• Journal of Korean Society of Forest Science
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• v.79 no.4
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• pp.367-375
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• 1990

In order to determine the effects of bedrock, organic matter, calcium and iron oxide on the soil aggregation, this research has performed with soils from bedrock regions of Limestone, Granite and Granite gneiss. This research was also to estimate how organic matter, calcium and iron oxide influence on soil aggregation under different forest conditions in various bedrock regions. And it also had a purpose to rate physical factors relevant to soil aggregation, their characteristics and aggregate diameter which closely relates to stabilities in the process of soil erosion. The following conclusions have been drawn in response to the overall research objectives. The rates of the soil aggregation on different bedrock regions were 21% in Limestone bedrock, 19.8% in Granite bedrock and 9.9% in Granite gneiss bedrock. A main factor in soil aggregation was the orgainc matter content in soils and the rate of soil aggregation increased in the constant proportion with the organic matter content. The relation could be formulated into Y=4.31X-4.37(Y : aggregation ratio X : organic matter content). The soil aggregation ratio under the deciduous forests eras higher than that under the coniferous forests. It was considered that this resulted from differences in organic matter content. Soil aggregates with larger diameter than 0.5mm were found more in Limestone bedrock than other smaller size soil aggregates of 0.25mm diameter were more distributed in Granite gneiss bedrock. Granite bedrock region had normal distribution in soil aggregate sizes with the highest frequency of 0.5mm diameter. Calcium and iron oxides had only partial influences on the soil aggregation in some specific conditions. But in Limestone bedrock region calcium influenced on the soil aggregation with the organic matter content.

• Journal of Korean Society of Forest Science
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• v.78 no.2
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• pp.103-118
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• 1989

The occurrence of witches' broom in Ligustrum ovalifolium was first noticed in Korea by author in 1984. The present study was carried out with particular emphasis on the symptomatology, etiology, transmission of the disease and antibiotic treatments. The infected tissue was observed by the fluorescence and electron microscopy and its biochemical characteristics were compared with healthy one by electrophoresis. The results are summarized as follows : 1. symptoms of the infected trees were characterized by the dwarfing of the organs, yellowing and brooming of the foliage. 2. The observation by the trans electron microscopy on the witches' broom of L. ovalifolium revealed the occurrence of numerous mycoplasma-like organisms(MLOs) in the phloem tissue cells of the midribs of infected leaves. 3. The MLOs were surrounded by a single unit membrane, and they appeared to be multiplied by binary fission. 4. The presence of crystals unidentified in the phloem parenchyma cells was noticed by electron rnicroscopy, 5. The disease was able to be transmitted by budding, crown, and greenwood graftings to L. ovalifolium, L. obtusifolium, L, japonicum and also transmitted, even when the stocks and scions were not completely grafted. 6. Insect transmission on L. ovalifolium and L, obtzrsifolium was carried by Hishimonus sellatus. 7. The infected roots dipped in the 1,000 ppm of teracyclin solution was only temporarily effective in controlling the disease. 8. Infected plant with MLOs showed specific fluorescent reactions in phloems with DAPI stain. 9. The protein and peroxidase separated by electrophoresis showed strikingly distinctive difference between the healthy and diseased leaves.

• Journal of the Korean Geotechnical Society
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• v.34 no.2
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• pp.19-32
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• 2018

During the process of gas hydrate extraction in the deep seabed, fine diatom particle migration occurs, which causes the seabed slope failure and the productivity deterioration of the gas hydrate. Therefore, a study related with the changes of the ground characteristics due to the fine particle migration is required. The objective of this study is to investigate the change of hydraulic properties of sand due to the migration of fine diatom particle in sandy soils. In order to simulate the sediments of the Ulleung basin gas hydrate in the East Sea, fifteen sand-diatom mixtures that have different diatom volume fractions (DVF) are prepared. During the falling head permeability tests, the coefficients of permeability are measured according to the DVF. In addition, for the simulation of the fine diatom particle migration, constant head permeability tests are conducted by applying the hydraulic pressures of 3 kPa, 6kPa, and 9 kPa on a specimen composed of two layers: a specimen with 50% DVF in upper layer and a specimen with 0% DVF in lower layer. Furthermore, the coefficient of permeability and the electrical resistivity of the migration zone are measured during the constant head permeability test. The falling head permeability tests show that the coefficient of permeability decreases as the DVF of the specimen increases. In addition, the gradient of the coefficient of permeability curve decreases in the DVF range of 10%~50% compared with that of 0%~10%, and increases above 50% in DVF. The result of constant head permeability tests shows that the coefficient of permeability decreases and electrical resistivity increases in the migration zone due to the fine diatom particle migration. This study demonstrates that fine diatom particle migration reduces the permeability of the soils and the behavior of the migration zone due to the fine diatom particle migration may be estimated based on the reversal relationship between the coefficient of permeability and the electrical resistivity.

• Journal of the Korean Geotechnical Society
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• v.33 no.11
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• pp.21-34
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• 2017

The ground penetrating radar (GPR) signal can be measured with different amplitudes according to the directivity, so the directivity of the antenna should be considered. The objective of this study is to investigate the directivity of antenna by analyzing the reflection characteristics of electromagnetic waves radiated from the antenna, and to evaluate effective range of angle that can inspect an abnormal area according to the directivity of antenna. For the measurement of the directivity, a circular metal bar is used as reflector and the signals are measured by changing the angle and the distance between reflector and antenna in the E- and H-plane. The boundary distance between the near field and the far field is determined by analyzing the amplitudes of reflected signals, and two points with different distances from each of near and far fields are designated to analyze radiation patterns in near and far fields. As a result of radiation pattern measurement, in the near field, minor lobes are observed at angle section at more than $50^{\circ}$ in both E- and H-plane. Therefore, antenna has the directivity for the direction of main lobe and minor lobes in near field. In the far field, antenna has the directivity for a single direction of main lobe because minor lobes are not observed. The amplitude of the signal reflected from the near field is unstable, but it can be distinguished from noise. Therefore, in the near field, the ground anomaly can be detected with high reliability. On the other hand, the amplitude of the signal reflected from the far field is stable, but it is hard to distinguish between reflected signal and noise because of the excessive loss of electromagnetic wave. The analyses of directivity in the near and the far fields performed in this study may be effectively used to improve the reliability of the analyses of abnormal area.

• Journal of Korean Home Economics Education Association
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• v.20 no.3
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• pp.145-161
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• 2008

The purpose of this paper is to find out the needs of housing contents in highschool Home Economics among students. The 105 housing contents and topics were chosen from the 3 textbooks and related references. The number of 516 questionnaire from 8 areas were used to analyze. Analyses indicated that respondents were more likely to favor Home Economics subject and one out of five wanted to select it. Average needs of the housing contents was above middle(3.4) and these was a little difference among 3 middle units in housing. The most needed unit was housing design. There was a more wide difference in 19 small units than in middle ones, ranged $3.00\sim3.91$. Individual contents showed the most variousness in needs from 2.89 to 4.30 in the middle unit of housing and environments, 3.00 to 4.01 in housing design, and 2.68 to 3.91 in housing management. The needs of additional contents were about the same as those textbook contents and it indicated that new textbook needs to adopt the newly demanded housing contents. Some of individual, family, and environmental characteristics were significantly related to the students needs. The higher positive attitude such as favor, interest, and selecting of the subject was related to the higher needs of housing contents. Residential areas and neighboring were also related to most of the needs of individual housing contents.

• Journal of Korean Home Economics Education Association
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• v.29 no.3
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• pp.141-160
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• 2017

At present, the whole world is characterized by openness, cooperation and integration as a society with information and the world, and it requires creative talents for this. The competitiveness of the nation depends on the cultivation of creative talents. It demands anthropological value by improving the competitiveness of the nation through cultivating creative talents to share and care, not to cultivate creative talents for personal desires and accomplishments. The purpose of this study is to develop a teaching - learning process to develop integrated creative talents by applying the characteristics of integrated education curriculum at the base of the 2015 revised curriculum. To do this, we first extracted the content elements of the Clothing Life area of the revised curriculum from the 1st to 2015 and the contents of the Clothing Life area of the technology and home Economics textbooks to which the 2009 revision curriculum was applied. Five topics were extracted according to content selection criteria And The Theme of 'The selection and management of clothing' was selected. Researcher developed a integrated thematic instruction Home Economics Education Clothing Life teaching - learning process (hereinafter referred to as "the process") focused on the theme of 'selection and management of clothing'. The Process was composed of 5 basic classes [basic inquiry - content 1 - content 2 - depth study - application]. The process considers integration within the curriculum and interdepartmental integration, and aims to improve the personality, creativity, and problem solving ability of consideration and sharing in the course of the integrated class. In detail, the curriculum goals of the home Economics Education curriculum and ITI goals are presented separately in the curriculum developed for each process. At the stage of the class, the element of creativity and the element of personal education were exposed and applied to the class. In Korea, new curriculum has been revised and announced from time to time, making it difficult for the teacher to carry out the class in accordance with the paradigm of change. Home curriculum is closely related to real life, so it is an appropriate subject for an integrated subject. It has the educational significance of the subject in that it allows students to integrate the creative and personal elements that are limited in other subjects. ITI process will be helpful to teachers who need to implement the 2015 revised curriculum in which the theme-centered integrated home Economics education teaching-learning process is newly introduced. It is necessary to follow - up research to verify the effectiveness of how to improve students' problem - solving ability and cultivate creativity.

• Journal of Korean Home Economics Education Association
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• v.30 no.3
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• pp.215-231
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• 2018

Attitudes to the health and dietary life of teachers affect their students. The purpose of this study was to investigate dietary and education awareness, eating habits and dietary management competency of the preliminary teachers and teachers. Data was collected from 812 pre-service teachers and teachers in South Korea using a 5-Likert self-administrated questionnaire in October to December of 2017. Data was analyzed using factor analysis, reliability, one-way analysis of variance, and correlation. The results of this study are as follows. Dietary and education awareness was classified into dietary concern and dietary management stress. Eating habits composed of healthy eating habit and bad eating habit. Dietary management competency was sub-grouped into dietary knowledge, cooking, dietary sanitation and safety, and environment. The all factors of pre - service teachers and teachers showed a significant difference except for the environmental ability factor (p <0.01). All factors were significantly different according to the age and the number of meal preparation (p <0.05). The eating habits were not significantly differences from sex. The major and health condition showed significant differences except dietary management stress and cooking factors (p <0.01). The obesity index showed significant difference in the dietary concern, bad eating habits, and cooking factors (p <0.01). In conclusion, it was required to education and develop education materials that can help the STEAM education using the dietary area. The dietary education program for the pre - service teachers and the teachers should increase the number of participating in the meal preparation considering the difference according to the general characteristics, so that the dietary management competency and the healthy eating habits should be formed.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.155-160
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• 2001

Changes in genetic diversity after seed-tree practice were simulated in test plantation of tulip tree at Sokdal-ri, Banwol-myon, Hwasung-gun, Kyungki Provence. I-SSR markers were analyzed in a total of 305 tulip trees. A total of 89 amplicon variants were observed by PCR with 9 I-SSR primers. Genetic diversity for 305 trees was relatively high (S. I. =0.4532). Individuals originated from the seed orchards in U.S.A. showed the highest level of genetic diversity (0.4530), those from Anyang showed the medium level (0.4152), and those from Cheonbuk showed the lowest (0.3929). Simulation of seed-tree practice accompanied by 2 consecutive thinnings was performed on the basis of morphological characteristics and planted distances of the individual trees, which left 37 trees as candidates for seed-trees. Decreasing rate of genetic diversity within seed sources was greatest for individuals from Cheonbuk (28.3%), moderate for those from Anyang (16.3%), and smallest for those from U.S.A. (8.0%). In spite of little difference in decreasing rate of individuals for the 3 seed sources (87.5~88.2%), large difference in decreasing rate of genetic diversity within seed sources might be due to difference in number of mother trees for the 3 seed sources. For example, whereas individuals originated from the seed orchard in U.S.A., which showed the smallest decreasing rate of genetic diversity, might be originated from relatively large number of mother trees, those from Anyang and Cheonbuk might be originated from relatively small number of mother trees. Although mean of 17.5% of the genetic diversity within seed sources was decreased through 2 consecutive thinnings, a decrease in genetic diversity for the whole individuals (37 trees) was only 6.1%. This observation suggests that the seed-tree practice on the basis of the criteria established in the present study may not result in great reduction in overall genetic diversity of the progenies.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.90-104
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• 2001

This study is aimed to analyze and to evaluate the revegetation and soil conservation technology in desertification-affected sandy land, resulting from the project of "Studies on the desertification combating and sand industry development". Main native plants for combating desertification : The general characteristics of vegetation distribution in desertified regions are partially concentrated vegetation distribution types including the a) desert plants in low zone of desert or sanddune of depressed basin, b) salt-resistant plants around saline lakes, c) grouped vegetation with Poplar and Chinese Tamarix of freshwater-lakes, saline-lakes and river-banks, d) gobi vegetation of gravel desert and e) grassland and oasis-woods around the alluvial fan of rivers, etc. Generally, Tamarix ehinensis Lour., Haloxylon ammodendron Bunge., Calligonum spp., Populus euphratica Oliver., Elaeagnus angustifolia L., Ulmus pumila L., Salix spp., Hedysarum spp., Caragana spp., Xanthoceras sorbifolia Bunge., Nitraria tangutorum Bobr., Lespedeza bicolor, Alhagi sparsifolia Shap., Capparis spinosa L., Artemisia arenaria DC., etc. are widely distributed in desertified regions. It is necessary for conducting research in the native plants in desertified regions. Analysis of intensive revegetation technology system for combating desertification : In the wind erosion region, the experimental research projects of rational farming systems (regional planning, shelterbelts system, protection system of oasis, establishment of irrigation-channel networks and management technology of enormous farmlands, etc.), rational utilization technology of plant resources (fuelwood, medicinal plants, grazing and grassland management, etc.), utilization technology of water resources (management and planning of watershed, construction of channel and technology of water saving and irrigation, etc.), establishment of sheltetbelts, control of population increase and increased production technology of agricultural forest, fuelwood and feed, etc. are preponderantly being promoted. And in water erosion region, the experimental research projects of development of rational utilization technology of land and vegetation, engineering technology and protection technology of crops, etc. are being promoted in priority. And also, the experimental researches on the methods of utilization of water (irrigation, drainage, washing and rice cultivation, etc.), agricultural methods (reclamation of land, agronomy, fertilization, seeding, crop rotation, mixed-cultivation and soil dressing works, etc.) and biological methods (cultivation of salt-resistant crops and green manure and tree plantation, etc.) for improvement of saline soil and alkaline soil in desertified-lands are actively being promoted. And the international cooperations on the revegetation technology development projects of desertified-lands are sincerely being required.

• Journal of Science and Technology Studies
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• v.16 no.2
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• pp.99-147
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• 2016

This paper critically reviews the previous discussion over public engagement with science and technology by Science and Technology Studies literatures with a focus on justification and acceptance. Recent studies pointed out that the "participatory turn" after the late 1990s was followed by confusion and disagreement over the meaning and agency of public engagement. Their discussion over the reproduction of the ever-present boundary between science and society along with so-called late modernity and post-normal science and sometimes through the very processes of public engagement draws fresh attention to the old problem: how can lay participation in decision-making be justified, even if we agree that privileging the position of experts in governance of science and technology is no longer justified? So far STS have focused on two conditions for participatory turn-1) uncertainties inherent in experts' ways of knowing and 2) practicability of lay knowledge. This paper first explicated why such discussion has not been logically sufficient nor successful in promoting a wide and well-thought-out acceptance of public engagement. Then the paper made a preliminary attempt to explain what new types of expertise can support the construction and sustainment of participatory governance in science and technology by focusing on one case of lay participation. The particular case discussed by the paper revolves around the actions of a civil organization and an activist who led legal and regulatory changes in wind power development in Jeju Special Self-governing Province. The paper analyzed the types of expertise constructed to be effective and legitimate during the constitution of participatory energy governance and the local society's support for it. The arguments of this paper can be summarized as follows. First, an appropriate basis of the normative claim that science and technology governance should make participatory turn cannot be drawn from the essential characteristics of lay publics-as little as of experts. Second, the type of 'expertise' which can justify participatory governance can only be constructed a posteriori as a result of the practices to re-construct the boundaries between factual statements and value judgment. Third, an intermediary expertise, which this paper defines as a type of expertise in forming human-nonhuman associations and their new pathways for circulations, made significant contribution in laying out the legal and regulatory foundation for revenue sharing in Jeju wind power development. Fourth, experts' conventional ways of knowing need to be supplemented, not supplanted, by lay expertise. Ultimately, the paper calls for the necessity to extend STS discussion over governance toward following the actors. What needs more thorough analysis is such actors' narratives and practices to re-construct the boundaries between the past and present, facts and values, science and society. STS needs a renewed focus on the actual sites of conflicts and decision-making in discussing participatory governance.