• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.4
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• pp.427-434
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• 2016

The aim of this study was to compare the mechanical properties of high viscosity bulk-fill resin composites, $Filtek^{TM}$ Bulk Fill Posterior Restorative (FBF) and $Tetric^{(R)}$ N-Ceram Bulk Fill (TBF), with conventional composite ($Filtek^{TM}$ Z-350 XT, Z-350). The Vickers hardness test which indicates the degree of conversion was performed and the dye penetration test was performed to measure the microleakage which indicates polymerization shrinkage amount. To minimize experimental error, the standardized 3D-printed molds and the bovine teeth were used. Obtained data were analyzed by the Kruskal-Wallis test and Mann-Whitney test with the confidence interval of 95%. In the microhardness test within 1 hour of polymerization, lower surface of FBF and TBF showed significantly lower value than that of Z-350 (p < 0.05). But after 24 hours, the microhardness of FBF had increased and showed no significant difference with Z-350 (p > 0.05). In top and 2 mm depth surface, mean microhardness values were in the following order: Z-350 > FBF > TBF (p < 0.05). The mean microleakage value of TBF was significantly lower than others (p < 0.05). For clinical application of bulk-fill resin composites, caution for applying masticatory forces during 24 hours after polymerization is advised and further studies to decrease microleakage should be conducted.

• Korean Journal of Poultry Science
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• v.45 no.3
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• pp.167-174
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• 2018

This study examined the effects of dietary processed pine needle tree powder (PPNP) on growth performance, visceral organ parameters, ileal digestibility, blood metabolites and ileal morphology of broiler chickens for 5-week after hatch. In total, 220 1-day-old male Ross 308 broiler chicks were randomly allocated to 30 pens (seven birds per pen), and each pen was assigned to one of five dietary treatments, a diet without PPNP (control) and diets with 0.5%, 1.0%, 1.5% and 2.0% PPNP. The body weight and feed intake were measured weekly. One bird from each pen was selected randomly and gently euthanized to collect the blood, visceral organs and digesta samples on 2, 3 and 5 week of age. Birds fed 2.0% PPNP showed decreased (P<0.05) overall body weight, average daily gain and average daily feed intake compared to those fed control, 0.5 and 1.0% PPNP. The small intestine length increased (P<0.05) as the level of PPNP in the diet increased. A deeper crypt depth was observed (P<0.05) when birds fed 2.0% PPNP compared to those fed the control diet at week 2. A higher V:C ratio was observed (P<0.05) in birds fed 1.0% PPNP than in those fed other treatments at week 3. Ileal protein digestibility improved (P<0.05) when birds fed 0.5% and 1.0% PPNP compared to that in those fed the control diet at week 3. The feed conversion ratio, ileal dry matter digestibility and blood urea nitrogen and cholesterol, and gizzard and ceca weights were not affected (P>0.05) by supplementation of any levels of PPNP. These results demonstrated that inclusion of PPNP in broiler diets could be a possible factor in improving overall growth performance suggesting early gut development when 1% PPNP is supplemented.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.2
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• pp.171-181
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• 2011

Recently, many studies have been attempted to save the cost of production and to build the ocean energy power generating system. The low-reflection structure with the wall-typed curtain which has a wave power generation system of OWC is known as the most effective energy conversion system. A three-dimensional numerical model was used to understand the characteristics of velocity of flows about compressed air and to estimate the pressure acting on the low-reflection structure due to the short-period waves. The three-dimensional numerical wave flume which is the model for the immiscible two-phase flow was applied in interpretation for this. The numerical simulation showed well about the changes in velocity of compressed air and the characteristics of pressure according to the change in the wave height and depth of the curtain wall. Additionally, the results found that there was the point of the maximum velocity of the compressed air when the reflection coefficient is at its lowest point.

• Journal of Digital Convergence
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• v.18 no.11
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• pp.177-185
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• 2020

The spread of COVID-19 has caused confusion in the education field as it has led to the implementation of untact classes without preparation. The purpose of study is to find ways to effectively design and operate untact classes for tax accounting department. The survey and FGI were conducted on professors and learners. As a result, video classes through lecture shooting and PPT-based video conversion were the most utilized. Students prefer these two types most, because they can learn repeatedly regardless of time and space. The improvement measures are as follows. For video classes that reflect various characteristics of the subject, supporting for equipment and human resources is needed, and for professors, teaching support for untact classes and education on equipment manipulation is needed. Continuous Quality Improvement for untact classes should be overhauled. In the future, in-depth research is needed to various majors, this will help find ways of untact classes suitable for the characteristics of the subjects.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.2
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• pp.263-271
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• 2010

This trial was conducted to determine the effects of feeding a diet containing solid-state fermented rapeseed meal on performance, nutrient digestibility, intestinal ecology and intestinal morphology of broiler chickens. A mixed liquid culture, containing approximately 5 log cfu/ml Lactobacillus fermentum, Enterococcus faecium, Saccharomyces cerevisae and Bacillus subtilis was prepared in a 1:1:1:1 ratio. A basal substrate (BS) containing 75% rapeseed, 24% wheat bran and 1% brown sugar was mixed with the liquid culture in a ratio of 10:3. Over the 30-day fermentation, isothiocyanates were reduced from 119.6 to 14.7 mmol/kg. A total of 168, day-old male Arbor Acres broiler chicks were assigned to one of three dietary treatments including a corn-soybean meal based control diet as well as two experimental diets in which the control diet was supplemented with 10% of the BS containing unfermented rapeseed meal or 10% of the BS containing rapeseed meal subjected to solid state fermentation. There were 8 pens per treatment and 7 birds per pen. From days 19-21 and days 40-42, uncontaminated excreta were collected from each pen for digestibility determinations. In addition, digesta from the colon and ceca were collected to determine the number of lactobacilli, enterobacteria and total aerobes. The middle sections of the duodenum, jejunum, and ileum were collected for intestinal morphology. Over the entire experimental period (d 1-42), the weight gain and feed conversion of birds fed fermented rapeseed meal were superior (p<0.05) to that of birds fed nonfermented rapeseed meal and did not differ from the soybean control. On day 42, birds fed fermented rapeseed meal had higher (p<0.05) total tract apparent digestibility coefficients for dry matter, energy, and calcium than birds fed non-fermented rapeseed meal. Colon and ceca digesta from broilers fed the fermented feed had higher (p<0.05) lactobacilli counts than birds fed the control and non-fermented rapeseed meal diets on day 21 and 42. Fermentation also improved (p<0.05) villus height and the villus height:crypt depth ratio in the ileum and jejunum on day 21 and 42. The results indicate that solid-state fermentation of rapeseed meal enhanced performance and improved the intestinal morphology of broilers and may allow greater quantities of rapeseed meal to be fed to broilers potentially reducing the cost of broiler production.

• Progress in Medical Physics
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• v.16 no.4
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• pp.161-165
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• 2005

The CT number corresponds to electron density and its influence on dose calculation was studied. Five kinds of CT scanners were used to obtain Images of electron density calibration phantom (Gammex RMI 467), Then the differences between CT numbers for each scanners were ${\pm}2\%$ In homogeneous medium and $9.5\%$ in high density medium. In order to Investigate the influence of CT number to dose calculation, patients' thoracic CT images were analyzed. The maximum dose difference was $0.48\%$ for each organ. It acquired the phantom Images inserted high density material in the water phantom. Comparing the doses calculated with CT Images from each CT scanner, the maximum dose difference was $2.1\%$ in 20 cm in depth. The exact density to CT number conversion according to CT scanner is required to minimize the uncertainty of dose depends on CT number Especially the each hospital with various CT scanners has to discriminate CT numbers for each CT scanner. Moreover a periodic quality assurance is required for reproducibility of CT number.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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• pp.217-223
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• 2006

Fifty castrated crossbred ($Landrace{\times}Yorkshire$) pigs, weighing an average of $60.6{\pm}3.1kg$ were allotted to one of five treatments in a randomized block design to examine the effects of dietary inclusion of 0.1% L-carnitine (50 ppm carnitine), 0.1% selenium-enriched yeast (0.3 ppm selenium), 0.1% Jujube fruit or 0.1% Hwangto (Red clay) on pig performance and carcass quality. All diets were based on corn, wheat, soybean meal and wheat bran and were formulated to supply 13.8 MJ DE/kg. Dietary supplementation did not influence daily gain (p = 0.57), feed intake (p = 0.52), or feed conversion (p = 0.32). Digestibility of dry matter (p = 0.60), organic matter (p = 0.74), crude protein (p = 0.76), crude fibre (p = 0.70) and energy (p = 0.75) were also unaffected by inclusion of any of the additives. Tissue samples taken from the longissimus muscle showed that the levels of carnitine (p = 0.0001) and selenium (p = 0.0001) were significantly higher with dietary inclusion of carnitine or selenium-enriched yeast. Dietary treatment did not affect dressing percentage (p = 0.33), carcass lean yield (p = 0.99) or first, $10^{th}$ and last rib midline backfat depth (p = 0.45, 0.82 and 0.47, respectively). Dietary treatment also did not affect the percentages of tenderloin (p = 0.37), bacon (p = 0.36), fat and bone (p = 0.56), picnic shoulder (p = 0.25), skirt (p = 0.80), fresh ham (p = 0.31) or ribs (p = 0.79). However, pigs fed the diet containing Jujube fruit had a higher percentage of Boston butt than pigs fed the carnitine or selenium supplemented diets (p = 0.01). Pigs fed added Hwangto had a higher (p = 0.04) percentage of loin compared with pigs fed supplementary selenium or Jujube fruit. Loin muscle from pigs fed carnitine had a significantly lower Hunter colour value for L (whiteness, p = 0.004) and a higher value for $a^*$ (redness; p = 0.069). The overall results indicate that supplementation with L-carnitine and selenium-enriched yeast can produce pork containing higher levels of carnitine and selenium, which could provide health benefits for consumers of pork without detrimental effects on pig performance.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.4
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• pp.605-614
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• 2020

Objective: This study was conducted to determine the effects of stale maize on growth performance, immunity, intestinal morphology, and antioxidant capacity in broilers. Methods: A total of 800 one-day-old male Arbor Acres broilers (45.4±0.5 g) were blocked based on body weight, and then allocated randomly to 2 treatments with 20 cages per treatment and 20 broilers per cage in this 6-week experiment. Dietary treatments included a basal diet and diets with 100% of control maize replaced by stale maize. Results: The content of fat acidity value was higher (p<0.05) while the starch, activities of catalase and peroxidase were lower (p<0.05) than the control maize. Feeding stale maize diets reduced (p<0.05) average daily feed intake (ADFI) throughout the experiment, feed conversion ratio (FCR) during d 0 to 21 and the whole experiment as well as relative weight of liver, spleen, bursa of Fabricius and thymus (p<0.05) on d 21. Feeding stale maize diets decreased jejunum villus height (VH) and VH/crypt depth (CD) (p<0.05) on d 21 and 42 as well as ileum VH/CD on d 42. The levels of immunoglobulin G, acid α-naphthylacetate esterase positive ratios and lymphocyte proliferation on d 21 and 42 as well as lysozyme activity and avian influenza antibody H₅N₁ titer on d 21 decreased (p<0.05) by the stale maize. Feeding stale maize diets reduced (p<0.05) serum interferon-γ, tumor necrosis factor-α, interleukin-2 on d 21 and interleukin-6 on d 21 and 42. Broilers fed stale maize diets had lower levels of (p<0.05) total antioxidative capacity on d 42, superoxide dismutase and glutathione peroxidase on d 21 and 42, but higher (p<0.05) levels of malondialdehyde on d 21 and 42. Conclusion: Feeding 100% stale maize decreased ADFI and FCR, caused adverse effects on immunity and antioxidant function and altered intestinal morphology in broilers.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.308-308
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• 2011

하천에서 유량을 산정하기 위해서 전자파표면유속계를 이용하여 표면유속을 측정하고 수심평균유속환산계수 0.85를 일률적으로 적용하여 수심평균유속을 산정하고 있다. 이 수심평균유속환산계수 0.85의 적절성에 대한 논의가 지속되어져 왔으나 그 동안에는 이에 대한 현장검증을 할 수 있는 방법이 없었던 실정이다. 하지만 최근 들어서는 ADCP(Acoustic Doppler Current Profiler)의 하천용 Application인 StreamPro ADCP가 개발되어 이를 이용하면 홍수기에 수심별 유속을 측정할 수 있다. 다만 홍수기에 StreamPro ADCP의 적용시에는 여러 가지 높은 위험성이 상존하는 것은 인지의 사실이지만, 그 외의 별다른 방법이 없는 실정이다. 따라서 홍수기에 StreamPro ADCP를 이용하여 수심별 유속을 측정하고 이와 동시에 측정한 표면유속을 이용하여 수심평균유속환산계수를 산정하여 기존에 환산계수로 적용하고 있는 0.85의 적절성을 파악하고자 하였다. 흐름조건별 수심평균유속환산계수 산정을 위하여 평수기 용담 수자원시험유역의 동향지점에서 수심평균유속환산계수를 산정한 결과 0.632~1.352로 넓게 분포하고 있음을 파악하였다. 이렇게 계수가 실제 적용하는 0.85와는 크게 차이가 나는 이유로는 수심이 얕아서 바닥마찰의 영향이 크기 때문인 것으로 판단되었다. 이에 본 연구에서는 여러 지점에서 홍수기 수심별 유속의 실측을 통하여 수심평균유속환산계수 분포정도를 산정하고자 하였다. 대청댐 상류의 수통수위표가 위치해 있는 적벽대교지점에서 StreamPro ADCP를 이용하여 수심평균유속환산계수를 산정한 결과 0.735~0.986 사이에 분포하고 있다. 측정한 결과의 수심평균유속환산계수의 평균값은 0.853으로 기존에 수심평균유속의 산정을 위하여 적용하고 있는 0.85와 거의 일치함을 보이고 있다. 측정당시 수심이 3.6 m에 이르고 있고 유속 또한 1.55 m/s에 이르고 있어 홍수시 일반하천에서 발생하는 수위와 유속임을 감안할 때, 0.735~0.986의 수심평균유속환산계수는 홍수시 순간적인 변화의 폭이 큼을 알 수 있다. 이렇게 순간적인 변화가 큰 이유로는 난류의 성분이 강해서 나타나는 것으로 이를 평균하면 0.853으로 나타나고 있어 홍수시에 수심평균유속환산계수를 0.85를 사용하여도 무방함을 알 수 있다. 동향지점에서 홍수기에 수심별 유속의 실측을 통하여 수심평균유속환산계수를 산정하고자 하였다. 그러나 이 지점은 강한 와류로 인하여 ADCP가 심하게 흔들림으로 인하여 순간적인 유속의 차이가 최대 4배까지 보임을 알 수 있다. 이로 인하여 수심평균유속환산계수의 범위는 0.233~0.983에 이른다. 측정당시 표면유속이 2.07 m/s 인 것을 감안하여 이 표면유속에 상응하는 수심별 유속 자료만을 이용하여 산정시, 수심평균유속환산계수는 0.876이다. 하천의 하류지점에서 수심별 유속을 측정하여 수심평균유속환산계수를 산정하고자 한강하류로 유입하는 굴포천의 구교 및 박촌1교 지점에서 유속측정을 실시하였다. 이들 두 지점은 홍수기에 조차도 유속이 1 m/s 에 이르지 못하는 지점으로, 수심평균유속환산계수를 산정한 결과 각각 0.826, 0.833을 나타내고 있어, 수심평균유속환산계수 0.85가 홍수기뿐만 아니라 평 갈수기에도 적용할 수 있는 가능성을 확인하였다.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1275-1284
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• 2018

Objective: A 28-d trial was conducted to evaluate the effect of diets with different energy and lipase levels on performance, nutrient digestibility, serum profiles, gut health, and carcass quality in broilers. Methods: A total of 720 one-day-old male Ross 308 broilers ($45.4{\pm}0.5g$) were randomly assigned to one of the following four treatments: i) RET, reduced energy treatment (metabolizable energy = 2,950 and 3,100 kcal/kg for starter and finisher diet), ii) BDT, basal diet treatment (metabolizable energy = 3,050 and 3,200 kcal/kg for starter and finisher diet, iii) RET015, RET+0.15 g/kg lipase, and iv) RET03, RET+0.3 g/kg lipase. There were 10 replications (cages) per treatment with 18 birds per cage. Results: During d 1 to 14, broilers fed BDT, RET015, and RET03 diets had higher (p<0.05) body weight gain than those fed RET diet. During d 1 to 14, 15 to 28 and the overall experiment, feed conversion ratio in RET03 treatment was lower (p<0.05) compared with RET treatment. On d 14, the apparent total tract digestibility (ATTD) of dry matter (DM), ether extract (EE), and gross energy in RET03 treatment was higher (p<0.05) than those in RET treatment, while the ATTD of N was increased (p<0.05) by RET03 treatment. On d 28, broilers fed RET03 diet had higher (p<0.05) ATTD of DM than those fed RET and RET015 diets, while the ATTD of EE in BDT and RET03 treatments was increased (p<0.05) compared with RET and RET015 treatments. Broilers fed RET03 diet had higher villus height (VH) and VH:crypt depth (CD) ratio than those fed RET and BDT diets. The activity of pancreatic lipase in BDT and RET03 treatments was higher (p<0.05) than that in RET treatment. Conclusion: Taken together, lipase supplementation (3,000 U/kg feed) increased growth performance, nutrient digestibility, VH, VH:CD ratio and lipase activity, but decreased triglyceride, low-density lipoprotein cholesterol and the abdominal fat percentage in broilers fed reduced energy diet.