• Korean Journal of Ecology and Environment
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• v.49 no.2
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• pp.89-101
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• 2016

To elucidate occurrence patterns of $C_4$ plants in agroecosystems, we surveyed flora inside fields and embankments in 222 sites in farming lands in summer and fall, 2013. We also observed Kranz anatomy and analyzed carbon stable isotope to classify photosynthesis types. Our study observed total 54 species of $C_4$ plants in 33 genera and 9 families of vascular plants besides cultivated crops occurring in farming fields. The most common species was Portulaca oleracea L. followed by Digitaria ciliaris and Echinochloa crusgalli (L.) P. Beauv. var. crusgalli among the $C_4$ plants. The ratios of $C_3$ and $C_4$ species number to total number of species tended to maintain constant regardless of survey times and habitat types. The proportion of $C_4$ species to the total number of species were more influenced by the number of $C_3$ species than those of other types in the surveyed sites. Sizes of cultivation areas did not affect the proportions of $C_4$ plants. Increasing number of simultaneous weeding methods, especially with cutting method, appeared to decrease the number of $C_3$ plants. On the other hand, as the number of cultivated crops increased, both $C_3$ and $C_4$ plants increased but the proportions of $C_4$ species remained. We interpret our results that proportion of $C_4$ species in agroecosystems, appear to be dependent on the number of $C_3$ species, which in turn, appear to be affected by cultivation methods.

• Journal for History of Mathematics
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• v.27 no.4
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• pp.259-269
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• 2014

In China and Joseon, the measurement of the areas of various plane figures is a very important subject for mathematical officials because it is connected directly with tax problems. Most of mathematical texts in China and Joseon contained Chinese character '田', which means a field for farming, in title name for parts that dealt with problems of areas and treated as areas of plane figures. The form of mathematical texts in Joseon is identical with those in China because mathematicians in Joseon referred to texts in China. Gyeong SeonJing and Hong JeongHa also referred to Chinese texts. But they added their interpretations or investigated new methods for the measurement of areas. In this paper, we investigate the history of the measurement of areas in Joseon, which described in two books MukSaJibSanBeob and GuIlJib, with comparing some mathematical texts in China.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.811-818
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• 2000

Agricultural chemicals spraying is one of the most efficient methods for pesticides control. General farming groups use Speed Sprayer but its deposition amount on practical crops is only 20% of total amount in SS case. Agricultural chemicals which fail to arrive the crops not only cause environmental contamination but loss of agriculture chemicals by lower deposition efficiency. For the purpose of improvement of these problems, this experiment proposes SS attachment type electrostatic induction spraying apparatus with DC power which improves deposition efficiency of agriculture chemicals on the crops.

• Journal of Agricultural Extension & Community Development
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• v.7 no.1
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• pp.31-44
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• 2000

Securing food safety, natural and social environmental protection, and activation of rural communities are some of challenging tasks for the 21st century. National consensus on agriculture as a basic and public industry would be needed to solve these challenging tasks. Agricultural policy and extension education should be focused on encouraging farmers to achieve better production and management by developing their motivation and ability. Systematic and organizational efforts to make a better environment for farming and farm management should be the major target of agricultural policy and extension services in the future. To meet changing needs of farmer, agricultural extension services should change programs, functions, information sources, and methods of delivery to adopt experiential learning for farmers. Functions for consultation, suggestion and organization should be extended and advisory services for farmers should be emphasized by providing extension education.

• Journal of the Korean housing association
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• v.9 no.3
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• pp.119-131
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• 1998

This paper is a part of "The Study of the Traditional Korean Ethnic Farmhousing in Yanbian, China". The purpose of this study focuses on Korean farm house and is twofold: 1) to survey the working space and storage space for tools: 2) to investigate the daily use of space according to the different work activities. It is based on a survey of 124 households in the farm villages of Lunching, China. Survey research methods included a field study in Dallajae. A questionnaire was used to conduct this study. the study found that the working space for the koran farm family is divided into an indoor area and outdoor area. The indoor space includes working areas where the families live their daily life, cook, launder, clean, mange the house keeping, usually stare the grain. The outdoor space includes areas to store the grain, farm tools, rice box, shelves and other things such as sewing machine, iron, and tools used for cleaning the house and for farming. The center of life and work for the farm family was the chung-ji-kan (the combined kitchen and major ondol living room) located in the indoor space.oor space.

• Journal of the Korean Society of Food Culture
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• v.9 no.2
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• pp.105-109
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• 1994

JOMONG is the period of the primitive economy of collection in Japan. YAYOI and KOBUHG is the period of beginning of rice farming and the period of introduction of many culture from Korea that made influence to food culture in Japan. In the period of JOMONG, people ate foods that became sooty. In the period of YAYOI and KOBUNG there were methods of steaming, boiling, roasting, broiling. At that time Koreans introduced Japanese the brewing and Japanese developed it. In the period of JOMONG, people used the earthenware of Jugu style(originated from Japan) and in YAYOI and KOBUNG, they used TOSAGI & SEHAEGI. (infuluced by KAYA period in Korea)

• Journal of the Korean Geographical Society
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• v.33 no.2
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• pp.127-142
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• 1998

Unsan alluvial plain is the backmarsh of Seomseokcheon which is a river originated from Chilseongdae(954m) on Mts Taeback, flowing into Donghae in southern Kangreung City, Kangwon Province. The vegetation change, geomorphic develoopment and depositional environment during the late Holocene have been investigated, using the methods such as boring, pollen analysis and radiocarbon dating. Because the deposits fo the study area are mainly consisted of peat and paety sand, they contained many pollen fossils. The peat layer has been sedimented since the high sea-level periods, 3,200 y. BP, and the records of vegetation change until now has well preserved here. According to archeological researches and the results of pollen analysis in east coast of Korea, it is supposed that the prehistoric rice farming in this area has begun since ca. 1,800 y. BP.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.619-622
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• 2015

Recently, there are growing fluctuations of productivity and price caused by severe weather conditions in the agriculture. Yield forecasting methods have been studied to solve the problems. This paper predicted yield per area, production area, and elements of weather based on the linear equation. A yield is calculated by multiplying the production area times the yield per area that is compensated using the weighted sum of the elements of weather. In experiments, proposed method shows that a forecasting precision is the more than 90%.

• Journal of Agricultural Extension & Community Development
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• v.18 no.4
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• pp.709-728
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• 2011

It might be considered as difficult process to apply current researching technology to the fields of agriculture. Before the 80's, distributing brochures and pamphlet and direct visits to farmers were the only means used for research. But as society evolved, so did the methods. Media began to its place in the process. This study's main objective was to identify how farmers solve the problem on farming itself and also on how they improve customer-satisfaction. The Service Consultation Center of Rural Development Administration totaled up 19,666 cases of farmers's inquiries on 2010 by internet surveys, phone-calls and by post. Customer satisfaction scored highest on horticulture (39.5%), being followed by rice(23.2%) and other crops.

• Journal of Radiation Industry
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• v.5 no.4
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• pp.285-295
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• 2011

Mushrooms belonging to macrofungi have been consumed by humans for their nutritional and medicinal values for centuries throughout the world. Mushroom farming is practiced in more than 100 countries of the world, with production increasing at a rate of 7% per annum. High yield and good quality are always the principal goals for agriculturally important crops, including mushrooms. Several breeding methods are employed for strain improvement such as mass selection based on the natural chance mutation and induced mutation (mutation breeding), protoplast fusion technology, cross breeding and transgenic breeding. However, mutation breeding has shown prominent success in crop plant improvement. Though several-hundred mutant crop varieties have been developed around the world, the mutation breeding of mushrooms is limited. This review paper explores the potential application of radiation on the development of mutant varieties of mushrooms for breeding with desired traits such as better quality and productivity.