• 제목/요약/키워드: $\Delta$f

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주기적 신호를 이용한 단일모드 광섬유의 상호 위상변조 해석 (Analysis of Cross-Phase Modulation using a periodic signal in a Single-Mode Fiber)

  • 이종형
    • 한국정보통신학회논문지
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    • 제19권12호
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    • pp.2963-2967
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    • 2015
  • 단일모드 광섬유를 사용한 WDM 시스템에서 CPM에 의한 성능저하를 이론적으로 분석하기 위해 펌프-프로브 구조에서 펌프신호가 주기적이라고 가정하였다. 주기적 펌프신호는 '0'과 '1'이 교대로 발생하는 경우를 모델링한 것으로 CPM에 의한 EOP를 이론적으로 예측할 수 있게 한다. 유도된 이론적 결과를 수치해석 결과와 비교하였으며, 그 결과 표준 단일모드 광섬유를 사용한 경우는 넓은 영역의 채널 간격 ${\Delta}f$에 대해 유도된 이론식이 수치해석의 결과와 잘 일치하고 분산천이 광섬유를 사용한 경우는 ${\Delta}f$>100GHz 에서 일치하였다. 분산천이 광섬유를 사용하여 ${\Delta}f$<100GHz 인 경우는 CPM뿐만 아니라 FWM에 의한 성능저하가 두드러지므로 이론적 결과와 수치 해석의 결과 사이의 편차가 증가한다. 펌브-프로브 구조가 광섬유의 비선형성중 CPM의 영향을 주로 분석하기 위한 것이므로 이 결과는 예상대로 이다.

Increased Frontal Gamma and Posterior Delta Powers as Potential Neurophysiological Correlates Differentiating Posttraumatic Stress Disorder from Anxiety Disorders

  • Moon, Sun-Young;Choi, Yoo Bin;Jung, Hee Kyung;Lee, Yoonji Irene;Choi, Soo-Hee
    • Psychiatry investigation
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    • 제15권11호
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    • pp.1087-1093
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    • 2018
  • Objective Posttraumatic stress disorder (PTSD) is distinct from anxiety disorders in its etiology and clinical symptomatology, and was reclassified into trauma- and stressor-related disorders in DSM-5. This study aimed to find neurophysiological correlates differentiating PTSD from anxiety disorders using resting-state quantitative electroencephalography (qEEG). Methods Thirty-six patients with either PTSD or acute stress disorder and 79 patients with anxiety disorder were included in the analysis. qEEG data of absolute and relative powers and patients' medication status on the day of qEEG examination were obtained. Electrodes were grouped into frontal, central, and posterior regions to analyze for regional differences. General linear models were utilized to test for group differences in absolute and relative powers while controlling for medications. Results PTSD patients differed from those with anxiety disorders in overall absolute powers [F(5,327)=2.601, p=0.025]. Specifically, overall absolute delta powers [F(1,331)=4.363, p=0.037], and overall relative gamma powers [F(1,331)=3.965, p=0.047] were increased in PTSD group compared to anxiety disorder group. Post hoc analysis regarding brain regions showed that the increase in absolute delta powers were localized to the posterior region [F(1,107)=4.001, p=0.048]. Additionally, frontal absolute gamma powers [F(1,107)=4.138, p=0.044] were increased in PTSD group compared to anxiety disorder group. Conclusion Our study suggests increased overall absolute delta powers and relative gamma powers as potential markers that could differentiate PTSD from anxiety disorders. Moreover, increased frontal absolute gamma and posterior delta powers might pose as novel markers of PTSD, which may reflect its distinct symptomatology.

GROWTH NORM ESTIMATES FOR ¯∂ ON CONVEX DOMAINS

  • Cho, Hong-Rae;Kwon, Ern-Gun
    • 대한수학회논문집
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    • 제22권1호
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    • pp.111-119
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    • 2007
  • We consider the growth norm of a measurable function f defined by defined by $${\parallel}f{\parallel}-\sigma=ess\;sup\{\delta_D(z)^\sigma{\mid}f(z)\mid:z{\in}D\}$$, where $\delta_D(z)$ denote the distance from z to ${\partial}D$. We prove some kind of optimal growth norm estimates for a on convex domains.

CERTAIN CLASS OF FRACTIONAL CALCULUS OPERATOR WITH TWO FIXED POINTS

  • Kwon, Oh-Sang
    • East Asian mathematical journal
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    • 제14권1호
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    • pp.107-116
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    • 1998
  • This paper deals with functions of the form $f(z)=a_1z-{\sum}{\limits}_{n=2}^{\infty}a_nz^n(a_1>0,\;a_n{\geqslant}0)$ with $(1-{\mu})f(z_0)/z_0+{\mu}f'(z_0)=1(-1. We introduce the class $\varphi({\mu},{\eta},{\gamma},{\delta},A,B;\;z_0)$ with generalized fractional derivatives. Also we have obtained coefficient inequalities, distortion theorem and radious problem of functions belonging to the calss $\varphi({\mu},{\eta},{\gamma},{\delta},A,B;\;z_0)$.

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Some Properties Subclasses of Analytic Functions

  • Frasin, Basem Aref
    • Kyungpook Mathematical Journal
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    • 제54권4호
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    • pp.531-543
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    • 2014
  • The object of the present paper is to discuss some interesting properties of analytic functions f(z) associated with the subclasses $\mathcal{D}({\beta}_1,{\beta}_2,{\beta}_3;{\lambda})$, $\mathcal{G}({\theta},{\alpha})$ and $\mathcal{Q}({\theta},{\alpha})$. Also, radius problems of $\frac{1}{\delta}f({\delta}z)$ for f(z) in the class $\mathcal{D}({\beta}_1,{\beta}_2,{\beta}_3;{\lambda})$, $\mathcal{G}({\theta},{\alpha})$ and $\mathcal{Q}({\theta},{\alpha})$ are considered.

UNICITY OF MERMORPHIC FUNCTIONS CONCERNING SHARED FUNCTIONS WITH THEIR DIFFERENCE

  • Deng, Bingmao;Fang, Mingliang;Liu, Dan
    • 대한수학회보
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    • 제56권6호
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    • pp.1511-1524
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    • 2019
  • In this paper, we investigate the uniqueness of meromorphic functions of finite order concerning sharing small functions and prove that if f(z) and ${\Delta}_cf(z)$ share a(z), b(z), ${\infty}$ CM, where a(z), b(z)(${\neq}{\infty}$) are two distinct small functions of f(z), then $f(z){\equiv}{\Delta}_cf(z)$. The result improves the results due to Li et al. ([9]), Cui et al. ([1]) and $L{\ddot{u}}$ et al. ([12]).

Mitochondrial Efficiency-Dependent Viability of Saccharomyces cerevisiae Mutants Carrying Individual Electron Transport Chain Component Deletions

  • Kwon, Young-Yon;Choi, Kyung-Mi;Cho, ChangYeon;Lee, Cheol-Koo
    • Molecules and Cells
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    • 제38권12호
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    • pp.1054-1063
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    • 2015
  • Mitochondria play a crucial role in eukaryotic cells; the mitochondrial electron transport chain (ETC) generates adenosine triphosphate (ATP), which serves as an energy source for numerous critical cellular activities. However, the ETC also generates deleterious reactive oxygen species (ROS) as a natural byproduct of oxidative phosphorylation. ROS are considered the major cause of aging because they damage proteins, lipids, and DNA by oxidation. We analyzed the chronological life span, growth phenotype, mitochondrial membrane potential (MMP), and intracellular ATP and mitochondrial superoxide levels of 33 single ETC component-deleted strains during the chronological aging process. Among the ETC mutant strains, 14 ($sdh1{\Delta}$, $sdh2{\Delta}$, $sdh4{\Delta}$, $cor1{\Delta}$, $cyt1{\Delta}$, $qcr7{\Delta}$, $qcr8{\Delta}$, $rip1{\Delta}$, $cox6{\Delta}$, $cox7{\Delta}$, $cox9{\Delta}$, $atp4{\Delta}$, $atp7{\Delta}$, and $atp17{\Delta}$) showed a significantly shorter life span. The deleted genes encode important elements of the ETC components succinate dehydrogenase (complex II) and cytochrome c oxidase (complex IV), and some of the deletions lead to structural instability of the membrane-$F_1F_0$-ATP synthase due to mutations in the stator stalk (complex V). These short-lived strains generated higher superoxide levels and produced lower ATP levels without alteration of MMP. In summary, ETC mutations decreased the life span of yeast due to impaired mitochondrial efficiency.

대릉(大陵)(PC7) 침자가 뇌파에 미치는 영향 (The Effect of Acupuncture at PC7(Daereung) on EEG in Normal Human Subject)

  • 박철진;이상룡
    • Korean Journal of Acupuncture
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    • 제27권2호
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    • pp.141-157
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    • 2010
  • Objectives : The aim of this study is to examine the effects of acupuncture at PC7(Daereung) on normal human EEG using power spectral analysis. Methods : EEG power spectrum exhibits site-specific and state-related differences in specific frequency bands. In this study, power spectrum was used as a measure of complexity. 30 subjects (16 males and 14 females; averaged age = 23.4 years) were engaged with thirty channel EEG study. Results : In $\alpha$(alpha) band, the power values at Fp1, Fp2, F7, F8 channels(p<0.05) during PC7 treatment were significantly decreased. But, the power values at Fz channel(p<0.05) during non-acupoint treatment was significantly decreased. In $\beta$(beta) band, the power values at Fp1, Fp2 channels(p<0.05) during PC7 treatment were significantly decreased. But, the power values at Fz channel(p<0.05) during non-acupoint treatment was significantly decreased and at F8, TCP2 channels(p<0.05) during non-acupoint treatment were increased. In $\theta$(theta) band, the power values at Fp1, Fp2, F7, F8 channels(p<0.05) during PC7 treatment were significantly decreased. But, the power values at Fz channel(p<0.05) during non-acupoint treatment was significantly decreased. In $\delta$(delta) band, the power values at Fp1, Fp2, F7, Fz, F8 channels (p<0.05) during PC7 treatment were significantly decreased. But, the power values at Fz channel (p<0.05) during non-acupoint treatment was significantly decreased. $\alpha/\beta$ values during PC7 treatment were decreased. $\beta/\theta$ values during PC7 treatment were decreased. Conclusion : These results suggest that acupuncture at PC7 induce the change on $\alpha$(alpha), $\beta$(beta), $\theta$ (theta), $\delta$(delta) wave values being decreased and and bothe $\alpha/\beta$ and $\beta/\theta$ values being decreased respectively. This is considered that acupuncture at PC7 affects the activity of cerebral cortex and endocrine system.

이천 지자기 관측소 플럭스게이트 자력계 온도 조절 장치 개발 및 설치 후 안정성 자체 평가 (Development of Thermostat for the Fluxgate Magnetometer in Icheon Geomagnetic Observatory and Stability Evaluation after Installation )

  • 최두영;이승욱;김준성;이대영;최규철;조정희
    • 우주기술과 응용
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    • 제2권3호
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    • pp.221-229
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    • 2022
  • 본 논문에서는 온도에 민감한 플럭스게이트 자력계 센서 온도를 일정하게 유지하기 위한 온도 조절 장치의 설계 및 설치, 그리고 설치 이후 데이터 안정성 평가에 대하여 기술하였다. 온도 조절 장치는 국립전파연구원 우주전파센터에서 운영 중인 이천 지자기 관측소에 설치되었다. 온도 조절 장치는 사고 안정성, 자기장 측정에 미치는 영향, 온도 조절 효율을 고려하여 설계하였다. 온도 조절 장치 설치 이후, 온도가 20℃ 수준에서 일정하게 유지되는 것을 확인하였다. 지자기 데이터 안정성 평가를 위하여 델타 F(delta-F)와 베이스라인(baseline) 값을 이용하였으며, 장치 설치 이후 델타 F와 베이스라인의 변동이 줄어든 것을 확인하였다.

OSCILLATORY BEHAVIOR AND COMPARISON FOR HIGHER ORDER NONLINEAR DYNAMIC EQUATIONS ON TIME SCALES

  • Sun, Taixiang;Yu, Weiyong;Xi, Hongjian
    • Journal of applied mathematics & informatics
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    • 제30권1_2호
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    • pp.289-304
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    • 2012
  • In this paper, we study asymptotic behaviour of solutions of the following higher order nonlinear dynamic equations $$S_n^{\Delta}(t,x)+{\delta}p(t)f(x(g(t)))=0$$ and $$S_n^{\Delta}(t,x)+{\delta}p(t)f(x(h(t)))=0$$ on an arbitrary time scale $\mathbb{T}$ with sup $\mathbb{T}={\infty}$, where n is a positive integer, ${\delta}=1$ or -1 and $$S_k(t,x)=\{\array x(t),\;if\;k=0,\\a_k(t)S_{{\kappa}-1}^{\Delta}(t),\;if\;1{\leq}k{\leq}n-1,\\a_n(t)[S_{{\kappa}-1}^{\Delta}(t)]^{\alpha},\;if\;k=n,$$ with ${\alpha}$ being a quotient of two odd positive integers and every $a_k$ ($1{\leq}k{\leq}n$) being positive rd-continuous function. We obtain some sufficient conditions for the equivalence of the oscillation of the above equations.