• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.580-580
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• 2015

하천에서의 수문/수리적 특성은 주수로의 다양한 지형학적 형태로 나타난다. 특히 흐름과 수반된 유사량의 변화는 하천의 지형학적, 수리기하적 특성을 지배하며, 하도의 물리적 시스템을 변화시켜 동적 평형에 이르게 된다. 하천에서 하도 형성에 지배적인 역할을 하는 수리특성은 하도형성 유량으로 지배유량이며, 보통 만제유량을 사용한다. Dunne and Leopold(1978)는 만제유량을 유사의 이송, 하천의 사행, 유선형의 변화 등 하천의 일반적인 형태를 변화시키며, 주수로의 특성을 형성하는 유량으로 정의하였다. 이와 같이 수리 지형학적 특성을 반영하는 만제유량은 하천의 특성을 나타내는 중요한 요소이다. 따라서 본 연구에서는 한강 수계 20개 하천, 27개 수위 관측소의 최소 10년 이상의 실측 자료를 기반으로 다년간의 연평균 실측유량을 산정하였으며, McCandless(2003)가 제시한 지형학적 만제지표를 이용하여 추정한 만제유량과의 상관성을 분석하였다. 추정된 만제유량은 HEC-RAS model을 이용하여 만제하폭, 만제수심, 만제 시 평균유속을 산정하였다. 27개 지점의 실측유량과 만제유량의 상관성 분석결과 만제유량은 연평균 일유량의 7.7배로 나타났다. 따라서 만제유량을 7일 평균유량(1 week mean discharge)으로 정의하였으며, 수정된 7일 유량과 만제유량의 RMSE는 13.90m/s, MAPE는 9.94 %로 상관성이 매우 높게 나타났다. 또한 만제유량과 만제하폭, 만제수심, 평균유량, 구간경사와 상관성 분석결과 개별적으로의 상관성은 나타나지 않았으나, 만제하폭, 수심, 평균유량과 만제유량에 대한 회귀 분석을 실시한 결과 $R^2$는 0.911로 매우 높게 나타났으며, 구간경사를 추가하여 분석한 결과 $R^2$가 0.914로 증가하였다. 따라서 만제유량은 수리 기하학적 특성이 모두 반영된 하천 특성을 나타내는 복합적인 지표임을 확인하였다. 아울러 만제유량을 통해 추정된 연평균 유량($48{\cdot}Q_{bf}$)을 우리나라의 월간 유출량 분포 비율을 이용하여 일유량으로 배분/생성하였으며, 생성된 일유량을 통해 CCHE2D model을 이용하여 하상변동 모의를 수행하였다. 대상 구간은 병성천 최하류로부터 상류로 7 km 구간이며, 2013년 1월과 12월 측량 자료를 통한 1년간의 실제 하상 변동 자료와 2013년 실측 유량자료에 따른 하상변동모의 결과 및 만제유량에 의해 배분/생성된 일유량에 따른 하상변동 모의 결과를 비교하였다. 비교 분석 결과 7일 평균 유량으로 정의된 만제유량을 통해 배분/생성된 유량의 수치모의 결과는 실제 측량자료 및 실측유량자료에 따른 하상변동 결과와 매우 일치하는 것을 확인하였다.

• Journal of the Korea Institute of Building Construction
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• v.19 no.6
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• pp.485-494
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• 2019

This study is to evaluate the effect of admixtures such as blast-furnace slag and fly ash on adhesion in flexure and tension of polymer cement mortar(PCM) using SAE emulsion. The test specimens are prepared with five polymer-cement ratios and five admixture contents, and tested for flexural strength, adhesion in flexure, tensile strength and adhesion in tension. Based on the test results, no improvement of flexural strength and adhesion in flexure caused by admixtures in PCM can be indicated, but the tensile strength and adhesion in tension is improved due to mixing of the admixtures. In particular, the maximum of adhesion in tension of PCM with P/C 20% and BF content of 10% is 3.35MPa which is about 2.36 times higher than that of ordinary cement mortar, and 1.32 times that of PCM that does not contain any admixture. The average ratio of adhesion in tension to tensile strength of PCM was 48.7%. It is apparent that admixture contents of 5% or 10% could be proposed for improvement of tensile strength and adhesion in tension of PCM.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.329-334
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• 2011

This study was conducted to establish a freezing method of miniature pig spermatozoa. The semen 더aculated from PWG M-type miniature pig was collected by gloved-hand method. The semen was diluted with same volume extender (m-Modena B). The frozen solution used frozen solution of four different (LEY, TCG, BF-5 and m-Modena+egg yolk) for find optimal frozen solution in miniature pig sperm. The diluted semen for frozen rate assay was added to LEY solution (solution I: 11% lactose+egg yolk; solution II: solution I+glycerol+OEP), and frozen depending on freezing rate by the three different freezing methods (A: until $5^{\circ}C$ for 1 hrs, holding at $-102^{\circ}C$ for 10 min; B: until $5^{\circ}C$ for 2 hrs, holding at $-102^{\circ}C$ for 10 min; C: until $5^{\circ}C$ for 3 hrs, holding at -80 and $-102^{\circ}C$ for 10 min). Semen cooled until $5^{\circ}C$ was added with glycerol 1, 3 and 5%, and take a equilibrium time for 0, 10 and 30min. Frozen-thawed sperm were evaluated for viability, acrosomal status and morphological abnormality. The results of frozen-thawed sperm ability by frozen solution, viability was higher in LEY solution compared to other three different frozen solution. AR pattern of LEY solution were lower than other three different frozen solution. The results of freezing rate, viability was higher in B method compared to other methods (p<0.05). Acrosomal statute was intacted in A and B methods than C method. The experiment for glycerol condition was showed that sperm viability was higher in extender with 1% and 3% glycerol and equilibrium time of 0 min. The acrosome damage was lower in extender with 1% glycerol and equilibrium time of 10 min than other conditions. In conclusion, the optimal conditions for cryopreservation of miniature pig spermatozoa obtained in LEY frozen solution, cooling rate of 1~2 hrs, 1~3% glycerol concentrations and glycerol equilibrium time of 0~10 min.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.255-262
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• 2010

The purpose of this study is to provide preliminary data on chloride diffusion of lightweight aggregate concrete containing crushed stone-powder. Accordingly, the study performed experiments using concrete aggregates of Crushed Aggregate (CG), Single-sized Lightweight Aggregate (SLG), Continuous Graded Lightweight Aggregate (CLG), and using water-binder ratio of 0.4, 0.5, 0.6, and using binder of FA and BFS. The chloride diffusion coefficient is calculated according to the NT BUILD 492. Diffusion coefficient of SLG and CLG were higher than that of CG concrete, but the difference was not significant. Also, chloride diffusion coefficient data indicated that it was highly affected by water-binder ratio, and it decreased with the decrease in waterbinder ratio. The admixture substitution of FA15% was effective in decreasing the diffusion coefficient only with water-binder ratio of 0.4 while admixture substitution of FA10+BFS20% was effective with all levels of water-binder ratio. The result of study shows lightweight aggregate concrete containing crushed stone-powder has slightly higher chloride diffusion coefficient than CG concrete, but the difference is not significant such that it can be overcome by adjusting water-binder ratio and admixture substitution. In addition, the data indicate the chloride diffusion coefficient of lightweight aggregate concrete can be estimated from the strength of lightweight aggregate.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.671-679
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• 2004

The purpose of this study was to develop a practical caries activity test by fluorescence using laser, plasma light and halogen light. The subjects of study were 45 children of 7-8 years old Argon laser, plasma light and halogen light were irradiated to buccal or labial surface of all teeth. Fluorescence of initial carious lesion from teeth was observed through barrier filter and the number of teeth showing lesion was counted. Visual examination for the dDfFtT, mutans streptococci screening test and Lactobacilli colony counting were also done. Data analysis was accomplished by Axelsson's method. The result from the present study can be summarized as follows. 1. Laser, plasma light and halogen light could detect the initial carious lesions better than visual examination(p<0.05). 2. There was positive correlation between laser(r=0.42), plasma light(r=0.41), halogen light(r=0.39) and dBfFtT rate(p<0.01). 3. The specificity sensitivity and predictive value was showed highest value in laser, but was showed favorable value in plasma light and halogen light. In regard to above results, laser, plasma light and halogen light all considered to be reliable method for determining individual caries activity. And they were also considered to be practical method because it would be simple, inexpensive, and time saving method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.2
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• pp.107-115
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• 2019

The many countries are facing the shortage of natural resources, and the supply of aggregates are being exhausted. To consider this situation a variety of studies were performed for the development of alternative resources. In particular, high density filler material was used for shielding radioactive waste, large amount of natural aggregates are required in order to produce filler material. Also, in order to improve the shielding performance of filler material, it is required to increase the density of the filler material. Therefore, in this study was carried out to provide basic data for expanding the feasibility of high density industrial waste resource as aggregate in heavyweight concrete. From the test results, OPC case, concrete strength decreased by using heavyweight waste glass as fine aggregate, however, it is improved by using mineral admixture as binder. Therefore, when the heavyweight waste glass and steel slag are applied to heavyweight concrete, it is desirable to use mineral admixture, especially to use BFS than FA. Meanwhile, when the steel slag was replaced as coarse aggregate of heavyweight concrete, elasticity of modulus and radiation shielding performance can be improved owing to high density of steel slag.

• Animal Bioscience
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• v.35 no.12
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• pp.1948-1956
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• 2022

Objective: This study was conducted to evaluate the effects of selenium (Se) source and level on the physiological response, reproductive performance, serum Se level, and milk composition in gestating sows. Methods: A total of 54 multiparous sows (Yorkshire×Landrace) with average body weight (BW), backfat thickness (BF), and parity were assigned to one of five treatments with 10 or 11 sows per treatment using a 2×2 factorial arrangement with one additional treatment in a completely randomized design. Inorganic or organic Se (IS or OS) sources were added to the diet at 0.30 ppm and 0.50 ppm Se. A non-Se-fortified corn-soybean meal basal diet served as a negative control. Treatments were as follows: i) Control: corn-soybean based diet, ii) IS30: control+inorganic Se 0.30 ppm, iii) IS50: control+inorganic Se 0.50 ppm, iv) OS30: control+ organic Se ppm, and v) OS50: control+organic Se 0.50 ppm. Results: At day 21 of lactation, piglet weight and weight gain in the OS treatments were higher than those in the IS treatments (p<0.05). Meanwhile, adding 0.5 ppm Se also resulted in the same significant differences in piglet BW and weight gain (p<0.05). Colostrum and milk Se concentrations increased (p<0.05) with Se level for both Se sources but were greater when sows were fed organic Se (p<0.05). Except for 24 hours postpartum, the Se concentrations were higher when sows were fed organic Se (p<0.05). Sow serum Se content was greater as Se levels increased from 0.3 ppm to 0.5 ppm at day 110 of gestation, 24 hours postpartum and day 21 of lactation (p<0.05). The pig serum Se concentration increased as the dietary Se level increased (p<0.05) and was higher when the sow dietary Se source was organic (p<0.05). Organic Se 0.5 ppm also had the highest serum Se level at two measured points (p<0.05). Conclusion: Consequently, supplementation with organic Se or 0.5 ppm Se in a gestating diet could improve piglet performance, the Se status of sows and piglets and milk composition, but organic Se at 0.5 ppm is optimal.

• Journal of Animal Science and Technology
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• v.44 no.5
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• pp.523-530
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• 2002

Repeatabilities and Correlations among Average Daily Gain, Backfat Thickness and Lean Percent in Swine The repeatability, correlation and rank correlation coefficients among average daily gain, backfat thickness and lean percent were estimated on the basis of records tested from August 1999 to February 2000 with 695 pigs of Duroc, Landrace and Yorkshire boars and gilts tested at 2nd Korea Swine Test Station located in Ha-dong, Kyeongnam Province. The effect of the sex, breed and month of measured were estimated by the least square method. The repeatabilities were estimated from the component of variance among repeated measurements of the trait for the same animal. The results obtained are summarized as follow ; 1. The means of the major economic traits studied were 142.1 days, 173.7 days and 182.5 days for age at 1st, 2nd and 3rd measure, 57.9%, 56.2% and 55.2% for lean percent at 1st, 2nd and 3rd measure, 1.33cm, 1.61cm and 1.63cm for backfat thickness at 1st, 2nd and 3rd measure, 946.6g, 879.2g and 879.4g for average daily gain at 1st, 2nd and 3rd measure, respectively. 2. The correlation coefficients between the backfat thicknesses measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.424, 0.700 and 1.424, respectively. The correlation coefficients between the lean percent measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.493, 0.619 and 0.471, respectively. The correlation coefficients between the average daily gain measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.716, 0.861 and 0.601, respectively. 3. The rank correlation coefficients between backfat thickness measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.438, 0.693 and 0.441, respectively. The rank correlation coefficients between lean percent measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.508, 0.593 and 0.478, respectively. The rank correlation coefficients between average daily gain measured at 1st and 2nd, at 2nd and 3rd, at 1st and 3rd were 0.704, 0.834 and 0.571, respectively. 4. The estimated repeatabilities of the traits studied were 0.428 for the lean percent, 0.374 for the backfat thickness and 0.673 for the average daily gain, respectively.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.289-293
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• 2010

3-MCPD created in manufacture process was regulated in our country about soy sauce and HVP. The latest paper reported that Bound 3-MCPD is created as intermediate. Germany common risk assesment reported that Bound 3-MCPD must be reduced because Bound 3-MCPD can be created in estimation circle when this is hydrolyzed in human body, but the data about the toxity of Bound 3-MCPD is lack. Therefore, We analysis about 209 items food such as soy sauce, seasoning food and meat-eating manufactured goods using bound 3-MCPD analysis method developed recently. As result of survey, bound 3-MCPD detected in 8 items among 44 traditional sauce (0.02~0.28ppm), 8 of soup 12 items (0.01~0.96ppm), in 22 items of sauce 60 items (0.01~0.55ppm), in 16 items of meat-eating manufactured foods 30 items (0.04~0.18ppm), in 20 items of snack cookies 28 items (0.09~1.43ppm), in 8 in roasted oil foods 10 items (0.04~1.22ppm), in 6 items of peanut processed food 10 items (0.06~0.25ppm), in 1 of vegetable cream 15 items (0.05ppm). Detected level was lower than the result of monitored by other countries.

• Journal of Animal Science and Technology
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• v.61 no.3
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• pp.154-162
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• 2019

This experiment was conducted to evaluate the effect of dietary energy and crude protein (CP) levels on reproductive performance, litter performance, milk quality, and blood profiles in gestating sows. A total of 59 multiparous sows (Yorkshire ${\times}$ Landrace) with similar body weights (BW), backfat thickness (BF), and parity were assigned to one of six treatments with 9 or 10 sows per treatment using a $2{\times}3$ factorial arrangement and completely randomized design. The first factor was two levels of dietary metabolizable energy (ME) density (13.40 or 13.82 MJ/kg) and the second factor was three dietary protein levels based from 35 day in gestating phases (10.5%, 12%, and 13.5%). Backfat thickness change in lactating sows decreased linearly as CP level increased (p = 0.03). Increased energy level in the gestating sow diet tended to increase the total number of piglets born (p = 0.07), but piglet weight decreased (p = 0.02). Dietary CP level had a negative effect on colostrum quality. Casein, protein, total solid, and solids-not-fat concentrations decreased linearly and lactose level increased linearly as CP level in the gestating sow diet increased (casein%: p = 0.03; protein%: p = 0.04; lactose%: p = 0.06; total solids: p = 0.03; solid-not-fat: p = 0.03, respectively). However, improving ME by 0.42 MJ/kg had no significant effect on the chemical composition of sow colostrum. There were no significant differences in blood glucose concentration in gestating sows when sows were fed different levels of energy during gestation, but blood glucose increased at 21 day of lactation when energy increased by 0.42 MJ/kg (p = 0.04). Blood urea nitrogen concentration increased linearly when dietary CP levels increased at 110 day in gestation, 24-hours postpartum, and 21 days of lactation (linear, p < 0.05, p < 0.05, and p < 0.05, respectively), and it also increased when dietary energy increased at 110 days of gestation and 24-hours postpartum (p < 0.01, and p < 0.01, respectively). A gestating sow diet containing 13.82 MJ/kg ME and 10.5% CP can improve reproductive performance, litter performance, and colostrum quality.