• Journal of Korea Water Resources Association
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• v.33 no.3
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• pp.365-374
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• 2000

This paper is to present the determination of the optimal Joss rate parameters and urnt bydrographs from the observed single rainfall-runoff event using optimization models coupled with a stochastic technique for the global solution. Two kinds of the linear program models are formulated to derive the optimal unit hydrographs and loss rate parameters for gaged basins; one mimmizes the summation of the absolute residual between predlCted and observed runoff ordinates and the other, the maximum absolute residuaL Multistart algorithm which is one or stochastic techniques for the global optimum is adopted to perturb the parameters of the loss rate equations. Multistart efficiently searches the feasIble region to identify the global optimlUll for loss rate parameters, which yields the optimal loss rate parameters and unit hydrograph for Kostiakov's, Plulip's, and Horton's equation. The unique unit hydrograph ordinates for a gIven rainfall-runoff event iS exclusrvely obtained WIth $\Phi$ index, but unit hydrograph ordinates depend upon the parameters [or each loss rate equations. The parameters of Green-Ampt's are determined through a trial and error method. In this paper the single rainfall-nmoff event observed from a watershed is considered to test the proposed method. The optimal unit hydrograph herein found has smaller deviations than the ones reported previously by other researchers.

• Journal of Animal Science and Technology
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• v.53 no.5
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• pp.435-440
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• 2011

In this experiment, two inclusion levels (15 and 30% of diets, as-fed basis) of brown rice (BR) were tested against a control diet with 0% BR (51% wheat flour of diet). Six female Maltese (8~9 months age, initial mean body weight of $2.8{\pm}0.3$ kg) were assigned to treatments in replicated $3{\times}3$ Latin square design. Total tract digestibilities of DM, OM, acid hydrolyzed fat, CP and gross energy by dogs fed experimental diets responded quadratically (P<0.01 or <0.05) to BR inclusion levels. Similarly, quadratic responses (P<0.001, P=0.015) were observed for digestible energy and metabolizable energy values, respectively. Wet and dry fecal output also exhibited quadratic responses (P=0.006, P=0.014, respectively) but no differences were observed between control and BR 30% diets. Linear (P=0.008) effect was observed for fecal score in dogs fed BR, and fecal ammonia concentration increased linearly (P=0.001) in response to increasing BR inclusion levels. It seems that the increase in fecal ammonia concentration may be partially related to the decrease tendency (P=0.07) in short-chain fatty acid concentration. In this experiment, inclusion of BR in dog diet did not result in pronounced changes in the digestibility but in fecal score. Although inclusion of BR in diets showed profound positive effect on fecal score, it is confounded by the high inclusion level of poultry offal meal.

• Korean Journal of Environmental Agriculture
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• v.11 no.2
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• pp.109-115
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• 1992

In order to investigate waether soil microorganism prefer diazinon to humic substances as their substate, the growth of soil bacteria and the activities of monooxygenase and ${\alpha}-,{\beta}-esterase$ were measured after treatment of diazinon and humic substances in defined medium at $30{\pm}1^{\circ}C$. Also, the degradation rate of diazinon was determined by addition of humic substances to the medium. The number of soil bacteria was increased from 1 day and 3 days after the treatment with humic substances and diazinon, respectively. And it showed about 1.5 times more with humic substances than diazinon at 10 days. Monooxygenase(MO) activity with the treatment of humic substances was higher than diazinon until 3 days after treatment in the order of HA > FA > humin. Esterase(ES) activity with the treament of humin and HA was higher than dizainon from 5 dyas, but FA was much similar to diazinon. The degradation rate of diazinon showed more persistancy by addition of humic substances ; 51.4% with humin treatment, 58.9% with HA, 62.4% with FA and 71.9% in control at 10 days after treatment. Therefore, as soil microorganisms perfer humic substances to diazinon, the degreadation rate of diazinon might be delayed by addition of humic stbstances in submerged soil.

• Journal of Environmental Impact Assessment
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• v.15 no.1
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• pp.1-12
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• 2006

Changes in the soil physical property and the topographic condition derived from agricultural activities like as farming activities, land clearance and cutting down resulted in environmental and economic problems including the outflow of nutrient from farms and the water pollution. Several theories on the soil conservation have been developed and reviewed to protect soil erosion in the regions having a high risk of erosion. This study was done using the USLE model developed by Wischmeier and Smith (1978), and model for the slope length and steepness made by Desmet and Govers (1996), and Nearing (1997) to evaluate the potential of the soil erodibility. Therefore, several results were obtained as follows. First, factors affecting the soil erosion based on the USLE could be extracted to examine the erosion potential in farms. Soil erodibility (K), slope length (L), and slope steepness (S) were used as main factors in the USLE in consideration of the soil, not by the land use or land cover. Second, the soil erodibility increased in paddy soils where it is low in soil content, and the very fine sandy loam exists. Analysis of the slope length showed that the value of a flat ground was 1, and the maximum value was 9.17 appearing on the steep mountain. Soil erodibility showed positive relationship to a slope. Third, the potential soil erodibility index (PSEI) showed that it is high in the PSEI of the areas of steep upland and orchard on the slope of mountainous region around Dokjigol mountain, Dunji mountain, and Deummit mountain. And the PSEI in the same land cover was different depending on the slope rather than on the physical properties in soil. Forth, the analysis of land suitability in soil erosion explained that study area had 3,672.35ha showing the suitable land, 390.88ha for the proper land, and 216.54ha for the unsuitable land. For unsuitable land, 8.71ha and 6.29ha were shown in fallow uplands and single cropping uplands, respectively.

• Korean Journal of Ecology and Environment
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• v.41 no.spc
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• pp.42-49
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• 2008

For this study, we collected fishes of four times at the four site during June 2006 ${\sim}$ September 2007. In the result, the tolerance and omnivore species like a Carassius auratus and Pseudorasbora parva were largely dominated over all, and the sensitive species was not appeared at all except S4 in Shingu reservoir. This reservoir was appeared the simplified of trophic guild was shown in Shingu reservoir. Demonstrating that the omnivore species was occupied 78% of whole. According to the water chemistry data set obtained from the Korea Rural community & Agriculture corporation during $2002{\sim}2005$, the Shingu reservoir showed severe eutrophication and water pollution, therefore the increase of primary production and frequent algal blooms had been occurred. On the other hand, ecosystem health of reservoir was appeared "Fair${\sim}$Poor", and we judged that eutrophication and water pollution were due to this. Consequently, we thought that interception of nutrients and organic matters from the farmland and village and management of reservoir would be need, after this.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.4
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• pp.335-340
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• 2004

This experiment was conducted to compare the dry matter yields and feed values of summer forage crops such as two cultivars of Maize, two cultivars of Sorghum hybrid and one Japanese millet at the Dae-Ho reclaimed tideland, Korea from 2002 to 2003. Seasonal changes of soil salt content maintained somewhat low at early stage and increased at growing stage and then decreased at harvest time. The dry matter yield was 6,102, 4,557 and 2,928 kg/ha, respectively, for Japanese millet Sorghum hybrid and Maize. The highest Crude protein(CP) content was recorded in sorghum hybrid. Neutral detergent fiber.(NDF) and acid detergent fiber(ADF) contents were highest in Japanese millet following Sorghum hybrid and Maize in turn. The highest sodium content in plant tissue was recorded in Japanese millet. These results suggest that Japanese millet is the most suitable summer forage crops for cultivation on reclaimed tideland in view of the good emergence and forage production.

• Food Science and Preservation
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• v.22 no.6
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• pp.811-816
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• 2015

The purpose of this study was to determine the optimum amount of Artemisia annua L. powder for adding rice flour. The A. annua powder was added to the rice flour at ratios of 1% (30 g/3 kg), 2% (60 g/3 kg), 3% (90 g/3 kg, w/w). As the amount of A. annua powder in rice cake dough increased, carbohydrate, ash content, total amino acid, and dietary fiber contents increased whereas the moisture content decreased. Hunter's L value decreased as A. annua powder content increased. On the contrary, the a- and b values increased. The sensory score of the rice cakes containing 30 g of A. annua powder was the highest of all the rice cakes tested. Based on these results, adding A. annua powder could improve the quality and sensory characteristics of rice cake.

• Weed & Turfgrass Science
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• v.4 no.4
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• pp.279-287
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• 2015

The present research was carried out in order to investigate the occurrence of problematic weed species in Cnidium officinale Makino. Field in South Korea. Total 53 sites of the 3 different regions in S. Korea were investigated from May to October, 2014. In Cnidium officinale fields, the identified weeds were distributed in 35 families and 99 species. Total 5 communities that consist of Commelina communis, Eleocharis kuroguwai, Persicaria vulgaris, Chenopodium album-Acalypha australis, and Galinsoga ciliata dominated the appearance. The weeds occurred in Cnidium officinale fields were divided into three groups in principal component plot analysis (PCA). It was observed that in control weeds plots; 20 plants of Cnidium officinale fresh weight is 739.9 g while the uncontrolled plots have no Cnidium officinale plants. The current investigation could be useful for estimation of future weeds occurrence, weed flora dynamics and establishment of weed control methods in Cnidium officinale fields in Korea.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.479-484
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• 2011

The number of comstock mealybug, Pseudococcus comstocki (Kuwana) suddenly increased at ginseng fields in Yangpyeong, Gyeonggi-do from mid July to early August. By the late of September just before digging up the roots of ginseng, more than 8 individuals of the comstock mealybug per plant were occurred and evenly dispersed around the roots. Through the bioassay in the laboratory, six environmental friendly agricultural materials (for example, Nobug, Kkagsami, GB-1, GB-2, GB-3, GB-5) containing sophora extract or paraffin oil as main components were selected by the effective control agents for controlling the comstock mealybug. These selected agents showed a quite similar insecticidal activities to 2 insecticides such as clothianidin and thiamethoxam registered in control of ginseng insect pests. Also. in the ginseng field test, the agent containing sophora extract and paraffin oil, like 2 insecticides showed high control effects against the comstock mealybug.

• The Korean Journal of Pesticide Science
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• v.12 no.2
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• pp.155-161
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• 2008

The inhibitory effect of herbal extracts using methanol and hexane collected from Sudan and Korea was evaluated on egg hatching of Meloidogyne incognita. The concentration of herbal extracts were 10,000, 1,000 and 100 ppm, respectively. They were treated to Meloidogyne incognita eggs after 3, 7, and 21 days of hatching. All herbal extracts inhibited egg hatching significantly compared to the control. The degree of inhibition was directly related to the concentration of the extracts. At 10,000 ppm, very fewer individuals were hatched at all the periods of exposure with the exception of the extract of fruits of Quisqalis indica which gave 84.4 and 54.5% at 7 and 21 days, respectively. Egg hatching was completely ceased, especially after 7 days for most of the extracts. While at 1,000 ppm relatively high numbers of eggs were hatched compared to the higher concentration, as well the extracts Q. indica reported many number of hatched eggs compared to others, especially at 21 days. On the other hand, the extract from pods of Cucumis mello var agrestis gave the least hatching number of eggs at all periods of exposure which gave 2, 8, and 3% at 3, 7, and 21 days, respectively in comparison to the control. Whereas at 100 ppm, inhibition increased with exposure time. However, the extract leaf of Desmodium caudatum represented the fewer hatching eggs at 3 and 7 days.