• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.374.1-374.1
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• 2016

Copper and zinc are well known elements with antibacterial effect. So in this research, Cu and Zn (CZ) nanofibers (NFs) were fabricated by electrospinning method using polyvinylpyrrolidone (PVP) for adjusting viscosity. The CZ/PVP precursor solutions were prepared with copper sulfate pentahydrate, and zinc acetate dihydrate. Distilled water was used for solvent and PVP was used to regulate the viscosity of precursor solution. The CZ/PVP NF composites were obtained by electrospinning method using the precursor solution. The average diameter of obtained CZ/PVP NFs was determined by optical microscopy using Motic image plus 2.0 program and was found to be 490 nm. The chemical environment of the obtained CZ/PVP NF composites was investigated with X-ray photoelectron spectroscopy (XPS). After heating the obtained CZ/PVP NF composites at 353 K, the solvent was removed. The characteristic C 1s, Cu 2p, and Zn 2p core level XPS peaks were observed. After calcination the CZ/PVP NF composites at 873 K in Ar environment for 5 hrs, PVP was decomposed at this temperature and CZ NF was obtained. This was confirmed by decreasing the intensity of C 1s.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.3 s.73
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• pp.259-269
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• 2006

In this paper, the stress intensity factor, energy release rate and crack opening displacement are computed using the finite element method for axisymmetric viscoelastic cylinders with the penny-shaped and circumferential cracks. The triangular elements with quarter point nodes are used to describe the stress singularity around the crack edge. The analytical solutions are also derived by using the elastic-viscoelastic correspondence principle and compared with the numerical results to show the validity and accuracy of the presented method. Viscoelastic materials are assumed to behave elastically in dilatation and like a three-parameter standard linear solid.

• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.204-207
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• 2011

A particle counting system that can also provide sensitive, specific chemical information, while consuming very less power, occupying less space, and being inexpensive has been developed. This system uses a microwave plasma torch (MPT) as the excitation source for atomic emission spectrometry (AES). Emission from a single particle can be detected, and the wavelength at which the emission is observed indicates the elements present in the particle. It is believed that correlating the particle size and emission intensity will allow us to estimate the particle size in addition to abovementioned capabilities of the system. In the long term, this system can be made field-portable, so that it can be used in atmospheric aerosol monitoring applications, which require real-time detection and characterization of particles at low concentrations.

• Journal of Korean Society of Steel Construction
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• v.10 no.3 s.36
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• pp.423-435
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• 1998

In this paper fatigue strength reduction of butt weld with penetration defect, which can be seen frequently in the steel bridge, was assessed quantitatively. S-N curves were derived and investigated through the constant amplitude fatigue test of fully or partially penetrated welded specimen made of SWS490 steel. The fracture mechanical method was applied in order to calculate the remaining fatigue life of the partially penetrated butt welds. The fatigue limit of the fully penetrated butt welds was higher than that of category A in AASHTO's fatigue design curves, and the slope of S-N curves with 5.57 was stiffer than that of other result for welded part generally accepted as 3. The fatigue strength of the partially Penetrated butt weld was strongly influenced by the size of lack of penetration, D. It decreased drastically with increasing D from 3.9 to 14.7mm. Fracture behaviour of the partially penetrated butt weld is able to be explained obviously from the beach mark test that a semi-elliptical surface crack with small a/c ratio initiates at a internal weld root and propagates through the weld metal. To estimate the fatigue life of the partially penetrated butt weld with fracture mechanics, stress intensity factors K of 3-dimensional semi-elliptical crack were calculated by appling finite elements method and fracture mechanics parameters such as C and m were derived through the fatigue test of CT-specimen. As a result, the fatigue lives obtained by using the fracture mechanical method agreed well with the experimental results. The results were applied to Sung-Su bridge collapsed due to penetration defects in butt weld of vertical member.

• Development and Reproduction
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• v.15 no.4
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• pp.325-329
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• 2011

The main objective of this study is to investigate the distribution of coat color among Ulleung Korean Native Brindle Cattle, and to identify basic genetic elements required for the fixation of coat color traits. 1. The distribution of coat color among Ulleung Korean Native Brindle Cattle was 24.3% yellow (67/276),13.0% black (36/276), 62.7% brindle (173/276). The frequency of Brindle coat color was slightly higher (66%, 105/159) among embryo transfer from outside than that of cows produced by embryo transfer from jurisdiction. 2. Investigation of coat color distribution in each sex group showed that the frequency of yellow coat color was lower in males (18.1%, 25/138) than in females (31.4%, 43/137). On the other hand, the frequency of brindle coat color was slightly higher among males (68.1%, 94/138) than in females (56.9%, 78/137). 3. Examination of Brindle coat color expression based on the intensity of black dots on the nose indicated that the expression of black coat color increase in proportion to the intensity of black dots.

• Phonetics and Speech Sciences
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• v.12 no.3
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• pp.25-32
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• 2020

An analysis of emotional English utterances with 7 emotions (calm, happy, sad, angry, fearful, disgust, surprised) was conducted using the measurement of prosodic distance between 672 emotional and 48 neutral utterances. Applying the technique proposed in the automatic evaluation model of English pronunciation to the present study on emotional utterances, Euclidean distance measurement of 3 prosodic elements such as F0, intensity and duration extracted from emotional and neutral utterances was utilized. This paper, furthermore, extended the analytical methods to include Euclidean distance normalization, z-score and z-score normalization resulting in 4 groups of measurement schemes (sqrF0, sqrINT, sqrDUR; norsqrF0, norsqrINT, norsqrDUR; sqrzF0, sqrzINT, sqrzDUR; norsqrzF0, norsqrzINT, norsqrzDUR). All of the results from perceptual analysis and acoustical analysis of emotional utteances consistently indicated the greater effectiveness of norsqrF0, norsqrINT and norsqrDUR, among 4 groups of measurement schemes, which normalized the Euclidean measurement. The greatest acoustical change of prosodic information influenced by emotion was shown in the values of F0 followed by duration and intensity in descending order according to the effect size based on the estimation of distance between emotional utterances and neutral counterparts. Tukey Post Hoc test revealed 4 homogeneous subsets (calm

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.4 s.310
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• pp.58-66
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• 2006

In this paper, we apply DCM(Dilation of Color and Motion information) mask and Active Contour Models(Snakes) to extract facial outline in moving pictures with complex background. First, we propose DCM mask which is made by applying morphology dilation and AND operation to combine facial color and motion information, and use this mask to detect facial region without complex background and to remove noise in image energy. Also, initial curves are automatically set according to rotational degree estimated with geometric ratio of facial elements to overcome the demerit of Active Contour Models which is sensitive to initial curves. And edge intensity and brightness are both used as image energy of snakes to extract contour at parts with weak edges. For experiments, we acquired total 480 frames with various head-poses of sixteen persons with both eyes shown by taking pictures in inner space and also by capturing broadcasting images. As a result, it showed that more elaborate facial contour is extracted at average processing time of 0.28 seconds when using interpolated initial curves according to facial rotation degree and using combined image energy of edge intensity and brightness.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.4
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• pp.457-467
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• 2022

Electron bombardment to silicate glass during electron probe microanalysis (EPMA) causes outward migration of Na from the excitation volume and subsequent decrease in the measured X-ray count rates of Na. To acquire precise Na₂O content of silicate glass, one should use proper analytical technique to avoid or minimize Na migration effect or should correct for decreases in the measured Na X-ray counts. In this study, we analyzed 8 silicate glass standard samples using automated Time Dependent Intensity (TDI) correction method of Probe for EPMA software that can calculate zero-time intercept by extrapolating X-ray count changes over analysis time. We evaluated an accuracy of TDI correction for Na measurements of silicate glasses with EPMA at 15 kV acceleration voltage and 20 nA probe current electron beam, which is commonly utilized analytical condition for geological samples. Results show that Na loss can be avoided with 20 ㎛-sized large beam (<0.1 nA/㎛²), thus silicate glasses can be analyzed without TDI correction. When the beam size is smaller than 10 ㎛, Na loss results in large relative errors up to -55% of Na₂O values without correction. By applying TDI corrections, we can acquire Na₂O values close to the reference values with relative errors of ~ ±10%. Use of weighted linear-fit can reduce relative errors down to ±6%. Thus, quantitative analysis of silicate glasses with EPMA is required for TDI correction for alkali elements such as Na and K.

• Journal of the Korean Vacuum Society
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• v.20 no.6
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• pp.409-415
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• 2011

The method to improve the detection sensitivity of Hand-held XRF (X-Ray Fluorescence) device currently being developed is discussed. To minimize the loss of the intensity due to atmospheric gas molecules, the vacuum module, which can be filled with atmospheric or He gas, between the sample and the detector was installed. And the change of the detection sensitivity was measured in a vacuum and in the He gas-filled state. As a result, the following three important results were obtained; Firstly, XRF intensity was increased 2~4 times in the low energy range (3~4 keV). It is a very important result because the enhancement of the detection sensitivity means shortening of the detection time in Hand-held XRF device. Secondly, the possibility of detection of the elements less than 3 keV in emission energy was confirmed. Thirdly, the absorption by atmospheric gas molecules can be minimized without vacuum- sealed vessel in Hand-held XRF device, if the vacuum module filled with He gas is used. We concluded that all of three results are very meaningful in the development of a Hand-held XRF device.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.33 no.3
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• pp.5-30
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• 2022

In this study, a survey of public library librarians was conducted to examine the current librarian's job status by conducting a survey on the library's environment, such as the size of books, number of employees, and operating subjects. As a result of the study, it was found that based on the current job content and recognition, librarians are mainly working in the order of operating reading culture programs, planning reading culture programs, and user information services. In addition, it can be seen that librarians highly value the importance of their respective duties, and in the case of labor intensity, more than half of them recognize that the current labor intensity is high. Among the detailed competency units corresponding to each task in the future, more appropriate competency unit elements should be considered in consideration of the essential competency, additional supplementation, and lower factors through this study. In addition, the higher the number and experience of regular workers in the library, the higher the degree of librarian certification, and the higher the current position, the higher the importance, difficulty, and expertise of the current work, so it is expected that the library should continue to build experience in the future.