• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.904-910
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• 2013

The aim of this study was to investigate the eating behavior and nutritional status of subjects according to their purpose of exercise. A total of 214 subjects, 20 to 30 years of age, who visited fitness centers in Seoul were enrolled. Anthropometrics, exercise habits, nutritional knowledge, and eating behaviors were analyzed using a questionnaire. Nutritional status was assessed by serial 24 h recalls. The subjects were divided into two groups based on their purpose of exercise: increasing muscle (Muscle growth, n=107) or losing body weight (Weight loss, n=107). The Muscle growth group contained a higher percentage of men, whereas the Weight loss group contained a higher percentage of women. The Muscle growth group showed significantly higher scores of nutritional knowledge and eating behaviors compared to the Weight loss group. The Muscle growth group also had a significantly higher intake of energy and protein compared to the Weight loss group. In fact, the intake of energy in the Weight loss group was lower than the estimated energy requirement (EER) for both men and women subjects. The intake of protein in the Muscle growth group was twice as much as the recommended nutrient intake (RNI). The intake of calcium in both groups was less than the RNI. In conclusion, those who exercised with the aim of increasing muscle took excess dietary protein and those who exercised with the aim of weight loss had a lower energy intake than the EER.

• Progress in Medical Physics
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• v.11 no.1
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• pp.19-27
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• 2000

In order to predict the propagation of road traffic noise over level terrain, this paper presents the model of the simple monopole and dipole source. Excess attenuations by ground acoustic impedance with continuity are investigated by outdoor experiments. In this results, the propagation of road traffic noise is affected by the acoustic impedance properties of the ground surface over which the noise travels, particularly when the receiver position is close to the surface. These results are then used to derive sound pressure level contours for the attenuation with distance of the equivalent energy level received from passing vehicle. The percentage of deep sleep and the number of wakings are studied for continuous traffic noise. The hearing loss and sensitivity threshold shift is investigated by changing the various parameters such as the effects of aging and noise exposure. Evaluation of the response of human to traffic noise is discribed. It is shown that exposure to excessive noise can cause temporary loss of hearing that may become permanent if the exposure is prolonged or intense.

• Toxicological Research
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• v.31 no.4
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• pp.347-354
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• 2015

Excess manganese (Mn) is neurotoxic. Increased manganese stores in the brain are associated with a number of behavioral problems, including motor dysfunction, memory loss and psychiatric disorders. We previously showed that the transport and neurotoxicity of manganese after intranasal instillation of the metal are altered in Hfe-deficient mice, a mouse model of the iron overload disorder hereditary hemochromatosis (HH). However, it is not fully understood whether loss of Hfe function modifies Mn neurotoxicity after ingestion. To investigate the role of Hfe in oral Mn toxicity, we exposed Hfe-knockout ($Hfe^{-/-}$) and their control wild-type ($Hfe^{+/+}$) mice to $MnCl_2$ in drinking water (5 mg/mL) for 5 weeks. Motor coordination and spatial memory capacity were determined by the rotarod test and the Barnes maze test, respectively. Brain and liver metal levels were analyzed by inductively coupled plasma mass spectrometry. Compared with the water-drinking group, mice drinking Mn significantly increased Mn concentrations in the liver and brain of both genotypes. Mn exposure decreased iron levels in the liver, but not in the brain. Neither Mn nor Hfe deficiency altered tissue concentrations of copper or zinc. The rotarod test showed that Mn exposure decreased motor skills in $Hfe^{+/+}$ mice, but not in $Hfe^{-/-}$ mice (p = 0.023). In the Barns maze test, latency to find the target hole was not altered in Mn-exposed $Hfe^{+/+}$ compared with water-drinking $Hfe^{+/+}$ mice. However, Mn-exposed $Hfe^{-/-}$ mice spent more time to find the target hole than Mn-drinking $Hfe^{+/+}$ mice (p = 0.028). These data indicate that loss of Hfe function impairs spatial memory upon Mn exposure in drinking water. Our results suggest that individuals with hemochromatosis could be more vulnerable to memory deficits induced by Mn ingestion from our environment. The pathophysiological role of HFE in manganese neurotoxicity should be carefully examined in patients with HFE-associated hemochromatosis and other iron overload disorders.

• Korean Journal of Metals and Materials
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• v.50 no.4
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• pp.285-292
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• 2012

Hot ductility behavior of precipitation-hardened low-carbon iron alloys containing 0.02 wt% Ti and 0.05 wt% Nb was characterized by a hot tensile stress test. Carbon (0.05, 0.1, 0.25 wt%) and boron (0.002 wt%) contents were varied to study the effect of precipitates on the high-temperature embrittlement of the alloys in the temperature range of $600{\sim}800^{\circ}C$. Ductility loss was observed at $700^{\circ}C$ for the tested alloys. The cause of the ductility loss was mainly attributed to the carbides and ferrite films formed at the grain boundaries during deformation. Although the carbon content tended to raise the total fraction of Nb (C, N), the precipitates were formed mostly in the grain interior as the precipitation temperature was raised above the deformation temperature by the high carbon content. Hence, carbon in excess suppressed the hot ductility loss. Meanwhile, boron addition improved the hot ductility of the alloys. The improvement is likely due to the boron atoms capturing carbon atoms and thus retarding the carbide formation.

• Clinical Nutrition Research
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• v.12 no.3
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• pp.177-183
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• 2023

Bariatric surgery is the most effective treatment for sustained weight reduction, and it can result in substantial improvements in the severity of type 2 diabetes, metabolic syndrome, nonalcoholic fatty liver disease, and quality of life. However, sleeve gastrectomy, a weight loss surgery that removes two-thirds of the stomach, reduces appetite and nutrient absorption, impairing digestion and the absorption of nutrients like iron, vitamin B₁₂, and protein-bound nutrients. This case study aims to demonstrate that patients undergoing sleeve gastrectomy require long-term and periodic monitoring of biochemical data, weight changes, and caloric and protein intake by a professional nutritionist to prevent malnutrition and nutritional deficiencies. In this case study, a 48-year-old woman was diagnosed with morbid obesity, hypertension, sleep apnea syndrome, and chronic gastritis. At initial evaluation, she was 160 cm tall and weighed 89 kg, with a body mass index of 34.8 kg/m². At 1 postoperative year, she consumed 650 kcal and 25 g of protein per day, the percentage of excess weight loss was 141.1%, and body mass index was 21 kg/m². Compared to preoperative levels, calcium and folic acid levels did not decrease after 1 postoperative year, but hemoglobin, ferritin, and vitamin B₁₂ levels decreased. In conclusion, when patients experience rapid weight loss after sleeve gastrectomy, follow-up should be frequent and long. Dietary education should be conducted according to digestive symptoms, and oral nutritional supplements, including vitamins and minerals.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.2
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• pp.87-90
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• 2002

$LiCoO_{2}$ powders were synthesized at various temperatures using lithium hydroxide and cobalt hydroxide as precursors prepared by precipitation process and freeze-drying. In this study, the$LiCoO_{2}$ samples were synthesized via a solid state reaction with various LiOH concentration between 10 % and 30 % excess. And $LiCoO_{2}$powders were calcined at 600~$800^{\circ}C$ in a short time. Measurements of XRD and SEM were performed to characterize the properties of the prepared materials. The effect of amount of Li ions on the structural change in powder has been examined using the XRD analysis. For the not added excess of LiOH, CoOOH phase presented in the XRD pattern of $LiCoO_{2}$ due to loss of Li ions during firing. The morphology and particle size of the powders were examined using SEM. The obtained powders are high temperature-$LiCoO_{2}$HT-LiCoO$_{2}$) and homogeneous with the range of grain size in the order of hundreds of nanometers. The effects of variation of LiOH concentration on the structural change in powder were investigated using the Rietveld analysis. As an analysis result, c/a is constant by 4.99 on all occasions. Finally, the structure of HT-$LiCoO_{2}$ was simulated by the commercial software $Creius^{2}$(Molecular Simulations, Inc.) from the results of Rietveld analysis.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.1
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• pp.45-51
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• 2015

In order to meet the enforced emission regulations and reduce fuel consumption, various new technologies are employed in engines. The problem of NOx emissions under a lean mixture condition should be solved, because a lean-burn direct-injection engine can realize stable lean combustion with a stratified mixture, which results in improvements in fuel economy and emissions. This study investigated the effects of intake and exhaust valve timing changes on the performance and emission characteristics of a lean-burn LPG direct-injection engine. Under a partial-load operating condition without throttling, an increase in the intake valve opening led to an increase in NOx emissions due to an increase in the amount of excess air. The fuel consumption deteriorated with an increase in the exhaust valve opening due to a decrease in the expansion work and an increase in the pumping loss.

• Korean Journal of Mathematics
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• v.20 no.1
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• pp.137-159
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• 2012

In this paper, we deal with recent researches on Ying N$\ddot{u}$ and Ying Buzu(盈不足) which were addressed in the book Jiu Zhang Suan Shu(九章算術, The Nine Chapters on the Mathematical Art). Ying N$\ddot{u}$(Ying Buzu) is a concept on profit and loss problems. Ying Buzu Shu(盈不足術, the method of excess and deficit) represents an algorithm which has been used for solving many mathematical problems. It is known as a rule of double false position in the West. We show the importance of Ying Buzu Shu via an analysis of some problems in 'Ying Buzu' chapter. In 1202, Fibonacci(c.1170-c.1250) used Ying Buzu Shu in his book. This shows some of Asian mathematics were introduced to the West even before the year 1200. We present the origin of Ying Buzu Shu, and its relationship with Cramer's Rule. We have discovered how Asia's Ying Buzu Shu spread to Europe via Arab countries. In addition, we analyze some characters of Ying N$\ddot{u}$(Ying Buzu) in the book Suan Xue Bao Jian(算學寶鑑).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2480-2486
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• 2012

The design of low voltage LC-VCO(LC Voltage Controlled Oscillator) has been presented to optimize the phase noise and power consumption for the block of frequency synthesis to satisfy WCDMA system specification in this paper. The parameters for minimum phase noise has been obtained in the region of design, using the lines of the tuning range and the excess gain in the plane of the inductance and the transconductance of MOS transistor to compensate the loss of LC-tank. As a result of simulation, the phase noise characteristics is -113dBc/Hz for offset of 1MHz. The optimum designed LC-VCO has been fabricated using the process of 0.25um CMOS. As a result of measurement for fabricated chip, the phase noise characteristics is -116dBc/Hz for offset of 1MHz. The power consumption is 15mW, and Kvco is 370MHz/V.

• International Journal of Highway Engineering
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• v.17 no.2
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• pp.1-11
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• 2015

PURPOSES : This study set out to investigate the fundamental properties of alkali-activated concrete (AAC) using modified slag as the pavement maintenance material. METHODS: The material properties of modified slag based alkali-activated concrete (MSAAC) were analyzed and evaluated against those of alkali-activated slag concrete (AASC). Several mix formulations were considered, including one MSACC and four AASCs. The main variables considered in the study were slump, air content, compressive strength, rapid chloride permeability test, scaling resistance, freeze-thaw test, XRD, SEM, and EDS. RESULTS: MSAAC exhibits a compressive strength in excess of 21 MPa six hours after curing. Also, the charge passed of the MSACC was found to be less than 2000 coulombs after seven days and about 1000 coulombs after 28 days. The weight loss determined from a scaling test did not exceed $1kg/cm^2$ in the case of the MSACC, but that of the AASCs had already exceeded $1kg/cm^2$ at the 10th cycle. Based on the results of the freeze-thaw test, the relative dynamic modulus of every mix was found to be in excess of 90%. An energy dispersive spectroscopy(EDS) analysis found that the weight rate percentage of the calcium and aluminum in the MSAAC mix is twice that of the AASC mixes. CONCLUSIONS : It was found that the MSAAC mix exhibits significantly better performance than AASC mixes, based on various fundamental properties.