• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.51-67
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• 1996

There are three main rice-growing regions in the United States: the prairie region along the Mississippi River Valley in eastern Arkansas; the Gulf Coast prairie region in southwestern Louisiana and southeastern Texas; and the Central Valley of California. The Central Valley of California is producing about 23% of the US rice(Fig. 1). In California. most of the crop has been produced in the Colusa, Sutter, Butte, Glenn Counties of the Sacramento Valley since 1912, when rice was commercially grown for the first time in the state(Fig. 2). Roughly speaking, the average annual area sown to rice in California is about 300,000 acres to 400,000 acres during the last forty years(Fig. 3). California rice is grown under a Mediterranean climate characterized by warm, dry, clear days, and a long growing season favorable to high photosynthetic rates and high rice yields. The average rice yield per acre is probably higher in California than in any other rice-growing regions of the world(Fig. 4). A dependable supply of irrigation water must be available for a successful rice culture. Most of the irrigation water for California rice comes from the winter rain and snow-fed reservoir of the Sierra Nevada mountain ranges. Less than 10 percent of rice irrigation water is pumped from wells in areas where surface water is not sufficient. It is also essential to have good surface drainage if maximum yields are to be produced. Rice production in California is highly mechanized, requiring only about four hours of labor per acre. Mechanization of rice culture in California includes laser-leveler technology, large tractors, self-propelled combines for harvesting, and aircraft for seeding, pest control, and some fertilization. The principal varieties grown in California are medium-grain japonica types with origins from the cooler rice climates of the northern latitudes (Table 1). Long-grain varieties grown in the American South are not well adapted to California's cooler environment. Nearly all the rice grown recently in California are improved into semidwarf varieties. Choice of variety depends on environment, planting date, quality desired, marketing, and harvesting scheduling. The Rice Experiment Station at Biggs is owned, financed, and administered by the rice industry. The station was established in 1912, as a direct result of the foresight and effort of Charles Edward Chambliss of the United States Department of Agriculture. Now, The station's major effort is the development of improved rice varieties for California.

• Horticultural Science & Technology
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• v.34 no.6
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• pp.818-829
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• 2016

This study evaluated the responses of 18 potato cultivars to three levels of salinity stress (electrical conductivity, EC: 1.0, 4.0, and $8.0dS{\cdot}m^{-1}$). Stem, leaf, root, chlorophyll, tuber yield, and proline content were investigated and statistically analyzed using analysis of variance (ANOVA) and correlations. Stem number and stem diameter were not affected by salinity, but stem length and aerial weight showed highly significant responses to salinity. Aerial weight decreased with increasing salinity levels in most cultivars, while it increased in some the cultivars 'Daejima', 'Goun', 'Haryeong', and 'LT-8'. Leaf number, leaf area index, and leaf weight were most significantly affected by salinity and the cultivar ${\times}$ salinity interaction. Root length, root weight, total chlorophyll and chlorophyll a were affected by salinity, but not by the cultivar ${\times}$ salinity interaction. The opposite trend was shown in chlorophyll b. Although there was great variability among cultivars, tuber yield decreased in all cultivars, and was most significantly influenced by salinity and the cultivar ${\times}$ salinity interaction. 'Superior', 'Kroda', 'Romana', and 'Duback' gave better tuber yields under salinity at EC 4.0 and $8.0dS{\cdot}m^{-1}$ than the cultivars with better aerial weights. Proline content was increased by salinity in all cultivars, and was more remarkable in the cultivars with better aerial weights than in cultivars such as 'Superior' and 'Kroda' with better tuber yields. Leaf number, leaf area index, leaf weight, and root length parameters were considered to be useful criteria in the evaluation of salt tolerance because of their high positive correlation with tuber yield; however, given its negative correlation with tuber yield under high salinity, proline content was not. Salinity tolerances varied greatly among potato cultivars. The low correlation between growth and yields of aerial parts under high salinity suggests that, in commercial agriculture, it might be more practical to compare relative yields to controls. Additionally, 'Superior', 'Kroda', 'Romana', and 'Duback' might be very useful cultivars to use in breeding programs to develop salinity-tolerant potatoes, as well as for sustainable potato production in saline areas.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.3
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• pp.212-223
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• 2014

For the better understanding of long-term and seasonal variations of water quality in Masan Bay, South Sea of Korea, we analyzed the archive data monitored at three stations of the bay during the last 13 years (2000-2012). The average concentrations of the chemical oxygen demand (COD), the dissolved inorganic nitrogen (DIN) and the dissolved inorganic phosphorus (DIP) during the monitoring period are $2.70{\pm}0.09{\mu}/L$, $19.66{\pm}1.84{\mu}m$ and $1.39{\pm}0.13{\mu}m$ in surface water, respectively, and $2.22{\pm}0.07{\mu}/L$, $18.53{\pm}1.36{\mu}m$ and $1.47{\pm}0.12{\mu}m$ in bottom water, respectively. The trophic state of the surface water was the eutrophic level in Masan Bay during the four seasons. The DIN concentrations of both surface and bottom waters increased from August to November and showed the highest average in November. However, The DIN decreased from February to May and showed the lowest average in May. The concentrations of the DIP and the dissolved silicate (DSi) in bottom waters had the highest averages in August because of the high water temperature and oxygen deficient condition. The results of correlation analysis and factor analysis showed that the main factors of surface waters were inflow of nutrients from terrestrial areas and internal production, and the main factors of bottom waters were the variations of the dissolved oxygen (DO), the DIP, and the DSi. The DIN and DIP average concentrations (2007~2012) had decreased in range of 68.1%~76.0% and 66.2~76.6%, respectively from 2007 in which the "Regulation of Total Emission" was established in Masan Bay. Therefore, it could have had positive effects on water quality improvement to take the "Regulation of Total Emission" and other actions such as reducing water pollutions in Masan Bay from 2007.

• Journal of Food Hygiene and Safety
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• v.33 no.5
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• pp.404-411
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• 2018

To evaluate bacteriological and toxicological safety hygienic indicator bacterium and paralytic and diarrhetic shellfish toxins in the shellfish produced in Hansan Geojeman 2013-2017 were investigated. Fecal coliforms were < 18~330 MPN/100 g in 404 oyster samples. But all samples tested, did not exceed 230 E. coli MPN/100 g. Geometric mean of E. coli for oyster samples collected during major shellfish production period was 24.3 MPN/100 g, considerde stable results. Bacteriological quality of oysters collected from Hansan Geojeman meets the standard value based on shellfish hygiene of the Food Sanitation Act of Korea and also meets Grade A, according to classification of shellfish harvesting areas of the European Union. For toxicological evaluation of Hansan Geojeman, 532 oyster samples and 268 mussel samples as an indicator, were analyzed. Paralytic shellfish toxins were detected in the range of 0.42~2.29 mg/kg in eight mussel samples, and exceeded criteria in three samples from early to late April 2013. Diarrhetic shellfish toxin was detected in three of 120 samples, but it was revealed to be under regulation value (0.16 mg Okadaic Acid equ./kg). As a result of toxicological evaluation, paralytic and diarrhetic shellfish toxins were not detected in oyster samples, but it was found that mussel as an indicator species, exceeded the threshold value of paralytic shellfish toxin. Accordingly, sanitary surveys were continuously requested for food safety management of shellfish.

• Journal of Science and Technology Studies
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• v.6 no.2 s.12
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• pp.131-183
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• 2006

The Korean genetics and genomics reveal a firm willingness to participate in and contribute to the production of creative scientific knowledge at a world level at present, though they have short past histories of introduction from the Western counterparts and those of education for the next generations. But the Korean genetics and genomics have been developed in a fragmented and biased manner. By reconfiguring the various research projects of genomics into the Genome Project of Korea, which reflect a worldly trend in life science, but have been established in a scattered fashion in Korea, and incorporating some neglected areas of genetics, such as human genetics and theoretical and population genetics which can be reconstructed in a new way, a genetics-genomics research system can be formulated on the multi-tiered perspective of concept, knowledge, and institution, while the system being a subsystem of the national research system of life science in Korea. Innovation can be pursued in the systematic practice through a culturalist strategy. The culturalist strategy with the practice based on the research system consists of 1) intensification of fundamentalness of genetics and genomics, 2) advancement of communitarianism in geneticist-genomicist community, 3) research on the cultural bio-species along with the promotion of scientific arts and culture, and 4)formation of the Korean science studies of genetics-genomics and the diffusion of the knowledge produced. The first two strategy components are the ones that intends to bring out changes in the structural aspect of the scientist community in Korea. The third is the one that attempts to magnify the interface between the scientist community and the Korean society at large and increase its connectivity between both, while the fourth is the one that has an intentionality toward the Korean society outside of the scientist community. This culturalist strategy is intended to increase the cultural constructivity of the genetics-genomics research system in Korea.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.2
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• pp.100-110
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• 2005

We carried oui a study on the marine environment and distribution of phytoplankton community, such as chlorophyll a, species composition, dominant species and standing crops in the Northern East China Sea during early summer of 2004. According to the analysis of a T-S diagram, three characteristics of water masses were identified. We classified them into the coastal water mass, the cold water mass and the oceanic water mass. The first was characterized by the low temperature and the low salinity originated from China territory, the secondary was characterized by the low temperature, the low salinity and the high density originated from bottom cold water of Yellow Sea, and the third was done by the high temperature and salinity originated from Tsushima warm current. The internal discontinuous layer among them was farmed at the intermediate depth (about $5{\sim}30m$ layer). And the thermal front by upwelling region between the cold water mass and Tsushima warm current appeared in the central parts of the South Sea of Korea. The Phytoplankton community in the surface and stratified layers was a total of 44 species belonging to 26 genera. Dominant species were Prorocentrum triestinum, Scrippsiella trochoidea, Skeletonema costatum & Leptocylindrus mediterraneus. Standing crops of phytoplankton in the surface layer fluctuated between $0.3{\times}10^3$ cells/L and $10.8{\times}10^3$ cells/L. Diatoms appeared mainly in the Tsushima warm current regions, and flagellates occurred in the frontal zone and the low salinity regions where was the transfer areas of Chinese continental coastal waters. Chlorophyll a concentration by controlled phytoflagellate ratio in the South Sea of Korea was high values in the frontal zone and sub-surface layer. It was high concentration in the upwelling and coastal waters regions, but low concentration in the Tsushima warm current regions. The Chl-a maximum layers appeared in the thermochline depth or sub-surface layer lower than thermocline. The phytoplankton production in the South Sea of Korea was controlled by the expanded coastal waters of Chinese Continent which include a high concentrations of nutrients.

• Journal of the Economic Geographical Society of Korea
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• v.19 no.2
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• pp.360-377
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• 2016

Since after the 1986 economic reform policy(Doi Moi), the central highland in Vietnam has transformed into one of the largest coffee producing areas. The transformation had been supported by mass migration of ethnic Kinhs from the coastal lowland. It did not take long for the Kinh migrants to be the ethnic majority in the region. Meanwhile the growth of coffee industry entailed in socio-economic disparity, specially between Kinh migrants and native ethnic minorities. The disparity has becomed obvious not only between coffee farming Kinhs and non-coffee farming ethnic minorities but also between coffee farming Kinhs and ehtnic minorities. The previous literatures highlight the lack of human and social capital and the lagging modernization in ethnic minority societies. However, they fall short in showing the explicit processes why ethnic minority coffee farmers earn less than ethnic majority counterparts. With a case study of Dak Lak province, this research attempts to show the reason why there is income gap between Kinh and ethnic minority Ede coffee farmers by comparing their ways of producing coffee and selling their products. The results show that Ede's land productivity is significantly lower than Kinh's. It is because Ede farmers use less fertilizer due to the shortage of the capital. Also they often get into debt for coffee production and should pay it back right after the harvest. It deprives them of chance to raise earning by selling the coffee beans at a higher price.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.2
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• pp.24-37
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• 2012

In this study, Community Garden of various national and international practices trends to an advanced research, the concept of community garden participated with a group operation out of initiative to produce safety food while securing space for the community, ensuring the area that has gone through a new form of active secure urban green space plan, urban renewal movement was defined as the mean. Furthermore, for the purpose of improving the poor welfare environment by attempting to experimentally make a community garden of a disabled welfare house rooftop and how to target its planning and construction process, partnership involvement, business processes have been investigated, such as cost sharing. The whole process including a budget for development of this case was conducted by the Busan Green Trust. Standard Chartered (SC) First Bank's 50% fund share by community chest, participation of volunteers, support of Busan City and Saba-gu, outside of that, sharing parts or trial to participate by diverse partnership of enterprise, public corporation and laboratory, these are the key in developing community garden's model. Established community garden places resulted food production to users of welfare center for the disabled, participating urban agricultural experience program, horticultural therapy, complex community chapter and cultural center. Furthermore, we could find the meaning of rooftop community garden in the point that it is a low cost garden by applying movable and unmovable planters. This study is profitable for improving urban environment, ensuring community chapter and urban green areas, regenerating a city to develop experimental community garden model by using a welfare house rooftop.

• Journal of Sericultural and Entomological Science
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• v.49 no.1
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• pp.14-17
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• 2007

A new silkworm variety Golden silk for spring rearing season is $F_1$ hybrid between Jam311, a Japanese race bred from introduction breeding and Jam312, a Chinese race from introduction breeding. In the local adaptability test performed at 8 local areas in spring of 2006, "Golden silk" was showed 7 percent higher in hatchability than authorized silk-worm races laval. "Golden silk" was receded higher 1.7 percent, 2.2 percent in pupation rate, best cocoon rate respectively than Chunsujam. The larval period shortened for 1.12 day even though low record to the several items including productivity than Chunsujam. "Golden silk" was showed 1,031 m, 2.97 denier in length of cocoon filament, weight of cocoon filament respectively. The concentration of Deoxynojirimycin(DNJ) was measured 4.34 mg in "Golden silk", high then to "Chunsujam"(3.81 mg). In the Paecilomyces tenuipes production ability test, the pupal weight of "Golden silk" was 1.20g.

• Journal of Mushroom
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• v.18 no.2
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• pp.125-134
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• 2020

To study the fairy ring and genet characteristics of Suillus bovinus based on thinning intensity in Pinus densiflora forests, a simple sequence repeat (SSR) analysis was performed on the fruiting bodies of the plant. In pine wood production forests, the thinning strengths applied were 34%, 45%, and 60%. As a result, the number of fruiting bodies in the 34% treatment area was 104, which was higher than that in the other treatment areas. In the 34% treatment area, fruiting bodies occurred in a circular shape, within a diameter of approximately 5 meters (m) of the trees. In the 45% treatment area, the fruiting bodies were randomly distributed between 6 to 7 m from the trees, while in the 60% treatment, fruiting bodies occurred in a narrow oval shape, 6 m from the trees. In the control area, two fruiting bodies were present around the root collar. Hybridity was confirmed in the SSR markers of Sb-CA1 and Sb-CA3. The fruiting bodies in the 34% treatment area had a He / Ho value lower than that in the 60% treatment area. In fruiting bodies of the 34% treatment area, a total of 20 genets were identified, with an average size of 14±11 ㎡; 60% of genets were formed by a single fruiting body. In fruiting bodies of the 45% treatment area, a total of 6 genets were identified and the average size was 11±12 ㎡; 50% of genets were formed by a single fruiting body. In fruiting bodies of the 60% treatment area, a total of 10 genets were identified, with an average size of 1.1±0.8 ㎡; 70% of genets were formed by a single fruiting body. Thus, the formation ratio of a new genet increases when the thinning intensity is increased.