• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.894-898
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• 2006

A model, which can analyze the hydrological performance for small hydropower(SHP) plants having no flow duration characteristics has been studied and developed. System performance of existing SHP plant under operating was analyzed by using the developed model. The annual operational rate of SHP plant showed that the data were in good agreement with predicted results from the model. Based on these results, several SHP sites to be exploited were selected and the performance characteristics were analyzed by using the developed model. Also, primary design values such as design flow rate, plant capacity, and operational rate were suggested. As a result, it was found that the methodology used in this study is useful tool to predict the hydrological system performances of SHP sites.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2004년도 학술발표회
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• pp.1321-1325
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• 2004

The continuous monitoring of the runoff in the small-scaled urban watershed and easily accessible experiment catchment is necessary to investigate the overall status of the development in the urban catchment and the varying aspects of the discharge characteristics due to the urbanization. However, the research on the management and the characteristics of the small-scaled model basin for discharge tests has not been actively performed up to now. This study selects the Dong-Eui university basin, which locates at Gaya-dong in Busan, as the experiment catchment to monitor the discharge rate in the urban watershed. EMS(DEMS, DATA-PCS EMS, mini rain gage & AWS(AWS-DEU, DATA-PCS AWS) monitoring system installed for the collection of hydrological data such as the rainfall and the waterlevel. This experiment catchment is the typical urban catchment and is under development, and it is possible to analyze the varying aspects of the discharge rate during and after the development.

• Nuclear Engineering and Technology
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• 제48권1호
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• pp.268-273
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• 2016

An innovative safety concept for a light water reactor has been developed at the Korea Atomic Energy Research Institute. It is a unique concept that adopts both a fast heat transfer mechanism for a small containment and a changing mechanism of the cooling geometry to take advantage of the potential, thermal, and dynamic energies of the cold water in the containment. It can bring about rapid cooling of the containment and long-term cooling of the decay heat. By virtue of this innovative concept, nuclear fuel damage events can be prevented. The ultimate heat transfer mechanism contributes to minimization of the heat exchanger size and containment volume. A small containment can ensure the underground construction, which can use river or seawater as an ultimate heat sink. The changing mechanism of the cooling geometry simplifies several safety systems and unifies diverse functions. Simplicity of the present safety system does not require any operator actions during events or accidents. Therefore, the unique safety concept of PX can realize both economic competitiveness and inherent safety.

• Nuclear Engineering and Technology
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• 제50권8호
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• pp.1412-1420
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• 2018

An experiment was performed using the large-scale test facility (LSTF), which simulated a 1% vessel upper head small-break loss-of-coolant accident with an accident management (AM) measure under an assumption of total-failure of high-pressure injection (HPI) system in a pressurized water reactor (PWR). In the LSTF test, liquid level in the upper head affected break flow rate. Coolant was manually injected from the HPI system into cold legs as the AM measure when the maximum core exit temperature reached 623 K. The cladding surface temperature largely increased due to late and slow response of the core exit thermocouples. The AM measure was confirmed to be effective for the core cooling. The RELAP5/MOD3.3 code indicated insufficient prediction of primary coolant distribution. The author conducted uncertainty analysis for the LSTF test employing created phenomena identification and ranking table for each component. The author clarified that peak cladding temperature was largely dependent on the combination of multiple uncertain parameters within the defined uncertain ranges.

• 한국물환경학회지
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• 제22권6호
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• pp.982-990
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• 2006

Generally CSOs (Combined Sewer Overflows) are regarded as one of the most serious nonpoint pollution source in the urban watershed, Particularly, the water quality of the Oncheon stream is seriously affected by CSOs because the capacity of interception sewer system connected to the Suyoung wastewater treatment plant is too small to intercept most storm water discharges. The objective of this study is to evaluate the effect of nonpoint source on an urban stream with regards to combined sewer system and separate sewer system using GIS (Geographic Information System) and SWMM (Storm Water Management Model), and to provide an insight for the management of urban stream water quality. In order to consider the effect of CSOs on the receiving water quality, the flow divider element in SWMM was applied. The model calibration and verification were performed by the measured data of quantity and quality on the Oncheon stream. The quantity data acquired from the Suyoung wastewater treatment plant were also used for this procedure. In case of separate sewer system, the modeling results showed the increased tendency in streamflow compared with the combined system in dry weather, In addition, the water quality is remarkably improved in rainfall events at the separate condition. The results imply that the construction of separate sewer system should be taken into first consideration to restore the quality and quantity of water in urban streams.

• 한국수자원학회논문집
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• 제37권7호
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• pp.517-526
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• 2004

농업용수는 국가의 수자원 관리에서 매우 중요한 부분이다. 관개회귀수는 농지에 관개한 수량 중에서 다시 하천으로 회귀되는 양이며 관개회귀수량을 정확하게 추정하는 것은 수자원 개발 계획과 관리에 있어서 매우 중요하다. 본 연구는 낙동강유역 내의 소규모 논지대에 조사지구를 선정하여 2003년도 영농기간 동안 농업용수 공급량과 배수량을 조사 분석하여 회귀율을 산출하고, 이를 향후 수자원계획의 기초자료로 활용하기 위하여 수행하였다. 조사대상 지구인 경북 청도 녹명지구의 관개기간 중 신속회귀율은 30.2%, 지연 회귀율은 23.5%로 전체 회귀율은 53.7%로 나타났다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.330-335
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• 2001

Characteristics of the present world market include demanding and sophisticated customers, requirement of high quality and innovative products, greater product diversity, increasing labour and products costs, availability of diverse alternatives to the customers and smaller batch sizes to satisfy a variety of customer profiles. To fulfil these characteristics, manufacturing companies need to be flexible adaptable, proactive and able to produce variety of products in short time at low cost. The aim of the study is to develop a computer-aided design system for water-gate on AutoCAD R2000 system. The developed system has been written in AutoCAD and VisualLISP with a personal computer, and is composed four modules which are the gate-lifter input module, guide-frame input module, and upgrade module. Based on knowledge-based rules, the system is designed by considering several factors, such as width and height of a water-gate, material, object of product and maximum depth of water.

• 설비공학논문집
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• 제20권9호
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• pp.631-636
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• 2008

Solar thermal systems are recently refocused by higher oil prices, but did not completely restore the people's confidence owing to the past bad systems. Several types of solar water heating systems were analyzed in characteristics and some proper systems were proposed under Korean climates and system scale. As a small system, natural circulation system should be installed only in a southern region of Korea, with a freeze protection valve instead of heating coil for freeze protection. In most area of Korea, the forced circulation type with a heat exchange coil inside a thermal storage tank or with a spiral-jacketed storage tank, proposed and verified by the authors, has a merit of stable performance and freeze protection.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.105-110
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• 2006

Several types of solar water heating system were analyzed in characteristics and proper systems were proposed under Korean climates. In particular, the forced circulation type with a spiral-jacketed storage tank has a potential to be used widely in a small and a part of middle systems when the stratification of the storage tank can be enhanced by a precise design.

• 한국식품위생안전성학회지
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• 제8권4호
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• pp.225-230
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• 1993

This study was conducted to examine the stages showing the antimutagenic effects on the microbial mutation by addition of the juice extracted from small water dropwort. It was not able to find out the signal showing the genic derepression or change of gene repair system by addition of the juice. And it was hardly possible to expect the conversion of 2-AF to inactive form by the juice. however the longer 2-AF and S-9 mix were contacted before addition of the juice, the stronger the microbial mutagenisity of 2-AF was, and after addition of the juice, the mutagenicity was decreased rapidly. It seems that some components in the juice act as inhibitor of a enzyme in S-9 mix, and block the conversion of 2-AF to the ultimate mutagen.