• Korean Journal of Agricultural Science
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• v.30 no.1
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• pp.41-58
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• 2003

This study was conducted to investigate bird community and to suggest a proper way how to manage protect bird community in Gap stream. The survey was carried out over four sections by the line transect method and point counts method from September 2001 to August 2002. Natural stream region as Gasuwon Bridge - Mannyeon Bridge are observed birds were 11 orders 29 families 67 species, Artificial stream region as Mannyeon Bridge - Daedeok Bridge are observed birds were 6 orders 10 families 30 species, Daedeok Bridge - Wonchon Bridge are 8 orders 12 families 28 species, Wonchon Bridge - Gap Stream Bridge are 8 orders 18 families 40 species. All the observed birds in artificial stream region are 8 orders 19 families 47 species. Number of species in natural stream region was higher than artificial stream region owe to a various habitat environment such as forest, cultivated land, streamside forest, sandy plain, gravelly field, reedy field etc. and can not add with the interface and the usage of the human. Number of species in artificial stream region was lower than natural stream region owe to a simple habitat environment and the water ecosystem is severed with embankment block and grass plot with the land ecosystem. The furtherance of various habitat environment which considers the ecosystem like the natural stream as the water ecosystem is joined together with the land ecosystem is desired to attract various wildbirds in Gap stream. The design is desired with the maintenance of the stream to consider the stream corridor which plays ecological important role as connect the fragment habitats.

• Radiation Oncology Journal
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• v.9 no.1
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• pp.7-15
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• 1991

Pentoxifylline (PENTO) has been known to improve RBC fluidity, and thus improve the flux of RBC through narrow capillaries. Additionally, PENTO also decreases the $O_2$ affinity of hemoglobin by increasing 2,3-DPG levels, thereby increasing the $O_2$ release from RBC. Nicotinamide (NA) has been reported to decrease the number of acutely hypoxic cells in tumors by temporarily increasing tumor blood flow. Therefore, the purpose of this study was to examine whether the combination of PENTO and NA (PENTO+NA) would reduce the radioresistance of the Fsall murine fibrosarcoma by oxygenating the hypoxic cells. We obsewed a significantly enhanced radiation-induced growth delay of the FSaII tumors by PENTO+NA. Thus the enhancement ratio was between 2.5 and 2.8 in growth delay assay. The $TCD_{50}$ of control tumors was about 57 Gy, but that of PENTO+NA treated tumors was about 32Gy. Thus $TCD_{50}$ was modified by a factor of 1.8. We also observed that PENTO+NA exerted no effect on the radiation-induced skin damage after the legs without bearing tumors were exposed to X-irradiation. In order to clarify radiosensitizing effects of PENTO+ NA, changes in tumor blood flow and intratumor pOf were measured using laser Doppler flowmetry and $O_2$ microelectrode methods. The tumor blood flow significantly increased at 10 min. after injection of PENTO+ NA. Furthermore, we also found that PENTO+ NA significantly increased intratumor $pO_2$ from 8 to 19 mmHg. We concluded that PENTO+MA was far more effective than NA alone or PENTO alone. The increase in the response of tumors in vivo to X-irradiation appeared to be due mainly to an increase in the tumor oxygenation. Further studies using various concentrations of PENTO alone and in combination with NA to obtain better sequencing and maximal radiosensitization are warranted.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.1
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• pp.50-61
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• 2010

This study was carried out to find out the way to build a comprehensive wetland ecosystem database using the technique of remote sensing and Geographic Information System. A Landsat TM image (taken in Oct. 30, 2002), Kompsat-2 images (Jan. 17, 2008 & Nov. 20, 2008), LiDAR(Mar. 1, 2009) were used for the primary source for the image analysis. Field surveys were conducted March to August of 2009 to help image analysis and examine the results. An actual wetland vegetation map was created based on the field survey. Satellite images were analyzed by unsupervised and supervised classification methods and finally categorized into such classes as Phragmites australis community, mixed community, sand beach, Scirpus planiculmis community and non-vegetation intertidal area. The map of wetland productivity was developed based on the productivity of Phragmites australis and the relationship to the proximity of adjacent water bodies. The developed 3 dimensional wetland map showed such several potential applications as flood inundation, birds flyway viewsheds and benthos distribution. Considering these results, we concluded that it is possible to use the remote sensing and GIS techniques for producing wetland ecosystem spatial database and these techniques are very effective for the development of the national wetland inventory in Korea.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.3
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• pp.104-115
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• 2014

A levee is defined as an man-made structure protecting the areas from temporary flooding. This paper suggests a methodology for establishing the levee GIS database using the airborne topographic LiDAR(Light Detection and Ranging) data taken in the Nakdong river basins and the WAMIS(WAter Management Information System) information. First, the National Levee Database(NLD) established by the USACE(United States Army Corps Engineers) and the levee information tables established by the WAMIS are compared and analyzed. For extracting the levee information from the LiDAR data, the DSM(Digital Surface Model) is generated from the LiDAR point clouds by using the interpolation method. Then, the slope map is generated by calculating the maximum rates of elevation difference between each pixel of the DSM and its neighboring pixels. The slope classification method is employed to extract the levee component polygons such as the levee crown polygons and the levee slope polygons from the slope map. Then, the levee information database is established by integrating the attributes extracted from the identified levee crown and slope polygons with the information provided by the WAMIS. Finally, this paper discusses the advantages and limitations of the levee GIS database established by only using the LiDAR data and suggests a future work for improving the quality of the database.

• Journal of the Korean Geographical Society
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• v.43 no.6
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• pp.808-823
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• 2008

Sediment abrasion in rivers is caused by the interaction between bedrock channel bed and sediment particles transported through the river. Abrasion rate of sediment particles in rivers is controlled by two major factors; Sediment transport conditions including hydraulic conditions form the erosive forces and physical and chemical strengths of the particles form a resistance force against abrasion and other erosional processes. Physical experiments were performed to find the role of each variable on sediment abrasion process. Total 266 sediment particles were used in this experiment. All sediment particles were divided into 11 independent sediment groups with sediment particle size and sediment loads. Each sediment groups were abraded in tumbling mill for up to 8 hours. Changes in weight were recorded by run and total: 2,128 cases of abrasion rate were recoded. Physical strength of rock particles was measured with point load strength index. It is found that sediment abrasion rate has a negative functional relationship point load strength index ($I_{a(50)}$) ($R^2=0.22$). It was suggested that physical strength of sediment particles set the "maximum possible abrasion rate'. As sediment flux increases, abrasion rates of sediment particles with similar point load strength index were changed. It could be concluded that not only physical characteristics of sediment particles, but also sediment transport conditions control sediment abrasion rates.

• Journal of the Korean earth science society
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• v.39 no.1
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• pp.89-102
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• 2018

We analyzed the meteorological and radiation characteristics of Seoul metropolitan area using data from energy flux towers that were installed and operated by the Weather Information Service Engine (WISE). The meteorological and radiation variables included temperature, pressure, wind speed, wind direction, relative humidity, surface temperature, rainfall amount, upward and downward solar radiation, upward and downward longwave radiation, albedo and emissivity from 14 energy flux stations located in the Seoul metropolitan area from July 2016 to July 2017. According to the monthly data during the period, the albedo is low and emissivity is high at the Jungnang station in the urban and opposite at Bucheon station in the suburban area. For a station in natural state, the albedo was higher than urban stations because solar radiation reflects effectively. Relatively high temperatures were shown at stations located in urban area with low albedo and high emissivity, in general. However, temperature was high at Gajwa and Ttukseom stations, the albedo was relatively high due to the station environment surrounded by glass wall buildings and the Han river. In the station located in suburban area, both emissivity and temperature were low. Among these stations, Bucheon station had the highest emissivity values because the surface temperature was relatively lower than that of the suburban area. As a result, the albedo decreased and the emissivity increased at stations in urban areas. Additionally, Seoul metropolitan area had less than $100Wm^{-2}$ of net radiation, which implied that radiation energy could be absorbed in the atmosphere.

• Journal of Korean Society of Forest Science
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• v.54 no.1
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• pp.60-67
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• 1981

The run-off experiment plots had been established for eight sets of plot comprising four treatments with two replications on $20^{\circ}$ slope land having the Wait-A-Bit Clay soil(locally known), at the Olive River Soil Conservation Centre, Trelawny in Jamaica. The location of plots was about 820 metres m.s.l. and sloped north-west. Each plot size was determined as $40m^2$ having 2.7 m wide and 15.8 m long along slope. All of the run-off soil and water were collected by using the receiving tanks through the collection troughs and conveyance pipes. These run-off materials were measured and sampled, dried and computed for determination of the soil loss from each treatment of plots. During the first period of experiment for about 10 month which was one crop-year cycle of yam crop, total amount of 1,295 mm rainfall received. The heaviest daily rainfall was recorded as 116.2 mm on August 5 followed by 100.4 mm on August 6, 1980. The soil sediment had been collected and analysed for eleven times during this experiment. Total amounts of soil sediment as over-dried weight by the treatment plot were estimated as 182 ton/ha from treatment I, 105 tons/ha from treatment II, 50 tons/ha from treatment III, 43 tons/ha from treatment IV respectively. It is recommendable at present that the treatment III and IV measure which treated with contour mounds with the hillside ditch and grass buffer strip should be adopt4ed for hillside farming particularly with yam cultivation in Jamaica.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.1
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• pp.11-19
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• 2013

As the temperature data show a distribution pattern with a number of peaks, assumption of normal distribution will result in a serious bias in the analysis. In this study, the Gaussian Mixture Distribution (GMD), a type of bimodal distribution, is presumed as a frequency distribution for the water temperature, in order to estimate the optimal parameter and to carry out the relation analysis between the optimal parameter and the basic statistical information such as mean and variance on the data. By the way, an estimation formulae to compute the frequency distribution of the data is developed by computing the parameters of GMD (i.e. ${\alpha}_1$, ${\mu}_1$, ${\sigma}_1$, ${\alpha}_2$, ${\mu}_2$, ${\sigma}_2$) by means of the major characteristic values, such as mean, standard deviation and skewness of the data. The formulae shows an excellent coincidence with the result from the observation data, in the RMS limit accuracy of 5%.

• The Journal of Engineering Geology
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• v.24 no.3
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• pp.431-440
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• 2014

Since the establishment of the Groundwater Act in Korea in 1993, the national policy on groundwater has focused on the preservation and management of groundwater, which should be used only as a subsidiary water resource. However, population growth, increased water demand, climate change, and the need for uniform water distribution have brought changes to groundwater policy, and have led to the prioritization of development projects such as groundwater dams and river bank filtration. Population growth, changes to the water environment, and increased water risks have all played a role in triggering rapid growth within the water industry; the size of the investment in water resources will also continue to increase worldwide. Until now, private wells and bottled mineral water have led the groundwater industry in South Korea. However, a new area of the groundwater industry, which includes the health and medical sciences, employs groundwater properties derived from regional geology, and is growing. This requires the advancement of groundwater research and technical development connected with ICT (Information and Communication Technology) and medical science, and that the public development of groundwater and its various applications is expanded through locating groundwater in the core of the water industry cluster.

• Journal of Environmental Impact Assessment
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• v.10 no.1
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• pp.21-37
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• 2001

항공 비디오의 가장 큰 장점은 협각조망범위에 동영상을 제공함으로서 저렴한 경비로 소폭/장거리 지상물체를 감시하는 최적의 원격탐사도구로 알려져 있다. 선형감시에 대한 비디오의 이와 같은 이론적인 장점에 의거하여 하천수질을 모니터링 하기 위한 비디오 샘플링 기법이 본 연구를 통해 제시되었다. 본 연구의 근본적인 의도는 전통적인 샘플링에 기반을항공 비디오의 가장 큰 장점은 협각조망범위에 동영상을 제공함으로서 저렴한 경비로 소폭/장거리 지상물체를 감시하는 최적의 원격탐사도구로 알려져 있다. 선형감시에 대한 비디오의 이와 같은 이론적인 장점에 의거하여 하천수질을 모니터링 하기 위한 비디오 샘플링 기법이 본 연구를 통해 제시되었다. 본 연구의 근본적인 의도는 전통적인 샘플링에 기반을 둔 현장조사의 개념을 디지털 비디오의 해석기법에 연계시키려는 것이었다. 특정 지점에서 시료를 채취하는 현지 샘플링조사와 동일한 방식으로 장거리에 걸친 하천의 수질감시를 위해 원격동영상을 컴퓨터 모니터에 디스플레이 하면서 비디오 샘플지점을 선정하여 수질을 감시하였다. 비디오 샘플링 기법은 하천 색조의 변화실태에 대한 가상현실의 형태로 정보를 제공했다. 다양한 샘플지점에서 나타나는 하천 색조의 변화추세를 가시적으로 파악할 수 있었으며 전통적인 현장 샘플링 방법으로는 추적하는 데 한계가 있는 특정오염원에 기인한 하천수질의 광역적인 변화패턴을 파악하는 데 상당한 가능성을 보여주었다. 이와 같이 영구적으로 보전된 영상기록은 오염 물질의 이동확산 등 수질환경의 광역적인 변화 추이에 대한 시각적인 정보를 제공하고 있어 현장샘플링과 동시에 사용할 경우 하천수질감시에 있어 상당히 유용한 도구가 될 수 있음을 보여주었다. 본 연구를 통해서 제시된 비디오 샘플링 기법이 도로, 철도, 송유관 등 다양한 선형지형지물의 환경감시에 효과적으로 사용될 수 있을 것으로 사료된다. 둔 현장조사의 개념을 디지털 비디오의 해석기법에 연계시키려는 것이었다. 특정 지점에서 시료를 채취하는 현지 샘플링조사와 동일한 방식으로 장거리에 걸친 하천의 수질감시를 위해 원격동영상을 컴퓨터 모니터에 디스플레이 하면서 비디오 샘플지점을 선정하여 수질을 감시하였다. 비디오 샘플링 기법은 하천 색조의 변화실태에 대한 가상현실의 형태로 정보를 제공했다. 다양한 샘플지점에서 나타나는 하천 색조의 변화추세를 가시적으로 파악할 수 있었으며 전통적인 현장 샘플링 방법으로는 추적하는 데 한계가 있는 특정오염원에 기인한 하천수질의 광역적인 변화패턴을 파악하는 데 상당한 가능성을 보여주었다. 이와 같이 영구적으로 보전된 영상기록은 오염 물질의 이동확산 등 수질환경의 광역적인 변화 추이에 대한 시각적인 정보를 제공하고 있어 현장샘플링과 동시에 사용할 경우 하천수질감시에 있어 상당히 유용한 도구가 될 수 있음을 보여주었다. 본 연구를 통해서 제시된 비디오 샘플링 기법이 도로, 철도, 송유관 등 다양한 선형지형지물의 환경감시에 효과적으로 사용될 수 있을 것으로 사료된다.