• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.675-678
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• 2008

An abnormal storm by the typhoon of RUSA in 2002th year was broken out with tremendous flood demages and inundations on the basin of Chogangcheon located in the upper middle part of Guem river's upstream. This flood could not be engaged because it was so big that the stage engaging Songcheon station stuck to Songcheon bridge was destroyed by submerging. In this study the quantity of the flood was calculated by use of Manning's equation and suitable roughness coefficient was suggested.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.2
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• pp.96-102
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• 2003

This study was conducted to determine the effects of two plant populations (28 and 14 plants per $m^2$) and two toppings in conventional plant population (28 plants per $m^2$) on soybean (Glycine max L. cv. Pungsannamulkong) cultivated in the paddy field. The two topping time were taken at 6$^{th}$ to 7$^{th}$ and 8$^{th}$ to 9$^{th}$ trifoliolate leaf stages in the conventional plant population. Experimental design for growth data was a randomized complete block with three replications, and samples were taken at R1 (July 31), R3 (August 19), R5 (September 2) and R7 (September 23) growth stages. The branch number of soybean was relatively higher in the low plant population (14 plants per $m^2$) and with the topping at the 6$^{th}$ to 7$^{th}$ leaf stage, in the conventional plant population (28 plants per $m^2$), and with topping at the 8$^{th}$ to 9$^{th}$ trifoliolate leaf stage in descending order. The highest average branch length of soybean was observed in the low population and the longest branch length was observed from the soybean with topping at the 6$^{th}$ to 7$^{th}$ leaf stage. The leaf number per plant was decreased in order of in the low population, with the topping at 6$^{th}$ to 7$^{th}$ trifoliolate leaf stage, with the topping at 8$^{th}$ to 9$^{th}$ trifoliolate leaf stage, and in the conventional population. The leaf area was high in the low population and with topping at 6$^{th}$ to 7$^{th}$ trifoliolate leaf stage and was relatively low in the conventional population and with the topping at 8$^{th}$ to 9$^{th}$ trifoliolate leaf stage in soybean. The dry weight of leaves and branches was high in the low population and with the topping at 6$^{th}$ to 7$^{th}$ trifoliolate leaf stage and was relatively low in the conventional population and with topping at 8$^{th}$ to 9$^{th}$ trifoliolate leaf stage. The leaf number per plant was high in the low population and with topping at 6$^{th}$ to 7$^{th}$ trifoliolate leaf stage and was relatively low in the conventional population and with topping at 8$^{th}$ to 9$^{th}$ trifoliolate leaf stage. The grain yield per 10a was high with the topping at 6$^{th}$ to 7$^{th}$ trifoliolate leaf stage.

• Plant Resources
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• v.5 no.2
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• pp.155-160
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• 2002

The heading date is known to be controlled by two kinds of genetic constituent, photosensitivity and basic vegetable phase. For the latter, the effect of temperature in early growth period is critical to determine the shortness of vegetative growth periods in plant's life. A phytotron experiment on 55 rice cultivars, consisting of two ecotypes of rices, indica and japonica, was conducted at high and low temperature treatments at early growth stage to investigate the possible role of plant growth stimulus by high temperature to associate with shortening of heading date. The high temperature during the early growth stage stimulated the rice growth as measured by plant height with much difference of the growth response between indica and japonica. The conclusive finding that these growth stimulus in early growth stage was highly correlated with the acceleration of heading is, more or less, correlated with the heading of the late growth stage although we could not conclude the genes for early plant growth stimulus by high temperature is the same genes as the genes for accelerating of heading in the late growth stage of plants.

• Journal of Communications and Networks
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• v.18 no.4
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• pp.600-609
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• 2016

In this paper, we propose a two-stage base station (BS) sleeping scheme to save energy consumption in cellular networks. The BS sleeping mode is divided into a light sleeping stage and a deep sleeping stage according to whether there is a user in the BS's coverage. In the light sleeping stage, a BS will retain its coverage and frequently switch between the on state and the doze state according to the service characteristics. While in the deep sleeping stage analysis, the BS will shut down its coverage, and neighbor BSs will patch the coverage hole. Several closed-form formulas are derived to demonstrate the power consumption in each sleeping stage and the stage switching conditions are discussed to minimize the average power consumption. The average traffic delay caused by BS sleeping and the average deep sleeping rate under a given traffic load have also been studied. In addition, it is shown that BS sleeping is not always possible because of the limited quality of service (QoS) requirements. Simulation results show that the proposed scheme can effectively reduce the average BS power consumption, at the cost of some extra traffic delay. In summary, our proposed framework provides an essential understanding of the design of future green networks that aim to take full advantage of different stages of BS sleeping to obtain the best energy efficiency.

• Journal of Embryo Transfer
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• v.24 no.3
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• pp.231-235
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• 2009

Oxygen consumption has been regarded as a useful indicator for assessment of mammalian embryo quality. However, there was no standard criterion to measure the oxygen consumption of embryos. Here, we measured oxygen consumption of bovine embryos at various developmental stages was measured using a scanning electrochemical microscopy (SECM). We found that the oxygen consumption significantly increased in blastocyst-stage embryos compared to other stage embryos (from 2-cell-stage to morula-stage), indicating that oxygen consumption reflects the cell number ($5.2{\sim}7.6{\times}10^{14}/mol\;s^{-1}$ versus $1.2{\sim}2.4{\times}10^{14}/mol\;s^{-1}$, p<0.05). In the morula-stage embryos, the oxygen consumption of in vivo derived embryos was significantly higher than that of in vitro produced embryos ($4.0{\times}10^{14}/mol\;s^{-1}$ versus $2.4{\times}10^{14}/mol\;s^{-1}$, p<0.05). However, there was no significant difference in consumption of oxygen by in vivo and in vitro-derived bovine blastocyst-stage embryos (p>0.05). In the frozen-thawed blastocyst-stage embryos, live embryos showed significantly higher oxygen consumption than dead embryos ($4.7{\times}10^{14}/mol\;s^{-1}$ versus $1.0{\times}10^{14}/mol\;s^{-1}$, p<0.05). These results indicate that the measuring oxygen consumption by SECM can be used to evaluate bovine embryo quality.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.38-43
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• 1999

Over 2,000 ha of rice fields in the western and southern coastal region of Korea were flooded with sea water during the spring tide, on August 19-21, 1997, and the rice plant at heading stage was injured. The field surveys were undertaken at the sea water flooded paddy fields in Chonbuk Province, to identify the injury symptoms and rice yield damage subjected to different flooding condition and desalinization methods. Five days after sea water flooding at heading stage, the flag leaves of rice plants flooded with 30 ㎝ deep sea water withered from the tip, the withering progressed to the lower leaves in deeper flooding. The spikelets were spotted black and discolored from the tip at 50 ㎝ deep flooded rice, and some panicles changed to white at 80 ㎝ deep flooded rice. Most of the rice leaves submerged completely for an hour were withered and most of panicles changed to white. The milled rice yield, percentage of ripened grain, and 1000 grain weight of flooded rice decreased with deeper flooding water, higher water salinity and longer flooding time. Even under the same flooding conditions, the damage of rice yield varied with the growth stage: heading stage>dough stage>booting stage. Rice yield damage was less in the fields on the upper riverside than those of the fields on the estuary and seaside, because of lower water salinity. In a flooded field, the rice yield damages were reduced as the distance increased from the levees where the sea water inflowed and increased as the distance increased from the fresh water irrigation gate. The desalinization treatments consisting of frequent exchange of irrigation water and spraying with fresh water soon after flooding effectively reduced the rice yield damage.

• Proceedings of the Korean Society of Crop Science Conference
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• 2003.10a
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• pp.136-137
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• 2003

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.4
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• pp.269-272
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• 2002

This study was carried out to investigate varietal differences on growth characteristics under the conditions of PE film-mulching and non-mulching in sesame. At maturing stage from 76 to 95 days after sowing, Yangbaeckkae, non-branching plant type, under non-mulching showed larger leaf area index (LAI) than that of film-mulching, while plant height and the number of capsules per plant were similar to those of film-mulching. LAI of Ahnsankkae, branching plant type, under non-mulching was similar to film-mulching, while plant height and the number of capsules per plant were smaller than those of film-mulching. Net assimilation rate (NAR) of two varieties under non-mulching was lower at seedling stage from 25 to 35 days after sowing but higher at flowering stage from 45 to 55 days after sowing. At maturing stage from 66 to 77 days after sowing, NAR and crop growth rate (CGR) of Yangbaeckkae under non-mulching were greater than those of film-mulching, whereas those of Ahnsankkae under non-mulching were lesser than those of film-mulching. Yield under non-mulching was decreased by 7 % in Yangbaeckkae and 33 % in Ahnsankkae compared with that of film-mulching, therefore Yangbaeckkae was more adaptable for non-mulching than Ahnsankkae. Main factors decreasing yield of Yangbaeckkae under non-mulching were small LAI, NAR, and CGR at the stage of young seedling, and small number of capsules at early maturing stage from first flowering to 20 days after first flowering.

• Journal of Embryo Transfer
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• v.24 no.4
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• pp.253-257
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• 2009

To enhance the embryo preservation technology and better application of embryo transfer technique to the field (dairy science or animal reproduction. etc.), we examined the viabilities of bovine embryos produced in vitro and in vivo after cryopreservation according to their developmental stage and thawing temperature. Bovine embryos from in vivo/vitro fertilization (Hanwoo) were examined at day 7, 8, and 9. Survival rates and total cell numbers of in vivo fertilized embryos were as follows: morulae 68.8% and $67\;{\pm}\;6.0$; blastocysts 80.5% and $120\;{\pm}\;10$; expanded blastocysts 77.4% and $138\;{\pm}\;9.7$, respectively. Rates of embryo development for blastocysts and expanded blastocysts after thawing were significantly higher than that of morula stage embryos (p<0.05). While survival rates of in vitro fertilized embryos according to developmental stage showed no significant difference among groups (morula 67.9%; blastocyst 74.3%; and expanded blastocyst 79.4%), total cell numbers were significantly lower than those of other groups (morula $64\;{\pm}\;5.9$; blastocyst $116\;{\pm}\;8.7$; and expanded blastocyst $135\;{\pm}\;9.1$) For the viability according to thawing temperature, survival rate was higher in $37^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.336-337
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• 1989