28 papers · ranked by Valyu relevance
David B. Chorlian, Jacquelyn L. Meyers, Andrey Anokhin, Chella Kamarajan + 4 more
Trajectories of resting state monopolar EEG power were analyzed using the means, variances, and correlations of data in seven frequency bands obtained from 17 electrodes of the 10-20 system from a sample of 5238 participants from the Collaborative Study on the Genetics of Alcoholism (COGA) with 11906 observations from…
Raanju R. Sundararajan, Scott A. Bruce
Information from frequency bands in biomedical time series provides useful summaries of the observed signal. Many existing methods consider summaries of the time series obtained over a few well-known, pre-defined frequency bands of interest. However, these methods do not provide data-driven methods for identifying…
Michael X Cohen
Electrophysiological recordings of the brain often exhibit neural oscillations, defined as narrowband bumps that deviate from the background power spectrum. These narrowband dynamics are grouped into frequency ranges, and the study of how activities in these ranges are related to cognition and disease is a major part…
Golan Karvat, Maité Crespo-García, Gal Vishne, Michael C Anderson + 1 more
Understanding the organizing principles of brain activity can advance neuro-technology and medical diagnosis and treatment. A prominent principle promoted over the last century is that brain activity consists of electrical field potentials that oscillate at different frequency bands. However, this principle has been…
Biao Sun, Zhigang Wei, Pei Liang, Hui-Rang Hou
—Classification of olfactory-induced electroencephalogram (EEG) signals has shown great potential in many fields. Since different frequency bands within the EEG signals contain different information, extracting specific frequency bands for classification performance is important. Moreover, due to the large…
Zhu-Qing Gong, Xi-Nian Zuo
Neural oscillations are fundamental for brain function, governing various cognitive processes. While electrophysiological studies have characterized the frequency properties of these oscillations, their spatial resolution is limited. In contrast, functional magnetic resonance imaging (fMRI) provides high spatial…
W. Liang, D. Eliyahu, V. S. Ilchenko, A. A. Savchenkov + 3 more
'A. B. Matsko' 'D. Seidel' 'L. Maleki'] Femtosecond laser-based generation of radio frequency signals has produced astonishing improvements in achievable spectral purity, one of the basic features characterizing the performance of an radio frequency oscillator. Kerr frequency combs hold promise for transforming these…
P. Markoš
We show that the frequency spectrum of two dimensional photonic crystals is strongly influenced by Fano resonances which can be excited already in the linear array of dielectric cylinders. To support this claim, we calculate the transmission of electromagnetic wave through linear array of dielectric cylinders and show…
Dong Ma, Pengcheng Zuo, Yang Chen
A novel photonic approach to the time-frequency analysis of microwave signals is proposed based on the stimulated Brillouin scattering (SBS)-assisted frequency-to-time mapping (FTTM). Two types of time-frequency analysis links, namely parallel SBS link and time-division SBS link are proposed. The parallel SBS link can…
Xingyuan Xu, Mengxi Tan, Jiayang Wu, Thach G. Nguyen + 5 more
'Brent E. Little' 'Roberto Morandotti' 'Arnan Mitchell' 'David Moss'] > We demonstrate high-resolution photonic RF filters using an RF bandwidth scaling approach based on integrated Kerr optical micro-combs. By employing both an active nonlinear micro-ring resonator (MRR) as a high-quality micro-comb source and a…
Yongchae Jeong, Phanam Pech, Lifeng Wang
This paper presents a design approach for a dual-band substrate-integrated waveguide (SIW) bandpass filter (BPF) featuring passband tunability and wide-stopband characteristics. The proposed circuit is realized using half-mode (HM) SIW cavities loaded with tunable stopband resonators (TSRs). The TSRs are realized using…
Abdullah J. Alazemi, Guo Liu
In this paper, two bandpass filters-one with a dual-band response and the other with a wideband response-were designed, implemented, and experimented with. The filters are based on the novel combination of series coupled lines and tri-stepped impedance stubs. However, coupled lines along with tri-stepped impedance open…
Quentin Perrenoud, Jessica A. Cardin
Cognitive and behavioral processes are often accompanied by changes within well-defined frequency bands of the local field potential (LFP i.e., the voltage induced by neuronal activity). These changes are detectable in the frequency domain using the Fourier transform and are often interpreted as neuronal oscillations.…
Amelia Carolina Sparavigna
Tsallis q-Gaussian functions are probability distributions possessing a shape which can be stretched from a Lorentzian to a Gaussian profile, according to the q-index parameter of their generalized exponentials. As we have previously shown, the q-Gaussian functions can be successfully applied to the deconvolution of…
Hannah M. Ogden, Joseph B. Murray, Matthew J. Murray, Brandon Redding
'Brandon Redding'] Frequency shifting loops, consisting of a fiber optic ring cavity, a frequency modulator, and an amplifier to compensate for loss, enable high-speed frequency scanning with precise and easily controlled frequency steps. This platform is particularly attractive for applications in spectroscopy and…
Nitin Muchhal, Abhay Kumar, Nidhi Tewari, Samriti Kalia + 2 more
'Shweta Srivastava' 'Ai-Qun Liu'] A substrate-integrated waveguide (SIW) bandpass filter (BPF) with extraordinary selectivity and an adequate upper stopband for C-band Satellite Communication (SATCOM) applications is proposed in this paper. The design comprises comb-shaped slots engraved on a half-mode SIW (HMSIW) that…
H. Schmickler
Depending on the application people use time-domain or frequency-domain signals in order to measure or describe processes. First we will look at the definition of these terms, produce some mathematical background and then apply the tools to measurements made in the accelerator domain. We will first look at signals…
Jason Samaha, Michael X Cohen
Oscillatory neural dynamics are highly non-stationary and require methods capable of quantifying time-resolved changes in rhythmic activity in order to understand neural function. Recently, a method termed ‘frequency sliding’ was introduced to estimate the instantaneous frequency of oscillatory activity, providing a…
Amelia Carolina Sparavigna
Recently, we have considered the Raman spectra of graphene and graphene oxide to understand the number of lines and the line shapes to be used for decomposing the spectra. Here we review some literature about the Raman spectroscopy of carbon nanotubes, focusing especially on the line shapes. As shown by literature, the…
Md Abu Zobair, Behzad Boroomandisorkhabi, Mina Esmaeelpour, Minh Long Hoang + 1 more
'Minh Long Hoang' 'Vikram Pakrashi'] This review explores various advanced photonic-assisted techniques for microwave frequency measurement, highlighting their distinct advantages and challenges in detecting multi-tone and broadband microwave frequency signals. Different optical processing techniques for instantaneous…
Authors not listed
We present a coupled-oscillator toy model that describes the low-frequency lattice-like vibrations observed in Raman and inelastic neutron scattering spectra of β-sheet structures found in amyloid fibrils. In this model, the strands of the fibril β-sheet structures are treated as harmonically oscillating rods with…
Authors not listed
We report on how low-frequency Raman measurements can be used as a facile tool to investigate the supramolecular structure of amyloid fibrils. We investigate the low-frequency Raman spectra (< 500 cm−1) of six different amyloid fibrils exhibiting parallel β-sheet structures prepared from amyloid-β1−40, amylin…
Pengcheng Zuo, Ma Dong, Xiaowei Li, Yang Chen
In this paper, the filter- and frequency-to-time mapping (FTTM)-based photonics-assisted time and frequency acquisition methods are comprehensively analyzed and the accuracy and resolution limitation in the fast sweep scenario is broken by broadening the filter bandwidth. It is found that when the sweep speed is very…
Amelia Carolina Sparavigna
A large literature exists about the Raman spectroscopy of water. Here we present some articles regarding the spectral region between 2800 and 3800 cm−1, that is the O-H stretching Raman band, and the proposed decomposition obtained by means of Gaussian profiles. We will also consider the decomposition of this region…
Shuyi Liu, Yan Jia, Yongqing Liu, Xiangkun Zhang + 1 more
Ultra-wideband (UWB) nonlinear frequency modulation (NLFM) waveforms have the advantages of low sidelobes and high resolution. By extending the frequency domain wideband synthesis method to the NLFM waveform, the synthetic bandwidth will be limited, and the grating lobe will grow as the number of subpulses increases at…
Qianqian Jia, Zichuan Xiang, Dechen Li, Jianguo Liu + 3 more
'Der-Yuh Lin' 'Chia-Feng Lin'] A simple microwave photonic, reconfigurable, instantaneous frequency measurement system based on low-voltage thin-film lithium niobate on an insulator phase modulator is put forward and experimentally demonstrated. Changing the wavelength of the optical carrier can realize the flexibility…
Authors not listed
Pyrite is identifiable. The Iron (II) disulfide [FeS2] structure becomes isoclinic with minimal tetragonal [CuFeS2], orthorhombic [FeS 2 ], or monoclinic [AsFeS 2 ] forms. Physical examination validates crystal structure and composition. A tetragonal, pale brassy yellow, 6.0 Moh’s hardness, indistinct cleavage, 4.68…
Rijia Khatun, Koushik Majhi, Subrata Sinha
In our previous work (Khatun et al., J. Phys. Chem. A 122 (2018) 7089-7098), synthesis and characterization of sulfonated polyaniline (SPANI) were discussed. Photophysical properties of SPANI in aqueous medium were also investigated using steady state spectroscopic techniques, which suggested the co-existence of two…