• 대한교통학회지
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• 제27권6호
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• pp.139-146
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• 2009

대기오염 물질배출량 중 도로이동오염원에 의한 배출량은 다른 오염원에 비해 월등히 높은 편이나 관련연구가 미흡한 실정이다. 본 연구에서는 교통량, 속도 및 기타기상 조건의 실시간 자료와 도로기하구조와 같은 도로특성인자를 반영하여, 대기오염 물질 배출에 도로환경요인이 미치는 영향을 분석하였다. 서울시의 실시간 대기오염 데이터와 교통량, 도로관련 데이터를 수집하여 대기오염 물질별 오염배출량 예측 회귀모형식을 구축하였다. 본 연구에서 얻어진 결과를 요약하면 다음과 같다. 첫째, 교통량이 증가할수록 오염물질의 측정량은 증가하며, 속도가 증가할수록 측정량은 감소한다. 둘째, 풍속, 온도, 습도가 증가할수록 측정량은 감소한다. 셋째, 교차로 형태가 복잡할수록 측정량은 감소한다. 예측모형을 검증하기 위하여 예측치와 실측치 데이터를 비교 분석한 결과 총 7곳의 도로변대기오염 측정망 중 실측치와 예측치가 가장 부합하는 측정망은 청계 4가 측정망인 것으로 나타났다. 본 연구는 실시간 대기오염배출량 데이터와 교통량 데이터, 도로환경 특성데이터를 이용하여 예측모형을 구축하여 현실적인 도로환경요인이 대기질에 미치는 영향을 설명하였다는 데 의의가 있다.

• 한국토양비료학회지
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• 제47권5호
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• pp.345-350
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• 2014

This study was conducted to investigate the changes in daily surface temperature of red pepper leaf compared to air and soil surface temperature. The maximum, minimum and average daily temperatures of red pepper leaf were 27.80, 11.40 and $19.01^{\circ}C$, respectively, which were lower by 0.10, 7.60 and $3.86^{\circ}C$ than air temperature, respectively, and lower by 15.00, 0.0 and $4.38^{\circ}C$ than soil surface temperature, respectively. Mean deviations of the difference between measured and estimated temperature by the E&E Model (Eom & Eom, 2013) for the air and surface temperature of red pepper leaf and soil were 0.64, 1.82 and $4.77^{\circ}C$, respectively. The relationships between measured and estimated scaled factor of the air and surface temperature of red pepper leaf and soil were very close to the 1:1 line. Difference between air and surface temperature of red pepper leaf showed a linear decreasing function with the surface temperature of red pepper leaf. Difference between soil surface temperature and air and surface temperature of red pepper leaf linearly increased with the soil surface temperature.

• Asian Journal of Business Environment
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• 제10권4호
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• pp.15-19
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• 2020

Purpose: This research aims to explore the level of air pollution in Jakarta, the epicenter of COVID-19 Pandemic in Indonesia and its surrounding provinces during the first month of the Pandemic. Research design, data and methodology: This study uses data, which have been obtained real time from API (Application Programming Interfaces) of air quality website. The measurements of Air Quality Index (AQI), temperature, humidity, and other factors from several cities and regencies in Indonesia were obtained eight times a day. The data collected have been analyzed using descriptive statistics and mapped using QGIS. Results: The finding of this study indicates that The Greater Jakarta Area experienced a decrease in pollutant levels, especially in the Bogor area. Nevertheless, some areas, such as the north Jakarta, have exhibited slow reduction. Furthermore, the regions with high COVID-19 confirmed cases have experienced a decline in AQI. Conclusions: The study concludes that the air quality of three provinces, Jakarta, Banten, and West Java, especially in cities located in the Jakarta Metropolitan Area during COVID-19 pandemic and large-scale social restrictions, is getting better. However, in some regions, the reduction of pollutant concentrations requires a longer time, as it was very high before the pandemic.

• 품질경영학회지
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• 제44권3호
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• pp.677-688
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• 2016

Purpose: In this study, we examine the effects of circulatory diseases mortality in South Korea 2005-2013 using the air pollution index, Methods: We cluster the region of high risk mortality by SaTScan$^{TM}$9.3.1 and compare this result with the regional distribution of air pollution. We use the Geographically Weighted Regression (GWR) to consider the spatial heterogeneity of data collected by administrative district in order to estimate the model. As GWR is spatial analysis techniques utilizing the spatial information, regression model estimated for each region on the assumption that regression coefficients are different by region. Results: As a result of estimating model of the collected air pollution index, circulatory diseases mortality data combined with the spatial information, GWR was found to solve the problem of spatial autocorrelation and increase the fit of the model than OLS regression model. Conclusion: GWR is used to select the air pollution affecting the disease each year, the K-means cluster analysis discover the characteristics of the distribution of air pollution by region.

• 설비공학논문집
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• 제22권4호
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• pp.205-212
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• 2010

In a typical data center, large numbers of IT sever racks are arranged multiple rows. IT environments, in which extensive electronic hardware is air-cooled, cooling system inefficiencies result when heated exhaust air from equipment prematurely mixes with chilled coolant air before it is used for cooling. Mixing of chilled air before its use with heated exhaust air results in significant cooling inefficiencies in many systems. Over temperatures may not only harm expensive electronic equipment but also interrupt critical and revenue generating services. Cool shield is a cost effective aisle partition system to contain the air in cold aisles and hot aisles of an IT server room. This paper focuses on the use of performance metrics for analyzing aisle partition system in data centers.

• 한국인공지능학회지
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• 제6권1호
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• pp.1-10
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• 2018

Compressed Air is an important energy source used in most factories nowadays. The automation trend using air compressor has been gradually increasing with the interest of the 4th industry in recent years. With the air compressor system, it is possible to construct the device at low cost and easily achieve automation and energy saving. In addition, With trend of FA, miniaturation and light weight manufacturing trend expand their use in the electronics, medical, and food sectors. Research method is to design the technology for the remote control of the following information as USN base. Development of flexible sensing module from real time observation module for fusion of IT technology in compressed air systems, design and manufacture of flexible sensing module, and realiability assessment. Design of real-time integrated management system for observation data of compressed air system - Ability to process observation data measured in real time into pre-processing and analysis data. This study expects unconventionally decreasing effect of energy cost that takes up 60~70% of air compressor layout and operation and maintenance management cost through USN(Ubiquitous Sensor Network) technology by using optimum operational condition from real time observation module. In addition, by preventing maintenance cost from malfunction of air compressor beforehand, maintenance cost is anticipated to cut back.

• 설비공학논문집
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• 제25권7호
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• pp.371-376
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• 2013

Recently, many studies related to reducing the energy consumption in data centers have been conducted. These studies have mainly focused on the air intake and exhaust system of a computer room air handling unit (CRAH) in the server room, diffuser type, suppression and discharge of the heat generated from the server, and the air-side economizer system. In this study, the energy consumption of the conventional central chilled water cooling system is compared with the energy consumption of the air-side economizer system. We also examined how changes of differential pressure by each filter have influenced energy consumption, using the power usage effectiveness (PUE). Results show that the PUE was improved, and energy consumption decreased, by applying the air-side economizer system.

• 한국가시화정보학회지
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• 제18권2호
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• pp.18-27
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• 2020

Air lift pump operated by buoyancy is mainly used for the continuous circulation and the purification of fluids. In this study, the computational flow analysis has been performed with the geometric and operating conditions of the air lift pump. The numerical data from the analysis have been verified by comparing with the previous experimental data. The following results are obtained which advance the efficiency of the air lift pump. As the submergence length of pipe increases and the pipe length over the water surface decreases, the non-dimensional mass flow ratio increases in both cases. When the position of the air injection hole is within the pipe, the circulation range of the surrounding fluid becomes widened with the distance between the air injection hole and the pipe inlet relatively becoming narrower. It is more efficient both when the air injection velocity is at 10 m/s and at 15 m/s, and when the diameter of the pipe with holes is doubled near the water surface. It is expected that these results can be provided as fundamental data for operating the air lift pump.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.427-432
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• 2005

This study developed a program for detecting charged refrigerant amount in system air-conditioner. System air-conditioner is an air-conditioning system with multiple indoor units. Due to the complexity of the system, it is more difficult to detect the refrigerant amount charged in system air-conditioner than in a general single air-conditioner. Experiments were performed for 6 HP outdoor units with 3 indoor units in a psychrometric calorimeter. The experimental amount of charged refrigerant were ranged from 60% to 140% with 10% increasement. Fuzzy algorithm were emploeed for detecting the charged refrigerant amount in a system air-conditioner. The experimental data were used for curve fitting for general ranges for indoor and outdoor temperature conditions. membership function were determined for whole ranges of experimentally measured data and rulebase were defined for each amount of refrigerant charge. Developed program successfully predicted the measured data within 10% resolution range.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.916-919
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• 2004

The monopole theory has long been used to model air-pumped effect from the elastic cavities in car tire. This approach models the change of an air as a piston moving backward and forward on a spring and equates local air movements exactly with the volume changes of the system. Thus, the monopole theory has a restricted domain of applicability due to the usual assumption of a small amplitude acoustic wave equation and acoustic monopole theory. This paper describes an approach to predict the air-pumping noise of a car ave with CFD/Kirchhoff integral method. The type groove is simply modeled as piston-cavity-sliding door geometry and with the aid of CFD technique flow properties in the groove of rolling car tyre are acquired. And these unsteady flow data are used as a air-pumping source in the next Cm calculation of full tyre-road geometry. Acoustic far field is predicted from Kirchhoff integral method by using unsteady flow data in space and time, which is provided by the CFD calculation of full tyre-road domain. This approach can cover the non-linearity of acoustic monopole theory with the aid of using Non-linear governing equation in CFD calculation. The method proposed in this paper is applied to the prediction of air-pumping noise of modeled car tyre and the predicted results are qualitatively compared with the experimental data.