• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.463-472
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• 2010

It was conducted to investigate the control efficacy of carboxylic acid amide (CAA) fungicides, such as benthiavalicarb, iprovalicarb, dimethomorph and mandipropamid, against pepper Phytophthora blight caused by P. capsid in the laboratory and the field. The fungicides inhibited mycelial growth and direct sporangium germination of P. capsid strongly, while there was no activity of all fungicides against zoospore release from sporangium. In greenhouse test, they showed the good protective and curative effect against pepper Phytophthora blight. Benthiavalicarb applied at $100{\mu}g\;mL^{-1}$ 7 days before inoculation prevented pepper Phytophthora blight by 100%, even though the zoosporangiurn suspension of P. capsid adjusted to not only $5{\times}10^3$ zoosporangia $mL^{-1}$ but also $1{\times}10^5$ zoosporangia $mL^{-1}$ was inoculated by soil-drenching. Except for dimethomorph, the other fungicides showed an excellent control activity over 2 years from 2009 to 2010 in the field test. The control value of dimethomorph applied at $250{\mu}g\;mL^{-1}$ was low, 27.2% in 2009, but that of dimethomorph applied even at $125{\mu}g\;mL^{-1}$ was high, 89.5% in 2010. All the fungicides showed good inhibitory effect on the mycelial growth and the direct germination of zoosporangiurn, and controlled pepper Phytophthora blight preventively and curatively, can be used to establish the spray system for control1ing the pepper disease.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.328-335
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• 2012

In order to use in the classification of minor crop for the mutual application of safe use guideline, it was investigated the residue property of fungicide dimethomorph and pyraclostrobin in green onion, a stem-crop. After pesticides were applied 2 times with 1 week interval in that day of harvest, 3 days, 7 days, 10 days and 14 days before harvest, a green onion was harvested. The residue of dimethomorph in a green onion was 26.31 and 39.08 mg/kg in that day of harvest, however, in according to elapse time, it was reduced to 6.86 and 9.34 mg/kg in 14 days before harvest. In case of pyraclostrobin, it was also reduced from 13.46 and 39.08 mg/kg to 3.57 and 5.21 mg/kg. Based on the residue in that day of harvest, the deposit of spray solution in a green onion was calculated. The deposit of spray solution of dimethomorph was 274.35~345.84 mL/kg, in case of pyraclostrobin, it was calculated 213.65~343.33 mL/kg. When the amount of the deposit of both pesticides was compared in a green onion, it was so similar. On the other hand, it was estimated the predicted dissipation curve of pesticides in the green onion during cultivation. The half-life of dimethomorph was 6.95~7.45 days, in case of pyraclostrobin, 7.15~7.45 days. When both pesticides were compared with the residue property, the deposit of spray solution and half-life of dissipation were so similar.

• Analytical Science and Technology
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• v.12 no.4
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• pp.290-298
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• 1999

A study on the application of impedance phase angle for redox titration, acid-base titration, chelate titration and precipitation titration has been carried out. A constant alternating current was passed between two platinum electrodes. One of them was a polarizable micro-electrode of $0.1cm^2$ or $0.026cm^2$ surface area and the other a non-polarizable large electrode of $1cm^2$ surface area dipped in the solution to be titrated. The impedance and the phase angle of the titration cell were measured with lock-in amplifier to obtain well behaved titration curve respectively. In titration of oxalic acid vs. potassium permanganate, the end-point was obtained successfully from the phase angle titration curve. In this experiment, the concentration of 0.0005 M to 0.05 M, the current of $50{\mu}A$ and the frequency of near 50 Hz were used. In titration of phosphoric acid vs. sodium hydroxide, the first end-point was obtained successfully on the optimum experimental condition of 0.001 M concentration, $50{\mu}A$ current and 25~97 Hz frequency. However, the end-point in titration of cupric sulfate vs. disodium-EDTA couldn't be obtained clearly. The end-point was obtained with the out-of-phase impedance curve on the experimental condition of 0.01 M concentration, $100{\mu}A$ current, 5~35 Hz frequency range. In titration of sodium chloride vs. silver nitrate, the end-point was obtained successfully on the experimental condition of 0.1 M concentration, $100{\mu}A$ current and 5~47 Hz frequency range. This study showed that the impedance phase angle was applicable for the detection of the end-points in redox titration curve, acid-base titration curve, chelate titration curve and precipitation titration curve.

• Journal of the Korean Geographical Society
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• v.47 no.4
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• pp.522-540
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• 2012

The main aim of the paper is to identify the position or status of Korean economic geography in changing global economic geography by reviewing papers published in Korean geographical journals since the mid-1950s. Since the late 20th century as economic geography has developed significantly with the introduction of new research issues, methodologies, and theory and concepts, economic geography in Korea also has gone through rapid development in terms of both quantitative and qualitative perspectives. The paper attempts to analyze trends in Korean economic geography by reviewing agricultural, industrial, commercial geographies, and others since the mid-1950s. The review of economic geography in Korea would be based on four periods classified by research issues and approaches; foundation (~1950s), positioning (1960s and 1970s), jump and rush (1980s and mid-1990s), and transitional period (late 1990s~). Agricultural geography in Korea has decreased due to increases of the interests in industrial geography since the 1980s. In particular, since the late 1990s industrial geography has undergone a significant transition in accordance with the emergence of new theories of institutional perspectives, centering around issues on value chains, innovative cluster, cooperative and competitive networks, foreign direct investment, flexible specialization and venture ecology. Along with this, there has been changes in the interest of commercial geography in Korea from researches on periodical markets, the structure of store formats, and distributions by commodity, to researches on producer services and retailer's locational behaviors and commercial supremacy according to the emergence of new store formats. Since the late 1990s, many researches and discussions associated with the new economic geography began to emerge in Korea. Various research issues are focused on analyzing changes of local, regional and global economic spaces and their processes in relation to institutional perspectives, knowledge and innovation, production chain and innovative networks, industrial clusters and RIS, and geographies of service. Although economic geography in Korea has developed significantly both in quantitative and qualitative perspectives, we pointed out that it has still limited in some specific scope and issues. Therefore, it is likely to imply that its scope and issues should be diversified with new perspectives and approaches.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.17
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• pp.45-78
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• 1974

To provide useful information for developing new high yielding soybean varieties and for improving cultural practices, an investigation was made on variation of dry matter production and on relationship among several agronomic characters of soybean plants grown under different planting times and densities as well as under different fertilizer levels, using Kwang-kyo, Dong puk-tae, and Suke ＃ 51 as determinate types and Shelby, SRF-300 and Harosoy as indeterminate types at the Crop Experiment Station during the period of 1972 and 1973. The results obtained were summarized as follow: 1. The dry weight, CGR and LAI at the initial flowering stage were high in the high plant population irrespective of varieties, planting times, and fertilizer levels. However, those characters of the indeterminate type were lower than those of the determinate types. The same characters of the indererminate type at the terminal leaf stage were either same or higher than those of the determinate types. 2. The dry weight of the determinate type at the initial flowering stage was similar to the indeterminate, type, when planting times were May 21 or June 15. The dry weights of both types of varieties were low when planted on July 10. When fertilizer levels were increased, the CGR, dry weight and LAI at the initial flowering stages were also increased. 3. Even though significant differences of LAI were obtained among the varieties within the same plant type, the indeterminate type was in general lower than that of the determinate type regardless of planting time and densities, or fertilizer levels, while the yield of the indeterminate type was comparable to the yield of the determinate type. 4. The high degree of leaf- and petiole-fall at the greenbean stage was highly associated with early planting and high levels of fertilizers. However, less amount of leaf- or petiole-fall was found when planted on July 10 or under low plant population. 5. The percent of stem weight was high under higher plant population, while the percent of leaf weight was high under lower plant population. When planting time was late, the percent of stem and petiole weight were reduced, while the leaf weight was increased. 6. The percent of pod weight of the determinate type at the terminal leaf stage was about 2% when planted on May 21, about 8% when planted on June 15, and about 9% when planted on July 10. The percent of pod weight of the indeterminate type at the terminal leaf stage were about 6 % when planted on May 21, 14% when planted on June 15 and 21% when planted on July 10. 7. Kwang kyo showed less degree of leaf-fall even when lodged due to high levels of fertilizer applied, while SRF-300 showed great damage due to lodging. 8. High yields were obtained when planted on May 21, but there were little yield differences between yields from May 21 and June 15 plantings. The reduction of yield due to late planting of July 10 was less apparent in the determinate type of varieties, while it was high in the indeterminate type. 9. The optimum plant population per are for high yield was 1, 250 to 2, 500 plants when planted on May 21, 2, 500 plants when planted on June 15, and 3, 333 plants when planted on July 10. 10. High correlation coefficients were obtained between dry matter weight and LAI at the terminal leaf stages, and between the dry matter weight and yield at the greenbean stages. The optimum dry weight for high yield in the determinate type was expected to be 25 kg. per are at the initial flowering stage and 50 kg. per are at the terminal leaf stage. In the indeterminate type the LAI and dry weight at the greenbean stage were 4 to 5 and 80 kg. per are, respectively. 11. Under the high plant population plant height was increased, while the stem diameter and the number of nodes and branches were reduced. Consequently, the percent of mainstem to main stem plus branches were increased, and the length of internode was also elongated. The ratios of stem weight, number of nodes and pods, and yield of main stem were increased when high plant population was associated with the early planting. The percent of main stem to branches for the indeterminate type was higher than that of the determinate type. 12. Under the high plant densities and late planting, the percent of the pod number and yields of main stem were increased, indicating that varieties with no or less branches were better adaptable under such conditions. 13. High degree of simple correlation coefficients was obtained between the LAI at the initial flowering stage and terminal leaf stage, and the total node number, dry matter and dry stem weight of both determinate and indeterminate types. Even though no significant correlation was found between the LAI at the initial flowering stage of the determinate type and the stem length and pod number per are, highly significant correlation coefficients were obtained between such characters in the indeterminate type of varieties. 14. The dry matter was positively correlated with the LAI, CGR, stem length, and pod number, node number and dry stem weight per are, while no significant correlation was found between the dry matter and stem diameter. 15. The correlation coefficients between lodging index and the LAI, dry weight, stem length and dry stem weight were highly significant. Negative correlation was obtained for the indeterminate type between the stem diameter and lodging index. The correlation coefficient between the stem diameter and lodging index was non-significant for the determinate type, while positive correlation was obtained between the yield and lodging index in the determinate type. The lodging index was also positively correlated with average length of internode of main stem. 16. The 100 seed weight appeared to be lowered under the high plant population and no fertilizer condition, and when planted late. Apparent differences of 100 seed weight were found between main stem and branches, being higher for the main stem than for the branches. 17. No variation of protein content was found due to different cultural practices. However, the oil content was apparently reduced when planted late.

• Korean Journal of Weed Science
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• v.5 no.2
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• pp.109-113
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• 1985

Experiments were conducted to know the ecology of injurious paddy field weeds, Scirpus hotarui and aneilema japonica in 1982-1983. Almost all emergences of the both species were on the soil surface in emergence depth. The vigorous growth stage was before Aug. 18, and the plant height and branch numbers were decreased and the days to flower were diminished by the shortday length treatment. A. japonica was not renewed by once cutting, but cutting S. hotarui on vigourous tillering stage was the most effective renew the growth and all of overwintered plants were renewed in emergence. The more these weeds emergence, the less rice yields.

• Journal of the Korea Convergence Society
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• v.7 no.5
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• pp.127-134
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• 2016

This study aims to investigate the factors affecting tooth loss and the association between smoking and tooth loss, by using the forth Korea National Health and National Examination Survey(2007-2009) of 1,565 elderly people over 65 years old. In terms of the characteristics, as age increases, tooth loss increases. In particular, according to the results of the analysis that identify the correlation between smoking to gender, socio-economic status and dental visiting patterns after correcting socio-economic factors and behavior, it is clear that male's tooth loss is higher than female's in current smoking and tooth loss is caused highly in the lower socio-economic status. In the dental visiting patterns, tooth loss is high when visiting more than twice a year. Therefore, it seems to need a preventive non-smoking policy at the level of dental services through further studies.

• Economic and Environmental Geology
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• v.57 no.2
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• pp.219-231
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• 2024

A survey of concrete plants in Incheon Metropolitan City and Gyeonggi Province was used to conduct an analysis of aggregate transport distance and production forms, as well as to evaluate the features and current status of aggregates distribution. As a result, areas such as Incheon, Siheung, Bucheon, Gimpo, and Siheung, where the distance to the demand points is less than 20 km, exhibited bidirectional distribution whereas Paju, Yongin, Yangju, and Pocheon, with distances ranging from 20 to 50 km is showed a unidirectional distribution pattern supplying aggregates exclusively to Incheon. Survey on manufacturing forms, more than 85% of the gravel dispersed in the Incheon area is made up of crushed aggregates derived from rocks discharged at construction sites indicating a considerable skew in supply chain. These findings are predicted to have a detrimental influence on aggregate supply in the long run, necessitating policy changes targeted at building an optimal aggregate distribution market.

• The Journal of Engineering Geology
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• v.34 no.2
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• pp.207-216
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• 2024

This study clarified the flow path of Choosan Spring, Nari Basin, Ulleung Island, South Korea. The orientations of faults and fractures developed on the inner edge of the caldera were identified as major factors affecting the flow path. The main flow paths include fracture zones oriented N-S and E-W. The spring also flows in a NE or NNE direction under the influence of the irregular shape of the caldera, which slopes to the NNE. Using Entrobacteriaceae species as tracers, it was found that Nari groundwater flows toward Choosan Yongchulso. However, the small number of water samples used in the analysis limits our understanding of the flow path from Sungin Valley to Nari Basin and Choosan Yongchulso.

• The Korean Journal of Pesticide Science
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• v.7 no.1
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• pp.51-57
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• 2003

For the purpose of a development of new agrochemical fungicides, new compound 4 in which 1,3-thiazoline scaffold as well as urea moiety in the structure was designed through molecular modification of lead compound, 2-imino-1,3-thiazone based on isosterism. The reaction of N-alkylthiourea 5 and bromoacetonitrile in ethanol gave 2,4-diimino-1,3-thiazolidine hydrobromide 6 regioselectively, which was treated with isocyanates gave the corresponding 8 which is tautomer of 4. Antifungal screening (in vivo) of the synthesized compound 8 against typical plant diseases, which include rice blast, rice sheath blight, cucumber gray mold, tomato late blight, wheat leaf rust, and barley powdery mildew, was carried out. Antifungal activities against rice blast of the compound 8 were weaker than those of 2-phenylimino-1,3-thiazoline 1. Some compounds showed weak antifungal activities against wheat leaf rust.