• Environmental and Resource Economics Review
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• v.27 no.1
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• pp.195-214
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• 2018

This study estimates the price elasticity of residential water demand in Korea. For that, annual panel data from the year of 2010 to 2013 for 161 local water services is estimated by using panel quantile model. As a result, the price elasticities of residental water demand in Korea are estimated to be between -0.156 and -0.189 depending on its quantile. In addition, the study finds that the estimated elasticity of residential water demand by traditional conditional mean regression is relatively more influenced by high demand areas because the distribution of residental water demand in Korea is left-skewed.

• Journal of the Korean Solar Energy Society
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• v.31 no.3
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• pp.8-16
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• 2011

The objective of this study is to analyze the characteristic of thermal environment in the summer season by conducting the field observation of temperature, relative humidity, and globe temperature in some parts of the city. Observation point was divided to a densely populated area, a residential area, a green area, a waterfront green area and a suburban district by the distribution ratio of green area. In this study, the correlation between maximum temperature and globe temperature, study on index for intensity of the tropical night and the temperature distribution characteristic of measurement points by the distribution ratio of green area were analyzed. The results of this study are as follows. (1) The difference between temperature and globe temperature by the distribution ratio of green area is confirmed. The difference of nighttime is more clearly that of daytime. (2) The average temperature and globe temperature of the densely populated area($29.2^{\circ}C$, $33.7^{\circ}C$) are higher than that of the waterfront green area($27.9^{\circ}C$, $32.0^{\circ}C$) by $1.3^{\circ}C$ and $1.7^{\circ}C$, respectively. (3) The number of tropical nights has different days of tropical nights by the distribution ratio of green area of 17days for the Daegu weather station, 14days for adensely populated area, 14days for a residential area, 6days for a green area, 2days for a waterfront green area, and 2days for a suburban district. (4) The results of the slope of trend line for the effects of the temperature on globe temperature change and the intercept for the size of the impact of radiant energy gained around by the analysis of the correlation between the maximum temperature and globe temperature can be utilized objective evaluation index of the each point's artificial effects.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.10
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• pp.1025-1029
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• 2005

A simple analysis of atmospheric sulfur dioxide($SO_2$) pollution in industrial region was investigated using badge type passive samplers. It were set up in 76 locations and the $SO_2$ distribution evaluated along the boundary of land use type. It changed considerably both monthly and seasonally. Soil samples were also collected in 120 locations to investigate influence of sulfur dioxide pollution on soil and heavy metal distribution in the study area, where the sulfur dioxide pollutants from industrial area could affect the soil environment of near residential and green areas. The relationship between the $SO_2$ concentrations in the atmosphere and heavy metal(Cu, Pb) concentrations in the soil were analyzed, by using the correlation coefficient values and the results were 0.17 and 0.08 in industrial area. And this study indicated that the atmospheric pollution in industrial region affect the level of the soil pollution adjacent to the residential and green area. The study result may be used to define correlativity for establishing an exposure index. It will subsequently be used for a more precise assessment measuring the exposure of plants and inhabitants, for the purposes of a study en effects on health.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.5
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• pp.495-508
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• 2010

The aim of this study is to develop a quantified water loss Index to evaluate and manage leakage scientifically for the reduction of non-revenue water in water distribution systems. For the purpose, unavoidable background leakage suggested from UK water industry and IWA, and allowable water leakage in accord with the concept of allowable water loss are proposed by analyzing the inflow into two study water districts and the short-term water use of each customer in the districts. The study distribution areas are selected among the metered districts with good maintenance of leakage after improvement activities in Nonsan, medium sized city in Korea. Estimation models of allowable leakage are developed by metering and analyzing the minimum night flow at residential and commercial areas in the city. In the results of the investigation, it is estimated that background night flow in residential area was larger than that of commercial area where the types of business shows small water use characteristics. Meanwhile, night flow and background water loss on internal plumbing systems show great differences for each district which is influenced much by the water use characteristics and facilities scale. Based on metering water use data in various districts, leakage management criteria can be established under the consideration of domestic conditions in Korea by analyzing separated real water use and background leakage and it is possible to apply into presentation of optimal leakage level and reasonable time for working activities for leakage reduction.

• The Research Journal of the Costume Culture
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• v.11 no.6
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• pp.889-901
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• 2003

The purpose of this study is to look into the physical features for each residential area by the age, with the female subjects residing in Beijing and Shanghai. This would provide the specific information regarding the body types of Chinese adult women, and additionally it would assist the effective advancement into the Chinese local markets by serving as the basic data for the size development and fitting improvement of clothing products for Chinese women. The body measurements were made with 525 adult female subjects of 20 to 49 years of age, residing in Beijing and Shanghai, China. The number of measurements items was 79. The results are as follows: As they grew older, the women residing in Beijing and Shanghai all showed increases in the items of width, thickness, girth, and length, which are highly correlated with the physical obesity, while they did not show any differences by the age range in the item of height. Differences were also found in the tendency of the type distribution by the age range of Chinese adult women in each residential area. As they grew older, the women residing on Beijing showed increases in the distribution of Body type 2 and Body type 4, which clearly indicated the features of obesity. On the other hand, the women residing in Shanghai showed the almost similar distribution in their 20's and 30's, while those in their 40's showed a high frequency in Body type 2 than in Body type 4.

• Journal of Forest and Environmental Science
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• v.37 no.3
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• pp.243-250
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• 2021

Information on butterflies in the Niger Delta Region is relatively scanty because monitoring of their activities and distribution has not been fully documented and these are paramount to establish their conservation protocols. The study therefore aimed at evaluating the species richness distribution pattern, and relative abundance of butterflies in the University of Port Harcourt. The University Park was purposively selected for this study. The park was stratified into three different habitat types (secondary forest, farmland, and residential/garden). A sampling of each stratum was done three times; twice in the morning between 8:00 am and 12:00 pm as well as once in the evening between 4:00 pm and 6:00 pm along a 100 m line transects for 16 months (May 2017-August 2018). Data collected were analyzed for species diversity indices, evenness, and similarity index. A total of 1,932 individual butterflies belonging to 28 species, 18 genera, and five 5 families were identified in the study area. Species diversity and evenness were higher on farmland (1-D=0.909; H'=2.615; E=0.833), and least in the residential area/gardens (1-D=0.744; H'=1.975; E=0.659). The family Nymphalidae (39.0%) had the highest number of species occurrence while Hesperidae (0.4%) had the lowest composition. Anthene larydas (24.12%) had the highest relative abundance in the entire study area, followed by Acraea serena (17.49%). The study, therefore, recommends continuous monitoring of butterfly species diversity and composition also in other regions.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.822-828
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• 2001

Three-phase four-wire electrical distribution systems are widely employed in manufacturing plants, commercial and residential buildings. Due to the nonlinear loads connected to the distribution system, the neutral conductor carries excessive harmonic currents even under balanced loading since the triplen harmonics in phase currents do not cancel each other. This may result in wiring failure of the neutral conductor and overloading of the distribution transformer. In response to these concerns, a cost-effective neutral current harmonic suppressor system has been proposed [6]. This paper proposes an improved control method for the harmonic suppressor system under unbalanced load conditions. The proposed control method compensates for only the harmonic components in the neutral conductor, and the zero-sequence fundamental component due to unbalanced loading is prevented from flowing through the harmonic suppressor system. This remedies overloading and power loss of the system. The experimental results on a prototype validate the proposed control approach.

• Journal of Power Electronics
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• v.3 no.3
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• pp.151-158
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• 2003

Three-phase four-wire electrical distribution systems are widely employed in manufacturing plants, commercial and residential buildings Due to the nonlinear loads connected to the distribution system, the neutral conductor carries excessive harmonic currents even under balanced loading since the triplen harmonics in phase currents do not cancel each other This may result in wiring failure of the neutral conductor and overloading of the distribution transformer In response to these concerns, a cost-effective neutral current harmonic suppressor system has been proposed. This paper proposes an improved control method for the harmonic suppressor system under unbalanced load conditions The proposed control method compensates for only the harmonic components in the neutral conductor, and the zero-sequence fundamental component due to unbalanced loading is prevented from flowing through the harmonic suppressor system This remedies overloading and power loss of the system The experimental results on a prototype validate the proposed control approach.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.5
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• pp.487-493
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• 1999

To predict the background level of harmonics produced by household appliances, information on the site, capacity, and usage pattern of these loads arenecessary. However, as household appliances are distributed widely and various in type, it is difficult to know these kinds of information accurately. This paper presents a method for estimation of background level of harmonics produced by distributed harmonic sources with readily available data. Large industrial customers are excluded from this study. In this paper, customers are grouped into three classes, i.e. residential, commercial, and industrial. Typical customers for each class are assumed and characteristics of their equipments are modeled. As the proposed method does not require harmonic measurement, it can be employed to forecast voltage total harmonic distribution (VTHD) in the future. An illustrative example is described.

• Economic and Environmental Geology
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• v.37 no.6 s.169
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• pp.631-645
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• 2004

This study assesses groundwater vulnerability to contaminants in industrial and residential/commercial areas of the city of Changwon, using DRASTIC technique and groundwater data. The DRASTIC technique was originally applied to situations in which the contamination sources are at the ground surface, and the contaminants flow into the groundwater with infiltration of rainfall. Mostly the industrial area has higher DRASTIC indices than the residential/commercial area. However, a part of the residential/commercial area having much groundwater production and great drawdown is more contaminated in groundwater than other industrial and the residential/commercial areas even if it has lowest DRASTIC indices in the study area. It indicates that groundwater contamination in urban areas can be closely related to excessive pumping resulting in a lowering of the water level. The correlation coefficient between minimum DRASTIC indices and the degree of poor water quality for 10 districts is as low as 0.40. On the other hand, the correlation coefficients between minimum DRASTIC indices and the groundwater discharge rate, and between minimum DRASTIC indices and well distribution density per unit area are 0.70 and 0.87, respectively. Thus, to evaluate the potential of groundwater contamination in urban areas, it is necessary to consider other human-made factors such as groundwater withdrawal rate and well distribution density per unit area as well as the existing seven DRASTIC factors.