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        검색결과 141

        62.
        1992.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Technology is unevenly distributed across countries, thus constituting an entry barrier. Under several simplifying assumptions, technology licensing strategies among incumbent and entrant firms in the intermational context are analyzed. First, in a model with two monopolistic firms, the conditions for licensing to occur are elaborated as a function of the costs of the two firms. Licensing is likely to occur only when the entrant has a more competitive cost position than the incumbent to compensate for the royalty payment. However, if the incumbent has much lower marginal cost than the entrant, the incumbent has an incentive not to license the technology. Second, a new set of issues arises when multiple potential licensors are considered. The maximum and minimum values of the royalty payment decrease as the number of incumbents with the technology increases. Moreover, each incumbent has an incentive to sell the technology before other incumbents do, which leads to a Prisoner`s Dilemma situation. Third, in the case of multiple licensees, a potential entrant`s willingness to pay for a license depends upon the strategies of other firms. The optimal pricing strategy of the licensor is identified.
        7,700원
        63.
        1990.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present (U-B) and (U-V) radial color distributions of 103 galaxies based on the UBV multiaperture photometry compiled by Longo, de Vaucouleurs, and Corwin (1983). About half of the galaxies show radial negative color gradients (i. e., bluer at the outer parts of the galaxies). E and SO galaxies have similar color gradients. and there appears to be no correlation between the size of color gradients in these galaxies and their luminosity, but the luminous spiral galaxies tend to have steeper color gradients. The metallicity gradients of elliptical galaxies derived from the (U-V) color gradients agree with those from the magnesium gradients within the errors.
        5,500원
        65.
        1983.12 구독 인증기관·개인회원 무료
        66.
        1983.12 구독 인증기관·개인회원 무료
        67.
        2020.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The human and capital resources from foreign investors are important sources of finance for developing countries. Foreign ownership can help the firm to raise funds for operations and the foreign management can help the firm expand the market and improve management. However, does this really happen to Vietnamese firm? To find the answer to that question, this paper examines the impact of foreign ownership and management on the financial performance of listed firms on Vietnam’s stock market. The data collected include 427 listed firms in all fields over five years, from 2014 to 2018. The financial performance is measured by Tobin’s Q, ROA and ROE. The study carried out testing of each model by the least squares method of Pool OLS, assessing random effects (REM) and evaluating fixed effects (FEM). The most effective model is the FEM model. The results show that the foreign ownership ratio and the size of the firm have a positive impact on the financial performance. The foreign management, the age of the firms, the liquidity and financial leverage have a negative impact on the financial performance. Based on the research results, the study proposes some recommendations to improve the financial performance of listed firms in Vietnam.
        68.
        2016.05 서비스 종료(열람 제한)
        Background : Water uptake and flow across cellular membranes is a fundamental requirement for plant growth and development, and plant water status is important not only for plant growth under favorable conditions but also for ability of a plant to tolerate adverse environmental conditions. Thus identification of plasma membrane water channel genes (aquaporins) in ginseng provides extensive information for functional studies and the development of markers for salinity stress tolerance. Methods and Results : For salinity treatment, the plants were grown for 4 weeks in culture medium gelled with 0.8% Phytoagar, and the old media were replaced with the fresh medium containing NaCl at 0, 50, 100, 200 and 400 mM, respectively. The samples for stress treated and non-stressed plants were collected from 6h to 72h, and frozen immediately into liquid nitrogen. According to the sequence information from the assembled transcripts, four primer pairs were designed from the aquaporin gene regions. In order to determine the pattern of aquaporins expression in ginseng seedlings to salinity stress, we conducted semi-quantitative RT-PCR. Conclusion : A tonoplast intrinsic protein 1 (TIP1)-type aquaporin is not only believed to be essential for plant life, but also to be beneficial for growth under salinity stress. Therefore, a deeper understanding of aquaporin genes in ginseng will be essential for crop improvement, which could help us to understand the molecular genetic basis for the ginseng genetic improvement and also provide the functional genetic resources for selective breeding and transgenic research.
        69.
        2016.05 서비스 종료(열람 제한)
        Background : This study was carried out to understand the effect of seedling weight (SW) on growth and flowering in Panax ginseng. Methods and Results : The testing materials were Chunpoong (CP), Yunpoong (YP) and Jakyeongjong (JK). The increase of seedling (1yr) weight led to an increase in ratio of flowering plant and in number of flower per plant. The seed setting rate of two year-old plant (CP, YP, JK) increased with increase of SW at the planting time (PT) and number of flower per plant of three year-old plant (CP, YP) increased also. In the two year-old plant (JK), the ratio of three leaves per plant was 8.8, 19.6, 31.0, 42.0, 44.7 and 58.2%, respectively, in the SW of >0.6, 0.6~0.8, 0.8~1.0, 1.02~1.2, 1.2~1.4 and 1.4g<. The growth of ginseng plant was good with increase of SW at the PT. Conclusion : There was a highly positive correlation between seedling weight and flowering characteristics.
        70.
        2016.05 서비스 종료(열람 제한)
        Background : Due to immature development of embryo in ripened berries, dehiscence process is required for the proper germination of ginseng seeds. Such process involves the preparation of the container with alternating layers of seed and moist sand. In order to make sand fully moist, water sprayer has been usually used by farmers, which is labor intensive, time consuming and causing uneven sand moisture. Methods and Results : In this study, we investigated the effects of different stratification methods on dehiscence ratio of ginseng seeds. Ginseng seeds were stratified for 90 days in a total of 12 different treatments and the dehiscence ratios were compared; drainage methods, drainage time, the ratio between ginseng seeds and sand, and etc. Seed stratification process was performed according to the guideline of ginseng GAP. One thousand ginseng seeds were used for each treatment. It was found that the average of dehiscence of the 12 treatments was 84.6 %. The highest dehiscence ratio (90.3 %) was observed in the seeds that were treated with water soaking, immediately followed by drainage. Higher ratio was also observed in the seeds that were soaked for 60 min, followed by drainage. Therefore, our findings indicate that ginseng seeds soaked in water less than 60 min could dehisce more efficiently than traditional method. Conclusion : Our study demonstrated that ginseng seeds that are subjected to water soaking and then drainage showed better ration of dehiscence. This method will eventually decrease the time and labor used for seed stratification.
        71.
        2016.05 서비스 종료(열람 제한)
        Background : An important feature of the nutrient solution is that they affect not only the growth but also quality of crops by changing nutrient uptake, especially due to changes of EC in nutrient solution. This study was carried out to investigate effect of EC in nutrient solution on growth and ginsenoside of ginseng. Methods and Results : EC in nutrient solution was controlled with 0.68, 0.84, 1.23, 1.41 dS/m. The root weight of ginseng treated by low EC levels in nutrient solution was higher during the initial of growth. However, the higher EC levels, the more increased the change rate of root weight from the initial to the middle of growth. The highest amount of ginsenoside was changed by growth period. Although the total amount of ginsenoside in root is highest treated by EC 0.68 dS/m at 45 days after treatment. the total amount of ginsenoside in root is highest treated by EC 1.23 dS/m at 135 days after treatment. Conclusions : EC in nutrient solution should to be controlled depending on the stage of growth and the part of use, i.e. root and leaves, when ginseng is cultivated through nutri-culture.
        72.
        2016.05 서비스 종료(열람 제한)
        Background : Boron (B) is an essential element required for the growth of plant. It has a narrow range of optimal concentration from minimum to maximum thresholds than other micro-elements. The study was carried out to investigate to the influence of B excess concentrations on physiological disorder of leaf, growth and mineral concentration of ginseng to obtain basic information for physiological disorder diagnose. Methods and Results : The ginseng cultivar ‘Gumpoong’ was cultivated by hydroponic system for 2 months. The toxicity symptoms which ginseng leaves were curved downwardly and induced to chlorosis after beginning to dry the edge appeared on leaves more than 30 ppm compared to the control(3 ppm). The growth of ginseng was more decreased with higher B concentration. Mn uptake was also decreased as B concentration increased. It was found that B excess hindered the growth of ginseng and was reversely related to Mn uptake. Conclusions : More than B 30 ppm can negatively affect growth and mineral uptake. Consequently, B excess can occur physiological disorder of ginseng.
        73.
        2016.05 서비스 종료(열람 제한)
        Background : For increasing saponin content of ginseng cultivated in shaded plastic house, this study was performed to investigate growth characteristics and saponin content of ginseng (Panax ginseng C.A. Mayer) according to foliar spray of germanium and water-soluble silicates processing. Methods and Results : Used a native species in this study is violet-stem variant that most commonly cultivated in ginseng’s farms. 1-year-old violet-stem variant was transplanted on March 24, 2015 and planting distance was 11 × 20 cm. Shading material of plastic house was used blue-white shading vinyl. The processing method of inorganic dissolved matter is as follows, we were diluted with germanium and water-soluble silicates to 500-fold, 1000-fold and investigated after foliar spray twice a month from May to September. The growth characteristics in above-ground part of 2-year-old ginseng was a good in the inorganic matters treatment compared to the control treatment, the difference of above-ground growth characteristics between the inorganic dissolved matters treatments was not significant. The growth characteristics in under-ground part of 2-year-old ginseng was a good in the inorganic matter treatments and root weight per plant in the 500-fold dilution of germanium was 12.4 g that increased by 29 % compared to the control (9.6 g). Crude saponin content of under-ground part was higher generally in inorganic matter treatments compared to the control (11.53 ㎎/g). In the 1000-fold dilution of water-soluble silicate and germanium (50:50), crude saponin content was the highest in 12.91 ㎎/g. Crude saponin content of above-ground part was higher generally in inorganic matter treatments compared to the control (61.76 ㎎/g). In the 1000-fold dilution of water-soluble silicate and germanium (50:50), crude saponin content was the highest in 65.69 ㎎/g. Conclusion : From the above results, we concluded that germanium and water-soluble silicates could be useful matters in promoting growth characteristics and saponin content of ginseng (Panax ginseng C.A. Mayer).
        74.
        2016.05 서비스 종료(열람 제한)
        Background : This study was performed to set proper soil moisture tension for promoting seed emergence and yield of ginseng when direct seeding cultivation of ginseng was carried out in shaded plastic house. Methods and Results : The test cultivars were used Cheonpung, Yeonpung, Geumpung and seeds were sown on November 20, 2013. Irrigation starting point was set to 30, 40, 50 kPa and irrigation breakpoint was set to 20 kPa. Ginseng was cultivated in clay loam soil and shading material of plastic house were used blue-white shading vinyl. The emergence rate of 3-year-old ginseng cultivars in accordance with soil moisture tension indicated Cheonpung 97.0%, Yeonpung 95.0%, Geumpung 95.3% in each 50 kPa, 50 kPa, 30 kPa. In general, emergence rate of ginseng was higher tendency in 50 kPa (93.3∼97.0%). The average absolute soil moisture content during the growing season indicated a moisture content of 19.3% (30 kPa), 17.9% (40 kPa), 16.2% (50 kPa). Looking at the growth characteristics in above-ground part of 3-year-old ginseng cultivars according to soil moisture tension, Yeonpung, Cheonpung and Geumpung were good growth tendency in each 30kPa, 40kPa, 50kPa. On the other hand, looking at the growth characteristics in underground part of 3-year-old ginseng cultivars according to soil moisture tension, Cheonpung, Geumpung and Yeonpung were good growth tendency in each 30kPa, 40kPa, 50kPa. Yield per 10a was indicated that Yeonpung was the highest in the 50kPa to 456kg. Yield per 10a of Cheonpung and Geumpung indicated 347kg, 263kg in each 30kPa, 50kPa. Conclusion : From the above results, we concluded that ginseng(Panax ginseng C.A. Mayer) seems to be a difference of growth characteristics according to soil moisture tension. Therefore, it is need to manage soil moisture for each ginseng cultivars
        75.
        2016.05 서비스 종료(열람 제한)
        Background : This study was conducted to determine the impact of temperature elevated and the effect of transplanting times based on climate change scenario on growth of 2-year-old korean ginseng (Panax ginseng C. A. Meyer.) in temperature gradient chambers (TGC). Methods and Results : As a plant materials, ‘Yunpoong’ was cultivated in TGC at ambient temperature(Amb), Amb+2℃, Amb+4℃ and Amb+6℃ respectively. Ginseng was also transplanted on March 29, April 12 and 26 respectively. Investigation on characteristic of aerial parts were carried out on 28, 56, 84 and 112 days after transplanting and characteristic of roots were conducted on October 19. As transplanting time was faster and temperature was higher, the growth of aerial parts were increased. Compared with those of ginseng transplanted on March 29 with Amb, the root weight which tend to decrease depending on late transplanting time and high temperature decreased about 11.1%, 35.4% and 42.4% in Amb+ 2℃, Amb+4℃ and Amb+6℃ respectively. Ginseng transplanted on April 12 and 26 decreased about 20.9%, 33.9% respectively. Conclusion : Consequently, the more transplanting time extend, the more quantity increased in all temperature treatment. So, it is possible to increase in quantity to advance transplanting time although high temperature will be caused by the climate change.
        76.
        2016.05 서비스 종료(열람 제한)
        Background : When ginseng seeds were gathered, the seeds were unripe. To grow immature embryo definitely, special treatment called dehiscence must be performed. Even though dehiscence is completed, most ginseng seeds are on enforced dormancy. The breaking seed dormancy is generally achieved using cold treatment. Also it is reported that gibberellin treatment can replace the treatment. It is very time consuming process in order to develop new ginseng cultivar because ginseng flowers after 3 years of growth. To shorten the ginseng breeding period, it is necessary to establish fast generation progress. Therefore, this study examined the possibility of breaking seed dormancy of ginseng using GA3 treatment and alternating temperature. Methods and Results : Seeds were obtained from local variety fruit which is not inbred. Gibberellin of 100 ppm was treated at seeds for 24 hours. Fixed cold condition was treated on both –2℃ and 2℃. Alternating cold condition was treated on 2℃ and then –2℃, finally 2℃. Fixed and alternating temperature was continued for 15, 30, 45, 60, 90 days that 15 days of alternating temperature is first 2℃ for 5days and then -2℃ for 5days, finally 2℃ for 5days. The other treatment periods such as 30, 45, 60, 90 days mean 10, 15, 20, 30 days respectively. Each of 48 seeds were sowed on tray in greenhouse at 3 replication. Experimental plot was completely randomized. Conclusion : Seeds untreated with GA3 were germinated little and there is no difference between 2℃ and –2℃. Alternating temperature until 60days made no difference with fixed temperature but germination rate increased up to 70.8% when seeds were treated for 90days. Germination of seeds treated with GA3 is much higher than untreated seeds especially combined with alternating temperature.
        77.
        2016.05 서비스 종료(열람 제한)
        Background : Cylindrocarpon root rot, caused by Cylindrocarpon destructans and Fusarium solani, is a major disease which lead to replanting failure in ginseng garden. Chlamydospores of C. destructans, generated by poor environmental condition, can survived more than ten years in soil without host plant, ginseng. Density of soil pathogens gradually decreased as the progress of time since ginseng was harvested. Methods and Results : Soil chemical properties was analyzed from soil samples of 43 regions in farmer’s ginseng garden to study the variation of content and the correlation among inorganic contents. Soil samples of 24 regions was also analyzed to study correlation between progressed-year after ginseng harvest and soil chemical properties. Variation of soil chemical properties in descending order was Fe, Zn, P2O4, NO3, Mn. The content of Fe and Zn were great variation among inorganic chemicals of soil of farmer’s field. Electrical conductivity to induce physiological demage in excessive concentration showed highly significant positive correlation with the content of NO3 and K. As the progress of year after ginseng harvest, the content of organic matter and zinc was increased, while pH and Na were decreased in farmer’s field to cultivate ginseng. There were highly significant positive correlation between the progress of year after ginseng harvest and zinc content in farmer’s field to cultivate ginseng. Ratio of root rot of 2-year-old ginseng showed significant positive correlation with K content, and negative correlation in experimental field cultured by six rotation crops for one year. Conclusion : Root rot by soil pathogens was closely related with the content of potassium and zinc in soil chemical properties.
        78.
        2016.05 서비스 종료(열람 제한)
        Background : Root diseases caused by Cylindrocarpon destructans and Fusarium solani decrease the yield and quality of ginseng. Cylindrocarpon root rot is a major disease caused by replanting failure in ginseng garden. Methods and Results : Solarization was done in the infested soil of the greenhouse for summer season (from July 24 to Autumn 31, 2014) after putting green manure (Sudan grass) and calcium cyanamide (CC) into the soil. Mycelium and conidia of C. destructans died at 4 0℃ after 15 hours, and 45℃ after 5 h, but it did not die at 35℃ after 15 h. Those of C. destructans died after keeping it for 2 hours daily at 40℃ for 9 days, and 45℃ for 8 days, but did not die at 38℃ for 9 days. Maximum soil temperature was 55.4℃ in 5 cm depth, 48.7℃ in 10 cm, 44.7℃ in 15 cm, 42.5℃ in 20 cm, and 31.9℃ in 30 cm by putting green manure into the soil and solarization. Reduction of sudan grass increased electrical conductivity (EC), organic matter, P2O5, K, and Mg, while decreased pH, NO3-N, and Na. Addition of calcium cyanamide and urea gave a negative effect on the growth of ginseng because EC and NO3-N were increased excessively than the optimal range. Solarization using green manure mixed with CC was the most effective in decreasing soil-borne pathogens of 2-year-old ginseng. But the root disease that occurred between single treatment of sudan grass and the treatment mixed with calcium cyanamide showed not a significant different. Addition of calcium cyanamide showed the decrease of root weight because leaves were dead early by a excessive increase of EC and NO3-N. Conclusion: Soil disinfection using green manure and solarization in greenhouse was effective in inhibiting root rot, however, it did not completely kill the soil-borne pathogens.
        79.
        2016.04 KCI 등재 서비스 종료(열람 제한)
        Background: Root diseases caused by Cylindrocarpon destructans and Fusarium solani decrease the yield and quality of ginseng. Cylindrocarpon root rot is a major disease caused by replant failure in ginseng fields. Methods and Results: Solarization of infested greenhouse soil was carried out during the summer season after applying green manure (Sudan grass) and Calcium Cyanamide (CC) on the soil. Mycelium and conidia of C. destructans died at 40℃ after 15 h, but they did not die at 35℃ after 15 h. They also died after keeping the soil at 40℃ for 2 h daily for 9 days, and at 45℃ for 8 days, but they did not die at 38℃ for 9 days. Maximum soil temperature was 55.4℃ at 5 ㎝ depth, 48.7℃ at 10 ㎝, 44.7℃ at 15 ㎝, 42.5℃ at 20 ㎝, and 31.9℃ at 30 ㎝ by incorporating green manure into the soil and using solarization. Solarization using green manure mixed with CC was the most effective in decreasing soil-borne pathogens of 2-year-old ginseng. However, the addition of CC decreased the root weight due to the increase in EC and NO3-N. Conclusions: Soil disinfection using green manure and solarization in a greenhouse environment was effective in inhibiting root rot, however, it did not completely kill the soil-borne pathogens.
        80.
        2015.12 KCI 등재 서비스 종료(열람 제한)
        Background : To control ginseng gray mold, farmers have mainly used inorganic chemical based fungicides. The recent emergence of fungicide resistance has reduced the effectiveness of such control methods. Such pesticides also carry additional problems, such as diffuse pollution. Methods and Results : Six treatments of organic agricultural materials were tested for control of ginseng gray mold, CAPW (Chrysophanic acid + Phytoncide +Wood vinegar), EmEWV (Emodin + Ethanol +Wood vinegar), CEWV (Curcumin + Eugenol +Wood vinegar), Bacillus subtilis, soybean oil and sulfur. The control effect for gray mold by a single application of the agrochemical fungicide industrial Fenhexamid wettable powder (WP) was 84.4%. The control effect by CAPW, EmEWV and CEWV varied between 52.7 - 64.9%. The control effect by B. subtilis, soybean oil, and sulfur were 32.9 - 59.2%. Conclusions : In the field tests, CAPW showed the highest control effects when used before, and at first stage of disease incidence, against ginseng gray mold.
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