• Journal of Korea Water Resources Association
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• v.40 no.12
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• pp.943-956
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• 2007

Among various statistics, the spatial correlation function, that is "correlogram", is frequently used to evaluate or design the rain gauge network and to model the rainfall field. The spatial correlation structure of rainfall has the significant variation due to many factors. Thus, the variation of spatial correlation structure of rainfall causes serious problems when deciding the spatial correlation function of rainfall within the basin. In this study, the spatial rainfall structure was modeled using bivariate mixed distributions to derive monthly spatial correlograms, based on Gaussian and lognormal distributions. This study derived the correlograms using hourly data of 28 rain gauge stations in the Keum river basin. From the results, we concluded as following; (1) Among three cases (Case A, Case B, Case C) considered, the Case A(+,+) seems to be the most relevant as it is not distorted much by zero measurements. (2) The spatial correlograms based on the lognormal distribution, which is theoretically as well as practically adequate, is better than that based on the Gaussian distribution. (3) The spatial correlation in July exponentially decrease more obviously than those in other months. (4) The spatial correlograms should be derived considering the temporal resolution(hourly, daily, etc) of interest.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.1
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• pp.25-33
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• 1983

This study is directed to propose a set of reliability based design provisions which gives more rational design for R.C. columns than the current WSD or USD standard design codes. Cornell's MFOSM theory is used for the derivation of the algorithm for the evaluation of uncertainties associated with resistances, whereas the magnitude of the uncertainties associated with load effects are chosen primarily by considering our level of practice. And thus the uncertainties so obtained are applied for the reliability analysis and the derivation of reliability based design criteria. A target reliability(${\beta}_0=4.0$) is selected as an appropriate value by comparing the values used in foreign countries and by analyzing the reliability levels of our current USD and WSD design standars. Then, a set of load and resistance factors corresponding to the target reliability is proposed as a reliability based design provision, and furthermoere a set of allowable stresses for reinforcing steel and concrete having same level of relibity with the corresponding LRFD criteria is also propared for the current WSD design provision. It may be concluded that the proposed LRFD reliability based design provisions and the corresponding allowable stresses give more rational design than the current code for R.C. columns and may be desirable to introdue into the current WSD and USD provision of R.C. column design.

• Journal of Soil and Groundwater Environment
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• v.12 no.1
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• pp.97-102
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• 2007

An environmental survey from three abandoned metal mine areas was undertaken on to assess the risk of adverse health effects on human exposure to heavy metals influenced by past mining activities. Tailings contained high concentrations of heavy metals may have a impact on soils and waters around the tailing piles. In order to perform the human risk assessment, chemical analysis data of soils, rice grains and waters for As, Cd, Cu and Pb have been used. The HQ values for heavy metals via the rice consumption were significantly higher compared with other exposure pathways in all metal mine areas. The resulting HI values in three mine areas were higher than 9.0, and their toxic risk due to rice ingestion was strong in these mine areas. The cancer risk of being exposed to As by the rice consumption from the A, B and C mine areas was $5.1\;{\times}\;10^{-3}$, $6.8\;{\times}\;10^{-3}$ and $3.1\;{\times}\;10^{-3}$, respectively. The As cancer risk via the exposure pathway of rice ingestion from these mine areas exceeds the acceptable risk of 1 in 10,000 set for regulatory purposes. Thus, the daily intakes of rice by the local residents from these mine areas can pose a potential health threat if exposed by long-term As exposure.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.517-524
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• 2004

The objective of this study was to investigate the environmental effects on duration time of milk flow, peak milk flow, and average milk flow in teats, and to estimate their relationships with milk yields in morning and evening milking, and to provide fimdamental information for the further study on their relationships with clinical mastitis and somatic cell in milk. A total of 6,768 milking records were studied in 72 Holstein cows. The influences of season, parity, lactation month, and milking interval on characteristics of milk flow considering in linear model were significant(p<.05). Duration of milk flow was longest at milking in fall, past first parity and second month of lactation, and with milking interval over than 13.5hrs. Average milk flow rate and peak milk flow rate were highest at milking in summer, past first parity and 8${\sim}$10 months of lactation, and with milking interval over than 13.5hrs. Milk flow rate was positively correlated to milk yield, and negatively correlated to the duration of milk flow. However duration milk flow was positively correlated to the milk yield with high level of correlation coefficient(+.60). For the establishment of optimum selection criteria on these traits, other aspects such as the udder health, disease and respective economic weights of milk flow characteristics in this study must be considered to develop the indices.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.294-299
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• 1991

Eight naked barley cultivars were grown in three production systems to select proper cultivars for dual production of forage and grain and to determine production system x cultivar interactions. In the forage systems. barley was seeded on September 27 and October 17, harvested for forage on November 1. December 10 and February 12 from the September 27 planting (forage system I) and on December 10 and February 12 from the October 17 seeding(forage system II). In the grain-only system, barley was planted on November 5. In forage system I, oven-dried forage yields of eight cultivars ranged 195 to 296kg/10a and Saessalbori and Naehanssalbori yielded significantly higher than the other cultivars recording 280 and 296kg/ l0a, respectively. In forage system II, oven-dried forage yields of eight cultivars ranged 106 to 143kg/10a showing no significant difference among cultivars. Production system x cultivar interactions were significant for lodging at maturity, powdery mildew rating, 1000 kernel weight and grain yield. Leaf area index and biomass at heading, no. of spikes per $m^2$, no. of kernels per spike and test weight were not affected by the production system. Forage utilization delayed heading by 3 days and reduced culm length, spike length, lodging due to heavy rain on May 5 and lodging at maturity except for Songhagbori and Naehanssalbori. Forage utilization did not significantly affect grain yield from the September 27 planting but reduced 9% from the October 17 planting. while Saessalbori and Hyangcheonggwa 1 yielded significantly less than in the grain-only system. Songhagbori appears to be a proper cultivar for dual production of forage and grain in Cheju, considering forage and grain yields. and lodging and powdery mildew resistance.

• Korean Journal of Plant Resources
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• v.27 no.4
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• pp.293-308
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• 2014

This study was carried out to investigate the vascular plants in the construction site of the National DMZ Native Botanic Garden. The period of survey was from May 2012 to November 2013. Vascular plants based on voucher specimen were summarized as 313 taxa including 79 families, 211 genera, 272 species, 4 subspecies, 32 varieties, 4 forms and 1 hybrids. The rare plant species designated by Korea Forest Service were 8 taxa including Galium boreale L., Eleutherococcus senticosus (Rupr. & Maxim.) Maxim., Eranthis stellata Maxim. and Lloydia triflora (Ledeb.) Baker, etc. Endemic plant species were 4 taxa including Salix koriyanagi Kimura, Clematis trichotoma Nakai, Philadelphus schrenkii Rupr. and Cirsium setidens (Dunn) Nakai. Furthermore, 51 taxa were listed as specific plant species based on phytogeographical in the investigated area. The naturalized plants were recorded as 11 taxa, and their Naturalization Ratio and Urbanization Index were recorded as 3.51%, and 3.43%, respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.713-716
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• 2013

The device performances of N-channel Tunneling FET have been characterized with different intrinsic length between drain and gate($L_{in}$), drain and source doping, permittivity and oxide thickness when the total effective channel length is constant. N-channel Tunneling FET of SOI structure have been used in characterization. $L_{in}$ was from 30nm to 70nm, dose concentration of drain and source were from $2{\times}10^{12}cm^{-2}$ to $2{\times}10^{15}cm^{-2}$ and from $1{\times}10^{14}cm^{-2}$ to $3{\times}10^{15}cm^{-2}$, permittivity was from 3.9 to 29, and oxide thickness was from 3nm to 9nm. The device performances were characterized by Subthreshold slope(S-slope), On/off ratio, and leakage current. From the simulation results, the leakage current have been reduced for long $L_{in}$ and low drain doping. S-slope have been reduced for high source doping, high permittivity and thin oxide thickness. With considering the leakage current and S-slope, it is desirable that are long $L_{in}$, low drain doping, high source doping, high permittivity and thin oxide thickness to optimize device performance in n-channel Tunneling FET.

• Spatial Information Research
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• v.20 no.5
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• pp.25-35
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• 2012

This study compared the influence of water quality according to the data sources of spatial information. Firstly, land cover map was constructed through image classification of Daecheong-dam basin and the accuracy of image classification from satellite image showed high as 88.76% in comparison with the large-scaled land cover map in Ministry of Environment, to calculate Event Mean Concentration (EMC) by land cover that impact on the evaluation of nonpoint source pollutant loads. Also curve number and direct runoff were calculated by spatial overlay with soil map and land cover map from image classification. And Seokcheon and Daecheong-Dam basin showed high in the analysis of curve number and direct runoff. Samgacheon-Joint and Sokcheon-Downstream basin showed high in the nonpoint source pollutant loads of BOD from direct runoff and EMC. And Samgacheon-Joint and Bonghwangcheon- Downstream basin showed high in the nonpoint source pollutant loads of TN and TP. Nonpoint source pollutant loads from image classification were compared with those by the land cover map from Ministry of Environment to present the effectivity of nonpoint source pollutant loads from satellite image. And Daecheong-Dam Upstream basin showed high as 10.64%, 11.70% and 20.00% respectively in the errors of nonpoint source pollutant loads of BOD, TN, and TP. Therefore, it is desirable that spatial information including with paddy and dry field is applied to the evaluation of nonpoint source pollutant loads in order to simulate water quality of basin effectively.

• Food Science and Preservation
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• v.18 no.4
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• pp.497-501
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• 2011

The object of this study was to evaluate the effect of gibberellins (GA) pasting on the bourse shoot, and not just on the fruit characteristics but also on the quality, of Niitaka pear (Pyrus pyryfolia L). The fruit stalk was treated with GA (control, 25mg/fruit stalk) 35 days after reaching full bloom. In the GA-treated tree, the occurrence of abnormal bourse shoot (52.5%) increased, and the spur bud and flower number decreased. The diameter of the GA-paste-treated fruit increased during the pear growth period with GA treatment. The diameter, length, and weight of the GA-paste-treated fruit increased at harvest time, but the hardness was lower than that of the control. The differences in soluble solid, acidity, and fruit color between the control and the GA-paste-treated fruit were not significant. Post-harvest, during the storage period, the hardness of the GA-paste-treated fruit was lower than that of the control, and its weight loss ratio was higher than that of the control on the $60^{th}$ days of storage.

• Journal of Aquaculture
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• v.10 no.4
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• pp.463-472
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• 1997

Floating and hatching rates, size and survival activity index(SAI) of spawned eggs of red spotted grouper, Epinephelus akaara were studied to understand egg qualities during the spawning periods in 1992, 1993 and 1995. The fish spawned from mid-July to mid-August when temperature ranged 23~$28^\circC$. Floating, fertilization and hatching rates were higher in the eggs from early to middle than those from late during the spawning period. SAI ranged 1.8~9.6, and it was closely related to survival rate until mouth operning time (SMOT). Egg diameter decreased gradually with the time of spawning, while diameter of oil globule was constant during the spawning periods. Induced spawnings were carried out with one injection of HCG over 5, 000 IU/kg body weight. Floating, fertilization and hatching rates of the induced spawning eggs were higher than those of untreated ones. Thus, induced spawning method with HCG was recommended for collecting fertilized eggs in bulk. Optimal time for the collection of high quality eggs was supposed to be from early to middle during the spawning periods. Considering that egg qualities were vulnerable within the period, hatchability, incidence of malformed larvae, SMOT and SAI were factors to be considered together to get good quality of eggs.