• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.208-208
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• 2011

하구는 하천의 담수와 염수가 교차되고 혼합되는 기 수역으로서 수생 생태계의 중요한 서식처이며 바다와 하천의 중요한 생태통로가 되고 있다. 국내에서는 4대 하천 중에서 한강하구가 유일하게 하구 둑이 없는 자연하구이며 나머지 대하천은 둑으로 인해 담수와 해수의 자연스러운 흐름이 제한되고 생태적인 연결이 단절된 형태이다. 한강하구에는 대규모 습지가 분포하고 있으며 특히 장항습지는 종단길이 약 7.5km, 폭 최대 500m에 달하는 대규모 습지로서 고라니를 비롯한 동물과 줄, 선버들을 비롯한 식물의 대규모 군락이 분포하는 등 생태적 가치가 높은 지역이다. 본 연구에서는 한강하구의 장항습지와 산남습지를 대상으로 특정구간의 물리적 특성, 식생의 분포특성을 파악하고 연관성을 분석하고자 하였다. 이를 위해 1차적으로 포괄적인 현장조사를 통해 전체 식생군락과 분포를 파악하고 특징적인 식생군락을 선정하였다. 2차적으로는 선정된 줄 및 선버들 군락지를 대상으로 토양단면, 토양입경을 분석하고, 새섬매자기 군락지를 대상으로 측량을 실시하였다. 3차적으로는 대상 군락의 지하수위를 측정하여 상호관계를 분석하였다. 이 결과는 우선 한강하구의 지역적 특징에 국한되지만 향후 타 지역과의 비교연구가 수행된다면 대상 식생과 물리적 생장조건과의 정량적인 관계가 도출될 것으로 판단된다.

• Korean Journal of Plant Resources
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• v.14 no.3
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• pp.277-285
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• 2001

This study was conducted to know about the distribution of naturalized plants growing in Jeiu Island. A field survey and flora lists of relevant literatures were also investigated. The results obtained from this study were as follows: Definition of naturalized plants was determined in this study as “non-native species in Korea which have been introduced anthropologically or naturally and can reproduce and survive in wild habitats by themselves.” It was suggested that the number of naturalized plants in Jeju Island were 31 families, 111 genera, 188 taxa including 178 species, 10 varieties. Family Compositae and Gramineae covered 23% and 14% of naturalized plants, respectively. The number of naturalized plants in Jeju Island were 188 taxa ; 97 taxa in the whole south Korea,39 taxa in the southern part of Korea,15 taxa in the central part of Korea, and 37 taxa only in Jeju.

• International Journal of Highway Engineering
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• v.12 no.1
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• pp.61-69
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• 2010

In this paper, we present the methodology about an optimal probability distribution selection as well as survival rate estimation with the national highway database from 1999 to 2008. Probability paper methods are adopted to estimate the parameters of each hazard model. The goodness-of-fit test, such as the Anderson-Darling statistics, was performed. As a result, we found that Lognormal distributionan is an appropriate distribution of newly constructed sections as well as overlayed sections. We also ascertained that the results of survival rate for pavement life between the proposed method and observed data are similar. Such a selection methodology and measures based on reliability theory can provide useful information for maintenance plans in pavement management systems as long as additional life data on pavement sections are accumulated.

• Korean Journal of Plant Taxonomy
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• v.38 no.4
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• pp.573-582
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• 2008

We report a newly found natural habitat of Abeliophyllum distichum in mountainous slope range of Yeongdong-gun, Chungbuk Province. Abeliophyllum distichum Nakai is one of the Korean monotypic endemic species. Natural growth habitats of this species have been recorded from seven sites up to now, and all of the natural habitats are located in middle (Chungbuk Prov.) and middle west (Jeonbuk Prov.) parts of South Korea. Among the previously recorded seven natural habitats, six sites have been designated as Korean national monuments and protected with in situ conservation. New natural habitat of A. distichum is located on northwest slope of stiff hillock area beside the small stream, Seolgye-ri, Yeongdong-eup, Yeongdong-gun, Chungbuk Province. Total growing area is nearly $3,000 m^2$. It is 10-25 cm in soil depth and pH 5.0-6.5 in soil acidity in that area. And many of A. distichum are clustered with 2-5 individuals extended by stoloniferous asexual reproduction. And the total numbers of A. distichum are about 700 individuals with only typical white flowers, and the ratio between pin type and thrum type is 37% and 63%, respectively. The huge population of A. distichum is growing with Quercus mongolica-Fraxinus rhynchophylla association in a mixed forest, and it shows high affinity with Stephanandra incisa, Ligustrum obtusifolium, Euonymus alatus for. ciliatodentatus, and Smilax sieboldi.

• Korean Journal of Environmental Agriculture
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• v.27 no.2
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• pp.120-132
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• 2008

Remotely sensed images from a satellite can be applied for detecting and quantifying spatial and temporal variations in terms of landuse & landcover, crop growth, and disaster for agricultural applications. The purposes of this study were to analyze topography using DEM(digital elevation model) and classify landuse & landcover into 10 classes-paddy field, dry field, forest, bare land, grass & bush, water body, reclaimed land, salt farm, residence & building, and others-using Landsat TM images in North Korea. Elevation was greater than 1,000 meters in the eastern part of North Korea around Ranggang-do where Kaemagowon was located. Pyeongnam and Hwangnam in the western part of North Korea were low in elevation. Topography of North Korea showed typical 'east-high and west-low' landform characteristics. Landcover classification of North Korea using spectral reflectance of multi-temporal Landsat TM images was performed and the statistics of each landcover by administrative district, slope, and agroclimatic zone were calculated in terms of area. Forest areas accounted for 69.6 percent of the whole area while the areas of dry fields and paddy fields were 15.7 percent and 4.2 percent, respectively. Bare land and water body occupied 6.6 percent and 1.6 percent, respectively. Residence & building reached less than 1 percent of the country. Paddy field areas concentrated in the A slope ranged from 0 to 2 percent(greater than 80 percent). The dry field areas were shown in the A slope the most, followed by D, E, C, B, and F slopes. According to the statistics by agroclimatic zone, paddy and dry fields were mainly distributed in the North plain region(N-6) and North western coastal region(N-7). Forest areas were evenly distributed all over the agroclimatic regions. Periodic landcover analysis of North Korea based on remote sensing technique using satellite imagery can produce spatial and temporal statistics information for future landuse management and planning of North Korea.

• Korean Journal of Environment and Ecology
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• v.33 no.3
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• pp.303-320
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• 2019

Plants interact with various biotic and abiotic environmental factors. It requires much information to understand the traits of a plant species. A shortage of information would restrict the assessment, especially in the evaluation of what kind of factors influence a plant species to face extinction. Polygonatum stenophyllum Maxim. is one of the northern plants of which Korea is the southern distribution edge. The Korean Ministry of Environment had designated it to be the endangered species until December 2015. Although it is comparatively widespread, and a large population has recently been reported, it is assessed to be vulnerable due to the low population genetic diversity. This study evaluated the current distribution of Polygonatum stenophyllum Maxim. We investigated the vegetational environment, population structures, phenology, soil environment, and self-incompatibility based on the results. Lastly, we evaluated the current threats observed in the habitats. The habitats tended to be located in the areas where the masses at the edge of the stream accumulated except for those that were located on slopes of some mountainous areas. Most of them showed a stable population structure and had re-established or recruited seedlings. Polygonatum stenophyllum Maxim. had the difference in time when the shoots appeared above the ground depending on the depth of the rhizome located in the underground. In particular, the seedlings and juveniles had their rhizome located shallow in the soil. Visits by pollinator insects and success in pollination were crucial factors for bearing of fruits by Polygonatum stenophyllum Maxim. The threats observed in the habitat of Polygonatum stenophyllum Maxim. included the expansion of cultivated land, construction of new buildings, and construction of river banks and roads. Despite such observed risk factors, it is not likely that there would be rapid population reduction or extinction because of its widespread distribution with the total population of more than 2.7 million individuals and the new populations established by the re-colonization.

• Korean Journal of Ichthyology
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• v.24 no.3
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• pp.234-241
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• 2012

Kichulchoia brevifasciata belonging to family Cobitidae is an endemic Korean freshwater fish and restricted to very small areas such as Goheung peninsula, and Geogum Island and Geumo Island flowing into the South Sea. As a decrease of its population was further accelerated, a close investigation on the distribution was required. Among a total of 21 sites surveyed, only 5 sites were confirmed in which K. brevifasciata existed. Based on this result, we classified the 5 sites into 3 categories: Being worthy of preserved, being subject to threaten and staying in good condition.

• The Korean Journal of Mycology
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• v.20 no.2
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• pp.144-148
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• 1992

This experiment was carried out to investigate on the flora and cardinal wild mushroom in Tricholoma matsutake producing sites at the Namweon area. The results were as follows: Flora of Tricholoma matsutake producing sites were prevailed over at tree layer (Pinus densiflora S. et. Z.), shrub layer (Rhododendora mucronulatum TURCZ., Quercus serrata THUNB.) and herb layer (Carex humilis LEYSS.). Piedominant wild mushrooms were Boletaceae (Suillusplacidus Bon.) and Ramariaceae (Ramaria botrytis Fr.)

• Journal of the Economic Geographical Society of Korea
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• v.27 no.2
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• pp.95-119
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• 2024

While several recent studies have investigated the spatial distribution of entrepreneurship within the Seoul metropolitan area, they have not thoroughly examined the relationship between the industrial composition and spatial distribution of entrepreneurial clusters. To address this gap, this study initially identified entrepreneurial clusters through hotspot analysis using Getis-Ord Gi* with venture capital investment data from 2021. Subsequently, to analyze the industrial composition of the identified clusters, we measured not only their industrial diversity and specialization, but also the share of software and non-software industries. Additionally, we examined the government policies related to the formation of the clusters. As a result, we identified fourteen prominent entrepreneurial clusters within the Seoul metro area and revealed that the clusters located closer to the city centers exhibited higher levels of industrial diversity and a greater share of software industries. Conversely, clusters situated farther from the city centers demonstrated a higher share of non-software industries. Furthermore, we found that government policies affect the industrial specialization of suburban clusters. Nevertheless, we observed several exceptions that diverged from the general trends due to policy interventions. These findings underscore that formulating policies for entrepreneurial clusters in metropolitan areas should be based on these insights.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.201-203
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• 2003

변압기에서 발생하는 유중가스는 고장부위의 온도크기에 따라서 특징가스도 다른 것으로 알려져 있다. 본 연구에서는 변압기 고장온도중에서 낮은 온도영역에 해당되는 $300^{\circ}C$이하의 온도에서 열열화를 실시하여 유중가스분포의 거동을 분석하였다. 유중가스 분석결과 이 온도 영역에서는 절연지가 없는 경우 에탄가스가 특징가스로 나타났고, 절연지가 없는 경우도 일산화탄소와 이산화탄소가스의 농도가 크게 나타났다.