• Journal of Environmental Health Sciences
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• v.33 no.5
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• pp.359-364
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• 2007

The aim of this study were to assess the personal exposure to volatile organic compounds (VOCs) and to estimate the personal exposure using time-weighted average model. Three target VOCs (benzene, toluene, xylene) were analyzed in personal exposure samples and residential indoor, residential outdoor and workplace indoor microenvironments samples in the iron mill 30 workers during working 5 days. Personal exposure to VOCs significantly correlated with workplace concentration p<0.05), suggesting workplace had strong source and major contribution to personal exposure. Personal exposure could be estimated with time activity pattern and time weighted average (TWA) model of residential indoor and workplace concentrations measured. Time weighted mean microenvironments concentrations were close approximately of personal exposure concentrations. Total exposure for participants can be estimated by TWA with microenvironments measurements and time activity pattern.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.6
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• pp.237-245
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• 1986

Most fossil steam generating units are currently being designed for base load operation and are not therefore generally suitable for large and rapid recurring load fluctuations. In particular the control systems adopted for such units are not adequate for the severe recurrent load fluctuations. In particular the control systems adopted for such units are not adequate for the severe recurrent load fluctuations that are expected by the plant supplying the power requirements of the electric are furnaces and rolling mills employed by the steel industry. This paper presents a feasible Anticipatory Control Algorithm which ensures that the fossil fuel fired plant can meet such severe requirements from the control point of view. Details of such a control algorithm and its dynamic simulation on a sample power system are also presented.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.5
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• pp.9-17
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• 2009

In this paper, we describe a flow meter system for pulverized coal developed for the pulverizer-burner system of a boiler or blast furnace, which uses the density and the velocity of the granule flow. The granule flow density is measured by a sensor that detects the capacitance from the electrode on the surface of the piping system. The velocity of granule flow can be calculated using the distance between two pairs of built-in sensors in the flow direction, the time obtained from the sampling cycle using the correlation method between two waveforms of the sensors. The flow rate is calculated from the density and velocity of the granule flow. The reliability and accuracy of the flow meter system has been verified by comparing the data with the weight measured from a load-cell.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.4
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• pp.404-408
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• 2003

This paper discusses the physical properties of permeable high quality concrete using blast furnace slag or steel slag as a part of aggregate. In the case of steel slag, aging treatment was adopted to prevent the volume expansion. With high range water reducing agent, the concrete using slag aggregate showed compressive strength up to 24MPa at the age of 28 days and the water permeability of the concrete was over the level of 0.1 m/s in this experiment. Also, there was no expansion problem in the concrete substituted with aged slag as a part of aggregate.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2002.11a
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• pp.15-24
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• 2002

Polychloinated biphenyls (PCBs) 및 유기염소계 농약은 UNEP에서 지속성유기오염물질(POPs)로 규정하고 있는 화합물로서 환경내 잔류성이 강하고 먹이사슬을 딸라 생물증폭되는 화합물로 알려지고 있다. 광양만의 유기염소계화합물의 오염현황을 파악하고자, 표층퇴적물, 생물, 해수 중의 농도를 정량ㆍ정성분석하였다. 해수의 용존상을 제외한 모든 매질에서 PCBs와 DDT 화합물이 주요 유기염소계 화합물로 검출되었다. 퇴적물 중의 총 PCBs, DDTs, CHLs(클로르단 화합물), HCHs (헥사클로르사이클로헥산)의 농도는 각 각 0.61-1.97 ng/g, 0.16-1.16 ng/g, nd-0.51 ng/g, 0.05-0.79 ng/g의 농도 범위를 나타냈다. 퇴적물 중의 유기염소계화합물의 농도수준은 우리나라 주요 만 (부산만, 영일만, 울산만, 경기만)에서 조사된 퇴적물 중의 농도와 비교할 때 낮은 수준이며, 저서생물에 독성학적 위해를 일으킬 수 있는 수준에 미치지 못한다. 이매패류 중의 유기염소계화합물의 농도는 총 PCBs (4.42-19.ng/g), 총 BBTs (7.54-22.6ng/g), CHLs (0.49-2.0ng/g), HCHs (0.82-7.32ng/g)의 범위를 나타었다. PCBs의 경우 산업시설 및 도시 주변에서 상대적으로 높았으나 전반적으로 비슷한 수준을 나타냈다. 해수 중의 PCBs 농도는 제철소 인근에서 상대적으로 높았으며, 해수의 용존상에서는 입자상에서와 달리 DDTs보다 HCHs가 상대적으로 높은 농도로 검출되었다. 이는 두 상에 분배되는 이들 화합물의 성향에 따르는 것으로 파악된다.

• Water for future
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• v.23 no.4
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• pp.487-497
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• 1990

The qualitative and quantitative prediction for the dispersion of thermal discharge from nuclear / fossil power plant, steel works etc. has significant roles for the cooling system. Design and environmental management. In this study, the several important physical properties for the behavior of a thermal discharge with strong turbulent and buoyant effects are described. The comparative evaluation between MIT and PDS models is carried out, which have the different model structures. In general, MIT and PDS models are commonly used to calculate the thermal discharge behavior with considering the ambient current and the angle of jet in an unstratified water body. The simulated results by these models have great discrepancies due to the different assumptions in modling.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.2
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• pp.309-314
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• 2017

Recently, the fields such as the service robot, the autonomous driving electric car, and the torpedo ladle cars operated autonomously to enhance the efficiency of management of the steel mill are receiving great attention. But development of automatic power supply that doesn't need human intervention be a problem. In this paper, a position tracking technology of power connector receptacle based on the computer vision is studied which can recognize and identify the position of the power connector receptacle, and finally its possibility is verified using OpenCV program.

• Resources Recycling
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• v.24 no.6
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• pp.17-23
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• 2015

Flue gas desulfurization(FGD) is the technique to remove $SO_2$ gas from stack gases of coal-fired plants. Many researcher have studied to replace the desulfurizing agent because FGD systems use a lot of limestone and energy. In this study, we use the limestone sludge which is a by-product of steel industry in order to replace desulfurizing agent of FGD system by control the particle size of limestone sludge. And desulfurization performance test is implemented by investigating $SO_2$ gas removal properties upon the characteristic of the limestone sludge with various particle size.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.2
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• pp.273-279
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• 1998

철강석 또는 석탄의 적치장에서는 이들 원석을 퍼내어 용광로로 보내주는 불출기(reclaimer)가 사용되고 있다. 불출기를 자동화하려면 야적파일에 불출용 회전 버킷(bucket)을 자동착지시키는 방법이 요구된다. 본 논문에서는 야적 파일 표면위의 버킷 착지점을 추출하는 방법을 제시한다. 이 방법은 파일의 3차원 형상 검출, 파일의 등고선 추출, 불출기의 역기구학해의 도출 및 착지점 추출 알고리즘으로 이루어진다. 파일의 3차원 형상과 거리를 측정하기 위한 3차원 형상 검출기가 2차원 레이저 검출기에 수평주사(scanning)용 모터를 부착하여 개발하였고, 다 단계의 영상처리를 통해 버킷이 작업할 수 있도록 파일의 작업 등고선을 추출하였다. 불출기가 회전 버킷에 의해 기구학적으로 여유자유도로 이루어 졌음을 보였으며, 역기구학 해를 구하는 방법을 아울러 제시하였다. 그리고 버킷의 착지점을 과부하 방지와 단위 시간당 생산성을 최대화하는 성능기준에 근거하여 구하였다. 또한 개발된 시스템을 제철소 원석 야적장의 불출기에 설치 시험하여 타당성을 입증하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.6
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• pp.35-42
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• 2006

Large steel industries have nonlinear loads including electric arc furnaces. These nonlinear loads generate harmonic currents and create distortions on the sinusoidal voltage of the power system. This paper provides an in depth analysis on harmonics field measurement of the electric arc furnace loads, adding a single-tuned filter at the customer bus for reducing harmonic distortion and harmonics assessment by the international harmonic standards IEC 61000-3-6 and IEEE Std. 519. The EDSA program was used as a simulation tool for the case study.