• The Journal of Korean Academy of Prosthodontics
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• v.50 no.1
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• pp.36-43
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• 2012

Purpose: To analyze the stress distribution of the implant and its supporting structures through 3D finite elements analysis for implants with different hexagon heights and to make the assessment of the mechanical stability and the effect of the elements. Materials and methods: Infinite elements modeling with CAD data was designed. The modeling was done as follows; an external connection type ${\phi}4.0mm{\times}11.5mm$ Osstem$^{(R)}$ USII (Osstem Co., Pusan, Korea) implant system was used, the implant was planted in the mandibular first molar region with appropriate prosthetic restoration, the hexagon (implant fixture's external connection) height of 0.0, 0.7, 1.2, and 1.5 mm were applied. ABAQUS 6.4 (ABAQUS, Inc., Providence, USA) was used to calculate the stress value. The force distribution via color distribution on each experimental group's implant fixture and titanium screw was studied based on the equivalent stress (von Mises stress). The maximum stress level of each element (crown, implant screw, implant fixture, cortical bone and cancellous bone) was compared. Results: The hexagonal height of the implant with external connection had an influence on the stress distribution of the fixture, screw and upper prosthesis and the surrounding supporting bone. As the hexagon height increased, the stress was well distributed and there was a decrease in the maximum stress value. If the height of the hexagon reached over 1.2mm, there was no significant influence on the stress distribution. Conclusion: For implants with external connections, a hexagon is vital for stress distribution. As the height of the hexagon increased, the more effective stress distribution was observed.

• Journal of The Korean Association For Science Education
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• v.31 no.8
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• pp.1158-1174
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• 2011

In this study, we examined the compositions, basic principles, and the area of the National Higher Education Entrance Examination (GaoKao) in 2009, we also analyzed the categories and characteristics of items. Also, the GaoKao was analyzed in terms of test specifications, the number of items, item patterns, difficulty levels, and implications of the College Scholastic Ability Test(CSAT) were explored. Results show Natural Science section of the National Test 1, 2 are 300 points per 150 min, and Natural Science, and Chemistry of Shanghai is 150 points each per 120 min. Also, the GaoKao contained multiple choice and fill in the blanks questions, and the description items are composed of experiments of various types. The GaoKao Natural Science section is composed of physics, chemistry, biology but not earth science, which is different from the CSAT. GaoKao requires basic understanding or the observation ability to reasoning, the complex thinking ability, especially emphasized on the experiment ability. The range of possible questions is in the examination outline, not the curriculum, and the ratio of questions from the University level is high. In the analysis of the behavioral domain, the ratios of the understanding and application items is higher than the CSAT, and inquiry items is lower, but the inquiry items are deeper. In case of the ratio of the expected correct answer, National Test 1 and National Test 2 is similar, but the difficult items or about 20~39% of the test is 4~5 times to that of the CSAT, making the GaoKao very difficult. The peculiar characteristics of GaoKao is the emphasis on the experiment, and even though the practical items is of lower ratio, they are very useful in life.

• The korean journal of orthodontics
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• v.36 no.2 s.115
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• pp.125-135
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• 2006

The purpose of this study was to measure and compare the level of frictional resistance generated from three currently used ceramic brackets; 1, Crystaline $V^{(R)}$, Tomy International Inc., Tokyo, Japan; 2, $Clarity^{(R)}$, 3M Unitek, Monrovia, CA, USA; 3, $Inspire^{(R)}$, Ormco, Orange, CA, USA; with composite resin brackets, Spirit, Ormco, Orange, CA, USA; and conventional stainless steel brackets, Kosaka, Tomy International Inc., Tokyo, Japan used as controls. In this experiment, the resistance to sliding was studied as a function of four angulations $(0^{\circ},\;5^{\circ},\;10^{\circ}\;and\;15^{\circ})$ using 2 different orthodontic wire alloys: stainless steel (stainless steel, SDS Ormco, Orange, CA, USA), and beta-titanium (TMA, SDS Ormco, Orange, CA, USA). After mounting the 22 mil brackets to the fixture and $.019{\times}.025$ wires ligated with elastic ligatures, the arch wires were slid through the brackets at 5mm/min in the dry state at $34^{\circ}C$. Silica-insert ceramic brackets generated a significantly lower frictional force than did other ceramic brackets, similar to that of stainless steel brackets. Beta-titanium archwires had higher frictional resistance than did stainless steel, and all the brackets showed higher static and kinetic frictional force as the angulation increased. When the angulation exceeded $5^{\circ}$, the active configuration emerged and frictional force quickly increased by 2.5 to 4.5-fold. The order of frictional force of the different wire-bracket couples transposed as the angle increased. The silica-insert ceramic bracket is a valuable alternative to conventional stainless steel brackets for patients with esthetic demands.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1830-1837
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• 2016

In this research, the perception and foodservice quality satisfaction of free school meals were surveyed by elementary school students in Busan. The survey was conducted on 600 elementary students of 4~6th graders. The total score for perception of free school meals was 4.47/5.00 points. Sixth graders showed a statistically significant higher score than fourth graders (P<0.01). The overall score for satisfaction of free school meals was 4.55 points. In terms of grade, sixth graders showed a statistically significant higher score than fifth graders (P<0.05). For satisfaction of foodservice quality, average score was 4.55 points. In terms of lower-level categories, areas of food, menu, sanitation, service, and environment yielded 4.47, 4.62, 4.62, 4.53, and 4.48 points, respectively. In terms of differences by grade, sixth graders showed a statistically significant higher average score for satisfaction of foodservice quality than fourth and fifth graders (P<0.01). The overall score for perception of free school meals and overall satisfaction of foodservice quality showed a statistically significant positive correlation (P<0.01, r=0.781). In each category of foodservice quality, areas of food (r=0.733), menu (r=0.677), sanitation (r=0.636), service (r=0.673), and environment (r=0.588) showed statistically significant positive correlations (P<0.01).

• Applied Microscopy
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• v.39 no.2
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• pp.133-139
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• 2009

A officinal mushroom, Phellinus linteus (PL) has been known to exhibit potent biological activities including antioxidative and anticancer effect. PL is consumed as a type of powder or extract for the purpose of health promotion and disease treatment. Recently superfine PL products was commercialized according to the development of pulverizing technology such as nanomill, so the evaluation of food safety is suggested. This study was conducted to evaluate the food safety of superfine PL (SPL) through hematological, biochemical and histological examination in mice as compared with fine PL (FPL). In the particle size distribution in volume after nanomill processing, the mean diameter of SPL and FPL particles was 11.78 ${\mu}m$ and 216.1 ${\mu}m$, and d (0.5), the particle diameter measured at 50% of distribution was 5.5 ${\mu}m$ and 147.9 ${\mu}m$, respectively. As the result of body weight, food intake and the weight of organs, SPL group didn't show any statistical difference compared with FPL group and normal group (N). Hematological and biochemical values were also involved in the normal range, although ALT (N vs. FPL, P<0.001) and BUN (N vs. FPL, P<0.01; N vs. SPL, P<0.01) showed significance compared with N group but there are no significance between FPL and SPL group. In the result of histological examination with liver, kidney, spleen, and small and large intestine, abnormal findings such as inflammatory reaction and histological changes were not observed. Our results suggest that the oral intake of SPL diet is not harmful to the animal in the hematological, biochemical and histological aspects although particle size was reduced to the level of superfine. However, further study will be necessary to confirm the histological safety in relation to the gastrointestinal contact of superfine particles in the case of large amount and long-term intake.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.420-432
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• 2011

Population dynamics of greenhouse whitefly, Trialeurodes vaporariorum (Westwood), were modeled and simulated to compare the temperature effects of air and tomato leaf inside greenhouse using DYMEX model simulator (pre-programed module based simulation program developed by CSIRO, Australia). The DYMEX model simulator consisted of temperature dependent development and oviposition modules. The normalized cumulative frequency distributions of the developmental period for immature and oviposition frequency rate and survival rate for adult of greenhouse whitefly were fitted to two-parameter Weibull function. Leaf temperature on reversed side of cherry tomato leafs (Lycopersicon esculentum cv. Koko) was monitored according to three tomato plant positions (top, > 1.6 m above the ground level; middle, 0.9 - 1.2 m; bottom, 0.3 - 0.5 m) using an infrared temperature gun. Air temperature was monitored at same three positions using a Hobo self-contained temperature logger. The leaf temperatures from three plant positions were described as a function of the air temperatures with 3-parameter exponential and sigmoidal models. Data sets of observed air temperature and predicted leaf temperatures were prepared, and incorporated into the DYMEX simulator to compare the effects of air and leaf temperature on population dynamics of greenhouse whitefly. The number of greenhouse whitefly immatures was counted by visual inspection in three tomato plant positions to verify the performance of DYMEX simulation in cherry tomato greenhouse where air and leaf temperatures were monitored. The egg stage of greenhouse whitefly was not counted due to its small size. A significant positive correlation between the observed and the predicted numbers of immature and adults were found when the leaf temperatures were incorporated into DYMEX simulation, but no significant correlation was observed with the air temperatures. This study demonstrated that the population dynamics of greenhouse whitefly was affected greatly by the leaf temperatures, rather than air temperatures, and thus the leaf surface temperature should be considered for management of greenhouse whitefly in cherry tomato grown in greenhouses.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.474-481
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• 2011

Potato late blight caused by the fungus Phytophthora infestans is one of the most vital diseases damaging the potato plant. It is for this reason that breeding potato cultivars resistant to late blight is now becoming a major concern around the world. The B3C1 clones has been introduced by the Highland Agriculture Research Center, RDA. The clones which came from International Potato Center in 2005 have a durable resistance to late blight. The clones were bred under a short-day condition in Peru. However, there was still no report on the adaptability of these clones to the long-day condition in Korea. Therefore, this study was conducted to evaluate the late blight resistance and major agronomic characteristics of B3C1 clones under Korea's long-day condition. This study was also done to generate genetic resources for developing new varieties resistant to late blight. In this study it was found out that in naturally infested field with P. infestans, AUDPC (area under disease progress curve) values of all B3C1 clones were significantly lower than those of the control varieties, 'Superior', 'Atlantic', and 'Haryeong'. It was found out that B3C1 clones had a high level of resistance to late blight and that they could be used as genetic resources to breed potato varieties with late blight resistance. However, several undesirable characteristics such as extremely late maturity, excessive growth of stems and stolons, and production of tubers that cannot easily be removed from the stolons were also observed. Among the twenty B3C1 clones, two clones, LB-8 (CIP393077.159) and LB-11 (CIP393371.159), were selected for cultivating at the highland area of Korea. Two B3C1 clones were crossed with Korean breeding lines and clonal selection for the progenies is still in progress.

• Journal of Animal Science and Technology
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• v.46 no.3
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• pp.469-478
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• 2004

Pig slurry, urine and fermented liquid manure were evaluated measuring electrical conductivity (EC), dry matter (DM) contents and other components. Samples were collected during a period from February to April, 2001: slurry samples from 70 storage tanks, urine samples from 19 and 20 fermented liquid manure samples from 109 pig farms in Jeju. Samples were analyzed for pH, EC, DM, $NH_4$-N, K, P, Ca, Mg, Na, BOD, S-S, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn and OM. Relationships between EC or DM and various mineral and $NH_4$-N contents were examined using linear regression. EC, DM, all mineral contents and $NH_4$-N were higher in slurry samples than in urine or fermented liquid manure. EC, $NH_4$-N, Ca, Mg and Na concentration was similar in urine and fermented liquid manure, but K and DM values in liquid manure were twice as much as in urine. P concentration was higher in urine than in liquid manure. $NH_4$-N and Na in slurry, $NH_4$-N in urine and $NH_4$-N, P and Ca in fermented liquid manure were highly correlated with EC, while $NH_4$-N, P, Ca and Mg in slurry, $NH_4$-N and Ca in urine, and K, P, Ca, Mg, and Na in fermented liquid manure with DM (P<0.05). BOO in slurry (22,520 mg/mL) was higher than that in urine (4,763) and fermented liquid manure (2,701). Results indicated that slurry is a better fertilizer source than urine or fermented liquid manure. However, slurry may pollute soil more than urine or fermented liquid manure when applied to land, although the levels are not above the permit.

• Food Science of Animal Resources
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• v.24 no.2
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• pp.135-145
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• 2004

The CLA used to add in diet was chemically synthesized by alkaline isomerization method with corn oil. Pigs were divided into 5 treatment groups (4 pigs/group) and subjected to one of five treatment diets (0, 1.25％ CLA for 2weeks, 2.5％ CLA for 2weeks, 1.25％ CLA for 4weeks and 2.5％ CLA for 4weeks, CLA diets; total fed diets) before slaughter. Pork loin were collected from the animals (110kg body weight) slaughtering at the commercial slaughter house. Manufacture press ham using CLA accumulated pork loin were vacuum packaged and then stored during 1, 7, 14, 21 and 28 days at 4$^{\circ}C$. Samples were analyzed for texture characteristics, sensory evaluation, fatty acid composition and CLA content. There was no significant difference in texture among control and CLA treatment groups. It was not clearly changed by storage time. No remarkable differences were found in sensory properties (color, flavor, texture and acceptability) between control and CLA treatment groups. It was not clearly changed by the passage of storage time. In the change of fatty acid composition, the contents of oleic, linoleic and arachidonic were decreased by dietary CLA-supplementation, whereas the increase level of CLA-supplementation resulted in the higher palmitic and stearic acid than control. As dietary CLA was increased in feed, the content of CLA in pork was increased.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.2
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• pp.48-56
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• 2014

Purpose $^{99m}Tc$-DTPA renal scintigraphy serves as a key indicator to measure a kidney donor's Glomerular Filtration Rate (GFR) and determine the possibility of kidney transplant. The Gates method utilized to measure GFR considers 3 variables of renal depth, injection dose, and net kidney counts. In this research, we seek to compare changes in kidney donors' GFR according to renal depth measurement methods of the 3 variables. Materials and Methods We investigated 32 kidney donors who had visited the hospital from October, 2013 to March, 2014 and received abdominal CT and $^{99m}Tc$-DTPA GFR examination. With the cross-section image of the CT and the lateral image from a gamma camera, we measured the renal depth and compared with renal depth calculation equations-Tonnesen, Taylor, and Itoh methods. Renal depth-specific GFR was calculated by using Xeleris Ver. 2.1220 of GE. Then the results were compared with MDRD (Modification of Diet Renal Disease) GFRs based on serum creatinine level. Results The renal depths measured based on the CT and gamma camera images showed high correlation. Tonessen equation gave the lowest GFR value while the value calculated by using the renal depth of CT image was the highest with a 16.62% gap. MDRD GFR showed no statistically significant difference among values calculated through Taylor, Itoh, CT and gamma camera renal depth application (P>0.05), but exhibited a statistically significant change in the value based on Tonnesen equation (P<0.05). Conclusion This research has found that, in GFR evaluation in kidney donors by utilizing $^{99m}Tc$-DTPA, Tonnesen equation-based Gates method underestimated the value than the MDRD GFR. Therefore, if a MDRD GFR value shows a huge difference from the actual examination value, using an image-based renal depth measurement, instead of Tonnesen equation applied to Gates method, is expected to give an accurate GFR value to kidney donors.