• Journal of agriculture & life science
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• v.43 no.6
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• pp.29-33
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• 2009

The purpose of this study was carried out to investigate the effects of plant growth regulators on in vitro propagation of Liliem cernum Komarov. Small bulblets were poliferated from callus explants after 2 weeks and leaf, root and bulb were formed after 4 weeks culture. Leaf differentiation was promoted vigorously by the combination of TDZ 0.1 mg/L and NAA 0.01 mg/L(87.5%). The rate of root differentiation was the greatest at BA 0.2 mg/L alone(81.8%). The rate of callus formation was the high in medium containing TDZ. The number of bulblets and leaves formed in bulb scales was the greatest at TDZ 0.1 mg/L(5.7). Also, the longest length of total length, leaf and root length were in Zeatin 1.0 mg/L + NAA 0.1 mg/L(10.5 cm). However the longest bulblet was in TDZ 0.1 mg/L(1.4 cm).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.393-396
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• 2009

This paper describes a design of variable-length FFT/IFFT processor for OFDM-based communication systems. The designed FFT/IFFT processor adopts the in-place single-memory architecture, and uses a hybrid structure of radix-4 and radix-2 DIF algorithms to accommodate FFT lengths of $N=64{\times}2^k$ ($0{\leq}k{\leq}7$). To achieve both memory size reduction and the improved SQNR, a two-step conditional scaling technique is devised, which conditionally scales the intermediate results of each computational stage. The performance analysis results show that the average SQNR's of 64~8,192-point FFT's are over 60-dB. The processor synthesized with a $0.35-{\mu}m$ CMOS cell library can operate with 75-MHz@3.3-V clock, and 64-point and 8,192-point FFT's can be computed in $2.55-{\mu}s$ and $762.7-{\mu}s$, respectively, thus it satisfies the specifications of wireless LAN, DMB, and DVB systems.

• Advances in nano research
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• v.14 no.3
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• pp.211-224
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• 2023

This work presents a modified analytical model for the bending behavior of axially functionally graded (AFG) carbon nanotubes reinforced composite (CNTRC) nanobeams. New higher order shear deformation beam theory is exploited to satisfy parabolic variation of shear through thickness direction and zero shears at the bottom and top surfaces.A Modified continuum nonlocal strain gradient theoryis employed to include the microstructure and the geometrical nano-size length scales. The extended rule of the mixture and the molecular dynamics simulations are exploited to evaluate the equivalent mechanical properties of FG-CNTRC beams. Carbon nanotubes reinforcements are distributed axially through the beam length direction with a new power graded function with two parameters. The equilibrium equations are derived with associated nonclassical boundary conditions, and Navier's procedure are used to solve the obtained differential equation and get the response of nanobeam under uniform, linear, or sinusoidal mechanical loadings. Numerical results are carried out to investigate the impact of inhomogeneity parameters, geometrical parameters, loadings type, nonlocal and length scale parameters on deflections and stresses of the AFG CNTRC nanobeams. The proposed model can be used in the design and analysis of MEMS and NEMS systems fabricated from carbon nanotubes reinforced composite nanobeam.

• Korean Journal of Ichthyology
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• v.11 no.1
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• pp.17-22
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• 1999

Two specimens of Decapterus macrosoma Bleeker and Carangoides orthogrammus (Jordan et Gilbert) were collected separately from the south-eastern sea of Cheju island and Cheju fish market in September, 1998. We named "Gin-ga-ra-ji" for D. macrosoma and "No-rang-jeom-muni-yu-jeon-gaeng-i" for C. orthogrammus since they are first recorded in the Korean waters. D. macrosoma shows some differences like the extent of scales on its dorsal head, the number of scutes, the shape of lateral line, and the length of pectoral fin in comparison of those of same genus. C. orthogrammus is characterized in having high body depth, scutes located on the straight lateral line, a few number of the yellow spot on the side of body, elongated rayon the front end of 2nd dorsal and anal fin, and the area of no scales in the base of breast.

• Korean Journal of Ichthyology
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• v.29 no.3
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• pp.224-228
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• 2017

Two specimens of Ruvettus pretiosus (227.0 and 238.3 mm in standard length), belonging to the family Gempylidae, was firstly collected by using a gill net from the eastern coastal waters of Jejudo Island, Korea in November 2013. This species is characterized by having the following morphological traits: XV, 17~19+2 dorsal fin rays; II, 15~16+2 anal fin rays; belly keeled between pelvic fin and anus; body covered with cycloid scales, interspaced with rows of sharp bony tubercles. R. pretiosus can be easily distinguished from three Korean Snake mackerels (Thyrsitoides marleyi, Rexea prometheoides and Gempylus serpens) by having belly keeled between pelvic fin and anus, and cycloid scales covered the body and interspaced with rows of sharp bony tubercles. Based on morphological and molecular approaches, the specimens were identified as R. pretiosus. We propose new Korean names, "Gi-reum-chi-sok" and "Gi-reum-chi" for the genus and species, respectively.

• Korean Journal of Plant Taxonomy
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• v.42 no.4
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• pp.335-339
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• 2012

An unrecorded species, Carex benkei T. Shimizu, was found in Is. Jaewondo, Jaewon-ri, Imja-myeon, Sinan-gun, Jeollanam-do and Dongbaik-dongsan, Seonheul-ri, Jocheon-eup, Jeju-si, Is. Jeju-do, South Korea. C. benkei is closely related to C. transversa Boott and C. brownii Tuck., and C. benkei is distingushied from the pistillate scales length, excluding the awn, similar to the achene and the beak of the achene with an annular appendage. A new Korean name, 'Gin-Hwa-Sal-Sa-Cho', was given based on its long pistillate scales excluding the awn compared with Carex transversa Boott. We provide here its redescription, illustrations, photographs, and a key to species of the sect. Confertiflorae Franch. ex Ohwi.

• Journal of The Korean Astronomical Society
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• v.45 no.4
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• pp.93-99
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• 2012

We present a 1.1mm emission map of the OMC1 region observed with AzTEC, a new large-format array composed of 144 silicon-nitride micromesh bolometers, that was in use at the James Clerk Maxwell Telescope (JCMT). These AzTEC observations reveal dozens of cloud cores and a tail of filaments in a manner that is almost identical to the submillimeter continuum emission of the entire OMC1 region at 450 and $850{\mu}m$. We perform Fourier analysis of the image with a modified periodogram and the density power spectrum, which provides the distribution of the length scale of the structures, is determined. The expected value of the periodogram converges to the resulting power spectrum in the mean squared sense. The present analysis reveals that the power spectrum steepens at relatively smaller scales. At larger scales, the spectrum flattens and the power law becomes shallower. The power spectra of the 1.1mm emission show clear deviations from a single power law. We find that at least three components of power law might be fitted to the calculated power spectrum of the 1.1mm emission. The slope of the best fit power law, ${\gamma}{\approx}-2.7$ is similar to those values found in numerical simulations. The effect of beam size and the noise spectrum on the shape and slope of the power spectrum are also included in the present analysis. The slope of the power law changes significantly at higher spatial frequency as the beam size increases.

• Journal of Convergence for Information Technology
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• v.10 no.5
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• pp.216-223
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• 2020

We investigated the morphology of the scalp hair shaft from the base to the distal end of the newborn hair and the ratio of the longitudinal axis diameter of the scale exposed to the surface of the hair to the diameter of the hair by scanning electron microscopy(SEM). Neonatal hair was observed to taper from the area adjacent to the scalp toward the end of the hair. In this study, as the thickness of the hair increases, the ratio of the long axis diameter of the exposed scale becomes relatively small, but the long axis diameter of the exposed scale on the surface of the hair is similar in length regardless of the thickness of the hair. In conclusion, it was confirmed that the major axis diameter of the scales exposed to the surface of fine or thick hair does not change significantly.

• Structural Engineering and Mechanics
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• v.44 no.4
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• pp.431-448
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• 2012

In this paper, the first-order shear deformation theory (FSDT) (Mindlin) for continuum incorporating surface energy is exploited to study the static behavior of ultra-thin functionally graded (FG) plates. The size-dependent mechanical response is very important while the plate thickness reduces to micro/nano scales. Bulk stresses on the surfaces are required to satisfy the surface balance conditions involving surface stresses. Unlike the classical continuum plate models, the bulk transverse normal stress is preserved here. By incorporating the surface energies into the principle of minimum potential energy, a series of continuum governing differential equations which include intrinsic length scales are derived. The modifications over the classical continuum stiffness are also obtained. To illustrate the application of the theory, simply supported micro/nano scaled rectangular films subjected to a transverse mechanical load are investigated. Numerical examples are presented to present the effects of surface energies on the behavior of functionally graded (FG) film, whose effective elastic moduli of its bulk material are represented by the simple power law. The proposed model is then used for a comparison between the continuum analysis of FG ultra-thin plates with and without incorporating surface effects. Also, the transverse shear strain effect is studied by a comparison between the FG plate behavior based on Kirchhoff and Mindlin assumptions. In our analysis the residual surface tension under unstrained conditions and the surface Lame constants are expected to be the same for the upper and lower surfaces of the FG plate. The proposed model is verified by previous work.

• Journal of Yeungnam Medical Science
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• v.38 no.2
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• pp.118-126
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• 2021

Background: This study is an analysis of evaluator factors affecting physician-patient interaction (PPI) scores in clinical performance examination (CPX). The purpose of this study was to investigate possible ways to increase the reliability of the CPX evaluation. Methods: The six-item Yeungnam University Scale (YUS), four-item analytic global rating scale (AGRS), and one-item holistic rating scale (HRS) were used to evaluate student performance in PPI. A total of 72 fourth-year students from Yeungnam University College of Medicine in Korea participated in the evaluation with 32 faculty and 16 standardized patient (SP) raters. The study then examined the differences in scores between types of scale, raters (SP vs. faculty), faculty specialty, evaluation experience, and level of fatigue as time passes. Results: There were significant differences between faculty and SP scores in all three scales and a significant correlation among raters' scores. Scores given by raters on items related to their specialty were lower than those given by raters on items out of their specialty. On the YUS and AGRS, there were significant differences based on the faculty's evaluation experience; scores by raters who had three to ten previous evaluation experiences were lower than others' scores. There were also significant differences among SP raters on all scales. The correlation between the YUS and AGRS/HRS declined significantly according to the length of evaluation time. Conclusion: In CPX, PPI score reliability was found to be significantly affected by the evaluator factors as well as the type of scale.