• Journal of Korea Water Resources Association
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• v.48 no.12
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• pp.1065-1075
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• 2015

In the estuary where the structure such as river-mouth weir has been installed, the flow is developed very complicatedly due to river water from upstream, tide of the sea and floodgate operation. Especially, if basin outlets more than one exists in one estuary, the boundary conditions will be significantly more complex form. Saemangeum(SMG) project area in Korea is the most typical example. There are Mankyung river and Dongjin river in upstream. The water of them inflows into SMG project area. In the downstream, river flow was drained from inland to sea over the SMG sea dike through the sluice. The connecting channel was located between Mankyung and Dongjin basins. It functions not only as transportation by ship in ordinary period but also as flood sharing by sending flood flow to each other in flood period. Therefore, in order to secure the safety against flood, it is very important to understand the flood sharing capacity for connecting channel. In this study, the flood control effect was analyzed using numerical simulation. Delft3D was used to numerical simulation and simulated period was set up with neap tide, in which the maximum flood stage occurred due to poor drainage. Actually, three connecting channels were designed in land use plan of the SMG Master Plan, but they were simplified to a single channel for conciseness of analysis in this study. According to the results of numerical analysis, the water level difference between two basins was increased and the maximum flood stage at dike sluice was also upraised depending on decrease of conveyance. And the velocity induced by same water level difference was decreased when the conveyance became smaller. In certain conveyance above, there was almost no flood control effect. Therefore, if the results of this study are considered for design of connecting channel, it will be expected to draw the optimal conveyance for minimizing dredging construction cost while maximizing the flood control effect.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.783-788
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• 2005

This study was conducted to investigate the optimal CP level in growing goat kids. Forty male goats were divided into four treatment groups fed diets containing CP 12, 14, 16, and 18% of concentrate feed, and rice straw, respectively. Results are summarized as follows. Average daily gain’s(ADG) of groups fed diets with CP 14% and CP 18% were 84.0 and 83.0g/d each, which were higher than group fed diets with CP 12% grown at 69.2g of ADG(P<0.05). Daily feed intakes of concentrate and rice straw were 590g and 45g each and there was no difference found between treatments. The amounts of feed required for body weight gain(g) were similar in the range of 7.0-7.3 for groups fed diets with CP 14%, 16% or 18%. But the group fed diets with CP 12% required somewhat more feed for gain at 8.8g. Dressing percentage of groups fed diet with CP 12% was 61.7%, which was higher than groups fed diets with CP 14% or CP 18%(P<0.05) but similar to that fed diet with CP 16%. Meat percentage from goats fed diet with CP 16% was 51.7%, which were higher than goats fed diets with CP 12% or CP 14%(P<0.05). Fat deposition of CP 12% group was higher than the other groups(P<0.05). Percentage of bone weight averaged 17.0% without any difference among treatment groups. Shear force and cooking loss, which are physical properties of goat meats, were lower in CP 16% and CP 14% groups than the other two groups. Water holding capacity of goats meats from CP 16% was higher than those from CP 18% group(P<0.05). Results from panel test showed that juiciness of meats from CP 16% group was higher than those from CP 12% group(P<0.05). Meats from CP 16% also was tested to be more tender than meats from the other groups. Results from this work suggest that the optimum crude protein level in growing goat's concentrate is 14-16% and that increase above this level seems not to improve meat production.

• Journal of Animal Science and Technology
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• v.50 no.4
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• pp.527-534
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• 2008

Effects of dietary concentrate levels based on whole-crop barley silage (BS) on development and meat quality in growing Korean black goats were examined. A total of 36 male goats with similar age and BW were equally allocated to dietary four treatments in a randomized complete block design. Dietary treatments included controls(rice straw ad libitum plus 2.0% concentrate BW－1), and BS ad libitum plus three increasing levels of concentrate BW－1(2.0, 1.5 and 1.0%, respectively), expressed as BS 2.0, BS 1.5 and BS 1.0, respectively. The trial was lasted for 5 months from 14th of May to 12th of October, 2007. At the end of trial, all animals were slaughtered to analyze carcass characteristics and meat quality. Average daily gain was significantly(p<0.05) higher for BS 1.5 and BS 2.0 treatments than for controls. Daily feed intakes for controls(689.3 g) were significantly(p<0.05) higher than those of BS 1.0(585.5 g), but they were significantly(p<0.05) lower than BS 2.0(734.3 g). Carcass and meat percentages were significantly (p<0.05) higher for BS 2.0 and BS 1.5 than for control and BS 1.0 treatments. Shear force and water-holding capacity was greater(p<0.05) for BS 2.0 and BS 1.5 than other treatments. On the basis of feeding whole-crop barley silage to Korean black goats, as dietary concentrate inclusion levels increased, sensory results showed to have a better tendency. In conclusion, it was estimated that the optimal level of dietary concentrates might be 1.5% BW－1, when diets based whole-crop barley silage were fed to growing Korean black goats for their improvements of growth and meat quality.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.1
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• pp.125-132
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• 2017

The development project of Busan New Port aims to be Logistics Hub Port but there are too many things to deal with ; enlargement of harbour, interport competition, modernization of harbour loading equipment and so on. At present, 23 berths of North and South container quay are in operation and 22 berths will be constructed on west and south-side by 2020. Namely, Busan New Port will operate 45 berths in 2020. When it comes to port distripark, a large-scale of Port distripark project is underway, such as Ung-Dong district 1,2 phase, West container 1,2phase, North distripark and so on. This study is to deduce traffic system problem of Busan New Port which is caused by the development project through predicting traffic need considering the development project. According to study, there are three main problems of traffic system : 1. traffic congestion caused on main crossroad, connecting second harbour back road. 2. It has been predicted that South-North road and traffic capacity of New Port road would lack compared to traffic volume-to-be-increased. Moreover, the detour volume of traffic is caused because New Port's 1st avenue and route 2 were not connected directly. Thus, this study suggests three kinds of improvement plan for smoother traffic flow. 1st. Operate roundabout on major intersection, for example, second harbour back road, west container wharf's subway corridors(South to North), and permit only right turn on sub-intersection. 2nd. Extend New Port road(North container's port road) by utilizing side walk and median. 3rd. Install exit ramp which utilizes Route 2 connecting New Port's 1st avenue and local road 1042. The method we used to analyze the effect of improvement is Vissim of Mircro Simulation Package.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.233-239
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• 2015

This study determined the optimum extraction conditions based on five response variables (yield, total phenolics, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavanging activity, oxygen radical absorbance capacity (ORAC), and ${\beta}$-1,3-glucan content) in chaga mushroom (Inonotus obliquus) using the response surface methodology, where three independent variables (ethanol concentration, extraction temperature, and extraction time) were optimized using a central composite design. The optimum ethanol concentration, extraction temperature, and extraction time were 50% (w/w), $88.7^{\circ}C$, and 14.5 h; 9.2%, $92.7^{\circ}C$, and 14.5 h; 50.8%, $92.7^{\circ}C$, and 14.5 h; 9.2%, $92.7^{\circ}C$, and 1.5 h; and 90.8%, $92.7^{\circ}C$, and 1.5 h for yield, total phenolics, ABTS, ORAC, and ${\beta}$-1,3-glucan content, respectively. The predicted values of the response variables were compared with those of the extracts under the optimal extraction conditions to verify the models. The optimum extraction condition for the five response variables was predicted to be 81.4% ethanol at $92.7^{\circ}C$ for 14.5 h.

• Korean Journal of Medicinal Crop Science
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• v.15 no.6
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• pp.367-370
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• 2007

To make the soil moisture proper is the important factor in the seedbed cultivation of Yangjik for producing a good quality of ginseng seedling. This study was carries out to investigate the effect of soil moisture on photosynthesis and yield of ginseng seedling under the different condition of the soil moisture, such as $100{\sim}400$ mbar. Photosynthesis rate was decreased gradually by the reduction of soil moisture, and in particular it was decreased distinctly under the lower condition of soil moisture, such as $300{\sim}400$ mbar. Photosynthesis rate in air temperature of $30^{\circ}C$ was decreased more distinct than that of $25^{\circ}C$, Light saturation point of leaves was at the quantum of $600{\mu}mol/m^3/s$ at $25^{\circ}C$ while it was decreased by $300{\mu}mol/m^3/s$ at $30^{\circ}C$ according to the increase of air temperature. Respiration rate was increased by the increase of quantum, and decreased by the reduction of soil moisture. Respiration rate under the condition of high quantum was increased regardless of air temperature, but it was decreased distinctly under the condition of low soil moisture and high air temperature, such as 400 mbar at $30^{\circ}C$. There were a gradual decrease by the reduction of soil moisture in leaf length, leaf width, chlorophyll content, and water content of leaves, but heat injury ratio was increased distinctly by the reduction of it. Total root weight, root weight per plant, the yield of usable seedling were decreased by the reduction of soil moisture, and optimal content of soil moisture to produce a good quality of seedling was 63% of field capacity or 18.9% in absolute soil moisture content.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.678-686
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• 2007

Human mesenchymal stem cells(hMSC), that have been reported to be present in bone marrow, adipose tissues, dermis, muscles and peripheral blood, have the potential to differentiate along different lineages including those forming bone, cartilage, fat, muscle and neuron. Therefore, hMSC are attractive candidates for cell and gene therapy. The optimal conditions for hMSC expansion require medium supplemented with fetal bovine serum(FBS). Some forms of cell therapy will involve multiple doses, raising a concern over immunological reactions caused by medium-derived FBS proteins. Previously, we have shown that hADSC can be cultured in human serum(HS) during their isolation and expansion, and that they maintain their proliferative capacity and ability for multilineage differentiation and promote engraftment of peripheral blood-derived CD34 cells mobilized from bone marrow in NOD/SCID mice. In this study we determined whether hADSC grown in HS maintain surface markers expression similar with cells grown in FBS during culture expansion and compared gene expression profile by Affymetrix microarray. Flow cytometry analysis showed that HLA-DR, CD117, CD29 and CD44 expression in HS-cultured hADSC during culture expansion were similar with that in FBS-cultured cells. However, the gene expression profile in HS-cultured hADSC was significantly different from that in FBS-cultured cells. Therefore, these data indicated that HS-cultured hADSC should be used in vivo animal study of hADSC transplantation for direct extrapolation of preclinical data into clinical application.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.163-174
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• 2017

This study analyzed how Korean firms' recapitalization affects their capital structure decision and firm value. Recapitalization was categorized into three groups according to the influence of the debt to equity ratio: debt ratio-increasing-recapitalization(capital reduction with refund, cash dividend), debt ratio-unchanging-recapitalization (capital reduction without refund, retirement of repurchased stocks), and debt ratio-decreasing-recapitalization(exercise the rights for convertible bonds, bond with stock warrants, exchangeable bonds and stock options). This article highlights how the relationship between the firms' recapitalization and the capital structure decision driven by the change in debt to equity ratio through the recapitalization should affect the firm value. The whole recapitalization sample used for this analysis comprised 22,814 enterprises listed on the Korea Exchange that were analyzed over the 16-year period from 2000 to 2015. To summarize the results of this Panel Data Analysis, firstly, when a firm executes debt ratio-increasing-recapitalization and debt ratio-decreasing-recapitalization at the period of t-1, the debt to equity ratio, which is increased or decreased, should affect the firm's debt capacity in the same period, then, at the period of t, the firm establishes a leverage policy to readjust the debt to equity ratio the other way around. These adjustments of debt-paying-ability from the leverage policy, including the capital structure decision, finally affect the firm value. Secondly, when a firm implements the debt ratio-unchanging-recapitalization in the period of t-1, the debt to equity ratio, which is neutral, should not affect the firm's capital structure decision. But, the firm value is positively affected by the influence of that recapitalization. Conclusively, we acknowledge a firm which carries out the recapitalization balances its capital structure to the optimal level of leverage and that the capital structure decision positively affects the corporate value.

• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.198-209
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• 2021

This study evaluated the effects of the dimensional characteristics of containers on the nitrogen status of Quercus serrata, Fraxinus rhynchophylla, and Zelkova serrata in the container nursery stage. Seedlings were grown using 16 container types [four growing densities (100, 144, 196, and 256 seedlings/m²) × four cavity volumes (220, 300, 380, and 460 cm³/cavity)]. Two-way ANOVA was performed to test the differences in nitrogen concentration and seedling content among container types. Additionally, we performed multiple regression analyses to correlate container dimensions and nitrogen content. Container types had a strong influence on nitrogen concentration and the content of the seedling species, with a significant interaction effect between growing density and cavity volume. Cavity volumes were positively correlated with the nitrogen content of the three seedling species, whereas growing density negatively affected those of F. rhynchophylla. Further, nutrient vector analysis revealed that the seedling nutrient loading capacities of the three species, such as efficiency and accumulation, were altered because of the different fertilization effects by container types. The optimal ranges of container dimension by each tree species, obtained multiple regression analysis with nitrogen content, were found to be approximately 180-210 seedlings/m² and 410-460 cm³/cavity for Q. serrata, 100-120 seedlings/m² and 350-420 cm³/cavity for F. rhynchophylla, and 190-220 seedlings/m² and 380-430 cm³/cavity for Z. serrata. This study suggests that an adequate type of container will improve seedling quality with higher nutrient loading capacity production in nursery stages and increase seedling growth in plantation stages.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.21-33
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• 2021

The purpose of this study is to determine the order of priority for the use of amendments, matching the optimal amendment to the specific site in Korea. This decision-making process must prioritize the stabilization and economic efficiency of amendment for heavy metals and metalloid based on domestic site contamination scenarios. For this study, total 5 domestic heavy metal contaminated sites were selected based on different pollution scenarios and 13 amendments, which were previously studied as the soil stabilizer. Batch extraction experiments were performed to quantify the stabilization efficiency for 8 heavy metals (including As and Hg) for 5 soil samples, representing 5 different pollution scenarios. For each amendment, the analyses using XRD and XRF to identify their properties, the toxicity characteristics leaching procedure (TCLP) test, and the synthetic precipitation leaching procedure (SPLP) test were also conducted to evaluate the leaching safety in applied site. From results of batch experiments, the amendments showing > 20% extraction lowering efficiency for each heavy metal (metalloid) was selected and the top 5 ranked amendments were determined at different amount of amendment and on different extraction time conditions. For each amendment, the total number of times ranked in the top 5 was counted, prioritizing the feasible amendment for specific domestic contaminated sites in Korea. Mine drainage treatment sludge, iron oxide, calcium oxide, calcium hydroxide, calcite, iron sulfide, biochar showed high extraction decreasing efficiency for heavy metals in descending order. When the economic efficiency for these amendments was analyzed, mine drainage treatment sludge, limestone, steel making slag, calcium oxide, calcium hydroxide were determined as the priority amendment for the Korean field application in descending order.