scholarly journals Sharper in the morning: Cognitive time of day effects revealed with high-frequency smartphone testing

2022 ◽  
pp. 1-13
Author(s):  
Hannah Wilks ◽  
Andrew J. Aschenbrenner ◽  
Brian A. Gordon ◽  
David A. Balota ◽  
Anne M. Fagan ◽  
...  
Keyword(s):  
High Frequency ◽  
Time Of Day

scholarly journals Sundown syndrome in patients with Alzheimer’s disease dementia

2019 ◽  
Vol 13 (4) ◽  
pp. 469-474 ◽  
Author(s):  
Cristiani Sartorio Menegardo ◽  
Fernanda Alencar Friggi ◽  
Julia Baldon Scardini ◽  
Tais Souza Rossi ◽  
Thais dos Santos Vieira ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
High Frequency ◽  
Neuropsychiatric Symptoms ◽  
Time Of Day ◽  
Neuropsychiatric Inventory ◽  
Cross Sectional ◽  
Symptom Intensity ◽  
The Family ◽  
Alzheimer’S Disease Dementia

ABSTRACT The sundown syndrome is a complex neurobehavioral disorder in patients with dementia associated with high financial cost and significant caregiver burden. It is a multifactorial phenomenon with unclear pathophysiology, characterized by the presence of neuropsychiatric symptoms in the evening period. Objective: To analyze the main neuropsychiatric symptoms, their correlation with one another, with comorbidities, and with time of day of greatest symptom intensity in patients with Alzheimer’s disease dementia. Methods: This is a cross-sectional, observational and explanatory study in which caregivers/relatives of elderly patients with dementia were interviewed using a structured tool called the Neuropsychiatric Inventory (NPI). Results: The sample studied was composed of 38 patients, 60.5% female and 39.5% male, with mean age of 81±6 (67-94) years. A high frequency of neuropsychiatric symptoms in the evening period was observed, predominantly irritability (55.3%), nocturnal behavior (47.4%), and aggressiveness (42.1%). Only 36.8% of the family caregivers used non-pharmacological strategies. Conclusion: The frequency of neuropsychiatric symptoms was exacerbated in the evening among patients with Alzheimer’s disease, especially for those behavioral symptoms that had a positive correlation with one another.

Variations in broadband seismic noise at IRIS/IDA stations in the USSR with implications for event detection

1990 ◽  
Vol 80 (6B) ◽  
pp. 2072-2088 ◽  
Author(s):  
Holly K. Given
Keyword(s):  
Noise Reduction ◽  
High Frequency ◽  
Signal To Noise Ratio ◽  
Low Frequency ◽  
Time Of Day ◽  
Signal Frequency ◽  
Seasonal Effect ◽  
Noise Levels ◽  
Power Spectral ◽  
Lower Noise

Abstract Ambient noise conditions at four IRIS/IDA sites in the USSR are characterized from 0.01 to 100 Hz as part of a study to ascertain the utility of broadband three-component seismic stations in monitoring regional Eurasian seismicity. Estimates of the power spectral density of noise levels were computed for a 5-day period in two seasons (winter and summer), at two times of the day. Of these periods, lower noise conditions were found at night in the summer. In general, at 1 Hz and above, noise levels and their variations correlate predictably with the soundness of vault construction and the proximity of the station to civilization. Absolute noise levels at the IRIS/IDA/USSR sites range from a high of about −120 dB to a low of −155 dB relative to (1 m/s2)2/Hz, between 1 and 5 Hz. A time-of-day variation in noise was observed at all sites, with noise levels during the work day ranging from 7 to 14 dB higher than night levels, depending on the site. This effect was observed only for frequencies above about 1 Hz. Observed seasonal variations (winter versus summer) are highly station dependent, although the seasonal effect is restricted to frequencies below 1 Hz and is in general centered on the microseism peak (0.1 to 0.2 Hz). Below 0.1 Hz, noise levels are influenced by the thermal and barometric isolation of the site. Low-frequency levels were not studied below 0.01 Hz. Minimum detectable magnitudes are estimated for the IRIS/IDA stations using the observed noise levels over 1 Hz. In general, a magnitude 3 event should be detectable at 1,000 km by all stations under night noise conditions if the dominant signal frequency is 1 Hz; the magnitude estimates increase with increasing frequency. These detectability estimates assume a conservative signal-to-noise ratio of 6. High-frequency data recorded by independent equipment co-located with the IRIS/IDA system during a 2-week experiment allow estimation of noise levels at the sites up to 100 Hz. Borehole versus surface noise levels recorded during the high-frequency experiment showed significant noise reduction (20 dB) can be achieved by borehole deployment at sites with exposed surface vaults. With well-isolated surface vaults, borehole noise reduction is about a factor of 2. Absolute noise levels between 1 to 10 Hz observed at IRIS/IDA/USSR sites are systematically higher than average NORESS noise by about 7 dB to 25 dB, depending on the station.

scholarly journals The Evolution of the Goddard Profiling Algorithm to a Fully Parametric Scheme

2015 ◽  
Vol 32 (12) ◽  
pp. 2265-2280 ◽  
Author(s):  
Christian D. Kummerow ◽  
David L. Randel ◽  
Mark Kulie ◽  
Nai-Yu Wang ◽  
Ralph Ferraro ◽  
...  
Keyword(s):  
High Frequency ◽  
A Priori ◽  
Time Of Day ◽  
Parametric Approach ◽  
Ancillary Data ◽  
Microwave Sensor ◽  
Precipitation Estimates ◽  
Combined Algorithm ◽  
Ku Band ◽  
The Ideal

AbstractThe Goddard profiling algorithm has evolved from a pseudoparametric algorithm used in the current TRMM operational product (GPROF 2010) to a fully parametric approach used operationally in the GPM era (GPROF 2014). The fully parametric approach uses a Bayesian inversion for all surface types. The algorithm thus abandons rainfall screening procedures and instead uses the full brightness temperature vector to obtain the most likely precipitation state. This paper offers a complete description of the GPROF 2010 and GPROF 2014 algorithms and assesses the sensitivity of the algorithm to assumptions related to channel uncertainty as well as ancillary data. Uncertainties in precipitation are generally less than 1%–2% for realistic assumptions in channel uncertainties. Consistency among different radiometers is extremely good over oceans. Consistency over land is also good if the diurnal cycle is accounted for by sampling GMI product only at the time of day that different sensors operate. While accounting for only a modest amount of the total precipitation, snow-covered surfaces exhibit differences of up to 25% between sensors traceable to the availability of high-frequency (166 and 183 GHz) channels. In general, comparisons against early versions of GPM’s Ku-band radar precipitation estimates are fairly consistent but absolute differences will be more carefully evaluated once GPROF 2014 is upgraded to use the full GPM-combined radar–radiometer product for its a priori database. The combined algorithm represents a physically constructed database that is consistent with both the GPM radars and the GMI observations, and thus it is the ideal basis for a Bayesian approach that can be extended to an arbitrary passive microwave sensor.

DEPENDENCE OF INTEGRATED DURATION OF METEOR ECHOES ON WAVELENGTH AND SENSITIVITY

1954 ◽  
Vol 32 (7) ◽  
pp. 450-467 ◽  
Author(s):  
D. W. R. McKinley
Keyword(s):  
Short Duration ◽  
High Frequency ◽  
Time Of Day ◽  
Very High Frequency ◽  
Forward Scatter ◽  
Long Duration ◽  
Meteor Trails ◽  
Cedar Rapids ◽  
Very High

The reflecting properties of short-duration and long-duration echoes from meteor trails are examined. For short-duration echoes only, the observed relation between relative numbers and durations of meteor echoes is independent of wavelength, the time of day, or the presence of a strong shower. Integrated duration times are determined from back-scatter experiments on 9.22 m., 5.35 m., and 2.83 m., and are found to vary with the 3.5th power of the wavelength, for either short- or long-duration echoes. The integrated echo power depends on the 6th power of the wavelength. The effect of changing the equipment sensitivity is considered. The data from the back-scatter observations are used to predict the integrated duration times in the forward-scatter case, and in particular, it is shown that the results of the Cedar Rapids – Sterling very-high-frequency experiment may be explained by meteoric reflections.

New underwater and aerial vocalizations of captive harp seals (Pagophilus groenlandicus)

2001 ◽  
Vol 79 (1) ◽  
pp. 75-81 ◽  
Author(s):  
A Serrano
Keyword(s):  
Fundamental Frequency ◽  
Breeding Season ◽  
High Frequency ◽  
Low Frequency ◽  
Time Of Day ◽  
Vocal Repertoire ◽  
Maximum Frequency ◽  
Pagophilus Groenlandicus ◽  
Vocal Activity ◽  
The Mean

Pinnipeds are ecologically and socially diverse, attributes that are reflected in their systems of communication. The purpose of this investigation was to document the vocal repertoire and annual cycle of vocal activity in the harp seal (Pagophilus groenlandicus), a species that communicates mainly under water, but whose social and communicative systems outside the breeding season are poorly known. The repertoire comprised 18 vocal classes, or call types; 7 that had not been described previously are described here. Vocal activity varied seasonally and with time of day. Calls of low frequency and with few pulse repetitions were predominantly used outside the breeding season, and calls of high frequency and with a high number of pulse repetitions predominated in the breeding season. The new vocalizations described here differed in several ways from those described previously. First, calls were relatively brief, with an average duration of 1.75 s (except call types 22 and 23, which averaged >2 s in duration). Second, some calls differed in mean fundamental frequency, the average being 677 Hz. Call types 22 and 23 differed the most, with an average of 838 Hz. The vocal repertoire described previously comprise calls with a fundamental frequency of approximately 400–500 Hz. Third, call types 22 and 25 differed from the rest of the vocalizations. The mean maximum frequency of call types 22 and 25 was 3.4 kHz, while the mean maximum frequency of the other call types is around 7.7 kHz.

scholarly journals Comparing Ionospheric MUF using IRI16 Model with Mid-Latitude Ionosonde Observations and Associated with Strong Geomagnetic Storms

2020 ◽  
pp. 3434-3444
Author(s):  
Ala'a A. Al-Shallal ◽  
Najat M. R. Al-Ubaidi
Keyword(s):  
Wave Propagation ◽  
Solar Activity ◽  
Radio Wave ◽  
High Frequency ◽  
Geomagnetic Storms ◽  
Time Of Day ◽  
Radio Wave Propagation ◽  
Model Data ◽  
Maximum Usable Frequency ◽  
Latitude Region

High frequency (HF) radio wave propagation depends on the ionosphere status which is changed with the time of day, season, and solar activity conditions. In this research, ionosonde observations were used to calculate the values of maximum usable frequency (MUF) the ionospheric F2- layer during strong geomagnetic storms (Dst ≤ -100 nT) which were compared with the predicted MUF for the same layer by using IRI-16 model. Data from years 2015 and 2017, during which five strong geomagnetic storms occurred, were selected from two Japanese ionosonde stations (Kokubunji and Wakkanai) located at the mid-latitude region. The results of the present work do not show a good correlation between the observed and predicted MUF values for F2- layer during the selected events of strong geomagnetic storms at these stations. Thus, there is a further need to improve the IRI-16 model for better matching with the observations during strong geomagnetic storms.

The Microstructure of Steatite (Protoenstatite)

1985 ◽  
Vol 43 ◽  
pp. 236-237
Author(s):  
W. E. Lee ◽  
A. H. Heuer
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Magnesium Silicate ◽  
Beam Current ◽  
Glassy Matrix ◽  
Angle Of Incidence ◽  
X Ray ◽  
Mechanical And Electrical Properties ◽  
Argon Ions ◽  
High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

Simulations of high-resolution images of amorphous silicon films

1986 ◽  
Vol 44 ◽  
pp. 544-545
Author(s):  
G. Y. Fan ◽  
J. M. Cowley
Keyword(s):  
Electron Microscope ◽  
High Frequency ◽  
Fourier Transformation ◽  
Amorphous Materials ◽  
Low Frequency ◽  
Chromatic Aberration ◽  
Structure Information ◽  
Frequency Components ◽  
High Resolution Images ◽  
Spatial Frequency Spectrum

It is well known that the structure information on the specimen is not always faithfully transferred through the electron microscope. Firstly, the spatial frequency spectrum is modulated by the transfer function (TF) at the focal plane. Secondly, the spectrum suffers high frequency cut-off by the aperture (or effectively damping terms such as chromatic aberration). While these do not have essential effect on imaging crystal periodicity as long as the low order Bragg spots are inside the aperture, although the contrast may be reversed, they may change the appearance of images of amorphous materials completely. Because the spectrum of amorphous materials is continuous, modulation of it emphasizes some components while weakening others. Especially the cut-off of high frequency components, which contribute to amorphous image just as strongly as low frequency components can have a fundamental effect. This can be illustrated through computer simulation. Imaging of a whitenoise object with an electron microscope without TF limitation gives Fig. 1a, which is obtained by Fourier transformation of a constant amplitude combined with random phases generated by computer.

SEM image sharpness analysis

1996 ◽  
Vol 54 ◽  
pp. 142-143
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Quantitative Information ◽  
Primary Electron ◽  
Image Sharpness ◽  
Critical Dimensions ◽  
Sem Image ◽  
Frequency Changes ◽  
Electron Microscopes ◽  
Scanning Electron

Fully automated or semi-automated scanning electron microscopes (SEM) are now commonly used in semiconductor production and other forms of manufacturing. The industry requires that an automated instrument must be routinely capable of 5 nm resolution (or better) at 1.0 kV accelerating voltage for the measurement of nominal 0.25-0.35 micrometer semiconductor critical dimensions. Testing and proving that the instrument is performing at this level on a day-by-day basis is an industry need and concern which has been the object of a study at NIST and the fundamentals and results are discussed in this paper.In scanning electron microscopy, two of the most important instrument parameters are the size and shape of the primary electron beam and any image taken in a scanning electron microscope is the result of the sample and electron probe interaction. The low frequency changes in the video signal, collected from the sample, contains information about the larger features and the high frequency changes carry information of finer details. The sharper the image, the larger the number of high frequency components making up that image. Fast Fourier Transform (FFT) analysis of an SEM image can be employed to provide qualitiative and ultimately quantitative information regarding the SEM image quality.

Real Ear Sound Pressure Levels Developed by Three Portable Stereo System Earphones

1992 ◽  
Vol 1 (4) ◽  
pp. 52-55 ◽  
Author(s):  
Gail L. MacLean ◽  
Andrew Stuart ◽  
Robert Stenstrom
Keyword(s):  
High Frequency ◽  
Sound Pressure ◽  
Low Frequency ◽  
Test System ◽  
Output Frequency ◽  
Frequency Effects ◽  
Adult Men ◽  
Frequency Responses ◽  
Significant Difference ◽  
Sound Pressure Levels

Differences in real ear sound pressure levels (SPLs) with three portable stereo system (PSS) earphones (supraaural [Sony Model MDR-44], semiaural [Sony Model MDR-A15L], and insert [Sony Model MDR-E225]) were investigated. Twelve adult men served as subjects. Frequency response, high frequency average (HFA) output, peak output, peak output frequency, and overall RMS output for each PSS earphone were obtained with a probe tube microphone system (Fonix 6500 Hearing Aid Test System). Results indicated a significant difference in mean RMS outputs with nonsignificant differences in mean HFA outputs, peak outputs, and peak output frequencies among PSS earphones. Differences in mean overall RMS outputs were attributed to differences in low-frequency effects that were observed among the frequency responses of the three PSS earphones. It is suggested that one cannot assume equivalent real ear SPLs, with equivalent inputs, among different styles of PSS earphones.

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