• Advances in Energy Research
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• v.5 no.1
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• pp.31-55
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• 2017

In the present study, PV/T collector was modeled via analysis of governing equations and physics of the problem. Specifications of solar radiation were computed based on geographical characteristics of the location and the corresponding time. Temperature of the collector plate was calculated as a function of time using the energy equations and temperature behavior of the photovoltaic cell was incorporated in the model with the aid of curve fitting. Subsequently, operational range for reaching to maximal efficiency was studied using Genetic Algorithm (GA) technique. Optimization was performed by defining an objective function based on equivalent value of electrical and thermal energies. Optimal values for equipment components were determined. The optimal value of water flow rate was approximately 1 gallon per minute (gpm). The collector angle was around 50 degrees, respectively. By selecting the optimal values of parameters, efficiency of photovoltaic collector was improved about 17% at initial moments of collector operation. Efficiency increase was around 5% at steady condition. It was demonstrated that utilization of photovoltaic collector can improve efficiency of solar energy-based systems.

• Journal of the Korean Institute of Rural Architecture
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• v.19 no.2
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• pp.17-24
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• 2017

The study aims to investigate problems underlying in an old local house in Iksan, Jeollabuk-do and hence improve performance and remodel the house. Based on a survey regarding current conditions of the house and several case studies on other successful renovation projects, this study suggests new renovation concepts for the old house into a guest house. The study analyzes the current state of Iksan in which the location is faced with population decline - especially among the young - and the lack of community facilities and infrastructure, and finally the unfavorable situation in the residential environment. the case study involves four successful renovated guest house projects: three renovated old single houses in Seoul and Jeonju, and a renovated old Japanese housing complex in Kunsan. The renovating concepts for the local old house is as follows: renovating for performance improvement (i.e. lighting, ventilation, heating, plumbing, insulation, structure, and water proofing), utilizing the local house to a guest house for a growing number of tourists, adding new guest rooms, installing convenient facilities in order to provide better living environments for the visitors, and improving community and street landscapes.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.1
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• pp.11-18
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• 2000

Taegu is notorious as hot and dry summer among Korea cities. One of the most important goals of the open space planning is to ameliorate urban climate of the city. The objective of this research is to evaluate the thermal mitigation effect of the cool islands in Taegu metropolitan city. Cool islands of this paper includes parks and rivers surrounded by or adjacent to urbanized areas. Based on the analysis of the thermal band of Landsat TM at May 17, 1997, the thermal mitigation effect of open spaces in the city could be summarized as follows ; Kumho river showed the largest mitigation effect in terms of the width of mitigation zone and temperature difference. Evaporation from wide water surface and evapo-transpiration from riparian grass land could bring into results. Significant mitigation effect of parks covered with forest can be observed. The temperature range of such parks were between 19.05$^{\circ}C$ and 19.44$^{\circ}C$ However, the thermal mitigation effect of Dalsung park and Apsan park was insignificant. The small size and high percentage of hard paving of the former and the relative low density of the residential areas adjacent to the latter could be the main reason. In conclusion, the thermal mitigation effect in urban ope spaces could be detectedby the employment of thermal band data of Landsat TM and GIS buffering technique.

• Journal of environmental and Sanitary engineering
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• v.21 no.1 s.59
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• pp.66-75
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• 2006

When we looked at the seasonal food dregs of the eastern side of gangwondo, gangneung city's summer and winter food dregs showed 25.9 and 25.8% respectively due to the presence of beach areas and ski resorts. Sokcho city showed 28.12% in summer and yangyang gun's summer food dregs showed 40.2%. Yangyang gun's august food dregs showed 2.7 times larger than annual average amount. Outlook density showed regional characteristics. Data showed that food dregs' amount rate has been reduced gradually from 2005 because of the prohibition of direct filling up. As a result of compositions analysis, the eastern side of gangwondo's water fraction of living dregs were lower than that of chuncheon city where is located at the gangwondo's inland area. chuncheon city's data showed residential areas 53.5%, community areas 56.8% and commercial areas 55.6%. These discrepancies caused by the characteristics of dregs discharge type and climate. The caloric value of dregs has been increased incrementally after the ban of food dregs' direct filling up. Therefore, heating value of the dregs exceeds the existing furnace design spec and it can cause high caloric value problems, so we need additional research to solve these problems.

• Journal of the Korean housing association
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• v.13 no.2
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• pp.47-53
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• 2002

The purposes of this study actually measure to the dimension and the quality of material play equipment's examine whether they meet safety standards or not, and intend to offer basic data to present proper safety standards concerning the dimension of play equipment in the end. The subjects for this study were 59 outdoor playgrounds, 30 among them located in apartment sites and the remainder did in residential districts. The time of actual measurement was in June 1999, and June 2000. Data were analyzed into frequency, percentage, mean, and standard deviation by using SPSSWIN program. The main results were as follows.: First, more than half of playgrounds were assessed for being traffic hazards due to the adjacent streets. And they were hardly equipped with the toilet and drinking water facilities, but were almost equipped with the shade of a tree and benches. Second, it was caused in inconvenience of children's use and difficulty of play equipments'management, since the quality of play equipments materials was consisted of wood or metal. Third, the standards for swing and slide were established in detail and actual measurement's results were suitable to standards'value as well, whereas the standards for seesaw and climber were not in detail and they did not design or install suitably.

• Journal of the Korean housing association
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• v.22 no.6
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• pp.61-69
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• 2011

Korea's traditional house type, the Hanok, has been the essence of Korean domestic culture for hundreds of years. However, Hanok, have begun to disappear as result of urbanization. Because mud walls are crude and weak in water walls are also easily broken by impact. There are further problems in that construction cost is expensive and takes more time than modern house construction, and that the maintenance of Hanok is more difficult than people sometimes predict. Despite much interest in Hanok construction, there is a lack of in younger generation. Thus seeking new ways of maintaining Korea's traditional housing culture and extending Korean traditional houses is important. This study proposes directions for creating new residential environments for the future generation of Korea. A Dry-wall alternative to the Korean traditional mud wall is particularly needed. Dry-walling, made by sustainable materials such as mud board and wood, can strengthen the advantages and make up for the weaknesses of the Korea traditional mud wall. In this study, both wall types underwent various evaluations in terms of their performance in insulation testing, freezing and thawing testing, impacting testing and weight measuring (the size of material in this experiment was $69cm{\times}105cm$). On all of these tests, findings revealed that the dry-wall alternative performed better than traditional mud wall.

• Journal of Soil and Groundwater Environment
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• v.18 no.7
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• pp.12-17
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• 2013

Heavy metal contamination of soil and water from industrial sources remains a worldwide environmental concern. Concentrations of toxic metals were measured in soil from banks of the Han and Anyang rivers. Pre-monsoon samples contained the highest heavy metal concentrations (Cu > As > Pb > Cd > $Cr^{6+}$; up to 57.80, 38.23, 25.43, 2.21, 0.32 mg/kg, respectively), but concentrations decreased at all sites during the monsoon and post-monsoon seasons. Higher heavy metal concentrations in pre-monsoon samples may be attributed to dust pollution, especially from roads near the river. A gradual reduction in heavy metal concentrations during the rainy season may be due to washing out. The high concentration of metals could cause health problems, especially in residential areas.

• Journal of Ecology and Environment
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• v.33 no.3
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• pp.237-244
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• 2010

In this study, we evaluated the distribution, habitat characteristics, and diet of two Korean freshwater turtle species (Chinemys reevesii, Pelodiscus sinensis) and an invasive turtle species (Trachemys scripta elegans) in the area surrounding the Seomjin River and the Nam River. We surveyed basking turtles in multiple locations along a 48-km stretch of the Seomjin River and in 99 reservoirs distributed along the Seomjin and Nam rivers from June to September, 2009. We observed 8 and 6 red-eared turtles in 3 reservoirs and at 3 sites in the Seomjin River, respectively, and 33 Reeve's turtles in 9 reservoirs. There were also 28 and 16 mud turtles detected at 15 sites along the Seomjin River and in 8 reservoirs, respectively. Among the 14 biotic and abiotic habitat characteristics that might influence the abundance of freshwater turtles in reservoirs, only the distance between a reservoir and the nearest residential areas was correlated negatively with abundance. With regard to the diet, all Reeve's and red-eared turtles investigated were determined to forage on water snails. Some turtles also foraged on vegetation and aquatic invertebrates. Additionally, we found fish in the stomach of one of the Reeve's turtles, and dragonflies in the stomachs of two red-eared turtles.

• Journal of Korean Society of Rural Planning
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• v.11 no.4 s.29
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• pp.99-108
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• 2005

In this study, thirteen villages in Chonnam province were selected as case study sites and the spatial distribution of the facilities in the villages was examined to provide basic information fur the establishment of rural plans. According to the questionnaire survey, various problem such as environmental pollution, position, scene, management etc. was brought owing to cattle shed, and dissension was more or less seen by scale of facilities, management of facilities and waste, regional factor(stock farming management condition, life style and attitude of inhabitants) and topographical factor (height, position physical aspect of a mountain, distance with water resources etc.) etc.. The facilities could be classified into 6 types based on the their spatial locations: 1) Type 1, facilities located at the waterside; 2) Type 2, facilities located at the entrance of village; 3) Type 3 facilities, scattered in the residential area: 4) Type 4 facilities, collectivized in village; 5) Type 5 facilities, adjoining village; and 6) Type 6 facilities, scattered irregularly inside and outside of village. Based on the classification, possible implementations for the reduction of environmental impacts were suggested. The results of this study could be used as an example of study on the distribution, classification, and rearrangement of environment-impacting facilities in rural areas for improvement of their roles in providing amenity resources.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.98.2-98.2
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• 2011

For optimal performance of a proton exchange membrane fuel cell (PEMFC), the membrane electrode assembly (MEA) requires hydration, and the membrane's conductivity depends on water content. A humidifier is required to ensure that the reactant gas, usually hydrogen and air, is hydrated before entering the fuel cell. Dry membrane operation or improper hydration causes performance degradation. Typically, the humidification of a fuel cell is carried out by means of an internal or external humidifier. A membrane humidifier is applied to the external humidification of transportation or residential power generation fuel cell due to its convenience and high performance. In this study, The experiments were constructed with a plate-type membrane humidifier in terms of geometric parameters and operating parameters. The results show that the temperature and pressure, the channel length, the membrane thickness and gas flow rate are critical parameters affecting the performance of the humidifier.