• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.11
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• pp.26-35
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• 2007

We characterized the properties of the fabricated filter with the total internal reflection mirror (TIR) in the rectangular ring resonator and very small multimode interference (MMI) couplers on an InP material platform for photonic integrated circuits. Coupling power in and out of a resonator is increased by using an optimum MMI length of 110 ${\mu}m$ and a width of 9 ${\mu}m$, respectively. The semiconductor optical amplifier with the length of 120 ${\mu}m$ is integrated in the resonator to compensate the loss of the internal waveguide and the TIR mirror. A free spectral range of approximately 2 nm (244 GHz) is observed with an on-off ratio of 13 dB. The curve fitting also yields the power coupled per pass as 42%. To reach critical coupling at this coupling level would require a round trip loss of about 2.4 dB.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.1
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• pp.107-112
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• 2004

The combining abilities in the 5 newly evolved thermo tolerant breeds viz., SR6, SR7, SR8 SR9 and SR10 of silkworm Bombyx mori L. and their 15 hybrids were made in a line${\times}$tester crossing programme. Data were analysed for seven quantitative traits i.e., pupation rate, cocoon yield, cocoon weight, cocoon shell weight, cocoon shell ratio, filament length and raw silk percentage under optimum room temperature $(25{\pm}{1^{\circ}C})$ conditions (In case of high temperature $(36{\pm}{1^{\circ}C})$ stress conditions five economic traits except filament length and raw silk percentage) with 3 widely adapted testers i.e., KA, CSR2 and CC1 as lines (females) and testers (males) respectively. The performance at high temperature and low humidity conditions aye only taken into consideration for selecting the best lines/hybrids. Among the lines SR6 exhibited positive General combining ability (GCA) effects for pupation rate, cocoon yield, cocoon weight and cocoon shell ratio traits, followed by SR7 for pupation rate, cocoon yield and cocoon shell weight and cocoon shell ratio. Among testers, KA exhibited positive GCA effects for two quantitative traits cocoon yield, cocoon weight and CSR2 for cocoon shell weight and cocoon shell ratio under adverse temperature conditions. The hybrid SR6${\times}$CC1 and SR7${\times}$CSR2 exhibited significant positive Specific combining ability (SCA) effects for majority of the traits in high temperature stress conditions of rearing. The better parent value of heterosis(Heterobeltiosis) was exhibited by the hybrid SR6${\times}$CC1 for pupation rate, cocoon yield, cocoon weight and cocoon shell weight and SR7${\times}$CSR2 for all the trails evaluated under high temperature conditions. Based on the results, the lines SR6 and SR7 was judged as best combiners and the hybrids SR6${\times}$CC1 and SR7${\times}$CSR2 can be selected for commercial exploitation in tropical climate.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.8
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• pp.746-752
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• 2009

In this paper, we deal with the development of an optimal design program for a triple-band PTFA(Planar Inverted-F Antenna) of 433 MHz, 912 MHz and 2.45 GHz by using evolution strategy. Generally, the resonance frequency of the PIFA is determined by the width and length of a U-type slot used. However the resonance frequencies of the multiple U slots are varied by the mutual effect of the slots. Thus the optimal width and length of U-type slots are determined by using an optimal design program based on the evolution strategy. To achieve this, an interface program between a commercial EM analysis tool and the optimal design program is constructed for implementing the evolution strategy technique that seeks a global optimum of the objective function through the iterative design process consisting of variation and reproduction. The resonance frequencies of the triple-band PIFA yielded by the optimal design program are 430 MHz, 910.5 MHz and 2.458 GHz that show a good agreement to the design target values.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.185-189
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• 2000

The object of this study was to determine the optimum seeding dates of "Donganbyeo", "Daesanbyeo", Hoanbyeo", "Nonghobyeo", and "Gwnganbyeo" for direct seeding on dry paddy in Youngnam region. Dry seeds of these varieties were sown 5 times with 10-day intervals from April 20 to May 30. It took 13 to 14 days from sowing to emergence. It was shortened in the delayed seeding date, but the emerged seedlings per unit area was decreased as the seeding date was advanced before May. Heading date was delayed as seeding was delayed. Culm length, panicle length and number of spikelets per panicle was not affected by seeding date, but number of panicle per $m^2$ and ripened grain ratio were high from April 30 to May 10 seeding date. Consequently, the optimum seeding date for high yield of "Donganbyeo", "Daesanbyeo", "Hoanbyeo", "Nonghobyeo", and "Gwanganbyeo" was estimated May 3, May 2, May 10, May 8, and May 1, respectively and "Gwanganbyeo" was estimated May 3, May 2, May 10, May 8, and May 1, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.4
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• pp.315-319
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• 1990

In order to determine the optimum sowing date of Cassia tora L., ecological characters, components and yield were investigated under vinyl-mulching and non-mulching condition. Emergence date and maturation date of vinyl-mulching condition were earlier than those of non-mulching condition. especially with maturation date being about 30 days earlier, Under vinyl-mulching condition, length of stem and pod were longer, number of branches, pods and seeds per plant were increased, stem diameter was thicker, and weight of 1000 grains was heavier. Seed yield per 10a under vinyl-mulching was twice as high as that of non-nulching condition. As sowing date was delayed, the maturation date was progressively delayed. At sowing date of April 10, plants showed the longest in length of stem and pod, the largest in number of pods per plant and number of grains per pod, and the highest in weight of 1000 grains and seed yield. Judging from the results, optimum sowing of Cassia tora L. appeared to be April 10.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.1
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• pp.52-56
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• 1991

In 1986, at Cheju and Seoguipo, a sweet com hybrid, Golden Cross Bantam 70, was grown at 5 phosphate rates (0, 8, 16, 24 and 32 kg/l0a) to determine effects of phosphate rate on growth and yield of sweet com and to recommend the optimum phosphate rate for sweet com production in volcanic ash soils of Cheju province. Days to silking were shortened 1 to 2 days by phosphate application of more than l6kg/10a. Culm length, ear height and fresh stover yield/l0a did not differ between two locations, but linearly increased as phosphate rate was increased from 0 to 32kg/10a. Average length and weight of marketable ears were greater at Cheju than at Seoguipo and linearly increased as phosphate rate increased. The number of marketable ears per plant and per l0a did not differ between two locations, but quadratically increased as phosphate rate increased. The economic optimum phosphate rate estimated on the basis of the quadratic model, ranged 25.6 to 27.4kg/10a at various fertilizer-to-ear price ratios.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.2
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• pp.159-163
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• 2004

Data pertaining to first lactation records of 316 Murrah buffaloes, progeny of 47 sires, maintained at NDRI Farm for a period of 18 years were analysed to construct selection indices and to examine their robustness by changing the relative economic values of different economic traits. A total of 120 selection indices were constructed for three sets of relative economic values ( 40 for each set) considering different combinations of seven first lactation traits viz. age at first calving (AFC), first lactation 305 day or less milk yield (FLMY), first lactation length (FLL), first calving interval (FCI), milk yield per day of first lactation length (MY/FLL), milk yield per day of first calving interval (MY/FCI) and milk yield per day age at second calving (MY/ASC). The three sets of relative economic values were based on economic values of different traits, 1% standard deviation of different traits and regression of different traits on FLMY. The 'optimum' indices for the first two sets had five traits each namely AFC, FLMY, FLL, FCI and MY/ASC giving improvement in aggregate genotype of Rupees 269.11 and Rs. 174.88, respectively. The accuracy of selection from both indices was 70.79 and 69.39%, respectively. The 'best' selection index from the third set of data again had five traits (AFC, FLMY, FLL, FCI and MY/FLL) giving genetic gain of Rs. 124.16 and accuracy of selection of 71.81%. The critcal levels or break-even points for FLMY for varying levels of AFC and FCI estimated from the "optimum index" suggested the need of enhancement of present production level of the herd or reduction of AFC or FCI. It was concluded that economic values of various first lactation traits were the most appropriate to construct selection indices as compared to other criteria of assigning relative economic weights in Murrah buffaloes.

• Composites Research
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• v.16 no.3
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• pp.18-24
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• 2003

Sandwich structures have been widely used in the applications of vessel industry, where high structural stiffness is required with small addition of weight. It is so significant to think of the effect of the variables in the design process of the sandwich structure for the concentrated loads. This paper describes the influence of design variables, such as core density, core thickness and face thickness ratio, on the strength of sandwich beam. The theoretical failure loads based on the 2-D elasticity theory agree well with the experimental yield or failure loads, which are measured at the three point bending laboratory test using AS4/3501-6 facing and polyurethane foam core sandwich beam. The comparison of those yield or failure loads was also done with the ratio of the top to bottom face thickness. The theoretical optimum condition is obtained by finding the intersection point of failure modes involved, which gives optimum core density of the sandwich beam for strength and stiffness. In the addition, the effect of unequal face thickness for the optimized and off-optimized sandwich beams for the strength was compared with the ratio of loading length to beam length, and the variations of strength and stiffness were discussed with the relative ratio of core to face mass.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.194-198
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• 1998

An experiment was carried out to find out the priming effects of rice seeds, Oryza sativa L. (cv. Ilpumbyeo) on. the seedling establishment and early emergence under excess soil moisture conditions. Seeds were primed by soaking in -0.6 MPa polyethylene glycol (PEG) solution at $25^{\circ}C$ for 4 days. The primed seeds were sown in soils with various soil moistures (60, 80, 100, 120, and 140% field capacity) at 17 and $25^{\circ}C$, respectively. Germination and emergence rates, plumule height, and radicle length of primed seeds were higher than those of untreated seeds at any soil moisture and temperature examined. The time from planting to 50% germination ($T_{50}$) of primed seeds was less than that of untreated seeds by 0.9～3.7 days. Germination rate, emergence rate, plumule height, and radicle length were highest at the soil moisture of 80% field capacity among the soil moistures. Priming effects of rice seeds on germination and emergence rates were more prominent under the unfavorable soil moistures (60, 100, 120, and 140% field capacity) than those under the optimum soil moisture condition (80% field capacity). However, priming effects on seedling growth were greater at near optimum soil moisture compared with too lower or higher soil moistures. Therefore, these findings suggest that priming of rice seeds may be a useful way for better seedling establishment under the adverse soil conditions.

• Korean Journal of Plant Resources
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• v.10 no.4
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• pp.397-400
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• 1997

The experiment was carried out to determine the optimum fertilization level showing high quality on Aralia cordata Thunb. Plant height of fertilization(27-15-27kg) was promoted significantly compared with conventional fertilization(17-9-17kg). This effect was followed with increment of blanched length. Among underground parts, main root length was increased in conventional fertilization, and more cultural year was prolonged, the more yield of dry root weight was increased. Fresh leaf yield to produce high quality of Aralia cordata plant was remarkably increased about 6% in fertilization of 27-15-27kg per 10a. As a result, to produce higher good quality of the plant. the optimum fertilization level was 27-15-27kg per 10a.