• The Plant Pathology Journal
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• v.34 no.2
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• pp.93-103
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• 2018

Leaf blotch of wheat caused by Bipolaris sorokiniana is a major constraint to wheat production, causing significant yield reduction resulting in severe economic impact. The present study characterizes to determine and compare pathogenic variability exist/not based on components of leaf blotch disease development and level of aggressiveness due to agroclimatic condition of B. sorokiniana in wheat. A total of 169 virulent isolates of B. sorokiniana isolated from spot blotch infected leaf from different wheat growing agroclimate of Bangladesh. Pathogenic variability was investigated on a susceptible wheat variety 'kanchan' now in Bangladesh. A clear evidence of positive relationship among the components was recorded. From hierarchical cluster analysis five groups were originating among the isolates. It resolved that a large amount of pathogenic diversity exists in Bipolaris sorokiniana. Variation in aggressiveness was found among the isolates from different wheat growing areas. Most virulent isolates BS 24 and BS 33 belonging to High Ganges River Flood Plain agro-climatic zones considered by rice-wheat cropping pattern, hot and humid weather, high land and low organic matter content in soil. Positive relationship was found between pathogenic variability and aggressiveness with agro-climatic condition.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.3
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• pp.47-55
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• 2010

Investigations on the inundation damage and improvement measures were carried out centering around the protected horticultural complex concentrated in lowlands on the side of Geum river, in Nonsan and Buyeo, Chungnam. Most greenhouses were single-span plastic houses in this area, and tomato, strawberry and watermelon were cultivated mainly. 45.8 % of whole farmhouse were experienced in damage by inundation, and a frequency of the damage was average once in 11 years. The most urgent problem at the greenhouse culture in this area was showed in order of drainage improvement, irrigation water resources and energy saving. Consideration items in drainage improvement project for protected horticulture were showed in order of extending drain pumps, extending drain canals, using concrete flume in drain ditch. It needs to consider systematic plans that can restrain new establishment of greenhouses on the lowland paddy field in drainage area. It is difficult to remove greenhouses which are already established or prohibit cultivation. Therefore we should impose minimum duty items so that greenhouse tillers can cope with inundation. And it is thought that managing agency need to minimize farmers damage by improving drainage ability and introducing maintenance pattern that is different from rice cropping.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.3
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• pp.158-164
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• 1988

The growth characteristics and yield per unit area of two cropping systems, corn monoculture and 'wrnsoybean intercropping, were compared and the obtained results were as follows; 1.The two cultivation systems were not significantly different in leaf length, leaf width and length of internode at harvesting time. 2.The weight of stalk and the leaves of a plant were decreased with maturity, while the weight of ear was markedly increased. The patterns of relative ratio of each components were essentialy same in each cultivation systems. In corn monoculture, the percentages of stalk, leaf, and ear at final harvesting stage were 22.9, 13.7, and 63.4 and in corn-soybean intercropping, they were 21.8, 10.9, and 67.3 respectively. 3.Dry matter yield per unit area (kg/lOa) of intercropped corn at yellow stage was similar to that of monocultured corn (1, 483 kg/ 10a vs 1, 509 kg/ 10a). At ripe stage, however, the dry matter yield of intercropped plant was more than that of monocultured (1, 679 vs 1, 660 kg/ 10a). 4.The same pattern was observed in organic matter yield.

• Korean Journal of Agricultural Science
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• v.17 no.1
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• pp.65-75
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• 1990

This study is purposed to examine how fanner's living conditions and managements have been improved during the last five years(1985 through 1989) on the basis of the information got from the sample survey of 30 farm households chosen in Galma-ri, Buseok-Myeon, Seosan county, Chungnam province. The followings are major results of the study. (1) There have been much improvement of kitchen facilities and increasing number of cultural goods, but not much in the condition of sanitation facilities. (2) The size of farm warehouse and stall have been greatly enlarged and there has been large variation in the heads of big animals such as cattle during the surveyed period. This may reflect the facts that farm managements become more diversified and commercialized. (3) It is shown that fanners more voluntarily accept new fanning techniques about their concerning crops. Also there have been rapid changes in the pattern of upland cropping system, adjusting to the commercialization of agriculture. (4) Currently, fanners tend to react to the price signal of market system more sensitively than before. Accordingly, agricultural income structure is varied subject to price fluctuation in the short run period.

• Magazine of the Korean Society of Agricultural Engineers
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• v.33 no.2
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• pp.104-111
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• 1991

In Korea, small-scale reclaimed areas have been suffering from many problems because of the lack of comprehensive developing strategy although considerable investments have been inputed by the public sector since 1970's. For 3 reclaimed sites in Chonnam Province choser as case study areas, the analysis, the second attempt of widely-spanned studies on areal conditions, concentrated on their farming and economic conditions. Its results were as follows ; 1. Although farming pattern has been transferred to the full4ime rice cropping type by the creation of reclaimed paddy field, farming size in the areas has not been increased more than that in existing agricultural areas. This means that agricultural planning should be included in the initial stage of reclamation projects, especially with reference to the substantial enlargement of farming size. 2. Block parcelling of severely fragmented holdings in new and old lands should be carried out, which can make farming activities efficient and farming route shortened. In large-scale reclaimed areas, new village planning could be considered in its central zone for efficent farming. 3. Because soil in the areas contains much more salt and water than that in other areas, new design methodology should be introduced for the efficient use of agricultural machines in reclaimed areas. 4. There are deep-seated economic problems in reclaimed area, which have been caused by very poor level and agriculturally dominated structure of household income. These problems should motivate farmers to give up positive action for qualitative and quantitative improvement in farming.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.1
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• pp.55-70
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• 2001

It was unusual crop weather for 1998 and 1999 compared with normal in Korea. The consecutive days of the optimum ripening period for rice plant that had daily mean temperature 21~23$^{\circ}C$ for 40 days after flowering, increased with long anomalies in 1998~99. The air temperature during ripening period was much higher than the optimum temperature and lower sunshine hour than norm in the local adaptability tests of newly developed rice lines during those years. In response of rice cultivation to warming and cloudy weather during crop season, the yield shall be decreased. Most scientists agree that the rate of heating is accelerating and temperature change could become increasingly disruptive. Weather patterns should also become more erratic. Agrometeorologists could be analyzed yearly variations of temperature, sunshine hour and rainfall pattern focused on transient agroclimate change for last a decade. Rice agronomists could be established taking advantage of real time agricultural meteorology information system for fertilization, irrigation, pest control and harvest. Also they could be analyzed the characteristics of flowering response of the recommended and newly bred rice cultivars for suitable cropping plan such as cultural patterns and sowing or transplanting date. Rice breeders should be deeply considered introducing the characteristics of basic vegetative type of flowering response like Togil rices as prospective rice cultivars corresponding to global warming because of the rices needed higher temperature at ripening stage than japonica rices, photoperiod-sensitive and thermo-sensitive ecotypes.

• Journal of Korea Multimedia Society
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• v.7 no.3
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• pp.327-339
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• 2004

In this paper, we propose a new watermark algorithm for halftone images using iterative error minimizing method. In the proposed method, watermark bits are hidden at pseudo-random locations within a halftone image. To remove the distortions due to the inserted watermark bits and increase the invisibility of watermark, an iterative error minimizing technique is used. We define the halftoning error is defined as the difference between the original grayscale image and HVS-filtered printed halftone image. Then we iteratively find the pixel pattern with minimum halftoning error and displace the original pixel pattern with it. In order to be robust to geometrical modification like cropping or rotation, we insert the same watermark periodically into halftone images. Experiments using printed and scanned images show that the proposed method is a robust method to the geometrical modification and to hide the large amount of data within a halftone image without noticeable distortion.

• Korean Journal of Weed Science
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• v.1 no.1
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• pp.30-43
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• 1981

On unwedded paddy fields, six cropping patterns of rice cultivation, namely direct broadcast seeding, direct row seeding, machine transplanting, early season hand transplanting, standard season hand transplanting, and late season hand transplanting, were detected with two representative rice cultivars (Milyang 23 and Sadominori) to estimate the comparative fluctuation patterns of weed flora. As a result, number of emerged weed species, most crowding stages, differences of weed growth among cropping patterns, possible tendencies of competition in plant heights among plant groups, variations in Importance Values, and Simpson's Index analysis were discussed, respectively.

• Korean Journal of Weed Science
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• v.17 no.4
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• pp.382-389
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• 1997

Collated data from the 1995-1996 floristic surveys of weeds of arable peat in Selangor district were analysed to assess composition and dominance and spatial distribution pattern based on quantitative and dispersion indices. Forty eight weed species belonging to 19 families of which 31 were broad leaves, 10 grasses and 7 sedges were sampled and these ware translated as 77.8 and 15% of the total cover, respectively, The respective important values were 71.11 and 18%. Ten species in the onder of dominance were Fimbristylis acuminata, Murdannia nudiflora, Hedyotis corymbosa, Ageratum conyzoides, Asystasia gangetica, Cleome rutidosperma, Cyperus sphacelatus, Lindernia crustacea, Ludwigia hyssopifolia of spatial distribution based on variance-to-mean ratios, Llouds mean crowding or Lloyds patchiness indices. Other species were either random or regular in their spatial distribution. Differences in species-dominance and spatial distribution pattern may be attributed to inherent variations in patchiness and fecundity schedules of each weed species, crops, cropping patterns and agronomic practices prevailing in the area.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.333-337
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• 1986

The fertilizer experiment was conducted to establish a pattern of a continuous application of organic matter in rice-barley cropping system. Fine textured gray lowland soil was used to grow the crops. The amount of nitrogen absorption and the yield of the crops were the highest in barnyard manure 1,000kg/10a. A correlation among the content of humus and nitrogen, the amount of nitrogen absorption, and the yield was significant while it was not significant among the the nitrogen content of the soil fertility, the total nitrogen, and the yield of crops. The result of this research suggests that revelation of available nitrogen after the decomposition of the organic matter depending on climate and regions should be studied for the organic matter application in due season.