• Korean Journal of Construction Engineering and Management
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• v.16 no.1
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• pp.35-43
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• 2015

It is important to have enough design and construction duration for infrastructure projects. However, recent water resource project in Korea shows several problems caused by their fast-tract schedule. National Audit Committee report several water resource projects have quality problems caused by insufficient project duration. Especially, water resource projects such as dam and water pipeline construction should have proper time to secure their structure quality. Normal project duration for these projects should be estimated based on previous similar projects' historical data analysis. However there is no standard model which can estimate normal project duration for water resource projects in Korea. There are several normal project duration estimation models for building project developed by public(LH) and private construction companies. However, there is no proper model for water resource projects. So, this study developed normal project duration model for dam and water pipeline projects using historical data and show application of models.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.2
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• pp.85-92
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• 2008

This study, the one concerning the evaluation analysis of the function of the wind generation using KLAM_21, has examined closely how the wind really flows on the space of the city, working with the object of case location. In the first place, the cold air formed at upper stream of Sincheon river, a ravine of whole area of Gachang gully and an inclined plane of neighboring mountainous district, flows to the north and expands itself along the upper stream of the Sincheon river, and as the time passes, it is tending upwards in the change of the volume and height as well as of the velocity and direction, of the cold air. It was learned that this phenomenon has made it clear that the spatial features of this area give rise to very good condition in generating and flowing the cold air. Meanwhile, it has been shown that in the area of park in the Ap-mountain, the generation and flow of the cold air are much interrupted because of the overpass traversing the whole area of the park of Ap-mountain, the congested area of large-scaled apartments and the urban development activities constructing the building in the park, and the volume and height of the cold air has been grown very small. In conclusion, It has been learned that for maximization of the spatial effect of the wind corridor, the areas where the cold air is generated, flowed, accumulated, and maintained, have to be connected spatially, and this spatial connection has a close relation with spatial features of the area.

• Journal of the Korean Institute of Telematics and Electronics
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• v.14 no.1
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• pp.5-14
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• 1977

"Electrical Properties of Barium Titanates with Addition Sb2O3." PTC BaTiO3 in low resistance at room temperature was prepatred. Al2O3, SiO2 and TiO2 were doped with a view to improving reproduction. Sb2O3 was doped as impurity in order to control of resistivity of the specimens. The relations between the amount of Sb3O3 and electrical properties wereinvestigated. Of the compositions studied, additions of 3.75mole% Al2O3, 1.25mole% SiO2, 2.25mole% TiO2 and 0.16~0.25wt% Sb2O3 to BaTiC3 was low resistivity in 14-300 ohm-cm.00 ohm-cm.

• 월간 기계설비
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• s.232
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• pp.50-70
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• 2009

T.A.B란 공기조화설비에 대한 종합시험조정으로 시험, 조정 및 균형(Testing, Adjusting & Balancing)이라는 뜻이다. 이는 설계 목적에 부합되도록 모든 빌딩의 환경시스템을 검토하고, 조정하는 과정이다. 따라서 T.A.B기술은 공기 및 물이라는 유체의 흐름과 온 습도에 관련된 분야이기 때문에 시각적으로 그 성과를 알아보기 힘들고, T.A.B를 적용한 후 결과치를 정밀 분석해 판단할 수 있으며 T.A.B기술을 적용하지 않은 건물과 간접비교하는 방법으로 그 효과를 쉽게 알 수 있다. T.A.B기술을 적용할 경우 시공 중인 건물에 설계도서가 완료되기 전, 또는 장비의 구매발주 전에 T.A.B측면에서 모든 기술 도서를 면밀히 검토하게 된다. 그 중 일부에서 발견되는 문제점들 즉, 적정치 못한 용량 선정, 시스템 구성상 미비점, 불필요한 장비 선정, 누락 사항을 발견할 수 있다. 따라서 T.A.B 기술을 적용할 경우 향상된 품질의 시공이 가능해 준공 후 빈번히 대두되는 하자 문제가 현격히 줄게 되며 또한 운전경비 절감, 쾌적한 실내환경 조성, 장비수명 연장 등 효율적인 운전관리 효과를 얻을 수 있다. 우리나라 공기조화설비기술은 꾸준한 발전을 이루었고, 최근에는 도입 초기단계시 전혀 고려되지 않던 공조공간의 쾌적성 및 소음 방지 대책 등의 문제가 주요사항으로 부각되고 있다. 이에 따라 공조설비에 T.A.B실행의 표준화 정착과정에 있으며, 국내 학계 및 연구기관에서 공조설비에 대한 연구 및 T.A.B용역업체의 기술축적 등 T.A.B분야 발전을 위해 노력하고 있다. 본지는 T.A.B의 수행절차 및 수행계획, TAB 수행업체 등에 대해 알아본다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.394-397
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• 2004

Working-day calculation with weather factors of construction-site has estimated wethout proper data. They usually estimate it with their own experience and intuition. It causes not only economic loss to time-adjustment but also conflict with each participants. Moreover, weather estimation becomes worse than before, due to tendency of recently weather change. So, in this paper we present optimal estimation method as assessment by period of the arithmetical mean methods. For that, we analyse characteristic of the regions and weather change of temperature and rainfall which affects time.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.532-537
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• 2000

The purpose of this study is to determine the performance of a commercial air cleaner in removing tobacco smoke indoors. Following injection of tobacco smoke in a room, decay rates for particle concentrations were obtained far mass concentration at each point. The size distribution of the tobacco smoke particles was approximately $1.266{\mu}m$ in mass median diameter with a geometric standard deviation of 1.313. The air cleaner consisted of an electrostatic filtration unit and a fan operated at a flow rate of 5.98 CMM. The collection efficiency for $>1\;{\mu}m$ was more than 99%. Without air cleaner operation, tobacco smoke concentration ratio in room decreased to 30% of initial values within 30 minutes and with air cleaner operation, decreased to 90% of initial values in the test chamber, volume $51.27\;m^3$. Without air cleaner operation, tobacco smoke concentration ratio in room decreased to 10% of initial values within 30 minutes and with air cleaner operation, decreased to 30-70% of initial values in the test chamber, volume $149.2\;m^3$.

• Fire Science and Engineering
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• v.25 no.5
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• pp.14-20
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• 2011

As the height of the building increases, the stack effect in stairwell that is main facilities for evacuation becomes stronger. While the pressure rise in stairwell causes difficulties on opening the door for evacuation and has effect on smoke control system, reduction of stack effect will be necessary for providing more safe evacuation environment. The field experiments on pressure field in high-rise building are carried out to present reduction method of stack effect and the numerical analyses using network model are proceeded to design quantitatively the reduction method. As the air flow supplied from outside in lower stair and exhausted to outside in upper stair is formed in stairwell, the stack effect in stairwell is expected to be decreased.

• Korean Journal of Microbiology
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• v.11 no.2
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• pp.101-106
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• 1973

The microwave of 2450 MHz, generated by a household cooking oven, was evaluated for its applicability to melt various rehydrated media and to remove dissolved oxygen from tubed media for anaerobic culture. The effect on the sterilization of E. coli in selective media was also evaluated. The following results were obtained. 10 The microwave oven was useful in saving time for melting media and in eliminating heat and combustion gas from the laboratory, which were inevitable by-products in the conventional flame method. 2) Dissolved oxygen could be removed without boiling over by exposing the tubes of anaerobic culture medium after putting them in a wire basket in a beaker with water. 30 The count of E. coli during the melting of MacConkey and EMB agar were similar to those treated with open flame. The microwave treatment was not considered a possible mean to replace autoclaving even in these selective media.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.9
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• pp.733-737
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• 2003

The purpose of this study is to analyze the particle removal characteristics of a commercial air cleaner based on the electrostatic precipitator. The air cleaner consists of a positive corona precharger to precharge particles and a collector to remove the charged particles. The test for particle removal efficiency is conducted with tobacco smoke particles of 1.27${\mu}{\textrm}{m}$ in mass median diameter. The result of one-pass filtration test shows that the filtration efficiency is more than 90% for the particles larger than 2.5 Um, while the efficiency for the particles of 0.5～1.0${\mu}{\textrm}{m}$ in case of 4.18 CMM is 70%. For the test room of 5,800${\times}$3,400${\times}$2,600㎣, the concentration of tobacco smoke particles decreases up to 30% of initial values within 30 minutes due to natural reduction and up to 90% of initial values within 30 minutes with the air cleaner operation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.3
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• pp.765-770
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• 2008

Ji, Syok-young wrote a book named Sinhaksinseol(新學新說) in 1891, one of the first hygiene books in Korea. There were the conditions of modern housing like lighting, ventilation and dry and fresh air of a housing site in the contents of the book. Because the book was written when the modern hygiene theory had just been accepted, traditional concept of 'Yangseng(養生),' but it dealt the main environmental conditions of hygienic housing at first, which makes it the leader of modern housing discourses through the newspapers, magazines, academic journals or textbooks from 1890s mid to 1910.