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1

Protective effects and potential mechanisms of Pien Tze Huang on cerebral chronic ischemia and hypertensive stroke  

PubMed Central

Background Stroke caused by brain ischemia is the third leading cause of adult disability. Active prevention and early treatment of stroke targeting the causes and risk factors may decrease its incidence, mortality and subsequent disability. Pien Tze Huang (PZH), a Chinese medicine formula, was found to have anti-edema, anti-inflammatory and anti-thrombotic effects that can prevent brain damage. This study aims to investigate the potential mechanisms of the preventive effects of Pien Tze Huang on brain damage caused by chronic ischemia and hypertensive stroke in rats. Methods The effects of Pien Tze Huang on brain protein expression in spontaneously hypertensive rat (SHR) and stroke prone SHR (SHRsp) were studied with 2-D gel electrophoresis and mass spectrometric analysis with a matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF)/TOF tandem mass spectrometer and on brain cell death with enzyme link immunosorbent assay (ELISA) and immunostaining. Results Pien Tze Huang decreased cell death in hippocampus and cerebellum caused by chronic ischemia and hypertensive stroke. Immunostaining of caspase-3 results indicated that Pien Tze Huang prevents brain cells from apoptosis caused by ischemia. Brain protein expression results suggested that Pien Tze Huang downregulated QCR2 in the electron transfer chain of mitochondria preventing reactive oxygen species (ROS) damage and possibly subsequent cell death (caspase 3 assay) as caused by chronic ischemia or hypertensive stroke to hippocampus and cerebellum. Conclusion Pien Tze Huang showed preventive effects on limiting the damage or injury caused by chronic ischemia and hypertensive stroke in rats. The effect of Pien Tze Huang was possibly related to prevention of cell death from apoptosis or ROS/oxidative damage in mitochondria.

2010-01-01

2

Protective effects and potential mechanisms of Pien Tze Huang on cerebral chronic ischemia and hypertensive stroke  

Microsoft Academic Search

BACKGROUND: Stroke caused by brain ischemia is the third leading cause of adult disability. Active prevention and early treatment of stroke targeting the causes and risk factors may decrease its incidence, mortality and subsequent disability. Pien Tze Huang (PZH), a Chinese medicine formula, was found to have anti-edema, anti-inflammatory and anti-thrombotic effects that can prevent brain damage. This study aims

Lihong Zhang; Wai Ping Lam; Lanhai Lü; Chunmei Wang; Yeuk Wa Wong; Lok Hang Lam; Hong Chai Tang; Maria Sen Mun Wai; Mingwei Wang; Wing Hang Kwong; Sai Ming Ngai; Ying Tat Mak; David Tai Wai Yew

2010-01-01

3

How would composite traditional Chinese medicine protect the brain--an example of the composite formula "Pien Tze Huang".  

PubMed

Chinese medicine has a long history of several thousand years. The main form of Traditional Chinese Medicine (TCM) is composite, i.e. a mixture of up to 10 medicinal products. Thus a composite prescription of 4-5 kinds of Chinese medicinal products may contain several hundred kinds of chemical composition. The active ingredients and clinical efficacy of which are difficult to characterize. We aim to review the Chinese literature of TCMs with neuroprotective effects. We illustrate with our study on Pien Tze Huang (PZH) the use of in vivo tests in the study of composite TCM. Our results show evidence that PZH might have neuropreventive effects in rats. PMID:21756225

Zhang, L; Lam, W P; Lü, L; Wang, Y-X J; Wong, Y W; Lam, L H; Tang, H C; Wai, M S; Mak, Y T; Wang, M; Yew, D T

2011-01-01

4

Inhibition of ovarian cancer cell proliferation by Pien Tze Huang via the AKT-mTOR pathway  

PubMed Central

Pien Tze Huang (PZH) is a well-known Chinese medicine that has been used as a therapeutic drug in the treatment of a number of diseases, such as hepatocellular carcinoma and colon cancer. However, few studies have analyzed the effects of PZH on ovarian cancer cell proliferation. In the present study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and Transwell assays, cell cycle and apoptosis rate analyses and western blotting were conducted to investigate the effects of PZH on the proliferation rate of ovarian cancer cells and its potential molecular pathway. The results showed that PZH inhibits the proliferation of the human ovarian cancer OVCAR-3 cell line by blocking the progression of the cell cycle from the G1 to S phase, however, PZH did not induce OVCAR-3 cell apoptosis. Increased PZH concentration may downregulate the expression of AKT, phosphorylated (p)-AKT, mammalian target of rapamycin (mTOR) and p-mTOR proteins in the OVCAR-3 cell line. In addition, it was observed that PZH may suppress the protein expression of cyclin-dependent kinase (CDK)4 and CDK6. Overall, the results of the present study indicated that PZH may inhibit ovarian cancer cell proliferation by modulating the activity of the AKT-mTOR pathway.

HE, FAN; WU, HUI-NI; CAI, MU-YAN; LI, CHANG-PENG; ZHANG, XIN; WAN, QUAN; TANG, SHUANG-BO; CHENG, JIAN-DING

2014-01-01

5

Pien Tze Huang inhibits hypoxia-induced epithelial-mesenchymal transition in human colon carcinoma cells through suppression of the HIF-1 pathway  

PubMed Central

Hypoxia-induced activation of the hypoxia-inducible factor 1 (HIF-1) signaling pathway is frequently observed in solid tumors and is strongly associated with numerous pathophysiological processes, including the induction of epithelial-mesenchymal transition (EMT), which result in cancer progression and metastasis. Thus, inhibiting EMT through the suppression of the HIF-1 pathway may be a promising strategy for anticancer chemotherapy. Pien Tze Huang (PZH), a well-established traditional Chinese medicine has been prescribed for >450 years and has been used for centuries to clinically treat various types of human cancer. We previously reported that PZH suppresses multiple intracellular signaling pathways and thereby promotes the apoptosis of cancer cells and the inhibition of cell proliferation and tumor angiogenesis. In the present study, to further explore the mechanisms underlying the antitumor action of PZH, HCT-8 human colon carcinoma cells were cultured under hypoxic conditions and the effect of PZH on hypoxia-induced EMT was assessed. Hypoxia was found to induce EMT-associated morphological changes in HCT-8 cells, including loss of cell adhesion and the development of spindle-shaped fibroblastoid-like morphology. In addition, hypoxia was observed to reduce the expression of the epithelial marker E-cadherin, but increase that of the mesenchymal marker N-cadherin. In addition, hypoxia significantly enhanced HCT-8 cell migration and invasion and induced the activation of the HIF-1 pathway. However, treatment of the HCT-8 cells with PZH significantly inhibited the hypoxia-mediated EMT and HIF-1 signaling. These findings suggest that PZH inhibits hypoxia-induced cancer EMT through the suppression of the HIF-1 pathway, which may be one of the molecular mechanisms by which PZH exerts its antitumor activity.

CHEN, HONGWEI; SHEN, ALING; ZHANG, YUCHEN; CHEN, YOUQIN; LIN, JIUMAO; LIN, WEI; SFERRA, THOMAS; PENG, JUN

2014-01-01

6

Revised Huang-Yang multipolar pseudopotential  

SciTech Connect

A number of authors have recently pointed out inconsistencies of results obtained with the Huang-Yang multipolar pseudopotential for low-energy scattering [K. Huang and K. C. Yang, Phys. Rev. 105, 767 (1957); later revised by Huang, Statistical Mechanics (Wiley, New York, 1963)]. The conceptual validity of their original derivation has been questioned. Here I show that these inconsistencies are rather due to an algebraic mistake made by Huang and Yang. With the corrected error, I present the revised version of the multipolar pseudopotential.

Derevianko, Andrei [Department of Physics, University of Nevada, Reno, Nevada 89557 (United States)

2005-10-15

7

Three new species of Coccobius Ratzeburg (Hymenoptera, Aphelinidae) and redescription of C. abdominis Huang and C. furviflagellatus Huang from China.  

PubMed

Three new species of Coccobius Ratzeburg (Hymenoptera: Aphelinidae) are described from China, Coccobius bimaculatus Wang, Huang & Polaszek sp. nov., Coccobius jinshanensis Wang, Huang & Polaszek sp. nov. and Coccobius leptocerus Wang, Huang & Polaszek sp. nov. Coccobius abdominis Huang 1994 and Coccobius furviflagellatus Huang 1994, originally described in Chinese, are redescribed in English and illustrated by macrophotography based on newly collected material. All five species were reared from Diaspididae (Hemiptera) scale insects on bamboo. Both the male of C. furviflagellatus and the diaspidid host association of C. abdominis and C. furviflagellatus are recorded for the first time. PMID:24871513

Wang, Zhu-Hong; Huang, Jian; Polaszek, Andrew

2014-01-01

8

Hilbert-Huang Transform in Ocean Turbulence  

NASA Astrophysics Data System (ADS)

Hilbert-Huang Transform is a relative novel time-frequency analysis technique for multi-scale processes. It is a wavelet-like data-driven methodology without a priori basis assumption. This meets the requirement of the analysis of the nonstationary and nonlinear data with short length or irregular sampling time interval. Since it is introduced in 1998 by Dr. N.E Huang, it has been widely applied to different scientific research fields and engineering problems, showing its simplicity and successes. We develop further this method to characterize the scale invariance for turbulence-like/scaling processes, e.g., velocity, temperature, dissolved oxygen observed in ocean, etc. In this talk, we first present a general introduction of this method. The key feature of this Hilbert-based method is that it is free with sub-harmonics when dealing with nonstationary and nonlinear data. This is accomplished by using an Intrawave-Frequency Modulation mechanism to characterize the so-called nonlinear distortion. Therefore, unlike the Fourier based methodologies, artificial energy redistribution in spectral space is constrained. We then show several applications of this method to experimental data from wind tunnel experiments and ocean observations. The interaction between two different scales and two variables are also discussed in statistics sense. The method is general and applicable to other systems, in which the multi-scale is relevant. Reference 1. Huang, N. E.; Shen, Z.; Long, S. R.; Wu, M. C.; Shih, H. H.; Zheng, Q.; Yen, N.; Tung, C. C. & Liu, H. H. The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis Proc. R. Soc. London, Ser. A, Royal Society, 1998, 454, 903-995 2. Huang, Y.; Schmitt, F.; Lu, Z. & Liu, Y. An amplitude-frequency study of turbulent scaling intermittency using Hilbert spectral analysis, Europhys. Lett., 2008, 84, 40010 3. Huang, Y.; Schmitt, F.; Lu, Z.; Fougairolles, P.; Gagne, Y. & Liu, Y. Second-order structure function in fully developed turbulence Phys. Rev. E, American Physical Society, 2010, 82, 26319 4. Huang, Y.; Schmitt, F. G.; Hermand, J.-P.; Gagne, Y.; Lu, Z. & Liu, Y. Arbitrary-order Hilbert spectral analysis for time series possessing scaling statistics: comparison study with detrended fluctuation analysis and wavelet leaders Phys. Rev. E, 2011, 84, 016208

Huang, Yongxiang

2013-04-01

9

The summary of Hilbert-Huang transform  

NASA Astrophysics Data System (ADS)

The widely investigated signals are mainly nonstationary and nonlinear signals, thus it is difficult to get the precise information from the nonstationary and nonlinear signals. Here we introduce a new method to process the nonstationary and nonlinear signals. And this new algorithm makes a good performance on processing the nonstationary and nonlinear signals. This paper mainly describe the basic theory of the new algorithm——Hilbert-Huang Transform. The Hilbert-Huang Transform is composed of Empirical Mode Decomposition and Hilbert transform. The problems of this arithmetic are summarized, such as the end effects, stop criterion and so on, and the solutions of these problems are put forward. This paper also provides some improved methods based on the Empirical Mode Decomposition in the end, such as Adaptive Time Varying Filter Decomposition, Extremum filed Mean Mode Decomposition and Improved Extremum field Mean Mode Decomposition.

Song, Shi-De; Yao, Zhi-chao; Wang, Xiao-Na

2013-09-01

10

Bearing Localized Fault Detection Based on Hilbert-Huang Transformation  

Microsoft Academic Search

The Hilbert-Huang transform and its marginal spectrum are applied to bearing fault diagnosis of ball bearing. The principle of Empirical mode decomposition (EMD), Hilbert-Huang transformation (HHT) and marginal spectrum is introduced. Firstly, the vibration signals of bearing fault are separated into several intrinsic mode functions (IMFs) using EMD method. Secondly, the marginal spectrum of each IMF is calculated. In the

Hui Li; Yuping Zhang

2007-01-01

11

Sleep stage classification based on EEG Hilbert-Huang transform  

Microsoft Academic Search

The aim of this work is to propose an automatic sleep stage classification technique of electroencephalogram's signals (EEG) using Hilbert-Huang transform. EEG signals are analyzed with the Hilbert-Huang transform, instantaneous frequency with the physical meaning is obtained; The energy-frequency distribution of EEG was used as features parameters for each sleep stage; Ultimately using nearest neighbor method for pattern classification complete

Yi Li; Fan Yingle; Li Gu; Tong Qinye

2009-01-01

12

Wear detection in gear system using Hilbert-Huang transform  

Microsoft Academic Search

Fourier methods are not generally an appropriate approach in the investigation of faults signals with transient components.\\u000a This work presents the application of a new signal processing technique, the Hilbert-Huang transform and its marginal spectrum,\\u000a in analysis of vibration signals and faults diagnosis of gear. The Empirical mode decomposition (EMD), Hilbert-Huang transform\\u000a (HHT) and marginal spectrum are introduced. Firstly, the

Hui Li; Yuping Zhang; Haiqi Zheng

2006-01-01

13

Method of speech enhancement based on Hilbert-Huang transform  

Microsoft Academic Search

A new speech enhancement method of Hilbert-Huang transform (HHT) was proposed. Hilbert-Huang transform is a new and powerful theory for the time-frequency analysis and is efficient for describing the local features of dynamic signals. On the basis of basic speech enhancement methods and HHT algorithm, a new method of speech enhancement is introduced. Using the EMD algorithm, firstly the speech

Xueyao Li; Xiaojie Zou; Rubo Zhang; Guanqun Liu

2008-01-01

14

Vibration Signal Analysis Based on Hilbert-Huang Transform  

Microsoft Academic Search

The time-frequency analysis by Hilbert-Huang transform (HHT) plays on a significant role in the analysis of singularities, which hide in the signal, and is an effective method for non-stationary signal. Based on empirical mode decomposition (EMD), the Hilbert-Huang method can obtain a true instantaneous frequency representation of a signal. The analytical background of the HHT is introduced, and its effectiveness

Ai-jun Hu; Ling Xiang; Gui-ji Tang

2008-01-01

15

Applications of the Hilbert-Huang Transform  

NASA Technical Reports Server (NTRS)

A new method, the Hilbert-Huang Transform, has been developed for analyzing nonlinear and nonstationary data. The key part of the method is the Empirical Mode Decomposition with which any complicated data set can be decomposed into a finite and often small number of Intrinsic Mode Functions (IMF). An M is defined as any function having the same numbers of zero-crossing and extrema, and also having symmetric envelopes defined by the local maxima and minima respectively. The IMF also admits well-behaved Hilbert transform. This decomposition method is adaptive, and, therefore, highly efficient. Since the decomposition is based on the local characteristic time scale of the data, it is applicable to nonlinear and nonstationary processes. With the Hilbert transform, the Intrinsic Mode Functions yield instantaneous frequencies'as functions of time that give sharp identifications of imbedded structures. The final presentation of the results is an energy-frequency-time distribution, designated as the Hilbert Spectrum. With this technique we can examine the detailed dynamics characteristics of a nonlinear system through the instantaneous frequency rather than harmonics. Thus it constitutes a new view of the nonlinear dynamics. Examples of classic nonlinear equations and other nonlinear and nonstationary data sets will be used as examples to illustrate the advantage of the application of this new data analysis method.

Huang, Norden E.; Zukor, Dorothy J. (Technical Monitor)

2001-01-01

16

[Doctor HUANG Shi-ping's acupuncture with golden needles].  

PubMed

Taking Doctor HUANG Shi-ping as the representative, the school of Huang's golden needle is based on Chinese martial art. Golden needles are adopted as main tool. Attaching great importance on the combination of acupuncture and moxibustioin, it is also characterized with penetrating needling with long needles. Through the development of three generations, it once outshone other schools in the field of acupuncture, and became famous all over the world. It made great contribution to the development of the course of acupuncture. However, with the development of the history, the form of acupuncture education as well as apparatus were all undergone an unified reform. Therefore, Doctor HUANG Shi-ping's acupuncture school be lost gradually. PMID:24195225

Chen, Teng-Fei; Ma, Zeng-Bin; Xin, Si-Yuan; Zhu, Jiang

2013-08-01

17

The Application of Hilbert-Huang Transforms to Meteorological Datasets  

NASA Technical Reports Server (NTRS)

Recently a new spectral technique as been developed for the analysis of aperiodic and nonlinear signals - the Hilbert-Huang transform. This paper shows how these transforms can be used to discover synoptic and climatic features: For sea level data, the transforms capture the oceanic tides as well as large, aperiodic river outflows. In the case of solar radiation, we observe variations in the diurnal and seasonal cycles. Finally, from barographic data, the Hilbert-Huang transform reveals the passage of extratropical cyclones, fronts, and troughs. Thus, this technique can flag significant weather events such its a flood or the passage of a squall line.

Duffy, Dean G.

2003-01-01

18

Speech Enhancement Based on Hilbert-Huang Transform Theory  

Microsoft Academic Search

Speech enhancement is effective in solving the problem of noisy speech. Hilbert-Huang transform (HHT) is efficient for describing the local features of dynamic signals and is a new and powerful theory for the time-frequency analysis. According to the theory of HHT, this text introduced a new method of speech enhancement to improve the speech quantity and the signal noise ratio

Xiaojie Zou; Xueyao Li; Rubo Zhang

2006-01-01

19

Speech enhancement based on Hilbert-Huang transform  

Microsoft Academic Search

The newly developed Hilbert-Huang transform (HHT) is introduced briefly in this paper. The HHT method is specially developed for analyzing nonlinear and non-stationary data. The method consists of two parts: (1) the empirical mode decomposition (EMD), and (2) the Hilbert spectral analysis. The EMD, which is the first part of the theory, can decompose any complicated data set into a

Zhuo-Fu Liu; Zhen-Peng Liao; En-Fang Sang

2005-01-01

20

The Fast Fourier and Hilbert-Huang Transforms: A Comparison  

Microsoft Academic Search

The conversion of time domain data via the fast Fourier (FFT) and Hilbert-Huang (HHT) transforms is compared. The FFT treats amplitude vs. time information globally as it transforms the data to an amplitude vs. frequency description. The HHT is not constrained by the assumptions of stationarity and linearity, required for the FFT, and generates both amplitude and frequency information as

Denis Donnelly

2006-01-01

21

Hilbert-Huang Transform for ECG DeNoising  

Microsoft Academic Search

The theories of empirical mode decomposition (EMD) and instantaneous frequency solution which are two parts of Hilbert-Huang Transformation (HHT) are discussed in the paper. We are focus on using the EMD to electrocardiogram (ECG) which can be decomposed into a limited number of intrinsic mode functions. Different thresholds are used to treat intrinsic mode function to achieve de-noising and then

Tang Jing-tian; Zou Qing; Tang Yan; Liu Bin; Zhang Xiao-kai

2007-01-01

22

Aeroelastic Flight Data Analysis with the Hilbert-Huang Algorithm  

NASA Technical Reports Server (NTRS)

This report investigates the utility of the Hilbert Huang transform for the analysis of aeroelastic flight data. It is well known that the classical Hilbert transform can be used for time-frequency analysis of functions or signals. Unfortunately, the Hilbert transform can only be effectively applied to an extremely small class of signals, namely those that are characterized by a single frequency component at any instant in time. The recently-developed Hilbert Huang algorithm addresses the limitations of the classical Hilbert transform through a process known as empirical mode decomposition. Using this approach, the data is filtered into a series of intrinsic mode functions, each of which admits a well-behaved Hilbert transform. In this manner, the Hilbert Huang algorithm affords time-frequency analysis of a large class of signals. This powerful tool has been applied in the analysis of scientific data, structural system identification, mechanical system fault detection, and even image processing. The purpose of this report is to demonstrate the potential applications of the Hilbert Huang algorithm for the analysis of aeroelastic systems, with improvements such as localized online processing. Applications for correlations between system input and output, and amongst output sensors, are discussed to characterize the time-varying amplitude and frequency correlations present in the various components of multiple data channels. Online stability analyses and modal identification are also presented. Examples are given using aeroelastic test data from the F-18 Active Aeroelastic Wing airplane, an Aerostructures Test Wing, and pitch plunge simulation.

Brenner, Martin J.; Prazenica, Chad

2006-01-01

23

Speech pitch determination based on Hilbert-Huang transform  

Microsoft Academic Search

Pitch determination is an essential part of speech recognition and speech processing. In this paper, a new pitch determination method based on Hilbert-Huang Transform (HHT) is presented. The assumption of linearity of the speech-production process and short-time stationarity of speech signals, which is generally employed in recent studies on speech recognition, is no longer needed, and hence the non-linearity of

Hai Huang; Jiaqiang Pan

2006-01-01

24

Speech Detection Based on Hilbert-Huang Transform  

Microsoft Academic Search

Under strong noise environments, the speech detection often performs bad, in order to make some improvements the Hilbert-Huang transform is used in the algorithm. The speech signal is decomposed into finite intrinsic mode functions, and then, with the Hilbert transform, the energy-frequency-time distribution of the original signal can be obtained. The EMD is used as a filter to remove unwanted

Wu Wang; Xueyao Li; Rubo Zhang

2006-01-01

25

Transient Signal Analysis Based on Hilbert-Huang Transform  

Microsoft Academic Search

This paper investigates the utility of Hilbert-Huang transform (HHT) for transient signal analysis. HHT represents a one-dimensional time series in a 2D time-frequency domain, thus is suited for analyzing nonstationary events commonly seen in rotary mechanical and electromechanical systems, where inception and propagation of structural defects during machine operations cause local perturbation to the periodic structural vibration signals. Using a

Ruqiang Yan; R. X. Gao

2005-01-01

26

A new envelope algorithm of Hilbert–Huang Transform  

Microsoft Academic Search

The algorithm to compute the envelope-line in Hilbert–Huang Transform (HHT) has major drawbacks. This paper first introduces the problem of an envelope-line algorithm in HHT, analyses the shortcomings of two classic algorithms, cubic spline interpolation algorithm and the Akima interpolation algorithm, and then proposes an important theory called the Segment Slide Theory in light of the principle of parabola parameter

S. R. Qin; Y. M. Zhong

2006-01-01

27

Aeroelastic Flight Data Analysis with the Hilbert-Huang Algorithm  

NASA Technical Reports Server (NTRS)

This paper investigates the utility of the Hilbert-Huang transform for the analysis of aeroelastic flight data. It is well known that the classical Hilbert transform can be used for time-frequency analysis of functions or signals. Unfortunately, the Hilbert transform can only be effectively applied to an extremely small class of signals, namely those that are characterized by a single frequency component at any instant in time. The recently-developed Hilbert-Huang algorithm addresses the limitations of the classical Hilbert transform through a process known as empirical mode decomposition. Using this approach, the data is filtered into a series of intrinsic mode functions, each of which admits a well-behaved Hilbert transform. In this manner, the Hilbert-Huang algorithm affords time-frequency analysis of a large class of signals. This powerful tool has been applied in the analysis of scientific data, structural system identification, mechanical system fault detection, and even image processing. The purpose of this paper is to demonstrate the potential applications of the Hilbert-Huang algorithm for the analysis of aeroelastic systems, with improvements such as localized/online processing. Applications for correlations between system input and output, and amongst output sensors, are discussed to characterize the time-varying amplitude and frequency correlations present in the various components of multiple data channels. Online stability analyses and modal identification are also presented. Examples are given using aeroelastic test data from the F/A-18 Active Aeroelastic Wing aircraft, an Aerostructures Test Wing, and pitch-plunge simulation.

Brenner, Marty; Prazenica, Chad

2005-01-01

28

Hilbert-Huang Transform and Marginal Spectrum for Detection of Bearing Localized Defects  

Microsoft Academic Search

This work presents the application of a new signal processing technique, the Hilbert-Huang transform and its marginal spectrum, in analysis of vibration signals and faults diagnosis of roller bearing. The empirical mode decomposition (EMD), Hilbert-Huang transform (HHT) and marginal spectrum is introduced. Firstly, the vibration signals are separated into several intrinsic mode functions (IMFs) using EMD. Then the marginal spectrum

Yuping Zhang

2006-01-01

29

Attitudes toward search engines as a learning assisted tool: approach of Liaw and Huang's research model  

Microsoft Academic Search

The purpose of this research is to develop new approach to investigate individual attitudes toward search engines as a learning assisted tool. This research is based on Liaw and Huang’s research model that included motivation perspective, social cognitive theory, and technology acceptance model. After factor analysis and regression analysis, the results show that the factor of perceived satisfaction of system’s

Shu-Sheng Liaw; Weng-Cheng Chang; Wu-Hsiung Hung; Hsiu-Mei Huang

2006-01-01

30

Hilbert-Huang transformation: application to postural stability analysis.  

PubMed

The aim objective of this paper is the analysis of the Centre Of Pressure (COP) time series by the means of the Hilbert Huang Transformation (HHT). The HHT consists of extracting the Intrinsic Mode Functions (IMFs) from an Empirical Mode Decomposition (EMD), and then applying the Hilbert Transformation on the IMFs. The trace of the HHT in the complex plane has a circular form, with each IMF having its own rotation frequency. The area of the circle represents a possible indicator of the postural stability status of the subjects. Experimental results show the effectiveness of the area of this circle in order to identify the post-vibratory effects on standing posture in healthy adult subjects. PMID:18002268

Amoud, Hassan; Snoussi, Hichem; Hewson, David J; Duchêne, Jacques

2007-01-01

31

Vibration analysis of a cracked rotor using Hilbert Huang transform  

NASA Astrophysics Data System (ADS)

In this paper, the startup transient response of a rotor with a propagating transverse crack is investigated using Hilbert-Huang Transform (HHT)—a relative novel time-frequency analysis method. The rotor with a growth crack is modeled by finite element method (FEM) and Dimarogonas' method. The influence of crack propagating ratio (CGR) on instantaneous response of the rotor as it passes through the critical speed and sub-harmonic resonances is analyzed. The 1X (one times rotating frequency), 2X (two times rotating frequency) and 3X (three times rotating frequency) vibration components are studied when they appear, reach its peak and decay during startup process. Some conclusions are achieved which may be useful to detect transverse crack on the shaft. It demonstrates that the HHT is an effective tool for the analysis of non-linear, unsteady transient vibration response.

Guo, D.; Peng, Z. K.

2007-11-01

32

On the Hilbert-Huang Transform Theoretical Foundation  

NASA Technical Reports Server (NTRS)

The Hilbert-Huang Transform [HHT] is a novel empirical method for spectrum analysis of non-linear and non-stationary signals. The HHT is a recent development and much remains to be done to establish the theoretical foundation of the HHT algorithms. This paper develops the theoretical foundation for the convergence of the HHT sifting algorithm and it proves that the finest spectrum scale will always be the first generated by the HHT Empirical Mode Decomposition (EMD) algorithm. The theoretical foundation for cutting an extrema data points set into two parts is also developed. This then allows parallel signal processing for the HHT computationally complex sifting algorithm and its optimization in hardware.

Kizhner, Semion; Blank, Karin; Huang, Norden E.

2004-01-01

33

Magnetotelluric Response Function Estimation Based on Hilbert-Huang Transform  

NASA Astrophysics Data System (ADS)

Magnetotelluric (MT) data series are non-stationary random signals that do not meet the basic requirements of conventional methods based on the Fourier transform. To minimize the estimation bias errors brought about by the non-stationary characteristics of MT data, a new method, based on the Hilbert-Huang transform (HHT), is proposed for the first time for estimating the MT response functions from a time series of electromagnetic field variations. With the HHT method, the amplitude of data series are expressed as a function of frequency and time and then response functions are estimated statistically from the time-frequency spectrum. Mathematical model and calculation processes are introduced and some simulated data are analyzed to verify the correctness of the method. Finally, the measured MT data is facilitated by applying the HHT to assess the ability of HHT method to quantify meaningful geologic information.

Cai, Jian-hua

2013-11-01

34

Hilbert-Huang Transform and Scaling Analysis of Various Geoscience data  

NASA Astrophysics Data System (ADS)

In geoscience, the field observation data are always nonlinear and nonstationary. They are also showing multiscale property since different spatial and temporal scales are involved. It is found that traditional methodologies, e.g., Fourier spectral analysis, structure-function analysis, etc., are strongly influenced by either nonlinear or nonstationary events. The Hilbert-Huang Transform (the combination of Empirical Mode Decomposition and Hilbert Spectral analysis) is efficient to handle both the nonlinearity and nonstationarity. In this talk, we apply this Hilbert-based methodology to various geoscience data collected from different field observations to characterize their scaling property. The collected data are daily river discharge, sea level, copepod abundance, wind energy, environmental data (temperature, dissolved oxygen) from coastal line, etc. Scaling property of these processes are then characterized in the frame of Hilbert spectral analysis. Reference 1. Huang Y, Schmitt F, Lu Z and Liu Y 2008 Europhys. Lett. 84, 40010. 2. Huang Y, Schmitt F, Lu Z and Liu Y 2009 J. Hydrol. 373, 103-111. 3. Schmitt F.G., Huang Y., Lu, Z., Liu Y., and Fernandez N. J. Mar. Sys., 2009, 77, 473-481 4. Schmitt F. G., Huang Y., Lu, Z., Zongo S. B., Molinero J. C. and Liu Y. Nonlinear Dynamics in Geosciences. edited by A. Tsonis and J. Elsner, Springer, 2007, 261-280 5. Huang Y. and Schmitt F. G. J. Mar. Sys., 2014, 130, 90-100 6. Calif R., Schmitt F. G. and Huang, Y. Physica A, 2013, 392, 4106-4120

Schmitt, Francois; Huang, Yongxiang

2014-05-01

35

Analysis of partial discharge signal using the Hilbert-Huang transform  

Microsoft Academic Search

The development of time-frequency and time-scale transforms has progressed rapidly over the last 20 years. The development and progression of numerical acquisition enable the utilization of these mathematical tools to analyze partial discharge in electrical equipment. This paper introduces a new transform, a Hilbert-Huang Transform to analyze partial discharge data. The mathematical model of a Hilbert-Huang Transform is described; and

Xiaodong Wang; Baoqing Li; Zhiwei Liu; Harry T. Roman; Onofrio L. Russo; Ken K. Chin; Kenneth R. Farmer

2006-01-01

36

Alpha and Theta Wave Localisation using Hilbert-Huang Transform: Empirical Study of the Accuracy  

Microsoft Academic Search

This paper proposes to apply the Hilbert-Huang Transform (HHT) to locate alpha and theta waves in an Electroence phalogram (EEG), in order to estimate the vigilance level of an operator. The Hilbert-Huang Transform (HHT) is a recent technique for non-stationary signal processing. Using the Empirical Mode Decomposition (EMD), the HHT allows decomposing a multi-modal signal into a sum of mono-contribution

Hassan SHARABATY; Jordi MARTIN; B. Jammes; D. Esteve

2006-01-01

37

Application of Hilbert-Huang Transform to Heart Rate Variability Analysis  

Microsoft Academic Search

The paper introduces a new methodology of heart rate variability(HRV) in time-frequency analysis, which is based on Hilbert-Huang transform. We adopt the empirical mode decompostition(EMD) technique to decompose the R-R interval series into several mono-component signals which become analytic signal by means of Hilbert transform. So a novel algorithm based on Hilbert-Huang transform is proposed to extract the features of

Li Helong; Yang Lihua; Huang Daren

2008-01-01

38

Effect of salicylic acid (SA) on delaying fruit senescence of Huang Kum pear  

Microsoft Academic Search

This experiment was undertaken to explore the effect of salicylic acid (SA) at different concentrations on regulating fruit\\u000a senescence of Huang Kum pear. Through dipping fruits and fruit discs for a series of hours in SA solution, enzyme activities\\u000a and physiological characteristics of Huang Kum pear were determined. The results revealed that SA enhanced the activity of\\u000a superoxide dismutase (SOD)

Hassan Imran; Yuxing Zhang; Guoqiang Du; Guoying Wang; Jianghong Zhang

2007-01-01

39

Hilbert-Huang transformation-based time-frequency analysis methods in biomedical signal applications.  

PubMed

Hilbert-Huang transformation, wavelet transformation, and Fourier transformation are the principal time-frequency analysis methods. These transformations can be used to discuss the frequency characteristics of linear and stationary signals, the time-frequency features of linear and non-stationary signals, the time-frequency features of non-linear and non-stationary signals, respectively. The Hilbert-Huang transformation is a combination of empirical mode decomposition and Hilbert spectral analysis. The empirical mode decomposition uses the characteristics of signals to adaptively decompose them to several intrinsic mode functions. Hilbert transforms are then used to transform the intrinsic mode functions into instantaneous frequencies, to obtain the signal's time-frequency-energy distributions and features. Hilbert-Huang transformation-based time-frequency analysis can be applied to natural physical signals such as earthquake waves, winds, ocean acoustic signals, mechanical diagnosis signals, and biomedical signals. In previous studies, we examined Hilbert-Huang transformation-based time-frequency analysis of the electroencephalogram FPI signals of clinical alcoholics, and 'sharp I' wave-based Hilbert-Huang transformation time-frequency features. In this paper, we discuss the application of Hilbert-Huang transformation-based time-frequency analysis to biomedical signals, such as electroencephalogram, electrocardiogram signals, electrogastrogram recordings, and speech signals. PMID:22558835

Lin, Chin-Feng; Zhu, Jin-De

2012-03-01

40

Identification of Velcro rales based on Hilbert-Huang transform  

NASA Astrophysics Data System (ADS)

Velcro rales, as a kind of crackles, are relatively specific for lung fibrosis and usually the first clinical clue of interstitial lung disease (ILD). We proposed an automatic analytic tool based on Hilbert-Huang transform (HHT) for the computerized identification of Velcro rales. In particular, HHT was utilized to extract the energy weight in various frequency bands (EW) of crackles and to calculate the portion of crackles during late inspiration. Support vector machine (SVM) based on the HHT-derived measures was used to differentiate Velcro rales from other crackles. We found that there were significant differences in the extracted parameters between Velcro rales and other crackles, including EW, EW and the proportion of crackles that appeared during the late inspiration. The discrimination results obtained from SVM achieved a concordance rate up to 92.20%±1.80% as confirmed by the diagnosis from experienced physicians. For practical purpose, the proposed approach may have potential applications to improve the sensitivity and accuracy of auscultation and conduct automatic ILD diagnose system.

Chen, Xue; Shao, Jie; Long, Yingjiao; Que, Chengli; Zhang, Jue; Fang, Jing

2014-05-01

41

On the Hilbert-Huang Transform Theoretical Developments  

NASA Technical Reports Server (NTRS)

One of the main heritage tools used in scientific and engineering data spectrum analysis is the Fourier Integral Transform and its high performance digital equivalent - the Fast Fourier Transform (FFT). Both carry strong a-priori assumptions about the source data, such as linearity, of being stationary, and of satisfying the Dirichlet conditions. A recent development at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC), known as the Hilbert-Huang Transform (HHT), proposes a novel approach to the solution for the nonlinear class of spectrum analysis problems. Using a-posteriori data processing based on the Empirical Mode Decomposition (EMD) sifting process (algorithm), followed by the normalized Hilbert Transform of the decomposition data, the HHT allows spectrum analysis of nonlinear and nonstationary data. The EMD sifting process results in a non-constrained decomposition of a source real value data vector into a finite set of Intrinsic Mode Functions (IMF). These functions form a near orthogonal adaptive basis, a basis that is derived from the data. The IMFs can be further analyzed for spectrum interpretation by the classical Hilbert Transform. A new engineering spectrum analysis tool using HHT has been developed at NASA GSFC, the HHT Data Processing System (HHT-DPS). As the HHT-DPS has been successfully used and commercialized, new applications post additional questions about the theoretical basis behind the HHT and EMD algorithms. Why is the fastest changing component of a composite signal being sifted out first in the EMD sifting process? Why does the EMD sifting process seemingly converge and why does it converge rapidly? Does an IMF have a distinctive structure? Why are the IMFs near orthogonal? We address these questions and develop the initial theoretical background for the HHT. This will contribute to the developments of new HHT processing options, such as real-time and 2-D processing using Field Programmable Array (FPGA) computational resources, enhanced HHT synthesis, and broaden the scope of HHT applications for signal processing.

Kizhner, Semion; Blank, Karin; Flatley, Thomas; Huang, Norden E.; Patrick, David; Hestnes, Phyllis

2005-01-01

42

On Certain Theoretical Developments Underlying the Hilbert-Huang Transform  

NASA Technical Reports Server (NTRS)

One of the main traditional tools used in scientific and engineering data spectral analysis is the Fourier Integral Transform and its high performance digital equivalent - the Fast Fourier Transform (FFT). Both carry strong a-priori assumptions about the source data, such as being linear and stationary, and of satisfying the Dirichlet conditions. A recent development at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC), known as the Hilbert-Huang Transform (HHT), proposes a novel approach to the solution for the nonlinear class of spectral analysis problems. Using a-posteriori data processing based on the Empirical Mode Decomposition (EMD) sifting process (algorithm), followed by the normalized Hilbert Transform of the decomposed data, the HHT allows spectral analysis of nonlinear and nonstationary data. The EMD sifting process results in a non-constrained decomposition of a source real-value data vector into a finite set of Intrinsic Mode Functions (IMF). These functions form a nearly orthogonal derived from the data (adaptive) basis. The IMFs can be further analyzed for spectrum content by using the classical Hilbert Transform. A new engineering spectral analysis tool using HHT has been developed at NASA GSFC, the HHT Data Processing System (HHT-DPS). As the HHT-DPS has been successfully used and commercialized, new applications pose additional questions about the theoretical basis behind the HHT and EMD algorithms. Why is the fastest changing component of a composite signal being sifted out first in the EMD sifting process? Why does the EMD sifting process seemingly converge and why does it converge rapidly? Does an IMF have a distinctive structure? Why are the IMFs nearly orthogonal? We address these questions and develop the initial theoretical background for the HHT. This will contribute to the development of new HHT processing options, such as real-time and 2-D processing using Field Programmable Gate Array (FPGA) computational resources,

Kizhner, Semion; Blank, Karin; Flatley, Thomas; Huang, Norden E.; Petrick, David; Hestness, Phyllis

2006-01-01

43

Seizure classification in EEG signals utilizing Hilbert-Huang transform  

PubMed Central

Background Classification method capable of recognizing abnormal activities of the brain functionality are either brain imaging or brain signal analysis. The abnormal activity of interest in this study is characterized by a disturbance caused by changes in neuronal electrochemical activity that results in abnormal synchronous discharges. The method aims at helping physicians discriminate between healthy and seizure electroencephalographic (EEG) signals. Method Discrimination in this work is achieved by analyzing EEG signals obtained from freely accessible databases. MATLAB has been used to implement and test the proposed classification algorithm. The analysis in question presents a classification of normal and ictal activities using a feature relied on Hilbert-Huang Transform. Through this method, information related to the intrinsic functions contained in the EEG signal has been extracted to track the local amplitude and the frequency of the signal. Based on this local information, weighted frequencies are calculated and a comparison between ictal and seizure-free determinant intrinsic functions is then performed. Methods of comparison used are the t-test and the Euclidean clustering. Results The t-test results in a P-value < 0.02 and the clustering leads to accurate (94%) and specific (96%) results. The proposed method is also contrasted against the Multivariate Empirical Mode Decomposition that reaches 80% accuracy. Comparison results strengthen the contribution of this paper not only from the accuracy point of view but also with respect to its fast response and ease to use. Conclusion An original tool for EEG signal processing giving physicians the possibility to diagnose brain functionality abnormalities is presented in this paper. The proposed system bears the potential of providing several credible benefits such as fast diagnosis, high accuracy, good sensitivity and specificity, time saving and user friendly. Furthermore, the classification of mode mixing can be achieved using the extracted instantaneous information of every IMF, but it would be most likely a hard task if only the average value is used. Extra benefits of this proposed system include low cost, and ease of interface. All of that indicate the usefulness of the tool and its use as an efficient diagnostic tool.

2011-01-01

44

Application of support vector regression machines to the processing of end effects of Hilbert–Huang transform  

Microsoft Academic Search

The end effects of Hilbert–Huang transform are represented in two aspects. On the one hand, the end effects occur when the signal is decomposed by empirical mode decomposition (EMD) method. On the other hand, the end effects occur again while the Hilbert transforms are applied to the intrinsic mode functions (IMFs). To restrain the end effects of Hilbert–Huang transform, the

Junsheng Cheng; Dejie Yu; Yu Yang

2007-01-01

45

Methods for detection and characterization of signals in noisy data with the Hilbert-Huang transform  

SciTech Connect

The Hilbert-Huang transform is a novel, adaptive approach to time series analysis that does not make assumptions about the data form. Its adaptive, local character allows the decomposition of nonstationary signals with high time-frequency resolution but also renders it susceptible to degradation from noise. We show that complementing the Hilbert-Huang transform with techniques such as zero-phase filtering, kernel density estimation and Fourier analysis allows it to be used effectively to detect and characterize signals with low signal-to-noise ratios.

Stroeer, Alexander; Cannizzo, John K.; Camp, Jordan B.; Gagarin, Nicolas [Laboratory for Gravitational Physics, Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States); Starodub, Incorporated, 3504 Littledale Road, Kensington, Maryland, 20895 (United States)

2009-06-15

46

Electricity prices neural networks forecast using the Hilbert-Huang transform  

Microsoft Academic Search

The problem of forecasting of electicity prices is addressed in terms of joint approach employing the general regression artificial neural network and empirical mode decomposition approaches (EMD) which is part of Hilbert-Huang transform. The application of developed approach to day-ahead hourly time series has demonstrated the whole accuracy increase as well as peaks prediction.

Victor Kurbatsky; Nikita Tomin; Denis Sidorov; Vadim Spiryaev

2010-01-01

47

Traveling Wave Based Distribution Lines Fault Location Using Hilbert-Huang Transform  

Microsoft Academic Search

A new traveling wave based distribution line fault location method using Hilbert-Huang transform (HHT) is presented in this paper. The intrinsic mode function (IMF) components of the fault generated traveling wave are extracted by empirical mode decomposition (EMD), and the instantaneous frequency changing time of each IMF component is obtained through Hilbert transform. The traveling wave arrival time in global

Xiao'an Qin; Xiangjun Zeng; Zhang Xiaoli; Li Zewen

2008-01-01

48

Power Systems Faults Location with Traveling Wave Based on Hilbert-Huang Transform  

Microsoft Academic Search

Identification of the signal of traveling wave is the key for power line faults location. Hilbert-Huang Transform (HHT), as a kind of time-frequency analysis method, is proposed to analysis the signal in the power system. Traveling wave of the fault circuitry is decomposed by the empirical mode decomposition (EMD), and the inherent mode functions (IMF) are extracted. Then Hilbert transform

Zhang Liguo; Han Xu; Jia Jian; Gao Tianye; Ma Yongsheng

2009-01-01

49

Hilbert-Huang transform based physiological signals analysis for emotion recognition  

Microsoft Academic Search

This paper presents a feature extraction technique based on the Hilbert-Huang Transform (HHT) method for emotion recognition from physiological signals. Four kinds of physiological signals were used for analysis: electrocardiogram (ECG), electromyogram (EMG), skin conductivity (SC) and respiration changes (RSP). Each signal is decomposed into a finite set of AM-FM mono components (fission process) by the Empirical Mode Decomposition (EMD)

Cong Zong; Mohamed Chetouani

2009-01-01

50

Detection and location of power quality disturbances based on mathematical morphology and hilbert-huang transform  

Microsoft Academic Search

With the power system development, the application of non-linear power components is becoming more and more extensive, and the power quality situation of power system has become increasingly severe. This paper proposes a novel method based on mathematical morphology (MM) and Hilbert-Huang transform (HHT), which is used to detect and analyze power quality disturbances. To effectively suppress noises, the traditional

Yong Huang; Yongqiang Liu; Zhiping Hong

2009-01-01

51

An Improved Hilbert-Huang Transform and its Application in Underwater Acoustic Signal Detection  

Microsoft Academic Search

The Hilbert-Huang transform (HHT) has the advantage in dealing with non-stationary signals, for its data driving. However there are some limitations of the original HHT. For getting more benefits in frequency resolution, an improved HHT is applied in this paper. In the improved version, the instantaneous harmonic retrieval method is applied to calculate the instantaneous frequencies of the intrinsic mode

Jia Liu; Xiu-Kun Li; Tao Ma; Sheng-Chun Piao; Qun-Yan Ren

2009-01-01

52

A Refined Hilbert–Huang Transform With Applications to Interarea Oscillation Monitoring  

Microsoft Academic Search

This paper focuses on the refinement of standard Hilbert-Huang transform (HHT) technique to accurately characterize time varying, multicomponents interarea oscillations. Several improved masking techniques for empirical mode decomposition (EMD) and a local Hilbert transformer are proposed and a number of issues regarding their use and interpretation are identified. Simulated response data from a complex power system model are used to

Dina Shona Laila; Arturo Roman Messina; Bikash C. Pal

2009-01-01

53

Adaptive magnitude spectrum algorithm for Hilbert–Huang transform based frequency identification  

Microsoft Academic Search

An innovative Hilbert–Huang transform (HHT) based frequency identification approach designated as adaptive magnitude spectrum algorithm (AMSA) is proposed in this paper. Characterized by the a posteriori property, the AMSA does not need the a priori information about the modal frequencies to be identified, and the situations that a modal frequency may be contained along specific segments of the whole time

K. C. G. Ong; Zengrong Wang; M. Maalej

2008-01-01

54

Stator short circuits detection in PMSM by means of Hilbert-Huang transform and energy calculation  

Microsoft Academic Search

This paper presents and analyzed short circuit failures for permanent magnet synchronous motor (PMSM). The study includes stated state and dynamic condition for experimental test. The stator current is analyzed by means of Hilbert-Huang transform (HHT) and energy spectrum.

J. Urresty; J. Riba; L. Romeral; J. Rosero; J. Serna

2009-01-01

55

Gear Fault Detection Based on Ensemble Empirical Mode Decomposition and Hilbert-Huang Transform  

Microsoft Academic Search

A new approach to fault diagnosis of gear crack based on ensemble empirical mode decomposition (EEMD) and Hilbert-Huang transform (HHT) technique is presented. Firstly, the time-domain vibration signal of the gearbox with gear crack fault is measured. Then the original vibration signal is separated into intrinsic oscillation modes, using the ensemble empirical mode decomposition. Secondly, Hilbert transform tracks the modulation

Shufeng Ai; Hui Li

2008-01-01

56

An improved Hilbert–Huang transform and its application in vibration signal analysis  

Microsoft Academic Search

The vibration generated by industrial machines always contains nonlinear and non-stationary signals. Recently, a number of new methods have been proposed to analyse these signals. One of the promising methods is the Hilbert–Huang Transform (HHT). The HHT is derived from the principals of empirical mode decomposition (EMD) and the Hilbert Transform. When applying the HHT, first, the EMD will decompose

Z. K. Peng; Peter W. Tse; F. L. Chu

2005-01-01

57

Analysis of Harmonic and Inter-Harmonic Based on Hilbert-Huang Transform  

Microsoft Academic Search

To analyze harmonic and inter-harmonic accurately is significant to the stability of power system. The Hilbert-Huang transform (HHT) is adopted to analyze harmonic and interharmonic in order to overcome the shortcoming of FFT method and wavelet analysis method. The power quality signals are decomposed by empirical mode decomposition (EMD) method, and then a series of intrinsic mode function (IMF) are

Jianming Yu; Liang Yang

2009-01-01

58

Analysis of Rotor Rubbing Fault Signal Based on Hilbert-Huang Transform  

Microsoft Academic Search

Vibration problems in rotors can be extremely frustrating and may lead to greatly reduced reliability. By utilizing the proper data collection and analysis techniques, the faults because of vibration can be discovered and predicted. The time-frequency analysis by Hilbert-Huang transform (HHT) plays on a significant role in the analysis of singularities, which hide in the signal, and is an effective

Xiang Ling; Tang Guiji; Hu Aijun

2009-01-01

59

Signal Feature Extraction From Microbarograph Observations Using the Hilbert–Huang Transform  

Microsoft Academic Search

The Hilbert-Huang transform (HHT) is a relatively new time-frequency analysis tool. We present a new signal feature extraction technique based on HHT. This technique is used to extract diurnal and semidiurnal tides from atmospheric pressure data obtained from a microbarograph stationed at the Arecibo Observatory. Observation of seasonal variations of semidiurnal tides is possible due to the high precision offered

Arnab Roy; Chun-Hsien Wen; John F. Doherty; John D. Mathews

2008-01-01

60

Applications of Hilbert-Huang transform to non-stationary financial time series analysisz  

Microsoft Academic Search

SUMMARY A new method, the Hilbert-Huang Transform (HHT), developed initially for natural and engineering sciences has now been applied to financial data. The HHT method is specially developed for analysing non- linear and non-stationary data. The method consists of two parts: (1) the empirical mode decomposition (EMD), and (2) the Hilbert spectral analysis. The key part of the method is

Norden E. Huang; Man-Li Wu; Wendong Qu; Steven R. Long; Samuel S. P. Shen

2003-01-01

61

Filter Principle of Hilbert-Huang Transform and Its Application in Time Series Analysis  

Microsoft Academic Search

Hilbert-Huang transform (HHT) is a typical realization of the local wave analysis (LWA) and especially powerful for analysis of nonlinear and non-stationary signal. In this paper, from the view of filter, the principle of HHT will be studied and a smoothing filter theory will be put forward for explaining empirical mode decomposition (EMD). And because intrinsic mode functions (IMFs) by

Shifu Tang; Hong Ma; Liyun Su

2006-01-01

62

Comparative study of Hilbert–Huang transform, Fourier transform and wavelet transform in pavement profile analysis  

Microsoft Academic Search

This study employs the Hilbert–Huang transform (HHT), the wavelet transform and the Fourier transform to analyse the road surface profiles of three pavement profiles. The wavelet and Fourier transforms have been the traditional spectral analysis methods, but they are predicated on a priori selection of basis functions that are either of infinite length or have fixed finite widths. The central

A. Y. Ayenu-Prah; N. O. Attoh-Okine

2009-01-01

63

Detecting anomalies in beams and plate based on the Hilbert–Huang transform of real signals  

Microsoft Academic Search

This paper illustrates the feasibility of the Hilbert–Huang transform (HHT) as a signal processing tool for locating an anomaly, in the form of a crack, delamination, stiffness loss or boundary in beams and plate, based on physically acquired propagating wave signals. The basis of detection hinges on simple wave propagation concepts using flight times, velocities and frequency changes. The basic

S T Quek; P S Tua; Q Wang

2003-01-01

64

A refined Hilbert-Huang transform with applications to inter-area oscillation monitoring  

Microsoft Academic Search

This paper focuses on the refinement of standard Hilbert Huang transform (HHT) technique to accurately characterize time varying, multi components inter area oscillations. Several improved masking techniques for empirical mode decomposition (EMD) and a local Hilbert transformer are proposed and a number of issues regarding their use and interpretation are identified. Simulated response data from a complex power system model

D. S. Laila; A. R. Messina; B. C. Pal

2009-01-01

65

Classification of Power Quality disturbances using the iterative Hilbert Huang Transform  

Microsoft Academic Search

The Hilbert Huang Transform (HHT) is a powerful tool for Power Quality (PQ) classifications. One of the main advantages of the HHT is its ability to analyse non-stationary complex waveforms with very good time resolution. However, like other waveform classification techniques, it has difficulty in resolving the instant of sudden changes in the waveform. It has also difficulty with signals

C. F. Drummond; D. Sutanto

2010-01-01

66

Power system harmonic analysis based on improved hilbert-huang transform  

Microsoft Academic Search

To analyze harmonic accurately is significant to the stability of power system. HHT (Hilbert-Huang Transform) is adopted to analyze harmonic in order to overcome the shortcoming of FFT method and wavelet analysis method. The power quality signals are decomposed by empirical mode decomposition (EMD) method, and then a series of intrinsic mode function (IMF) are obtained. Owing to different IMFs

Shi Zhang; Qun Wang; Ruirui Liu

2009-01-01

67

Doppler frequency extraction of foliage penetration radar based on the Hilbert-Huang transform technology  

Microsoft Academic Search

The paper deals with Doppler frequency extraction in foliage penetrating radar (FPR). The strong echoes from dense foliage and the high attenuation of the radar microwaves often make it difficult for traditional time-frequency distributions to represent the Doppler frequency clearly and locally. A Hilbert-Huang transform (HHT) technology is proposed to extract the desired signal from interference and to give a

Chengjie Cai; Weixian Liu; J. S. Fu; Yilong Lu

2004-01-01

68

Multiple scale identification of power system oscillations using an improved Hilbert-Huang transform  

Microsoft Academic Search

This paper presents a new algorithm for the identification of spectral properties of power system oscillations using an improved Hilbert-Huang transform. Firstly, a relevant vector machine is used as a preprocessor to extend the length of the signal at both ends. Secondly, the empirical mode decomposition method is utilized to decompose the power system oscillation signal into a set of

Xingzhi Wang; Zheng Yan

2009-01-01

69

Identification of the components of wave spectra by the Hilbert Huang transform method  

Microsoft Academic Search

The Hilbert Huang Transform method is applied to identify different components of the spectra of real sea waves. Field data collected at the Portuguese coast are used in this study. The ability of Empirical Mode Decomposition to extract the different oscillation modes, embedded in the sea surface elevation records, is demonstrated. The contribution of different Intrinsic Mode Functions to the

A. D. Veltcheva; C. Guedes Soares

2004-01-01

70

Signal period analysis based on Hilbert-Huang transform and its application to texture analysis  

Microsoft Academic Search

An approach to analyze the period of a signal based on Hilbert-Huang transform is presented in this paper. For an approximately periodic signal which contains plenty of high frequency components, the relation between its period and its main frequency is established. Our main result is that, for an approximately periodic signal which contains plenty of high frequency components, its period

Zhihua Yang; Dongxu Qi; Lihua Yang

2004-01-01

71

A review on Hilbert-Huang transform: Method and its applications to geophysical studies  

Microsoft Academic Search

Data analysis has been one of the core activities in scientific research, but limited by the availability of analysis methods in the past, data analysis was often relegated to data processing. To accommodate the variety of data generated by nonlinear and nonstationary processes in nature, the analysis method would have to be adaptive. Hilbert-Huang transform, consisting of empirical mode decomposition

Norden E. Huang; Zhaohua Wu

2008-01-01

72

Analysis of earthquake ground motions using an improved Hilbert–Huang transform  

Microsoft Academic Search

Some limitations of the Hilbert–Huang transform (HHT) for nonlinear and nonstationary signal processing are remarked. As an enhancement to the HHT, a time varying vector autoregressive moving average (VARMA) model based method is proposed to calculate the instantaneous frequencies of the intrinsic mode functions (IMFs) obtained from the empirical mode decomposition (EMD) of a signal. By representing the IMFs as

Dong Yinfeng; Li Yingmin; Xiao Mingkui; Lai Ming

2008-01-01

73

Mean frequency derived via Hilbert-Huang transform with application to fatigue EMG signal analysis  

Microsoft Academic Search

The mean frequency (MNF) of surface electromyography (EMG) signal is an important index of local muscle fatigue. The purpose of this study is to improve the mean frequency (MNF) estimation. Three methods to estimate the MNF of non-stationary EMG are compared. A novel approach based on Hilbert-Huang transform (HHT), which comprises the empirical mode decomposition (EMD) and Hilbert transform, is

Hongbo Xie; Zhizhong Wang

2006-01-01

74

A Novel Pitch Period Detection Algorithm Based on Hilbert-Huang Transform  

Microsoft Academic Search

\\u000a In this paper, a novel event detection pitch detector is presented. Hilbert-Huang Transform is employed to locate the instant\\u000a at which the glottal pulse takes place. Then, the pitch period is detected accurately by measuring the time interval between\\u000a two glottal pulses. Experiments show encouraging detection results.

Zhihua Yang; Daren Huang; Lihua Yang

2004-01-01

75

Dependence structure and symmetry of Huang-Kotz FGM distributions and their extensions  

Microsoft Academic Search

.   An extension of FGM class of bivariate distributions with given marginals is presented. For Huang-Kotz FGM distributions\\u000a some theorems characterizing symmetry and conditions for independence are obtained. The new family of distributions allows\\u000a us to achieve correlation between the components greater than 0.5.

Ismihan Bairamov; Samuel Kotz

2002-01-01

76

An Improved Hilbert–Huang Method for Analysis of Time-Varying Waveforms in Power Quality  

Microsoft Academic Search

The Hilbert-Huang method is presented with modifications, for time-frequency analysis of distorted power quality signals. The empirical mode decomposition (EMD) is enhanced with masking signals based on fast Fourier transform (FFT), for separating frequencies that lie within an octave. Further, the instantaneous frequency and amplitude of the constituent modes obtained by Hilbert spectral analysis are improved by demodulation. The method

Nilanjan Senroy; Siddharth Suryanarayanan; Paulo F. Ribeiro

2007-01-01

77

Hilbert-Huang transform and marginal spectrum for detection and diagnosis of localized defects in roller bearings  

Microsoft Academic Search

This work presents the application of a new signal processing technique, the Hilbert-Huang transform and its marginal spectrum,\\u000a in analysis of vibration signals and fault diagnosis of roller bearings. The empirical mode decomposition (EMD), Hilbert-Huang\\u000a transform (HHT) and marginal spectrum are introduced. First, the vibration signals are separated into several intrinsic mode\\u000a functions (IMFs) by using EMD. Then the marginal

Hui Li; Yuping Zhang; Haiqi Zheng

2009-01-01

78

Combination of wavelet packet transform and Hilbert-Huang transform for recognition of continuous EEG in BCIs  

Microsoft Academic Search

An improved Hilbert-Huang transform(HHT) combined with wavelet packet transform(WPT) is proposed for recognizing continuous electroencephalogram (EEG) in brain computer interfaces (BCIs). The HHT consists of empirical mode decomposition(EMD) and Hilbert-Huang spectrum (HHS). Firstly, the WPT decomposes the signal into a set of narrow band signals, then a series of intrinsic mode functions (IMFs) can be obtained after application of the

Ling Yuan; Banghua Yang; Shiwei Ma; Biao Cen

2009-01-01

79

A metabolomic analysis of medicinal diversity in Huang-qin ( Scutellaria baicalensis Georgi) genotypes: discovery of novel compounds  

Microsoft Academic Search

In vitro manipulation of plant regeneration in the Chinese medicinal species Scutellaria baicalensis Georgi (Huang-qin) resulted in 26 chemically distinct germplasm lines. Antioxidant potential, growth rate and concentration of baicalin, baicalein, melatonin, and wogonin were the selective markers used to identify elite lines. Metabolomic analysis of a subset of the most distinct lines revealed that Huang-qin extracts contained over 2,000

Susan J. Murch; H. P. Vasantha Rupasinghe; D. Goodenowe; Praveen K Saxena

2004-01-01

80

Application of hilbert-huang transform to denoising in vortex flowmeter  

Microsoft Academic Search

Due to piping vibration, fluid pulsation and other environmental disturbances, variations of amplitude and frequency to the\\u000a raw signals of vortex flowmeter are imposed. It is difficult to extract vortex frequencies which indicate volumetric flowrate\\u000a from noisy data, especially at low flowrates. Hilbert-Huang transform was adopted to estimate vortex frequency. The noisy\\u000a raw signal was decomposed into different intrinsic modes

Zhi-qiang Sun; Jie-min Zhou; Ping Zhou

2006-01-01

81

The Hilbert-Huang Transform for Detection of Otoacoustic Emissions and Time-Frequency Mapping  

Microsoft Academic Search

Abstract. This paper presents an application of the Hilbert–Huang transform (HHT) and ensem- ble correlation for detection of the transient evoked otoacoustic emissions (TEOAEs), and high resolution time–frequency mapping. The HHT provides a powerful tool for nonlinear analysis of nonstationary signals such as TEOAEs. Since the HHT itself does not distinguish between,sig- nal and noise it was,used with ensemble,correlation to

Arturas Janusauskas; Vaidotas Marozas; Arunas Lukosevicius; Leif Sörnmo

2006-01-01

82

Analysis of Low Frequency Oscillations using improved Hilbert-Huang Transform  

Microsoft Academic Search

As a non-linear and time-varying tool, Hilbert-Huang Transform (HHT) has been widely used to analyze Low Frequency Oscillation (LFO) signals in power systems. It utilizes Empirical Mode Decomposition (EMD) to decompose the LFO signals into a collection of Intrinsic Mode Functions (IMFs), and then the instantaneous parameters including magnitude, frequency of every IMF can be calculated by applying the Hilbert

D. C. Yang; C. Rehtanz; Y. Li

2010-01-01

83

Interpretation of mechanical signals using an improved Hilbert–Huang transform  

Microsoft Academic Search

Attribute to providing a more accurate ‘real-life’ representation of a signal without any artefacts imposed by the non-locally adaptive limitations of the fast Fourier transform (FFT) and wavelet processing, the Hilbert–Huang transform (HHT) has been regarded as a powerful tool for adaptive analysis of non-linear and non-stationary signals. The HHT allows direct algorithmic analysis of signals through the combined use

Wen-Xian Yang

2008-01-01

84

Surface electromyography signal analysis and pattern recognition based on Hilbert-Huang transform  

Microsoft Academic Search

The surface electromyography signal of stump was applied to recognize the intention of disable people, and control the intelligent above-knee prosthesis. Since the electromyography signal was non-stationary and non-linear signal, Hilbert-Huang transform was applied to extract the frequency feature. The time and frequency features of surface electromyography signal recorded from biceps femoris of the disable people's stump, were applied to

Lingling Chen; Peng Yang; Linan Zu; Tengyu Zhang; Lifeng Li

2009-01-01

85

Studies of spectral properties of short genes using the wavelet subspace Hilbert–Huang transform (WSHHT)  

Microsoft Academic Search

This paper presents a new algorithm for the analysis of spectral properties of short genes using the wavelet transform and the Hilbert–Huang transform (HHT). A wavelet subspace algorithm combined with the empirical mode decomposition (EMD) is introduced to create subdivided intrinsic mode functions (IMFs) and a cross-correlation analysis is applied to remove pseudo-spectral components. Experiments are carried out on DNA

Rong Jiang; Hong Yan

2008-01-01

86

Hilbert-Huang Transform-Based Vibration Signal Analysis for Machine Health Monitoring  

Microsoft Academic Search

This paper presents a signal analysis technique for machine health monitoring based on the Hilbert-Huang Transform (HHT). The HHT represents a time-dependent series in a two-dimensional (2-D) time-frequency domain by extracting instantaneous frequency components within the signal through an Empirical Mode Decomposition (EMD) process. The analytical background of the HHT is introduced, based on a synthetic analytic signal, and its

Ruqiang Yan; Robert X. Gao

2006-01-01

87

Hilbert-huang transform and wavelet analysis of time history signal  

Microsoft Academic Search

The brief theories of wavelet analysis and Hilbert-Huang transform (HHT) are introduced firstly in the present paper. Then\\u000a several signal data were analyzed by using wavelet and HHT methods, respectively. The comparison shows that HHT is not only\\u000a an effective method for analyzing non-stationary data, but also is a useful tool for examining detailed characters of time\\u000a history signal.

Chun-Xiang Shi; Qi-Feng Luo

2003-01-01

88

Pulse transit time-based blood pressure estimation using hilbert-huang transform  

Microsoft Academic Search

The pulse transit time (PTT) based method has been suggested as a continuous, cuffless and non-invasive approach to estimate blood pressure. It is of paramount importance to accurately determine the pulse transit time from the measured electrocardiogram (ECG) and photoplethysmo-gram (PPG) signals. We apply the celebrated Hilbert-Huang Transform (HHT) to process both the ECG and PPG signals, and improve the

Qiao Zhang; Yang Shi; Daniel Teng; Anh Dinh; Seok-Bum Ko; Li Chen; Jenny Basran; Vanina Dal Bello-Haas; Younhee Choi

2009-01-01

89

Speech endpoint detection in strong noisy environment based on the Hilbert-Huang Transform  

Microsoft Academic Search

Speech endpoint detection in strong noise environment plays an important role in speech signal processing. Hilbert-Huang Transform (HHT) is based on the local characteristics of signals, which is an adaptive and efficient transformation method. It is particularly suitable for analyzing the non-linear and non-stationary signals such as speech signal. In this paper, we chose the noisy speech signal when the

Zhimao Lu; Baisen Liu; Liran Shen

2009-01-01

90

THE PSEUDO DYNAMIC TEST OF RC BRIDGE COLUMNS ANALYZED THROUGH THE HILBERT-HUANG TRANSFORM  

Microsoft Academic Search

SUMMARY In this paper, the analysis of the responses of the pseudo dynamic test of a rectangular reinforced concrete (RC) bridge column using the Hilbert-Huang transform (HHT) is introduced. Firstly, a 40%-scaled rectangular RC bridge column is subjected to the pseudo dynamic test. The input of the pseudo dynamic test is set as the near-fault ground accelerations of the Chi-Chi

Yeou-Fong Li; Shuenn-Yih Chang; Wen-Ching Tzeng; Kang Huang

91

Vibration analysis of a cracked rotor using Hilbert–Huang transform  

Microsoft Academic Search

In this paper, the startup transient response of a rotor with a propagating transverse crack is investigated using Hilbert–Huang Transform (HHT)—a relative novel time-frequency analysis method. The rotor with a growth crack is modeled by finite element method (FEM) and Dimarogonas’ method. The influence of crack propagating ratio (CGR) on instantaneous response of the rotor as it passes through the

D. Guo; Z. K. Peng

2007-01-01

92

INTRODUCTION TO THE HILBERT HUANG TRANSFORM AND ITS RELATED MATHEMATICAL PROBLEMS  

Microsoft Academic Search

The Hilbert-Huang transform (HHT) is an empirically based data-analysis method. Its basis of expansion is adaptive, so that it can produce physically mean- ingful representations of data from nonlinear and non-stationary processes. The advantage of being adaptive has a price: the difficulty of laying a firm theoretical foundation. This chapter is an introduction to the basic method, which is fol-

Norden E. Huang

93

Causes and solutions of overshoot and undershoot and end swing in Hilbert-Huang transform  

Microsoft Academic Search

There are overshoot and undershoot phenomenon and end swing phenomenon in the cubic spline fitting in Hilbert-Huang transform.\\u000a The two problems influence data quality of the empirical mode decomposition seriously. The cubic spline fitting has been analysed,\\u000a and the causes of producing the overshoot and undershoot phenomenon and the end swing phenomenon have been pointed out in\\u000a this paper. Two

Si-Sheng Long; Tie-Bao Zhang; Feng Long

2005-01-01

94

Dynamic characteristic analysis of power system low frequency oscillation using Hilbert-Huang transform  

Microsoft Academic Search

Based on Hilbert-Huang transform (HHT), the authors propose a practical method to extract time-varying oscillation characteristic of power system from the data measured by wide area measurement system (WAMs). The proposed method can analyze local dynamic behavior and characteristics of non-stationary nonlinear signals, better reflect the time-varying law of multi modes involved in oscillation process as well as the mutual

Song Han; Bin Sun; Cheng Wu; Li-quan He

2009-01-01

95

Fundamental frequency estimation for music signals with modified Hilbert-Huang transform (HHT)  

Microsoft Academic Search

In this work, we propose a modified Hilbert-Huang transform (HHT) method to detect low pitch musical signals within a short analysis temporal window for real-time fundamental frequency estimation. HHT is a non-linear method which is suitable for the analysis of non-stationary AM\\/FM like data. However, to apply HHT directly to music signals encounters several problems. Here, we modify HHT so

EnShuo Tsau; Namgook Cho; C.-C. Jay Kuo

2009-01-01

96

Concatenated trial based Hilbert-Huang transformation on event-related potentials  

Microsoft Academic Search

Time-frequency analysis is critical to study event-related potentials (ERPs) now. ERPs are usually generated through averaging over a number of trials, and such averaging limits the application of a nonlinear time-frequency analysis method-Hilbert-Huang transformation (HHT). This is because HHT usually requires very long recordings to sufficiently decompose the complicated signal into oscillations and the averaged ERP trace tends to possess

F. Cong; T. Sipola; X. Xu; T. Huttunen-Scott; H. Lyytinen; T. Ristaniemi

2010-01-01

97

Harmonic and Inter-harmonic Signal Analysis Based on Hilbert-Huang Transform  

Microsoft Academic Search

Because of the extensive application of the non- linear electrical equipment, aircraft power system contains a number of harmonic and inter-harmonic components. Aiming at the situation that Fourier transform and wavelet transform method could not effectively extract and analyze these harmonic and inter-harmonic signal, made use of Hilbert- Huang Transform (HHT) to extract and analyze harmonic and inter-harmonic components for

Wei Fu; Yan Zhu

2011-01-01

98

[Clinical experiences of professor WU Bing-Huang on emergency treatment with acupressure].  

PubMed

The key points of acupoint selection and manipulations of Professor WU Bing-huang's experiences on emergency treatment with acupressure are introduced. It includes emergency treatment on coma (collapse, faint, faint at the sight of blood, faint during acupuncture, faint during moxibustion, shock, etc.), and pain, cough as well as asthma relieving with acupressure (include abdominal pain, vomiting, diarrhea, headache, toothache, dysmenorrhea, lumbago, neck stiffness after sleep, cough, asthma, etc.). At the same time, typical cases are given as examples. PMID:21644319

Hong, Kun-Da; Wan, Tian; Wang, Lin-Lin; Wu, Ming-Xia

2011-03-01

99

A technique to improve the empirical mode decomposition in the Hilbert-Huang transform  

Microsoft Academic Search

The Hilbert-based time-frequency analysis has promising capacity to reveal the time-variant behaviors of a system. To admit\\u000a well-behaved Hilbert transforms, component decomposition of signals must be performed beforehand. This was first systematically\\u000a implemented by the empirical mode decomposition (EMD) in the Hilbert-Huang transform, which can provide a time-frequency representation\\u000a of the signals. The EMD, however, has limitations in distinguishing different

Yangbo Chen; Maria Q. Feng

2003-01-01

100

Application of the Hilbert-Huang transform to the search for gravitational waves  

SciTech Connect

We present the application of a novel method of time-series analysis, the Hilbert-Huang transform, to the search for gravitational waves. This algorithm is adaptive and does not impose a basis set on the data, and thus the time-frequency decomposition it provides is not limited by time-frequency uncertainty spreading. Because of its high time-frequency resolution it has important applications to both signal detection and instrumental characterization. Applications to the data analysis of the ground and space based gravitational wave detectors, LIGO and LISA, are described.

Camp, Jordan B.; Cannizzo, John K.; Numata, Kenji [Laboratory for Gravitational Physics, Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

2007-03-15

101

[Characteristics of precipitation pH and conductivity at Mt. Huang].  

PubMed

To understand the general characteristics of pH distribution and pollution in precipitation at Mt. Huang, statistical analyses were conducted for the routine measurements of pH and conductivity (K) at Mt. Huang during 2006-2011. The results showed that: (1) Over the period of study, the annual volume weighted mean (VWM) precipitation pH varied from 4.81 to 5.57, with precipitation acidity strengthening before 2009 and weakening thereafter. The precipitation acidity showed evident seasonal variations, with the VWM pH lowest in winter (4.78), and highest in summer (5.33). The occurrence frequency of acid rain was 46% , accounting for 45% of total rainfalls and with the most frequent pH falling into weak acid to neutral rain. (2) The annual VWM K varied from 16.91 to 27.84 microS x cm(-1), with no evident trend. As for ions pollution, the precipitation was relatively clean at Mt. Huang, with the most frequent K range being below 15 microS x cm(-1), followed by 15-25 microS x cm(-1). From February 2010 to December 2011, precipitation samples were collected on daily basis for ions analysis, as well as pH and K measurement in lab. Detailed comparisons were conducted between the two sets of pH and K, one set from field measurement and the other from lab measurement. The results indicated: (1) The lab measured pH (K) was highly correlated with the field pH (K); however, the lab pH tended to move towards neutral comparing with the corresponding field pH, and the shift range was closely correlated with the field pH and rainfall. The shift range of K from field to lab was highly correlated with the total ion concentration of precipitation. The field K showed evident negative correlation with the field pH with a correlation coefficient of -0.51. (2) When sampling with nylon-polyethylene bags, the statistics showed smaller bias between two sets of pH, with higher correlation coefficient between two sets of K. Furthermore, the lab K also showed evident negative correlation with the lab pH. Comparing with the observations at other alpine sites in central to eastern China, the natural precipitation at Mt. Huang was weaker in acidity and contains lower ion concentration. PMID:23914555

Shi, Chun-e; Deng, Xue-liang; Wu, Bi-wen; Hong, Jie; Zhang, Su; Yang, Yuan-jian

2013-05-01

102

Using the Hilbert-Huang transform to measure the electroencephalographic effect of propofol.  

PubMed

Monitoring the effect of anesthetic drugs on the central nervous system is a major ongoing challenge in anesthesia research. A number of electroencephalogram (EEG)-based monitors of the anesthetic drug effect such as the bispectral (BIS) index have been proposed to analyze the EEG signal during anesthesia. However, the BIS index has received some criticism. This paper offers a method based on the Hilbert-Huang transformation to calculate an index, called the Hilbert-Huang weighted regional frequency (HHWRF), to quantify the effect of propofol on brain activity. The HHWRF and BIS indices are applied to EEG signals collected from nine patients during a controlled propofol induction and emergence scheme. The results show that both the HHWRF and BIS track the gross changes in the EEG with increasing and decreasing anesthetic drug effect (the prediction probability P(k) of 0.85 and 0.83 for HHWRF and BIS, respectively). Our new index can reflect the transition from unconsciousness to consciousness faster than the BIS, as indicated from the pharmacokinetic and pharmacodynamic modeled parameters and also from the analysis around the point of reawakening. This method could be used to design a new EEG monitoring system to estimate the propofol anesthetic drug effect. PMID:22273803

Shalbaf, R; Behnam, H; Sleigh, J W; Voss, L J

2012-02-01

103

Identification of flow regime in a slurry bubble column by Hilbert-Huang transform analysis  

NASA Astrophysics Data System (ADS)

Experiments were conducted in a two-dimensional (2-D) slurry bubble column, which had a length of 0.1m, a width of 0.01m and a total height of 0.8m. The gas phase was oil-free air, tap water was used as the liquid phase, glass powders with particle diameter of 58?m-75?m constituted the solid phase, which belonged to the Geldart A particles. Time-domain analysis and the Hilbert-Huang transform methods were employed to analyze the differential pressure signals obtained and to identify the transition points of the flow regimes in the slurry bubble column. Useful qualitative and quantitative information about the changes in flow structure and particle distributions were extracted. Changes in the standard deviation, skewness and flatness of measured pressure time series with superficial gas velocity are proposed. Hilbert-Huang transform was applied to extract information from signals, and flow structures of the slurry bubble column were characterized by the energy distribution of the multi-resolution signals and the EMD energy entropy. Particle distributions were obtained and analyzed from flow pattern images.

Li, Weiling; Zhong, Wenqi; Jin, Baosheng; Xiao, Rui

2013-06-01

104

[Temperature characteristics of huang-Ryes factor of all-trans-beta-carotene].  

PubMed

A visible absorption and Raman spectra of all-trans-beta-beta-carotene was measured in cyclohexanol solution in the temperature range from 68 degrees C to 26 degrees C. The results indicated that the visible absorption spectra are red-shifted, Raman scattering cross section increases, Huang-Ryes factor and electron-phonon coupling constants of CC bond vibration modes decreases with the temperature decreasing. The changes are interpreted using the theory of "coherent weakly damped electronic-lattice vibration model" and "effective conjugation length model". The red shift of the absorption spectra and intensity of the Raman active are attributed to the thermal conformational change-induced increase in the effective conjugation length in all-trans-beta-carotene chains. All-trans-beta-carotene has strong coherent weakly damped CC bonds vibrational properties, which lead to large Raman scattering cross section in the solvent of low temperature. The electron-phonon coupling constants with dimension are used, which can easily establish relation with the Huang-Rhys factor and calculate the electron-phonon coupling constants of CC bond vibration modes. Effective conjugation length, the pi-electron delocalization range and the Raman scattering cross section are described by the electron-phonon coupling constants. PMID:24371847

Li, Shuo; Sun, Shang; Li, Zuo-wei; Qu, Guan-nan; Liu, Tian-yuan; Sun, Cheng-lin; Fan, Li-mei

2013-09-01

105

Performance and limitations of the Hilbert–Huang transformation (HHT) with an application to irregular water waves  

Microsoft Academic Search

This paper relates to the newly developed Hilbert–Huang transformation (HHT). An overview of this time-frequency analysis technique and its applications are given. Key elements of the numerical procedure and principles of the Hilbert transformation (HT) are established. A simple parameter study with trigonometric functions to get an idea about the numerical performance of the empirical mode decomposition (EMD) is performed.

Marcus Dätig; Torsten Schlurmann

2004-01-01

106

Comparison between Hilbert Huang transform and scalogram methods on non-stationary biomedical signals: application to laser Doppler flowmetry recordings  

Microsoft Academic Search

A significant transient increase in laser Doppler flowmetry (LDF) signals is observed in response to a local and progressive cutaneous pressure application on healthy subjects. This reflex may be impaired in diabetic patients. The work presents a comparison between two signal processing methods that provide a clarification of this phenomenon. Analyses by the scalogram and the Hilbert-Huang transform (HHT) of

Rémy Roulier; Anne Humeau; Thomas P. Flatley; Pierre Abraham

2005-01-01

107

Research on instantaneous feature of non-stationary signal based on hilbert-huang transform and wavelet packet decomposition  

Microsoft Academic Search

An improved analysis method for non-stationary signal based on Hilbert-Huang transform (HHT) and the wavelet packets decomposition (WPD) is presented in this paper. First, the WPD is used to decompose the signal into a set of narrow band signals prior to HHT. Second, the suitable threshold value is selected for each decomposed components. Last, HHT is only applied to those

Fabin Cheng; Baoping Tang; Qiyuan He

2006-01-01

108

Application of Hilbert-Huang transform and Mahalanobis-Taguchi System in mechanical fault diagnostics using vibration signals  

Microsoft Academic Search

As for non-destructive condition monitoring method, vibration signals are measured and analyzed to diagnose mechanical faults. A method of mechanical fault levels identification is proposed in this paper using vibration signals. Firstly, Hilbert-Huang transform is used to analyze the signal. Fault information is obtained. And energy ratio of intrinsic mode functions is taken as fault characteristics. Secondly, different levels of

Ren Jiangtao; Cai Yuanwen; Xing Xiaochen

2011-01-01

109

Anti-inflammatory effects of Huang-Lian-Jie-Du decoction, its two fractions and four typical compounds  

Microsoft Academic Search

Ethnopharmacological relevanceHuang-Lian-Jie-Du decoction (HLJDD) (Oren-gedoku-to in Japanese) as a famous traditional Chinese recipe is composed of Rhizoma coptidis, Radix scutellariae, Cortex phellodendri and Fructus gardeniae. It has been used to treat inflammation for nearly two thousand years.

Juan Lu; Jun-Song Wang; Ling-Yi Kong

2011-01-01

110

Geographical, meteorological and vectorial factors related to malaria re-emergence in Huang-Huai River of central China  

Microsoft Academic Search

: BACKGROUND: Malaria still represents a significant public health problem in China, and the cases dramatically increased in the areas along the Huang-Huai River of central China after 2001. Considering spatial aggregation of malaria cases and specific vectors, the geographical, meteorological and vectorial factors were analysed to determine the key factors related to malaria re-emergence in these particular areas. METHODS:

Shui S Zhou; Fang Huang; Jian J Wang; Shao S Zhang; Yun P Su; Lin H Tang

2010-01-01

111

An enhanced Hilbert-Huang transform technique for bearing condition monitoring  

NASA Astrophysics Data System (ADS)

A new technique, enhanced Hilbert-Huang transform (eHHT), is proposed in this work for fault detection in rolling element bearings. It includes two processes: firstly, the collected vibration signal is denoised to highlight defect-related impulses; and secondly the denoised signal is further processed by the use of the proposed eHHT technique to identify the defect features for bearing fault detection. Signal denoising is carried out by the use of the minimum entropy deconvolution filter to reduce impedance effect of the transmission path of the measured signal. In the proposed eHHT, a novel strategy is proposed to enhance feature extraction based on the analysis of correlation and mutual information. The effectiveness of the proposed eHHT technique in feature extraction and analysis is verified by a series of experimental tests corresponding to different bearing conditions. Its robustness is examined by using data sets from a different resource.

Osman, Shazali; Wang, Wilson

2013-08-01

112

Phase demodulation using adaptive windowed Fourier transform based on Hilbert-Huang transform.  

PubMed

The phase demodulation method of adaptive windowed Fourier transform (AWFT) is proposed based on Hilbert-Huang transform (HHT). HHT is analyzed and performed on fringe pattern to obtain instantaneous frequencies firstly. These instantaneous frequencies are further analyzed based on the condition of AWFT to locate local stationary areas where the fundamental spectrum will not be interfered by high-order spectrum. Within each local stationary area, the fundamental spectrum can be extracted accurately and adaptively by using AWFT with the background, which has been determined previously with the presented criterion during HHT, being eliminated to remove the zero-spectrum. This method is adaptive and unconstrained by any precondition for the measured phase. Experiments demonstrate its robustness and effectiveness for measuring the object with discontinuities or complex surface. PMID:23038397

Wang, Chenxing; Da, Feipeng

2012-07-30

113

Hilbert-Huang processing for single-exposure two-dimensional grating interferometry.  

PubMed

Single-shot crossed-type fringe pattern processing and analysis method called Hilbert-Huang grating interferometry (HHGI) is proposed. It consist of three main procedures: (1) crossed pattern is resolved into two fringe families using novel orthogonal empirical mode decomposition approach, (2) separated fringe sets are filtered using modified automatic selective reconstruction aided by enhanced fast empirical mode decomposition and mutual information detrending, and (3) Hilbert spiral transform is employed for fringe phase demodulation. Numerical and experimental studies corroborate the validity, versatility and robustness of the proposed HHGI technique. It can be successfully applied to multiplicative and additive type crossed patterns with sinusoidal and binary orthogonal component structures. Efficient adaptive filtering enables successful fast processing and analysis of complex and defected patterns. PMID:24514346

Trusiak, Maciej; Patorski, Krzysztof; Pokorski, Krzysztof

2013-11-18

114

Simulations of the linear plasma synthetic jet actuator utilizing a modified Suzen-Huang model  

NASA Astrophysics Data System (ADS)

The linear plasma synthetic jet actuator (L-PSJA) is a unique form of flow control device which harnesses the interaction of induced flows from two linear plasma actuators to form an upward jet. Since each injection can be manipulated in intensity, the synthetic jet has thrust vectoring properties. Our study simulates the L-PSJA by utilizing a modified Suzen-Huang (S-H) model that accounts for drift and diffusive properties in the surface charge. The results of the present model show that the centreline velocity is closer to the experimental values found in literature as compared to the default form of S-H modelling. Thrust vectoring simulations were also performed to demonstrate the feasibility of flow directional variation in the L-PSJA.

Ibrahim, I. H.; Skote, M.

2012-11-01

115

Hilbert Huang transform for detection and monitoring of crack in a transient rotor  

NASA Astrophysics Data System (ADS)

The dynamics and diagnostics of a cracked rotor have been gaining importance in the recent years. Vibration monitoring during start-up or shut-down is as important as during steady-state operations to detect cracks especially for machines such as aircraft engines which start and stop quite frequently and run at high speeds. In the present study a relatively new signal processing technique namely Hilbert-Huang transform (HHT) has been applied to transient response of a cracked rotor and few interesting results have been observed. And in all cases it has been found that HHT appears to be a better tool compared to fast Fourier transform and continuous wavelet transform for crack detection in a transient rotor.

Ramesh Babu, T.; Srikanth, S.; Sekhar, A. S.

2008-05-01

116

Hilbert-Huang Transform based multifractal analysis of China stock market  

NASA Astrophysics Data System (ADS)

In this paper, we employ the Hilbert-Huang Transform to investigate the multifractal character of Chinese stock market based on CSI 300 index. The measured Hilbert moment Lq(?) shows a power-law behavior on the range 0.01

Li, Muyi; Huang, Yongxiang

2014-07-01

117

Hilbert-Huang versus Morlet wavelet transformation on mismatch negativity of children in uninterrupted sound paradigm  

PubMed Central

Background Compared to the waveform or spectrum analysis of event-related potentials (ERPs), time-frequency representation (TFR) has the advantage of revealing the ERPs time and frequency domain information simultaneously. As the human brain could be modeled as a complicated nonlinear system, it is interesting from the view of psychological knowledge to study the performance of the nonlinear and linear time-frequency representation methods for ERP research. In this study Hilbert-Huang transformation (HHT) and Morlet wavelet transformation (MWT) were performed on mismatch negativity (MMN) of children. Participants were 102 children aged 8–16 years. MMN was elicited in a passive oddball paradigm with duration deviants. The stimuli consisted of an uninterrupted sound including two alternating 100 ms tones (600 and 800 Hz) with infrequent 50 ms or 30 ms 600 Hz deviant tones. In theory larger deviant should elicit larger MMN. This theoretical expectation is used as a criterion to test two TFR methods in this study. For statistical analysis MMN support to absence ratio (SAR) could be utilized to qualify TFR of MMN. Results Compared to MWT, the TFR of MMN with HHT was much sharper, sparser, and clearer. Statistically, SAR showed significant difference between the MMNs elicited by two deviants with HHT but not with MWT, and the larger deviant elicited MMN with larger SAR. Conclusion Support to absence ratio of Hilbert-Huang Transformation on mismatch negativity meets the theoretical expectations, i.e., the more deviant stimulus elicits larger MMN. However, Morlet wavelet transformation does not reveal that. Thus, HHT seems more appropriate in analyzing event-related potentials in the time-frequency domain. HHT appears to evaluate ERPs more accurately and provide theoretically valid information of the brain responses.

Cong, Fengyu; Sipola, Tuomo; Huttunen-Scott, Tiina; Xu, Xiaonan; Ristaniemi, Tapani; Lyytinen, Heikki

2009-01-01

118

A revised Hilbert–Huang transformation based on the neural networks and its application in vibration signal analysis of a deployable structure  

Microsoft Academic Search

A revised Hilbert–Huang method is proposed to deal with the non-linear and non-stationary signals generated from any kinds of the sensors, in order to overcome shortcomings of the Hilbert–Huang method, such as the end swings problem and the undesired intrinsic mode functions (IMFs) at the low-frequency range. Firstly, a radial basis function neural network is used as a pre-processor to

Jian Xun; Shaoze Yan

2008-01-01

119

Huang's three-step maneuver for laparoscopic spleen-preserving No. 10 lymph node dissection for advanced proximal gastric cancer  

PubMed Central

Due to the complexity of the splenic hilar vessels, their anatomical variation and the narrow and deep space, as well as the bleeding-prone splenic parenchyma and the difficulty to manage splenic or vascular bleeding at the splenic hilum,the procedure remains challenging and technically demanding procedure for the performance of laparoscopic pancreas- and spleen-preserving splenic hilar lymph nodes dissection. Based on our experiences, we gradually explored a set of procedural operation steps called “Huang’s three-step maneuver”. In this paper, we not only provide the concrete operation steps for the surgeon, but we also provide our recommended technique of pulling and exposure for assistants. This new maneuver simplifies the complicated procedure and improves the efficiency of laparoscopic spleen-preserving splenic hilar lymphadenectomy, making it easier to master and allowing for its widespread adoption.

Chen, Qi-Yue; Lin, Jian-Xian; Zheng, Chao-Hui; Li, Ping; Xie, Jian-Wei

2014-01-01

120

Steganalysis of JPEG2000 Lazy-Mode Steganography using the Hilbert-Huang Transform Based Sequential Analysis  

Microsoft Academic Search

In this paper, we present a steganalytic method to attack JPEG2000 lazy-mode steganography proposed by Su et al. The key element of the method is the Hilbert-Huang trans- form based analysis of the code-block noise variance se- quences of stego images and non-stego noisy images. The Hilbert transform based characteristic vectors are constructed via empirical mode decomposition of the sequences

Shunquan Tan; Jiwu Huang; Zhihua Yang; Yun Q. Shi

2006-01-01

121

Detection of Image Splicing Based on Hilbert-Huang Transform and Moments of Characteristic Functions with Wavelet Decomposition  

Microsoft Academic Search

Image splicing is a commonly used technique in image tampering. This paper presents a novel approach to passive detection\\u000a of image splicing. In the proposed scheme, the image splicing detection problem is tackled as a twoclass classification problem\\u000a under the pattern recognition framework. Considering the high non-linearity and non-stationarity nature of image splicing\\u000a operation, a recently developed Hilbert-Huang transform (HHT)

Dongdong Fu; Yun Q. Shi; Wei Su

2006-01-01

122

Application of time–frequency entropy method based on Hilbert–Huang transform to gear fault diagnosis  

Microsoft Academic Search

When faults occur in the gear, energy distribution of gear vibration signals measured in time–frequency plane would be different from the distribution under the normal state. Therefore, it is possible to detect a fault by comparing the energy distribution of gear vibration signals with and without fault conditions. Hilbert–Huang transform can offer a complete and accurate energy–frequency–time distribution. On the

Dejie Yu; Yu Yang; Junsheng Cheng

2007-01-01

123

Hilbert–Huang transform based signal analysis for the characterization of gas–liquid two-phase flow  

Microsoft Academic Search

This paper reports the application of the Hilbert–Huang Transform (HHT) to the dynamic characterization of gas–liquid two-phase flow in a horizontal pipeline. A differential pressure fluctuation signal of gas–liquid two-phase flow is adaptively decomposed into Intrinsic Mode Functions (IMFs) through the use of Empirical Mode Decomposition (EMD) methods. Based on the EMD, the associated time–frequency–energy distribution, i.e., the Hilbert spectrum,

Hao Ding; Zhiyao Huang; Zhihuan Song; Yong Yan

2007-01-01

124

Comparison between Windowed FFT and Hilbert-Huang Transform for Analyzing Time Series with Poissonian Fluctuations: A Case Study  

Microsoft Academic Search

Hilbert-Huang Transform (HHT) is a novel data analysis technique for nonlinear and non-stationary data. We present a time-frequency analysis of both simulated light curves and an X-ray burst from the X-ray burster 4U 1702--429 with both the HHT and the Windowed Fast Fourier Transform (WFFT) methods. Our results show that the HHT method has failed in all cases for light

Dong Han; Shuang-Nan Zhang

2006-01-01

125

Phase retrieval for noisy fringe pattern by using empirical mode decomposition and Hilbert Huang transform  

NASA Astrophysics Data System (ADS)

To address the issue of the intermittent noise in optical fringe pattern, an adaptive method of noise reduction is given based on empirical mode decomposition (EMD) and Hilbert Huang transform (HHT), and then the wrapped phase is obtained by performing the Hilbert transform on the refined pattern. Firstly, the signal of the fringe pattern is decomposed into several intrinsic mode functions (IMFs). With the instantaneous frequencies and marginal spectra of each IMF obtained by HHT, the criterion of identifying the noise IMF is determined. Then, it is judged whether a mode-mixing problem, which is the frequent problem in traditional EMD, appears in each noise IMF. If the problem appears, the ``noise,'' which is designed according to the signal adaptively, is added to the original signal, and then the obtained new signal is decomposed again. The process will be repeated until there is no mode mixing in the noise IMF. Finally, the wrapped phase is obtained by performing a Hilbert transform on the refined pattern with noise and background components removed. The proposed method can solve the mode-mixing problem effectively. It can reduce most of the noise and maintain a large amount of detailed phase information simultaneously. Simulation and compared experiments show the efficiency, robustness, and accuracy of the proposed method.

Wang, Chenxing; Da, Feipeng

2012-06-01

126

Hilbert-Huang-based tremor removal to assess postural properties from accelerometers.  

PubMed

Tremor is one of the symptoms of several disorders of the central and peripheral nervous system, such as Parkinson's disease (PD). The impairment of postural control is another symptom of PD. The conventional method of posture analysis uses force plates, but accelerometers can be a valid and reliable alternative. Both these measurement techniques are sensitive to tremor. Tremor affects postural measures and may thus lead to misleading results or interpretations. Linear low-pass filters (LPFs) are commonly employed for tremor removal. In this study, an alternative method, based on Hilbert-Huang transformation (HHT), is proposed. We examined 20 PD subjects, with and without tremor, and 20 control subjects. We compared the effectiveness of LPF and HHT-based filtering on a set of postural parameters extracted from acceleration signals. HHT has the advantage of providing a filter, which with no a priori knowledge, efficiently manages the nonlinear, nonstationary interference due to tremor, and beyond tremor, gives descriptive measures of postural function. Some of the differences found using LPF can instead be ascribed to inefficient noise/tremor suppression. Filter order and cutoff frequency are indeed critical when subjects exhibit a tremorous behavior, in which case LPF parameters should be chosen very carefully. PMID:21335305

Mellone, Sabato; Palmerini, Luca; Cappello, Angelo; Chiari, Lorenzo

2011-06-01

127

Damage detection in structures under traveling loads by Hilbert-Huang transform  

NASA Astrophysics Data System (ADS)

Hilbert-Huang transform (HHT) is an innovative data-processing technique for analyzing nonstationary and nonlinear signals. A novel HHT-based method for damage detection of bridge structures under a traveling load is proposed. The technique uses a single point measurement and is able to identify the presence and the location of the damage along the beam. The measured data are processed by the HHT technique, and none a priori information is needed about the response of the undamaged structure. Damage location is revealed by direct inspection of the first instantaneous frequency, which presents a sharp crest in correspondence of the damaged section. The identification capabilities of the proposed technique are studied varying the damage locations, crack depths and velocity of the moving load. The effect of ambient noise is also taken into account. Theoretical as well as numerical results show the identification is rather accurate, results are not very sensitive to the crack depth and ambient noise, while they are sensibly affected by the damage location and by the speed of the moving load as well. Theoretical analysis identifies a characteristic load velocity interval, depending both on the first natural frequency of the bridge and the damage location, within which the HHT can be successfully applied.

Roveri, N.; Carcaterra, A.

2012-04-01

128

Application of the Hilbert-Huang Transform to the Estimation of Air-Sea Turbulent Fluxes  

NASA Astrophysics Data System (ADS)

The Hilbert-Huang transform (HHT) is applied to analyzing the turbulent time series obtained within the atmospheric boundary layer over the ocean. A method based on the HHT is introduced to reduce the influence of non-turbulent motions on the eddy-covariance based flux by removing non-turbulent modes from the time series. The scale dependence of the flux is examined and a gap mode is identified to distinguish between turbulent modes and non-turbulent modes. To examine the effectiveness of this method it is compared with three conventional methods (block average, moving-window average, and multi-resolution decomposition). The data used are from three sonic anemometers installed on a moored buoy at about 6, 4 and 2.7 m height above the sea surface. For each method, along-wind and cross-wind momentum fluxes and sensible heat fluxes at the three heights are calculated. According to the assumption of a constant-flux layer, there should be no significant difference between the fluxes at the three heights. The results show that the fluxes calculated using HHT exhibit a smaller difference and higher correlation than the other methods. These results support the successful application of HHT to the estimation of air-sea turbulent fluxes.

Wang, Juanjuan; Song, Jinbao; Huang, Yansong; Fan, Conghui

2013-06-01

129

Lagrangian single-particle turbulent statistics through the Hilbert-Huang transform  

NASA Astrophysics Data System (ADS)

The Hilbert-Huang transform is applied to analyze single-particle Lagrangian velocity data from numerical simulations of hydrodynamic turbulence. The velocity trajectory is described in terms of a set of intrinsic mode functions Ci(t) and of their instantaneous frequency ?i(t). On the basis of this decomposition we define the ?-conditioned statistical moments of the Ci modes, named q-order Hilbert spectra (HS). We show that such quantities have enhanced scaling properties as compared to traditional Fourier transform- or correlation-based (structure functions) statistical indicators, thus providing better insights into the turbulent energy transfer process. We present clear empirical evidence that the energylike quantity, i.e., the second-order HS, displays a linear scaling in time in the inertial range, as expected from a dimensional analysis. We also measure high-order moment scaling exponents in a direct way, without resorting to the extended self-similarity procedure. This leads to an estimate of the Lagrangian structure function exponents which are consistent with the multifractal prediction in the Lagrangian frame as proposed by Biferale [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.93.064502 93, 064502 (2004)].

Huang, Yongxiang; Biferale, Luca; Calzavarini, Enrico; Sun, Chao; Toschi, Federico

2013-04-01

130

Application of Hilbert-Huang transform based instantaneous frequency to seismic reflection data  

NASA Astrophysics Data System (ADS)

Empirical mode decomposition (EMD) is designed to decompose non-stationary, nonlinear data into a series of intrinsic mode functions (IMFs) adaptively. This procedure is automatic, data-driven and time-variant. And then a Hilbert transform is applied to these IMFs. The combination of EMD with a Hilbert transform is known as Hilbert-Huang transform (HHT). HHT can be used to calculate meaningful multi-resolution instantaneous frequency (HHT based instantaneous frequency). Currently, the application of EMD and HHT to seismic data is performed mainly for noise attenuation. In this paper, we demonstrate new insights of EMD and HHT to seismic data analysis. We first extend the research of Flandrin et al. and analyze how EMD behaves on a Gaussian band-pass signal; we then employ HHT based instantaneous frequency on wedge model and real seismic data to delineate thickness variations. Numerical examples of Gaussian band-pass noise indicate that EMD acts as an adaptive, multi-band overlapping filter bank. The analysis of a wedge model and 2D real seismic data illustrates that HHT based instantaneous frequency is more effective than conventional Hilbert transform based instantaneous frequency in delineating the thickness variation of seismic thin bed.

Zhou, Yanhui; Chen, Wenchao; Gao, Jinghuai; He, Yongqiang

2012-07-01

131

Hilbert-Huang transform analysis of dynamic and earthquake motion recordings  

USGS Publications Warehouse

This study examines the rationale of Hilbert-Huang transform (HHT) for analyzing dynamic and earthquake motion recordings in studies of seismology and engineering. In particular, this paper first provides the fundamentals of the HHT method, which consist of the empirical mode decomposition (EMD) and the Hilbert spectral analysis. It then uses the HHT to analyze recordings of hypothetical and real wave motion, the results of which are compared with the results obtained by the Fourier data processing technique. The analysis of the two recordings indicates that the HHT method is able to extract some motion characteristics useful in studies of seismology and engineering, which might not be exposed effectively and efficiently by Fourier data processing technique. Specifically, the study indicates that the decomposed components in EMD of HHT, namely, the intrinsic mode function (IMF) components, contain observable, physical information inherent to the original data. It also shows that the grouped IMF components, namely, the EMD-based low- and high-frequency components, can faithfully capture low-frequency pulse-like as well as high-frequency wave signals. Finally, the study illustrates that the HHT-based Hilbert spectra are able to reveal the temporal-frequency energy distribution for motion recordings precisely and clearly.

Zhang, R. R.; Ma, S.; Safak, E.; Hartzell, S.

2003-01-01

132

Study of the Lee-Huang-Yang correction for atomic bosons  

NASA Astrophysics Data System (ADS)

The famous Lee-Huang-Yang (LHY) term describes the first-order correction to the mean-field energy for strongly interacting bosons [1], yet it has only been detected with bosons composed of loosely bound fermion pairs [2,3]. Tan's universal relations, originally calculated for fermions [4], connect a property called the Contact to many macroscopic parameters of a quantum gas, such as its total energy. These relations have been verified experimentally for Fermi systems [5]. We apply these relations to a Bose gas to realize a unique tool to study the LHY correction. We perform RF spectroscopy on a BEC of ^85Rb close to a Feshbach resonance, and measure the strength of the RF lineshape tail which decays as 1/w^3/2. From this we extract the Contact, which increases as a function of the interaction strength. This allows us to quantitatively study the LHY term for atomic bosons, as well as investigate time-dependent effects that arise from the rate of change of the interaction strength compared to various experimental time scales.

Wild, Robert; Pino, Juan; Makotyn, Philip; Cornell, Eric; Jin, Deborah

2011-06-01

133

Observations of cloud condensation nuclei in Mt. Huang: instrumentation and early observations  

NASA Astrophysics Data System (ADS)

A new commercial instrument for measuring Cloud Condensation Nuclei (CCN), the Droplet Measurement Technologies Cylindrical Continuous-Flow Streamwise Thermal Gradient CCN Chamber (CFSTGC), installed on Mount Huang meteorological station (30°19'N, 118°14'E, 1840m above sea level) from 16 April to 28 July 2008. This instrument can measure CCN concentrations at supersaturations from 0.1% to 2% (potentially up to 6%), as well as a 1 Hz sampling rate that is sufficient for ground-based or airborne platform operation. The instrument records data continuously at 1-second intervals 24 hours a day. For the 98-day, continuous study the average CCN concentration was found to range between a few hundred and a few thousand nuclei per cm3 at supersaturations between 0.3 and 1%. Diurnal variations were observed, as well as other possible influences, such as wind speed, wind direction and mixing depth. At a constant supersaturation of 0.5% the CCN concentration is typically on the order of 361 to 2297 nuclei per cm3. A description of the instrumentation and early observations are presented and discussed.

Chen, Kui; Yin, Yan; Chen, Chen; Yang, Weifeng; Deng, Wei; Hu, Zhenghua; Wu, Fangfang

2009-07-01

134

Novel pharmacokinetic studies of the Chinese formula Huang-Lian-Jie-Du-Tang in MCAO rats.  

PubMed

Our previous studies showed that after oral administration of an Huang-Lian-Jie-Du-Tang (HLJDT) decoction, there is a higher concentration of the pure components, berberine, baicalin and gardenoside in the plasma of Middle cerebral artery occlusion (MCAO) rats than in sham-operated rats, The aim of the present study was to determine whether these components could be reliably measured in MCAO rat tissues. First, the plasma concentration-time profiles of berberine, palmatine, baicalin, baicalein and gardenoside were characterised in MCAO rats after oral administration of the aqueous extract of HLJDT. Subsequently, liver, lung and kidney tissues were obtained from sudden death MCAO rats in the absorption phase (0.25 h), the distribution phase (1.0 h) and the elimination phase (8.0 h) after administration of the HLJDT aqueous extract. An HPLC method was developed and validated for the determination of the distribution characteristics of berberine, palmatine, baicalin, baicalein and gardenoside simultaneously from the above-mentioned rat tissues. The results indicated that berberine, palmatine, baicalin and baicalein distributed rapidly and accumulated at high levels in the lung, while gardenoside distributed widely in the lung and the kidney. To the best of our knowledge, this is the first report to describe the distribution of the active ingredients derived from HLJDT in MCAO rat tissues. The tissue distribution results provide a biopharmaceutical basis for the design of the clinic application of HLJDT in cerebrovascular disease. PMID:23628154

Zhu, Huaxu; Qian, Zhilei; He, Feng; Liu, Mengzhu; Pan, Linmei; Zhang, Qichun; Tang, Yuping

2013-07-15

135

NINJA data analysis with a detection pipeline based on the Hilbert-Huang transform  

NASA Astrophysics Data System (ADS)

The NINJA data analysis challenge allowed the study of the sensitivity of data analysis pipelines to binary black hole numerical relativity waveforms in simulated Gaussian noise at the design level of the LIGO observatory and the VIRGO observatory. We analyzed NINJA data with a pipeline based on the Hilbert-Huang transform, utilizing a detection stage and a characterization stage: detection is performed by triggering on excess instantaneous power, characterization is performed by displaying the kernel density enhanced (KD) time-frequency trace of the signal. Using the simulated data based on the two LIGO detectors, we were able to detect 77 signals out of 126 above signal-to-noise ratio, SNR 5 in coincidence, with 43 missed events characterized by SNR < 10. Characterization of the detected signals revealed the merger part of the waveform in high time and frequency resolution, free from time-frequency uncertainty. We estimated the timelag of the signals between the detectors based on the optimal overlap of the individual KD time-frequency maps, yielding estimates accurate within a fraction of a millisecond for half of the events. A coherent addition of the data sets according to the estimated timelag eventually was used in a final characterization of the event.

Stroeer, Alexander; Camp, Jordan

2009-06-01

136

Analysis of fatigue and tremor during sustained maximal grip contractions using Hilbert-Huang Transformation.  

PubMed

The objective of this study was to evaluate muscle fatigue and tremor during a Sustained Maximal Grip Contraction (SMGC) using the Hilbert-Huang Transformation (HHT). Thirty-nine healthy subjects volunteered for the study and performed a 25-s SMGC. Fatigue parameters such as the relative force output (RFO) were calculated from the residual of SMGC after applying Empirical Mode Decomposition (EMD). Using the energy spectrum of the Intrinsic Mode Functions (IMF) obtained using HHT, isometric force tremor was identified from the 4 to 12 Hz region in IMF3 and IMF4. Data were analysed for five consecutive 5-s epochs to identify changes in fatigue and tremor over time. The HHT method was able to identify a greater resistance to fatigue in women compared to men (p?0.05) and in non-dominant hands compared to dominant hands (p?0.05). Consistent with the results for fatigue, women had less tremor than men (p?0.05), while non-dominant hands trembled less than did dominant hands (p?0.05). Higher levels of tremor were observed for non-fatigue-resistant subjects for both 10-15 s and 15-20 s epochs (p?0.05). The HHT is an appropriate method to identify both fatigue and tremor during SMGC. It would be of interest to apply this method to the study the elderly or patients with neuromuscular disorders. PMID:22177573

Li, Ke; Hogrel, Jean-Yves; Duchêne, Jacques; Hewson, David J

2012-09-01

137

A novel analysis method for near infrared spectroscopy based on Hilbert-Huang transform  

NASA Astrophysics Data System (ADS)

Near Infrared Imager (NIRI) has been widely used to access the brain functional activity non-invasively. We use a portable, multi-channel and continuous-wave NIR topography instrument to measure the concentration changes of each hemoglobin species and map cerebral cortex functional activation. By extracting some essential features from the BOLD signals, optical tomography is able to be a new way of neuropsychological studies. Fourier spectral analysis provides a common framework for examining the distribution of global energy in the frequency domain. However, this method assumes that the signal should be stationary, which limits its application in non-stationary system. The hemoglobin species concentration changes are of such kind. In this work we develop a new signal processing method using Hilbert-Huang transform to perform spectral analysis of the functional NIRI signals. Compared with wavelet based multi-resolution analysis (MRA), we demonstrated the extraction of task related signal for observation of activation in the prefrontal cortex (PFC) in vision stimulation experiment. This method provides a new analysis tool for functional NIRI signals. Our experimental results show that the proposed approach provides the unique method for reconstructing target signal without losing original information and enables us to understand the episode of functional NIRI more precisely.

Zhou, Zhenyu; Yang, Hongyu; Liu, Yun; Ruan, Zongcai; Luo, Qingming; Gong, Hui; Lu, Zuhong

2007-05-01

138

Structural modal parameter identification and damage diagnosis based on Hilbert-Huang transform  

NASA Astrophysics Data System (ADS)

Traditional modal parameter identification methods have many disadvantages, especially when used for processing nonlinear and non-stationary signals. In addition, they are usually not able to accurately identify the damping ratio and damage. In this study, methods based on the Hilbert-Huang transform (HHT) are investigated for structural modal parameter identification and damage diagnosis. First, mirror extension and prediction via a radial basis function (RBF) neural network are used to restrain the troublesome end-effect issue in empirical mode decomposition (EMD), which is a crucial part of HHT. Then, the approaches based on HHT combined with other techniques, such as the random decrement technique (RDT), natural excitation technique (NExT) and stochastic subspace identification (SSI), are proposed to identify modal parameters of structures. Furthermore, a damage diagnosis method based on the HHT is also proposed. Time-varying instantaneous frequency and instantaneous energy are used to identify the damage evolution of the structure. The relative amplitude of the Hilbert marginal spectrum is used to identify the damage location of the structure. Finally, acceleration records at gauge points from shaking table testing of a 12-story reinforced concrete frame model are taken to validate the proposed approaches. The results show that the proposed approaches based on HHT for modal parameter identification and damage diagnosis are reliable and practical.

Han, Jianping; Zheng, Peijuan; Wang, Hongtao

2014-03-01

139

Multimodal Pressure Flow Analysis: Application of Hilbert Huang Transform in Cerebral Blood Flow Regulation.  

PubMed

Quantification of nonlinear interactions between two nonstationary signals presents a computational challenge in different research fields, especially for assessments of physiological systems. Traditional approaches that are based on theories of stationary signals cannot resolve nonstationarity-related issues and, thus, cannot reliably assess nonlinear interactions in physiological systems. In this review we discuss a new technique "Multi-Modal Pressure Flow method (MMPF)" that utilizes Hilbert-Huang transformation to quantify dynamic cerebral autoregulation (CA) by studying interaction between nonstationary cerebral blood flow velocity (BFV) and blood pressure (BP). CA is an important mechanism responsible for controlling cerebral blood flow in responses to fluctuations in systemic BP within a few heart-beats. The influence of CA is traditionally assessed from the relationship between the well-pronounced systemic BP and BFV oscillations induced by clinical tests. Reliable noninvasive assessment of dynamic CA, however, remains a challenge in clinical and diagnostic medicine.In this brief review we: 1) present an overview of transfer function analysis (TFA) that is traditionally used to quantify CA; 2) describe the a MMPF method and its modifications; 3) introduce a newly developed automatic algorithm and engineering aspects of the improved MMPF method; and 4) review clinical applications of MMPF and its sensitivity for detection of CA abnormalities in clinical studies. The MMPF analysis decomposes complex nonstationary BP and BFV signals into multiple empirical modes adaptively so that the fluctuations caused by a specific physiologic process can be represented in a corresponding empirical mode. Using this technique, we recently showed that dynamic CA can be characterized by specific phase delays between the decomposed BP and BFV oscillations, and that the phase shifts are significantly reduced in hypertensive, diabetics and stroke subjects with impaired CA. In addition, the new technique enables reliable assessment of CA using both data collected during clinical test and spontaneous BP/BFV fluctuations during baseline resting conditions. PMID:18725996

Lo, Men-Tzung; Hu, Kun; Liu, Yanhui; Peng, C-K; Novak, Vera

2008-01-01

140

Multimodal Pressure Flow Analysis: Application of Hilbert Huang Transform in Cerebral Blood Flow Regulation  

PubMed Central

Quantification of nonlinear interactions between two nonstationary signals presents a computational challenge in different research fields, especially for assessments of physiological systems. Traditional approaches that are based on theories of stationary signals cannot resolve nonstationarity-related issues and, thus, cannot reliably assess nonlinear interactions in physiological systems. In this review we discuss a new technique “Multi-Modal Pressure Flow method (MMPF)” that utilizes Hilbert-Huang transformation to quantify dynamic cerebral autoregulation (CA) by studying interaction between nonstationary cerebral blood flow velocity (BFV) and blood pressure (BP). CA is an important mechanism responsible for controlling cerebral blood flow in responses to fluctuations in systemic BP within a few heart-beats. The influence of CA is traditionally assessed from the relationship between the well-pronounced systemic BP and BFV oscillations induced by clinical tests. Reliable noninvasive assessment of dynamic CA, however, remains a challenge in clinical and diagnostic medicine. In this brief review we: 1) present an overview of transfer function analysis (TFA) that is traditionally used to quantify CA; 2) describe the a MMPF method and its modifications; 3) introduce a newly developed automatic algorithm and engineering aspects of the improved MMPF method; and 4) review clinical applications of MMPF and its sensitivity for detection of CA abnormalities in clinical studies. The MMPF analysis decomposes complex nonstationary BP and BFV signals into multiple empirical modes adaptively so that the fluctuations caused by a specific physiologic process can be represented in a corresponding empirical mode. Using this technique, we recently showed that dynamic CA can be characterized by specific phase delays between the decomposed BP and BFV oscillations, and that the phase shifts are significantly reduced in hypertensive, diabetics and stroke subjects with impaired CA. In addition, the new technique enables reliable assessment of CA using both data collected during clinical test and spontaneous BP/BFV fluctuations during baseline resting conditions.

Lo, Men-Tzung; Hu, Kun; Liu, Yanhui; Peng, C.-K.; Novak, Vera

2008-01-01

141

Study of nonlinear oscillations in a glow discharge plasma using empirical mode decomposition and Hilbert Huang transform  

NASA Astrophysics Data System (ADS)

Hilbert Huang transform (HHT) based time series analysis was carried out on nonlinear floating potential fluctuations obtained from hollow cathode glow discharge plasma in the presence of anode glow. HHT was used to obtain contour plots and the presence of nonlinearity was studied. Frequency shift with time, which is a typical nonlinear behaviour, was detected from the contour plots. Various plasma parameters were measured and the concepts of correlation coefficients and the physical contribution of each intrinsic mode function have been discussed. Physically important quantities such as instantaneous energy and their uses in studying physical phenomena such as intermittency and non-stationary data have also been discussed.

Wharton, A. M.; Sekar Iyengar, A. N.; Janaki, M. S.

2013-02-01

142

Oscillator strengths, Huang-Rhys parameters, and vibrational quantum energies of cerium-doped gadolinium oxyorthosilicate  

SciTech Connect

Temperature-dependent optical absorption of cerium-doped gadolinium oxyorthosilicate (Gd{sub 2}SiO{sub 5}:Ce) has been measured and analyzed for impurity-ion-lattice coupling parameters and oscillator strengths. Although the spectrum consists of overlapping Ce{sup 3+} bands and Gd{sup 3+} lines, two well-resolved Ce{sup 3+} bands with 10 K maxima at 3.32 eV (peak a) and 3.61 eV (peak b) are amenable to spectral analysis. These bands, previously assigned to Ce{sup 3+} ions occupying crystallographically inequivalent substitutional sites, are characterized by Gaussian line shapes and temperature-dependent half widths that are well described by the linear model of impurity-ion-lattice coupling. Huang-Rhys [Proc. R. Soc. A 204, 404 (1950)] parameters of peaks a and b are 22.7 and 5.7, respectively, indicating strong ion-lattice coupling, with vibrational frequencies 1.83x10{sup 13} s{sup -1} (peak a) and 5.07x10{sup 13} s{sup -1} (peak b). Peak b centroid is approximately temperature independent, but peak a centroid shifts to higher energy with increasing temperature. This dependence is adequately described by including higher-order coupling terms in the ion-lattice interaction, although crystal-field contributions cannot be excluded. Absorption band oscillator strengths, f, are calculated from Smakula's [Z. Phys. 59, 603 (1930)] formula and knowledge of cerium concentration for the two inequivalent sites. In the interval 10-300 K, peak a f values range from (9.8 to 26.8)x10{sup -4} and peak b f values vary from (7.8 to 5.8)x10{sup -3}. From the known correlation between oscillator strength and metal-ion-ligand separation, we identify peaks a and b as the seven- and nine-oxygen-coordinated sites, respectively. (c) 2000 American Institute of Physics.

Cooke, D. W. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Bennett, B. L. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); McClellan, K. J. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Roper, J. M. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Whittaker, M. T. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2000-06-01

143

The Hilbert-Huang Transform Applied to Quasi-Periodic Volcanic Tremor  

NASA Astrophysics Data System (ADS)

The Hilbert-Huang Transform (HHT) is applied to nonlinear, quasi-periodic harmonic tremor on an erupting volcano to extract detailed variations in explosion dynamics. The HHT relies upon the Empirical Mode Decomposition (EMD) method to split signals into Intrinsic Mode Functions (IMFs) that are amenable to the Hilbert Transform. Instantaneous time/frequency/power traces of each transformed IMF can be combined to yield a composite Hilbert spectrogram of the signal's evolution through time. Unlike Fourier-based methods, the HHT does not use linear combinations of sinusoids to approximate signals. The advantage of the HHT is that it does not require its basis to be linear and stationary; furthermore, it can provide instantaneous amplitude and frequency for each sample in the data set. We use the HHT to examine tremor signals recorded at Santiaguito volcano, Guatemala, in 2009. The time interval between successive tremor pulses exhibits a linear relationship with amplitude over several sequences, suggesting a nonlinear process. This indicates that at least some of the pulse sequences cannot be modeled as sinusoidal signal. For this reason, the HHT, rather than a Fourier method, is used to examine how signal frequency and amplitude change through time. We focus on an example tremor signal that has both seismic and infrasound recordings. The infrasound portion of the example event includes two frequency modulated signals, one centered at 0.5 Hz and the other centered at 1 Hz. In contrast, the seismic portion of this event is a frequency modulated signal centered at 1 Hz with distributed energy in the 2-5 Hz range. Certain time intervals contain series of repeating frequency modulations that may indicate either nonlinear waveforms or the superposition of low amplitude riding waves on higher amplitude carrier waves. These frequency modulations do not correlate between infrasound and seismic records. Detailed deconstruction of the tremor via HHT provides a basis for examination of physical transients in the otherwise apparently harmonic signal. We have also applied the HHT method on harmonic tremor sequences at other volcanoes including Renventador and Karymsky.

Bowman, D. C.; Lees, J. M.; Johnson, J.

2012-12-01

144

Temperature and Precipitation Suitability Evaluation for the Winter Wheat and Summer Maize Cropping System in the Huang-Huai-Hai Plain of China  

Microsoft Academic Search

The Huang-Huai-Hai Plain is the most important winter wheat and maize production region in China. In response to the increasing population pressure, the Chinese authorities strongly invested in improving the irrigation systems and increasing ground and surface water exploitation within the plain to increase the crop productivity. This resulted in a reduction of water resource availability and in turn indirectly

Nguyen Thanh Tuan; Jian-jun QIU; Ann Verdoodt; Hu LI; Eric Van Ranst

2011-01-01

145

Automated Flaw Detection Scheme For Cast Austenitic Stainless Steel Weld Specimens Using Hilbert Huang Transform Of Ultrasonic Phased Array Data  

SciTech Connect

The objective of this work is to develop processing algorithms to detect and localize the flaws using NDE ultrasonic data. Data was collected using cast austenitic stainless steel (CASS) weld specimens on-loan from the U.S. nuclear power industry’s Pressurized Water Reactor Owners Group (PWROG) specimen set. Each specimen consists of a centrifugally cast stainless steel (CCSS) pipe section welded to a statically cast (SCSS) or wrought (WRSS) section. The paper presents a novel automated flaw detection and localization scheme using low frequency ultrasonic phased array inspection signals in the weld and heat affected zone of the base materials. The major steps of the overall scheme are preprocessing and region of interest (ROI) detection followed by the Hilbert Huang transform (HHT) of A-scans in the detected ROIs. HHT offers time-frequency-energy distribution for each ROI. The accumulation of energy in a particular frequency band is used as a classification feature for the particular ROI.

Khan, T.; Majumdar, Shantanu; Udpa, L.; Ramuhalli, Pradeep; Crawford, Susan L.; Diaz, Aaron A.; Anderson, Michael T.

2012-01-01

146

Pharmacochemistry and integrated pharmacokinetics of six alkaloids after oral administration of Huang-Lian-Jie-Du-Tang decoction.  

PubMed

Pharmacochemistry and integrated pharmacokinetics of six alkaloids (groenlandicine, berberine, palmatine, epiberberine, jatrorrhizine, and columbamine) after oral administration of Huang-Lian-Jie-Du-Tang (HLJDT) decoction were investigated in this paper. The method of plasma pharmacochemistry was applied to predict the potential bioactive components in HLJDT decoction. Based on the accurate molecular weight, 10 components including 2 flavonoids (baicalin and wogonoside), 1 iridoid glycoside (geniposide), and 7 alkaloids (above-mentioned 6 alkaloids and coptisine) were structurally identified. Then, integrated pharmacokinetics of the alkaloids in Sprague-Dawley rats after oral administration of HLJDT decoction was investigated by HPLC method. The results showed that the pharmacokinetic behaviors of the alkaloids were different although their chemical structures were similar. This study developed a method to predict the potential bioactive components in HLJDT decoction and research the pharmacokinetic behaviors of the potential bioactive components. PMID:24797560

Ma, Zhao-Tang; Yang, Xiu-Wei; Zhang, Ying; Liu, Jian-Xun

2014-05-01

147

A Novel Preprocessing Method Using Hilbert Huang Transform for MALDI-TOF and SELDI-TOF Mass Spectrometry Data  

PubMed Central

Motivation Mass spectrometry is a high throughput, fast, and accurate method of protein analysis. Using the peaks detected in spectra, we can compare a normal group with a disease group. However, the spectrum is complicated by scale shifting and is also full of noise. Such shifting makes the spectra non-stationary and need to align before comparison. Consequently, the preprocessing of the mass data plays an important role during the analysis process. Noises in mass spectrometry data come in lots of different aspects and frequencies. A powerful data preprocessing method is needed for removing large amount of noises in mass spectrometry data. Results Hilbert-Huang Transformation is a non-stationary transformation used in signal processing. We provide a novel algorithm for preprocessing that can deal with MALDI and SELDI spectra. We use the Hilbert-Huang Transformation to decompose the spectrum and filter-out the very high frequencies and very low frequencies signal. We think the noise in mass spectrometry comes from many sources and some of the noises can be removed by analysis of signal frequence domain. Since the protein in the spectrum is expected to be a unique peak, its frequence domain should be in the middle part of frequence domain and will not be removed. The results show that HHT, when used for preprocessing, is generally better than other preprocessing methods. The approach not only is able to detect peaks successfully, but HHT has the advantage of denoising spectra efficiently, especially when the data is complex. The drawback of HHT is that this approach takes much longer for the processing than the wavlet and traditional methods. However, the processing time is still manageable and is worth the wait to obtain high quality data.

Wu, Li-Ching; Chen, Hsin-Hao; Horng, Jorng-Tzong; Lin, Chen; Huang, Norden E.; Cheng, Yu-Che; Cheng, Kuang-Fu

2010-01-01

148

Changes in extreme precipitation in the Huang-Huai-Hai River basin of China during 1960-2010  

NASA Astrophysics Data System (ADS)

With the increasing exposure of populations and economy to the natural hazards, it is of vital importance to study the spatiotemporal characteristics of extreme precipitation. Based on daily precipitation at 154 meteorological stations in the Huang-Huai-Hai River basin of China during 1960-2010, the spatial and temporal changes in extreme precipitation were analyzed using twelve indices. The basin was divided into five climate areas using clustering analysis to detect the spatial changes of the extreme indices, and the temporal changes in the probability distributions of the extreme indices were also examined. The results showed that maximum 5-day precipitation, wet days and consecutive wet days decreased significantly while consecutive dry days showed a weak increasing trend. The other precipitation indices had insignificant decreasing trends. The probability distribution functions of simple daily intensity index and consecutive dry days were positively shifted while the rest of the indices were negatively shifted. The temporal changes of extreme indices implied that the frequency of extreme precipitation was decreasing, but the intensity of extreme precipitation was increasing in the Huang-Huai-Hai River basin. The spatial changes in the aspect of precipitation extreme events showed obvious spatial differences between different climate areas. In addition, the series including maximum 1-day precipitation and maximum 5-day precipitation were fitted by generalized extreme-value distribution for risk analysis and the results showed that the generalized extreme-value distribution could fit the series well. The amounts of extreme precipitation for different return periods were calculated and high risk areas for flooding disaster were presented.

Zhang, Dong-Dong; Yan, Deng-Hua; Wang, Yi-Cheng; Lu, Fan; Wu, Di

2014-05-01

149

Multi-criteria decision analyses. Viewing MCDA in terms of both process and aggregation methods: some thoughts, motivated by the paper of Huang, Keisler and Linkov.  

PubMed

The paper of Huang, Keisler and Linkov (HKL) (Huang et al., 2011) has motivated us to this note about the relation between ranking procedures and Multi-Criteria Decision Analysis (MCDA) tools. The key concept in the HKL-paper is in our eyes the 'trade-off'. A 'trade-off' seems necessary, when conflicting indicator values are present. HKL stress that the general application of MCDA is hampered by different terminology. We do not claim to have a solution for that problem. Nevertheless, we think that the discussion is worthwhile and this note presents some of our ideas, which basically imply the need of a broadening of the definition of MCDA. PMID:22475219

Bruggemann, Rainer; Carlsen, Lars

2012-05-15

150

Correlation of black carbon aerosol and carbon monoxide in the high-altitude environment of Mt. Huang in Eastern China  

NASA Astrophysics Data System (ADS)

Understanding the relationship between black carbon (BC) and carbon monoxide (CO) will help improve BC emission inventories and the evaluation of global/regional climate forcing effects. In the present work, the BC (PM1) mass concentration and CO mixing ratio were continuously measured at a high-altitude background station on the summit of Mt. Huang (30.16° N, 118.26° E, 1840 m a.s.l.). Annual mean BC mass concentration was 1004.5 ± 895.5 ng m-3 with maxima in spring and autumn, and annual mean CO mixing ratio was 424.1 ± 159.2 ppbv. A large increase of CO was observed in the cold season, implying the contribution from the large-scale domestic coal/biofuel combustion for heating. The BC-CO relationship was found to show different seasonal features but strong positive correlation (R>0.8). In Mt. Huang area, the ?BC/?CO ratio showed unimodal diurnal variations and had a maximum during the day (09:00-17:00 LST) and minimum at night (21:00-04:00 LST) in all seasons, indicating the impact of planetary boundary layer and the intrusion of clean air masses from the high troposphere. Back trajectory cluster analysis showed that the ?BC/?CO ratio of plumes from the Eastern China (Jiangsu, Zhejiang provinces and Shanghai) was 8.8 ± 0.9 ng m-3 ppbv-1. Transportation and industry were deemed as controlling factors of the BC-CO relationship in this region. The ?BC/?CO ratios for air masses from Northern China (Anhui, Henan, Shanxi and Shandong provinces) and southern China (Jiangxi, Fujian and Hunan provinces) were quite similar with mean values of 6.5 ± 0.4 and 6.5 ± 0.2 ng m-3 ppbv-1 respectively. The case studies combined with satellite observations demonstrated that the ?BC/?CO ratio for biomass burning (BB) plumes were 10.3 ± 0.3 and 11.6 ± 0.5ng m-3 ppbv-1, significantly higher than those during non-BB impacted periods. The loss of BC during transport was also investigated on the basis of the ?BC/?CO-RH (relative humidity) relationship along air mass pathways. The results showed that BC particles from Eastern China area was much more easily removed from atmosphere than other inland regions due to the higher RH along transport pathway, implying the importance of chemical compositions and mixing states on BC residence time in the atmosphere.

Pan, X. L.; Kanaya, Y.; Wang, Z. F.; Liu, Y.; Pochanart, P.; Akimoto, H.; Sun, Y. L.; Dong, H. B.; Li, J.; Irie, H.; Takigawa, M.

2011-09-01

151

Evaluation of the Hilbert-Huang transform application for the recognition of seismic precursory phenomena by the analysis of VLF transmission signals of the European Network.  

NASA Astrophysics Data System (ADS)

In this paper the authors evaluate the suitability of the Hilber-Huang transformation (Empirical Mode Decomposition) in the recognition of seismic precursory phenomena from the analysis of signals which are transmitted by European station in the VLF frequency band. So, the results of the measurements and analysis of the received signals for the time periods of the earthquake occurrence in the area of Greece and the effectiveness of the method is being discussed.(in Greeks)

Skeberis, C.; Xenos, T. D.; Arabelos, D. N.; Spatalas, S.

2013-01-01

152

Comparative pharmacokinetics of baicalin after oral administration of pure baicalin, Radix scutellariae extract and Huang-Lian-Jie-Du-Tang to rats  

Microsoft Academic Search

Huang-Lian-Jie-Du-Tang (HLJDT) is an important “heat-clearing” multiherb remedy of traditional Chinese medicine, and Radix scutellariae (Scutellaria baicalensis Georgi, Labiatae) is a key ingredient herb in it. Baicalin and wogonoside are two main effective ingredients enriched in Radix scutellariae. In the present study, pharmacokinetic differences of baicalin following oral administration of pure baicalin, Radix scutellariae extract, baicalin co-administrated with extract of

Tong Lu; Jue Song; Fang Huang; Yuanxiong Deng; Lin Xie; Guangji Wang; Xiaodong Liu

2007-01-01

153

Application of Hilbert-Huang transform to characterize soil liquefaction and quay wall seismic responses modeled in centrifuge shaking-table tests  

Microsoft Academic Search

In this paper, a Hilbert-Huang Transform data-processing technique is successfully used to characterize the seismic responses of soil–quay wall systems using measured data in a series of geotechnical centrifuge shaking-table tests. The predominant frequency of a liquefied deposit shifts down to a low frequency level; however, “de-liquefaction” leads to frequent, local higher-frequency spikes in the time histories of predominant instantaneous

Yu-Chen Wei; Chung-Jung Lee; Wen-Yi Hung; Huei-Tsyr Chen

2010-01-01

154

Protective effect of Oren-gedoku-to (Huang-Lian-Jie-Du-Tang) against impairment of learning and memory induced by transient cerebral ischemia in mice  

Microsoft Academic Search

The protective effect of Oren-gedoku-to (OGT; Huang-Lian-Jie-Du-Tang), a traditional Chinese medicine, against impairment of learning and memory induced by transient cerebral ischemia was investigated in mice. The cerebral ischemia caused a reduction of step-down latency and an increase of step-down errors in the passive avoidance task. Pretreatment with oral administration of OGT (2, 4 or 8 g of herbs per

Jinghua Xu; Yukihisa Murakami; Kinzo Matsumoto; Michihisa Tohda; Hiroshi Watanabe; Shaohui Zhang; Qinghai Yu; Jia Shen

2000-01-01

155

Characterization of gear faults in variable rotating speed using Hilbert-Huang Transform and instantaneous dimensionless frequency normalization  

NASA Astrophysics Data System (ADS)

The objective of this research is to investigate the feasibility of utilizing the instantaneous dimensionless frequency (DLF) normalization and Hilbert-Huang Transform (HHT) to characterize the different gear faults in case of variable rotating speed. The normalized DLF of the vibration signals are calculated based on the rotating speed of shaft and the instantaneous frequencies of Intrinsic Mode Functions (IMFs) which are decomposed by Empirical Mode Decomposition (EMD) process. The faulty gear features on DLF-energy distribution of vibration signal can be extracted without the presence of shaft rotating speed, so that the proposed approach can be applied for characterizing the malfunctions of gearbox system under variable shaft rotating speed. A test rig of gear transmission system is performed to illustrate the gear faults, including worn tooth, broken tooth and gear unbalance. Different methods to determine the instantaneous frequency are employed to verify the consistence of characterization results. The DLF-energy distributions of vibration signals are investigated in different faulty gear conditions. The analysis results demonstrate the capability and effectiveness of the proposed approach for characterizing the gear malfunctions at the DLFs corresponding to the meshing frequency as well as the shaft rotating frequency. The support vector machine (SVM) is then employed to classify the vibration patterns of gear transmission system at different malfunctions. Using the energy distribution at the characteristic DLFs as the features, the different fault types of gear can be identified by SVM with high accuracy.

Wu, T. Y.; Chen, J. C.; Wang, C. C.

2012-07-01

156

An approach based on wavelet packet decomposition and Hilbert-Huang transform (WPD-HHT) for spindle bearings condition monitoring  

NASA Astrophysics Data System (ADS)

In order to prevent possible damages to the spindle systems, reliable monitoring techniques are required to provide valuable information on the condition of the spindle condition. A technique is proposed for monitoring spindle bearings conditions via the use of acoustic emission (AE) signals, which implements Hilbert-Huang transform (HHT) analysis to extract the crucial characteristic from the measured data to correlate spindle running condition. The HHT becomes a promising technique in extracting the properties of nonlinear and non-stationary signal. However, the original HHT has several deficiencies, which eventually lead to misinterpretation to the final results. The improved version of HHT is proposed and used to overcome the weakness of the original HHT. The simulation and experimental results are used to verify the effectiveness of the WPD-HHT and therefore Hilbert marginal spectral, compared to traditional Fourier transform. Experimental results are presented to examine and explore the effectiveness of AE for monitoring spindle bearings conditions. It is concluded that good correlation existed between the results obtained by AE data and the increase in the preload, and change in the dimensions and geometry of the spindle bearings and their housings as the temperature increases. In support of this finding, vibration and acceleration data are also used to assess the amount changes in the antistrophic stiffness and radial error motion.

Law, Leh-Sung; Kim, Jong Hyun; Liew, Willey Y. H.; Lee, Sun-Kyu

2012-11-01

157

Influence of signals length and noise in power spectral densities computation using Hilbert-Huang Transform in synthetic HRV  

NASA Astrophysics Data System (ADS)

Among non-invasive techniques, heart rate variability (HRV) analysis has become widely used for assessing the balance of the autonomic nervous system. Research in this area has not stopped and alternative tools for the study and interpretation of HRV, are still being proposed. Nevertheless, frequency-domain analysis of HRV is controversial when the heartbeat sequence is non-stationary. The Hilbert-Huang Transform (HHT) is a relative new technique for timefrequency analyses of non-linear and non-stationary signals. The main purpose of this work is to investigate the influence of time serie? length and noise in HRV from synthetic signals, using HHT and to compare it with Welch method. Synthetic heartbeat time series with different sizes and levels of signal to noise ratio (SNR) were investigated. Results shows i) sequencés length did not affect the estimation of HRV spectral parameter, ii) favorable performance for HHT for different SNR. Additionally, HHT can be applied to non-stationary signals from nonlinear systems and it will be useful to HRV analysis to interpret autonomic activity when acute and transient phenomena are assessed.

Rodríguez, María. G.; Altuve, Miguel; Lollett, Carlos; Wong, Sara

2013-11-01

158

Tracking the Evolution of Quasi-periodic Oscillation in RE J1034+396 Using the Hilbert-Huang Transform  

NASA Astrophysics Data System (ADS)

RE J1034+396, a narrow-line Seyfert 1 active galactic nucleus (AGN), is the first example of AGNs that exhibited a nearly coherent quasi-periodic oscillation (QPO) for the data collected by XMM-Newton in 2007. The spectral behaviors and timing properties of the QPO have been studied since its discovery. We present an analysis of the QPO in RE J1034+396 based on the Hilbert-Huang transform. Comparing with other time-frequency analysis methods, the Hilbert spectrum reveals the variation of the QPO period in great detail. Furthermore, the empirical mode decomposition provides bandpass-filtered data that can be used in the O - C and correlation analysis. We suggest that it is better to divide the evolution of the QPO in this observation into three epochs according to their different periodicities. In addition to the periodicities, the correlations between the QPO periods and corresponding mean count rates are also different in these three epochs. Further examining the phase lags in these epochs, we found no significant phase lags between the soft and hard X-ray bands, which is also confirmed in the QPO phase-resolved spectral analysis. Finally, we discuss the indications of current models including a spotted accretion disk, diskoseismology, and oscillation of shock according to the observed time-frequency and spectral behaviors.

Hu, Chin-Ping; Chou, Yi; Yang, Ting-Chang; Su, Yi-Hao

2014-06-01

159

Plasma Metabolomic Profiling to Reveal Antipyretic Mechanism of Shuang-Huang-Lian Injection on Yeast-Induced Pyrexia Rats  

PubMed Central

Shuang-huang-lian injection (SHLI) is a famous Chinese patent medicine, which has been wildly used in clinic for the treatment of acute respiratory tract infection, pneumonia, influenza, etc. The existing randomized controlled trial (RCT) studies suggested that SHLI could afford a certain anti-febrile action. However, seldom does research concern the pharmacological mechanisms of SHLI. In the current study, we explored plasma metabolomic profiling technique and selected potential metabolic markers to reveal the antipyretic mechanism of SHLI on yeast-induced pyrexia rat model using UPLC-Q-TOF/MS coupled with multivariate statistical analysis and pattern recognition techniques. We discovered a significant perturbance of metabolic profile in the plasma of fever rats and obvious reversion in SHLI-administered rats. Eight potential biomarkers, i.e. 1) 3-hydeoxybutyric acid, 2) leucine, 3) 16?0 LPC, 4) allocholic acid, 5) vitamin B2, 6) Cys-Lys-His, 7) 18?2 LPC, and 8) 3-hydroxychola-7, 22-dien-24-oic acid, were screened out by OPLS-DA approach. Five potential perturbed metabolic pathways, i.e. 1) valine, leucine, and isoleucine biosynthesis, 2) glycerophospholipid metabolism, 3) ketone bodies synthesis and degradation, 4) bile acid biosynthesis, and 5) riboflavin metabolism, were revealed to relate to the antipyretic mechanisms of SHLI. Overall, we investigated antipyretic mechanisms of SHLI at metabolomic level for the first time, and the obtained results highlights the necessity of adopting metabolomics as a reliable tool for understanding the holism and synergism of Chinese patent drug.

Peng, Long; Liu, Haiyu; Zhang, Li; Bai, Xu; Wang, Yingxin; Li, Jian; Cai, Chengke

2014-01-01

160

San-Huang-Xie-Xin-Tang extract suppresses hepatitis C virus replication and virus-induced cyclooxygenase-2 expression.  

PubMed

Chronic hepatitis C virus (HCV) infection is associated with chronic inflammation of liver, which leads to the development of cirrhosis and hepatocellular carcinoma (HCC). Because of severe side effects and only a 50-70% cure rate in genotype 1 HCV-infected patients upon current standard treatment with pegylated interferon-? plus ribavirin, new therapeutic regimens are still needed. San-Huang-Xie-Xin-Tang (SHXT) is a transitional Chinese herbal formula, composed of Rhei rhizoma, Scutellaria radix and Coptidis rhizome, and possesses anti-inflammatory effect. Here, we describe a (+)-catechin-containing fraction extracted from SHXT, referred as SHXT-frC, exhibited effective inhibition of HCV replication, with selectivity index value (SI; CC50 /EC50) of 84, and displayed synergistic anti-HCV effects when combined with interferon-?, HCV protease inhibitor telaprevir or polymerase inhibitor 2'-C-methylcytidine. The activation of factor-?B (NF-?B) and cyclooxygenase-2 (COX-2) signalling pathway has particular relevance to HCV-associated HCC. SHXT-frC treatment also caused a concentration-dependent decrease in the induction of COX-2 and NF-?B expression caused by either HCV replication or HCV NS5A protein. Collectively, SHXT-frC could be an adjuvant treatment for patients with HCV-induced liver diseases. PMID:21692943

Lee, J C; Tseng, C K; Wu, S F; Chang, F R; Chiu, C C; Wu, Y C

2011-07-01

161

Bioinformatics analysis for the antirheumatic effects of huang-lian-jie-du-tang from a network perspective.  

PubMed

Huang-Lian-Jie-Du-Tang (HLJDT) is a classic TCM formula to clear "heat" and "poison" that exhibits antirheumatic activity. Here we investigated the therapeutic mechanisms of HLJDT at protein network level using bioinformatics approach. It was found that HLJDT shares 5 target proteins with 3 types of anti-RA drugs, and several pathways in immune system and bone formation are significantly regulated by HLJDT's components, suggesting the therapeutic effect of HLJDT on RA. By defining an antirheumatic effect score to quantitatively measure the therapeutic effect, we found that the score of each HLJDT's component is very low, while the whole HLJDT achieves a much higher effect score, suggesting a synergistic effect of HLJDT achieved by its multiple components acting on multiple targets. At last, topological analysis on the RA-associated PPI network was conducted to illustrate key roles of HLJDT's target proteins on this network. Integrating our findings with TCM theory suggests that HLJDT targets on hub nodes and main pathway in the Hot ZENG network, and thus it could be applied as adjuvant treatment for Hot-ZENG-related RA. This study may facilitate our understanding of antirheumatic effect of HLJDT and it may suggest new approach for the study of TCM pharmacology. PMID:24348693

Fang, Haiyang; Wang, Yichuan; Yang, Tinghong; Ga, Yang; Zhang, Yi; Liu, Runhui; Zhang, Weidong; Zhao, Jing

2013-01-01

162

Plasma metabolomic profiling to reveal antipyretic mechanism of shuang-huang-lian injection on yeast-induced pyrexia rats.  

PubMed

Shuang-huang-lian injection (SHLI) is a famous Chinese patent medicine, which has been wildly used in clinic for the treatment of acute respiratory tract infection, pneumonia, influenza, etc. The existing randomized controlled trial (RCT) studies suggested that SHLI could afford a certain anti-febrile action. However, seldom does research concern the pharmacological mechanisms of SHLI. In the current study, we explored plasma metabolomic profiling technique and selected potential metabolic markers to reveal the antipyretic mechanism of SHLI on yeast-induced pyrexia rat model using UPLC-Q-TOF/MS coupled with multivariate statistical analysis and pattern recognition techniques. We discovered a significant perturbance of metabolic profile in the plasma of fever rats and obvious reversion in SHLI-administered rats. Eight potential biomarkers, i.e. 1) 3-hydeoxybutyric acid, 2) leucine, 3) 16?0 LPC, 4) allocholic acid, 5) vitamin B2, 6) Cys-Lys-His, 7) 18?2 LPC, and 8) 3-hydroxychola-7, 22-dien-24-oic acid, were screened out by OPLS-DA approach. Five potential perturbed metabolic pathways, i.e. 1) valine, leucine, and isoleucine biosynthesis, 2) glycerophospholipid metabolism, 3) ketone bodies synthesis and degradation, 4) bile acid biosynthesis, and 5) riboflavin metabolism, were revealed to relate to the antipyretic mechanisms of SHLI. Overall, we investigated antipyretic mechanisms of SHLI at metabolomic level for the first time, and the obtained results highlights the necessity of adopting metabolomics as a reliable tool for understanding the holism and synergism of Chinese patent drug. PMID:24940599

Gao, Xiaoyan; Guo, Mingxing; Li, Qiang; Peng, Long; Liu, Haiyu; Zhang, Li; Bai, Xu; Wang, Yingxin; Li, Jian; Cai, Chengke

2014-01-01

163

Study on the antiviral activity of San Huang Yi Gan Capsule against hepatitis B virus with seropharmacological method  

PubMed Central

Background Seropharmacology arising recently is a novel method of in vitro pharmacological study on Chinese herb using drug-containing animal serum. As seropharmacology possesses the advantages of experiments in vitro and in vivo, it is increasingly applied in pharmacological research on Chinese medicine. However, some issues of seropharmacology remain controversial and need to be clearly defined. San Huang Yi Gan Capsule (SHYGC) is a Chinese herbal formula with antiviral property against hepatitis B virus (HBV), but little is known about the mechanism underlying its anti-HBV activity. The aim of the present study was to elucidate the action mechanism of SHYGC using seropharmacological method and systematically address the methodology of preparing drug-containing serum. Methods New Zealand rabbits were orally administrated SHYGC with various regimens, followed by preparation of SHYGC-containing rabbit sera with a variety of methods. After HBV-producing HepG2 2.2.15 cells were treated with SHYGC-containing sera or entecavir for 9 days, the levels of hepatitis B surface antigen (HBsAg) and HBV DNA and the activity of DNA Polymerase were determined in HepG2 2.2.15 cells-conditioned media. Results An optimally standardized method of preparing drug-containing serum was raised for seropharmacology, with which SHYGC was demonstrated to suppress HBsAg expression, HBV DNA replication and DNA Polymerase activity in a dose-dependent fashion. Conclusions This seropharmacological study shows SHYGC is a potentially powerful anti-HBV agent. Additionally, seropharmacology is a promising pharmacological method with a broad range of advantages, and it can be widely used in biomedical research, if combined with pharmacokinetics.

2013-01-01

164

A Comparative study of VLF and LF disturbunces prior earthquake events by the use of Hilbert-Huang Transformation  

NASA Astrophysics Data System (ADS)

It is well known that the lower ionospheric layer acts as a waveguide for the VLF and LF radiowaves.In the frame of the International Network for Frontier Research on Earthquake Precursors(INFREP)an Elettronica radio receiver was set in operation in Thessaloniki-Greece, in order to collect the VLF-LF signals transmitted by ten stations across Europe. The sampling rate was one-minute. The collected signal samples were analysed using the Hilbert-Huang transformation (HHT). More specifically the VLF and LF variations during three earthquakes were analysed; (1) the earthquake at Peshkopia-Albania (6 September 2009, Long. 41.62, Lat. 20.41, 5.4 R, 10 km depth) at a distance of 242.45 km from Thessaloniki; (2)the earthquakes at Libolesh-Albania (12 September 2009, Lat. 41.49, Long 20.44, 4.2 R, depth 13 ?m) 228 km away from Thessaloniki and (3) the Durres-Albania (15 September 2009, Lat. 41.42, Long 19.16, 4.0 Richter, depth 33 km) 329 km away from Thessaloniki. The results of our analysis indicate that: a) The VLF signal variations seem to be stronger compared to the LF ones when the earthquakes are stronger, whereas the opposite seems to hold for weaker earthquakes.b) The HHT analysis used to de-noise the signals indicated that the first 4 or 5 IMFs represent noise in these three case studies. In concluding we may say that it is possible to distinguish ionospheric precursor phenoma from natural noise using HHT analysis.

Anastasiadis, H.; Xenos, Th. D.; Contadakis, M. E.; Arabelos, D. N.; Migga, E.

2010-05-01

165

Simultaneous analysis of nine components in patch preparations of Ru-Yi-Jin-Huang-San by high-performance liquid chromatography  

Microsoft Academic Search

A facile high-performance liquid chromatography (HPLC) method for the resolution and quantitative measurement of nine marker\\u000a substances, the active ingredients in patch preparations of Ru-Yi-Jin-Huang-San, was established using gradient elution in\\u000a the reversed-phase mode. These marker substances included berberine (Phellodendri Cortex), curcumin (Curcumae Rhizoma), imperatorin\\u000a (Angelicae Dahuricae Radix), magnolol (Magnoliae Cortex), hesperidin (Citri Leiocarpae Exocarpium), glycyrrhizin (Glycyrrhizae\\u000a Radix), and emodin,

Horng-Liang Lay; Chia-Chi Chen; Shiow-Chyn Huang; Thau-Ming Cham; Tian-Shung Wu; I-Hsin Lin

2010-01-01

166

Development of an LC-MS method for determination of three active constituents of Shuang-huang-lian injection in rat plasma and its application to the drug interaction study of Shuang-huang-lian freeze-dried powder combined with levofloxacin injection.  

PubMed

A sensitive and specific high performance liquid chromatography coupled with mass spectrometric (LC-MS) method was developed and validated for the simultaneous determination of three main active constituents of Shuang-huang-lian injection with and without the combination use of levofloxacin injection in rat plasma. After addition of the internal standard rutin, plasma samples were protein precipitated with acetonitrile, the chromatographic separation was achieved on a Kromasil C?? column (250 mm × 4.6 mm, 5 ?m), using a gradient mobile phase system of acetonitrile-water containing 0.05% formic acid. The analytes were detected without interference in the selected ion monitoring (SIM) mode with positive electrospray ionization. The linear range was 0.04-20 ?g/mL for chlorogenic acid, 0.8-400 ?g/mL for baicalin and 0.01-5.0 ?g/mL for phillyrin, respectively. The accuracy (relative error, R.E.%) were between -2.7 and 3.4%, while the intra-day and inter-day precisions were less than 9.2 and 9.6% for the three analytes, respectively. This method was successfully applied to the drug interaction study of Shuang-huang-lian freeze-dried powder combined with levofloxacin injection after intravenous administration to rats. The results indicated that there were obvious differences in the pharmacokinetic behaviors after combination compared with only administration of Shuang-huang-lian injection. PMID:22608805

Ye, Jing; Song, Xiaowei; Liu, Zhihong; Zhao, Xu; Geng, Lulu; Bi, Kaishun; Chen, Xiaohui

2012-06-01

167

Geographical, meteorological and vectorial factors related to malaria re-emergence in Huang-Huai River of central China  

PubMed Central

Background Malaria still represents a significant public health problem in China, and the cases dramatically increased in the areas along the Huang-Huai River of central China after 2001. Considering spatial aggregation of malaria cases and specific vectors, the geographical, meteorological and vectorial factors were analysed to determine the key factors related to malaria re-emergence in these particular areas. Methods The geographic information of 357 malaria cases and 603 water bodies in 113 villages were collected to analyse the relationship between the residence of malaria cases and water body. Spearman rank correlation, multiple regression, curve fitting and trend analysis were used to explain the relationship between the meteorological factors and malaria incidence. Entomological investigation was conducted in two sites to get the vectorial capacity and the basic reproductive rate to determine whether the effect of vector lead to malaria re-emergence. Results The distances from household of cases to the nearest water-body was positive-skew distributed, the median was 60.9 m and 74% malaria cases were inhabited in the extent of 60 m near the water body, and the risk rate of people live there attacked by malaria was higher than others(OR = 1.6, 95%CI (1.042, 2.463), P < 0.05). The annual average temperature and rainfall may have close relationship with annual incidence. The average monthly temperature and rainfall were the key factors, and the correlation coefficients are 0.501 and 0.304(P < 0.01), respectively. Moreover, 75.3% changes of monthly malaria incidence contributed to the average monthly temperature (Tmean), the average temperature of last two months(Tmean01) and the average rainfall of current month (Rmean) and the regression equation was Y = -2.085 + 0.839I1 + 0.998Tmean0 - 0.86Tmean01 + 0.16Rmean0. All the collected mosquitoes were Anopheles sinensis. The vectorial capacity and the basic reproductive rate of An. sinensis in two sites were 0.6969, 0.4983 and 2.1604, 1.5447, respectively. Conclusion The spatial distribution between malaria cases and water-body, the changing of meteorological factors, and increasing vectorial capacity and basic reproductive rate of An. sinensis leaded to malaria re-emergence in these areas.

2010-01-01

168

Simultaneous analysis of nine components in patch preparations of Ru-Yi-Jin-Huang-San by high-performance liquid chromatography.  

PubMed

A facile high-performance liquid chromatography (HPLC) method for the resolution and quantitative measurement of nine marker substances, the active ingredients in patch preparations of Ru-Yi-Jin-Huang-San, was established using gradient elution in the reversed-phase mode. These marker substances included berberine (Phellodendri Cortex), curcumin (Curcumae Rhizoma), imperatorin (Angelicae Dahuricae Radix), magnolol (Magnoliae Cortex), hesperidin (Citri Leiocarpae Exocarpium), glycyrrhizin (Glycyrrhizae Radix), and emodin, sennoside A, sennoside B (Rhei Rhizoma). The ingredients in the water-based and oil-based patches of the formula from different manufactures were also analyzed for quality evaluation. Extracted samples were analyzed by HPLC using a reversed-phase column (Inertsil 5 ODS-2, 4.6-mm I.D. x 250 mm) at 30 degrees C and eluted with a mixture of 20 and 70% acetonitrile aqueous solution in gradient manner at a flow rate of 1.0 ml/min. The detection wavelength varied with time as follows: 275 nm, 0-72 min; 250 nm, 72-105 min; 220 nm, 105-145 min. Relative coefficients of variations of intra- and interday analysis were less than 5%. All the recoveries were 93.30-113.63%. This method could be applied for the simultaneous determination of nine marker substances in Ru-Yi-Jin-Huang-San. PMID:20082147

Lay, Horng-Liang; Chen, Chia-Chi; Huang, Shiow-Chyn; Cham, Thau-Ming; Wu, Tian-Shung; Lin, I-Hsin

2010-04-01

169

Quality evaluation of commercial Huang-Lian-Jie-Du-Tang based on simultaneous determination of fourteen major chemical constituents using high performance liquid chromatography.  

PubMed

Huang-Lian-Jie-Du-Tang (HLJDT), comprising Coptidis Rhizoma, Scutellariae Radix, Phellodendri Cortex and Gardeniae Fructus, is one of the commonly used Chinese medicine formulas for clearing heat and detoxifying. Quality control of the herbal complex like Chinese medicine formulas still remains a challenge. The successful approval of botanical drug Veregen by FDA indicated the importance of quantitative analysis in quality control of herbal medicines. In this study, an effective quantitative method based on conventional HPLC-DAD was developed for simultaneous determination of fourteen major ingredients (seven alkaloids, four flavonoids, three terpenes) in HLJDT. The established method was well validated in terms of linearity, sensitivity, precision, accuracy and stability and then successfully applied to quality evaluation of commercial HLJDT samples. The developed method can quantitatively determine up to 70% of the chemicals of commercial HLJDT sample and effectively revealed the significant variation in the quality of the commercial HLJDT samples collected from different locations. PMID:23973454

Kwok, Ka-Yan; Xu, Jun; Ho, Hing-Man; Chen, Hu-Biao; Li, Min; Lang, Yan; Han, Quan-Bin

2013-11-01

170

An LC-MS/MS method for the simultaneous determination of chlorogenic acid, forsythiaside A and baicalin in rat plasma and its application to pharmacokinetic study of shuang-huang-lian in rats.  

PubMed

An LC-MS/MS method was developed for the simultaneous determination of chlorogenic acid, forsythiaside A and baicalin, three major ingredients in Shuang-huang-lian preparations, in rat plasma. Following extraction by methanol-ethyl acetate-trifluoroacetic acid (49:49:2, v/v/v), the extracted analytes were separated on a reverse phase C12 column using a gradient mobile phase system of acetonitrile-water containing 0.1% formic acid. The limits of quantification were between 1.0 and 2.1ng/mL, the precision was <7% and the accuracy was between 94% and 107%. The validated method was applied to a comparative pharmacokinetic study in rats after administration of Shuang-huang-lian solutions via intravenous, peroral or intratracheal routes. The results showed that the three chemical markers were more rapidly and thoroughly absorbed following pulmonary delivery as compared with peroral administration. PMID:20153596

Ye, Jun-Xiao; Wei, Wang; Quan, Li-Hui; Liu, Chun-Yu; Chang, Qi; Liao, Yong-Hong

2010-08-01

171

Possible effect of solar activity on variation of the tree-rings of a 500 a platycladus orientalis at the Mausoleum of Emperor Huang  

NASA Astrophysics Data System (ADS)

The variation of the tree-ring’s index of a platycladus orientalis at the Mausoleum of Emperor Huang and of a long series of sunspots relative number during AD1470-1974 are analyzed by using the wavelet power spectrum method, and their variation characters are also discussed. It is determined that the tree-ring’s variation has cycles of approximate 2-7, 11, 93 and 150 a. Two data series are used for analyzing sunspot relative number (SSN) variation. First, the analysis of the annual average SSN during AD1700-1974 proved that variation cycles are about 11, 50, and 93 a; then, the data during AD1465-1975 obtained from the decadal average SSN train over 7000 a reconstructed on the geomagnetic data is analyzed and its variation cycles are about 50, 90, and 160 a. Besides the tree-rings cycle of 2-7 a is commonly considered to be related to ENSO, while 11 a cycle is related to solar Schwabe cycle; in addition, it is possible that the cycles of 90 and150 a are likely to be related to solar Gleissberg cycle and Suess cycle. The correlations between them are possibly due to the effect of solar activity on the climate and additionally on the tree’s growth.

Feng, Bo; Han, Yanben

2009-04-01

172

Simultaneous determination of various bioactive redox components in Shuang-Huang-Lian preparations using a novel three-channel isocratic elution liquid chromatography with electrochemical detection system.  

PubMed

A novel three-channel isocratic elution high performance liquid chromatography with electrochemical detection (3LC-ECD) system was developed for the simultaneous determination of various bioactive redox components in Shuang-Huang-Lian (SHL) preparations. This 3LC-ECD system consists of three isocratic elution flow ways, two switching valves, four columns, and three electrochemical detectors. Through alternately rotating switching valves to change the elution flow way, six caffeoylquinic acids, four flavonoids, and one phenylethanoid glycoside compound were simultaneously determined within 70min by the present 3LC-ECD method, in which three compounds of protocatechuic aldehyde, propyl gallate, and kaempferol were used as internal standards. The results demonstrated that the present 3LC-ECD method has achieved desired linearity (r>0.999), precision (relative standard deviation <2.5%), accuracy (recovery, 95.6-103.6%), and high sensitivity (limit of detection, 0.11-0.90ng/mL). In addition, we successfully determined the contents of these 11 bioactive redox components in 14 batches of SHL oral liquid and 12 batches of SHL lyophilized powder for injection produced by different manufacturers in China. PMID:24657677

Chen, Liangmian; Hakamata, Hideki; Kusu, Fumiyo; Wang, Zhimin; Gao, Huimin; Kotani, Akira

2014-07-01

173

Assessing the expression of large-scale climatic fluctuations in the hydrological variability of daily Seine river flow (France) between 1950 and 2008 using Hilbert-Huang Transform  

NASA Astrophysics Data System (ADS)

SummaryDaily Seine river flow variability from 1950 to 2008 was analyzed and compared to the winter-months North-Atlantic Oscillation (NAO) using Hilbert-Huang Transform (HHT). For the last 10 years, HHT has proven its efficiency for the analysis of transient oscillatory signals. HHT provides an interesting alternative to other techniques for time-frequency or time scale analysis of non-stationary signals. In this study we aimed at delineating the different components characterizing daily flow of the Seine river, on the short-term, intra-seasonal, annual and interannual time scales and eventually interpret them in the context of regional North-Atlantic climate regime fluctuations. HHT results highlighted the existence of similar scales of variability beard by internal components of each NAO or river flow signal at interannual scales. Hypotheses on a possible link between the Madden-Julian Oscillation pattern and intra-seasonal variability of river flow could be also proposed, which would highlight linkages between river flow variability and global climate oscillations. Finally, all oscillating components were found to increase in amplitude in both climatic and hydrological signals in the end of the 1950-2008 period of study, with a first step in the late 1960s-early 1970s and a second step in the early 1990s, which demonstrated the capabilities of HHT to handle non-stationarity of natural processes and to help interpreting hydrological variability in a context of climate changes.

Massei, Nicolas; Fournier, Matthieu

2012-07-01

174

Comparative pharmacokinetic study of chlorogenic acid after oral administration of Lonicerae Japonicae Flos and Shuang-Huang-Lian in normal and febrile rats.  

PubMed

Shuang-Huang-Lian (SHL), a famous traditional Chinese medicine recipe containing Lonicerae Japonicae Flos (LJF), Forsythiae Fructus, and Scutellariae Radix, is clinically used for the treatment of fever and acute upper respiratory tract infection. In this research, a comparative study was conducted to compare the pharmacokinetic difference of chlorogenic acid (ChA) after oral administration of LJF and SHL to normal and febrile rats with approximately the same dose of 60 mg/kg, and the antipyrexia effect of LJF and SHL on rectal temperature changes induced by Baker's yeast was investigated. The results indicated that AUC(0-t) and plasma concentrations of ChA in the febrile rats were significantly higher than normal rats whether in the extract of LJF or SHL. In addition, SHL increased the values of AUC of ChA in both febrile and normal rats compared with LJF alone (p < 0.05), and SHL showed better antipyrexia effect than LJF. These results indicate that fever could play an important role in pharmacokinetic process of ChA. Meanwhile, the combined formula SHL exhibits higher bioavailability of ChA and superior antipyrexia effect than the single herb. PMID:23447366

Gao, Ru; Lin, Yining; Liang, Ge; Yu, Boyang; Gao, Yuan

2014-01-01

175

In-vivo and in-vitro studies on the effect of Huang-Lian-Jie-Du-Tang on nimodipine transport across rat blood-brain barrier.  

PubMed

Huang-Lian-Jie-Du-Tang (HLJDT), an aqueous extract of Rhizoma Coptidis, Radix Scutellariae, Cortex Phellodendri and Fructus Gardeniae (3:2:2:3) is an important multi-herb remedy in traditional Chinese medicine (TCM). The aim of this study was to evaluate the effect of HLJDT on nimodipine transport across rat blood-brain barrier (BBB). It was found that in-vivo the brain concentrations of nimodipine significantly increased when rats were pretreated with HLJDT. In-vitro, the serum of HLJDT-treated rats increased the accumulation of nimodipine in primary cultured rat brain microvessel endothelial cells (rBMECs) and decreased the expression of P-glycoprotein (P-gp) on rBMECs. Our previous study showed that the peak concentration of baicalin and berberine in rats after administration of HLJDT was 5 mug mL(-1) and 10 ng mL(-1), respectively. This study showed that 5 mug mL(-1) baicalin significantly increased the accumulation of nimodipine in rBMECs, while 10 ng mL(-1) berberine had no effect on the accumulation of nimodipine in rBMECs. Both the in-vivo and in-vitro experimental findings indicated that HLJDT pretreatment may alter the transport of nimodipine across rat BBB. PMID:18053337

Zhang, Dong Mei; He, Zhen Wei; Liu, Xiao Dong; Li, Yang; Xie, Lin; Wang, Guang Ji; Liu, Li

2007-12-01

176

Toxicology Evaluation of Realgar-Containing Niu-Huang-Jie-Du Pian as Compared to Arsenicals in Cell Cultures and in Mice  

PubMed Central

Niu-Huang-Jie-Du Pian (NHJD) is a widely used traditional Chinese medicine containing realgar (As4S4). Realgar has been included in many traditional medicines, but is often taken as arsenite for risk assessment. To evaluate true risk of realgar and realgar-containing NHJD, their toxicity was compared with common arsenicals. In cultured cells, the LC50 for NHJD (1200??M) and realgar (2000??M) was much higher than arsenite(35??M), arsenic trioxide (280??M), and arsenate (400??M). Acute toxicity in mice showed more severe liver and kidney injury after arsenite or arsenate, but was mild after realgar and NHJD, corresponding to cellular and tissue arsenic accumulation. The expressions of arsenic-sensitive stress gene metallothionein-1 were increased 3–7-folds after arsenite or arsenate, but were unaltered after NHJD and realgar. Thus, realgar and NHJD are much less toxic than arsenite and arsenate. The use of total arsenic to evaluate the safety of realgar and realgar-containing NHJD is inappropriate.

Miao, Jia-Wei; Liang, Shi-Xia; Wu, Qin; Liu, Jie; Sun, An-Sheng

2011-01-01

177

Characterization of the multiple absorbed constituents in rats after oral administration of Chai-Huang decoction by liquid chromatography coupled with electrospray-ionization mass spectrometry.  

PubMed

A rapid, sensitive, and specific method by high-performance liquid chromatography (HPLC) coupled to diode-array detection (DAD) and tandem mass spectrometry (MS) techniques was developed for the identification of absorbed constituents and their metabolites in rats after the oral administration of a Chai-Huang decoction (CHD), which consists of Bupleurum chinense and Scutellaria baicalensis in the proportion 1?:?1 (w/w). By comparing their retention times and MS data with those of authentic compounds and published data, a total of 14 compounds were identified in the CHD samples. In addition, eleven and seven compounds were characterized in the urine and serum samples of the rats, respectively. The results indicated that the main absorbed constituents were chrysin-6-C-arabinosyl-8-C-glucoside, chrysin-6-C-glucosyl-8-C-arabinoside, baicalin, wogonin-5-O-glucoside, oroxylin A-7-O-glucuronide, wogonoside, saikosaponin A, saikosaponin C, saikosaponin D, baicalein, and wogonin. These compounds might be responsible for the curative effects of the CHD. The findings demonstrated that the proposed method could be used to rapidly and simultaneously analyze and screen the multiple absorbed bioactive constituents in a formula of traditional Chinese medicines (TCM). This is very important not only for the pharmaceutical discovery process and the quality control of crude drugs but also to explain the mechanisms of action of TCM. PMID:21162005

Ye, Guan; Tang, Yi-Hong; Wang, Gui-Yun; Li, Zhi-Xiong; Zhu, Hai-Yan; Ma, Chun-Hui; Sun, Zhao-Ling; Huang, Cheng-Gang

2010-12-01

178

Functional representation for the born-oppenheimer diagonal correction and born-huang adiabatic potential energy surfaces for isotopomers of H3.  

PubMed

Multireference configuration interaction (MRCI) calculations of the Born-Oppenheimer diagonal correction (BODC) for H(3) were performed at 1397 symmetry-unique configurations using the Handy-Yamaguchi-Schaefer approach; isotopic substitution leads to 4041 symmetry-unique configurations for the DH(2) mass combination. These results were then fit to a functional form that permits calculation of the BODC for any combination of isotopes. Mean unsigned fitting errors on a test grid of configurations not included in the fitting process were 0.14, 0.12, and 0.65 cm(-1) for the H(3), DH(2), and MuH(2) isotopomers, respectively. This representation can be combined with any Born-Oppenheimer potential energy surface (PES) to yield Born-Huang (BH) PESs; herein, we choose the CCI potential energy surface, the uncertainties of which ( approximately 0.01 kcal/mol) are much smaller than the magnitude of the BODC. Fortran routines to evaluate these BH surfaces are provided. Variational transition state theory calculations are presented comparing thermal rate constants for reactions on the BO and BH surfaces to provide an initial estimate of the significance of the diagonal correction for the dynamics. PMID:19290604

Mielke, Steven L; Schwenke, David W; Schatz, George C; Garrett, Bruce C; Peterson, Kirk A

2009-04-23

179

Functional Representation for the Born-Oppenheimer Diagonal Correction and Born-Huang Adiabatic Potential Energy Surfaces for Isotopomers of H3  

SciTech Connect

Multireference configuration interaction (MRCI) calculations of the Born-Oppenheimer diagonal correction (BODC) for H3 were performed at 1397 symmetry-unique configurations using the Born-Handy approach; isotopic substitution leads to 4041 symmetry-unique configurations for the DH2 mass combination. These results were then fit to a functional form that permits calculation of the BODC for any combination of isotopes. Mean unsigned fitting errors on a test grid of configurations not included in the fitting process were 0.14, 0.12, and 0.65 cm?1 for the H3, DH2, and MuH2 isotopomers, respectively. This representation can be combined with any Born-Oppenheimer potential energy surface (PES) to yield Born-Huang (BH) PESs; herein we choose the CCI potential energy surface, the uncertainties of which (~0.01 kcal/mol) are much smaller than the magnitude of the BODC. FORTRAN routines to evaluate these BH surfaces are provided. Variational transition state theory calculations are presented comparing thermal rate constants for reactions on the BO and BH surfaces to provide an initial estimate of the significance of the diagonal correction for the dynamics.

Mielke, Steven L.; Schwenke, David; Schatz, George C.; Garrett, Bruce C.; Peterson, Kirk A.

2009-04-23

180

Huang-Lian-Jie-Du-Tang Protects Rats from Cardiac Damages Induced by Metabolic Disorder by Improving Inflammation-Mediated Insulin Resistance  

PubMed Central

Huang-lian-jie-du-tang (HLJDT), a traditional Chinese medicine, has been shown to improve insulin resistance (IR) induced by inflammation, a key event in the development of metabolic syndrome (MS). The present study aimed to investigate the protective effects of HLJDT on MS and explore the underlying mechanism. MS rats were established with obese-diets and treated with normal saline, aspirin or HLJDT. The myocardial lesions were identified by echocardiogram, transmission electron microscope, and Sirius-red staining. The inflammatory cytokines were measured by ELISA and real-time PCR. The activation of NF-?B, JNK, SOCS3, IRS1 and AKT in the heart was detected by immunohistochemistry and Western blot analysis. Compared with the controls, MS rats developed obvious obesity, hypertension, dyslipidemia, IR, inflammation, and cardiac damage. Moreover, phosphorylated IRS-1 at Ser307 was correlated with the activation of NF-?B, JNK and SOCS3 and the inhibition of AKT in the heart from MS rats. These data suggest that serine phosphorylation of IRS-1 in response to inflammation is mediated, in part, by NF-?B, JNK and SOCS3. Notably, HLJDT inhibited the activation of NF-?B and reduced serine phosphorylation of IRS-1. In summary, HLJDT protects myocardium from IR-mediated injury by inhibiting serine phosphorylation of IRS-1 in MS rats.

Li, Chuan Bao; Li, Xiao Xing; Chen, Yu Guo; Gao, Hai Qing; Bu, Pei Li; Zhang, Yun; Ji, Xiao Ping

2013-01-01

181

A traditional Chinese medicine JiuHuangLian (Rhizoma coptidis steamed with rice wine) reduces oxidative stress injury in type 2 diabetic rats.  

PubMed

Oxidative stress and oxidative stress mediated ?-cell injury are the initial factors of diabetes pathogenesis. Traditional Chinese medicine believes that JiuHuangLian (JHL, Rhizoma Coptidis steamed with rice wine) is an effective agent on diabetes treatment. In present study, we evaluated the antioxidant and lightening ?-cell injury of JHL in streptozotocin and a high-glucose/high-fat diet-induced diabetic rats. After 30 days treatment with JHL, glucose tolerance and insulin tolerance of diabetic rats were improved significantly. JHL also could decrease fasting blood glucose and glycosylated hemoglobin levels, increase insulin level and insulin sensitivity index. Moreover, lipid metabolism disorder also adjusted, which manifested as decreased total cholesterol, total glyceride and free fatty acid levels. Meanwhile, a significant increase in superoxide dismutase activity and glutathione content were observed in JHL treated rats, oxidative stress markers such as reactive oxygen species, malondialdehyde and nitric oxide also were decreased by JHL treatment. Furthermore, low expression of caspase-3 were shown in pancreatic immunohistochemistry of JHL treated rats, which exhibited anti-apoptosis effect of ?-cell. The histological evidence suggests that JHL effectively rescues the islet atrophied from oxidative stress-mediated ?-cell damage. These findings demonstrate the ?-cell functional protective nature of JHL by attenuating oxidative stress and inhibiting ?-cell damage. PMID:23791751

Li, Jia-chuan; Shen, Xiao-fei; Meng, Xian-li

2013-09-01

182

Thyroxine and reserpine-induced changes in metabolic profiles of rat urine and the therapeutic effect of Liu Wei Di Huang Wan detected by UPLC-HDMS.  

PubMed

The promise of metabonomics, a new "omics" technique, to validate Chinese medicines and the compatibility of Chinese formulas has been appreciated. The present study was undertaken to explore the excretion pattern of low molecular mass metabolites in the male Wistar-derived rat model of kidney yin deficiency induced with thyroxine and reserpine as well as the therapeutic effect of Liu Wei Di Huang Wan (LW) and its separated prescriptions, a classic traditional Chinese medicine formula for treating kidney yin deficiency in China. The study utilized ultra-performance liquid chromatography/electrospray ionization synapt high definition mass spectrometry (UPLC/ESI-SYNAPT-HDMS) in both negative and positive electrospray ionization (ESI). At the same time, blood biochemistry was examined to identify specific changes in the kidney yin deficiency. Distinct changes in the pattern of metabolites, as a result of daily administration of thyroxine and reserpine, were observed by UPLC-HDMS combined with a principal component analysis (PCA). The changes in metabolic profiling were restored to their baseline values after treatment with LW according to the PCA score plots. Altogether, the current metabonomic approach based on UPLC-HDMS and orthogonal projection to latent structures discriminate analysis (OPLS-DA) indicated 20 ions (14 in the negative mode, 8 in the positive mode, and 2 in both) as "differentiating metabolites". PMID:20605388

Wang, Ping; Sun, Hui; Lv, Haitao; Sun, Wenjun; Yuan, Ye; Han, Ying; Wang, Dongwu; Zhang, Aihua; Wang, Xijun

2010-11-01

183

Hilbert-Huang Transform: A Spectral Analysis Tool Applied to Sunspot Number and Total Solar Irradiance Variations, as well as Near-Surface Atmospheric Variables  

NASA Astrophysics Data System (ADS)

Hilbert-Huang transform (HHT) is a relatively new data analysis tool which is used to analyze nonstationary and nonlinear time series data. It consists of an algorithm, called empirical mode decomposition (EMD), which extracts the cyclic components embedded within time series data, as well as Hilbert spectral analysis (HSA) which displays the time and frequency dependent energy contributions from each component in the form of a spectrogram. The method can be considered a generalized form of Fourier analysis which can describe the intrinsic cycles of data with basis functions whose amplitudes and phases may vary with time. The HHT will be introduced and compared to current spectral analysis tools such as Fourier analysis, short-time Fourier analysis, wavelet analysis and Wigner-Ville distributions. A number of applications are also presented which demonstrate the strengths and limitations of the tool, including analyzing sunspot number variability and total solar irradiance proxies as well as global averaged temperature and carbon dioxide concentration. Also, near-surface atmospheric quantities such as temperature and wind velocity are analyzed to demonstrate the nonstationarity of the atmosphere.

Barnhart, B. L.; Eichinger, W. E.; Prueger, J. H.

2010-12-01

184

Novel non-linear processing methods of VLF signals for seismic-ionospheric precursor detection: Evaluation of Zhao-Atlas-Marks and Hilbert-Huang Transforms  

NASA Astrophysics Data System (ADS)

This study investigates the application of three different methods of extracting spectra from VLF signals in order to detect disturbances that can be attributed to seismic-ionospheric precursor phenomena. The methods tested here are the Wavelet Transform (WT) as a benchmark method, the Hilbert-Huang Transform (HHT) and the application of Zhao-Atlas-Marks (ZAM) Distribution, which is a quadratic representation, to process the signals in question. For the purpose of this paper, data acquired in Thessaloniki (40.59N, 22,78E) from the VLF station in Tavolara, Italy (ICV station Lat 40.923, Lon. 9.731) for over three years (December 2010 - December 2013) are used. The receiver was developed by Elettronika Srl and is part of the International Network for Frontier Research on Earthquake Precursors (INFREP). A normalization of the received VLF signals is applied prior to their analysis. The efficacy of the processing methods and the results produced by these processes are then discussed. Finally, comparative spectra are presented along with an evaluation of the discrimination and detection capabilities of each method on disturbances of the received signals. These methods provide different resolution and filtering capabilities. HHT provides frequency range filtering by making Intrinsic Mode Function (IMF) selection thus allowing us to focus on specific frequency ranges on the phenomena in question, whereas ZAM has an emphasis on improving frequency resolution and thus provides cross-term suppression, therefore this method gives clearer spectra without having the option of filtering that HHT provides. Based upon the results, a suitable processing method can be chosen to further improve the current analysis method by using data produced by seismic-ionospheric precursor phenomena and also contribute to a real-time method for correlating seismic activity with the observed disturbances.

Skeberis, Christos; Zaharis, Zaharias; Xenos, Thomas; Theochari, Sophia; Spatalas, Spyridon; Arabelos, Dimitrios; Contadakis, Michael

2014-05-01

185

The Anticancer Properties and Apoptosis-inducing Mechanisms of Cinnamaldehyde and the Herbal Prescription Huang-Lian-Jie-Du-Tang (????? Hu?ng Li?n Ji? D? Tang) in Human Hepatoma Cells  

PubMed Central

Hepatocellular carcinoma (HCC) has long been one of the most important causes of cancer mortality in the world. Many natural products and traditional herbal medicines have been used to treat HCC in Asian countries such as Japan, Korea, Taiwan, and China. The present review aims to describe the anticancer properties and apoptotic mechanisms of cinnamaldehyde, the bioactive ingredient isolated from cinnamon trees, and the herbal prescription Huang-Lian-Jie-Du-Tang (????? Huáng Lián Ji? Dú Tang; HLJDT) against human hepatoma cells in vitro and in vivo. Implication of their treatment for the development of targeted therapy against HCC is discussed.

Lin, Liang-Tzung; Wu, Shu-Jing; Lin, Chun-Ching

2013-01-01

186

In vitro metabolism in Sprague-Dawley rat liver microsomes of forsythoside A in different compositions of Shuang-Huang-Lian.  

PubMed

Shuang-Huang-Lian (SHL), a traditional Chinese formula containing Lonicerae japonicae flos (LJF), Scutellariae radix (SR) and Forsythiae fructus (FF), is commonly used to treat acute upper respiratory tract infection, acute bronchitis and light pneumonia. Forsythoside A is one of the main active ingredients in Forsythiae fructus, a key herb in SHL. In the present study, effects of different compositions in SHL on the in vitro metabolism in Sprague-Dawley rat liver microsomes of forsythoside A were investigated. The observations from Sprague-Dawley rat liver microsomes in the presence of ?-NADPH or UDPGA that forsythoside A may be the substrates of CYP3A4, CYP2C9, CYP1A2, UGT1A6, UGT1A3, UGT1A1 and UGT1A9; Chlorogenic acid may be the substrates of CYP3A4, CYP2C9, CYP1A2, CYP2C19, UGT1A6, UGT1A3 and UGT1A1; Baicalin may be the substrates of CYP3A4, CYP2C19, CYP1A2, UGT1A9, UGT1A1 and UGT1A3; Baicalein may be the substrates of CYP3A4, CYP2E1 and UGT1A6. It was also found that the residue of forsythoside A in SHL, FF+LJF and FF+SR was greatly increased compared with that in FF in Sprague-Dawley rat liver microsomes in the presence of ?-NADPH or UDPGA, which indicated that the metabolism of forsythoside A in SHL may be influenced by chlorogenic acid in LJF acting on the CYP3A4, CYP2C9, CYP1A2, UGT1A6, UGT1A3 and UGT1A1; baicalin in SR acting on the CYP3A4, CYP1A2, UGT1A9, UGT1A1 and UGT1A3; baicalein acting on the CYP3A4 and UGT1A6 respectively. PMID:21888954

Zhou, Wei; Di, Liu-qing; Shan, Jin-jun; Bi, Xiao-lin; Chen, Le-tian; Wang, Ling-chong; Cai, Bao-chang

2011-12-01

187

[The soul outlook in the bamboo slips Fan yin (Anti-excessiveness) of Western Han Dynasty collected at Peking University and in Huang di nei jing (Inner Canon of Yellow Emperor)].  

PubMed

The bamboo slips Fan yin (Anti-excessiveness) of the Western Han Dynasty, written in the form of conversation in 7-syllable prose-verse between hun (ethereal soul) and po (corporeal soul), with po as the host, and hun as the guest, reflecting the dualism of hun and po. In Huang di nei jing (Inner Canon of Yellow Emperor), appeared nearly at the same time, in which the hypothesis of all the five viscera embodies the spirit and its soul defined at the level of spirit-emotion, claiming that the physique and ethereal soul are born at the same time, and the spirit of Yang qi within the corporeal soul is the ethereal soul, which is different from the description in the Fan yin. PMID:24429031

DU, Feng

2013-09-01

188

Comparative analysis of the anti-inflammatory activity of Huang-lian extracts in lipopolysaccharide-stimulated RAW264.7 murine macrophage-like cells using oligonucleotide microarrays.  

PubMed

In this study, we attempted to determine the anti-inflammatory activity of a medicinal plant huang-lian using gene expression profiles as an index. Huang-line extracts (CEXs) were prepared from seven different plant origins and compared for their chemical composition and biological activity. In order to achieve this, RAW264.7 cells were treated with CEXs in the absence or presence of LPS for 6 h, and the differential gene expression profiles were analyzed using oligonucleotide microarrays. The alkaloid content of CEXs was determined by high performance liquid chromatography analysis. Evaluation of anti-inflammatory activity of CEXs was by measuring a decrease in cytokines and nitric oxide production in LPS-stimulated RAW264.7 cells. Hierarchical clustering analysis revealed that three CEXs from Coptis chinensis formed a cluster separate from the other four CEXs in LPS-stimulated cells, and were the most effective anti-inflammatoryagents. The extract prepared from Picrorrhiza kurrooa neither induced any changes in gene expression profiles nor possessed any anti-inflammatory activity. The extract from Jeffersonia dubia, which exhibited the highest cytotoxicity among the CEXs tested, was most effective in suppressing LPS-induced nitric oxide production but was not able to inhibit proinflammatory cytokine production. The results obtained in this study demonstrate that overall gene expression profiles of the extracts correlated well with their biological activity and that CEXs prepared from plants of diverse origins vary in their biological activity. These data also suggest that gene expression profiles may serve as a good indicator for the pharmacological activities of medicinal plants arising from diverse origins. PMID:20803116

Kim, Jong Min; Jung, Hyun Ah; Choi, Jae Sue; Min, Byung Sun; Lee, Na Gyong

2010-08-01

189

[Changes of China agricultural climate resources under the background of climate change. IV. Spatiotemporal change characteristics of agricultural climate resources in sub-humid warm-temperate irrigated wheat-maize agricultural area of Huang-Huai-Hai Plain].  

PubMed

Based on the 1961-2007 observation data from 66 meteorological stations in the sub-humid and warm-temperate irrigated wheat-maize agricultural area of Huang-Huai-Hai Plain, this paper analyzed the spatiotemporal change characteristics of agro-climate resources for chimonophilous and thermophilic crops in the area in 1961-1980 and 1981-2007. The analyzed items included the length of temperature-defined growth season and the active accumulative temperature, sunshine hours, precipitation, reference evapotranspiration, and aridity index during the temperature-defined growth season. With climate warming, the length of temperature-defined growth season of chimonophilous and thermophilic crops in the area in 1981-2007 extended by 7. 4 d and 6. 9 d, and the > or = 0 degrees C and > or = 10 degrees C accumulative temperature increased at a rate of 4.0-137.0 and 1.0-142.0 degrees C d (10 a)(-1), respectively, compared with those in 1961-1980. The sunshine hours during the temperature-defined growth season of the crops decreased markedly; and the precipitation during the temperature-defined growing season decreased in most parts of the area, being obvious in Hebei and north Shandong Province, but increased in north Anhui and southeast Henan Province. In most parts of the area, the reference evapotranspiration of chimonophilous and thermophilic crops during their temperature-defined growth season decreased, and the aridity index increased. PMID:21774311

Liu, Zhi-juan; Yang, Xiao-guang; Wang, Wen-feng

2011-04-01

190

A Metabolomic Strategy to Screen the Prototype Components and Metabolites of Shuang-Huang-Lian Injection in Human Serum by Ultra Performance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Mass Spectrometry  

PubMed Central

Shuang-huang-lian injection (SHLI) is a famous Chinese patent medicine, which has been wildly used in clinic to treat acute respiratory tract infection, pneumonia, influenza, and so forth. Despite the widespread clinical application, the prototype components and metabolites of SHLI have not been fully elucidated, especially in human body. To discover and screen the constituents or metabolites of Chinese medicine in biofluids tends to be more and more difficult due to the complexity of chemical compositions, metabolic reactions and matrix effects. In this work, a metabolomic strategy to comprehensively elucidate the prototype components and metabolites of SHLI in human serum conducted by UPLC-Q-TOF/MS was developed. Orthogonal partial least squared discriminant analysis (OPLS-DA) was applied to distinguish the exogenous, namely, drug-induced constituents, from endogenous in human serum. In the S-plot, 35 drug-induced constituents were found, including 23 prototype compounds and 12 metabolites which indicated that SHLI in human body mainly caused phase II metabolite reactions. It was concluded that the metabolomic strategy for identification of herbal constituents and metabolites in biological samples was successfully developed. This identification and structural elucidation of the chemical compounds provided essential data for further pharmacological and pharmacokinetics study of SHLI.

Guo, Mingxing; Zhao, Baosheng; Liu, Haiyu; Zhang, Li; Peng, Long; Qin, Lingling; Zhang, Zhixin; Li, Jian; Cai, Chengke; Gao, Xiaoyan

2014-01-01

191

Chemical profiling and quantification of Chinese medicinal formula Huang-Lian-Jie-Du decoction, a systematic quality control strategy using ultra high performance liquid chromatography combined with hybrid quadrupole-orbitrap and triple quadrupole mass spectrometers.  

PubMed

To clarify and quantify the chemical profiling of Huang-Lian-Jie-Du decoction (HLJDD) rapidly, a feasible and accurate strategy was developed by applying high speed LC combined with hybrid quadrupole-orbitrap mass spectrometer (Q-Exactive) and UHPLC-triple quadruple mass spectrometer (UHPLC-QqQ MS). 69 compounds, including iridoids, alkaloids, flavonoids, triterpenoid, monoterpene and phenolic acids, were identified by their characteristic high resolution mass data. Among them, 18 major compounds were unambiguously detected by comparing with reference standards. In the subsequent quantitative analysis, 17 representative compounds, selected as quality control markers, were simultaneously detected in 10 batches of HLJDD samples by UHPLC-QqQ MS. These samples were collected from four different countries (regions). Icariin, swertiamarin and corynoline were employed as internal standards for flavonoids, iridoids and alkaloids respectively. All the analytes were detected within 12min. Polarity switching mode was used in the optimization of multiple reaction monitoring (MRM) conditions. Satisfactory linearity was achieved with wide linear range and fine determination coefficient (r(2)>0.9990). The relative standard deviations (RSD) of inter- and intra-day precisions were less than 5.0%. This method was also validated by repeatability, stability (8h) and recovery, with respective RSDs less than 4.6%, 5.0% and 6.3%. This research established a high sensitive and efficient method for the integrating quality control, including identification and quantification of Chinese medicinal formulas. PMID:24231264

Yang, Yang; Wang, Hong-Jie; Yang, Jian; Brantner, Adelheid H; Lower-Nedza, Agnieszka D; Si, Nan; Song, Jian-Fang; Bai, Bing; Zhao, Hai-Yu; Bian, Bao-Lin

2013-12-20

192

Qualitative and quantitative analysis of traditional Chinese medicine Niu Huang Jie Du Pill using ultra performance liquid chromatography coupled with tunable UV detector and rapid resolution liquid chromatography coupled with time-of-flight tandem mass spectrometry.  

PubMed

An ultra performance liquid chromatography coupled with tunable UV detector (UPLC-TUV) and rapid resolution liquid chromatography coupled with time-of-flight tandem mass spectrometry (RRLC-Q-TOF) method was developed for the quality assessment of Niu Huang Jie Du Pill (NHJDP), a commonly used traditional Chinese medicine (TCM). Ten compounds were simultaneously identified by electrospray ion mass spectrometry (ESI/MS) and comparison with reference standards and literature data. All of them were quantified by UPLC method. Baseline separation was achieved on an ODS-140HTP C(18) column (2.3mum, 100mmx2.1mm I.D.) with linear gradient elution of acetonitrile-0.1% formic acid. This developed method provides good linearity (r(2)>0.9996), repeatability (RSD<3.63%), intra- and inter-day precisions (RSD<0.86%) with accuracies (97.88-101.56%) and recovery (98.88-101.92%) of 10 major constituents, namely baicalin, baicalein, wogonoside, wogonin, glycyrrhizic acid, liquiritin, rhein, emodin, chrysophanol and physcion. In addition, the principal component analysis (PCA) coupled with the UPLC fingerprint was applied to classify the NHJDP samples according to their manufacture corporation. This proposed method with high sensitivity and selectivity was successfully utilized to analyze 10 major bioactive compounds in 30 batches of NHJDPs, and the results demonstrate that this analytical method is simple and suitable for the original discrimination and quality control of this TCM. PMID:19783115

Liang, Xu; Zhang, Lin; Zhang, Xi; Dai, Weixing; Li, Haiyun; Hu, Liwei; Liu, Hui; Su, Juan; Zhang, Weidong

2010-02-01

193

Chinese Patent Medicine Liu Wei Di Huang Wan Combined with Antihypertensive Drugs, a New Integrative Medicine Therapy, for the Treatment of Essential Hypertension: A Systematic Review of Randomized Controlled Trials  

PubMed Central

Objectives. To assess the beneficial and adverse effects of Liu Wei Di Huang Wan (LWDHW), combined with antihypertensive drugs, for essential hypertension. Methods. Five major electronic databases were searched up to August 2012 to retrieve any potential randomized controlled trials designed to evaluate the clinical effectiveness of LWDHW combined with antihypertensive drugs for essential hypertension reported in any language, with main outcome measures as blood pressure. The quality of the included studies was assessed with the Jadad scale and a customized standard quality assessment scale. Results. 6 randomized trials were included. The methodological quality of the trials was evaluated as generally low. The pooled results showed that LWDHW combined with antihypertensive drugs was more effective in blood pressure and the scale for TCM syndrome and symptom differentiation scores compared with antihypertensive drugs alone. Most of the trials did not report adverse events, and the safety is still uncertain. Conclusions. LWDHW combined with antihypertensive drugs appears to be effective in improving blood pressure and symptoms in patients with essential hypertension. However, the evidence remains weak due to the poor methodological quality of the included studies.

Wang, Jie; Yao, Kuiwu; Yang, Xiaochen; Liu, Wei; Feng, Bo; Ma, Jizheng; Du, Xinliang; Wang, Pengqian; Xiong, Xingjiang

2012-01-01

194

Simultaneous determination of two iridoid glycosides, two anthraquinones and four flavonoid glycosides of Zhi-Zi-Da-Huang decoction in rat plasma by UFLC-MS/MS: Application to a comparative pharmacokinetic study in normal and cholestatic liver injury rats.  

PubMed

A selective, sensitive and reliable ultra fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) method has been developed for the simultaneous determination of two iridoid glycosides (geniposide and genipin gentiobioside), two anthraquinones (rhein and emodin) and four flavonoid glycosides (isonaringin, naringin, hesperidin and neohesperidin), the major active ingredients of Zhi-Zi-Da-Huang decoction (ZZDHD), in rat plasma using paeoniflorin as internal standard (IS). After liquid-liquid extraction with ethyl acetate-isopropanol (1:1, v/v), separation was achieved on a Shim-pack XR-ODS C18 column (75mm×3.0mm, 2.2?m) using gradient elution with a mobile phase consisting of water (containing 0.1% formic acid) and acetonitrile at a flow rate of 0.4mL/min. Detection was performed on 4000 QTRAP mass spectrometry equipped with turbo ion spray source in the negative ionization and multiple reaction monitoring (MRM) mode. The intra- and inter-day precisions (as relative standard deviation) were less than 11.4%, and accuracy (as relative error) was within ±10.0%. The lower limits of quantification (LLOQ) were 4.0, 0.5, 2.0, 0.1, 1.0, 2.0, 1.0, 2.0ng/mL for geniposide, genipin gentiobioside, rhein, emodin, isonaringin, naringin, hesperidin and neohesperidin, respectively. The extraction recoveries of the analytes and IS from rat plasma were all more than 86.0%. The method was fully validated and applied to compare the pharmacokinetic profiles of the analytes in normal and cholestatic liver injury (CLI) rats after oral administration of ZZDHD. Results showed that there were remarkable differences in pharmacokinetic properties of the analytes between normal and CLI group. PMID:24793084

Zhu, Heyun; Bi, Kaishun; Han, Fei; Guan, Jiao; Tang, Zheng; Chen, Kelin; Zhao, Longshan; Li, Qing; Yin, Ran; Hou, Xiaohong

2014-06-01

195

Alice Huang, Microbiologist/ Molecular Geneticist, 1939- present  

NSDL National Science Digital Library

This biography and associated teaching material is part of a book of 20 life sciences modules designed to increase students' exposure both to female science role models and to hands-on, inquiry approach activities as recommended by the National Science Education Standards. Modules are designed to drop easily into middle and high school life sciences curricula, not to "add on". Each module includes: a brief biography of a female science role model and hands-on, inquiry approach and/or problem-solving life sciences, activities with a multidisciplinary focus. Role models include both contemporary and historical women, women of color and women with physical disabilities. Each activity is related to the work of the role model. Activity format includes suggestions for teachers, assessment ideas, and handouts for students.

PhD Marsha L Matyas (American Physiological Society Education)

2007-01-01

196

Comment on “Magnetostratigraphic study of the Kuche Depression, Tarim Basin, and Cenozoic uplift of the Tian Shan Range, Western China” Baochun Huang, John D.A. Piper, Shoutao Peng, Tao Liu, Zhong Li, Qingchen Wang, Rixiang Zhu [Earth Planet. Sci. Lett., 2006, doi:10.1016/j.epsl.2006.09.020  

NASA Astrophysics Data System (ADS)

The recent publication of "Magnetostratigraphic study of the Kuche Depression, Tarim Basin, and Cenozoic uplift of the Tian Shan Range,Western China" by B.C. Huang, J.D.A. Piper, S.T. Peng, T. Liu, Z. Li, Q.C. Wang, R.X. Zhu [Earth Planet. Sci. Lett., 2006, doi:10.1016/j.epsl.2006.09.020] discusses the Cenozoic uplift history of the Tianshan Mountains by studying the magnetostratigraphy of Paleogene to Neogene continental sediments from two sections located in the Kuche basin at the northern edge of the Tarim basin. To support their conclusion they reinterpreted a magnetostratigraphic study of the Yaha section, which lies ~ 10 km south of their sections, we previously published [J. Charreau, S. Gilder, Y. Chen, S. Dominguez, J.-P. Avouac, S. Sen, M. Jolivet, Y. Li and W. Wang, Magnetostratigraphy of the Yaha section, Tarim Basin (China): 11 Ma acceleration in erosion and uplift of the Tianshan Mountains, Geology 34(3), 2006, 181­184.]. Here, (1) we argue that the interpretations of the sedimentation rate changes they proposed for the Kuche sections are partially invalid, (2) we disagree with their reinterpretation of the age of the Yaha section, and (3) we think that the way they interpret their AMS data is incorrect.

Charreau, Julien; Chen, Yan; Gilder, Stuart; Barier, Laurie

2008-04-01

197

On the Hilbert-Huang transform data processing system development  

Microsoft Academic Search

One of the main heritage tools used in scientific and engineering data spectrum analysis is the Fourier Integral Transform and its high performance digital equivalent - the fast Fourier transform (FFT). The Fourier view of nonlinear mechanics that had existed for a long time, and the associated FFT (fairly recent development), carry strong a-priori assumptions about the source data, such

Semion Kizhner; Thomas P. Flatley; N. E. Huang; Karin Blank; Evette Conwell

2004-01-01

198

On certain theoretical developments underlying the Hilbert-Huang transform  

Microsoft Academic Search

One of the main traditional tools used in scientific and engineering data spectral analysis is the Fourier integral transform and its high performance digital equivalent - the fast Fourier transform (FFT). Both carry strong a-priori assumptions about the source data, such as being linear and stationary, and of satisfying the Dirichlet conditions. A recent development at the National Aeronautics and

Semion Kizhner; Karin Blank; Thomas Flatley; Norden E. Huang; David Petrick; Phyllis Hestnes

2006-01-01

199

First International Conference between West and East--Leonardo and Lao-Tze. Western Science Meets Eastern Wisdom. Experiences of Scientists and Intellectuals for the Creation of a New Paradigm of Modern Science  

PubMed Central

The Conference was organized and supported by: Nei Dan School (European School of Internal Martial Arts), NIB (Laboratory of Molecular Biology and Stem Cell Bioengineering, National Institute of Biostructures and Biosystems, Institute of Cardiology, S.Orsola-Malpighi Hospital, Bologna), WACIMA (Worldwide Association Chinese Internal Martial Arts), Arti D’Oriente (Magazine of Eastern culture and traditions), Nuovo Orizzonte (Taiji Quan School in Florence), Samurai (Journal on Martial Arts), and Pinus (First National Institute for the Unification of Medical Strategies). Nei Dan School (www.taichineidan.com, neidan@libero.it) was in charge of the organization. Future meetings of the Centro studi ‘Tao and Science’ will take place in spring 2007 in Firenze and in October 2007 in Bologna. For information: E-mail: neidan@libero.it; web site: www.taichineidan.com, www.taoandscience.com

2008-01-01

200

The use of the Hilbert-Huang transform to analyze transient signals emitted by sperm whales  

Microsoft Academic Search

One of the objectives of sperm whale signal analysis is to automatically detect the clicks emitted by sperm whales in continuous recordings and to then extract features that allow for the tracking of these animals. Sperm whale signals are particularly brief with a large band spectrum. Also, during the recordings, the noise levels are not always constant. These features make

Olivier Adam

2006-01-01

201

Ultrasonic detection of defects in strongly attenuating structures using the Hilbert–Huang transform  

Microsoft Academic Search

Non-destructive testing of polymer materials meets specific problems caused by a high attenuation of ultrasonic signals. When the expected flaws are close to the interfaces, the signals reflected by the flaws may be hidden in the tail of much stronger signals caused by front reflection from the sample and by interfaces between the adjacent layers. For improved detection of defects

R. Kažys; O. Tumšys; D. Pagodinas

2008-01-01

202

Evaluation of Stress Using Ultrasonic Technique Based on Hilbert-Huang Transform  

Microsoft Academic Search

Pressures vessel are widely used in the modern industry. It is important to measure pressure of vessels. It has been proved that the change of ultrasonic velocity can be used to detect the stress of the material, and the velocity change can be obtained by estimating the time delay of two ultrasonic pulses. In this paper, the Rayleigh wave is

Q He; H J Zhang; H L Zhou

2006-01-01

203

Hilbert–Huang transform for detection and monitoring of crack in a transient rotor  

Microsoft Academic Search

The dynamics and diagnostics of a cracked rotor have been gaining importance in the recent years. Vibration monitoring during start-up or shut-down is as important as during steady-state operations to detect cracks especially for machines such as aircraft engines which start and stop quite frequently and run at high speeds. In the present study a relatively new signal processing technique

T. Ramesh Babu; S. Srikanth; A. S. Sekhar

2008-01-01

204

A Novel spectral Analysis Method of Atrial Fibrillation Signal Based on Hilbert-Huang Transform  

Microsoft Academic Search

Time\\/frequency analysis has been extensively used in biomedical signal processing. By extracting some essential features from the electro-physiological signals, these methods are able to determine the clinical pathology mechanisms of some diseases. Fourier spectrum analysis provides a common framework for examining the distribution of global energy in the frequency domain. However, this method assumes that the signal should be stationary,

Zhongchao Huang; Jijun Tong; Yuquan Chen; Ming Pan

2005-01-01

205

Flute breakage detection during end milling using Hilbert–Huang transform and smoothed nonlinear energy operator  

Microsoft Academic Search

Real time tool condition monitoring has great significance in modern manufacturing processes. In order to prevent possible damages to the workpiece or the machine tool, reliable monitoring techniques are required to provide fast response to the unexpected tool failure. Milling is one of the most fundamental machining operations. During the milling process, the current of feed motor is weakly related

A. M. Bassiuny; Xiaoli Li

2007-01-01

206

Fault diagnosis of partial rub and looseness in rotating machinery using Hilbert-Huang transform  

Microsoft Academic Search

Partial rub and looseness are common faults in rotating machinery because of the clearance between the rotor and the stator.\\u000a These problems cause malfunctions in rotating machinery and create strange vibrations coming from impact and friction. However,\\u000a non-linear and non-stationary signals due to impact and friction are difficult to identify. Therefore, exact time and frequency\\u000a information is needed for identifying

Seung-Mock Lee; Yeon-Sun Choi

2008-01-01

207

Classification of Normal and Hypoxia EEG Based on Hilbert Huang Transform  

Microsoft Academic Search

This paper reports a novel method to classify EEGs from subjects under normal and hypoxia conditions, which provides a potential efficient method to evaluate hypoxia in real time. The EEG data are collected from 3 healthy subjects while their neurobehaviors are evaluated to assess the degree of hypoxia. The specific energy in a sub-band of 30-60 Hz of the Hilbert

Meng Hu; Guang Li; Qiuping Ding; Jiaojie Li

2005-01-01

208

Application of Hilbert-Huang transform for the study of motor imagery tasks  

Microsoft Academic Search

A motor based Brain-Computer Interface (BCI) translates the subject's motor intention into a control signal by means of the method which extracts characteristic feature from EEG recorded from the scalp. In this paper, the EEG signal recorded during three motor imagery tasks, which were imagination of left hand, right hand and foot movements, was investigated. A novel method named Hilbert

Lei Wang; Guizhi Xu; JiangWang; Shuo Yang; Weili Yan

2008-01-01

209

Bearing fault diagnosis using FFT of intrinsic mode functions in Hilbert–Huang transform  

Microsoft Academic Search

A number of techniques for detection of faults in rolling element bearing using frequency domain approach exist today. For analysing non-stationary signals arising out of defective rolling element bearings, use of conventional discrete Fourier transform (DFT) has been known to be less efficient. One of the most suited time–frequency approach, wavelet transform (WT) has inherent problems of large computational time

V. K. Rai; A. R. Mohanty

2007-01-01

210

Transient detection of eccentricity-related components in induction motors through the Hilbert–Huang Transform  

Microsoft Academic Search

The identification and extraction of characteristic patterns are proposed in this work for the diagnosis and evaluation of mixed eccentricities in induction electrical machines with parallel stator branches. Whereas the classical diagnosis approaches, deeply spread in the industrial environment, are based on the Fourier analysis of the steady-state current, the basis of the proposed methodology consist of analysing the current

J. Antonino-Daviu; P. Jover Rodriguez; M. Riera-Guasp; A. Arkkio; J. Roger-Folch; R. B. Pérez

2009-01-01

211

Trend detection and data mining via wavelet and Hilbert-Huang transforms  

Microsoft Academic Search

This paper presents the formulation and evaluation of effective algorithms of reliable data analysis for real-time monitoring of incipient faults and anomalies, data fusion and event classification. The objective is to alleviate the shortcomings of the existing techniques for data mining by taking advantage of nonlinear filtering to handle non-Gaussian and non-stationary multiplicative noise and uncertainties. New concepts have been

Murat Yasar; Asok Ray

2008-01-01

212

Application of Hilbert-Huang transform for improved defect detection in terahertz NDE of shuttle tiles  

Microsoft Academic Search

Terahertz NDE is being examined as a method to inspect the adhesive bond-line of Space Shuttle tiles for defects. Terahertz signals are generated and detected, using optical excitation of biased semiconductors with femtosecond laser pulses. Shuttle tile samples were manufactured with defects that included repair regions unbond regions, and other conditions that occur in Shuttle structures. These samples were inspected

Robert F. Anastasi; Eric I. Madaras

2005-01-01

213

Hilbert-Huang Transform (HHT) Analysis of Human Activities Using Through-Wall Noise Radar  

Microsoft Academic Search

Various parts of the human body have different movements when a person is performing different physical activities. There is a need to remotely detect human heartbeat and breathing for applications involving anti-terrorism and search-and-rescue. Ultrawideband noise radar systems are attractive because they are covert and immune from interference. The conventional time-frequency analyses of human activity are not generally applicable to

Chieh-Ping Lai; Qing Ruan; Ram M. Narayanan

2007-01-01

214

Optically-sectioned two-shot structured illumination microscopy with Hilbert-Huang processing.  

PubMed

We introduce a fast, simple, adaptive and experimentally robust method for reconstructing background-rejected optically-sectioned images using two-shot structured illumination microscopy. Our innovative data demodulation method needs two grid-illumination images mutually phase shifted by ? (half a grid period) but precise phase displacement between two frames is not required. Upon frames subtraction the input pattern with increased grid modulation is obtained. The first demodulation stage comprises two-dimensional data processing based on the empirical mode decomposition for the object spatial frequency selection (noise reduction and bias term removal). The second stage consists in calculating high contrast image using the two-dimensional spiral Hilbert transform. Our algorithm effectiveness is compared with the results calculated for the same input data using structured-illumination (SIM) and HiLo microscopy methods. The input data were collected for studying highly scattering tissue samples in reflectance mode. Results of our approach compare very favorably with SIM and HiLo techniques. PMID:24787840

Patorski, Krzysztof; Trusiak, Maciej; Tkaczyk, Tomasz

2014-04-21

215

Radar micro-motion feature extraction of cone target based on Hilbert-Huang transform  

Microsoft Academic Search

This paper studies on the cone target. Firstly, the modulating function of a precession target on the radar is analyzed. Then, the decomposition method of multi-component sinusoidal frequency modulated signal based on empirical mode decomposition (EMD) is studied. The instantaneous frequency of each intrinsic mode function is gained by using Hilbert Transform (HT). The precession features of precession period, precession

Jie Niu; Yupeng Zhu; Yongxiang Liu; Xiang Li; Gangyao Kuang

2012-01-01

216

A Bridge Health Monitoring Method Using the Hilbert-Huang Transform: A Case Study  

NASA Technical Reports Server (NTRS)

We have developed a new method for nondestructive instrument method to monitor the health of a bridge. This new method is based on a transient test load and simple data collection. The nuclear of the method is the new invented nonstationary and nonlinear time series analysis method, the Empirical Mode Decomposition and Hilbert Spectral Analysis. The final decision on the health of the bridge structure is based on the nonlinear characteristic of the data, and on the comparison between the free and the forced vibration frequencies. Thus this alternative method enjoys many advantages: (1) no a priori data required, (2) simple data collection, and (3) minimum traffic disruption. Results from a case study of the Shing-Nan Bridge in Hou-Wei will be reported.

Huang, Norden E.; Chiang, Weiling; Busalacchi, Antonio J. (Technical Monitor)

2000-01-01

217

Hilbert–Huang-Based Tremor Removal to Assess Postural Properties From Accelerometers  

Microsoft Academic Search

Tremor is one of the symptoms of several disorders of the central and peripheral nervous system, such as Parkinson's disease (PD). The impairment of postural control is another symp- tom of PD. The conventional method of posture analysis uses force plates, but accelerometers can be a valid and reliable alternative. Both these measurement techniques are sensitive to tremor. Tremor affects

Sabato Mellone; Luca Palmerini; Angelo Cappello; Lorenzo Chiari

2011-01-01

218

Properties of an atomized iron powder  

Microsoft Academic Search

ction Association by atomization of molten EP-612 steel with water under a pressure of 40 atm gauge [2] and two reduced iron powders - Brovary Powder Metallurgy Factory PZh4M2 powder and Hoeganaes NC 100.24 powder, in addition, a similar study was made of specially prepared atomized powders having particle-size distributions corresponding to those of PZh4M2 and NC 100.24 powders. By

A. E. Kushchevskii; A. T. Pekarik; O. S. Nichiporenko; A. B. Medvedovskii

1978-01-01

219

The Study on the sEMG Signal Characteristics of Muscular Fatigue Based on the Hilbert-Huang Transform  

Microsoft Academic Search

\\u000a Muscular fatigue refers to temporary decline of maximal power ability or contractive ability for muscle movement system. The\\u000a signal of surface electromyographic signal (sEMG) can reflect the changes of muscular fatigue at certain extent. In many years,\\u000a the application of signal of sEMG on evaluation muscular fatigue mainly focus on two aspects of time and frequency respectively.\\u000a The new method

Bo Peng; Xiaogang Jin; Yong Min; Xianchuang Su

2006-01-01

220

Fault Detection by Means of Hilbert–Huang Transform of the Stator Current in a PMSM With Demagnetization  

Microsoft Academic Search

This paper presents a novel method to diagnose demagnetization in permanent-magnet synchronous motor (PMSM). Simulations have been performed by 2-D finite-element analysis in order to determine the current spectrum and the magnetic flux distribution due to this failure. The diagnostic just based on motor current signature analysis can be confused by eccentricity failure because the harmonic content is the same.

Antonio Garcia Espinosa; Javier A. Rosero; Jordi Cusidó; Luis Romeral; Juan Antonio Ortega

2010-01-01

221

A comparison study of improved Hilbert–Huang transform and wavelet transform: Application to fault diagnosis for rolling bearing  

Microsoft Academic Search

For rolling bearing fault detection, it is expected that a desired time–frequency analysis method should have good computation efficiency, and have good resolution in both time domain and frequency domain. As the best available time–frequency method so far, the wavelet transform still cannot fulfill the rolling bearing fault detection task very well since it has some inevitable deficiencies. The recent

Z. K. Peng; Peter W. Tse; F. L. Chu

2005-01-01

222

Hilbert–Huang analysis of BWR neutron detector signals: application to DR calculation and to corrupted signal analysis  

Microsoft Academic Search

In this paper, we present an application of the empirical mode decomposition method [Proc. R. Soc. Lond. A 454 (1998) 903], to the stability analysis of BWR. The methodology developed in this paper decomposes the original time series data in intrinsic oscillation modes or IMFs. Then we compute for each IMF, its Hilbert amplitude spectrum and its Hilbert marginal spectrum.

M. E. Montesinos; J. L. Muñoz-Cobo; C. Pérez

2003-01-01

223

A Novel Preprocessing Method Using Hilbert Huang Transform for MALDI-TOF and SELDI-TOF Mass Spectrometry Data  

Microsoft Academic Search

MotivationMass spectrometry is a high throughput, fast, and accurate method of protein analysis. Using the peaks detected in spectra, we can compare a normal group with a disease group. However, the spectrum is complicated by scale shifting and is also full of noise. Such shifting makes the spectra non-stationary and need to align before comparison. Consequently, the preprocessing of the

Li-Ching Wu; Hsin-Hao Chen; Jorng-Tzong Horng; Chen Lin; Norden E. Huang; Yu-Che Cheng; Kuang-Fu Cheng; William C. S. Cho

2010-01-01

224

Bin Han, Tze-Yun Leong and Guo-liang Li, Learning the Dynamic Bayesian Networks Structure of Ventilation Process in a Linear System Identification Perspective Appeared in Working Note of IEEE Workshop on Life Science Data Mining, 2004 Learning the Dynamic Bayesian Networks Structure of Ventilation Process in a Linear System Identification Perspective  

Microsoft Academic Search

Ventilation process model is important for automatically appropriate ventilation for patients residing in the intensive care unit (ICU). Based on other researchers' work, we try to build a data driven ventilation model under the framework of dynamic Bayesian networks (DBNs). All the variables in our model are suggested by the doctor in ICU. They are all non- invasive measurements obtained

Bin Han; Tze-Yun Leong; Guo-liang Li

225

Empirical study of the scaling behavior of the amplitude-frequency distribution of the Hilbert-Huang transform and its application in sunspot time series analysis  

NASA Astrophysics Data System (ADS)

Investigating long-range correlation by the Hurst exponent, H, is crucial in the study of time series. Recently, empirical-mode-decomposition-based arbitrary-order Hilbert spectral analysis (EMD-HSA) has been proposed to numerically obtain without proof a scaling relationship, generated from the amplitude-frequency distribution, related to H. We propose a formalism to empirically study EMD-HSA, to deduce its scaling exponent ?(q) from the perspective of EMD-based arbitrary-order Hilbert marginal spectrum (EMD-HMS), and to numerically compare the results with the expected H. EMD-HSA and EMD-HMS experiments show that, by incompletely removing (quasi-)periodic trends, the sunspot series should have an H value around 0.12.

Zhou, Yu; Leung, Yee; Ma, Jian-Min

2013-03-01

226

Alleviative Effects of a Kampo (a Japanese Herbal) Medicine "Maoto (Ma-Huang-Tang)" on the Early Phase of Influenza Virus Infection and Its Possible Mode of Action  

PubMed Central

A Kampo medicine, maoto, has been prescribed in an early phase of influenza-like illness and used for a treatment of influenza clinically in Japan these days. However, the efficacy of maoto against the virus infection remains to be elucidated. This study was conducted to evaluate the alleviative effects of maoto against early phase of influenza virus infection and its preliminary mode of actions through immune systems. When maoto (0.9 and 1.6?g/kg/day) was orally administered to A/J mice on upper respiratory tract infection of influenza virus A/PR/8/34 from 4?hours to 52?hours postinfection (p.i.) significant antipyretic effect was shown in comparison with water-treated control. Administration of maoto (0.8 and 1.3?g/kg/day) significantly decreased the virus titers in both nasal (NLF) and bronchoalveolar lavage fluids (BALF) at 52 hours p.i., and significantly increased the anti-influenza virus IgM, IgA, and IgG1 antibody titers in NLF, BALF, and serum, respectively. Maoto also increased significantly the influenza virus-bound IgG1 and IgM antibody titers in serum and the virus-bound IgM antibody titer in even the BALF of uninfected A/J mice. These results indicate that maoto exerts antipyretic activity in influenza virus-infected mice and virus reducing effect at an early phase of the infection through probably augmentation of the virus-bound natural antibodies.

Kataoka, Erika; Aoki, Yuka; Hokari, Rei

2014-01-01

227

[Branches of the National Institute of Hygiene].  

PubMed

National Epidemiological Institute (National Institute of Hygiene, from 7th September 1923) was established in 1918 in Warsaw and acted at national level. Its actions in the field of diseases combat were supported by bacteriological stations and vaccine production in voivodeship cities, which were taken charge of by the state, and names "National Epidemiological Institutes". According to the ministers resolution from 6th July 1921,Epidemiological Institutes were merged to National Central Epidemiological Institutes (PZH), the epidemiological institutes outside Warsaw were named branches, which were to be located in every voivodeship city, according to the initial organizational resolutions. There were country branches of NCEI in: Cracow, Lwów, Lód?, Toru?, Lublin, and Wilno in the period 1919-1923. New branches in Pozna? (1925), Gdynia(1934), Katowice (Voivodeship Institute of Hygiene (1936), Luck (1937), Stanis?awów (1937), Kielce(1938), and Brze??/Bug (Municipal Station acting as branch of National Central Epidemiological Institute. Branches were subordinated to NCEI-PZH) in Warsaw where action plans and unified research and diagnostic method were established and annual meeting of the country branches managers took place. All branches cooperated with hospitals, national health services, district general practitioners and administration structure in control of infectious diseases. In 1938, the post of branch inspector was established, the first of whom was Feliks Przesmycki PhD. Branches cooperated also with University of Cracow, University of Lwów and University of Wilno. In 1935, National Institutes of Food Research was incorporated in PZH, Water Department was established, and these areas of activity began to develop in the branches accordingly. In 1938 there were 13 branches of PZH, and each had three divisions: bacteriological, food research and water research. Three branches in Cracow, Kielce and Lublin worked during World War II under German supervision. PZH activities were restored in 1945 with new branches in Gda?sk, Wroc?aw(1945), Olsztyn and Szczecin (1947), and Rzeszów (1950). In 1951 there were already 14 country branches of National Institute of Hygiene (PZH) in voivodeship cities and 4 minor branches in Zakopane, Radom, Czestochowa and Walbrzych. In 31th December branches of the National Institute of Hygiene (PZH) were restructured and named Sanitary-Epidemiological Stations. PMID:19209733

Gromulska, Marta

2008-01-01

228

Enhanced bioavailability of zeaxanthin in a milk-based formulation of wolfberry (Gou Qi Zi;Fructus barbarum L.)  

Microsoft Academic Search

The carotenoid zeaxanthin is concentrated within the macula. Increased macular zeaxanthin is suggested to lower the risk of age-related macular degeneration. The small red berry, wolfberry (Fructus barbarum L.; Gou Qi Zi and Kei Tze), is one of the richest natural sources of zeaxanthin. However, carotenoid bioavailability is low, and food-based products with enhanced bioavailability are of interest. The present

Iris F. F. Benzie; Wai Y. Chung; Junkuan Wang; Myriam Richelle; Peter Bucheli

2006-01-01

229

A College Semester Abroad Study Program in Tanzania: Evaluation and Grading of Intercultural Competencies  

Microsoft Academic Search

This Capstone Paper attempted to answer the following question: how are the intercultural competencies as they are proposed in the WorldLearning, Inc.\\/SIT Intercultural Competency Checklist at the present time evaluated in the College Semester Abroad (CSA), Tanzania Wildlife Ecology and Conservation program (Tze). The study includes a review of institutional documents and program guidelines as well as an overview of

Charlotte KirKirkegaard Blessing

1998-01-01

230

Achtsamkeit: Konzeptuelle Aspekte und Ergebnisse zum Freiburger Achtsamkeitsfragebogen  

Microsoft Academic Search

Einleitung: Im Rahmen verhaltenstherapeutischer und verhaltensmedizinischer Ans?tze wurde dem Prinzip Achtsamkeit (?Mindfulness?) in den letzten Jahren verst?rkt Aufmerksamkeit geschenkt: Neben der achtsamkeitsbasierten Stressreduktion nach Kabat-Zinn wurde von Segal, Williams und Teasdale die achtsamkeitsbasierte kognitive Therapie entwickelt. Bis vor wenigen Jahren gab es keine evaluierten psychometrischen Instrumente zur empirischen Erfassung von Achtsamkeit. In diesem Beitrag werden mehrere neu entwickelte Verfahren vorgestellt:

Thomas Heidenreich; Johannes Michalak

2006-01-01

231

Identification and quantification of eight flavones in root and shoot tissues of the medicinal plant Huang-qin ( Scutellaria baicalensis Georgi) using high-performance liquid chromatography with diode array and mass spectrometric detection  

Microsoft Academic Search

A method of analysis of eight flavones using high-performance liquid chromatography (HPLC)-diode array detection (DAD)-mass spectrometry (MS) in root and aerial tissues of the medicinal plant Scutellaria baicalensis was developed. The identity of the analytes was confirmed using retention time, UV–vis and mass spectral comparisons to commercial standards. Both UV–vis and mass spectral patterns were characterized for glycosylated flavones. Two

Christopher R. Horvath; Perry A. Martos; Praveen K. Saxena

2005-01-01

232

Simultaneous determination of berberine and palmatine in rat plasma by HPLC–ESI-MS after oral administration of traditional Chinese medicinal preparation Huang-Lian-Jie-Du decoction and the pharmacokinetic application of the method  

Microsoft Academic Search

A sensitive and specific liquid chromatography–electrospray ionization-mass spectrometry (LC–ESI-MS) method has been developed and validated for the identification and quantification of berberine and palmatine in rat plasma. After the addition of the internal standard (IS) and alkalization with 0.5M sodium hydroxide solution, plasma samples were extracted by ethyl ether and separated by HPLC on a Shim-pack ODS (4.6?m, 150mm×2.0mm i.d.)

Tong Lu; Yan Liang; Jue Song; Lin Xie; Guang Ji Wang; Xiao Dong Liu

2006-01-01

233

Fake "Returnee" Earns 4 Million through Fraudulent Marriages: More than Ten Women Fall for His Claims of Being a Boss and Possessing a House and Car  

ERIC Educational Resources Information Center

This article discusses the case of Wang Ruiliang. Ms. Huang filed a case against Wang Jun, alleging that he had defrauded her. Ms. Huang met a man named Wang Jun in April 2002 through a certain matrimonial agency. Before they had been together for very long, Wang Jun asked to borrow money from Ms. Huang, claiming that he was having difficulties in…

Chinese Education and Society, 2005

2005-01-01

234

Alternative or Herbal Therapy Interactions  

MedlinePLUS

... or adversely affect the intended effects of certain medicines used to treat heart failure: Ephedra (ma huang) Ephedrine metabolites Chinese herbs Hawthorne (cratageus) products Additionally, the following substances ...

235

From the representation theory of vertex operator algebras to modular tensor categories in conformal field theory  

Microsoft Academic Search

This is an expository article invited for the ``Commentary'' section of PNAS in connection with Y.-Z. Huang's article, ``Vertex operator algebras, the Verlinde conjecture, and modular tensor categories,'' appearing in the same issue of PNAS. Huang's solution of the mathematical problem of constructing modular tensor categories from the representation theory of vertex operator algebras is very briefly discussed, along with

James Lepowsky

2005-01-01

236

Effects of ice storm on forest ecosystem of southern China in 2008 Shaoqiang Wang1, Lei Zhou1, Weimin Ju2, Kun Huang1 1Key Lab of Ecosystem Network Observation and Modeling, Institute of Geographical Sciences and Natural Resources Research, Beijing, 10010  

NASA Astrophysics Data System (ADS)

Evidence is mounting that an increase in extreme climate events has begun to occur worldwide during the recent decades, which affect biosphere function and biodiversity. Ecosystems returned to its original structures and functions to maintain its sustainability, which was closely dependent on ecosystem resilience. Understanding the resilience and recovery capacity of ecosystem to extreme climate events is essential to predicting future ecosystem responses to climate change. Given the overwhelming importance of this region in the overall carbon cycle of forest ecosystems in China, south China suffered a destructive ice storm in 2008. In this study, we used the number of freezing day and a process-based model (Boreal Ecosystem Productivity Simulator, BEPS) to characterize the spatial distribution of ice storm region in southeastern China and explore the impacts on carbon cycle of forest ecosystem over the past decade. The ecosystem variables, i.e. Net primary productivity (NPP), Evapotranspiration (ET), and Water use efficiency (WUE, the ratio of NPP to ET) from the outputs of BEPS models were used to detect the resistance and resilience of forest ecosystem in southern China. The pattern of ice storm-induced forest productivity widespread decline was closely related to the number of freezing day during the ice storm period. The NPP of forest area suffered heavy ice storm returned to normal status after five months with high temperature and ample moisture, indicated a high resilience of subtropical forest in China. The long-term changes of forest WUE remain stable, behaving an inherent sensitivity of ecosystem to extreme climate events. In addition, ground visits suggested that the recovery of forest productivity was attributed to rapid growth of understory. Understanding the variability and recovery threshold of ecosystem following extreme climate events help us to better simulate and predict the variability of ecosystem structure and function under current and future climate change.

Wang, Shaoqiang

2014-05-01

237

Mathematically rigorous formulation of the Fermi pseudopotential for higher-partial-wave scattering in arbitrary dimension  

SciTech Connect

The Huang-Yang multipolar pseudopotential [see Huang and Yang, Phys. Rev. 105, 767 (1957); later revised by Huang, Statistical Mechanics (Wiley, New York, 1963)] is derived in a mathematically rigorous way using distribution theory in arbitrary dimension. For higher partial waves (i.e., all except s waves), the original pseudopotential contained wrong numerical factors in dimension 3, which were corrected only recently [see Derevianko, Phys. Rev. A 72, 044701 (2005); Stampfer and Wagner, J. Math. Anal. Appl. 342, 202 (2008)]. Here, we generalize the expression for the pseudopotential, in particular to even dimension, enabling the study of scattering processes in a large class of systems, especially in dimension 2.

Stampfer, F.; Wagner, P. [University of Innsbruck, Technikerstrasse 13, A-6020 Innsbruck (Austria)

2010-05-15

238

Three new species of Baeoentedon Girault (Hymenoptera: Eulophidae) from China, with the first record of whitefly host association (Hemiptera: Aleyrodidae).  

PubMed

Three new species of Baeoentedon Girault (Hymenoptera: Eulophidae) are described from China, Baeoentedon balios Wang, Huang & Polaszek sp. nov., Baeoentedon bouceki Wang, Huang & Polaszek sp. nov. and Baeoentedon virgatus Wang, Huang & Polaszek sp. nov. Both female and male of Baeoentedon balios were reared from the whitefly Pealius spina (Singh) (Hemiptera: Aleyrodidae) on the bodhi tree Ficus religiosa L. (Urticales: Moraceae). The male and the whitefly host association of Baeoentedon are recorded for the first time. A key is also provided to females of the world species of the genus.  PMID:24990066

Wang, Zhu-Hong; Huang, Jian; Polaszek, Andrew

2014-01-01

239

Study of phase-separation dynamics by use of cell dynamical systems. I. Modeling  

NASA Astrophysics Data System (ADS)

We present a computationally efficient scheme of modeling the phase-ordering dynamics of thermodynamically unstable phases. The scheme utilizes space-time discrete dynamical systems, viz., cell dynamical systems (CDS). Our proposal is tantamount to proposing new Ansa$iuml-tze for the kinetic-level description of the dynamics. Our present exposition consists of two parts: part I (this paper) deals mainly with methodology and part II [S. Puri and Y. Oono, Phys. Rev. A (to be published)] gives detailed demonstrations. In this paper we provide a detailed exposition of model construction, structural stability of constructed models (i.e., insensitivity to details), stability of the scheme, etc. We also consider the relationship between the CDS modeling and the conventional description in terms of partial differential equations. This leads to a new discretization scheme for semilinear parabolic equations and suggests the necessity of a branch of applied mathematics which could be called ``qualitative numerical analysis.''

Oono, Y.; Puri, S.

1988-07-01

240

Working Group 2 Summary:. Space Charge Effects in Bending Systems  

NASA Astrophysics Data System (ADS)

Participants in Working Group 2 included: Y. Batygin, C. Bohn, B. Carlsten, J. Ellison, P. Emma, Z. Huang, A. Kabel, R. Kishek, R. Li, P. Musumeci, S. Nagaitsev, J. Qiang, M. Reiser, A. Ruggerio, R. Warnock, and M. Zeitlin.

Bohn, Courtlandt L.; Emma, Paul J.

2000-12-01

241

Note on Analyzing Nonlinear and Nonstationary Ocean Wave Data.  

National Technical Information Service (NTIS)

The Huang-Hilbert transformation (HHT, composed of empirical mode decomposition and Hilbert transformation), can be applied to calculate the spectrum of nonlinear and nonstationary signals. The superior temporal and frequency resolutions of the HHT spectr...

P. A. Hwang N. E. Huang D. W. Wang

2003-01-01

242

Piezoresistive Strain Sensors and Multiplexed Arrays for Transportation Infrastructures.  

National Technical Information Service (NTIS)

During Year 5 of SAFETEA-LU, ITI researcher Professor Yonggang Huang, an expert in the science of stretchable and flexible electronics, collaborated with researchers at University of Illinois to engineer stretchable and flexible piezoresistive strain sens...

Y. Huang

2012-01-01

243

Breakout Group 4 -- Summary and Discussion  

Cancer.gov

Access to databases - security, confidentiality, ownership, integrity Bernie Huang, Larry Schwartz,Chris Carr, Mel Greberman,Richard Hanusik, Mary Lou Ingeholm, Eliot Siegel, andJohn Perry Cancer Imaging Informatics Sept 27, 2002 (footer on all slides) Charges

244

Comparison Between the Drags Predicted by Boundary-Layer Theory and Experimental Drag Data for Bodies of Revolution.  

National Technical Information Service (NTIS)

A finite-difference method used by Wang and Huang to predict the drag coefficients of axisymmetric bodies is systematically applied to eight series of model forms comprising nearly fifty bodies. Calculations of residual drag are compared to available expe...

N. M. White

1977-01-01

245

Urban Latino African American Cancer (ULAAC) Disparities Project at Centinela Freeman Regional Medical Center  

Cancer.gov

Our Team Principal Investigator Michael Steinberg, MD Co-Principal Investigators David Khan, MD, Radiation Oncologist, CF David Huang, MD, Radiation Oncologist, CF Nell Forge, PhD, MPH, Assoc. Behavioral Scientist, RAND Allen Fremont, MD, PhD, Assoc.

246

Urban Latino African American Cancer (ULAAC) Disparities Project at Centinela Freeman Regional Medical Center, Memorial Campus  

Cancer.gov

Our Team Principal Investigator Michael Steinberg, MD Co-Principal Investigators David Khan, MD, Radiation Oncologist, CF David Huang, MD, Radiation Oncologist, CF Nell Forge, PhD, MPH, Assoc. Behavioral Scientist, RAND Allen Fremont, MD, PhD, Assoc.

247

76 FR 40822 - Endangered and Threatened Wildlife and Plants; Endangered Status for the Largetooth Sawfish  

Federal Register 2010, 2011, 2012, 2013

...so popular shark fin categories. Based on photographs and descriptions, the category huang jiao (literally: ``yellow-glue'') comes from sawfishes, the trade name deriving from its beige color and the especially copious gelatine it produces...

2011-07-12

248

75 FR 25174 - Endangered and Threatened Wildlife and Plants; Proposed Listing for the Largetooth Sawfish  

Federal Register 2010, 2011, 2012, 2013

...so popular shark fin categories. Based on photographs and descriptions, the category huang jiao (literally: ``yellow-glue'') comes from Pristis sawfishes, the trade name deriving from its beige color and the especially copious gelatine it...

2010-05-07

249

78 FR 31570 - Prospective Grant of a Start-Up Exclusive Patent License Agreement: Treatment of Graves' Disease...  

Federal Register 2010, 2011, 2012, 2013

...Antagonists for the TSH Receptor, Inventors: Marvin Gershengorn (NIDDK), Susanne Neumann (NIDDK), Wenwei Huang (NCATS), Craig Thomas (NCATS). 2. Australian...Doc. 2013-12375 Filed 5-23-13; 8:45 am] BILLING CODE...

2013-05-24

250

Vibration Signal Analysis of Rotor System Based on Time-Frequency Attributes  

Microsoft Academic Search

The time-frequency analysis by Hilbert-Huang transform (HHT) plays on a significant role in the analysis of singularities, which hide in the signal, and is an effective method for non-stationary signal. Based on empirical mode decomposition (EMD), the Hilbert-Huang method can obtain a true instantaneous frequency representation of a signal. The analytical background of the HHT is introduced, and its effectiveness

Ling Xiang; Guiji Tang; Yongli Zhu

2008-01-01

251

Nonrelativistic hyperfine splitting in muonic helium by adiabatic perturbation theory  

NASA Technical Reports Server (NTRS)

Huang and Hughes have discussed the hyperfine splitting delta mu of muonic helium using a variational approach. In this paper, the Born-Oppenheimer approximation is used to simplify the evaluation of delta mu in the nonrelativistic limit. The first-order perturbed wave function of the electron is obtained in closed form by modifying the method used by Dalgarno and Lynn. The result is close to those of Huang and Hughes which required a large Hylleraas expansion and considerable extrapolation.

Drachman, R. J.

1980-01-01

252

Arbitrary-Order Hilbert Spectral Analysis: Theory and Application in Turbulence Research  

NASA Astrophysics Data System (ADS)

Multiscale statistics are relevant in many phenomena since different spatial and temporal scales are involved. Meanwhile, there are intrinsically nonlinear and nonstationary on different scales in these multiscale phenomena. Traditional statistical methods, such as, Fourier power spectrum analysis, structure-function analysis, etc., are failed to handle the nonlinearity and nonstationarity of the collected data from either laboratory experiments or the real world observations. The Empirical Mode Decomposition (EMD) is proposed by N.E. Huang in 1998 to overcome some potential shortcomings of the traditional method to handle the nonlinearity and nonstationarity by combining the classical Hilbert spectral analysis (HSA). Later, we generalized this Hilbert-based method into an arbitrary-order version, namely arbitrary-order Hilbert spectral analysis, to characterize the scale invariant property of a scaling process in a joint frequency-physical domain. In this talk, we present first the basic idea of this Hilbert-based methodology. It is then validated by numerical experiments and is applied in different turbulent systems, e.g., Eulerian velocity, passive scalar turbulence, two-dimensional turbulence, etc., to show the efficiency of this Hilbert-based method. Reference 1. Huang Y, Schmitt F, Lu Z and Liu Y 2008 Europhys. Lett. 84, 40010. 2. Huang Y, Schmitt F, Lu Z and Liu Y 2009 J. Hydrol. 373, 103-111. 3. Huang Y, Schmitt F, Lu Z, Fougairolles P, Gagne Y and Liu Y 2010 Phys. Rev. E 82(2), 026319. 4. Huang Y, Schmitt F G, Hermand J P, Gagne Y, Lu Z and Liu Y 2011 Phys. Rev. E 84(1), 016208. 5. Huang Y, Biferale L, Calzavarini E, Sun C and Toschi F 2013 Phys. Rev. E 87, 041003(R). 6. Tan H.S., Huang Y. and Meng J.-P. 2014 Phys. Fluids 26, 015106.

Huang, Yongxiang; Schmitt, Francois

2014-05-01

253

Oxygen activation by nonheme iron(II) complexes: alpha-keto carboxylate versus carboxylate.  

PubMed

Mononuclear iron(II) alpha-keto carboxylate and carboxylate compounds of the sterically hindered tridentate face-capping ligand Tp(Ph2) (Tp(Ph2) = hydrotris(3,5-diphenylpyrazol-1-yl)borate) were prepared as models for the active sites of nonheme iron oxygenases. The structures of an aliphatic alpha-keto carboxylate complex, [Fe(II)(Tp(Ph2))(O(2)CC(O)CH(3))], and the carboxylate complexes [Fe(II)(Tp(Ph2))(OBz)] and [Fe(II)(Tp(Ph2))(OAc)(3,5-Ph(2)pzH)] were determined by single-crystal X-ray diffraction, all of which have five-coordinate iron centers. Both the alpha-keto carboxylate and the carboxylate compounds react with dioxygen resulting in the hydroxylation of a single ortho phenyl position of the Tp(Ph2) ligand. The oxygenation products were characterized spectroscopically, and the structure of the octahedral iron(III) phenolate product [Fe(III)(Tp(Ph2))(OAc)(3,5-Ph(2)pzH)] was established by X-ray diffraction. The reaction of the alpha-keto carboxylate model compounds with oxygen to produce the phenolate product occurs with concomitant oxidative decarboxylation of the alpha-keto acid. Isotope labeling studies show that (18)O(2) ends up in the Tp(Ph2) phenolate oxygen and the carboxylate derived from the alpha-keto acid. The isotope incorporation mirrors the dioxygenase nature of the enzymatic systems. Parallel studies on the carboxylate complexes demonstrate that the oxygen in the hydroxylated ligand is also derived from molecular oxygen. The oxygenation of the benzoylformate complex is demonstrated to be first order in metal complex and dioxygen, with activation parameters DeltaH++ = 25 +/- 2 kJ mol(-1) and DeltaS++ = -179 +/- 6 J mol(-1) K(-1). The rate of appearance of the iron(III) phenolate product is sensitive to the nature of the substituent on the benzoylformate ligand, exhibiting a Hammett rho value of +1.3 indicative of a nucleophilic mechanism. The proposed reaction mechanism involves dioxygen binding to produce an iron(III) superoxide species, nucleophilic attack of the superoxide at the alpha-keto functionality, and oxidative decarboxylation of the adduct to afford the oxidizing species that attacks the Tp(Ph2) phenyl ring. Interestingly, the alpha-keto carboxylate complexes react 2 orders of magnitude faster than the carboxylate complexes, thus emphasizing the key role that the alpha-keto functionality plays in oxygen activation by alpha-keto acid-dependent iron enzymes. PMID:12823001

Mehn, Mark P; Fujisawa, Kiyoshi; Hegg, Eric L; Que, Lawrence

2003-07-01

254

Blue-emitting platinum(II) complexes bearing both pyridylpyrazolate chelate and bridging pyrazolate ligands: synthesis, structures, and photophysical properties.  

PubMed

A new Pt(II) dichloride complex [Pt(fppzH)Cl2] (1), in which fppzH = 3-(trifluoromethyl)-5-(2-pyridyl)pyrazole, was prepared by the treatment of a pyridylpyrazole chelate fppzH with K2PtCl4 in aqueous HCl solution. Complex 1 could further react with its parent pyrazole (pzH), 3,5-dimethylpyrazole (dmpzH), or 3,5-di-tert-butylpyrazole (dbpzH) to afford the monometallic [Pt(fppz)(pzH)Cl] (2), [Pt(fppz)(dmpzH)Cl] (3), [Pt(fppz)(dmpzH)2]Cl (4), or two structural isomers with formula [Pt(fppz)(dbpzH)Cl] (5a,b). Single-crystal X-ray diffraction studies of 2, 4, and 5a,b revealed a square planar Pt(II) framework, among which a strong interligand hydrogen bonding occurred between fppz and pzH ligands in 2. This interligand H-bonding is replaced by dual N-H...Cl interaction in 4 and both intermolecular N-H...O (with THF solvate) and N-H...Cl interaction in 5a,b, respectively; the latter are attributed to the bulky tert-butyl substituents that force the dbpzH ligand to adopt the perpendicular arrangement. Furthermore, complex 2 underwent rapid deprotonation in basic media to afford two isomeric complexes with formula [Pt(fppz)(mu-pz)]2 (6a,b), which are related to each other according to the spatial orientation of the fppz chelates, i.e., trans- and cis-isomerism. Similar reaction exerted on 3 afforded isomers 7a,b. Both 6a,b (7a,b) are essentially nonemissive in room-temperature fluid state but afford strong blue phosphorescence in solid state prepared via either vacuum-deposited thin film or 77 K CH2Cl2 matrix. As also supported by the computational approaches, the nature of emission has been assigned to be ligand-centered triplet pipi* mixed with certain metal-to-ligand charge-transfer character. PMID:18027932

Chang, Sheng-Yuan; Chen, Jing-Lin; Chi, Yun; Cheng, Yi-Ming; Lee, Gene-Hsiang; Jiang, Chang-Ming; Chou, Pi-Tai

2007-12-24

255

A comparison of two Hilbert spectral analyses of heart rate variability.  

PubMed

The present paper compares the performance of two Hilbert spectral analyses when applied to a synthetic RR series from a nonstationary integral pulse frequency modulation model and to real RR series from a dataset of normal sinus arrhythmia. The Hilbert-Huang transformation based on empirical mode decomposition is compared to the presently introduced Hilbert-Olhede-Walden transformation based on stationary wavelet packet decomposition. The comparison gives consistent results pointing to a superior performance of the Hilbert-Olhede-Walden transformation showing 33-163 times smaller deviations when estimating the instantaneous frequency traces of the synthetic RR series. Artificial fluctuations caused by mode mixing in the Hilbert-Huang spectrum are seen in both the synthetic and real RR series. It can be concluded that the instantaneous frequencies and amplitudes estimated by the Hilbert-Huang transformation should be interpreted with caution when investigating heart rate variability. PMID:19521730

Ihlen, Espen Alexander Fürst

2009-10-01

256

Signal Processing Methods Monitor Cranial Pressure  

NASA Technical Reports Server (NTRS)

Dr. Norden Huang, of Goddard Space Flight Center, invented a set of algorithms (called the Hilbert-Huang Transform, or HHT) for analyzing nonlinear and nonstationary signals that developed into a user-friendly signal processing technology for analyzing time-varying processes. At an auction managed by Ocean Tomo Federal Services LLC, licenses of 10 U.S. patents and 1 domestic patent application related to HHT were sold to DynaDx Corporation, of Mountain View, California. DynaDx is now using the licensed NASA technology for medical diagnosis and prediction of brain blood flow-related problems, such as stroke, dementia, and traumatic brain injury.

2010-01-01

257

Molecular dynamics simulation studies of absorption in piperazine activated MDEA solution.  

PubMed

Development of more efficient solvent solutions for removal of CO(2) from natural gas and flue gases is a major task, which contributes to improved design of process plants and leads to decreased costs for its removal. Understanding the mechanisms of CO(2) absorption as well as analysis of undesired simultaneous processes is crucially important in this regard. In this work, we have applied Molecular Dynamics (MD) to investigate the absorption of CO(2) from a binary mixture of CO(2) and CH(4) into aqueous piperazine activated MDEA solution. The MD simulations were performed at a constant temperature of 298 K for five different systems with a loading factor of 0.07 to provide insight into molecular distribution in the amine solution and to enhance understanding of absorption mechanisms on the molecular scale. Force field parameters that were missing from the OPLS-AA force field, as well as charge distribution of piperazine (PZ), protonated piperazine (PZH(+)), piperazine carbamate (PZCOO(-)) and MDEA were obtained by QM calculations. The results of our simulations emphasize the importance of piperazine and piperazine carbamate in accelerating the absorption process. For the first time, we have shown the undesirable trapping of CH(4) by the amine solution and revealed that amine groups are mainly responsible for both absorption of CO(2) and the undesired trapping of CH(4). PMID:21691636

Farmahini, Amir Hajiahmadi; Kvamme, Bjørn; Kuznetsova, Tatiana

2011-07-28

258

Protein phosphatase Z modulates oxidative stress response in fungi.  

PubMed

The genome of the filamentous fungus Aspergillus nidulans harbors the gene ppzA that codes for the catalytic subunit of protein phosphatase Z (PPZ), and the closely related opportunistic pathogen Aspergillus fumigatus encompasses a highly similar PPZ gene (phzA). When PpzA and PhzA were expressed in Saccharomyces cerevisiae or Schizosaccharomyces pombe they partially complemented the deleted phosphatases in the ppz1 or the pzh1 mutants, and they also mimicked the effect of Ppz1 overexpression in slt2 MAP kinase deficient S. cerevisiae cells. Although ppzA acted as the functional equivalent of the known PPZ enzymes its disruption in A. nidulans did not result in the expected phenotypes since it failed to affect salt tolerance or cell wall integrity. However, the inactivation of ppzA resulted in increased sensitivity to oxidizing agents like tert-butylhydroperoxide, menadione, and diamide. To demonstrate the general validity of our observations we showed that the deletion of the orthologous PPZ genes in other model organisms, such as S. cerevisiae (PPZ1) or Candida albicans (CaPPZ1) also caused oxidative stress sensitivity. Thus, our work reveals a novel function of the PPZ enzyme in A. nidulans that is conserved in very distantly related fungi. PMID:22750657

Leiter, Éva; González, Asier; Erdei, Éva; Casado, Carlos; Kovács, László; Ádám, Csaba; Oláh, Judit; Miskei, Márton; Molnar, Monika; Farkas, Ilona; Hamari, Zsuzsanna; Ariño, Joaquín; Pócsi, István; Dombrádi, Viktor

2012-09-01

259

Delocalized Davydov D1 Ansatz for the Holstein polaron.  

PubMed

An efficient, yet very accurate trial wave function, constructed from projecting the well-known Davydov D1 Ansatz onto momentum eigenstates, is employed to study the ground state properties of the generalized Holstein Hamiltonian with simultaneous diagonal and off-diagonal coupling. Ground-state energies have been obtained with a precision matching that of the computationally much more demanding density-matrix renormalization group method. The delocalized D1 Ansatz lowers the ground-state energies at the Brillouin zone boundary significantly compared with the Toyozawa and Global-Local Ansa?tze in the weak coupling regime, while considerable improvement is demonstrated to have been achieved over the entire Brillouin zone in the strong coupling regime. Unique solutions are obtained with the delocalized D1 for different initial conditions when the transfer integral is 20 times the phonon frequency at the zone center, implying the absence of any self-trapping discontinuity. The scaled correlation variance is found to fit satisfactorily well with the predictions of the perturbation theories. PMID:23656123

Sun, Jin; Duan, Liwei; Zhao, Yang

2013-05-01

260

Decontamination of chemical and biological warfare (CBW) agents using an atmospheric pressure plasma jet (APPJ)  

SciTech Connect

The atmospheric pressure plasma jet (APPJ) [A. Sch{umlt u}tze {ital et al.}, IEEE Trans. Plasma Sci. {bold 26}, 1685 (1998)] is a nonthermal, high pressure, uniform glow plasma discharge that produces a high velocity effluent stream of highly reactive chemical species. The discharge operates on a feedstock gas (e.g., He/O{sub 2}/H{sub 2}O), which flows between an outer, grounded, cylindrical electrode and an inner, coaxial electrode powered at 13.56 MHz rf. While passing through the plasma, the feedgas becomes excited, dissociated or ionized by electron impact. Once the gas exits the discharge volume, ions and electrons are rapidly lost by recombination, but the fast-flowing effluent still contains neutral metastable species (e.g., O{sub 2}{sup {asterisk}}, He{sup {asterisk}}) and radicals (e.g., O, OH). This reactive effluent has been shown to be an effective neutralizer of surrogates for anthrax spores and mustard blister agent. Unlike conventional wet decontamination methods, the plasma effluent does not cause corrosion and it does not destroy wiring, electronics, or most plastics, making it highly suitable for decontamination of sensitive equipment and interior spaces. Furthermore, the reactive species in the effluent rapidly degrade into harmless products leaving no lingering residue or harmful by-products. {copyright} {ital 1999 American Institute of Physics.}

Herrmann, H.W.; Henins, I.; Park, J.; Selwyn, G.S. [Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

1999-05-01

261

Penetration of high latitude ionospheric electric field to the equatorial region: a case study based on SuperDARN data and the IMech model  

Microsoft Academic Search

In a recent paper, Huang et al. (2007) described in detail, for the April 5, 2003, event, the penetration of the interplanetary electric field to the equatorial ionosphere as measured by the Jicamarca incoherent radar. Or this event, we reconstructed and carefully examined all SuperDARN convection maps in the 1400-2200 UT time period for the southern and northern hemispheres and

Monio Kartalev; Ermanno Amata; Igino Coco; Valentina Keremidarska

2008-01-01

262

Deja Vu All over Again: Re-Revisiting the Conceptual Status of Early Word Learning: Comment on Smith and Samuelson (2006)  

ERIC Educational Resources Information Center

The authors assert that L. B. Smith and L. Samuelson's (2006; see record EJ750228) most recent critique of A. E. Booth, S. R. Waxman, and Y. T. Huang's (2005; see record EJ684979) work missed its mark, deflecting attention from the important theoretical difference between the two sets of authors' positions and focusing instead on imagined…

Booth, Amy E.; Waxman, Sandra R.

2006-01-01

263

Analysis of Metropolitan Highway Capacity and the growth in vehicle miles of travel  

Microsoft Academic Search

A number of recent studies have examined the hypothesis of induced travel in an attempt to quantify the phenomenon (Hansen & Huang 1997; Noland, forthcoming). No study has yet attempted to adjust for potential simultaneity bias in the results. This study addresses this issue by the use of an instrumental variable (two stage least squares) approach. Metropolitan level data compiled

Robert B. Noland; William A. Cowart

2000-01-01

264

The genus Scutellaria an ethnopharmacological and phytochemical review  

Microsoft Academic Search

Scutellaria (HUANG QIN) (Lamiaceae), which includes about 350 species commonly known as skullcaps, is widespread in Europe, the United States and East Asia. Some species are taken to clear away the heat-evil and expel superficial evils in traditional Chinese medicine (TCM). The present paper reviews the ethnopharmacology, the biological activities and the correlated chemical compounds of Scutellaria species. More than

Xiaofei Shang; Xirui He; Xiaoying He; Maoxing Li; Ruxue Zhang; Pengcheng Fan; Quanlong Zhang; Zhengping Jia

2010-01-01

265

Elastic interaction energy calculations for Guinier--Preston zones in Al--Cu and CuBe  

Microsoft Academic Search

Computer experiments were performed in order to study elastic strain effects of small coherent precipitates. The model calculations were based on the harmonic theory of microscopic elasticity, which is a modification of lattice statics theory. The theoretical model requires as input only Born--Huang force constants of the host material and the elements of a symmetric stress-free distortion tensor for describing

E. Seitz; D. de Fontaine

1978-01-01

266

The Non-Gaussian Joint Probability Density Function of Slope and Elevation for a Nonlinear Gravity Wave Field  

Microsoft Academic Search

On the basis of the mapping method developed by Huang et al. (1983), an analytic expression for the non-Gaussian joint probability density function of slope and elevation for nonlinear gravity waves is derived. Various conditional and marginal density functions are also obtained through the joint density function. The analytic results are compared with a series of carefully controlled laboratory observations,

Norden E. Huang; Steven R. Long; Larry F. Bliven; Chi-Chao Tung

1984-01-01

267

From Lexical Semantics to Conceptual Metaphors: Mapping Principle Verification with WordNet and SUMO  

Microsoft Academic Search

The goal of this paper is to further develop methods for verifying Mapping Principles between source and target domain pairings of conceptual metaphors. Previous work (Ahrens, Chung & Huang, 2003) integrated the Conceptual Mapping Model with an ontology-based knowledge representation (i.e. SUMO) in order to demonstrate that conceptual metaphor analysis could be restricted and eventually, automated. However, that study relied

Kathleen Ahrens; Siaw-Fong Chung; Chu-Ren Huang

268

Breakout Group 4  

Cancer.gov

Group 4 Access to databases – security, confidentiality, ownership, integrity Bernie Huang, Larry Schwartz, Chris Carr, Mel Greberman, Richard Hanusik, Mary Lou Ingeholm, Eliot Siegel, and John Perry Cancer I m a g ing Infor m ati c s S ept 27,2002 Charges •

269

Reply to Cattell and Elphic,  

National Technical Information Service (NTIS)

Cattell and Elphic 1987 state that the conclusions of our statistical study (1986a) are flawed by the methodology used. In refuting this assertion, we employ an extended data base that includes plasma sheet intervals sampled in 1979 Huang and Frank, 1986b...

C. Y. Huang L. A. Frank

1987-01-01

270

Interlending Section. Collections and Services Division. Papers.  

ERIC Educational Resources Information Center

Papers on interlibrary lending which were presented at the 1982 International Federation of Library Associations (IFLA) conference include: (1) "Inter-Library Loan Service of the National Library of China," a description by Huang Jungui and Zhao Qikang (People's Republic of China) of the history, organization, purposes, and possible future…

International Federation of Library Associations, The Hague (Netherlands).

271

MODULATION OF HYPOXIC PULMONARY VASOCONSTRICTION BY ERYTHROCYTIC NITRIC OXIDE  

EPA Science Inventory

Abstract American Heart Association 2001 Modulation of Hypoxic Pulmonary Vasoconstriction by Erythrocytic NO McMahon TJ1, Gow AJ1, Huang YCT4, Stamler JS1,2,3 Departments of Medicine1 and Biochemistry2, and Howard Hughes Medical Institute3, Duke University Med...

272

Structural integrity monitoring of steam generator tubing using transient acoustic signal analysis  

Microsoft Academic Search

The integrity diagnosis of tubular structures is studied in this research using guided acoustic waves. A smart sensor array is deployed to activate and collect Lamb wave signals that propagate along metallic tubes. Several advanced techniques have been explored to extract representative features from acoustic time series. Among them, the Hilbert-Huang Transform (HHT) is a recently developed technique for nonlinear

Baofu Lu; Belle R. Upadhyaya; Rafael B. Perez

2005-01-01

273

Commissioning the NOAO Data Management System  

Microsoft Academic Search

The NOAO Data Management System (Barg et al. 2007) is comprised of several large subsystems. Its Data Transport System (Huang et al. 2007) annually conveys Tbytes of data between six remote, intercontinental sites. The NOAO Science Archive (NSA) has been safeguarding key NOAO data products for almost five years. NSA release 3.0 will dramatically increase the data holdings as well

H. H. Lanning; R. Seaman; R. C. Smith

2007-01-01

274

Comparison on the anti-inflammatory effect of Cortex Phellodendri Chinensis and Cortex Phellodendri Amurensis in 12-O-tetradecanoyl-phorbol-13-acetate-induced ear edema in mice  

Microsoft Academic Search

Ethnopharmacological relevanceCortex Phellodendri is derived from the dried bark of Phellodendron chinense Schneid. or Phellodendron amurense Rupr. Traditionally, Cortex Phellodendron Chinensis (CPC) and Cortex Phellodendron Amurensis (CPA) are used interchangeably under the name “Huang Bai” for the treatment of gastroenteritis, abdominal pain or diarrhea. The present study aims to compare the anti-inflammatory effect of ethanol extracts of Cortex Phellodendri Chinensis

Yan-Fang Xian; Qing-Qiu Mao; Siu-Po Ip; Zhi-Xiu Lin; Chun-Tao Che

2011-01-01

275

Synchronization of coupled oscillators is a game  

Microsoft Academic Search

The purpose of this paper is to understand phase transition in noncooperative dynamic games with a large number of agents. Applications are found in neuroscience, biology, economics, as well as traditional engineering applications. The focus of analysis is a variation of the large population LQG model of Huang et. al. 2007, comprised here of a controlled nonlinear N-dimensional stochastic differential

Huibing Yin; Prashant G. Mehta; Sean P. Meyn; Uday V. Shanbhag

2010-01-01

276

Synchronization of Coupled Oscillators is a Game  

Microsoft Academic Search

The purpose of this paper is to understand phase transition in noncooperative dynamic games with a large number of agents. Applications are found in neuroscience, biology, and economics, as well as traditional engineering applications. The focus of analysis is a variation of the large population linear quadratic Gaussian (LQG) model of Huang 2007, comprised here of a controlled $N$-dimensional stochastic

Huibing Yin; Prashant G. Mehta; Sean P. Meyn; Uday V. Shanbhag

2012-01-01

277

ALTERATION OF CARDIAC ELECTRICAL ACTIVITY BY WATER-LEACHABLE COMPONENTS OF RESIDUAL OIL FLY ASH (ROFA)  

EPA Science Inventory

Alteration of cardiac electrical activity by water-leachable components of residual oil fly ash (ROFA) Desuo Wang, Yuh-Chin T. Huang*, An Xie, Ting Wang *Human Studies Division, NHEERL, US EPA 104 Mason Farm Road, Chapel Hill, NC 27599 Department of Basic ...

278

76 FR 37706 - Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition To List Castanea...  

Federal Register 2010, 2011, 2012, 2013

...over a century. The pathogen is slow spreading. Phytopthora cinnamomi spores spread...diversity is a result of the chestnut blight epidemic. Huang et al. (1998, pp. 1015-1019...allozyme variation are less susceptible to epidemics. In the absence of knowledge of...

2011-06-28

279

VANADL SULFATE INHIBITS NO PRODUCTION BY DIFFERENTIALLY REGULATING SERINE/THREONINE PHOSPHORYLATION OF ENOS  

EPA Science Inventory

VANADYL SULFATE INHIBITS NO PRODUCTION BY DIFFERENTIALLY REGULATING SERINE/THREONINE PHOSPHORYLATION OF eNOS. Zhuowei Li, Jacqueline D. Carter, Lisa A. Dailey, Joleen Soukup, Yuh-Chin T. Huang. CEMALB, University of North Carolina and ORD, US EPA, Chapel Hill, North Carolina V...

280

Advancement in OCT and image-processing techniques for automated ophthalmic diagnosis  

Microsoft Academic Search

Optical Coherence Tomography (OCT) is a recently developed, non-invasive, biomedical imaging modality. It is progressively gaining popularity in ophthalmologic diagnostics. Compared to any other imaging modality, OCT enables clinicians to obtain retinal images with much higher resolution. This paper discusses the basic functioning principle of OCT and various advancements that it has gone through starting from its invention by Huang

Rupsa Datta; S. Aditya; D. N. Tibrewala

2010-01-01

281

Evaluating the Impact of Human Resource Development.  

ERIC Educational Resources Information Center

These four papers are from a symposium on evaluating the impact of human resource development (HRD). "Pre-Job Training and the Earnings of High-Tech Employees in Taiwan" (Tung-Chun Huang) reports on a study that concludes that public training programs have no impact on participants' earnings in later jobs, but participation in private training…

1999

282

IFLA General Conference, 1986. Bibliographic Control Division. Section: Bibliography. Papers.  

ERIC Educational Resources Information Center

Papers on bibliographic control presented at the 1986 International Federation of Library Associations (IFLA) conference include: (1) "Bibliographic Interchange/Coordination in Southeast Asia (Huck Tee Lim, Malaysia); (2) "Project for 'Chinese National Bibliography' and Its Progress" (Huang Jungui, China); (3) "Subject Bibliography in the…

International Federation of Library Associations and Institutions, The Hague (Netherlands).

283

A new approach for crude oil price analysis based on Empirical Mode Decomposition  

Microsoft Academic Search

The importance of understanding the underlying characteristics of international crude oil price movements attracts much attention from academic researchers and business practitioners. Due to the intrinsic complexity of the oil market, however, most of them fail to produce consistently good results. Empirical Mode Decomposition (EMD), recently proposed by Huang et al., appears to be a novel data analysis method for

Xun Zhang; K. K. Lai; Shou-Yang Wang

2008-01-01

284

Image compression with best local cosine bases  

Microsoft Academic Search

We apply the framework of multitree dictionaries introduced in Y. Huang et al. (2005, 2003), to design a novel image coder based on lapped orthogonal bases of local cosines. We show that our image coder outperforms both the quadtree-based approach of F. Meyer (2002) and SPIHT (A. Said and W.A. Pearlman, 1996) for textured images

Y. Huang; I. Pollak

2005-01-01

285

A Comparative Study of Canadian and Taiwanese Grade 5 Children's Environmental Behaviors, Attitudes, Concerns, Emotional Dispositions, and Knowledge.  

ERIC Educational Resources Information Center

This study explored the cultural influences on children's self-reported environmental actions, perceptions, and understandings; investigated the relationships among the behavioral, affective, cognitive, and demographic variables; and developed models of children's responsible environmental behavior (Huang, 2001). The cross-cultural comparison…

Huang, Hsin-Ping; Yore, Larry D.

286

Graphical model architectures for speech recognition  

Microsoft Academic Search

This article discusses the foundations of the use of graphical models for speech recognition as presented in J. R. Deller et al. (1993), X. D. Huang et al. (2001), F. Jelinek (19970, L. R. Rabiner and B. -H. Juang (1993) and S. Young et al. (1990) giving detailed accounts of some of the more successful cases. Our discussion employs dynamic

Jeff A. Bilmes; Chris Bartels

2005-01-01

287

A rapid biosensor-based method for quantification of free and glucose-conjugated salicylic acid  

Microsoft Academic Search

BACKGROUND: Salicylic acid (SA) is an important signalling molecule in plant defenses against biotrophic pathogens. It is also involved in several other processes such as heat production, flowering, and germination. SA exists in the plant as free SA and as an inert glucose conjugate (salicylic acid 2-O-?-D-glucoside or SAG). Recently, Huang et al. developed a bacterial biosensor that responds to

Christopher T DeFraia; Eric A Schmelz; Zhonglin Mou

2008-01-01

288

Northwest Pacific Response to Centennial-Scale Changes in Global T.H.C. During the Last Glacial Cycle and Brunhes Chron  

Microsoft Academic Search

In contrast to previous GCM simulations, the ocean model of Huang et al. (2000) shows that any slowdown or shut off of deepwater formation in the North Atlantic will lead to a deepening of the thermocline in regions of deepwater upwelling, which in turn will make sea surface temperatures (SST) warm in the northwesternmost Pacific. To test this model we

M. Sarnthein; T. Kiefer; H. Erlenkeuser; P. Grootes; C. Kissel; U. Röhl; F. Schmieder

2003-01-01

289

Note on Uniqueness of Limit Cycles in a Lienard-Type System.  

National Technical Information Service (NTIS)

Huang and Sun (5) proposed a theorem to guarantee the uniqueness of limit cycles for the generalized Lienard system dx over dt = h(y) - F(x), dy over dt = -g(x). We will give a counterexample to their theorem. It will be shown that their theorem is only v...

R. E. Kooij J. Sun

1996-01-01

290

Author Affiliation Index: A New Approach to Marketing Journal Ranking  

ERIC Educational Resources Information Center

Previous research has adopted various methods to assess the relative quality of academic marketing journals. This study, as a replication and extension of Chen and Huang (2007), introduces the Author Affiliation Index (AAI) as an alternative approach to assessing marketing journal quality. The AAI is defined as the ratio of articles authored by…

Pan, Yue; Chen, Carl R.

2011-01-01

291

Detecting cloud vertical structures from radiosondes and MODIS over Arctic first-year sea ice  

Microsoft Academic Search

The cloud vertical structure (CVS) of Arctic clouds is analyzed with data mainly from radiosondes launched between November 2003 and June 2004 during the Canadian Arctic Shelf Exchange Study (CASES). The feasibility of using a radiosonde-based cloud detection method [Minnis, P., Yi, Y. Huang, J., and Ayers, K. 2005: Relationships between radiosonde and RUC-2 meteorological conditions and cloud occurrence determined

X. Jin; J. Hanesiak; D. Barber

2007-01-01

292

Infrared spectroscopy of Kh2Po4-type ferroelectrics  

Microsoft Academic Search

The peculiar profiles of infrared reflectivity spectra of KDP-type crystals and the inadequacy of the classical Born-Huang dielectric function model to fit them already recognized for a long time, gave rise to many investigations for some 30 years. Most recent works have shown that the factorized form of the dielectric function is able to fit all spectra satisfactorily. The analysis

Françlois Gervais; Patrick Simon

1987-01-01

293

On Deriving CED Effects from the PIC  

Microsoft Academic Search

This article shows that a version of the Condition on Extraction Domain (Huang 1982) can be derived from the Phase Impenetrability Condition (PIC; Chomsky 2001, 2008) if the following assumptions are made: (a) All syntactic operations are driven by features of lexical items. (b) These features are ordered on lexical items. (c) All phrases are phases. (d) Edge features that

Gereon Müller

2010-01-01

294

CONTRIBUTION OF INSPIRATORY FLOW TO ACTIVATION OF EGFR, RAS, MAPK, ATF-2 AND C-JUN DURING LUNG STRETCH  

EPA Science Inventory

Contribution of Inspiratory Flow to Activation of EGFR, Ras, MAPK, ATF-2 and c-Jun during Lung Stretch R. Silbajoris 1, Z. Li 2, J. M. Samet 1 and Y. C. Huang 1. 1 NHEERL, ORD, US EPA, RTP, NC and 2 CEMALB, UNC-CH, Chapel Hill, NC . Mechanical ventilation with larg...

295

Identity, Stress, and Resilience in Lesbians, Gay Men, and Bisexuals of Color  

ERIC Educational Resources Information Center

The author addresses two issues raised in Moradi, DeBlaere, and Huang's Major Contribution to this issue: the intersection of racial/ethnic and lesbian, gay, and bisexual (LGB) identities and the question of stress and resilience. The author expands on Moradi et al.'s work, hoping to encourage further research. On the intersection of identities,…

Meyer, Ilan H.

2010-01-01

296

76 FR 5595 - Center for Scientific Review; Notice of Closed Meetings  

Federal Register 2010, 2011, 2012, 2013

...Page 5595] [FR Doc No: 2011-2202...Immunology. Date: February 22, 2011. Time: 10 a.m. to 1 p...Call). Contact Person: Jin Huang, PhD, Scientific Review Officer...Etiology. Date: February 28, 2011. Time: 8 a.m. to 5...

2011-02-01

297

Optimality of Some Subset Selection Procedures.  

National Technical Information Service (NTIS)

As measures of goodness of a selection rule, usually two quantities, the probability of a correct selection and the expected size of the selected subset, are considered. Based on these two criteria, Gupta and Huang (1980) proved a theorem to derive a sele...

L. Y. Leu

1984-01-01

298

Estimation of a semiparametric varying-coefficient partially linear errors-in-variables model  

Microsoft Academic Search

This paper studies the estimation of a varying-coefficient partially linear regression model which is a generalization of the partially linear regression model and varying-coefficient regression model [Fan and Huang, Manuscript, University of North Carolina, Chapel Hill, USA, 2002]. We focus on the case where some covariates are measured with additive errors. The usual profile least squares and local polynomial estimations

Jinhong You; Gemai Chen

2006-01-01

299

Gaining Insight to Transfer of Training through the Lens of Social Psychology  

ERIC Educational Resources Information Center

The article deals with the question under which conditions people change their behavior through vocational trainings or not. Following the demand of more theory-driven investigations in transfer research (Blume, Ford, Baldwin, & Huang, 2010) we wish to add the perspective of social psychology. We therefore illustrate how well-known concepts from…

Weisweiler, Silke; Nikitopoulos, Alexandra; Netzel, Janine; Frey, Dieter

2013-01-01

300

Short circuit fault detection in PMSM by means of empirical mode decomposition (EMD) and wigner ville distribution (WVD)  

Microsoft Academic Search

This paper presents and analyzes short circuit failures for Permanent Magnet Synchronous Motor (PMSM). The study includes stable condition and speed transients in simulation and realistic experimental conditions. The stator current is analyzed by the empirical mode decomposition (EMD) method, which will generate a collection of intrinsic mode functions (IMF). Finally, the Hilbert-Huang transform (HHT) is used to compute the

J. Rosero; J. A. O. Romeral; L. Romeral; E. Rosero

2008-01-01

301

A critical review of experimental results and constitutive models for BCC and FCC metals over a wide range of strain rates and temperatures  

Microsoft Academic Search

Four currently utilized constitutive models for metals (i.e. Johnson–Cook, Zerilli–Armstrong, Bodner–Partom and Khan–Huang) are investigated and used to predict the mechanical behaviors of the materials and compared with experimental results. Limitations for each model in describing work-hardening behavior of metals are discussed.

Riqiang Liang; Akhtar S. Khan

1999-01-01

302

TRANSCRIPTION FACTOR ACTIVATION FOLLOWING EXPOSURE OF AN INTACT LUNG PREPARATION TO METALLIC PARTICULATE MATTER  

EPA Science Inventory

TRANSCRIPTION FACTOR ACTIVATION FOLLOWING EXPOSURE OF AN INTACT LUNG PREPARATION TO METALLIC PARTICULATE MATTER James M. Samet1,2, Robert Silbajoris1, Tony Huang1 and Ilona Jaspers3 1Human Studies Division, National Health and Environmental Effects Research Laborato...

303

Heightening Reflection Through Dialogue: A Case for Electronic Journaling and Electronic Concept Mapping in Science Classes  

Microsoft Academic Search

The literature on concept mapping and on journaling in the science classroom is well established (Ambron, 1991; Anderson & Huang, 1989; Barenholtz & Tamir, 1992; Emig, 1977; Fulwiler, 1980; Jegede, Alaiyemola, & Okebukola., 1990; Langer & Applebee, 1987; Nakhleh & Krajcik, 1991; Novak, Gowin, & Johansen, 1983; Novak & Gowin, 1984; Richardson, 1990; Wallace & Mintzes, 1990; Wandersee, 1990; Zulich

Paul Germann; Kim Young-Soo; Martha D. Patton

2001-01-01

304

Slide 1  

Cancer.gov

Ying Huang Toxicology Study Design Appropriate controls Mimic clinical scenario as closely as possible Product, formulation, ROA, dose regimen, etc. Reasonable group size to provide adequate interpretation of the data The number of animals will vary depending on the species, disease model, delivery system, product class, etc.

305

Technology Transfer/Commercialization Report  

NASA Technical Reports Server (NTRS)

Contents include the following: (1) Who we are. (2) Technology opportunities and successes in 2002: Hilbert-Huang transform; new sensors via sol-gel-filled fiber optics; hierarchical segmentation software. (3) Activities in 2002: encouraging researcher involvement; inventorying new technologies; patenting Goddard technologies; promoting Goddard technologies; establishing new agreements;seeking and bestowing awards. (4) How to reach Goddard's: technology commercialization office.

2002-01-01

306

Individualized Risks of First Adverse Events in Patients With Fanconi Anemia  

Cancer.gov

Individualized Risks of First Adverse Events in Patients With Fanconi Anemia 1 Philip S. Rosenberg, PhD, 2Yi Huang, MS, 3Blanche P. Alter, MD, MPH From 1 Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute,

307

Nonlocal mode mixing and surface-plasmon-polariton-mediated enhancement of diffracted terahertz fields by a conductive grating  

Microsoft Academic Search

This work generalizes our previous study of the effect of plasma-wave induced longitudinal fields [D. H. Huang J. Appl. Phys. 100, 113711 (2006)]. We incorporate a conductive grating on top of a conducting sheet for generating and mixing Bragg modes arising from a reflected and\\/or transmitted electromagnetic field. It also generalizes our recent work on the coupling of electronically modulated

Danhong Huang; Godfrey Gumbs; P. M. Alsing; D. A. Cardimona

2008-01-01

308

Silver(I) complexes of tris(pyrazolyl)borate ligands bearing six trifluoromethyl and three additional electron-withdrawing substituents.  

PubMed

Sodium salts of two new tris(pyrazolyl)borates [HB(4-Cl-3,5-(CF3)2Pz)3](-) and [HB(4-(NO2)-3,5-(CF3)2Pz)3](-), which are not only highly fluorinated, but also loaded with additional electron-withdrawing substituents, have been synthesized by reacting 4-Cl-3,5-(CF3)2PzH or 4-(NO2)-3,5-(CF3)2PzH with NaBH4 under nitrogen in a solventless process, and isolated after a work up in tetrahydrofuran (THF) or diethyl ether (Et2O), as their THF or Et2O adducts. Metathesis of these sodium salts with AgOTf in THF leads to [HB(4-Cl-3,5-(CF3)2Pz)3]Ag(THF) and [HB(4-(NO2)-3,5-(CF3)2Pz)3]Ag(THF). The corresponding cis-cyclooctene (c-COE) complexes [HB(4-Cl-3,5-(CF3)2Pz)3]Ag(c-COE) and [HB(4-(NO2)-3,5-(CF3)2Pz)3]Ag(c-COE) were obtained by displacing THF with cis-cyclooctene. The related [HB(3,5-(CF3)2Pz)3]Ag(c-COE) can also be obtained via a similar process. X-ray crystal structures show that [HB(4-(R)-3,5-(CF3)2Pz)3]Ag(c-COE) (R = H, Cl, NO2) feature pseudo-tetrahedral silver sites supported by ?(3)-bound tris(pyrazolyl)borate ligands. [HB(4-(NO2)-3,5-(CF3)2Pz)3]Ag(c-COE) displays the smallest upfield shift of the alkene carbon peak (versus free alkene) followed by [HB(4-Cl-3,5-(CF3)2Pz)3]Ag(c-COE) and [HB(3,5-(CF3)2Pz)3]Ag(c-COE). Experimental and computational data indicate very electron poor silver(I) sites in all three [HB(4-(R)-3,5-(CF3)2Pz)3]Ag(c-COE) adducts with minimal Ag ? (cis-cyclooctene) backbonding. Although the impact of R (H, Cl, NO2) on the alkene carbon chemical shift of these adducts and the olefin ?/?* populations is small, the (13)C NMR chemical shifts and NBO analysis suggest that [HB(4-(NO2)-3,5-(CF3)2Pz)3]Ag(c-COE) possesses the most electrophilic metal site, which correlates with the pKa values of the free pyrazoles. [HB(4-(R)-3,5-(CF3)2Pz)3]Ag(c-COE) adducts effectively catalyze the insertion of the carbene moiety of ethyl diazoacetate into C-H bonds of 2,3-dimethylbutane. The [HB(4-(NO2)-3,5-(CF3)2Pz)3]Ag(c-COE) catalyst shows a higher selectivity for primary C-H bonds compared to the reactions catalyzed by [HB(3,5-(CF3)2Pz)3]Ag(c-COE). PMID:24013162

Jayaratna, Naleen B; Pardue, Daniel B; Ray, Sriparna; Yousufuddin, Muhammed; Thakur, Krishna G; Cundari, Thomas R; Dias, H V Rasika

2013-11-21

309

Protein phosphatase CaPpz1 is involved in cation homeostasis, cell wall integrity and virulence of Candida albicans.  

PubMed

The opportunistic pathogen Candida albicans has a single protein phosphatase Z (PPZ) candidate gene termed CaPPZ1, which shows significant allele variability. We demonstrate here that bacterially expressed CaPpz1 protein exhibits phosphatase activity which can be inhibited by recombinant Hal3, a known inhibitor of Saccharomyces cerevisiae Ppz1. Site-directed mutagenesis experiments based on natural polymorphisms allowed the identification of three amino acid residues that affect enzyme activity or stability. The expression of CaPPZ1 in ppz1 S. cerevisiae and pzh1 Schizosaccharomyces pombe cells partially rescued the salt and caffeine phenotypes of the deletion mutants. CaPpz1 also complemented the slt2 S. cerevisiae mutant, which is crippled in the mitogen-activated protein (MAP) kinase that mediates the cell wall integrity signalling pathway. Collectively, our results suggest that the orthologous PPZ enzymes have similar but not identical functions in different fungi. The deletion of the CaPPZ1 gene in C. albicans resulted in a mutant that was sensitive to salts such as LiCl and KCl, to caffeine, and to agents that affect cell wall biogenesis such as Calcofluor White and Congo red, but was tolerant to spermine and hygromycin B. Reintegration of the CaPPZ1 gene into the deletion mutant alleviated all of the mutant phenotypes tested. Thus CaPpz1 is involved in cation homeostasis, cell wall integrity and the regulation of the membrane potential of C. albicans. In addition, the germ tube growth rate, and virulence in the BALB/c mouse model, were reduced in the null mutant, suggesting a novel function for CaPpz1 in the yeast to hypha transition that may have medical relevance. PMID:22343349

Adám, Csaba; Erdei, Eva; Casado, Carlos; Kovács, László; González, Asier; Majoros, László; Petrényi, Katalin; Bagossi, Péter; Farkas, Ilona; Molnar, Monika; Pócsi, István; Ariño, Joaquín; Dombrádi, Viktor

2012-05-01

310

How should doctors approach patients? A Confucian reflection on personhood  

PubMed Central

The modern doctor-patient relationship displays a patient-centred, mutual-participation characteristic rather than the former active-passive or guidance-cooperation models in terms of medical decision making. Respecting the wishes of patients, amounting to more than mere concern for their welfare, has become the feature central to certain modern bioethics theories. A group of ethical principles such as respect for autonomy, beneficence, non-maleficence, and justice has been proposed by bioethicists and widely adopted by many medical societies as an ethical guide to how doctors, in their daily practice, should treat their patients. However, seeing patients as persons who are rational, self-conscious beings capable of valuing their own lives, and who are consequently entitled to the liberty and rights to choose for themselves, is in general the backbone of Western bioethical principles. Since Confucian philosophy has long been a representative of the East-Asia cultural tradition and Confucian bioethics has recently been developed as a theory of applied ethics, examining Confucius's idea of "persons" may shed some light on the current bioethical debates. Confucius's concept of persons, which is best interpreted via his theories of "chun-tze", (the morally ideal person) encapsulating a two-dimensional approach, (the "autonomous person" and the "relational person"), provides a more comprehensive model regarding what a person is and how he/she should be treated. This two-dimensional approach sees a person not only as a rational, autonomous agent but also as a relational, altruistic identity whose self actualisation involves incessant participating in and promoting of the welfare of his fellow persons. Hence this may balance the current bioethical trend whereby "respect for autonomy" often triumphs. Key Words: Personhood • autonomy • Confucian ethics • physician-patient relationship • principle-oriented bioethics

Tsai, D. F.

2001-01-01

311

Mass estimation of loose parts in nuclear power plant based on multiple regression  

NASA Astrophysics Data System (ADS)

According to the application of the Hilbert-Huang transform to the non-stationary signal and the relation between the mass of loose parts in nuclear power plant and corresponding frequency content, a new method for loose part mass estimation based on the marginal Hilbert-Huang spectrum (MHS) and multiple regression is proposed in this paper. The frequency spectrum of a loose part in a nuclear power plant can be expressed by the MHS. The multiple regression model that is constructed by the MHS feature of the impact signals for mass estimation is used to predict the unknown masses of a loose part. A simulated experiment verified that the method is feasible and the errors of the results are acceptable.

He, Yuanfeng; Cao, Yanlong; Yang, Jiangxin; Gan, Chunbiao

2012-05-01

312

Identification of the flavonoids in mungbean (Phaseolus radiatus L.) soup and their antioxidant activities.  

PubMed

Mung bean soup (MBS) has been traditionally taken as a kind of health food in China. To learn the mechanisms underlying its health benefits, antioxidant capacities of the soup prepared with three cultivars of mung bean were measured. The highest DPPH radical scavenging or ferric reducing activity was observed in soup of mung bean cv. Huang. The MBS of cv. Huang and Mao exhibited higher ABTS(+) reducing activities than MBS of cv. Ming. The two major flavonoids in the MBS were purified and identified as vitexin and isovitexin, respectively. Modeling samples containing vitexin and isovitexin at the same levels as them in the MBS were prepared to assess their antioxidant contributions in the MBS. Our results showed that antioxidant capacities of the MBS mainly derived from vitexin and isovitexin, these flavonoids accounted for the most of total DPPH radicals scavenging, ferric reducing and ABTS(+) reducing scavenging activities in MBS of all the three cultivars. PMID:22980894

Li, He; Cao, Dongdong; Yi, Jianyong; Cao, Jiankang; Jiang, Weibo

2012-12-15

313

An exact frequency equation in closed form for Timoshenko beam clampled at both ends  

NASA Astrophysics Data System (ADS)

The author has discovered several errors which are not typographical in the frequency equations for a Timoshenko beam clamped at both ends by Huang who presented the frequency equations and normal mode equations for all six common types of simple, finite beams in closed form for the first time. The exact frequency equations in closed form for Timoshenko beams clamped at both ends are derived based on his analysis. And then in order to justify the amended solutions of Huang, two versions of the closed form exact method and the Ritz method are applied. The frequency equations by the previous researcher present frequencies for only the flexural modes, while the closed form exact method and the Ritz method give ones for the thickness–shear modes as well as the bending modes. The purpose of the present study is to reveal the errors, correct them, and give some numerical results.

Kang, Jae-Hoon

2014-07-01

314

Resonant Double Photoionization of Li Studied with High Energy Resolution  

NASA Astrophysics Data System (ADS)

Employing monochromatized synchrotron radiation of the new VLS-PGM beamline at the Synchrotron Radiation Center (SRC), we have measured with high energy resolution the relative photoionization cross-sections for the formation of Li^+ and Li^2+ ions between 148 and 161 eV photon energy. This energy region is characterized by double and triple excitations that lead to strong enhancements in the cross sections, particularly in the Li^2+ cross section. In an earlier study performed by Huang et al. only a moderate energy resolution was used. Our high-resolution data exhibit a dramatic resonance structure in the double-to-single ionization ratio not seen before. M.-T. Huang, R. Wehlitz, Y. Azuma, L. Pibida, I.A. Sellin, J.W. Cooper, M. Koide, H. Ishijima, and T. Nagata, Phys. Rev. A 59, 3397 (1999)

Wehlitz, R.; Jurani?, P. N.

2006-05-01

315

Spectral representation theory of graded composite materials  

NASA Astrophysics Data System (ADS)

In graded composite materials, the physical properties can vary continuously in space and it may give different physical phenomena when compared with homogeneous materials. The Bergman-Milton spectral representation is a rigorous mathematical formalism to express the effective dielectric constant of nongraded composite materials [1]. In this study, we consider a material (rather than microsture [2]) graded composites, and generalize the Bergman-Milton spectral representation to extract the spectral density function for the effective dielectric constant of this graded composite material in the frequency domain [3]. Analytic and numerical solution will be presented for graded films and graded spheres. [1] D. J. Bergman, Phys. Rev. B 14, 4304 (1976). [2] J. P. Huang, K. W. Yu, G. Q. Gu, M. Karttunen, Phys. Rev. E 67, 051405 (2003). [3] L. Gao, J. P. Huang, K.W. Yu, Eur. Phys. J. B 36, 475 (2003).

Chan, K. L.; Kwok, C. M.; Yu, K. W.

2008-03-01

316

Two RFID-based solutions to enhance inpatient medication safety.  

PubMed

Owing to the low cost and convenience of identifying an object without physical contact, Radio Frequency Identification (RFID) systems provide innovative, promising and efficient applications in many domains. An RFID grouping protocol is a protocol that allows an off-line verifier to collect and verify the evidence of two or more tags simultaneously present. Recently, Huang and Ku (J. Med. Syst, 2009) proposed an efficient grouping protocol to enhance medication safety for inpatients based on low-cost tags. However, the Huang-Ku scheme is not secure; an attacker can easily make up fake grouping records to cheat the verifier. This weakness would seriously endanger the safety of inpatient medication safety. This paper will show the weaknesses, and then propose two RFID-based solutions to enhance medication safety for two different scenarios. The proposed schemes are practical, secure and efficient for medication applications. PMID:20703553

Chien, Hung-Yu; Yang, Chia-Chuan; Wu, Tzong-Chen; Lee, Chin-Feng

2011-06-01

317

Analytic unit quadrature signals with nonlinear phase  

NASA Astrophysics Data System (ADS)

The notion of intrinsic mode functions (IMFs) in the algorithm of Hilbert-Huang transform (HHT) [N.E. Huang, Z. Shen, S.R. Long, M.C. Wu, H.H. Shih, Q. Zheng, N.-C. Yen, C.C. Tung, H.H. Liu, The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis, Proc. R. Soc. London A 454 (1998) 903-995] is essentially an engineering description in relation to mono-components of nonlinear and non-stationary signals. In this note we prove a version of Bedrosian’s theorem on the unit circle. We give a sufficient condition together with an example for nonlinear phases ?(t) that make the unit quadrature signals e to be analytic. We also establish a corresponding relationship between the periodic and non-periodic signals on the whole time range.

Qian, Tao; Chen, Qiuhui; Li, Luoqing

2005-04-01

318

Making metals transparency for white light by surface plasmons  

NASA Astrophysics Data System (ADS)

We demonstrate both experimentally and theoretically that metallic gratings consisting of narrow slits become transparent for extremely broad bandwidths under oblique incidence. This phenomenon can be explained by a concrete picture in which the incident wave drives free electrons on the conducting surfaces and part of the slit walls to form surface plasmons (SPs). The SPs then propagate on the slit walls but are abruptly discontinued by the bottom edges to form oscillating charges that emit the transmitted wave. This picture explicitly demonstrates the conversion between light and SPs and indicates clear guidelines for enhancing SP excitation and propagation. Making structured metals transparent may lead to a variety of applications. References: Xian-Rong Huang, Ru-Wen Peng, and Ren-Hao Fan, Phys. Rev. Lett. (2010)105, 243901; and Ren-Hao Fan, Ru-Wen Peng, Xian-Rong Huang, Jia Li, Qing Hu, and Mu Wang, manuscript prepared(2011).

Peng, Ru-Wen; Huang, Xian-Rong; Fan, Ren-Hao; Li, Jia; Hu, Qing; Wang, Mu

2012-02-01

319

Asymptotic behavior of solutions to Euler-Poisson equations for bipolar hydrodynamic model of semiconductors  

NASA Astrophysics Data System (ADS)

In this paper we study the Cauchy problem for 1-D Euler-Poisson system, which represents a physically relevant hydrodynamic model but also a challenging case for a bipolar semiconductor device by considering two different pressure functions and a non-flat doping profile. Different from the previous studies (Gasser et al., 2003 [7], Huang et al., 2011 [12], Huang et al., 2012 [13]) for the case with two identical pressure functions and zero doping profile, we realize that the asymptotic profiles of this more physical model are their corresponding stationary waves (steady-state solutions) rather than the diffusion waves. Furthermore, we prove that, when the flow is fully subsonic, by means of a technical energy method with some new development, the smooth solutions of the system are unique, exist globally and time-algebraically converge to the corresponding stationary solutions. The optimal algebraic convergence rates are obtained.

Donatelli, Donatella; Mei, Ming; Rubino, Bruno; Sampalmieri, Rosella

320

The comparison of two constructions of the refined analytic torsion on compact manifolds with boundary  

NASA Astrophysics Data System (ADS)

The refined analytic torsion on compact Riemannian manifolds with boundary has been discussed by B. Vertman (Vertman, 2009, 2008) and the authors (Huang and Lee, 2010, 2012) but these two constructions are completely different. Vertman used a double of de Rham complexes consisting of the minimal and maximal closed extensions of a flat connection and the authors used well-posed boundary conditions P, P for the odd signature operator. In this paper we compare these two constructions by using the BFK-gluing formula for zeta-determinants, the adiabatic method for stretching cylinder part near boundary and the result for comparison of eta invariants in Huang and Lee (2012) when the odd signature operator comes from a Hermitian flat connection.

Huang, Rung-Tzung; Lee, Yoonweon

2014-02-01

321

Nonlinear optical properties of semiconductor quantum dots  

Microsoft Academic Search

The crystallite radius R that is ascertained by X-ray techniques is noted to exert an influence on the shift of the lowest quantized state in quantum dots (QDs). On the basis of the Stokes shift of absorption and emission, and their half-widths, an upper limit is obtained for the Huang-Rhys factor S. Pump and probe beam measurements exhibit absorption structure

A. Uhrig; A. Woerner; C. Klingshirn; L. Banyai; S. Gaponenko; I. Lacis; N. Neuroth; B. Speit; K. Remitz

1992-01-01

322

Bearing Damage Detection of BLDC Motors Based on Current Envelope Analysis  

NASA Astrophysics Data System (ADS)

This paper proposes current envelope analysis (CEA) to analyze bearing fault signals in brushless direct current (BLDC) motors, and back propagation neural networks (BPNN) to automatically identify bearing faults. We made sample motors which contained different types of fault, recorded the current signals, and extracted the current features using CEA and Hilbert Huang transform (HHT) for BPNN fault identification. The results indicate that this approach can efficiently identify bearing faults in BLDC motors.

Lee, Chun-Yao; Hsieh, Yu-Hua

2012-12-01

323

The effects of being conscious: Looking for the right evidence.  

PubMed

Huang & Bargh's (H&B's) general picture might underestimate the role played by conscious self and overestimate the behavioral inconsistencies at the personal level. This follows from how they delimit the goals under consideration: Their theses that goals are not consciously selected and that the conscious self is involved just in post hoc rationalization should also be tested against concrete and long-term goals. PMID:24775136

Mazzone, Marco

2014-04-01

324

Ab initio study of beryllium-decorated fullerenes for hydrogen storage  

Microsoft Academic Search

We have found that a beryllium (Be) atom on nanostructured materials with H2 molecules generates a Kubas-like dihydrogen complex [Lee, Huang, Duan, and Ihm, Appl. Phys. Lett. 96, 143120 (2010)]. Here, we investigate the feasibility of Be-decorated fullerenes for hydrogen storage using ab initio calculations. We find that the aggregation of Be atoms on pristine fullerenes is energetically preferred, resulting

Hoonkyung Lee; Bing Huang; Wenhui Duan; Jisoon Ihm

2010-01-01

325

Inhibitory Effects of Curcumin on in Vitro Lipoxygenase and Cyclooxygenase Activities in Mouse Epidermis1  

Microsoft Academic Search

Topical application of curcumin, the yellow pigment in turmeric and curry, strongly inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)- induced ornithine decarboxylase activity, DNA synthesis, and tumor promotion in mouse skin (Huang et al., Cancer Res., 48: 5941-5946, 1988). Chlorogenic acid, caffeic acid, and ferulic acid (structurally related dietary compounds) were considerably less active. In the present study, topical application of curcumin markedly inhibited

Mou-Tuan Huang; Thomas Lysz; Thomas Ferrara; Tanveer F. Abidi; Jeffrey D. Laskin; Allan H. Conney

326

A time-frequency method for ultrasonic flaw inspection based on HHT  

Microsoft Academic Search

A time-frequency analysis method based on Hilbert-Huang transform (HHT) was employed to character ultrasonic flaw echo signals. In this method, time and frequency characteristics of ultrasonic transducers used in inspection were considered to eliminate noises and identify the flaws. First, the flaw echo signals were decomposed into a series of mono-components called intrinsic mode functions (IMF) using the theories of

Tao Kong; Chunguang Xu; Shiyuan Zhou

2010-01-01

327

PredictorCorrector Smoothing Newton Method for Solving the Second-Order Cone Complementarity  

Microsoft Academic Search

In this paper we study predictor-corrector smoothing Newton method which were designed by Z. H. Huang, J. Han, and Z. Chen for nonlinear complementarity problem, we extends the Algorithm to second-order cone complementarity (SOCCP). Based on the Chen and Mangasarian smoothing function, we present a predictor-corrector smoothing Newton algorithm for solving the SOCCP. The neighbourhood of the path does not

Huali Zhao; Hongwei Liu

2010-01-01

328

Diverse dinosaur, pterosaur, and bird-track assemblages from the Hakou Formation, Lower Cretaceous of Gansu Province, northwest China  

Microsoft Academic Search

Diverse and well-preserved assemblages of dinosaur (theropod, sauropod and ornithopod), pterosaur, and bird tracks from the Hekou Formation (Lower Cretaceous) in the Yellow River (Huang He) valley represent the first significant fossil footprint discoveries in Gansu Province, China. However, the sites are large, visually spectacular, and well-exposed thanks to labor-intensive hand excavation. The sites have the potential for development as

Jianping Zhang; Daqing Li; Minglu Li; Martin G. Lockley; Z. Bai

2006-01-01

329

Regularity results on the parabolic Monge-Ampère equation with VMO type data  

NASA Astrophysics Data System (ADS)

This paper establishes interior estimates for Lp-norms, Orlicz norms of solutions to the parabolic Monge-Ampère equation -utdet D2u=f(x,t) provided that f(x,t) is positive, bounded, and satisfies a VMO-type condition, and some integrability conditions for ft. Our results improve the corresponding results in Gutiérrez and Huang (2001) [8] in some sense.

Tang, Lin

330

4th Annual Early Detection Research Network (EDRN) Scientific Workshop, Philadelphia, PA  

Cancer.gov

Speakers, Moderators, and Chairs Stephen Baylin Johns Hopkins University Tim Bestor Columbia University W. Debinsky Univ. of Pennsylvania Andy Feinberg Johns Hopkins University James Herman Johns Hopkins University Tim Huang Ellis Fischel Cancer Center Jean-Pierre Issa M.D. Anderson Cancer Center Peter Jones Univ. of Southern California (Workshop Chair) Peter Laird Univ. of Southern California David Sidransky Johns Hopkins University Dominic Smiraglia Ohio State University Benjamin Tycko Columbia University Fyodor Urnov Sangamo Biosciences Keith Wilson Univ.

331

The Application of English and American Literature Input in Reading Class Teaching of English Major  

Microsoft Academic Search

\\u000a Taking extensive reading textbooks of English major, Extensive Reading (Higher Education Press, the edition of 2006, total\\u000a editor: Huang Yuanshen), as an example. This article analyzed the significance of English and American literature input in\\u000a reading class teaching of English major. English and American literature input were carried in such ways, preview before class,\\u000a input in class, extensional reading after

Honglan Lü; Bingwei Wang; Xinyu Wang; Yan Su

332

Differential thermal analysis of the reaction properties of raw and retorted oil shale with air  

SciTech Connect

The results of a study to determine the kinetics of combustion of oil shale and its char by using differential thermal analysis are reported. The study indicates that Colorado oil shale and its char combustion rate is the fastest while Fushun oil shale and its char combustion rate is the slowest among the six oil shales used in this work. Oil shale samples used were Fushun oil shale, Maoming oil shale, Huang county oil shale, and Colorado oil shale.

Wang, T.F.

1984-01-01

333

Audio watermarking robust against time-scale modification and MP3 compression  

Microsoft Academic Search

In continuation to earlier work where the problem of time-scale modification (TSM) has been studied [S. Xiang, J. Huang, R. Yang, Time-scale invariant audio watermarking based on the statistical features in time domain, in: Proceedings of the 8th Information Hiding Workshop (IH 2006), Lecture Notes in Computer Science, vol. 4437, Springer, Berlin, pp. 93–108] by modifying the shape of histogram

Shijun Xiang; Hyoung-joong Kim; Jiwu Huang

2008-01-01

334

A note on \\  

Microsoft Academic Search

A flipping structure for the discrete wavelet transform (DWT) was proposed by Huang et al., which aimed at shortening the critical path of the lifting-based one-dimensional (1-D) architecture and reducing the number of pipeline register used in 1-D architecture as well as the size of temporal buffer (TB) required in the line-based two-dimensional (2-D) architecture. In this paper, we explore

Cheng-Yi Xiong; Jin-Wen Tian; Jian Liu

2006-01-01

335

Further investigation on the dynamic compressive strength enhancement of concrete-like materials based on split Hopkinson pressure bar tests. Part II: Numerical simulations  

Microsoft Academic Search

Split Hopkinson pressure bar (SHPB) tests have been used widely to measure the dynamic compressive strength of concrete-like materials at high strain-rates between 101 and 103s?1. It has been shown in companion paper (Zhang M, Wu HJ, Li QM, Huang FL. Further investigation on the dynamic compressive strength enhancement of concrete-like materials based on split Hopkinson pressure bar tests Part

Q. M. Li; Y. B. Lu; H. Meng

2009-01-01

336

Model-based analysis of concept maps  

Microsoft Academic Search

A concept map is a data collection tool developed in psychology and education to obtain\\u000ainformation about mental representations of concept associations. This methodology has\\u000arecently been introduced to marketing to study consumers' brand perceptions (John et al.\\u000a(2006); Joiner (1998)) and attitudes towards health risk (e.g., Huang (1997)). In\\u000aconjunction with other more established methods (e.g., Multidimensional scaling), concept

Sam K. Hui; Yanliu Huang; Edward I. George

2008-01-01

337

Limb Deficiency and Prosthetic Management. 1. Decision Making in Prosthetic Prescription and Management  

Microsoft Academic Search

Nelson VS, Flood KM, Bryant PR, Huang ME, Pasquina PF, Roberts TL. Limb deficiency and prosthetic management. 1. Decision making in prosthetic prescription and management.This self-directed learning module highlights decision making in prosthetic management in pediatric and adult patients. This chapter reviews classification of congenital limb deficiency and management of congenital pediatric upper-extremity amputees. Differences in management of amputees of

Virginia S. Nelson; Katherine M. Flood; Phillip R. Bryant; Mark E. Huang; Paul F. Pasquina; Toni L. Roberts

2006-01-01

338

Ovarian cancer in pregnancy: a clinicopathologic analysis of 22 cases and review of the literature  

Microsoft Academic Search

Zhao XY, Huang HF, Lian LJ, Lang JH. Ovarian cancer in pregnancy: a clinicopathologic analysis of 22 cases and review of the literature. Int J Gynecol Cancer 2006;16:8-15. The aim of this study was to summarize our experience of ovarian cancer diagnosed during pregnancy, to review the literature concerned, and to discuss the rationale for therapy. Twenty-two patients of ovarian

X. Y. ZHAO; H. F. HUANG; L. J. LIAN; J. H. LANG

2006-01-01

339

Self-interstitial atoms, vacancies and their agglomerates in electron-irradiated nickel investigated by diffuse scattering of X-rays  

Microsoft Academic Search

Frenkel defects of concentrations varying between 200 and 600 PPM were produced in single crystals of Ni by irradiation with 3 MeV electrons at 4.5K. These radiation-induced defects and their reactions during thermal annealing were investigated by measuring the Huang diffuse scattering of X-rays, the change of the lattice parameter and the electrical resistivity. At 6K the authors observed statistically

O. Bender; P. Ehrhart

1983-01-01

340

Diffuse X-ray scattering studies of defect reactions in electron-irradiated dilute nickel alloys. II. Ni-Ge  

Microsoft Academic Search

For pt.I see ibid., vol.14, p.1347 (1984). Defect properties in dilute Ni-Ge alloys are investigated by Huang diffuse scattering and the results for this alloy (oversized impurity) are compared with those for Ni-Si (undersized impurity). Ni alloys containing 1 at.% and 0.05 at.% Ge were irradiated with electrons at 4.2K and were subsequently isochronally annealed. It was found that, prior

P. Ehrhart; R. S. Averback

1984-01-01

341

Diffuse X-ray scattering studies of defect reactions in electron-irradiated dilute nickel alloys. I. NiSi  

Microsoft Academic Search

Huang diffuse scattering was employed to study defect properties in dilute Ni-Si alloys. Ni alloys containing 1 at.% and 0.05 at.% Si were irradiated with electrons at 4.2K and were subsequently isochronally annealed. It was found that, prior to annealing, the Frenkel-pair resistivities and self-interstitial atom configurations were the same in the alloys as in pure Ni. The independence of

R. S. Averback; P. Ehrhart

1984-01-01

342

Topological insulators on a Mobius Strip  

NASA Astrophysics Data System (ADS)

We study the two dimensional Chern insulator and spin Hall insulator on a non-orientable Riemann surface, the Mobius strip, where the usual bandstructure topological invariant is not defined. We show that while the flow pattern of edge currents can detect the twist of the Mobius strip in the case of Chern insulator, it can not do so in spin Hall insulator [1]. [4pt] [1] Lang-Tao Huang and Dung-Hai Lee, Phys. Rev. B 84, 193106 (2011)

Huang, Lang-Tao; Lee, Dung-Hai

2012-02-01

343

Iterative approximation of a unique solution of a system of variational-like inclusions in real q -uniformly smooth Banach spaces  

Microsoft Academic Search

In this paper, we give the notion of P-?-proximal-point mapping, an extension of ?-m-accretive mapping [C.E. Chidume, K.R. Kazmi, H. Zegeye, Iterative approximation of a solution of a general variational-like inclusion in Banach spaces, Int. J. Math. Math. Sci. 22 (2004) 1159–1168] and P-proximal-point mappings [Y.-P. Fang, N.-J. Huang, H-accretive operators and resolvent operator technique for solving variational inclusions in

K. R. Kazmi; F. A. Khan

2007-01-01

344

Iterative approximation of a solution of multi-valued variational-like inclusion in Banach spaces: A P-[eta]-proximal-point mapping approach  

Microsoft Academic Search

In this paper, we introduce a class of P-[eta]-accretive mappings, an extension of [eta]-m-accretive mappings [C.E. Chidume, K.R. Kazmi, H. Zegeye, Iterative approximation of a solution of a general variational-like inclusion in Banach spaces, Int. J. Math. Math. Sci. 22 (2004) 1159-1168] and P-accretive mappings [Y.-P. Fang, N.-J. Huang, H-accretive operators and resolvent operator technique for solving variational inclusions in

K. R. Kazmi; F. A. Khan

2007-01-01

345

Iterative approximation of a solution of multi-valued variational-like inclusion in Banach spaces: A P- ?-proximal-point mapping approach  

Microsoft Academic Search

In this paper, we introduce a class of P-?-accretive mappings, an extension of ?-m-accretive mappings [C.E. Chidume, K.R. Kazmi, H. Zegeye, Iterative approximation of a solution of a general variational-like inclusion in Banach spaces, Int. J. Math. Math. Sci. 22 (2004) 1159–1168] and P-accretive mappings [Y.-P. Fang, N.-J. Huang, H-accretive operators and resolvent operator technique for solving variational inclusions in

K. R. Kazmi; F. A. Khan

2007-01-01

346

Micro and nanofluidic structures for cell sorting and genomic analysis  

Microsoft Academic Search

Microfluidic systems promise rapid analysis of small samples in a compact and inexpensive format. But direct scaling of lab bench protocols on-chip is challenging because laminar flows in typical microfluidic devices are characterized by non-mixing streamlines. Common microfluidic mixers and sorters work by diffusion, limiting application to objects that diffuse slowly such as cells and DNA. Recently Huang et.al. developed

Keith J. Morton

2008-01-01

347

Climate, traffic-related air pollutants and allergic rhinitis prevalence in middle-school children in Taiwan  

Microsoft Academic Search

Climate, traffic-related air pollutants and allergic rhinitis prevalence in middle-school children in Taiwan. Y-L. Lee, C-K. Shaw, H-J. Su, J-S. Lai, Y-C. Ko, S-L. Huang, F-C. Sung, Y.L. Guo. #ERS Journals Ltd 2003. ABSTRACT: The prevalence of allergic rhinitis, a common respiratory disorder, may be rapidly increasing. Epidemiological studies, however, indicate little about its association with climatic factors and air

Y. L. Lee; H. J. Su; J. S. Lai; S. L. Huang; Y. L. Guo

2003-01-01

348

COMMITTEES: SQM2006 Organising and International Advisory Committees  

NASA Astrophysics Data System (ADS)

Organising Committee Kenneth Barish Huan Zhong Huang Joseph Kapusta Grazyna Odyniec Johann Rafelski Charles A Whitten Jr International Advisory Committee Jörg Aichelin Federico Antinori Tamas Biró Jean Cleymans Lazlo Csernai Tim Hallman Ulrich Heinz Sonja Kabana Rob Lacey Yu-Gang Ma Jes Madsen Yasuo Miake Berndt Mueller Grazyna Odyniec Helmut Oeschler Apostolos Panagiotou Johann Rafelski Hans Ritter Karel Safarik Jack Sandweiss Jürgen Schaffner-Bielich Wen-Qing Shen Georges Stephans Horst Stöcker Thomas Ullrich Bill Zajc

2006-12-01

349

STRUCTURAL BIOLOGY: Breaching the Barrier  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. There are a huge number of membrane transporter proteins that transport molecules across the impermeable barrier presented by cellular membranes. In their Perspective, Locher et al. discuss a double tour de force (Abramson et al., Huang et al.), which provide structural determinations of two bacterial transporters, LacY and GlpT, and insights into how they work.

Kaspar P. Locher (Eidgenössische Technische Hochschule Zürich;Institut für Molekularbiologie und Biophysik); Randal B. Bass (California Institute of Technology;Division of Chemistry and Chemical Engineering); Douglas C. Rees (California Institute of Technology;Division of Chemistry and Chemical Engineering)

2003-08-01

350

Room temperature ferromagnetism in Cu-doped ZnO synthesized from CuO and ZnO nanoparticles  

Microsoft Academic Search

AC susceptibility and ferromagnetic resonance (FMR) measurements indicate that ZnO doped with Cu by a simple sintering process starting from nanoparticles of ZnO and CuO is ferromagnetic above room temperature. FMR measurements above room temperature indicate the ordering temperature to be above 520K. The observation supports the recent theoretical calculations of Huang et al. which predict ferromagnetism in copper-doped ZnO.

Frank J. Owens

2009-01-01

351

Room temperature ferromagnetism in Cu-doped ZnO synthesized from CuO and ZnO nanoparticles  

Microsoft Academic Search

AC susceptibility and ferromagnetic resonance (FMR) measurements indicate that ZnO doped with Cu by a simple sintering process starting from nanoparticles of ZnO and CuO is ferromagnetic above room temperature. FMR measurements above room temperature indicate the ordering temperature to be above 520 K. The observation supports the recent theoretical calculations of Huang et al. which predict ferromagnetism in copper-doped

Frank J. Owens

2009-01-01

352

Massively representational minds are not always driven by goals, conscious or otherwise.  

PubMed

The language of conscious and unconscious goals is rooted in a folk-taxonomy that is likely to inhibit progress in cognitive science. Severing the commitment to this taxonomy would allow Huang & Bargh (H&B) to consider a wider variety of representational forms with motivational force and to entertain the intriguing possibility that variations in the number of active-but-redundant representations account for variance in social behavior. PMID:24775132

Huebner, Bryce; Rupert, Robert D

2014-04-01

353

Neuroprotective Potential of Fasudil Mesylate in Brain Ischemia-Reperfusion Injury of Rats  

Microsoft Academic Search

We previously reported that inhibition of Rho-kinase (ROCK) by hydroxyl fasudil improves cognitive deficit and neuronal damage\\u000a in rats with chronic cerebral ischemia (Huang et al., Cell Mol Neurobiol 28:757–768, 2008). In this study, fasudil mesylate\\u000a (FM) was investigated for its neuroprotective potential in rats with ischemia following middle cerebral artery occlusion (MCAO)\\u000a and reperfusion. The effect of fasudil mesylate

Qin Li; Xian-Ju Huang; Wei He; Jie Ding; Jun-Ting Jia; Gang Fu; Hong-Xing Wang; Lian-Jun Guo

2009-01-01

354

Orengedokuto and berberine improve indomethacin-induced small intestinal injury via adenosine  

Microsoft Academic Search

Background  Recent endoscopic technology has revealed that small intestinal injury is a serious threat to patients receiving nonsteroidal\\u000a anti-inflammatory drugs (NSAIDs). We previously showed that Japanese herbal medicine, Orengedokuto (OGT; Huang-Lian-Jie-Du-Tang\\u000a in Chinese), protects mice from lethal indomethacin (IND)-induced enteropathy. To elucidate the mechanism of the protective\\u000a effect of OGT, we performed microarray analyses and high power statistical analyses of microarray

Yoko Watanabe-Fukuda; Masahiro Yamamoto; Naoko Miura; Masato Fukutake; Atsushi Ishige; Rui Yamaguchi; Masao Nagasaki; Ayumu Saito; Seiya Imoto; Satoru Miyano; Junzo Takeda; Kenji Watanabe

2009-01-01

355

A thermo-viscoelastic–viscoplastic–viscodamage constitutive model for asphaltic materials  

Microsoft Academic Search

A temperature-dependent viscodamage model is proposed and coupled to the temperature-dependent Schapery’s nonlinear viscoelasticity and the temperature-dependent Perzyna’s viscoplasticity constitutive model presented in Abu Al-Rub et al. (2009) and Huang et al. (in press) in order to model the nonlinear constitutive behavior of asphalt mixes. The thermo-viscodamage model is formulated to be a function of temperature, total effective strain, and

Masoud K. Darabi; Rashid K. Abu Al-Rub; Eyad A. Masad; Chien-Wei Huang; Dallas N. Little

2011-01-01

356

Thermodynamic Database for the NdO(1.5)-YO(1.5) -YbO(1.5)-ScO(1.5)-ZrO2 System.  

National Technical Information Service (NTIS)

A database for YO(1.5)-NdO(1.5) -YbO(1.5)-ScO(1.5)-ZrO2 for ThermoCalc (ThermoCalc AB, Stockholm, Sweden) has been developed. The basis of this work is the YO(1.5)-ZrO2 assessment by Y. Du, Z. Jin, and P. Huang, 'Thermodynamic Assessment of the ZrO2-YO(1....

E. H. Copland L. Kaufman N. S. Jacobson

2001-01-01

357

Reply to ``Comment on `Lattice Boltzmann method for simulations of liquid-vapor thermal flows' ''  

NASA Astrophysics Data System (ADS)

In this reply to the Comment by Huang and Krafczyk [Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.84.038701 84, 038701 (2011)], we clarify that a correct set of parameter values was used in our original work, and that the simulation was performed in a proper water-vapor two phase flow regime [R. Zhang and H. Chen, Phys. Rev. EPLEEE81063-651X10.1103/PhysRevE.67.066711 67, 066711 (2003)].

Zhang, Raoyang; Chen, Hudong

2011-09-01

358

Historical Perspective On the Study of Epsilon Aurigae  

NASA Astrophysics Data System (ADS)

Epsilon Aurigae has been known since 1821 as an eclipsing binary with a 27 year period, but has defied interpretation for nearly 2 centuries. The high luminosity F star is eclipsed by an invisible companion, now recognized as a debris-like disk. I will briefly review prior ideas proposed by Struve, Eggleton and Huang and others, to set the stage for the remarkable revelations made possible during the current 2009-2011 eclipse.

Guinan, Edward F.

2011-01-01

359

Resolved structure in the quenching band of the EL2 center in GaAs, studied by infrared spectroscopy  

Microsoft Academic Search

Infrared measurements at low temperature on undoped semi-insulating GaAs reveal additional details in the photoresponse of the EL2 center. In the continuous spectral recording of the optical cross section for the bleaching of the EL2 absorption the zero phonon line (ZPL) at 1.039 eV and six phonon replicas with 11 meV separation have been observed. A modified Huang Rhys calculation

F. Fuchs; B. Dischler

1987-01-01

360

Using the self-synchronizing method to improve security of the multi chaotic systems-based image encryption  

NASA Astrophysics Data System (ADS)

In this paper, we analyze the problems of vulnerability in the original multi chaotic systems-based image encryption scheme proposed by Huang and Nien [Optics Communications 282 (2009) 2123-2127]. A self-synchronizing method is proposed as enhancement measures to solve the problems and defeat cryptanalysis. Theoretical analysis and computer simulation indicate that the proposed encryption scheme is much more secure than the original one. At the same time, it holds the merits of the original scheme.

Xiao, Di; Shih, Frank Y.

2010-08-01

361

PLCO Publications - 2009  

Cancer.gov

Ahn, J., Albanes, D., Berndt, S.I., Peters, U., Chatterjee, N., Freedman, N.D., Abnet, C.C., Huang, W.-Y., Kibel, A.S., Crawford, E.D., Weinstein, S.J., Chanock, S.J., Schatzkin, A. and Hayes, R.B. for the Prostate, Lung, Colorectal and Ovarian Trial Project Team. (2009) Vitamin D-related genes, serum vitamin D concentrations, and prostate cancer risk. Carcinogenesis 2009 May. (Epub ahead of print).

362

Quasi-static and dynamic loading responses and constitutive modeling of titanium alloys  

Microsoft Academic Search

The results from a systematic study of the response of a Ti–6Al–4V alloy under quasi-static and dynamic loading, at different strain rates and temperatures, are presented. The correlations and predictions using modified Khan–Huang–Liang (KHL) viscoplastic constitutive model are compared with those from Johnson–Cook (JC) model and experimental observations for this strain rate and temperature-dependent material. Overall, KHL model correlations and

Akhtar S. Khan; Yeong Sung Suh; Rehan Kazmi

2004-01-01

363

A comparative evaluation of modern English corpus grammatical annotation schemes  

Microsoft Academic Search

Many English Corpus Linguistics projects reported in ICAME Journal and else-where involve grammatical analysis or tagging of English texts (eg Atwell 1983, Leech et al 1983, Booth 1985, Owen 1987, Souter 1989a, O'Donoghue 1991, Belmore 1991, Kyt? and Voutilainen 1995, Aarts 1996, Qiao and Huang 1998). Each new project has to review existing tagging schemes, and decide which to adopt

Eric Atwell; George Demetriou; John Hughes; Amanda Schiffrin; Clive Souter; Sean Wilcock

364

Unconscious goals: specific or unspecific? The potential harm of the goal/gene analogy.  

PubMed

Huang & Bargh's (H&B's) definition of goals is ambiguous between "specific goals" - the end-state of a token action I am about to perform - and "unspecific goals" - the end-state of an action-type (without specifying how this would be achieved). The analogy with selfish genes pushes the authors towards the former interpretation, but the latter would provide a more robust theoretical framework. PMID:24775140

Nanay, Bence

2014-04-01

365

Technology Transfer/Commercialization Report 2002  

NASA Technical Reports Server (NTRS)

Contents include the following: 1. Technology opportunities and successes in 2002: Hilbert-Huang transform. New sensors via sol-gel-filled fiber optics. Hierarchical segmentation software. 2. Activity in 2002: encouraging researcher involvment. 10th annual new technology reporting award program. Commercial technology development program. 3. Inventorying new technologies: Sensors and detectors. Environmental systems. Information systems. Guidance, navigation, and control. Thermal and cryogenics. Optics. Patenting Goddard technologies. Striking gold with NASA technology transfer.

2002-01-01

366

PLCO Publications - 2006  

Cancer.gov

Chang, S.-C., Ziegler, R.G., Dunn, B., Stolzenberg-Solomon, R., Lacey Jr, J.V., Huang, W.-Y., Schatzkin, A., Reding, D., Hoover, R.N., Hartge, P. and Leitzmann, F.F. (2006) Association of energy intake and energy balance with postmenopausal breast cancer in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Cancer Epidemiol Biomarkers Prev 2006 Feb.

367

Resonance Raman overtone intensities and electron-phonon coupling strengths in semiconductor nanocrystals.  

PubMed

For linear electron-phonon coupling, the Huang-Rhys factor, S, gives the intensity ratio of the one-quantum vibronic transition (0 ? 1) to the purely electronic origin transition (0 ? 0) in a vibrationally resolved, zero-temperature absorption or emission spectrum. It is often assumed that the overtone to fundamental integrated intensity ratio in resonance Raman scattering of semiconductor nanocrystals is equal to or proportional to S, or that S may be determined from the overtone intensity in some other straightforward manner. In fact, this is not generally possible because of different excitation profiles for overtones and fundamentals, differential sensitivity of overtones and fundamentals to electronic dephasing, and interference effects from partially overlapping electronic transitions. Here we examine the relationship between the Huang-Rhys factor and the overtone to fundamental intensity ratio through spectroscopic simulations using parameters appropriate to II-VI semiconductor nanocrystals such as CdSe. A simple equation relating the overtone to fundamental Raman intensity ratio to the Huang-Rhys factor is obtained only in the case of a single resonant electronic state, excitation at the maximum of the inhomogeneously broadened absorption band, and a homogeneous line width small compared with the phonon frequency. PMID:23432140

Kelley, Anne Myers

2013-07-25

368

Quantum optics with superconducting qubits in the dispersive limit  

NASA Astrophysics Data System (ADS)

Several recent experiments have demonstrated that superconducting circuits are ideal systems for the study of quantum mechanical effects on large scale and promising candidates for quantum computation. It was recently proposed [1] and experimentally demonstrated [2,3] that superconducting circuits fabricated inside a high quality on-chip transmission line resonator can be used to study solid-state analogs of quantum optics experiments and, in particular, to reach the strong-coupling regime of cavity quantum electrodynamics (CQED). In this talk, this theoretical proposal will be reviewed and experimental results in the dispersive regime will be presented, for both the time and frequency domain. Results in the time domain show our ability to coherently control the state of the qubit, while detailed analysis of the frequency domain results yields insights into the measurement process and its backaction. [1] A. Blais, R.-S. Huang, A. Wallraff, S. M. Girvin and R. J. Schoelkopf, Phys. Rev. A 69, 062320 (2004). [2] A. Wallraff, D. Schuster, A. Blais, L. Frunzio, R.-S. Huang, J. Majer, S. Kumar, S. M. Girvin and R. J. Schoelkopf, Nature 431, 162 (2004). [3] D. Schuster, A. Wallraff, A. Blais, L. Frunzio, R.-S. Huang, J. Majer, S. M. Girvin and R. J. Schoelkopf, cond-mat/0408367.

Blais, Alexandre

2005-03-01

369

EPR of Barium Titanate to 36 kbar between 0 and - 40 degrees Celsius  

NASA Astrophysics Data System (ADS)

A few years ago we made EPR measurements of barium titanate in a specially designed pressure apparatus at temperatures below ambient. The description of the apparatus has been published(1) and the results of the experiment are reported in Huang's dissertation(2). These measurements were taken near the ferroelectric-paraelectric phase line in the ferroelectric phase. Recently I have been refining the analysis of the data to get the maximum amount of information available on the response of barium titanate to high pressures as one approaches the tricritical point. We have found that the EPR signal for the respective transitions of the 5/2 spin state of Fe, which is a very dilute impurity in the material, is not purely Lorentzian but can be very accurately represented by two slightly separated Lorentzian lines, as if there were two types of iron sites both with tetragonal or nearly tetragonal symmetry. We will discuss the method of analysis and show some interesting results of the measurement as a function of the relative distance from the phase transition line. 1. Ke Huang, D.L. Decker, H.M. Nelson, and J.D. Barnett, Rev. of Sci. Instr. 68, 3877 (1997). 2. Ke Huang, Dissertation, Brigham Young University, Provo, UT (1995).

Decker, D. L.

1998-04-01

370

New scaling for compressible wall turbulence  

NASA Astrophysics Data System (ADS)

Classical Mach-number (M) scaling in compressible wall turbulence was suggested by van Driest (Van Driest E R. Turbulent boundary layers in compressible fluids. J Aerodynamics Science, 1951, 18(3): 145-160) and Huang et al. (Huang P G, Coleman G N, Bradshaw P. Compressible turbulent channel flows: DNS results and modeling. J Fluid Mech, 1995, 305: 185-218). Using a concept of velocity-vorticity correlation structure (VVCS), defined by high correlation regions in a field of two-point cross-correlation coefficient between a velocity and a vorticity component, we have discovered a limiting VVCS as the closest streamwise vortex structure to the wall, which provides a concrete Morkovin scaling summarizing all compressibility effects. Specifically, when the height and mean velocity of the limiting VVCS are used as the units for the length scale and the velocity, all geometrical measures in the spanwise and normal directions, as well as the mean velocity and fluctuation (r.m.s) profiles become M-independent. The results are validated by direct numerical simulations (DNS) of compressible channel flows with M up to 3. Furthermore, a quantitative model is found for the M-scaling in terms of the wall density, which is also validated by the DNS data. These findings yield a geometrical interpretation of the semi-local transformation (Huang et al., 1995), and a conclusion that the location and the thermodynamic properties associated with the limiting VVCS determine the M-effects on supersonic wall-bounded flows.

Pei, Jie; Chen, Jun; Fazle, Hussain; She, ZhenSu

2013-09-01

371

HPLC and chemometrics for the quality consistency evaluation of shuanghuanglian injection.  

PubMed

A high-performance liquid chromatography method with diode array detection was developed for simultaneous analysis of organic acids (chlorogenic acid, caffeic acid, 4,5-dicaffeoylquinic acid) and flavonoids (baicalin, baicalein, wogonin) in Shuang-huang-lian injection, a traditional Chinese medicine being prescribed widely for anti-bacterial, anti-viral and immunostimulant activity. All calibration curves showed good linear correlation (r(2) > 0.9997) within the test ranges. Validation proved that the repeatability of the method was good and recovery was satisfactory. The validated method was successfully applied to 24 batches of Shuang-huang-lian injection. The result showed that there was a great variation among different samples. Principal component analysis further proved considerable variations among the samples from eight manufacturers, and suggested that chlorogenic acid and baicalin might have the greatest variations among the 24 batches. In conclusion, these results demonstrated that the method proposed was very useful for the analysis and quality consistency evaluation of Shuang-huang-lian injection. PMID:23868179

Luan, Lan; Wang, Gangli; Lin, Ruichao

2014-08-01

372

Electron-phonon coupling in CdSe nanocrystals from an atomistic phonon model.  

PubMed

Phonon frequencies and eigenvectors, electron-phonon couplings, and the associated resonance Raman spectra have been calculated for approximately spherical, wurtzite form CdSe nanocrystals having radii of 1.4 to 2.3 nm and containing 318 to 1498 atoms. Calculations of the equilibrium geometries and phonon modes are carried out using an empirical force field, and the electron and hole wave functions are calculated as particle-in-a-sphere envelope functions multiplying the Bloch functions, with valence-band mixing included for the hole functions. The coupling of each phonon mode to the 1S(e)-1S(3/2) and 1S(e)-2S(3/2) excitations is evaluated directly from the change in Coulombic energy along the phonon coordinate. Ten to 50 different modes in each crystal have significant Huang-Rhys factors, clustered around two frequency regions: acoustic phonons at 20-40 cm(-1) depending on crystal size, and optical phonons at 185-200 cm(-1). The Huang-Rhys factors are larger for the acoustic modes than for the optical modes and decrease with increasing crystal size, and the Huang-Rhys factors for each group of modes are smaller for the 1S(e)-2S(3/2) than for the 1S(e)-1S(3/2) excitation. These results are compared with measurements of electron-phonon coupling in CdSe nanocrystals using different experimental techniques. PMID:21598957

Kelley, Anne Myers

2011-06-28

373

Changes in carotenoid content and biosynthetic gene expression in juice sacs of four orange varieties (Citrus sinensis) differing in flesh fruit color.  

PubMed

The contribution of carotenoid composition to the color range of the fruit juice sacs of four orange varieties (Citrus sinensis) differing in flesh color, namely, Shamouti (normal orange color), Sanguinelli ("blood cultivar" purple color), Cara Cara navel (pink-reddish), and Huang pi Chen (yellowish color), was investigated. To this end, qualitative and quantitative analyses of carotenoid contents were first performed by high-performance liquid chromatography (HPLC) using a C30 column and a photodiode array detector in February, at a late developmental fruit stage. Concomitantly, transcript levels of Dxs, the gene controlling the first step of the MEP pathway, and six genes involved in beta,beta-xanthophyll biosynthesis (Psy, Pds, Zds, Lcy-b, Hy-b, and Zep) were determined in August, November, and February. Transcript level measurement was carried out by real-time RT-PCR on total RNA from juice sacs. The four orange varieties displayed different carotenoid profiles. Shamouti and Sanguinelli oranges accumulated mainly beta,beta-xanthophylls as expected in typically colored oranges, whereas Cara Cara navel orange accumulated linear carotenes in addition to cis-violaxanthin. Huang pi Chen fruit flesh orange was characterized by a strong reduction of total carotenoid content. Whereas gene expression was relatively low and similar in August (before color break) in all four varieties, in November (during color break), Dxs, Zds, Hy-b, and Zep expression was higher in Cara Cara and Huang pi Chen oranges. The beta,beta-xanthophyll accumulation observed in February in Shamouti and Sanguinelli oranges was apparently related to the increase of transcript levels of all measured genes (i.e., Dxs, Psy, Pds, Zds, Hy-b, and Zep) except Lcy-b. At this time, however, transcript levels in Cara Cara were rather similar to those found in Sanguinelli, although both showed different carotenoid compositions. The Huang pi Chen phenotype correlated with lower expression of Dxs and Psy genes. These results revealed a general pattern of transcript change in juice sacs of citrus fruit, characterized by an apparent coordination of Dxs and Psy expression and a general increase in mRNA levels of carotenoid biosynthetic genes. These transcript changes correlated well with the beta,beta-xanthophyll accumulation, the normal carotenoid set, observed in Shamouti and Sanguinelli oranges and suggest that the preferential accumulation of linear carotenes in Cara Cara navel and the practical absence of carotenoids in Huang pi Chen oranges were not predominantly due to changes in regulation of carotenoid biosynthetic genes at the transcriptional level. PMID:18433104

Fanciullino, Anne-Laure; Cer?os, Manuel; Dhique-Mayer; Froelicher, Yann; Talón, Manuel; Ollitrault, Patrick; Morillon, Raphaël

2008-05-28

374

Di-, tri- and tetranuclear molecular vanadium phosphonates: a chloride encapsulated tetranuclear bowl.  

PubMed

The reaction of vanadium(iii) trichloride with tert-butylphosphonic acid (t-BuPO3H2) in the presence of 1,10-phenanthroline/2,2'-bipyridine as an ancillary ligand in acetonitrile at room temperature afforded two dinuclear dicationic vanadium(iv) complexes [(VO)2(phen)2{t-BuPO2(OH)}2(OH2)2]·2Cl [] and [(VO)2(bipy)2{t-BuPO2(OH)}2(OH2)2]·2Cl []. On the other hand, when the reaction was carried out in methanol, the dinuclear vanadium(v) complex [(VO)2(bipy)2(?2-O)2(t-BuPO3)2]·2CH3OH·0.5CH2Cl2 [] was isolated. While and contain two six-membered V2P2O4 rings, contains a unique four-membered V2O2 ring. Replacement of tert-butylphosphonic acid by tritylphosphonic acid (Ph3CPO3H2) under the same reaction conditions in methanol leads to the formation of dicationic trinuclear vanadium(iv) complexes [(VO)3(phen)3(Ph3CPO3)2(OH2)3]·CHCl3·2(OH)·2MeOH·1.5H2O [] and [(VO)3(bipy)3(Ph3CPO3)2(CH3OH)3]·2(OH)·4CH3OH·5H2O []. In these complexes, the triangular V(iv) platform is held together by two bicapping tripodal phosphonate ligands. Replacement of the chelating 2,2'-bipyridine ligand with 3,5-dimethyl-1H-pyrazole, under the same reaction conditions, afforded a tetranuclear vanadium(v) complex [{(VO)4(Ph3CPO3Me)4(?-O)4}Cl]{3,5-Me2PzH2}·3C7H8·H2O·CH3OH []. Remarkably possesses a unique bowl-shaped structure encapsulating a chloride anion. PMID:24901892

Sahoo, Dipankar; Suriyanarayanan, Ramakirushnan; Chandrasekhar, Vadapalli

2014-06-24

375

Effect of PCBM concentration on photoluminescence properties of composite MEH-PPV/PCBM nanoparticles investigated by a Franck-Condon analysis of single-particle emission spectra.  

PubMed

The emission of composite conjugated polymer (MEH-PPV)/fullerene (PCBM) nanoparticles is investigated by single particle spectroscopy (SPS), and changes in vibronic structure with nanoparticle composition are evaluated by means of a detailed Franck-Condon analysis. Consistent with previous reports we find that the emission spectra can be modeled as the superposition of two types of emitters, one with aggregate character and one with molecular character. Major findings from the fitting of the SPS data to a Franck-Condon model are that 1) the occurrence of each of the two types of emitters changes with nanoparticle composition to the point that no aggregate emitters are detected (at 50 wt% PCBM), 2) at the highest PCBM doping levels (75 wt% PCBM) aggregate emitters reappear due to nanoscale phase separation in the composite nanoparticles, 3) the molecular emitters show small Huang-Rhys factors that increase with PCBM doping, indicative of extensive delocalization and exciton migration that is reduced by the disorder introduced in the polymer material by PCBM doping and 4) the aggregate emitters show large Huang-Rhys factors, indicative of the localized nature of these energy trap sites, with a broad distribution of values of these Huang-Rhys factors. The latter observation suggests a broad heterogeneous distribution of aggregate morphologies in blended conducting polymer materials, which can be attributed to variations in polymer chain folding and stacking at the aggregate sites. The reported results obtained by the SPS approach show how blending conjugated polymers with fullerenes at various doping levels induces changes in interchain interactions and aggregate site density even at length scales below a few tens of nanometers that affect conjugated polymer material properties, an observation that has gone unnoticed in bulk studies of blended conjugated polymer films. PMID:19787692

Tenery, Daeri; Gesquiere, Andre J

2009-10-01

376

Astrocyte-Neuron Interaction During One-trial Aversive Learning in the Neonate Chick * * These results were originally presented at the Second Annual International Behavioral Neuroscience Society Conference, Clearwater Beach, Florida, USA, 22–25 April 1993  

Microsoft Academic Search

HERTZ, L., M.E. GIBBS, B.S. O'DOWD, G.L. SEDMAN, S.R. ROBINSON, E. SYKOVÁ, I. HAJEK, E. HERTZ, L. PENG, R. HUANG AND K.T. NG. Astrocyte-neuron interaction during one-trial aversive learning in the neonate chick. NEUROSCI BIOBEHAV REV 20(3)537–551, 1996.—During two specific stages of the Gibbs-Ng model of one-trial aversive learning in the neonate chick, we have recently found unequivocal evidence for

LEIF HERTZ; MARIE E. GIBBS; BRONA S. O'DOWD; GARRY L. SEDMAN; STEPHEN R. ROBINSON; EVA SYKOVÁ; I IVAN HAJEK; ELNA HERITZ; PENG LIANG; HUANG RONG; T. NG KIM

1996-01-01

377

Herbal ephedra\\/caffeine for weight loss: a 6-month randomized safety and efficacy trial  

Microsoft Academic Search

Objective: To examine long-term safety and efficacy for weight loss of an herbal Ma Huang and Kola nut supplement (90\\/192 mg\\/day ephedrine alkaloids\\/caffeine).Design: Six-month randomized, double-blind placebo controlled trial.Subjects: A total of 167 subjects (body mass index (BMI) 31.8±4.1 kg\\/m2) randomized to placebo (n=84) or herbal treatment (n=83) at two outpatient weight control research units.Measurements: Primary outcome measurements were changes

CN Boozer; PA Daly; P Homel; JL Solomon; D Blanchard; JA Nasser; R Strauss; T Meredith

2002-01-01

378

Acoustical Applications of the HHT Method  

NASA Technical Reports Server (NTRS)

A document discusses applications of a method based on the Huang-Hilbert transform (HHT). The method was described, without the HHT name, in Analyzing Time Series Using EMD and Hilbert Spectra (GSC-13817), NASA Tech Briefs, Vol. 24, No. 10 (October 2000), page 63. To recapitulate: The method is especially suitable for analyzing time-series data that represent nonstationary and nonlinear physical phenomena. The method involves the empirical mode decomposition (EMD), in which a complicated signal is decomposed into a finite number of functions, called intrinsic mode functions (IMFs), that admit well-behaved Hilbert transforms. The HHT consists of the combination of EMD and Hilbert spectral analysis.

Huang, Norden E.

2003-01-01

379

HHT-based crack identification method for start-up rotor  

NASA Astrophysics Data System (ADS)

This paper presents a crack identification method for start-up rotor based on the Hilbert-Huang transform (HHT). With this method, the instantaneous frequency (IF) of each intrinsic mode function is obtained through the Hilbert transform, and the spectrum of IF is calculated accordingly. The influence of acceleration and crack depth on the rotor is analyzed through experiments. HHT is employed to detect the shallower crack, and is then tested during the start-up process of the rotor. The results of the experiment show that HHT is a better tool for crack detection than fast Fourier transform.

Li, Bing; Zhang, Chunlin; He, Zhengjia

2012-09-01

380

Zou Receives 2010 F. L. Scarf Award  

NASA Astrophysics Data System (ADS)

Shasha Zou has been awarded the F. L. Scarf Award, given annually to a recent Ph.D. recipient for outstanding dissertation research that contributes directly to solar planetary sciences. Zou's dissertation is entitled “Evolution of high latitude ionospheric convection associated with substorms: Multiple radar observations.” She is scheduled to present an invited talk in the Multipoint Perspective on the Auroral Acceleration Region and M-I Coupling session (SM10) during the 2010 AGU Fall Meeting, held 13-17 December in San Francisco, Calif. Huang will be formally presented with the award at the Space Physics and Aeronomy section dinner on 14 December 2010.

2010-11-01

381

Effect of quark gluon plasma on charm quark produced in relativistic heavy ion collision  

NASA Astrophysics Data System (ADS)

Charm quarks are produced mainly in the pre-equilibrium stage of heavy ion collision and serve as excellent probes entering the thermalized medium. They come out with altogether different momenta and energies and fragments into D-mesons and decay into non-photonic electrons which are observed experimentally. Here we present the effect of QGP on charm quark production using two different models: first one based on Wang-Huang-Sarcevic model of multiple scattering of partons and the second one is based on Parton Cascade Model with Boltzmann transport equation used for charm quark evolution in QGP.

Younus, Mohammed; Srivastava, Dinesh K.; Bass, Steffen A.

2014-05-01

382

HPLC DETERMINATION OF BERBERINE IN MEDICINAL HERBS AND A RELATED TRADITIONAL CHINESE MEDICINE  

Microsoft Academic Search

A HPLC method was developed for the determination and identification of the berberine content in Coptidis Radix, Phellodendri Cortex and a related commercially prepared traditional Chinese medicine, Huang-Lian-Jiee-Dwu-Tang. Berberine was separated by a phenyl-bound column with two kinds of mobile phases of acetonitrile : methanol : 20 mM phosphate (35 : 20 : 45, v\\/v\\/v) and acetonitrile : 20 mM phosphate (30 : 70, v\\/v) for single herb and herbal preparation, respectively. Both mobile

Pi-Lo Tsai; Tung-Hu Tsai

2002-01-01

383

Effect of an allophanic soil on humification reactions between catechol and glycine: Spectroscopic investigations of reaction products  

NASA Astrophysics Data System (ADS)

Adduction of amino acids to phenols is a possible humification reaction pathway [F.J. Stevenson, Humus Chemistry: Genesis, Composition, Reaction, second ed., Wiley, New York, 1994, pp. 188-211; M.C. Wang, P.M. Huang, Sci. Total Environ. 62 (1987) 435; M.C. Wang, P.M. Huang, Soil Sci. Soc. Am. J. 55 (1991) 1156; M.C. Wang, P.M. Huang, Geoderma 112 (2003) 31; M.C. Wang, P.M. Huang, Geoderma 124 (2005) 415]. To elucidate the reaction kinetics and products of abiotic humification, the effects of an allophanic soil on the adduction of amino acids to phenols were investigated using catechol (CT) and glycine (Gly) as a model phenol and amino acid, respectively. An aqueous solution containing CT and Gly (pH 7.0) in the presence of allophanic soil was incubated for 2 weeks, and the kinetics of the humification reactions were monitored by analysis of absorptivity at 600 nm ( E600). A mixture of CT and Gly in the absence of allophanic soil was used as a control. The E600 value increased markedly in the presence of allophanic soil. In addition, unreacted CT was detected in the control reaction mixture, but not in the allophane-containing reaction mixture. Under the sterilized conditions, absorbance at 600 nm for the control reaction mixture was significantly smaller than that for the allophanic soil-containing reaction mixture, which indicates there was no microbial participation during incubation. These results indicate that the allophanic soil effectively facilitated humification reactions between CT and Gly. The reaction mixtures were acidified and humic-like acid (HLA) was isolated as a precipitate. The elemental composition, acidic functional group contents, molecular weight, FT-IR, solid-state CP-MAS 13C NMR, and 1H NMR spectra of the purified HLAs were analyzed. The results of these analyses indicate that the nitrogen atom of Gly binds to the aromatic carbon of CT in the HLA products.

Fukushima, Masami; Miura, Akitaka; Sasaki, Masahide; Izumo, Kenji

2009-01-01

384

Outstanding Student Paper Awards  

NASA Astrophysics Data System (ADS)

The following members in the Space Physics & Aeronomy Section received Outstanding Student Paper Awards at the 2003 AGU Fall Meeting in San Francisco, California. Arve Aksnes; Aroh Barjatya; Jacob Bortnik; Amir Caspi; Ruben Delgado; Galen Fowler; Paul G. Hanlon; Sid Henderson; Tara B. Hiebert; Chia-Lin Huang; Steven P. Joy; Eun-Hwa Kim; Colby Lemon; Yingjuan Ma; Elizabeth A. MacDonald; Jaco Minnie; Mitsuo Oka; Yoshitaka Okazaki; Erin J. Rigler; Ina P. Robertson; Patrick A. Roddy; Sang-Il Roh; Albert Y. Shih; Christopher Smithtro; Emma Spanswick; Maria Spasojevic; Hiroki Tanaka; Linghua Wang; Deirdre E. Wendel; Jichun Zhang>

2003-01-01

385

Outstanding Student Paper Awards  

NASA Astrophysics Data System (ADS)

The following members in the Space Physics & Aeronomy Section received Outstanding Student Paper Awards at the 2003 AGU Fall Meeting in San Francisco, California. Arve Aksnes; Aroh Barjatya; Jacob Bortnik; Amir Caspi; Ruben Delgado; Galen Fowler; Paul G. Hanlon; Sid Henderson; Tara B. Hiebert; Chia-Lin Huang; Steven P. Joy; Eun-Hwa Kim; Colby Lemon; Yingjuan Ma; Elizabeth A. MacDonald; Jaco Minnie; Mitsuo Oka; Yoshitaka Okazaki; Erin J. Rigler; Ina P. Robertson; Patrick A. Roddy; Sang-Il Roh; Albert Y. Shih; Christopher Smithtro; Emma Spanswick; Maria Spasojevic; Hiroki Tanaka; Linghua Wang; Deirdre E. Wendel; Jichun Zhang>

2004-04-01

386

Proposal of Yaniellaceae fam. nov., Yaniella gen. nov. and Sinobaca gen. nov. as replacements for the illegitimate prokaryotic names Yaniaceae Li et al. 2005, Yania Li et al. 2004, emend Li et al. 2005, and Sinococcus Li et al. 2006, respectively.  

PubMed

The prokaryotic generic names Yania Li et al. 2004 and Sinococcus Li et al. 2006 are illegitimate because they are later homonyms of the names Yania Roewer 1919 (Opiliones, Arachnida, Arthropoda, Animalia), Yania Huang 1997 (Lepidoptera: Hesperiidae) and Sinococcus Wu and Zheng 2000 (Homoptera: Coccomorpha) [Principle 2 of the Bacteriological Code (1990 Revision)]. Therefore, new generic names, Yaniella gen. nov. and Sinobaca gen. nov., are proposed for these taxa. In addition, a new family name, Yaniellaceae fam. nov., is proposed to accommodate Yaniella gen. nov. As a result, new combinations are required for the species to replace the illegitimate species names. PMID:18218962

Li, Wen-Jun; Zhi, Xiao-Yang; Euzéby, Jean P

2008-02-01

387

Reconstruction from three orthographic views  

NASA Astrophysics Data System (ADS)

As Ullman (1979) showed, an object can be reconstructed uniquely from three orthographic views, if at least four homologous tripels of points are known. If only three homologous tripels of points are observed, the reconstruction problem has a finite number of solutions (cf. Huang and Lee (1989)). In this article the 3-point-problem is reduced to a quadratic problem: If the squares of the sides of the considered triangles are interpreted as coordinates in a three-dimensional parameter space, the reconstruction problem is equivalent to the determination of the intersection of three parallelly shifted cones subject to certain constraints.

Urban, Herbert

1996-05-01

388

COMMITTEES: SQM2004 Organising and International Advisory Committees  

NASA Astrophysics Data System (ADS)

Organising Committee Jean Cleymans (Chairman) Zeblon Vilakazi Roger Fearick Peter Steinberg Rory Adams Bruce Becker Sarah Blyth Gareth de Vaux Heather Gray Mark Horner Nawahl Razak Artur Szostak Spencer Wheaton International Advisory Committee Federico Antinori Tim Hallman John Harris Tetsuo Hatsuda Ulrich Heinz Huan Z Huang Sonja Kabana Volker Koch Rob Lacey Jes Madsen Yasuo Miake Maurizio Morando Berndt Mueller Grazyna Odyniec Helmut Oeschler Apostolos Panagiotou Josef Pochodzalla Johann Rafelski Karel Safarik Jack Sandweiss Jürgen Schaffner-Bielich Georges Stephans Horst Stoecker Herbert Stroebele Thomas Ullrich Orlando Villalobos-Baillie Bill Zajc Joseph Zimanyi

2005-06-01

389

The SNA analysis of a minimal model for bistability in the MAPK signaling cascade model  

NASA Astrophysics Data System (ADS)

Successive phosphorylation cascades mediated by mitogen-activated protein kinases (MAPKs) are known to act as switches initiating various cellular processes. In addition, models of the MAPK reaction network are displaying other nonlinear phenomena including bistability and periodic oscillations. Recently bistability has been explained as a consequence of interaction between single and double phosphorylation/dephosphorylation pathways in the Stage 2 subsystem of the Huang-Ferrell model of the MAPK and a core bistable model has been proposed. Here we focus on a detailed stability analysis of the steady states of this minimal model. The analysis uses methods of convex analysis and stoichiometric network theory.

Hada?, O.; Schreiber, I.

2013-12-01

390

A generalized tool for accurate time-domain separation of excited modes in spin-torque oscillators  

NASA Astrophysics Data System (ADS)

We propose and develop an advanced signal processing technique that, combined with micromagnetic simulations, is able to deeply describe the non-stationary behavior of spin-torque oscillators, both in terms of time domain and spatial distribution of the magnetization dynamics. The Hilbert-Huang Transform is used for the identification of the time traces of each oscillation in a multimode excitation and enhanced with masking signals and the Ensemble Empirical Mode Decomposition. We emphasize that the technique developed here is general and can be used for any physical non-linear system in the presence of multimode dynamical excitation or intermittence.

Siracusano, Giulio; La Corte, Aurelio; Puliafito, Vito; Finocchio, Giovanni

2014-05-01

391

Evidence of nonadiabatic exciton-phonon interaction probed by second-order LO-phonon replicas of single quantum dots  

NASA Astrophysics Data System (ADS)

In this experimental study of single InGaAs/GaAs quantum dots (QDs) the photoluminescence intensity of the second order LO-phonon replica of the excitonic interband recombination was measured along with the intensities of the first and zeroth orders. The results show that the intensity of the second-order replica is three to four times stronger than expected from the adiabatic Huang-Rhys theory, indicating that the neglected nonadiabaticity plays an important role for the understanding of the exciton-phonon coupling in QDs.

Dufåker, D.; Karlsson, K. F.; Mereni, L. O.; Dimastrodonato, V.; Juska, G.; Pelucchi, E.; Holtz, P. O.

2013-02-01

392

Accurate computation of low-temperature thermodynamics for quantum spin chains  

NASA Astrophysics Data System (ADS)

We apply the biorthonormal transfer-matrix renormalization group (BTMRG) [Huang, Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.83.036702 83, 036702 (2011)] to study low-temperature properties of quantum spin chains. Simulations on anisotropic Heisenberg spin-1/2 chains demonstrate that the BTMRG outperforms the conventional transfer-matrix renormalization group by successfully accessing far lower temperature than previously reported, while retaining the same level of accuracy. The power of the method is further illustrated by the calculation of the low-temperature specific heat for a frustrated spin chain.

Huang, Yu-Kun; Chen, Pochung; Kao, Ying-Jer

2012-12-01

393

Asymptotic convergence to planar stationary waves for multi-dimensional unipolar hydrodynamic model of semiconductors  

NASA Astrophysics Data System (ADS)

In this study, we consider the high dimensional unipolar hydrodynamic model for semiconductors in the form of Euler-Poisson equations. Based on the results that we have obtained in the first part (Huang, et al., 2011 [16]) for the 1-D case, we can further show the stability of planar stationary waves in multi-dimensional case. Utilizing the energy method, we obtain the global existence of the solutions of high dimensional Euler-Poisson equations for the unipolar hydrodynamic model, and prove that the solutions converge to the planar stationary waves time-exponentially.

Huang, Feimin; Mei, Ming; Wang, Yong; Yu, Huimin

394

A wireless strain sensor consumes less than 10 mW  

NASA Astrophysics Data System (ADS)

This paper presents a wireless strain sensor that consumes about 9 mW. To achieve such an ultra-low power operation, a voltage-controlled oscillator (VCO) is utilized to convert the direct-current (DC) strain signal to a high frequency oscillatory signal. This oscillatory signal is then transmitted using an unpowered wireless transponder (Huang et al 2011 Smart Mater. Struct. 20 015017). A photocell-based energy harvester was developed to power the wireless strain sensor. The energy harvested from a flash light placed at 65 cm away is sufficient to power the wireless strain sensor continuously. The implementation of the wireless strain sensor and its characterization are presented.

Hew, Y.; Deshmukh, S.; Huang, H.

2011-10-01

395

Repeatability observations from a time-lapse seismic survey  

USGS Publications Warehouse

Time-lapse seismic surveys have proven extremely valuable in recent years, having numerous economical and environmental applications. To fully utilize this monitoring technique, problems associated with recording repeatability must be minimized. Much work has been done to equalize data from one survey to the next via processing techniques (Huang et al., 1998). The purpose of this study is to investigate the potential for minimized processing, allowing study of extremely small changes in subsurface characteristics. The goal is to evaluate source and receiver terrain combination to optimize signal repeatability, and to improve deconvolution with the ground force to suppress different types of noise and increase repeatability. ?? 2005 Society of Exploration Geophysicists.

Walters, S. L.; Miller, R. D.; Raef, A. E.

2006-01-01

396

Communications, customs, organization slowed project  

SciTech Connect

This paper reports that completion of a recently commissioned pipeline automation system in China overcame delays caused by serious difficulties in communications, organization, customs, and distance. The 153 mile, 28 in. hot-oil pipeline is located in the Shangdong Province, east of Beijing, China, and runs from Dongying, in the Shengli oil field, to the port of Huangdao on the Yellow Sea. The Shengli Oil Pipeline Co. (SOPC) now operates the fully automated Dong-Huang liquid pipeline with capability for central control in Weifang.

Blair, J.T. (Novacorp International Consulting Inc., Calgary (CA))

1992-09-21

397

Non-Born–Oppenheimer molecular wave functions of H2 by extended multi-configuration time-dependent Hartree–Fock method  

NASA Astrophysics Data System (ADS)

A ground state wave function of a one-dimensional H2 molecule is derived numerically by the extended multi-configuration time-dependent Hartree–Fock (MCTDHF) method. The electronic orbitals and the amplitudes for the nuclear motion constituting the ground-state wave function are derived by solving the coupled equations of motion by the imaginary time propagation. Comparisons with the results obtained by the Born–Huang (BH) expansion method as well as with the exact wave function reveal that the memory size required in the extended MCTDHF method is about two orders of magnitude smaller than in the BH expansion method.

Ide, Yoshihiro; Kato, Tsuyoshi; Yamanouchi, Kaoru

2014-03-01

398

Rapid fluctuations of chaotic maps on RN  

NASA Astrophysics Data System (ADS)

The iterates fn of a chaotic map f display heightened oscillations (or fluctuations) as n-->[infinity]. If f is a chaotic interval map in one dimension, then it is now known that the total variation of fn on that interval grows exponentially with respect to n [G. Chen, T. Huang, Y. Huang, Chaotic behavior of interval maps and total variations of iterates, Internat. J. Bifur. Chaos 14 (2004) 2161-2186]. However, the characterization of chaotic behavior of maps in multi-dimensional spaces is generally much more challenging. Here, we generalize the definition of bounded variations for vector-valued maps in terms of the Hausdorff measure and then use it to study what we call rapid fluctuations on fractal sets in multi-dimensional chaotic discrete dynamical systems. The relations among rapid fluctuations, strict turbulence and positive entropy are established for Lipschitz continuous systems on general N-dimensional Euclidean spaces. Applications to planar monotone or competitive systems, and triangular systems on the square are also given.

Huang, Yu; Chen, Goong; Ma, Daowei

2006-11-01

399

Computing a Stability Spectrum by Use of the HHT  

NASA Technical Reports Server (NTRS)

The Hilbert-Huang transform (HHT) is part of the mathematical basis of a method of calculating a stability spectrum. This method can be regarded as an extended and improved version of a prior HHT-based method of calculating a damping spectrum. In the prior method, information on positive damping (which leads to stability) and negative damping (which leads to instability) becomes mixed into a single squared damping loss factor. Hence, there is no way to distinguish between stability and instability by examining a damping spectrum. In contrast, in the present stabilityspectrum method, information on the mathematical sign of the damping is retained, making it possible to identify reThe Hilbert-Huang transform (HHT) is part of the mathematical basis of a method of calculating a stability spectrum. This method can be regarded as an extended and improved version of a prior HHT-based method of calculating a damping spectrum. In the prior method, information on positive damping (which leads to stability) and negative damping (which leads to instability) becomes mixed into a single squared damping loss factor. Hence, there is no way to distinguish between stability and instability by examining a damping spectrum. In contrast, in the present stabilityspectrum method, information on the mathematical sign of the damping is retained, making it possible to identify regions of instability in a spectrum. This method is expected to be especially useful for analyzing vibration-test data for the purpose of predicting vibrational instabilities in structures (e.g., flutter in airplane wings).

Huang, Norden E.

2007-01-01

400

Algorithms and Results of Eye Tissues Differentiation Based on RF Ultrasound  

PubMed Central

Algorithms and software were developed for analysis of B-scan ultrasonic signals acquired from commercial diagnostic ultrasound system. The algorithms process raw ultrasonic signals in backscattered spectrum domain, which is obtained using two time-frequency methods: short-time Fourier and Hilbert-Huang transformations. The signals from selected regions of eye tissues are characterized by parameters: B-scan envelope amplitude, approximated spectral slope, approximated spectral intercept, mean instantaneous frequency, mean instantaneous bandwidth, and parameters of Nakagami distribution characterizing Hilbert-Huang transformation output. The backscattered ultrasound signal parameters characterizing intraocular and orbit tissues were processed by decision tree data mining algorithm. The pilot trial proved that applied methods are able to correctly classify signals from corpus vitreum blood, extraocular muscle, and orbit tissues. In 26 cases of ocular tissues classification, one error occurred, when tissues were classified into classes of corpus vitreum blood, extraocular muscle, and orbit tissue. In this pilot classification parameters of spectral intercept and Nakagami parameter for instantaneous frequencies distribution of the 1st intrinsic mode function were found specific for corpus vitreum blood, orbit and extraocular muscle tissues. We conclude that ultrasound data should be further collected in clinical database to establish background for decision support system for ocular tissue noninvasive differentiation.

Jurkonis, R.; Janusauskas, A.; Marozas, V.; Jegelevicius, D.; Daukantas, S.; Patasius, M.; Paunksnis, A.; Lukosevicius, A.

2012-01-01

401

Algorithms and results of eye tissues differentiation based on RF ultrasound.  

PubMed

Algorithms and software were developed for analysis of B-scan ultrasonic signals acquired from commercial diagnostic ultrasound system. The algorithms process raw ultrasonic signals in backscattered spectrum domain, which is obtained using two time-frequency methods: short-time Fourier and Hilbert-Huang transformations. The signals from selected regions of eye tissues are characterized by parameters: B-scan envelope amplitude, approximated spectral slope, approximated spectral intercept, mean instantaneous frequency, mean instantaneous bandwidth, and parameters of Nakagami distribution characterizing Hilbert-Huang transformation output. The backscattered ultrasound signal parameters characterizing intraocular and orbit tissues were processed by decision tree data mining algorithm. The pilot trial proved that applied methods are able to correctly classify signals from corpus vitreum blood, extraocular muscle, and orbit tissues. In 26 cases of ocular tissues classification, one error occurred, when tissues were classified into classes of corpus vitreum blood, extraocular muscle, and orbit tissue. In this pilot classification parameters of spectral intercept and Nakagami parameter for instantaneous frequencies distribution of the 1st intrinsic mode function were found specific for corpus vitreum blood, orbit and extraocular muscle tissues. We conclude that ultrasound data should be further collected in clinical database to establish background for decision support system for ocular tissue noninvasive differentiation. PMID:22654643

Jurkonis, R; Janušauskas, A; Marozas, V; Jegelevi?ius, D; Daukantas, S; Patašius, M; Paunksnis, A; Lukoševi?ius, A

2012-01-01

402

Diagnostics of gear faults based on EMD and automatic selection of intrinsic mode functions  

NASA Astrophysics Data System (ADS)

Signal processing is an important tool for diagnostics of mechanical systems. Many different techniques are available to process experimental signals, among others: FFT, wavelet transform, cepstrum, demodulation analysis, second order ciclostationarity analysis, etc. However, often hypothesis about data and computational efforts restrict the application of some techniques. In order to overcome these limitations, the empirical mode decomposition has been proposed. The outputs of this adaptive approach are the intrinsic mode functions that are treated with the Hilbert transform in order to obtain the Hilbert-Huang spectrum. Anyhow, the selection of the intrinsic mode functions used for the calculation of Hilbert-Huang spectrum is normally done on the basis of user's experience. On the contrary, in the paper a merit index is introduced that allows the automatic selection of the intrinsic mode functions that should be used. The effectiveness of the improvement is proven by the result of the experimental tests presented and performed on a test-rig equipped with a spiral bevel gearbox, whose high contact ratio made difficult to diagnose also serious damages of the gears. This kind of gearbox is normally never employed for benchmarking diagnostics techniques. By using the merit index, the defective gearbox is always univocally identified, also considering transient operating conditions.

Ricci, Roberto; Pennacchi, Paolo

2011-04-01

403

Seed priming with chitosan improves maize germination and seedling growth in relation to physiological changes under low temperature stress.  

PubMed

Low temperature stress during germination and early seedling growth is an important constraint of global production of maize. The effects of seed priming with 0.25%, 0.50%, and 0.75% (w/v) chitosan solutions at 15 degrees C on the growth and physiological changes were investigated using two maize (Zea mays L.) inbred lines, HuangC (chilling-tolerant) and Mo17 (chilling-sensitive). While seed priming with chitosan had no significant effect on germination percentage under low temperature stress, it enhanced germination index, reduced the mean germination time (MGT), and increased shoot height, root length, and shoot and root dry weights in both maize lines. The decline of malondialdehyde (MDA) content and relative permeability of the plasma membrane and the increase of the concentrations of soluble sugars and proline, peroxidase (POD) activity, and catalase (CAT) activity were detected both in the chilling-sensitive and chilling-tolerant maize seedlings after priming with the three concentrations of chitosan. HuangC was less sensitive to responding to different concentrations of chitosan. Priming with 0.50% chitosan for about 60 approximately 64 h seemed to have the best effects. Thus, it suggests that seed priming with chitosan may improve the speed of germination of maize seed and benefit for seedling growth under low temperature stress. PMID:19489108

Guan, Ya-jing; Hu, Jin; Wang, Xian-ju; Shao, Chen-xia

2009-06-01

404

An Efficient Grid Generation Method for Arbitrary Domains  

NASA Astrophysics Data System (ADS)

This paper describes an efficient grid generation method for arbitrary or multiply connected domains. Our method, essentially based on the edge swapping techniques, combines the advantages of the Delaunay triangulation method and the advancing front method. The latter two methods are in popular use nowadays. But both suffer some limitations. Delaunay method generates high quality grid but grid may cut across the boundary in concave regions. Advancing front method works for general domain but may encounter difficulties where fronts have to be merged. The current method garantees the boundary integrity and attains the nice Delaunay features into the domain. This is achieved by carefully documenting the grid information so that each edge is readily identified to be inside or outside the domain; and (2) continuously swapping out those bad edges that destroy the Delaunay properties. The computer program built on this method allows users to control the grid density distribution by specifying typical grid sizes on a few chosen points. Interesting examples are demonstrated here. One of them is a circular domain with three letters APS inside. (see huang/fig1.gif>figure 1 and huang/fig2.gif>figure 2 ). Given a grid size for APS and another size for the circle, the program automatically generates a smooth triangular grid regardless of the complex multiply connected geometry.

Orme, Melissa; Huang, Changzheng

1997-11-01

405

Investigation of antioxidant interactions between Radix Astragali and Cimicifuga foetida and identification of synergistic antioxidant compounds.  

PubMed

The medicinal plants of Huang-qi (Radix Astragali) and Sheng-ma (Cimicifuga foetida) demonstrate significantly better antioxidant effects when used in combination than when used alone. However, the bioactive components and interactional mechanism underlying this synergistic action are still not well understood. In the present study, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay was employed to investigate the antioxidant capacity of single herbs and their combination with the purpose of screening synergistic antioxidant compounds from them. Chromatographic isolation was performed on silica gel, Sephadex LH-20 columns and HPLC, and consequently to yield formononetin, calycosin, ferulic acid and isoferulic acid, which were identified by their retention time, UV ?max, MS and MS/MS data. The combination of isoferulic acid and calycosin at a dose ratio of 1?1 resulted in significant synergy in scavenging DPPH radicals and ferric reducing antioxidant power (FRAP) assay. Furthermore, the protective effects of these four potential synergistic compounds were examined using H2O2-induced HepG2 Cells bioassay. Results revealed that the similar synergy was observed in the combination of isoferulic acid and calycosin. These findings might provide some theoretical basis for the purported synergistic efficiency of Huang-qi and Sheng-ma as functional foods, dietary supplements and medicinal drugs. PMID:24498048

Wang, Fei; Zhao, Shancang; Li, Feng; Zhang, Bo; Qu, Yi; Sun, Tianlei; Luo, Ting; Li, Dapeng

2014-01-01

406

Modelling of in vitro chondrocyte detachment  

NASA Astrophysics Data System (ADS)

The experimental work of Huang et al. [Huang, W., Bahman, A., Torres, J.H., LeBaron R.G., Athanasiou, K.A., 2003. Temporal effects of cell adhesion on mechanical characteristics of the single chondrocyte. J. Orthop. Res. 21, 88-95] provides a novel experimental characterisation of the force required to detach single chondrocytes from a flat substrate with a horizontally moving probe. Measurements reveal that the force required to detach cells spread for six hours is eleven times greater than that required to detach cells spread for one hour. However, it is not clear if this phenomenon is entirely due to geometric changes of chondrocytes during spreading and the consequent increase in adhesion area between cell and substrate. The current computational study, using experimentally measured cell geometries and a cohesive zone model to simulate the cell-substrate interface, reveals that this is not the case. It is demonstrated that both an increase in cell stiffness and an increase in the cell-substrate interface strength during cell spreading are necessary to explain the experimental measurements. It is also revealed that the mechanism of cell detachment involves exclusively tangential debonding, with no lifting of the cell taking place at the cell-substrate interface. Finally, the effect of discrete focal adhesion regions on cell detachment is considered.

McGarry, J. P.; McHugh, P. E.

407

Mode shape reconstruction of an impulse excited structure using continuous scanning laser Doppler vibrometer and empirical mode decomposition.  

PubMed

For vibration testing, discrete types of scanning laser Doppler vibrometer (SLDV) have been developed and have proven to be very useful. For complex structures, however, SLDV takes considerable time to scan the surface of structures and require large amounts of data storage. To overcome these problems, a continuous scan was introduced as an alternative. In this continuous method, the Chebyshev demodulation (or polynomial) technique and the Hilbert transform approach have been used for mode shape reconstruction with harmonic excitation. As an alternative, in this paper, the Hilbert-Huang transform approach is applied to impact excitation cases in terms of a numerical approach, where the vibration of the tested structure is modeled using impulse response functions. In order to verify this technique, a clamped-clamped beam was chosen as the test rig in the numerical simulation and real experiment. This paper shows that with additional innovative steps of using ideal bandpass filters and nodal point determination in the postprocessing, the Hilbert-Huang transformation can be used to create a better mode shape reconstruction even in the impact excitation case. PMID:18681730

Kyong, Yongsoo; Kim, Daesung; Dayou, Jedol; Park, Kyihwan; Wang, Semyung

2008-07-01

408

Mode shape reconstruction of an impulse excited structure using continuous scanning laser Doppler vibrometer and empirical mode decomposition  

NASA Astrophysics Data System (ADS)

For vibration testing, discrete types of scanning laser Doppler vibrometer (SLDV) have been developed and have proven to be very useful. For complex structures, however, SLDV takes considerable time to scan the surface of structures and require large amounts of data storage. To overcome these problems, a continuous scan was introduced as an alternative. In this continuous method, the Chebyshev demodulation (or polynomial) technique and the Hilbert transform approach have been used for mode shape reconstruction with harmonic excitation. As an alternative, in this paper, the Hilbert-Huang transform approach is applied to impact excitation cases in terms of a numerical approach, where the vibration of the tested structure is modeled using impulse response functions. In order to verify this technique, a clamped-clamped beam was chosen as the test rig in the numerical simulation and real experiment. This paper shows that with additional innovative steps of using ideal bandpass filters and nodal point determination in the postprocessing, the Hilbert-Huang transformation can be used to create a better mode shape reconstruction even in the impact excitation case.

Kyong, Yongsoo; Kim, Daesung; Dayou, Jedol; Park, Kyihwan; Wang, Semyung

2008-07-01

409

Characterization of Na+- beta-Zeolite Supported Pd and Pd Ag Bimetallic Catalysts using EXAFS, TEM and Flow Reactor  

SciTech Connect

Flow reactor studies of the selective hydrogenation of acetylene in the presence of ethylene have been performed on Na+ exchanged {beta}-zeolite supported Pd, Ag and PdAg catalysts, as an extension of our previous batch reactor studies [W. Huang, J.R. McCormick, R.F. Lobo, J.G. Chen, J. Catal. 246 (2007) 40-51]. Results from flow reactor studies show that the PdAg/Na+-{beta}-zeolite bimetallic catalyst has lower activity than Pd/Na+-{beta}-zeolite monometallic catalyst, while Ag/Na+-{beta}-zeolite does not show any activity for acetylene hydrogenation. However, the selectivity for the PdAg bimetallic catalyst is much higher than that for either the Pd catalyst or Ag catalyst. The selectivity to byproduct (ethane) is greatly inhibited on the PdAg bimetallic catalyst as well. The results from the current flow reactor studies confirmed the pervious results from batch reactor studies [W. Huang, J.R. McCormick, R.F. Lobo, J.G. Chen, J. Catal. 246 (2007) 40-51]. In addition, we used transmission electron microscope (TEM), extended X-ray absorption fine structure (EXAFS), and FTIR of CO adsorption to confirm the formation of Pd-Ag bimetallic alloy in the PdAg/Na+-{beta}-zeolite catalyst.

Huang,W.; Lobo, R.; Chen, J.

2008-01-01

410

Test of a low-mass contact binary model by comparing the relations obtained from theory with those from observations  

NASA Astrophysics Data System (ADS)

The W UMa-type contact binaries have been observed for several decades. To construct the evolutionary model for W UMa-type contact binaries, many difficulties were encountered due to the existence of complicated physical processes in such systems. The model introduced by Huang, Song and Bi includes some special and unique understandings of the physical processes of contact binaries. It is necessary to test whether this model can be used for W UMa-type contact binaries. The best way to test a theoretical model is to know whether this model can explain the observational phenomena of such systems. For this aim, a comparison is performed for the relations of mass-luminosity, mass-radius, and the distribution in the HR diagram obtained from the model introduced by Huang et al. and those from the astronomical observations. The result of the comparison indicates that this model can be applied to W UMa-type contact binaries and can explain the observational phenomena of such binaries.

Song, Fen; Huang, RunQian

2012-04-01

411

A test of an early-type contact binary model by comparing the relations obtained from theory with those from observations  

NASA Astrophysics Data System (ADS)

Contact binary systems, including massive, middle-mass and low-mass systems, have been observed. It is necessary to construct the evolutionary model for contact binary systems with all different masses. The model introduced by Huang, Song and Bi indicates some special and unique understandings of the physical processes occurring in the contact binaries. It is necessary to test whether this model can be applied to the early-type contact binaries. The best way to test a theoretical model is to know whether this model can explain the observational phenomena of such binaries. For this aim, a comparison is performed for the relations of mass-luminosity, mass-radius, and the distribution in the HR diagram obtained from the model introduced by Huang et al. and those from the astronomical observations. A good result is obtained by the comparison. This means the model can be used in calculating the evolution of early-type contact binaries, and can explain the observational phenomena of such binaries.

Song, Fen; Huang, RunQian

2012-02-01

412

The geoid computed from a new generalized theory of the figure of the Earth  

NASA Astrophysics Data System (ADS)

The geoid serves as the reference frame in geodesy. The Clairaut equation, Darwin - de Sitter theory and the series work of Denis are regarded as the standard theories of equilibrium figures of the Earth to the first - , second - , and third - order precision, respectively. Recently, a new generalized theory to obtain the interior figures to third - order accuracy was developed (Liu & Huang, 2008; Huang & Liu, 2012), in which, both the direct and indirect contribution of the anti - symmetric crust layer are included, thus, all the non - zero order and odd degree terms, up to degree/order of six, are included in the spherical harmonic expression of the equilibrium figures. As a result, the global dynamical flattening (H) was obtained as 1/306.68, i.e., the difference of H between the calculated value from above traditional theories and the value from precession observations is reduced from 1.1%, by about 2/3, to 0.38%. In this presentation, based on the above new generalized theory, the geoid is calculated and compared with the one derived from EGM96. Some further discussion will be also presented.

Huang, Cheng-li; Liu, Cheng-jun; Liu, Yu

2012-08-01

413

Can medical herbs stimulate regeneration or neuroprotection and treat neuropathic pain in chemotherapy-induced peripheral neuropathy?  

PubMed

Chemotherapy-induced neuropathy (CIPN) has a relevant impact on the quality of life of cancer patients. There are no curative conventional treatments, so further options have to be investigated. We conducted a systematic review in English and Chinese language databases to illuminate the role of medical herbs. 26 relevant studies on 5 single herbs, one extract, one receptor-agonist, and 8 combinations of herbs were identified focusing on the single herbs Acorus calamus rhizoma, Cannabis sativa fructus, Chamomilla matricaria, Ginkgo biloba, Salvia officinalis, Sweet bee venom, Fritillaria cirrhosae bulbus, and the herbal combinations Bu Yang Huan Wu, modified Bu Yang Huan Wu plus Liuwei Di Huang, modified Chai Hu Long Gu Mu Li Wan, Geranii herba plus Aconiti lateralis praeparata radix , Niu Che Sen Qi Wan (Goshajinkigan), Gui Zhi Jia Shu Fu Tang (Keishikajutsubuto), Huang Qi Wu Wu Tang (Ogikeishigomotsuto), and Shao Yao Gan Cao Tang (Shakuyakukanzoto). The knowledge of mechanism of action is still limited, the quality of clinical trials needs further improvement, and studies have not yielded enough evidence to establish a standard practice, but a lot of promising substances have been identified. While CIPN has multiple mechanisms of neuronal degeneration, a combination of herbs or substances might deal with multiple targets for the aim of neuroprotection or neuroregeneration in CIPN. PMID:23983777

Schröder, Sven; Beckmann, Kathrin; Franconi, Giovanna; Meyer-Hamme, Gesa; Friedemann, Thomas; Greten, Henry Johannes; Rostock, Matthias; Efferth, Thomas

2013-01-01

414

Identifying Modes of Temperature Variability Using AIRS Data.  

NASA Astrophysics Data System (ADS)

We use the Atmospheric Infrared Sounder (AIRS) and Advance Microwave Sounding Unit (AMSU) data obtained on Aqua spacecraft to study mid-tropospheric temperature variability between 2002-2007. The analysis is focused on daily zonal means of the AIRS channel at 2388 1/cm in the CO2 R-branch and the AMSU channel #5 in the 57 GHz Oxygen band, both with weighting function peaking in the mid-troposphere (400 mb) and the matching sea surface temperature from NCEP (Aumann et al., 2007). Taking into account the nonlinear and non- stationary behavior of the temperature we apply the Empirical Mode Decomposition (Huang et al., 1998) to better separate modes of variability. All-sky (cloudy) and clear sky, day and night data are analyzed. In addition to the dominant annual variation, which is nonlinear and latitude dependent, we identified the modes with higher frequency and inter-annual modes. Some trends are visible and we apply stringent criteria to test their statistical significance. References: Aumann, H. H., D. T. Gregorich, S. E. Broberg, and D. A. Elliott, Geophys. Res. Lett., 34, L15813, doi:10.1029/2006GL029191, 2007. Huang, N. E. Z. Shen, S. R. Long, M. C. Wu, H. H. Shih, Q. Zheng, N.-C. Yen, C. C. Tung, and H. H. Liu, Proc. R. Soc. Lond., A 454, 903-995, 1998.

Ruzmaikin, A.; Aumann, H. H.; Yung, Y.

2007-12-01

415

Two new species of free-living marine nematodes (Nematoda: Oncholaimida: Enchelidiidae) from Maemul Island, Korea.  

PubMed

Two new species of the family Enchelidiidae Filipjev, 1918 were collected from marine sediments near Maemul Island in South Korea: a new species of Abelbolla Huang & Zhang, 2004 and a new species of Ledovitia Filipjev, 1927. Abelbolla maemulensis sp. nov. is characterized by its small size (1,493 × 38 µm, body length × maximum body diameter); the presence of a circular amphid; the gubernacular apophysis with swollen distal tip; and the complex structure of the gubernaculum. It is close to Abelbolla huanghaiensis Huang & Zhang, 2004, but differs by the structure of gubernacular apophysis and body length (1,493 vs 2,303 µm). Ledovitia brevis sp. nov. can be separated from its congeners by its small size of body, the length of gubernacular apophysis, and the length of the spicules. It is close to Ledovitia pharetrata Wieser, 1953a, but differs by the length of the body (1,699 vs 2,640 µm) and the spicules (40 vs 100 µm). PMID:24872235

Hong, Jung-Ho; Lee, Wonchoel

2014-01-01

416

Quantifying spin torque effects using a current-driven magnetic vortex  

NASA Astrophysics Data System (ADS)

Spin transfer torques offer great potential for the development of spin-based devices for processing and storing information but there is still debate surrounding the relative contributions of the adiabatic and non-adiabatic spin torque effects. Magnetic vortices in patterned magnetic films provide a model system that can be used to quantify these effects. Micromagnetic calculations of the current-driven motion of a magnetic vortex in a patterned Permalloy element show that the two spin torque effects have distinguishable influences on the trajectories of the vortex core and, furthermore, that the effect of the current-generated magnetic fields (Oersted) that are often non-negligible when current flows through magnetic nanostructures can also be separated out. An analysis of a series of experimental images of vortex trajectories obtained using a recently developed dynamic Lorentz transmission electron microscopy technique provides a measure of the non-adiabatic spin torque parameter with greatly improved precision [1]. The work described here was carried out in collaboration with Shawn Pollard, L. Huang, Dario Arena, and Yimei Zhu (Brookhaven). [4pt] [1] S. Pollard, L. Huang, K. S. Buchanan, D. Arena, and Y. Zhu, Nature Communications 3, 1028, 2012.

Buchanan, Kristen

2013-03-01

417

New expectations from the well-known medicinal properties of Arctium lappa.  

PubMed

AMP-activated protein kinase (AMPK) serves as a major regulator of energy homeostasis and is activated by different glucose-lowering agents. Indeed, AMPK has been identified as an attractive target for the development of innovative molecules to treat type 2 diabetes. In this issue of Diabetologia (doi: 10.1007/s00125-011-2366-3 ), Huang and co-workers report that arctigenin activates muscle uptake of glucose and inhibits hepatocyte gluconeogenesis and lipogenesis by reducing mitochondrial respiration and inducing AMPK activity. Importantly, it is reported that arctigenin improves glucose and lipid metabolism in ob/ob mice. Based on this evidence, Huang and co-workers suggest that arctigenin may represent a valuable lead compound for developing innovative glucose-lowering molecules. While these findings are not entirely novel and mechanistic investigations are needed, the results strongly support the concept that arctigenin deserves to be further considered because of its several potentially beneficial in vivo effects. In particular, the authors conclude that further mechanistic studies on arctigenin might provide novel insight and opportunities for selective modulation of subcutaneous and visceral fat mass. PMID:22358500

Miele, C; Beguinot, F

2012-05-01

418

Inverted spectra of SWCNT films  

NASA Astrophysics Data System (ADS)

Diffuse Reflectance for purified single wall carbon nanotube (SWCNT) films and its relation to absorptance in the wavelength range 0.6 ?m to 2 ?m are inverted when compared to absorptivity data in the literature. This surprising behavior has been corroborated by diffuse reflectance measurements and shows that the reflectance is a substantial part of the unique optical behavior. Typically, the absorptance is fairly assumed to be complementary to the transmittance, while the reflectivity is insignificant. Only in certain instances (see for example, Barnes, et. al[1], Wang, et. al[2]), is the small reflectance explicitly accounted for. In the present work, we present diffuse reflectance and specular absorptance at normal incidence of SWCNT films. [1] T. M. Barnes, J. van de Lagemaat, D. Levi,1 G. Rumbles, T. J. Coutts, C. L. Weeks, D. A. Britz, I. Levitsky, J. Peltola, P. Glatkowski, Phys. Rev. B 75, 235410 (2007). [2] F. Wang, M. Y. Sfeir, L. Huang, X. M. H. Huang, Wu, J. Kim, J. Hone, S. O'Brien, L. E. Brus, T. F. Heinz, PRL 96, 167401 (2006).

Lehman, John; Hurst, Katherine; Roberson, Lara; Nield, Kathryn; Hamlin, John

2008-03-01

419

Seed priming with chitosan improves maize germination and seedling growth in relation to physiological changes under low temperature stress*  

PubMed Central

Low temperature stress during germination and early seedling growth is an important constraint of global production of maize. The effects of seed priming with 0.25%, 0.50%, and 0.75% (w/v) chitosan solutions at 15 °C on the growth and physiological changes were investigated using two maize (Zea mays L.) inbred lines, HuangC (chilling-tolerant) and Mo17 (chilling-sensitive). While seed priming with chitosan had no significant effect on germination percentage under low temperature stress, it enhanced germination index, reduced the mean germination time (MGT), and increased shoot height, root length, and shoot and root dry weights in both maize lines. The decline of malondialdehyde (MDA) content and relative permeability of the plasma membrane and the increase of the concentrations of soluble sugars and proline, peroxidase (POD) activity, and catalase (CAT) activity were detected both in the chilling-sensitive and chilling-tolerant maize seedlings after priming with the three concentrations of chitosan. HuangC was less sensitive to responding to different concentrations of chitosan. Priming with 0.50% chitosan for about 60~64 h seemed to have the best effects. Thus, it suggests that seed priming with chitosan may improve the speed of germination of maize seed and benefit for seedling growth under low temperature stress.

Guan, Ya-jing; Hu, Jin; Wang, Xian-ju; Shao, Chen-xia

2009-01-01

420

Spectrally and spatially resolved cathodoluminescence of nanodiamonds: local variations of the NV(0) emission properties.  

PubMed

Here we report the spectrally and spatially resolved cathodoluminescence of diamond nanoparticles using focused fast electron beams in a transmission electron microscope. We demonstrate the possibility of quickly detecting various individual colour centres of different kinds on wide areas (several micrometres square) contained in nanoparticles separated by subwavelength distances. Among them, nanoparticles containing one or more neutral nitrogen-vacancy (NV(0)) intensity maxima have been seen, attributable to individual emitters. Thanks to a spatial resolution which is solely limited by charge carrier diffusion in the case of a fast electron (80 keV) setup, the spectra of two individual NV(0) emitters separated by 80 nm inside a nanoparticle have been spatially discerned. A shift of the zero phonon line (ZPL) between the two emitters, which we attribute to internal stress, is shown to arise even within the same nanoparticle. Detailed emission spectra (ZPL, phonon lines and Huang-Rhys factor, directly linked to the relaxation energy of the colour centre) in 51 individual NV(0) centres have been measured in 39 particles. The ZPL and Huang-Rhys factor are found to be measurably dispersed, while the phonon energies keep constant. PMID:22481219

Tizei, L H G; Kociak, M

2012-05-01

421

Spectrally and spatially resolved cathodoluminescence of nanodiamonds: local variations of the NV0 emission properties  

NASA Astrophysics Data System (ADS)

Here we report the spectrally and spatially resolved cathodoluminescence of diamond nanoparticles using focused fast electron beams in a transmission electron microscope. We demonstrate the possibility of quickly detecting various individual colour centres of different kinds on wide areas (several micrometres square) contained in nanoparticles separated by subwavelength distances. Among them, nanoparticles containing one or more neutral nitrogen-vacancy (NV0) intensity maxima have been seen, attributable to individual emitters. Thanks to a spatial resolution which is solely limited by charge carrier diffusion in the case of a fast electron (80 keV) setup, the spectra of two individual NV0 emitters separated by 80 nm inside a nanoparticle have been spatially discerned. A shift of the zero phonon line (ZPL) between the two emitters, which we attribute to internal stress, is shown to arise even within the same nanoparticle. Detailed emission spectra (ZPL, phonon lines and Huang-Rhys factor, directly linked to the relaxation energy of the colour centre) in 51 individual NV0 centres have been measured in 39 particles. The ZPL and Huang-Rhys factor are found to be measurably dispersed, while the phonon energies keep constant.

Tizei, L. H. G.; Kociak, M.

2012-05-01

422

Investigation of Antioxidant Interactions between Radix Astragali and Cimicifuga foetida and Identification of Synergistic Antioxidant Compounds  

PubMed Central

The medicinal plants of Huang-qi (Radix Astragali) and Sheng-ma (Cimicifuga foetida) demonstrate significantly better antioxidant effects when used in combination than when used alone. However, the bioactive components and interactional mechanism underlying this synergistic action are still not well understood. In the present study, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay was employed to investigate the antioxidant capacity of single herbs and their combination with the purpose of screening synergistic antioxidant compounds from them. Chromatographic isolation was performed on silica gel, Sephadex LH-20 columns and HPLC, and consequently to yield formononetin, calycosin, ferulic acid and isoferulic acid, which were identified by their retention time, UV ?max, MS and MS/MS data. The combination of isoferulic acid and calycosin at a dose ratio of 1?1 resulted in significant synergy in scavenging DPPH radicals and ferric reducing antioxidant power (FRAP) assay. Furthermore, the protective effects of these four potential synergistic compounds were examined using H2O2-induced HepG2 Cells bioassay. Results revealed that the similar synergy was observed in the combination of isoferulic acid and calycosin. These findings might provide some theoretical basis for the purported synergistic efficiency of Huang-qi and Sheng-ma as functional foods, dietary supplements and medicinal drugs.

Wang, Fei; Zhao, Shancang; Li, Feng; Zhang, Bo; Qu, Yi; Sun, Tianlei; Luo, Ting; Li, Dapeng

2014-01-01

423

Intrinsic Spin Seebeck Effect in Gold  

NASA Astrophysics Data System (ADS)

In Spin Seebeck Effect (SSE), a pure spin current can be generated by a temperature gradient (?T) and detected by the inverse spin Hall effect usually by Pt. Due to the propensity of out-of-plane ?zT through substrate, the SSE in the transverse configuration with an in-plane ?xT has been shown contaminated by the anomalous Nernst effect.footnotetextS. Y. Huang, et al. Phys. Rev. Lett. 107, 216604 (2011) The SSE in the longitudinal configuration with ?zT suffers from the magnetic proximity effect (MPE) of Pt in contact with a ferromagnetic material thus also contaminated.footnotetextS. Y. Huang, et al. Phys. Rev. Lett. 109, 107204 (2012) In this work, we demonstrate that Au does not exhibit MPE and reveals the intrinsic SSE. In contrast to Pt/YIG, Au/YIG shows no anomalous Hall signals, very weak inverse MR, and non-monotonic thickness dependence of spin thermal voltage, thus very weak if any MPE. Our results place an upper limit to the intrinsic SSE of 0.1?V/K at the Au thickness of 8nm, two orders of magnitude smaller than that in Pt/YIG. Spin-polarized density-functional calculations also show a sizable Pt but a negligible Au magnetic moment in contact with YIG, in agreement with experiments.

Qu, Danru; Huang, Ssu-Yen; Hu, Jun; Wu, Ruqian; Chien, Chia-Ling

2013-03-01

424

Nano-scale Strain Mapping using Near-field Microscopy  

NASA Astrophysics Data System (ADS)

Advances in nanophotonics are beginning to allow for the creation of nano-scale light emitting devices. Improving the quality of these next-generation emitters requires similarly advanced methods for characterization. These techniques need to be capable of imaging operational prototypes with nanometric resolution. We demonstrate here a new method for mapping strain capable of meeting the demands of next-generation device characterization. This technique makes use of near-field spectroscopy along with theoretical modelling to achieve non-destructive strain mapping with a resolution on the order of 10-100nm. An InGaN ELOG MQW sample is mapped using a SNOM, producing near-field maps of the intensity and Huang-Rhys parameter. Theoretical calculations are then used to obtain the relation between the Huang-Rhys parameter and the biaxial strain ?xx, thereby allowing the production of a near-field map of the biaxial strain in the sample. Finally, to verify the efficacy of the method, we compare the results with those obtained using high-resolution XRD.

Llopis, Antonio; Krokhin, Arkadii; Pereira, Sergio; Watson, Ian; Neogi, Arup

2011-03-01

425

Dissolved platinum in major rivers of East Asia: Implications for the oceanic budget  

NASA Astrophysics Data System (ADS)

Dissolved platinum concentrations of eleven large pristine river systems in East Asia (˜200 samples) were determined to better constrain the oceanic platinum budget. Most samples had concentrations less than 1.4 pM; relatively high concentrations up to 5.8 pM were measured in only approximately 6% of the samples. The median Pt concentrations of the individual river systems had only a small range, from 0.18 pM (Duman) to 0.63 pM (Huang He), and the difference in Pt yield mainly resulted from the difference in runoff. The rivers draining the eastern Tibetan Plateau - the Salween, Mekong, Chang Jiang (Yangtze), Hong (Red), and Huang He (Yellow) - had higher Pt yield than the rivers of the Russian Far East - the Amur, Lena, Yana, Indigirka, and Kolyma. If the discharge-weighted mean Pt concentration of our samples (0.36 pM) is extrapolated globally, the estimated riverine flux of dissolved Pt to the ocean is 13 × 103 mol y-1. Based on this riverine flux, the estimated oceanic residence time of Pt is 24 ± 10 kyrs. A 50% release and 50% uptake of Pt in estuaries would modify this to 16 kyrs and 45 kyrs, respectively.

Soyol-Erdene, Tseren-Ochir; Huh, Youngsook

2012-06-01

426

Quantum chemistry study on internal conversion of diphenyldibenzofulvene in solid phase.  

PubMed

We investigate the nonradiative decay process of diphenyldibenzofulvene (DPDBF) in solid phase by using the quantum chemistry methods. To carry out the nonradiative rate constant calculation, we construct a solid phase model based on the ONIOM method. The geometry of the DPDBF molecule is optimized for the ground state by DFT and the first excited state by TD-DFT, and the corresponding vibrational frequencies and normal coordinates are computed. Under displaced-distorted harmonic oscillator potential approximation, Huang-Rhys factors are obtained. Vibronic coupling constants are calculated as a function of the normal mode based on Domcke's scheme. We find that vibronic coupling constants of 12 modes with large reorganization energies are of similar order, and if this result is still valid for other modes, the internal conversion rate would be determined by high frequency modes because they have a significant nuclear factor that is related to Franck-Condon overlap intergrals. We also find that geometrical changes are suppressed due to the stacking effect, which yields small Huang-Rhys values in the solid phase. PMID:22047212

Li, Ming-Chung; Hayashi, Michitoshi; Lin, Sheng-Hsien

2011-12-22

427

Plasmoid Instability in High-Lundquist-Number Magnetic Reconnection  

NASA Astrophysics Data System (ADS)

Our understanding of magnetic reconnection in resistive magnetohydrodynamics has gone through a fundamental change in recent years. The conventional wisdom is that magnetic reconnection mediated by resistivity is slow in high Lundquist (S) plasmas, due to the S-1/2 scaling of reconnection rate predicted by the classical Sweet-Parker theory. However, recent studies showed that when S exceeds a critical value ˜10^4, the Sweet-Parker current sheet is unstable to a super-Alfvenic plasmoid instability, with a growth rate that increases with S [1]. Consequently, the reconnection layer changes to a chain of plasmoids connected by secondary current sheets that, in turn, may become unstable again. Eventually the reconnection layer will tend to a statistical steady state governed by complex dynamics of plasmoid formation and plasmoid loss due to advection and coalescence. The averaged reconnection rate in this regime is nearly independent of S [2,3], and the distribution function f(?) of magnetic fluxes ? in plasmoids follows a power-law f˜&-1circ;. When Hall effects are included, the plasmoid instability may trigger onset of Hall reconnection even when the conventional criterion for onset is not satisfied. In addition to the usual single X-point topology of Hall reconnection, our large-scale resistive Hall MHD simulations reveal a novel intermediate regime, where formation of new plasmoids is observed after onset of Hall reconnection [4]. Qualitatively similar results have also been found when resistivity is replaced by hyper-resistivity. Our findings suggest that plasmoid formation may be a generic feature of magnetic reconnection in large systems, regardless of the mechanism of breaking the frozen-in condition. (In collaboration with A. Bhattacharjee and B. P. Sullivan).[4pt] [1] N. F. Loureiro, A. A. Schekochihin, and S. C. Cowley, Phys. Plasmas 14, 100703 (2007).[0pt] [2] A. Bhattacharjee, Y.-M. Huang, H. Yang, and B. Rogers, Phys. Plasmas 16, 112102 (2009).[0pt] [3] Y.-M. Huang and A. Bhattacharjee, Phys. Plasmas 17, 062104 (2010).[0pt] [4] Y.-M. Huang, A. Bhattacharjee, and B. P. Sullivan, Phys. Plasmas 18, 072109 (2011).

Huang, Yi-Min

2012-10-01

428

Verification of Pharmacogenetics-Based Warfarin Dosing Algorithms in Han-Chinese Patients Undertaking Mechanic Heart Valve Replacement  

PubMed Central

Objective To study the performance of pharmacogenetics-based warfarin dosing algorithms in the initial and the stable warfarin treatment phases in a cohort of Han-Chinese patients undertaking mechanic heart valve replacement. Methods We searched PubMed, Chinese National Knowledge Infrastructure and Wanfang databases for selecting pharmacogenetics-based warfarin dosing models. Patients with mechanic heart valve replacement were consecutively recruited between March 2012 and July 2012. The predicted warfarin dose of each patient was calculated and compared with the observed initial and stable warfarin doses. The percentage of patients whose predicted dose fell within 20% of their actual therapeutic dose (percentage within 20%), and the mean absolute error (MAE) were utilized to evaluate the predictive accuracy of all the selected algorithms. Results A total of 8 algorithms including Du, Huang, Miao, Wei, Zhang, Lou, Gage, and International Warfarin Pharmacogenetics Consortium (IWPC) model, were tested in 181 patients. The MAE of the Gage, IWPC and 6 Han-Chinese pharmacogenetics-based warfarin dosing algorithms was less than 0.6 mg/day in accuracy and the percentage within 20% exceeded 45% in all of the selected models in both the initial and the stable treatment stages. When patients were stratified according to the warfarin dose range, all of the equations demonstrated better performance in the ideal-dose range (1.88–4.38 mg/day) than the low-dose range (<1.88 mg/day). Among the 8 algorithms compared, the algorithms of Wei, Huang, and Miao showed a lower MAE and higher percentage within 20% in both the initial and the stable warfarin dose prediction and in the low-dose and the ideal-dose ranges. Conclusions All of the selected pharmacogenetics-based warfarin dosing regimens performed similarly in our cohort. However, the algorithms of Wei, Huang, and Miao showed a better potential for warfarin prediction in the initial and the stable treatment phases in Han-Chinese patients undertaking mechanic heart valve replacement.

Zhao, Li; Chen, Chunxia; Li, Bei; Dong, Li; Guo, Yingqiang; Xiao, Xijun; Zhang, Eryong; Qin, Li

2014-01-01

429

Transition Metal Geochemistry of Ko'olau lavas  

NASA Astrophysics Data System (ADS)

Hawaiian shield lavas are too siliceous to be in equilibrium with garnet peridotite. Hauri (1996) and Huang and Frey (2005) proposed that dacitic melts from eclogite mix with picritic melts from garnet peridotites to yield high- SiO2 lavas. Alternatively, Sobolev et al. (2005, 2007) proposed a two-stage reaction model in which partial melts from eclogite first react with peridotite, and form a secondary garnet pyroxenite (SGP). Addition of varying amounts of partial melts from SGP to picritic magma could explain the high SiO2 content and high Ni content in olivine observed in Hawaiian shield lavas. For example, Makapu'u-stage Ko'olau lavas, characterized by the highest SiO2 content at a given MgO content, require >90% contribution from partial melts of SGP, implying a very high mass ratio of eclogite:peridotite in the mantle source. Complementing previously reported precise Fe/Mn ratios (Huang et al., 2007), we have precisely analyzed the entire first-row transition metals in Ko'olau and Kilauea lavas by ICP-MS. Here, we use Sc and Mn abundances to test the two models proposed for the origin of high-Si magmas from Hawaii. Both Sc and Mn are moderately incompatible during partial melting of garnet peridotite, but strongly compatible during partial melting of eclogite or SGP. Sc15 (abundance adjusted to MgO=15%) ranges from 19 to 24ppm in Makapu'u-stage Ko'olau lavas, 21 to 28ppm in Kalihi-stage Ko'olau lavas, 24 to 30ppm in Mauna Kea lavas, 27 to 42ppm in Detroit Seamount lavas. For comparison, EPR MORB has Sc8 (abundance adjusted to MgO=8%) of 41±5. Our calculations indicate an upper limit of 20ppm Sc in SGP, assuming [Sc]=25ppm in peridotite and 50ppm in eclogite. Since Sc is compatible during partial melting of SGP, the resulting partial melts are too low in Sc to explain the Makapu'u-stage Ko'olau lavas. Rather, the lower Sc15 in Makapu'u-stage Ko'olau lavas are consistent with adding up to 30% dacitic magma ([Sc]=8.6ppm) to picritic magma ([Sc]=27ppm). Using MnO content, Huang et al. (2007) also concluded that Makapu'u-stage Ko'olau lavas sampled up to 30% dacitic magma. Consequently, we imply an eclogite:peridotite mass ratio of 1:5 for the source of Makapu'u-stage Ko'olau lavas, significantly less than the estimate of Sobolev et al. (2005; 2007).

Huang, S.; Humayun, M.

2008-05-01

430

Downward continuation methods for gravimetric geoid modelling  

NASA Astrophysics Data System (ADS)

The determination of a gravimetric geoid model based on the Stokes integral requires that gravity anomalies must be on the geoid and that the anomalous potential must be harmonic above the geoid. To fulfill these requirements, gravity observations (or gravity anomalies) collected on the surface of the Earth need to be reduced to the geoid by a) removing the masses above the geoid and compensating for this removal; and b) continuing the gravity anomalies downward to the geoid. A well-known case is the determination of the Helmert gravity anomalies on the geoid in terms of Helmert's 2nd condensation method (e.g. Martinec et al. 1993). There are two procedures to follow for the evaluation of the Helmert gravity anomalies on the geoid: a) the Helmert gravity anomalies are evaluated on the irregular Earth surface, then are continued downward to the geoid, i.e., masses above the geoid are removed and restored as a condensed layer on the geoid prior to the downward continuation; b) alternatively the refined Bouguer anomalies on the surface of the Earth are downward-continued to the geoid, then the Helmert gravity anomalies are evaluated on the geoid, i.e., the condensed masses are restored after the downward continuation. Both procedures are theoretically equivalent (Huang et al. 2002a). In theory, the inclusion of the downward continuation should improve the geoid regardless of the approach chosen. However, different authors arrive at contradictory conclusions pertaining to its applications (e.g. Pavlis 1998; Ardalan 2000; Jekili and Serpas 2002; Véronneau and Huang 2002). This raises an open question as to how researchers should evaluate the downward continuation in order to improve geoid modeling. In this research, the two procedures described above are used to determine the geoid in Canada. The downward continuations are evaluated using the Poisson and Moritz methods (e.g. Moritz 1980; Sideris 1988; Vanícek et al. 1996; Martinec 1996; Sjöberg 1998; Nahavandchi 2000; Novák and Heck 2001; Huang et al. 2002b). The geoid models resulting from each combination of the two procedures and the two downward continuation methods are compared to the GPS/Levelling derived geoid heights at benchmarks in Canada. The results show that the geoid model is improved no matter which approach is used for the downward continuation. Finally, we describe the proper procedure for using the digital elevation model for the evaluation of the terrain correction and its condensation on the Earth surface.

Huang, J.; Véronneau, M.

2003-04-01

431

Pulse-like rupture induced by three-dimensional fault zone flower structures  

NASA Astrophysics Data System (ADS)

Mature faults are often embedded in low-velocity fault zones (LVFZs). Numerical simulations of dynamic rupture including a LVFZ by Huang and Ampuero (2011) showed that if the wave velocity contrast between the LVFZ and the country rock is strong enough, ruptures can behave as pulse-like ruptures. The healing front that stops the rupture is generated by reflected waves from the LVFZ-country rock interface. However, the numerical study by Huang and Ampuero (2011) was limited to two-dimensional problems with fault-parallel fault zone structures. Natural fault zones include complexities such as flower structures with depth-dependent velocity and thickness, and limited depth extent. We will show here that the mechanism of pulse generation induced by the LVFZ also operates efficiently in such three-dimensional fault zone structures. This investigation requires high resolution and flexible mesh generation, which are enabled here by the high-order accurate ADER-DG method with an unstructured tetrahedral element discretization (Pelties et al., 2012). Our simulations show that the pulse generation mechanism is robust to the depth extent of the LVFZ and to the position of the hypocenter (whether it is inside or below the LVFZ). In particular, for events with hypocenter deeper than a shallow LVFZ, we find that a healing front emerges soon after the rupture enters the LVFZ, with rise time controlled by the LVFZ properties. Moreover, this healing front reflects from the free surface and propagates downdip beyond the bottom of the LVFZ, inducing there pulse-like rupture with longer rise time. Thus, we find that the depth-dependence of rise time might reflect the depth extent of the LVFZ. References: Huang, Y. and J.-P. Ampuero (2011), Pulse-like ruptures induced by low-velocity fault zones, J. Geophys. Res., 116, B12307, doi:10.1029/2011JB008684. Pelties, C., J. de la Puente, J.-Pl Ampuero, G. B. Brietzke, and M. Käser (2012), Three-Dimensional Dynamic Rupture Simulation with a High-order Discontinuous Galerkin Method on Unstructured Tetrahedral Meshes, J. Geophys. Res., 117, B02309, doi:10.1029/2011JB008857.

Pelties, Christian; Huang, Yihe; Ampuero, Jean-Paul

2013-04-01

432

Comment on ‘multifractal diffusion entropy analysis on stock volatility in financial markets’ [Physica A 391 (2012) 5739-5745  

NASA Astrophysics Data System (ADS)

In their recent article ‘multifractal diffusion entropy analysis on stock volatility in financial markets’ Huang, Shang and Zhao (2012) [6] suggested a generalization of the diffusion entropy analysis method with the main goal of being able to reveal scaling exponents for multifractal times series. The main idea seems to be replacing the Shannon entropy by the Rényi entropy, which is a one-parametric family of entropies. The authors claim that based on their method they are able to separate long range and short correlations of financial market multifractal time series. In this comment I show that the suggested new method does not bring much valuable information in obtaining the correct scaling for a multifractal/mono-fractal process beyond the original diffusion entropy analysis method. I also argue that the mathematical properties of the multifractal diffusion entropy analysis should be carefully explored to avoid possible numerical artefacts when implementing the method in analysis of real sequences of data.

Morozov, A. Yu.

2013-05-01

433

[QRS complex detection using empirical mode decomposition and windowing technique].  

PubMed

A QRS complex detection algorithm based on empirical mode decomposition (EMD) and adaptive windowing technique is proposed in this paper. In this algorithm we mainly used Hilbert-Huang transform to propose EMD method suitable for QRS complex detection, with which the 30th signal in sddb database and the 208th signal in mit-db database could be processed, and then obtained R wave detection results. At the same time, Q and S points' detection technique was analyzed with adaptive windowing technique. The detection results, through proceeding R wave detection on part data of MIT/BIT arrhythmia database, showed that the proposed algorithm in this paper had a very good detection effect, and that its average correct detection rate of R wave reached 99.62%, its average sensitivity of QRS complex was 98.91%, and the corresponding average specificity was 99.35%. PMID:22826929

Zhang, Kaiyu; Wang, Li; Wang, Yujing; Song, Lixin

2012-06-01

434

Psuedosymmetry and pseudomerodry or nonmerohedral twinning for the known structure of diaquabis(quinolin-8-olato-?²N,O)zinc(II).  

PubMed

The structure of the title centrosymmetric compound, [Zn(C?H?NO)?(H?O)?], has already been solved three times [Merritt, Cady & Mundy (1954). Acta Cryst. 7, 473-476; Palenik (1964). Acta Cryst. 17, 696-700; Chen, Zhang, Shi, Huang, Liang & Zhou (2003). Acta Cryst. E59, m814-m815]. The authors of the two most recent papers state that they attained lower R1 values than that obtained in the 1954 paper, but they do not mention that Merritt et al. had derived the structural model from a twinned crystal. Also, from a structural point of view, there are strong indications that the most recent report is in fact the isostructural CuII complex already reported by Okabe & Saishu [Acta Cryst. (2001), E57, m251-m252] and not the ZnII complex. The structure of the title compound is reported here based on data obtained from a twinned crystal. PMID:23907878

Varelas, Georgios; Salifoglou, Athanasios; Psycharis, Vassilis

2013-08-01

435

Interaction of an electromagnetic wave with a rapidly created spatially periodic plasma  

SciTech Connect

The interaction of electromagnetic waves with rapidly created time-varying spatially periodic plasmas is studied. The numerical results of the collisionless case show that both frequency upshifted and frequency downshifted waves are generated. Moreover, the frequency downshifted waves are trapped by the plasma when the plasma frequency is larger than the wave frequency. The trapping has the effect of dramatically enhancing the efficiency of the frequency downshift conversion process, by accumulating incident wave energy during the plasma transition period. A theory based on the wave impedance of each Floquet mode of the periodic structure is formulated, incorporating with the collisional damping of the plasma. Such a theory explains the recent experimental observations [Faith, Kuo, and Huang, Phys. Rev. E {bold 55}, 1843 (1997)] where the frequency downshifted signals were detected repetitively with considerably enhanced spectral intensities while the frequency upshifted signals were missing. {copyright} {ital 1997} {ital The American Physical Society}

Kuo, S.P.; Faith, J. [Department of Electrical Engineering and Weber Research Institute, Polytechnic University, Route 110, Farmingdale, New York 11735 (United States)] [Department of Electrical Engineering and Weber Research Institute, Polytechnic University, Route 110, Farmingdale, New York 11735 (United States)

1997-08-01

436

The observations of FORMOSAT-3/COSMIC ionospheric electron density profiles during 2006-2010 major solar eclipses  

NASA Astrophysics Data System (ADS)

This study examines three-dimensional structures of the ionospheric response using electron density profiles derived from the GPS radio occultation experiment (GOX) on board FORMOSAT-3/COSMIC (F3/C) satellites and global ground-based GPS receivers during solar eclipses of 2006-2010. FS3/C electron density profiles observed before, during, and after the solar eclipses are used to find the induced traveling ionospheric disturbances (TIDs) in the vertical direction. We further apply the Hilbert-Huang transform (HHT) to compute the instantaneous frequencies and amplitudes for every point of the decomposed intrinsic mode functions (IMFs) from the F3/C electron density profiles. Meanwhile, total electron contents (TECs) derived from co-located ground-based GPS receivers are employed to obtain associated frequencies of the TIDs in the horizontal direction. Comparisons of the TIDs in the concurrent F3/C electron density profiles and GPS TEC allow us to find characteristics of the induced waves.

Hsu, C.; Liu, J. G.

2012-12-01

437

Simulation and signal processing of through wall UWB radar for human being's periodic motions detection  

NASA Astrophysics Data System (ADS)

The human's Micro-Doppler signatures resulting from breathing, arm, foot and other periodic motion can provide valuable information about the structure of the moving parts and may be used for identification and classification purposes. In this paper, we carry out simulate with FDTD method and through wall experiment with UWB radar for human being's periodic motion detection. In addition, Advancements signal processing methods are presented to classify and to extract the human's periodic motion characteristic information, such as Micro-Doppler shift and motion frequency. Firstly, we apply the Principal Component Analysis (PCA) with singular value decomposition (SVD) to denoise and extract the human motion signal. Then, we present the results base on the Hilbert-Huang transform (HHT) and the S transform to classify and to identify the human's micro-Doppler shift characteristics. The results demonstrate that the combination of UWB radar and various processing methods has potential to detect human's Doppler signatures effectively.

Li, Jing; Liu, Fengshan; Xu, Penglong; Zeng, Zhaofa

2013-05-01

438

Research on vibration response of a multi-faulted rotor system using LMD-based time-frequency representation  

NASA Astrophysics Data System (ADS)

Unbalance, fatigue crack and rotor-stator rub are the three common and important faults in a rotor-bearing system. They are originally interconnected each other, and their vibration behaviors do often show strong nonlinear and transient characteristic, especially when more than one of them coexist in the system. This article is aimed to study the vibration response of the rotor system in presence of multiple rotor faults such as unbalance, crack, and rotor-stator rub, using local mean decomposition-based time-frequency representation. Equations of motion of the multi-faulted Jeffcott rotor, including unbalance, crack, and rub, are presented. By solving the motion equations, steady-state vibration response is obtained in presence of multiple rotor faults. As a comparison, Hilbert-Huang transformation, based on empirical mode decomposition, is also applied to analyze the multi-faults data. By the study some diagnostic recommendations are derived.

Jiao, Weidong; Qian, Suxiang; Chang, Yongping; Yang, Shixi

2012-12-01

439

Transversal vibration analysis of an axially moving string with unilateral constraints using the HHT method  

NASA Astrophysics Data System (ADS)

In this paper, the transversal vibration characteristics of an axially moving string with unilateral constraints were examined using the Hilbert-Huang transform (HHT), due to its wide range of applications. Experiments were conducted on five test cases, and the subsequent analyses were discussed. The experimental results show that the introduction of a guide has the effect of causing low-frequency vibration suppression. The vibration behaviors of the guided segment and the free portion are highly sensitive to the initial tension, the initial clearance between the string and the guide, the transport speed and the guiding length. The details of the string vibrations revealed in this work will be used as a reference for engineering designs and relative system identifications.

Xia, Chunlin; Wu, Yangfang; Lu, Qianqian

2013-08-01

440

A comparison between advanced time-frequency analyses of non-stationary magnetization dynamics in spin-torque oscillators  

NASA Astrophysics Data System (ADS)

We report re`sults of different time-frequency analyses (Wavelet and Hilbert-Huang Transform (HHT)) of voltage measurements related to a spin-torque oscillator working in a regime of non-stationary dynamics. Our results indicate that the Wavelet analysis identifies the non-stationary magnetization dynamics revealing the existence of intermittent and independent excited modes while the HHT is able to accurately extract the time domain traces of each independent mode. Overall performance indicates a route for a complete characterization of time-frequency domain data of a STO, pointing out that the combined Wavelet-HHT methodology developed is general and can be also used for a variety of other different scenarios.

Siracusano, Giulio; Corte, Aurelio La

2014-02-01

441

Noise reduction in the surface plasmon resonance array sensor  

NASA Astrophysics Data System (ADS)

Methods to improve the performance of the surface plasmon resonance array sensor at ambient temperature are studied. A self-reference channel was used to eliminate the long-term drift caused both by the temperature and the light source. The Hilbert-Huang transform-based signal post-processing algorithm was employed to improve the signal-to-noise ratio and reduce high-frequency noise. Finally, an adaptive moving-average method was adopted to reduce noise while preserving important high-frequency signal characteristics. A combination of these methods decreased the baseline noise to 3.6×10-6 refractive index unit. Acceptable repeatability was achieved with relative standard deviation 2.20% (n=8). The limit of detection of NaCl was measured at 69 mg/L.

Huang, Zihao; Wang, Xiaoping

2013-04-01

442

Time-frequency analysis of nonlinear and non-stationary weak signals of corona discharge  

NASA Astrophysics Data System (ADS)

It is very useful to study the signals radiated from corona discharges for the purposes of high-voltage line monitoring. Time-frequency analysis can clearly reveal the time-varying spectrum characteristics of such signals, which is very useful for analyzing and processing the non-linear and non-stationary weak signals, such as the signals radiated from corona discharges. Several time-frequency analysis methods, such as the Short-Time Fourier Transform (STFT), Wigner-Ville distribution and the Hilbert-Huang Transform (HHT) and so on, are used in this paper. The simulation data with the same and different amplitudes are comparatively analyzed by these time-frequency distribution methods. It can be concluded that the time-frequency analysis method based on HHT is more efficient to identify and suitable for the non-linear and non-stationary weak signals.

Wang, Lei; Liu, Shanghe; Wei, Ming; Hu, Xiao Feng

2013-03-01

443

Periodicity in the most violent solar eruptions: recent observations of coronal mass ejections and flares revisited  

NASA Astrophysics Data System (ADS)

Using the Hilbert-Huang Transform method, we investigate the periodicity in the monthly occurrence numbers and monthly mean energy of coronal mass ejections (CMEs) observed by the Large Angle and Spectrometric Coronagraph Experiment on board the Solar and Heliographic Observatory from 1999 March to 2009 December. We also investigate the periodicity in the monthly occurrence numbers of H? flares and monthly mean flare indices from 1996 January to 2008 December. The results show the following. (1) The period of 5.66 yr is found to be statistically significant in the monthly occurrence numbers of CMEs; the period of 10.5 yr is found to be statistically significant in the monthly mean energy of CMEs. (2) The periods of 3.05 and 8.70yr are found to be statistically significant in the monthly occurrence numbers of H? flares; the period of 9.14yr is found to be statistically significant in the monthly mean flare indices.

Gao, Peng-Xin; Xie, Jing-Lan; Liang, Hong-Fei

2012-03-01

444

A finite-dimensional quantum model for the stock market  

NASA Astrophysics Data System (ADS)

We present a finite-dimensional version of the quantum model for the stock market proposed in C. Zhang and L. Huang [A quantum model for the stock market, Physica A 389 (2010) 5769]. Our approach is an attempt to make this model consistent with the discrete nature of the stock price and is based on the mathematical formalism used in the case of the quantum systems with finite-dimensional Hilbert space. The rate of return is a discrete variable corresponding to the coordinate in the case of quantum systems, and the operator of the conjugate variable describing the trend of the stock return is defined in terms of the finite Fourier transform. The stock return in equilibrium is described by a finite Gaussian function, and the time evolution of the stock price, directly related to the rate of return, is obtained by numerically solving a Schrödinger type equation.

Cotfas, Liviu-Adrian

2013-01-01

445

Multicomponent AM-FM demodulation based on energy separation and adaptive filtering  

NASA Astrophysics Data System (ADS)

Multicomponent AM-FM demodulation is an important tool in many engineering applications. To improve the demodulation accuracy of the commonly used methods, such as iterative Hilbert transform (IHT) and Hilbert-Huang transform (HHT), a new multicomponent AM-FM demodulation method is proposed in this paper. The proposed method achieves multicomponent demodulation by using an iteratively energy separation algorithm and adaptive low-pass filtering. Using the frequency spectra of instantaneous amplitude and frequency obtained by the energy separation algorithm at each level, the used filters are adaptively designed. In addition, this proposed method uses symmetric extension to solve the boundary effect in the estimation of instantaneous amplitudes and frequencies. The demodulation process is automatic for an arbitrary signal. Simulation and application results show that the proposed method has high demodulation accuracy than IHT, HHT and other typical methods, and it can be effectively applied to extracting weak fault feature from mechanical vibration signals.

Qin, Yi

2013-07-01

446

Toward fewer EEG channels and better feature extractor of non-motor imagery mental tasks classification for a wheelchair thought controller.  

PubMed

This paper presents a non-motor imagery tasks classification electroencephalography (EEG) based brain computer interface (BCI) for wheelchair control. It uses only two EEG channels and a better feature extractor to improve the portability and accuracy in the practical system. In addition, two different features extraction methods, power spectral density (PSD) and Hilbert Huang Transform (HHT) energy are compared to find a better method with improved classification accuracy using a Genetic Algorithm (GA) based neural network classifier. The results from five subjects show that using the original eight channels with three tasks, accuracy between 76% and 85% is achieved. With only two channels in combination with the best chosen task using a PSD feature extractor, the accuracy is reduced to between 65% and 79%. However, the HHT based method provides an improved accuracy between 70% and 84% for the classification of three discriminative tasks using two EEG channels. PMID:23367117

Chai, Rifai; Ling, Sai Ho; Hunter, Gregory P; Nguyen, Hung T

2012-01-01

447

Optical properties of the Bi+ center in KAlCl4  

NASA Astrophysics Data System (ADS)

Temperature behavior of the Bi+ center emission, excitation bands and luminescence decay law in KAlCl4 crystal are investigated. Abrupt changes of the monocation optical properties are observed at phase transitions of the host. The observed optical transitions are assigned to the specific energy states of Bi+ ion. It is shown that two thermalized levels are responsible for the luminescence. The experimental temperature behavior of the emission and excitation bands are in agreement with theory of electron-phonon interaction of impurity centers in solids; the effective-phonon frequencies and Huang-Rhys parameters are estimated. The configuration coordinate diagram is determined for the Bi+ center in KAlCl4 crystal.

Veber, A. A.; Romanov, A. N.; Usovich, O. V.; Fattakhova, Z. T.; Haula, E. V.; Korchak, V. N.; Trusov, L. A.; Kazin, P. E.; Sulimov, V. B.; Tsvetkov, V. B.

2014-07-01

448

Quantum studies of the vibrations in H3O2- and D3O2-.  

PubMed

The vibrations of H3O2- and D3O2- are investigated using diffusion Monte Carlo (DMC) and vibrational configuration-interaction approaches, as implemented in the program MULTIMODE. These studies use the potential surface recently developed by Huang et al. [ J. Am. Chem. Soc. 126, 5042 (2004)]. The focus of this work is on the vibrational ground state and fundamentals which occur between 100 and 3700 cm(-1). In most cases, excellent agreement is obtained between the fundamental frequencies calculated by the two approaches. This serves to demonstrate the power of both methods for treating this very anharmonic system. Based on the results of the MULTIMODE and DMC treatments, the extent and nature of the couplings in H3O2- and D3O2- are investigated. PMID:16122318

McCoy, Anne B; Huang, Xinchuan; Carter, Stuart; Bowman, Joel M

2005-08-01

449

Quantum studies of the vibrations in H3O2- and D3O2-  

NASA Astrophysics Data System (ADS)

The vibrations of H3O2- and D3O2- are investigated using diffusion Monte Carlo (DMC) and vibrational configuration-interaction approaches, as implemented in the program MULTIMODE. These studies use the potential surface recently developed by Huang et al. [ J. Am. Chem. Soc. 126, 5042 (2004)]. The focus of this work is on the vibrational ground state and fundamentals which occur between 100 and 3700 cm-1. In most cases, excellent agreement is obtained between the fundamental frequencies calculated by the two approaches. This serves to demonstrate the power of both methods for treating this very anharmonic system. Based on the results of the MULTIMODE and DMC treatments, the extent and nature of the couplings in H3O2- and D3O2- are investigated.

McCoy, Anne B.; Huang, Xinchuan; Carter, Stuart; Bowman, Joel M.

2005-08-01

450

Drift wave instability in the Io plasma torus  

NASA Technical Reports Server (NTRS)

A linear normal mode analysis of the drift wave instability in the Io plasma torus was carried out on the basis of the Richmond (1973) and Huang et al. (1990) analyses of drift waves in the vicinity of the earth's plasmapause. Results indicate that the outer torus boundary is linearly unstable to the growth of electrostatic drift waves. It is shown that the linear growth rate is proportional to the ion drift frequency and to the ratio of the flux tube charge content to the Jovian ionospheric Pedersen conductance. It is also shown that various theoretical models of global radial transport in Jupiter's atmosphere (including corotating convection, interchange diffusion, and transient flux tube convection) can be understood as plausible nonlinear evolutions of electrostatic drift waves.

Huang, T. S.; Hill, T. W.

1991-01-01

451

First-principles study of bubble nucleation and growth behaviors in ? U-Zr  

NASA Astrophysics Data System (ADS)

Bubble nucleation and growth is responsible for swelling in metallic fuels such as U-Zr. Computational modeling is useful for understanding and ultimately developing mitigation strategies for the swelling behavior of the fuel. However, the relevant fundamental parameters are not currently available. In our previous work, the formation energy and migration barrier of uranium vacancies and interstitials in ? U have been obtained by first-principles calculations, and the calculated diffusion activation energy agrees reasonably well with the experimental results, within 0.1 eV (Huang and Wirth 2011 J. Phys.: Condens. Matter 23 205402). In this paper, the formation energy and migration barrier of Xe, Zr, Pu, in addition to the binding energy of small vacancy clusters, Xe-vacancy clusters, and small interstitial clusters are investigated. These are among the essential data essential for the analysis and computational modeling of swelling in metallic nuclear fuel.

Huang, Gui-Yang; Wirth, B. D.

2012-10-01

452

Comparison of Signals from Gravitational Wave Detectors with Instantaneous Time-Frequency Maps  

NASA Technical Reports Server (NTRS)

Gravitational wave astronomy relies on the use of multiple detectors, so that coincident detections may distinguish real signals from instrumental artifacts, and also so that relative timing of signals can provide the sky position of sources. We show that the comparison of instantaneous time-frequency and time-amplitude maps provided by the Hilbert-Huang Transform (HHT) can be used effectively for relative signal timing of common signals, to discriminate between the case of identical coincident signals and random noise coincidences and to provide a classification of signals based on their time-frequency trajectories. The comparison is done with a X(sup 2) goodness-offit method which includes contributions from both the instantaneous amplitude and frequency components of the HHT to match two signals in the time domain. This approach naturally allows the analysis of waveforms with strong frequency modulation.

Stroeer, A.; Blackburn, L.; Camp, J.

2011-01-01

453

Skeleton graph expansion of critical exponents in "cultural revolution" years  

NASA Astrophysics Data System (ADS)

Kenneth Wilson's Nobel Prize winning breakthrough in the renormalization group theory of phase transition and critical phenomena almost overlapped with the violent "cultural revolution" years (1966-1976) in China. An unexpected chance in 1972 brought the author of these lines close to the Wilson-Fisher ?-expansion of critical exponents and eventually led to a joint paper with Lu Yu published entirely in Chinese without any English title and abstract. Even the original acknowledgment was deleted because of mentioning foreign names like Kenneth Wilson and Kerson Huang. In this article I will tell the 40-year old story as a much belated tribute to Kenneth Wilson and to reproduce the essence of our work in English. At the end, I give an elementary derivation of the Callan-Symanzik equation without referring to field theory.

Hao, Bailin

2014-04-01

454

Effects of various drug therapies on Kleine-Levin syndrome: a case report.  

PubMed

Kleine-Levin syndrome (KLS) is a rare sleep disorder, predominantly affecting adolescent males, which presents as recurrent episodes of hypersomnia, behavioral and cognitive disturbances, hyperphagia and sometimes hypersexuality (Lisk, "Kleine-Levin syndrome." Pract Neurol 2009;9:42-45). Modafinil has been reported to show an effect in shortening the duration of symptomatic periods, but does not affect the recurrence rate (Huang et al., "Kleine-Levin syndrome: current status." Med Clin N Am 2010;94:557-562). However, no single drug therapy has been consistently successful, despite various psychotropic agents, including lithium, anticonvulsants and antidepressants, having been systematically tried (Arnulf et al., "Kleine-Levin syndrome: a systematic study of 108 patients." Ann Neurol 2008;63:482-492). This study reports a male adolescent with KLS who received several courses of drug therapy, providing a chance to compare differential drug effects over time. PMID:22520717

Yao, Chi-Chun; Lin, Ying; Liu, Hui-Ching; Lee, Chau-Shoun

2013-01-01

455

Berberine induces double-strand DNA breaks in Rev3 deficient cells.  

PubMed

Berberine is a natural isoquinoline alkaloid, the majority of which is extracted from Huang Lian and other medicinal herbs. Numerous studies have revealed that berberine exhibits anticancer activity, however the mechanisms underlying this effect remain elusive. To examine these mechanisms, we analyzed the effects of berberine on a panel of DNA repair deficient chicken B lymphocyte (DT40) clones. Our results revealed that DT40 cells deficient in Rev3 (Rev3-/-), a translesion DNA synthesis (TLS) gene, were hypersensitive to berberine. Following berberine treatment, cell cycle analysis identified that G2/M arrest was increased in Rev3-/- cells. Furthermore, compared with wild-type cells (WT), berberine also induced a significant increase in double-strand breaks (DSBs) in Rev3-/- cells, as revealed by chromosomal aberration (CA) analysis. These results suggest that berberine is able to induce DNA damage, and that the Rev3 associated DNA repair pathway participates in the processes that aid its repair. PMID:24584584

Hu, Xiaojuan; Wu, Xiaohua; Huang, Yunfei; Tong, Qingyi; Takeda, Shunichi; Qing, Yong

2014-05-01

456

Spin relaxation assisted by optical phonon scattering in quantum dots: Dresselhaus versus Rashba spin-orbit coupling  

NASA Astrophysics Data System (ADS)

In the frame of the Huang-Rhys's model, we theoretically investigate the spin relaxation via longitudinal optical phonon scattering in quantum dots by considering the effect of lattice relaxation that arises from the electron-deformation potential acoustic phonon coupling. We find that the relaxation rate displays a cusp-like structure for both the Dresselhaus spin-orbit coupling (SOC) and Rashba SOC mechanisms. We compare the relaxation rates between these two mechanisms and find that the contribution of the Dresselhaus mechanism to the relaxation rate is one order of magnitude larger than the Rashba case at the same SOC strength. However, the same contribution can be obtained when the Rashba SOC strength is four times the Dresselhaus case. In addition, the influences of the external magnetic field and temperature on the relaxation rates are also qualitatively discussed.

Li, Wei-Ping; Li, Shao-Juan; Yin, Ji-Wen; Yu, Yi-Fu; Wang, Zi-Wu

2014-08-01

457

Azimuthal correlation of charm quark pair produced in heavy ion collision  

NASA Astrophysics Data System (ADS)

It is known that heavy quarks are produced in pairs. There always exists a correlation in azimuthal angle in transverse momentum plane between the members in a pair. The quark and anti-quark in a pair may lose different amount of energy while traveling through QGP and it is expected that the correlation of Qbar Q will alter considerably. Also in a complete different picture, collective flow of the medium can change the correlation of heavy quark pair. Here we present the effect of charm quark energy loss based on Wang-Huang-Sarcevic model on its correlation. The flow feature is shown using a naive model based on Cautle-Páic model.

Younus, Mohammed; Srivastava, Dinesh K.

2014-04-01

458

The distribution-based p-value for the outlier sum in differential gene expression analysis  

PubMed Central

Outlier sums were proposed by Tibshirani & Hastie (2007) and Wu (2007) for detecting outlier genes where only a small subset of disease samples shows unusually high gene expression, but they did not develop their distributional properties and formal statistical inference. In this study, a new outlier sum for detection of outlier genes is proposed, its asymptotic distribution theory is developed, and the p-value based on this outlier sum is formulated. Its analytic form is derived on the basis of the large-sample theory. We compare the proposed method with existing outlier sum methods by power comparisons. Our method is applied to DNA microarray data from samples of primary breast tumors examined by Huang et al. (2003). The results show that the proposed method is more efficient in detecting outlier genes.

Chen, Lin-An; Chen, Dung-Tsa; Chan, Wenyaw

2010-01-01

459

Alternative therapies: Part I. Depression, diabetes, obesity.  

PubMed

Natural supplements are widely used in the United States and, while claims of their therapeutic effects abound, medical research does not always support their effectiveness. St. John's wort acts as a weak selective serotonin reuptake inhibitor with fewer side effects. S-Adenosylmethionine (SAMe) has enough of an antidepressant effect to warrant further research. More human studies are needed before garlic, bitter melon, soy and fenugreek supplements can be recommended for the management of diabetes, although chromium may be a promising treatment in some cases. Alpha lipoic acid is used in the treatment of diabetic neuropathy. The effects of ma huang/guarana combinations in obesity have not been well studied. These combinations may have potentially serious side effects but may also offer some benefit. The combination of hydroxycitric acid and garcinia has proved no more effective than placebo. PMID:10997530

Morelli, V; Zoorob, R J

2000-09-01

460

Nanobeacons: Far-field-radiating nanoscale optical waveguides  

NASA Astrophysics Data System (ADS)

Some of us have recently demonstrated that visible light can be transmitted through coaxial waveguides having subwavelength transverse dimensions [1]. Here, we used focused ion beam-assisted (FIB) deposition to precisely position and fabricate vertical nanopillars that will function as inner conductors of nanocoaxial optical waveguides. The coax annuli were prepared by atomic layer deposition of a 100 nm thick conformal oxide coating, with sputtered metal used for the outer electrodes. Using high resolution optical microscopy, we successfully demonstrated the transmission of visible light into, along and out of these subwavelength nanocoaxes prepared by this in situ FIB method. The macroscopic distance between the coax termini and the detecting microscope confirms that the nanocoaxes are functioning as ``nanobeacons'', radiating far-field light.[4pt][1] J. Rybczynski, K. Kempa, A. Herczynski, Y. Wang, M.J. Naughton, Z.F. Ren, Z.P. Huang, D. Cai, and M. Giersig, Appl. Phys. Lett. 90, 021104 (2007).

Dhakal, Pashupati; Peng, Yun; McMahon, G.; Kempa, K.; Naughton, M. J.

2010-03-01

461

Complex dynamics of a delayed discrete neural network of two nonidentical neurons.  

PubMed

In this paper, we discover that a delayed discrete Hopfield neural network of two nonidentical neurons with self-connections and no self-connections can demonstrate chaotic behaviors. To this end, we first transform the model, by a novel way, into an equivalent system which has some interesting properties. Then, we identify the chaotic invariant set for this system and show that the dynamics of this system within this set is topologically conjugate to the dynamics of the full shift map with two symbols. This confirms chaos in the sense of Devaney. Our main results generalize the relevant results of Huang and Zou [J. Nonlinear Sci. 15, 291-303 (2005)], Kaslik and Balint [J. Nonlinear Sci. 18, 415-432 (2008)] and Chen et al. [Sci. China Math. 56(9), 1869-1878 (2013)]. We also give some numeric simulations to verify our theoretical results. PMID:24697370

Chen, Yuanlong; Huang, Tingwen; Huang, Yu

2014-03-01

462

Remote sensing and hydrogeological methodologies for irrigation canal leakage detection: the Osasco and Fossano test sites (NorthWestern Italy)  

NASA Astrophysics Data System (ADS)

Seventy percent of global fresh water is usually used for irrigation. This rate is three times the amount of water used by industry and ten times the amount used in domestic and urban environment (Hotchkiss et al., 2001). However, the average efficiency of the water transport for agricultural purposes in different contexts (at world scale) is variable between 30% and 80%. Studies conducted in Italy confirms that rates are similar from the case studies abroad. In this research, satellite image analysis and hydrological-hydrogeological methods were used in two pilot sites (Osasco channel and Fossano channel, in the Noth-Western Italy) to identify the areas most prone to this problem and to quantify the losses. The aim of the study is to define a multidisciplinary approach in order to identify the critical situations of irrigation channels for a sustainable water resource use and management. The use of remote sensing techniques can identify, on a regional scale and at relative low cost, the channels section potentially critical upon which focus the attention and perform in-situ investigation. The presence of leakage from the irrigation canals, indeed, tends to induce variations of moisture on the surface ground. These variations affect the vegetation (e.g. vegetation state), and certain physical characteristics of the soil (e.g. the capacity and thermal conductivity). The analysis of these anomalies, conducted with digital image processing techniques (with infrared spectrum bands particularly sensitive to the above indicators) help to identify those areas with anomalies related to increased losses (Huang and Fipps, 2002). The use of satellite imagery in the proposed approach is an innovative application of Earth Observation for land and water monitoring (Huang et al., 2005). After the identification of anomalies, hydrological-hydrogeological methods were applied to evaluate the losses. At fist an hydrogeological characterisation of the study area and the bottom of the irrigation channel were conducted. Then the canals seepage rates were estimated using inflow-outflow tests and tests with double-tracer, an adaptation from QUEST method (Rieckermann and Gujer, 2002). This approach allowed an experimental calibration and validation of the satellite images analysis. The applied multidisciplinary approach seem to be a promising way for a good general screening for a rapid detection of irrigation channels water losses. References Hotchkiss, R.H., Wingert, C.B., Kelly, W.E., 2001. Determining irrigation canal seepage with electrical resistivity. ASCE J. Irrig. Drain 127, 20-26. Huang Y and Fipps G. (2002). Thermal Imaging of Canals for Remote Detection of Leaks: Evaluation in the United Irrigation District. Technical Report. Biological and Agricultural Engineering Department, Texas A&M University. Huang Y, Fipps G, Maas S, Fletcher R. (2005). Airborne multispectral remote sensing imaging for detecting irrigation canal leaks in the lower rio grande valley - 20th Biennial Workshop on Aerial Photography, Videography, and High Resolution Digital Imagery for Resource Assessment October 4-6, Weslaco, Texas. Rieckermann J., Gujer W. (2002) - Quantifying Exfiltration from Leaky Sewers with Artificial Tracers - Proceedings of the International Conference on "Sewer Operation and Maintenance. 2002", Bradford, UK.

Perotti, Luigi; Clemente, Paolo; De Luca, Domenico Antonio; Dino, Giovanna; Lasagna, Manuela

2013-04-01

463

Origin of long-lived coherences in light-harvesting complexes.  

PubMed

A vibronic exciton model is applied to explain the long-lived oscillatory features in the two-dimensional (2D) electronic spectra of the Fenna-Matthews-Olson (FMO) complex. Using experimentally determined parameters and uncorrelated site energy fluctuations, the model predicts oscillations with dephasing times of 1.3 ps at 77 K, which is in a good agreement with the experimental results. These long-lived oscillations originate from the coherent superposition of vibronic exciton states with dominant contributions from vibrational excitations on the same pigment. The oscillations obtain a large amplitude due to excitonic intensity borrowing, which gives transitions with strong vibronic character a significant intensity despite the small Huang-Rhys factor. Purely electronic coherences are found to decay on a 200 fs time scale. PMID:22642682

Christensson, Niklas; Kauffmann, Harald F; Pullerits, Tõnu; Man?al, Tomáš

2012-06-28

464

The bromine content of micrometeorites - Arguments for stratospheric contamination  

NASA Technical Reports Server (NTRS)

Bromine-salt nanocrystals are associated with a porous chondritic micrometeorite (W7029E5) that was collected in the lower stratosphere. These salt nanocrystals occur together with volcanic Na and K salt nanocrystals embedded in sulfuric acid droplets that were originally adhered to the particle. These materials were concentrated during hexane rinsing as part of routine curation procedures at the NASA Johnson Space Center Cosmic Dust Curatorial Facility. This observation is fortuitous to the extent that the concentration of nanocrystals and sulfuric acid is an experimental artifact of curation. If bromine is a stratospheric contaminant due to surface adsorption, there should be a positive linear relationship between the mass-normalized residence time and bromine content of individual micrometeorites. I show that the predicted correlation exists using a new model to calculate the stratospheric residence time of individual nonspherical micrometeorites in the slow-settling Wilson-Huang regime of the stratosphere.

Rietmeijer, Frans J. M.

1993-01-01

465

Herbs in exercise and sports  

PubMed Central

The use of herbs as ergogenic aids in exercise and sport is not novel. Ginseng, caffeine, ma huang (also called 'Chinese ephedra'), ephedrine and a combination of both caffeine and ephedrine are the most popular herbs used in exercise and sports. It is believed that these herbs have an ergogenic effect and thus help to improve physical performance. Numerous studies have been conducted to investigate the effects of these herbs on exercise performance. Recently, researchers have also investigated the effects of Eurycoma longifolia Jack on endurance cycling and running performance. These investigators have reported no significant improvement in either cycling or running endurance after supplementation with this herb. As the number of studies in this area is still small, more studies should be conducted to evaluate and substantiate the effects of this herb on sports and exercise performance. For instance, future research on any herbs should take the following factors into consideration: dosage, supplementation period and a larger sample size.

2012-01-01

466

Exciton-LO-phonon interaction in CuCl spherical quantum dots studied by resonant hyper-Raman spectroscopy  

NASA Astrophysics Data System (ADS)

Resonant hyper-Raman-scattering spectroscopy was applied for studies of the exciton-LO-phonon interaction in spherical CuCl nanocrystals of different sizes embedded in a glass matrix. Both the LO and 2LO phonon bands have shown a prominent resonance with the lowest energy 1S confined exciton state. The ratio of the integral intensities of the LO and 2LO bands ? was found to increase with increase of the incident photon energy, or decrease of the nanocrystal radius. The Huang-Rhys factor S has been calculated as a function of the nanocrystal size from the experimentally measured values of ? on the offset harmonic-oscillator model of electron-vibrational coupling. It has been found that S increases monotonically from 0.22 to 0.7, with the nanocrystal radius decreasing from 3.6 to 1.6 nm.

Baranov, A. V.; Yamauchi, S.; Masumoto, Y.

1997-10-01

467

Solution of evolutionary partial differential equations using adaptive finite differences with pseudospectral post-processing  

SciTech Connect

A coordinate transformation approach is described that enables pseudospectral methods to be applied efficiently to unsteady differential problems with steep solutions. The work is an extension of a method presented by Mulholland, Huang, and Sloan for the adaptive pseudospectral solution of steady problems. A coarse grid is generated by a moving mesh finite difference method that is based on equidistribution, and this grid is used to construct a time-dependent coordinate transformation. A sequence of spatial transformations may be generated at discrete points in time, or a single transformation may be generated as a continuous function of space and time. The differential problem is transformed by the coordinate transformation and then solved using a method that combines pseudospectral discretisation in space with a suitable integrator in time. Numerical results are presented for unsteady problems in one space dimension. 18 refs., 8 figs., 12 tabs.

Mulholland, L.S.; Qiu, Y.; Sloan, D.M. [Univ. of Strathclyde, Glasgow (United Kingdom)] [Univ. of Strathclyde, Glasgow (United Kingdom)

1997-03-01

468

Graduating Underrepresented African American, Latino, and American Indian Students in Science  

NASA Astrophysics Data System (ADS)

African American, Latino, and American Indian students are less likely to graduate in science than comparable White and Asian students (Gándara & Maxwell-Jolly, 1999; Huang, Taddese, & Walter, 2000). After controlling for preparation and need (p < .05), logistic regression modeling of data from the University of Colorado, Boulder, confirmed this. However, students in the University of Colorado Minority Arts and Sciences Program (MASP) were more likely to graduate in science than White and Asian students (p < .05). MASP students valued the program's financial support, academic community, and relationships with professors, but not, notably, academic enrichment workshops. This finding provides insight into factors that increase retention of well prepared African American, Latino, and American Indian students and calls for further research and theory.

Johnson, Angela

469

Berezinskii-Kosterlitz-Thouless Transition in Heavy Fermion Superlattices  

NASA Astrophysics Data System (ADS)

We propose an explanation of the superconducting transitions discovered in the heavy fermion superlattices by Mizukami et al. (Nature Physics 7, 849 (2011)) in terms of Berezinskii-Kosterlitz-Thouless transition. We observe that the effective mass mismatch between the heavy fermion superconductor and the normal metal regions provides an effective barrier that enables quasi 2D superconductivity in such systems. We show that the resistivity data, both with and without magnetic field, are consistent with BKT transition. Furthermore, we study the influence of a nearby magnetic quantum critical point on the vortex system, and find that the vortex core energy can be significantly reduced due to magnetic fluctuations. Further reduction of the gap with decreasing number of layers is understood as a result of pair breaking effect of Yb ions at the interface. Reference: Jian-Huang She, Alexander V. Balatsky, Phys. Rev. Lett. 109, 077002 (2012)

She, Jian-Huang; Balatsky, Alexander

2013-03-01

470

Towards Nuclear Polarization of Nanodiamond  

NASA Astrophysics Data System (ADS)

Nanoparticles with long nuclear spin relaxation times [1] are candidates for use in targeted therapeutic delivery [2] and magnetic resonance imaging [3]. We report progress towards the development of contrast agents based on 13C in nanodiamond. Nuclear relaxation and electron spin resonance data is presented. We describe the development of a DNP setup at X band frequencies based on an ENDOR cavity, together with a novel brute force setup that combines milli-Kelvin temperatures of a dilution refrigerator, high magnetic fields and fast sample exchange. [1] J. Aptekar, et al., ACS Nano, 3, 4003-4008 (2009). [2] H. Huang , E. Pierstorff, E. Osawa, and D. Ho, Nano Lett, 7, 3305-3314 (2007). [3] L Manus T. J. Meade, Nano Lett, 10, 484-489 (2010).

Rej, Ewa; Waddington, David; Gaebel, Torsten; Reilly, David

2013-03-01

471

Nonlinear, non-stationary image processing technique for eddy current NDE  

NASA Astrophysics Data System (ADS)

Automatic analysis of eddy current (EC) data has facilitated the analysis of large volumes of data generated in the inspection of steam generator tubes in nuclear power plants. The traditional procedure for analysis of EC data includes data calibration, pre-processing, region of interest (ROI) detection, feature extraction and classification. Accurate ROI detection has been enhanced by pre-processing, which involves reducing noise and other undesirable components as well as enhancing defect indications in the raw measurement. This paper presents the Hilbert-Huang Transform (HHT) for feature extraction and support vector machine (SVM) for classification. The performance is shown to significantly better than the existing rule based classification approach used in industry.

Yang, Guang; Dib, Gerges; Kim, Jaejoon; Zhang, Lu; Xin, Junjun; Udpa, Lalita

2012-05-01

472

Giant Efficiency of Fröhlich Interaction in Self-Assembled Quantum Dots  

NASA Astrophysics Data System (ADS)

A transition is being observed from an inhomogeneously broadened photoluminescence band under non-resonant excitation of InAs/GaAs Self-Assembled quantum Dots (SAD's) into up to five phonon-assisted emission bands under selective excitation. A similar effect is obtained from photoluminescence excitation experiments (PLE). We interpret the phonon-assisted PL as being due to a giant efficiency of the Fröhlich interaction between an exciton polarized by strain in the SAD and LO-phonons. The model is consistent with the pronounced p-type polarization of the emission observed in our cleaved-side PL-measurements. Further support is obtained from our calculations in which a different localization of the electrons and holes is assumed: The limiting case of this theoretical framework gives a Huang-Rhys factor of ˜ 0.1, which is the same order of magnitude as the experimental value.

Minnaert, A. W. E.; Silov, A. Yu.; Haverkort, J. E. M.; Wolter, J. H.; Garcia, A.; Gladilin, V. N.; Fomn, V. M.; Devreese, J. T.

1999-04-01