• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.343-349
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• 1993

This study was conducted 1)to determine the factors responsible for the gradually increased rice yield by examining any improvements in yield-related characters and physiological characters among the historically recommended varieties of rice in Korea, and 2)to reveal the way of achieving further yield improvement by breeding in the future. Eight recommended varieties from 1911 to 1988 were selected and grown at the same conditions. The yield-related characters were observed at the harvest time, and the physiological characters such as RGR, NAR, LAR, SLA and L WR were estimated by the classical method of growth analysis. The newer varieties are shorter and those released after 1970's are greater in percent of filled spikelets and harvest index than the older varieties. There are no definite changing trends in the variations of number of panicles per hill, number of spikelets per panicle and 1000 grain weight according to the course of evolution in the recommended varieties. There is little evidence of improvement in the physiological characters such as NAR, LAR, SLA and LWR among the recently developed varieties compared with those of the older varieties. The increase in grain yield due to variety improvement, if any, is largely associated with the greater harvest index and percent of filled spikelets by breeding blight resistant and / or lodging resistant genotypes with short culm. It is suggested that increase in NAR should be carried out simultaneously with increase in harvest index to breed high yielding genotypes. I t appears to be important to breed genotypes with long culm in order to enhance light penetration into the canopy as long as they are lodging resistant. Since NAR is negatively correlated with LAR, it is unlikely to succeed to improve both characters simultaneously. The direct effect of NAR on RGR by path analysis is much larger than that of LAR, and hence it is suggested that breeding genotype with large NAR is more effective on enhancing RGR. It is also suggested that improving LAR through LWR is likely effective on increasing RGR.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.1
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• pp.25-30
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• 2006

This experiment was conducted to compare the fresh yield and dry matter yield, and nutritive values of whole crop barley treated with Urea (200 kg/ha, T2) and ammonium sulfate fertilizer as 200 kg/ha (T3), 300 kg/ha (T4) and 400 kg/ha (T5) at the Bae-Ho reclaimed tideland. Korea from 2003 to 2005. Salt contents of soil in the ammonium sulfate plots (T3, T4, T5) were lower than those of T2. The fresh yields of ammonium sulfate plots (T3, T4, T5) were higher than those of T2 as 62% (p>0.05), 41% (p>0.05) and 23% (p<0.05), respectively. The dry matter yield of T3, T4 and T5 (ammonium sulfate) was significantly (p<0.05) higher at 5,080 kg/ha, 4,667 ka/ha, 4,040 kg/ha, respectively. The total digestible nutrients (TDN) yield tends to have a similar result. Crude protein (CP) content was highest in T3 and CP trends to decrease as the level of ammonium sulfate was increased. Total digestible nutrient (TDN) were high in T3 and T4. The sodium content of T3 and T4 were lower than T2. Based on the study, it was more desirable to use ammonium sulfate (200 kg N/ha) rather than Urea as fertilizer on reclaimed land in terms of forage production and nutritive value.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.302-302
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• 2017

This study was conducted to evaluated the effects of different sowing time(October 22, February 20, March 3, March 13, and March 23) and sowing quantities(150kg/ha, 200kg/ha, 250kg/ha, and 300kg/ha) on growth of naked oat(Avena sativa L.) cultivar(Choyang-Gwiri) at a cultivation area in Iksan, south Korea. Heading times were delayed with later sowing times. In autumn seeding(Oct. 22) the ear was headed at April 30, in spring seeding(Feb. 20, Mar. 3, Mar. 13, and Mar. 23) heading times were respectively May 14, May 14, May 15, and May 19. Heading time of spring seeding was delayed about 3 weeks than autumn seeding. Ripening times were similar trends to the heading times. In autumn seeding ears were ripened at June 7, in spring seeding each times were respectively Jun. 15, Jun. 13, Jun. 20, and Jun. 20. Ripening time of spring seeding was delayed about 2 weeks than autumn seeding. Culm length and ear length were shortened in spring seeding, but number of plants per $m^2$ were increased. Number of grains per a ear were 106 in autumn seeding, but grains per a ear in spring seeding were respectively 88, 83, 83, and 73. Weight of 1,000 grains in spring seeding was heavier than that in autumn seeding, the weights were tend to light as later seeding times. Yield of grains was declined as later seeding times, yield of in autumn seeding was 2,900kg/ha, whereas that in spring seeding was 2,180kg/ha. The highest yield of spring seeding time was in Mar. 13, before this seeding time soil surfaces were severely dried as few rain fall, so germination was poor in those seeding times. As several seeding quantities were seeding, earing and ripening times were not different. but increasing seeding quantity, culm length was lengthened and ear length was shortened, number of plants per $m^2$ were increased and grains per a ear were reduced. Yield of grains were increased more seeding quantities, yield was highest up to 250kg/ha seeding quantity.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.2
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• pp.84-90
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• 1986

This experiment was carried out to evaluate the effect of cutting frequency and the last cutting date on the dry matter yield, the initial characteristics of spring growth, the yield of the first crops after winter, crude protein and crude fiber yield and the correlation efficients among the above items in timothy-dominated award. Cutting frequency was scheduled by 2, 3 and 4 times a year as main plot and the last cutting date in autumm were sept. 30, Oct. 10 and Oct. 20 as subplot. Experiment was arranged as a split-plot design with three replications and was performed for 4 years from 1980 to 1983 at the alpine area. The results obtained are summarized as follows: 1. The start of spring growth was somehow early as cutting frequency increased but not significant, and was not influenced by the last cutting data. 2. The dry matter yield was decreased by cutting frequency, but was not affected by the last cutting data. 3. The dry matter yield of the first crops after winter significantly decreased by cutting frequency, but failed to show and significant differences by the last cutting date. 4. Crude protein yield was increased by cutting frequency, while dry matter percentage was decreased. Crude fiber yield did not show the same trends. 5. There was a significant positive correlation between DM yield and DM percentage and yield of the first crops after winter, and between DM percentage and yield of the first crops after winter. However, there was a significant negative correlation between crude protein yield and DM percentage and yield of the first crops after winter. 6. It may be concluded from the above results that three times as cutting frequency and Sept. 30 as the last cutting data were desirable for the DM yield, but four times as cutting frequency and Sept. 30 as the last cutting data for the crude protein yield.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.8-9
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• 2017

Soybean yield has been low and unstable in Japan and other areas in East Asia, despite long history of cultivation. This is contrasting with consistent increase of yield in North and South America. This presentation tries to describe perspective of breaking stagnation of soybean yield in East Asia, considering the factors of the different yields between regions. Large amount of rainfall with occasional dry-spell in the summer is a nature of monsoon climate and as frequently stated excess water is the factor of low and unstable soybean yield. For example, there exists a great deal of field-to-field variation in yield of 'Tanbaguro' soybean, which is reputed for high market value and thus cultivated intensively and this results in low average yield. According to our field survey, a major portion of yield variation occurs in early growth period. Soybean production on drained paddy fields is also vulnerable to drought stress after flowering. An analysis at the above study site demonstrated a substantial field-to-field variation of canopy transpiration activity in the mid-summer, but the variation of pod-set was not as large as that of early growth. As frequently mentioned by the contest winners of good practice farming, avoidance of excess water problem in the early growth period is of greatest importance. A series of technological development took place in Japan in crop management for stable crop establishment and growth, that includes seed-bed preparation with ridge and/or chisel ploughing, adjustment of seed moisture content, seed treatment with mancozeb+metalaxyl and the water table control system, FOEAS. A unique success is seen in the tidal swamp area in South Sumatra with the Saturated Soil Culture (SSC), which is for managing acidity problem of pyrite soils. In 2016, an average yield of $2.4tha^{-1}$ was recorded for a 450 ha area with SSC (Ghulamahdi 2017, personal communication). This is a sort of raised bed culture and thus the moisture condition is kept markedly stable during growth period. For genetic control, too, many attempts are on-going for better emergence and plant growth after emergence under excess water. There seems to exist two aspects of excess water resistance, one related to phytophthora resistance and the other with better growth under excess water. The improvement for the latter is particularly challenging and genomic approach is expected to be effectively utilized. The crop model simulation would estimate/evaluate the impact of environmental and genetic factors. But comprehensive crop models for soybean are mainly for cultivations on upland fields and crop response to excess water is not fully accounted for. A soybean model for production on drained paddy fields under monsoon climate is demanded to coordinate technological development under changing climate. We recently recognized that the yield potential of recent US cultivars is greater than that of Japanese cultivars and this also may be responsible for different yield trends. Cultivar comparisons proved that higher yields are associated with greater biomass production specifically during early seed filling, in which high and well sustained activity of leaf gas exchange is related. In fact, the leaf stomatal conductance is considered to have been improved during last a couple of decades in the USA through selections for high yield in several crop species. It is suspected that priority to product quality of soybean as food crop, especially large seed size in Japan, did not allow efficient improvement of productivity. We also recently found a substantial variation of yielding performance under an environment of Indonesia among divergent cultivars from tropical and temperate regions through in a part biomass productivity. Gas exchange activity again seems to be involved. Unlike in North America where transpiration adjustment is considered necessary to avoid terminal drought, under the monsoon climate with wet summer plants with higher activity of gas exchange than current level might be advantageous. In order to explore higher or better-adjusted canopy function, the methodological development is demanded for canopy-level evaluation of transpiration activity. The stagnation of soybean yield would be broken through controlling variable water environment and breeding efforts to improve the quality-oriented cultivars for stable and high yield.

• Earthquakes and Structures
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• v.9 no.4
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• pp.831-849
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• 2015

Seismic-design procedures for walls require that the confinement in the critical (plastic hinge) regions should extend over a length in the compression zone of the cross section at the wall base where concrete strains in the Ultimate Limit State (ULS) exceed the limit of 0.0035. In a performance-based framework, confinement is linked to required curvature ductility so that the drift demand at the performance point of the structure for the design earthquake may be met. However, performance of flexural walls in the recent earthquakes in Chile (2010) and Christchurch (2011) indicates that the actual compression strains in the critical regions of many structural walls were higher than estimated, being responsible for several of the reported failures by toe crushing. In this study, the method of estimating the confined region and magnitude of compression strain demands in slender walls are revisited. The objective is to account for a newly identified kinematic interaction between the normal strains that arise in the compression zone, and the lumped rotations that occur at the other end of the wall base due to penetration of bar tension yielding into the supporting anchorage. Design charts estimating the amount of yield penetration in terms of the resulting lumped rotation at the wall base are used to quantify the increased demands for compression strain in the critical section. The estimated strain increase may exceed by more than 30% the base value estimated from the existing design expressions, which explains the frequently reported occurrence of toe crushing even in well confined slender walls under high drift demands. Example cases are included in the presentation to illustrate the behavioral parametric trends and implications in seismic design of walls.

• Applied Biological Chemistry
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• v.8
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• pp.51-59
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• 1967

A split plot was laid out in 1965 for perennial application of straw by 500kg per 10 are, as main plot, and of chemical fertilizer in conventional way, as sub-plots. The sub-plot included the following 5 fertilizer treatments as (1) non-fertilized, (2) nitrogen-free, (3) phosphate-free (4) potassium-free, (5) completely fertilizer applied plots. Trends in the growth and yield of rice was observed at present experimental site in the first year, 1965, and second year, 1966, as follows: 1. Each treatmental plot showed nearly identical trends between the first and second year, in term of growth, yield and yield components. 2. Straw application deterred the initial growth at non-fertilized and nitrogen-free plots. But straw application raised the effective stem ratio and enlarged the values in yield components, finally to be resulted in the second year with significant difference. 3. Both phosphate and potassium did not much affected to plants for longer stem and larger number of tillers. 4. Effect of nitrogen, phosphate and potassium was recorded as investigated by previous research works. Phospate deficiency decreased maturing rate to a great extent. 5. Numerical index was calculated for the comparison of plots in yield, where the non-straw, completely fertilizer applied plot stands for 100. The indexes of the first and second year were as follows : at non-straw plot(indexes in the blank are from the first year trial); non-fertilized : 80.2(80.9), nitrogen-free: 83.6(89.4), phosphate-free : 89.4(93.1) and potassium-free plot: 93.5(102.4) at non-straw plot. On the other hand, indexes at straw applied plots were non-fertilized : 84.0(86.6), nitrogen-free 82.6(93.9), phosphate-free : 91.7(96.3), potassium-free: 103.2(102.0) and complete plot: 98.7(109.8).

• Journal of Powder Materials
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• v.27 no.5
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• pp.420-428
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• 2020

Additive manufacturing technology is recognized as an optimal technology for mass-customized distributed production because it can yield products with high design freedom by applying an automated production system. However, the introduction of novel technologies to the additive manufacturing industry is generally delayed, and technology uncertainty has been pointed out as one of the main causes. This paper presents the results of the research and analysis of current standardization trends that are related to additive manufacturing by examining the hierarchical structure of the quality system along with the various industry and evaluation standards. Consequently, it was confirmed that the currently unfolding standardization does not sufficiently reflect the characteristics of additive manufacturing technology, and rather can become a barrier to entry for market participants or an element that suppresses the lateral shearing ability of additive manufacturing technology.

• Nuclear Engineering and Technology
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• v.10 no.1
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• pp.1-12
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• 1978

Concanavalin-A, lectin extracted from Korean native plant “Banha”(Pine-llia Termata) and their conjugation products with tyrosine and 5-iodo-6-aminouracil were labelled by radioactive iodiae-125, and these labelled compounds were subjected to a hemagglutination test in vitro. The labelling procedures were presented with respect to labelling yield and the trends on the conjugation reaction of lectin with various amino acids were discussed. The preliminary results on the hemagglutination tests against cancer tissues were presented and the potential clinical applications of these labelled compounds were discussed.

• Electronics and Telecommunications Trends
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• v.33 no.6
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• pp.50-57
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• 2018

As devices have evolved, traditional flip chip bonding and recently commercialized thermocompression bonding techniques have been limited. Laser-assisted bonding is attracting attention as a technology that satisfies both the requirements of mass production and the yield enhancement of advanced packaging interconnections, which are weak points of these bonding technologies. The laser-assisted bonding technique can be applied not only to a two-dimensional bonding but also to a three-dimensional stacked structure, and can be applied to various types of device bonding such as electronic devices; display devices, e.g., LEDs; and sensors.