• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.7
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• pp.64-73
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• 2002

This study was performed to evaluate effects of physical characteristics of both watershed and reservoir on nutrient-chlorophyll relationship in Korean reservoirs. Simple linear models were developed with published data in Korea including 415 reservoirs and 11 multi-purpose dams, and physico-chemical parameters of reservoirs and characteristics relationship of models were analyzed. Theoretical residence time in Korean reservoirs was strongly correlated with the ratio of TA/ST (drainage area + surface area / storage volume) in the logarithmic function. As a result of monthly nutrients-chlorophyll-a regression analysis, significant Chl-a-TP relationship appeared during May～July. The high Chl-a yields per total phosphorus appeared during this time (R$\^$2/=0.51, p<0.001, N= 1088). Chlorophyll-a demonstrated much stronger relationship with TP. than TN. Seasonal algal-nutrient coupling were closely related with N:P ratio in the reservoir water, and it was, in turn, dependent on the monsoon climatic condition (precipitation). Based on the results of regression analysis and high N:P ratio, a major limiting factor of algal growth appeared to be phosphorus during this time. Unlikely TA/ST ratio, DA/SA ratio (drainage area f surface area) was likely to influence directly on the nutrient-Chl-a relationship, indicating that if storage volume and inflowing water volume were the same, algal biomass could be developed more in reservoirs with large surface area. Thus, DA/SA ratio seemed to be an important factor to affect the development of algal biomass in Korean reservoirs. With low determination coefficient of TP-Chl-a relationship, our findings indicated not only nutrient (phosphorus) but also other physical factors, such as DA/SA ratio, may affect algal biomass development in Korean reservoirs, where actual residence time appears to be more closely related to reservoir surface area rather than storage volume.

• Journal of Ocean Engineering and Technology
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• v.33 no.6
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• pp.597-606
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• 2019

Due to climate change, coastal areas are being flooded with torrential rain, typhoons, and tsunamis. In addition, non-point source pollutants (NPSs) that accumulated on the ground, streets, and buildings during the dry season are washed off by rain and stormwater runoff, which adds to the damage associated with environmental pollution, e.g., pollution that makes its way into the ocean. Recently, low impact development (LID) has been considered as a means of controlling water circulation and NPSs. In the coastal area, permeable blocks have been constructed mainly to reduce the flood damage caused by waves. Some important design factors that must be considered to ensure long-term performance are the permeability coefficient, clogging, and the efficiency of the removal of total suspended solids (TSS), but currently there are no standardized design criteria or testing techniques that are used worldwide. Herein, we analyzed the permeability coefficient and the TSS removal efficiency tendency according to the permeability area ratio with an easily-detachable, permeable block filled with calcinated yellow soils as the filter media. Our lab-scale tests indicated that, when the permeability area ratio was 25%, the reduction of the permeability coefficient after clogged was 11%, which was a significant decrease compared to other cases. Permeability persistence increased when the permeability area ratio increased from 50% to 75%. The TSS removal efficiency decreased as the permeability area ratio increased. Our pilot-scale test indicated that the TSS removal efficiency was more than 80% higher in all cases. We also found that the permeability persistence was excellent as the permeability area ratio increased, and, in actual construction, it is effective to set 5.3% of the total area as permeable area in terms of permeability and economic feasibility.

• Journal of the Korean Institute of Rural Architecture
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• v.9 no.1
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• pp.35-42
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• 2007

This study is the research of occupation distribution about citizen members of autonomy organization in Cheongju area. Investigation of autonomy organization members acting as local readers makes it possible to understand direction for community promotion. Result of this study sums up two type occupational categories. First, in urban area independently managers is above participation ratio in public affairs appeared. On the other hand, ratio of private organization, employee, and experts are low. In rural area, it shows the participation ratio of functional representatives and farmers highly. Second, with investigation of detailed occupation, most independent contractors and such as architecture, real-estate, whole and retail sales, restaurant, nursery, and private educational institute. And small number of insurance, news paper, car sales, gas station mangers participate in autonomy organization. Private organization consist of educational organization, social welfare corporate and district head council, as well as some teachers and farmers.

• Membrane and Water Treatment
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• v.10 no.1
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• pp.19-28
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• 2019

To minimize the impact of urbanization, accurate performance evaluation of Low Impact Development (LID) facilities is needed. In Korea, the method designed to evaluate large-scale non-point pollution reduction facilities is being applied to LID facilities. However, it has been pointed out that this method is not suitable for evaluating the performance of relatively small-scale installed LID facilities. In this study, a new design formula was proposed based on the ratio of LID facility area and contributing drainage area, for estimating the Stormwater Interception Ratio (SIR) for LID facilities. The SIR was estimated for bio-retentions, infiltration trenches and vegetative swales, which are typical LID facilities, under various conditions through long-term stormwater simulation using the LID module of EPA SWMM. Based on the results of these numerical experiments, the new SIR formula for each LID facility was derived. The sensitivity of the proposed SIR formula to local rainfall properties and design variables is analysed. In addition, the SIR formula was compared with the existing design formula, the Rainfall Interception Ratio (RIR).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.11-19
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• 1999

This experiment was conducted with nine wheat geno-types to choose the wheat which has excellent early vigour. 'Vigour 18' and 'ZL 59A' are excellent in the long coleoptile genotype, while 'Amery' and 'Janz' are excellent in the short coleoptile genotype. Responding to the growth stage and nitrogen level, Vigour 18 is predominant in the long coleoptile genogype, while Janz in the short coleoptile genotype. Responding to sowing density and nitrogen level, the higher the sowing density was, the shorter the leaf area of Vigour 18 and Janz. Also the leaf area turned out to larger in the plot fertilized with high nitrogen than in the plot fertilized with low nitrogen. This is true of leaf weight and root weight. Concerning specific leaf area (SLA) and leaf area ratio (LAR), the higher the sowing density was, the SLA tended to grow larger, while the SLA grew larger in the plot fertilized with low nitrogen, as were found in Vigour 18 and Janz. The roots of long coleoptile genotype, Vigour 18, turned out to grow longest on the plot sown with 3 seeds. While the roots of short coleoptile genotype, Janz, grew longest on the plot sown with 2 seeds. The relative growth rate (RGR) was the same at low N rates and high N rates. The RGR was 0.071 and 0.072 g $g^{-1}d^{-1}$ at low N rates and high N rates. The partitioning of RGR into net assimilation rate (NAR) and LAR showed that the average LAR at low N rates was similar to the LAR at high N rates. Variation within each cultivar in the LAR and NAR was small relative to the difference between them at low N rates and high N rates. Above ground mass was 8.2 mg greater at high N rates than low N rates, whereas leaf area was 0.05 $\textrm{m}^2$$kg^{-l}$ greater at high N rates than low N rates. The NAR was similar at low N rates and high N rates, whereas LAR was greater at high N rates (0.05 $\textrm{m}^2$$kg^{-l}$); variation in SLA was responsible for the variation in NAR and LAR both at low N rates and high N rates. NAR was more closely associated with the reciprocal of SLA.

• Journal of Environmental Science International
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• v.15 no.5
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• pp.405-415
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• 2006

Sixteen soil samples around six areas (residental area, traffic area, power plant area, incineration area and factory area) where the stationary and mobile sources of polycyclic aromatic hydrocarbons (PAHs) are estimated to be emitted in Jeju City, were collected during Feburuary to March, 2004, and analyzed for 16 PAHs recommended by US EPA as primary pollutants to investigate their distribution characteristics. The concentrations of total PAHs (t-PAHs) and total carcinogenic PAHs $(t-PAH_{CARC})$ in soils of Jeju City were in the range of $21.7\sim264.2ng/g$ on a dry weight basis with a mean value of 87.2 ng/g and $6.3\sim118.0ng/g$ with a mean value of 33.4 ng/g, respectively. The concentrations of t-PAHs were low in comparison with those in soils of other domestic and foreign countries. The mean concentrations of t-PAHs and $(t-PAH_{CARC})$ with area decreased in the following sequences: traffic area> incineration area > factory area > power generation area > harbor area enli residental area. The correlation between t-PAHs and $(t-PAH_{CARC})$ were very high $(\gamma^2=0.9701)$, indicating that $(t-PAH_{CARC})$ concentration increases in proportion with t-PAHs. Comparing the distribution ratio of ring PAHs with area among 16 PAHs, it decreased in the order of 4-ring > 5-ring > 6-ring > 3-ring > 2-ring in all the areas except for harbor area. whitens for harbor area it was similar among 3-, 4- and 5-ring with high value. Low and no correlations between t-PAHs and soil compositions (organic matter content and particle size distribution) were observed, which is considered to be caused by the complex factors, such as the loading and characteristics of PAHs and diverse soil environment change, etc. From the examination of the three PAH origin indices, such as LMW/HMW (low molecular weight $2\sim3$ ring PAHs over high molecular weight $4\sim6$ ring PAHs), phenanthrene/anthracene ratio and fluoranthene/pyrene ratio, it can be concluded that the soil PAH contaminations were ascribed to strong pyrogenic origin in ail areas except for harbor area and to both pyrogenic and petrogenic origins.

• Journal of Korean Society on Water Environment
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• v.24 no.3
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• pp.333-339
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• 2008

This study was carried out to assay the relationships between empirical factors and water quality in 23 agricultural reservoirs. Based on the trophic state index (TSI) deviation analysis, phosphorus in type II and III was the primary limiting factor on algal growth. BOD, COD, TP and chl.a concentration in type III reservoirs showed higher concentration than those of other types, while SS and TN concentration was no noticeable difference among three types. Characteristics of type III reservoirs showed large reservoir surface and drainage area, large surface area to volume (SAV) ratio, small drainage area to reservoir area (DA/RA) ratio, relatively old age, large paddy field and upland field to drainage area ratio (Mean 17.4%) and high generation and discharge loads compared to other types of reservoirs. In type I and II reservoirs, trends of BOD, TN, TP concentration in water column, were similar to those of the discharge load of pollutants. Although type II reservoirs generally showed low phosphorus discharge loads compared to type I reservoirs, TP and chl.a concentration in water column was greater than that of type I. Characteristics of type II reservoirs showed relatively large SAV ratio and old age compared to type I reservoirs and was similar to those of type III including eutrophic reservoirs.

• Korean Journal of Veterinary Service
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• v.19 no.3
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• pp.221-226
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• 1996

IBD's antibody level and morphological change of immune organ was examined in chicken. The results were as follows ; 1. Seventy percent at 42 day and 40% at 45 day of age chickens were reacted positively by the agar gel immunodiffusion test and 42 day and 45 day of age chickens indicated 1859, 1425 by the ELISA test, respectively. 2. In 2 and 5 day young broiler chickens, the level of maternal antibody was not proper. B/B ratio showed low level, but S/B ratio and BS were normal. 3. In layer, 100% of 8 and 86 day of age chicken and 70% at 40 day of age chicken had antibody aganist IBDV. The level of antibody was high as 2293 and 3336 in 8 and 86 day of age chicken, while was low as 1186 in 40 day of age chicken. B/B ratio showed low level and S/B ratio high level, but BS was normal.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.6
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• pp.597-607
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• 2016

The goal of this study was to analyze landslide susceptibility using two different models and compare the results. For this purpose, a landslide inventory map was produced from a field survey, and the inventory was divided into two groups for training and validation, respectively. Sixteen landslide conditioning factors were considered. The relationships between landslide occurrence and landslide conditioning factors were analyzed using the FR (Frequency Ratio) and EBF (Evidential Belief Function) models. The LSI (Landslide Susceptibility Index) maps that were produced were validated using the ROC (Relative Operating Characteristics) curve and the SCAI (Seed Cell Area Index). The AUC (Area under the ROC Curve) values of the FR and EBF LSI maps were 80.6% and 79.5%, with prediction accuracies of 72.7% and 71.8%, respectively. Additionally, in the low and very low susceptibility zones, the FR LSI map had higher SCAI values compared to the EBF LSI map, as high as 0.47%p. These results indicate that both models were reasonably accurate, however that the FR LSI map had a slightly higher accuracy for landslide susceptibility mapping in the study area.

• Journal of Fashion Business
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• v.12 no.4
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• pp.114-130
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• 2008

The purpose of this study is to investigate the effect of Dot Pattern Size(0.8, 1.8, 2.5, 5, 8), color combination(W/Bk, Bk/Gr, Gr/W), Area-Ratio(Background/Dot, Dot/Background) on wearing dot-printed dresses image. Sets of stimulus and response scales(7 point semantic) were used as experimental materials. The stimuli were 30 color pictures manipulated with the combination of Dot Pattern Size, color combination, and Area-Ratio using computer simulation. The subjects were 180 female undergraduates living in Gyeongnam-do. The data was analyzed by using SPSS program. Analyzing methods were ANOVA and LSD test. Image factor of the stimulus was composed of 5 different components, visibility, chastity, attractiveness, cuteness and feminity. Among them, the visibility and chastity were important. Each dimensional image was affected by dot pattern size, color combination and Area-Ratio. In the visibility image, color combination(W/Bk is the most effective) is more influential, the larger size is effective pattern. In the cuteness and feminity image, area ratio(low-brightness dot pattern is the more effective) is more effective than color combination or dot pattern size. Even the same dot pattern size and area was recognized as different image depending on the area ratio. According to the variation of dot pattern size, color combination and area-ratio, it was investigated that the images for a dress wearer were expressed diversely, were shown differently in image dimensions, and could be produced to different images.