• Journal of Microbiology and Biotechnology
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• 제31권11호
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• pp.1519-1525
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• 2021

Hexavalent chromium (Cr(VI)) is recognized to be carcinogenic and toxic and registered as a contaminant in many drinking water regulations. It occurs naturally and is also produced by industrial processes. The reduction of Cr(VI) to Cr(III) has been a central topic for chromium remediation since Cr(III) is less toxic and less mobile. In this study, fermentative Fe(III)-reducing bacterial strains (Cellu-2a, Cellu-5a, and Cellu-5b) were isolated from a groundwater sample and were phylogenetically related to species of Cellulomonas by 16S rRNA gene analysis. One selected strain, Cellu-2a showed its capacity of reduction of both soluble iron (ferric citrate) and solid iron (hydrous ferric oxide, HFO), as well as aqueous Cr(VI). The strain Cellu-2a was able to reduce 15 μM Cr(VI) directly with glucose or sucrose as a sole carbon source under the anaerobic condition and indirectly with one of the substrates and HFO in the same incubations. The heterogeneous reduction of Cr(VI) by the surface-associated reduced iron from HFO by Cellu-2a likely assisted the Cr(VI) reduction. Fermentative features such as large-scale cell growth may impose advantages on the application of bacterial Cr(VI) reduction over anaerobic respiratory reduction.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2002년도 연료전지심포지움 2002논문집
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• pp.165-170
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• 2002

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2017년도 추계학술논문요약집
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• pp.67-68
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• 2017

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.372-376
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• 1990

This paper represents a control method of improving the performance of direct drive robot. The direct transfer of torque and rotational speed of direct drive motor to the robot body without reduction gear makes the robot speed fast. However, the variation of inertia matrix and low friction cause the control difficult, and one more effort must be in the reducing the acceleration and deceleration time to reduce the cycle time. To fasten the cycle time and to improve the robustness of robot, one control method is developed, and implemented in the Goldstar DD robot. This method does not need to change the conventional PI type control structure, but one additional compensational control law is required. The control law can be obtained via inverse dynamic model of robot, and inverse model of existing control loop. The effects of this control law are shown in this paper.

• Asian-Australasian Journal of Animal Sciences
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• 제10권5호
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• pp.510-513
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• 1997

This study examined the effects of ignoring inbreeding depression on (co)variance components for weaning weight through the use of Monte Carlo simulation. Weaning weight is of particular interest as a trait for which additive direct and maternal genetic components exist and there then is the potential for a direct-maternal genetic covariance. Ignoring inbreeding depression in the analytical model (.8 kg reduction of phenotypic value per 1% inbreeding) led to biased estimates of all genetic (co) variance components, all estimates being larger than the true values of the parameters. In particular, a negative bias in the direct-maternal genetic covariance was observed in analyses that ignored inbreeding depression. A small spurious sire-by-year interaction variance was also observed.

• 대한의용생체공학회:의공학회지
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• 제26권4호
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• pp.251-255
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• 2005

When the extracorporeal shock wave lithotriptor is operated, sounds can be heard. Then that might be a question about the location where the sounds come from. For the purpose of investigating the fact, we identify the location of the sounds radiated using one hydrophone. In order to carry out the experiment, it is needed to obtain direct waves from objects. Therefore, we present an experimental method to reduce reflected waves for obtaining direct waves only. The experimental results show the amplitude of waves can be attenuated about 28dB due to a silicon rubber plate of 8.5mm attached at the bottom. This is a quantified result that can expect to obtain the direct waves using the proposed method. Then, we carried out the experiment for the sound source location. From the experimental results, we can undoubtedly present a fact that the sounds are radiated from the objects to be shot due to shock waves.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.507-515
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• 2002

Remote Sensing Monitoring and Loss Estimated System of Flood Disaster based on GIS is an integrated system comprised flood disaster information receiving and collection, flood disaster simulation, and flood disaster estimation. When the system receives and collects remote sensing monitoring and conventional investigation information, the distributional features of flood disaster on space and time is obtained by means of image processing and information fusion. The economic loss of flood disaster can be classified into two pus: direct economic loss and indirect economic loss. The estimation of direct economic loss applies macroscopic economic analysis methods, i.e. applying Product (Industry and Agriculture Gross Product or Gross Domestic Product - GDP) or Unit Synthetic Economic Loss Index, direct economic loss can be estimated. Estimating indirect economic loss applies reduction coefficient methods with direct economic loss. The system can real-timely ascertains flood disaster and estimates flood Loss, so that the science basis fur decision-making of flood control and relieving disaster may be provided.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.686-688
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• 1996

Network reconfiguration is performed by opening/closing two types of switches, tie and sectionalizing switches. A whole feeder, or part of a feeder, may be served from another feeder by closing a tie switch linking the two while an appropriate sectionalizing switch must be opened to maintain radial structures. In loss reduction, the problem is to identify tie and sectionalizing switches that should be closed and opened, respectively, to achieve a maximum loss reduction. In this paper, it is introduced to propose the reconfiguration plan for loss reduction by using the Civanlar's loss reduction formular.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.148-149
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• 2007

In this paper, an advanced torque control scheme of SRM using DITC(Direct Instantaneous Torque Control) and PWM(pulse width modulation) is investigated. The proposed DITC-PWM regulates a duty ratio of the phase switch according to the torque error and simple control rules of DITC without any hysteresis bandwidth. The proposed control method is verified by the simulations and experimental results.

• 방사성폐기물학회지
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• 제3권2호
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• pp.105-112
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• 2005

650$^{\circ}C$의 LiCl-Li$_{2}$O 용융염계에서 10 g U$_{3}$O$_{8}$/batch 규모의 장치를 이용해서 우라늄산화물의 전해환원 특성에 대한 평가를 수행하였다. 일체형 음극은 고체전극, 우라늄산화물과 우라늄산화물을 담아주는 다공성 용기(멤브레인)로 구성된다. 멤브레인 재료로는 325-mesh 스테인레스강막과 다공성 마그네시아 도가니를 사용하였다. 일체형 음극의 재질에 따른 LiCl-3 wt$\%$ Li$_{2}$O계와 U$_{3}$O$_{8}$-LiCl-3 wt$\%$ Li$_{2}$O계의 순환 전압측정법 결과로부터 전해환원 반웅 메커니즘을 규명하였다. 일체형 음극의 재질에 따른 우라늄산화물의 직접 및 간접 전해환원에 대한 실험을 수행하였다. 그 결과, 325-mesh스테인레스강막을 사용하여 직접 및 간접 전해환원으로 금속전환을 수행하였을 때 낮은 전류효율로 인해 우라늄산화물을 금속우라늄으로 환원시키지 못했으며, 마그네시아 다공성 도가니를 사용하여 간접 전해환원으로 금속전환을 수행하였을 때는 높은 전류효율로 인해 우라늄산화물을 금속우라늄으로 환원시킬 수 있었다