• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.78-85
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• 1987

In order for Paldanghomil (winter rye) to be investigated if its grain yield is able to be produced after clipping just before winter season for forage utilization this experiment was carried out under the four sowing dates of four locations in Korea (Chunchon, Suwon, Hwasung and Chungju). In rye clipping plot earlier sowing showed taller plant height, more number of tillers/㎡ and higher forage yield before winter season, indicating the highest forage yield (1803 kg/10a) in Chunchon by sowing of September II. Forage yield of rye before winter season was mainly influenced by plant height and number of tillers/㎡, showing more effect of plant height. Rye plants were more or less affected on winter damages, late heading and short culm by clipping before winter season. Analysis of variance indicated that only number of spikes/㎡ among grain yield components showed the high significance according to the clipping method, and that there showed little variation for other yield components due to the sowing date and clipping method. There showed more grain yield in non-clipping rather than that of clipping plot, indicating the difference of 46kg/10a. This was resulted from short culm and severe winter damages caused by clipping before winter season. Of the grain yield components, number of spikes/㎡ was greatly influenced for grain yield by analysis of stepwise regression. Therefore, grain yield of rye was able to produce after forage utilization before winter season due to the appropriate crop and soil managements, by resulting from the little variation in grain yield between clipping or non-clipping plots and from the higher grain yield by the early sowing.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.346-346
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• 2017

In Northern Laos, maize is cultivated in continuous cropping without fertilizer, fallowing nor any other soil conservation practice. It is expected that this inadequate management in maize cultivation will degrade soil and decrease yield. However, there is limited information about the change of soil condition and yield under continuous maize cultivation. We tried to evaluate the change of soil condition and yield under continuous maize cultivation in Northern Laos. Our study was conducted in farmer's flat and slope fields in Sainyabuli province where maize cultivation had been introduced earlier than the other provinces of Northern Laos. Our study was conducted in 21 fields in 2014, and in 19 fields in 2015. We analyzed grain yield and soil characteristic (total carbon (TC), total nitrogen (TN), available phosphorus (Av-P), exchangeable cation, pH, soil texture) at 3 places in each field. The 3 places were set at different elevation level (lower position, middle position, upper position) in slope fields. Further, the period of continuous maize cultivation and crop management practice were investigated. Then, by evaluating the relation between the period of continuous maize cultivation and yield and the soil characteristics, the effect of maize cultivation was estimated. Crop management practices were similar among the investigated fields. Maize was cultivated in rain season. Grain seed and cob were harvested on September or October, but shoot was left on the fields. No crop was cultivated during dry season. Fertilization and fallowing has never been conducted under continuous maize cultivation. On the other hand, the period of maize cultivation was different among the fields, and ranged from 2 years to 30 years. In the slope fields, as the period of continuous maize cultivation was longer, the contents of TC and TN were lower at all 3 positions, Av-P content was lower at the upper position, exchangeable potassium (Ex-K) content was lower at the middle and the upper positions. The other soil characteristics weren't related with the period of maize cultivation in the slope fields. In contrast, soil characteristics weren't related with the period of maize cultivation in the flat fields. Yield was lower as the period of maize cultivation was longer at the upper position of the slope fields. At middle position of slope fields, yield tended to be low with increase of the period of maize cultivation. In contrast, yield wasn't related with the period of continuous maize cultivation in flat fields. From the results about crop management, it was presumed that the period of maize cultivation was one of the main factors causing the difference of yield and soil characteristics among the fields. Therefore, from the result of yield and soil condition, it was considered that the continuous maize cultivation decreased soil productivity in the slope fields with decline of TC, TN, Av-P, Ex-K and yield at upper position of slope fields, and decline of TC and TN in the other positions in Sainyabuli province.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.317-317
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• 2017

We performed this experiment to select high quality rice adapted to wheat-rice double cropping system. We sowed barley and wheat seed in November 2, 2015. After harvesting barley and wheat, we transplanted high quality rice cultivars: 'Unkwang', 'Hopun', 'Haepum', 'Hyunoum' in June 17 and 24. We used 'sindongjin' rice as a control. As a result, 'Hyunpum' had a highest head rice yield regardless of transplanting date. Head rice yield of 'Hyunpum' was 488.1kg/10a when transplanted in June 17, and 453.6kg/10a when transplanted in June 24. The reason for this highest head rice yield was not percentage of head rice but milled rice yield. Milled rice yield of 'Hyunpum' was 526.5kg/10a when transplanted in June 17, and 490.0kg/10a when transplanted in June 24. Percentage of head rice had little differences between rice cultivars. Among yield components, only number of panicle per $m^2$ had an effect on the differences of yield between rice cultivars. The other yield components didn't have an effect on the differences of yield between rice cultivars. Compared to June 17, only 'Unkwang' had higher head rice percentage and head rice yield in June 24. Head rice percentage of 'Unkwang' changed from 67.3% to 85.0% and head rice yield changed from 324kg/10a to 393.8kg/10a when transplanting date delayed from June 17 to June 24. When transplanting date was delayed, heading date of 'Unkwang' was more delayed than other rice cultivars. By delay of heading date, mean temperature for 40days changed from $25.0^{\circ}C$ to $22.9^{\circ}C$ which improved temperature condition during grain filling stage. This improved head rice percentage and head rice yield of 'Unkwang' transplanted in June 24. If transplanting date is more delayed than June 24, 'Unkwang' could have higher head rice percentage and head rice yield. Therefore, if you transplant rice before June 24 in rice-wheat double cropping system, 'Hyunpum' is recommended as adequate rice cultivar. But if you transplant rice after June 24, further research is needed to find out adequate rice cultivar.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.234-234
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• 2017

Recent abnormal weather, especially continued rainfall during sowing season causes difficulty in proper sowing of wheat and delayed sowing after November 15 is concerned about freezing damage during winter, resulting in reduction of wheat yield. To correspond government policy of crop sufficiency improvement and produce and supply raw wheat and barley steadily, expansion of cultivation area is necessary and spring sowing of wheat is required. To obtain basic information on the improvement of spring sown wheat and barley production, comparison and path coefficients analysis was conducted for yield and yield related components from autumn and spring sown wheat and barley. Path analyses were known as very useful in clarifying the effects of yield components on grain yield formation, which were not accurately reflected in simple correlation anaylses. Most cultivated 5 wheat and 9 barley cultivars were sown on October and February at Cheon-ju province according to standard sowing method. For the spring sowing of wheat and barley, the varieties having vernalization degree I~III are seeded in the mid of February and seeding rate is 200~250kg/ha which is increased by 25% than autumn sowing. N-fertilizer of 95 kg/ha and the same amount of P, K dressed in autumn are applied at once as basal fertilizer. The magnitude of direct effect in each yield components on yield was in sequence as follows. In autumn wheat, grain number per $spike{\geq}$ the number of spike per $m^2$>1000-grain weight and in spring wheat, grain number per $ spike{\geq}the$ number of spike per $m^2$> 1000-grain weight. In autumn naked barley, 1000-grain weight> the number of spike per $m^2$, grain number per spike and in spring barely, the number of spike per $m^2$> grain number per spike > 1000-grain weight. In autumn covered barley, grain number per spike>the number of spike per $m^2$ and in spring coverd barley, the number of spike per $m^2$> grain number per spike, 1000-grain weight. In autumn malt barley, the number of spike per $m^2$>1000-grain weight and in spring malt barley, the direct effects of three yield components were similar. According to the path analysis of yield components for spring sown wheat and barley, it was suggested that adequate number of spike per $m^2$ was most important factor for yield increase.

• The Korean Journal of Mycology
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• v.11 no.1
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• pp.1-7
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• 1983

Nutritional characteristics and conditions for mycelial yield of Pleurotus ostreatus and Auricularia auricula-judae in shaking culture were investigated. Among the sugar substances, glucose and mannitol showed the good effect for mycelial yield of P. ostreatus, and mannitol and fructose were good for the mycelial yield of A. auricula-judae. Among the various organic acids, fumaric acid were good for the mycelial yield of P. ostreatus and A. auricula-judae. Among the nitrogen sources, peptone and urea showed the good result for mycelial yield of P. ostreatus, and peptone and casamino acid were good for mycelial yield of A. auricula-judae. Among the various amino acids, asparagin and threonine showed the good result for mycelial yield of P. ostreatus, and serine and threonine were good for mycelial yield of A. auricula-judae. Among the various vitamins, folic acid and thiamine were suitable for mycelial yield of P. ostreatus, and folic acid, inositol and riboflavin were suitable for mycelial yield of A. auricula-judae. Mycelial yield of P. ostreatus and A. auricula-judae were enhanced by the addition of $MgSO_4\;and\;KH_2PO_4$ at the concentration of 0.08 and 0.2% respectively. The optimum temperature and pH for mycelial yield were from $25\;to\;30^{\circ}C$ and pH 5.5 to 6.5 in P. ostreatus, and from $25\;to\;30^{\circ}C$ and pH 6.0 to 7.0 in A. auricula-judae.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.12
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• pp.1696-1701
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• 2006

A random regression model was applied for the first time for the analysis of test day records and to study the genetic persistency of first lactation milk yield of Indian Murrah buffaloes. Wilmink's Function was chosen to describe the shape of lactation curves. Heritabilities of test day milk yield varied from 0.33 to 0.58 in different test days. The highest heritability was found in the initial test day ($5^{th}$ day) milk yield. Genetic correlations among test day milk yields were higher in the initial test day milk yield and decreased when the test day interval was increased. The magnitude of genetic correlations between test day and 305 day milk yield varied from 0.25 to 0.99. The genetic persistencies of first lactation milk yield were estimated based on daily breeding values using two methods. $P_1$ is the genetic persistency estimated as a summation of the deviation of estimated daily breeding value on days to attain peak yield from each day after days to attain peak yield to different lactation days. $P_2$ is the genetic persistency estimated as the additional genetic yield (gained or lost) from days to attain peak yield to estimated breeding value on different lactation days relative to an average buffalo having the same yield on days to attain peak yield. The mean genetic persistency on 90, 120, 180, 240, 278 and 305 days in milk was estimated as -4.23, -21.67, -101.67, -229.57, -330.06 and -388.64, respectively by $P_1$, whereas by $P_2$ on same days in milk were estimated as -3.96 (-0.32 kg), -23.94 (-0.87 kg), -112.81 (-1.96 kg), -245.83 (-2.81 kg), -350.04 (-3.28 kg) and -407.58 (-3.40 kg) respectively. Higher magnitude of rank correlations indicated that the ranking of buffaloes based on their genetic persistency in both methods were similar for evaluation of genetic persistency of buffaloes. Based on the estimated range of genetic persistency three types of genetic persistency were identified. Genetic correlations among genetic persistency in different days in milk and between genetic persistencies on the same day in milk were very high. The genetic correlations between genetic persistency for different days in milk and estimated breeding value for 305 DIM was increased from 90 DIM to 180 DIM, and highest around 240 DIM which indicates a minimum of 240 days as an optimum first lactation length might be required for genetic evaluation of Indian Murrah buffaloes.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.3
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• pp.164-168
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• 2002

Yield prediction model of rice based on the boundary line analysis of the relationships between rice yield and meteorological conditions during rice growing period was reported in the previous report (Kim et al, 2001). Using the 15-year data of the 20 locations used for the model formulation and of the 12 locations not used, the model was tested for its predictability of location to location, year to year, and variety to variety variation of rice yield. The model predicted reliably the mean yield differences among locations, the yearly yield variation in each location, and the yield variation by variety. However, the model showed relatively lower predictability for the years of cool weather injury especially in mountainous locations. In conclusion, the model using boundary line analysis could be used to predict the yield responses to meteorological conditions during rice growth period and the locational, yearly, and varietal variations of rice yield. And the predictability of the present yield prediction model might be improved by including the boundary line analysis for the other factors such as soil characteristics, fertilization levels, etc.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.5
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• pp.247-251
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• 2004

We report highly improved yield strength of nickel thin film, prepared using electroplating. The micro-scaled nickel cantilever is found to have significantly higher yield strength than bulk nickel. For the yield strength test, the heights of the micro-scaled cantilever were varied up to 60 ${\mu}{\textrm}{m}$ and electrostatic force was used for actuation. Stress of the bent cantilever was estimated using the FEM large deflection model. The yield strength of the thin nickel film is found to be over five times higher than that of the bulk nickel previously published. Results from this study indicate that metal microstructures can be used for MEMS applications requiring large deflection.

• Korean Journal of Organic Agriculture
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• v.4 no.2
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• pp.79-85
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• 1995

This experiment was carried out to broadcating effect of chitosan solution levels on dry matter production in Ladino clover(Trifolium repens). Chitosan solution was applie at 6 levels, 0%, 0.01%, 0.05%, 0.1%, 0.5% and 1.0%, respectively. The results obtained were summarized as follows ; 1. The dry matter yields of chitosan treatment plot were about 30%~63% more than the dry matter yield of control plot in all cuts. 2. Total dry matter yield was produced by 659.7kg/10a at levels of 0.05%, it was significantly higher than other chitosan solution levels. 3. The predictable highest yield and economic yield of Ladino clover could be obtained at 0.05% and 0.01% solution levels, respectively. 4. The relative dry matter yields for total dry matter yield were 66.7%, 18.3% and 15.0% at 1st, 2nd and 3rd cut, respectively. Chitosan application at early spring was affected to increasing the dry matter yield of 1st cut.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.3
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• pp.371-385
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• 1995

The yield of semiconductor chips is dependent not only on the average defect density but also on the distribution of defects over a wafer. The distribution of defects leads to consider a cluster index. This paper briefly reviews the existing yield prediction models ad proposes a new cluster index, which utilizes the information about the defect location on a wafer in terms of the coefficient of variation. An extensive simulation is performed under a variety of defect distributions and a yield prediction model is derived through the regression analysis to relate the yield with the proposed cluster index and the average number of defects per chip. The performance of the proposed simulation-based yield prediction model is compared with that of the well-known negative binomial model.