• Polymer(Korea)
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• v.37 no.5
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• pp.618-624
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• 2013

Hydroquinone bis(trimellitic anhydride) (HQ-TA) was synthesized from trimellitic anhydride chloride and hydroquinone. Poly(amic acid)s (PAAs) were synthesized by reacting a HQ-TA with six different diamines, which were cyclized to yield polyimides (PIs) containing ester linkages by chemical- and thermal-imidization methods. The various PIs were synthesized from structurally different aromatic diamines. The glass transition temperatures ($T_g$) were in the range of 167-$215^{\circ}C$, and the decomposition temperatures (${T_D}^i$) were in the range of $364-451^{\circ}C$. The maximum improvements in coefficient of thermal expansion (CTE) and barrier to oxygen permeation were observed in PIs using TFB (3.23 $ppm/^{\circ}C$) and 4,4-ODA (< $10^{-2}cc/m^2/day$), respectively. The PI films possessed a transmittance of 65-89% at 500 nm and had a yellowish color with a yellow index (YI) of 3.01-69.52.

• Progress in Medical Physics
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• v.23 no.4
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• pp.229-233
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• 2012

A small water phantom (dual-window phantom) was developed to improve the output measurement efficiency of medical linacs. This phantom is suitable for determining the quality index and output dose for high-energy photon beams. The phantom has two opposite windows and two independently rotating axes. The two axes measure the tissue phantom ratio (TPR) and the percentage depth dose (PDD) simply without requiring chamber movement by rotating the phantom around its axis. High-energy photon beams from a Co-60 irradiator and a medical linac were used to evaluate the phantom. The measured quality index is in good agreement with the reference values; the measured and reference values are within 0.2% of each other for the Co-60 gamma rays and within 1.4% for 6 and 10 MV X-rays. This phantom is more practical for routine output measurements, resulting in the prevention of potential human errors.

• Korean Journal of Community Nutrition
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• v.14 no.6
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• pp.831-845
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• 2009

Hypertension and obesity are important modifiable risk factors for cardiovascular disease, the leading cause of death in Korea. Therefore, we assessed the association between dietary pattern and obesity in hypertensive patients to formulate health promotion strategies for the older population. Dietary information was collected from hypertensive patients visiting community health education and information center by using 24 hour recall method. The 2005 DRIs for Koreans was used to evaluate the dietary adequacy. When subjects were categorized by body mass index (BMI) as normal, overweight and obese, no significant difference in energy intake was found among groups. Dietary intakes of folate, and vitamin C in obese hypertensive patients were significantly lower than in normal weight patients (p < 0.05). When we compare the nutritional status by waist circumferences, dietary intakes of zinc, vitamin A, thiamin, vitamin C and folate were significantly lower in the obese group. Vegetable intake was significantly lower in the obese group according to BMI as well as waist circumference. Energy intake from carbohydrate was significantly higher in obese hypertensive patients (p < 0.05). Obese hypertensive patients had a higher risk of nutritional inadequacy compared to normal weight patients. Our results indicated the need for developing interventions that encourage greater consumption of vegetables while cutting down salt intake with wise selection of staple foods, for obese hypertensive patients.

• Korean Journal of Community Nutrition
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• v.18 no.1
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• pp.65-76
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• 2013

The purpose of this study was to investigate the effects of a nutrition education and personalized lunch service program in a senior welfare center. A total of 30 elderly (14 males, 16 females) aged 62~89 years participated in this study. Nutrition education lessons (2 hour/lesson/week) were provided for 4 weeks. Also, ten weeks from week 3rd to week 12th, personalized lunch providing 1/3 personal needed energy was served 5 times for a week. After the nutrition intervention program, we compared anthropometric characteristics, blood biochemical characteristics, nutrition knowledge, dietary attitude and dietary intake using 24 hr recall with those before the intervention. The body weight (p < 0.001) and body mass index (BMI) (p < 0.001) were decreased. There were significant increases in score of nutrition knowledge (p < 0.01) and consumption of milk & milk products for snacks. There was a positive effect on fasting blood sugar (FBS) showing significant decreases in portion of impaired fasting glucose and diabetes mellitus (p < 0.05). Also, serum triglyceride (TG) was significantly decreased (p < 0.05). In evaluation of nutrient intake by Dietary Reference Intakes for Koreans (KDRIs), riboflavin (p < 0.01), vitamin C (p < 0.001), calcium (p < 0.05) were positively improved. The index of nutritional quality (INQ) and intakes of vitamin C (p < 0.001), riboflavin (p < 0.05), Ca (p < 0.01) and Fe (p < 0.05) were increased. In conclusion, this nutrition education and lunch service program providing 1/3 personal needed energy can be used to develop and implement a tailored nutritional intervention programs in the setting of a community senior welfare center to improve health and nutritional status of Korean elderly.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.122-129
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• 2020

To conduct probabilistic seismic fragility analysis for nuclear power plants, it is very important to define the failure modes and criteria that can represent actual serious accidents. The seismic design criteria for piping systems, however, cannot fully reflect serious accidents because they are based on plastic collapse and cannot express leakage, which is the actual limit state. Therefore, it is necessary to clearly define the limit state for reliable probabilistic seismic fragility analysis. Therefore, in this study, the limit state of the SCH80 3-inch steel pipe elbow, the vulnerable part of piping systems, was defined as leakage, and the in-plane cyclic loading test was conducted. Moreover, an attempt was made to quantify the failure criteria for the steel pipe elbow using the damage index, which was based on the dissipated energy that used the moment-deformation angle relationship.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.11
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• pp.873-879
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• 2014

In the present study, water vapor is injected at various positions in a Clean Dry Air (CDA) system such as a system inlet duct, compressor inlet, and compressor outlet by humidified air turbines. The application of evaporative cooling reduces the compression work and enhances the Energy Consumption Index (ECI) per unit volume. The main purpose of this study is to investigate the compressor power performance with different inlet air temperatures and humidity conditions. It is found that the actual power consumption and discharge flow are significantly influenced by the inlet air temperature as well as relative humidity. The results obtained during this study are compared both numerically and experimentally and are found to be in very good agreement.

• Clinical Nutrition Research
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• v.5 no.4
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• pp.279-289
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• 2016

The adequate dietary intake is important to maintain the nutritional status of the patients after pancreatic cancer surgery. This prospective study was designed to investigate the dietary intake and the nutritional status of the patients who had pancreatic cancer surgery. Thirty-one patients (15 men, 16 women) were enrolled and measured body weight, body mass index (BMI), nutritional risk index (NRI), and Malnutrition Universal Screening Tool (MUST). Actual oral intake with nutritional impact symptoms recorded on the clinical research foam at every meal and medical information were collected from electronic medical charts. The rates of malnutrition at admission were 45.1% (14/31) and 28.9% (9/31) by NRI and MUST method, respectively, but those were increased to 87% (27/31) and 86.6% (26/31) after operation on discharge. The median values of daily intake of energy, carbohydrates, fat, and protein were 588.1 kcal, 96.0 g, 11.8 g, and 27.0 g, respectively. Most patients (n = 20, 64.5%) experienced two or more symptoms such as anorexia, abdominal bloating and early satiety. There were negative correlations between C-reactive protein (CRP) levels and the intake of total energy, protein, fat, and zinc. The rates of malnutrition were increased sharply after surgery and the dietary intake also influenced the inflammatory indicators. The results suggested that need of considering special therapeutic diets for the patients who received pancreatic surgery.

• Journal of the Korean Solar Energy Society
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• v.30 no.2
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• pp.72-80
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• 2010

The main thrust of this paper is to investigate a practical way of generating the monthly averaged daily horizontal solar radiation in Korea. For estimating the horizontal solar radiation, the clearness index($K_T$) and the clearness number($C_N$) which are required for the use of Liu and Jordan's model and ASHRAE Clear Sky model were derived based on the measured weather data. Third-order polynomials returning $K_T$ and��$C_N$ for a given location were derived as a function of cloud amount, month, date, latitude and longitude. The predicted monthly averaged daily horizontal solar radiation values were compared with those acquired from the established design weather data. The MBE(Mean Bias Error) and RMSE (Root Mean Squares for Error) between the predicted values and the measured data were near zero. It means that the suggested third-order polynomials for $K_T$ and $C_N$ have good applicability to Liu and Jordan's model and ASHRAE Clear Sky model.

• Laboraroty Animal Research
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• v.34 no.4
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• pp.185-194
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• 2018

The different polymorphisms of the transcription factor 7-like 2 (TCF7L2) gene promote variances in diabetes susceptibility in humans. We investigated whether these genotypes also promote differences in diabetic susceptibility in commercial pigs. Growing pigs (Landrace, both sex, 50-60 kg) with the C/C (n=4) and T/T (n=5) TCF7L2 genotypes were identified and intravenously injected with streptozotocin (STZ, 40 mg/kg) twice in weekly intervals, then a high-energy diet was offered. Oral glucose tolerance tests, blood analyses and the homeostasis model assessment-insulin resistance (HOMA-IR) index calculations were performed. The animals were sacrificed at the end of 12 weeks of treatment to reveal the pancreas histomorphometry. The results showed that all of the treated pigs grew normally despite exhibiting hyperglycemia at two weeks after the induction. The glycemic level of the fasting or postprandial pigs gradually returned to normal. The fasting insulin concentration was significantly decreased for the T/T carriers but not for the C/C carriers, and the resulting HOMA-IR index was significantly increased for the C/C genotype, indicating that the models of insulin dependence and resistance were respectively developed by T/T and C/C carriers. The histopathological results illustrated a significant reduction in the pancreas mass and insulin active sites, which suggested increased damage. The results obtained here could not be compared with previous studies because the TCF7L2 background has not been reported. Growing pigs may be an excellent model for diabetic in children if the animals are genetically pre-selected.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.169-178
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• 2019

Now a day, we can perform various predictions by applying machine learning, which is a field of artificial intelligence; however, the finding of best algorithm in the field is always the problem. This paper predicts monthly power trading amount, monthly power trading amount of money, monthly index of production extension, final consumption of energy, and diesel for automotive using machine learning supervised algorithms. Then, we find most fit algorithm among them for each case. To do this we show the probability of predicting the value for monthly power trading amount and monthly power trading amount of money, monthly index of production extension, final consumption of energy, and diesel for automotive. Then, we try to average each predicting values. Finally, we confirm which algorithm is the most superior algorithm among them.