• Title/Summary/Keyword: ${\alpha}$-stable process

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H$\"{O}$LDER CONTINUITY OF H-SSSI S$\alpha$S PROCESSES

  • Kim, Joo-Mok
    • Communications of the Korean Mathematical Society
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    • v.15 no.1
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    • pp.123-131
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    • 2000
  • Let {X(t) : t $\geq$B 0} be a Symmetric $\alpha$ Stable and H-Self-similar process with stationary increments. We examine a.s. Holder unboundedness of S$\alpha$S H-sssi Chentsov processes and H-sssi Chentsov fields for order ${\gamma}$>H. Finally, we prove a.s. Holder continuity of S$\alpha$S H-sssi processes with ergodic seating transformations for the case of H>1/$\alpha$.

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Quantitative Recognition of Stable State of EEG using Wavelet Transform and Power Spectrum Analysis (웨이브렛 변환과 파워스펙트럼 분석을 통한 EEG 안정상태의 정량적 인식)

  • Kim, Young-Sear;Park, Seung-Hwan;Nam, Do-Hyun;Kim, Jong-Ki;Kil, Se-Kee;Min, Hong-Ki
    • Journal of the Institute of Convergence Signal Processing
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    • v.8 no.3
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    • pp.178-184
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    • 2007
  • The EEG signal in general can be categorized as the Alpha wave, the Beta wave, the Theta wave, and the Delta wave. The alpha wave, showed in stable state, is the dominant wave for a human EEG and the beta wave displays the excited state. The subject of this paper was to recognize the stable state of EEG quantitatively using wavelet transform and power spectrum analysis. We decomposed EEG signal into the alpha wave and the beta wave in the process of wavelet transform, and calculated each power spectrum of EEG signal, using Fast Fourier Transform. And then we calculated the stable state quantitatively by stable state ratio, defined as the power spectrum of the alpha wave over that of the beta wave. The study showed that it took more than 10 minutes to reach the stable state from the normal activity in 69 % of the subjects, 5 -10 minutes in 9%, and less than 5 minutes in 16 %.

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Stochastic analysis of external and parametric dynamical systems under sub-Gaussian Levy white-noise

  • Di Paola, Mario;Pirrotta, Antonina;Zingales, Massimiliano
    • Structural Engineering and Mechanics
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    • v.28 no.4
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    • pp.373-386
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    • 2008
  • In this study stochastic analysis of non-linear dynamical systems under ${\alpha}$-stable, multiplicative white noise has been conducted. The analysis has dealt with a special class of ${\alpha}$-stable stochastic processes namely sub-Gaussian white noises. In this setting the governing equation either of the probability density function or of the characteristic function of the dynamical response may be obtained considering the dynamical system forced by a Gaussian white noise with an uncertain factor with ${\alpha}/2$- stable distribution. This consideration yields the probability density function or the characteristic function of the response by means of a simple integral involving the probability density function of the system under Gaussian white noise and the probability density function of the ${\alpha}/2$-stable random parameter. Some numerical applications have been reported assessing the reliability of the proposed formulation. Moreover a proper way to perform digital simulation of the sub-Gaussian ${\alpha}$-stable random process preventing dynamical systems from numerical overflows has been reported and discussed in detail.

MULTIDIMENSIONAL SYMMETRIC STABLE PROCESSES

  • Chen, Zhen-Qing
    • Journal of applied mathematics & informatics
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    • v.6 no.2
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    • pp.329-368
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    • 1999
  • This paper surveys recent remarkable progress in the study of potential theory for symmetric stable processes. It also contains new results on the two-sided estimates for Green functions Poisson kernels and Martin kernels of discontinuous symmetric $alpha$ -stable process in bounded $C^{1,1}$ open sets. The new results give ex-plicit information on how the comparing constants depend on pa-rametrer $alpha$ and consequently recover the green function and Poisson kernel estimates for Brownian motion by passing $alpha{\uparrow}2$. In addition to these new estimates this paper surveys recent progress in the study of notions of harmonicity integral representation of harmonic func-tions boundary harnack inequality conditional gauge and intrinsic ultracontractivity for symmetric stable processes. Here is a table of contents.

Recognition of Stable State of EEG using Wavelet Transform and Power Spectrum Analysis (웨이브렛 변환과 파워 스펙트럼 분석을 이용한 EEG의 안정 상태 인식에 관한 고찰)

  • Kim, Young-Seo;Kil, Se-Kee;Lim, Seon-Ah;Min, Hong-Ki;Her, Woong;Hong, Seung-Hong
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.879-880
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    • 2006
  • The subject of this paper is to recognize the stable state of EEG using wavelet transform and power spectrum analysis. An alpha wave, showed in stable state, is dominant wave for a human EEG and a beta wave displayed excited state. We decomposed EEG signal into an alpha wave and a beta wave in the process of wavelet transform. And we calculated each power spectrum of EEG signal, an alpha wave and a beta wave using Fast Fourier Transform. We recognized the stable state by making a comparison between power spectrum ratios respectively.

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SAMPLE PATH PROPERTY OF CHENTSOV FIELDS

  • Kim, Joo-Mok
    • Journal of the Chungcheong Mathematical Society
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    • v.11 no.1
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    • pp.35-44
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    • 1998
  • Let {X(t), $t{\in}\mathbb{R}^n$} be a $S{\alpha}S$ H-sssis Chentsov random field with control measure m. We consider a geometric construction for L$\acute{e}$vy-Chentsov random fields and Takenaka random fields. Finally, we proved some property of conjugate classes and a.s. H$\ddot{o}$lder unboundedness of $S{\alpha}S$ H-sssis Chentsov random fields for all order ${\gamma}$ > H.

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Robust Multiuser Detection Based on Least p-Norm State Space Filtering Model

  • Zha, Daifeng
    • Journal of Communications and Networks
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    • v.9 no.2
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    • pp.185-191
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    • 2007
  • Alpha stable distribution is better for modeling impulsive noises than Gaussian distribution in signal processing. This class of process has no closed form of probability density function and finite second order moments. In general, Wiener filter theory is not meaningful in S$\alpha$SG environments because the expectations may be unbounded. We proposed a new adaptive recursive least p-norm Kalman filtering algorithm based on least p-norm of innovation process with infinite variances, and a new robust multiuser detection method based on least p-norm Kalman filtering. The simulation experiments show that the proposed new algorithm is more robust than the conventional Kalman filtering multiuser detection algorithm.

Comparative studies of various transfection processes for the optimal luminescence signal analysis (최적의 luminescence 신호 분석을 위한 유전자 전달 방법의 비교연구)

  • Park, Seohyun;Lee, Sunghou
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.11
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    • pp.640-647
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    • 2016
  • By minimizing fluorescence interference phenomena, aequorin-based luminescence technology can provide a relatively sensitive detection platform with integration of $G{\alpha}16$ protein in order to track internal calcium mobilization by G protein-coupled receptors (GPCR). In this type of cell-based functional assay format, it is essential to optimize the transfection process of a receptor and $G{\alpha}16$ protein. For this study, corticotropin releasing factor receptor subtype 2(CRF2) was set as a model system to generate three stable cells with CRF2 and $G{\alpha}16$ in addition to transiently transfected cells under three different conditions. Agonist (sauvagine) and antagonist (K41498) responses in those cells were analyzed to develop the optimum transfection process. As a result, the effective signal ratio in the dose response experiments of sauvagine and K41498 were at least 10-fold higher (z'=0.77) in CRF2-$G{\alpha}16$ stable cells. For the transient transfection cells, stable expression of $G{\alpha}16$ prior to the CRF2 represented a two-fold higher signal (z'=0.84) than the other cases of transient transfection. In conclusion, for the utilization of transient transfection processes to develop a cell-based GPCR functional assay system, it is suggested to introduce various target receptors after stable expression of $G{\alpha}16$ protein.

Characterization of Multiphase in $Fe_2O_3$ Thin Film by PECVD

  • Kim, Bum-Jin;Lee, Eun-Tae;Jang, Gun-Eik;Chung, Yong-Sun
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1997.06a
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    • pp.79-85
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    • 1997
  • Fe$_2$O$_3$ thin films were prepared on $Al_2$O$_3$ substrate by PECVD(Plasma-Enhanced Chemical Vapor Deposition) process. The phase transformation of iron oxide film was determined as the substrate temperature and reduction-oxidation process. $\alpha$-Fe$_2$O$_3$ was stable in deposition temperature ranges of 80~15$0^{\circ}C$. Fe$_3$O$_4$ phase was obtained by the reduction process of $\alpha$-Fe$_2$O$_3$ phase in H$_2$ ambient. Fe$_3$O$_4$ phase was transformed into a ${\gamma}$-Fe$_2$O$_3$ thin film under controlled oxidation conditions at 280~30$0^{\circ}C$.

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A Novel Integrative Expression Vector for Sulfolobus Species

  • Choi, Kyoung-Hwa;Hwang, Sungmin;Yoon, Naeun;Cha, Jaeho
    • Journal of Microbiology and Biotechnology
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    • v.24 no.11
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    • pp.1503-1509
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    • 2014
  • With the purpose of facilitating the process of stable strain generation, a shuttle vector for integration of genes via a double recombination event into two ectopic sites on the Sulfolobus acidocaldarius chromosome was constructed. The novel chromosomal integration and expression vector pINEX contains a pyrE gene from S. solfataricus P2 ($pyrE_{sso}$) as an auxotrophic selection marker, a multiple cloning site with histidine tag, the internal sequences of malE and malG for homologous recombination, and the entire region of pGEM-T vector, except for the multiple cloning region, for propagation in E. coli. For stable expression of the target gene, an ${\alpha}$-glucosidase-producing strain of S. acidocaldarius was generated employing this vector. The malA gene (saci_1160) encoding an ${\alpha}$-glucosidase from S. acidocaldarius fused with the glutamate dehydrogenase ($gdhA_{saci}$) promoter and leader sequence was ligated to pINEX to generate pINEX_malA. Using the "pop-in" and "pop-out" method, the malA gene was inserted into the genome of MR31 and correct insertion was verified by colony PCR and sequencing. This strain was grown in YT medium without uracil and purified by His-tag affinity chromatography. The ${\alpha}$-glucosidase activity was confirmed by the hydrolysis of $pNP{\alpha}G$. The pINEX vector should be applicable in delineating gene functions in this organism.