• Title/Summary/Keyword: simultaneous

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Simultaneous controller of electronic ballast and PFC for a fluorescent lamp (형광등용 전자식 안정기 및 PFC 동시제어기)

  • Park, Hyo-Sik;Han, Woo-Yang;Lee, Gong-Hee
    • Proceedings of the KIEE Conference
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    • 2005.10a
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    • pp.118-121
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    • 2005
  • In this paper, it has been proposed the simultaneous controller of electronic ballast and PFC(power factor corrector) for fluorescent lamp by one chip micro-controller. Boost DC-DC converter is adopted for PFC, and half bridge inverter for electronic ballast. It controls, simultaneously and independently, the boost DC-DC converter and the half bridge inverter. As electronic ballast and PFC are controlled by one chip micro-controller, it is possible to achieve the cheaper controller for fluorescent lamp. Experimental result has shown the feasibility of the proposed simultaneous controller of PFC and electronic ballast.

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Ethanol Production from Artificial Domestic Household Waste Solubilized by Steam Explosion

  • Nakamura, Yoshitoshi;Sawada, Tatsuro
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.3
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    • pp.205-209
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    • 2003
  • Solubilization of domestic household waste through Steam explosion with Subsequent ethanol production by the microbial saccharifitation and fermentation of the exploded product was studied. The effects of steam explosion on the changes of the density, viscosity, pH, and amounts of extractive components in artificial household waste were determined. The composition of artificial waste used was similar to leftover waste discharged from a typical home in Japan. Consecutive microbial saccharification and fermentation, and simultaneous microbial saccharification and fermentation of the Steam-exploded product were attempted using Aspergillus awamori, Trichoderma viride, and Saccharomyces cerevisiae; the ethanol yields of each process were compared. The highest ethanol yield was obtained with simultaneous microbial saccharification and fermentation of exploded product at a steam pressure of 2 MPa and a steaming time of 3 min.

Simultaneous Derivative Spectrophotometric Determination of Levodopa and Carbidopa in Pharmaceutical Preparations

  • Madrakian, T.;Afkhami, A.;Borazjani, M.;Bahram, M.
    • Bulletin of the Korean Chemical Society
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    • v.25 no.12
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    • pp.1764-1768
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    • 2004
  • The present work reports on the investigations based on the interaction of sodium hydroxide with catechol derivatives. The first derivative spectra allowed the simultaneous determination of levodopa and carbidopa. The calibration graph was constructed from the first derivative signals by measuring $^1D$ at 350 nm for standard samples containing between 3 and 30 mg $L^{-1}$ of levodopa and at 305 nm for standard samples containing between 3 and 80 mg $L^{-1}$ of carbidopa. This method offers the advantages of simplicity, rapidity, selectivity and higher sensitivity than most of the existing spectophotometric methods.

Simultaneous Temperature and Velocity Fields Measurements near the Boiling Point

  • Doh, Deog-Hee;Hwang, Tae-Gyu;Koo, Bon-Young;Kim, Seok-Ro
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.5
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    • pp.531-542
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    • 2007
  • Simultaneous measurement technique for temperature and velocity fields near a heated solid body has been constructed. The measurement system consists of a 3-late CCD color camera, a color image grabber, a 1ighting system, a host computer and a software for the whole quantification process. Thermo Chromic Liquid Crystals (TCLC) was used as temperature sensors. A neural network was used to get a calibration curve between the temperature and the color change of the TCLC in order to enhance the dynamic range of temperature measurement. The velocity field measurement was attained by the use of the fray-level images taken for the flow field, and by introducing the cross-correlation technique. The temperature and the velocity fields of the forced and the natural convective flows neat the surface of a cartridge heater were measured simultaneously with the constructed measurement system.

Characterization and Studies of Compromised Experimental Conditions for the Simultaneous Multielemental Analysis by Flame Atomic Absorption Spectrometry (원자흡수법을 이용한 다원소 동시 분석 실험 조건에 관한 기초 특성 연구)

  • 최성규;이현주;박양순;김효진
    • YAKHAK HOEJI
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    • v.39 no.2
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    • pp.148-152
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    • 1995
  • For comparison between the compromised experimental condition and the best conditions for each element by flame atomic absorption spectrometer, the absorbances were measured with changing the burner height and HCL current. The optimum absorbance for simultaneous analysis of 6 elements was observed at 1 mA of HCL current and at 4 mm of burner height except Cr and Co. The stability of flame atomic absorption spectrometer on each element was found to be better than 5%. To investigated the accuracy of this instrument, POSCO RM-07 as a real sample was analysed at these compromised experimental conditions and found to be better than 0.04%.

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Simultaneous Nitrification and Denitrification in a Fluidized Biofilm Reactor with a Hollow Fiber Double Layer Biofilm Media (이중층 중공사 생물막 담체를 이용한 유동층 생물막 반응기에서의 동시 질산화와 탈질)

  • 이수철;이현용;김동진
    • KSBB Journal
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    • v.15 no.5
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    • pp.514-520
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    • 2000
  • Simultaneous nitrification and denitrification of ammonia and organic compounds-containing wastewater were performed in a fluidized bed biofilm reactor with polysulfone(PS) hollow fiber as a double layer biomass carrier. The PS hollow fiber fragment has both aerobic and anoxic environments for the nitrifiaction and denitrification at the shell and lumen-side respectively. The reactor system showed about 80% nitrification efficiency stably throughout the ammonia load conditions applied in the experiment. Denitrification efficiency depended on organic load and C/N ratio. High free ammonia concentration and low dissolved oxygen resulted in nitrite accumulation which leads to enhance organic carbon efficiency in denitrification when compared to nitrate denitrification. The simultaneous nitrification and denitrification reactor system has an economic advantages in reduced chemical cost of organic carbon for denitrification as well as compact reactor configuration.

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A study on the AC dielectric breakdown characteristics and mechanical characteristics of interpenetraing polymer network epoxy composites (상호침입망목 에폭시 복합재료의 교류절연파괴 특성 및 기계적 특성에 관한 연구)

  • 손인환;이덕진;김명호;김경환;김재환
    • Electrical & Electronic Materials
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    • v.9 no.7
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    • pp.702-707
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    • 1996
  • In this paper, in order to improve the withstand voltage properties of epoxy resin, IPN(interpenetrating polymer network) method was introduced and the influence was investigated. The single network structure specimen(E series), simultaneous interpenetrating polymer network specimen(EM series) and pseudo interpenetrating polymer network(EMP series) specimen were manufactured. In order to understand the internal structure properties, scanning electron microscopy method was utilized, and glass transition temperature was measured. Also, AC voltage dielectric breakdown strength, tensile strength and impact strength were measured to investigate the influence upon electrical and mechanical properties. As a result, it was confirmed that simultaneous interpenetrating polymer network specimen was the most execellent.

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Simultaneous optical ignition and spectroscopy of a two-phase spray flame for feedback control System (이상상태 분무 화염에서의 레이저 점화 및 분광 측정을 통한 피드백 제어 연구)

  • Lee, Seok Hwan;Kim, Hyunwoo;Do, Hyungrok;Yoh, Jack J.
    • 한국연소학회:학술대회논문집
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    • 2015.12a
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    • pp.215-218
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    • 2015
  • Simultaneous laser ignition and spectroscopy is a scheme that enables rapid determination of the local equivalence ratio and condensed fuel concentration during a reaction in a two phase spray flame. We have conducted quantitative analysis of the LIBS signals according to the equivalence ratio, droplet size, droplet number density and droplet concentration as a part of novel feedback control strategy proposed for flame ignition and stabilization with simultaneous in situ combustion flow diagnostics. This is a desirable scheme since such real time information onboard an engine for instance can be constantly monitored and fed back to the control loop to enhance the mixing process and minimize emissions of unwanted species and potential combustion instability.

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Simultaneous Estimation of Rotor Speed and Rotor Resistance of an Induction Motor Using Variable Rotor Flux

  • Lee Zhen-Guo;Jeong Seok-Kwon
    • Journal of Power Electronics
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    • v.5 no.4
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    • pp.282-288
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    • 2005
  • In this paper, a new speed sensorless induction motor scheme which can estimate rotor speed and rotor resistance simultaneously is presented. The rotor flux with a low frequency sinusoidal waveform is used to conduct on-line simultaneous estimation of the rotor speed and rotor resistance. Hence the proposed sensorless control method is robust to rotor resistance variations. Also, the control scheme has no current minor loop to determine voltage references. It contributes to good control performance at low speeds. Some simulation results supported by experiments are given to show the effectiveness of this method.

Toward global optimization of case-based reasoning for the prediction of stock price index

  • Kim, Kyoung-jae;Ingoo Han
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2001.06a
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    • pp.399-408
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    • 2001
  • This paper presents a simultaneous optimization approach of case-based reasoning (CBR) using a genetic algorithm(GA) for the prediction of stock price index. Prior research suggested many hybrid models of CBR and the GA for selecting a relevant feature subset or optimizing feature weights. Most studies, however, used the GA for improving only a part of architectural factors for the CBR system. However, the performance of CBR may be enhanced when these factors are simultaneously considered. In this study, the GA simultaneously optimizes multiple factors of the CBR system. Experimental results show that a GA approach to simultaneous optimization of CBR outperforms other conventional approaches for the prediction of stock price index.

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