• Korean Journal of Soil Science and Fertilizer
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• v.27 no.2
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• pp.72-77
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• 1994

This study was conducted to investigate the influence of treatment of fly ash on heavy metal contents of the arable soil. Rice was cultivated on the two types of paddy field clay loam and sandy loam with 0, 12ton/10a of anthracite fly ash and bituminous coal fly ash application. And soybean was cultivated at the same type of upland fields with those ashes of 0, 9ton/10a, yearly for three years. At the harvest time, the heavy metal contents in the different layer were investigated. The results were summarized as follows : 1. The contents of some heavy metal were increased in the surface soils but didn't show the tendency in the deeper layer or soil texture. 2. In the paddy fields, the contents of Cd, Cu, Zn, Cr were increased. Meanwhile and the upland fields, the contents of Cd and Cr were increased with the successive application of Anthracite fly ash, but the others didn't show those tendency. 3. The contents of Cd, Cu and Zn in the paddy field, were increased but the upland field, the contents of Cd, Cr and Ni were increased by the successive application of bituminous coal fly ash.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.1
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• pp.31-42
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• 1999

To investigate the effects of the composts made of sewage sludges on the physico-chemical properties of soil and growth of paddy rice, the variations of chemical properties in soil, the contents of inorganic matters and heavy metals in plant tissues, the contents of heavy metals in brown rice, the growth response of paddy rice and grain yield were investigated. The results were summarized as follows : The contents of organic matters, N, available $P_2O_5$ and exchangeable K in soil were increased by application of the composts. The contents of N and available $P_2O_5$ in soil were remarkably decreased at the harvesting time in comparing with the 20th day after application of the composts. The contents of heavy metals in soil were increased very slightly by application of the com-post. At the harvesting time, the contents of N and K were not varied in all plant tissues at the plot of the compost in comparing with the plot of the NPK. The content of $P_2O_5$ in plant was increased by application of the composts. The contents of heavy metals in plant tissues and brown rice were not changed among the treatments. When the composts were applied to the pot at the rates of 1,000, 2,000, 4,000 and 6,000kg/10a with NPK, the numbers of grain yield were increased with 3, 18, 44 and 54% in comparing with NPK plot, respectively. Dry weight, the numbers of tillers and spikelet of the rice plant were increased by application of the composts.

• Progress in Superconductivity and Cryogenics
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• v.18 no.1
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• pp.28-32
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• 2016

There are a few thousand abandoned metal mines in South Korea. The abandoned mines cause several environmental problems including releasing acid mine drainage (AMD), which contain a very high acidity and heavy metal ions such as Fe, Cu, Cd, Pb, and As. Iron oxides can be formed from the AMD by increasing the solution pH and inducing precipitation. Current study focused on the formation of iron oxide in an AMD and used the oxide for adsorption of heavy metals. The heavy metal adsorbed iron oxide was separated with a superconducting magnet. The duration of iron oxide formation affected on the type of mineral and the degree of magnetization. The removal rate of heavy metal by the adsorption process with the formed iron oxide was highly dependent on the type of iron oxide and the solution pH. A high gradient magnetic separation (HGMS) system successfully separated the iron oxide and harmful heavy metals.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.8-10
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• 2005

In a general purpose inverter, a dead-time compensation strategy is very important for reducing torque ripples and acoustic noises of motors. However, in the case of small capacity inverter, the accurate dead-time compensation is hard to be obtained because a removal of the switching noise in a feedback current signal is difficult on condition of low-cost implementation. In this paper, the operation characteristics of the general purpose inverter applied the dead time compensation algorithm using an instantaneous back calculation of the phase angle of the current are presented.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.117-121
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• 2002

This study was conducted to find out the effect of municipal sewage sludge on the growth and heavy metal content of rose and soil chemical properties. Municipal sewage sludge was applied to soil at rate of 0, 3, 5, 10 and 15 ton/10a, the plant height, flower number and stem size of rose were found to be increase in the treatments of sewage sludge. Contents of mineral nutrients in rose stem were determined to be higher at municipal sewage sludge application plots than those of no application. But, there were not any significant increases of heavy metal contents in soil and rose stem with the sludge applications. from the results of this study, it is apparent that the application of municipal sewage sludge would not increase available heavy metals in soil.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.103-104
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• 2006

Since the first proposition of IEC61850 object model at 1993, many questions about making a seamless model have been issued. the reason which they have worry about is that the functions of the equipment are supposed to be changed properly and new equipment and scheme are need to be introduced according to user's application. To handle those issues, TC57 which is a IEC committee for power control and communication has continuously updated the object model. Nowadays along with the new object model involving power quality, distribution resource and wind power, the committee has a plan to announce the revision of IEC61850-7-4. In the study, authors will present the prediction and diagnosis object models for transformer. Transformer models for protection and control have already been dealt with in the international standard but the models for prediction and diagnosis have never mentioned until now. Designing the prediction and diagnosis functions with the existing IEC61850-7-4, it'll be shown what is a proper object model for prediction and diagnosis.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1374-1375
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• 2008

본 논문은 3상 일괄형 GIS의 부분방전 진단을 위해 새롭게 개발한 진단 알고리즘에 관한 것이다. 진단 알고리즘 개발을 위해, 먼저 실시간 부분방전 데이터를 행벡터 및 열벡터로 구성하고 각각의 벡터에서 통계 특징량 및 질감 특징량을 추출하였다. 다음으로 이들 특징량을 GA-NN(Genetic Algorithm - Neural Network) 학습에 적용하여 진단 알고리즘을 구성하였다. 또한 진단 알고리즘의 위상독립성은 부분방전 신호의 위상변화에 관계없이 진단결과가 일치하는 것을 확인함으로써 검증하였다. 개발한 진단알고리즘의 실증 평가를 위해, 부분방전이 발생되고 있는 국내 3상 일괄형 GIS 변전소에 적용하였다. 적용 결과, 위상에 관계없이 부분방전 발생원을 정확히 진단함을 확인하였고, 이를 통해 개발 알고리즘의 우수성을 입증하였다.

• Journal of radiological science and technology
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• v.42 no.6
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• pp.413-422
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• 2019

Heavy ion particle, represented carbon ion, radiotherapy is currently most advanced radiation therapy technique. Conventional radiation therapy has made remarkable changes over a relatively short period of time and leading various developments such as intensity modulated radiation therapy, 4D radiation therapy, image guided radiation therapy, and high precisional therapy. However, the biological and physical superiority of particle radiation, represented by Bragg peak, can give the maximum dose to tumor and minimal dose to surrounding normal tissues in the treatment of cancers in various areas surrounded by radiation-sensitive normal tissues. However, despite these advantages, there are some limitations and factors to consider. First, there is not enough evidence, such as large-scale randomized, prospective phase III trials, for the clinical application. Secondly, additional studies are needed to establish a very limited number of treatment facilities, uncertainty about the demand for heavy particle treatment, parallel with convetional radiotherapy or indications. In addition, Bragg peak of the heavy particles can greatly reduce the dose to the normal tissues front and behind the tumor compared to the photon or protons. High precision and accuracy are needed for treatment planning and treatment, especially for lungs or livers with large respiratory movements. Currently, the introduction of the heavy particle therapy device is in progress, and therefore, it is expected that more research will be active.

• Journal of the Korean Society of Combustion
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• v.14 no.4
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• pp.25-32
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• 2009

In commercial combustion systems, heavy oil is one of main hydrocarbon fuel because of its economical efficiency. Regarding heavy oil combustion, due to increasing concerns over environmental pollutants such as carbon monoxide, unburned hydrocarbon and nitrogen oxides, development of low pollutant emission methods has become an imminent issue for practical application to numerous combustion devices. Also a great amount of effort has been tried to developed effective methods for practical using of biomass. It is also an important issue to reduce carbon tax. In this paper, an experimental study has been conducted to evaluate the effect of biomass reburning on NOx formation in a heavy oil flamed combustion furnace. Experiments were performed in flames stabilized by a multi-staged burner, which was mounted at the front of the furnace. Experimental tests were conducted using air-carried rice husk powder and LNG as the reburn fuel and heavy oil as the main fuel. The paper reports data on flue gas emissions and temperature distribution in the furnace for several kinds of experimental conditions. NOx concentration in the exhaust has decreased considerably due to effect of reburning. The maximum NOx reduction rate was 62% when the rice husk was used by reburn fuel, however it was 59% when the LNG was used by reburn fuel. The result shows the positive possibility of biomass reburning system for optimal NOx reduction.

• Journal of Ship and Ocean Technology
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• v.6 no.4
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• pp.13-18
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• 2002

Active control has been partly applied to suppress the re-reflecting waves in wave basin with plunger-type wave maker to obtain desirable waves. This limitation comes from the non-confirmable theoretical background to the control algorithm. This paper proposes control logic to overcome this drawback, based on the impulse response function for propagating waves between control input and the wave height. The performances have been verified as reasonable in practical application by comparing with the propagating wave components in numerical wave basin, using wave decomposition method. Moreover, the control logic can also give useful wave-absorbing performance after cessation of wave generation.