• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.167-167
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• 2020

Annual sediment deposition in reservoirs behind weirs poses flood risk, while its accurate prediction remains a challenge. Sediment management by hydraulic flushing is an effective method to maintain reservoir storage. In this study, an integrated approach to predict sediment inflow and sediment flushing simulation in reservoirs is presented. The annual sediment inflow prediction was carried out with Artificial Neural Networks (ANN) modelling. RESCON model was applied for quantification of sediment flushing feasibility criteria. The integrated approach was applied on Sangju Weir and also on estuary of Nakdong River (NREB). The mean annual sediment inflow predicted at Sangju Weir and NREB was 400,000 ㎥ and 170,000 ㎥, respectively. The sediment characteristics gathered were used to setup RESCON model and sediment balance ratio (SBR) and long term capacity ratio (LTCR) were used as flushing efficiency indicators. For Sangju Weir, the flushing discharge, Q_f = 140 ㎥/s with a drawdown of 5 m, and flushing duration, T_f = 10 days was necessary for efficient flushing. At NREB site, the parameters for efficient flushing were Q_f = 80 ㎥/s, T_f = 5 days, N = 1, El_f = 2.24 m. The hydraulic flushing was concluded feasible for sediment management at both Sangju Weir and NREB.

• 대한기계학회논문집B
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• 제21권7호
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• pp.948-961
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• 1997

The effects of intake port eccentricity and a partition between the two intake ports on the incylinder swirl characteristics in a 4 valve diesel engine having the two intake ports, one is a helical intake port and the other is a tangential intake port, were investigated by using the impulse swirl meter(ISM) in a steady flow test rig. Mean flow coefficient ( $C_{f(mean)}$, swirl ratio ( $R_{s}$) and the mass flowrate through the two intake ports with and without intake port partition were measured. The results showed that the characteristics of in-cylinder swirl ratio formed by a 4-valve cylinder head were largely affected by valve eccentricity ratio ( $N_{y}$) and the existence of an intake port partition between the two intake ports. Mean flow coefficient ( $C_{f(mean)}$) increases and swirl ratio ( $R_{s}$) decreases in case of being the partition between the two intake ports. And also the mass flowrate through the tangential intake port is 19.0% and 7.7% more than that of the helical intake port in case of the two intake ports with and without partition respectively.ively.

• Asian-Australasian Journal of Animal Sciences
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• 제11권2호
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• pp.185-191
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• 1998

A total of 240 weaned pigs (BW 5.4 kg) were allotted in a completely randomized block design to find out the optimum lactose : sucrose ratio for the weaned pigs. Treatments were 100:0 (A), 75:25 (B), 50:50 (C), 25:75 (D) and 0:100 (E) in lactose : sucrose ratio. For the first week after weaning, average daily gain (ADG) and feed/gain (F/G) were improved (p < 0.05) for pigs fed A, B and C diets compared to pigs fed diets D and E, but the average daily feed intakes (ADFI) of the pigs were not different. From d 7 to 14, no significant differences was found in ADG and ADFI among the treatments, but pigs fed the diets A, B and C had improved F/G compared with the pigs fed diets D and E (p < 0.05). From d 15 to 21, no significant differences were found in ADG, ADFI and F/G among the treatments. The digestibility of nutrients was not influenced by the lactose : sucrose ratio except nitrogen. Nitrogen digestibility of A diet was significantly higher than D and E diets (p < 0.05) but no significant differences were found among diets A, B and C. Dry matter and phosphorus excretions were not influenced by the treatments. The pigs fed diets A, B and C excreted significantly less nitrogen than the pigs fed diets D and E. In conclusion, the results suggest that sucrose can effectively replace up to 50% lactose in starter diets.

• 한국의류학회지
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• 제19권3호
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• pp.471-482
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• 1995

Using the acetate velvet and viscose velvet whose pile lengths were sheared as 1.45, 1.55, 1 65, 1.75, 1.85, 1.90mm under the condition equating the weaving process of ground fabric, the conclusions were as follows through the results of the sensory assessments estimated by women students in our university and the physical properties, H. V and T. H. V obtained by KES-F system. 1. In the sensory assessments estimated by the method of paired comparison and ranking of samples, the longer pile length was, the more the hand values of smoothness, softness, thickness, heaviness increased on the whole. 2. The H V. and T. H. V. measured by KES-F system were as follows; Kohi increased to pile length 1.85mm and then decreased a little at 1.90mm. hummer increased as pile length was longer. Fukurami increased to pile length 1.75mm and then decreased gradually as pile length was longer. Total hand value increased gradually from 1. 45mm to 1.85mm, had the top value at 1.85mm, and then decreased a little at 1.90mm. 3. In the results of summarizing $\ulcorner$the physical properties correlated closely with the H. V obtained by sensory assessments$\lrcorner$ and tithe Physical properties correlated closely with the H. V. and T. H. V obtained by KES-F systems, it showed that all the sensory properties correlated closely with compressive energy, flexural rigidity, thickness, weight and pile ratio in the former and that the physical properties correlated closely with each H V and T. H. V were different in the latter. 4. It showed that factor 1 was related to compressive energy, thickness, weight, pile ratio, factor 2 was related to recovery energy, compressive resilience, compressive index, and factor 3 was related to compressive recovery ratio in the result of factor analysis. 5. In the multiple repression analysis, the expressions of all sensory properties had compressive ratio, frictional coefficient in the regression expressions of $\ulcorner$H. V. obtained by sensory assessments$\lrcorner$, while the expressions of each H. V. and different physical properties in the regression expressions of $\ulcorner$H. V. obtained by KES-F system$\lrcorner$.

• Macromolecular Research
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• 제10권5호
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• pp.253-258
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• 2002

The multi-wall carbon nanotubes (MWNTs) with graphite crystal structure were synthesized by the catalytic decomposition of a ferrocene-xylene mixture in a quartz tube reactor to use as the conductive filler in the binary polymer matrix composed of poly(vinylidene fluoride) (PVdF) and poly(vinyl pyrrolidone) (PVP) for the EMI (electromagnetic interference) shielding applications. The yield of MWNTS was significantly dependent on the reaction temperature and the mole ratio of ferrocene to xylene, approaching to the maximum at 800 $^{\circ}C$ and 0.065 mole ratio. The electrical conductivity of the MWNTs-filled PVdF/PVP composite proportionally depended on the mass ratio of MWNTs to the binary polymer matrix, enhancing significantly from 0.56 to 26.7 S/cm with the raise of the mass ratio of MWNTs from 0.1 to 0.4. Based on the higher electrical conductivity and better EMI shielding effectiveness than the carbon nanofibers (CNFs)-filled coating materials, the MWNTs-filled binary polymer matrix showed a prospective possibility to apply to the EMI shielding materials. Moreover, the good adhesive strength confirmed that the binary polymer matrix could be used for improving the plastic properties of the EMI shielding materials.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.465-468
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• 2008

본 연구는 영, 호남 지역의 레미콘 공장에서 현재 사용하고 있는 잔골재의 특성을 분석하고, 혼합사용 시 잔골재율 조정에 따른 콘크리트의 특성실험을 통하여 혼합사용 시 최적조건을 분석한 것으로 그 결과를 요약하면 다음과 같다. 영, 호남에서 사용하는 골재 종류별 물성은 조립률 및 0.08mm체 통과량을 제외하고 모두 KS F 2526 및 KS F 2527의 규정에 적합한 것으로 나타났는데, 각 공장에서는 단독사용이 부적합한 골재를 2종 이상 적절한 비율로 혼합사용하고, KS규정에 적합하게 품질을 관리하고 있었다. 영, 호남 각 공장에서 단위용적질량법에 의해 산출한 잔골재율로 조정한 콘크리트의 배합은 기존의 출하배합보다 높은 유동성을 보이는 것으로 나타났는데, 이는 잔골재율 약 2% 저감에 따라 잔골재의 표면적 감소 및 공극감소에 따른 시멘트 페이스트의 유동성에 미치는 잉여수량의 상대적 증가에 기인한 것으로 분석된다. 따라서 최적 잔골재율을 적용함으로써 단위수량 감소로 인한 경제적인 콘크리트 배합과 콘크리트의 내구성을 증진시키는 효과가 있을 것이라 사료된다.

• 말소리와 음성과학
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• 제2권4호
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• pp.185-192
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• 2010

The acoustic vowel space has been used as an acoustic parameter in dysarthric speech. The aim of this work was to examine mathematical formulae for acoustic vowel space and to apply these to Korean speakers with idiopathic Parkinson's disease(IPD). Five acoustic parameters were chosen from earlier works and one new parameter was proposed, the pentagonal vowel space. The six parameters included triangular vowel space (3 area), irregular quadrilateral vowel space (4 area), irregular pentagonal vowel space (5 area), vowel articulatory index (VAI), formant centralization ratio (FCR) and F2i/F1u ratio (F2 ratio). An experimental group of 32 IPD patients(male:female=16:16) and a control group of twenty healthy people (male:female=8:12) participated in the study and repeated vowels (/a-i-u-e-o/) three times. A correlation analysis was performed among the six parameters, 2-way ANOVA was done with gender and groups as independent factors, and an independent sample t-test was conducted between the male and the female group as post hoc comparison. All parameters were highly correlated with each other and only the FCR showed a high negative correlation with the others. The results of ANOVA showed a significant difference in F2 ratio, 3 area, 4 area and 5 area between gender and in 4 area and 5 area between groups. For the male members of the two groups, significant statistical differences were found in all parameters whereas no such differences were found for the female members. These findings indicated that the vowel space of the female group was wider than the vowel space of the male group. These differences may have been caused by gender-specific speech styles rather than by patho-physiological mechanisms. We also claim that the pentagonal vowel space is better than the other vowel spaces at representing the disordered speech in natural speech situations.

• 한국산학기술학회논문지
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• 제18권2호
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• pp.226-234
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• 2017

본 논문에서는 경량기포 콘크리트에 EPS 폐기물과 난연성 EPS 폐기물 보강재를 각각 혼입해 물성 특성을 연구하였다. 물시멘트비는 50%로 고정시켰으며 단위시멘트량은 300, $400kgf/m^3$으로 설정하였다. 독립기포용 기포제를 사용하였고, 희석농도는 10%로 설정하여 혼합하였다. 혼입률은 0, 10, 20, 30, 40%로 혼입하였으며, 선 기포 방식으로 제조하였다. 상기 배합조건 별로 제작된 경량기포 콘크리트 시험체의 겉보기 밀도, 휨강도, 열전도율 및 흡수율을 측정하고 분석하였다. 실험결과, 겉보기 밀도는 단위시멘트량에 관계없이 2~3% 내외의 차이를 보였고 각각 KS F 4039 겉보기 밀도의 0.5품, 0.6품을 만족시켰다. 휨강도는 압축강도를 통해 치환하여 압축강도 기준 0.4품, 0.5품, 0.6품을 만족 시켰으며, 열전도율은 난연성 EPS 폐기물 보다 EPS 폐기물이 보강재일 경우가 3~5% 정도 높게 나왔지만 두 보강재 모두 KS F 4039 0.4품 기준을 만족하였다. 흡수율 측면에서는 EPS 폐기물과 난연성 EPS 폐기물 보강재를 혼입한 경우 1~3%정도의 차이를 보였지만 모두 20%가 넘는 높은 수치를 보여 추가적인 보강재나 배합비가 필요할 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권7호
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• pp.967-972
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• 2017

Objective: Two experiments were conducted to determine the effects of forage-to-concentrate (F:C) ratio on the nutrient digestibility and enteric methane ($CH_4$) emission in growing goats and Sika deer. Methods: Three male growing goats (body weight $[BW]=19.0{\pm}0.7kg$) and three male growing deer ($BW=19.3{\pm}1.2kg$) were respectively allotted to a $3{\times}3$ Latin square design with an adaptation period of 7 d and a data collection period of 3 d. Respiration-metabolism chambers were used for measuring the enteric $CH_4$ emission. Treatments of low (25:75), moderate (50:50), and high (73:27) F:C ratios were given to both goats and Sika deer. Results: Dry matter (DM) and organic matter (OM) digestibility decreased linearly with increasing F:C ratio in both goats and Sika deer. In both goats and Sika deer, the $CH_4$ emissions expressed as g/d, g/kg $BW^{0.75}$, % of gross energy intake, g/kg DM intake (DMI), and g/kg OM intake (OMI) decreased linearly as the F:C ratio increased, however, the $CH_4$ emissions expressed as g/kg digested DMI and OMI were not affected by the F:C ratio. Eight equations were derived for predicting the enteric $CH_4$ emission from goats and Sika deer. For goat, equation 1 was found to be of the highest accuracy: $CH_4(g/d)=3.36+4.71{\times}DMI(kg/d)-0.0036{\times}neutral$ detergent fiber concentrate (NDFC,g/kg)+$0.01563{\times}dry$ matter digestibility (DMD,g/kg)-$0.0108{\times}neutral$ detergent fiber digestibility (NDFD, g/kg). For Sika deer, equation 5 was found to be of the highest accuracy: $CH_4(g/d)=66.3+27.7{\times}DMI(kg/d)-5.91{\times}NDFC(g/kg)-7.11{\times}DMD(g/kg)+0.0809{\times}NDFD(g/kg)$. Conclusion: Digested nutrient intake could be considered when determining the $CH_4$ generation factor in goats and Sika deer. Finally, the enteric $CH_4$ prediction model for goats and Sika deer were estimated.

• 한국농공학회지
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• 제28권4호
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• pp.41-48
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• 1986

This study was fulfilled by the weighing lysimeter method at the experimental farm of KonKuk University from April to June of 1986 to investgate the amount of evapotranspiration ( ET-lettuec )by the growing periods, evapotranspiration ratio, amount of watering per one time, days of intermission and soil moisture extraction pattern of the crisphead lettuce cultivated in the clay loam soil by different watering points of pFl.7, pF2.O, pF2.7. The results obtained are summar ized as follows : 1.The total evapotranspiration(ETlettuce) of the pFl.7 treatment plot was 358,9mm., 314.9mm in the pF2.O plot and 281.8mm in the pF2.7 plot, therefore the total ETlettuec increased with the difference of 33mm-44mm by the decrease of watering point. 2.The daily maximum ETlettuce by the watering points was 7.66mm, 6:54mm, 5.98mm, respectively in the last ten days of May, and the mean daily ETlettuce during the growing season by the watering points of pFl.7, pF2.O and pF2.7 was 5.44mm(384.5g), 4.77mm(337.2g) and 4.27mm(301.8g), respectively. 3.The evapotranspiration ratio showed maximum value in the middle of May which was the beginning of mid-season stage, and the mean evapotranspiration ratio during the total growing period was 1A7, 1.29, 1.15 by the watering points. 4.The days of watering intermission by the watering points of pFl.7, pF2.O and pF2.7 was 1.0day, 2.9days and 12.Sdays, respectively. 5.The yield of the crisphead lettuce by the watering treatments showed very high significance, and the pF2.O was confirmed as a optimum watering point. 6.The soil moisture extraction pattern(SMEP) of the pF2.0 treatment plot in the initial stage was 85.6% in the 1st and 2nd soil layer and 14.4% in the 3rd and 4th layer, and in the midseason stage, the moisture extraction proportion of the under layer accounted for 34.7%which showed that the root elongated to the lowest soil layer, and there was no difference of the SMEP between the mid-season and late-season stage. 7.The correlation coefficient between the ETlettuce and yield of lettuce by the three watering points was.739, which showed the significance of 5%.