• 한국수자원학회논문집
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• 제41권8호
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• pp.825-834
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• 2008

선진국에서의 강변여과수 개발은 150년 정도의 역사를 가지고 있다. 한국에서도 지속적으로 증가하고 있는 용수수요에 안정적으로 대처하기 위한 원수 확보방안으로 강변여과수에 대한 조사가 1990년대부터 4대강 유역을 중심으로 시작되었으며, 현재 낙동강을 중심으로 강변여과를 활용한 상수도 공급이 이루어지고 있다. 본 논문은 서울의 원수수질 안정을 위한 방안으로 강변여과 도입의 타당성에 대한 연구이다. 개발 적지의 선정을 위해 여러 가지 속성들을 계층적으로 분류하고 각 속성의 중요도를 파악함으로써 최적 대안을 선정하는 계층분석과정기법(AHP)을 적용하였다. 한강 유역의 경우 개발후보지역을 대상으로 적지분석을 실시한 결과, 수질 및 기존시설연계성 등에서 유리한 광나루지구가 최적지로 선정되었다.

• 한국해양공학회지
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• 제34권5호
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• pp.351-360
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• 2020

Of late, demand for test sites for marine equipment such as ASV, AUV, ROV, and various underwater sensors is increasing. The authors have focused on an oscillating water column (OWC), which is being constructed near Chagwido Island Jeju, as one of the test-sites. The main objective of the OWC is to produce wave energy and develop technologies. It has been built in the sea approximately 1 km off the coast. It has berth accommodation and some rooms that can be used as laboratories. To investigate the feasibility of its usage as a test site for marine equipment, we acquired bathymetric data around the OWC by using a multi-beam echo sounder and a single-beam scanning sonar. The accessibility of the OWC from nearby ports and the use of support vessels or ships were also investigated. 3D point cloud data from the multi-beam echo sounder and 2D acoustic images from the scanning sonar are expected to be used as references for identifying changes over time. In addition, through these experiments, we derived a procedure to use this facility as a test site by using the IDEF0 functional modelling method. Based on this preliminary investigation and previously reported examples, we determined the general conditions and preferences for evaluating the performance of various marine equipment heuristically. Finally, we developed five applications that were derived from this investigation.

• Nuclear Engineering and Technology
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• 제56권6호
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• pp.2274-2281
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• 2024

RESRAD-ONSITE v7.2 code is used to assess the radiation effects on a farmer resident located in a hypothetical contaminated site planned for the first nuclear power plant project in Vietnam, namely Ninh Thuan 1, after decommissioning. Derived concentration guideline levels are preliminarily calculated for 17 radionuclides that are assumed to remain on a contaminated surface soil with an initial concentration of 1 pCi/g in the protected area of NPP site. For a reliable estimation, the site-specific conditions regarding the geological, hydrological, climate, and occupancy data gathered from the Feasibility Study Report (FSR) and relevant literatures for the Ninh Thuan 1 NPP site is employed as input parameters. The calculation results indicate that the peak of total exposure dose is estimated to be ca. 0.191 mSv/yr at the time of decommissioning, and then decrease over time. Furthermore, the protected site is assessed to be released at ca. 6.71 years after decommissioning under the regulation on radiation protection in Vietnam. Through this study, a radiation exposure model for residents living near the Ninh Thuan 1 NPP is preliminarily established by using the RESRAD-ONSITE code, which are expected to be useful for future implementation of the Ninh Thuan 1 NPP project in Vietnam.

• 한국환경복원기술학회지
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• 제18권6호
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• pp.227-237
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• 2015

From January 2013 to October 2015, weed invasion control techniques was tested in the test road of Jungbunaeryuk expressway so as to collect preliminary data for the management methods of the upper exterior banking of expressway shoulders. Then, monitoring was conducted and its results are as follows. Mat (sheet), solidifying agent, and mulching (wood chips) were applied for the test and their initial effects of preventing weed invasion were all excellent. It was found that the homogeneity of the wood chip mulching method needs to improve. In the mat method and the mulching method were found to have the most excellent economic feasibility and aesthetics, respectively. The covering degree was found to be the highest at 80% in the control site, followed by the wood chip site at 20% and the solidifying agent site and the non-woven fabric site at 5% each. As for species diversity, the control had the largest variety of species. Two years after the construction, many different species of plants invaded and were growing. Plants including weed didn't tend to invade the slopes applied with non-woven fabric. In addition, weed didn't invade the solidifying agent site and the aesthetics of the upper exterior banking of expressway shoulders was found to be excellent. The wood chip site was found to require consistent management for preventing weed invasion. The mat (sheet) site, the solidifying agent site, and the wood chip mulching site were found to have excellent weed prevention effects. As time passed, the mat (sheet) site and the solidifying agent site showed better weed prevention effects. However, they need consistent monitoring for further application.

• 한국습지학회지
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• 제15권2호
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• pp.265-269
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• 2013

본 연구는 아질산성 질소의 간이분석을 위한 기초 연구로 수행되었다. 수중 질소는 부영양화를 유발하는 암모니아, 아질산 및 질산으로 주로 구성되어 있다. 질소화합물을 제거하기 위한 많은 연구들이 진행되었고, 이에 따른 분석기술도 발달했다. 현장 모니터링을 위한 간이 분석방법의 개발은 수질관리를 위해 필요하므로, 본 연구는 아질산성 질소의 현장 분석법 개발을 위해 진행되었다. BCDMA와 바이페닐로 코팅된 PVC 흡착 칼럼을 이용한 아질산성 질소 분석의 기초 연구를 수행하였다. 흡착칼럼내의 흡착제는 4~20 $mgNO_2-N/L$ 범위내에서 발색길이를 나타내었고, 흡광도는 pH의 영향을 받는 것으로 나타났다.

• 한국측량학회지
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• 제13권2호
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• pp.219-228
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• 1995

1960년대 이후 건설된 발전시설들이 오늘날에 이르러 노후화 되었고, 급속히 늘어나는 전력 소비량을 충당하기 위해 각종 발전시설들이 확충되고 있다. 따라서 이들 시설물에 대한 안전성확보차원의 조치가 이루어져야 한다. 본 연구에서는 전력구조물의 유지관리방안마련에 대한 일환으로 RC시험보를 제작 구성하여 외력작용시 RC시험 보의 변형 상태에 대한 모니터링과 변형량 산출을 위해 근거리사진측량방법에 대한 방법을 모색하였고, 이를 토대로 토류벽공사현장에 대한 변형량산출 및 모니터링을 통한 변형상태 파악 및 지하굴착으로 인한 인접구조물에 미치는 영향을 측정·해석 하므로서 전력구조물에 대한 유지관리에 활용할 수 있는 자료를 제공하였다.

• Nuclear Engineering and Technology
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• 제16권4호
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• pp.217-223
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• 1984

본 연구에서는 냉각수 상실사고(LOCA)시 격납용기내의 수소농도를 제어하기 위해 수소재결합기 없이 수소 퍼지계통만을 사용할 때의 타당성을 분석하였다. 이 타당성 연구를 위해 격납응기내의 수소농도, 수소퍼지 계통의 수소제거, 그리고 퍼지로 인한 추가소외 선량이 계산되었다 또한 비용-편익 개념을 사용하여 수소 재결합기 계통(2대의 재결합기 설치)의 경제성을 분석하였다. 분석결과, 수소퍼지 계통은 수소 재결합기 없이도 수소농도를 제어하기에 충분하며, 10 CFR 100에 있는 선량 제한치를 만족시키고 있었다. 비용-편익 개념에 의하면 수소 재결합기 계통은 동일부지내에 있는 4∼6기의 발전소에 공용될 때 경제성이 있는 것으로 입증되었다.

• 건축역사연구
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• 제15권2호
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• pp.77-94
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• 2006

"Mixed construction of platform" means the platform which was constructed by mixing heterogeneous materials such as roof tiles or bricks with divided stone of trimmed stone. This kind of construction technique was not known or found from the building sites of Goguryo or Silla so far and therefore it used to be understood as a unique platform construction technique or the product of technology and creativeness of Baikje's craftsman. The mixed construction of platform of Baikje came to position itself as one of the patterns of platform mainly used over Sabi period and we found the pattern from the sites including Imryugak site in Gongju, temple for royal tomb in Gwanbuk-ri, Wangheungsa Temple site, building site in Keumseong Mountain, Ohapsa Temple site in Byryeong. From the fact that they used a variety of materials which they could easily get around them such as roof tiles or bricks in addition to stones for the construction of platforms, we can see the feasibility and decoration characteristics of their material supply at that time. On the other hand, this mixed construction of platform was not popular in Goguryo and Silla, the major reason for which is judged to be non-existence of platforms to construct using bricks or roof tiles which could be constructed together with platform using divided stones. This is supported by the results of excavation of Hwangryongsa Temple site, Bunhwangsa Temple site, Heungryunsa Temple site of Silla which gave us comparatively abundant excavation data, and Jeongreungsa Temple site, Cheongamsa Temple site, Toseongrisa Temple site and building site in Daeseong Mountain castle and Anhak Palace site of Goguryo. For further progressive study on the mixed construction of platform of Baikje in the future, we will have to review more on the social background and technical background with the linkage with archeology and architecture at that time which led to the creation of such platform.

• 한국도로학회논문집
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• 제15권2호
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• pp.57-63
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• 2013

PURPOSES : This study was performed to investigate a feasibility of job-site use of recycled concrete aggregate exceeding 3% of absorption rate. Test variables are coarse aggregate types such as natural aggregate, job-site processed recycled aggregate, and recycled aggregate processed from the intermediate waste treatment company. METHODS : First, aggregate properties such as gradation, specific gravity and absorption rate were determined. Next a basic series of mechanical properties of concrete was tested. RESULTS : All strength test results such as compression, flexure and modulus were satisfied for the minimum requirements. Finally up to first 48 elapsed days the shrinkage strains of concretes made from both recycled aggregates (in case of volume-surface ratio of 300) appeared to be greater than 26% of the companion concretes made from natural aggregates. CONCLUSIONS : Drying shrinkage result is ascribed to greater absorption rate and specific gravity of those specimens made from recycled aggregate. This may be reduced with an addition of admixtures.

• Structural Engineering and Mechanics
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• 제45권1호
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• pp.1-18
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• 2013

The typhoon wind characteristics designing for buildings or bridges located in complex terrain and typhoon prone region normally cannot be achieved by the very often few field measurement data, or by physical simulation in wind tunnel. This study proposes a numerical simulation procedure for predicting directional typhoon design wind speeds and profiles for sites over complex terrain by integrating typhoon wind field model, Monte Carlo simulation technique, CFD simulation and artificial neural networks (ANN). The site of Stonecutters Bridge in Hong Kong is chosen as a case study to examine the feasibility of the proposed numerical simulation procedure. Directional typhoon wind fields on the upstream of complex terrain are first generated by using typhoon wind field model together with Monte Carlo simulation method. Then, ANN for predicting directional typhoon wind field at the site are trained using representative directional typhoon wind fields for upstream and these at the site obtained from CFD simulation. Finally, based on the trained ANN model, thousands of directional typhoon wind fields for the site can be generated, and the directional design wind speeds by using extreme wind speed analysis and the directional averaged mean wind profiles can be produced for the site. The case study demonstrated that the proposed procedure is feasible and applicable, and that the effects of complex terrain on design typhoon wind speeds and wind profiles are significant.