• Journal of Korean Society of Forest Science
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• v.77 no.2
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• pp.242-251
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• 1988

Private forestland in Korea occupies about 48 percent of the total land area. But, the ownership size is too small to expect self-supporting management of forestowners. In order to improve individual management of the small-sized forest through the to the state of self-support, a cooperative forest management has been demanded, enlargement of the size of the management units by combining the different individual management units. The cooperative management of the private forest is to combine forestry production factors such as forestland, labor-power, and capitals according to the agreement. For the cooperative forest management, a proper plan should be established and well-trained working-crew should be produced. In addition, forestry facilities should be provided and operated jointly. Though the cooperative forest management by owners is considered to be favorable theoretically, it is difficult for forestowners including many nonresidents to organize the forest management cooperatives without outside help. Therefore, intensive pulblication and extension programmes are required and a financial support by the government should be followed.

• Land and Housing Review
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• v.8 no.4
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• pp.249-256
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• 2017

Urbanization can be remarkable affected flood, pollutant loading, ecological system, and green infrastructure by distortion of hydrologic cycle. In order to mitigate these problems in urban, Low Impact Development(LID) technique has been introduced and applied in the world. SWMM model was calibrated with sets of field monitoring data and applied for calculation of runoff and pollutant loading in Asan-tangjung LID city under 2016 rainfall. Runoff reduction of watershed and catchment basins were showed efficiency 12.2% and 62.0%, respectively. Reduction of COD and TP loading also high efficiency in catchment basins were evaluated 74.9 and 71.4%. The results of this study can be used effectively in decision making processes of urban development project by comparing watershed runoff and pollutant reduction by designs of sort of LID technique, LID volume and location.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.528-535
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• 2020

Recently, the protection coordination method of DC systems has been presented because renewable energy and distributed resources are being installed and operated in distribution systems. On the other hand, it is difficult to detect ground faults because there is no significant difference compared to a steady-state current in ungrounded IT systems, such as DC load networks and urban railways. Therefore, this paper formulates the detection principle of IMD (Insulation Monitoring Device) to use it as a protection coordination device in a DC system. Based on the signal injection method of IMD, which is analyzed by a wavelet transform, this paper presents an algorithm of detecting ground faults in a DC system in a fast and accurate manner. In addition, this paper modeled an IMD and an ungrounded DC system using the PSCAD/EMTDC S/W and performed numerical analysis of a wavelet transform with the Matlab S/W. The simulation results of a ground fault case in an ungrounded DC system showed that the proposed algorithm and modeling are useful and practical tools for detecting a ground fault in a DC system.

• Korean Journal of Ecology and Environment
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• v.51 no.3
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• pp.234-244
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• 2018

The roadkill that animals die after bumping by vehicles on the roads is acting as a factor to decrease the size of various animal populations. It has also been known to be the biggest artificial causations of Vertebrata deaths not only in urban areas but also protected areas such as national parks. Nevertheless, in the national park areas which are major protected national areas for conservation of national biodiversity and ecological diversity, snake roadkills occur frequently. Up to date, related studies are rare. Therefore, in this study, we described snake roadkill patterns on the roads in six national parks between 2006 and 2015. We identified total 736 snake roadkills compromising 10 different species. Five species, Rhabdophis lateralis, Elaphe dione, Gloydius ussuriensis, Lycodon rufozonatus, Gloydius brevicaudus occupied more than 91.7% of total roadkill cases. Active forager snakes were killed by roadkills more than ambush foragers, and the snake roadkill frequency was the highest in September, a migration period and in August when the young individuals dispersed at between 100 and 799 m altitude areas. Roads where roadkills were frequent lie between forest and hydrosphere or between forest and crop field road sides. Our results could be used to identify the trend of snake roadkills on the roads in national parks, and to establish effective roadkill mitigation measures and policies.

• The Korean Journal of Applied Statistics
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• v.29 no.1
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• pp.13-25
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• 2016

High-speed railway (Korea Train Express) has had a deep impact on the regional economy of Korea. Current high-speed rail research is mostly theoretical, there is a lack of quantitative research using a precise algorithm to study the effect of high-speed railway on the regional economy. This paper analyses the influence of high-speed rail on the regional economy, with a focus on the Daegu area. Quantitative analysis using department store indexes and regional medical records is performed to calculate the economic influence of high-speed rail. The result shows that high-speed railway effects the regional economy though regional consumption growth and medical care trends.

• Economic and Environmental Geology
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• v.25 no.3
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• pp.317-336
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• 1992

The garden soils, main road dusts, residential road dusts, and playground soils/dusts of Seoul, Geumsan, Onsan, and Taebaek areas were analyzed in order to investigate the level of heavy metal pollution by urbanization and industrialization. The soil pH is in the range of 5.48~8.40 and was generally neutral. The color of soils and dusts is mainly Raw Umber to dark greyish Raw Umber. Some samples from Taebaek city, a coal mining area, showed a deep black color due to contamination by coal dusts. Major minerals of the dusts and soils are quartz, feldspars, and micas, reflecting the composition of the parent rocks. However, pyrite was found as a major mineral in the samples of industrial road dusts of Onsan, a smelting area, and resicential road dusts of Taebaek. Thus, the high level of heavy metals in mining and smelting areas can be explained with the sulfide minerals. The mode of occurences of heavy metals in Seoul, a comprehensive urbanized area, were related to the metallic pollutants and organic materials through observation by scanning eletron microscopy. In main road and residential road dusts of Onsan area, Cd, Zn, and Cu were extremely high. Some industrial road and residential road dusts of Seoul area showed high Cu, Zn, and Pb contents, wereas some garden soils and residential road dusts of Taebaek area were high in As content. In general, the heavy metal contents in dust samples were two to three times higher than those in soil samples. Main road dust samples were the most reflective from the discriminant analysis of multi-element data. Cadmium, Sb, and Se in Onsan area, As in Taebaek area, Pb and Te in Seoul area were most characteristic in discriminating the studied areas. Therefore, Cd in smelting areas, As in coal mining areas, and Pb in metropolitan areas can be suggested as the characteristic elements of each pollution pattern. The dispersion of heavy metal elements in urban areas tends to orignate in main roads and deposit in garden soils through the atmosphere and residential roads. The heavy metal contamination in Seoul is characteristic in areas with high population, factory, road, and traffic decsities. Heavy metal contents are high in the vicinity of smelters in Onsan area and are decayed to background levels from one kilometer away from the smelters.

• Journal of Korean Home Economics Education Association
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• v.16 no.4 s.34
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• pp.141-156
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• 2004

The purpose of this study was to examine the relationship between marital satisfaction and job performance among secondary school married female teachers. The subjects of this study were 237 married female teachers who worked in middle-and high-schools in Seoul and Gyeonggido. To gauge how they were pleased with their married lives. Lee Jeong-ryeon(1987)'s scale that was based on Synder's scale and made up for its segment about relations with family-in-law. As for job performance. Yun Gyeong-hye(2001)'s scale that was based on Son Jeong-hwan(1990)'s teacher job scale was employed. For data analyses. t-tests. ANOVAs. Scheffe tests for pairwise comparison. Pearson's correlations were utilized. The findings of this study illustrated that the marital satisfaction of the secondary school married female teachers were significantly related to their job performance. This indicated that their marital satisfaction served to enhance their job performance. and furthermore. that could be said to determine the quality of school education.

• Journal of Wetlands Research
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• v.22 no.4
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• pp.312-320
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• 2020

Various LIDs with natural water circulation function are applied to reduce urban environmental problems and environmental impact of development projects. However, excessive Infiltration and evaporation of LID facilities dry the LID internal soil, thus reducing plant and microbial activity and reducing environmental re duction ability. The purpose of this study was to develop a real-time measurement system with complex sensors to derive the management plan of LID facilities. The test of measurable sensors and Internet of Things (IoT) application was conducted in artificial wetlands shaped in acrylic boxes. The applied sensors were intended to be built at a low cost considering the distributed LID and were based on Arduino and Raspberry Pi, which are relatively inexpensive and commercialized. In addition, the goal was to develop complex sensor measurements to analyze the current state o f LID facilities and the effects of maintenance and abnormal weather conditions. Sensors are required to measure wind direction, wind speed, rainfall, carbon dioxide, Micro-dust, temperature and humidity, acidity, and location information in real time. Data collection devices, storage server programs, and operation programs for PC and mobile devices were developed to collect, transmit and check the results of measured data from applied sensors. The measurements obtained through each sensor are passed through the Wifi module to the management server and stored on the database server in real time. Analysis of the four-month measurement result values conducted in this study confirmed the stability and applicability of ICT technology application to LID facilities. Real-time measured values are found to be able to utilize big data to evaluate the functions of LID facilities and derive maintenance measures.

• The Journal of the Korea Contents Association
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• v.14 no.9
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• pp.437-449
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• 2014

In order to suggest alternative directions for the regional development of Chungcheongbukdo through social network analysis (SNA) methods, this study highlights networking features of Chungcheongbukdo-based top 300 enterprises. In particular, it has paid attention to network relationships among participating enterprises and their basic structure, all of which play pivotal roles in provincial development. Major networking features among Chungcheongbukdo-based top 300 enterprises are dichotomized between structural and positional dimensions. Firstly, in terms of structural approach, this research confirms that both relational density indices and average connectivity levels among key enterprises have been extremely low. Therefore, the exchange networks seem relatively limited. That is, two enterprises could be interconnected after 1.1 stages in average, implying that the most popular types come from direct relationship among participating enterprises. In addition, this research finds that 7 major networks hinged upon 'distributed centralization types' present active information exchange, taking in charge of brokerage roles, all of which have contributed to broader network formation. Nonetheless, as the weight of minor network outweighs that of major network, more active supporting measures should be designed.

• The Journal of the Petrological Society of Korea
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• v.18 no.1
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• pp.1-17
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• 2009

This article carried studies of the petrographical and petrochemical characteristics on the Cretaceous volcanic rocks in the area of Janggun peak and Gyemyeong peak which is located at the northeastern area of Mt. Geumjeong, Busan. The areas are composed of andesitic rock, sedimentary rock, rhyolitic rock, and intrusive hornblende, biotite granites, in ascending order. According to petrochemistry, the major elements show the calc-alkaline rock series ranged medium-K to high-K. With increasing $SiO_2$, $Al_{2}O_{3}$, $Fe_{2}O_{3}$, $TiO_2$ CaO, MgO MnO and $P_{2}O_{5}$ are decreased and $K_{2}O$ and $Na_{2}O$ are increased in the volcanic rocks. The trace element compositions show high LILE/HFSE ratios and negative anomaly of Nb, and REE patterns show enrichments in LREE and (-) anomaly values increase of Eu from the basaltic andesite to andesite facies, therefore the volcanic rocks have typical characteristics of continental margin arc calc-alkaline volcanic rocks, produced in the subduction environment. The volcanic rock show nearly the same patterns in spider and REE diagram. Fractional crystallization of the basaltic magma would have produced the calc-alkaline andesitic magma. And the rhyolitic magma seems to have been evolved from the basaltic andesitic magma with fractional crystallization of plagioclase, pyroxene, hornblende, biotite.