• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.22 no.1
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• pp.47-51
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• 2011

Background and Objectives: Vocal polyps arc one of the most frequent benign laryngeal diseases. They arc usually found at the midpoint of the vocal fold. They are mainly caused by vocal overuse. Vocal polyps arc usually removed surgically. Generally, age-related changes to speech are attributed to change in anatomy and physiology of the speech mechanism. These changes result in increased variability in the acoustic properties of speech with age. Still, not 'all studies of age-related changes in speech have taken differences between the young group and adult group after laryngeal microsurgery into account. The aim of this investigation was to compare improvement of acoustic analysis in young patients and elderly patients with vocal polyps, before and after the laryngeal microsurgery. Materials and Method: One hundred and twenty-eight patients who underwent laryngeal microsurgery for vocal polyps from 2008 through 2011 were reviewed retrospectively. 105 of the 128 patients under age 60 were classified as adult group (AG), and remaining 23 patients as elderly group (EG). The speech of AG and EG were evaluated before and after surgery for identification of differences for age group across measures of fundamental frequency (F0), Jitter, Shimmer and Maximum phonation time (MPT). Results: There were not significant differences between two groups for improvement of F0, Jitter, Shimmer, NHR, and MPT before and after surgery. The findings suggest that elderly group compares quite well with adult group in effectiveness of surgery. However, comparison between elderly group and young group (Age under 40) there was significant difference of improvement in Jitter and Shimmer. Conclusion: In general, the results of the present research showed significant improvement in vocal quality after phonosurgery of vocal polyp in both elderly and adult group. However, comparison of improvement between elderly group and young group, there were significant differences of improvement in jitter and shimmer. Therefore, in treatment planning of elderly group, we should consider age related changes of vocal cord.

• Journal of the Korean Magnetics Society
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• v.6 no.6
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• pp.405-410
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• 1996

Valence band photoemission spectroscopy (PES) measurements have been performed for $Co_{x}Pd_{100-x}$ alloy films using synchrotron radiation (x = 0, 25, 40, 65). Then the partial spectral weight distributions (PSW's) of Co 3d and Pd 4d electrons have been determined. The Co 3d PSW's exhibit some structures which are quite different from those of the Co film for x < 25 %, whereas they become very similar to those of the Co film for x > 40 %. For x < 25 %, the peak near the Fermi level ($E_F$) and a shoulder around 2 eV binding energy in the Co 3d PSW reflect large hybridization between Pd 4d and Co 3d electrons, suggesting that the hybridization might play an inportant role in determining perpendicualr magnetic anisotropy. The Pd 4d PSW's in Co-Pd alloy films are found to have larger FWHM's (full widths at half maximum), larger binding energies of the main peaks, and larger spectral intensities at $E_F$ than the PES spectrum of the Pd film. The FWHM of the Pd 4d PSW increases with decreasing Pd concentration, which are considered to reflect the disordering effect in the alloy formation or the change in the Pd 4d electronic structure due to hybridization between Co 3d and Pd 4d electrons.

• Journal of the Korean institute of surface engineering
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• v.53 no.4
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• pp.131-137
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• 2020

A series of Dy³⁺, Sm³⁺, and Dy³⁺/Sm³⁺ doped Gd₂WO₆ phosphors were synthesized by the conventional solid-state reaction. The X-ray diffraction patterns revealed that all of the diffraction peaks could be attributed to the monoclinic Gd₂WO₆ crystal structure, irrespective of the type and the concentration of activator ions. The photoluminescence (PL) excitation spectra of Dy³⁺-doped Gd₂WO₆ phosphors contained an intense charge transfer band centered at 302 nm in the range of 240-340 nm and two weak peaks at 351 and 386 nm. Under an excitation wavelength of 302 nm, the PL emission spectra consisted of two strong blue and yellow bands centered at 482 nm and 577 nm. The PL emission spectra of the Sm³⁺-doped Gd₂WO₆ phosphors had a series of three peaks centered at 568 nm, 613 nm, and 649 nm, corresponding to the ⁶G_5/2 → ⁶H_5/2, ⁶G_5/2 → ⁶H_9/2, and ⁶G_5/2 → ⁶H_11/2 transitions of Sm³⁺, respectively. The PL emission spectra of the Dy³⁺- and Sm³⁺-codoped Gd₂WO₆ phosphors showed the blue and yellow emission lines originating from the ⁴F_9/2 → ⁶H_15/2 and ⁴F_9/2 → ⁴H_13/2 transitions of Dy³⁺ and reddish-orange and red emission bands due to the ⁴G_5/2 → ⁶H_7/2 and ⁴G_5/2 → ⁶H_9/2 transitions of Sm³⁺. As the concentration of Sm³⁺ increased from 1 to 15 mol%, the intensities of two PL spectra emitted by the Dy³⁺ ions gradually decreased, while those of the three emission bands due to the Sm³⁺ ions slowly increased, thus producing the color change from white to orange. The CIE color coordinates of Gd₂WO₆:5 mol% Dy³⁺, 1 mol% Sm³⁺ phosphors were (0.406, 0.407), which was located in the warm white light region.

• Clean Technology
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• v.20 no.4
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• pp.415-424
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• 2014

In this study, two kinds of polymer (PPQX-2hdPTZ (P1), POPQX-2hdPTZ (P2)) were synthesised by Suzuki coupling reaction based on phenothiazine derivative as electron-donor and quinoxaline derivative as electron-acceptor. Microwave synthesis workstation was used to shorten the polymerization time and increase the degree of polymerization. The physical, thermal stability, optical and electrochemical properties of the synthesized polymer were confirmed. The thermal stability of two polymers was outstanding as the initial decomposition temperature was $323-328^{\circ}C$. And additional substituted alkoxy chain on P2 showed higher degree of polymerization. An analysis of electrochemical properties, all polymer had similar HOMO energy level values. Device was fabricated by ITO/PEDOT:PSS/active layer/$BaF_2$/Al structure and photovoltaic properties were confirmed. Each device has a different film thickness and the resulting change in PCE was confirmed. As a result the thinner thickness of the film showed a high efficiency ($PCE_{max}:P1=1.0%$, P2 = 1.1%).

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.4
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• pp.313-325
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• 2011

Finite element grid system using h-refinement on the Yellow Sea was constructed based on previous study (Suh, 1999b) from 14 K to 210 K and special attention was concentrated on refining the coastal zone. In grid generation, depth change between adjacent points and non-dimensional tidal wave length ratio were considered. As a result approximately a quarter of the total nodes are located nearby 5 m of shallow area. Accurate bathymetry data using 30's and ETOPO1 with open boundary conditions of 8 major tidal constituents extracted automatically from FES2004 have been applied. In tidal simulation a 3-dimensional nonlinear harmonic model was setup and tidal amplification due to changes in vertical turbulent and bottom friction were simulated. In this study not only 8 major tidal constituents but also nonlinear shallow tides $M_4,$, $MS_4$ and long period $M_f,$, $M_{sf}$ were reproduced. It is found that implication of spatial variation of friction coefficient plays a very important role in reproduction of astronomical and shallow tides which are computed by iterative computation of nonlinear terms. Also it should be considered differently with respect to tidal periods. To understand the distribution of tidal asymmetry, amplitude ratio of $M_4/M_2$ and phase differences $2g(M_2)-g(M_4)$ were calculated. Tidal distortion ratio marks up to 0.2 on the west coast showing shallow coastal characteristics and somewhat wide range of ebb-dominances in front of Mokpo area are reproduced.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.766-777
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• 1997

The purpose of this study was to investigate inheritance modes of low temperature germinability(LTG) on rice. Two experiments were carried out: In experiment I, the seeds of 10 rice varieties yielded at the different cultivation conditions which were transplanted in a paddy field from May 20 to July 5 with 15-day interval, were tested at fixed temperature (13$^{\circ}C$) in-door and at field with natural conditions to find out the change of LTG according to different cultivating condition among the each variety, In experiment II, F$_1$ seeds of full diallal cross from six parents, were analyzed for combining ability and reciprocal differences of low temperature germinability. The results are summarized as follows. The seeds of 10 varieties showed significant differences of LTG at the different cultivation conditions, varieties and their interaction. And the relationship between LTG coefficient at 13$^{\circ}C$ and low temperature emergence(LTE) coefficient at field was highly significantly positive(r=0.511). From the analysis of the diallel cross, high significance was found at reciprocal difference and alpha inheritance. The mean squares of general combining ability(GCA) and specific combining ability of LTG were highly significant with higher mean squares of GCA. Seventeen out of 30 cross combinations showed transgressive segregation.

• Journal of Korean Society of Forest Science
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• v.112 no.3
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• pp.267-279
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• 2023

This research assessed the feasibility of using high-resolution aerial images and deep learning algorithms for estimating the land-use and land-cover areas at the Approach 3 level, as outlined by the Intergovernmental Panel on Climate Change. The results from different sampling densities of high-resolution (51 cm) aerial images were compared with the land-cover map, provided by the Ministry of Environment, and analyzed to estimate the accuracy of the land-use and land-cover areas. Transfer learning was applied to the VGG16 architecture for the deep learning model, and sampling densities of 4 × 4 km, 2 × 4 km, 2 × 2 km, 1 × 2 km, 1 × 1 km, 500 × 500 m, and 250 × 250 m were used for estimating and evaluating the areas. The overall accuracy and kappa coefficient of the deep learning model were 91.1% and 88.8%, respectively. The F-scores, except for the pasture category, were >90% for all categories, indicating superior accuracy of the model. Chi-square tests of the sampling densities showed no significant difference in the area ratios of the land-cover map provided by the Ministry of Environment among all sampling densities except for 4 × 4 km at a significance level of p = 0.1. As the sampling density increased, the standard error and relative efficiency decreased. The relative standard error decreased to ≤15% for all land-cover categories at 1 × 1 km sampling density. These results indicated that a sampling density more detailed than 1 x 1 km is appropriate for estimating land-cover area at the local level.

• Korean Chemical Engineering Research
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• v.62 no.3
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• pp.246-252
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• 2024

In this study, impurities such as Li and F were removed from waste graphite through citric acid treatment, and changes in structural properties, capacity, and cycle stability of regenerated graphite were observed accordingly. Regenerated graphite pretreated in a nitrogen atmosphere was treated with citric acid, and its structure and characteristics were analyzed through SEM (Scanning Electron Microscope), FT-IR (Fourier Transform Infrared spectroscopy), XRD (X-ray Diffraction), and XPS (X-ray Photoelectron Spectroscopy). Waste graphite that was not treated with acid had a rapid decrease in capacity before 70 cycles, but graphite that had been treated with citric acid showed a capacity of 302.9 mAh g^-1 and a capacity retention rate of 93.1% at 100 cycles. In addition, despite changes in current density in rate performance, samples treated with citric acid showed 340.2 mAh g^-1 performance at 1.0C without change in capacity. As a result, it was confirmed that citric acid treatment not only effectively removed impurities and showed a high capacity retention rate, but also showed stability even at high current densities.

• Research in Plant Disease
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• v.30 no.3
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• pp.288-293
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• 2024

Fusarium basal rot (FBR), caused by the ascomycete fungus Fusarium oxysporum, is an economically important disease of onion worldwide. The most economical and effective way to manage FBR would be the use of FBR resistant onion cultivars. This study was carried out to develop a rapid screening method for resistant onion cultivars in seedling stage. We used the F. oxysporum 19-385 isolate, which causes damping-off in onion seedlings and basal rot in onion bulbs. We optimized broth incubation and medium composition for the production of inoculum, and determined conidial concentration for the preparation of F. oxysporum infected soil. Ten commercial cultivars of onion were evaluated the seedling survival rates and heights by infected soil inoculation methods. As a result, 'K-force' was the most resistant cultivar with 97.4% of relative seedling survival rate against the pathogen, whereas 'Sunpower' was the most susceptible cultivar with 20.0% of relative seedling survival rate.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.15 no.2
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• pp.128-132
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• 2004

Objectives : The total laryngectomy for laryngeal cancer has made patients be afraid of voice loss. Early staged glottic or supraglottic cancer can be treated with conservative laryngeal surgery which preserve voice, though which was not normal voice comparing before. Voice analysis is used to evaluates objectively the quality of the voice in pre- and postoperation, 4 different types of conservative laryngeal surgery : laser cordectomy, supracticoid partial laryngectomy, vertical partial laryngectomy, and supralottic laryngectomy. Materials and Methods : The patients who received conservative laryngeal surgery(laser cordectomy : 23 cases, vertical partial laryngecotmy : 9cases, supracriocoid partial laryngectomy : 6cases, supraglottic laryngectomy : 8cases) from 1995 to 2001 in the Asan medical center. Fundamental frequency(F0), shimmer, jitter, noise to harmony ratio(NHR), maximum comfortable phonation time and subglottic pressure were used as parameters for voice analysis. Results : The patients who received laser cordectomy(shimmer : 5.26${\pm}$1.12%, jitter : 3.33${\pm}$0.42%, NHR : 0.47${\pm}$0.02, MPT : 9.32${\pm}$3.59sec) and supraglottic laryngectomy(shimmer : 4.39${\pm}$1.03%, jitter : 1.49${\pm}$0.14%, NHR : 0.51${\pm}$0.06, MPT : 8.9${\pm}$0.59sec) showed better results than other two procedures, but differed from normal value. Especially the patients who received supracricoid partial laryngectomy(shimmer : 9.23${\pm}$1.56%, jitter : 5.81${\pm}$1.23%, NHR : 5.89${\pm}$1.13, MPT : 6.3${\pm}$1.18sec, MFR : 632${\pm}$89ml/sec) had poorer quality of voice but presented fast functional recovery time, and the subjective symptom was improved as time goes by slowly. Conclusion : The appropriate conservative laryngeal surgery for each cancers and stage can preserve the acceptable voice for patients. Supracricoid partial laryngectomy for T1b glottic cancer can be used for acceptable voice despite its poor voice analysis.