• Journal of Korean Institute of Industrial Engineers
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• v.23 no.1
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• pp.115-127
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• 1997

A GDHS(Geothermal District Heating System) is a heating system supplying a group of districts with heat extracted from geothermal sources. The advantages of GDHS include saving fuel consumption as well as reducing air pollution. This paper presents a case study for the economic feasibility model and analysis of a GDHS with which central/individual heating systems are replaced. Configuring to a simplified GDHS which consisits of subsurface systems, surface systems, and transmission/distribution systems, we find out the properties of the system and the model parameters affecting the initial investment/operating costs in order to develop a classical economic feasibility model given geothermal temperature. Based on our model parameter space, we analyzed the geothermal development project of the Jejoo Island probabilistically given prior information such as the expected geothermal power, the demand size and the length of transmission/distribution pipes.

• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.1-6
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• 2009

A flow analysis for the erosion-corrosion damaged automotive water pump which causes vehicle fire is numerically performed using the CFX program, computational fluid dynamics (CFD) code. The blade bending deformation and the blade clearance enlargement are considered in the analysis of performance reduction. For the cavitation analysis, the homogeneous multi phase model is adopted using the Ralyleigh-Plesset model for the rate equation controlling vapor generation and condensation.

• Parasites, Hosts and Diseases
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• v.50 no.3
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• pp.249-251
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• 2012

There have been several reports on the relationship between toxocariasis and eosinophilia, but all have been limited to the areas of Seoul or Gangwon-do. In the present study, we investigated the seroprevalence of toxocariasis among eosinophilia patients in Chungcheongnam-do, the central district of Korea. Among the 101 patients tested, 51 (50.5%) were identified as positive by Toxocara ELISA, and 46 (45.5%) were confidently diagnosed with toxocariasis because of absence of any other cause of eosinophilia. Whereas 22 of 42 seropositive patients (52.3%) had a recent history of consuming raw livers, especially the cow liver, only 1 of 25 seronegative patients (4%) had done so (P<0.01). From these results, we could confirm that toxocariasis is related to eosinophilia, and infer that ingestion of raw cow liver plays a vital role in the transmission of toxocariasis in Chungcheongnam-do.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.2 s.119
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• pp.160-167
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• 2007

In this study, the influences of environmentally friendly visual and auditory information on traffic noise perception were surveyed by the using electroencephalogram. Green rural region image and CBD (central business district) image in urban city were used as visual informations. And traffic noise, signal and environmental music were used to detect the impact on electroencephalogram variance. It was revealed that green rural region image caused ${\alpha}-wave$ ratio increase about 10% and environmental music increased ${\alpha}-wave$ ratio approximately $40{\sim}50%$. The results of this study improved that environmentally friendly visual and auditory information had an effect on decreasing traffic noise loudness to some extents.

• Journal of Plant Biology
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• v.14 no.3
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• pp.66-73
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• 1971

Pollen analysis was made on peat deposits in the area of Pyung Taek County, Central Korea. Arboreal pollen(AP) of Alnus, Abies, Ligustrum, Viburnum and Carpinus composed 70-80% of the total pollen detected in this sample area. Judging from the large amount of arboreal pollens, one can assume that those species were dominant in this district when the pollen was deposited. Among the arboreal pollens, Alnus pollen occurred more often than any other trees. Pollens of Betula, Tilia and Ulmus occurred rarely in each layers of peat deposit. The pollen diagram showed that Pinus and Abies markedly increased from the bottom to the top of the peat, while Ligustrum, Quercus and Tilia decreased proportionately. Non-arboreal pollens (NAP) and spores composed about 30 percent at the lower layer, but decreased considerably in the upper layer.

• International Journal of High-Rise Buildings
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• v.5 no.2
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• pp.145-154
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• 2016

When the tall office building first appeared in the street of Chicago in the end of Nineteenth Century, this building type has become a commodity in the development of real estate and been defined as a machine that makes the land pay. With the investigation of land price samples of the high-rise commercial buildings and the overall land price development in the central district of International Settlement in Shanghai, this paper tries to examine the site selection and construction of high-rise commercial buildings have important positive effect on the land value development.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.214-220
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• 2011

This paper studies about the assessment of thermal performance between wet ondol system and electric ondol system. Electrical ondol systems shows faster warm-up time, higher floor surface temperature distribution and lower power consumption than wet ondol system. However, if we provide heat regularly wet ondol system which has more heat capacity shows greater thermal storage than electric ondol system. Therefore, we could conclude that wet ondol system which keeps temperature regularly by the thermal storage show better energy-efficiency in case of using the central heating and district heating system. However, Electrical ondol system shows better efficiency in case of using the space during short time or individual heating systems which needs to heat quickly. The Experiment says that electric ondol system has more benefits on timing to reach the set temperature and energy-efficiency than wet ondol system.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.77-81
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• 2010

This study carried out hydraulic model test for water circulation system in Cheongna district as part of Incheon Free Economic Zone. Canal way project of Cheongna was planned to establish for environment-friendly water circulation system, improve quality of life and diversification of traffic through using boat as a water-friendly international business city. The navigation canal, There are two intake facility in central park and it can purify water 15,000$m^3$ per day. After purify, water move to 8 facility of water culture area which supplies water in canal way. This process called water circulation system in cheongna. Also, there are several flow induction machine in canal way except south-north way. Therefore, this study will verify about validity of water circulation system's safety through hydraulic model test.

• Journal of Mechanical Science and Technology
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• v.20 no.8
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• pp.1275-1283
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• 2006

Condensation heat transfer coefficients in a 7.92 mm inside diameter copper smooth tube were obtained experimentally for R22, R134a, and R410A. Working conditions were in the range of $30-40^{\circ}C$ condensation temperature, $95-410 kg/m^2s$ mass flux, and 0.15-0.85 vapor quality. The experimental data were compared with the eight existing correlations for an annular flow regime. Based on the heat-momentum analogy, a condensation heat transfer coefficients correlation for the annular flow regime was developed. The Breber et al. flow regime map was used to discern flow pattern and the Muller-Steinhagen & Heck pressure drop correlation was used for the term of the proposed correlation. The proposed correlation provided the best predicted performance compared to the eight existing correlations and its root mean square deviation was less than 8.7%.

• Journal of Korean Institute of Fire Investigation
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• v.9 no.1
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• pp.61-64
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• 2006

지난 2005년 8월 18일 대전광역시 중구 문화동 가옥에서 발생한 화재를 사례로 하여 현재 발생되고 있는 보험범죄의 잔인하고 반인륜적인 모델을 제시하였다. 동 사례는 일가족 4명이 화재로 인하여 사망하였으며, 초기에는 전기누전에 의한 단순한 화재로 오인되었으나, 현장의 정밀감정, 소사체의 정밀 부검 및 면밀한 수사를 통하여 보험금을 노린 살인 방화사건으로 밝혀진 사례이다. 본 고찰에서는 화재현장의 상황, 가옥 내부의 연소형태, 전기적인 특이점, 연소매개체, 피의자의 행위, 연소지연시간의 발생 및 수사 자료를 근거로 제시하고, 종합적으로 고찰하여 일가족 4명을 살해한 후, 시너를 연소매개체로 사용한 방화에 의해 화재가 발생한 것으로 판단한 사례이다.