• Korean Journal of Agricultural Science
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• v.35 no.2
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• pp.137-145
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• 2008

A layer feeding trial was conducted to investigate the effects of high quality corn distiller's dried grains with solubles(DDGS) on laying performance and nutrient metabolizabilities. A total of 216 Hy-line Brown layers, 23-wk of age, were employed in a 10-wk feeding trial consisting of three dietary treatments(0%, 10%, and 20% DDGS), and six replicates per treatment. All experimental diets were prepared as iso-protein(17%) and iso-calorie(2,780 kcal/kg). At the end of the trial, the effect of DDGS on fecal ammonia emission was also estimated. The use of DDGS up to 20% in layer diets did not affect the feed intake, laying rate, egg weight, and feed conversion ratio(P>0.05). The DM metabolizability decreased significantly(P<0.05) by the DDGS supplementation(P<0.05). The NFE metabolizability decreased gradually as the level of DDGS increased(P<0.05). The fecal ammonia emission from DDGS-fed birds tended to decrease as the storage days extended. In conclusion, albeit DDGS has some unfavorable effects on DM and NFE metabolizabilities, it could be included in layer diets up to 20% level without any harmful effects on laying performance.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.216-227
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• 2004

A new cavitating model by using bubble size distribution based on bubbles-mass has been proposed. Both liquid and vapor phases are treated with Eulerian framework as a mixture containing minute cavitating bubbles. In addition vapor phase consists of various sizes of vapor bubbles, which are distributed to classes based on their mass. The bubble number-density for each class was solved by considering the change of the bubble-mass due to phase change as well as generation of new bubbles due to heterogeneous nucleation. In this method, the bubble-mass is treated as an independent variable, and the other dependent variables are solved in spatial coordinates and bubble-mass coordinate. Firstly, we employed this method to calculate bubble nucleation and growth in stationary super-heated liquid nitrogen, and bubble collapse in stationary sub-cooled one. In the case of bubble growth in super-heated liquid, bubble number-density of the smallest class based on its mass is increased due to the nucleation. These new bubbles grow with time, and the bubbles shift to larger class. Therefore void fraction of each class is increased due to the growth in the whole class. On the other hand, in the case of bubble collapse in sub-cooled liquid, the existing bubbles are contracted, and then they shift to smaller class. It finally becomes extinct at the smallest one. Secondly, the present method is applied to a cavitating flow around NACA00l5 foil. Liquid nitrogen and liquid oxygen are employed as working fluids. Cavitation number, $\sigma$, is fixed at 0.15, inlet velocities are changed at 5, 10, 20 and 50m/s. Inlet temperatures are 90K in case of liquid nitrogen, and 90K and 1l0K in case of liquid oxygen. 110K of oxygen is corresponding to the 90K of nitrogen because of the same relative temperature to the critical one, $T_{r}$=$T/T_c^{+}$. Cavitating flow around the NACA0015 foils was properly analyzed by using bubble size distribution. Finally, the method is applied to a cavitating flow in an inducer of the LE-7A hydrogen turbo-pump. This inducer has 3 spiral foils. However, for simplicity, 2D calculation was carried out in an unrolled channel at 0.9R cross-section. The channel moves against the fluid at a peripheral velocity corresponding to the inducer revolutions. Total inlet pressure, $Pt_{in}$, is set at l00KPa, because cavitation is not generated at a design point, $Pt_{in}$=260KPa. The bubbles occur upstream of the foils and collapse between them. Cavitating flow in the inducer was successfully predicted by using the bubble size distribution.

• Proceedings of the Ginseng society Conference
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• 1988.08a
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• pp.99-107
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• 1988

Samples of red ginseng. which had been manufactured and packaged by the Korea Monopoly Corporation. were stored at ambient temperatures $(12-28^{\circ}C)$ and humidities $(55-68\%)$ for one to nine years to examine their overall quality stability and. in particular. antioxidant activity. The approximate compositions. contents of various solvent extracts. and TLC and HPLC patterns of ginsenosides in the samples which are otherwise susceptible to oxidation. were stable as judged by the changes of the TLC and GLC patterns of the lipids and fatty acids. It was also found that polyunsaturated fatty acids such as linoleic (C18: 2) and linolenic acid (C18: 3) present in the samples had been very stable during the long storage periods. The intensity of the brown color of the red ginseng samples increased significantly with storage time. The pH of the aqueous extracts of the samples also increased slightly during storage. The coloration changes seem to indicate that extensive browning reactions had occurred during storage. The reducing powers of aqueous and ethanol extracts and antioxidant activity of ethyl acetate extracts also increased with storage time. The increase in reducing powers and antioxidant activity appeared to be directly attributable to the increased amounts of non-enzymatic browning reaction products formed progressively during the long storage periods. Therefore. it seems that those antioxidative compounds. which will be progressively formed in red ginseng through non-enzymatic browning reactions during the manufacturing process and long-term storage. will not only contribute to their overall quality stability but also have some significant relationship with their antiaging pharmacological effects.

• Journal of the Korea Computer Graphics Society
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• v.15 no.4
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• pp.1-11
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• 2009

In this paper, we present a prism-based mesh culling method to improve effectiveness of continuous collision detection which is a major bottleneck in a simulation using polygonal mesh models. A prism is defined based on two matching triangles between a sequence of times m a polygonal model. In order to detect potential colliding set(PCS) of prism between two polygonal models in a unit time, we apply the visibility test based on the occlusion query to two sets of prisms which are defined from two polygonal models in a unit time. Moreover, we execute the narrow band culling based on SAT(Separating Axis Test) to define potential colliding prism pairs from PCS of prisms extracted as a result of the visibility test. In the SAT, we examine one axis to be perpendicular to a plane which divides a 3D space into two half spaces to include each prism. In the experiments, we applied the proposed culling method to pairs of polygonal models with the different size and compared the number of potential colliding prism pairs with the number of all possible prism pairs of two polygonal models. We also compared effectiveness and performance of the visibility test-based method with those of the SAT-based method as the second narrow band culling. In an experiment using two models to consist of 2916 and 2731 polygons, respectively, we got potential colliding prism pairs with 99 % of culling rate.

• Journal of Biomedical Engineering Research
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• v.29 no.1
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• pp.66-72
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• 2008

The major risk associated with the use of automated power injectors is the well known complication of contrast material extravasation at the injection site. Automated injection of computed tomography (CT) contrast media can produce the compartment syndrome. The purpose of this study was to assess the ability of this device during clinically important episodes of extravasation. The extravasation detection accessory (EDA) system was composed of a strain gage, an amplifier and a computer based system. A strain gage pliable adhesive patch was applied to the skin aver the intravenous catheter and the catheter was connected to the power injector with a cable to monitor the resolution data. If the programmed monitoring, which was developed with MS Visual C++, at the extravasation occurred, then the injection was interrupted the auto injector. CT was used to demonstrate the clinically important extravasation. This study was a prospective, observational study in which the EDA system was used to monitor the automated mechanical injection of contrast material in 7 dogs. There were two true-positive cases (range of extravasation volumes: $18{\sim}22ml$), twenty three true-negative cases, three false-positive cases and no false-negative cases. The EDA system had a sensitivity of 100% and a specificity of 88% for the detection of clinically important extravasation. The EDA system had good sensitivity for the detection of clinically important extravasation and the EDA system has the clinical potential for the early detection of extravasation of the contrast medium that is administered with power injectors. The EDA system is easy to use safe and accurate for the monitoring extravasation of the intravenous injections, and this system may prove especially useful in CT applications.

• Korean Journal of Weed Science
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• v.15 no.2
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• pp.131-140
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• 1995

This experiment was conducted to test the effect on germination and seedling growth of major industrial crops and weed control potential using alfalfa plant. When dried alfalfa residues were mixed into vermiculite, germination, length of shoot and root of crops, such as Perilla frutescens, Sorghum nevosum, Platycodon grandiflorum and weeds, Digitaria saguinalis, Setaria viridis, Siegesbechia pubescens, Ammaranthus lividus, and Solanum nigrum, were significantly inhibited as the dried residue concentration increased. More than 10% concentration of the dired residue caused 80% germination and growth inhibition. The fresh alfalfa exudation also inhibited the germination and seedling growth of crop, barley, rye, alfalfa, and sesame, and weeds, Echinochloa crus-galli, Siegesbechia viridis, and Portulaca oleracea. The degree of inhibition showed the different response according to the fresh exudation concentration, types of crops and weeds. Generally, as the exudation concentration increased, the germination and seedling growth of crops and weeds inhibited. The exudation of dried residue also exhibited the strong inhibition effect on germination and seedling growth of crops, alfalfa, Platycodon grandiflorum, barley, sesame, rye and weeds, D. sanguinalis, S. pubescens, S. viridis, P. oleracea, E. crus-galli, At the 10% concentrations, S. pubescens, and P. oleracea were not germinated and showed only 15% germination in the S. viridis. From this study, would conclude that alfalfa plant contained water soluble phytotoxic substances which were inhibitory to weeds and crops. This results suggest that alfalfa had some possibility to control some weed species using toxic compounds like natural herbicide.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.528-531
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• 2011

A new spray rose cultivar 'Cherry Tea' was bred from a cross between pink spray cultivar 'Pinocchio' and yellow spray cultivar 'Flair' at the National Institute of Horticultural Research Institute. The cross was made in 2003 and 'Cherry Tea' was finally selected in 2008 after evaluating characteristics for three years from 2006 to 2008. 'Cherry Tea', a light orange spray cultivar grows vigorously and has good vase life. The major characteristics of this cultivar are $137stems/m^2/year$ in yield, 68.8 cm in length of cut flower, 5.5 cm in flower diameter, 34.0 in petal number, and 12.4 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumer's preference of this cultivar is relatively higher than that of control cultivar, 'Little Marble'.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.284-287
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• 2009

A new spray rose cultivar "Morning Star" was bred from the cross between orange spray cultivar 'Macarena' and yellow spray cultivar 'Lion Sunshine' at the National Institute of Horticultural Research Institute. The cross was made in 2002 and "Morning Star" was finally selected in 2007 after investigating characteristics for three years from 2005 to 2007. "Morning Star", a orange spray cultivar grows vigorously and has good flower shape. The major characteristics of this cultivar are 170.2 stems/$m^2$/year in yield, 57.4cm in length of cut flower, 5.5cm in flower diameter, 48.5 in petal number, and 11.4 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumer's preference of this cultivar is relatively higher than that of control cultivar, 'Sunny Lady'.

• FLOWER RESEARCH JOURNAL
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• v.16 no.3
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• pp.205-210
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• 2008

Sedum kamtschaticum has been used as one of the native valuable plants for ornamental purpose. This experiment was conducted to find out the optimum media for pot cultured Sedum kamtschaticum using peatmoss and coir-based mixtures. Four mixtures such as peatmoss:perlite(5:5, v/v), peatmoss:perlite(7:3, v/v), coir:perlite(5:5, v/v), and coir:perlite(7:3, v/v) were used. Plants were irrigated with a Sonneveld solution in an ebb & flow system. The content of T-N, K, and Ca in the peatmoss-based media was higher than those of the coir-based media. The concentration of T-N, K, and Ca in the shoots of Sedum kamtschaticum increased when plants were cultured with peatmoss-based media. In the peatmoss-based media, plant growth, such as number of branches, leaf length and shoot fresh and dry weights, were significantly increased than those of plant grown in the coir-based media. As the results, the optimum media for pot cultured Sedum kamtschaticum in an ebb & flow system was considered to be the peatmoss-based mixtures.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.461-461
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• 2016

이상기후로 인하여 제방붕괴에 대한 위험성이 높아지고 있고, 이로 인해 발생하는 제내지 내 붕괴 홍수파에 대한 연구가 증가하고 있다. 특히 홍수파 선단의 이동 속도 추정은 제내지의 위험성을 예측하고, EAP 등을 수립하는데 매우 중요한 자료가 될 수 있다. 제내지에서의 선단 홍수파에 대한 예측을 하기 위해서는 해당 지역의 하천특성, 수리특성 및 제방 등 수공구조물 특성뿐만 아니라, 제내지의 지형 및 토지이용 현황 등을 조사하여 수리실험이나 수치모의를 수행해야 하는 것이 일반적이다. 수치해석의 경우 수리실험에 비하여 경제성 및 효율성 측면에서 뛰어날 수 있으나, 제방 붕괴과정 및 메커니즘을 반영하기가 불가능하다. 이에 반해 수리모형실험의 경우 제방붕괴 양상 및 그 과정의 재현이 가능하기 때문에, 제내지에서의 선단홍수파 전파에 관한 보다 정확한 양상을 파악할 수 있을 것이다. 그러나 이러한 실험은 실제 크기의 하천이 아닌 축소모형 또는 개수로에서 수행되었기 때문에, 초기 홍수파의 전파가 축척효과(Scale effect)의 영향을 받을 가능성이 매우 크다. 특히 선단 홍수파의 경우 파가 진행되면서 수심이 낮아지고, 유속이 느려지기 때문에 그 영향은 점차 증대된다고 할 수 있다. 이에 본 연구에서는 이러한 초기 선단 홍수파의 표면장력 영향을 고려한 보정 계수 산정에 대한 연구를 수리실험을 통해 수행하였다. 연구는 크게 4가지 과정으로 구성되었다. 첫째는 농도-표면장력의 관계 규명이며, 둘째는 표면장력-홍수파 전파 속도 관계 규명이다. 셋째는 표면장력과 Weber Number(We)의 관계를 도출하는 것이며, 마지막은 We를 이용하여 한계조건을 제시하는 것이다. 실험은 계면활성제의 농도를 변화시켜가며, 얇은 유리관(D=1.0 mm)에서 물의 상승 높이 및 접촉각을 측정하여 농도와 표면장력의 관계를 측정하였으며, 이러한 결과를 바탕으로 물의 표면장력을 변화시켜 가며 $0.5(B){\times}0.3(L){\times}0.2(H)m$의 Head-tank에 설치된 수문을 빠르게 개방하여, 홍수파가 퍼지는 양상을 관측하였다. 홍수파의 이동 속도는 진행시간에 따라서 퍼짐 넓이를 측정하여 제곱근을 취하는 방식으로 평균속도를 산정하였다. 이러한 관계를 이용하여 표면장력이 없을 경우의 이동속도 및 ??를 도출하였다. 본 연구를 통해 홍수파 전파 특성에 대한 수리실험 자료를 바탕으로 Weber 수를 도출하여 표면장력의 영향을 받는지 여부를 판단할 수 있으며, 표면장력의 영향을 받을 경우, 제시된 결과를 이용하여 홍수파 선단의 속도를 보정할 수 있다. 본 연구 결과는 토대로 축소모형으로 수행되는 홍수파 전파에 대한 수리실험결과의 보정 기초자료로 매우 유용할 것으로 판단된다.