• Journal of Korean Society of Forest Science
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• v.28 no.1
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• pp.50-66
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• 1975

Since it is an undeniable fact that the so-called illegal field-burning cultivation is directly implicated in the causes of forest devastation, land erosion, and drought and flood, thus, barring the nation from a well-balanced economic growth, the policy to exterminate its practices must have the topmost priority. Eighty percent of Gangweon-do is mountain forests and naturally of all others this province has the largest area of illegally burned hill-side farminglands, stubbornly retarding the provincial development policy as well as directly causing tremendous forest damages. In 1965 a 7-year plan mapped out to rehabilitate these gypsy type field burning farmers only to be suspended in 1968 to give way to the mandatory project of clearing the isolated farmsteads set in deep mountain to circumvent the guerilla forces signaled by the so-called Samcheok-Uljin area infiltration. In the meantime, new hordes of roving farmers burned the forests, working a renewed havoc. To cope with this situation, the provincial government, taking the year 1973 as a planning year, launched another three year project (1974-76) and has been enforcing the rehabilitation project mobilizing the whole administrative power. Whether or not this project will succeed solely depends upon whether the forcedly rehabilitated roving farmers can really establish self-supporting homesteads. Among the various difficulties facing the newly established homesteaders are: (1) First of all, the homesteaders must be given money-earning jobs. (2) Financial supports or subsidies must be provided them with which to establish self-supporting homesteads. (3) Private enterprises as well as public organizations must offer them jobs with priority. (4) The rehabilitated rovers themselves must establish self-supporting homesteads before expecting the external assistance. (5) The rehabilitated rovers themselves must have the spirit of self-help, welcoming all levels and all kinds of jobs. (6) The rural revitalization movement must expand the self-help reconstruction projects to give them the opportunity to work. (7) All citizen in the province must receive and protect them with brethren love. (8) The evacuated burned-forests must be reforestrated with the principle of "best trees to the best lands". (9) The seedlings of species that the forest owners select must anyhow be secured and supplied (10) The organization and function of the village forestry association must be strengthened to take effective care of the reforestated burned-forests.

• Korean Journal of Microbiology
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• v.51 no.1
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• pp.39-47
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• 2015

Secondary metabolism in actinomycetes has been known to be controlled by a small molecule, ${\gamma}$-butyrolactone autoregulator, the binding of which to each corresponding receptor leads to the regulation of the transcriptional expression of the secondary metabolites. We expected that expression of an autoregulator receptor or a pleiotropic regulator in a non-host was to be gained insight of effective production of new metabolic materials. In order to study the function of the receptor protein (seaR), which is isolated from Saccharopolyspora erythraea, we introduced the seaR gene to Streptomyces coelicolor A3(2) as host strains. An effective transformation procedure for S. coelicolor A3(2) was established based on transconjugation by Escherichia coli ET12567/pUZ8002 with a ${\varphi}C31$-derived integration vector, pSET152, which contained int, oriT, attP and $ermEp^*$ (erythromycin promotor). Therefore, the pEV615 was introduced into S. coelicolor A3(2) by conjugation and integrated at the attB locus in the chromosome of the recipients by the ${\varphi}C31$ integrase (int) function. Exconjugant of S. coelicolor A3(2) containing the seaR gene was confirmed by PCR and transcriptional expression of the seaR gene in the transformant was analyzed by RT-PCR. In case of S. coelicolor A3(2), a phenotype microarray was used to analyze the phenotype of transformant compared with wild type by seaR expression. After that, in order to confirm the accuracy of the results obtained from the phenotype microarray, an antimicrobial susceptibility test was carried out. This test indicated that sensitivity of the transformant was higher than wild type in tetracycline case. These results indicated that some biosynthesis genes or resistance genes for tetracycline biosynthesis in transformant might be repressed by seaR expression. Therefore, subsequent experiments, analysis of transcriptional pattern of genes for tetracycline production or resistance, are needed to confirm whether biosynthesis genes or resistance genes for tetracycline are repressed or not.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.2
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• pp.171-181
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• 2018

Genistein is one of the representative isoflavone compounds isolated from soybeans and has been studied very well for its anti-aging and anti-inflammatory activity through previous studies. However, although genistein exhibits high solubility in organic solvents, it shows low bioavaility due to the low water solubility. In this study, we compared directly the functional difference between genistein and genistein cyclodextrin complex which has the improved water solubility and stability by cell based assay. Cell cytotoxicity experiment were carried out on RAW264.7 with CCK-8 assay and cytotoxicity was appeared from $10{\mu}g/mL$, thereby maximum concentration was set to $10{\mu}g/mL$ in all condition. We discovered that genistein CD complex suppressed NO production and iNOS expression as concentration dependent manner in the condition of LPS rather than genistein. Also, we could understand that genistein CD complex was able to down-regulate mRNA expression of anti-inflammatory cytokines such as $IL1-{\alpha}$, $IL1-{\beta}$, IL-6, and $TNF-{\alpha}$ as concentration dependent manner in the presence of LPS. In addition, we verified that genistein CD complex increased TEER of HaCaT human keratinocyte cells as concentration dependent pattern and stimulated cell division and migration rather than genistein in cell migration assay. Thus, it is expected that it can be used as an effective cosmetic raw material for improving atopic dermatitis or skin barrier if clinical studies on skin regeneration and skin barrier of the genistein CD complex are carried out.

• Journal of Korean Society of Forest Science
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• v.22 no.1
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• pp.7-17
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• 1974

Eighty percent of Gangweon-Do area is mountain forests, and of all others this province has the largest number of "Hwajeon-farmers" (who illegally reclaim the mountain forests to do farming as long as the soil is fertile enough to yield profit, but when it fails, move to other places to repeat the same forest burning, causing tremendous forest damages). In 1965 a 7-year plan was mapped out to exterminate this gipsy-farmers only to be suspended in 1969 to give way to the stronger urge from the national security view-point to first displace those isolated farmers set in deep mountains. In the meantime an increased number of the Hwajeon-farmers burned the forests, working new havoc. To cope with the situation, the provincial government lounched another 4-year plan in 1973 and has been enforcing the resettlement policy with renewed enthusiasm. Whether the plan will succeed depends entirely on the authority involved can solve the problems listed below with regard to the Hwajeon-farmers who are to lose their only means of survival and move down to the low-lands: 1) Their living must be taken care of until they can have definite means of self-supporting. 2) They must be provided with the opportunity to work in connection with the government-sponsored labor programs. 3) Not only the public organizations but also the private firms must give them the priority to get work. 4) The rural revitalization movement must expand the self-help reconstruction projects to absorb their labor powers. 5) The Hwajeon-farmers themselves must have the spirit of self-help and self-supporting. 6) All the citizens in the province must receive and protect them with brethren love. 7) The function of the watch-posts against the Hwajeon-farmers must be strengthened again.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.509-518
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• 2019

This study was conducted to investigate single crossing condition of M. sacchariflrous and M. sinensis for breeding of M. ${\times}$ giganteus cultivar. Compared with natural day length condition, cultivation in short day length condition shorten days to heading to 18~27 days in both species. Pollen germination ratio of were 75.8% at 6 o'clock in M. sacchariflorus and 51.9% at 7 o'clock in M. sinensis but decreased to below 10% at 8 o'clock in both species. When cut ears immerged in 150 mL of cut-flowers conservation solution and isolated with covering of white non-woven fabric, flowering and pollen dispersal were persisted for 7 days, and the ratio of pollen germination were above 40% for 4 days. The ratio of self-fertilization of both species were below 2.5%, but open pollenation ratio were above 50%. We obtained 437 seeds with experimental single cross of 14 combinations between tetraploid M. sacchariflorus and diploid M. siensis by application of developed single crossing methods. In the single cross, numbers of seed set were different by mother plants. Thus, the newly investigated single crossing condition will be used to breed M. ${\times}$ giganteous cultivar which is sterile and has superior characteristics of biomass yield.

• Journal of Mushroom
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• v.18 no.4
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• pp.398-402
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• 2020

This study was conducted to set up a proper replacement cycle of High Efficiency Particulate Air (HEPA) filters by observing the microbial populations in the air of the cultivation house of Pleurotus eryngii, before and after HEPA filter replacement at different periods. The density of bacteria and fungi in the air during each cultivation stage was measured using a sampler before the replacement of the HEPA filter. The results showed that airborne microorganisms had the highest density in the mushroom medium preparation room, with 169.7 CFU/㎥ of bacteria and 570 CFU/㎥ of fungi, and the removed old spaun had 126.3 CFU/㎥ of bacteria and 560 CFU/㎥ of fungi. The density of bacteria and fungi in the air at each cultivation stage before the replacement of the HEPA filter was 169.7 CFU/㎥ and 570 CFU/㎥, and 126.3 CFU/㎥ and 560 CFU/㎥, during the medium production and harvesting processes, respectively. After the replacement of the HEPA filter, the bacterial density was the lowest in the incubation room and the fungal density was the lowest in the cooling room. The microbial populations isolated at each period consisted of seven genera and seven species before the replacement, including Cladosporium sp., six genera and six species after 1 month of replacement, including Penicillium sp., 5 genera and 7 species after 3 months of replacement, including Mucor plumbeus, and 5 genera and 12 species, 5 genera and 10 species, and 5 genera and 10 species, 4, 5, and 6 months after the replacement, respectively, including Penicillium brevicompactum. During the period after replacement, the species were diversified and their number increased. The density of airborne microorganisms decreased drastically after the replacement of the HEPA filter. Its lowest value was recorded after 2 months of replacement, and it increased gradually afterwards, reaching a level similar to or higher than that of the pre-replacement period. Therefore, it was concluded that replacing the HEPA filter every 6 months is effective for reducing contamination.

• Journal of Intelligence and Information Systems
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• v.20 no.2
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• pp.137-148
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• 2014

Recommender system has become one of the most important technologies in e-commerce in these days. The ultimate reason to shop online, for many consumers, is to reduce the efforts for information search and purchase. Recommender system is a key technology to serve these needs. Many of the past studies about recommender systems have been devoted to developing and improving recommendation algorithms and collaborative filtering (CF) is known to be the most successful one. Despite its success, however, CF has several shortcomings such as cold-start, sparsity, gray sheep problems. In order to be able to generate recommendations, ordinary CF algorithms require evaluations or preference information directly from users. For new users who do not have any evaluations or preference information, therefore, CF cannot come up with recommendations (Cold-star problem). As the numbers of products and customers increase, the scale of the data increases exponentially and most of the data cells are empty. This sparse dataset makes computation for recommendation extremely hard (Sparsity problem). Since CF is based on the assumption that there are groups of users sharing common preferences or tastes, CF becomes inaccurate if there are many users with rare and unique tastes (Gray sheep problem). This study proposes a new algorithm that utilizes Social Network Analysis (SNA) techniques to resolve the gray sheep problem. We utilize 'degree centrality' in SNA to identify users with unique preferences (gray sheep). Degree centrality in SNA refers to the number of direct links to and from a node. In a network of users who are connected through common preferences or tastes, those with unique tastes have fewer links to other users (nodes) and they are isolated from other users. Therefore, gray sheep can be identified by calculating degree centrality of each node. We divide the dataset into two, gray sheep and others, based on the degree centrality of the users. Then, different similarity measures and recommendation methods are applied to these two datasets. More detail algorithm is as follows: Step 1: Convert the initial data which is a two-mode network (user to item) into an one-mode network (user to user). Step 2: Calculate degree centrality of each node and separate those nodes having degree centrality values lower than the pre-set threshold. The threshold value is determined by simulations such that the accuracy of CF for the remaining dataset is maximized. Step 3: Ordinary CF algorithm is applied to the remaining dataset. Step 4: Since the separated dataset consist of users with unique tastes, an ordinary CF algorithm cannot generate recommendations for them. A 'popular item' method is used to generate recommendations for these users. The F measures of the two datasets are weighted by the numbers of nodes and summed to be used as the final performance metric. In order to test performance improvement by this new algorithm, an empirical study was conducted using a publically available dataset - the MovieLens data by GroupLens research team. We used 100,000 evaluations by 943 users on 1,682 movies. The proposed algorithm was compared with an ordinary CF algorithm utilizing 'Best-N-neighbors' and 'Cosine' similarity method. The empirical results show that F measure was improved about 11% on average when the proposed algorithm was used