• Journal of the Korea Institute of Building Construction
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• v.9 no.4
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• pp.55-61
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• 2009

Recently, the number of high-rise buildings being built in Korea by major construction companies for residential and commercial use has been increasing. When constructing a high-rise building, it is necessary to apply massive amounts of concrete to form a mat foundation that can withstand the huge load of the upper structure. However, it is of increasing concern that due to limitations in terms of the amount of placing equipment, available job-sites and systems for mass concrete placement in the construction field, it is not always possible to place a great quantity of concrete simultaneously in a large-scale mat foundation, and for this reason consistency between placement lift cannot be secured. In addition, a mat foundation Is likely to crack due to the stress caused by differences inhydration heat generation time. To derive a solution for these problems, this study provides test results of a hydration heat crack reduction method by applying placement lift change and setting time control with a super retarding agent for mass concrete in a large-scale mat foundation. Mock-up specimens with different mixtures and placement liftswere prepared at the job-site of a newly-constructed high-rise building. The test results show that slump flow of concrete before and after adding the super retarding agent somewhat Increases as the target retarding time gets longer, while the air content shows no great difference. The setting time was observed to be retarded as the target retarding time gets longer. As the target retarding time gets longer, compressive strength appears to be decreased at an early stage, but as time goes by, compressive strength gets higher, and the compressive strength at 28 days becomes equal or higher to that of plain concrete without a super retarding agent. For the effect of placement lift change and super retarding agent on the reduction of hydration heat, the application of 2 and 4 placement lifts and a super retarding agent makes it possible to secure consistency and reduce temperature difference between placement lifts, while also extending the time to reach peak temperature. This implies that the possibility of thermal crack induced by hydration heat is reduced. The best results are shown in the case of applying 4 placement lifts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.5
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• pp.713-720
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• 2013

The purpose of this study was to evaluate the effectiveness of vegetable-related nutrition education for fourth grade elementary school students in Gyeongnam province. A comparative analysis of nutritional knowledge on vegetables, vegetable preferences, and vegetable intake in school foodservices were assessed between a control group and an experimental group. The control and experimental group contained 62 and 67 students, respectively, and the experimental group received nutritional education in four sessions (40 minutes each session) per week. A self-administered survey was conducted before and after this education, and 122 questionnaires (for 61 members of the experimental group and 61 members of control group) were analyzed. In the experimental group, there was a significant (p<0.001) increase in vegetable-related nutrition knowledge (form 5.02 to 6.10 out of a total score of 9), while there were no significant differences in the control group. Vegetable preference scores also significantly (p<0.001) increased (from 3.44 to 3.85 on the 5-point Likert scale) in experimental group, while there were no significant difference in control group. We also observed a significant (p<0.001) increase in vegetable intake from school foodservices (89.34% to 95.49%) in the experimental group, but there were no significant differences in the control group. In conclusion, a vegetable-related nutrition education for fourth grade elementary school students was effective at improving the nutritional knowledge of vegetables, vegetable preferences, and vegetable intake from school foodservices. Therefore, to encourage the vegetable-related right dietary habits, sustainable, and systematic nutrition education programs should be implemented for elementary students.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7524-7533
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• 2015

The purpose of this study was to investigate the effects of purple sweet potato(PSP) intake and aerobic combined exercise in obese middle school girls. Twenty-four, obese(%body fat > 30%) middle school girls composed of the purple sweet potato intake and aerobic combined exercise group(A, n=6), the aerobic combined exercise group(B, n=6), the purple sweet potato intake group(C, n=6), the control group(D, n=6). The variables of health related fitness, blood lipid profile, insulin resistance were measured in all the subjects before the start and after the end of 12 week aerobic combined exercise program(40~70%HRR, 3 times per week, 70 mins). The test data were analyzed by paired t-test and one way ANOVA, and the alpha level of p<.05 was set for all tests of significance. In the comparison within each group, %body fat[A(p<.01), C(p<.05) groups], TC[A(p<.05), B(p<.01), C(p<.01) groups] and insulin resistance[A(p<.05) group] were significantly decreased and LBM[A(p<.01), B(p<.01) groups], muscular strength[A(p<.01), B(p<.001), C(p<.05) groups], muscular endurance[A(p<.05), B(p<.001) groups], flexibility[A(p<.05), B(p<.01) groups] and cardiorespiratory endurance[A(p<.05), B(p<.001), C(p<.01) groups] were significantly increased. In the comparison between groups, A group was significantly decreased in %body fat, TC and TG than D group(p<.05). A group was significantly increased in muscular strength and cardiorespiratory endurance than C, D groups (p<.05). A group was significantly increased in muscular endurance and HDL-C than D group(p<.05). A, B groups were significantly increased in flexibility than D group(p<.05). A, B, C groups were significantly decreased in insulin resistance than D group(p<.05). In conclusion, purple sweet potato intake and aerobic combined exercise were effective in improving the health related fitness, blood lipid profile and insulin resistance in obese middle school girls.

• Restorative Dentistry and Endodontics
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• v.31 no.4
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• pp.312-322
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• 2006

The objectives of this study were to evaluate the effect of surface roughness on the surface color and translucency of the composite resins. Two composite resins (Esthet-X, Dentsply, Milford, USA and Charisma, Kulzer, Domagen, Germany) were used to investigate the surface color. Charisma was used to investigate the translucency. 40 disc samples (diameter: 8 mm, thickness: 5 mm) were made by each product to measure the surface color. Polymerized each sample's one side was treated by Sof-Lex finishing and polishing system (Group C, M, F, SF). 40 disc samples (diameter: 6 mm, thickness: 1 mm) were prepared to measure the opacity. 1 mm samples were ground one side with #600, #1000, #1500 and #2000 sandpapers. CIE $L^{*}a^{*}b^{*}$ values of each 5 mm thickness samples, and XYZ values of 1 mm thickness samples on the white and black background were measured with spectrophotometer (Spectrolino, GretagMacbeth, Regensdorf, Switzerland). Mean surface roughness (Ra) of all samples before and after surface treatment was measured using the Surface Roughness Tester SJ-301 (Mytutoyo, Tokyo, Japan). Regardless of type and shade of the composite resin, $L^{*}$ values measured in group C were higher than others (p < 0.05), and $L^{*}$ value decreased as the Ra value decreased except B3 shade of Esthet-X. But there were no significant difference in $a^{*}$ values among groups. In control group and SF, highest $b^{*}$ values were measured (p < 0.05), except B1 shade of Esthet-X. Contrast ratio decreased as the Ra value decreased (p < 0.05). With the above results, difference of surface roughness has influence on surface color and translucency of dental composite resins.

• The Korean Journal of Physiology
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• v.20 no.1
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• pp.1-7
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• 1986

It has been well documented that the peripheral autonomic nervous system plays an important role in exocrine pancreatic secretion. However, the role of the central nervous system in pancreatic function is still obscure even though the central nervous system has been known to control gastrointestinal functions through the autonomic nervous system. Since the reticular formation in the mesencephalone seems to integrate the autonomic function, the present study was undertaken to investigate a possible influence of the reticular formation upon the exocrine pancreatic secretion. Twenty·two albino rats fasted for 24 hours were anesthetized by intraperitoneal injection of urethane in a dose of 1 g/kg, The pancreatic duct was cannulated to collect pancreatic juice and bile juice was diverted to the jejunum. The gastroduodenal junction was ligated to Prevent passage of gastic juice into the duodenum. A pair of electrodes were bilaterally inserted in the reticualr formation of the mesencephalone with aid of a stereotaxic apparatus. When the volume of pancreatic juice secreted for 10 min became constant, the reticular formation was electrically stimulated for 10 min. Parameters of the electical stimulation was 1.3V, 40 Hz and 2 msec. When the pancreatic secretion returned to the level before the electrical stimulation, cervical vagotomy (11 rats) or administration of propranolol (11 rats) in a dose of 0.1 mg/kg through the jugular vein was carried out. Ten minutes after the treatment, the electrical stimulation of the reticular formation was repeated. The brain was fixed by perfusion of 10% formaline solution through the heart, and then placement of the electrode tip was examined histologically. Protein concentration and amylase activity in samples of Pancreatic secretion were measured. The electrical stimulation of the reticular formation significantly increased in volume $({\mu}l/10\;min)$, Protein output $({\mu}g/10\;min)$ and amylase output (U/10 min) in the pancreatic secretion. The stimulatroy effects were not affected by the cervical vagotomy but completely abolished by propranolol. Meantime, it was also observed that both vagotomy and propranolol significantly reduced the pancreatic secretory function. These results indicate that the reticular formation in the mesencephalone may exert a stimulatory effect upon the Pancreatic secretory function not through the vagus nerve but through the sympathetic pathway in anesthetized rats.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.304-310
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• 2017

This study was conducted over a 3-year period from 2013 to 2015 in the mid-northern inland, Cheolweon, Korea, to investigate changes in flowering date, daily mean temperature during grain filling, and yield characteristics affected by transplanting date in an early-maturing rice variety, 'Joun'. Thirty-day-old seedlings were transplanted at four different dates at 15-day interval from May 5 to June 19. Flowering dates were July 16, July 21, July 31, and August 14 when transplanting was performed on May 5, May 20, June 4, and June 19, respectively. Late transplanting resulted in higher daily mean temperature before flowering but late-transplanted rice required fewer days and lower cumulative temperature to reach flowering from transplanting. As transplanting was delayed, daily mean temperature for 40 days after flowering decreased, whereas daily sunshine hours for the same period increased, with a temperature of $24.8^{\circ}C$ and sunshine for 5.8 hours being recorded at the transplanting on May 5, and with a temperature of $21.0^{\circ}C$ and sunshine for 7.7 hours at the transplanting on June 19. With late transplanting, panicles per square meter significantly decreased, whereas spikelets per panicle showed an increasing trend. Regression analysis showed that maximum head rice yield was attained from the transplanting on May 18, for which the flowering date was July 21, and daily mean temperature for 40 days from that flowering date was $24.6^{\circ}C$. A decrease in head rice yield by 5% and 10% of the maximum was observed for rice transplanted on June 6 and June 15, which resulted in flowering dates of August 2 and August 11, respectively, and the daily mean temperatures for 40 days from flowering were 23.2 and $21.7^{\circ}C$, respectively. Therefore, in mid-northern inland, it is recommended to transplant 'Joun' on May 18 to induce flowering on July 21, when grain filling is subjected to a daily mean temperature of $24.6^{\circ}C$ during active filling stage.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.11
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• pp.783-789
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• 2011

Recently, auto-thermal thermophilic aerobic digestion (ATAD) has a great attention for destruction of wasted sludge biomass in wastewater treatment plant. Reduction of sludge concentration has been successfully achieved with pilot scale ATAD and ceramic filtration process in field condition. However, high concentration of COD, total nitrogen (TN) and total phosphorus (TP) was observed in filtrate, which should be treated before recirculation of filtrate to biological wastewater treatment plant. This study was focused on removal of nitrogen and phosphorus contained in the filtrate of ATAD, using struvite crystallization method. The effect of operational and environmental parameters (such as, N, P and Mg ion concentration and molar ratio, pH, reaction time, agitation strength, seed dosage, and reaction temperature) on the treatment of TN and TP with struvite crystallization were evaluated. Magnesium (as $MgCl_26H_2O$) and phosphorus (as $K_2HPO_4$) ions were, if necessary, added to increase nitrogen removal efficiency by the crystal formation. Average concentration of $NH_4^+-N$ and $PO_4^{3-}-P$ of the filtrate were 1716.5 mg/L and 325.5 mg/L, respectively. Relationship between removal efficiencies of nitrogen and phosphorus and molar ratios of $Mg^{2+}$ and $PO_4^{3-}-P$ to $NH_4^+-N$ was examined. Crystal formation and nitrogen removal efficiencies were significantly increased as increasing molar ratios of magnesium and phosphorus to nitrogen. As molar ratio of $Mg^{2+}:PO_4^{3-}-P:NH_4^+-N$ were maintained to 2 : 1 : 1 and 2 : 2 : 1, removal efficiencies of nitrogen and phosphorus were 71.6% and 99.9%, and 93.8% and 98.6%, respectively. However, the effect of reaction time, mixing intensity, seed dose and temperature on the struvite crystallization reaction was not significant, comparing to those of molar ratios. Settled sludge volume after struvite crystallization was observed to be reduced with increase of seed dose and to be increased at high temperature.

• Journal of Dairy Science and Biotechnology
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• v.32 no.2
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• pp.121-129
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• 2014

This study was carried out to investigate the quality characteristics of protein enriched fermented milk made with whey and soybean flour. Protein-enriched fermented milk was prepared as follows: Soybean flour was added before fermentation. No synthetic aroma was added. The fermentation starter culture was ABT-4 (Chr. Hansen). Whey protein was added after fermentation. Sensory evaluation indicated that sample containing soybean flour amount of 5% were better than other samples. The pH values and titratable acidities of stored protein-enriched fermented milk and fermented milk, respectively, were not remarkably different. Crude protein was more than 3 times higher in protein-enriched fermented milk (8.77%) than in fermented milk (2.49%). The crude fat content of protein-enriched fermented milk was not remarkably different compared to that of fermented milk. Dietary fiber was more than 2.7 times higher in protein-enriched fermented milk (1.67%) than in fermented milk (0.62%), and the free amino acid content was more than 14 times higher in protein-enriched fermented milk (37.9%) than in fermented milk (2.6%).

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.4
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• pp.280-292
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• 2017

Hail is not a frequently occurring weather event, and there are even fewer reports of hail damages to forest stands. Since the 2000s, an increase in hail incidence has been documented in Europe and the United States. In Korea, severe hails occurred in Jeollanam-do province on May 31 and in Gyeongsangbuk-do province on June 1, 2017. Hail size was ranged from 0.5 to 5.0 cm in diameter in Jeollanam-do, and from 1.5 to 3.0 cm in Gyeongsangbuk-do. This study was aimed to analyze the hail damages to forests by species and topography based on damage-categorized maps created by using drones and aerial photographs, and to analyze relationships of the damages with meteorological factors. The total damaged forest area was 1,163.1ha in Jeollanam-do, and 2,942.3ha in Gyeongsangbuk-do. Among the 'severe' damaged area 326.7ha, 91% was distributed in Jeollanam-do, and concentrated in the city of Hwasun which covers 57.2% of the total 'severe' damaged area. The most heavily damaged species was Korean red pine(Pinus densiflora S. & Z.) followed by P. rigida. Most broad-leaved trees species including oaks were recovered without any dead trees found. Liliodendron tulipifera was the most severely damaged in terms of the rate of 'severe' degree individuals which are needed to be checked whether they will die or be recovered. Cause of the death of pines was considered as the combination of physical damage caused by the hail and long-lasting drought with high air temperature that occurred before and after the hail event. No pathogens and insects were found which might have affected to tree deaths. We suggested a dieback mechanism of the pine trees damaged by hail and drought.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1407-1415
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• 2006

Japan started to colonize Korea in 1910. It's when It forced and made Chosun sign on the Treaty of Protectorate. The Chosun faithfully practiced Japan's colonial policy over Korea. Futhermore, it stopped many Koreans from an anti-Japanese movement and tried to make Koreans have a positive attitude towards Japan. For this, Japan advertised the policy called Nae-sun-il-che which meant Korea and Japan were a community together from the same root. Ultimately, it targeted on absorbing Korea within their territory. With this goal, Japan kept on practicing the policy to acculturize and brainwash Koreans, totally depending on force and pressure from 1910 to 1919. However, this policy had changed by the overall anti-Japanese movement happening on March 1st 1919. Saito, the third governor-general who was appointed laster on, made an effort to win over He favor of Koreans in a less forceful way of the cultural politics. The change of policy had been specified in diverse actions such as permitting civil mass-media bodies forming the observation groups and opening conferences. In the case of daily newspapers, Japan had permitted only the ones by the Government-General of Chosun such as Maeil-shinbo, Kyunsung-ilbo, and Seoul Press before, but then other civil newspapers In Korean stated to be released. Along His Japan formed both Korean and Japanese observation groups to promote the mutual understanding and showed off Japan's goods in the propaganda films by implementing a film department. It's because Japan totally recognized and understood the impact of films. Therefore, Japan distincitively established a film agency for the production of propaganda movies while it banned the civil film production after 1937 when Japan started the war against China and USA in row. So, only one film agency, ruled by the Government-General of Chosun, produced movies from 1942 to 1945.