• Horticultural Science & Technology
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• v.29 no.4
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• pp.311-316
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• 2011

This study aimed to determine the effect of EC (electrical conductivity) levels of nutrient solution in hydroponic culture on allyl-isothiocyanate (AITC) content within plant tissues, Vitamin C content and physiological responses in wasabi plant (Wasabia japonica M. 'Darma'). The 'Darma' was grown for 5 weeks with a deep flow technique (DFT) system controlled at 5 different EC levels, including 0.5, 1, 2, 3, and $5dS{\cdot}m^{-1}$. In result, the highest total content of AITC showed at EC level 5 and $3dS{\cdot}m^{-1}$ for 1 or 5- week, respectively. The total content of AITC increased about 1.2-1.4 times when the plants were grown in the EC levels between 0.5 and $2dS{\cdot}m^{-1}$, whereas the content decreased about 6 and 56 % in the EC level 3 and $5dS{\cdot}m^{-1}$, respectively. The content of AITC was relatively higher in petiole tissue, about 53 %, taken from 1 week-grown plants when the EC was controlled between 0.5 and $2dS{\cdot}m^{-1}$. Root tissue also had relatively higher content of AITC, about 45.1 %, when the EC was controlled at 3 and $5dS{\cdot}m^{-1}$. However, a 5-fold decrease in the AITC content was found in blade tissue and a 6.8-fold decrease in root when the EC was controlled at $5dS{\cdot}m^{-1}$ for 5 weeks. There was no significant difference in the vitamin C content in 1-week grown leaf tissues under the different EC level treatments; but, the content increased about 27% in 5-week grown plants at the EC level between 0.5 and $2dS{\cdot}m^{-1}$, compared to the 1 week-grown leaf tissue. Electrolyte leakage of leaf tissue taken from 3-week grown plant was 3-fold higher at the EC level $5dS{\cdot}m^{-1}$, compared to the EC level between 0.5 and $2dS{\cdot}m^{-1}$. Chlorophyll content, photosynthesis rate and transpiration rate were decreased when the EC was controlled at higher than $2dS{\cdot}m^{-1}$. Leaf water content, specific leaf area and growth were decreased when the EC was controlled at $5dS{\cdot}m^{-1}$ for 5 weeks. All the integrated results in this study suggest that the EC level of nutrient solution should be maintained at lower than $3dS{\cdot}m^{-1}$ in order to improve nutritional value and quantity required for hydroponically grown wasabi as functional vegetable.

• Horticultural Science & Technology
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• v.31 no.3
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• pp.359-365
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• 2013

Chrysanthemum is one of the most popular ornamental plants worldwide. Recently, lots of new and novel chrysanthemum varieties have been developed using mutagenesis. However, there was no study for comparison of tissue culture condition among the mutant varieties derived from one original variety, until now. This study was conducted to compare the efficient regeneration condition of the two chrysanthemum mutant varieties, 'ARTI-purple' and 'ARTI-queen'. Two different flower parts (disk and ray florets) at the unopened and early blooming stages were used for comparison of regeneration condition on MS medium supplemented with combinations of three growth regulators (BA, NAA, and IAA). The highest regeneration rate was identified on the NAA and BA combination when the disk florets at unopened blooming stage are used. The best optimum combinations of growth regulators were identified as NAA $1.0mg{\cdot}L^{-1}$ and BA $0.5mg{\cdot}L^{-1}$ at 'ARTI-purple', which displayed 47.9% regeneration. However, regeneration of 'ARTI-queen' was the highest as 25.6% at NAA $2.0mg{\cdot}L^{-1}$ and BA $1.0mg{\cdot}L^{-1}$. There results indicate that there is a difference for the optimum regeneration condition between the mutant varieties derived from one original variety. These results will be useful for construction of efficient regeneration system of diverse chrysanthemum mutants developed by mutation breeding.

• Journal of Embryo Transfer
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• v.16 no.3
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• pp.193-201
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• 2001

This study was designed to examine the factors affecting in fertilization and development of embryos in vitro, and to examine whether zone drilling by laser irradiation can improve the hatching rate of IVF embryos from DNA marker-proved Hanwoo. DNA markers related to marbling score were identified using DNA fingerprinting with Ml3 probe and restriction enzyme Hae III. Oocytes were aspirated from immature ovarian follicles using a combined method of rectal ovarian-palpation and transvaginal ultrasound-guidance(6.5MHz) under local anesthesia. The aspirated oocytes were washed twice with fresh D-PBS containing 5% FBS and were rewashed 4 to 5 times with TCM-199 containing 5% FBS. A morphological grade of I to IV was assigned to each oocyte. Data were analyzed using the GLM procedure of SAS. Sperm separation methods did not have any significant effect on cleavage or developmental abilities of IVF embryos. Significantly(P<0.05) higher cleavage rate was observed in embryos from GI(60.0%, 3/5), GII(69.2%, 18/26) and GIII(62.1%, 59/95) compared to embryos from GIV oocytes(36.2%, 25/69). And the developmental rate to blastocyst stage was higher(P<0.05) in embryos from GI(33.3%, 1/3) and GII oocytes(38.9%, 7/18) than those from GIII(16.9%,10/59) and GIV oocytes(4.0%, 1/25). There was no significant difference in development of IVF embryos to blastocyst by media for in vitro culture. Proportion of hatched blastocyst was significantly(P<0.05) higher in embryos received zona drilling by laser than those of non-drilled.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.2
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• pp.91-97
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• 2001

The effects of sudden changes of water temperature (WT) on the stress response and physiological change of the cultured olive flounder in large (FL) and small (FS) size, and fat cod (FC) were examined by manipulating WT (2 types) in a flow through seawater culture system with 6 tanks (water vol. 270 L/tank). The WT was decreased from $20^{\circ}C$ to $10^{\circ}C$ within 5 hours ($2^{\circ}C/hour$) and maintained at $10^{\circ}C$ for 21 hours (Exp. I), and it was raised from $20^{\circ}C$ to $30^{\circ}C$ within 5 hours and maintained at $30^{\circ}C$ for 21 hours (Exp.II). In Exp. I, the levels of blood hematocrit at 5 hours ($10^{\circ}C$) in FS was significantly decreased from $13.5\pm2.0\%\;to\;11.3\pm2.3\%$, but FC at 2.5 hours ($15^{\circ}C$) ($19.0\pm0.3\%\;to\;23.2\pm3.8\%$) was increased, The blood hemoglobin concentration of all fish in Exp, II was significantly increased until 8 hours after raising WT from $20^{\circ}C$ to $30^{\circ}C$. In Exp. I and II , the levels of plasma cortisol in FL, FS and FC was changed from $5.2\pm8.5ng/mL,\;4.4\pm4.5ng/mL\;and\;2.7\pm0.4ng/mL$, respectively, before sudden drop and rise of WT. The levels of plasma cortisol of in FL ($164.0\pm53.1ng/mL$) and FC ($207.9\pm25.4ng/mL$) were significantly increased by the lowering WT sharply during whole experiment. The FL ($12.6\pm2.0ng/mL$) and FS ($4.0\pm3.9ng/mL$) showed no significant differences in cortisol level according to sudden rise of WT (5 hours). But it in FC ($44.7\pm18.2ng/mL$) was increased. In Exp. I, the plasma glucose levels of all fish groups were decreased after 5 hours ($10^{\circ}C$), The plasma lactic acid concentration of FL and FS showed no significant differences until 5 hours after raising WT from $20^{\circ}C$ to $30^{\circ}C$, But it in FC was significantly increased with WT raise.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.465-472
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• 2001

The effects of water level reduction in rearing tank and fish transference during fish selection process on the stress response (hematological factors, cortisol, glucose, lactic acid and osmolality) of tank-reared olive flounder Paralichthys olivaceus of large (FL), small (FS) and Japanese croaker, Nibea japonica (JC) were examined in running seawater culture system. The water level of rearing unit was lowered from 33 cm to 8 cm in the course of 2 minutes in the water level reduction experiment. The fish were removed from rearing tank (12 ton) to 450 L tank in 30 seconds after capture in the fish transference experiment, In water level reduction, the hematocrit of FL was significantly increased from $14.6\%$ at beginning to $23.5\%$ after 10 hours, However, it decreased to the value of beginning after 46 hours. Plasma cortisol concentration of FL was the highest concentration (13.7 ng/mL) after 22 hours, but it decreased to 4.0 ng/mL at the end of experiment. Cortisol concentration of FS did not show any significant difference during the experiment. The cortisol concentration of JC were significantly higher at 4 hours (282.3 ng/mL) and 22 hours (350.5 ng/mL), Glucose concentration of JC was the highest (138.0 mg/dL) at 22 hours. Lactic acid concentration was not different between experimental groups. In the fish transference experiment, red blood cell of FL was increased from $1.9\times10^6\;cell/{\mu}\;L\;to\;4.2\times10^6\;cell/{\mu}L$ in 24 hours. Blood hemoglobin of JC were significantly elevated in 24 hours. At 1 hour after transference, plasma cortisol concentrations in both fish species were increased to 95.3 ng/mL in FL and 175.5 ng/mL in JC. Glucose concentration of JC was increased to 132.5 mg/dL at 1 hour, 129.5 mg/dL at 3 hours after transference.

• 대한공업교육학회지
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• v.32 no.1
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• pp.153-171
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• 2007

The purpose of this research was to investigate the degree of perceptional change of career education through overseas training of specialized high school teachers who take the leading role in applying Korean vocational education to reality. To accomplish this purpose, the following method were employed: 25 specialized department teachers of Keyngido educational institute who visited career education institute in USA and Canada were selected, and pretest and posttest were taken. Collected data were analyzed by Windows Korean version SPSS 14.0. M, SD, t-test and significant level p<.05 were employed for statistical analysis. The result of this research was as follows: There was significant difference in the degree of perceptional change of vocational education by overseas training of specialized high school teachers. But There was no significant differences in the management of vocational education curriculum(${\alpha}=.327$), reinforcement of preparatory training for technique contest(${\alpha}=.327$) in the statistical significant level(p<.05). The perception level of the trainees varied respectively in these domains. And means of posttest were relatively low in the comparison with those of pretest in the domains of visit of educational institute, educational facilities, scholarship and financial support, and reinforcement of preparatory training for technique contest. It is attributed to the Korea's uniqueness of culture, emotion, school system, educational facilities and financial support different from U.S.A. and Canada. The vocational education program of vocational education training institute in U.S.A. and Canada is mainly composed of industrial department, so there was no statistical significant difference(p<.05) in some questions taken by subjects of agricultural and commercial department. In conclusion, The overseas training program is very helpful for the perceptional change of vocational education and it is desirable to be expanded continuously.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.5
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• pp.33-47
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• 2011

One of the most fundamental jobs of contemporary government is to look into various ways of providing its citizens with the best service work. This study aims to establish a procedure through which to consign the management of city parks to private companies, thus inviting participation and satisfaction on the part of citizens. In particular, this procedure includes creating a system of selecting private managing companies, for instance, specifying standards of selection and assembling selection committees. The results of this study can be summarized as follows. First, city parks can be managed better by private companies than by local governments in terms of cost cuts, personnel training, business efficiency, and know-how accumulation. The legal background for this is found in central and local legal articles. Second, it is recommended that the selection committee be composed of 6 to 9 members, both insiders and outsiders. In addition to selecting private managing companies for contracting-out, the committee should under take the role of consulting on how to perform and revise selecting standards, so that they can continue to improve these procedures. Third, the decision on private management should be noticed in advance and be made based on standards considering each local government's condition. These standards should consider the aspects of the public good, cost saving, quality of service, managing supervision, and citizen participation. The committee's assessment takes into account both the quality and the quantity of the standards. Fourth, the contracting-out for city park management should follow the order of: announcing consignment and receiving applicants, organizing selection committees and assessing applications, selecting and contracting, midterm evaluation, and re-announcement and re-consignment. To run city parks through the contracting-out is expected to increase the number of park visitors. Additionally, private consignment will involve a participation of diverse citizenship, thus playing an important role in city parks' building of a green-culture community.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.4
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• pp.60-73
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• 2011

Since Jeju Ollegil opened in September 2007 and attracted the sensation of popularity throughout the country, the interest in 'Walking Trails' has increased, and the central ministries and the local governments composite and assign various 'Walking Trails'. Walking trails are not tours on which people go to see one spot and move to another spot by vehicle, but a long linear journey that leads people to see, to feel and to experience a region's landscape and culture while walking on the trail. 'Walking Trails' are efficient routes to discover and to use a former way and to link the various ecological regions' histories and cultural resources, so it is most important to select a route. Although the routes were selected by considering the various planning factors and giving each route a specified theme, some problems like the inconvenience of visitors caused by lack of facilities have occurred. After designation and construction of the trails, they were not properly evaluated by visitors. Therefore, it is the purpose of this study to suggest a better way to construct the trails by surveying visitor satisfaction and by analyzing the impact of planning a route on visitor satisfaction at Bukhansan Dulegil which was completed. For this study, with a questionnaire based on the literature review to identify the important planning factors for selecting a route, a survey was conducted on visitor satisfaction for each section and their intention to revisit and to recommend that trail. Based on the characteristics of each section that was identified in the field research, the trails were classified into five types and satisfaction of each type and each type was analyzed. In addition, analyzing the impact of planning factors on satisfaction, the impact of satisfaction on revisiting and recommending and visitors' perception of the theme, further improvement for better construction of the trail was presented. Satisfaction of sectors with strong natural elements was higher; 'walking comfort' was the highest planning factor affecting satisfaction. In addition, satisfaction was surveyed to have high influence on revisiting and recommending.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.2
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• pp.20-33
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• 2020

This study aims to examine the trends in the preservation of urban public parks with a focus on the international movement to acknowledge and preserve the heritage value of urban parks. First, the background in which the concept of "historic urban park" first appeared internationally, as well as the current situation were investigated. Then, the cases of the United Kingdom (UK), the United States (US), and Japan, all of which are already preserving and managing urban public parks, were analyzed. In the ICOMOS-IFLA Document on Historic Urban Public Parks, the International Council on Monuments and Sites (ICOMOS), which is a group of specialists dedicated to the conservation and management of cultural heritage, mentions that it is necessary to maintain the social, intangible, aesthetic, ecological, and civic values of historic urban public parks. In addition, according to ICOMOS, it is necessary to preserve elements of parks, such as space composition, topography, light, and environment. The UK, the USA, and Japan have their own unique characteristics for the background of preserving urban parks, the preservation system, the selection of parks to be preserved, and the elements to be preserved within the park. The UK has categorized parks into certain types from each period and has tried to preserve the common elements in each type. The US has selected the parks to preserve by determining the meaning of the parks itself considering multiple aspects, embracing not only the physical form of the parks, but also the culture, monumentality, and social values. Recently, Japan began the preservation of historic urban parks as a matter of policy and started to implement a preservation policy by investigating modern parks that are believed to be worth preserving. Specialists in cultural heritage preservation have argued that the method of preservation of historic urban parks must differ from that of other parks or gardens. Nonetheless, observing cases in these three countries showed that, regardless of their administrative and legal systems regarding cultural heritage and urban public parks, their policies were still limited to preserving only the physical elements of parks. The direction and methodology for the preservation of historic urban parks must be developed further and elaborated upon in terms of the evolving concept and definition of heritage. Urban parks are where various historic values are accumulated, connoting historical meanings dealing with the memories of the parks and the urban dwellers. This study found that, worldwide, park management has been carried out in a way that the historic values of parks are respected and preserved. This global trend in preserving the historic values of urban public parks has significant implications for the management of urban public parks in Korea that are being formed and renewed repeatedly.

• Journal of Sericultural and Entomological Science
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• v.16 no.1
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• pp.1-20
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• 1974

These studies are conducted to find out inducing factors for the non-sprouting bud which appears in the utility reclaimed hill mulberry held and to establish control method for it since 1971. The results are as follows： 1. In spring, winter bud does not germinate at all on the top of branches or does wither suddenly after or during its germination. Necrosis and browning are appeared in cortex and phloem of non-sprouting bud branch. In autumn, the deterioration of leaves, the abnormal leaves on the top of branch, and browning of veins or petioles are also observed. 2. The soil of non-sprouting bud mulberry Held were found to be sand loom derived from granite rocks. The sub soil of it was very poor in development of root system because it had hard soil and lower pore space ratio. Especially, the sub soil to bring about severe non-sprouting bud had been easily appeared with deficiency of moisture content because of high density solid. 3. Content of soil moisture was significantly lower in the severe non-sprouting bud soil than in the healthy field. The sub soil o( the healthy field contained proper moisture content. On the other hand, the sub soil of the severe non-sprouting bud held contained almost critical moisture content for wilting. 4. The depth of available soil was shallow in the non-sprouting bud than in the healthy fold. The more rate of the non-sprouting bud was severe, the more available soil depth was sallow. 5. Available boron content in soil was affected by moisture content in soil. There was. lower moisture content in the non-sprouting bud field than that in healthy fold during 5, June to 5, September. 6. There was no significant correlation between soil pH and available boron content. On the other hand, the correlation of the content of organic matter and available boron content appeared to be highly positive significance. 7. The quantity of boron was significantly contained more in healthy mulberry field (0.34∼0.43ppm) than in non-sprouting bud field (0.10∼0.28ppm). 8. Boron content in leaves and barks was significantly lower in the non-sprouting bud trees than in healthy trees. 9. The symptom of non-sprouting bud induced from boron free sand culture was similar with that arised in the non-sprouting bud field. 10. The rate of non-sprouting bud was high by the increased application of lime. Considering the facts mentioned the above, author may conclude that the non-sprouting bud of mulberry tree is caused by boron deficiency, but also it is affected by the parent rocks, organic matter, soil moisture content and lime application. 11. The non$.$sprouting bud may be completely controlled by the application of 6∼9kg borax per 10a mulberry field twice a year in spring and summer.