• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.92-97
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• 1995

The objective of this study is to investigate the growth characters of overhead flooded soybean plants at four growth stage. Overhead flooding treatments were applied at the vegetative growth stage ($V_3,\;V_6$) and the reproductive stage ($R_2,\;R_4$) for 6.12.24 hrs, respectively. Yield and yield components were more decreased as the overhead flooding duration was longer and the growth stage was later. Yield was not reduced significantly in soybean plants flooded at $V_3$ stage regardless of flooding duration, and flooded 6 or 12 hrs at $V_6$ stage. When compared to the control, 27 to 36% of yield reduction was observed in soybean plants flooded for 24 hrs at $V_6$ stage, 6 or 12 hrs at $R_2$ stage, and 6 hrs at $R_4$ stage. And 43%, 53% and 66% of yield were reduced through the flooding treatment for 24 hrs at $R_2$ stage 12 hrs and 24 hrs at $R_4$ stage, respectively. So yield reduction was higher in overhead flooded soybean plants at the reproductive stage than that at the vegetative growth stage.

• Economic Analysis
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• v.26 no.3
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• pp.1-47
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• 2020

This paper surveys research since the 1990s on the ability of the yield spread and its components (i.e., expectation spread and term premium components) for future economic activity, and also conducts an empirical analysis of their forecasting ability using the yield data of Korean government bonds. This paper's survey, particularly for the US, shows that the yield spread has significant predictive power for some macroeconomic variables, but since the mid-1980s, its predictive power seems to have declined, possibly due to stronger inflation targeting. Next, this paper's empirical analysis using Korean data indicates that the yield spread, and the term premium component in particular, has significant predictive power for industrial production (IP) growth, consumer price index growth, and the IP gap. An out-of-sample analysis shows that the prediction equations are unstable over time, and that in predicting IP growth, the yield spread decomposition makes a significant contribution to the prediction of IP growth.

• Journal of Service Research and Studies
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• v.6 no.4
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• pp.59-74
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• 2016

The purpose of this paper is to see what the problem is and what the direction of the Investment of ELB is after this study has analyzed an achievable possibility for a suggested yield of ELB. It analyzes estimated yields from January in 2010 to June in 2016 for ELB Structures issued during 2015~2016. It carries correlation analysis and regression analysis between ELB yield and minimum guarantee yield, maximum stock price growth limit, participation rate. As the study result, a probability of achievement over 2% yield was below 20% as stock price growth had been inside maximum limit. An estimated average yield of ELB was 1.49% and it was lowed than 1.72% of Bank Deposit in 2015. So a realized yield was not satisfied the expected yield. As the correlation coefficient between ELB yield and minimum guarantee yield was 0.843, the correlation coefficient between ELB yield and maximum limit yield was 0.279, the correlation of minimum guarantee yield was high. The suggestion is that the a realized yield of ELB is lower than Bank Deposit interest and that the probability of stock growth inside maximum limit is low.

• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.1
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• pp.6-11
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• 1992

This experiment was carried out to study the biological yields(BY) of varieties by the developmental growth stages and shoot weight(SHW), leaf area(LA), root dry weight(RW), number of tillers(NT), shoot and root ratio(S/R), weight of a tiller(WT) as factors of yield components with 5 varieties of perennial ryegrass. The results are summarized as follows; 1. The biological yields in summer were about 115 of spring yield. 2. The biological yields of Manhattan were the highest until1 third developmental growth stage among perennial ryegrasses, and those for Maprima and P-2 varieties were the highest in the following stages. In terms of shoot dry weight, the similarly tendency appeared in the fifth developmental growth stage. 3. The shoot dry weight increased highly with the root dry weight. 4. The Tempo variety of biological yield was generally low but the weight of a tiller was the highest. 5. The highest increasing stage of biological yields was between fifth and sixth developmental growth stage, but the lowest increasing stage of biological yields was between first and second developmental growth stage, respectively. The dominant factors of biological yields were influenced to shoot and root dry weight.

• Fisheries and Aquatic Sciences
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• v.4 no.2
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• pp.98-100
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• 2001

• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.341-351
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• 2022

The physiological characteristics, growth, and yield of each regional rice variety ('Odaebyeo', 'Saechucheong', 'Ilmibyeo') were investigated depending on the impact of changes in temperature and CO₂ concentration. Experiments were conducted with a control group, which reflected atmospheric CO₂ concentration and temperature, and treatment groups, in which the CO₂ concentration and temperature were increased by 250 ppm and 2.0℃ from those in the control group. The results showed that the increase in CO₂ concentration and temperature reduced the growth and yield of the rice 'Odaebyeo', but did not substantially change the productivity of the 'Saechucheong' and 'Ilmibyeo'. The increase in CO₂ concentration and temperature increased stomatal conductance and rate of transpiration of the 'Odaebyeo' variety, thereby decreasing its water use efficiency (WUE). In contrast, the increase in CO₂ concentration and temperature increased the photosynthetic rate and WUE of the 'Saechucheong' and 'Ilmibyeo' varieties. The gradual change in climate is considered to directly affect growth and development of rice and diversely affect the productivity of each variety. Therefore, it is necessary to implement technological development, select regionally optimal rice varieties, develop new rice varieties, as well as conduct long-term monitoring of each rice variety for climate adaptation to counter global warming.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.1
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• pp.39-45
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• 1976

The content of nitrogen, phosphorus, potassium, calcium and magnesium of hulled barley grown on farmer's field with various N.P.K rates were investigated at various growth stages. Correlation analyses between N.P.K contents and yield and use efficiency of N.P.K and other results were as follows. 1. According to concentration and its change at various growth stages N is similar to K and P, Ca, Mg are similar each other. 2. Yield showed significant positive correlation in most fields with nitrogen content just after thawing. However P and N content were more significantly correlated with yield just before freezing in Kangwon and Chungnam (northern and central province). At the other growth stages negative correlation trend was shown between yield and P, especially K. 3. N.P.K contents in plant increased with the increase of fertilizer rate clearly in early growth stage, and especially in nitrogen, indicating that N was relatively short than P and K in the later stage. N and K contents at various fertilizer rates also indicated a probable competition between them. 4. Fertilizer recovery (use efficiency) decreased in the order of N (55)>K (27)>P (12%) and that of N tended to increase with yield increase. 5. Most effective growth stage for nutritional diagnosis in relation to yield appears to be just after thawing or just before freezing. Nutritional criteria for N.P.K at various growth stages were proposed.

• Korean journal of applied entomology
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• v.19 no.3 s.44
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• pp.153-155
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• 1980

In pot experiment, relations between bulb nemationde, Ditylenchus dipsaci, and growth and yield of garlic were followed. There was no effect of height growth on bulb nematode, but growth of volume was reduced at more than 250 nematodes per pot. Yield loss of garlic was more than $20\%$ when nematode density was about 30 per bulb in late-April. Tolerance limit should be about 20 nematodes per bulb at early growing stage. Reproduction of bulb nematode was good when initial population had been low.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.11
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• pp.142-149
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• 2003

Domain switching effect on crack growth in ferroelectric ceramics under combined electric and mechanical loading is investigated. The shape and size of the switching zone is shown to depend strongly on the relative magnitude between the applied electric field and stress field as well as on the ratio of the coercive electric field to the yield electric field. The toughening mechanism is thought to be ferroelectric domain switching leading to the development of a process zone around the crack. Crack-tip stress intensity factor induced by domain switching for the steady state crack growth is numerically obtained.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.1
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• pp.12-22
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• 1988

The effects of pH and Aluminum treatment on the seedling growth were examined with 11 cultivar under three levels of pH in nutri-culture.. Growth and yield responses of soil pH and nitrogen fertilization were also studied with five cultivars under 3 levels of soil pH and 3 levels of nitrogen application in the field experiment. The effect of pH on the seedling growth was not significant, but Aluminum treatment significantly decreased the seedling growth in nutri-culture except Dusan ＃12. Chlorophyll contents of leaves, dry weight of plants, culm length, spike numbers per unit area, grain numbers per spike, grain weight, and yield were decreased as the decrease of soil pH, and thus highly significant correlation between soil pH during barley growth and yield was observed in all cultivars examined. The stable cultivars to different soil pH with high yield was not found although the decreases of yield were different with cultivars. The increase of nitrogen fertilization significantly increased the nitrogen and chlorophyll contents of leaves, and dry weight of plants, while showed a little effects on the culm length, spike number per unit area, grain number per spike, grain weight and yield. The yield was significantly correlated with culm length, dry weight of plants, grain numbers per spike and 1000 grain weight at each pH levels.