• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.193-198
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• 2007

The present study was examined the expression patterns of cdx2 gone, n lineage marker, in the mouse and bovine developmental stage embryos and whether one blastomere of two- and/or four-cell bovine embryos develop to specific lineage (ICM or TE) of blastocyst by injection of Texas red conjugated dextran as a lineage tracer. It was also investigated the allocation of ICM and n cells in bovine blastocysts derived from one blastomere of two-and/or four-cell stage embryos. Firstly, it was observed that expression of cdx2 appeared symmetric and asymmetric distribution at the two-cell stage mouse embryos. from four-cell to morula stage mouse embryos, the expression of cdx2 gene was observed in almost all blastomeres. In case of bovine embryos, localization of cdx2 was similar to pattern of mouse embryos. The Dextran-labeled blastomere of two- and/or four-cell embryos contributed to both ICM and TE cells in bovine blastocysts. And also, it was confirmed that a single blastomere derived from two-cell stage bovine embryos could develop to the normal blastocyst with both ICM and TE cells. These results show that two-and/or four-cell stage is not the specific stage to determine the cell rate for ICM and TE, and which is not correlated with the expression of cdx2 gene.

• Journal of the Korean association of regional geographers
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• v.12 no.2
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• pp.323-337
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• 2006

This thesis aims to study Change of the Land Use in Yanji city since the reformation and opening of China in the Connection with Urbanization Process. This study is based on Landsat image and maps and data related to topography, urban planning basic, the cadastral map were employed. Softwares such as Arcview3.3, ArcGis8.0 were used. The result of the research is as follows. It clearly appears that there have decreased in the ratio of agricultural areas since the increase in other urban usage of land. There has greatly increased in residential, commercial and industrial areas. Such as the capitalist and market economic city the highest point of city land price emerged in downtown of the old city center. In addition spatial pattern of land price is unusually quite different from the western city in its pattern of land price surface declining tendency between the highest land price and the lowest land price. The land price surface shows irregular patterns with increase of distance from downtown due to various urban developments. According to the land price distribution map, it is possible to guess spatial development of the city that the north-eastern part of Yanji was developed prior to south-western area. The center of the city, or downtown expanded to eastward, and the city expanded to south-westward out skirt. Along the main road, Xin-xing areas developed toward east and west ward.

• Journal of the Korean association of regional geographers
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• v.2 no.2
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• pp.93-102
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• 1996

The Korean Peninsula is located on the east coast of monsoon Asia of the midlatitude, where the Pacific polar front moves. As a result variations of spatial and temporal distribution of precipitation occur. A great variation of precipitation during the summer months created frequent droughts and floods. The purpose of this study is to identify distributional characteristics and to analyze synopic characteristics of summer droughts in Korea. The research methods used are ; (1) to identify droughts based on the anomaly of monthly precipitation during summer of 1994. (2) to analyze correlations between drought and weather systems by using the calender of rain days. (3) to compare a synoptic mechanism of summer droughts with that of typical normal summer. The characteristics of summer droughts of 1994 may be summarized as follows ; 1) While most regions were affected by the droughts some regions displayed specific characteristics. The southern part of the Korean Peninsula was severely affected during the month of June. August droughts severely affected east part of the Sobek Mountains, thus showing that the droughts of June and August are highly localized. 2) In the pressure anomaly of surface field. the positive anomaly appears in June around Korean Peninsula, but in July when all parts of the South Korea were under severe droughts, the anomaly changes and becomes negative. 3) Extracyclones occurred less frequently in the summer of 1994. Those that did occur were located in areas far off the Korean Peninsula having little consequences on the drought patterns. 4) The trough of westerly wave at 500hPa height patterns in June is located far from the eastern sea of Korean Peninsula, but in July and August Korean Peninsula belongs to ridge of westerly wave. 5) In June the positive height anomaly at 500hPa surface appears zonally from Siberia to the western Parts of North Pacific Ocean, and in July and August, the strong positive anomaly appears around Korean Peninsula. As a result the zonal index of westerlies at during each month of summer in Korean sector has a large value, which in turn implies that drought will prevails when zonal flow is strong.

• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.151-164
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• 1996

The regional division by the characteristics of the drainage patterns is important to understand its physical environment comprehensively, because the drainage network develops in reflecting characteristics of geological, geographical and climatical features in the drainage basin keenly. This study is the attempt to divide physical region in China whose drainage pattern is diverse. Chinese drainage basin is mainly divided into the interior drainage basin and the peripheral drainage basin. The interior drainage basin is divided into (1)the deranged pattern and (2)the centripetal pattern. The peripheral drainage basin is divided into (1)the dendritic pattern, (2)the parallel pattern, (3)the radial pattern and (4)the anastomatic pattern. Drainage patterns of the interior drainage basin are formed by affecting geographical features and climatic conditions mainly. In the peripheral drainage basin, drainage patterns are formed by other factors: the parallel pattern is connected with geological structure lineament by tectonic movement, the radial pattern with changes of the river channel resulted from the Yellow River's overflow, the anastomotic pattern with human's activities. The distributional features of the physical region in China are as follows: The deranged pattern appears in Zangbai Plateau, the centripetal pattern does in arid basin of the northwest China. the parallel pattern does in Hengduan mountains affected strongly by tectonic movement between Yangtze paraplatform and Indian Plate, does in the upper stream of Yangtze River and Ganges River in the south of Qinghai-Xizang Plateau, the radial pattern in Huaihe Haihe River drainage basin appearing in the alluvial fan region of Yellow River's downstream and the anastomotic pattern does in the delta of Yangtze River, in the northern coastal plain of the Jiangsu-Province and in the delta of Zhujiang River. Except these areas in the peripheral drainage basin, the dendritic pattern is usually found in the other areas.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.4
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• pp.191-199
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• 2013

It is estimated and analyzed that the design wave height and the confidence interval (hereafter CI) according to the return period using the fourteen-year wave data obtained at Pusan New Port. The functions used in the extreme value analysis are the Gumbel function, the Weibull function, and the Kernel function. The CI of the estimated wave heights was predicted using one of the Monte-Carlo simulation methods, the Bootstrap method. The analysis results of the estimated CI of the design wave height indicate that over 150 years of data is necessary in order to satisfy an approximately ${\pm}$10% CI. Also, estimating the number of practically possible data to be around 25~50, the allowable error was found to be approximately ${\pm}$16~22% for Type I PDF and ${\pm}$18~24% for Type III PDF. Whereas, the Kernel distribution method, a typical non-parametric method, shows that the CI of the method is below 40% in comparison with the CI of the other methods and the estimated design wave height is 1.2~1.6 m lower than that of the other methods.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.6
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• pp.375-382
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• 2016

In the present study, the wave hindcasting has been performed, and then the characteristics of storm waves at Gangnueng port was investigated, in which the high waves are observed. Comparing the numerical results with the wave measurements at Gangneung port, Niigata, and Hamada, there were good agreements between them. In particular, the Pearson correlation coefficients of significant wave heights and peak periods at Gangneung port were 0.92 and 0.72, respectively. Then the extreme wave analysis on the significant wave heights was carried out for the estimation of the frequency of storm waves. In this analysis, the storm waves over the threshold were fitted to GPD(Generalized Pareto Distribution). According to this analysis, the return period of the storm wave on February, 24, 2008, one of the large storm waves at Gangneung port, was 8.2 months. Among the computed significant wave heights larger than one-year wave, 58.3% of them were resulted from the storm, while the others were from the typhoon. Additionally, the regression analysis on the waves larger than one-month wave has been conducted, and then the relationship between the computed significant wave heights and the significant wave period, $T_{1/3}=7H_s^{0.25}$ was obtained.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.3
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• pp.219-225
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• 2011

The physicochemical properties of rice endosperm from five rice varieties and effects of milling on baking bread properties of rice flour were investigated. Five rice varieties exhibited different level of amylose content. The ratio of longer amylopectin chain length to the distribution of endosperm starches was the highest in Goami3. According to the RVA measurement of rice flours, the pasting temperatures of Seolgaengbyeo and Goamibyeo were lower than those of the other rice varieties. There were differences in the changes of swelling power of rice flour under increasing temperature. Each rice flour sample for bread-making was processed into two different particle size by using an air-classification mill, and significant differences were observed among cultivars in the average particle size and damaged starch content of rice flours. Rice flour of Seolgaengbyeo with fine particle size showed the highest value in specific volume after baking.

• Economic and Environmental Geology
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• v.43 no.4
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• pp.371-379
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• 2010

Fresh water injection test in a fractured bedrock aquifer was applied as an efficient approach to lower saline concentrations in the saltwater-freshwater transition zone formed by seawater intrusion in a coastal area. The methodology and effectiveness of fresh water injection for hydraulically controlling seawater intrusion is overwhelmingly site dependent, and there is an urgent need to characterize the permeable fractures or unconsolidated porous formations which can allow for seawater flow and transport. Considering aquifer characteristics, injection and monitoring boreholes were optimally designed and completed to inject fresh water through sand layer and fractured bedrock, respectively. We devised and used the injection system using double packer for easy field operation and maintenance. Overall fracture distribution was systematically identified from borehole image logs, and the section of fresh water injection was decided from injection test and monitoring. With fresh water injection, the fluid electrical conductivity of the monitoring well started to be lowered by the inflow of fresh water at the specific depth. And this inflow leaded to the replacement of the fluid in the upper parts of the borehole with fresh water. Furthermore, the injection effect lasted more than several months, which means that fresh water injection may contribute to the mitigation of seawater intrusion in a coastal area.

• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.371-376
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• 2014

A Study on zooplankton fauna and phytoplankton flora was carried out three times in June, August and September 2012 at the Hyuncheon wetland in Gangwon-do, Korea. A total of 14 taxa of zooplankton were distributed, which consisted of six rotifers, four cladocerans, two copepods, one nematode and one aquatic insect larvae. Occurrence of Simulium japonicum supports that studied water is the first grade clear water. It was observed that the abundance of zooplankton was never exceeded over $55ind.L^{-1}$. Rotifers dominated in the months of June and August, whereas cladocerans in September, respectively. The phytoplankton flora was consisted of 26 species. The standing crops varied between $4,080{\sim}10,120cell.L^{-1}$. Docidium undulatum is the typical species distributed in muddy wetland and Closterium acerosum is distributed widely from wetlands through lakes. Navicula spp. and Nitzchia spp. were recorded to be distributed in lentic waters of big lakes such as Paldang Lake. Species diversity indices decreased gradually from June to September between 1.3~1.9 in zooplankton but lowest in August between 0.9~1.6 in phytoplankton, respectively. Based on my study observation, I anticipate that the poor distribution of zooplankton, phytoplankton, and low values of species diversity index are likely to be a cause of narrow area with shallowness of waters during the short period.

• Korean Journal of Environmental Biology
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• v.38 no.3
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• pp.371-387
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• 2020

This study was conducted to investigate the flora of Mt. Unbongsan in the basalt areas of Korea. From the results of eight field surveys undertaken from March to October 2017, we identified 404 total taxa, representing 364 species, seven subspecies, and 33 varieties, which were placed in 256 genera and 91 families. The plant formation of Mt. Unbongsan is a deciduous broad-leaved and conifer mixed forest, which is common in the middle part of the Korean peninsula. Most of the mountain is covered by a young secondary forest, which is mainly composed of Quercus monglica and Pinus densiflora. Out of these 404 taxa, 193 were the first records for the region, six were endemic to Korea, three were listed on the Korean Red List of threatened species, 34 were floristic target species, and 40 were invasive alien species. The naturalized index(NI) percentage was 9.9%. Mt. Unbongsan has plant diversity, which was associated with the geomorphological landscapes. We considered that the composition and distribution of the species were affected by different environmental factors according to the presence of granite, taluses, block streams, drying ridges, valleys, puddles, wetlands, and streams.