• Applied Microscopy
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• v.29 no.3
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• pp.353-362
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• 1999

Di-(2-ethylhexyl) phthalate (DEHP) is a plasticize. known as one of endocrine disruptors. The present study was carried out to investigate the ultrastructural changes of prepubertal rat testis after oral administration of DEHP in dosages of 1 g/kg, 3 g/kg or 5g/kg in 0.5 ml of corn oil daily for a week. This study revealed the DEHP inhibited the development of seminiferous tubules and induced structural changes on various cell types of the rat testis. Leydig cells, Sertoli cells and the developing germ cells seemed to be impaired their differentiations in terms of the structural changes of cell organelles. The increase of heterochromatin in amount were common features in all 3 cell types. In addition, the Leydig cells were characterized by the increases in number and size of lysosomes and the scantiness of smooth endoplasmic reticulum. The Sertoli cells became irregular in nuclear envelope and the cytoplasm decreased, but the number of lysosomes and vacuoles seemed to be increased. There were some indications of necrosis of the germ cells, such as vacuolized nucleus and segregated nucleolus. These detrimental effects of DEHP on the rat testis were dose dependent and suppressed spermatogenesis decreasing developing germ cells in number and appearances. The effect of DEHP on ultrastructure of rat testis, as its known physiological functions, seems come from the decreased level of testosterone by Leydig cells, followed by the abnomalities of Sertoli cells and the germ cells.

• Korean Journal of Environmental Agriculture
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• v.20 no.3
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• pp.192-200
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• 2001

The event-based agricultural non-point source(AGNPS) pollution model was applied to estimate the loads of nitrogen and phosphorus in a stream draining small agricultural watersheds. Calibration and verification of the model were performed using observed data collected from rainfall events in the Imgo watersheds during 1997-1998. Parameter calibrations were made for the runoff curve number. The peak flow volumes in the watersheds were well reproduced by the modified model. Average deviation between observed and simulated values was 10%, and this match was confirmed by the coefficient of efficiency value of 0.97. The deviations tended to increase as the peak flows increased. The simulated total N concentrations in the stream water were fairly close to the measured values, and the coefficient of efficiency in the estimation was 0.93. However, there were relatively large variations between calculated and observed values of total P concentration, and the coefficient of efficiency in the estimation was 0.74. Any inaccuracies that arise in estimating runoff flow and nutrient loading can not be explained exactly and further adjustment and refinements may be needed for application of AGNPS in agricultural watersheds. With this restrictions in mind, it can be concluded that AGNPS can provide realistic estimates of nonpoint source nutrient yields.

• Journal of the Korean Geographical Society
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• v.44 no.4
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• pp.447-462
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• 2009

Kohyun River basin is located at southern parts of Taebaek Mountains and most of river basins consists of sedimentary rock. The aims of this study are to investigate the distribution characteristics and processes of fluvial terraces at Kohyun River, using scientific methods such as classification of fluvial landforms, analysis of geomorphological deposits, XRD and OSL age dating. In Kohyun River basin are three levels terraces from T1 to T3. Fluvial terraces are assumed to be erosional terraces according to deposited situation of alurium and existences of bedrock riverbed. From the result of OSL age dating, formation age of fluvial terrace 1(T1) is calculated about 37,000 yr.B.P.(MIS 3), and fluvial terrace 2(T2) is calculated about 113,000 yr.B.P.(MIS 5). Therefore, fluvial terraces at Kohyun River are assumed to be formed at warmer period in the glacial stages or cooler period in the interglacial stages. The incision rate of fluvial terrace 1 at Kohyun River is calculated to be 0.054m/ka, and the incision rate of fluvial terrace 2 is calculated to be 0.115m/ka. This results suggest to lower incision rate than other rivers in Korea because of low uplift rates and little discharge.

• Journal of the Korean association of regional geographers
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• v.11 no.6
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• pp.530-542
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• 2005

In this study, GIS method has been used to get fractal characteristics. Using the projected area and surface area, 2 dimensional fractal characteristic of terrain was found out. Correlation of fractal dimension and mean slope were also checked over. Results are as below. 1) To get a fractal dimension, the method which is using the surface area is also directly proportional to complexity of the terrain as other fractal dimension. 2) Fractal dimensions using the surface area, that is proposed in this thesis are carried out as below : Uiseong : $2.02{\sim}2.15$ Yeongcheon : $2.10{\sim}2.24$. These values are in a range of fractal $2.10{\sim}2.20$ dimensions which has known. 3) Correlation of mean slope and fractal dimension is diminished about 30% in a region which is more than $25^{\circ}$ of mean slope. So, in this region using the fractal dimension method is better than using the mean slope. From this study, on formula using the projected area and surface area is still good to get a fractal dimension that has been found. But to confirm this method the region of research should be wider and be set up the correlation of mean slope, surface area and fractal dimension. It can be applicable to restoration of terrain and traffic flow analysis in the future research.

• Journal of Conservation Science
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• v.32 no.4
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• pp.535-548
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• 2016

Hanging paintings are used for special ceremonies in Buddhist temple. They are stored in special storage box called "Gwaebulgwae" which means storage box for a hanging painting. Studies regarding pigments, background fibers and textiles of hanging paintings are carried out with many data in the field of conservation science. However, there are only few studies for the axes of hanging paintings and storage boxes. In this study, species identification for wooden axes of hanging paintings and storage boxes from the Joseon dynasty are carried out. Hanging painting of Beopjusa temple, Magoksa temple, Sudeoksa temple, Gaeamsa temple, Sudosa temple, Bukjangsa temple, Dorimsa temple, Tongdosa temple and Daeryeonsa temple are selected. Sampling is carried out from the axes of hanging paintings and storage boxes. 81 samples are collected from hanging paintings and storage boxes. As a result, 51 hard pines of Pinus spp., 8 Tilia spp., 6 Juniperus spp., 5 soft pines of Pinus spp., 4 Tsuga spp., 3 Pseudotsuga spp., 2 Berchemia spp., 1 Pyrus spp., 1 Bambusoideae are identified. Tsuga spp. and Pseudotsuga spp. might be used in conservation and restoration works in modern times because those species do not naturally grow in Korea. Most hanging paintings and storage boxes are made of hard pine. Also, some of are made of Tilia spp., because it represents the symbol of Buddha. Some unique kinds of trees used for wooden sculpture are identified, such as Juniperus spp. and Berchemia spp. Authentic conservation and restoration works could be carried out with this data-base.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1687-1692
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• 2015

Since the domestic grape wine industry has been stagnant, the quality of Korean wine must be improved to compete with imported wines. For improving the quality of domestic wine up to 'unfined' or 'unfiltered' wine, this study investigated the possibility of producing 'unfined' or 'unfiltered' wine and their physicochemical characteristics. Muscat Bailey A as a domestic grape was selected to make wine. Prior to refining process after alcohol fermentation, the wine samples were divided into three specimens depending on the treatment of bentonite for clarification and filter (sample A treated with both bentonite and filter, sample B treated with bentonite only, and sample C treated without bentonite and filter). The physicochemical characteristics of each specimen after one week matureness were then investigated. Sample C showed highest values in total phenol and organic acid content among others. Samples B and C showed more stability in intensity, hue, and color. Although it is hard to compare domestic wine with imported wine, it may be possible to improve the quality of domestic wine and contribute to the development of the domestic wine industry when further studies are conducted on in-depth fermentation of wine and improvement of microbiological stability.

• Journal of Life Science
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• v.20 no.5
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• pp.639-643
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• 2010

Sudden deaths have occurred in feedlot cattle with marked necro-hemorrhagic enteritis of the jejunum, ileum and colon. Suckling beef calves are the most frequently affected. Over-consumption of large amounts of milk, inadequate colostrum intake, chilling and stress are conducive to the development of enterotoxemia. Enterotoxemia caused by Clostridium perfringens type D mostly occurs following a sudden change of diet, particularly to feeds made richer in order to grow the cattle to market weight in feedlots. During July 2006, sudden deaths of cattle occurred in the Youngcheon regional area of Gyeongbuk province. There were no significant clinical signs except anorexia, depression, intermittent diarrhea and mild respiratory failure. Histological findings revealed a prominent intranuclear inclusion as well as infiltration of the globular leukocytes in various organs including the heart, kidneys, liver, spleen and lymph nodes. Spleen and lymphatic tissues showed lymphatic necrosis and a starry sky appearance. In the submucosa of the small intestines, basophilic aggregation was detected with massive infiltration of the globular leukocytes and eosinophils. Gram staining for the tissue sections containing inclusions of the small intestines revealed a positive histochemical reaction. Taken together, we suggest that Clostridium perfringens type D-induced enterotoxemia is determined to be the cause of sudden death of feedlot cattle.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.4
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• pp.177-186
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• 2008

This study was carried out to analyze the relationship between major climatic factors (temperature and precipitation) and tree ring growth of Pinus densiflora in 28 cities and counties in Korea. To examine tree ring growth of Pinus densiflora and the response of the climatic factors to climate change, the regional climatic data (for how many years??) from weather stations were categorized by five groups using cluster analysis for major climatic factors. In terms of relationship between monthly average temperature and tree ring growth of Pinus densiflora, negative correlations were observed for the temperatures in March of the present year in Baekdudaegan region and those in February and March in Gyeongbuk and East coast region. In addition, the temperature in October of the previous year was also negatively correlated with tree ring growth. Precipitation was positively correlated with the April and June temperatures of the present year in Baekdudaegan region and Gyeongbuk, respectively. Precipitation effect on the tree ring growth with current year June in Honam and Gyeongnam inland region and June, September in East coast region.

• The Korean Journal of Ecology
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• v.26 no.1
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• pp.23-28
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• 2003

In order to identify plant species and communities characteristic of lithospheric condition, forest vegetations of igneous(mainly granite) and sedimentary(mainly sandstone) areas in Kyungpook province were compared. We collected 108 phytosociological releves from the older forests over 20 years old. 444 vascular plant species and 25 plant communities were identified. Results of Principal Coordinates Analysis (PCA) indicated that lithospheric conditions and human impacts were the most important factors related to the plant community diversity and species richness. In the igneous rock areas net contribution degree (rNCD) of 139 species including Quercus serrata, Q. mongolica, Lindera obtusiloba and Fraxinus sieboldiana increased and those of Carpinus laxiflora and Styrax japonica decreased. In the sedimentary rock areas, to a lesser extent, 96 species including Q. aliena, Zanthoxylum schinifolium, Potentilla fragarioides var. major, Rhus javanica, and Plectranthus japonicus increased, whereas character species of Lindero-Quercion mongolicae such as Q. mongolica, Q. serrata, Rhododendron schlippenbachii, Acer mono and Styrax obassia decreased, and particularily the species Sasa borealis, the Alangium-Zelkova serrata community and the Philadelphus-Fraxinus mandshurica community were absent. The vegetation of sedimentary rock area is characterized as a regional type shaping dwarf pine forests and sparse and light broad-leaved forests.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9B
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• pp.778-790
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• 2004

In this paper, we propose the functional models of optical burst switching (OBS) routers to apply GMPLS (Generalized Multiprotocol Label Switching) to optical networks based on OBS. In addition, we introduce a connection admission control (CAC) algorithms which are operated in this models and can accommodate the required QoS. Firstly, the characteristics of current GMPLS and OBS for the optical Internet are basically considered. With this consideration, the models are proposed to accept OBS features which include the recognition of data bounda η with control information and the statistical multiplexing in terms of bursts. Secondly, we use an offset time decision (OTD) algorithm on behalf of controlling the connection admission with taking QoS parameters such as burst loss rate(BLR) and service-differentiation ratio(SDR) into consideration. The proposed CAC algorithms use the offered load of LSP (Label Switched Path), wavelength information, and QoS parame ‘ ers as inputs of OTD algorithm. A call setup request will be accepted when the offset time decided by OTD algorithm is reasonable for guaranteeing its requested QoS. Simulation is used for performance evaluation Results show the proposed schemes can guarantee the required QoS and those are better than the previous one in terms of channel utilization.