• 제목/요약/키워드: variability of spectrum

검색결과 135건 처리시간 0.038초

Prenatal diagnosis of 4p deletion syndrome: A case series report

  • Kwak, Dong Wook;Ahn, Hyun Kyong
    • Journal of Genetic Medicine
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    • 제14권1호
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    • pp.38-42
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    • 2017
  • The 4p deletion syndrome, also known as Wolf-Hirschhorn syndrome, is a well-known genetic disorder caused by a partial deletion of the short arm of chromosome 4. The great variability in the extent of the 4p deletion and the possible contribution of additional genetic rearrangements leads to a wide spectrum of clinical manifestations. Herein, we present our experience with eight cases of 4p deletion syndrome, ascertained prenatally between 1998 and 2016 at our hospital.

우리 나라 주요 지점에 대한 가뭄지수의 산정과 비교 (Calcualtion and Comparison of Drought Indices on Major Weatehr Stations in Korea)

  • 김상민
    • 한국농공학회지
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    • 제41권5호
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    • pp.43-52
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    • 1999
  • In an effort to identify quantitatively historical drought conditions, and to evaluate their temporal and spatial variability , two commonly used drougth indices, the standardized precipitation index, SPI by Mckee and the Palmer drought severity index. PDSI were calculated from 54 meteorological stations, SPI was evaluated for different time scales, 3 to 48 months. As the compjtational spans for SPI increase from 3 to 48 months the frequency and intensity of drought decrease, but the duration of drought increase. When monthly and ten-day PDSIs were compared, the frequency and duratin of drought were almost equal and the intensity of drought differ slightly. The three month SPI has the advatage to detect the drought resulting from short-term shortage of rainfall, while PDSI had the advantage to detect the state of drought resulting from cumulated shortage of rainfall. The period-frequency spectrum analyses at Kangnung statino showed that the maximum value of relative frequency was 24.4% when the period was 5.2months, and the 6month SPI has most similar trends to PDSI.

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Effects of ground motion scaling on nonlinear higher mode building response

  • Wood, R.L.;Hutchinson, T.C.
    • Earthquakes and Structures
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    • 제3권6호
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    • pp.869-887
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    • 2012
  • Ground motion scaling techniques are actively debated in the earthquake engineering community. Considerations such as what amplitude, over what period range and to what target spectrum are amongst the questions of practical importance. In this paper, the effect of various ground motion scaling approaches are explored using three reinforced concrete prototypical building models of 8, 12 and 20 stories designed to respond nonlinearly under a design level earthquake event in the seismically active Southern California region. Twenty-one recorded earthquake motions are selected using a probabilistic seismic hazard analysis and subsequently scaled using four different strategies. These motions are subsequently compared to spectrally compatible motions. The nonlinear response of a planar frameidealized building is evaluated in terms of plasticity distribution, floor level acceleration and uncorrelated acceleration amplification ratio distributions; and interstory drift distributions. The most pronounced response variability observed in association with the scaling method is the extent of higher mode participation in the nonlinear demands.

뇌 손상 환자(Cerebral palsy)의 Head up Tilt 상태에서의 심박변동과 자율 신경 활동 평가 (Assessment of autonomic function in Cerebral palsy patients during graded head-up tilt)

  • 최종주;조성래;이정환;이명호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 D
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    • pp.2693-2695
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    • 2002
  • In this paper, the power spectral analysis of heart rate variability(HRV) was performed to evaluate effects of orthostatic stress with head-up tilt on autonomic nervous system(ANS) for 20 healthy male subjects(age : 245 yr.) and a new method was proposed to assess the autonomic balance. The ECG signals wore recorded for 3 minutes in both the supine and 70 head-up tilt positions, and then the HRV signals underwent power spectrum analysis at each position. The results of this study suggest that cardiac autonomic functions, such as sympathetic tone in autonomic balance with the increment of sympathetic tone and the decrement of parasympathetic tone which occur during head-up tilt position, arc not sufficient to overcome tile orthostatic stress arising in Cerebral Palsy.

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RF 전송 모듈을 통한 HRV 모니터링 시스템 (HRV Monitoring System with RF Communication)

  • 윤태호;김경섭;신승원;김성회;이정환;이강휘;김동준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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    • pp.2157-2158
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    • 2006
  • Heart Rate Variability (HRV) system is useful for evaluating the balance in homeostasis of autonomic nervous system. In this study, we implement HRV monitoring system by performing real time FFT spectrum analysis on R-R intervals data acquired from Electrocardiogram (ECG) acquisition and transmitting the data by RF communication module.

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The Fine Power Spectra of the Southern Oscillation Index and Its Components and their Implication

  • Lim, G.-H.;Suh, Y.-C.
    • 대기
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    • 제25권3호
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    • pp.559-568
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    • 2015
  • As is evident from its definition, Southern Oscillation Index variability conformed to a combination of the variations of Darwin and Tahiti pressure. Over the El-$Ni{\tilde{n}}o$ Southern Oscillation spectra, the Darwin pressure shared variations associated with the SSN tendency while the Tahiti had a connection with the stratospheric quasi-biennial oscillation modulating annual cycle. The power peak near the 3.5-year period comprised the third harmonic of the sun and the second of the modulated annual cycle. The derived harmonics came from both sources, so the initiation of El-$Ni{\tilde{n}}o$ could be predicted more successfully when including the effects of the sun and QBO.

복합모드감쇠를 고려한 구조물의 지진취약도분석 (Seismic Fragility Analysis of the Structure Considering Composite Modal Damping)

  • 조성국;조양희;박형기;황규호
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
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    • pp.200-207
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    • 2001
  • This paper introduces a methodology of seismic fragility analysis and discusses the basic input variables, focusing on the conservatism and variability of reference response spectrum. The procedures to consider the composite modal damping in the seismic fragility analysis is presented and its effects on the seismic capacity of structure is evaluated through an example analysis of the nuclear power plant structure which has typical composite modal damping characteristics. Two seismic fragility analyses were performed to obtain the seismic capacities which evaluated by considering the composite modal damping and the single damping characteristics. The results showed that the seismic fragility analysis without considering the different values of composite modal damping may considerably overestimate the seismic capacity of coupled structures.

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Bayesian Nonstationary Flood Frequency Analysis Using Climate Information

  • Moon, Young-Il;Kwon, Hyun-Han
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2007년도 학술발표회 논문집
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    • pp.1441-1444
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    • 2007
  • It is now widely acknowledged that climate variability modifies the frequency spectrum of hydrological extreme events. Traditional hydrological frequency analysis methodologies are not devised to account for nonstationarity that arises due to variation in exogenous factors of the causal structure. We use Hierarchical Bayesian Analysis to consider the exogenous factors that can influence on the frequency of extreme floods. The sea surface temperatures, predicted GCM precipitation, climate indices and snow pack are considered as potential predictors of flood risk. The parameters of the model are estimated using a Markov Chain Monte Carlo (MCMC) algorithm. The predictors are compared in terms of the resulting posterior distributions of the parameters associated with estimated flood frequency distributions.

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HRV을 이용한 폐쇄성 수면 무호흡 환자의 수면 단계 분석 (Sleep Stage Analysis of Obstructive Sleep Apnea Patient using HRV)

  • 예수영;엄상희;전계록
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 추계학술대회
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    • pp.464-467
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    • 1997
  • In this study, ECG was recorded during sleep patients with obstructive sleep apnea. We detecte(heart rate variability) signal from the ECG wa QRS detection algorithm. And we observed HRV by the power spectrum density using autoregr modeling. The experimental results were analysis sleep stage 1, sleep stage 2, sleep stage 3, sleep s sleep stage REM. In experimental result, the PSD with obstructive sleep apnea patients was distributed low frequency band except sleep step 4. These effect means that the sympathetic nervous system affected the sleep stage 1, 2, REM and the parasympathetic nervous system affected the sleep stage 3, 4 with obstructive sleep apnea patients.

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신박변동신호의 추정 - Kaiser Windowin 기법 (Estimation of HRV - the Kaiser Window)

  • 최규섭;이준영;서현우;윤성언;이명호
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.543-543
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    • 2000
  • A new method for HRV(heart rate variability) detection from the R-wave signal, based on the IPFM(integral pulse frequency modulation) model and its similarity to pulse position modulation, is presented. The proposed method exert lowpass filtering with a Kaiser window. In this paper, The proposed method presents a powerful, but simple, tool for investigation of HRV. It also guarantees real-time behavior. simplicity in design, and phase linearity. Even without the basic assumption of IPFM model. the new algorithm can still be used on-line and with higher performance. It is thoroughly proved that lowpass filtering is an ideal method for PSD(Power Spectrum Density) analysis of HRV.

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