• Korean Journal of Weed Science
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• v.31 no.1
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• pp.41-48
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• 2011

This survey of weed population by different soil moisture with paddy-upland rotation was conducted to investigate information on weed flora and its ecology between two years. Weed species were assessed in April : 2009, 2010. Soil samples were taken from each study plot to assess the impact soil moisture on the occurrence and abundance of dominance weed species. Soil water of poorly drained field ranged from 10.2~18.2% more than 11.8~14.3% of somewhat poorly drained field. Weeds of fields composed of 19 species belonging to 12 families. Among 12 families, 6 weed species belonged to Compositae (31.6%) were the biggest family, Cruciferae were 2 species (10.5%), and Rubiaceae were 2 species (10.5%), respectively. Youngia japonica had the highest summed dominance ratio(SDR) (97.0%) and followed by Conyza canadensis (92.1%), Galium spurium (35.3%) and Hemistepta lyrata (28.4%) of somewhat poorly drainage in 2009. Artemisia princeps the highest SDR (100%) and followed by Stellaria alsine(55.2%), Y. japonica (38.3%) and Nasturtium officinale (28.5%) of poorly drainage in 2009. And, Stellaria alsine had the highest SDR (86.8%) and followed by Alopecurus aequalis (77.7%), Astragalus sinicus (68.7%) and Y. japonica (46.3%) of somewhat poorly drainage in 2010. S. alsine the highest SDR (93.7%) and followed by A. aequalis (78.6%), Nasturtium officinale (31.3%) and Y. japonica (30.4%) of poorly drainage in 2010. Simpson's index was calculated to 0.12~0.23, which showed that weed occurrence with different soil moisture in paddy-upland rotation and between years was various. Similarity coefficient between years was 43.0% (2009) and 74.2% (2010), which indicate a low diversity because of the moisture in the agro-ecosystem.

• Journal of Society of Preventive Korean Medicine
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• v.5 no.1
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• pp.10-30
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• 2001

Oriental medicine needs to be armed with theories on health-improvement concept under it and basic data matching its views, in order to participate in the health-improvement service in industrial work places. The Orient medicine health-improvement program defines factors that determine individuals' lifestyle, and provides information and technologies for workers to practice in life. To that end, this research compares and analyzes health-improvement concept and health care, defines relations between individuals' health state and their lifestyle as the basic data needed to perform health-improvement business for workers. 1. The subjects employed for this research is categorized into; by gender, males 52.1% and females 47.9% with no big difference between them; and by age, 20s, 6.1%, 30s. 33.9%, 40s, 34.1%, and 50s, 24.8% with 30-50 accounting for most of it. By marriage status, unmarried represents 7.1%, and married 79.1% with most of them married; by revenue, under one million won represents 3.0%, 1-2 million won 26.4%, 2-2.49 million won 11.2%, above 2.5 million won 11.2%, and 1-2.5 million won a majority. By living location, owned houses represents 65.4%, rented houses 14.7%, monthly-rented 9.5%; and by education, elementary and middle school represent 16.9%, high school and its dropouts 22.6%, and junior college and higher 51.6%, with high school and higher occupying most of the group. 2. By job, office workers and managerial workers represent 12.3%, part-timers 21.0%, manual workers 11.4%, jobless 0.6%, professionals 35.6%, service 0.6%, housewives 8.4%, and equipment/machinery operation/assemblers 10.1%. Of this, jobless and part-timers, totaling three, are dropped from this research. By years worked, 0-3.9 years represents 9.7%, 4-7.9 years 6.7%, 8-14.9 years 18.4%, above 15 years 28.7%, and no respondents 36.5%. 3. The degree of the subjects practicing life-improvement lifestyle, on a scale of 1 to 4, is an average of 2.69, personal relations 3.04, self-realization 2.92, stress management 2.76, nutritional state 2.73, responsibility for health 2.47, and athletic activities 2.18, with personal relations earning the highest points and athletic activities the lowest. As for factors influencing health-improvement lifestyle, there is no significant difference between gender, age, and marriage status. Meanwhile, there is significant difference between revenue, dwelling pattern, education level, etc. That is, higher income-bracket, owned houses, rented houses, monthly-rented houses, and higher-educated, in this order, show higher average in health-enhancement lifestyle. By job, housewives, manual workers, office workers, professionals, equipment/ machinery operation/ assemblers, and part-timers, in this order show higher points, while there is no difference with significance by years worked. 4. Factors that affect health-improvement lifestyle are shown below. Self-realization is influenced by age, marriage status, type of dwellings, and level of education; responsibility for health by type of dwellings; athletic activities by gender and age; nutrition by age, marriage status and type of dwellings; personal relations by marriage status; and stress management by type of dwellings. 5. Areas with high points by job show this: in self-realization, office workers, manual workers, housewives, professionals, equipment/ machinery operation/ assemblers, in this order, show difference with significance; in the area of responsibility for health, manual workers, housewives, equipment/ machinery operation/ assemblers, professionals, office workers and part-timers, in this order, do. In athletic activities, manual workers, housewives, office workers, professionals, equipment/ machinery operation/ assemblers, and part-timers, in this order, show difference with significance; in nutrition, housewives, office workers, manual workers, professionals, equipment/ machinery operation/ assemblers, and part-timers, in this order do; and in stress, housewives, office workers, manual workers, professionals, equipment/ machinery operation/ assemblers, part-timers, in this order do. By years worked, more years showed higher points in the area of responsibility for health and nutrition; in the area of athletic activities, above 15 years, 4-8 years, below 4 years and 8-14 years, in this order, show higher points; and no difference shows in realization, personal relation, and stress area. 6. To look at correlation between overall and divisional health-improvement practice degree, this researcher has analyzed it using Person's correlation coefficient. Self-realization, responsibility for health, athletic activities, nutrition, support for personal relations, and stress management show significant correlation with the sub-divisions, while all health-improvement lifestyle shows significant correlation with the six sub-divisions.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.1
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• pp.31-44
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• 2017

Pfiesteria piscicida is one of heterotrophic dinoflagellate having toxic metaboliges, and it is difficult to detect and quantify this dinoflagellate via light microscope due to small size and morphological similarity with Pfiesteria-like dinoflagellate (PLD) species. Alternatively, we developed quantitative real-time PCR assay based on EvaGreen and determined field accessibility throughout the investigation of distribution in the entire Korean coastal waters and population dynamics in Shihwa Lake. The P. piscicida-specific primers based on internal transcribed spacer 1 (ITS 1) were designed and the specificity of primers was confirmed by PCR with other genomic DNAs which have genetic similarity with target species. Through real-time PCR assay, a standard curve which had a significant linear correlation between log cell number and $C_T$ value ($r^2{\geq}0.999$) and one informative melting peak ($88^{\circ}C$) were obtained. These results implies that developed real-time PCR can accurately detect and quantify P. piscicida. Throughout the field applications of real-time PCR assay, P. piscicida was distributed in western (Mokpo and Kimje) and easthern (Gangneng) Korean coastal water even though light microscopy failed to identify P. piscicida. In the investigation of population dynamics in Shihwa Lake, the density of P. piscicida was peaked in June, July and August 2007 at St. 1 where salinity (${\leq}15psu$) was lower than the other 2 sites. In this study, we successed to develop EvaGreen bassed real-time PCR for detection and quantification of P. piscicida in fields, so this developed assay will be useful for various ecological studies in the future.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.329-333
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• 2006

Most of volcanic ash soils in South Korea are distributed in Jeju province which is an island placed on southern part of Korea and has steep slope mountain area. There are many soils containing high contents of organic matter (OM) derived from volcanic ash in Jejudo, also. Therefore, irrigation and drainage in volcanic ash soil different with general soil which has low OM content have to be applied with another management way, but studies searching appropriate methods for them are set on insufficient situation because the area of volcanic ash soil in South Korea is only 1.3% (130,000ha). This study was conducted for analysis of soil water content and irrigation quantity appropriate for crops cultivated in volcanic ash soil with high OM content. Although soils with different soil color have the same soil texture, soil water characteristics curve by soil color showed the difference of water retention capability by OM content. But, this characteristics classified with soil color could be unified by scaling technique with similitude analysis method which get dimensionless water content using a present water content, a residual water content and saturated water content (or water content at 10kPa). A relation of gravimetric soil water content (GSWC) and dimensionless water content by the results showed a form of power function. The dimensionless water content (DWC) express a relative saturation degree of present water content. This was also expressed by van Genuchten model which describe the relation between relative saturation degrees and matric potentials. These results on soil water characteristics curve (SWCC) of volcanic ash soil will be the basic of irrigation plan in area having high organic contents into soil.

• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.63-70
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• 2012

This study was conducted to investigated the distribution, ecological character and life cycle of Black Soldier Fly(BSF), Hermetia illucens, to determine effects of BSF on composing ability to the livestock feces. The distribution of BSF was defined in all parts of the country in Korea. Its main habitat was found to be areas near cattle sheds, feces sheds, living waste dump grounds, and food waste dump grounds. Excellent species of the bio-conversion using the livestock feces were selected out of two kinds of solider flies(Hermetia illucens and Ptecticus tenebrifer). And effects of BSF on composing ability to the livestock feces were pig feces 0.5 g, cattle feces 0.43 g and chicken feces 0.3 g per a larvae of BSF. In the examination of the ability of BSF to decompose food waste, volume of the livestock feces decreased by weight pig feces 77, cattle feces 83.62 and chicken feces 80%. Observed characteristics of BSF larvae and pupae stage were by developmental stage may be summarized as follows: size and length of larvae and pupae of BSF were higher than in pig feces and mixed sawdust treatments. In order to develop artificial indoor rearing techniques, The pupation and emergence rate were not visible the difference but important factor of the mating and egg-laying was a sun light. And it was visible the difference in mating ratio. Mating rate of H. illucens by seasonal change was the highest from May to July. Mating mostly occurred between 10 : 00 and 12 : 00 during which light intensity is high. As the egg-laying medium for artificial egg collection, calf feed and food waste were most effective. The ratio of egg-laying medium is waste food : sawdust(1 : 1) in volume. For egg-laying materials, flower foam and wood with holes were used; holes sized 3 ~ 5 mm in diameter, 7 ~ 10 mm in depth were most preferred for egg-laying.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.462-477
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• 2021

The purpose of this study was to understand changes in domestic forest policy and social perception of forests from a macro perspective using big data analysis of news articles and editorials. A total of 13,570 'forest' related data were collected from metropolitan and economic journals from 1946-2017 using keyword and CONCOR (Convergence of iterated Correlations) analysis. First, we found the percentage of articles and editorials using the keyword 'forest'increased overall. Second, news data on 'forest' in the field of reporting was concentrated in the "social" sector during the first period (1946-1966), followed by forest-related issues expanding to various fields from the second (1967-1972) to fifth (1988-1997) periods, then toward the "culture" sector in the sixth (1998-2007) and "politics" after the seventh (2008-2017) period. Third, we found changes in the policy paradigm over time significantly changed social awareness. In the first and second periods, people experienced livelihood issues rather than forest greening or forest protection policy and expanded their awareness of planned and scientific afforestation (third) to environmental protection (fourth) and ecological perspectives (sixth to seventh). The key outcome of our analysis was leveraging news big data that reflected polices on forests and public social perception To further derive future social issues,more in-depth analysis of public discourse and perception will be possible using textual big data and GDP of various social network services (SNS), such as combining blogs and YouTube.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.341-354
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• 2021

A large part of Gapyeong is occupied by Korean pine (Pinus koraiensis) and Japanese larch (Larix kaempferi) plantations. Abies holophylla stands are scattered throughout Gapyeong, but little information on their distribution is available. This study explored the potential of succession from planted species to native A. holophylla in plantations. Trees were inventoried and regeneration of A. holoplhylla and stand management history were examined in Korean pine, Japanese larch, and A. holophylla-dominated stands. The importance percentage of A. holophylla was the highest among species with a range of 36.1% to 79.1% in all stands and the density of A. holophylla in understory (DBH <2 cm or <1.3 m height) ranged from 50 to 5,820 trees ha^-1. Non-metric multidimensional scaling classified stands into four types, AN, AP, AM, and P. The AN type showed a reverse J-shape DBH distribution, which was similar to that in natural A. holophylla stands. Both AP and AM types included Korean pine plantations with A. holophylla seed trees within stands. For AP, A. holophylla competed with planted species in overstory and deciduous broadleaved species in understory. The AM type was once thinned from below, thus stem density in the mid DBH classes was lower than upper or lower DBH classes. The P type consisted of plantations without A. holophylla seed trees. However, understory regeneration of A. holophylla was abundant through seed supply from A. holophylla in adjacent stands. Plantations with A. holophylla seed trees within or in adjacent stands showed vigorous natural regeneration of A. holophylla, highlighting the potential for succession from planted species to native A. holophylla in the Gapyeong area. Further studies can help develop techniques to restore plantations to native species-dominated natural stands using ecological succession.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.369-392
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• 2021

This study aimed to provide basic data for efficient flora management of vascular plants, halophytes, and naturalized plants in the Gwangpo Bay area in Sacheon city, Gyeongsangnam-do. The flora found in this area incorporated 520 taxa, including 93 families, 299 genera, 466 species, 3 subspecies, 41 varieties, and 10 forma, and accounted for approximately 10.6% of total vascular plants (4,884 species) in Korea. According to the survey, 76 species of Gramineae showed the highest frequency (14.6%), followed by 67 species of Compositae (12.8%), 34 species of Leguminosae (6.5%), 27 species of Cyperaceae (5.2%), and 22 species of Rosaceae (4.2%). Rare plant species designated by the Korea Forest Service were categorized into six taxa, including three taxa in the LC grade, one taxon in the CR grade, one taxon in the VU grade, and one taxon in the EN grade. Korea endemic plants belonged to nine taxa consisting of seven families, seven genera, and nine species. The special floristic plants included 44 taxa, including one taxon (Prunus yedoensis) in the V grade, four taxa in the IV grade, ten taxa in the III grade, six taxa in the II grade, and 23 taxa in the I grade. Naturalized plants included 62 taxa consisting of 15 families, 47 genera, 59 species and 3 varieties. Halophytes consisted of 27 taxa, including 13 families, 24 genera, 24 species, 2 varieties, 1 forma, which consisted of Atriplex gmelinii, Suaeda glauca, Suaeda maritima, and Lathyrus japonicus. Invasive alien species in the Gwangpo Bay area included seven taxa. Since Ambrosia artemisiifolia, Sicyos angulatus, andPaspalum distichum var. indutummay have harmful effects on native plants, these plants must be artificially controlled.

• Journal of the Korean earth science society
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• v.42 no.3
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• pp.311-324
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• 2021

Recently, ten geosites have been considered in Hwaseong for endorsement as national geoparks, including the Jebudo, Gojeongri Dinosaur Egg Fossils, and Ueumdo geosites. The Jebudo geosite in the southern part of the Seoul metropolitan area has great potential for development as a new geoscience educational site because it has geological, geographical (landscape), and ecological significance. In this study, we described the geological characteristics through field surveys in the Jebudo geosite. We evaluated its potential as a geo-education site based on comparative analysis with other geosites in Hwaseong Geopark. In addition, we reviewed the practical effect of field education at geosites on the essential concepts and critical competence-oriented education emphasized in the current 2015 revised science curriculum. The Jebudo Geosite is geologically diverse, with various metamorphic rocks belonging to the Precambrian Seosan Group, such as quartzite, schist, and phyllite. Various geological structures, such as clastic dikes, faults, joints, foliation, and schistosity have also been recorded. Moreover, coastal geological features have been observed, including depositional landforms (gravel and sand beaches, dunes, and mudflats), sedimentary structures (ripples), erosional landforms (sea cliffs, sea caves, and sea stacks), and sea parting. The Jebudo geosite has considerable value as a new geo-education site with geological and geomorphological distinction from the Gojeongri Dinosaur Egg Fossils and Ueumdo geosites. The Jebudo geosite also has opportunities for geo-education and geo-tourism, such as mudflat experiences and infrastructures, such as coastal trails and viewing points. This geosite can help develop diverse geo-education programs that improve key competencies in the science curriculum, such as critical thinking, inquiry, and problem-solving. Furthermore, by conducting optimized geo-education focused on the characteristics of each geosite, the following can be established: (1) the expansion of learning space from school to geopark, (2) the improvement of understanding of specific content elements and linkage between essential concepts, and (3) the extension of the education scope throughout the earth system. There will be positive impacts on communication, participation, and lifelong learning skills through geopark education.

• Korean Journal of Environment and Ecology
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• v.33 no.2
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• pp.187-201
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• 2019

This study examined the physicochemical water quality and evaluated the ecological health in 14 sites of Geum River (upstream, mid-stream, and downstream) using the fish community distribution and guilds and eight multi-variable matrices of FAI (Fish Assessment Index) during June 2008-May 2009. The analysis of the water quality variables showed no significant variation in the upstream and mid-stream but a sharp variation due to the accumulation of organic matter from the point where the treated water of Gap and Miho streams flew. The analysis of physicochemical water properties showed that BOD, COD, TN, TP, Cond, and Chl-a tended to increase while DO decreased to cause eutrophication and algae development from the downstream where Miho and Gap stream merged. The analysis of fish community showed that the species richness index and species diversity index increased in the mid-stream area but decreased in the downstream area, indicating the stable ecosystem in the upper stream and the relatively unstable ecosystem in the downstream. The analysis of the species distribution showed that the dominant species were Zacco platypus that accounted for 20.9% of all fish species and Zacco koreanus that accounted for 13.1%. The analysis of the fish tolerance and feeding guild characteristics showed that the sensitive species, the insectivore species, and the aquatic species were dominant in the mid-stream point. On the other hand, contaminants from the sewage water treatment plant of Miho stream had a profound effect in the downstream to show the dominance of tolerant species, omnivorous species, and lentic species. Therefore, it is necessary to improve water quality by reducing the load of urban pollutants and to pay attention to the conservation and restoration of aquatic ecosystems.