• Journal of the Korean Geotechnical Society
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• v.30 no.6
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• pp.23-39
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• 2014

An artificial rainwater reservoir installed in urban areas for recycling rainwater is an eco-friendly facility for reducing storm water effluence. However, in order to recycle the rainwater directly, the artificial rainwater reservoir requires an auxiliary system that can remove non-point source pollutants included in the initial rainfall of urban area. Therefore, the conventional soil filtration technology is adopted to capture non-point source pollutants in an economical and efficient way in the purification system of artificial rainwater reservoirs. In order to satisfy such a demand, clogging characteristics of the sand filter layers with different grain-size distributions were studied with real non-point source pollutants. For this, a series of lab-scale chamber tests were conducted to make a prediction model for removal of non-point source pollutants, based on the clogging theory. The laboratory chamber experiments were carried out by permeating two types of artificially contaminated water through five different types of sand filter layers with different grain-size distributions. The two artificial contaminated waters were made by fine marine-clay particles and real non-point source pollutants collected from motorcar roads of Seoul, Korea. In the laboratory chamber experiments, the concentrations of the artificial contaminated water were measured in terms of TSS (Total Suspended Solids) and COD (Chemical Oxygen Demand) and compared with each other to evaluate the performance of sand filter layers. In addition, the accumulated weight of pollutant particles clogged in the sand filter layers was estimated. This paper suggests a prediction model for removal of non-point source pollutants with theoretical consideration of the physical characteristics such as the grain-size distribution and composition, and change in the hydraulic conductivity and porosity of sand filter layers. The lumped parameter ${\theta}$ related with the clogging property was estimated by comparing the accumulated weight of pollutant particles obtained from the laboratory chamber experiments and calculated from the prediction model based on the clogging theory. It is found that the lumped parameter ${\theta}$ has a significant influence on the amount of the pollutant particles clogged in the pores of sand filter layers. In conclusion, according to the clogging prediction model, a double-sand-filter layer consisting of two separate layers: the upper sand-filter layer with the effective particle size of 1.49 mm and the lower sand-filter layer with the effective particle size of 0.93 mm, is proposed as the optimum system for removing non-point source pollutants in the field-sized artificial rainwater reservoir.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.4
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• pp.221-233
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• 2000

Evaluation method of soil fertility by application of geographic information system (GIS) which includes landscape characteristics and soil map data was investigated from productivities of red pepper and tobacco grown on the fields with no fertilization. Total 131 fields experiments, 64 fields of red pepper and 67 fields of tobacco were conducted from 22 and 23 fields for red pepper and tobacco, respectively, located at Cheangweon and Eumseong counties in 1996, from 20 and 25 fields at Boeun and Goesan counties in 1997, and 22 and 19 fields at Jincheon and Chungju counties in 1998. All the experimental sites were selected on the basis of wide range of distribution in landscape and soil attributes. Dry weights and nutrients (N, P and K) uptakes by red pepper plant and tobacco leaves were considered as basic fertility of the soil (BFS). The BFS was estimated by twenty-five independent variables including 13 chemical properties and 12 GIS data. Twenty-five independent variables were classified by two groups, 15 quantitative variables and 10 qualitative variables, and were analyzed by multiple linear regression (MLR) of REG and GLM models of SAS. Dry weight of red pepper (DWRP) and dry weight of tobacco leaves (DWTL) every year showed high variations by five times in difference plots with minimum yield and maximum yield indicating the diverse soil fertility among the experimental fields. Evaluation for the BFS by the MLR including independent variables was better than that by simple regression showing gradual improvement by adding chemical properties, quantitative variables, and qualitative variables of the GIS. However the evaluation for the BFS by the MLR showed the better result for tobacco than red pepper. For example the variability in the DWTL by MLR was explained 34.2% by only chemical properties, 35.0% by adding quantitative variables, and 72.5% by adding both the quantitative and qualitative variables of the GIS compared with 21.7% by simple regression with $NO_3-N$ content in soil. Consequently, it is assumed that this approach by the MLR including both the quantitative and qualitative variables was available as an evaluation model of soil fertility for upland field.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.38-43
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• 1992

A field experiment was conducted to find out the effect level of nitrogen fertilization on the yield and quality of hop (Hallertau variety) emphasis given to ${\alpha}$-acid content. Nitrogen was applied by the rates of 0, 12, 18, 24, 30 and 36kg per 10a. Results were summarized as follows. 1. Stages of cone-hair developing and coneripening were delayed with increment of nitrogen applied. Number of nodes and length of vine increased with nitrogen applid by up to 24kg N/10a. 2. Yield was the highest in the 24kg N/10a plot and cone weight had high significant correlations with yield without regard to the years of growth. No.of flower per side blanch and weight of 100 cones had a significant correlation with yield in the four-year old and five-year old Hop plants. 3. Nutrient content in Hop plants was in the order of CaO, total nitrogen, $K_2O$, MgO and $P_2O_5$. Content of total nitrogen, CaO and MgO was high in leaves while that of $P_2O_5$ and $K_2O$ was high in cone. Nitrogen, phosphorus and magnesium increased with increment of nitrogen fetilized while potassium and calcium decreased. 4. As for the distribution of nutrients in cone developing stage $SiO_2$ content was higher in lower part than in the upper part while $P_2O_5$ contetn was higher in upper part than in lower part of the plant. And content of nitrogen and potassium was higher in middle height than in upper and lower part. 5. The optimum levels of nitrogen application were 19.3kg for 2 years, 24.3kg for 3-year, 27.9kg for 4 years and 31.8kg/10a for 5-year old Hop, respectively. 6. Nitrogen uptake in cone showed a positive correlation with the content of ${\alpha}$-acid and ${\beta}$-acid in cone.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.3
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• pp.241-258
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• 1998

The experimental demersal trawl surveys to provide the essential information for the assessment, management and utilization of commercially important fish stocks in the southern waters of Korea were carried out during five research cruises between October 1996 and October 1997 by the training ship “KAYA” of Pukyong National University. The biological sampling was conducted by using the trawl net with a cover net of 36 mm in mesh size at 64 planned trawl stations during daylight to identify the biological characteristics of fish. Each catch was standardized into catch per unit of time and the catches at each trawl station were sorted, weighed and counted by species. The changes in catches of each fish species and the shifts in dominant species by seasions and sampling regions in the research area were analyzed, and the abundance of fish was estimated from the relationship between the trawl catches and the volume of the water column sampled by demersal trawls. The results obtained can be summarized as follows : 1. During the 64 demersal trawls conducted in the southern waters of Korea, 129 species including 112 species of fishes, 8 species of Cephalopoda and 7 species of Crustacea, were identified Also, during the 1996 and 1997 trawl surveys in the reseach area, a large number of commercially important species with small differences in proportion was found. me proportion of Japanese horse mackerel which comprised 19.8% of the total catch by weight was highest, followed by chub mackerel(15.0%), swordtip squid(9.0%), redwing searobin(6.2%), konoshiro gizzard shad(6.1%), Japanese flying squid(5.8%), silver pomfet(5.1%), blackmouth goosefish(5.1%), etc. Swordtip squid, Japanese flying squid, blackmouth goosefish and blackthroat seaperch were among the dominant species in all seasons with a relatively high and stab1e proportion(3.6~9.0%), and were widely distributed in the entire southern water of Korea. 2. The catch rates by cover net varied at 0.7~91.9% by weight of the total trawl catch by codend and cover net at 64 planned trawl stations and the mean catch rate was 44.4%. Species comprising a major portion of the catches by cover net mainly were swordtip squid, konoshiro gizzard shad, the juveniles of Japanese horse mackerel, blackthroat seaperch and chub mackerel, etc. 3. The distribution density of fish in terms of biomass per unit volume which derived from the catch data by 63 bottom trawl hauls in the southern waters of Korea ranged from 17.9 $\times$ 10-6 to 1,440.9 $\times$ 10-6kg/m3 with the mean value of 153.8 $\times$ 10-6 kg/m3. These fish densities varied between seasons, location of sampling stations and sea conditions. From these results, it is worth noting that the catch composition of multispecies and the increased occurrence of small fish in the southern waters of Korea may also result in new problems in determining the total allowable catch(TAC) levels for economically important species.

• Journal of Korean Society of Forest Science
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• v.58 no.1
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• pp.8-16
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• 1982

To study the comparison of aboveground biomass of paulownia coreana Uyeki of 6-year-old, located in Seongju of non-attacked forest and Ulsan of damaged forest by the air pollution were selected. Ten sample trees in Seongju district and seven trees in Ulsan selected taking account of DBH were measured for 16 trees in total within a $10{\times}10m$ experimental plot. The diagram of oven-dry weight distribution of stem, branch and needle for each 1m segment was constructed. The logarithmic regression equations between dry weight of each component and the two-variables, DBH and tree height, combined term were presented. IF the estimations are extended to a hectare area stand, it contains 47.49 tons of aboveground biomass in Seongju district and 19.05 tons of it in Ulsan. The annual net productions were 11.64 tons of above 2.29 kg/kg/yr in Ulsan and the efficiency of leaf to produce stem was 2.99kg/kg/yr in Seongju and 0.83kg/kg/yr in Ulsan.

• The Korean Journal of Food And Nutrition
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• v.18 no.3
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• pp.207-218
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• 2005

In room temperature, Kimchi becomes acidified and a little decayed, scenting a bad smell, and It couldn't be well kept. But if it should be made into a pill, it could be preserved for a long time for marketing, with nutrition highly concentrated as well as with no scent. Therefore, making Kimchi into a pill needs drying. When dried Kimchi, lactic acid and fragrant ingredient will vanish along with volatilization. The cyclodextrin(CD) as a stabilizer shows that the protecting rate of volatility of lactic acid in Kimchi is higher before than that of after fermentation, and it is higher at the addition $2\%\;than\;of\;1\%$ in case of Kimchi with CD. But it doesn't give much effect on total sugar, reducing sugar, protein and amino acid. Evaporation rate of lactic acid is the least in freeze dry, and natural dry, heat dry come next, respectively. In heat dry, if dried at more than $60^{\circ}C$ for a long time, Kimchi exudes boiling and scorched scent, causing bitter taste. The result of HPLC with superose 12 column at 280nm and 210nm shows that place and amount of main peak is almost the same, but the distribution of other peaks are different, with the revelation of various peaks like peptide and amino acid. The Kimchi pill made by the addition of $1\%$ CD shows that concentration is eight times higher than general Kimchi, total sugar is $14.4\%$, reducing sugar is $8.8\%$, protein is $4.8\%$, amino acid is $2.4\%$, and other contents are $74.4\%$, acidity is 32.8, and pH is 3.5 each. The result of letting 20 people with obesity, 20 patients with constipation have 30 pills(total weight 30g) three times a day for 60 days reveals they lost $2.29\%$ in weight on the average, and 7 among 20 were all relieved in constipation, and 8 responded that they experienced its efficacy.

• Journal of Mushroom
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• v.12 no.1
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• pp.67-72
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• 2014

This study was carried out to provide standardization for mushroom production of high quality at farmhouse. The standardization does much to improve merchantable quality, distribution efficiency and fair dealings by shipping of the standard agricultural products. Therefore, modification of these standards is required to fit farmhouse situations. The standardization for production of Pleurotus eryngii of high quality follows like this. A grades were above 90 g at average weight, more 50 mm at stipe thick, 1.6~1.7 at stipe length/stipe thick rate and 1.1~1.2 at pileus diameter/stipe thick ratio. B grades were more 45 g at average weight, above 40 mm at stipe thick, 1.8~1.9 at stipe length/stipe thick ratio and 1.2~1.4 at pileus diameter/stipe thick ratio.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.509-516
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• 2004

This study is to investigate the amount of biased estimates for heritability and genetic correlation according to data structure on marbling scores in Korean cattle. Breeding population with 5 generations were simulated by way of selection for carcass weight, Longissimus muscle area and latent values of marbling scores and random mating. Latent variables of marbling scores were categorized into five by the thresholds of 0, I, 2, and 3 SD(DSI) or seven by the thresholds of -2, -1, 0,1I, 2, and 3 SD(DS2). Variance components and genetic pararneters(Heritabilities and Genetic correlations) were estimated by restricted maximum likelihood on multivariate linear mixed animal models and by Gibbs sampling algorithms on multivariate threshold mixed animal models in DS1 and DS2. Simulation was performed for 10 replicates and averages and empirical standard deviation were calculated. Using REML, heritabilitis of marbling score were under-estimated as 0.315 and 0.462 on DS1 and DS2, respectively, with comparison of the pararneter(0.500). Otherwise, using Gibbs sampling in the multivariate threshold animal models, these estimates did not significantly differ to the parameter. Residual correlations of marbling score to other traits were reduced with comparing the parameters when using REML algorithm with assuming linear and normal distribution. This would be due to loss of information and therefore, reduced variation on marbling score. As concluding, genetic variation of marbling would be well defined if liability concepts were adopted on marbling score and implemented threshold mixed model on genetic parameter estimation in Korean cattle.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.185-197
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• 1992

Differences in the amount and chemical characteristics of the epicuticular waxes on rice leaves were studied for the active tillering and heading stages of rice varieties differing widely in gross leaf-surface property and genetics. The amount of waxes on surfaces of rice leaf-blades was determined by extraction with chloroform and chemical composition of the waxes was characterized by thin layer chromatography, gas liquid chromatography and infrared spectrophotometry. The amount of waxes varied by variety and significantly with growth stage. The amount at the heading stage was 1.7 to 3.6 mg/g fresh weight of leaves, which was two to three times as much as that at the tillering stage of 0.8 to 1.8 mg/g fresh weight. The waxes consisted of seven chemical classes, namely diols, fatty acids, fatty alcohols, fatty aldehydes, fatty esters, saturated and unsaturated hydrocarbons. Diols and unsaturated hydrocarbons were identified as new chemical classes of the rice epicuticular waxes. The polar constituents such as dials, fatty acids and fatty alcohols and the non-polars such as fatty aldehydes, fatty esters, and saturated and unsaturated hydrocarbons were identified at the heading stage, but at the tillering stage only the non-polar compounds were identified. In the carbon numbers (C) of the chemical classes, diols were composed entirely of C30 and acids were mainly of C30 and C31. In alcohols, primary alcohols were composed of C13 and C32, and the secondary alcohols were of C14, C16 and / or C30 regardless of the rice varieties. The acid portion of fatty esters, mainly composed of C22 and C23, showed low cabon numbers compared with the aldehydes. The alcohol portion of them showed a wide distribution in carbon numbers from C13 to C26 depending on the rice varieties. Hydrocarbons had odd carbon numbers, consisting mainly of C29 and C31.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.666-672
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• 2014

The effect of nitric oxide (NO) treatment on the quality of kiwifruit, cv. Hayward, was studied at room temperature after cold storage for one or three months at $0^{\circ}C$. Kiwifruits cold-stored for one month were treated with $200{\mu}L{\cdot}L^{-1}$ NO and subsequently transferred to room temperature to monitor quality changes over the course of their shelf life. Weight loss was high in fruits not treated with NO. Ethylene production was delayed for two days by NO treatment, and respiration rate was reduced to less half than that of the control. The kiwifruits stored for three months were treated with $N_2$ and 100, 200, or $500{\mu}L{\cdot}L^{-1}$ NO, or air alone. The highest weight loss was observed in kiwifruit treated with $100{\mu}L{\cdot}L^{-1}$ NO. While ethylene production was high in fruits treated with $100{\mu}L{\cdot}L^{-1}$ NO and without the treatment, it was relatively low in the kiwifruit treated with 200 and $500{\mu}L{\cdot}L^{-1}$ NO. Firmness was abruptly decreased in fruits not treated with NO, while the kiwifruit exposed to $200{\mu}L{\cdot}L^{-1}$ NO maintained the s ame level of f irmness for 9 days a t room t emp erature. In addition, growth o f Botrytis cinerea was inhibited by NO as compared with the air and $N_2$ treatments. Our findings indicate that NO can be used effectively for prolonging shelf life and maintaining fruit quality during distribution after cold storage. The optimum NO concentration for cold-stored kiwifruits was found to be $200{\mu}L{\cdot}L^{-1}$.