• Journal of Audiology & Otology
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• 제25권2호
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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.

• 대한청각학회지
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• 제25권2호
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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.

• 한국재료학회지
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• 제8권10호
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• pp.890-897
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• 1998

n-InP(001)기판과 PECVD법으로 ${Si}_3N_4$(200nm)막이 성장된 InP 기판사이의 direct wafer bonding을 분석하였다. 두 기판을 접촉시켰을 때 이들 사이의 결합력에 크게 영향을 주는 표면 상태를 접촉각 측정과 AFM을 통해서 분석하였다. InP 기판은 $50{\%}$ 불산용액으로 에칭하였을 때 접촉각이 $5^{\circ}$, RMS roughness는 $1.54{\AA}$이었다. ${Si}_3N_4$는 암모니아수 용액으로 에칭하였을 때 RMS roughness가 $3.11{\AA}$이었다. Inp 기판과 ${Si}_3N_4$/InP를 각각 $50{\%}$ 불산 용액과 암모니아수 용액에 에칭한 후 접촉시켰을 때 상당한 크기의 초기 겹합력을 관찰할 수 있었다. 기계적으로 결합된 시편을 $580^{\circ}C$-$680^{\circ}C$, 1시간동안 수소 분위기와 질소분우기에서 열처리하였다. SAT(Scanning Acoustic Tomography)측정으로 두 기판 사이의 결합여부를 확인하였다. shear force로 측정한 InP 기판과 ${Si}_3N_4$/InP사이의 결합력은 ${Si}_3N_4$/InP 계면의 결합력만큼 증가되었다. TEM과 AES를 이용해서 di-rect water bonding 계면과 PECVD계면을 분석하였다.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제16권3호
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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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• 제37권3호
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• pp.129-134
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• 2013

본 연구는 약 254일령(${\pm}2$)의 재래돼지 총 30두(암 15, 수 15)를 공시축으로 이용하여 성별에 따른 도체 및 육질 특성, 아미노산 및 지방산 조성을 비교 분석하여 고급돈육 생산에 필요한 기초자료를 얻고자 실시하였다. 도체중은 수퇘지가 유의하게 무거웠으나, 도체율은 암퇘지가 더 높게 나왔다(p<0.01). 등심부위의 일반성분 조성을 성별에 따라 비교한 결과, 수분 함량은 수퇘지에서 높게 나타났으며, 조단백질 함량은 암퇘지에서 높은 것으로 관찰되었다(p<0.01). 육질 특성을 분석한 결과에서 pH는 수퇘지에서 유의적으로 높게 나타났으나(p<0.01), 가열감량(p<0.01), 전단력, 육색의 명도와 황색도, 황색도(p<0.05)는 유의수준으로 암퇘지에서 높게 나타났다. 재래돼지 등심육의 아미노산 조성은 arginine (p<0.05), alanine, aspartic acid, histidine, leucine, lysine, phenylalanine, serine, threonine 및 tyrosin (p<0.01)의 함량이 암퇘지에서 수퇘지에 비해 유의적으로 높게 나타났다. 재래돼지 등심육의 지방산 조성은 암퇘지가 단가불포화지방산인 C16:1n7, C18:1n9, C20:1n9(p<0.01)의 함량이 수퇘지보다 유의적으로 더 높은 반면, 다가불포화지방상인 C18:2n6, C20:4n6 (p<0.01), 그리고 C18:3n3 (p<0.05)의 함량이 수퇘지에서 암퇘지보다 유의적으로 높게 관찰되었다. 결론적으로 본 연구는 재래돼지의 성별에 따른 도체 및 육질 특성, 아미노산 및 지방산 조성을 비교 분석한 것으로 앞으로 고품질의 재래돼지고기 생산을 위한 중요한 기초자료로 이용될 수 있을 것으로 사료된다.

• Journal of applied mathematics & informatics
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• 제5권1호
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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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• 제56권1호
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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}.

• 한국결정성장학회지
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• 제9권1호
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• pp.39-42
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• 1999

N-도핑된 3C-SiC (N-SiC(3C))을 화학기상증착(CVD)으로 $1250^{\circ}C$에서 Si(111) 기판 위에 tetramethylsilane(TMS)를 열분해하여 성장하였다. 수송가스는 $H_{2}$이었고, N-SiC(3C) 에피층은 CVD로 성장되는 동안 $NH_{3}$에 의하여 n-형으로 도핑되었다. N-SiC(3C)의 물리적 특성은 적외선 분광(FTIR), X-선 회절(XRD), 라만 스펙트럼(Raman spectrum), 단면 투과전자영상(XTEM), Hall 측정 및 p/n 다이오드의 전압-진압(I-V) 특성에 의하여 조사되었다. N-도핑된 SiC(3C) 에피층의 전도형은 n-형이었고, 전도형은 $NH_{3}$를 사용한 N-dopant에 의하여 저온에서 잘 조절될 수 있다.

• 대한전자공학회논문지SD
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• 제38권6호
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• pp.398-403
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• 2001

본 논문에서는 6H-SiC의 유효 이온화 계수를 추출하였고, 이 이온화 계수를 이용하여 6H-SiC p＋n 접합의 해석적 항복 전압 식을 유도하였다. 해석적 항복 전압 결과는 10/sup 15/ cm/sup -3/ ∼ 10/sup 18/ cm/sup -3/의 농도 범위에서 Dmitriev의 수치적 결과［3］ 및 Cree Research의 실험 결과［9］와 비교하여 잘 일치하였다.

• 한국세라믹학회지
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• 제30권12호
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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.