We seek optimal methods of estimating power spectrum and chirp (frequency change) rate for the case that one has incomplete noisy data on values y(t) of a time series. The Schuster periodogram turns out to be a \su cient statistic" for the spectrum, a generalization playing the same role for chirped signals. However, the optimal processing is not a linear ltering operation like the Blackman{Tuk...

Spectral depth-profiling of optically turbid samples is of high interest to a broad range of applications. We present a method for measuring spatially-offset Raman spectroscopy (SORS) over a range of length scales by incorporating a digital micro-mirror device (DMD) into a sample-conjugate plane in the detection optical path. The DMD can be arbitrarily programmed to collect/reject light at spat...

Takashi Kawamura, Hiroshi Shimotahira, Akihito Otani [Summary] Rapid progress in millimeter-wave wireless communication technologies requires accurate spectrum analysis in the frequency domain over 100 GHz. A tunable preselection filter is a key device in building such a spectrum analyzer. This paper proposes a new tunable filter as a preselector in the frequency range from 110 to 140 GHz. The ...

The coherence analysis is based on spectral analysis, which describe the synchronization of electroencephalogram (EEG) rhythms between brain areas. Coherence analysis is a noninvasive technique for studying functional relationships between brain regions. The coherence analysis is a kind of study based on spectrum analysis, which can describe the coordination of the brain electric activities of ...

The Swept Wavelength Optical Resonant Raman Detector (SWOrRD) at the Naval Research Laboratory is scanned through the 220 nm to 260 nm window of the ultraviolet and generates two dimensional spectral maps allowing for rapid identification of chemical materials. We create a library of chemicals whose Raman spectral features partially overlap and then measure the mixtures created by combinations ...

Objectives: The incidence of stereotyped behaviors is one of the major symptoms of diagnosis of individuals with autism spectrum disorder that causes disruption in daily life. This study aimed at evaluating the effectiveness of ball exercises on the reduction of stereotypical behavior of children with autism spectrum disorder. Methods: In this study, 16 children (boys) with autism spectrum dis...

Fine-scale spatial information on soil properties is needed to successfully implement precision agriculture. Proximal gamma-ray spectroscopy has recently emerged as a promising tool to collect fine-scale soil information. The objective of this study was to evaluate a proximal gamma-ray spectrometer to predict several soil properties using energy-windows and full-spectrum analysis methods in two...

Real-time electrical spectrum analysis is of great significance for applications involving radio astronomy and electronic warfare, e.g. the dynamic spectrum monitoring of outer space signal, and the instantaneous capture of frequency from other electronic systems. However, conventional electrical spectrum analyzer (ESA) has limited operation speed and observation bandwidth due to the electronic...