• Magazine of the Korean Society of Agricultural Engineers
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• v.8 no.1
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• pp.1088-1096
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• 1966

The following is a method of synthetic unitgraph derivation based on the routing of a time area diagram through channel storage, studied by Clark-Jonstone and Laurenson. Unithy drograph (or unitgraph) is the hydrograph that would result from unit rainfall\ulcorner excess occuring uniformly with respect to both time and area over a catchment in unit time. By thus standarzing rainfall characteristics and ignoring loss, the unitgraph represents only the effects of catchment characteristics on the time distribution of runoff from a catchment The situation abten arises where it is desirable to derive a unitgraph for the design of dams, large bridge, and flood mitigation works such as levees, floodways and other flood control structures, and are also used in flood forecasting, and the necessary hydrologie records are not available. In such cases, if time and funds permit, it may be desirable to install the necessary raingauges, pruviometers, and stream gaging stations, and collect the necessary data over a period of years. On the otherhand, this procedure may be found either uneconomic or impossible on the grounds of time required, and it then becomes necessary to synthesise a unitgraph from a knowledge of the physical charcteristics of the catchment. In the preparing the approach to the solution of the problem we must select a number of catchment characteristic(shape, stream pattern, surface slope, and stream slope, etc.), a number of parameters that will define the magnitude and shape of the unit graph (e.g. peak discharge, time to peak, and base length, etc.), evaluate the catch-ment characteristics and unitgraph parameters selected, for a number of catchments having adequate rainfall and stream data and obtain Correlations between the two classes of data, and assume the relationships derived in just above question apply to other, ungaged, Catchments in the same region and, knowing the physical characteritics of these catchments, substitute for them in the relation\ulcorner ships to determine the corresponding unitgraph parameters. This method described in this note, based on the routing of a time area diagram through channel storage, appears to provide a logical line of research and they allow a readier correlation of unitgraph parameters with catchment characteristics. The main disadvantage of this method appears to be the error in routing all elements of rainfall excess through the same amount of storage. evertheless, it should be noted that the synthetic unitgraph method is more accurate than the rational method since it takes account of the shape and tophography of the catchment, channel storage, and temporal variation of rainfall excess, all of which are neglected in rational method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1500-1506
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• 2015

The headcut erosion at the confluence section of a mainstream and tributary can migrate up the tributary streams, and rapid degradation can threaten the stability of hydraulic structures installed in the channel. Therefore, quantitative analysis for the development and mechanism of headcut erosion is needed to prevent damage due to the headcut. In this study, hydraulic experiments for headcut erosion in the channel with noncohesive materials were performed and the knickpoint movement and final bed slope change were analyzed based on the different hydraulic conditions. As a result, the knickpoint movement was 1.5 times faster when the difference in velocity between the upstream and downstream sections was 2.5 times greater and the central part of the cross-section was eroded and collapsed earlier than the left and right sides. The movement length of headcut erosion was longer and the final bed slope was milder as the velocity difference between the upstream and downstream sections was increased. This study showed that a correlation between the knickpoint movement and bed slope change by headcut erosion and the water level difference of upstream and downstream sections was not constant compared to the velocity difference.

• Korean Journal of Remote Sensing
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• v.30 no.5
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• pp.627-639
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• 2014

Accurate correction of surface effect from back scattered solar radiance is one of key issue to retrieve aerosol information from satellite measurements. In this study, two different methods are applied to retrieve surface reflectance by using single visible channel measurement from meteorological imager onboard COMS. The first one is minimum reflectance method, which composes the minimum value among previously measured reflectances at each pixel over a certain search window length. This method assumes that the darkest pixel corresponds to the aerosol-free condition, and deduces surface reflectance by correcting atmospheric scattering from the measured visible reflectance. The second method, named as the "atmospheric correction method" in this study, estimates the result by correcting aerosol and atmospheric scattering with ground-based observation of aerosol optical properties. The purpose of this study is to investigate the retrieval accuracy of the widelyused minimum reflectance method. Also, the retrieval error caused by the loading of background aerosol is mainly estimated. The comparison between surface reflectances retrieved from the two methods shows good agreement with the correlation coefficient of 0.87. However, the results from the minimum reflectance method are slightly overestimated than the values from the atmospheric correction method when surface reflectance is lower than 0.2. The average difference between the two results is 0.012 without the background aerosol correction. By considering the background aerosol effect, however, the difference is reduced to 0.010.

• Korean Journal of Medicinal Crop Science
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• v.18 no.3
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• pp.168-172
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• 2010

This experiment was carried out to investigate the effect of several organic compost on the growth and root yield of Scutellaria baicalensis G. with organic cultivation from 2008 to 2009. Four organic compost were used ; Rice bran compost (RC : 1.1-3.6-1.4), Wheat bran compost (WC: 1.1-3.4-1.4), Hangawi compost (HC : 3.7-4.0-1.0), Cheonnyeonjigi compost (CC : 12.4-3.4-5.4) and Fermented chicken droppings compost (FC : 2.9-6.1-3.2). Organic matter, available phosphate and $K_2O$ of soil increased in all plots with the addition of organic compost, specifically in HC, CC and FC application. Treatment of HC, CC and FC application increased emergence rate and improved the growth characters of shoot, root parts of plants compared to those of RC application. Subterranean part yields by different organic compost was high 149~156 kg per 10a as by growth increment of dried root yield. length of main root and diameter of main root. respectively, 17.4~18.4 cm, 12.65~12.94 mm from HC, CC and FC application. There were significantly positive correlation between the growth characters of shoot, root parts of plants, dry root yield in Scutellaria baicalensis G. grown under organic compost application.

• Parasites, Hosts and Diseases
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• v.58 no.2
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• pp.153-159
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• 2020

The chigger mite Leptotrombidium sialkotense is one of the 6 main vectors of scrub typhus in China. Before present study, L. sialkotense was found in some parts of Hunan province, China with a narrow geographical distribution. During field investigation 2016-2017, we found L. sialkotense in Jingha, southern Yunnan, China. Of 15 small mammal host species, L. sialkotense were collected from 6 species of the hosts. Rattus brunneusculus was a dominant host of L. sialkotense, from which 98.3% of the mites were collected. The chigger mite showed a relatively high infestation prevalence (P_M =11.7%) and mean abundance (MA=0.5) in comparison with the rest 5 host species. These results reveal a certain host specificity of L. sialkotense to a rat R. brunneusculus. The mite L. sialkotense showed an aggregated distribution on the host (P<0.05). A positive correlation observed between L. sialkotense and the body length of hosts. There was a positive interspecific association between L. sialkotense and 2 other dominant vectors, L. deliense and L. scutellare.

• Korean Journal of Plant Tissue Culture
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• v.25 no.2
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• pp.75-80
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• 1998

Disbudded epicotyl cuttings from light-grown 6-day-old seedings of Vigna angularis Owhi et Ohashi were preincubated in $2\;\times\;10^{-4}M$ IAA solution for 48 hr to promote adventitious root formation in upright or inverted direction and then incubated in upright direction for 96 hr. Adventitious root formation occurred only at the morphological base of the cuttings which were preincubated in upright direction, while at the both ends in inverted direction. IAA treatment enhanced the adventitious root formation in all cuttings regardless of their orientation during preincubation. To elucidate localized root development, the activity of enzymes involved in root initiation and development was measured 24 hr, 48 hr, and 148 hr after epicotyl incubation. IAA oxidase, peroxidase and catalase were assayed in the apical, middle and basal segment of the epicotyls, and their fresh weight and length were measured. Elongation occurred the most in the upper segment of the epicotyl while fresh weight gain was the most in the basal segment. At root initiation phase, 24 hr after incubation IAA peroxidase and catalase activities appeared high at rooting zone while IAA oxidase activity was low at both ends, IAA oxidase and peroxidase activities declined at the rooting zone during the adventitious root formation at 48 ht. Inversion of cuttings during preincubation caused a chrange of enzyme activities along their epicotyl cuttings. Only peroxidase activity showed a high correlation with root initiation. Therefore, the biochemical change is highly correlated with change in IAA level in the rooting zone of the epicotyl, resulting in root formation in unusual rooting zone of epicotyl.

• Journal of Distribution Science
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• v.12 no.8
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• pp.55-69
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• 2014

Purpose - Despite the importance of price, many companies do not implement pricing policies smoothly, because typical price management strategies insufficiently consider logistics efficiency and an increase in logistics costs due to logistics waste. This study attempts to examine the effect of product line pricing, which corresponds to product mix pricing, on logistics efficiency in the case of manufacturer A, and analyzes how logistics performance changes in response to these variables. Research design, data, and methodology - This study, based on the case of manufacturer A, involved research through understanding the current status, analyses, and then proposing improvement measures. Among all the products of manufacturer A, product group B was selected as the research object, and its distribution channel and line pricing were examined. As a result of simulation, for products with low loading efficiency, improvement measures such as changing the number of bags in the box were suggested, and a quantitative analysis was conducted on how these measures influence logistics costs. The TOPS program was used for the Pallet loading efficiency simulation tool in this study. To prevent products from protruding out of the pallet, the maximum measurement was set as 0.0mm, and loading efficiency was based on the pallet area, and not volume. In other words, its size (length x width) was focused upon, following the purpose of this study and, then, the results were obtained. Results - As a result of the loading efficiency simulation, when the number of bags in the box was changed for 36 products with low average loading efficiency of 73.7%, as shown in