• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.27 no.4
• /
• pp.52-64
• /
• 2019

The purpose of this study is to analyze the impact of macroeconomic variables on air passenger demand and provide useful information to airport managers and policymakers. Therefore, using the quarterly macroeconomic indicators from 2002 to 2017, the relationship with air passenger demand was demonstrated by multiple regression analysis. In the previous studies, they used GDP, Korea Treasury Bond, KOSPI index, USD/KRW Exchange Rate, and WTI Crude Oil Price variables. In this study, we used the Coincident Composite Index, Employment Rate, Consumer Sentiment Index, and Private Consumption Rate used as additional variables. It has confirmed that if the consumption of research results expands or the economic environment is right, it will affect the increase in international passengers. In other words, it confirmed that the overall economic situation acts as the main factor determining air passenger demand. It confirmed that the economic environment at the past has a significant impact on air passenger demand.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.12 no.1
• /
• pp.75-82
• /
• 2000

This paper presents the predicted results by CFD technique of air flow and contaminant distribution in a full-scale kitchen opened to a living room, ventilated by a exhaust hood. To analyze the characteristics of the indoor environment, the concept of contaminant index was defined. In this study, the locations of the gas range and the window were chosen as the parameters to investigate the indoor environment. The values of the contaminant index for several layout of the gas range and the window were calculated and compared. When the gas range is installed along the wall with specified window location, its position in relation to the wall has unnoticed effect on contaminant infer. Once the location of the gas range is fixed, the indoor air quality may deteriorate by the proximity of the window to the gas range. This is due to the shorter distance that external fresh air must travel within the kitchen before it reaches the exhaust fan.

• Journal of Environmental Science International
• /
• v.25 no.6
• /
• pp.897-904
• /
• 2016

We investigated the local climatological characteristics of the mountain adjacent the Dongyeong herb garden in Chilgok. We established one set of automatic weather system (AWS) on a hill where development of herb garden is in progress. The observations were continued for 2 years(2013. 07-2015.06). In this study, we analyzed the observed data comparing the data of Gumi meteorological observatory (GMO). The results showed that the air temperature(relative humidity) of Dongyeong herb garden were lower(higher) than those of GMO. Especially the differences are more during warm climate season. It means that the gaps of thermal environment between two points are mainly caused by the evaporation effects of forest. In addition, we analyzed the warmth indices(warmth index and coldness index) with the observed air temperature. The warmth and coldness indices indicate about 107 and -12, respectively. The values correspond to warm temperature climate.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 1999.04a
• /
• pp.309-311
• /
• 1999

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.23 no.9
• /
• pp.610-619
• /
• 2011

This paper investigates the simplified comfort index and control logic for VRF (Variable Refrigerant Flow) system by using 3 environmental factors such as temperature, humidity and air flow. Indoor test under thermal load was conducted to explore relationship of each environment factors that is related to simplified comfort index. Simplified comfort function that has 3 environmental variables was proposed based on survey results. Each factor is measured and comfort preference was surveyed by more than 30 subjects in the indoor comfort test. Moreover, control logic for VRF system was developed and then simulated by using thermal load calculation method and verified with test. The proposed comfort function was in good agreement with survey results, and also verification test trend of comfort change and maintenance are quite similar with survey. Furthermore, through the additional test data analysis some differences of comfort according to position of people staying in the test room were additionally investigated by air flow. People being under an exit of air in the indoor air-conditioner feel more comfortable condition and speed of response to comfort change is relatively fast.

• International Journal of Internet, Broadcasting and Communication
• /
• v.12 no.3
• /
• pp.149-155
• /
• 2020

Air pollution is a problem of environmental health risk in big cities. Recently, researchers have proposed using various artificial intelligence technologies to predict air pollution. The proposed model is Cooperative of Artificial Neural Network (ANN) and Fuzzy Inference System (FIS), to predict air pollution of Korean cities using Python. Data air pollutant variables were collected and the Air Korean Web site air quality index was downloaded. This paper's aim was to predict on the health risks and the very unhealthy values of air pollution. We have predicted the air pollution of the environment based on the air quality index. According to the results of the experiment, our model was able to predict a very unhealthy value.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.31 no.5
• /
• pp.457-466
• /
• 2007

A numerical and experimental study on the evaluation and the prediction of cleanliness level in the mini-environment system was carried out. Using the concept of local mean air-age (LMA) and effective flow rate, the new direct method for estimating the mini-environment was developed and compared with the previous performance index of airflow pattern characteristics. It was found out that the airflow pattern analysis is a restricted method to estimate the real performance of the mini-environment. The reason is that the airflow pattern cannot predict the effect of the increment of the ventilation rate on the cleanliness level in the mini-environment. While LMA is capable of showing the effects of the contaminant accumulation caused by turbulent intensity, eddy, and the increment of the effective flow rate. This result showed that LMA is more exact and effective performance index than the previous one like the airflow pattern characteristics.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2004.11a
• /
• pp.379-381
• /
• 2004

• Journal of Environmental Impact Assessment
• /
• v.6 no.1
• /
• pp.33-45
• /
• 1997

Nowadays, the environmental conservation has become a hot issue. Also the sustainable city issue is recognized as one of the most important tasks to be solved urgently for urban development. Therefore, the current indicator for sustainable city has been analyzed only as a segment of the environmental indicator which is one kind of branch of social indicator. However, considering the degree of pollution and heightened concern, it is time to develop a new and improved framework for the analysis of the sustainable city indicator. This study aims for the development of sustainable city indicator and the examination of practical method for the use of them. Urban sustainable city indicators are based on the "Pressure-State-Response (PSR) framework" which has been adopted by Organization for Economic Cooperation and Development (OECD). The indicators suggested in this study is composed of the following categories: 1. Indicators of natural environment itself, such as land structure (available land use index etc.), bio-species (bio-diversity index etc.), environment resources (water quantity index etc.) 2. Indicators of relationship between man and environment, such as sustainability of using material (recycle of water index etc.), pressure size (pressure index on air etc.), effort of prevention (environmental basic facility index, etc.) 3. Indicators of environmental state, such as landscape and culture (historical & cultural index etc.), environmental pollution (air pollution index etc.) A sustainable city environment is necessary and obtainable, yet its realization seems to be difficult. The urban pollution problems have become more serious than ever before thus requiring much interest. Therefore, this kind of study is meaningful for the establishment of policy objective, and the development and management environmentally sound and sustainable cities.

• Journal of Korean Society for Atmospheric Environment
• /
• v.24 no.2
• /
• pp.153-161
• /
• 2008

The guidelines for indoor air quality of public transportations such as subway, train and bus was presented by Korean Ministry of Environment last end of year 2006 based on the great consequence of indoor air quality in daily life. Two main parameters, carbon dioxide($CO_2$) and particulate matters smaller than $10\;{\mu}m(PM_{10})$, were selected as index pollutants for the management of indoor air quality. The former pollutant, $CO_2$, is regarded as index of ventilation status and the major source of $CO_2$ in the train or subway is the exhalation of passengers. It is publically perceived that the high $CO_2$ concentration in a crowded subway will be reduced and ventilated with outdoor air by door-opening taken every 2 or 3 minutes when the train stops each station. However, there has not been any scientific proof and quantitative information on the effect of door-opening on the $CO_2$ reduction by ventilation with outdoor air. In this study, $CO_2$ concentration and number of passengers were measured at each station on the 3 lines of Korail metropolitan subway. In order to evaluate the effect of $CO_2$ reduction by door opening, the theoretical approach using the $CO_2$ balance equation was performed. By comparing the predicted data with monitoring one, the optimum $CO_2$ dilution factor was determined. For the first time, it was quantified that about 35% of $CO_2$ concentration in the subway indoor was removed by the door-opening at each station.