• International journal of advanced smart convergence
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• v.5 no.4
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• pp.15-20
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• 2016

When a virtual sound source for 3D auditory system is reproduced by a linear loudspeaker array, listeners can perceive not only the direction of the source, but also its distance. Control over perceived distance has often been implemented via the adjustment of various acoustic parameters, such as loudness, spectrum change, and the direct-to-reverberant energy ratio; however, there is a neglected yet powerful cue to the distance of a nearby virtual sound source that can be manipulated for sources that are positioned away from the listener's median plane. This paper address the problem of generating binaural signals for moving sources in closed or in open environments. The proposed perceptual enhancement algorithm composed of three main parts is developed: propagation, reverberation and the effect of the head, torso and pinna. For propagation the effect of attenuation due to distance and molecular air-absorption is considered. Related to the interaction of sounds with the environment, especially in closed environments is reverberation. The effects of the head, torso and pinna on signals that arrive at the listener are also objectives of the consideration. The set of HRTF that have been used to simulate the virtual sound source environment for 3D auditory system. Special attention has been given to the modelling and interpolation of HRTFs for the generation of new transfer functions and definition of trajectories, definition of closed environment, etc. also be considered for their inclusion in the program to achieve realistic binaural renderings. The evaluation is implemented in MATLAB.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.403-412
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• 2017

The study were to identify the effect of ego-resilience, nursing professionalism, social support on department satisfaction in nursing students. Data were collected from April to May 2017 from 272 nursing students. The study tools were ego-resilience, nursing professionalism, social support, department satisfaction. The data were analyzed by descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients, multiple linear regression using SPSS/WIN 21.0 program. The result showed that the difference in department satisfaction relating to general characteristics were significant for reason for choosing a department, student activity, academic record. The correlation among ego-resilience, nursing professionalism, social support, department satisfaction were significant, and the significant factors influencing department satisfaction in nursing students were social support, nursing professionalism, ego-resilience. It is necessary to find ways to improve the department satisfaction through the activities that can enhance the social support, nursing professionalism, and ego-resilience of nursing students. This will help them adjust to college life.

• International Commerce and Information Review
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• v.13 no.1
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• pp.123-144
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• 2011

This study used a non-parametric linear program, Data Envelopment Analysis(DEA) to compare the efficiency of Korean and global container shipping companies from 2005 to 2009. The sample shipping companies were 7 Korean container shipping companies and 11 global container shipping companies. The main objective of our research is to compare their efficiency, as well as the changes in efficiency periodically according to the types of the container shipping companies. According to the periodical analysis, both Korean and Global container shipping companies showed a steady decrease in efficiency. The study showed that Korean container shipping companies have greater efficiency than their global rivals.

• Journal of Korean Biological Nursing Science
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• v.22 no.1
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• pp.53-60
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• 2020

Purpose: This study used raw data from the fifth (2010-2012) Korea National Health and Nutrition Examination Survey (KNHANES) to assess the relationship between vitamin D level and glycemic control of diabetes, and to provide basic data about the use of vitamin D for preparation of a treatment plan for diabetes in South Korea. Methods: For this study, data of 1,713 diabetes from KNHANES (2010-2012) were used. The collected data were analyzed using SPSS 18.0 program, and complex sample frequency analysis, descriptive statistics, complex sample cross analysis, complex sample general linear regression, and complex sample logistic regression analysis were performed. Results: It was found that the poor glycemic control group among the diabetes subjects had significantly lower level of blood vitamin D than the good glycemic control group. Factors affecting glycemic control included drinking, vitamin D levels, hypertriglyceridemia, duration of diabetes, and treatment of diabetes. Also, diabetics with vitamin D deficiency or shortage showed 3.55- and 2.61-times higher odds ratios, respectively, to be diagnosed as the poor glycemic control group than diabetics without vitamin D deficiency or shortage. Conclusion: This study is significant because it provides rationale and basic data about the use of vitamin D for preparation of a treatment plan for diabetes in South Korea by assessing the dependence of glycemic control on the vitamin D level of diabetics. Additionally, future studies are necessary to determine the appropriate concentration of vitamin D for diabetes prevention and treatment to prevent the side effects of excessive supplementation.

• Journal of the Korea Concrete Institute
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• v.25 no.2
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• pp.145-153
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• 2013

Recently, accelerated chloride diffusion coefficients are used for an evaluation of chloride behavior. Similar as apparent diffusion coefficients, accelerated diffusion coefficients decrease with time. In this study, decrease in diffusion coefficient with time is simulated with porosity. Utilizing DUCOM-program, porosities from 15 mix proportions are obtained and diffusion coefficients are modelled with regression analysis of porosity for 270 days. Considering non-linear binding capacity which means the relation between free and bound chloride ion, chloride behavior in high performance concrete is evaluated. Through utilizing the previous test results for concrete under chlorides for 180 days, the applicability of the proposed technique is verified. The proposed technique is evaluated to reasonably predict the chloride behavior in concrete with various w/c (water to cement) ratios and mineral admixtures (GGBFS and FA). It is also shown that decrease in chloride diffusion should be considered for chloride prediction in concrete with mineral admixture since it has very clear decrease in diffusivity with time.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.65.1-65.1
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• 2016

We present results of long-term multi-wavelength polarization observations of the powerful blazar 3C 279 after its ${\gamma}$-ray flare on 2013 December 20. We followed up this flare by means of single-dish polarization observations with two 21-m telescopes of the Korean VLBI Network, carried out weekly from 2013 December 25 to January 11, and at 22, 43, and 86 GHz, simultaneously. These observations were part of the Monitoring Of GAmma-ray Bright AGNs (MOGABA) program. We Measured 3C 279 total flux densities at 22, 43, and 86 GHz, showing a mild variability of a factor of ${\leq}50%$ over the period of our observations. The spectral index ranged from -0.13 to -0.36 at between 22 and 86 GHz. The degree of linear polarization was in the range of 6 ~ 12 %, and slightly decreased with time at all frequencies. We found Faraday rotation measures (RM) of -300 to $-1200rad\;m^{-2}$ between 22 and 43 GHz, and -800 to $-5100rad\;m^{-2}$ between 43 and 86 GHz. The RM values follow a power law ${\mid}RM{\mid}{\propto}{\nu}^{\alpha}$, with a mean ${\alpha}$ of 2.2, implying that the polarized emission at these frequencies travels through a Faraday screen in or near the jet. We conclude that the regions emitting polarized radio emission may be different from the region responsible for the 2013 December ${\gamma}$-ray flare, and that these regions are maintained by the dominant magnetic field perpendicular to the direction of the radio jet at milliarcsecond scales.

• Journal of the Korean Institute of Intelligent Systems
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• v.27 no.2
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• pp.144-149
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• 2017

In this paper, we developed an intelligent and wideband RF-receiver module to represent a high dynamic range and good linearity characteristics up to 650MHz-2700MHz frequency band. and implemented an intelligent digital-RF- distorted signal measuring system for the RF distortion (intermodulation) signals. Broadband RF-receive module was designed to represent the optimized linear parameters of the receiver to meet the low noise and wide dynamic range. The designed intelligent digital-distortion(intermodulation) signal measument system measured by applying the 1MHz IF of third intermodulation signal of DUT and Measured data was recorded by program on the PC monitor with GUI interface. By variable up to 650MHz-2700MHz measured data showed up to -127.8dBc to -138dBc of the distortion (intermodulation) signal. And developed intelligent digital- distortion signal measurement system can be used to measure intermodulation distortion signal of wireless system widely.

• Korea Journal of Hospital Management
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• v.25 no.1
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• pp.46-57
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• 2020

Objectives: The purpose of this study is to evaluate the factors affecting patient satisfaction for the nursing service of comprehensive nursing care service unit in Tertiary hospital Methods: This study employed a descriptive survey to investigate the nursing satisfaction and the study data was collected from 74 patients among 83 patient who were admitted to the nursing care integration service ward of an tertiary hospital for 10 days from May 9, 2018 to May 19, 2018. Data was analyzed by descriptive statistics, t-test, ANOVA, and multiple linear regression using SPSS 21 program. Results: The average with nursing satisfaction was significantly different according to marriage type and KPCS level. It was found that physical factor and educational factor have statistically significant effect on nursing satisfaction. As physical care increase by one unit, patient satisfaction increase by 0.226(95% CI; 0.061-0.390) and also satisfaction increase by 0.443(95% CI; 0.070-0.816) as education care increase by one unit. Conclusions: As a result of study, it was found that it is necessary to provide patients with more careful nursing service in physical and educational perspective, in order to improve the service quality of comprehensive nursing care service unit.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.1
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• pp.33-42
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• 2003

This paper deals with the FEM analysis of nonlinear sloshing of incompressible, invicid and irrotational flow in two dimensional rectangular tank. We use laplace equation based on potential theory as governing equation. For large amplitude sloshing motion, kinematic and dynamic free surface conditions derived from Bernoulli equation are applied. This problem is solved by FEM using 9-node elements. For the time integration and accurate velocity calculation, we introduce predictor-corrector time marching scheme and least square method. Also, numerical stability in tracking of free surface is obtained by direct calculation of free surface location to time variation. Numerical results of sloshing induced by harmonic excitations, while comparing with those of linear theory and references, prove the accuracy and stability. After verification of our program, we analyze sloshing response characteristics to the fluid height and the excitation amplitude.

• BMB Reports
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• v.37 no.4
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• pp.408-415
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• 2004

The expression of the Paenibacillus sp. A11 cyclodextrinase (CDase) gene using the pUC 18 vector in Escherichia coli JM 109 resulted in the formation of an insoluble CDase protein in the cell debris in addition to a soluble CDase protein in the cytoplasm. Unlike the expression in Paenibacillus sp. A11, CDase was primarily observed in cytoplasm. However, by adding 0.5 M sorbitol as an osmolyte, the formation of insoluble CDase was prevented while a three-fold increase in cytoplasmic CDase activity was achieved after a 24 h-induction. The recombinant CDase protein was purified to approximately 14-fold with a 31% recovery to a specific activity of 141 units/mg protein by 40-60% ammonium sulfate precipitation, DEAE-Toyopearl 650 M, and Phenyl Sepharose CL-4B chromatography. It was homogeneous by non-denaturing and SDS-PAGE. The enzyme was a single polypeptide with a molecular weight of 80 kDa, as determined by gel filtration and SDS-PAGE. It showed the highest activity at pH 7.0 and $40^{\circ}C$. The catalytic efficiency ($k_{cat}/K_m$) values for $\alpha$-, $\beta$-, and $\gamma$-CD were $3.0{\times}10^5$, $8.8{\times}10^5$, and $5.5{\times}10^5\;M^{-1}\;min^{-1}$, respectively. The enzyme hydrolyzed CDs and linear maltooligosaccharides to yield maltose and glucose with less amounts of maltotriose and maltotetraose. The rates of hydrolysis for polysaccharides, soluble starch, and pullulan were very low. The cloned CDase was strongly inactivated by N-bromosuccinimide and diethylpyrocarbonate, but activated by dithiothreitol. A comparison of the biochemical properties of the CDases from Paenibacillus sp. A11 and E. coli transformant (pJK 555) indicates that they were almost identical.