• Advances in pediatric surgery
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• 제6권1호
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• pp.19-26
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• 2000

This paper reports our 9-year experience treating 34 infants with biliary atresia utilizing a new non-invasive diagnostic method, ultrasonographic "triangular cord"(TC) sign. The TC sign is present when there is visualization of a triangular or a band-like echogenicity just cranial to the portal vein. The ultrasonographic TC sign appears to be a simple, non-invasive, time-saving and useful tool in the diagnosis of biliary atresia. Sensitivity is 84 %. Active bile excretion was restored in 90 % of the patients who were treated between 31-60days, 78 % of those between 61-90 days, and 33 % of those being 91days or older. The incidence of postoperative cholangitis was 36 %. Construction of an antireflux valve in the Roux-en-Y loop did not affect the incidence of postoperative cholangitis(p=0.18). Among 34 infants with biliary atresia, 23(68 %) are alive for 2-102 months after operation, and 12 are alive for more than 5 years. Five-year estimate survival by Kaplan-Meier method was 66 %.

• KIEAE Journal
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• 제10권1호
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• pp.19-24
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• 2010

Modern people are spending most of time in interior area. Indoor air environmental problem is one of the most effective factors influenceable to human health. Furthermore, saving energy and making ventilation system for pleasant indoor environment are necessary when it is faced shortage of energy over the world. In our country's case, it is already imposed that required quantity of air ventilation in buildings is 0.7 times per hour on "The regulation on building engineering system". As on the rise of the interests about Indoor air environment, Heat and Carbon dioxide emissions from User's metabolism, activity, furniture, and construction materials etc. could be the causes of Indoor air pollution. If these materials stays in Indoor air for so long, it could directly influence the user's health condition with a disease. As of building's sterilization improved that raised more mechanical ventilation. It also leads much energy waste in a period of high price of fossil fuel. Therefore, the way that saves energy and effective control of indoor ventilation is urgently needed. So, this study places the purpose on validating volume of indoor ventilation and user's comfortable degree by comparison CO2 emission rate through changing floor temperature.

• Structural Engineering and Mechanics
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• 제73권5호
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• pp.543-554
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• 2020

This paper aims to investigate the seismic performance of RC short columns and long columns with welding stirrups. Through the low-cyclic horizontal loading test of specimens, the seismic performance indexes such as failure modes, hysteretic curve, skeleton curve, ductility, energy dissipation capacity, stiffness degradation and strength degradation were emphatically analyzed. Furthermore, the effects of shear span ratio, stirrups ratio and axial compression ratio on the performance of specimens were studied. The results showed that the seismic performance of the RC short columns with welding stirrups were basically the same as that of the RC short columns with traditional stirrups, but the seismic performance of RC long columns with welding stirrups was better than that of RC long columns with traditional stirrups. The seismic performance of RC short columns and long columns with welding stirrups could be improved by increasing stirrup ratio and shear span ratio and reducing axial pressure ratio. Moreover, the welding stirrup have the advantages of steel saving, industrialization and standardization production, convenient construction, and reducing time, which indicated that the welding stirrups could be applied in practical engineering.

• 한국태양에너지학회 논문집
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• 제39권2호
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• pp.45-55
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• 2019

More than 76% of the detached houses in Korea are over 20 years old. These old detached houses have poor energy efficiency. According to the 2017 Housing Census (Statistics Korea), more than 50% of low-income families live in detached houses. Therefore, the improvement of energy efficiency in old detached houses is needed from the viewpoint of energy welfare. The general method of building energy modelling for the verification of energy efficiency is based on the construction year data of "Building Design Criteria for Energy Saving" due to the cost and time involved in collecting the thermal performance data of buildings. There is poor accuracy with the deterioration of long-term aging of building materials. Also, the selection of alternatives for energy performance improvement is based on the items to be applied, not a performance improvement goal. It is difficult to calculate energy performance that reflects variations in various parameters with dynamic energy simulations. In this study, the influence of long-term aging is used to accurately predict the energy performance of old detached houses. The building energy modelling method is called ENERGY#, which is a static analysis method based on ISO13790. Energy performance is evaluated by a combination of input variables including building orientation, insulation of walls and roof, thermal performance of windows and window/wall ratio, and infiltration rate. Finally, this study provides a way to determine alternatives that meet energy performance improvement goals.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권3호
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• pp.814-836
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• 2021

Wildlife ecologists and biologists recapture deer to collect tracking data from deer collars or wait for a drop-off of a deer collar construction that is automatically detached and disconnected. The research teams need to manage a base camp with medical trailers, helicopters, and airplanes to capture deer or wait for several months until the deer collar drops off of the deer's neck. We propose an intelligent robust base-station research with a low-cost and time saving method to obtain recording sensor data from their collars to a listener node, and readings are obtained without opening the weatherproof deer collar. We successfully designed the and implemented a robust base station system for automatically collecting data of the collars and listener motes in harsh wilderness environments. Intelligent solutions were also analyzed for improved data collections and pattern predictions with drone-based detection and tracking algorithms.

• 한국건설관리학회논문집
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• 제17권5호
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• pp.78-88
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• 2016

최근 국내에서는 BIM 적용을 의무화하는 프로젝트의 증가로 인하여 BIM 기술의 도입이 확대되고 있지만, 중소설계사무소에서는 관련 제도 미비, 인프라 구축비용, 상이한 프로세스 등과 같은 다양한 문제로 인해 BIM 확산이 저조한 실정이다. 본 연구에서는 이러한 문제 중에서 BIM 운영관리를 위해 필요한 인프라 구축 및 유지비용 절감 방안으로 타 산업에서 최근 적용이 모색되고 있는 클라우드 컴퓨팅 기술 중 하나인 VDI 시스템을 BIM 분야에 적용하기 위한 연구를 수행하였다. 연구 수행절차로는 중소설계사무소의 BIM 기반 환경에서 문제점을 분석하고 타 산업에서 VDI의 활용 요소가 BIM 환경의 저해요인을 해소 할 수 있는지 분석한 후, 건설 산업에 적합한 VDI 시스템 적용 방안을 모색하여 Server 규모산정 프로세스를 구축하였다. 이를 바탕으로 BIM 인프라 환경에 적용하여 자원관리의 효율성을 분석하여 BIM 환경에서 성공적인 VDI 도입에 일조 하고자 한다.

• 대한토목학회논문집
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• 제37권6호
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• pp.1109-1117
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• 2017

최근 3D 프린터 기술은 다양한 산업분야에서 주목받는 기술로, 건설 산업에서도 3D 프린터를 활용하고자 하는 연구들이 활발히 진행되고 있다. 실제 교량, 건축물 등 구조물을 3D 프린터로 출력하는 사례가 증가하고 있으며, 3D 프린터를 활용한 목업 구조물 등 다양한 활용 방안이 제시되고 있다. 3D 프린터 기술을 건설 분야에 활용하기 위해서는 3D 모델이 필요하며, 설계단계에서 제작된 3D BIM데이터를 3D 프린터로 출력 시 3D 모델 제작비용과 시간을 절약할 수 있다. 하지만 설계단계의 3D BIM데이터는 3D 프린터 출력을 위한 조건을 만족하지 않는 경우가 많아 출력 시 많은 오류를 발생시킨다. 이에 본 연구에서는 BIM데이터의 3D 모델을 3D 프린터로 출력 시 발생하는 문제점 분석과 오류를 줄일 수 있는 방안을 제시하고자 하며, 더불어 3D 프린터로 출력된 BIM모델의 실무적 활용방안을 제시한다.

• 대한공간정보학회지
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• 제9권1호
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• pp.39-47
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• 2001

지형의 특성을 공간상에 수치적으로 표현하는 수치지형모형(DTM)은 전산기의 발달과 더불어 최근 건설 분야의 계획 단계에서 광범위하게 적용이 되고 있으며, 특히 도로설계와 도시계획에 있어서 DTM을 이용한 토공량과 정지표고 및 면적 산정은 대표적인 적용 분야들이다. 따라서, 본 연구에서는 DTM을 이용한 토공량 계산에 정확도에 관련된 요소를 고려하여 최적 토공량 산정을 연구하는데 있어서, 부산광역시 15개 구를 연구 대상지역으로 선정하여 국립지리원 발행 1:5,000 지형도를 수치화하였다. 또한, 토공량과 높이별 정지면적 및 정지표고를 결정하여 향후 절 성토 등으로 인하여 발생 가능한 지형의 변화를 추정할 수 있는 정지표고 산정 모형을 제시하였으며, 그리고 토공량 계산시 사용되는 보간 기법별 토공량의 차이를 분석하였다. 분석결과 역거리보간법이 면적과 표면적 그리고 토공량에서 가장 큰 값을 보였고, 최근린기법이 가장 적을 값이 분포를 나타내었다. 최종적으로 본 연구에서 산정된 토공량은 부산광역시에서 추정한 값들과 매우 근사한 값을 보였다.

• 한국BIM학회 논문집
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• 제4권2호
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• pp.25-32
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• 2014

Today, there is a growing need of environment-friendly buildings, so-called 'green', facilities, and energy saving buildings to decrease environmental pollutants released into cities by construction activities. Green-Building Information Modeling (Green-BIM) is a purpose-built solution which supports to forecast energy consumption of 3-D model of a building by augmenting its primary 3-D measurements (width, height and depth) with many more dimensions (e.g. time, costs, social impacts and environmental consequences) throughout a series of sequential phases in the lifecycle of a building. The current study was carried out in order to integrate vegetation systems (particularly green roof and green wall systems) and investigate thermal performance of the new Sainsbury's building which will be built on Melton road, Leicester, United Kingdom. Within this scope, a 3-D building model of the news Sainsbury's building was first developed in $Autodesk^{(R)}$ $Revit^{(R)}$ and this model was then simulated in $Autodesk^{(R)}$ $Ecotect^{(R)}$once weather data of the construction site was obtained from $Autodesk^{(R)}$ Green Building $Studio^{(R)}$. This study primarily analyzed data from (1) solar radiation, (2) heat gains and losses, and (3) heating and cooling loads simulation to evaluate thermal performance of the building integrated with vegetation system or conventionally available envelops. The results showed that building integrated vegetation system can potentially reduce internal solar gains on the building rooftops by creating a 'bioshade'. Heat gains and losses through roofs and walls were markedly diminished by offering greater insulation on the building. Annual energy loads for heating and cooling were significantly reduced by vegetation more significantly through the green roof system in comparison to green wall system.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2010년도 춘계학술발표대회 초록집
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• pp.51-51
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• 2010

Recently just as in the automobile industry, shipbuilders also try to reduce material consumption and weight in order to keep operating costs as low as possible and improve the speed of production. Naturally industry is ever searching for welding techniques offering higher power, higher productivity and a better quality. Therefore it is important to have a details research based on the various welding process applied to steel and other materials, and to have the ability both to counsel interested companies and to evaluate the feasibility of implementation of this process. Submerged-arc welding (SAW) process is usually used about 20% of shipbuilding. Similar to gas metal arc welding(GMAW), SAW involves formation of an arc between a continuously-fed bare wire electrode and the work-piece. The process uses a flux to generate protective gases and slag, and to add alloying elements to the weld pool and a shielding gas is not required. Prior to welding, a thin layer of flux powder is placed on the work-piece surface. The arc moves along the joint line and as it does so, excess flux is recycled via a hopper. Remaining fused slag layers can be easily removed after welding. As the arc is completely covered by the flux layer, heat loss is extremely low. This produces a thermal efficiency as high as 60% (compared with 25% for manual metal arc). SAW process offers many advantages compared to conventional CO2 welding process. The main advantages of SAW are higher welding speed, facility of workers, less deformation and better than bead shape & strength of welded joint because there is no visible arc light, welding is spatter-free, fully-mechanized or automatic process, high travel speed, and depth of penetration and chemical composition of the deposited weld metal. However it is difficult to application of thin plate according to high heat input. So this paper has been focused on application of the field according to SAW process for thin plate in ship-structures. For this purpose, It has been decided to optimized welding condition by experiments, relationship between welding parameters and bead shapes, mechanical test such as tensile and bending. Also finite element(FE) based numerical comparison of thermal history and welding residual stress in A-grade 3.2 thickness steel of SAW been made in this study. From the result of this study, It makes substantial saving of time and manufacturing cost and raises the quality of product.