• 한국안전학회지
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• 제33권6호
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• pp.144-156
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• 2018

Level 3 Probabilistic Safety Assessment (PSA) is performed for the risk assessment that calculates radioactive material dispersion to the environment. This risk assessment is performed with a tool of MELCOR Accident Consequence Code System (MACCS2 or WinMACCS). For the off-site consequence analysis of multi-unit nuclear power plant (NPP) accident, the single location (Center Of Mass, COM) method has been usually adopted with the assumption that all the NPPs in the nuclear site are located at the same COM point. It was well known that this COM calculation can lead to underestimated or overestimated radionuclide concentration. In order to overcome this underestimation or overestimation of radionuclide concentrations in the COM method, Multiple Location (ML) method was developed in this study. The radionuclide concentrations for the individual NPPs are separately calculated, and they are summed at every location in the nuclear site by the post-processing of radionuclide concentrations that is based on two-dimensional Gaussian Plume equations. In order to demonstrate the efficiency of the ML method, radionuclide concentrations were calculated for the six-unit NPP site, radionuclide concentrations of the ML method were compared with those by COM method. This comparison was performed for conditions of constant weather, yearly weather in Korea, and four seasons, and the results were discussed. This new ML method (1) improves accuracy of radionuclide concentrations when multi-unit NPP accident occurs, (2) calculates realistic atmospheric dispersion of radionuclides under various weather conditions, and finally (3) supports off-site emergency plan optimization. It is recommended that this new method be applied to the risk assessment of multi-unit NPP accident. This new method drastically improves the accuracy of radionuclide concentrations at the locations adjacent to or very close to NPPs. This ML method has a great strength over the COM method when people live near nuclear site, since it provides accurate radionuclide concentrations or radiation doses.

• 한국건축시공학회지
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• 제2권4호
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• pp.137-144
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• 2002

In the modern age. Building is getting higher and larger according to owner and social demands. Now when we are facing the need of the cost down and the reduction of economic loss. In this paper, the characteristics of the present conditions of site management were investigated with the field survey. And The Purpose of this study is to suggest the rational plans of construction planning in site management. The method of site management. however depends on experience of a construction manager. in order to solve this situation, it is necessary to create a method of site management that is adequate for the condition of construction. By cultivating excellent sub contractors, we can expect precise construction with a few experts. improvement in qualify of construction from standardization, computerization of each process. And the expectancies of this paper are that it can be used as efficient data for improvement of system to systematize site management work in Korea.

• Nuclear Engineering and Technology
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• 제14권1호
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• pp.17-21
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• 1982

본 논문에서는 원자력발전소 부지의 안전성 평가 방법으로서 부지의 인구를 평가하는 USNRC의 SPF를 보다 발전시켜 정상 가동시나 사고시 방출되는 방사성 물질이 대기에로의 확산으로 인하여 주거 인구가 받는 영향을 고려하여 SPMF를 정의하고 고리 부지에 대한 SPF와 SPMF를 비교함으로써 SPMF모델의 타당성을 검토했다. 아울러 미국 주요 발전소와 국내 발전소 부지의 SPF를 비교하여 국내발전소 부지의 상대적 안전성을 평가했다.

• Environmental Engineering Research
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• 제19권3호
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• pp.269-274
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• 2014

On-site sanitation systems are typically installed to treat grey and toilet wastewaters in areas without sewer and centralized treatment systems. It is well known that, due to inappropriate design and operation, treatment performance of these systems in developing countries is not satisfactory in the removal of pathogens and organic matters. This research aimed to investigate the hydraulic conditions occurring in some on-site sanitation systems and the effects of hydraulic retention times (HRTs) on the system performance. The experiments were conducted with a laboratory-scale septic tank (40L in size) and an actual septic tank (600L in size), to test the hydraulic conditions by using tracer study with HRTs varying at 12, 24 and 48 hr. The experimental results showed the dispersion numbers to be in the range of 0.017-0.320 and the short-circuit ratios in the range of 0.014-0.031, indicating the reactors having a high level of sort-circuiting and approaching complete-mix conditions. The removal efficiency of $BOD_5$ was found to be 67% and the $k_{30}$ values for $BOD_5$ was $2.04day^{-1}$. A modified complete-mix model based on the relationship between $BOD_5$ removal efficiencies and HRTs was developed and validated with actual-scale septic tank data having a correlation coefficient ($R^2$) of 0.90. Therefore, to better protect our environment and minimizing health risks, new generation toilets should be developed that could minimize short-circuiting and improving treatment performance.

• The Korean Journal of Ecology
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• 제21권3호
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• pp.187-193
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• 1998

Seasonal changes of nitrogen fixation and growth characteristics of Melilotus suaveolens population under different light conditions were quantitatively analyzed during growting period. Height growth of M. suaveolens population was promoted after April and the shade (site 2) showed 10-20% increase of height growth in compared with that of sunny (site 1). Seasonal changes of biomass were in creased after March, the biomass at site 1 attained 78.5% that of site 2 in May. Chlorophyll content was maintained high value from March to April but, Chlorophyll content of leaf at site 1 was decreased 11.7% compared to that of site 2 in May. The nitrogen content of each organ of M. suaveolens showed higher value in March and then decreased, the high nitrogen contents of reproductive organ were achieved at the flowering stage at site 1. The root nodule of M. suaveolens population appeared in March and showed maximum value in early June and decreased remarkably after July, the amount of nodule formation of M. suaveolens at site 2 showed higher than that of site 1. The nitrogen fixation activity of root nodule of M. suaveolens initiated with shoot growth and showed maximum value in mid April, and attained second peak in early June and then decreased after July. The total nitrogen fixation of the plant showed higher value at site 2 than that of site 1. From the overall results, M. suaveolens showed increased growth under half-shady, well ventilated barren soil than fertile sunny site.

• 한국농림기상학회지
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• 제5권4호
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• pp.247-254
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• 2003

본 연구는 수치 산림입지도에서 추출한 28개 입지환경 인자를 사용하여 경기ㆍ충청지역의 몇 가지 주요 수종에 대한 지위지수 추정식을 개발하였다. 수종별로 4∼5개의 변수에 의하여 개발된 수종별 최적 지위지수 추정식은 결정계수가 0.91 이상으로 높은 설명력을 보였다. 이상과 같이 개발된 수종별 지위지수 추정식에 대하여 연구 대상지에서 수집한 수종별 독립자료에 근거하여 모형의 평균 편의, 정도, 표준오차 등의 3가지 평가통계량을 계산한 후 그 실용성을 검증하였다. 수종별 지위지수 추정식으로부터 얻어진 추정치와 실제 지위지수의 평균편의는 낙엽송의 경우 1.82 m로 상대적으로 큰 차이를 보였으나, 전반적으로 본 연구에서 개발된 수종별 지위지수 추정식의 평가통계량은 낮은 것으로 판명되어 실제 사용하는데 문제가 없는 것으로 평가되었다. 결과적으로 본 연구에서 개발한 경기ㆍ충청지역의 지위지수 추정식은 사용된 변수가 적음에도 불구하고 결정계수는 상당히 높았으며, 조사된 실측치와 비교하여 검증한 결과 그 정도(精度)가 비교적 높았다. 따라서 몇 가지의 환경인자 만으로도 지역별 특성을 고려한 수종별 지위지수를 추정할 수 있어 활용가치가 높은 것으로 판단된다. 특히 이러한 정보는 앞으로 입지조건에 따른 적지적수 선정에 활용될 수 있을 것으로 기대된다. 하지만 앞으로 입지조건에 따른 적지적수 문제를 해결하기 위해서는 본 연구에서 사용된 수종 외에 다른 주요 수종에 대한 지위지수 추정식을 개발하는 작업도 필요할 것으로 판단된다.

• 한국농촌건축학회논문집
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• 제2권2호
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• pp.89-100
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• 2000

Current techniques of residential planning are based upon planning theories and experiences which have evolved over time. These techniques are prerequisite conditions in establishing a firm foundation upon which residential sites can be developed. Residential planning techniques, which have been introduced to Korea from such areas as Western Europe, North America and Japan, have been changing as a result of attempt to properly acculturate these foreign influences into a traditional, yet rapidly progressing Korean society. It has been this objective of Korean planners, of considering domestic conditions while incorporating planning experiences of other countries, that has spearheaded Korea's phenomenal development in recent times. In this study, the changes and perspectives of residential planning concepts are examined from a historically comparative point of view. This approach allows for a macroscopic perspective on the various theories of residential planning which are constantly changing.

• 천문학논총
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• 제11권1호
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• pp.197-220
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• 1996

The climatological characteristics at the Choejung-san site were statistically analyzed using monthly normals for the various meteorological elements at Taegu meteorological station for 30 years from January 1960 to December 1990. Various synoptic weather conditions were classified by the estimated geostrophic wind speeds and direction determined using the 850 hPa geopotential height field for 10 years from December 1980 to November 1989. Also the analysis of number of clear days were monthly and seasonally performed using the satellite infrared image data which were obtained from GMS 5 for 5 years from December 1990 to November 1995. The results reveal that the meteorological environments of astronomical observation at Choejung-san site were very good conditions during three hours after midnight except for summer season.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.86-87
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• 2021

As non-road mobile pollutants such as construction equipment are emerging as the main cause of air pollutants emission, construction equipment regulations are gradually strengthening. Research was conducted by correcting the emission coefficient to calculate and predict air pollutant emissions of construction equipment, but it did not reflect site variables such as field and equipment conditions that affect actual emissions. This study derived an Artificial Neural Network emission prediction model based on the actual emission data of excavators and trucks measured at the site and proposed a platform to predict the emission of air pollutants at the site according to the working size and conditions. Through this, it is possible to establish an eco-friendly process plan using a model from the construction plan.

• 지식경영연구
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• 제10권2호
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• pp.49-63
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• 2009

In this study, sub domain of flow was investigated on literature survey, and suggested of the measuring method of web-site flow and its simulation analysis. Constructing of measuring method of flow, and using this method what-if analysis was simulated when several condition changed. Using causal map approach to extract knowledge from web-site domain experts and to derives a causal relationship of knowledge. Specially, in our study, describes method of developing and building causal map, and suggests guide line of this method on practical application. This research results show that web-site flow starts "direct searching" or "interesting of special issue(domain)", and when challenges of web-site were accorded with user's skills web-site flow grows. Further, in the web-site, information searching intention results in increase of user's duration time and experience flow to discovery new interesting issues in this process. If user's web-site of interaction is increased, awareness of environment conditions decreased, finally, user's telepresense results in increased web-site flow. This paper contained thai this method make used of measuring flow in the web-site and developing of practical strategy.