• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.13 no.2
• /
• pp.121-128
• /
• 2008

As an aquatic ecotoxicity test method, a bioassay using the inhibition of sporualtion of the green macroalga, Ulva pertusa, has been developed. Optimal test conditions determined for photon irradiance, pH, salinity and temperature were $100\;{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, $7{\sim}9$, $25{\sim}35\;psu$ and $15{\sim}20^{\circ}C$, respectively. The validity of the test endpoint was evaluated by assessing the toxicity of four metals (Cd, Cu, Pb, Zn) and elutriates of sewage or waste sludge collected from 9 different locations. When the metals were assayed, the $EC_{50}$ values indicated the following toxicity rankings: Cu ($0.062\;mg{\cdot}L^{-1}$) > Cd ($0.208\;mg{\cdot}L^{-1}$) > Pb ($0.718\;mg{\cdot}L^{-1}$) > Zn ($0.776\;mg{\cdot}L^{-1}$). When compared with other commonly used bioassays of metal pollution listed on US ECOTOX database, the sporualtion test proved to be the most sensitive. Ulva sporulation was significantly inhibited in all elutriates with the greatest and least effects observed in elutriates of sludge from industrial waste ($EC_{50}=6.78%$) and filtration bed ($EC_{50}=15.0%$), respectively. The results of the Spearman rank correlation analysis for $EC_{50}$ data versus the concentrations of toxicants in the sludge presented a significant correlation between toxicity and four heavy metals(Cd, Cu, Pb, Zn). The method described here is sensitive to toxicants, simple to use, easy to interpret and economical. It is also easy to procure samples and maintain cultures. The present method would therefore probably make a useful assessment of aquatic toxicity of a wide range of toxicants. In addition, the genus Ulva has a wide geographical distribution and species have similar reproductive processes, so the test method would have a potential application worldwide.

• Journal of Korea Water Resources Association
• /
• v.57 no.8
• /
• pp.509-518
• /
• 2024

Flash drought is a rapid-onset drought that occurs rapidly over a short period due to abrupt changes in meteorological and environmental factors. In this study, we utilized satellite-based soil moisture product from the Advanced Microwave Scanning Radiometer-2(AMSR2) ascending X-band to calculate the weekly Flash Drought Intensity Index (FDII). We also analyzed the characteristics of flash droughts on the Korean Peninsula over a 10-year period from 2013 to 2022. The analysis of monthly spatial distribution patterns of the irrigation period across the Korean Peninsula revealed significant variations. In North Korea (NK), a substantial increase in the rate of intensification (FD_INT) was observed due to the rapid depletion of soil moisture, whereas South Korea (SK) experienced a significant increase in drought severity (DRO_SEV). Additionally, regional time series analysis revealed that both FD_INT and DRO_SEV were significantly high in the Gangwon province of both NK and SK. The estimation of probability density by region revealed a clear difference in FD_INT between NK and SK, with SK showing a higher probability of severe drought occurrence primarily due to the high values of DRO_SEV. As a result, it is inferred that the occurrence frequency and damage of flash droughts in NK are higher than those in SK, as indicated by the higher density of large FDII values in the NK region. We analyzed the correlation between DRO_SEV and the Evaporative Stress Index (ESI) across the Korean Peninsula and confirmed a positive correlation ranging from 0.4 to 0.6. It is concluded that analyzing overall drought conditions through the average drought severity holds high utility. These findings are expected to contribute to understanding the characteristics of flash droughts on the Korean Peninsula and formulating post-event response plans.

• Journal of agricultural medicine and community health
• /
• v.23 no.2
• /
• pp.157-174
• /
• 1998

A survey was conducted to study the influence of socia-demographic factors on health-related behaviors. from June 1 to July 31, 1996. The study population was 1,903 adults in Kyongju City. A questionnaire method was used to collect data. Health-related behaviors included 24 items for men and 26 items for women. The followings are summaries of findings : The compliance of health promotion activities was higher when the age was older in men, when married, when having no religion and when the education level was higher than the other groups. And it was significantly higher when the income was lower in men and higher in women, in the residents living in apartment, in white collar workers, in the chronic ill people and when the body weight was lower than the other groups. Notable differences were found in the composition of health behavior factors for socio-demographic characteristics. Men used more tobacco, coffee and tea, salt and alcohol than women. However, the practice rates of regular exercise and physical examination were higher in men than women. On the other hand, the practice rates of fruit/vegetable intake, milk drinking and regular tooth brushing were higher in women than men. When the age was old, the amount of fruit/vegetable intake, the frequency of physician visit and health check-up, and regularity of meal were increased. When the income was high, the use rate of seat-belts, the amount of coffee, milk, fruit/vegetable and red meat intake were increased. The frequency of regular exercise. tooth brushing, health check-up, pap test and breast self examination were higher in the rich than the poor. When the education level was high, the frequency of regular exercise and tooth brushing, and the use rate of seat belts were increased, and the amount of alcohol consumption and salt intake were decreased. These findings suggest that socio-demographic factors are significantly associated with the patterns of health behaviors. In conclusion public health programs and individual counseling efforts should be multifaceted and behavior-specific to encourage to practice healthy life-style.

• Journal of agricultural medicine and community health
• /
• v.18 no.2
• /
• pp.141-151
• /
• 1993

This study was done about 371 tuberculosis(TB) patients composed 195 newly registered at Kyungju Gun Health Center from May 1989 to April 1990 (Group A) and 176 being treated at hospitals or private clinics from January 1988 to November 1989(Group B). When Group A patients visited and newly registered at Health Center, data was obtained by interviewing with a prepared questionnaire paper. And well trained inquirer visited Group B patients and obtained data by the same method from February 1990 to April 1990. The results are as follows ; Group A was generally lower than Group B in socioeconomic status and in family history of TB, the rate of Group A was 24.1% and higher than 11.9% in Group B(p<0.05). Knowledge about TB was improved more than past, but those who answered that TB is 'a communicable disease' were 59.5% in Group A and 51.7% in Group B(p<0.05). Those answered that TB is 'a inherited disease' were 9.2% and 11.4% each. And 1.7% of Group B answered that TB is 'a incurable disease'. Knowledge about TB treatment also was improved more than past, but in the rate of those who answered that TB is a curable disease provided by well treatment Group B(77.8%) was worse than Group A(91.3%). The rate of those who answered that TB were been able to cure by regularly anti-TB medication were 98.0% in Group A and 89.8% in Group B. Its difference was statistically significant. The rate that patients took the first diagnosis and wanted to receive treatments at the same organ were 34.9% of Group A at Health Center and 72.2% of Group B at hospitals or private clinics. And its difference was statistically significant. In the reasons that Group B knew Health Center treated pulmonary TB but they was treated at hospitals or private clinics, unreliability to Health Center was 48.1%. The reasons that Group A was treated at Health Center were 'because of trust' 63.1%, 'because of low cost' 50.3%, 'because of low cost except trust' 9.3%, 'no specific reasons' 27.7%. In the courses of knowing that TB was controlled at Health Center, 'by neighborhood, health worker and doctors' were 84.9% in Group A and 69.0% in Group B. But 'by TV or radio' were 8.2% in Group A and 14.7% in Group B, 'by school education' 2.5% in Group A and 6.2% in Group B. Conclusively, Group A patients were lower than Group B in socioeconomic status, but better than in knowledge about TB. Its reasons was suggested that Health Center had controlled TB patients better than hospitals and private clinics. But considering, that difference in the rate of the same organ for the first diagnosis and treatment, that the only 63.0% of Group A have treated due to 'reliability to Health Center', and that 48.1% of Group B knew that Health Center treated pulmonary TB but didn't visit it due to 'unreliability to Health Center', that public relations(PR) about use Health Center for pulmonary TB and health education for TB was thought to have to strengthened.

• Atmosphere
• /
• v.33 no.2
• /
• pp.275-295
• /
• 2023

In Korea, there are four institutions related to atmospheric science: the university's atmospheric science-related department, the Korea Meteorological Administration (KMA), the ROK Air Force Weather Group, and the Meteorological Industry Association. These four institutions have developed while maintaining a deep cooperative relationship with the Korea Meteorological Society (KMS) for the past 60 years. At the university, 6,986 bachelors, 1,595 masters, and 505 doctors, who are experts in meteorology and climate, have been accredited by 2022 at 7 universities related to atmospheric science. The KMA is carrying out national meteorological tasks to protect people's lives and property and foster the meteorological industry. The ROK Air Force Weather Group is in charge of military meteorological work, and is building an artificial intelligence and space weather support system through cooperation with universities, the KMA, and the KMS. Although the Meteorological Industry Association has a short history, its members, sales, and the number of employees are steadily increasing. The KMS greatly contributed to raising the national meteorological service to the level of advanced countries by supporting the development of universities, the KMA, the Air Force Meteorological Agency, and the Meteorological Industry Association.

• Journal of Sasang Constitutional Medicine
• /
• v.10 no.2
• /
• pp.533-564
• /
• 1998

In order to know the effect of proliferation and differentiation on edipocyte 3T3-L1 by prescriptions and herbs, Taeyangin(太陽人)'s Okapijangcheok-tang(五加皮壯脊湯) Mihudeungsikjangtang Acanthopanacis Cortex(五加皮) Phragmitis Rhizoma(蘆根) and Taeumin(太陰人)'s Taeumjowi-tang(太陰調胃湯) Cheongsimyonja-tang(淸心蓮子湯) Cheongpaesagan-tang(淸肺瀉肝湯) Galkeunbupyong-tang(葛根浮萍湯) Coicis Semen(薏苡仁) Rhei Undulati Rhizoma(大黃) Mori Cortex(桑白皮) Ulmi Cortex(楡根白皮) Holotrichia Vermiculus Kalopanaxii Cortex(海桐皮) Ephedrae Herba(麻黃) Imperatae Rhizoma(白茅根), were used and had some effects. 1. The proliferation effect of edipocyte 1) At the Taeyangin(太陽人)'s prescriptions and herbs, Okapijangcheok-tang(五加皮壯脊湯) Mihudeungsikjang-tang Acanthopanacis Cortex(五加皮) have a control effect at the boiling water-extract and ethyl alcohol-extract. Phragmitis Rhizoma(蘆根) have a control effect at the ethyl alcohol-extract. 2) At the Taeyangin(太陽人)'s prescriptions and herbs, Taeumjowi-tang(太陰調胃湯) Cheongsimyonja-tang(淸心蓮子湯) Cheongpaesagan-tang(淸肺瀉肝湯) Galkeunbupyong-tang(葛根浮萍湯) have a control effect at the boiling water-extract and ethyl alcohol-extract. Coicis Semen(薏苡仁) Rhei Undulati Rhizoma(大黃) Morl Cortex(桑白皮) Ulmi Cortex(楡根白皮) Kalopanaxii Cortex(海桐皮) · Ephedrae Herba(麻黃) of the boiling water-extract, Holotrichia Vermiculus Kalopanaxii Cortex(海桐皮) of ethyl alcohol-extract have a control effect on edipocytes. Rhei Undulati Rhizoma(大黃) Ulmi Cortex(楡根白皮) Ephedrae Herba(麻黃) of high-density have a cyto-toxicity. 2. The differentiation effect of edipocyte 1) At the Taeyangin(太陽人)'s prescriptions and herbs during the natural differentiation, Phragmitis Rhizoma(蘆根) of the boiling water-extract, Okapijangchek-tang(五加皮壯脊湯) Acanthopanacis Cortex(五加皮) of the ethyl alcohol-extract have a cyto-toxicity on the first-differentiation. 2) At the Taeumin(太陰人)'s prescriptions and herbs during the natural differentiation, Ulmi Cortex (楡根白皮) Kalopanaxii Cortex(海桐皮) of the boiling water-extract have a cyto-toxicity on the first-differentiation. Cheongsimyonja-tang(淸心蓮子湯) Ephedrae Herba(麻黃) of ethyl alcohol-extract have a control effect on the redifferentiation. 3) At the Taeyangin(太陽人)'s prescriptions and herbs on the first-differentiation during the induced differentiation, Acanthopanacis Cortex(五加皮) of ethyl alcohol-extract has a control effect. Okapijangchek-tang(五加皮壯脊湯) Acanthopanacis Cortex(五加皮) Phragmitis Rhizoma(蘆根) of the boiling water-extract have a cyto-toxicity. 4) At the Taeumin(太陰人)'s prescriptions and herbs on the first-differentiation during the induced differentiation, Coicis Semen(薏苡仁) Ephedrae Herba(麻黃) Imperatae Rhizoma(白茅根) of the boiling water-extract and Ephedrae Herba(麻黃) of the ethyl alcohol-extract have a control effect. Kalopanaxii Cortex(海桐皮) of the boiling water-extract and the ethyl alcohol-extract has a cyto-toxicity. Considering this result, the Taeyangin(太陽人) Taeumin(太陰人)'s prescriptions and herbs have a control effect on edipocytes during the proliferation. Acanthopanacis Cortex(五加皮), Coicis Semen(薏苡仁) Ephedrae Herba(麻黃) Imperatae Rhizoma(白茅根) have a control effect on edipocytes during the induced differentiation. In the future, for treating a obesity need a vivo assay and hope this study to help to know the mechanisms of obesity.

• Korean Journal of Soil Science and Fertilizer
• /
• v.32 no.2
• /
• pp.182-191
• /
• 1999

A study was conducted for the determination of application rate of pig-dung composted with sawdust (referred as pig manure hereafter) for wetland rice. The study involved the field experiments with the cultivation of rice under different rates of application of pig manure in combination of different rates of chemical fertilizers, in a wetland rice soil. The field experiment involved following treatments : (I) Without fertilizer, (II) Standard rate of chemical fertilizers based on soil testing($98-73-71kg\;ha^{-1}$ as $N-P_2O_5-K_2O$), (III) $2.1Mg\;ha^{-1}$ of pig manure $>+80-37kg\;ha^{-1}$ of $N- K_2O$ as chemical fertilizer(Less $N-P_2O_5-K_2O$ contained in the compost), (IV) $4.2Mg\;ha^{-1}$ of pig manure+ $62-3kg\;ha^{-1}$ of $N-K_2O$as chemical fertilizer(Less $N-P_2O_5-K_2O$ contained in the compost), (V) $10Mg\;ha^{-1}$ of pig manure+ Treatment(II), (VI) $20Mg\;ha^{-1}$ of pig manure +Treatment(II). Number of tillers in treatment (I) were higher than other treatments in tillering and panicle formation stage. After heading stage, treatments (V) and (VI) have higher number of tillers, but treatment (III) and (IV) have fewer number of tillers during all growing stage. Uptake of NPK in rice plants was higher in treatment (VI), but the efficiency of N, P and K was higher in treatment (I), (III) and (IV). The yield of unhulled rice were in order of tretments (VI)>(V)>(IV)>(II)>(III), although the difference was not statistically significant. Inorganic nitrogen, available P and exchangable K contents in soil were highest at tillering stage in all treatments and became low from panicle formation to harvest stage. Available P in soil was increased by the application of pig manure upto 20 cm depth. Exchangeable cation contents in 40 to 60 cm soil depth was much higher in treatment (VI) than in other treatments. Treatment (V) and (VI) showed much higher losses of N. $P_2O_5 $ and $K_2O$ than other treatment. Though treatment (VI) tended yield higher than in other treatments, showed lodging and occurrence of leaf and neck blast in this treatment. Yield of unhulled rice in treatment (IV) was not significant statistically and reduced nutritional losses. It is conclude that treatment (IV) seems to be the most reasonable one for the application of pig manure in combination of chemical fertilizers.

• Korean Journal of Microbiology
• /
• v.51 no.4
• /
• pp.389-397
• /
• 2015

Dongchun, one of the representative streams in urban area, is a downstream that is connected to Hogyechun, Bujeonchun, Jeonpochun, Danggamchun, and Gayachun as its upstream. Hogyechun has been mostly covered with concrete structures for decades, causing sewage pollution from the upstream, overflow of the downstream region and other serious pollution that gave rise to many civil complaints from the residents nearby. In this study, we analyzed 3 stations, including control station for water quality and malodor changes of Hogyechun after applying the microbial augmentation (BM-2) for a few months including the rainy season. Amounts (g/h) of DO in the middle site (Middle) and the downstream site (Borim) increased by 1.7 times compared with the upstream site (Chuhae) after augmentation for about 2 months. Amounts (g/h) of COD and $NO_3{^-}N$ decreased by 2 and 1.7 times, respectively, in the middle and downstream sites while SS increased by 7.5 and 22 times in the middle and downstream sites, respectively. Moreover, odor removal efficiencies at the middle and downstream sites were 65% and 19%, respectively, indicating the microbial activity in reduction of malodor in the polluted stream. The dominant microbial species of the sampling sites were Hydrogenophaga caeni, Sphaerotilus natans, Acidovorax radicis, Acidovorax delafieldii, and Cloacibacterium rupense. Densities of the two species Sphaerotilus natans and Acidovorax delafieldii were significantly increased in the middle site after augmentation which possessed potential odor removal and denitrification activity, respectively. Potential pathogens (e.g., Arcobacter cryaerophilus) were also removed from the middle site after the implementation.

• KDI Journal of Economic Policy
• /
• v.12 no.4
• /
• pp.47-69
• /
• 1990

Using an aggregator model, we look into the possibilities for substitution between Korea's exports, imports, domestic sales and domestic inputs (particularly labor), and substitution between disaggregated export and import components. Our approach heavily draws on an economy-wide GNP function that is similar to Samuelson's, modeling trade functions as derived from an integrated production system. Under the condition of homotheticity and weak separability, the GNP function would facilitate consistent aggregation that retains certain properties of the production structure. It would also be useful for a two-stage optimization process that enables us to obtain not only the net output price elasticities of the first-level aggregator functions, but also those of the second-level individual components of exports and imports. For the implementation of the model, we apply the Symmetric Generalized McFadden (SGM) function developed by Diewert and Wales to both stages of estimation. The first stage of the estimation procedure is to estimate the unit quantity equations of the second-level exports and imports that comprise four components each. The parameter estimates obtained in the first stage are utilized in the derivation of instrumental variables for the aggregate export and import prices being employed in the upper model. In the second stage, the net output supply equations derived from the GNP function are used in the estimation of the price elasticities of the first-level variables: exports, imports, domestic sales and labor. With these estimates in hand, we can come up with various elasticities of both the net output supply functions and the individual components of exports and imports. At the aggregate level (first-level), exports appear to be substitutable with domestic sales, while labor is complementary with imports. An increase in the price of exports would reduce the amount of the domestic sales supply, and a decrease in the wage rate would boost the demand for imports. On the other hand, labor and imports are complementary with exports and domestic sales in the input-output structure. At the disaggregate level (second-level), the price elasticities of the export and import components obtained indicate that both substitution and complement possibilities exist between them. Although these elasticities are interesting in their own right, they would be more usefully applied as inputs to the computational general equilibrium model.

• Journal of agricultural medicine and community health
• /
• v.24 no.1
• /
• pp.145-159
• /
• 1999

To find the association, between vinyl house work and the prevalence of low back pain, a questionnaire survey was made toward 215 vinyl house farmers and 228 general farmers without vinyl house who are cared by Jungjung Community health Practioners at Soobuk Myun, Damyang-gun, Chollanamdo. 1. Vinyl house farmers were significantly younger in age, higher in educational status higher survival rate of spouse, higher economic state and less cared by medical aid than general farmers. 2. Vinyl house farmers showed shorter career for agricultural work, used modern farming instrument more frequently and worked with sitting position. 3. During unbusy season in general agriculture, vinyl house farmers consumed significantly more time in agricultural work and general activity, but no significant difference of time of the above activity among busy season. 4. During the last spring season when most vinyl house work was performed, vinyl house farmers showed significantly higher prevalence of low back pain than general farmers, but no significant difference of prevalence among the two groups for the last one week. 5. By the simple analysis statistical significant related variables with low back pain was found to be sex(p<0.001), educational status(p<0.05), work posture(p<0.001) and use of modern agricultural machine(p<0.05). 6. By the multiple logistic regression the odds ratio for low back pain among vinyl house farmers were 2.08(95% confidence interval 1.31-3.00) compared to general farmers, the odds ratio among female was 2.35(95% confidence interval 1.24-4.47) to male, the odds ratio among illiterate persons were 2.60(95% confidence interval 1.24-4.47) to high school graduate, and the odds ration among primary school graduate was 2.19(95% confidence interval 1.04-4.47) to high school graduate. In conclusion because vinyl house farmers showed significantly higher rates of low back pain compared to farmers without vinyl house, continuous study to find the true cause of low back pain among vinyl-house farmers and active effort to prevent low back pain are necessary.