• Wind and Structures
• /
• 제21권1호
• /
• pp.1-23
• /
• 2015

Wind tunnel testing of a low-rise building with openings (holes) of different sizes and shapes on a roof corner is conducted to measure the internal and external pressures from the building model. Detailed analysis of the testing data is carried out to investigate the characteristics of the internal and external pressures of the building with different openings' configurations. Superimposition of the internal and external pressures makes the emergence of positive net pressures on the roof. The internal pressures demonstrate an overall uniform distribution. The probability density function (PDF) of the internal pressures is close to the Gaussian distribution. Compared with the PDF of the external pressures, the non-Gaussian characteristics of the net pressures weakened. The internal pressures exhibit strong correlation in frequency domain. There appear two humps in the spectra of the internal pressures, which correspond to the Helmholtz frequency and vortex shedding frequency, respectively. But, the peak for the vortex shedding frequency is offset for the net pressures. Furthermore, the internal pressure characteristics indirectly reflect that the length of the front edge enhances the development of the conical vortices.The objective of this study aims to further understanding of the characteristics of internal, external and net pressures for low-rise buildings in an effort to reduce wind damages to residential buildings.

• 한국경제지리학회지
• /
• 제19권4호
• /
• pp.630-641
• /
• 2016

호주 멜버른지역에 소재한 맬버농은 작은 시급정부로, 시 정부 주도로 과거 군수산업용지를 정화하여 주택지구로 재개발하였고, 도시기반시설을 정비하여 경관을 개선하는 한편, 도심을 활성화하고 있다. 도심의 빈 점포를 임대하여 대학 캠퍼스를 조성하고, 도심에 Little Saigon이란 베트남 촌을 조성하는가 하면, 빅토리아 대학과 연계해서 창조산업 관련 창업보육사업을 통해 기업유치 및 기업육성을 위해 노력하고 있다. 이 사례에 기초해서 볼 때, 호주는 창조도시사업을 통해 사회 경제적, 도시경관적 여건을 개선하는데 성공하고 있으며, 그러한 과정에서 대학과 각급 정부, 그리고 시민단체의 역할이 큰 것으로 파악된다.

• 환경영향평가
• /
• 제19권3호
• /
• pp.259-270
• /
• 2010

We conducted human risk assessment for exposure to inhalation of chemical substances emitted from the storage tanks of petroleum refineries. To assess human risk, this study calculated chemical emissions from the external floating roofs on storage tank at petroleum refineries, as well as concentrations thereof in the ambient air using the K-SCREEN model, and then determined risk in accordance with the Reference Concentration (RfC) values and Inhalation Unit Risk criteria developed by the US Environmental Protection Agency. The results indicated that non-carcinogenic chemicals have a hazard quotient of less than 1, meaning they have an insignificant effect on human health for residential areas near the storage tanks. Among the known carcinogens, the hazard risk for benzene slightly exceeded $10^{-6}$, indicating the need for corrective reduction measures. The methodology for health impact assessment devised herein provides findings useful in decision making for policy makers and the general public with respect to construction of industrial complexes. However, the methodology proposed herein does have limitations, including discrepancy in results induced by use of U.S. data (due to the lack of usable domestic data). More systematic studies from related researchers will be needed to address these issues and produce more reliable outcomes.

• 한국산학기술학회:학술대회논문집
• /
• 한국산학기술학회 2009년도 추계학술발표논문집
• /
• pp.310-313
• /
• 2009

본 연구의 목적은 환자가 거주지가 아닌 타 지역에서 입원의료를 이용하는 요인을 규명하여 주민들의 의료이용에 대한 지역적 접근성을 향상시킬 수 있는 방안을 제시하는데 있다. 2005년 환자조사 입원자료 523,782건을 연구대상으로 하였으며, 2004년 의료기관평가 자료, 2005년 인구센서스, 2006년 보건의료자원실태조사를 이용하였다. 자료분석은 기술통계, 카이제곱 검정, 로지스틱 회귀분석을 실시하였다. 타 지역 입원의료 이용의 가장 큰 요인은 의료기관 소재지의 의료서비스 수준으로, 인구 10만명당 의료기관평가 점수가 9.5점 이상인 지역이 9.5점 미만인 지역에 비해 타지역 입원의료 이용확률이 8.3배가 높았다. 반면 인구 10만명당 병상수가 910병상 이상인 지역이 910병상 미만인 지역에 비해 타 지역 입원의료 이용확률이 2.0배 높았다. 정부는 지역주민의 의료의 접근성을 높이기 위해 의료공급량의 확충과 분배보다는 지역의료의 질적 수준을 향상시키는 방향으로 정책을 펼쳐야 한다.

• 전기학회논문지
• /
• 제63권2호
• /
• pp.211-216
• /
• 2014

Construction of power plants and T&D facilities is so difficult because of the civil complaints and the additional cost according to the concerning field conditions. Therefore, various researches and methods have been considered to get solutions in the demand side and energy storage systems have been in the spotlight because of the various functions such as peak shaving, load shifting, and power system stabilizing, and so on. Residential small size batteries are considered in this paper and the economic analysis is carried out to evaluate the reasonable subsidy levels for the deployment of energy storage systems. Various economic parties are considered to find reasonable subsidy level comparing each other, which parties consist of utilities, participants and non-participants in general. The evaluation is based on California Standard Practice Test and the results are able to be used as subsidy guidelines.

• Earthquakes and Structures
• /
• 제9권4호
• /
• pp.893-910
• /
• 2015

Earthquake safety of existing buildings has gained considerable importance after earthquakes which have occurred in our country especially in the last 30 years. Performance based assessment methods have been widely used for existing reinforced concrete structures. This study aims to investigate the earthquake performances of the building stock located in Van Lake basin in Eastern Anatolia of Turkey. The case study of buildings has been modeled on and the structural performances have been determined by employing the non-linear methods described in the latest Turkish Earthquake Code published in 2007. The Van lake basin is located on the very seismically active in a region. On October 23, 2011, a magnitude of Mw 7.2 earthquake struck the Van province in eastern Turkey. The earthquake ground motion was recorded as about 0.1g in Bitlis province. Performance evaluations have been performed by taking samples from each district consisting urban building stocks of Bitlis. A total of 16 reinforced concrete buildings have been evaluated. Among them, 53% of those buildings were determined in the Fully Operational performance level; 13% of them in the Life Safety performance and 34% of them could not be evaluated because of the ratio of the effective mass of first mode to the total mass of the buildings was smaller than 0.70. Therefore, incremental equivalent seismic load methods, which are a part of Turkish Earthquake Code -2007, cannot be used.

• Wind and Structures
• /
• 제20권3호
• /
• pp.469-488
• /
• 2015

A full-scale instrumented low-rise building with gable roof was built at a coastal site with a high incidence of tropical cyclones for monitoring of wind effects on the building during windstorms. This paper presents the field measurements of the wind velocity field around and the wind-induced pressures on the low-rise building during the passage of severe tropical storm Soudelor. Near-ground wind characteristics such as wind speed, wind direction, turbulence intensity, gust factor, turbulence integral length scale and wind velocity spectra were investigated. The wind-induced pressures on the roof of the building were analyzed and discussed. The results revealed that the eave and ridge edges on the roof were subjected to the most severe suction pressures under quartering winds. These suction pressures showed obvious non-Gaussian behavior. The measured results were compared with the provisions of ASCE 7-10 to assess the suitability of the code of practice for the wind-resistant design of low-rise buildings under tropical cyclones. The field study aims to provide useful information that can enhance our understanding of the extreme wind effects on low-rise buildings in an effort to reduce tropical cyclone wind damages to residential buildings.

• Environmental Engineering Research
• /
• 제25권2호
• /
• pp.147-162
• /
• 2020

The main objective of this study is to estimate the levels of pollution to which the community is presently exposed and to model the regimes of local air quality. Diurnal, daily, and monthly variations of NO, NO₂, SO₂, and O₃ were thoroughly investigated in three areas; namely, residential, industrial, and terminal in Ras Al-Khafji. There is obvious diurnal variation in the concentration of these pollutants that clearly follows the diurnal variation of atmospheric temperature and main anthropogenic and industrial activities. Correlation analysis showed that meteorological conditions play a vital role in shaping the pattern and transportation of air pollutants and photochemical processes affecting O₃ formation and destruction. Bivariate polar plots, an effective graphical tool that utilizes air pollutant concentrations' dependence on wind speed and wind direction, were used to identify prevailing emission sources. Non-buoyant ground-level sources like domestic heating and street transport emissions, various industrial stacks, and airport-related activities were considered dominant emission sources in observatory sites. This study offers valuable and detailed information on the status of air quality, which has considerable, quantifiable, and important public health benefits.

• 한국항해항만학회지
• /
• 제34권4호
• /
• pp.293-298
• /
• 2010

The residential comfort and safety on ship are more focused than ever, in accordance with the increase of the crews' onboard time and interest in cruiser sailing. To grasp the safety characteristics on ships against various scenarios of evacuations, this study performed experiments and simulations for the evacuation times on a training ship. Through the experiments, the average walking speed is 3.0m/s on 100% visibility, and 1.2m/s on 8% visibility, but the speeds go down 1.3m/s and 0.7m/s, respectively, when obstacles are happened without any previous notification. From the simulation, it is clearly reconfirmed that the worse visibility and many people make evacuation time comparatively longer. And unlike the common expectation of the effect of emergency announcement, the difference of evacuation times between cases of announcement and non-announcement is negligible on this study. From the survey after experiments, it is known that experiment participants feel unsafe and fear when the evacuation routes are longer in bad visible condition, even if they know the perfect evacuation route. And the survey results also show that the evacuees give more careful consideration to make a evacuation route decision under bad visibility.

• Journal of Power Electronics
• /
• 제18권2호
• /
• pp.573-587
• /
• 2018

Recently evolved power electronics' based domestic/residential appliances have begun to behave as single phase non-linear loads. Performing as voltage/current harmonic sources, those loads when connected to a three phase distribution network contaminate the line current with harmonics in addition to creating a neutral wire current increase. In this paper, an enhanced performance three phase four leg shunt active power filter (SAPF) controller is presented as a solution for this problem. The presented control strategy incorporates a hybrid predictive fuzzy-logic based technique. The predictive part is responsible for the SAPF compensating current generation while the DC-link voltage control is performed by a fuzzy logic technique. Simulations at various loading conditions are carried out to validate the effectiveness of the proposed technique. In addition, an experimental test rig is implemented for practical validation of the of the enhanced performance of the proposed technique.