gap. This study analyze the total measurement uncertainties of the commercial dielectric constant test cell using 3 kinds of Standard Reference Materials. As a results, the total measurement uncertainty is much bigger than 1 % and the most of the uncertainty can be reduced by compensation of the error values evaluated in this study.

• ETRI Journal
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• 제17권3호
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• pp.45-63
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• 1995

This paper proposes an algorithm to improve the correlation between giga-hertz transverse electromagnetic (GTEM) cell and open area test site (OATS). It is based on the dipole modeling process of an unknown source object in a GTEM cell and on the evaluation of the approximate far field equations correlated with measured GTEM powers at output port of the GTEM cell. In this algorithm, the relative phase differences between dipole moments play an important part in modeling the test object as a set of dipoles and offer stable calculation of emission values. The radiated emission test using this algorithm requires fifteen orientations of equipment under test, but the increased orientations as compared with the previous method have little effect on the time needed for testing. Radiation from a notebook computer has been tested for statistical analysis of the correlation between GTEM data and OATS data. The emission test results of the notebook computer show that the mean, the standard deviation, and the correlation coefficient are -0.62, 1.99, and +0.85, respectively. These figures indicate that this algorithm provides improved accuracy in the measurement of electromagnetic emissions over the previous method.

• KSBB Journal
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• 제13권1호
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• pp.13-19
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• 1998

Biopolymer membrane was prepared using two oppositely charged natural biopolymers. The biopolymer membrane was used for the encapsulation of two hybridoma cell lines(ATCC CRL-1606, ATCC HB-8852) to produce monoclonal antibodies. In order to reduce the down stream steps, the pre size of the membrane was controlled to retain the monoclonal antibodies in the capsules based on the diffusion experiments with standard proteins. T-flask culture showed cell densities of 8$\times$107 cells/mL and 3$\times$107 cells/mL, and MAb concentrations of 506$\mu$g/mL and 109$\mu$g/mL for encapsulated ATCC CRL-1606 and HB-8852, respectively. Two liter perfusion cultures with encapsulated ATCC HB-8852 were performed to enhance the MAb production. The MAb production of the encapsulated hybridoma increased considerably comparing to the culture using silicon tubing for oxygen transfer.

• Journal of Ship and Ocean Technology
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• 제10권3호
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• pp.1-16
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• 2006

Despite the high cost of memory and CPU time required to resolve the boundary layer, a viscous unstructured grid solver has many advantages over a structured grid solver such as the convenience in automated grid generation and vortex capturing by solution adaption. In present study, an unstructured Cartesian grid solver is developed on the basis of the existing Euler solver, NASCART-GT. Instead of cut-cell approach, immersed boundary approach is applied with ghost cell boundary condition, which can be easily applied to a moving grid solver. The standard $k-{\varepsilon}$ model by Launder and Spalding is employed for the turbulence modeling, and a new wall function approach is devised for the unstructured Cartesian grid solver. Developed approach is validated and the efficiency of the developed boundary condition is tested in 2-D flow field around a flat plate, NACA0012 airfoil, and axisymmetric hemispheroid.

• Archives of Pharmacal Research
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• 제15권4호
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• pp.275-282
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• 1992

The present work was designed to investigate the effects of barzilin on ConAinducedd TCGF release, responsiveness to standardd IL-2, and mitogens-induced proliferation of splenocyte when administered intraperitoneally to 8 week-old C57BL/6 mice for 2 consecutive days. Immunological tests were performed 72 hours after the treatment of brailin. The administration of 50 mg/kg brazilin caused a noticeable increase in TCGF release and responsiveness to standard II-2 but inhibited mitogens-induced proliferation of splenocyte. These results that brazilin is able to modular immunological functions despite of its inhibitory effect on mitogen induced cell proliferation.