• Journal of Audiology & Otology
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• v.25 no.2
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• pp.98-103
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• 2021

Background and Objectives: The aim of the study was to compare effects of tone-burst (TB) and narrow-band (NB) Claus Elberling (CE)-chirp stimuli on amplitude, latency and interaural asymmetry ratio (IAR) of cervical vestibular evoked myogenic potentials (cVEMP) in healthy individuals. Subjects and Methods: The study included 50 healthy volunteers. cVEMP procedure was carried out using 500 Hz TB and NB-CE-chirp stimulus (360-720 Hz, up-chirp) in random order. cVEMP were recorded at 100 dB nHL. For each ear and each stimulus, P1 latency, N1 latency and P1N1 amplitude were measured. IAR was also calculated. Results: Mean age was 26.66±9.48 years. cVEMP's in response to both TB and NB CE-chirp stimuli were obtained in all subjects. No statistically significant difference in P1 latency, N1 latency, and P1N1 amplitude was found between the right and left ears for both TB and NB CE-chirp stimuli (p>0.05). In both sides, P1 and N1 latencies were significantly shorter in NB CE-chirp stimulation compared to TB stimulation (p=0.000). In both sides, no statistically significant difference was found in P1N1 amplitude between two types of stimuli (p>0.05). Conclusions: The chirp stimulus produces robust but earlier cVEMP than TB does. This largest series study on NB chirp cVEMP shows that NB chirp is a good and new reliable alternative.

• Korean Journal of Audiology
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• v.25 no.2
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• pp.98-103
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• 2021

Background and Objectives: The aim of the study was to compare effects of tone-burst (TB) and narrow-band (NB) Claus Elberling (CE)-chirp stimuli on amplitude, latency and interaural asymmetry ratio (IAR) of cervical vestibular evoked myogenic potentials (cVEMP) in healthy individuals. Subjects and Methods: The study included 50 healthy volunteers. cVEMP procedure was carried out using 500 Hz TB and NB-CE-chirp stimulus (360-720 Hz, up-chirp) in random order. cVEMP were recorded at 100 dB nHL. For each ear and each stimulus, P1 latency, N1 latency and P1N1 amplitude were measured. IAR was also calculated. Results: Mean age was 26.66±9.48 years. cVEMP's in response to both TB and NB CE-chirp stimuli were obtained in all subjects. No statistically significant difference in P1 latency, N1 latency, and P1N1 amplitude was found between the right and left ears for both TB and NB CE-chirp stimuli (p>0.05). In both sides, P1 and N1 latencies were significantly shorter in NB CE-chirp stimulation compared to TB stimulation (p=0.000). In both sides, no statistically significant difference was found in P1N1 amplitude between two types of stimuli (p>0.05). Conclusions: The chirp stimulus produces robust but earlier cVEMP than TB does. This largest series study on NB chirp cVEMP shows that NB chirp is a good and new reliable alternative.

• Korean Journal of Materials Research
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• v.8 no.10
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• pp.890-897
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• 1998

The direct wafer bonding between n-InP(001) wafer and the ${Si}_3N_4$(200 nm) film grown on the InP wafer by PECVD method was investigated. The surface states of InP wafer and ${Si}_3N_4$/InP which strongly depend upon the direct wafer bonding strength between them when they are brought into contact, were characterized by the contact angle measurement technique and atomic force microscopy. When InP wafer was etched by $50{\%}$ HF, contact angle was $5^{\circ}$ and RMS roughness was $1.54{\AA}$. When ${Si}_3N_4$ was etched by ammonia solution, RMS roughness was $3.11{\AA}$. The considerable amount of initial bonding strength between InP wafer and ${Si}_3N_4$/InP was observed when the two wafer was contacted after the etching process by $50{\%}$ HF and ammonia solution respectively. The bonded specimen was heat treated in $H^2$ or $N^2$, ambient at the temperature of $580^{\circ}C$-$680^{\circ}C$ for lhr. The bonding state was confirmed by SAT(Scannig Acoustic Tomography). The bonding strength was measured by shear force measurement of ${Si}_3N_4$/InP to InP wafer increased up to the same level of PECVD interface. The direct wafer bonding interface and ${Si}_3N_4$/InP PECVD interface were chracterized by TEM and AES.

• The Pure and Applied Mathematics
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• v.16 no.3
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• pp.255-258
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• 2009

It is well known that for a sequence a = ($a_0,\;a_1$,...) the general term of the dual sequence of a is $a_n\;=\;c_0\;^n_0\;+\;c_1\;^n_1\;+\;...\;+\;c_n\;^n_n$, where c = ($c_0,...c_n$ is the dual sequence of a. In this paper, we find the general term of the sequence ($c_0,\;c_1$,... ) and give another method for finding the inverse matrix of the Pascal matrix. And we find a simple proof of the fact that if the general term of a sequence a = ($a_0,\;a_1$,... ) is a polynomial of degree p in n, then ${\Delta}^{p+1}a\;=\;0$.

• Reproductive and Developmental Biology
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• v.37 no.3
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• pp.129-134
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• 2013

A total of 30 Korean native pigs (gilt 15, boar 15) were used to investigate the carcass characteristics, meat quality, amino acid, and fatty acid composition by gender. The carcass weight of boars were significantly higher than gilts, whereas the carcass yield of gilts had significantly higher than boars (p<0.01). Boars had significantly higher moisture contents in loin muscle than gilts, whereas the protein contents of loin muscle had significantly higher in gilts than boars (p<0.01). In the results of meat quality analysis, the cooking loss (p<0.01), shearing force (p<0.05), lightness (L) and yellowness (b) in meat color (p<0.05) were significantly higher, but the pH was significantly lower (p<0.01) in gilts compared with boars. Arginine (p<0.05), alanine, aspartic acid, histidine, leucine, lysine, phenylalanine, serine, threonine and tyrosin (p<0.01) for gilts were significantly higher than those for boars. The results of fatty acid composition showed that gilts had significantly higher contents of C16:1n7, C18:1n9, C20:1n9 (p<0.01) than boars in intramuscular fat, whereas boars had significantly higher contents of C18:2n6, C20:4n6 (p<0.01) and C18:3n3 (p<0.05) than gilts in intramuscular fat.

• Journal of applied mathematics & informatics
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• v.5 no.1
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• pp.235-240
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• 1998

Given a Unimodular polynomial P of degree N$\geq$1, the exteremal problem for ${\gamma}$ =max{｜P(eit)｜:0 $\leq$t$\leq$2$\pi$} satisfies ${\gamma}$$\leq$C{{{{ SQRT { N+1} where C is a universal constant. Here we show that C < 2+{{{{ whenever N is fixed and P has the coefficients of a Rudin-Shapiro polynomial.

• Kyungpook Mathematical Journal
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• v.56 no.1
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• pp.257-271
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• 2016

In this paper, we compute the trace field of C(2, s), the complement of two component chain link with s left half twists in ${\mathbb{S}}^3$, for every s. As a result, for every $n{\in}{\mathbb{N}}{\backslash}\{1\}$, we can find $s{\in}{\mathbb{Z}}$ such that the degree of the trace field of C(2, s) is n. We also prove that if for fixed p, the degree of the trace field of C(p, s) runs over ${\mathbb{N}}{\backslash}\{1\}$, then p is contained in {1, 2, 4, 8}.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.1
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• pp.39-42
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• 1999

Nitrogen-doped SiC(3C) (N-SiC(3C)) epliayers were grown on Si(111) substrate at $1250^{\circ}C$ using chemical vapor deposition (CVD) technique by pyrolyzing tetramethylsilane(TMS) in $H_{2}$ carrier gas. SiC(3C) layer was doped using $NH_{3}$ during the CVD growth to be n-type conduction. Physical properties of N-SiC(3C) were investigated by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) patterns, Raman spectroscopy, cross-sectional transmission electron microscopy (XTEM), Hall measurement, and current-voltage(I-V) characteristcs of the N-SiC(3C)/Si(p) diode. N-SiC(3C) layers exhibited n-type conductivity. The n-type doping of SiC(3C) could be controlled by nitrogen dopant using $NH_{3}$ at low temperature.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.6
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• pp.398-403
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• 2001

In this paper, effective ionization coefficient for 6H-SiC is determined. Analytical formulas for the parallel plane breakdown voltage of the 6H-SiC p＋n junction are derived by employing the ionization coefficients. The analytical breakdown voltages show good agreement with the numerical results of Dmitriev＇s［3］and the experimental results of Cree Research［9］over the doping range from 10$^{15}$ cm$^{-3}$ to 10$^{18}$ cm$^{-3}$.

• Journal of the Korean Ceramic Society
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• v.30 no.12
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• pp.999-1006
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• 1993

Si3N4(p)-SiC(p) composites were prepared by gas pressure sintering at 190$0^{\circ}C$ for 1 hour. $\alpha$-SiC with average particle size of 0.48${\mu}{\textrm}{m}$ were dispersed from zero to 50vol% in $\alpha$-Si3N4 with average particle size of 0.5${\mu}{\textrm}{m}$. Y2O3-Al2O3 system was used as sintering aids. When 10vol% of SiC was added to Si3N4, optimum mechanical properties were observed; relative density of 98.8%, flextural strength of 930MPa, fracture toughness of 5.9MPa.m1/2 and hardness value of 1429kg/$\textrm{mm}^2$. Grain growth of $\beta$-Si3N4 was inhibited as the amount of added SiC was increased. SiC particles were found inside the $\beta$-Si3N4 intragrains in case of 10, 20 and 30vol%SiC added composites.