• KIEAE Journal
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• v.15 no.3
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• pp.49-56
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• 2015

Purpose: Due to recent increase on energy consumption for light in building, many studies to mitigate this issue have been conducted. Various researches have been carried out to suggest light shelf as one of the solutions, but researches for its reflectivity is very few. In fact, existing research on light shelf shows that utilizing more than 90% of high-illumination materials causes imbalance of glare and illuminance. Method: Therefore this research aimed to evaluate the performance of light shelves depending on reflectivity and to identify proper solution through test-bed. Result: The results are following: 1) Increased reflectivity generally contributed to increase of indoor illuminance but degrade uniformity factor related with indoor comfort of light environment. 2) The $0^{\circ}fixed$ light shelf with 75% of reflectivity and width of 300mm and 40mm appeared to consume more energy than other shelves. Therefore, it is analyzed as unsuitable. 3) This research was conducted by calculating appropriate angle of light shelf around winter and summer solstices and vernal/autumnal equinox. Based on this, performance evaluation was undertaken depending on reflectivity of movable light shelf, which is activated by external sources and can be applied with lower reflectivity than fixed shelf. However, one exception was a movable shelf with width of 600mm that increased light energy consumption when 75% of reflectivity was applied. 4) Performance evaluation of fixed and movable light shelf showed that the shelf with 80% of reflectivity came up with suitable results, but 75% of reflectivity may be applied depending on the width and angle of the shelf. This research is meaningful in that estimation of appropriate reflectivity of light shelf can resolve the glare problem and improve light environment, and further research would be desirable under more diverse conditions to identify proper solution.

• Journal of Ecology and Environment
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• v.33 no.4
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• pp.343-349
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• 2010

In Korea, man-caused forest fires are known originate primarily in coniferous forests. We have hypothesized that the vulnerability of Pinus densiflora forests is principally a consequence of the ignition characteristics of the species. To assess this hypothesis, we conducted two combustion experiments using fallen leaves with a reference species, Quercus variabilis. In the first experiments, in which a cigarette was employed as a primary heat source for the initiation of a forest fire, the Pinus leaves caught fire significantly faster (1'1" at Pinus, 1'31" at Quercus, P < 0.001), and ignition proceeded normally. Quercus leaves, on the other hand, caught fire but did not ignite successfully. In the second set of experiments utilizing different moisture contents and fuel loads, the maximum flame temperature of the Pinus leaves was significantly higher ($421^{\circ}C$ at Pinus, $361^{\circ}C$ at Quercus, P < 0.001) and the combustion persisted for longer than in the Quercus leaves (8'8" at Pinus, 3'38" at Quercus, P < 0.001). The moisture contents of the leaves appeared to be a more important factor in the maximum temperature achieved, whereas the most important factor in burning time was the amount of fuel. Overall, these results support the assumption that Pinus leaves can be ignited even by low-heat sources such as cigarettes. Additionally, once ignited, Pinus leaves burn at a relatively high flame temperature and burn for a prolonged period, thus raising the possibility of frequent fire occurrences and spread into crown fires in forests of P. densiflora.

• KIEAE Journal
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• v.13 no.5
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• pp.43-50
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• 2013

Recent researches on plant factory system deal with the convergence of lighting technology, agricultural technology inclusive to the high-tech industries worldwide in order to respond to the decreasing crop harvest due to global warming and abnormal weather phenomena. However, the fundamental performance standard is not currently being introduced in the case of plants factory and its commercialization is not activated because of high initial investment and operating cost. Large portion of the initial investment and operating cost of a plant factory is ascribed to artificial light sources and thermal control facilities, therefore, innovation should be provided in order to improve the economics of the plant factory. As an alternative, new plant factory could harness solar thermal and geothermal systems for heating, cooling and ventilation. In this study, a natural light dependent multi-layer plant factory's thermal environment was analyzed with two-dimensional numerical methods to elicit efficient operation conditions for optimized internal physical environment. Depending on the supply air temperature and airflow rate introduced in the facility, the temperature changes around the crops was interpreted. Since the air supplied into the plant factory does not stay long enough, the ambient temperature predicted around the plating trays was not significantly different from that of the supplied air. However, the changes of airflow rate and air flow pattern could cause difference to the temperature around the planting trays. Increasing the amount of time of air staying around the planting trays could improve energy performance in case the thermal environment of a natural light based multi-layer plant factory is considered.

• Korean Journal of Ecology and Environment
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• v.46 no.4
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• pp.471-487
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• 2013

This review paper was written to provide background information as well as future application for aquatic ecologists interested in using stable isotope. Stable isotope techniques has proved to be an extremely useful to elucidate a lot of environmental and ecological problems. Stable isotopes have been used as possible tracers to identify sources, to quantify relative inputs in a system. When utilized carefully, stable isotope tools provides apparent advantages for the scientists to find out the processes of material cycles in various environments and energy flows in natural ecosystems.

• Journal of Plant Biotechnology
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• v.43 no.2
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• pp.248-254
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• 2016

The purpose of this study was to investigate biological activities of Brassica rapa (Turnip) plant callus extracts of Ganghwa-gun of Incheon city using water, ultrasonic wave and ethanol extractions to develop functional materials. DPPH radical scavenging activities of the callus extracts were increased in a concentration-dependent manner, as compared with control. The astringent effects of the ethanol extracts were higher, as compared to water and ultrasonic extracts. In the collagen synthesis assay, the ethanol extract showed significant anti-wrinkle effects of 59% and 78% at a concentration of 5 ppm and 10 ppm, respectively. These results suggested that water, ultrasonic wave and ethanol extracts of turnip plant calluses are natural antioxidant sources. Especially, the ethanol extract can be regarded as a functional, natural cosmetic material with astringent and anti-wrinkle effects.

• Journal of Ecology and Environment
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• v.36 no.3
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• pp.183-191
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• 2013

Dissolved organic carbon (DOC) concentrations and zooplankton and particulate organic matter (POM) ${\delta}^{13}C$ values were measured in five reservoirs in Korea. Zooplankton ${\delta}^{13}C$ and POM ${\delta}^{13}C$ showed large range from -33‰ to -22‰ and a significant difference among the reservoirs. One eutrophic reservoir, Lake Masan, showed unique characteristics with the highest zooplankton density, the highest ${\delta}^{13}C$, and the highest DOC. Zooplankton ${\delta}^{13}C$ was similar to POM ${\delta}^{13}C$, implying that zooplankton occupies substantial portion of POM or that zooplankton isotopic composition is related to selective grazing and assimilation of food sources from bulk POM. Except Lake Masan zooplankton ${\delta}^{13}C$ values were negatively correlated to DOC concentration in four reservoirs with mostly forest land use. This pattern can be probably attributed to intensive agricultural land use in the watershed of Lake Masan compared to the mostly forest land use in the other watersheds. Understanding the relationship between zooplankton ${\delta}^{13}C$ values and the origin of organic matter associated with watershed characteristics will be valuable to better understand trophic relationships in reservoirs in the summer monsoon region.

• KIEAE Journal
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• v.7 no.1
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• pp.15-22
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• 2007

Indoor air quality(IAQ) problems are not limited to large office buildings that are inadequately operated. In fact, many school buildings have significant potentials of air pollution and indoor air pollutants may be of particular concern because it is estimated that most young students who are physically weak to the pollutants spend about 90% of their time in classrooms. The goal of the study is to provide academic and architectural information on the major factors that influence indoor air quality in the elementary school. In order to gain a better understanding of IAQ problems in schools, a series of measurement studies of indoor air quality were designed and 3 different elementary school buildings located in Chuncheon were selected. The levels of CO, $CO_2$, and total volatile organic compounds(TVOCs) including formaldehyde(HCHO), major concern of this study, were measured in absence of students after class. As the results, it is noticeable that most indoor air pollution comes from sources inside the building, which are, for example, adhesives, upholstery, manufactured wood products, art and scientific supplies. The level of CO was measured similarly to that of outdoors, which means no impact on the indoor air problems since it is lower than the code. Ventilation played an important role in the level of $CO_2$ of which difference was 1.7 times in rough and 230 % of difference in the level was detected among the 3 school buildings. This concludes that indoor air problems might be result of poor building design with inadequate location of corridors within space organization or occupant activity patterns of ventilation.

• Journal of Korean Society of Rural Planning
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• v.19 no.4
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• pp.213-226
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• 2013

Agricultural tourism is a new kind of industry, which combined agriculture with tourism. It not only has the productive function, but also has the function of improving the quality of ecological environment and supplying people with sightseeing, leisure, vacation. Agricultural tourism is a new kind of industry from the amalgamation of agriculture and tourism: it is based on farm work, characterized by agricultural management, combines agriculture and tourism, and includes the city as a market-place. It satisfies tourist demand with food, lodging, excursions, shopping and entertainment provided by agricultural places and agricultural products. After combining the substance of this study with the primary sources regarding the development of agricultural tourism, I suggest plans for the development of local agricultural tourism on the basis of sustainable tourism theory in case of the Inner Mongolia region. To conduct research, various data such as literature research and surveys are collected and analyzed. According to the result of the research, the Inner Mongolia region has great-wealthy resources for agricultural tourism. However, they have problems as well such as lack of funds, low infrastructure, low business-mind level, low management-mind, the scarcity of mid-supporting organizations for research and education, low awareness, and low service level of the agricultural tourism. In order to solve these problems, have to strengthen publicity, strengthen the county and city communication, educates continuously profession talented person, establish related laws and regulations, increase the integrity of infrastructure. As a developing industry, agricultural tourism is a new field of study which needs more encouraging research. The agricultural tourism of Inner Mongolia Autonomous Region has only just started development resulting in a limited amount of information available for this study. Future planned work entails a continuous in-depth study of Chinese agricultural tourism, considering Inner Mongolia Autonomous Region in particular.

• Korean Journal of Environmental Biology
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• v.28 no.3
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• pp.125-132
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• 2010

In order to assess the effect of pollution on marine ecosystem, we examined the plankton health assessment at 16 stations during summer season in Jinhae Bay. The organic and inorganic pollutant sources (dissolved organic carbon; DOC, chemical oxygen demand; COD and Chlorophyll a; Chl.a), including planktonic orangism such as enterobacteria Escherichia coli, heterotrophic bacteria (HB), autotrophic nano-flagellates (ANF), heterotrophic nano flagellates (HNF), ciliate and harmful algal bloom species (HABs) were used to characterize marine ecosystem health assessment. Of these, we tentatively selected those items Chl.a, HABs, HB and E. coli for plankton health index (PHI). Also, the scoring criteria for each metric were based on a statistical analysis and then, the grades are rated on four levels. As a result, the ecological assessment of these data reveals that PHI in Jinhae Bay is rated as "Good or fair" for overall conditions. The present study suggests that the PHI might be considered as one of important management tool to assess marine ecosystem health of Jinhae Bay.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.4
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• pp.11-22
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• 2009

This was a 2nd-year study aiming at developing the procedure of alternative system that was intended to restore not only biophysically disturbed areas but also psychologically and socially damaged community. It was suggested that this participatory restoration system could be constructed based on integrative categorization processes consisting of damage types and readiness of local residents for participation. Three case study sites-High-One resort, Lafarge-Halla cement, and high-altitude farmland near Gangneung city, were selected to apply the theoretical framework proposed as a result of 1st-year work. In order to develop introductory programs, key concepts such as forest for future, carbon offset forest, and healing forest, have been suggested based on analysis of 6 system components including human resources, communication, legal and institutional support, financial sources, restoration methods, and activity programs for each site. More detailed processes and procedures can be identified, defined, and refined after the end of final, 3rd-stage of the study in April of 2010.