• Economic and Environmental Geology
• /
• v.37 no.5
• /
• pp.533-541
• /
• 2004

A steadily consolidated conglomerate formation (CCF) is developed thickly around Tabjeong-ri and Janghang-ri to the east of Tohamsan, Gyeongju City. The CCF has been regarded to a basal conglomerate, Cheonbug Conglomerate, of the Yonil Group by Tateiwa (1924). Son et al. (2000) correlated the CCF to the Songjeon Formation, which occupies the southwestern block of Tertiary Waup Basin. However, the Songjeon Formation stratigraphically does not face to the extension of the CCF. OSL (Optically Stimulated Luminescence) data on the reddish brown to bluish gray psammitic layers, which are intercalated in the CCF, yielded to 85∼92 ka. Therefore, the age of CCF constrains to the last interglacial stage (MIS 5c-5e) rather than the Early Miocene Cheonbug Conglomerate. The Late Pleistocene Tohamsan Formation (TF) is newly named to the CCF and is subdivided to megabreccias and boulders. A rectangular basin, in which the TF is accumulated, is bounded by Oedong and Yonil faults (segments of Yonil Tectonic Line) and is given a name of Toham Basin. Neotectonically, Pliocene EW-transpression gave an effect of the top-up-to-the-west reverse faulting and the accompanied normal fault movement during the last interglacial age (ca. 100 ka). The basin is graben type, in which basin fills are composed of collapsed colluvial deposits, TF.

• Journal of The Korean Digital Architecture Interior Association
• /
• v.10 no.1
• /
• pp.39-47
• /
• 2010

The officetel introduced into Korea in the mid-1980s has thus far been in the limelight as the object of investment for the substitute for small-sized housing and for lease income. But to raise the possibility of succeeding in officetel investment in the future, it has been necessary to make a systematic analysis of the changed direction of the officetel market and the profitability and stability of investment. Accordingly, this study attempted to analyze demand for officetel with a focus on the possibility of increase in the households composed of one or two members, the major consuming bracket of small-sized housing. And it attempted to analyze the possibility of investment in officetel as the investment goods for lease income due to the entry of Korea into aging society. And past analysis of investment in officetel was confined to profitability analysis, but this study sought to develop the stability indicator of the officetel for the analytical purpose. As a result, it is predicted that demand for small-sized housing will increase due to the increase in 1-to 2-person households. Accordingly, it is predicted that demand for officetel as the place of residence will come to increase. And taking into consideration the more serious degree of sustained aging in the population, older people's preference for real estate and need for lease income, it is predicted that preference for officetel as the object of investment will increase. An attempt was made to analyze the profitability and stability of investment in the metropolitan area which the officetel has principally been supplied, in order to analyze the profitability and stability of officetels. For the purpose of this study, Yeoksam-dong in Kangnam-gu, Yeoui-dong in Youngdeungpo-gu, Bongcheon-dong in Kwanak-gu were selected in Seoul as the area for analysis. Jung-dong in Wonmi-gu, Bucheon, Seohyun-dong in Bundang-gu, Seongnam, Janghang-dong in Ilsan-gu, Koyang were selected in Kyonggi province as the area for analysis. As a result, it was found that the small-sized officetel had higher profitability and stability than the large-sized officetel. It was found that the area of Kyonggi Province had the larger deviation by size. That is, it was found that the small-sized officetel in the area of Kyonggi Province was significant as the object of investment for stable lease income.

• Journal of Aquaculture
• /
• v.16 no.3
• /
• pp.179-186
• /
• 2003

Reproductive cycle, gonadal development and the spawning period of the Korean anchovy Coilia nasus were investigated by histologhical observations. Samples were collected at the coastal area of Geumgang dyke which is connected to Gunsan and Janghang, Korea, from February 2002 to January 2003. C. nasus is dioecious; the ovary consists of a pair of saccular structure with many ovarian lobules, and the testis consists of a pair of lobular structure with many testicular lobules and connected to the posterior seminal vesicle. Monthly changes in the gonadosomatic index (GSI) began to increase in April when seawater temperature increased and reached the maximum in June when the ovary was getting mature, the summer season of longer day length with higher water temperature. The reproductive cycle can be classified into five successive stage in females: early growing stage (February to March), late growing stage (March to April), mature stage (May to June), ripe and spent stage (June to July), and recovery and resting stage (July to January): in males, the cycle can be divided into four successive stages; growing stage (February to April), mature stage (May to July), ripe and spent (June to July), and recovery and resting stages (July to January). According to the frequency distributions of egg diameters in the spawning season. C. nasus is presumed to be summer spawning species and polycyclic species to spawn 2 times or more during the spawning season.

• Korean Journal of Environment and Ecology
• /
• v.23 no.3
• /
• pp.250-257
• /
• 2009

This study was conducted to investigate the habitat use of White-naped Cranes Grus vipio in Han river estuary during the wintering period from 2006 to 2008 (October$\sim$March). The average numbers of wintering White-naped Cranes were 106.6$\pm$21.7 (Mean$\pm$SD) individuals, and the highest number of 140 individuals were recorded in the early January, 2008. The wintering habitat use of White-naped Cranes between rice field and mudflat was not significantly different (Mann-Whitney test. p=0.40) during the wintering period. However, White-naped Cranes spent more time on the rice field in the early winter (p<0.01), and on the mudflat in the late winter(p<0.01). There was not a difference of the habitat use rate on middle winter. White-naped cranes used four different sites of rice field: Hongdopyoung, Pyoungdong, Ihwadong and Janghang rice fields. Among them, Hongdopyoung was the main foraging site. There was significant differences of habitat use ratio in the early and mid winter ((Kruskal-wallis test. p<0.01). White-naped Cranes used mudflat area from Gimpo Daegyo to Nusanri of Han river estuary. Especially, they preferred four sites from Gimpo Daegyo to Ilsan Daegyo more than the other sites. Habitat use rate of mud flats were significantly different among each site during the wintering period (Kruskal-wallis test. p<0.01)

• 대한공업교육학회지
• /
• v.31 no.2
• /
• pp.64-82
• /
• 2006

This study investigated what effects multiple intelligence, through which the diverse intelligence abilities of a learner are identified, has on technological problem solving ability according to sex. And it was carried out to present a way to reduce the gap between boys and girls in technological problem solving ability. The subject was 833 middle school students in the third grade (boys: 423, girls: 410) whose schools are located in a megalopolis or more large area. And the instruments developed by Yong-Lyn Moon(2001) and in CRESST(1998) were used. The results of this study are as follows. First, it appeared that there were statistically meaningful differences at six items in multiple intelligence between boys and girls. The six items were bodily-kinesthetic intelligence, logical-mathematical intelligence, naturalistic intelligence, musical intelligence, interpersonal intelligence, and introspective intelligence. Second, in technological problem solving ability, it appeared that boys and girls showed statistically meaningful differences at self-regulation and problem solving strategy. Third, it appeared that logical-mathematical intelligence, linguistic intelligence, introspective intelligence, and natural intelligence had an effect on boys in the way of self-regulation and logic-mathematical intelligence, introspective intelligence, naturalistic intelligence, and linguistic intelligence did on girls. Fourth, it appeared that logical-mathematical intelligence, musical intelligence, and bodily-kinesthetic intelligence had an effect on boys in the way of problem solving ability and linguistic intelligence and musical intelligence had on girls. Fifth, it appeared that logical-mathematical intelligence did an effect on both sexes in drawing up the understanding of contents. On the basis of the results of this study, the area related to multiple intelligence directly or indirectly should be developed in the course of designing the primary and secondary curriculums to reduce the gap between boys and girls in multiple intelligence. With these efforts, the scholastic attainments gap caused by the difference of multiple intelligence will be overcome.

• Journal of fish pathology
• /
• v.34 no.1
• /
• pp.81-98
• /
• 2021

As Korea declared that the entire country is free from ISA (Infectious salmon anaemia) based on the OIE aquatic code in 2019, it is necessary to improve the import quarantine system that meets the level of ISA management in Korea. Currently, Korea imports Atlantic salmon and rainbow trout from countries which have history of ISA outbreak such as Norway and the United States, so there is a constant possibility that trade with these countries will bring ISAV (Infectious salmon anaemia virus) into Korea. Therefore, some amendments to the Aquatic Life Diseases Control Act (ALDCA) are needed to prevent the entry of ISAV into the Korea through international trade. The amendment to the ALDCA should contain a list of countries, zones or compartments that the Korean competent authority has allowed or banned imports of ISA-susceptible fish. In addition, the subordinate statutes or administrative rules of the ALDCA need to be revised so that on-site inspections/audit can be conducted for the evaluation of the ISA management system in exporting countries. After the revision of the subordinate statutes or administrative rules, it is necessary to strengthen the present import conditions in line with those that meet the level of ISA management in Korea. As for the strengthened import conditions, the competent authorities of exporting countries must export only salmonid fish produced in zones or compartments declared freedom of ISA to Korea, and must prove through lab-testing that ISAV should not be detected in the fish exporting to Korea. In addition, official veterinarians/fish health professionals of the exporting country should check the health status of the fish within 72 hours prior to export. Also, competent authorities of the exporting countries must attest that fish storage containers and water, ice and other equipment used for transportation should be cleaned and disinfected to avoid contamination with pathogens, including ISA. Therefore, the proposed measures presented here will further improve the current import condition for salmonid fish and assist decision-making on strategies to reduce the risk of ISA introduction into Korea. Also, it is expected to contribute to maintain the status of ISA-free country.

• Journal of Environmental Health Sciences
• /
• v.48 no.4
• /
• pp.236-243
• /
• 2022

Background: In the case of multiple exposures to different types of heavy metals, such as the conditions faced by residents living near a smelter, it would be preferable to group hazardous substances with similar characteristics rather than individually related substances and evaluate the effects of each group on the human body. Objectives: The purpose of this study is to evaluate the utility of factor analysis in the assessment of health effects caused by exposure to two or more hazardous substances with similar characteristics, such as in the case of residents living near a smelter. Methods: Heavy metal concentration data for 572 people living in the vicinity of the Janghang smelter area were grouped based on several subfactors according to their characteristics using factor analysis. Using these factor scores as an independent variable, multiple regression analysis was performed on health effect markers. Results: Through factor analysis, three subfactors were extracted. Factor 1 contained copper and zinc in serum and revealed a common characteristic of the enzyme co-factor in the human body. Factor 2 involved urinary cadmium and arsenic, which are harmful metals related to kidney damage. Factor 3 encompassed blood mercury and lead, which are classified as related to cardiovascular disease. As a result of multiple linear regression analysis, it was found that using the factor index derived through factor analysis as an independent variable is more advantageous in assessing the relevance to health effects than when analyzing the two heavy metals by including them in a single regression model. Conclusions: The results of this study suggest that regression analysis linked with factor analysis is a good alternative in that it can simultaneously identify the effects of heavy metals with similar properties while overcoming multicollinearity that may occur in environmental epidemiologic studies on exposure to various types of heavy metals.

• Korean Journal of Environmental Agriculture
• /
• v.15 no.1
• /
• pp.1-10
• /
• 1996

The contents of heavy metals in soil near the Janghang smelter area were observed to understand present status and relationship between their fraction and the absorption by rice. The soil samples were taken from the eight sites of the paddy fields in 1982 and 1990, and analysis on heavy metals including Cd, Zn, Cu and Pb was performed. The results were as follows: Total contents of heavy metals in the samples of 1990 were higher than those of 1982. The order of increasing ratio was Cu > Zn > Pb > Cd and the variation of Cd content by sequential differente extracting was residual > exchangeable > dilute acid-extractable fractions and its increasing range was from 38 to 71% during nine years. The ratio of immobile heavy metals bound within an oxide or silicate matrix of Fe-Mn oxide bound and residual in surface soil was that Cd, Pb, Cu and Zn were 31.65, 42.22, 76.57 and 79.49%, respectively, and their mobile ratios of exchangeable, dilute acid-extractable and organically bound were more than 20.28%. Those of mobile Cd, Pb, Cu and Zn were 68.35, 55.78, 23.43 and 20.28%, respectively. Correlation between the heavy metal contents in surface soil and those in tissue of rice plant, such as leaf blade, leaf sheath, stem and panicle axis, were significant, but were not significant in subsurface soil. The dilute acid-extractable and organically bound fractions of Cd, Cu, Pb and Zn in surface soil were more significantly correlated with those in tissues of paddy rice.

• Korean Journal of Environmental Agriculture
• /
• v.21 no.1
• /
• pp.50-56
• /
• 2002

This experiment was carried out to obtain some information about overwintering, physiological and ecological characteristics of apple snails. Another purpose of this experiment was to characterize an appetite for rice plants by apple snails and to elucidate their choice of fresh green ones (vegetables, some other crops, weeds in rice fields). The freshwater snails were found with higher population at sites abundant organic compounds such as plant debris and at regions with high temperature. They also prefer calcium-rich water. This is a naturally occurring process. Apple snails were exceptionally veil-adapted to the south regions of Korea, especially Janghang, Jangseong and Haenam, even if the temperature of winter season is cold below 0$^{\circ}C$. Apple snails were not very selective in their food choice and eat almost everything available in their environment. A snail have something called a radula in its mouth for grinding up its food. A apple snail also chews on fruits and young succulent plant barks. In case of reproduction. apple snails deposit about 157$\sim$784 (average of 321 eggs) milky white to pale orange colored eggs above the waterline. In approximately every 22.4 seconds a new egg appears. The total time needed to deposit a egg mass varies from 58 minutes$\sim$4 hours 13 minutes. Apple snails reproduct actively from May to June and from September to October. An appetite of apple snails for rice plants was the different depending on their size and glowing stage for rice plants. Apple snails had a great appetite of rice plants as well as dropwort, tomato, cabbage, radish, aquatic plants etc. They preferred to eat young rice plants and drastically quit eating rice plants of over 40 cm in height. Thus considering the food preference of apple snail for various plants including rice, they were thought to be a potentially strong predator in fields, especially, at regions with warmer winter.