• 한국균학회소식:학술대회논문집
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• 2016.05a
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• pp.25-25
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• 2016

Biological control has many advantages as a disease control method, particularly when compared with pesticides. One of the most important benefits is that biological control is an environmental friendly method and does not introduce pollutants into the environment. Another great advantage of this method is its selectivity. Selectivity is the important factor regarding the balance of agricultural ecosystems because a great damage to non target species can lead to the restriction of natural enemies' populations. The objective of this research was to evaluate the effects of several different bacterial isolates on the efficacy of biological control of soil borne diseases. White rot caused by Sclerotium cepivorum was reported to be severe disease of garlic and chive. The antifungal bacteria Burkholderia pyrrocinia CAB08106-4 was tested in field bioassays for its ability to suppress white rot disease. In field tests, B. pyrrocinia CAB08106-4 isolates suppressed white rot in garlic and chive, with the average control efficacies of 69.6% and 58.9%, respectively. In addition, when a culture filtrate of B. pyrrocinia CAB08106-4 was sprayed onto wounded garlic bulbs after inoculation with a Penicillium hirstum spore suspension in a cold storage room ($-2^{\circ}C$), blue mold disease on garlic bulbs was suppressed, with a control efficacy of 79.2%. These results suggested that B. pyrrocinia CAB08106-4 isolates could be used as effective biological control agents against both soil-borne and post-harvest diseases of Liliaceae. Chinese cabbage clubroot caused by Plasmodiophora brassicae was found to be highly virulent in Chinese cabbage, turnips, and cabbage. In this study, the endophytic bacterium Flavobacterium hercynium EPB-C313, which was isolated from Chinese cabbage tissues, was investigated for its antimicrobial activity by inactivating resting spores and its control effects on clubroot disease using bioassays. The bacterial cells, culture solutions, and culture filtrates of F. hercynium EPB-C313 inactivated the resting spores of P. brassicae, with the control efficacies of 90.4%, 36.8%, and 26.0%, respectively. Complex treatments greatly enhanced the control efficacy by 63.7% in a field of 50% diseased plants by incorporating pellets containing organic matter and F. hercynium EPB-C313 in soil, drenching seedlings with a culture solution of F. hercynium EPB-C313, and drenching soil for 10 days after planting. Soft rot caused by Pectobacterium carotovorum subsp. carotovorum was reported to be severe disease to Chinese cabbage in spring seasons. The antifungal bacterium, Bacillus sp. CAB12243-2 suppresses the soft rot disease on Chinese cabbage with 73.0% control efficacy in greenhouse assay. This isolate will increase the utilization of rhizobacteria species as biocontrol agents against soft rot disease of vegetable crops. Sclerotinia rot caused by Sclerotinia sclerotiorum has been reported on lettuce during winter. An antifungal isolate of Pseudomonas corrugata CAB07024-3 was tested in field bioassays for its ability to suppress scleritinia rot. This antagonistic microorganism showed four-year average effects of 63.1% of the control in the same field. Furthermore, P. corrugata CAB07024-3 has a wide antifungal spectrum against plant pathogens, including Sclerotinia sclerotiorum, Sclerotium cepivorum, Botrytis cinerea, Colletotrichum gloeosporioides, Phytophotra capsici, and Pythium myriotylum.

• Journal of Korea Water Resources Association
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• v.53 no.9
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• pp.681-690
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• 2020

Generally, the design capacity of the rainwater harvesting unit is determined by trial and error method that is repeatedly calculating various analysis scenarios with capacity, reliability, and rainwater utilization ratio, etc. This method not only takes a lot of time to analyze but also involves a lot of calculations, so analysis errors may occur. In order to solve the problem, this study suggested a way to directly determine the minimum capacity to meet arbitrary target reliabilities using the global optimization method. The method was implemented by simulation model with particle swarm optimization (PSO) algorithms using Python language. The pyswarm that is provided as an open-source of python was used as optimization method, that can explore global optimum, and consider constraints. In this study, the developed program was applied to the design data for the rainwater harvesting constructed in Cheongna district 1 in Incheon to verify the efficiency, stability, and accuracy of the analysis. The method of determining the capacity of the rainwater harvesting presented in this study is considered to be of practical value because it can improve the current level of analytical technology.

• Journal of the Korean association of regional geographers
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• v.22 no.4
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• pp.792-808
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• 2016

Due to the high importance of foreign trade in the national economy, Korea has a lot of ports designated as trade ports compared to the small land size. However, because of the poor utilization results, some small trade ports have been criticized for wasteful financing due to redundant investment in SOC. This is because the characteristics and comparative advantage of foreign trade in trade ports have not been analyzed in detail by region. Therefore, this study analyzes the patterns and types of change in the size of trade, number of cargo items handled, and the number of trade target countries in the past 20 years for 19 domestic small trade ports using the time-series cluster analysis technique. As a result of analysis, Korean small trade ports were classified into five growth pattern types according to the analysis index, and characteristics and implications for each type could be derived. Today, as the foreign trade environment changes drastically and the importance of balanced regional development is emphasized, it is very important to study the growth types and implications of small trade ports and the results of this study are expected to provide meaningful implications for regional port development and operation in the future.

• Economic and Environmental Geology
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• v.47 no.6
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• pp.625-633
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• 2014

The Aquistore project is the world's first commercial capture, transportation, utilization and storage project of post-combustion $CO_2$ from a coal-fired thermo electric power plant, and the proposed storage is a saline aquifer at a depth of about 3,500 m. Deep saline aquifer, compared to hydrocarbon reservoir, provides the great volumetric potential for storage of $CO_2$ anywhere in the world, therefore the research results from the project may be exported globally to other sites. Geological $CO_2$ storage characterization for saline aquifer instead of hydrocarbon reservoir needs to estimate the geophysical properties of subsurface geology. This study calculated the geophysical property of water-saturated formation by applying amplitude variation analysis developed from oil and gas exploration. We correlated horizon tops at the well logs to seismic traveltime of 1,815 and 1,857 ms as Winnipeg and Deadwood formations. Gradient analysis from seismic traces showed correlation coefficient of 45 - 81 % on amplitude variation with respect to incident angle. Crossplot of intercept and gradient shows the inverse proportional trend which represents typical water saturated sediments. Product attribute of intercept and gradient described the base of wet sediment. Poisson's ratio change attribute increased at the top of target area satisfying with wet sediment and decreased at the top of basement in a dry rock bed.

• The KIPS Transactions:PartD
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• v.18D no.4
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• pp.275-286
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• 2011

The purpose of this study is to find the beneficial plan for business success by the advantage of social media service in the business organization. There is few research for applying social media on a variety of fields in business organization although many companies are trying to find the way for its application. Hence, this study identifies the possibility for the utilization of social media services, and it also finds the plan for their effective application. The social relationship is created by increasing communications between users of social media service. The research model is established on the basis of the hypothesis that the social relationship affects knowledge share, pursuit of ego, social participation, amusement. To maximize the impact of results, the research was conducted on the basis of the target on two groups including the business men and non-business men who use social media services. As results of the research, the business men tend to appeal their impression based on sharing knowledge with anonymous people. Also, it is necessary to make a social participation to a management participation, and to utilize the social media in the organization by including amusement to its function. This research is expected to have significant implication to companies which wants to apply social media services in the future.

• Korea journal of population studies
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• v.11 no.1
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• pp.14-31
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• 1988

The national family planning program in Korea, which was instituted as an integral part of the nation's economic development plans since 1962, has contributed greatly to a reduction in the fertility and population growth rate. The total fertility rate dipped from 6.0 births per women in 1960 to 2.0 in 1985, and the population growth rate rom 2.84 percent per year to 1.25 percent during the same period, while the contraceptive practice rate for the 15-44 married women increased from 9 percent in 1965 to 70 percent in 1985. Study findings indicate that the fertility reduction in the past 26 years is largely attributed to the virgorous implementation of the national family planning program, rising age at marriage, wide-spread use of induced abortion, and the changes in attitude regarding the value of children that came into being in the wake of the rapid socio-economic development over the period. Among the strengths of the national family planning program are the following : 1) a pluralistic system of program manageent with active participation of various government and voluntary organizations, 2) utilization of a large corps of family planning field workers to conduct face-to-face communication and motivation activities, 3) use of private physicians with government support to provide contraceptive services, 4) a systematic program management system including program planning of traget allocation, evaluation, and supervision with a broad MIS and award system, 5) numerous incentive and disincentive schemes for stimulating the small family norm and contraceptive use, and 6) strong commitments to the family planning program by political leaders. The new demographic targets during the Sixth Five-Year Economic and Social Development plan period(1987-91) have been set for a further reduction in the population growth rate to 1.0 percent by 1993, assuming that the TFR will decline to 1.75 level in 1995. This target is, however, not easy to achieve due to anticipated unfavorable factors like the strong boy preference, high discontinuation rates of reversible contraceptive methods, fertility termination-oriented contraceptive use, a plateau level of contraceptive practice rate that has mostly accounted for a sterilization, shortened length of birth intervals, and the changing patterns of contraceptive mix. The recent changes in contraceptive and fertility behaviors clearly indicate that the past quantity-oriented management system of the national program should be redirected toward a quality-oriented approach. Particularly, program efforts should be expanded to recruit new contraceptive users in the 20s of younger age groups, both for birth spacing and controlling their fertility since the women aged 20 to 29 account for more than 80 percent of the total annual births in recent years. In addition, the current contraceptive fee system of the national family planning program should be gradually shifted from free contraceptive services to a acceptor's charge system, and the provision of contraceptive services through the medical insurance system, which will cover the entire population by 1989, should be accelerated as a means of integration of family planning program with other health programs.

• Korean Journal of Ecology and Environment
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• v.54 no.3
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• pp.151-155
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• 2021

The application of environmental DNA in the domestic ecosystem is also accelerating, but the processing and analysis of the produced data is limited, and doubts are raised about the reliability of the analyzed and produced biological taxa identification data, and the sample medium (target sample, water, air, sediment, Gastric contents, feces, etc.) and quantification and improvement of analysis methods are also needed. Therefore, in order to secure the reliability and accuracy of biodiversity research using the environmental DNA of the domestic ecosystem, it is a process of actively using the database accumulated through ecological taxonomy and undergoing verification procedures, and experts verifying the resolution of the data increased by gene sequence analysis. This is absolutely necessary. Environmental DNA research cannot be solved only by applying molecular biology technology, and interdisciplinary research cooperation such as ecology-taxa identification-genetics-informatics is important to secure the reliability of the produced data, and researchers dealing with various media can approach it together. It is an area in desperate need of an information sharing platform that can do this, and the speed of development will proceed rapidly, and the accumulated data is expected to grow as big data within a few years.

• Ecology and Resilient Infrastructure
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• v.8 no.4
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• pp.273-280
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• 2021

In the past, the government made a total of 357 hydrophilic districts into parks to create rest areas in the national river with the four major river projects. According to the results of the survey, 60 water-friendly districts with low utilization were lifted in January 2017, and 297 water-friendly districts are currently being managed. Local governments are in charge of the maintenance costs necessary to maintain these hydrophilic districts, which require considerable costs, so it is necessary to accurately grasp the characteristics and needs of local residents at the operation stage after designation. In this study, the characteristics of local residents in the hydrophilic district were analyzed by correlating social factors with river users, crawling social network data to analyze visit patterns, and derived related Keywords, and analyzed the characteristics of the hydrophilic district. The study target areas are Samrak and Daejeo Ecological Park, located downstream of the Nakdonggang River. Social factors analyzed real estate transaction price data, economic activity income, households, stress perception rate, and pet breeding status through public data provided by Statistics Korea, and analyzed user visit patterns and image keywords on weekends.

• Korean journal of applied entomology
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• v.60 no.2
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• pp.215-220
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• 2021

To establish the systematic biological control system for various insect pests in strawberry under plastic houses, we were investigated the biological traits of lesser strawberry aphid, Chaetosiphon minus (Forbes), as a target pest. The lesser strawberry aphid is adapted to low temperatures while examining the availability of and selecting useful natural enemies. The development, survivorship and reproduction of lesser strawberry aphid were evaluated at four constant temperatures (10, 15, 20, and 25℃). The developmental periods of the nymphal stages ranged from 41.7 d at 10℃ to 9.8 d at 25℃. The developmental threshold temperature and degree day of nymphal stages are 5.5℃ and 185 DD. The reproduction rate (R₀) was higher at 20℃ (30.16) than at 25℃ (22.38). The 50 % survival rate and maximum longevity of adult females were 31 d and 59 d at 20℃, and 25 d and 36 d at 25℃, respectively. The average progeny per female was 35 at 20℃, and 26 at 25℃. We confirmed that compared to other strawberry aphids under plastic houses, the lesser strawberry aphid is more adapted to lower temperatures. It is, therefore, necessary to commercialize natural enemies such as syrphid flies with high activity at low temperatures.

• Journal of Environmental Health Sciences
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• v.47 no.2
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• pp.111-122
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• 2021

Objectives: There was a judgment of acquittal for the manufacturer SK Chemical and the vendor Aekyung regarding humidifier disinfectant (HD) containing 5-chloro-2-methylisothiazol-3(2H)-one/2-methylisothiazol-3(2H)-one (CMIT/MIT). The rationale used in this judgement is discussed here in the light of scientific consideration. Methods: The sentencing document for the judgements was obtained from the Korea Supreme Court Service. In particular, the judgements made by the court related to the risk of HD and external and internal exposure to CMIT/MIT are discussed based on scientific evidence. Results: Rendering a determination in a criminal trial of insufficient evidence of causation, the court dismissed the prosecution's motion that humidifier disinfectant-associated lung injuries (HDLI) and asthma were associated with the utilization of these products. However, CMIT/MIT, a strong sensitizing and corrosive substance, has been reported to be associated with brain toxicity, allergic contact dermatitis, and asthma. Furthermore, the judgment did not consider total consumption amounts or the cumulative dose of CMIT/MIT in the humidifier. Lastly, there are several cases supporting the fact that exposure to water-soluble substances including CMIT/MIT can cause lower respiratory tract diseases. In addition to cases of asthma among the workers exposed to CMIT/MIT, we identified lung injury victims who were exposed to HDs exclusively containing CMIT/MIT. Conclusions: We conclude that there is sufficient evidence supporting the assertion that HDs containing CMIT/MIT cause lung injuries, including asthma, contrary to the court's judgement.