• Korean Journal of Agricultural Science
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• v.34 no.2
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• pp.131-134
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• 2007

This study was carried out to identity the major characteristics of inbred lines and to develop early waxy colored hybrid at the Maize Genetics and Breeding Lab. in Chungnam National University. The eight colored waxy maize were planted on April 27, 2007 under Randomized Completely Block (RCB) Design with three replications. Stem height of IK1/H26-2 and Heunchal lines in this experiment were high as 196cm and 186cm compared to control as 156cm, respectively, while ear height of Local-2 and IK/LE were lower than that of check and ear diameter of IK/H26-1, IK/H26-2 and Local-2 were 10.3mm, 17.7mm and 18mm compared to control (21mm), respectively. Days to tasseling of Local-1, Local-2, and IK/LE lines were earlier than check. As a result of this experiment, the developed inbred lines were regard as useful germplasm for early hybrid development.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.179-184
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• 2006

This study was carried out to evaluate major agronomical characterization and phenol compound contents, Xanthine oxidase inhibitory activity (XO), Catalase activity, Superoxide dismutase activity (SOD) and 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) radical sacvenging activity were analyzed in colored waxy corns. The mean of stem height and ear length were 248.8 cm and 18.6 cm, respectively. The pericarp thickness in CNU108 $(30.3{\mu}m)$ was thinner than other hybrids. The period of tasseling days in CNU69 and CNU202 were very shorter than other hybrids (59 days). 100-kernel weight of CNU50 was 35.6 g and heavier than the others. The antioxidant activities such as xanthin oxidase (XO), catalase and superoxide dismutase (SOD) were higher in CNU70 and CNUI 38. Especially highest EDA (electron donating ability) in DPPH radical scavenging effect was 94.8% and 94.6% in CNU160 and CNU193, respectively. In the results, the antioxidant enzyme activity and antioxidant acticity were higher in CNU109 and CNU 34 hybrids. The hybrids, CNU34, CNU70, CNU108, CNU 138 and CNU193 may be considered higher functional color waxy corn.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.4
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• pp.307-314
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• 2008

No comprehensive tillage system of corn (Zea mays L.) has been conducted in Korea. Therefore, this experiment was carried to determine soil characteristics, weed and forage production in tillage system of corn. Plot was allotted to one of four treatments in a randomized block design using tillage system. The four treatments were (T1) conventional tillage, plow and rotary till, (T2) rotary till, (T3) disk till, and (T4) no-till system. In soil characteristics before planting and after harvest of corn, pH and organic matter at planting date was higher than at harvest date, however, there were no difference among tillage system. Days from planting to silking of no-till was the longest among tillage system. Lodging resistance of disk and no-till were higher than conventional and rotary till due to its thicken stem diameter. Main weed in corn field are barnyard grass (Echinochloa crusgall), velvetleaf(Abutilon avicennae), crabgrass (Digitatia saguinalis), and redroot pigweed (Amaranthus retroflexus). Weed population was lower in no-till than others tillage system. Dry matter (DM) content and ear percentage of conventional and rotary till were higher than others in corn field. However, DM and total digestible nutrients (TDN) yields of disk and no-till were higher than those of conventional and rotary till. Therefore, disk and no-till are more suitable in corn silage system because of high lodging resistance and forage yield, and low weed population.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.2
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• pp.137-143
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• 1987

To find out the optimum storage temperature and duration, changes in the content of sugars and soluble solids and flavor rate of two sweet corn hybrids (Great Bell and Golden Cross Bantam) and a super sweet corn (Crisp Super Sweet 720) were observed after storing at -20, 0, 5, 10, 15, 20, and 25$^{\circ}C$ for 1,3,5, and 7 days. At the temperatures below 10$^{\circ}C$, contents of soluble solids and total sugars and flavor rate were not changed significantly, but at the temperatures higher than 15$^{\circ}C$ they decreased as storage temperatures increased and duration extended. Storage duration conserving flavor seems to be 7 days at temperatures below 10$^{\circ}C$, 3 days at 15$^{\circ}C$, and 1-2 days at 25$^{\circ}C$. When corn was frozen, flavor rate was a little low compared with corn stored at 0$^{\circ}C$ although sugar content was higher. Both soluble solids and total sugar contents were positively correlated with flavor rate of cooked corn.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.4
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• pp.401-411
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• 2015

Drought stress has detrimental effects on the seedling development, vegetative/ reproductive growth, photosynthesis, root proliferation, anthesis, anthesis-silking interval (ASI), pollination and grain yield in maize. Typically, two weeks before silking through pollination are an important time in maize life. Here we reviewed the effects of drought stress on growth, physiological/ molecular researches for drought tolerance, and breeding to genomics in maize. Drought stress during kernel development increases leaf dying and lodging, decreases grain filling period and grain yield. Physiological factors of drought stress/ effects are water content, water deficits, and water potential. Nowdays molecular marker assisted breeding method is becoming increasingly useful in the improvement of new germplasm with drought stress tolerance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.3
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• pp.334-340
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• 2007

A super sweet corn hybrid, "Cambella 90", was grown at 5 plant populations (35,000, 45,000, 55,000, 65,000, 75,000 plants/ha) on 1 April, 1 May, and 1 June in 2004 under black polyethylene (P. E.) film mulch to find out the optimum plant populations at different planting dates. Emergence rate and percent stand increased as planting dates delayed. Culm length and ear height were highest at the planting on 1 May and increased with increased plant population. Soluble solids content was highest at the planting on 1 May and decreased as plant population increased. Ear length, seed set ear length, ear diameter, and ear weight decreased as plant population increased. Seed set ear length could not substitute for ear weight to evaluate marketable ears. The optimum plant population of "Cambella 90" was $65,000{\sim}75,000$ plants/ha at the planting on 1 April when emergence rate was low due to low temperature, $55,000{\sim}65,000$ plants/ha at the planting on 1 May, and 65,000 plants/ ha after the planting on 1 June.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.2
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• pp.23-28
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• 2008

Purpose: To develop the 2~8X zoom beam expander for the 1064 nm laser source. Methods: After developing the program by which the initial design values of 3-component zoom tracks can be quickly obtaind, we design and develop the zoom beam expander by applying this program and the commercial program of Sigma 2000. Results: In this study, we could develop the program by which the initial design values of zoom tracks can be quickly obtaind, and by applying this program and the commercial program of Sigma 2000 we could design and develop the zoom beam expander for 1064 nm which is able to zoom from 2${\times}$ to 8${\times}$. The developed zoom beam expander has an efficient diameter of the incidence side of 8 mm, an efficient diameter of the exit side of 32 mm, and a capacity with the finite ray aberration within 0.0001rad. Because the overall length (OAL) is restricted between 125 mm and 135 mm, the change of the whole barrel length which is caused by variations of the zoom driving becomes to be within 10 mm. Conclusions: we could develop the program by which the initial design values of zoom tracks can be quickly obtaind, and by applying this program we could design and develop the zoom beam expander for 1064 nm which is able to zoom from 2${\times}$ to 8${\times}$.

• Korean Journal of Agricultural Science
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• v.28 no.1
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• pp.8-17
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• 2001

This study was carried out to obtain a basic intonation for the development of a new com hybird with tillers. Materials used in this study were 20 lines having three to four tillers per plant including the PI213749 U.S. line with non-tillers. These 20 lines were compared for the botanical characteristics and genetic distances were measured using RAPD analysis. Flowering date of the K15 was very earlier, while the K07 was very late in flowering date. Stem height and ear height were similar except for K04 and the K15. K06, K13 and K19 lines were appeared to be resistant to lodging due to decreased ear height. Number of tillers per plant of lines used were shown three to five on average. K09 showed the highest kernel yield, while the K08 was low. Among characteristics measured tiller per plant and flowering dates, and silking dates showed a positive correlation, while 100 kernels weight, flowering date and ear height were shown a negative with tillers per plant. A total of 17 bands by RAPD analysis using four per primer were appeared and these lines were classified into three groups, especially the third group could be classified into of four sub-groups.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.3
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• pp.133-147
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• 2005

Various types of ray-tracing methods are used to predict the quantity measures of radiation illumination, the uniformity of illumination, radiation performance of LCD BLU(Hack-Light Unit). The uniformity of radiation illumination is one of the most important design factor of BLU and is usually controlled by the diffusive-ink pattern printed on the bottom of light-guide panel of BLU. Therefore it is desirable to produce an improved (ideally, the optimal) ink pattern to achieve the best uniformity of radiation illumination. In this paper, we applied the Welder-Mead simplex-search method among various direct search method to compute the optimal ink pattern. Direct search methods are widely used to optimize the functions which are often highly nonlinear, unpredictably discontinuous, and nondifferentiable, The ink-pattern controlling the uniformity of radiation illumination is one type of these functions. In this paper, we found that simplex search methods are well suited to computing the optimal diffusive-ink pattern. In extensive numerical testing, we have found the simplex search method to be reasonably efficient and reliable at computing the optimal diffusive-ink pattern. The result also suggests that optimization can improve the functionality of simulation tools which are used to design LCD BLU.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.3
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• pp.212-219
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• 1985

The field experiment was conducted to study on the growth analysis of early variety, MTC-1, and late variety, Suweon 19, in response to seeding time at Suweon. The results summarized as follows: 1. Days required for Leaf-Formation(L-phase) of MTC-1 and Suweon 19 was same but that of Node-Thickening(N-phase) was quite different, e.g. late variety has two times longer. The period of Ear-Development (E-phase) in MTC-1 was 41 days and 53 days in Suweon 19. L-and N-phase were shortened by late seeding but E-phase was not influenced by seeding time. 2. Leaf Area Index(LAI) was decreased and Leaf Area Ratio(LAR) was increased by late seeding. Days required to maximum LAR was less by late seeding. Net Assimilation Rate(NAR) of L-, N-, and E-phase was decreased but its tendency in E-phase was remarkable at late seeding. 3. Crop Growth Rate(CGR) was increased gradually in the process of plant growth and it was the highest at Husk-stage. Relative Growth Rate(RGR) was increased in L-phase and was decreased in N- and E-phase, but its tendency in N-phase was great. 4. The period required to the maximum dry matter yield was shortened by late seeding and dry matter yield was increased by early seeding.