• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.79-95
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• 2017

Euiam and Paldang Reservoirs have often been facing water quality problems, such as eutrophication, algal blooms and off-flavors by treated wastewater effluent (TWE) in the North-Han and the Han River basins, but little is examined on the direct biological effect of TWE. This study tested algal growth potential (AGP) of four TWEs discharged into Euiam and Paldang Reservoirs to evaluate water fertility in September 2014 and March and September 2015. Test alga was used Anabaena circinalis isolated from Paldang Reservoir. Mean concentration of T-N and T-P in TWEs was $3,956.7{\mu}g\;N\;L^{-1}$ and $50.8{\mu}g\;P\;L^{-1}$, and the proportion of $NO_3-N$ and $PO_4-P$ to the total fraction was 72.1% and 40.8%, respectively. Both N and P were high in TWEs, but much higher N than P concentration indicates strong P-limitation. As a consequence, the maximum AGP was determined by $PO_4-P$ concentration (r=0.998, p<0.01). Mean AGP value was $15.4mg\;dw\;L^{-1}$ among four effluents indicating its eutrophic condition. Due to the establishment of tertiary (advanced T-P) treatment method in the studied plants recently, P concentration was significantly decreased in TWEs compared to the years prior to 2012. However, P concentration seems to be still high enough to cause eutrophication and algal blooms. Therefore, wastewater treatment to P-free level needs to be considered if effluents are directly discharged into the drinking water resources.

• Journal of Engineering Education Research
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• v.12 no.1
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• pp.3-16
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• 2009

The purpose of this study is to prepare diverse measures to enhance the utilization of national authorized qualification. The detail objectives of this study are first, to re-establish the utilization scope and range of national authorized qualification through analysis of advance research and theory in various fields of learning on the function of qualification; and second, to set the direction to strengthen the utilization of national authorized qualification. Based on discussions on the various fields of learning on the function of qualification, this study divided the utilization scope of qualification into personal utilization for the benefit of the qualification acquirer him or herself and public utilization for the social and economic benefits. And according to this distinction, we prepared measures to strengthen the utilization of national authorized qualification. First of all, as a way to strengthen personal utilization of the national authorized qualification, we prepared measures to enhance accessibility and facilitate further improvement. As a means to enhance accessibility, we proposed restriction on setting the application condition, diversification of qualification authorization method, facilitation of partial qualification system and minimization of expense required to acquire qualification. Also for the further improvement, we proposed creation of job-level centered grade system and development of job-level centered qualification item by stage. For strengthening the public utilization of national authorized qualification, we come up with ways of strengthening flexibility, transparency, public trust and compatibility. As a way to strengthen flexibility, we proposed establishment of qualification demand monitoring system, expansion of direct participation of users on qualification management, establishment of qualification expiration period and its renewal. For the strengthening of transparency, we proposed to build general qualification information system and to utilize qualification recommendation system. To strengthen public trust, we proposed to strengthen the management of qualification management regulation, secure independency, establish internal audit system and strengthen post management of national authorized qualification. And lastly, we suggested that compatibility comparison standard between qualification and qualification level standard be developed for the strengthening of compatibility.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.2
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• pp.61-69
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• 2003

Surface energy and $CO_2$ fluxes have been measured over a farmland in Haenam, Korea since July 2002. Eddy covariance technique, which is the only direct flux measurement method, was employed to quantitatively understand the interaction between the farmland ecosystem and the atmospheric boundary layer. Maintenance of eddy covariance system was the main concern during the early stage of measurement to minimize gaps and uncertainties in the dataset. Half-hourly averaged $CO_2$ concentration showed distinct diurnal and seasonal variations, which were closely related to changes in net ecosystem exchange (NEE) of $CO_2$. Daytime maximum $CO_2$ uptake was about -1.0 mg $CO_2$ m$^{-2}$ s$^{-1}$ in August whereas nighttime $CO_2$ release was up to 0.3 mg $CO_2$ m$^{-2}$ s$^{-1}$ during the summer. Both daytime $CO_2$ uptake and nighttime release decreased gradually with season. During the winter season, NEE was from near zero to 0.05 mg $CO_2$ m$^{-2}$ s$^{-1}$ . FK site was a moderate sink of atmospheric $CO_2$ until September with daily NEE of 22 g $CO_2$ m$^{-2}$ d$^{-1}$ . In October, it became a weak source of $CO_2$ with an emission rate of 2 g $CO_2$ m$^{-2}$ d$^{-1}$ . Long-term flux measurements will continue at FK site to further investigate inter-annual variability in NEE. to better understand these exchange mechanism and in-depth analysis, process-level field experiments and intensive short-term intercomparisons are also expected to be followed.

• Tuberculosis and Respiratory Diseases
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• v.39 no.4
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• pp.334-342
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• 1992

Background: The activated T lymphocyte by inhalaed mycobacterial antigen may evoke cell-mediated immunity in patients with active pulmonary tuberculosis. These activated lymphocyte may influence the response of tuberculin-purified protein derivative (PPD) in skin test. But occasionally, anergy to PPD appear in patients with pulmonary tuberculosis in spite of active stage. Thus we evaluated the effect of change of subtypes of lymphocyte in bronchoalveolar lavage fluid (BAL) and peripheral blood on anergy to PPD in patients with active pulmonary tuberculosis. Method: We performed tuberculin skin test and flow-cytometry analysis of lymphocytes obtained from BAL fluid and peripheral blood in 11 healthy normal volunteers and 20 patients with active pulmonary tuberculosis. Results: 1) The composition of lymphocyte significantly increased in patients with active pulmonary tuberculosis when compared with that in healthy control ($25.2{\pm}4.8$ vs $6.5{\pm}1.3%$, p<0.01), but composition of monocyte significantly decreased ($69.6{\pm}5.7$ vs $89.2{\pm}1.4%$, p<0.05) in analysis of BAL fluid. 2) There were no differences in compositions of cells in BAL fluid between responders and no-responders to PPD. 3) The compositions of CD3 (+), CD4 (+), CD3 (+) IL-2R (+), CD3 (+) HLA-DR (+) significantly increased in BAL fluid when compared with those in peripheral blood in patients with active pulmonary tuberculosis. But the composition of CDS (+), CD4/CDS were not different between BAL fluid and peripheral blood. 4) There were no correlations between response to PPD and compositions of cells and lymphocyte subtypes in BAL fluid and peripheral blood in all patients with tuberculosis, responders, and no-responders, respectively. Conclusion: From these results, we suggest no direct relationship between compositions of inflammatory cells in bronchoalveolar lavage fluid and we could not rule out the possibility of compartmentalization of activated lymphocyte involving in anergy to PPD in skin test in patients with active pulmonary tuberculosis.

• Tuberculosis and Respiratory Diseases
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• v.48 no.3
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• pp.331-338
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• 2000

Background : While the incidence of lung cancer is gradually leveling off in developed countries, it is continuing to rise in Korea. With the rapid increase in the prevalence of smoking among women and the young, the incidence of lung cancer is also expected to increase within the next three and four decades. The aims of the present study are to analyze the smoking habits in patients with lung cancer and to evaluate of the relative risk of lung cancer according to patients' smoking habits. Method : This investigation was a hospital-based, case control study, which included data of 93 case subjects with lung cancer and 1132 controls with disease unrelated to smoking, obtained through a smoking history questionnaire by a direct personal interview. Result : Compared with non-smokers, those who smoked for more than 50 years had an odds ratio for lung cancer of 8.8(1.8-20.7). The odds ratios was 8.5(3.5-20.7) for those who smoke more than a total of 40 cigarettes per day and 5.5(2.3-13.3) for men who started habitual smoking under the age of 20. The risk increased for men with more than of cigarette smoking(OR : 5.5, 95% CIa : 2.6-11.9). Odds ratios associated with cigarette smoking were 2.5(1.1-5.8) and 5.1(2.6-10.4) for ex-smokers and current smokers, respectively and 2.2(0.0-4.6) for non-filter smokers of more than 16 years. Conclusion : There was a clear dose-response relationship between the risk of lung cancer and smoking. It can be concluded that dose is an important risk factor for lung cancer, as well as smoking habits.

• Radiation Oncology Journal
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• v.23 no.1
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• pp.51-60
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• 2005

Purpose : Selective inhibition of multiple molecular targets may improve the antitumor activity of radiation. Two specific inhibitors of selective cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) were combined with radiation on the HeLa cell line. To investigate cooperative mechanism with selective COX-2 inhibitor and EGFR blocker, in vitro experiments were done. Materials and Methods : Antitumor effect was obtained by growth inhibition and apoptosis analysis by annexin V-Flous method. Radiation modulation effects were determined by the clonogenic cell survival assay. Surviving fractions at 2 Gy ($SF_2$) and dose enhancement ratio at a surviving fraction of 0.25 were evaluated. To investigate the mechanism of the modulation of radiosensitivity, the cell cycle analyses were done by flow cytometry. The bcl-2 and bax expressions were analyzed by western blot. Results : A cooperative effect were observed on the apoptosis of the HeLa ceil line when combination of the two drugs, AG 1478 and NS 398 with radiation at the lowest doses, apoptosis of $22.70\%$ compare with combination of the one drug with radiation, apoptosis of $8.49\%$. In cell cycle analysis, accumulation of cell on $G_0/G_l$ phase and decrement of S phase fraction was observed from 24 hours to 72 hours after treatment with radiation, AG 1478 and NS 398. The combination of NS 398 and AG 1478 enhanced radiosensitivity on a concentration-dependent manner in HeLa cells with dose enhancement ratios of 3.00 and $SF_2$ of 0.12 but the combination of one drug with radiation was not enhanced radlosensitivity with dose enhancement ratios of 1.12 and SF2 of 0.68 (p=0.005). The expression levels of bcl-2 and bax were reduced when combined with AG 1478 and NS 398. Conclusion : Our results indicate that the selective COX-2 inhibitor and EGFR blocker combined with radiation have potential additive or cooperative effects on radiation treatment and may act through various mechanisms including direct inhibition of tumor cell proliferation, suppression of tumor cell cycle progression and inhibition of anti-apoptotic proteins.

• Journal of Korea Port Economic Association
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• v.32 no.4
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• pp.73-87
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• 2016

The purpose of this study is to investigate the empirical results of Analytic Hierarchy Process/Data Envelopment Analysis-Assurance Region(AHP/DEA-AR) by using multiple regression analysis during the period of 2009-2012 with 5 inputs (number of gantry cranes, number of berth, berth length, terminal yard, and mean depth) and 2 outputs (container TEU, and number of direct calling shipping companies). Assurance Region(AR) is the most important tool to measure the efficiency of seaports, because individual seaports are characterized in terms of inputs and outputs. Traditional AHP and multiple regression analysis techniques have been used for measuring the AR. However, few previous studies exist in the field of seaport efficiency measurement. The main empirical results of this study are as follows. First, the efficiency ranking comparison between the two models (AHP/DEA-AR and multiple regression) using the Wilcoxon signed-rank test and Mann-Whitney signed-rank sum test were matched with the average level of 84.5 % and 96.3% respectively. When data for four years are used, the ratios of the significant probability are decreased to 61.4% and 92.5%. The policy implication of this study is that the policy planners of Korean port should introduce AHP/DEA-AR and multiple regression analysis when they measure the seaport efficiency and consider the port investment for enhancing the efficiency of inputs and outputs. The next study will deal with the subjects introducing the Fuzzy method, non-radial DEA, and the mixed analysis between AHP/DEA-AR and multiple regression analysis.

• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.219-226
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• 1986

A study was conducted to provide direct comparisons of the effect of variations in herbage use, grazing and social behaviour upon the flat, slope and forest grassland with a total 30 Korean Native Cattle and 5 Korean Native Goats under 4-year old grassland established by intensive sowing method in Daecheon. The results obtained are summarized as follows; 1. Relative intake index, dry matter intake per animal and dry matter digestibility by Korean Native Goats in flat, slope and forest grassland were 35.2%-462g-63.7%, 35.0%-459g-63.0% and 29.8%-391g-62.1%, respectively. 2. Grazing time by Korean Native Cattle was not different among the grassland types, but ruminating time was increased in slope grassland, whereas in forest grassland was decreased. Resting time was increased in forest grassland, whereas in slope grassland was decreased. Walking time was increased in flat grassland, but loafing time was increased in forest grassland. The number of rumination, chews per bolus and defecation number were decreased in forest grassland. The number of drinks, total drinking water and walking distance were increased in slope grassland. 3. Animal distance, occupied area per animal and sub group formation by Korean Native Cattle in flat, slope and forest grassland were $3.4m-11.9m^2-3.6head$, $3.56m-11.0m^2-3.7head$ and $3.70m-14.6m^2-3.4head$, respectively. The order of grazing movement was similar to the pear-shaped grazing formation, but the relations of dominance between first grazer and last grazer upon different grassland types was not clear.

• Korean Journal of Plant Resources
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• v.28 no.5
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• pp.608-615
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• 2015

Garlic (Allium sativum L.) has been used as both food and medicine in many cultures for thousands of years. Garlic cultivars are completely sterile and propagated through vegetative method. Collection of a large number of fertile accessions of these genus is needed to explore genetic variability. In order to investigate genetic variation among Allium species and its possibilities for direct cultivation in Korea, we characterized 12 accessions of A. longicuspis, flowering wild garlic which had collected from Central Asia, the main center of garlic diversity. Most of A. longicuspis accessions showed higher over-wintering and bolting rate, longer scape length and more number of bulbils than Korean landraces cultivar, Danyang and Euiseong, but A. longicuspis accessions exhibited smaller size of bulbs and bulbils. Most accessions of A. longicuspis had more number of cloves per bulb, except K229596 and K248824 than Korean landraces. All the accessions of A. longicuspis from Central Asia had complete bolters having many flowers and topsets in umbel. Further studies of A. longicuspis should focus on securing true seeds through removal of topsets and crosses among accessions to create the genetic variability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1344-1350
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• 2003

This study was performed to investigate the antioxidative effect as the inhibition of malondialdehyde (MDA) and bovine serum albumin (BSA) conjugation reaction, inhibition of lipid peroxidation and the scavenging effect on 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical, and antimutagenic capacities as the Ames test in 7 common vegetables taken by Korean for suggestion of prevention and dietetic treatment of chronic diseases and development of antioxidative and antimutagenic functional food. The water fractions of perilla leaves and sedum were most effective in the inhibition of MDA and BSA conjugation reaction showing 62.5% of inhibition rate among 7 vegetables. The inhibition rates of ethanol fractions of sedum and wild water dropwort on the lipid peroxidation were 67.1% and 61.5%, respectively. The ethanol fractions of crown daisy and wild water dropwort showed the most effective results among 7 vegetables in the DPPH radical scavenging capacities showing inhibition rate of 78.8% and 73.6%, respectively. The indirect and direct antimutagenic effects of ethanol extract of 7 vegetables were examined by Ames test using Salmonella typimurium TA98 and TA100. Inhibitory effects of wild water dropwort was superior to the other vegetables on the Ames test. These results suggest that common 7 vegetables taken by Korean are believed to be a possible antioxidative and antimutagenic capacities, although the results were different, more or less, according to the assay method and vegetables used.