• The Journal of Korean Society for Radiation Therapy
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• v.23 no.1
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• pp.51-58
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• 2011

Purpose: In this study, we tried to check the usefulness of two Linear Accelerators, Clinac IX and 21EX (Varian, Palo Alto, CA), which are equipped in Ajou Medical Center. From 2008 to 2010, we evaluated the error range of Absolute Dose based on the daily output, which was measured by CHECKMATE$^{TM}$ (Sun Nuclear, Melbourne, FL). Materials and Methods: For Daily Q.A, photon beams of two linear accelerators, 21EX and IX (6 MV and 10 MV, respectively) were measured daily by using CHECKMATE$^{TM}$ just before the treatment began, while the absolute dose was measured biweekly by using water phantom. We analyzed the data of measured values from the daily Q.A and the absolute dose from 2008 to 2010 for 21EX, and from 2009 to 2010 for IX. We utilized Excel 2007 (Microsoft, USA) to evaluate Average, Standard deviation and Confidence level of the data. Furthermore, in order to check the measured values of CHECKMATE$^{TM}$ and the significance of absolute dose, each error value was compared and analyzed. Results: During the observation period, the output of two equipment's absolute dose increased in process of time and in both 6 MV and 10 MV, there was a similar increasing trend. In addition, the error rate of the measured value of CHECKMATE$^{TM}$ and the value of absolute dose were under 0.34, which means that there is a similarity relationship between the two measured values. After checking that the measured value of CHECKMATE$^{TM}$ increased, We measured the absolute dose to adjust that. When the error range was close to 2~3%, the number of changing the output was four for 21EX and three for IX. Conclusion: As a result of measuring and analyzing the daily output changes for two years by using CHECKMATE$^{TM}$, we could find that there is a significance between the output which we should obey during Q.A, and the measured value of absolute dose within the error tolerance of 2~3%. Thus, the use of CHECKMATE$^{TM}$ can be positively considered for more efficient and reliable daily output verification of linear accelerator. It can also be a good standard for other medical centers to understand the trends of linear accelerator and to refer to for the correction of each output.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.278-286
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• 2019

Sesbania, an annual herb, is known for its high forage value and salt tolerance. It has merits as a forage crop that is adaptable to reclaimed land in the Republic of Korea. Therefore, we collected Sesbania genetic resources from the Republic of Korea and other countries, and conducted experiments to evaluate their potential as a forage crop in Korean climate and soil conditions. In the preliminary experiments, 15 genetic resources which were able to set seeds in Korean environment were selected out of a total of 46 collected genetic resources. Among 15 genetic resources, SL13 was the tallest and it was followed by that of SC04, SR01 and SE07. The accessions with the earliest flowering started flowering 101 days after sowing and set seed in early August. Fifteen accessions were evaluated for their salt tolerance at germination stage based on germination rate and growth of germinated seedlings at 0 mM, 150 mM and 300 mM NaCl concentrations. Five genetic resources like SC04, SL13, SS20, SS24 and SR01 were selected to be tolerant to NaCl treatment. Forage value was evaluated based on crude protein, acid detergent fiber, neutral detergent fiber and in vitro dry matter digestibility. The forage value of leaves was significantly higher than that of stems, and the forage value of the stem was slightly better than that of rice straw. The forage value of leaves of all the genetic resources was higher than grade 1 by the American Forage and Grassland Council grade. Among five selected genetic resources, the relative feed value of SC04 was the highest and it was followed by that of SS20, SL13, SS24 and SR01.

• Information Systems Review
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• v.10 no.3
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• pp.21-38
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• 2008

After the introduction stage, Korean mobile game market is approaching to the growing stage leading mobile contents market. The environment for the mobile contents business is getting better by the expansion of the 3G mobile networks and the enhancement of the mobile devices. In this research, at a content level, not a service level, market success factors of mobile games and the differences by genres and their changes over time were investigated through the analysis of the real market data of mobile games launched by a Korean mobile carrier. The most important factors for market success, especially for the genres of RPG/Tycoon/Simulation and Shooting/Action/Arcade, were found to be the 'design' factor and its effect turned to be getting stronger as time goes by after the launch. Consumers' purchase rate was actually higher for the mobile games of popular genres or in relation with socially popular subject matters. Also 'design' and 'creativity' factors which are related to the quality of contents, have gotten more important over time. One of the most interesting results was that there existed a "blue ocean" genres like Sports/Racing/Leisure which had a steady demand but not many competing games. In the analysis of the 'convenience' factor, one interesting implication for mobile game producers was that there exists a trade off between the ease of initial adoption and the steady sales of a mobile game.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3562-3569
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• 2013

The performance of concrete structure decreases with change in time and the external environment. In order to reinforce the structure, the research about new material development and application of newly developed materials are widely conducted. In the case of composite FRP, it received good attention in the academia due to its high intensity-weight ratio, excellent corrosion resistency as well as good workability. When applying at the construction field, however, the utilization of FRP did not increase as much due to lack of reliability and design standard. Current study investigated the material characteristics during the temperature change at high temperature and the structural behavior from restraint effect for GFRP reinforcing materials. Two experimental variables were set in this study: GFRP reinforcements due to tensile properties of temperature and restraint compression effects. Three concrete specimen were selected for each set temperatures. For this reason, as a variable to experiment with the effects confined compression concrete members value and tensile properties with temperature reinforcement GFRP, experiment produced three pieces each for each set temperature, the concrete specimen, which is confined in the GFRP was selected each I did. For the temperature change during the experiment, the concrete specimen were mounted in order to expose to experimental high temperature for certain period of time. For compression performance evaluation, reinforcement effect from horizontal constraint of the fiber were measured using an Universal Material Testing Machine (UTM). Finally, this study revealed that the binding characteristics of GFRP materials from temperature change decreased. Also, this study showed that the maximum compression intensity decreased as the temperature increased up to $150^{\circ}C$ in the constraints ability of the GFRP reinforcements during the horizontal constraint of concrete.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.11 no.2
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• pp.186-197
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• 2000

This study evaluated the improvement of autistic symptoms during the 4-7 year follow-up in autistic children. Fifty subjects(44 males and 6 females whose age ranged between one to 13 years) diagnosed with DSM-III-R autistic disorder were included in this study. Their autistic symptoms were assessed with DSM-III-R diagnostic criteria of autistic disorder(grouped as A, B and C which include 5, 6 and 5 items respectively). The mean of follow-up duration was 6.4${\pm}$1.1 years. Symptoms between baseline and follow-up were examined according to treatment types, age, sex, IQ and physical problems of them were identified. There were statistically significant decreases of symptom items at follow-up as a whole and A, B and C, respectively. The most symptom decrease occurred in communication and followed social interaction, and activities and interests at follow-up assessment. Symptom items that decreased more than 50% at follow-up evaluation include A1, A2, A3 and B1, B2, B3, B4, B5, and C1, C3. Groups with special education only and combined treatment of special education and seizure pharmacotherapy showed better improvement of symptoms than the group with psychiatric pharmacotherapy with special education. Age was a significant factors in the improvement of symptoms. The author concluded that some autistic children improved with aging, therefore they should be treated actively with special education, pharmacothrapy and other scientific methods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.533-541
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• 2016

Effect of polyphenols-rich cacao extract (CE) on lipid hydrolysis by pancreatic lipase was investigated by pH-stat digestion. Two types of substrate (oil vs. emulsion) prepared from soybean oil and CE were studied as types I and II. In the case of type I, addition of CE did not show retardation of lipid hydrolysis, showing that pancreatic lipase was not inhibited. Final digestibility rate (${\Phi}$ max, %) and initial rate (mM/s) of the 24-h aged control (52.31%, 0.03 mM/s) were similar to those of the CE-added sample (58.88%, 0.03 mM/s). However, in the case of typeII, the hydrolysis rates of the control and CE-added emulsion showed distinct differences as aging time increased to 43 days, showing lower digestion in the CE-added emulsion than the control. After 43 days, ${\Phi}$ max values of the control and CE-added emulsion were 92.13% and 77.68%, respectively.

• Korean Journal of Biological Psychiatry
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• v.6 no.1
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• pp.21-29
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• 1999

Traumatic Brain Injury(TBI) of any severity can result in broad and persisting biopsychosocial sequelae. Depression after TBI occur at a greater frequency than in the general population, with estimates approaching 25% to 50% for major depression, and 155 to 30% for dysthmia. Acute onset depressions are related to lesion location and may have their etiology in biological response of the injured brain, whereas delayed onset depressions may be mediated by psychosocial factors, suggesting psychological reactions as a possible mechanism. Anxious depressions are associated with right hemisphere lesions, whereas major depressions alone are associated with left dorsolateral frontal and left basal ganglia lesions. However, there is insufficient information to postulate a specific neuroanatomic model for TBI-related depression.

• Applied Biological Chemistry
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• v.44 no.3
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• pp.185-190
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• 2001

Alginate, a well-known biopolymer, is universally applied for immobilization of microbial cells. Biosorption characteristics of lead by waste biomass of immobilized A. niger beads, used in fermentation industries to produce citric acid, were studied. The immobilized A. niger beads, prepared via capillary extrusion method using calcium chloride, were applied in the removal of lead. Pb uptake was the highest in A. niger beads cells grown for 3 days with medium producing citric acid (12% sucrose, 0.5% $NH_4NO_3$, 0.1% $KH_2PO_4$, and 0.025% $MgSO_4$). Lead uptake by the immobilized A. niger beads and free A. niger mycellia beads increased sharply with time. However, while uptake by the immobilized A. niger beads continued to increase slowly, that by free A. niger mycellia beads stopped after 30 min. The optimum pH and temperature of lead uptake were found to be 6 and $35^{\circ}C$, respectively. The maximum uptake of lead was achieved with $50{\sim}100$ beads and 50 ml lead solution in a 250-ml Erlenmeyer flask, while, at over 100 beads, uptake of the lead decreased. The order of biosorption capacity for heavy metals was Pb>Cu>Cd. Pb uptake capacity of the immobilized A. niger beads treated with 0.1 M $CaCI_2$, 0.1 M NaOH, and 0.1 M KOH decreased compared to the untreated beads. On testing the desorption of Pb from the immobilized A. niger beads, re-uptake of Pb was found possible after desorption of the binding metal with 0.1 M HCI.

• Journal of Astronomy and Space Sciences
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• v.25 no.4
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• pp.435-444
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• 2008

High energy charged particles are trapped by geomagnetic field in the region named Van Allen Belt. These particles can move to low altitude along magnetic field and threaten even low altitude spacecraft. Space Radiation can cause equipment failures and on occasions can even destroy operations of satellites in orbit. Sun sensors aboard Science and Technology Satellite (STSAT-l) was designed to detect sun light with silicon solar cells which performance was degraded during satellite operation. In this study, we try to identify which particle contribute to the solar cell degradation with ground based radiation facilities. We measured the short circuit current after bombarding electrons and protons on the solar cells same as STSAT-1 sun sensors. Also we estimated particle flux on the STSAT-l orbit with analyzing NOAA POES particle data. Our result clearly shows STSAT-l solar cell degradation was caused by energetic protons which energy is about 700keV to 1.5MeV. Our result can be applied to estimate solar cell conditions of other satellites.

• The Korean Journal of Pharmacology
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• v.30 no.3
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• pp.337-342
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• 1994

It is well known that angiotensin converting enzyme inhibitors(ACEIs) increase endothelium-dependent relaxation in aortic strips of spontaneously hypertensive rats(SHR) and this increase in relaxation may be due to altered endothelial nitric oxide breakdown. But there are few studies on the effect of the angiotensin II receptor blocker on the nitric oxide-mediated relaxation. So we attempted to investigate the effect of angiotensin II receptor blocker on the nitric oxide-dependent relaxation in isolated aorta of SHR. Two week-treatment of losartan (30 mg/kg/day) increased the acetylcholine$(10^{-9}\;to\;10^{-5}\;M)$-and histamine$(10^{-8}\;to\;10^{-4}\;M)$-induced relaxation in endothelium intact strips but 90 minutes-treatment of losartan $(10^{-4}\;M)$ showed no increase in relaxation. The phenylephrine $(10^{-7}\;M)$-induced contraction, repeated every 2 hours, was diminished gradually following lipopolysaccharide (LPS)-treatment $(100\;{\mu}g/ml)$ but there was no significant difference in enalapril- and losartan-treated group compared with control group. These results suggest that activity of the endothelial constitutive NO synthase may be changed by chronic treatment of angiotensin II receptor blockers and ACEIs but angiotensin II antagonist and ACEI have no effect on the inducible NO synthase activity in the isolated aorta of SHR