• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.6
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• pp.293-299
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• 2015

In Korea, it is the law that an apartment building which consists of over 100 households must have a ventilation system installed, either natural or mechanical. The heat recovery ventilator (HRV) is great way to reduce energy consumption. In this research we confirmed that based on site's construction plan and existing diffuser form, performed purpose CFD which simulates operation in temperatures below $-5^{\circ}C$ to circumstances of installation of an HRV in an apartment. As a result of this research we found that when the diffuser's aperture area was adjusted, the distribution of air temperature and residence time of air was more equally distributed and air temperature was higher, compared to when the diffuser has an identical aperture area. We also found that we are able to increase even more air temperature and air distribution of air temperature and residence time of air was even more equally distributed when run in parallel with a splitter damper.

• Journal of the Korea Institute of Building Construction
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• v.12 no.4
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• pp.415-425
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• 2012

Green Frame was developed to embody a Green structural system that can provide long life, resource reduction, and availability of remodeling in apartment buildings. Composite precast concrete column and beam, the major structural material of Green Frame, can be installed precisely and promptly through connection of steels and concrete. The connection of Green Frame can be divided into four types, based on the method and characteristics of connection. To select an appropriate type for the site, a comparative analysis of the four types is necessary. The objective of this study is to compare the duration, cost, quality, and safety of four types. The findings of this study can be applied during the selection that appropriate composite precast concrete column reflected project characteristics in design phase.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.12
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• pp.1096-1102
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• 2013

The useful practical land shall be reserved when an artificial land covers the railway and road. However, the problem is that since the artificial land places directly on the top of noise sources likely on the railway and road there will arise the weak points, noise and vibration. On this study based on creating the artificial land on the top of a railway vehicle base and placing a tenement on that land, it was comprehended the noise influence from the railway car through the simulation. In order to secure the input value for the simulation, at first measured the noise condition of the railway station building and the railway vehicle base. The output value for the railway station building (place A) was around (53.6~57.6) dB(A), the equivalent continuous sound level for an hour, and for the railway station building (place B) it was around (63.7~68.9) dB. The maximum outdoor noise of the tenement on the artificial land was measured as 64.1 dB(A) under the fixed condition on the simulation modeling. The built purpose of placing the artificial land to prevent the noise influence from the railway met the expectation to be less influenced on the tenement. Rather, because of placing the artificial land the noise level on the lower space could be increased so there requires having a noise control.

• Journal of Yeungnam Medical Science
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• v.21 no.1
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• pp.74-81
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• 2004

Purpose: To evaluate the computed tomography (CT) findings of pulmonary cryptococcosis in immunocompetent patients. Materials and Methods: CT scans of 25 patients with biopsy-proven cryptococcosis [surgery (n=3), percutaneous needle biopsy (n=21), and bronchoscopic biopsy (n=1)] were analyzed. Thirteen patients were men and 12 patients were women, with a mean age of 53.7 years. Presenting symptoms were cough, sputum, and dyspnea and 12 patients presented with incidentally found chest radiographic abnormalities. Results: Nodule or multiple conglomerate nodules (n=10, 40%) and segmental or lobular consolidation (n=9, 36%) were most common, followed by mixed patterns (n=5, 20%). Predilection sites were lower lobe (n=21/37, 57%) and subpleural areas (n=23, 92%). Air bronchograms within consolidations (n=11/14, 79%) with mild volume loss (n=10/14, 71%) were common. While interlobular septal thickening (n=11, 44%) and cavitation or central low-attenuations (n=11, 44%) were relatively common, lymphadenopathy (n=2, 8%) or free pleural effusions (n=1, 4%) were uncommon. Conclusion: Nodules or airspace consolidation with a predilection of lower lobe and subpleural area are the most common appearances of pulmonary cryptococcosis in immunocompetent patients.

• Fire Science and Engineering
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• v.25 no.4
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• pp.89-93
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• 2011

It is not recommended that elevator use for egress at (super) high rise buildings because elevator shaft main roles to spread of fire smoke. But in North America used to protect this area by elevator shaft pressurization. These tests are performed at high rise apartment to verify that elevator shaft pressurization can protect to spread of fire smoke or not. and verify to used for egress at fire. Pressurization at elevator shaft make pressure difference of 50 Pa all floor at 150 CMM because this method have low friction loss from air flow. Also when dwelling door and elevator door are opened that critical velocity is performed to protect of back-layering from fire room for escape routs by 180 CMM. Therefore through out these pressurization tests by elevator shaft are estimated to have less overpressure because supply air difference are low between to satisfy critical velocity at one door opened and maintain to pressure difference all doors closed. Finally we verified that disable or residual people can use elevator for egress at fire by elevator shaft pressurization.

• Composites Research
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• v.33 no.3
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• pp.101-107
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• 2020

This study investigates the characterization on the thermal insulation properties of silicon carbide coating on the C_f-C composites. The silicon carbide coatings by chemical vapor deposition on the C/C composites are prepared to evaluate thermal resistance. Firstly, we perform the basic insulation test by thermal shock at 1350℃ in air on the C/C composite and SiC-coated C/C composite. We also performed the burner tests on the surface of the composites at high temperatures such as 1700 and 2000℃, and the weight change after burner tests are measured. The damages on the surface of C/C composite and SiC-coated composite are observed. As a result, the SiC coating is beneficial to protect the C/C composite from high temperature even though damages such as defoliation, crack and voids are observed during burner test at 2000℃.

• Tuberculosis and Respiratory Diseases
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• v.40 no.2
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• pp.153-157
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• 1993

Background: Patients with pyogenic lung abscess who do not respond to medical therapy are usually candidates for thoracotomy with pulmonary resection. Percutaneous tube drainage, used routinely and with good results before the antibiotic era, has nearly been forgotten. Methods: We treated 8 patients who had poor cadidates for a lobectomy and didn't respond to medical management. A pig-tail catheter (6 to 10 Fr.) was inserted into the abscess under the fluoroscopic guidance. Results: All patients brought about dramatic clinical responses with prompt closure of cavity and radiographic improvement. Conclusion: Percutaneous pig-tail catheter drainage provides excellent clnical results with ease and safety, and avoids unnecessary loss of functioning lung parenchyma. But lobectomy should be considered in patients who major life-threatening bleeding or massive pulmonary necrosis.

• Fire Science and Engineering
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• v.28 no.5
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• pp.30-36
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• 2014

The pressurized smoke control system in the vestibule is important for fire safety in buildings because it is concerned with egress time of people and the safety of fire fighters. The vestibule pressurization system can prevent smoke from entering the vestibule using differential pressure when fire doors are closed and using the egress velocity when fire doors are open. Air supplying units in the vestibule need to be arranged by taking account of the location of doors and the volume of the vestibule in order to assure the uniform air egress velocity through a fire door when it is open. In this study, computational fluid dynamics (CFD) simulations were conducted for the vestibule where multiple doors are installed and it was found that the reverse flow occurs when the damper position in vestibule is not appropriate.

• Journal of the Korea Institute of Building Construction
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• v.18 no.3
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• pp.277-283
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• 2018

This study is conducted to improve the manufacturing process of the modular construction method, which is a pre-fabricated construction method recognized for its advantage on the shortening of construction time. This study first identified the factors that result in shortening of pre-fabrication processes in the current module-processing factory. In addition, those identified factors were further considered for installing the M.E.P. system that is being outsourced on the main module in the production line. A manufacturing process of the construction modules, which considers installation of a M.E.P. system most suitable for shortening the time on the outsourcing of modular construction, is introduced throughout the research. Furthermore, this study suggests the factors in need of improvement during design phase of modular construction and improvement measures to consider the quality of unit modules by focusing on the module parts that are most exposed to defects.

• Journal of Environmental Health Sciences
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• v.33 no.1 s.94
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• pp.1-10
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• 2007

This study accomplished to grasp the present condition of HAPs and to examine efficiently carcinogenic and non-carcinogenic health effects through health risk assessment in new apartments from June, 2004 to May,2005. Moreover, we performed uncertainty analysis by Monte-Carlo analysis to control uncertainty of exposure factors. The major results obtained from this study were as follows. Firstly, cancer risk of formaldehyde for male was $1.67{\times}10^{-5}$ in CTE in point estimation. Cancer risk of formaldehyde was showed $2.94{\times}10^{-3}$ in RME that applied worst case used results of 95 percentile in point estimation. It exceeds $10^{-6}$ of guide line in US EPA. Moreover, cancer risks of formaldehyde for female were $3.98{\times}10^{-5}$ in CTE and $3.93{\times}10^{-3}$ RME. Secondly, every hazard index for non-carcinogenic pollutants was less than 1 of permitted standards in CTE. However, in RME of male, hazard indexes of 1,2-Dichloropropane and Toluene were 1.3 and 2.0, respectively. Hazard indexes of 1,2-Dichloropropane and Totuene for female in RME were 1.7 and 2.6, respectively.