• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.692-700
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• 2007

A trial run of locally-developed tilting train has been in process on Chungbuk line since the test vehicle was first produced. For the system stabilization, interface verification among the systems including track, structure, catenary and signaling system, not to mention the rolling stock, is very crucial. In the area of wayside structure, the stability of track structure and train run shall be evaluated through the review of impact by increased speed by developed train on track structure. The study thus was intended to evaluate the impact on track while a tilting train is running the curve section, which is vulnerable to accelerated train speed. The analysis of tilting train test running the part of Chungbuk line and Honam line was conducted to identify the impact on existing track performance by tilting train. To identify the movement behavior of each part of track while tilting train, high speed train and traditional train (Mugunghwa and freight train) were running the existing line, wheel load, lateral wheel load, rail bending stress, vertical and lateral displacement of rail and vertical displacement of sleeper were compared and analyzed so as to evaluate the expected impact by tilting train for improving the train speed.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.701-708
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• 2007

A tilting train, which was developed to run the curve section without reducing the speed and compromising the riding quality, can improve the speed so as to reduce the travel time, compared to the existing trains. Then the force generated by the train operation to the track is in proportion to train operation speed, which means the track shall bear the increased force as much as the increase in train operation speed. Particularly, wheel load and lateral wheel load generated by train operation and distributed to the rail tend to cause the track to suffer the strain and furthermore the severe disaster such as derailment. To deal with such problem and ensure the train will run safety and stably, the tolerance in wheel load change, lateral wheel load and derailment coefficient was determined for quantitative evaluation of the train operation stability. In this study, derailment coefficient of inner and outer rail at existing curve section of tilting train was determined to evaluate the curve radius, possibility of acceleration and the need of rail improvement, which was then compared with the existing traditional train and high speed train. Conducting the quantitative evaluation of dynamic wheel load and lateral wheel load of each train, which was based on field survey, derailment coefficient and static & dynamic wheel load change, which serve the evaluation criteria of train operation stability, were determined for comparison with the standards, thereby analyzing the stability of the tilting train.

• Journal of Ginseng Research
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• v.37 no.1
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• pp.135-141
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• 2013

A rapid, sensitive and selective analytical method was developed and validated for the determination of compound K, a major intestinal bacterial metabolite of ginsenosides in human plasma. Liquid-liquid extraction was used for sample preparation and analysis, followed by liquid chromatography tandem spectrometric analysis and an electrospray-ionization interface. Compound K was analyzed on a Phenomenex Luna C18 column ($100{\times}2.00$ mm, 3 ${\mu}m$) with the mobile phase run isocratically with 10 mM ammonium acetate-methanol-acetonitrile (5:47.5:47.5, v/v/v) at a flow rate of 0.5 mL/min. The method was validated for accuracy (relative error <12.63%), precision (coefficient of variation <9.14%), linearity, and recovery. The assay was linear over the entire range of calibration standards i.e., a concentration range of 1 ng/mL to 1,000 ng/mL ($r^2$ >0.9968). The recoveries of compound K after liquid-liquid extraction at 1, 2, 400, and 800 ng/mL were $106.00{\pm}0.08%$, $103.50{\pm}0.19%$, $111.45{\pm}5.21%$, and $89.62{\pm}34.46%$ for intra-day and $85.40{\pm}0.08%$, $94.50{\pm}0.09%$, $112.50{\pm}5.21%$, and $95.87{\pm}34.46%$ for inter-day, respectively. The lower limit of quantification of the analytical method of compound K was 1 ng/mL in human plasma. The developed method was successfully applied to a pharmacokinetic study of compound K after oral administration in ten of healthy human subjects.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.585-589
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• 2015

Physical inactivity may an important outcome in the prognosis of breast cancer. Physical activity levels decrease significantly for breast cancer patients following the treatment and remain low after oncology treatment is completed. The aim of this study was to determine physical activity levels and to examine associations among physical activity, comorbidity, functional capacity, peripheral muscle strength, and psychosocial status in breast cancer patients. Forty breast cancer survivors were included in this study. Demographic and clinical characteristics were recorded. Physical activity was assessed with a short form of the International Physical Activity Questionnaire (IPAQ). We defined comorbid diseases according to the Charlson Comorbidity Index (CCI). Functional capacity was evaluated with a six-minute walk test (6MWT). Peripheral muscle strength was measured for quadriceps femoris muscle with a hand-held dynamometer. Psychosocial status was measured with the Hospital Anxiety Depression Scale (HADS). Forty percent of patients were inactive. The IPAQ total score was significantly related with quadriceps muscle strength (r=0.492; p<0.001) and HADS depression score (r=0.341; p<0.05). Marked correlations were also observed between IPAQ walking score and quadriceps muscle strength (r=0.449; p<0.001), HADS depression score (r=0.341; p<0.05), and CCI (r=-0.433; p<0.001). The CCI score was also markedly associated with quadriceps muscle strength (r=-0.413; p<0.001). 6MWT distance was not significantly correlated with any of the parameters. Regression analyses revealed that psychosocial status and peripheral muscle strength were significant predictors of physical activity estimated with the IPAQ short form and when combined, they explained 35% of the variance. Comorbidities, peripheral muscle strength and psychosocial status partially explain the variability of physical activity level in breast cancer survivors. These results suggest that physical inactivity contributes to worsening health in breast cancer survivors.

• Korean journal of communication and information
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• v.42
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• pp.44-78
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• 2008

The present study explored the agenda setting effects of replies called "Daet-Gul", and perception of the news replies. This study has established three research questions: 1) the recognition of the online communication 2) the degree of the reading and writing on online spare 3) the amount of the effects on the online communication. This study is performed using survey method. The survey results indicated in that the participants are very passive readers and writers on the online spare. In addition, the survey repliers evaluated that replies' mechanical device and antigravitational speed have high score, whereas they marked low store in the content and credibility of 'the replies. Therefore, they did not estimate the effects of the replies highly. All the results indicate that 'the replies' is not the fundamental factors of the deliberative democracy. It's because online communication with 'the replies' are thought to be fated the abuse and slander. Therefore, it's essential to improve the online communication with 'the replies', through the introduction of the 'trackback', which is a sort of the 'remote replies'

• The Korean Journal of Malacology
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• v.30 no.1
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• pp.95-99
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• 2014

In the present study, we surveyed the molluscan fauna in a lagoon located near Seong-san harbor on the east coast of Jeju Island in July 2012. For the survey, a $25{\times}25cm$ quadrat was deployed over 3 randomly selected sites in the intertidal area of the lagoon. Sediment from the surface to a depth of 25 cm in the quadrat was removed and sieved using a 1 mm mesh sieve. All molluscan fauna retained on the sieve was identified to the species level. From the survey, 25 species of mollusca belonging to 2 orders and 16 families were identified. Species richness, in terms of total number of species, was found to be the highest at sampling site 1, where the substrate was composed of coarse sand and some rocks, while it was lowest at sampling site 3, composed of compact fine sand. Regardless of the type of substrate at the sampling sites, the mud-creeping snail Batillaria cumingii (Crosse, 1862) occurred at a high density, ranging from $324-468ind./m^2$. The luciniid bivalve Pillucina pisidium also occurred at a high density at sampling site 1, at $336ind./m^2$, while the density of this species was only $4ind./m^2$ at sampling site 3. The Manila clam Ruditapes philippinarum could be found at all 3 sampling sites with very low density ranging from $16-48ind./m^2$. The density and species richness of molluscs observed in this study was lower compared to the previously reported molluscan fauna in Jeju Island, suggesting that further investigation needs to be carried out to conserve the unique marine lagoon ecosystem in Jeju Island.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.2 s.31
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• pp.1-9
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• 2004

We investigated the effect of $BaTiO_3$ powder content on the dielectric constant of epoxy/$BaTiO_3$ composite embedded capacitor films (ECFs). Variations of the dielectric constant of epoxy/$BaTiO_3$ composite ECFs with unimodal $BaTiO_3$ powder content were measured. To explain this result, density of the ECFs was measured, and surface and cross section images of the ECFs were observed. In addition, variations of the dielectric constant of epoxy/$BaTiO_3$ composite ECFs with various bimodal combinations were measured. In the case of unimodal powder, the maximum dielectric constant was about 60 at $60\;vol\%$ S4 powder. And more powder addition lowered the dielectric constant of the ECFs, which was due to voids or pores formation by excess $BaTiO_3$ powder. In the case of bimodal combination, $75vol\%\;BaTiO_3$ powder loading and the dielectric constant of 90 were achieved using $S_5+C_1$ combination, biggest and smallest powder combination.

• Sleep Medicine and Psychophysiology
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• v.25 no.1
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• pp.9-14
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• 2018

Objectives: Chronic insomnia disorder is a common and one of the most distressing sleep disorders. This pilot study was conducted to compare the spatial function between insomnia disorder patients and good sleeping control. Methods: We enrolled the 22 patients with chronic insomnia during over one year who met the DSM-5 diagnostic criteria of insomnia disorder and 27 normal sleeping controls. The Cambridge Neuropsychological Test Automated Battery (CANTAB) has been performed to compare the spatial cognitive function between insomnia disorder patients and good sleeping controls. Results: The CANTAB results showed significant differences in the problems solved in minimum moves of Stockings of Cambridge test (t = -2.499, p = 0.017). The significant difference between two groups remained after controlling age, sex, and Beck Depression Index non-sleep scores (F = 5.631, p = 0.022). Conclusion: This study suggests that the patients with insomnia disorder have poor spatial planning function.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.244-248
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• 2013

We studied the development of schizandrin as a marker compound in Jangsu Omija. Schizandrin was validated for its LOD (limit of detection), LOQ (limit of quantitation), precision, accuracy, and recovery by HPLC relative to Omija powder. It showed a high linearity in the calibration curve with a coefficient of correlation ($R^2$) of 0.9990. The LOD and LOQ were 0.2 ${\mu}g/mL$ and 0.5 ${\mu}g/mL$, respectively. The intra- and inter-day precision of schizandrin calibration standards was 0.06~0.66% and 0.13~1.19%, respectively, and the intra- and inter-day accuracy of schizandrin was 98.35~103.30% and 98.35~103.00%, respectively. Overall, schizandrin was validated through our analytical methods as a marker compound in Jangsu Omija.

• Journal of the Korea Concrete Institute
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• v.28 no.3
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• pp.317-328
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• 2016

This research intends to understand the impact of super-absorbent polymer (SAP) as an internal curing agent in Ultra-High Performance Concrete (UHPC). Two different types of SAPs of acrylic acid (SAP_AA) and acrylic acid-co-acrylamide (SAP_AM) were examined with UHPC formulation. Isothermal calorimetry and x-ray diffraction experiments revealed the impact of polymers with the different chemical bonds on cement hydration. To test its feasibility as a shrinkage reducing admixture for UHPC, a series of experiments including flowability, compressive strength, rapid chloride permeability and autogenous shrinkage profile was performed. While both SAPs showed a reduction in autogenous shrinkage, it has been concluded that the SAP size and chemical form significantly affect the performance as an internal curing agent in UHPC by controlling cement hydration and porosity modification. Between the tested SAPs, SAP_AM which absorbs more water in UHPC than SAP_AA, shows better mechanical and durability performance.