• Title/Summary/Keyword: wind assessment

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An Evaluation of Thermal Comfort of New Towns in Seoul Metropolitan Area (수도권 신도시의 열쾌적성 평가)

  • Oh, Kyu Shik;Lee, Min Bok;Lee, Dong Woo
    • Spatial Information Research
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    • v.21 no.2
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    • pp.55-71
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    • 2013
  • This study assessed the thermal comfort of new towns in the Seoul Metropolitan Area (Ilsan, Bundang, Dongtan1) using PET (Physiologically Equivalent Temperature) which refers to real human heat stress. The relationship between PET and urban spatial elements was also analyzed using multiple regression analysis. The study results show that the thermal comfort of Dongtan 1, which is considering a reduction of the urban heat island effect in the planning phase, is higher than other cities. In addition, through regression results, the impervious ratio, floor area ratio, commercial area ratio, and residential area ratio were found to be major factors increasing PET. Moreover, the river area ratio and NDVI were found to be major factors decreasing PET. This study has scientific significance as research that focuses on the assessment of thermal comfort scientifically and definitely, by estimating PET for an entire urban area using GIS analysis that included remote sense analysis and the wind field model. The results of this study can be used in preparing more effective urban plans for the promotion of citizen thermal comfort.

Research Trends of Randomized Controlled Trials on Herbal Medicine Treatment for Atopic Dermatitis-Focusing on CNKI (아토피 피부염의 한약 치료에 대한 무작위대조군연구 중심의 연구 동향 - CNKI를 중심으로)

  • Yang, Geum-Jin;Jo, Eun-hee;Kang, Su-Jin;Hong, Jieun;Shim, Yu-Hwa;Lee, Ju-Hyun;Park, Min-cheol
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.34 no.2
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    • pp.102-116
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    • 2020
  • The purpose of this study was to analyze the research trends of randomized controlled trials on herbal medicine treatment for atopic dermatitis in China for the last 5 years. We searched for randomized controlled trials with the intervention of herbal medicine for the treatment of atopic dermatitis in the CNKI (China National Knowledge Infrastructure) from January 2014 to December 2018. For the screening of the paper, we used '特应性皮炎' and '异位性皮炎' which mean atopic dermatitis and search was limited to three areas within Medicine & Public Health: Traditional Chinese Medicine, Traditional Chinese Medicinal Herbs, Combination of Traditional Chinese Medicine with Western Medicine. Among the 136 searched studies, we selected a total of 34 studies and analyzed a year of publication, subject characteristics, study design and intervention, prescribed herbal medicine and herbs, pattern identification, evaluation criteria, and outcomes. Longmu decoction (龍牡湯) and Polia Sclerotium (茯笭) was the most frequently prescribed medicine and herb. The most commonly used pattern identification was Blood deficiency and Wind-dryness (血虛風燥), and among them, the most frequently prescribed herb is Rehmanniae Radix (生地黃). In most studies using the total effectiveness and SCORAD index as an outcome measure, the herbal medicine treatment group showed statistically better results than the control group. As a result of the safety assessment, the herbal medicine treatment group was reported having significantly fewer side effects compared to the control group. Hence, it was confirmed that the intervention including herbal medicine had a significant effect on atopic dermatitis. This study would be able to provide the basis of clinical research on atopic dermatitis and applied to the treatment of atopic dermatitis.

Assessment of Metal Pollution of Road-Deposited Sediments and Marine Sediments Around Gwangyang Bay, Korea (광양만 내 도로축적퇴적물 및 해양퇴적물의 금속 오염 평가)

  • JEONG, HYERYEONG;CHOI, JIN YOUNG;RA, KONGTAE
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.25 no.2
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    • pp.42-53
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    • 2020
  • In this study, heavy metal in road-deposited sediments (RDS) and marine sediment around Gwangyang Bay area have been investigated to assess the pollution status of metals and to understand the environmental impact of RDS as a potential source of metal pollution. Zn concentration for <63 ㎛ size fraction was the highest (2,982 mg/kg), followed by Cr, Ni, Pb, Cu, As, Cd, and Hg. Metal concentrations in RDS increased with decreasing particle size and relatively higher concentrations were observed around the metal waste and recycling facilities. For particle size in RDS smaller than 125 ㎛, EF values indicated that Zn was very high enrichment and Cr, Cd, Pb were significant enrichment. The concentrations of metals in marine sediments were mostly below the TEL value of sediment quality guidelines of Korea. However, the Zn concentrations has increased by 30~40% compared to 2010 year. The amounts of Zn, Cd and Pb in less than 125 ㎛ fraction where heavy metals can be easily transported by stormwater runoff accounted for 54% of the total RDS. The study area was greatly affected by Zn pollution due to corrosion of Zn plating materials by traffic activity as well as artificial activities related to the container logistics at Gwangyang container terminal. The fine particles of RDS are not only easily resuspended by wind and vehicle movement, but are also transported to the surrounding environments by runoff. Therefore, further research is needed on the adverse effects on the environment and ecosystem.

Seismic safety assessment of eynel highway steel bridge using ambient vibration measurements

  • Altunisik, Ahmet Can;Bayraktar, Alemdar;Ozdemir, Hasan
    • Smart Structures and Systems
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    • v.10 no.2
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    • pp.131-154
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    • 2012
  • In this paper, it is aimed to determine the seismic behaviour of highway bridges by nondestructive testing using ambient vibration measurements. Eynel Highway Bridge which has arch type structural system with a total length of 216 m and located in the Ayvaclk county of Samsun, Turkey is selected as an application. The bridge connects the villages which are separated with Suat U$\breve{g}$urlu Dam Lake. A three dimensional finite element model is first established for a highway bridge using project drawings and an analytical modal analysis is then performed to generate natural frequencies and mode shapes in the three orthogonal directions. The ambient vibration measurements are carried out on the bridge deck under natural excitation such as traffic, human walking and wind loads using Operational Modal Analysis. Sensitive seismic accelerometers are used to collect signals obtained from the experimental tests. To obtain experimental dynamic characteristics, two output-only system identification techniques are employed namely, Enhanced Frequency Domain Decomposition technique in the frequency domain and Stochastic Subspace Identification technique in time domain. Analytical and experimental dynamic characteristic are compared with each other and finite element model of the bridge is updated by changing of boundary conditions to reduce the differences between the results. It is demonstrated that the ambient vibration measurements are enough to identify the most significant modes of highway bridges. After finite element model updating, maximum differences between the natural frequencies are reduced averagely from 23% to 3%. The updated finite element model reflects the dynamic characteristics of the bridge better, and it can be used to predict the dynamic response under complex external forces. It is also helpful for further damage identification and health condition monitoring. Analytical model of the bridge before and after model updating is analyzed using 1992 Erzincan earthquake record to determine the seismic behaviour. It can be seen from the analysis results that displacements increase by the height of bridge columns and along to middle point of the deck and main arches. Bending moments have an increasing trend along to first and last 50 m and have a decreasing trend long to the middle of the main arches.

A Study on Analysis Method for Performance Evaluation of Double-leaf facade of Office Building (업무용 건물의 이중외피 성능평가를 위한 해석기법의 고찰 - 이중외피 설계안의 에너지 저감 성능 및 환기성능을 중심으로 -)

  • Chung, Hwan-Kyo;Chung, Kwang-Seop;Lee, Yong-Jun;Shin, Seung-Chul;Kim, Young-Il
    • Journal of Energy Engineering
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    • v.21 no.2
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    • pp.168-178
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    • 2012
  • The objective of this study is applied to office buildings to evaluate quantitative evaluation method about performance of double-skin at design stage to establish the basis for the purpose of evaluation performance. Select the evaluation building about design plan for applying the double-skin using the dynamic heat load analysis program the annual heating and cooling load of before and after the double-skin. Using CFD to analyze wind factor and applied ventilation for realistic results. Effects of double-skin to apply, and control techniques that can be done more realistically proposed through to set and control for shade control mode of ventilator and inside cavity wall of double-skin. Apply for the building the double-skin due to interpretation of the annual heating and cooling loads applied to interpret the quantitative effect confirmed the possibility. According to the form of a double skin was confirmed cavity environmental changes.

Study on the Assessment of the Criteria on a Door Closer for the Optimum Design of the Access Door of a Smoke Control Zone (제연구역 출입문의 최적 설계를 위한 도어클로저의 기준 산정에 관한 연구)

  • Lee, Jae-Ou;Choi, Chung-Seog
    • Fire Science and Engineering
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    • v.27 no.3
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    • pp.66-71
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    • 2013
  • The purpose of this study is to assess the criteria on a floor hinge and door closer for the optimum design of the access door of a smoke control room. The door opening force due to differential pressure is 60.75 N, 40.5 N, 32.91 N and 12.66 N when the differential pressure is 60 Pa, 40 Pa, 32.5 Pa and 12.5 Pa, respectively. The door opening force of the floor hinge and door closer to which the criteria of KS F 2806 are applied is 27.5 N, 40 N, 75 N, 100 N and 125 N for the Nos. 1, 2, 3, 4 and 5 class floor hinges and door closers, respectively. This study compared the differential pressure and opening force limits of floor hinges and door closers with the values specified in NFSC 501A and found that they exceeded the criteria specified in NFSC 501A. Therefore, it is necessary to reflect the differential pressure and smoke control wind speeds as well as the opening forces specified in NFSC 501A on the design of floor hinges and door closers. The installation conditions of floor hinges and door closers of access doors differ depending on the type and name of a smoke control damper. This study found that Nos. 1, 2 and 3 floor hinges and door closers could be installed for access doors with low differential pressure and that Nos. 1 and 2 floor hinges and door closers could be installed for access doors with normal differential pressure.

Prediction of SWAT Stream Flow Using Only Future Precipitation Data (미래 강수량 자료만을 이용한 SWAT모형의 유출 예측)

  • Lee, Ji Min;Kum, Donghyuk;Kim, Young Sug;Kim, Yun Jung;Kang, Hyunwoo;Jang, Chun Hwa;Lee, Gwan Jae;Lim, Kyoung Jae
    • Journal of Korean Society on Water Environment
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    • v.29 no.1
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    • pp.88-96
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    • 2013
  • Much attention has been needed in water resource management at the watershed due to drought and flooding issues caused by climate change in recent years. Increase in air temperature and changes in precipitation patterns due to climate change are affecting hydrologic cycles, such as evaporation and soil moisture. Thus, these phenomena result in increased runoff at the watershed. The Soil and Water Assessment Tool (SWAT) model has been used to evaluate rainfall-runoff at the watershed reflecting effects on hydrology of various weather data such as rainfall, temperature, humidity, solar radiation, wind speed. For bias-correction of RCP data, at least 30 year data are needed. However, for most gaging stations, only precipitation data have been recorded and very little stations have recorded other weather data. In addition, the RCP scenario does not provide all weather data for the SWAT model. In this study, two scenarios were made to evaluate whether it would be possible to estimate streamflow using measured precipitation and long-term average values of other weather data required for running the SWAT. With measured long-term weather data (scenario 1) and with long-term average values of weather data except precipitation (scenario 2), the estimate streamflow values were almost the same with NSE value of 0.99. Increase/decrease by ${\pm}2%$, ${\pm}4%$ in temperature and humidity data did not affect streamflow. Thus, the RCP precipitation data for Hongcheon watershed were bias-corrected with measured long-term precipitation data to evaluate effects of climate change on streamflow. The results revealed that estimated streamflow for 2055s was the greatest among data for 2025s, 2055s, and 2085s. However, estimated streamflow for 2085s decreased by 9%. In addition, streamflow for Spring would be expected to increase compared with current data and streamflow for Summer will be decreased with RCP data. The results obtained in this study indicate that the streamflow could be estimated with long-term precipitation data only and effects of climate change could be evaluated using precipitation data as shown in this study.

An Assessment of Areal Evaportranspiration Using Landsat TM Data (Landsat TM 자료를 이용한 광역 증발산량 추정)

  • Chae, Hyo-Seok;Song, Yeong-Su;Park, Jae-Yeong
    • Journal of Korea Water Resources Association
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    • v.33 no.4
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    • pp.471-482
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    • 2000
  • Surface energy balance components were evaluated by Landsat TM data and GIS with meteorological data. Calibration and validation for the applicability of this methodology were made through the estimating of the large-scale evapotranspiration (ET). In addition, sensitivity and error analysis was conducted to see the effects of the surface energy balance components on ET and the accuracy of each components. Bochong-chon located on the upper part of Guem River basin was selected as the case study area. Spatial distribution map of ET were produced for five dates: Jan. 1, Apr. 3, May. 10, and Nov. 27, 1995. The study results showed tat ET was greatly varied with the aspect and theland use type on the surface. In the case of having northeast and southeast in the aspect, ET was linearly increased depending on growing net radiation. While surface temperature has a high value, NDVI(Normalized Difference Vegetation Index) has a low value in the vegetated area. Therefore, ground heat flux was increased but ET was relatively decreased. The results of sensitivity and error analysis showed that net radiation is most sensitive and effective, ranging from 12.5% to 23.6% of sensitivity. Furthermore, the surface temperature, air temperature, and wind speed have the significant effects on ET estimation using remotely sensed data.

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Analysis of Reliability of Weather Fields for Typhoon Maemi (0314) (태풍 기상장의 신뢰도 분석: 태풍 매미(0314))

  • Yoon, Sung Bum;Jeong, Weon Mu;Jho, Myeong Hwan;Ryu, Kyong Ho
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.32 no.5
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    • pp.351-362
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    • 2020
  • Numerical simulations of the storm surge and waves induced by the Typhoon Maemi incident on the south sea of Korea in 2003 are performed using the JMA-MSM forecast weather field, NCEP-CFSR reanalysis weather field, ECMWF-ERA5 reanalysis weather field, and the pressure and wind fields obtained using the best track information provided by JTWC. The calculated surge heights are compared with the time history observed at harbours along the coasts of Korea. For the waves occurring coincidentally with the storm surges the calculated significant wave heights are compared with the measured data. Based on the comparison of surge and wave heights the assessment of the reliability of various weather fields is performed. As a result the JMA-MSM weather fields gives the highest reliability, and the weather field obtained using JTWC best track information gives also relatively good agreement. The ECMWF-ERA5 gives in general surge and wave heights weaker than the measured. The reliability of NCEP-CFSR turns out to be the worst for this special case of Typhoon Maemi. Based on the results of this study it is found that the reliable weather fields are essential for the accurate simulation of storm surges and waves.

A Study on Electromagnetic Compatibility Performance Evaluation of Power Conditioning System for Residential Fuel Cell (가정용 연료전지 전력변환장치 전자파적합성 성능 평가 연구)

  • Choi, Young-Joo;Nam, Tae-Ho;Lee, Eun-Kyung;Lee, Duk-Gwon;Lee, Jung-Woon;Lee, Seung-Kuk;Moon, Jong-Sam
    • Journal of the Korean Institute of Gas
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    • v.21 no.6
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    • pp.23-29
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    • 2017
  • Solar and wind energy among the renewable energy produce irregular power because resource is difficult to control. When connected to grid have unstable. However, when the fuel cell system is connected to grid more stable because regular frequency and output power based on controllable hydrogen energy. To using fuel cell system in the household, it is important that the safety performance of power conditioning system(PCS) and it is important that evaluation method of electromagnetic compatibility(EMC). In this study, we consider that introduce power-frequency magnetic field immunity test before analyzed that compare with the EMC of the international standards and KGS AB 934 PC53. Also, we conduct that actual assessment and study on available the quantitative analysis as using complementary indicator.