WorldWideScience

Sample records for radio noise levels

  1. Radio Astronomy Explorer (RAE) 1 observations of terrestrial radio noise

    Science.gov (United States)

    Herman, J. R.; Caruso, J. A.

    1971-01-01

    Radio Astonomy Explorer (RAE) 1 data are analyzed to establish characteristics of HF terrestrial radio noise at an altitude of about 6000 km. Time and frequency variations in amplitude of the observed noise well above cosmic noise background are explained on the basis of temporal and spatial variations in ionospheric critical frequency coupled with those in noise source distributions. It is shown that terrestrial noise regularly breaks through the ionosphere and reaches RAE with magnitudes 15 or more db higher than cosmic noise background. Maximum terrestrial noise is observed when RAE is over the dark side of the Earth in the neighborhood of equatorial continental land masses where thunderstorms occur most frequently. The observed noise level is 30-40 db lower with RAE over oceans.

  2. Radio Astronomy Explorer /RAE/. I - Observations of terrestrial radio noise.

    Science.gov (United States)

    Herman, J. R.; Caruso, J. A.; Stone, R. G.

    1973-01-01

    Radio Astronomy Explorer (RAE) I data are analyzed to establish characteristics of HF terrestrial radio noise at an altitude of about 6000 km. Time and frequency variations in amplitude of the observed noise well above cosmic noise background are explained on the basis of temporal and spatial variations in ionospheric critical frequency coupled with those in noise source distributions. It is shown that terrestrial radio noise regularly breaks through the ionosphere and reaches RAE with magnitudes 15 dB and more above cosmic noise background, on frequencies above the F-layer critical frequency.

  3. A novel method for the evaluation of polarization and hemisphere coverage of HF radio noise measurement antennas

    NARCIS (Netherlands)

    Witvliet, Ben A.; van Maanen, Erik; Bentum, Mark J.; Slump, Cornelis H.; Schiphorst, Roel

    2015-01-01

    In HF (3-30 MHz) communications the ambient electromagnetic background noise or 'radio noise' generally is the limiting factor in reception. Radio noise measurements are needed for spectrum pollution control and to provide reference levels for radio system design. This article discusses the

  4. RADIO NOISE ADVANCES SEXUAL MATURITY

    African Journals Online (AJOL)

    ansistf-lewis

    Mean age at first egg for the radio birds (143 d) was 13 d significantly earlier than controls, but body weight at ... the first 8 h of a 12-h photoperiod with radio noise, to leave only 4 h of light (4L:20D), supported rates of lay ... Age (AFE) and body weight at, and weight of, first egg were recorded for individual birds, and, after a.

  5. Noise and intercept point calculation for modern radio receiver planning

    DEFF Research Database (Denmark)

    Iversen, Christian Rye; Kolding, T. E.

    2001-01-01

    The paper presents analytical expressions for determining noise and intercept points for cascaded radio receiver stages. The theory allows for active receiver stages with frequency selectivity and flexible impedance levels. This makes the method highly usable for planning of modem receivers where...

  6. Cosmic noise: a history of early radio astronomy

    National Research Council Canada - National Science Library

    Sullivan, Woodruff Turner

    2009-01-01

    .... The whole of worldwide radio and radar astronomy is covered, beginning with the discoveries by Jansky and Reber of cosmic noise before World War II, through the wartime detections of solar noise...

  7. SOLAR RADIO TYPE-I NOISE STORM MODULATED BY CORONAL MASS EJECTIONS

    International Nuclear Information System (INIS)

    Iwai, K.; Tsuchiya, F.; Morioka, A.; Misawa, H.; Miyoshi, Y.; Masuda, S.; Shimojo, M.; Shiota, D.; Inoue, S.

    2012-01-01

    The first coordinated observations of an active region using ground-based radio telescopes and the Solar Terrestrial Relations Observatory (STEREO) satellites from different heliocentric longitudes were performed to study solar radio type-I noise storms. A type-I noise storm was observed between 100 and 300 MHz during a period from 2010 February 6 to 7. During this period the two STEREO satellites were located approximately 65° (ahead) and –70° (behind) from the Sun-Earth line, which is well suited to observe the earthward propagating coronal mass ejections (CMEs). The radio flux of the type-I noise storm was enhanced after the preceding CME and began to decrease before the subsequent CME. This time variation of the type-I noise storm was directly related to the change of the particle acceleration processes around its source region. Potential-field source-surface extrapolation from the Solar and Heliospheric Observatory/Michelson Doppler Imager (SOHO/MDI) magnetograms suggested that there was a multipolar magnetic system around the active region from which the CMEs occurred around the magnetic neutral line of the system. From our observational results, we suggest that the type-I noise storm was activated at a side-lobe reconnection region that was formed after eruption of the preceding CME. This magnetic structure was deformed by a loop expansion that led to the subsequent CME, which then suppressed the radio burst emission.

  8. Cosmic Noise: The Pioneers of Early Radio Astronomy and Their Discoveries

    Science.gov (United States)

    Sullivan, Woodruff T., III

    2012-01-01

    Extraterrestrial radio waves (the galactic background), often referred to as "cosmic noise", were first detected accidentally by Karl Jansky at a frequency of 20 MHz in 1932, with significant followup by Grote Reber. Yet after World War II it was England and Australia that dominated the field. An entirely different sky from that of visual astronomy was revealed by the discoveries of solar noise, "radio stars” (discrete sources such as Cas A, Tau A, Cyg A, Cen A and Vir A), galactic noise, lunar and meteor radar experiments, the detection of the 21 cm hydrogen line, and eventually optical identifications such as the Crab Nebula and M87. Key players included wartime radar experts such as Stanley Hey (the British Army's Operational Research Group), Martin Ryle (Cambridge University), Bernard Lovell (Jodrell Bank) and Joe Pawsey (Radiophysics Lab, Sydney). Younger leaders also emerged such as Graham Smith, Tony Hewish, John Davies, "Chris" Christiansen, Bernie Mills, Paul Wild, and John Bolton. Some optical astronomers (Jan Oort, Henk van de Hulst, Jesse Greenstein, Rudolph Minkowski, and Walter Baade) were also extremely supportive. By the end of the postwar decade, radio astronomy was firmly established within the gamut of astronomy, although very few of its practitioners had been trained as astronomers. I will also trace the technical and social aspects of this wholly new type of astronomy, with special attention on military and national influences. I argue that radio astronomy represents one of the key developments in twentieth century astronomy not only because of its own discoveries, but also its pathfinding for the further opening the electromagnetic spectrum. This study is based on exhaustive archival research and over one hundred interviews with pioneering radio astronomers. Full details are available in the book "Cosmic Noise: A History of Early Radio Astronomy" (Cambridge Univ. Pr.).

  9. Propagation effects on radio range and noise in earth-space telecommunications

    Science.gov (United States)

    Flock, W. L.; Slobin, S. D.; Smith, E. K.

    1982-01-01

    Attention is given to the propagation effects on radio range and noise in earth-space telecommunications. The use of higher frequencies minimizes ionospheric effects on propagation, but tropospheric effects often increase or dominate. For paths of geostationary satellites, and beyond, the excess range delay caused by the ionosphere and plasmasphere is proportional to the total electron content along the path and inversely proportional to frequency squared. The delay due to dry air is usually of the order of a few meters while the delay due to water vapor (a few tens of centimeters) is responsible for most of the temporal variation in the range delay for clean air. For systems such as that of the Voyager spacecraft, and for attenuation values up to about 10 dB, increased sky noise degrades the received signal-to-noise ratio more than does the reduction in signal level due to attenuation.

  10. Absorption of cosmic radio noise at different frequencies at Sanae

    International Nuclear Information System (INIS)

    Steyn, T.F.J.

    1983-12-01

    Electron density profiles are simulated as a function of altitude for the D- and E-regions during disturbed ionospheric conditions using auroral absorption data from riometers recording cosmic radio noise at 20, 30 and 51 MHz at Sanae, Antarctica. An elliptical function was used to simulate, as a function of height, the electron density profiles. Using these profiles the measured absorption was calculated by utilizing the Appleton-Hartree treatment for radio waves crossing the ionosphere. The frequency dependence of the riometer absorption is represented by a power law of the frequency: A(f) = C.f -n , and values of n were determined from calculations of the absorptions from the simulated electron density profiles. This power law is a fairly accurate representation in the frequency range 20 to 51 MHz. It appears that the exponent of the power law and the height of maximum absorption are effective parameters to determine the hardness of the energy spectra of precipitating electrons. A method is discussed whereby interferences on the riometer recordings are filtered from the data. Quiet day curves are obtained by the superposition of successive riometer recordings with a period of one sidereal day. A Fourier series is fitted to the points of maximum density to represent the quiet day recordings. Absorption events on day 175 and day 178 (1982) are analized for each riometer frequency, and the hardness of the precipitating electrons is inferred from the n-values of power law presentation. It is shown that the absorption of cosmic radio noise increases by increasing the depth of ionization without increasing the ionization rate (number of electrons /m 3 ) in the upper D-region. This may mean that a hardening of a precipitation spectrum will increase the absorption of cosmic radio noise

  11. Snow noise disturbance in Antarctic radio communications and development of mobile antenna for snow vehicle in Antarctica

    Directory of Open Access Journals (Sweden)

    Isao Fukushima

    1997-07-01

    Full Text Available Radio operators of the Japanese Antarctic Research Expedition (JARE have encountered critical radio noise disturbances caused by blizzards during oversnow travel. This noise appears to be caused by corona discharge at the edges of the vertical whip antenna. This paper describes several examples of snow noise experienced in Antarctica by JARE, the mechanism of generation of the noise, and a method of reducing the intensity of the noise. It also describes a High Effeciency Transmission Line Antenna which is small enough to mount on a snow vehicle and reduces the intensity of the snow noise.

  12. Modal noise impact in radio over fiber multimode fiber links.

    Science.gov (United States)

    Gasulla, I; Capmany, J

    2008-01-07

    A novel analysis is given on the statistics of modal noise for a graded-index multimode fiber (MMF) link excited by an analog intensity modulated laser diode. We present the speckle contrast as a function of the power spectrum of the modulated source and the transfer function of the MMF which behaves as an imperfect transversal microwave photonic filter. The theoretical results confirm that the modal noise is directly connected with the coherence properties of the optical source and show that the performance of high-frequency Radio Over Fiber (ROF) transmission through MMF links for short and middle reach distances is not substantially degraded by modal noise.

  13. Energetics of small electron acceleration episodes in the solar corona from radio noise storm observations

    Science.gov (United States)

    James, Tomin; Subramanian, Prasad

    2018-05-01

    Observations of radio noise storms can act as sensitive probes of nonthermal electrons produced in small acceleration events in the solar corona. We use data from noise storm episodes observed jointly by the Giant Metrewave Radio Telescope (GMRT) and the Nancay Radioheliograph (NRH) to study characteristics of the nonthermal electrons involved in the emission. We find that the electrons carry 1021 to 1024 erg/s, and that the energy contained in the electrons producing a representative noise storm burst ranges from 1020 to 1023 ergs. These results are a direct probe of the energetics involved in ubiquitous, small-scale electron acceleration episodes in the corona, and could be relevant to a nanoflare-like scenario for coronal heating.

  14. Observations of a low-frequency cutoff in magnetospheric radio noise received on Imp 6

    International Nuclear Information System (INIS)

    Vesecky, J.F.; Frankel, M.S.

    1975-01-01

    Observations of magnetospheric radio noise by the Goddard Space Flight Center radio experiment on the Imp 6 spacecraft have revealed a quasi-continuous component at frequencies between 30 and 110 kHz. When the spacecraft is in the interplanetary medium or the magnetosheath, a low-frequency cutoff often characterizes the otherwise power law (f - /sup alpha/) spectrum of this noise. A positive correlation is observed between this cutoff frequency f) and the solar wind plasma frequency f), deduced from the Los Alamos plasma experiment on the same spacecraft; on the average, f)approx. =1.3f). If one pictures the magnetosheath as a homogeneous layer of plasma lying between the radio noise source (at Lapprox.4--7) and the spacecraft in the interplanetary medium and having an electron density 2--3 times that of the solar wind, then one will expect f)approximately-greater-than2 1 / 2 f)--3 1 / 2 f). Within the limits of experimental error this simple model correctly accounts for the observations. A rough calculation shows that radio wave scattering by electron density fluctuations in the magnetosheath plasma is likely to be important for frequencies below 200 kHz. However, the effects of such scattering cannot be detected in the Imp 6 observations considered here because neither concurrent measurements nor sufficiently accurate models of the necessar []magnetosheath plasma parameters are presently available

  15. Time Delay Mechanical-noise Cancellation (TDMC) to Provide Order of Magnitude Improvements in Radio Science Observations

    Science.gov (United States)

    Atkinson, D. H.; Babuscia, A.; Lazio, J.; Asmar, S.

    2017-12-01

    Many Radio Science investigations, including the determinations of planetary masses, measurements of planetary atmospheres, studies of the solar wind, and solar system tests of relativistic gravity, rely heavily on precision Doppler tracking. Recent and currently proposed missions such as VERITAS, Bepi Colombo, Juno have shown that the largest error source in the precision Doppler tracking data is noise in the Doppler system. This noise is attributed to un-modeled motions of the ground antenna's phase center and is commonly referred to as "antenna mechanical noise." Attempting to reduce this mechanical noise has proven difficult since the deep space communications antennas utilize large steel structures that are already optimized for mechanical stability. Armstrong et al. (2008) have demonstrated the Time Delay Mechanical-noise Cancellation (TDMC) concept using Goldstone DSN antennas (70 m & 34 m) and the Cassinispacecraft to show that the mechanical noise of the 70 m antenna could be suppressed when two-way Doppler tracking from the 70 m antenna and the receive-only Doppler data from the smaller, stiffer 34 m antenna were combined with suitable delays. The proof-of-concept confirmed that the mechanical noise in the final Doppler observable was reduced to that of the stiffer, more stable antenna. Caltech's Owens Valley Radio Observatory (OVRO) near Bishop, CA now has six 10.4 m diameter antennas, a consequence of the closure of Combined Array for Research in Millimeter Astronomy (CARMA). In principle, a 10 m antenna can lead to an order-of-magnitude improvement for the mechanical noise correction, as the smaller dish offers better mechanical stability compared to a DSN 34-m antenna. These antennas also have existing Ka-band receiving systems, and preliminary discussions with the OVRO staff suggest that much of the existing signal path could be used for Radio Science observations.

  16. Cosmic radio-noise absorption bursts caused by solar wind shocks

    Directory of Open Access Journals (Sweden)

    A. Osepian

    2004-09-01

    Full Text Available Bursts of cosmic noise absorption observed at times of sudden commencements (SC of geomagnetic storms are examined. About 300SC events in absorption for the period 1967-1990 have been considered. It is found that the response of cosmic radio-noise absorption to the passage of an interplanetary shock depends on the level of the planetary magnetic activity preceding the SC event and on the magnitude of the magnetic field perturbation associated with the SC (as measured in the equatorial magnetosphere. It is shown that for SC events observed against a quiet background (Kp<2, the effects of the SC on absorption can be seen only if the magnitude of the geomagnetic field perturbation caused by the solar wind shock exceeds a threshold value ΔBth. It is further demonstrated that the existence of this threshold value, ΔBth, deduced from experimental data, can be related to the existence of a threshold for exciting and maintaining the whistler cyclotron instability, as predicted by quasi-linear theory. SC events observed against an active background (Kp<2 are accompanied by absorption bursts for all magnetic field perturbations, however small. A quantitative description of absorption bursts associated with SC events is provided by the whistler cyclotron instability theory.

  17. Self-noise in interferometers - radio and infrared

    International Nuclear Information System (INIS)

    Kulkarni, S.R.

    1989-01-01

    A complete theory of noise in a synthesis image is proposed for a source of arbitrary strength. In the limit of faint sources, the standard estimates of noise in a synthesis image are recovered, while in the limit of strong sources, the noise in the synthesis image is found to be dominated by either self noise or by the noise generated by the source signal itself. It is found that the best VLBI maps (with noise approaching the thermal noise) may in fact be limited by self noise, and that there is a negligible bias in the standard definitions of the bispectrum phasor and the closure phase. The results suggest that at the low signal levels which are characteristic of infrared interferometers, it is best to fit the model to all the closure phases and fringe amplitudes. 13 refs

  18. Variations in voice level and fundamental frequency with changing background noise level and talker-to-listener distance while wearing hearing protectors: A pilot study.

    Science.gov (United States)

    Bouserhal, Rachel E; Macdonald, Ewen N; Falk, Tiago H; Voix, Jérémie

    2016-01-01

    Speech production in noise with varying talker-to-listener distance has been well studied for the open ear condition. However, occluding the ear canal can affect the auditory feedback and cause deviations from the models presented for the open-ear condition. Communication is a main concern for people wearing hearing protection devices (HPD). Although practical, radio communication is cumbersome, as it does not distinguish designated receivers. A smarter radio communication protocol must be developed to alleviate this problem. Thus, it is necessary to model speech production in noise while wearing HPDs. Such a model opens the door to radio communication systems that distinguish receivers and offer more efficient communication between persons wearing HPDs. This paper presents the results of a pilot study aimed to investigate the effects of occluding the ear on changes in voice level and fundamental frequency in noise and with varying talker-to-listener distance. Twelve participants with a mean age of 28 participated in this study. Compared to existing data, results show a trend similar to the open ear condition with the exception of the occluded quiet condition. This implies that a model can be developed to better understand speech production for the occluded ear.

  19. Practical Ranges of Loudness Levels of Various Types of Environmental Noise, Including Traffic Noise, Aircraft Noise, and Industrial Noise

    Directory of Open Access Journals (Sweden)

    Sabine A. Janssen

    2011-05-01

    Full Text Available In environmental noise control one commonly employs the A-weighted sound level as an approximate measure of the effect of noise on people. A measure that is more closely related to direct human perception of noise is the loudness level. At constant A-weighted sound level, the loudness level of a noise signal varies considerably with the shape of the frequency spectrum of the noise signal. In particular the bandwidth of the spectrum has a large effect on the loudness level, due to the effect of critical bands in the human hearing system. The low-frequency content of the spectrum also has an effect on the loudness level. In this note the relation between loudness level and A-weighted sound level is analyzed for various environmental noise spectra, including spectra of traffic noise, aircraft noise, and industrial noise. From loudness levels calculated for these environmental noise spectra, diagrams are constructed that show the relation between loudness level, A‑weighted sound level, and shape of the spectrum. The diagrams show that the upper limits of the loudness level for broadband environmental noise spectra are about 20 to 40 phon higher than the lower limits for narrowband spectra, which correspond to the loudness levels of pure tones. The diagrams are useful for assessing limitations and potential improvements of environmental noise control methods and policy based on A-weighted sound levels.

  20. Radio frequency interference noise reduction using a field programmable gate array for SQUID applications

    International Nuclear Information System (INIS)

    Sakuta, K; Narita, Y; Itozaki, H

    2007-01-01

    It is important to remove large environmental noise in superconducting quantum interference device (SQUID) measurement without magnetic shielding. Active noise control (ANC) is one of the effective methods to reduce environmental noise. Recently, SQUIDs have been used in various applications at high frequencies, such as nuclear quadrupole resonance (NQR). The NQR frequency from explosives is in the range 0.5-5 MHz. In this case, an NQR sensor is exposed to AM radio frequency interference (RFI). The feasibility of the ANC system for RFI that used digital signal processing was studied. Our investigation showed that this digital ANC system can be applied to SQUID measurements for RFI suppression

  1. Background noise levels in Europe

    OpenAIRE

    Gjestland, Truls

    2008-01-01

    - This report gives a brief overview of typical background noise levels in Europe, and suggests a procedure for the prediction of background noise levels based on population density. A proposal for the production of background noise maps for Europe is included.

  2. Acceptable noise level

    DEFF Research Database (Denmark)

    Olsen, Steen Østergaard; Nielsen, Lars Holme; Lantz, Johannes

    2012-01-01

    The acceptable noise level (ANL) is used to quantify the amount of background noise that subjects can accept while listening to speech, and is suggested for prediction of individual hearing-aid use. The aim of this study was to assess the repeatability of the ANL measured in normal-hearing subjects...... using running Danish and non-semantic speech materials as stimuli and modulated speech-spectrum and multi-talker babble noises as competing stimuli....

  3. Acceptable noise level

    DEFF Research Database (Denmark)

    Olsen, Steen Østergaard; Nielsen, Lars Holme; Lantz, Johannes

    2012-01-01

    The acceptable noise level (ANL) is used to quantify the amount of background noise that subjects can accept while listening to speech, and is suggested for prediction of individual hearing-aid use. The aim of this study was to assess the repeatability of the ANL measured in normal-hearing subjec...... using running Danish and non-semantic speech materials as stimuli and modulated speech-spectrum and multi-talker babble noises as competing stimuli....

  4. Noise levels in Damascus city

    International Nuclear Information System (INIS)

    Al-Oudat, M.; Maslmani, Y.

    2004-01-01

    Outdoor noise levels were measured at 22 sites in Damascus city. Sound level meter model NC-10 with a 20-140 dBA selectable range was used in the current investigation. At each site noise data were collected from 7 to 21 o'clock. The results showed that the noise levels were higher than WHO (World Health Organization) standard by 5-24.7 dB, 10-16 dB, 10-11 dB and 12-17 dB in residential, commercial, Commercial-industrial, and Heavy traffic streets respectively. Indoor and outdoor noise levels in some hospitals were higher than WHO standard by 15-28 dB and 19-23 dB respectively. The study showed that the authorities administration must take necessary procedures to reduce the noise levels in residential regions and in the regions surrounding the hospitals. (author)

  5. Radio Frequency Interference: The Study of Rain Effect on Radio Signal Attenuation

    International Nuclear Information System (INIS)

    Roslan Umar; Roslan Umar; Shahirah Syafa Sulan; Atiq Wahidah Azlan; Zainol Abidin Ibrahim

    2015-01-01

    The intensity of radio waves received by radio telescopes is always not subject to human control. In the millimetre band, the propagation of the electromagnetic waves is severely affected by rain rate, dust particle size and drop size in the terms of attenuation, noise and depolarization. At the frequency above 10 GHz, the absorption and scattering by rain cause a reduction in the transmitted signal amplitude which will lead to the reducing of the availability, reliability and performance on the communications link. In this study, the rain effect on radio signal has been investigated. Spectrum analyzer and weather stations were used to obtain the RFI level and rain rate data respectively. The radio frequency interference (RFI) pattern due to rain factor was determined. This will benefit radio astronomer in managing sites for radio observation for radio astronomy purposes. (author)

  6. Improvement in the Accuracy of Flux Measurement of Radio Sources by Exploiting an Arithmetic Pattern in Photon Bunching Noise

    Energy Technology Data Exchange (ETDEWEB)

    Lieu, Richard [Department of Physics, University of Alabama, Huntsville, AL 35899 (United States)

    2017-07-20

    A hierarchy of statistics of increasing sophistication and accuracy is proposed to exploit an interesting and fundamental arithmetic structure in the photon bunching noise of incoherent light of large photon occupation number, with the purpose of suppressing the noise and rendering a more reliable and unbiased measurement of the light intensity. The method does not require any new hardware, rather it operates at the software level with the help of high-precision computers to reprocess the intensity time series of the incident light to create a new series with smaller bunching noise coherence length. The ultimate accuracy improvement of this method of flux measurement is limited by the timing resolution of the detector and the photon occupation number of the beam (the higher the photon number the better the performance). The principal application is accuracy improvement in the signal-limited bolometric flux measurement of a radio source.

  7. Improvement in the accuracy of flux measurement of radio sources by exploiting an arithmetic pattern in photon bunching noise

    Science.gov (United States)

    Lieu, Richard

    2018-01-01

    A hierarchy of statistics of increasing sophistication and accuracy is proposed, to exploit an interesting and fundamental arithmetic structure in the photon bunching noise of incoherent light of large photon occupation number, with the purpose of suppressing the noise and rendering a more reliable and unbiased measurement of the light intensity. The method does not require any new hardware, rather it operates at the software level, with the help of high precision computers, to reprocess the intensity time series of the incident light to create a new series with smaller bunching noise coherence length. The ultimate accuracy improvement of this method of flux measurement is limited by the timing resolution of the detector and the photon occupation number of the beam (the higher the photon number the better the performance). The principal application is accuracy improvement in the bolometric flux measurement of a radio source.

  8. The importance of Radio Quiet Zone (RQZ) for radio astronomy

    Science.gov (United States)

    Umar, Roslan; Abidin, Zamri Zainal; Ibrahim, Zainol Abidin

    2013-05-01

    Most of radio observatories are located in isolated areas. Since radio sources from the universe is very weak, astronomer need to avoid radio frequency interference (RFI) from active spectrum users and radio noise produced by human made (telecommunication, mobile phone, microwave user and many more. There are many observatories around the world are surrounded by a Radio Quiet Zone (RQZ), which is it was set up using public or state laws. A Radio Quiet Zone normally consists of two areas: an exclusive area in which totally radio emissions are forbidden, with restrictions for residents and business developments, and a larger (radius up to 100 km above) coordination area where the power of radio transmission limits to threshold levels. Geographical Information System (GIS) can be used as a powerful tool in mapping large areas with varying RQZ profiles. In this paper, we report the initial testing of the usage of this system in order to identify the areas were suitable for Radio Quiet Zone. Among the important parameters used to develop the database for our GIS are population density, information on TV and telecommunication (mobile phones) transmitters, road networks (highway), and contour shielding. We will also use other information gathered from on-site RFI level measurements on selected 'best' areas generated by the GIS. The intention is to find the best site for the purpose of establishing first radio quiet zones for radio telescope in Malaysia.

  9. Deka-keV X-ray emission associated with the onset of radio noise storms

    DEFF Research Database (Denmark)

    Crosby, N.; Vilmer, N.; Lund, Niels

    1996-01-01

    Radio noise storms show that suprathermal electrons (a few tens of keV) are present in the vicinity of active regions during several hours or even a few days. Where and how these electrons are energized is not yet well known. A flare-like sudden energy release in the active region is in general o...

  10. Noise in restaurants: levels and mathematical model.

    Science.gov (United States)

    To, Wai Ming; Chung, Andy

    2014-01-01

    Noise affects the dining atmosphere and is an occupational hazard to restaurant service employees worldwide. This paper examines the levels of noise in dining areas during peak hours in different types of restaurants in Hong Kong SAR, China. A mathematical model that describes the noise level in a restaurant is presented. The 1-h equivalent continuous noise level (L(eq,1-h)) was measured using a Type-1 precision integral sound level meter while the occupancy density, the floor area of the dining area, and the ceiling height of each of the surveyed restaurants were recorded. It was found that the measured noise levels using Leq,1-h ranged from 67.6 to 79.3 dBA in Chinese restaurants, from 69.1 to 79.1 dBA in fast food restaurants, and from 66.7 to 82.6 dBA in Western restaurants. Results of the analysis of variance show that there were no significant differences between means of the measured noise levels among different types of restaurants. A stepwise multiple regression analysis was employed to determine the relationships between geometrical and operational parameters and the measured noise levels. Results of the regression analysis show that the measured noise levels depended on the levels of occupancy density only. By reconciling the measured noise levels and the mathematical model, it was found that people in restaurants increased their voice levels when the occupancy density increased. Nevertheless, the maximum measured hourly noise level indicated that the noise exposure experienced by restaurant service employees was below the regulated daily noise exposure value level of 85 dBA.

  11. Noise in restaurants: Levels and mathematical model

    Directory of Open Access Journals (Sweden)

    Wai Ming To

    2014-01-01

    Full Text Available Noise affects the dining atmosphere and is an occupational hazard to restaurant service employees worldwide. This paper examines the levels of noise in dining areas during peak hours in different types of restaurants in Hong Kong SAR, China. A mathematical model that describes the noise level in a restaurant is presented. The 1-h equivalent continuous noise level (Leq,1-h was measured using a Type-1 precision integral sound level meter while the occupancy density, the floor area of the dining area, and the ceiling height of each of the surveyed restaurants were recorded. It was found that the measured noise levels using Leq,1-h ranged from 67.6 to 79.3 dBA in Chinese restaurants, from 69.1 to 79.1 dBA in fast food restaurants, and from 66.7 to 82.6 dBA in Western restaurants. Results of the analysis of variance show that there were no significant differences between means of the measured noise levels among different types of restaurants. A stepwise multiple regression analysis was employed to determine the relationships between geometrical and operational parameters and the measured noise levels. Results of the regression analysis show that the measured noise levels depended on the levels of occupancy density only. By reconciling the measured noise levels and the mathematical model, it was found that people in restaurants increased their voice levels when the occupancy density increased. Nevertheless, the maximum measured hourly noise level indicated that the noise exposure experienced by restaurant service employees was below the regulated daily noise exposure value level of 85 dBA.

  12. Practical ranges of loudness levels of various types of environmental noise, including traffic noise, aircraft noise, and industrial noise

    NARCIS (Netherlands)

    Salomons, E.M.; Janssen, S.A.

    2011-01-01

    In environmental noise control one commonly employs the A-weighted sound level as an approximate measure of the effect of noise on people. A measure that is more closely related to direct human perception of noise is the loudness level. At constant A-weighted sound level, the loudness level of a

  13. Noise levels, noise annoyance, and hearing-related problems in a dental college.

    Science.gov (United States)

    Ahmed, Hafiz Omer; Ali, Wesal Jasim

    2017-05-04

    Through a cross-sectional survey and integrated sound level meter, this research examined noise exposure and auditory- and nonauditory-related problems experienced by students of a dentistry college located in the United Arab Emirates (UAE). A structured interview questionnaire was used to examine hearing-related problems, noise annoyance, and awareness of 114 students toward noise. The results showed that maximum noise levels were between 65 and 79 dB(A) with peak levels (high and low frequencies) ranging between 89 and 93 dB(A). Around 80% of the students experienced a certain degree of noise annoyance; 54% reported one of the hearing-related problems; and about 10% claimed to have hearing loss to a certain extent. It is recommended that sound-absorbent materials be used during the construction of dental clinics and laboratories to reduce the noise levels.

  14. radio frequency based radio frequency based water level monitor

    African Journals Online (AJOL)

    eobe

    ABSTRACT. This paper elucidates a radio frequency (RF) based transmission and reception system used to remotely monitor and .... range the wireless can cover but in this prototype, it ... power supply to the system, the sensed water level is.

  15. Investigations of internal noise levels for different target sizes, contrasts, and noise structures

    Science.gov (United States)

    Han, Minah; Choi, Shinkook; Baek, Jongduk

    2014-03-01

    To describe internal noise levels for different target sizes, contrasts, and noise structures, Gaussian targets with four different sizes (i.e., standard deviation of 2,4,6 and 8) and three different noise structures(i.e., white, low-pass, and highpass) were generated. The generated noise images were scaled to have standard deviation of 0.15. For each noise type, target contrasts were adjusted to have the same detectability based on NPW, and the detectability of CHO was calculated accordingly. For human observer study, 3 trained observers performed 2AFC detection tasks, and correction rate, Pc, was calculated for each task. By adding proper internal noise level to numerical observer (i.e., NPW and CHO), detectability of human observer was matched with that of numerical observers. Even though target contrasts were adjusted to have the same detectability of NPW observer, detectability of human observer decreases as the target size increases. The internal noise level varies for different target sizes, contrasts, and noise structures, demonstrating different internal noise levels should be considered in numerical observer to predict the detection performance of human observer.

  16. Noise

    Science.gov (United States)

    Noise is all around you, from televisions and radios to lawn mowers and washing machines. Normally, you ... sensitive structures of the inner ear and cause noise-induced hearing loss. More than 30 million Americans ...

  17. Noise level in a pediatric intensive care unit.

    Science.gov (United States)

    Carvalho, Werther B; Pedreira, Mavilde L G; de Aguiar, Maria Augusta L

    2005-01-01

    The purpose of this study was to verify the noise level at a PICU. This prospective observational study was performed in a 10 bed PICU at a teaching hospital located in a densely populated district within the city of São Paulo, Brazil. Sound pressure levels (dBA) were measured 24 hours during a 6-day period. Noise recording equipment was placed in the PICU access corridor, nursing station, two open wards with three and five beds, and in isolation rooms. The resulting curves were analyzed. A basal noise level variation between 60 and 70 dBA was identified, with a maximum level of 120 dBA. The most significant noise levels were recorded during the day and were produced by the staff. The basal noise level identified exceeds International Noise Council recommendations. Education regarding the effects of noise on human hearing and its relation to stress is the essential basis for the development of a noise reduction program.

  18. Electromagnetic noise spectrum at John TS [transmission station

    International Nuclear Information System (INIS)

    Hatanaka, G.K.

    1992-01-01

    Canadian National (CN) is proposing the development of a commercial office tower on a site directly south of John Transmission Station (TS). CN is concerned about the potential effects of fields originating from John TS and other nearby sources on the operation of sensitive equipment and occupants of the building. Potential equipment and tenants might include data processing equipment and television and radio broadcasting companies. A study was conducted to characterize the severity of the electromagnetic environment at the site in order to address these concerns. Measurements of the electromagnetic spectrum from 100 kHz to 300 MHz were performed from a mobile test facility that features a 5 kW diesel generator and an extendible antenna mast. Peak measurements were made using a selectable measurement time of 0.05 s. It was found that the highest noise levels result from micro-gap discharges under dry weather conditions. The micro-gap discharges are characteristic of defect noise sources associated with substation hardware. At 0.5 MHz the noise levels are typical of median noise levels expected for the International Radio Consultive Committee (CCIR) defined business environment. At 74 MHz the noise levels are more severe than the expected levels for this type of environment. However, levels more representative of the business environment will be achieved by eliminating the micro-gap noise sources attributed to John TS. 6 refs., 11 figs., 2 tabs

  19. Nuisance levels of noise effects radiologists' performance

    Science.gov (United States)

    McEntee, Mark F.; Coffey, Amina; Ryan, John; O'Beirne, Aaron; Toomey, Rachel; Evanoff, Micheal; Manning, David; Brennan, Patrick C.

    2010-02-01

    This study aimed to measure the sound levels in Irish x-ray departments. The study then established whether these levels of noise have an impact on radiologists performance Noise levels were recorded 10 times within each of 14 environments in 4 hospitals, 11 of which were locations where radiologic images are judged. Thirty chest images were then presented to 26 senior radiologists, who were asked to detect up to three nodular lesions within 30 posteroanterior chest x-ray images in the absence and presence of noise at amplitude demonstrated in the clinical environment. The results demonstrated that noise amplitudes rarely exceeded that encountered with normal conversation with the maximum mean value for an image-viewing environment being 56.1 dB. This level of noise had no impact on the ability of radiologists to identify chest lesions with figure of merits of 0.68, 0.69, and 0.68 with noise and 0.65, 0.68, and 0.67 without noise for chest radiologists, non-chest radiologists, and all radiologists, respectively. the difference in their performance using the DBM MRMC method was significantly better with noise than in the absence of noise at the 90% confidence interval (p=0.077). Further studies are required to establish whether other aspects of diagnosis are impaired such as recall and attention and the effects of more unexpected noise on performance.

  20. Noise pollution levels in the pediatric intensive care unit.

    Science.gov (United States)

    Kramer, Bree; Joshi, Prashant; Heard, Christopher

    2016-12-01

    Patients and staff may experience adverse effects from exposure to noise. This study assessed noise levels in the pediatric intensive care unit and evaluated family and staff opinion of noise. Noise levels were recorded using a NoisePro DLX. The microphone was 1 m from the patient's head. The noise level was averaged each minute and levels above 70 and 80 dBA were recorded. The maximum, minimum, and average decibel levels were calculated and peak noise level great than 100 dBA was also recorded. A parent questionnaire concerning their evaluation of noisiness of the bedside was completed. The bedside nurse also completed a questionnaire. The average maximum dB for all patients was 82.2. The average minimum dB was 50.9. The average daily bedside noise level was 62.9 dBA. The average % time where the noise level was higher than 70 dBA was 2.2%. The average percent of time that the noise level was higher than 80 dBA was 0.1%. Patients experienced an average of 115 min/d where peak noise was greater than 100 dBA. The parents and staff identified the monitors as the major contribution to noise. Patients experienced levels of noise greater than 80 dBA. Patients experience peak noise levels in excess of 100 dB during their pediatric intensive care unit stay. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Adaptive EMG noise reduction in ECG signals using noise level approximation

    Science.gov (United States)

    Marouf, Mohamed; Saranovac, Lazar

    2017-12-01

    In this paper the usage of noise level approximation for adaptive Electromyogram (EMG) noise reduction in the Electrocardiogram (ECG) signals is introduced. To achieve the adequate adaptiveness, a translation-invariant noise level approximation is employed. The approximation is done in the form of a guiding signal extracted as an estimation of the signal quality vs. EMG noise. The noise reduction framework is based on a bank of low pass filters. So, the adaptive noise reduction is achieved by selecting the appropriate filter with respect to the guiding signal aiming to obtain the best trade-off between the signal distortion caused by filtering and the signal readability. For the evaluation purposes; both real EMG and artificial noises are used. The tested ECG signals are from the MIT-BIH Arrhythmia Database Directory, while both real and artificial records of EMG noise are added and used in the evaluation process. Firstly, comparison with state of the art methods is conducted to verify the performance of the proposed approach in terms of noise cancellation while preserving the QRS complex waves. Additionally, the signal to noise ratio improvement after the adaptive noise reduction is computed and presented for the proposed method. Finally, the impact of adaptive noise reduction method on QRS complexes detection was studied. The tested signals are delineated using a state of the art method, and the QRS detection improvement for different SNR is presented.

  2. Existing Noise Level at Railway Stations in Malaysia

    Directory of Open Access Journals (Sweden)

    Shahidan Shahiron

    2017-01-01

    Full Text Available Railway transportation known as one of the most environmental friendly transportation mode. However, the significance problems of railway transportation are noise pollution and negatively impact the wellbeing of the whole community. Unfortunately, there has been lack of public awareness about the noise level produce by the railway transportation in Malaysia. This study investigates the noise level produced by railway transportation in Malaysia specifically by Keretapi Tanah Melayu Berhad (KTMB. Methods of collecting existing noise level at railway stations in Malaysia are briefly discussed in this study. The finding indicates that the noise level produced by the railway transportation in Malaysia which is by KTMB is considered as dangerous to human being and also exceed the noise limit that has been assigned by Department of Environment Ministry of Natural Resources and Environment of Malaysia. A better noise barrier and improved material should be developed to mitigate the existing noise level produced by railway transportations in Malaysia.

  3. Evolution of extra-galactic nebulae and the origin of metagalactic radio noise

    International Nuclear Information System (INIS)

    Bruce, C.E.R.

    1975-01-01

    It is pointed out that the discovery of the 'jet' in the radio source NGC 4486 fulfils a prediction made many years ago that such 'jets' would exist in some globular or elliptical nebulae. They are the channels of electrical discharges on a nebular scale then postulated, which will last for about 10 million years. It is emphasized that the discharge hypothesis would account for - 1. the existence of irregular nebulae; 2. the 'cataclysmic action' which Hubble regarded as required to account for the transition from nebulae of Type E to Type Sa; 3. the fact that the arms of spiral nebulae are never seen in process of formation; 4. the gathering of the matter towards the discharge channels by magnetic pinch effect; 5. the frequent occurrence of two diametrically opposed major arms; 6. the origin of radio waves throughout an extensive volume of space surrounding the 'jet' or discharge channel in NGC 4486; 7. the effect of one extra galactic nebula, NGC 3187, on another, NGC 3190; 8. the existence of diffuse patches of luminosity, 'emission nebulae', in the spiral arms of our own galaxy and in those of the 'Andromeda Nebula'. On the discharge theory about one per cent of all nebulae will be passing through the discharge phase at any one time, i.e., the number required to account for the observed intensity of metagalactic radio noise. (author)

  4. Opto-Electromechanical Devices for Low-Noise Detection of Radio Waves

    DEFF Research Database (Denmark)

    Bagci, Tolga

    factors. For example, a hybrid system like this, would enable the use of well-established shot-noise limited optical sensing technologies for detecting weak radio-frequency (rf) signals, rf-to-optical photon conversion and transmission of information in low-loss fiber-optic links over long distances......There is currently an increasing interest in developing hybrid devices that unite the desirable features of different systems. Opto-electromechanics has emerged as one of these promising hybrid fields, where the functionality of conventional electrical circuits can be combined with the salient...... features of optical systems for various technological and sensing applications. Nanomechanical resonators stand as promising candidates in terms of linking the two systems, primarily thanks to their versatility in coupling to various physical systems, together with their excellent mechanical quality...

  5. High level white noise generator

    International Nuclear Information System (INIS)

    Borkowski, C.J.; Blalock, T.V.

    1979-01-01

    A wide band, stable, random noise source with a high and well-defined output power spectral density is provided which may be used for accurate calibration of Johnson Noise Power Thermometers (JNPT) and other applications requiring a stable, wide band, well-defined noise power spectral density. The noise source is based on the fact that the open-circuit thermal noise voltage of a feedback resistor, connecting the output to the input of a special inverting amplifier, is available at the amplifier output from an equivalent low output impedance caused by the feedback mechanism. The noise power spectral density level at the noise source output is equivalent to the density of the open-circuit thermal noise or a 100 ohm resistor at a temperature of approximately 64,000 Kelvins. The noise source has an output power spectral density that is flat to within 0.1% (0.0043 db) in the frequency range of from 1 KHz to 100 KHz which brackets typical passbands of the signal-processing channels of JNPT's. Two embodiments, one of higher accuracy that is suitable for use as a standards instrument and another that is particularly adapted for ambient temperature operation, are illustrated in this application

  6. High level white noise generator

    Science.gov (United States)

    Borkowski, Casimer J.; Blalock, Theron V.

    1979-01-01

    A wide band, stable, random noise source with a high and well-defined output power spectral density is provided which may be used for accurate calibration of Johnson Noise Power Thermometers (JNPT) and other applications requiring a stable, wide band, well-defined noise power spectral density. The noise source is based on the fact that the open-circuit thermal noise voltage of a feedback resistor, connecting the output to the input of a special inverting amplifier, is available at the amplifier output from an equivalent low output impedance caused by the feedback mechanism. The noise power spectral density level at the noise source output is equivalent to the density of the open-circuit thermal noise or a 100 ohm resistor at a temperature of approximately 64,000 Kelvins. The noise source has an output power spectral density that is flat to within 0.1% (0.0043 db) in the frequency range of from 1 KHz to 100 KHz which brackets typical passbands of the signal-processing channels of JNPT's. Two embodiments, one of higher accuracy that is suitable for use as a standards instrument and another that is particularly adapted for ambient temperature operation, are illustrated in this application.

  7. Radio and television interference caused by corona discharges from high-voltage transmission lines

    International Nuclear Information System (INIS)

    Sarmadi, M.

    1996-01-01

    Increase in power utility loads in industrialized countries, as well as developing countries, demands a higher level of transmission line voltage. Radio interference (RI) problems have been determined to be a limiting factor in selecting the size of transmission line conductors. Transmission line noise is primarily caused by corona discharges in the immediate vicinity of the conductor. It has been observed that discharges occur during both half-cycles of the applied voltage, but positive corona is usually predominant at AM radio frequencies range with practical high-voltage and extra high-voltage transmission lines. The corona radio noise effect is highly dependent upon the presence of particles on the surface of the conductor and the increase of the electrical gradient beyond the breakdown value of the air. Therefore, corona radio noise varies significantly with the weather and atmospheric conditions and generally increases by 10 to 30 dB in foul weather

  8. Type 2 solar radio burst with the reverse frequency drift on the background of a noise storm

    International Nuclear Information System (INIS)

    Korolev, O.S.; Fomichev, V.V.; Chertok, I.M.

    1979-01-01

    Discussed are the main peculiarities of solar radio burst of the 2nd type recorded on November, 19, 1975 in 11sup(h)02sup(m)-11sup(h)06sup(m)UT in the 45-90 MHz range. The burst considered occurred at the background of the developed noise storm with continuum radiation chearacteristic of it and narrow band. Short-term burst of the first type. The burst band drift was accompanied by the successive cessation of noise storm radiation at frequencies of 50-70 MHz. This phenomenon is interpreted as the result of the interaction between the shock wave spreading in the direction of increasing electron density, and the source of noise storm in coronal plasma. Estimated is the shock wave rate and the paremeters of coronal plasma in the direction of its spreading. A mechanism of interaction between the shock wave and the noise storm source is studied. The observed cessation of noise storm generation is explained by violation of conditions of development of instabilities, in particular, with the isotropization of electrons in the radiation source

  9. Pilot survey of subway and bus stop noise levels.

    Science.gov (United States)

    Gershon, Robyn R M; Neitzel, Richard; Barrera, Marissa A; Akram, Muhammad

    2006-09-01

    Excessive noise exposure is a serious global urban health problem, adversely affecting millions of people. One often cited source of urban noise is mass transit, particularly subway systems. As a first step in determining risk within this context, we recently conducted an environmental survey of noise levels of the New York City transit system. Over 90 noise measurements were made using a sound level meter. Average and maximum noise levels were measured on subway platforms, and maximum levels were measured inside subway cars and at several bus stops for comparison purposes. The average noise level measured on the subway platforms was 86 +/- 4 dBA (decibel-A weighting). Maximum levels of 106, 112, and 89 dBA were measured on subway platforms, inside subway cars, and at bus stops, respectively. These results indicate that noise levels in subway and bus stop environments have the potential to exceed recommended exposure guidelines from the World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA), given sufficient exposure duration. Risk reduction strategies following the standard hierarchy of control measures should be applied, where feasible, to reduce subway noise exposure.

  10. Wideband Low Noise Amplifiers Exploiting Thermal Noise Cancellation

    NARCIS (Netherlands)

    Bruccoleri, F.; Klumperink, Eric A.M.; Nauta, Bram

    2005-01-01

    Low Noise Amplifiers (LNAs) are commonly used to amplify signals that are too weak for direct processing for example in radio or cable receivers. Traditionally, low noise amplifiers are implemented via tuned amplifiers, exploiting inductors and capacitors in resonating LC-circuits. This can render

  11. [Noise level in a care and teaching hospital institution].

    Science.gov (United States)

    Mendoza-Sánchez, R S; Roque-Sánchez, R H; Moncada-González, B

    1996-01-01

    Noise in the environment is increasing over the years. Disturbances produced by noise are varied, some lead to serious health consequences. Noise level was registered in a teaching hospital. Levels in the wards were between 50 and 59 dB. In the Intensive Care Unit, main hallways and outpatients department levels were higher than 59 dB. Isolated peaks up to 90.0 dB (Pediatrics) were detected. The noise level recommended for a hospital is under 50.0 dB. We found that the principal source of noise came from the medical and nursing staff.

  12. Effect of dipole-quadrupole Robinson mode coupling upon the beam response to radio-frequency phase noise

    Directory of Open Access Journals (Sweden)

    R. A. Bosch

    2006-09-01

    Full Text Available In an electron storage ring, coupling between dipole and quadrupole Robinson oscillations modifies the spectrum of longitudinal beam oscillations driven by radio-frequency (rf generator phase noise. In addition to the main peak at the resonant frequency of the coupled dipole Robinson mode, another peak occurs at the resonant frequency of the coupled quadrupole mode. To describe these peaks analytically for a quadratic synchrotron potential, we include the dipole and quadrupole modes when calculating the beam response to generator noise. We thereby obtain the transfer function from generator-noise phase modulation to beam phase modulation with and without phase feedback. For Robinson-stable bunches confined in a synchrotron potential with a single minimum, the calculated transfer function agrees with measurements at the Aladdin 800-MeV electron storage ring. The transfer function is useful in evaluating phase feedback that suppresses Robinson oscillations in order to obtain quiet operation of an infrared beam line.

  13. Effect of external classroom noise on schoolchildren's reading and mathematics performance: correlation of noise levels and gender.

    Science.gov (United States)

    Papanikolaou, M; Skenteris, N; Piperakis, S M

    2015-02-01

    The present study investigated the effect of low, medium, and high traffic road noise as well as irrelevant background speech noise on primary school children's reading and mathematical performance. A total of 676 participants (324 boys, 47.9% and 352 girls, 52.1%) of the 4th and 5th elementary classes participated in the project. The participants were enrolled in public primary schools from urban areas and had ages ranging from 9 to 10 years and from. Schools were selected on the basis of increasing levels of exposure to road traffic noise and then classified into three categories (Low noise: 55-66 dB, Medium noise: 67-77 dB, and High noise: 72-80 dB). We measured reading comprehension and mathematical skills in accordance with the national guidelines for elementary education, using a test designed specifically for the purpose of this study. On the one hand, children in low-level noise schools showed statistically significant differences from children in medium- and high-level noise schools in reading performance (plevel noise schools differed significantly from children in high-level noise schools but only in mathematics performance (p=0.001). Girls in general did better in reading score than boys, especially in schools with medium- and high-level noise. Finally the levels of noise and gender were found to be two independent factors.

  14. Reflectivity level of radio anechoic chambers

    DEFF Research Database (Denmark)

    Appel-Hansen, Jørgen

    1973-01-01

    A comparison between the antenna-pattern comparison technique and the free-space voltage standing-wave ratio technique for evaluating the reflectivity level of radio anechoic chambers is presented. Based on an analysis of the two techniques, it is pointed out which parameters influence the measured...

  15. Optical detection of radio waves through a nanomechanical transducer

    DEFF Research Database (Denmark)

    Bagci, T.; Simonsen, A.; Schmid, Silvan

    2014-01-01

    Low-loss transmission and sensitive recovery of weak radio-frequency and microwave signals is a ubiquitous challenge, crucial in radio astronomy, medical imaging, navigation, and classical and quantum communication. Efficient up-conversion of radio-frequency signals to an optical carrier would...... strong coupling between the voltage fluctuations in a radio-frequency resonance circuit and the membrane's displacement, which is simultaneously coupled to light reflected off its surface. The radio-frequency signals are detected as an optical phase shift with quantum-limited sensitivity....... The corresponding half-wave voltage is in the microvolt range, orders of magnitude less than that of standard optical modulators. The noise of the transducer--beyond the measured 800 pV Hz-1/2 Johnson noise of the resonant circuit--consists of the quantum noise of light and thermal fluctuations of the membrane...

  16. Traffic background level and signal duration effects on aircraft noise judgment

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, G W; Haasz, A A

    1977-04-22

    The effects of background traffic noise level and signal duration on perceived aircraft noise levels during a flyover event are investigated. Tapes of traffic noise at different levels on which aircraft flyover noise events of different durations were superimposed were played to groups of observers in a room simulating indoor conditions. It is found that the presence of steady background traffic noise reduces the perceived noisiness of aircraft flyovers provided that the duration of the flyover event is sufficiently short in relation to flyover time. For a given event level, a reduction of 21 dB(A) in background noise level leads to the perception of a 5.5 dB(A) increase in peak event level. Regressions of observer response with the noise pollution index show a lower correlation than those with variables based on background noise level and peak signal level, although the data are found to exhibit a number of significant trends associated with noise pollution index variations.

  17. Noise Levels in Dental Offices and Laboratories in Hamedan, Iran

    Directory of Open Access Journals (Sweden)

    F. Mojarad

    2009-12-01

    Full Text Available Objective: Noise pollution is one of the most important situations requiring a solution by the contemporary world. The National Institute for Occupational Safety and Health has identified noise as one of the ten leading causes of work-related diseases and injuries.Dentists and dental auxiliaries are exposed to different noise levels while working in dental offices or laboratories. The purpose of this study was to measure the noise level made by different dental instruments in dental offices and laboratories.Materials and Methods: Measurement of the noise level was performed in 89 dental offices and nine dental laboratories. The noise levels were determined using a sound level meter; type SL-4011(Lutron ,which was placed at the operator’s ear level in dental offices and laboratories and also at two-meter distance from the technician’s ear in laboratories.Results: The maximum sound level was 85.8 dB in dental offices and 92.0 dB in laboratories.In dental clinics, the highest noise was produced by the ultrasonic-scaler (85.8 dB and the lowest noise (49.7 dB by the high-volume aspirator, whereas in the laboratory,the highest noise was caused during grinding by the stonecutter (92.0 dB and the lowest by the denture-polishing unit (41.0 dB.Conclusion: After close evaluation, we believe that the maximum noise level in dental offices, although often beneath the damaging noise level for the human ear, is very close to the limit of hearing loss (85.0 dB. However, laboratory technicians may be at risk ifthey choose not to wear ear protection (earplugs or earmuffs.

  18. Definition of 1992 Technology Aircraft Noise Levels and the Methodology for Assessing Airplane Noise Impact of Component Noise Reduction Concepts

    Science.gov (United States)

    Kumasaka, Henry A.; Martinez, Michael M.; Weir, Donald S.

    1996-01-01

    This report describes the methodology for assessing the impact of component noise reduction on total airplane system noise. The methodology is intended to be applied to the results of individual study elements of the NASA-Advanced Subsonic Technology (AST) Noise Reduction Program, which will address the development of noise reduction concepts for specific components. Program progress will be assessed in terms of noise reduction achieved, relative to baseline levels representative of 1992 technology airplane/engine design and performance. In this report, the 1992 technology reference levels are defined for assessment models based on four airplane sizes - an average business jet and three commercial transports: a small twin, a medium sized twin, and a large quad. Study results indicate that component changes defined as program final goals for nacelle treatment and engine/airframe source noise reduction would achieve from 6-7 EPNdB reduction of total airplane noise at FAR 36 Stage 3 noise certification conditions for all of the airplane noise assessment models.

  19. Measurement of macroscopic plasma parameters with a radio experiment: Interpretation of the quasi-thermal noise spectrum observed in the solar wind

    Science.gov (United States)

    Couturier, P.; Hoang, S.; Meyer-Vernet, N.; Steinberg, J. L.

    1983-01-01

    The ISEE-3 SBH radio receiver has provided the first systematic observations of the quasi-thermal (plasma waves) noise in the solar wind plasma. The theoretical interpretation of that noise involves the particle distribution function so that electric noise measurements with long antennas provide a fast and independent method of measuring plasma parameters: densities and temperatures of a two component (core and halo) electron distribution function have been obtained in that way. The polarization of that noise is frequency dependent and sensitive to the drift velocity of the electron population. Below the plasma frequency, there is evidence of a weak noise spectrum with spectral index -1 which is not yet accounted for by the theory. The theoretical treatment of the noise associated with the low energy (thermal) proton population shows that the moving electrical antenna radiates in the surrounding plasma by Carenkov emission which becomes predominant at the low frequencies, below about 0.1 F sub P.

  20. Reduction of environmental MHz noise for SQUID application

    Energy Technology Data Exchange (ETDEWEB)

    Araya, T. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)]. E-mail: araya@sup.ee.es.osaka-u.ac.jp; Kitamura, Y. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Kamishiro, M. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Sakuta, K. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan); Itozaki, H. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)]. E-mail: itozaki@ee.es.osaka-u.ac.jp

    2006-10-01

    It is important to remove large environmental noise in measurement using SQUIDs without magnetic shielding. Active noise control (ANC) is an effective method to remove the environmental noise. The environmental noise has been reduced by the ANC system in the radio frequency region around MHz. The anti-phase waves of the environmental noise should be generated by this system. The ANC system including the phase and amplitude control circuit was developed to make the anti-phase waves in the MHz region. In this paper, sinusoidal waves with a MHz frequency were used as the environmental noise. When a coil antenna was used for a receiver antenna, this ANC system suppressed these sinusoidal waves to the white noise level about 40 dB. When we used a SQUID as a receiver antenna, we also cancelled sinusoidal waves to the white noise level by this system. This shows that the ANC system is useful to reduce an environmental noise when this ANC system is developed to cancel multi-frequency noise.

  1. Reduction of environmental MHz noise for SQUID application

    International Nuclear Information System (INIS)

    Araya, T.; Kitamura, Y.; Kamishiro, M.; Sakuta, K.; Itozaki, H.

    2006-01-01

    It is important to remove large environmental noise in measurement using SQUIDs without magnetic shielding. Active noise control (ANC) is an effective method to remove the environmental noise. The environmental noise has been reduced by the ANC system in the radio frequency region around MHz. The anti-phase waves of the environmental noise should be generated by this system. The ANC system including the phase and amplitude control circuit was developed to make the anti-phase waves in the MHz region. In this paper, sinusoidal waves with a MHz frequency were used as the environmental noise. When a coil antenna was used for a receiver antenna, this ANC system suppressed these sinusoidal waves to the white noise level about 40 dB. When we used a SQUID as a receiver antenna, we also cancelled sinusoidal waves to the white noise level by this system. This shows that the ANC system is useful to reduce an environmental noise when this ANC system is developed to cancel multi-frequency noise

  2. Speech understanding in noise with integrated in-ear and muff-style hearing protection systems

    Directory of Open Access Journals (Sweden)

    Sharon M Abel

    2011-01-01

    Full Text Available Integrated hearing protection systems are designed to enhance free field and radio communications during military operations while protecting against the damaging effects of high-level noise exposure. A study was conducted to compare the effect of increasing the radio volume on the intelligibility of speech over the radios of two candidate systems, in-ear and muff-style, in 85-dBA speech babble noise presented free field. Twenty normal-hearing, English-fluent subjects, half male and half female, were tested in same gender pairs. Alternating as talker and listener, their task was to discriminate consonant-vowel-consonant syllables that contrasted either the initial or final consonant. Percent correct consonant discrimination increased with increases in the radio volume. At the highest volume, subjects achieved 79% with the in-ear device but only 69% with the muff-style device, averaged across the gender of listener/talker pairs and consonant position. Although there was no main effect of gender, female listener/talkers showed a 10% advantage for the final consonant and male listener/talkers showed a 1% advantage for the initial consonant. These results indicate that normal hearing users can achieve reasonably high radio communication scores with integrated in-ear hearing protection in moderately high-level noise that provides both energetic and informational masking. The adequacy of the range of available radio volumes for users with hearing loss has yet to be determined.

  3. Self-reported sleep disturbances due to railway noise: exposure-response relationships for nighttime equivalent and maximum noise levels.

    Science.gov (United States)

    Aasvang, Gunn Marit; Moum, Torbjorn; Engdahl, Bo

    2008-07-01

    The objective of the present survey was to study self-reported sleep disturbances due to railway noise with respect to nighttime equivalent noise level (L(p,A,eq,night)) and maximum noise level (L(p,A,max)). A sample of 1349 people in and around Oslo in Norway exposed to railway noise was studied in a cross-sectional survey to obtain data on sleep disturbances, sleep problems due to noise, and personal characteristics including noise sensitivity. Individual noise exposure levels were determined outside of the bedroom facade, the most-exposed facade, and inside the respondents' bedrooms. The exposure-response relationships were analyzed by using logistic regression models, controlling for possible modifying factors including the number of noise events (train pass-by frequency). L(p,A,eq,night) and L(p,A,max) were significantly correlated, and the proportion of reported noise-induced sleep problems increased as both L(p,A,eq,night) and L(p,A,max) increased. Noise sensitivity, type of bedroom window, and pass-by frequency were significant factors affecting noise-induced sleep disturbances, in addition to the noise exposure level. Because about half of the study population did not use a bedroom at the most-exposed side of the house, the exposure-response curve obtained by using noise levels for the most-exposed facade underestimated noise-induced sleep disturbance for those who actually have their bedroom at the most-exposed facade.

  4. Sky-distribution of intensity of synchrotron radio emission of relativistic electrons trapped in Earth’s magnetic field

    Directory of Open Access Journals (Sweden)

    Klimenko V.V.

    2017-12-01

    Full Text Available This paper presents the calculations of synchrotron radio emission intensity from Van Allen belts with Gaussian space distribution of electron density across L-shells of a dipole magnetic field, and with Maxwell’s relativistic electron energy distribution. The results of these calculations come to a good agreement with measurements of the synchrotron emission intensity of the artificial radiation belt’s electrons during the Starfish nuclear test. We have obtained two-dimensional distributions of radio brightness in azimuth — zenith angle coordinates for an observer on Earth’s surface. The westside and eastside intensity maxima exceed several times the maximum level of emission in the meridian plane. We have also constructed two-dimensional distributions of the radio emission intensity in decibels related to the background galactic radio noise level. Isotropic fluxes of relativistic electrons (Е~1 MeV should be more than 107 cm–2s–1 for the synchrotron emission intensity in the meridian plane to exceed the cosmic noise level by 0.1 dB (riometer sensitivity threshold.

  5. Noise level in neonatal incubators: A comparative study of three models.

    Science.gov (United States)

    Fernández Zacarías, F; Beira Jiménez, J L; Bustillo Velázquez-Gaztelu, P J; Hernández Molina, R; Lubián López, Simón

    2018-04-01

    Preterm infants usually have to spend a long time in an incubator, excessive noise in which can have adverse physiological and psychological effects on neonates. In fact, incubator noise levels typically range from 45 to 70 dB but differences in this respect depend largely on the noise measuring method used. The primary aim of this work was to assess the extent to which noise in an incubator comes from its own fan and how efficiently the incubator can isolate external noise. Three different incubator models were characterized for acoustic performance by measuring their internal noise levels in an anechoic chamber, and also for noise isolation efficiency by using a pink noise source in combination with an internal and an external microphone that were connected to an SVAN958 noise analyzer. The incubators studied produced continuous equivalent noise levels of 53.5-58 dB and reduced external noise by 5.2-10.4 dB. A preterm infant in an incubator is exposed to noise levels clearly exceeding international recommendations even though such levels usually comply with the limit set in the standard IEC60601-2-19: 2009 (60 dBA) under normal conditions of use. Copyright © 2018. Published by Elsevier B.V.

  6. Measurement and control of occupational noise

    International Nuclear Information System (INIS)

    Elammari, Muftah Faraj

    2007-01-01

    High level of environmental and occupational noise remain a problem all over the world. As problems and complaints increased dramatically by the end of the 19th and beginning of the 20th centuries focusing on the problem was intensified. In this thesis occupational noise levels at different places were measured and compared with the international permissible levels using the integrating sound level meter (Quest 2800). The calibration of the instrument was carried out before and after each measurement using the acoustic calibrator (Quest CA-12B calibrator). The method which was followed was measuring the sound pressure level of the different noise sources over a broad frequency band covering the audible frequency range using the (octave band filter, model OB-100), disregrading variation with time. Since the human ear is most sensitive in the 2-5 khz range of frequencies and least sensitive at extremely high and low frequencies the instrument was adjusted on the A weighting net work which varies with frequencies in a very similar way as that of the human ear. From the obtained results, some noise levels which were recorded were within the permissible levels i.e. below 90 dba and some noise levels were higher than the permissible limit as in janzour textile factory (95 dba), The welding workshop (120 dba), Benghazi Macaroni factory (100 dba), and near the air blowers at Zletin cement factory, Benghazi cement factory (97-10-dba) in these cases suggestions were made to minimize the problem. Concerning the noise control, four methods of noise control were tested, these methods were: reducing noise by sound absorbing material at Sirt local broadcasting radio, reducing noise by keeping a distance from the noise source, at the Boilers hall at REWDC, reducing noise by enclosures, at the compressors room at Zletin cement factory, and finally reducing noise by performing regular maintenance at Garabolli photo development centre. The percentage of noise reduction was 21%, 12

  7. Are the noise levels acceptable in a built environment like Hong Kong?

    Science.gov (United States)

    To, Wai Ming; Mak, Cheuk Ming; Chung, Wai Leung

    2015-01-01

    Governments all over the world have enacted environmental noise directives and noise control ordinances/acts to protect tranquility in residential areas. However, there is a lack of literature on the evaluation of whether the Acceptable Noise Levels (ANLs) stipulated in the directive/ordinance/act are actually achievable. The study aimed at measuring outdoor environmental noise levels in Hong Kong and identifying whether the measured noise levels are lower than the stipulated ANLs at 20 categories of residential areas. Data were gathered from a territory-wide noise survey. Outdoor noise measurements were conducted at 203 residential premises in urban areas, low-density residential areas, rural areas, and other areas. In total, 366 daytime hourly Leq outdoor noise levels, 362 nighttime hourly Leq outdoor noise levels, and 20 sets of daily, that is, 24 Leq,1-h outdoor noise levels were recorded. The mean daytime Leq,1-h values ranged 54.4-70.8 dBA, while the mean nighttime Leq,1-h values ranged 52.6-67.9 dBA. When the measured noise levels were compared with the stipulated ANLs, only three out of the 20 categories of areas had outdoor noise levels below ANLs during daytime. All other areas (and all areas during nighttime) were found to have outdoor noise levels at or above ANLs. PMID:26572703

  8. Period analysis at high noise level

    International Nuclear Information System (INIS)

    Kovacs, G.

    1980-01-01

    Analytical expressions are derived for the variances of some types of the periodograms due to normal-distributed noise present in the data. The equivalence of the Jurkevich and the Warner and Robinson methods is proved. The optimum phase cell number of the Warner and Robinson method is given; this number depends on the data length, signal form and noise level. The results are illustrated by numerical examples. (orig.)

  9. LOW-NOISE PAVEMENT AS A WAY OF LIMITATION OF TRAFFIC NOISE LEVEL

    Directory of Open Access Journals (Sweden)

    Władysław Gardziejczyk

    2014-11-01

    Full Text Available Road surface can significantlyreduce the trafficnoise level. Depending on the characteristic of the upper surface layers the differences between the maximum rolling noise levels from passing vehicles to reach values about 10 dB (A. A special group is low-noise pavements characterized by the presence of voids above 15%. Application the porous asphalt layers or asphalt mixture type BBTM affects a significantreduction the width of land surrounded the roads where permissible equivalent sound level is exceeded. Such solutions in some cases can replace acoustic barriers. Road pavements with a higher content of voids require proper maintenance because their acoustic performances are reduced during operation.

  10. Anthropogenic noise alters bat activity levels and echolocation calls

    Directory of Open Access Journals (Sweden)

    Jessie P. Bunkley

    2015-01-01

    Full Text Available Negative impacts from anthropogenic noise are well documented for many wildlife taxa. Investigations of the effects of noise on bats however, have not been conducted outside of the laboratory. Bats that hunt arthropods rely on auditory information to forage. Part of this acoustic information can fall within the spectrum of anthropogenic noise, which can potentially interfere with signal reception and processing. Compressor stations associated with natural gas extraction produce broadband noise 24 hours a day, 365 days a year. With over half a million producing gas wells in the U.S. this infrastructure is a major source of noise pollution across the landscape. We conducted a ‘natural experiment’ in the second largest gas extraction field in the U.S. to investigate the potential effects of gas compressor station noise on the activity levels of the local bat assemblage. We used acoustic monitoring to compare the activity level (number of minutes in a night with a bat call of the bat assemblage at sites with compressor stations to sites lacking this infrastructure. We found that activity levels for the Brazilian free-tailed bat (Tadarida brasiliensis were 40% lower at loud compressor sites compared to quieter well pads, whereas the activity levels of four other species (Myotis californicus, M. cillolabrum, M. lucifugus, Parastrellus hesperus were not affected by noise. Furthermore, our results reveal that the assemblage of bat species emitting low frequency (35 kHz echolocation did not exhibit altered activity levels in noise. Lower activity levels of Brazilian free-tailed bats at loud sites indicate a potential reduction in habitat for this species. Additionally, a comparison of echolocation search calls produced by free-tailed bats at sites with and without compressor stations reveal that this species modifies its echolocation search calls in noise—producing longer calls with a narrower bandwidth. Call alterations might affect prey

  11. Supplementary radio noise advances sexual maturity in domestic ...

    African Journals Online (AJOL)

    Plasma melatonin concentrations midway through the 7-h dark period in which the radio was played were similar to those of non-radio controls, indicating that this period was not regarded as being part of a 14-h subjective day. Keywords: Environmental cue; sound; sexual maturity. South African Journal of Animal Sciences ...

  12. Phase Evolution of the Crab Pulsar between Radio and X-Ray

    Energy Technology Data Exchange (ETDEWEB)

    Yan, L. L.; Ge, M. Y.; Zheng, S. J.; Lu, F. J.; Tuo, Y. L.; Zhang, S. N.; Lu, Y. [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Yuan, J. P.; Tong, H. [Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi, Xinjiang 830011 (China); Han, J. L. [National Astronomical Observatory, Chinese Academy of Sciences, Jia 20 Datun Road, Beijing 100012 (China); Du, Y. J., E-mail: yanlinli@ihep.ac.cn [Qian Xuesen Laboratory of Space Technology, No. 104, Youyi Road, Haidian District, Beijing 100094 (China)

    2017-08-20

    We study the X-ray phases of the Crab pulsar utilizing the 11-year observations from the Rossi X-ray Timing Explorer , 6-year radio observations from Nanshan Telescope, and the ephemeris from Jodrell Bank Observatory. It is found that the X-ray phases in different energy bands and the radio phases from the Nanshan Telescope show similar behaviors, including long-time evolution and short-time variations. Such strong correlations between the X-ray and radio phases imply that the radio and X-ray timing noises are both generated from the pulsar spin that cannot be well described by the the monthly ephemeris from the Jodrell Bank observatory. When using the Nanshan phases as references to study the X-ray timing noise, it has a significantly smaller variation amplitude and shows no long-time evolution, with a change rate of (−1.1 ± 1.1) × 10{sup −7} periods per day. These results show that the distance of the X-ray and radio emission regions on the Crab pulsar has no detectable secular change, and it is unlikely that the timing noises resulted from any unique physical processes in the radio or X-ray emitting regions. The similar behaviors of the X-ray and radio timing noises also imply that the variation of the interstellar medium is not the origin of the Crab pulsar’s timing noises, which is consistent with the results obtained from the multi-frequency radio observations of PSR B1540−06.

  13. Evaluation of noise pollution level based upon community exposure and response data

    Science.gov (United States)

    Edmiston, R. D.

    1972-01-01

    The results and procedures are reported from an evaluation of noise pollution level as a predictor of annoyance, based on aircraft noise exposure and community response data. The measures of noise exposure presented include composite noise rating, noise exposure forecast, noise and number index. A proposed measure as a universal noise exposure measure for noise pollution level (L sub NP) is discussed.

  14. Profiles of noise exposure levels in South African mining

    CSIR Research Space (South Africa)

    Edwards, A

    2011-05-01

    Full Text Available were exposed to noise levels of above the 85 dBA legislated occupational exposure level. The conclusion was made that information obtained through the study could be developed into a national personal noise exposure database, including audiometric...

  15. Studies on assessment of traffic noise level in Aurangabad city, India

    Directory of Open Access Journals (Sweden)

    B J Bhosale

    2010-01-01

    Full Text Available With the rapid rate of urbanization of Aurangabad city due to the expanding industrialization, the problem of noise pollution has become a concern for urban dwellers and government authority too. Noise pollution due to vehicular traffic is one of the growing environmental problems of urban centers. The study deals with the assessment of traffic noise levels in Aurangabad city. With respect to the total number of vehicles passing the road in unit time, which was surveyed by direct count method, six different sites from Aurangabad city, viz., Nagar Naka, Kranti Chowk, CIDCO bus stand, Railway station area, Dhoot Hospital and Baba petrol pump were selected to study the vehicular noise level. Noise measurements were carried out at these six locations on both working day and holiday during the peak traffic hours, i.e. 8:00 a.m. - 11:a.m., 1:00 p.m. - 4:00 p.m. and 5:00 p.m. - 8:00 p.m., in the morning, afternoon and evening sessions, respectively, after 5 minutes time interval. The noise level was monitored using noise level meter. The results obtained from this investigation showed that the Nagar Naka, Kranti chowk and CIDCO bus stand area have dense traffic zones when compared with the Railway station area, Dhoot Hospital and Baba petrol pump. The minimum and the maximum noise levels are 74 and 86 dB, respectively, on working day and 70 and 81 dB, respectively, on holiday. The measured noise level values exceed the prescribed noise level.

  16. Pilot task-based assessment of noise levels among firefighters.

    Science.gov (United States)

    Neitzel, Rl; Hong, O; Quinlan, P; Hulea, R

    2013-11-01

    Over one million American firefighters are routinely exposed to various occupational hazards agents. While efforts have been made to identify and reduce some causes of injuries and illnesses among firefighters, relatively little has been done to evaluate and understand occupational noise exposures in this group. The purpose of this pilot study was to apply a task-based noise exposure assessment methodology to firefighting operations to evaluate potential noise exposure sources, and to use collected task-based noise levels to create noise exposure estimates for evaluation of risk of noise-induced hearing loss by comparison to the 8-hr and 24-hr recommended exposure limits (RELs) for noise of 85 and 80.3 dBA, respectively. Task-based noise exposures (n=100 measurements) were measured in three different fire departments (a rural department in Southeast Michigan and suburban and urban departments in Northern California). These levels were then combined with time-at-task information collected from firefighters to estimate 8-hr noise exposures for the rural and suburban fire departments (n=6 estimates for each department). Data from 24-hr dosimetry measurements and crude self-reported activity categories from the urban fire department (n=4 measurements) were used to create 24-hr exposure estimates to evaluate the bias associated with the task-based estimates. Task-based noise levels were found to range from 82-109 dBA, with the highest levels resulting from use of saws and pneumatic chisels. Some short (e.g., 30 min) sequences of common tasks were found to result in nearly an entire allowable daily exposure. The majority of estimated 8-hr and 24-hr exposures exceeded the relevant recommended exposure limit. Predicted 24-hr exposures showed substantial imprecision in some cases, suggesting the need for increased task specificity. The results indicate potential for overexposure to noise from a variety of firefighting tasks and equipment, and suggest a need for further

  17. Advanced supersonic propulsion study. [with emphasis on noise level reduction

    Science.gov (United States)

    Sabatella, J. A. (Editor)

    1974-01-01

    A study was conducted to determine the promising propulsion systems for advanced supersonic transport application, and to identify the critical propulsion technology requirements. It is shown that noise constraints have a major effect on the selection of the various engine types and cycle parameters. Several promising advanced propulsion systems were identified which show the potential of achieving lower levels of sideline jet noise than the first generation supersonic transport systems. The non-afterburning turbojet engine, utilizing a very high level of jet suppression, shows the potential to achieve FAR 36 noise level. The duct-heating turbofan with a low level of jet suppression is the most attractive engine for noise levels from FAR 36 to FAR 36 minus 5 EPNdb, and some series/parallel variable cycle engines show the potential of achieving noise levels down to FAR 36 minus 10 EPNdb with moderate additional penalty. The study also shows that an advanced supersonic commercial transport would benefit appreciably from advanced propulsion technology. The critical propulsion technology needed for a viable supersonic propulsion system, and the required specific propulsion technology programs are outlined.

  18. Analysis of noise pollution level in a University campus in South India

    Science.gov (United States)

    Thattai, D.; Sudarsan, J. S.; Sathyanathan, R.; Ramasamy, Visalatchi

    2017-07-01

    Noise comprises those sounds occurring around us that are not part of the environment under consideration. Noise is also a type of pollution and impacts on our health and wellness. The prevalence of noise is increasing in magnitude and severity because of growing population and urbanization. Noise pollution leads to many chronic and socially significant impacts. This study analyzes the level of noise at different points in SRM University. As the University encompasses a hospital also, it is more important to identify the sources of high noise levels and control them. As per Indian standards the desirable noise pollution for educational institutions and hospitals in daytime is 50 dbA. Noise levels were measured with a sound level meter at 19 points within the campus at three different timings (8-10 am, 12-2 pm, and 3-5 pm) over two cycles of measurements. The preliminary results show higher noise levels during morning and evening. Noise during Cycle 2 (latter half of semester) was 20% more compared to that of Cycle 1 (beginning of semester).

  19. Assessment of Work Zone Noise Levels at a Cement Factory in ...

    African Journals Online (AJOL)

    Assessment of Work Zone Noise Levels at a Cement Factory in Tanga, Tanzania. ... measured in most production sections exceeded the allowed limit value of 85 ... Keywords: Noise levels, Noise exposure, Cement factory, Survey, Tanzania ...

  20. Radio astronomy

    CERN Document Server

    Alder, Berni

    1975-01-01

    Methods in Computational Physics, Volume 14: Radio Astronomy is devoted to the role of the digital computer both as a control device and as a calculator in addressing problems related to galactic radio noise. This volume contains four chapters and begins with a technical description of the hardware and the special data-handling problems of using radioheliography, with an emphasis on a selection of observational results obtained with the Culgoora radioheliograph and their significance to solar physics and to astrophysics in general. The subsequent chapter examines interstellar dispersion, i

  1. The Effect of Age and Type of Noise on Speech Perception under Conditions of Changing Context and Noise Levels.

    Science.gov (United States)

    Taitelbaum-Swead, Riki; Fostick, Leah

    2016-01-01

    Everyday life includes fluctuating noise levels, resulting in continuously changing speech intelligibility. The study aims were: (1) to quantify the amount of decrease in age-related speech perception, as a result of increasing noise level, and (2) to test the effect of age on context usage at the word level (smaller amount of contextual cues). A total of 24 young adults (age 20-30 years) and 20 older adults (age 60-75 years) were tested. Meaningful and nonsense one-syllable consonant-vowel-consonant words were presented with the background noise types of speech noise (SpN), babble noise (BN), and white noise (WN), with a signal-to-noise ratio (SNR) of 0 and -5 dB. Older adults had lower accuracy in SNR = 0, with WN being the most difficult condition for all participants. Measuring the change in speech perception when SNR decreased showed a reduction of 18.6-61.5% in intelligibility, with age effect only for BN. Both young and older adults used less phonemic context with WN, as compared to other conditions. Older adults are more affected by an increasing noise level of fluctuating informational noise as compared to steady-state noise. They also use less contextual cues when perceiving monosyllabic words. Further studies should take into consideration that when presenting the stimulus differently (change in noise level, less contextual cues), other perceptual and cognitive processes are involved. © 2016 S. Karger AG, Basel.

  2. Subjective annoyance caused by indoor low-level and low frequency noise and control method

    Institute of Scientific and Technical Information of China (English)

    DI Guo-qing; ZHANG Bang-jun; SHANG Qi

    2005-01-01

    The influence of low-level noise has not been widely noticed. This paper discovered that low-level and low frequency noise(Aweighted equivalent level Leq < 45 dB) causes higher probability of subjective annoyance. The fuzzy mathematic principle was applied to deal with the threshold level of subjective annoyance from noise in this study; there is preferable relationship between the indoor noise and noise annoyance at low frequency noise level. Study indicated at the same centered noise level, the change of annoyance probability is mainly caused by the change of the frequency spectrum characteristic of the indoor noise. Under low noise level environment, without change of the medium-low frequency noise, the slight increase of medium-high frequency noise level with the help of noise sheltering effect can significantly reduce the noise annoyance. This discovery brings a new resolution on how to improve the environmental quality of working or living places. A noise control model is given in this study according to the acoustic analysis.

  3. REDUCTION OF CLASSROOM NOISE LEVELS USING GROUP CONTINGENCIES

    OpenAIRE

    Ring, Brandon M.; Sigurdsson, Sigurdur O.; Eubanks, Sean L.; Silverman, Kenneth

    2014-01-01

    The therapeutic workplace is an employment-based abstinence reinforcement intervention for unemployed drug users where trainees receive on-the-job employment skills training in a classroom setting. The study is an extension of prior therapeutic workplace research, which suggested that trainees frequently violated noise standards. Participants received real-time graphed feedback of noise levels and had the opportunity to earn monetary group reinforcement for maintaining a low number of noise v...

  4. A low-frequency radio survey of the planets with RAE 2

    Science.gov (United States)

    Kaiser, M. L.

    1977-01-01

    Over one thousand occultations of each planet in the solar system have occurred during the period from mid-1973 through mid-1976 as seen from the lunar orbiting Radio Astronomy Explorer 2 (RAE 2) spacecraft. These occultations have been examined for evidence of planetary radio emissions in the 0.025-13.1 MHz band. Only Jupiter and the earth have given positive results. Lack of detection of emission from the other planets can mean that either they do not emit radio noise in this band or the flux level of their emissions and/or its occurrence rate are too low to be detected by RAE 2.

  5. A low-frequency radio survey of the planets with RAE-2

    International Nuclear Information System (INIS)

    Kaiser, M.L.

    1976-08-01

    Over one thousand occultations of each planet in the solar system have occurred during the period from mid-1973 through mid-1976 as seen from the lunar orbiting Radio Astronomy Explorer-2 (RAE-2) spacecraft. These occultations have been examined for evidence of planetary radio emissions in the 0.025 to 13.1 MHz band. Only Jupiter and the earth have given positive results. Lack of detection of emission from the other planets can mean that either they do not emit radio noise in this band or the flux level of their emissions and/or its occurrence rate are too low to be detected by RAE-2

  6. A low-frequency radio survey of the planets with RAE-2

    Science.gov (United States)

    Kaiser, M. L.

    1976-01-01

    Over one thousand occultations of each planet in the solar system have occurred during the period from mid-1973 through mid-1976 as seen from the lunar orbiting Radio Astronomy Explorer-2 (RAE-2) spacecraft. These occultations have been examined for evidence of planetary radio emissions in the 0.025 to 13.1 MHz band. Only Jupiter and the earth have given positive results. Lack of detection of emission from the other planets can mean that either they do not emit radio noise in this band or the flux level of their emissions and/or its occurrence rate are too low to be detected by RAE-2.

  7. A low-frequency radio survey of the planets with RAE 2

    International Nuclear Information System (INIS)

    Kaiser, M.L.

    1977-01-01

    Over one thousand occultations of each planet in the solar system have occurred during the period from mid-1973 through mid-1976 as seen from the lunar orbiting Radio Astronomy Explorer 2 (RAE 29) spacecraft. These occultations have been examined for evidence of planetary radio emissions in the 0.025--13.1 MHz band. Only Jupiter and the earth have given positive results. Lack of detection of emission from the other planets can mean that either they do not emit radio noise in this band or the flux level of their emissions and/or its occurrence rate are too low to be detected by RAE 2

  8. Environmental noise levels affect the activity budget of the Florida manatee

    Science.gov (United States)

    Miksis-Olds, Jennifer L.; Donaghay, Percy L.; Miller, James H.; Tyack, Peter L.

    2005-09-01

    Manatees inhabit coastal bays, lagoons, and estuaries because they are dependent on the aquatic vegetation that grows in shallow waters. Food requirements force manatees to occupy the same areas in which human activities are the greatest. Noise produced from human activities has the potential to affect these animals by eliciting responses ranging from mild behavioral changes to extreme aversion. This study quantifies the behavioral responses of manatees to both changing levels of ambient noise and transient noise sources. Results indicate that elevated environmental noise levels do affect the overall activity budget of this species. The proportion of time manatees spend feeding, milling, and traveling in critical habitats changed as a function of noise level. More time was spent in the directed, goal-oriented behaviors of feeding and traveling, while less time was spent milling when noise levels were highest. The animals also responded to the transient noise of approaching vessels with changes in behavioral state and movements out of the geographical area. This suggests that manatees detect and respond to changes in environmental noise levels. Whether these changes legally constitute harassment and produce biologically significant effects need to be addressed with hypothesis-driven experiments and long-term monitoring. [For Animal Bioacoustics Best Student Paper Award.

  9. Annoyance from Road Traffic, Trains, Airplanes and from Total Environmental Noise Levels.

    Science.gov (United States)

    Ragettli, Martina S; Goudreau, Sophie; Plante, Céline; Perron, Stéphane; Fournier, Michel; Smargiassi, Audrey

    2015-12-29

    There is a lack of studies assessing the exposure-response relationship between transportation noise and annoyance in North America. Our aims were to investigate the prevalence of noise annoyance induced by road traffic, trains and airplanes in relation to distance to transportation noise sources, and to total environmental noise levels in Montreal, Canada; annoyance was assessed as noise-induced disturbance. A telephone-based survey among 4336 persons aged >18 years was conducted. Exposure to total environmental noise (A-weighted outdoor noise levels-LAeq24h and day-evening-night equivalent noise levels-Lden) for each study participant was determined using a statistical noise model (land use regression-LUR) that is based on actual outdoor noise measurements. The proportion of the population annoyed by road traffic, airplane and train noise was 20.1%, 13.0% and 6.1%, respectively. As the distance to major roads, railways and the Montreal International Airport increased, the percentage of people disturbed and highly disturbed due to the corresponding traffic noise significantly decreased. When applying the statistical noise model we found a relationship between noise levels and disturbance from road traffic and total environmental noise, with Prevalence Proportion Ratios (PPR) for highly disturbed people of 1.10 (95% CI: 1.07-1.13) and 1.04 (1.02-1.06) per 1 dB(A) Lden, respectively. Our study provides the first comprehensive information on the relationship between transportation noise levels and disturbance in a Canadian city. LUR models are still in development and further studies on transportation noise induced annoyance are consequently needed, especially for sources other than road traffic.

  10. Assessment of noise level and noise propagation generated by light-lift helicopters in mountain natural environments.

    Science.gov (United States)

    Grigolato, Stefano; Mologni, Omar; Proto, Andrea Rosario; Zimbalatti, Giuseppe; Cavalli, Raffaele

    2018-01-20

    The use of helicopter rises discussion about environmental noise propagation especially when it operates in proximity of environmentally sensitive areas (ESAs) for an extended period because of its potential implications in wildlife behaviours. In order to support decisions on helicopter logging operation management in proximity of ESAs, this study focused on (i) analysing the noise spectrum of a light-lift helicopter during logging operations and on (ii) assessing the noise propagation in the surrounding environments. This study investigated a helicopter logging operation for wood fuel extraction in the eastern part of the Italian Alps. The potential disturbance area covered for the entire helicopter logging operation was evaluated by a specific GIS application according to hearing sensitivity of the most sensitive wildlife species in the study area (different strigiform species). The noise level at the ground appeared to be affected by the location regardless both the use of equivalent continuous sound pressures level dB(A) (LAeq) and the single-event level (SEL) noise metrics. The lowest values were recorded when the helicopter was flown over the sound meter level located under the forest canopy, while the highest was recorded when the helicopter was unhooking the loads at the landing. The GIS application highlighted the consistent of the exceeded noise area (weighted to strigiform hearing range and sensitivity) for the lower frequency bands (0.016-0.250 kHz). A more restricted exceeded noise area concerned instead the most sensitive frequency bands" for the strigiform (1-2 kHz). Graphical abstract ᅟ.

  11. Environmental impact of noise levels in and around opencast bauxite mine.

    Science.gov (United States)

    Kisku, G C; Barman, S C; Kidwai, M M; Bhargava, S K

    2002-01-01

    Until recently, noise pollution has not been paid adequate attention as air, water and land pollution. In order to assess (predict) the impact of bauxite mine noise on employees health and in and around bauxite mine environment, general noise sources and equipment noise were monitored. All these noise sources were compared with prescribed standard noise levels laid down by Central Pollution Control Board (CPCB). Data has also been compared with reference site, north block hill top which is barren and virgin plateau/top covered with grass only and free from human interference. Equipment noise levels were much higher than the other zone of the mine which does not have the corresponding standards. Rock breaker recorded the highest noise level with 73.1 +/- 14.2 to 89.5 +/- 10.1 dB (A) while from ripper dozer it was least with 61.0 +/- 17.3 to 76.2 +/- 6.2 dB (A). Meteorological parameters did not have much influence upon equipment noise up to 100 feet from the source.

  12. Noise sensitivity, rather than noise level, predicts the non-auditory effects of noise in community samples: a population-based survey

    Directory of Open Access Journals (Sweden)

    Jangho Park

    2017-04-01

    Full Text Available Abstract Background Excessive noise affects human health and interferes with daily activities. Although environmental noise may not directly cause mental illness, it may accelerate and intensify the development of latent mental disorders. Noise sensitivity (NS is considered a moderator of non-auditory noise effects. In the present study, we aimed to assess whether NS is associated with non-auditory effects. Methods We recruited a community sample of 1836 residents residing in Ulsan and Seoul, South Korea. From July to November 2015, participants were interviewed regarding their demographic characteristics, socioeconomic status, medical history, and NS. The non-auditory effects of noise were assessed using the Center of Epidemiologic Studies Depression, Insomnia Severity index, State Trait Anxiety Inventory state subscale, and Stress Response Inventory-Modified Form. Individual noise levels were recorded from noise maps. A three-model multivariate logistic regression analysis was performed to identify factors that might affect psychiatric illnesses. Results Participants ranged in age from 19 to 91 years (mean: 47.0 ± 16.1 years, and 37.9% (n = 696 were male. Participants with high NS were more likely to have been diagnosed with diabetes and hyperlipidemia and to use psychiatric medication. The multivariable analysis indicated that even after adjusting for noise-related variables, sociodemographic factors, medical illness, and duration of residence, subjects in the high NS group were more than 2 times more likely to experience depression and insomnia and 1.9 times more likely to have anxiety, compared with those in the low NS group. Noise exposure level was not identified as an explanatory value. Conclusions NS increases the susceptibility and hence moderates there actions of individuals to noise. NS, rather than noise itself, is associated with an elevated susceptibility to non-auditory effects.

  13. Some insights into the relationship between urban air pollution and noise levels.

    Science.gov (United States)

    Kim, Ki-Hyun; Ho, Duy Xuan; Brown, Richard J C; Oh, J-M; Park, Chan Goo; Ryu, In Cheol

    2012-05-01

    The relationship between noise and air pollution was investigated in eight different districts across Seoul, Korea, between September and November 2010. The noise levels in each district were measured at both roadside and non-roadside locations. It was found that the maximum levels of noise were generally at frequencies of around 1000 Hz. The equivalent noise levels (L(eq)), over all districts, averaged 61.4 ± 7.36 dB which is slightly lower than the noise guidelines set by the World Health Organization (WHO) of 70 dB for industrial, commercial, traffic, and outdoor areas. Comparison of L(eq) levels in each district consistently indicates that noise levels are higher at roadside sites than non-roadside sites. In addition the relative dominance of noise during daytime as compared to nighttime was also apparent. Moreover, the results of an analysis relating sound levels with air pollutant levels indicate strongly that the correlation between these two parameters is the strongest at roadside sites (relative to non-roadside sites) and during nighttime (relative to daytime). The results of our data analysis point to a positive, but complex, correlation between noise levels and air pollution. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Reducing Indoor Noise Levels Using People's Perception on Greenery

    Science.gov (United States)

    Mediastika, Christina E.; Binarti, Floriberta

    2013-12-01

    Employees working in cubicles of open-plan offices in Indonesia were studied in regard to their perception on the ability of indoor greenery to reduce noise levels. Sansevieria trifasciata and Scindapsus sp were used. Each was placed in the cubicle and noise levels were measured without plants, with Sansevieria, and with Scindapsus in place. The meters showed very insignificant difference. However, responses to surveys indicated a perception of lower noise in the presence of greenery. This seemed to be supported by prior knowledge and preconception and may be useful in creating a "quieter" indoor environment.

  15. [Equivalent continuous noise level in neonatal intensive care unit associated to burnout syndrome].

    Science.gov (United States)

    Garrido Galindo, A P; Camargo Caicedo, Y; Vélez-Pereira, A M

    2015-01-01

    Noise levels in neonatal intensive care units allow the appearance of symptoms associated with burnout such as stress, irritability, fatigue and emotional instability on health care personnel. The aim of this study was to evaluate the equivalent continuous noise levels in the neonatal intensive care unit and compare the results with noise levels associated with the occurrence of burnout syndrome on the care team. Continuous sampling was conducted for 20 days using a type I sound level meter on the unit. The maximum, the ninetieth percentile and the equivalent continuous noise level (Leq) values were recorded. Noise level is reported in the range of 51.4-77.6 decibels A (dBA) with an average of 64 dBA, 100.6 dBA maximum, and average background noise from 57.9 dBA. Noise levels exceed the standards suggested for neonatal intensive care units, are close to maximum values referred for noise exposure in the occupational standards and to noise levels associated with the onset of burnout; thus allowing to infer the probability of occurrence of high levels of noise present in the unit on the development of burnout in caregivers. Copyright © 2013 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

  16. METHODS OF NOISE LEVEL REDUCTION OF DRIVE IN LATHES

    Directory of Open Access Journals (Sweden)

    Janusz ROGULA

    2014-06-01

    Full Text Available The aim of this work is method presentation to noise level reduction of fixed headstock of the lathe. It is connected with the causes finding of non-uniform work of lathe headstock, description of recent design and its analysis. Problem of the excessive noise level concern to near 35% of the lathes have been produced. In spite of lack of noise reduction possibility there were no system solution of problem. Design optimisation weren’t done after application the electric motor with inverter. New solution of electric motor control let to reduce number of gear wheels in lathe drive system. For this drive solution there weren’t made the analysis of drive particular parts influence on the noise generation.

  17. Ambient noise levels and characterization in Aegean region, Turkey

    Science.gov (United States)

    Sevim, Fatih; Zor, Ekrem; Açıkgöz, Cem; Tarancıoğlu, Adil

    2018-03-01

    We assessed the ambient noise level in the Aegean region and analyzed its diurnal variation and its relation to the earthquake detection capability of the Aegean Region Seismic Network (ARSN). We prepared probability density functions (PDFs) for 19 broadband stations in the Aegean region operated by the Earth and Marine Sciences Institute (EMSI) of the Marmara Research Center (MRC) of the Turkish Scientific Research Council (TÜBİTAK). The power spectral densities (PSDs) used to construct PDFs for each station were computed for the periods between 0.02 and 180 s. In addition, we generated noise map of the Aegean region for different periods using the PDFs to assess the origin of the noise. We analyzed earthquake activity in the region and found that there are more local events recorded at night than during the day for each station. This difference is strongly related to diurnal variation of background noise level for the period range mostly covering the frequency range for the local events. We observed daytime noise level 15 to 20 dB higher than that at the nighttime in high frequencies for almost all stations caused by its proximity to settled areas and roads. Additionally, we observed a splitting peak within the Double Frequency (DF) microseism band; it showed a clear noise increase around the short period DF band at all the stations, decreasing inland. This peak may be related to sea waves locally generated in the Aegean Sea. We also identified a prominent increase related to marble saw companies in some stations' noise PDFs.

  18. Ambient and at-the-ear occupational noise exposure and serum lipid levels

    DEFF Research Database (Denmark)

    Arlien-Søborg, Mai C; Schmedes, Astrid S; Stokholm, Z A

    2016-01-01

    -the-ear occupational noise exposure and serum levels of total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, and triglycerides when accounting for well-established predictors of lipid levels. METHODS: This cross-sectional study included 424 industrial workers and 84 financial......OBJECTIVES: Occupational and residential noise exposure has been related to increased risk of cardiovascular disease. Alteration of serum lipid levels has been proposed as a possible causal pathway. The objective of this study was to investigate the relation between ambient and at...... workers to obtain contrast in noise exposure levels. They provided a serum sample and wore portable dosimeters that every 5-s recorded ambient noise exposure levels during a 24-h period. We extracted measurements obtained during work and calculated the full-shift mean ambient noise level. For 331 workers...

  19. The influence of subway station design on noise levels.

    Science.gov (United States)

    Shah, Ravi R; Suen, Jonathan J; Cellum, Ilana P; Spitzer, Jaclyn B; Lalwani, Anil K

    2017-05-01

    To investigate the impact of subway station design on platform noise levels. Observational. Continuous A-weighted decibel (dBA) sound levels were recorded in 20 New York City subway stations, where trains entered on either a straight track or curved track in 10 stations each. Equivalent continuous noise levels (L eq ) at various locations on the boarding platform (inbound end, midplatform, and outbound end) during train entry and exit were compared between the straight and curved stations in broadband as well as narrow one-third octave bands. Overall, curved stations trended louder than straight stations, although the difference in broadband L eq did not reach statistical significance (curve, 83.4 dBA; straight, 82.6 dBA; P = .054). Noise levels were significantly louder at the inbound end of the platform during train entry (inbound, 89.7 dBA; mid, 85.5 dBA; outbound, 78.7 dBA; P < .001) and at the outbound end during train exit (inbound, 79.7 dBA; mid, 85.3 dBA; outbound, 89.1 dBA; P < .001). Narrow band analysis showed that curved stations were significantly louder than straight stations at 100 Hz and high frequencies from 8 to 20 kHz. Peak impact levels ranged from 104 to 121 dBA. Curved stations have a different noise profile compared to straight stations and are significantly louder than straight stations at high frequencies. Designing stations with straight tracks within the platform can help reduce commuter noise exposure. NA Laryngoscope, 127:1169-1174, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  20. evaluation of the environmental noise levels in abuja municipality

    African Journals Online (AJOL)

    ABSTRACT. Background: Noise remains a nuisance which impacts negatively on the ..... Furthermore, Erikson et al postulated that a persistent noise level .... Hessel PA, Sluis-Cremer G K. Hearing loss in ... Ear & Hearing 2006; 27(1): 1-19. 13.

  1. Effects of self-reported sensitivity and road-traffic noise levels on the immune system.

    Directory of Open Access Journals (Sweden)

    Ahra Kim

    Full Text Available Sensitivity to noise, particularly road traffic noise, can increase cortisol levels and result in changes in immune system biomarkers. Therefore, continuous exposure to noise can have an effect on immune function, hormonal levels, and cardiovascular function, leading to hypertension and stress. The purpose of this study was to investigate the changes in stress-and immune system-related biomarkers according to the self-reported sensitivity to noise and exposure to road traffic noise, to ultimately determine the potential effects of noise on health. A survey was conducted through questionnaire (ISO/TS 15666 sent to 172 female subjects in Korea, including 128 from Ulsan and 44 from Seoul. The average noise level was calculated, and blood samples were collected for measurements of cortisol levels, Natural killer (NK / Natural killer T (NKT cell populations, and NK cell activity (through measurements of interleukin-12 (IL-12 and interferon-gamma (INF-γ concentrations. Multivariate linear regression analysis of the measured biomarkers according to the road traffic noise level and self-reported noise sensitivity was conducted adjusting for the effects of age, alcohol status, smoking status, regular exercise, and residence period. IL-12 levels increased, whereas the NKT cell population decreased with increasing noise levels. The results further suggested that cortisol levels are more influenced by the subject's sensitivity to noise than to the level of chronic road traffic noise. Therefore, noise appears to have the largest effect on IL-12 levels as well as the population and activity of NKT cells. In conclusion, our results suggest that low-level road traffic noise and sensitivity to noise can affect health by causing changes in the immune response through mechanisms other than increased cortisol.

  2. A preliminary assessment of noise level during Deepawali festival in Balasore, India.

    Science.gov (United States)

    Goswami, Shreerup; Swain, Bijay Kumar; Mohapatra, Hara Prasad; Bal, Kshirod Kumar

    2013-11-01

    A preliminary assessment of noise levels during Deepawali, was made in the present study. In order to assess the situation of noise levels in and around Balasore during two consecutive Deepawali of the year 2010 and 2011; noise monitoring was carried out in three different specified times (4:30-7:00 p.m., 7:00-10:30 p.m., 10:30 p.m.-1:00 a.m.). Noise descriptors such as L10, L50, L90, Leq, noise pollution level and noise climate were assessed to reveal the extent of noise pollution in this festival of crackers. Permissible limit of noise levels (Leq) prescribed by WHO during the festival was 100 dB and Lmax must not exceed 110 dB during such occasion. However, in all the cases Lmax and NPL values exceeded 110 dB, while Leq values ranged from 92.9 to 101.9 dB during 2010 Deepawali and 81.5 to 100.8 dB during 2011 Deepawali. On the other hand, all the noise monitoring sites belonged to residential areas. The assessed noise levels during such festivity are much more than 55/45 dB i.e. prescribed for residential areas for day/night time by CPCB. However, it was observed that the noise of Deepawali (Leq) decreased considerably and was less during 2011 than 2010. These may be due to increased environmental awareness among the public. Subsequently, the people of Balasore prefered to celebrate Deepawali, the festival of lights without sound and smoke. Noise policy should also be worked out for a better understanding of such local, social and cultural festivals in which annoyance arise.

  3. Ambient noise levels in the Taiwan region

    Science.gov (United States)

    Liang, W.; Liu, C.; Chen, R.; Huang, B.; Wu, F. T.; Wang, C.

    2008-12-01

    To characterize the island-wide background seismic noise in Taiwan, we estimate the power spectral density (PSD) at broadband stations of both the BATS (Broadband Array in Taiwan for Seismology) and the TAIGER experiment (Apr. 2006~Apr. 2008) for periods ranging from ~0.2 to 100 seconds. A new approach to calculate the probability density functions of noise power (PDFs, MaNamara and Buland, 2004) is used in this study. The results indicate that the cultural noise at higher frequencies is significant at populated area, which shows diurnal and weekly variation as what we expected. The noise power for microseisms centered at a period of ~5 seconds around the western costal plain show ~20dB higher than what observed at eastern Taiwan. This observation supports the inference that the coastal regions having narrow shelf with irregular coastlines are know to be especially efficient at radiating the predominat microseisms. Results from the linear array across central Taiwan demonstrate that the average noise power is quietest at the eastern Central Range. We have mapped the PDF mode for stations at various periods to see the spatial distribution of ambient noise levels, which could be used as the basic information for future station siting. Temporal variation of noise PSD is also present to provide a quantitative description of the seismic data quality collected by both BATS and TAIGER experiment. Some operational problems like base tilt, sensitivity change can be identified easily as well.

  4. Antenna design and implementation for the future space Ultra-Long wavelength radio telescope

    Science.gov (United States)

    Chen, Linjie; Aminaei, Amin; Gurvits, Leonid I.; Wolt, Marc Klein; Pourshaghaghi, Hamid Reza; Yan, Yihua; Falcke, Heino

    2018-04-01

    In radio astronomy, the Ultra-Long Wavelengths (ULW) regime of longer than 10 m (frequencies below 30 MHz), remains the last virtually unexplored window of the celestial electromagnetic spectrum. The strength of the science case for extending radio astronomy into the ULW window is growing. However, the opaqueness of the Earth's ionosphere makes ULW observations by ground-based facilities practically impossible. Furthermore, the ULW spectrum is full of anthropogenic radio frequency interference (RFI). The only radical solution for both problems is in placing an ULW astronomy facility in space. We present a concept of a key element of a space-borne ULW array facility, an antenna that addresses radio astronomical specifications. A tripole-type antenna and amplifier are analysed as a solution for ULW implementation. A receiver system with a low power dissipation is discussed as well. The active antenna is optimized to operate at the noise level defined by the celestial emission in the frequency band 1 - 30 MHz. Field experiments with a prototype tripole antenna enabled estimates of the system noise temperature. They indicated that the proposed concept meets the requirements of a space-borne ULW array facility.

  5. Noise levels of neonatal high-flow nasal cannula devices--an in-vitro study.

    Science.gov (United States)

    König, Kai; Stock, Ellen L; Jarvis, Melanie

    2013-01-01

    Excessive ambient noise levels have been identified as a potential risk factor for adverse outcome in very preterm infants. Noise level measurements for continuous positive airway pressure (CPAP) devices demonstrated that these constantly exceed current recommendations. The use of high-flow nasal cannula (HFNC) as an alternative non-invasive ventilation modality has become more popular in recent years in neonatal care. To study noise levels of two HFNC devices commonly used in newborns. As a comparison, noise levels of a continuous flow CPAP device were also studied. In-vitro study. The noise levels of two contemporary HFNC devices (Fisher & Paykel NHF™ and Vapotherm Precision Flow®) and one CPAP device (Dräger Babylog® 8000 plus) were measured in the oral cavity of a newborn manikin in an incubator in a quiet environment. HFNC flows of 4-8 l/min and CPAP pressures of 4-8 cm H2O were applied. The CPAP flow was set at 8 l/min as per unit practice. Vapotherm HFNC generated the highest noise levels, measuring 81.2-91.4 dB(A) with increasing flow. Fisher & Paykel HFNC noise levels were between 78.8 and 81.2 dB(A). The CPAP device generated the lowest noise levels between 73.9 and 77.4 dB(A). Both HFNC devices generated higher noise levels than the CPAP device. All noise levels were far above current recommendations of the American Academy of Pediatrics. In light of the long duration of non-invasive respiratory support of very preterm infants, less noisy devices are required to prevent the potentially adverse effects of continuing excessive noise exposure in the neonatal intensive care unit. Copyright © 2013 S. Karger AG, Basel.

  6. Noise storm coordinated observations

    International Nuclear Information System (INIS)

    Elgaroey, Oe.; Tlamicha, A.

    1983-01-01

    The usually accepted bipolar model of noise storm centers is irrelevant for the present observations. An alternative model has been proposed in which the different sources of a noise storm center are located in different flux tubes connecting active regions with their surroundings. Radio emission is observed from the wide, descending branch of the flux tubes, opposite to the flaring site. The relation between the sense of circular polarization of the radio emission and the magnetic polarity, has been more precisely defined. The radiation is in the ordinary mode with respect to the underlying large scale photospheric magnetic polarity. Thus the ''irregular'' polarity of noice storm center ''B'' is explained. As regards center ''C'', one should note that although the observed radio emission is polarized in the ordinary mode with respect to the leading spot of region HR 17653, center ''C'' is not situated in flux tubes originating from the leading part of this region according to the proposed model. Rather, the radio sources are located in the wide and descending part of flux tubes connecting a large, quiet area of south magnetic polarity with the following part of the region HR 17653 (of north magnetic polarity). Thus it is the polarity of the extended area which determines the polarization of the radio emission. The observed polarization should result rather from the emission process than from complicated conditions of propagation for the radio waves

  7. Variations in the microseismic noise level observed at the Bucovina Seismic Array (BURAR)

    International Nuclear Information System (INIS)

    Ghica, Daniela; Radulian, Mircea; Popa, Mihaela

    2005-01-01

    The microseismic noise level analysis for a seismic array is an essential step to accurately process the data recorded by the system. Basically, the observed background noise is a complex combination of natural and cultural sources as local geology, specific area activity (roads traffic, agricultural and industrial activities) or weather conditions.The understanding of the BURAR site noise characteristics is important for the array specific techniques (beamforming, f-k analysis), to apply the correct bandpass filtering, in order to obtain noise suppression and conservation of the 'true' seismic signal. The array monitoring potential of very small earthquakes and explosions will be enhanced, based on the best signal-to-noise ratio.The noise study at BURAR was carried out over one-year period, considering the noise power spectra in a 0.1 to 10 Hz frequency interval, for every 24 hours: 5 minutes during day and 5 minutes during night. Only short-period vertical sensors were considered. Systematic variations in the microseismic noise level at the BURAR site were observed:- diurnal: a decreasing of about 40% in night noise level at 1 Hz frequency; at 6 Hz frequency, the decreasing could reach 80-90% for 'non-winter' months (May to October); - seasonal: during the winter time, a lower noise level is observed, due to the restraining of the local specific activity (especially agriculture and farming) and of the road traffic. To summarize the level of microseismic noise observed at BURAR for one-year observations, a model curve for array noise level has been estimated, including upper and lower bounds of noise power density together with average spectrum. The BURAR noise model will be useful in the process of local site conditions estimation, by eliminating the noise contribution from the array recording. Also, the detection processing, phase identification and events location procedures will be significantly improved. (authors)

  8. Investigating impact of motor oil quality on vehicles engine induced noise level

    Directory of Open Access Journals (Sweden)

    I. Arefian

    2015-09-01

    Full Text Available Introduction: Vehicle engine id one of the main sources of noise which its level is influenced by various parameters. The aim of this study was to investigate the impact of motor oils quality before and after oil change on the variability of vehicle engine induced noise level. In this study it is tried to follow-up the efficacy of motor oil quality on engines sound level. Material and Method: First, engine noise of 94 vehicles were recorded for 30 seconds before and after oil change and all the vehicles technical information including mileage, type of motor oil, and type of vehicle were registered. Following, the recorded noises were calibrated in semi-anechoic chamber and the sound pressure levels were measured with A and C-weighting network and main octav bands, using a sound level meters. The obtained results analyzed using SPSS software version 17. Results: The effects of motor oil quality on different noise levels of engines were determined and a significant reduction in noise level of vehicles engine was observed. Investigation of the relationship between mileage and motor oil quality on various engines sound level manifested that vehicles with mileage ranged 100000-150000 miles had significant reduction in their sound pressure levels in comparison with other vehicles. Conclusion: The results revealed that engine oil is among factors reducing the vehicle engine induced noise level. Moreover, the engine oil type and the vehicle mileage are key variables which determine the impact of engine oil quality on reduction of the sound level of vehicles engine.

  9. Predictive modelling of noise level generated during sawing of rocks

    Indian Academy of Sciences (India)

    This paper presents an experimental and statistical study on noise level generated during of rock sawing by circular diamond sawblades. Influence of the operating variables and rock properties on the noise level are investigated and analysed. Statistical analyses are then employed and models are built for the prediction of ...

  10. Potential of neuro-fuzzy methodology to estimate noise level of wind turbines

    Science.gov (United States)

    Nikolić, Vlastimir; Petković, Dalibor; Por, Lip Yee; Shamshirband, Shahaboddin; Zamani, Mazdak; Ćojbašić, Žarko; Motamedi, Shervin

    2016-01-01

    Wind turbines noise effect became large problem because of increasing of wind farms numbers since renewable energy becomes the most influential energy sources. However, wind turbine noise generation and propagation is not understandable in all aspects. Mechanical noise of wind turbines can be ignored since aerodynamic noise of wind turbine blades is the main source of the noise generation. Numerical simulations of the noise effects of the wind turbine can be very challenging task. Therefore in this article soft computing method is used to evaluate noise level of wind turbines. The main goal of the study is to estimate wind turbine noise in regard of wind speed at different heights and for different sound frequency. Adaptive neuro-fuzzy inference system (ANFIS) is used to estimate the wind turbine noise levels.

  11. Noise-level determination for discrete spectra with Gaussian or Lorentzian probability density functions

    International Nuclear Information System (INIS)

    Moriya, Netzer

    2010-01-01

    A method, based on binomial filtering, to estimate the noise level of an arbitrary, smoothed pure signal, contaminated with an additive, uncorrelated noise component is presented. If the noise characteristics of the experimental spectrum are known, as for instance the type of the corresponding probability density function (e.g., Gaussian), the noise properties can be extracted. In such cases, both the noise level, as may arbitrarily be defined, and a simulated white noise component can be generated, such that the simulated noise component is statistically indistinguishable from the true noise component present in the original signal. In this paper we present a detailed analysis of the noise level extraction when the additive noise is Gaussian or Lorentzian. We show that the statistical parameters in these cases (mainly the variance and the half width at half maximum, respectively) can directly be obtained from the experimental spectrum even when the pure signal is erratic. Further discussion is given for cases where the noise probability density function is initially unknown.

  12. Industrial noise level study in a wheat processing factory in ilorin, nigeria

    Science.gov (United States)

    Ibrahim, I.; Ajao, K. R.; Aremu, S. A.

    2016-05-01

    An industrial process such as wheat processing generates significant noise which can cause adverse effects on workers and the general public. This study assessed the noise level at a wheat processing mill in Ilorin, Nigeria. A portable digital sound level meter HD600 manufactured by Extech Inc., USA was used to determine the noise level around various machines, sections and offices in the factory at pre-determined distances. Subjective assessment was also mode using a World Health Organization (WHO) standard questionnaire to obtain information regarding noise ratings, effect of noise on personnel and noise preventive measures. The result of the study shows that the highest noise of 99.4 dBA was recorded at a pressure blower when compared to other machines. WHO Class-4 hearing protector is recommended for workers on the shop floor and room acoustics should be upgraded to absorb some sounds transmitted to offices.

  13. A comparison of high-frequency noise levels on Cascadia Initiative ocean-bottom seismometers

    Science.gov (United States)

    Hilmo, R.; Wilcock, W. S. D.; Roland, E. C.; Bodin, P.; Connolly, J.

    2017-12-01

    The Cascadia Initiative (CI) included a four-year deployment of 70 ocean bottom seismometers (OBSs) on the Cascadia subduction zone and the Juan de Fuca plate for the purposes of characterizing seismicity and imaging the Earth's interior. The Cascadia subduction zone megathrust exhibits very low rates of seismicity relative to most other subduction zones, and there is great motivation to understand deformation on the megathrust because of its potential to produce a catastrophic M9 earthquake. An understanding of earthquake detectability of the CI network, based on knowledge of noise levels, could contribute to the interpretation of earthquake catalogs derived from the experiment and aid in the design of future networks. This project is aimed at estimating these thresholds of local earthquake detectability and how they change across the array both geographically and temporally. We characterize background noise levels recorded from 0.1 to 20 Hz with an emphasis on the frequency band used to detect local seismicity ( 3-15 Hz) to understand how noise levels depend on instrument design and environmental parameters including seafloor depth, season and oceanographic conditions. Our initial analysis of 3 weeks of vertical channel data in September, January, and May 2012-2013 shows that noise increase significantly moving from the continental shelf to deeper water. Noise levels at a given depth vary with instrument type but further analysis is required to determine whether this reflects variations in instrumental noise and ground coupling noise or errors in the scaling of the instrument response. There is also a strong seasonality in recorded noise levels at some frequencies, with winter noise levels exceeding spring and fall noise levels by up to 10 decibels in both the microseism band and in the fin whale calling band (15-20 Hz). In contrast, the seasonal noise level in the local seismicity band for a given instrument type and location shows smaller noise variation

  14. Statistics of A-weighted road traffic noise levels in shielded urban areas

    NARCIS (Netherlands)

    Forssén, J.; Hornikx, M.C.J.

    2006-01-01

    In the context of community noise and its negative effects, the noise descriptors used are usually long-term equivalent levels and, sometimes, maximum levels. An improved description could be achieved by including the time variations of the noise. Here, the time variations of A-weighted road traffic

  15. Annoyance from Road Traffic, Trains, Airplanes and from Total Environmental Noise Levels

    Directory of Open Access Journals (Sweden)

    Martina S. Ragettli

    2015-12-01

    Full Text Available There is a lack of studies assessing the exposure-response relationship between transportation noise and annoyance in North America. Our aims were to investigate the prevalence of noise annoyance induced by road traffic, trains and airplanes in relation to distance to transportation noise sources, and to total environmental noise levels in Montreal, Canada; annoyance was assessed as noise-induced disturbance. A telephone-based survey among 4336 persons aged >18 years was conducted. Exposure to total environmental noise (A-weighted outdoor noise levels—LAeq24h and day-evening-night equivalent noise levels—Lden for each study participant was determined using a statistical noise model (land use regression—LUR that is based on actual outdoor noise measurements. The proportion of the population annoyed by road traffic, airplane and train noise was 20.1%, 13.0% and 6.1%, respectively. As the distance to major roads, railways and the Montreal International Airport increased, the percentage of people disturbed and highly disturbed due to the corresponding traffic noise significantly decreased. When applying the statistical noise model we found a relationship between noise levels and disturbance from road traffic and total environmental noise, with Prevalence Proportion Ratios (PPR for highly disturbed people of 1.10 (95% CI: 1.07–1.13 and 1.04 (1.02–1.06 per 1 dB(A Lden, respectively. Our study provides the first comprehensive information on the relationship between transportation noise levels and disturbance in a Canadian city. LUR models are still in development and further studies on transportation noise induced annoyance are consequently needed, especially for sources other than road traffic.

  16. Annoyance from Road Traffic, Trains, Airplanes and from Total Environmental Noise Levels

    Science.gov (United States)

    Ragettli, Martina S.; Goudreau, Sophie; Plante, Céline; Perron, Stéphane; Fournier, Michel; Smargiassi, Audrey

    2015-01-01

    There is a lack of studies assessing the exposure-response relationship between transportation noise and annoyance in North America. Our aims were to investigate the prevalence of noise annoyance induced by road traffic, trains and airplanes in relation to distance to transportation noise sources, and to total environmental noise levels in Montreal, Canada; annoyance was assessed as noise-induced disturbance. A telephone-based survey among 4336 persons aged >18 years was conducted. Exposure to total environmental noise (A-weighted outdoor noise levels—LAeq24h and day-evening-night equivalent noise levels—Lden) for each study participant was determined using a statistical noise model (land use regression—LUR) that is based on actual outdoor noise measurements. The proportion of the population annoyed by road traffic, airplane and train noise was 20.1%, 13.0% and 6.1%, respectively. As the distance to major roads, railways and the Montreal International Airport increased, the percentage of people disturbed and highly disturbed due to the corresponding traffic noise significantly decreased. When applying the statistical noise model we found a relationship between noise levels and disturbance from road traffic and total environmental noise, with Prevalence Proportion Ratios (PPR) for highly disturbed people of 1.10 (95% CI: 1.07–1.13) and 1.04 (1.02–1.06) per 1 dB(A) Lden, respectively. Our study provides the first comprehensive information on the relationship between transportation noise levels and disturbance in a Canadian city. LUR models are still in development and further studies on transportation noise induced annoyance are consequently needed, especially for sources other than road traffic. PMID:26729143

  17. Tools of radio astronomy

    CERN Document Server

    Wilson, Thomas L; Hüttemeister, Susanne

    2013-01-01

    This 6th edition of “Tools of Radio Astronomy”, the most used introductory text in radio astronomy, has been revised to reflect the current state of this important branch of astronomy. This includes the use of satellites, low radio frequencies, the millimeter/sub-mm universe, the Cosmic Microwave Background and the increased importance of mm/sub-mm dust emission. Several derivations and presentations of technical aspects of radio astronomy and receivers, such as receiver noise, the Hertz dipole and  beam forming have been updated, expanded, re-worked or complemented by alternative derivations. These reflect advances in technology. The wider bandwidths of the Jansky-VLA and long wave arrays such as LOFAR and mm/sub-mm arrays such as ALMA required an expansion of the discussion of interferometers and aperture synthesis. Developments in data reduction algorithms have been included. As a result of the large amount of data collected in the past 20 years, the discussion of solar system radio astronomy, dust em...

  18. GREEN BANK TELESCOPE AND SWIFT X-RAY TELESCOPE OBSERVATIONS OF THE GALACTIC CENTER RADIO MAGNETAR SGR J1745–2900

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, Ryan S.; Archibald, Robert F.; Kaspi, Victoria M.; Scholz, Paul, E-mail: rlynch@physics.mcgill.ca [Department of Physics, McGill University, 3600 University Street, Montreal, Quebec, H3A 2T8 (Canada)

    2015-06-20

    We present results from eight months of Green Bank Telescope 8.7 GHz observations and nearly 18 months of Swift X-ray telescope observations of the radio magnetar SGR J1745–2900. We tracked the radio and X-ray flux density, polarization properties, profile evolution, rotation, and single-pulse behavior. We identified two main periods of activity. The first is characterized by approximately 5.5 months of relatively stable evolution in radio flux density, rotation, and profile shape, while in the second these properties varied substantially. Specifically, a third profile component emerged and the radio flux also became more variable. The single pulse properties also changed, most notably with a larger fraction of pulses with pulse widths ∼5–20 ms in the erratic state. Bright single pulses are well described by a log-normal energy distribution at low energies, but with an excess at high energies. The 2–10 keV flux decayed steadily since the initial X-ray outburst, while the radio flux remained stable to within ∼20% during the stable state. A joint pulsar timing analysis of the radio and X-ray data shows a level of timing noise unprecedented in a radio magnetar, though during the time covered by the radio data alone the timing noise was at a level similar to that observed in other radio magnetars. While SGR J1745–2900 is similar to other radio magnetars in many regards, it differs by having experienced a period of relative stability in the radio that now appears to have ended, while the X-ray properties evolved independently.

  19. Propagation engineering in radio links design

    CERN Document Server

    Ghasemi, Abdollah; Ghasemi, Farshid

    2013-01-01

    Propagation Engineering in Radio Link Design covers the basic principles of radiowaves propagation in a practical manner.  This fundamental understanding enables the readers to design radio links efficiently. This book elaborates on new achievements as well as recently developed propagation models.  This is in addition to a comprehensive overview of fundamentals of propagation in various scenarios. It examines theoretical calculations, approaches and applied procedures needed for radio links design. The authors study and analysis of the main propagation phenomena and its mechanisms based on the recommendations of International Telecommunications Union, (ITU). The book has been organized in 9 chapters and examines the role of antennas and passive reflectors in radio services, propagation mechanisms related to radar, satellite, short distance, broadcasting and trans-horizon radio links, with two chapters devoted to radio noise and main  parameters of radio link design. The book presents some 278 illustration...

  20. Detection System of Sound Noise Level (SNL) Based on Condenser Microphone Sensor

    Science.gov (United States)

    Rajagukguk, Juniastel; Eka Sari, Nurdieni

    2018-03-01

    The research aims to know the noise level by using the Arduino Uno as data processing input from sensors and called as Sound Noise Level (SNL). The working principle of the instrument is as noise detector with the show notifications the noise level on the LCD indicator and in the audiovisual form. Noise detection using the sensor is a condenser microphone and LM 567 as IC op-amps, which are assembled so that it can detect the noise, which sounds are captured by the sensor will turn the tide of sinusoida voice became sine wave energy electricity (altering sinusoida electric current) that is able to responded to complaints by the Arduino Uno. The tool is equipped with a detector consists of a set indicator LED and sound well as the notification from the text on LCD 16*2. Work setting indicators on the condition that, if the measured noise > 75 dB then sound will beep, the red LED will light up indicating the status of the danger. If the measured value on the LCD is higher than 56 dB, sound indicator will be beep and yellow LED will be on indicating noisy. If the noise measured value <55 dB, sound indicator will be quiet indicating peaceful from noisy. From the result of the research can be explained that the SNL is capable to detecting and displaying noise level with a measuring range 50-100 dB and capable to delivering the notification noise in audiovisual.

  1. Preferred listening levels of mobile phone programs when considering subway interior noise

    Directory of Open Access Journals (Sweden)

    Jyaehyoung Yu

    2016-01-01

    Full Text Available Today, people listen to music loud using personal listening devices. Although a majority of studies have reported that the high volume played on these listening devices produces a latent risk of hearing problems, there is a lack of studies on "double noise exposures" such as environmental noise plus recreational noise. The present study measures the preferred listening levels of a mobile phone program with subway interior noise for 74 normal-hearing participants in five age groups (ranging from 20s to 60s. The speakers presented the subway interior noise at 73.45 dB, while each subject listened to three application programs [Digital Multimedia Broadcasting (DMB, music, game] for 30 min using a tablet personal computer with an earphone. The participants′ earphone volume levels were analyzed using a sound level meter and a 2cc coupler. Overall, the results showed that those in their 20s listened to the three programs significantly louder with DMB set at significantly higher volume levels than for the other programs. Higher volume levels were needed for middle frequency compared to the lower and higher frequencies. We concluded that any potential risk of noise-induced hearing loss for mobile phone users should be communicated when users listen regularly, although the volume level was not high enough that the users felt uncomfortable. When considering individual listening habits on mobile phones, further study to predict total accumulated environmental noise is still needed.

  2. Preferred listening levels of mobile phone programs when considering subway interior noise.

    Science.gov (United States)

    Yu, Jyaehyoung; Lee, Donguk; Han, Woojae

    2016-01-01

    Today, people listen to music loud using personal listening devices. Although a majority of studies have reported that the high volume played on these listening devices produces a latent risk of hearing problems, there is a lack of studies on "double noise exposures" such as environmental noise plus recreational noise. The present study measures the preferred listening levels of a mobile phone program with subway interior noise for 74 normal-hearing participants in five age groups (ranging from 20s to 60s). The speakers presented the subway interior noise at 73.45 dB, while each subject listened to three application programs [Digital Multimedia Broadcasting (DMB), music, game] for 30 min using a tablet personal computer with an earphone. The participants' earphone volume levels were analyzed using a sound level meter and a 2cc coupler. Overall, the results showed that those in their 20s listened to the three programs significantly louder with DMB set at significantly higher volume levels than for the other programs. Higher volume levels were needed for middle frequency compared to the lower and higher frequencies. We concluded that any potential risk of noise-induced hearing loss for mobile phone users should be communicated when users listen regularly, although the volume level was not high enough that the users felt uncomfortable. When considering individual listening habits on mobile phones, further study to predict total accumulated environmental noise is still needed.

  3. Measurement of speech levels in the presence of time varying background noise

    Science.gov (United States)

    Pearsons, K. S.; Horonjeff, R.

    1982-01-01

    Short-term speech level measurements which could be used to note changes in vocal effort in a time varying noise environment were studied. Knowing the changes in speech level would in turn allow prediction of intelligibility in the presence of aircraft flyover noise. Tests indicated that it is possible to use two second samples of speech to estimate long term root mean square speech levels. Other tests were also performed in which people read out loud during aircraft flyover noise. Results of these tests indicate that people do indeed raise their voice during flyovers at a rate of about 3-1/2 dB for each 10 dB increase in background level. This finding is in agreement with other tests of speech levels in the presence of steady state background noise.

  4. Prediction and comparison of noise levels from ground and elevated flare systems

    International Nuclear Information System (INIS)

    Obasi, E.

    2009-01-01

    Flaring is a process to dispose of hydrocarbons during clean-up, emergency shut downs or dispose a small volume waste streams of mixed gasses that cannot easily or safely be separated. This presentation discussed flaring as a noise issue. It focused on flaring noise characterization; flare noise modeling; flare sound power levels; and flare sound pressure level comparison at a distance of 1.5 km. The presentation included a photograph of flaring at a gas plant in Nigeria. The presentation listed some of the potential health effects associated with long term exposure to excessive noise, such as hearing loss; headaches; stress; fatigue; sleep disturbance; and high blood pressure. Companies flare gas to dispose waste gases in a safe and reliable manner through combustion and to depressurize gas lines during maintenance and emergencies. This presentation also discussed ground and elevated flares; components of flare noise characterization; and key factors affecting flare noise. A model to predict flaring noise was also presented. It demonstrated that at the same gas mass flow rate, the noise level from elevated flare stacks are significantly higher than ground flares. tabs., figs.

  5. Prediction and comparison of noise levels from ground and elevated flare systems

    Energy Technology Data Exchange (ETDEWEB)

    Obasi, E. [Stantec Consulting Ltd., Surrey, BC (Canada)

    2009-07-01

    Flaring is a process to dispose of hydrocarbons during clean-up, emergency shut downs or dispose a small volume waste streams of mixed gasses that cannot easily or safely be separated. This presentation discussed flaring as a noise issue. It focused on flaring noise characterization; flare noise modeling; flare sound power levels; and flare sound pressure level comparison at a distance of 1.5 km. The presentation included a photograph of flaring at a gas plant in Nigeria. The presentation listed some of the potential health effects associated with long term exposure to excessive noise, such as hearing loss; headaches; stress; fatigue; sleep disturbance; and high blood pressure. Companies flare gas to dispose waste gases in a safe and reliable manner through combustion and to depressurize gas lines during maintenance and emergencies. This presentation also discussed ground and elevated flares; components of flare noise characterization; and key factors affecting flare noise. A model to predict flaring noise was also presented. It demonstrated that at the same gas mass flow rate, the noise level from elevated flare stacks are significantly higher than ground flares. tabs., figs.

  6. Acceptable noise level with Danish, Swedish, and non-semantic speech materials

    DEFF Research Database (Denmark)

    Brännström, K Jonas; Lantz, Johannes; Nielsen, Lars Holme

    2012-01-01

    reported results from American studies. Generally, significant differences were seen between test conditions using different types of noise within ears in each population. Significant differences were seen for ANL across populations, also when the non-semantic ISTS was used as speech signal. Conclusions......Abstract Objective: Acceptable noise level (ANL) has been established as a method to quantify the acceptance of background noise while listening to speech presented at the most comfortable level. The aim of the present study was to generate Danish, Swedish, and a non-semantic version of the ANL...... test and investigate normal-hearing Danish and Swedish subjects' performance on these tests. Design: ANL was measured using Danish and Swedish running speech with two different noises: Speech-weighted amplitude-modulated noise, and multitalker speech babble. ANL was also measured using the non...

  7. Effects of pedagogical ideology on the perceived loudness and noise levels in preschools.

    Science.gov (United States)

    Jonsdottir, Valdis; Rantala, Leena M; Oskarsson, Gudmundur Kr; Sala, Eeva

    2015-01-01

    High activity noise levels that result in detrimental effects on speech communication have been measured in preschools. To find out if different pedagogical ideologies affect the perceived loudness and levels of noise, a questionnaire study inquiring about the experience of loudness and voice symptoms was carried out in Iceland in eight private preschools, called "Hjalli model", and in six public preschools. Noise levels were also measured in the preschools. Background variables (stress level, age, length of working career, education, smoking, and number of children per teacher) were also analyzed in order to determine how much they contributed toward voice symptoms and the experience of noisiness. Results indicate that pedagogical ideology is a significant factor for predicting noise and its consequences. Teachers in the preschool with tighter pedagogical control of discipline (the "Hjalli model") experienced lower activity noise loudness than teachers in the preschool with a more relaxed control of behavior (public preschool). Lower noise levels were also measured in the "Hjalli model" preschool and fewer "Hjalli model" teachers reported voice symptoms. Public preschool teachers experienced more stress than "Hjalli model" teachers and the stress level was, indeed, the background variable that best explained the voice symptoms and the teacher's perception of a noisy environment. Discipline, structure, and organization in the type of activity predicted the activity noise level better than the number of children in the group. Results indicate that pedagogical ideology is a significant factor for predicting self-reported noise and its consequences.

  8. Evaluation of noise level in architecture department building in University of Sumatera Utara

    Science.gov (United States)

    Amran, Novrial; Damanik, Novita Hillary Christy

    2018-03-01

    Noise is one the comfort factors that need to be noticed, particularly in an educational environment. Hearing a high noise in a period can affect students’ learning performance. The aims of this study were to know the noise level and get an appropriate design to reduce noise in Architecture Department building in the University of Sumatera Utara, considering that architecture students often spend most of their time inside the room. The measurement was conducted in four rooms for two days each from 09:00 – 12:00 and from 13:00 – 16:00 by using Sound Level Meter that placed near the noise source of the room. The result indicated that the average of noise level exceeded the 55 dB(A) so it still needs the appropriate design to reduce the noise that occurs in the building.

  9. 33 CFR 149.697 - What are the requirements for a noise level survey?

    Science.gov (United States)

    2010-07-01

    ... and Equipment Noise Limits § 149.697 What are the requirements for a noise level survey? (a) A survey... measured over 12 hours to derive a time weighted average (TWA) using a sound level meter and an A-weighted filter or equivalent device. (c) If the noise level throughout a space is determined to exceed 85 db(A...

  10. Determination of the level of noise in nurseries and pre-schools and the teachers′ level of annoyance

    Directory of Open Access Journals (Sweden)

    Ozan Gokdogan

    2016-01-01

    Full Text Available Objective: The aim of this article is to determine the level of noise in nurseries and pre-schools and also to compare measured levels with standard levels and evaluate the teachers’ level of annoyance. Materials and Methods: The level of noise was measured in three different schools. A total of 162 students, whose ages were between 3 and 6 years, and 12 teachers were included the study. Every age groups’ level of noise was measured during sleeping, gaming, and eating activity. In addition, teachers’ annoyance was assessed in different age groups. Results: The 4- to 6-year-old groups were found to have higher level of sounds than 3-year-old group. Eating period was found to be the highest level of sound whereas sleeping was found the lowest. Furthermore, teachers’ annoyance was found higher as the age decreased. Conclusion: Nurseries and pre-schools have noisy environment both for the students and the teachers. High level of noise, which has bad effects on health, is a public health problem. Both the students’ families and teachers must be aware of this annoying situation.

  11. Can weekly noise levels of urban road traffic, as predominant noise source, estimate annual ones?

    Science.gov (United States)

    Prieto Gajardo, Carlos; Barrigón Morillas, Juan Miguel; Rey Gozalo, Guillermo; Vílchez-Gómez, Rosendo

    2016-11-01

    The effects of noise pollution on human quality of life and health were recognised by the World Health Organisation a long time ago. There is a crucial dilemma for the study of urban noise when one is looking for proven methodologies that can allow, on the one hand, an increase in the quality of predictions, and on the other hand, saving resources in the spatial and temporal sampling. The temporal structure of urban noise is studied in this work from a different point of view. This methodology, based on Fourier analysis, is applied to several measurements of urban noise, mainly from road traffic and one-week long, carried out in two cities located on different continents and with different sociological life styles (Cáceres, Spain and Talca, Chile). Its capacity to predict annual noise levels from weekly measurements is studied. The relation between this methodology and the categorisation method is also analysed.

  12. Fast noise level estimation algorithm based on principal component analysis transform and nonlinear rectification

    Science.gov (United States)

    Xu, Shaoping; Zeng, Xiaoxia; Jiang, Yinnan; Tang, Yiling

    2018-01-01

    We proposed a noniterative principal component analysis (PCA)-based noise level estimation (NLE) algorithm that addresses the problem of estimating the noise level with a two-step scheme. First, we randomly extracted a number of raw patches from a given noisy image and took the smallest eigenvalue of the covariance matrix of the raw patches as the preliminary estimation of the noise level. Next, the final estimation was directly obtained with a nonlinear mapping (rectification) function that was trained on some representative noisy images corrupted with different known noise levels. Compared with the state-of-art NLE algorithms, the experiment results show that the proposed NLE algorithm can reliably infer the noise level and has robust performance over a wide range of image contents and noise levels, showing a good compromise between speed and accuracy in general.

  13. Noise levels from toys and recreational articles for children and teenagers.

    Science.gov (United States)

    Hellstrom, P A; Dengerink, H A; Axelsson, A

    1992-10-01

    This study examined the noise level emitted by toys and recreational articles used by children and teenagers. The results indicate that many of the items tested emit sufficiently intense noise to be a source of noise induced hearing loss in school-age children. While the baby toys provided noise exposure within the limits of national regulations, they are most intense in a frequency range that corresponds to the resonance frequency of the external auditory canal of very young children. Hobby motors emit noise that may require protection depending upon the length of use. Fire-crackers and cap guns emit impulse noises that exceed even conservative standards for noise exposure.

  14. I'm trying to heal...noise levels in a pediatric intensive care unit.

    Science.gov (United States)

    Milette, Isabelle H; Carnevale, Franco A

    2003-01-01

    The literature demonstrates clearly that most intensive care units exceed the standard recommendations for noise levels in hospitals, and that high noise levels have negative impacts on patients and staff. The purpose of this study was to evaluate the level of noise in a PICU and compare it to the recommendations of international bodies. We outline recommendations to promote the awareness of this problem and suggest strategies to decrease the level of noise in a PICU. The orientations of these strategies are threefold: 1) architectural-acoustic design, 2) equipment design and, most importantly, 3) staff education.

  15. Lateralization of noise bursts in interaurally correlated or uncorrelated background noise using interaural level differences.

    Science.gov (United States)

    Reed, Darrin K; van de Par, Steven

    2015-10-01

    The interaural level difference (ILD) of a lateralized target source may be effectively reduced when the target is presented together with background noise containing zero ILD. It is not certain whether listeners perceive a position congruent with the reduced ILD or the actual target ILD in a lateralization task. Two sets of behavioral experiments revealed that many listeners perceived a position at or even larger than that corresponding to the presented target ILD when a temporal onset/offset asynchrony between the broadband target and the broadband background noise was present. When no temporal asynchrony was present, however, the perceived lateral position indicated a dependency on the coherence of the background noise for several listeners. With interaurally correlated background noise, listeners reported a reduced ILD resulting from the combined target and background noise stimulus. In contrast, several of the listeners made a reasonable estimate of the position corresponding to the target ILD for interaurally uncorrelated, broadband, background noise. No obvious difference in performance was seen between low- or high-frequency stimuli. Extension of a weighting template to the output of a standard equalization-cancellation model was shown to remove a lateral bias on the predicted target ILD resulting from the presence of background noise. Provided that an appropriate weighting template is applied based on knowledge of the background noise coherence, good prediction of the behavioral data is possible.

  16. Estimating the level of dynamical noise in time series by using fractal dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Sase, Takumi, E-mail: sase@sat.t.u-tokyo.ac.jp [Graduate School of Information Science and Technology, The University of Tokyo, Tokyo 153-8505 (Japan); Ramírez, Jonatán Peña [CONACYT Research Fellow, Center for Scientific Research and Higher Education at Ensenada (CICESE), Carretera Ensenada-Tijuana No. 3918, Zona Playitas, C.P. 22860, Ensenada, Baja California (Mexico); Kitajo, Keiichi [BSI-Toyota Collaboration Center, RIKEN Brain Science Institute, Wako, Saitama 351-0198 (Japan); Aihara, Kazuyuki; Hirata, Yoshito [Graduate School of Information Science and Technology, The University of Tokyo, Tokyo 153-8505 (Japan); Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505 (Japan)

    2016-03-11

    We present a method for estimating the dynamical noise level of a ‘short’ time series even if the dynamical system is unknown. The proposed method estimates the level of dynamical noise by calculating the fractal dimensions of the time series. Additionally, the method is applied to EEG data to demonstrate its possible effectiveness as an indicator of temporal changes in the level of dynamical noise. - Highlights: • A dynamical noise level estimator for time series is proposed. • The estimator does not need any information about the dynamics generating the time series. • The estimator is based on a novel definition of time series dimension (TSD). • It is demonstrated that there exists a monotonic relationship between the • TSD and the level of dynamical noise. • We apply the proposed method to human electroencephalographic data.

  17. Estimating the level of dynamical noise in time series by using fractal dimensions

    International Nuclear Information System (INIS)

    Sase, Takumi; Ramírez, Jonatán Peña; Kitajo, Keiichi; Aihara, Kazuyuki; Hirata, Yoshito

    2016-01-01

    We present a method for estimating the dynamical noise level of a ‘short’ time series even if the dynamical system is unknown. The proposed method estimates the level of dynamical noise by calculating the fractal dimensions of the time series. Additionally, the method is applied to EEG data to demonstrate its possible effectiveness as an indicator of temporal changes in the level of dynamical noise. - Highlights: • A dynamical noise level estimator for time series is proposed. • The estimator does not need any information about the dynamics generating the time series. • The estimator is based on a novel definition of time series dimension (TSD). • It is demonstrated that there exists a monotonic relationship between the • TSD and the level of dynamical noise. • We apply the proposed method to human electroencephalographic data.

  18. An evaluation of primary school students' views about noise levels in school

    Directory of Open Access Journals (Sweden)

    Nermin Bulunuz

    2017-06-01

    Full Text Available Effective education and teaching requires keeping classroom noise levels within specific limits. The purpose of this study is to evaluate students’ views about the noise level in school, its effects, and control of it at two primary schools (one public school and one private school located in a district of Bursa - within the scope of the TÜBİTAK 1001 project numbered 114K738. The research sample consists of 432 third and fourth graders, 223 of whom are from the public school and 209 of whom are from the private school. To collect data, a 20-question survey was administered to the students, and noise measurements were carried out in the schools. According to the findings obtained from the analysis of the answers from the student questionnaire, the students think that the noise level is high especially during break times. In parallel with the student views, the average noise level at break time during recess was found to be 74.56 dBA at the private primary school and 82.18 dBA at the public primary school. These values are much higher than the limits prescribed in the Regulation on Assessment and Management of Environmental Noise in Turkey (RAMEN European Union Harmonization Laws. The research findings show that this important problem must be dealt with urgently, and substantive efforts and activities must be launched to reduce high noise levels in schools.

  19. Effects of pedagogical ideology on the perceived loudness and noise levels in preschools

    Science.gov (United States)

    Jonsdottir, Valdis; Rantala, Leena M.; Oskarsson, Gudmundur Kr.; Sala, Eeva

    2015-01-01

    High activity noise levels that result in detrimental effects on speech communication have been measured in preschools. To find out if different pedagogical ideologies affect the perceived loudness and levels of noise, a questionnaire study inquiring about the experience of loudness and voice symptoms was carried out in Iceland in eight private preschools, called “Hjalli model”, and in six public preschools. Noise levels were also measured in the preschools. Background variables (stress level, age, length of working career, education, smoking, and number of children per teacher) were also analyzed in order to determine how much they contributed toward voice symptoms and the experience of noisiness. Results indicate that pedagogical ideology is a significant factor for predicting noise and its consequences. Teachers in the preschool with tighter pedagogical control of discipline (the “Hjalli model”) experienced lower activity noise loudness than teachers in the preschool with a more relaxed control of behavior (public preschool). Lower noise levels were also measured in the “Hjalli model” preschool and fewer “Hjalli model” teachers reported voice symptoms. Public preschool teachers experienced more stress than “Hjalli model” teachers and the stress level was, indeed, the background variable that best explained the voice symptoms and the teacher's perception of a noisy environment. Discipline, structure, and organization in the type of activity predicted the activity noise level better than the number of children in the group. Results indicate that pedagogical ideology is a significant factor for predicting self-reported noise and its consequences. PMID:26356370

  20. Radio and line transmission 2

    CERN Document Server

    Roddy, Dermot

    2013-01-01

    Radio and Line Transmission, Volume 2 gives a detailed treatment of the subject as well as an introduction to additional advanced subject matter. Organized into 14 chapters, this book begins by explaining the radio wave propagation, signal frequencies, and bandwidth. Subsequent chapters describe the transmission lines and cables; the aerials; tuned and coupled circuits; bipolar transistor amplifiers; field-effect transistors and circuits; thermionic valve amplifiers; LC oscillators; the diode detectors and modulators; and the superheterodyne receiver. Other chapters explore noise and interfere

  1. Effects of venting on wind noise levels measured at the eardrum.

    Science.gov (United States)

    Chung, King

    2013-01-01

    Wind noise can be a nuisance to hearing aid users. With the advent of sophisticated feedback reduction algorithms, people with higher degrees of hearing loss are fit with larger vents than previously allowed, and more people with lesser degrees of hearing loss are fit with open hearing aids. The purpose of this study was to examine the effects of venting on wind noise levels in the ear canal for hearing aids with omnidirectional and directional microphones. Two behind-the-ear hearing aids were programmed when they were worn on a Knowles Electronics Manikin for Acoustic Research. The hearing aid worn on the right ear was programmed to the omnidirectional microphone mode and the one on the left to the directional microphone mode. The hearing aids were adjusted to linear amplification with flat frequency response in an anechoic chamber. Gains below 10 dB were used to avoid output limiting of wind noise levels at low input levels. Wind noise samples were recorded at the eardrum location in a wind tunnel at wind velocities ranging from a gentle to a strong breeze. The hearing aids were coupled to #13 tubings (i.e., open vent), or conventional skeleton earmolds with no vent, pressure vents, or 3mm vents. Polar and spectral characteristics of wind noise were analyzed off-line using MatLab programs. Wind noise levels in the ear canals were mostly predicted by vent-induced frequency response changes in the conventional earmold conditions for both omnidirectional and directional hearing aids. The open vent condition, however, yielded the lowest levels, which could not be entirely predicted by the frequency response changes of the hearing aids. This indicated that a wind-related vent effect permitted an additional amount of sound reduction in the ear canal, which could not be explained by known vent effects. For the microphone location, form factor, and gain settings tested, open fit hearing aids yielded lower noise levels at the eardrum location than conventional behind

  2. Real-Time Measurements for Adaptive and Cognitive Radio Systems

    Directory of Open Access Journals (Sweden)

    Hüseyin Arslan

    2009-01-01

    Full Text Available Adaptive and cognitive radios (CR have been becoming popular for optimizing mobile radio system transmission and reception. One of the most important elements of the adaptive radio and CR concepts is the ability to measure, sense, learn about, and be aware of parameters related to the radio channel characteristics, availability of spectrum and power, interference and noise temperature, operational environment of radio, user requirements and applications, available networks and infrastructures, local policies, other operating restrictions, and so on. This paper discusses some of the important measurement parameters for enabling adaptive radio and CR systems along with their relationships and impacts on the performance including relevant challenges.

  3. Sea-Level Trend Uncertainty With Pacific Climatic Variability and Temporally-Correlated Noise

    Science.gov (United States)

    Royston, Sam; Watson, Christopher S.; Legrésy, Benoît; King, Matt A.; Church, John A.; Bos, Machiel S.

    2018-03-01

    Recent studies have identified climatic drivers of the east-west see-saw of Pacific Ocean satellite altimetry era sea level trends and a number of sea-level trend and acceleration assessments attempt to account for this. We investigate the effect of Pacific climate variability, together with temporally-correlated noise, on linear trend error estimates and determine new time-of-emergence (ToE) estimates across the Indian and Pacific Oceans. Sea-level trend studies often advocate the use of auto-regressive (AR) noise models to adequately assess formal uncertainties, yet sea level often exhibits colored but non-AR(1) noise. Standard error estimates are over- or under-estimated by an AR(1) model for much of the Indo-Pacific sea level. Allowing for PDO and ENSO variability in the trend estimate only reduces standard errors across the tropics and we find noise characteristics are largely unaffected. Of importance for trend and acceleration detection studies, formal error estimates remain on average up to 1.6 times those from an AR(1) model for long-duration tide gauge data. There is an even chance that the observed trend from the satellite altimetry era exceeds the noise in patches of the tropical Pacific and Indian Oceans and the south-west and north-east Pacific gyres. By including climate indices in the trend analysis, the time it takes for the observed linear sea-level trend to emerge from the noise reduces by up to 2 decades.

  4. Seismic noise level variation in South Korea

    Science.gov (United States)

    Sheen, D.; Shin, J.

    2008-12-01

    The variations of seismic background noise in South Korea have been investigated by means of power spectral analysis. The Korea Institute of Geoscience and Mineral Resources (KIGAM) and the Korea Meteorological Administation (KMA) have national wide seismic networks in South Korea, and, in the end of 2007, there are 30 broadband stations which have been operating for more than a year. In this study, we have estimated the power spectral density of seismic noise for 30 broadband stations from 2005 to 2007. Since we estimate PSDs from a large dataset of continuous waveform in this study, a robust PSD estimate of McNamara and Buland (2004) is used. In the frequency range 1-5 Hz, the diurnal variations of noise are observed at most of stations, which are especially larger at coastal stations and at insular than at inland. Some stations shows daily difference of diurnal variations, which represents that cultural activities contribute to the noise level of a station. The variation of number of triggered stations, however, shows that cultural noise has little influence on the detection capability of seismic network in South Korea. Seasonal variations are observed well in the range 0.1-0.5 Hz, while much less found in the frequency range 1-5 Hz. We observed that strong peaks in the range 0.1-0.5 Hz occur at the summer when Pacific typhoons are close to the Korean Peninsula.

  5. Training Methods for Image Noise Level Estimation on Wavelet Components

    Directory of Open Access Journals (Sweden)

    A. De Stefano

    2004-12-01

    Full Text Available The estimation of the standard deviation of noise contaminating an image is a fundamental step in wavelet-based noise reduction techniques. The method widely used is based on the mean absolute deviation (MAD. This model-based method assumes specific characteristics of the noise-contaminated image component. Three novel and alternative methods for estimating the noise standard deviation are proposed in this work and compared with the MAD method. Two of these methods rely on a preliminary training stage in order to extract parameters which are then used in the application stage. The sets used for training and testing, 13 and 5 images, respectively, are fully disjoint. The third method assumes specific statistical distributions for image and noise components. Results showed the prevalence of the training-based methods for the images and the range of noise levels considered.

  6. Projected contributions of future wind farm development to community noise and annoyance levels in Ontario, Canada

    International Nuclear Information System (INIS)

    Whitfield Aslund, Melissa L.; Ollson, Christopher A.; Knopper, Loren D.

    2013-01-01

    Wind turbines produce sound during their operation; therefore, jurisdictions around the world have developed regulations regarding the placement of electricity generating wind farms with the intent of preventing unacceptable levels of ‘community noise’ in their vicinity. However, as survey results indicate that the relationship between wind turbine noise and annoyance may differ from noise-annoyance relationships for other common noise sources (e.g., rail, traffic), there are concerns that the application of general noise guidelines for wind turbines may lead to unacceptably high levels of annoyance in communities. In this study, previously published survey results that quantified wind turbine noise and self-reported annoyance were applied to the predicted noise levels (from turbines and transformers) for over 8000 receptors in the vicinity of 13 planned wind power developments in the province of Ontario, Canada. The results of this analysis indicate that the current wind turbine noise restrictions in Ontario will limit community exposure to wind turbine related noise such that levels of annoyance are unlikely to exceed previously established background levels of noise-related annoyance from other common noise sources. This provides valuable context that should be considered by policy-makers when evaluating the potential impacts of wind turbine noise on the community. -- highlights: •Wind turbine noise-annoyance relationship used to predict annoyance in Ontario. •Noise annoyance predicted to be <8% for non-participants <1 km from turbines. •Predicted levels of wind turbine noise annoyance similar to that from traffic noise. •Wind turbine noise annoyance not expected to exceed existing background levels

  7. Evaluation of noise level at intensive care units in selected hospitals of Sanandaj

    Directory of Open Access Journals (Sweden)

    Nammam Ali Azadi

    2015-08-01

    Conclusion: We found the noise levels were always above the EPA thresholds at all three hospitals both during the day and night. It is recommended to train hospital officials and staffs for keeping noise levels to an acceptable level.

  8. Modeling signal-to-noise ratio of otoacoustic emissions in workers exposed to different industrial noise levels

    Directory of Open Access Journals (Sweden)

    Parvin Nassiri

    2016-01-01

    Full Text Available Introduction: Noise is considered as the most common cause of harmful physical effects in the workplace. A sound that is generated from within the inner ear is known as an otoacoustic emission (OAE. Distortion-product otoacoustic emissions (DPOAEs assess evoked emission and hearing capacity. The aim of this study was to assess the signal-to-noise ratio in different frequencies and at different times of the shift work in workers exposed to various levels of noise. It was also aimed to provide a statistical model for signal-to-noise ratio (SNR of OAEs in different frequencies based on the two variables of sound pressure level (SPL and exposure time. Materials and Methods: This case–control study was conducted on 45 workers during autumn 2014. The workers were divided into three groups based on the level of noise exposure. The SNR was measured in frequencies of 1000, 2000, 3000, 4000, and 6000 Hz in both ears, and in three different time intervals during the shift work. According to the inclusion criterion, SNR of 6 dB or greater was included in the study. The analysis was performed using repeated measurements of analysis of variance, spearman correlation coefficient, and paired samples t-test. Results: The results showed that there was no statistically significant difference between the three exposed groups in terms of the mean values of SNR (P > 0.05. Only in signal pressure levels of 88 dBA with an interval time of 10:30–11:00 AM, there was a statistically significant difference between the right and left ears with the mean SNR values of 3000 frequency (P = 0.038. The SPL had a significant effect on the SNR in both the right and left ears (P = 0.023, P = 0.041. The effect of the duration of measurement on the SNR was statistically significant in both the right and left ears (P = 0.027, P < 0.001. Conclusion: The findings of this study demonstrated that after noise exposure during the shift, SNR of OAEs reduced from the

  9. [Environmental noise levels in 2 intensive care units in a tertiary care centre].

    Science.gov (United States)

    Ornelas-Aguirre, José Manuel; Zárate-Coronado, Olivia; Gaxiola-González, Fabiola; Neyoy-Sombra, Venigna

    2017-04-03

    The World Health Organisation (WHO) has established a maximum noise level of 40 decibels (dB) for an intensive care unit. The aim of this study was to compare the noise levels in 2 different intensive care units at a tertiary care centre. Using a cross-sectional design study, an analysis was made of the maximum noise level was within the intensive coronary care unit and intensive care unit using a digital meter. A measurement was made in 4 different points of each room, with 5minute intervals, for a period of 60minutes 7:30, 14:30, and 20:30. The means of the observations were compared with descriptive statistics and Mann-Whitney U. An analysis with Kruskal-Wallis test was performed to the mean noise level. The noise observed in the intensive care unit had a mean of 64.77±3.33dB (P=.08), which was similar to that in the intensive coronary care unit, with a mean of 60.20±1.58dB (P=.129). Around 25% or more of the measurements exceeded the level recommended by the WHO by up to 20 points. Noise levels measured in intensive care wards exceed the maximum recommended level for a hospital. It is necessary to design and implement actions for greater participation of health personnel in the reduction of environmental noise. Copyright © 2017 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

  10. Radio emission in the Virgo cluster and in SO galaxies

    International Nuclear Information System (INIS)

    Kotanyi, C.

    1981-01-01

    A survey of the radio continuum emission from the galaxies in the Virgo Cluster is presented. The sample of 274 galaxies in total contains a subsample of 188 galaxies complete down to magntiude msub(p) = 14. The observations consisted mostly of short (10 minutes) observations providing one-dimensional (East-West) strip distributions of the radio brightness at 1.4 GHz, with an East-West resolution of 23'' allowing separation of central sources from extended emission, and an r.m.s. noise level of 2 mJy. The radio emission of SO galaxies is examined. A sample of 145 SO galaxies is obtained by combining the Virgo cluster SO's with the nearby non-cluster SO's. The radio data, mainly from short observations, are used to derive the RLF. The radio emission in SO galaxies is at least three times weaker than that in ellipticals and spirals. Flat-spectrum compact nuclear sources are found in SO galaxies but they are at least 10 times weaker than in elliptical galaxies, which is attributed to the small mass of the bulges in SO's as compared to the mass of elliptical galaxies. The absence of steep-spectrum, extended central sources and of disk radio emission in SO's is attributed to their low neutral hydrogen content. (Auth.)

  11. High levels of X-linked Inhibitor-of-Apoptosis Protein (XIAP) are indicative of radio chemotherapy resistance in rectal cancer

    International Nuclear Information System (INIS)

    Flanagan, L.; Kehoe, J.; Fay, J.; Bacon, O.; Lindner, A.U.; Kay, E.W.; Deasy, J.; McNamara, D.A.; Prehn, J.H.M.

    2015-01-01

    The mainstay of treatment in rectal cancer is neoadjuvant radio chemotherapy prior to surgery, in an attempt to downstage the tumour, allowing for more complete removal during surgery. In 40 % of cases however, this neoadjuvant radio chemotherapy fails to achieve tumour regression, partly due insufficient apoptosis signaling. X-linked Inhibitor of Apoptosis Protein (XIAP) is an anti-apoptotic protein that has been reported to contribute to disease progression and chemotherapy resistance. We obtained rectal biopsy normal and matched tumour tissue from 29 rectal cancer patients with varying degrees of tumour regression, and using Western blot, examined anti-apoptotic XIAP and pro-apoptotic Smac protein levels in these tissues, with the aim to examine whether disturbed XIAP/Smac levels may be an indicator of neoadjuvant radio chemotherapy resistance. Expression of inhibitor of apoptosis proteins cIAP-1 and cIAP-2 was also examined. We found that levels of XIAP increased in accordance with the degree of radio chemotherapy resistance of the tissue. Levels of this protein were also significantly higher in tumour tissue, compared to matched normal tissue in highly resistant tissue. In contrast, Smac protein levels did not increase with radio chemotherapy resistance, and the protein was similarly expressed in normal and tumour tissue, indicating a shift in the balance of these proteins. Post treatment surgical resection tissue was available for 8 patients. When we compared matched tissue pre- and post- radio chemotherapy we found that XIAP levels increased significantly during treatment in both normal and tumour tissue, while Smac levels did not change. cIAP-1 and cIAP-2 levels were not differentially expressed in varying degrees of radio chemotherapy resistance, and neoadjuvant therapy did not alter expression of these proteins. These data indicate that disturbance of the XIAP/Smac balance may be a driver of radio chemotherapy resistance, and hence high levels of XIAP may

  12. Ambient Noise Levels in Acute Neonatal Intensive Care Unit of a Tertiary Referral Hospital

    Directory of Open Access Journals (Sweden)

    Sonia R. B D'Souza

    2017-10-01

    Full Text Available Background: Advances in neonatal care have resulted in improved survival of neonates admitted to the intensive care of the Neonatal Intensive Care Unit (NICU. However, the NCU may be an inappropriate milieu, with presence of overwhelming stimuli, most potent being the continuous presence of noise in the ambience of the NICU. Aim and Objectives: To determine and describe the ambient noise levels in the acute NICU of a tertiary referral hospital. Material and Methods: The ambient noise, in this study was the background sound existing in the environment of the acute NICU of a tertiary referral hospital in South India. The ambient noise levels were analyzed by an audiologist and acoustical engineer using a standardized and calibrated Sound Level Meter (SLM i.e., the Hand Held Analyzer type 2250, Brüel and Kjær, Denmark on a weighted frequency A and reported as dB (A. Results: The ambient noise levels were timed measurements yielded by the SLM in terms of L eq, L as well as L exceeded the standard A 10 Aeqmax levels (Leq< 45 dB, L ≤ 50 dB, and Lmax ≤ 65 10 dB.The L eq ranged from 59.4 to 62.12 dB A. A Ventilators with alarms caused the maximum amount of ambient noise yielding a L Sound Pressure Level AF (SPL of 82.14 dB A. Conclusion: The study has found high levels of ambient noise in the acute NICU. Though there are several measures to reduce the ambient noise levels in the NICU, it is essential to raise awareness among health care personnel regarding the observed ambient noise levels and its effects on neonates admitted to the NICU.

  13. Measuring and Assessment the Noise Level in Different Regions in Baghdad City And Compare it with The Allowable Levels

    Directory of Open Access Journals (Sweden)

    Ibtihaj Abdulwahhab Abdulrazzak

    2017-05-01

    Full Text Available This study includes measurement of the noise level of four regions in the city of Baghdad (industrial region, commercial region, residential region and quiet region and compare the value of noise in each region with the World Health Organization (WHO allowable limits, and the effect of noise on human health was explained. The "sound level meter (SLM" instrument measuring the noise value in the four regions, three measurement per month through one year was recorded (one measurement every ten days from 1/1/2015 to 30/12/2015. The noise level of the industrial region (75dB compared with the World Health Organization level allowable limit (65dB, while the commercial region (76.28dB versus (55dB and the residential region (74.94dB versus (50dB and the quiet region was (62.36dB versus (40dB of the (WHO allowable limit.

  14. Measurement of Acceptable Noise Level with Background Music.

    Science.gov (United States)

    Ahn, Hyun-Jung; Bahng, Junghwa; Lee, Jae Hee

    2015-09-01

    Acceptable noise level (ANL) is a measure of the maximum background noise level (BNL) that a person is willing to tolerate while following a target story. Although researchers have used various sources of target sound in ANL measures, a limited type of background noise has been used. Extending the previous study of Gordon-Hickey & Moore (2007), the current study determined the effect of music genre and tempo on ANLs as possible factors affecting ANLs. We also investigated the relationships between individual ANLs and the familiarity of music samples and between music ANLs and subjective preference. Forty-one participants were seperated into two groups according to their ANLs, 29 low-ANL listeners and 12 high-ANL listeners. Using Korean ANL material, the individual ANLs were measured based on the listeners' most comfortable listening level and BNL. The ANLs were measured in six conditions, with different music tempo (fast, slow) and genre (K-pop, pop, classical) in a counterbalanced order. Overall, ANLs did not differ by the tempo of background music, but music genre significantly affected individual ANLs. We observed relatively higher ANLs with K-pop music and relatively lower ANLs with classical music. This tendency was similar in both low-ANL and high-ANL groups. However, the subjective ratings of music familiarity and preference affected ANLs differently for low-ANL and high-ANL groups. In contrast to the low-ANL listeners, the ANLs of the high-ANL listeners were significantly affected by music familiarity and preference. The genre of background music affected ANLs obtained using background music. The degree of music familiarity and preference appears to be associated with individual susceptibility to background music only for listeners who are greatly annoyed by background noise (high-ANL listeners).

  15. Modeling Speech Level as a Function of Background Noise Level and Talker-to-Listener Distance for Talkers Wearing Hearing Protection Devices

    DEFF Research Database (Denmark)

    Bouserhal, Rachel E.; Bockstael, Annelies; MacDonald, Ewen

    2017-01-01

    Purpose: Studying the variations in speech levels with changing background noise level and talker-to-listener distance for talkers wearing hearing protection devices (HPDs) can aid in understanding communication in background noise. Method: Speech was recorded using an intra-aural HPD from 12...... complements the existing model presented by Pelegrín-García, Smits, Brunskog, and Jeong (2011) and expands on it by taking into account the effects of occlusion and background noise level on changes in speech sound level. Conclusions: Three models of the relationship between vocal effort, background noise...

  16. Assessment of noise levels generated by music shops in an urban city in Nigeria.

    Science.gov (United States)

    Ebare, M N; Omuemu, V O; Isah, E C

    2011-09-01

    To assess the level of noise generated by music shops in an urban city in Nigeria. Cross-sectional, descriptive study. The study involved music shops in three out of eight identified clusters of market areas in Benin City. A semi-structured, researcher-administered questionnaire was also used to collect data from music shop owners. Noise levels generated by speakers in the music shops were measured using a sound level meter, and blood pressure measurements were taken with a mercury sphygmomanometer. Of the 250 music shops studied, more than 90.0% generated noise levels >85 dB, and 54.8% had a continuous pattern of noise. Longer duration of working years was significantly associated with decreased hearing (P = 0.01), shouting when talking (P = 0.04) and high blood pressure (P = 0.003). The position of music dealers in relation to the speakers was significantly associated with shouting when talking (P = 0.000). A significant association was found between higher levels of noise and high blood pressure (P = 0.004). This study found very high levels of noise in music shops, which could be a source of occupational noise exposure among music dealers. Enlightenment campaigns on the hazards of exposure to loud noise and periodic audiometry examinations are recommended for this occupational group. Copyright © 2011 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  17. Neutron noise in nuclear reactors

    International Nuclear Information System (INIS)

    Blaquiere, A.; Pachowska, R.

    1961-06-01

    The power of a nuclear reactor, in the operating conditions, presents fluctuations due to various causes. This random behaviour can be included in the study of 'noises'. Among other sources of noise, we analyse hereafter the fluctuations due: a) to the discontinuous emissions of neutrons from an independent source; b) to the multiplication of neutrons inside the reactor. The method which we present makes use of the analogies between the rules governing a nuclear reactor in operation and a number of radio-electrical systems, in particular the feed-back loops. The reactor can be characterized by its 'passing band' and is described as a system submitted to a sequence of random pulses. In non linear operating condition, the effect of neutron noise is defined by means of a non-linear functional, this theory is thus related to previous works the references of which are given at the end of the present report. This leads us in particular in the case of nuclear reactors to some results given by A. Blaquiere in the case of radio-electrical loops. (author) [fr

  18. MMSE-based algorithm for joint signal detection, channel and noise variance estimation for OFDM systems

    CERN Document Server

    Savaux, Vincent

    2014-01-01

    This book presents an algorithm for the detection of an orthogonal frequency division multiplexing (OFDM) signal in a cognitive radio context by means of a joint and iterative channel and noise estimation technique. Based on the minimum mean square criterion, it performs an accurate detection of a user in a frequency band, by achieving a quasi-optimal channel and noise variance estimation if the signal is present, and by estimating the noise level in the band if the signal is absent. Organized into three chapters, the first chapter provides the background against which the system model is pr

  19. Study on traffic noise level of Sylhet by multiple regression analysis associated with health hazards

    Directory of Open Access Journals (Sweden)

    J. B. Alam, M. Jobair Bin Alam, M. M. Rahman, A. K. Dikshit, S. K. Khan

    Full Text Available The study reports the level of traffic-induced noise pollution in Sylhet City. For this purpose noise levels have been measured at thirty-seven major locations of the city from 7 am to 11 pm during the working days. It was observed that at all the locations the level of noise remains far above the acceptable limit for all the time. The noise level on the main road near residential area, hospital area and educational area were above the recommended level (65dBA. It was found that the predictive equations are in 60-70% correlated with the measured noise level. The study suggests that vulnerable institutions like school and hospital should be located about 60m away from the roadside unless any special arrangement to alleviate sound is used.

  20. Reduction of 1/f noise in graphene after electron-beam irradiation

    International Nuclear Information System (INIS)

    Zahid Hossain, Md.; Rumyantsev, Sergey; Shur, Michael S.; Balandin, Alexander A.

    2013-01-01

    We investigated experimentally the effect of the electron-beam irradiation on the level of the low-frequency 1/f noise in graphene devices. It was found that 1/f noise in graphene reduces with increasing concentration of defects induced by irradiation. The increased amount of structural disorder in graphene under irradiation was verified with micro-Raman spectroscopy. The bombardment of graphene devices with 20-keV electrons reduced the noise spectral density, S I /I 2 (I is the source-drain current) by an order-of magnitude at the radiation dose of 10 4 μC/cm 2 . We analyzed the observed noise reduction in the limiting cases of the mobility and carrier number fluctuation mechanisms. The obtained results are important for the proposed graphene applications in analog, mixed-signal, and radio-frequency systems, integrated circuits and sensors.

  1. Preparation of Ultracold Atom Clouds at the Shot Noise Level

    DEFF Research Database (Denmark)

    Gajdacz, M.; Hilliard, A. J.; Kristensen, Mick

    2016-01-01

    We prepare number stabilized ultracold atom clouds through the real-time analysis of nondestructive images and the application of feedback. In our experiments, the atom number N∼10^6 is determined by high precision Faraday imaging with uncertainty ΔN below the shot noise level, i.e., ΔN... on this measurement, feedback is applied to reduce the atom number to a user-defined target, whereupon a second imaging series probes the number stabilized cloud. By this method, we show that the atom number in ultracold clouds can be prepared below the shot noise level....

  2. Effects of background noise on total noise annoyance

    Science.gov (United States)

    Willshire, K. F.

    1987-01-01

    Two experiments were conducted to assess the effects of combined community noise sources on annoyance. The first experiment baseline relationships between annoyance and noise level for three community noise sources (jet aircraft flyovers, traffic and air conditioners) presented individually. Forty eight subjects evaluated the annoyance of each noise source presented at four different noise levels. Results indicated the slope of the linear relationship between annoyance and noise level for the traffic noise was significantly different from that of aircraft and of air conditioner noise, which had equal slopes. The second experiment investigated annoyance response to combined noise sources, with aircraft noise defined as the major noise source and traffic and air conditioner noise as background noise sources. Effects on annoyance of noise level differences between aircraft and background noise for three total noise levels and for both background noise sources were determined. A total of 216 subjects were required to make either total or source specific annoyance judgements, or a combination of the two, for a wide range of combined noise conditions.

  3. HIGH-RESOLUTION IMAGING OF THE ATLBS REGIONS: THE RADIO SOURCE COUNTS

    Energy Technology Data Exchange (ETDEWEB)

    Thorat, K.; Subrahmanyan, R.; Saripalli, L.; Ekers, R. D., E-mail: kshitij@rri.res.in [Raman Research Institute, C. V. Raman Avenue, Sadashivanagar, Bangalore 560080 (India)

    2013-01-01

    The Australia Telescope Low-brightness Survey (ATLBS) regions have been mosaic imaged at a radio frequency of 1.4 GHz with 6'' angular resolution and 72 {mu}Jy beam{sup -1} rms noise. The images (centered at R.A. 00{sup h}35{sup m}00{sup s}, decl. -67 Degree-Sign 00'00'' and R.A. 00{sup h}59{sup m}17{sup s}, decl. -67 Degree-Sign 00'00'', J2000 epoch) cover 8.42 deg{sup 2} sky area and have no artifacts or imaging errors above the image thermal noise. Multi-resolution radio and optical r-band images (made using the 4 m CTIO Blanco telescope) were used to recognize multi-component sources and prepare a source list; the detection threshold was 0.38 mJy in a low-resolution radio image made with beam FWHM of 50''. Radio source counts in the flux density range 0.4-8.7 mJy are estimated, with corrections applied for noise bias, effective area correction, and resolution bias. The resolution bias is mitigated using low-resolution radio images, while effects of source confusion are removed by using high-resolution images for identifying blended sources. Below 1 mJy the ATLBS counts are systematically lower than the previous estimates. Showing no evidence for an upturn down to 0.4 mJy, they do not require any changes in the radio source population down to the limit of the survey. The work suggests that automated image analysis for counts may be dependent on the ability of the imaging to reproduce connecting emission with low surface brightness and on the ability of the algorithm to recognize sources, which may require that source finding algorithms effectively work with multi-resolution and multi-wavelength data. The work underscores the importance of using source lists-as opposed to component lists-and correcting for the noise bias in order to precisely estimate counts close to the image noise and determine the upturn at sub-mJy flux density.

  4. Noise level estimation in weakly nonlinear slowly time-varying systems

    International Nuclear Information System (INIS)

    Aerts, J R M; Dirckx, J J J; Lataire, J; Pintelon, R

    2008-01-01

    Recently, a method using multisine excitation was proposed for estimating the frequency response, the nonlinear distortions and the disturbing noise of weakly nonlinear time-invariant systems. This method has been demonstrated on the measurement of nonlinear distortions in the vibration of acoustically driven systems such as a latex membrane, which is a good example of a time-invariant system [1]. However, not all systems are perfectly time invariant, e.g. biomechanical systems. This time variation can be misinterpreted as an elevated noise floor, and the classical noise estimation method gives a wrong result. Two improved methods to retrieve the correct noise information from the measurements are presented. Both of them make use of multisine excitations. First, it is demonstrated that the improved methods give the same result as the classical noise estimation method when applied to a time-invariant system (high-quality microphone membrane). Next, it is demonstrated that the new methods clearly give an improved estimate of the noise level on time-varying systems. As an application example results for the vibration response of an eardrum are shown

  5. Direct observations of low-energy solar electrons associated with a type 3 solar radio burst

    Science.gov (United States)

    Frank, L. A.; Gurnett, D. A.

    1972-01-01

    On 6 April 1971 a solar X-ray flare and a type 3 solar radio noise burst were observed with instrumentation on the eccentric-orbiting satellite IMP 6. The type 3 solar radio noise burst was detected down to a frequency of 31 kHz. A highly anisotropic packet of low-energy solar electron intensities arrived at the satellite approximately 6000 seconds after the onset of the solar flare. This packet of solar electron intensities was observed for 4200 seconds. Maximum differential intensities of the solar electrons were in the energy range of one to several keV. The frequency drift rate of the type 3 radio noise at frequencies below 178 kHz also indicated an average particle speed corresponding to that of a 3-keV electron. The simultaneous observations of these solar electron intensities and of the type 3 solar radio burst are presented, and their interrelationships are explored.

  6. Noise Levels in Two Emergency Departments Before and After the Introduction of Electronic Whiteboards

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2013-01-01

    . The maximum equivalent continuous noise levels across 1 second were above 80 dB(A) at all four coordination centres. At two of the centres above 80 dB(A) noises also occurred at night. After the introduction of electronic whiteboards the noise level was lowered at one ED but unchanged at the other ED...

  7. Maintaining reduced noise levels in a resource-constrained neonatal intensive care unit by operant conditioning.

    Science.gov (United States)

    Ramesh, A; Denzil, S B; Linda, R; Josephine, P K; Nagapoornima, M; Suman Rao, P N; Swarna Rekha, A

    2013-03-01

    To evaluate the efficacy of operant conditioning in sustaining reduced noise levels in the neonatal intensive care unit (NICU). Quasi-experimental study on quality of care. Level III NICU of a teaching hospital in south India. 26 staff employed in the NICU. (7 Doctors, 13 Nursing staff and 6 Nursing assistants). Operant conditioning of staff activity for 6 months. This method involves positive and negative reinforcement to condition the staff to modify noise generating activities. Comparing noise levels in decibel: A weighted [dB (A)] before conditioning with levels at 18 and 24 months after conditioning. Decibel: A weighted accounts for noise that is audible to human ears. Operant conditioning for 6 months sustains the reduced noise levels to within 62 dB in ventilator room 95% CI: 60.4 - 62.2 and isolation room (95% CI: 55.8 - 61.5). In the preterm room, noise can be maintained within 52 dB (95% CI: 50.8 - 52.6). This effect is statistically significant in all the rooms at 18 months (P = 0.001). At 24 months post conditioning there is a significant rebound of noise levels by 8.6, 6.7 and 9.9 dB in the ventilator, isolation and preterm room, respectively (P =0.001). Operant conditioning for 6 months was effective in sustaining reduced noise levels. At 18 months post conditioning, the noise levels were maintained within 62 dB (A), 60 dB (A) and 52 dB (A) in the ventilator, isolation and pre-term room, respectively. Conditioning needs to be repeated at 12 months in the ventilator room and at 18 months in the other rooms.

  8. The Relationship between Personality Type and Acceptable Noise Levels: A Pilot Study.

    Science.gov (United States)

    Franklin, Cliff; Johnson, Laura V; White, Letitia; Franklin, Clay; Smith-Olinde, Laura

    2013-01-01

    Objectives. This study examined the relationship between acceptable noise level (ANL) and personality. ANL is the difference between a person's most comfortable level for speech and the loudest level of background noise they are willing to accept while listening to speech. Design. Forty young adults with normal hearing participated. ANLs were measured and two personality tests (Big Five Inventory, Myers-Briggs Type Indicator) were administered. Results. The analysis revealed a correlation between ANL and the openness and conscientious personality dimensions from the Big Five Inventory; no correlation emerged between ANL and the Myers-Briggs personality types. Conclusions. Lower ANLs are correlated with full-time hearing aid use and the openness personality dimension; higher ANLs are correlated with part-time or hearing aid nonuse and the conscientious personality dimension. Current data suggest that those more open to new experiences may accept more noise and possibly be good hearing aid candidates, while those more conscientious may accept less noise and reject hearing aids, based on their unwillingness to accept background noise. Knowing something about a person's personality type may help audiologists determine if their patients will likely be good candidates for hearing aids.

  9. Pilot study of methods and equipment for in-home noise level measurements.

    Science.gov (United States)

    Neitzel, Richard L; Heikkinen, Maire S A; Williams, Christopher C; Viet, Susan Marie; Dellarco, Michael

    2015-01-15

    Knowledge of the auditory and non-auditory effects of noise has increased dramatically over the past decade, but indoor noise exposure measurement methods have not advanced appreciably, despite the introduction of applicable new technologies. This study evaluated various conventional and smart devices for exposure assessment in the National Children's Study. Three devices were tested: a sound level meter (SLM), a dosimeter, and a smart device with a noise measurement application installed. Instrument performance was evaluated in a series of semi-controlled tests in office environments over 96-hour periods, followed by measurements made continuously in two rooms (a child's bedroom and a most used room) in nine participating homes over a 7-day period with subsequent computation of a range of noise metrics. The SLMs and dosimeters yielded similar A-weighted average noise levels. Levels measured by the smart devices often differed substantially (showing both positive and negative bias, depending on the metric) from those measured via SLM and dosimeter, and demonstrated attenuation in some frequency bands in spectral analysis compared to SLM results. Virtually all measurements exceeded the Environmental Protection Agency's 45 dBA day-night limit for indoor residential exposures. The measurement protocol developed here can be employed in homes, demonstrates the possibility of measuring long-term noise exposures in homes with technologies beyond traditional SLMs, and highlights potential pitfalls associated with measurements made by smart devices.

  10. The Relationship between Personality Type and Acceptable Noise Levels: A Pilot Study

    OpenAIRE

    Franklin, Cliff; Johnson, Laura V.; White, Letitia; Franklin, Clay; Smith-Olinde, Laura

    2013-01-01

    Objectives. This study examined the relationship between acceptable noise level (ANL) and personality. ANL is the difference between a person’s most comfortable level for speech and the loudest level of background noise they are willing to accept while listening to speech. Design. Forty young adults with normal hearing participated. ANLs were measured and two personality tests (Big Five Inventory, Myers-Briggs Type Indicator) were administered. Results. The analysis revealed a correlation bet...

  11. BAYESIAN ANALYSIS OF WHITE NOISE LEVELS IN THE FIVE-YEAR WMAP DATA

    International Nuclear Information System (INIS)

    Groeneboom, N. E.; Eriksen, H. K.; Gorski, K.; Huey, G.; Jewell, J.; Wandelt, B.

    2009-01-01

    We develop a new Bayesian method for estimating white noise levels in CMB sky maps, and apply this algorithm to the five-year Wilkinson Microwave Anisotropy Probe (WMAP) data. We assume that the amplitude of the noise rms is scaled by a constant value, α, relative to a pre-specified noise level. We then derive the corresponding conditional density, P(α | s, C l , d), which is subsequently integrated into a general CMB Gibbs sampler. We first verify our code by analyzing simulated data sets, and then apply the framework to the WMAP data. For the foreground-reduced five-year WMAP sky maps and the nominal noise levels initially provided in the five-year data release, we find that the posterior means typically range between α = 1.005 ± 0.001 and α = 1.010 ± 0.001 depending on differencing assembly, indicating that the noise level of these maps are biased low by 0.5%-1.0%. The same problem is not observed for the uncorrected WMAP sky maps. After the preprint version of this letter appeared on astro-ph., the WMAP team has corrected the values presented on their web page, noting that the initially provided values were in fact estimates from the three-year data release, not from the five-year estimates. However, internally in their five-year analysis the correct noise values were used, and no cosmological results are therefore compromised by this error. Thus, our method has already been demonstrated in practice to be both useful and accurate.

  12. Performance evaluation of a real time OFDM radio over fiber system at 2.5 GHz using software defined radio SDR

    DEFF Research Database (Denmark)

    David Cepeda, Juan; Rodriguez, Santiago Isaac; Rico-Martinez, Monica

    2017-01-01

    This paper presents the implementation of an OFDM radio over fiber (RoF) system at 2.5 GHz using software defined radio (SDR). In this work, first we present an introduction of the main concepts about radio over fiber and an orthogonal frequency-division multiplexing (OFDM) system at 2.5 GHz......, then we present a comparison of an OFDM RoF system in three scenarios, modifying the wireless distances and the optical fiber distance in order to evaluate the performance of the system taking into account the symbol error rate (SER) vs signal to noise ratio (SNR) curves....

  13. Synthesis imaging in radio astronomy

    International Nuclear Information System (INIS)

    Perley, R.A.; Schwab, F.R.; Bridle, A.H.

    1989-01-01

    Recent advances in techniques and instrumentation for radio synthesis imaging in astronomy are discussed in a collection of review essays. Topics addressed include coherence in radio astronomy, the interferometer in practice, primary antenna elements, cross correlators, calibration and editing, sensitivity, deconvolution, self-calibration, error recognition, and image analysis. Consideration is given to wide-field imaging (bandwidth and time-average smearing, noncoplanar arrays, and mosaicking), high-dynamic-range imaging, spectral-line imaging, VLBI, solar imaging with a synthesis telescope, synthesis imaging of spatially coherent objects, noise in images of very bright sources, synthesis observing strategies, and the design of aperture-synthesis arrays

  14. Critical assessment of day time traffic noise level at curbside open-air microenvironment of Kolkata City, India.

    Science.gov (United States)

    Kundu Chowdhury, Anirban; Debsarkar, Anupam; Chakrabarty, Shibnath

    2015-01-01

    The objective of the research work is to assess day time traffic noise level at curbside open-air microenvironment of Kolkata city, India under heterogeneous environmental conditions. Prevailing traffic noise level in terms of A-weighted equivalent noise level (Leq) at the microenvironment was in excess of 12.6 ± 2.1 dB(A) from the day time standard of 65 dB(A) for commercial area recommended by the Central Pollution Control Board (CPCB) of India. Noise Climate and Traffic Noise Index of the microenvironment were accounted for 13 ± 1.8 dB(A) and 88.8 ± 6.1 dB(A) respectively. A correlation analysis explored that prevailing traffic noise level of the microenvironment had weak negative (-0.21; p air temperature and relative humidity. A Varimax rotated principal component analysis explored that motorized traffic volume had moderate positive loading with background noise component (L90, L95, L99) and prevailing traffic noise level had very strong positive loading with peak noise component (L1, L5, L10). Background and peak noise component cumulatively explained 80.98 % of variance in the data set. Traffic noise level at curbside open-air microenvironment of Kolkata City was higher than the standard recommended by CPCB of India. It was highly annoying also. Air temperature and relative humidity had little influence and the peak noise component had the most significant influence on the prevailing traffic noise level at curbside open-air microenvironment. Therefore, traffic noise level at the microenvironment of the city can be reduced with careful honking and driving.

  15. A Comparative Land Use-Based Analysis of Noise Pollution Levels in Selected Urban Centers of Nigeria.

    Science.gov (United States)

    Baloye, David O; Palamuleni, Lobina G

    2015-09-29

    Growth in the commercialization, mobility and urbanization of human settlements across the globe has greatly exposed world urban population to potentially harmful noise levels. The situation is more disturbing in developing countries like Nigeria, where there are no sacrosanct noise laws and regulations. This study characterized noise pollution levels in Ibadan and Ile-Ife, two urban areas of Southwestern Nigeria that have experienced significant increases in population and land use activities. Eight hundred noise measurements, taken at 20 different positions in the morning, afternoon, and evening of carefully selected weekdays, in each urban area, were used for this study. Findings put the average noise levels in the urban centers at between 53 dB(A) and 89 dB (A), a far cry from the World Health Organization (WHO) permissible limits in all the land use types, with highest noise pollution levels recorded for transportation, commercial, residential and educational land use types. The result of the one-way ANOVA test carried out on the dependent variable noise and fixed factor land use types reveals a statistically significant mean noise levels across the study area (F(3,34) = 15.13, p = 0.000). The study underscores noise pollution monitoring and the urgent need to control urban noise pollution with appropriate and effective policies.

  16. Distributed Robust Power Minimization for the Downlink of Multi-Cloud Radio Access Networks

    KAUST Repository

    Dhifallah, Oussama Najeeb; Dahrouj, Hayssam; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

    2017-01-01

    Conventional cloud radio access networks assume single cloud processing and treat inter-cloud interference as background noise. This paper considers the downlink of a multi-cloud radio access network (CRAN) where each cloud is connected to several

  17. A noise level prediction method based on electro-mechanical frequency response function for capacitors.

    Science.gov (United States)

    Zhu, Lingyu; Ji, Shengchang; Shen, Qi; Liu, Yuan; Li, Jinyu; Liu, Hao

    2013-01-01

    The capacitors in high-voltage direct-current (HVDC) converter stations radiate a lot of audible noise which can reach higher than 100 dB. The existing noise level prediction methods are not satisfying enough. In this paper, a new noise level prediction method is proposed based on a frequency response function considering both electrical and mechanical characteristics of capacitors. The electro-mechanical frequency response function (EMFRF) is defined as the frequency domain quotient of the vibration response and the squared capacitor voltage, and it is obtained from impulse current experiment. Under given excitations, the vibration response of the capacitor tank is the product of EMFRF and the square of the given capacitor voltage in frequency domain, and the radiated audible noise is calculated by structure acoustic coupling formulas. The noise level under the same excitations is also measured in laboratory, and the results are compared with the prediction. The comparison proves that the noise prediction method is effective.

  18. Hybrid cognitive engine for radio systems adaptation

    KAUST Repository

    Alqerm, Ismail; Shihada, Basem

    2017-01-01

    of our hybrid engine is validated using software defined radios implementation and simulation in multi-carrier environment. The system throughput, signal to noise and interference ratio, and packet error rate are obtained and compared with other schemes

  19. The Effect of Solar Radiation on Radio Signal for Radio Astronomy Purposes

    International Nuclear Information System (INIS)

    Nor Hazmin Sabri; Atiq Wahidah Azlan; Roslan Umar; Roslan Umar; Shahirah Syafa Sulan; Zainol Abidin Ibrahim; Wan Zul Adli Wan Mokhtar

    2015-01-01

    Radio astronomy is a subfields of astronomy which is discovers the celestial objects at radio frequencies. Observation in radio astronomy is conducted using single antenna or array of antennas, known as radio telescope. Other than that, radio astronomy also holds an advantage over other alternatives to optical astronomy due to its capability of observing from the ground level. In this study, the effect of solar radiation that contributes the Radio Frequency Interferences (RFI) is reviewed. The low RFI level is required to set up the radio telescope for radio astronomy observation. The effect of solar radiation on radio signal was investigated by determining the RFI pattern using spectrum analyzer. The solar radiation data was obtained from weather station located at KUSZA Observatory, East Coast Environmental Research Institute (ESERI), UniSZA. We can conclude that the solar radiation factor give the minimum significant effect to radio signal. (author)

  20. Calibration of an audio frequency noise generator

    DEFF Research Database (Denmark)

    Diamond, Joseph M.

    1966-01-01

    a noise bandwidth Bn = π/2 × (3dB bandwidth). To apply this method to low audio frequencies, the noise bandwidth of the low Q parallel resonant circuit has been found, including the effects of both series and parallel damping. The method has been used to calibrate a General Radio 1390-B noise generator...... it is used for measurement purposes. The spectral density of a noise source may be found by measuring its rms output over a known noise bandwidth. Such a bandwidth may be provided by a passive filter using accurately known elements. For example, the parallel resonant circuit with purely parallel damping has...

  1. Sedimentary noise and sea levels linked to land-ocean water exchange and obliquity forcing.

    Science.gov (United States)

    Li, Mingsong; Hinnov, Linda A; Huang, Chunju; Ogg, James G

    2018-03-08

    In ancient hothouses lacking ice sheets, the origins of large, million-year (myr)-scale sea-level oscillations remain a mystery, challenging current models of sea-level change. To address this mystery, we develop a sedimentary noise model for sea-level changes that simultaneously estimates geologic time and sea level from astronomically forced marginal marine stratigraphy. The noise model involves two complementary approaches: dynamic noise after orbital tuning (DYNOT) and lag-1 autocorrelation coefficient (ρ 1 ). Noise modeling of Lower Triassic marine slope stratigraphy in South China reveal evidence for global sea-level variations in the Early Triassic hothouse that are anti-phased with continental water storage variations in the Germanic Basin. This supports the hypothesis that long-period (1-2 myr) astronomically forced water mass exchange between land and ocean reservoirs is a missing link for reconciling geological records and models for sea-level change during non-glacial periods.

  2. Interplanetary radio storms. II - Emission levels and solar wind speed in the range 0.05-0.8 AU

    Science.gov (United States)

    Bougeret, J.-L.; Fainberg, J.; Stone, R. G.

    1984-01-01

    Storms of interplanetary type III radio bursts (IP storms) are commonly observed in the interplanetary medium by the ISEE-3 radio instrument. This instrument has the capability of accurately determining the arrival direction of the radio emission. At each observing frequency, the storm radio sources are tracked as they cross the line-of-sight to the sun. Using a simple model, the emission levels are determined at a number of radio frequencies for four separate storms. The IP storm radiation is found to occur in regions of enhanced density at levels of 0.05 to 0.8 AU. The density in these enhancements falls off faster than R(-2). The solar wind speed in the storm region is also measured. The analysis is consistent with steady conditions in the storm region during a few days around the III storm burst radio emission at the harmonic of the local plasma frequency.

  3. Assessment of ambient noise levels in the intensive care unit of a university hospital

    Directory of Open Access Journals (Sweden)

    Hatem O Qutub

    2009-01-01

    Conclusion : Some sources of environmental noise, such as the use of oxygen, suction equipment or respirators are unavoidable. Nevertheless, hospital ICUs should have measures to minimize the level of exposure to noise in the ICU. Further research in this area might focus on the noise level and other modifiable environmental stress factors in the ICU that affect patients as well as the staff.

  4. Hybrid cognitive engine for radio systems adaptation

    KAUST Repository

    Alqerm, Ismail

    2017-07-20

    Network efficiency and proper utilization of its resources are essential requirements to operate wireless networks in an optimal fashion. Cognitive radio aims to fulfill these requirements by exploiting artificial intelligence techniques to create an entity called cognitive engine. Cognitive engine exploits awareness about the surrounding radio environment to optimize the use of radio resources and adapt relevant transmission parameters. In this paper, we propose a hybrid cognitive engine that employs Case Based Reasoning (CBR) and Decision Trees (DTs) to perform radio adaptation in multi-carriers wireless networks. The engine complexity is reduced by employing DTs to improve the indexing methodology used in CBR cases retrieval. The performance of our hybrid engine is validated using software defined radios implementation and simulation in multi-carrier environment. The system throughput, signal to noise and interference ratio, and packet error rate are obtained and compared with other schemes in different scenarios.

  5. Observations of a post-flare radio burst in X-rays

    Science.gov (United States)

    Svestka, Z.; Hoyng, P.; Van Tend, W.; Boelee, A.; De Jager, C.; Stewart, R. T.; Acton, L. W.; Bruner, E. C.; Gabriel, A. H.; Rapley, C. G.

    1982-01-01

    More than six hours after the two-ribbon flare of May 21, 1980, the hard X-ray spectrometer aboard the SMM imaged an extensive arch above the flare region which was found to be the lowest part of a stationary post-flare noise storm recorded at the same time at Culgoora. The bent crystal spectrometer aboard the SMM confirms that the arch emission was basically thermal. Variations in brightness and energy spectrum at one of the supposed footpoints of the arch are seen as correlation in time with radio brightness, suggesting that suprathermal particles from the radio noise regions dumped in variable quantities onto the low corona and transition layer.

  6. A comparative study of noise pollution levels in some selected areas in Ilorin Metropolis, Nigeria.

    Science.gov (United States)

    Oyedepo, Olayinka S; Saadu, Abdullahi A

    2009-11-01

    The noise pollution is a major problem for the quality of life in urban areas. This study was conducted to compare the noise pollution levels at busy roads/road junctions, passengers loading parks, commercial, industrial and residential areas in Ilorin metropolis. A total number of 47-locations were selected within the metropolis. Statistical analysis shows significant difference (P noise pollution levels between industrial areas and low density residential areas, industrial areas and high density areas, industrial areas and passengers loading parks, industrial areas and commercial areas, busy roads/road junctions and low density areas, passengers loading parks and commercial areas and commercial areas and low density areas. There is no significant difference (P > 0.05) in noise pollution levels between industrial areas and busy roads/road junctions, busy roads/road junctions and high density areas, busy roads/road junctions and passengers loading parks, busy roads/road junctions and commercial areas, passengers loading parks and high density areas, passengers loading parks and commercial areas and commercial areas and high density areas. The results show that Industrial areas have the highest noise pollution levels (110.2 dB(A)) followed by busy roads/Road junctions (91.5 dB(A)), Passengers loading parks (87.8 dB(A)) and Commercial areas (84.4 dB(A)). The noise pollution levels in Ilorin metropolis exceeded the recommended level by WHO at 34 of 47 measuring points. It can be concluded that the city is environmentally noise polluted and road traffic and industrial machineries are the major sources of it. Noting the noise emission standards, technical control measures, planning and promoting the citizens awareness about the high noise risk may help to relieve the noise problem in the metropolis.

  7. Advantages of binaural amplification to acceptable noise level of directional hearing aid users.

    Science.gov (United States)

    Kim, Ja-Hee; Lee, Jae Hee; Lee, Ho-Ki

    2014-06-01

    The goal of the present study was to examine whether Acceptable Noise Levels (ANLs) would be lower (greater acceptance of noise) in binaural listening than in monaural listening condition and also whether meaningfulness of background speech noise would affect ANLs for directional microphone hearing aid users. In addition, any relationships between the individual binaural benefits on ANLs and the individuals' demographic information were investigated. Fourteen hearing aid users (mean age, 64 years) participated for experimental testing. For the ANL calculation, listeners' most comfortable listening levels and background noise level were measured. Using Korean ANL material, ANLs of all participants were evaluated under monaural and binaural amplification with a counterbalanced order. The ANLs were also compared across five types of competing speech noises, consisting of 1- through 8-talker background speech maskers. Seven young normal-hearing listeners (mean age, 27 years) participated for the same measurements as a pilot testing. The results demonstrated that directional hearing aid users accepted more noise (lower ANLs) with binaural amplification than with monaural amplification, regardless of the type of competing speech. When the background speech noise became more meaningful, hearing-impaired listeners accepted less amount of noise (higher ANLs), revealing that ANL is dependent on the intelligibility of the competing speech. The individuals' binaural advantages in ANLs were significantly greater for the listeners with longer experience of hearing aids, yet not related to their age or hearing thresholds. Binaural directional microphone processing allowed hearing aid users to accept a greater amount of background noise, which may in turn improve listeners' hearing aid success. Informational masking substantially influenced background noise acceptance. Given a significant association between ANLs and duration of hearing aid usage, ANL measurement can be useful for

  8. Judgments of aircraft noise in a traffic noise background

    Science.gov (United States)

    Powell, C. A.; Rice, C. G.

    1975-01-01

    An investigation was conducted to determine subjective response to aircraft noise in different road traffic backgrounds. In addition, two laboratory techniques for presenting the aircraft noise with the background noise were evaluated. For one technique, the background noise was continuous over an entire test session; for the other, the background noise level was changed with each aircraft noise during a session. Subjective response to aircraft noise was found to decrease with increasing background noise level, for a range of typical indoor noise levels. Subjective response was found to be highly correlated with the Noise Pollution Level (NPL) measurement scale.

  9. Wideband noise observed at ground level in the auroral region

    International Nuclear Information System (INIS)

    Benson, R.F.; Desch, M.D.

    1991-01-01

    A sideband noise event was detected at ground level from the Andoya Rocket Range in Norway in January 1989. The signals were observed on four commercial communication receivers (tuned to 159, 515, 905, and 1200 kHz), an ionosonde (200-kHz to 3.5-MHz interference-free observations) and a riometer (32.5 MHz). The event, which occurred during a period of magnetic disturbance near magnetic midnight, was the only one observed during nearly 3 weeks of operations. This low frequency-of-occurrence is attributed partly to high local noise levels. The ease with which this event was identified on the ionograms produced by the local ionosonde suggests that routine ionosonde recordings should be inspected in search for such events. Such an effort would enhance existing research directed toward developing techniques for identifying quiet communication channels and help to identify the origin and frequency-of-occurrence of high-latitude wideband noise events. 20 refs

  10. Photonic microwave signals with zeptosecond-level absolute timing noise

    Science.gov (United States)

    Xie, Xiaopeng; Bouchand, Romain; Nicolodi, Daniele; Giunta, Michele; Hänsel, Wolfgang; Lezius, Matthias; Joshi, Abhay; Datta, Shubhashish; Alexandre, Christophe; Lours, Michel; Tremblin, Pierre-Alain; Santarelli, Giorgio; Holzwarth, Ronald; Le Coq, Yann

    2017-01-01

    Photonic synthesis of radiofrequency (RF) waveforms revived the quest for unrivalled microwave purity because of its ability to convey the benefits of optics to the microwave world. In this work, we perform a high-fidelity transfer of frequency stability between an optical reference and a microwave signal via a low-noise fibre-based frequency comb and cutting-edge photodetection techniques. We demonstrate the generation of the purest microwave signal with a fractional frequency stability below 6.5 × 10-16 at 1 s and a timing noise floor below 41 zs Hz-1/2 (phase noise below -173 dBc Hz-1 for a 12 GHz carrier). This outperforms existing sources and promises a new era for state-of-the-art microwave generation. The characterization is achieved through a heterodyne cross-correlation scheme with the lowermost detection noise. This unprecedented level of purity can impact domains such as radar systems, telecommunications and time-frequency metrology. The measurement methods developed here can benefit the characterization of a broad range of signals.

  11. Theory of deep level trap effects on generation-recombination noise in HgCdTe photoconductors

    International Nuclear Information System (INIS)

    Iverson, A.E.; Smith, D.L.

    1985-01-01

    We present a theory of the effect of deep level centers on the generation-recombination (g-r) noise and responsivity of an intrinsic photoconductor. The deep level centers can influence the g-r noise and responsivity in three main ways: (i) they can shorten the bulk carrier lifetime by Shockley--Read--Hall recombination; (ii) for some values of the capture cross sections, deep level densities, and temperature, the deep levels can trap a significant fraction of the photogenerated minority carriers. This trapping reduces the effective minority carrier mobility and diffusivity and thus reduces the effect of carrier sweep out on both g-r noise and responsivity; (iii) the deep level centers add a new thermal noise source, which results from fluctuations between bound and free carriers. The strength of this new noise source decreases with decreasing temperature at a slower rate than band-to-band thermal g-r noise. Calculations have been performed for a X = 0.21, n-type Hg/sub 1-x/Cd/sub x/Te photoconductor using the parameters of a commonly occurring deep level center in this material. We find that for typical operating conditions photoconductive detector performance begins to degrade as the deep level density begins to exceed 10 16 cm -3

  12. Listening level of music through headphones in train car noise environments.

    Science.gov (United States)

    Shimokura, Ryota; Soeta, Yoshiharu

    2012-09-01

    Although portable music devices are useful for passing time on trains, exposure to music using headphones for long periods carries the risk of damaging hearing acuity. The aim of this study is to examine the listening level of music through headphones in the noisy environment of a train car. Eight subjects adjusted the volume to an optimum level (L(music)) in a simulated noisy train car environment. In Experiment I, the effects of noise level (L(train)) and type of train noise (rolling, squealing, impact, and resonance) were examined. Spectral and temporal characteristics were found to be different according to the train noise type. In Experiment II, the effects of L(train) and type of music (five vocal and five instrumental music) were examined. Each music type had a different pitch strength and spectral centroid, and each was evaluated by φ(1) and W(φ(0)), respectively. These were classified as factors of the autocorrelation function (ACF) of the music. Results showed that L(music) increased as L(train) increased in both experiments, while the type of music greatly influenced L(music). The type of train noise, however, only slightly influenced L(music). L(music) can be estimated using L(train) and the ACF factors φ(1) and W(φ(0)).

  13. Investment strategy due to the minimization of portfolio noise level by observations of coarse-grained entropy

    OpenAIRE

    Krzysztof Urbanowicz; Janusz A. Holyst

    2004-01-01

    Using a recently developed method of noise level estimation that makes use of properties of the coarse grained-entropy we have analyzed the noise level for the Dow Jones index and a few stocks from the New York Stock Exchange. We have found that the noise level ranges from 40 to 80 percent of the signal variance. The condition of a minimal noise level has been applied to construct optimal portfolios from selected shares. We show that implementation of a corresponding threshold investment stra...

  14. STUDY ON NOISE LEVEL GENERATED BY HUMAN ACTIVITIES IN SIBIU CITY, ROMANIA

    Directory of Open Access Journals (Sweden)

    Cristina STANCA-MOISE

    2014-10-01

    Full Text Available In this paper I have proposed an analysis and monitoring of the noise sources in the open spaces of air traffic, rail and car in Sibiu. From centralizing data obtained from the analysis of the measurements performed with equipment noise levels, we concluded that the noise and vibration produced by means of Transportation (air, road, rail can affect human health if they exceed limits. Noise is present and part of our lives and always a source of pollution as any of modern man is not conscious.

  15. Quality-aware features-based noise level estimator for block matching and three-dimensional filtering algorithm

    Science.gov (United States)

    Xu, Shaoping; Hu, Lingyan; Yang, Xiaohui

    2016-01-01

    The performance of conventional denoising algorithms is usually controlled by one or several parameters whose optimal settings depend on the contents of the processed images and the characteristics of the noises. Among these parameters, noise level is a fundamental parameter that is always assumed to be known by most of the existing denoising algorithms (so-called nonblind denoising algorithms), which largely limits the applicability of these nonblind denoising algorithms in many applications. Moreover, these nonblind algorithms do not always achieve the best denoised images in visual quality even when fed with the actual noise level parameter. To address these shortcomings, in this paper we propose a new quality-aware features-based noise level estimator (NLE), which consists of quality-aware features extraction and optimal noise level parameter prediction. First, considering that image local contrast features convey important structural information that is closely related to image perceptual quality, we utilize the marginal statistics of two local contrast operators, i.e., the gradient magnitude and the Laplacian of Gaussian (LOG), to extract quality-aware features. The proposed quality-aware features have very low computational complexity, making them well suited for time-constrained applications. Then we propose a learning-based framework where the noise level parameter is estimated based on the quality-aware features. Based on the proposed NLE, we develop a blind block matching and three-dimensional filtering (BBM3D) denoising algorithm which is capable of effectively removing additive white Gaussian noise, even coupled with impulse noise. The noise level parameter of the BBM3D algorithm is automatically tuned according to the quality-aware features, guaranteeing the best performance. As such, the classical block matching and three-dimensional algorithm can be transformed into a blind one in an unsupervised manner. Experimental results demonstrate that the

  16. [Preventive effects of sound insulation windows on the indoor noise levels in a street residential building in Beijing].

    Science.gov (United States)

    Guo, Bin; Huang, Jing; Guo, Xin-biao

    2015-06-18

    To evaluate the preventive effects of sound insulation windows on traffic noise. Indoor noise levels of the residential rooms (on both the North 4th ring road side and the campus side) with closed sound insulation windows were measured using the sound level meter, and comparisons with the simultaneously measured outdoor noise levels were made. In addition, differences of indoor noise levels between rooms with closed sound insulation windows and open sound insulation windows were also compared. The average outdoor noise levels of the North 4th ring road was higher than 70 dB(A), which exceeded the limitation stated in the "Environmental Quality Standard for Noise" (GB 3096-2008) in our country. However, with the sound insulation windows closed, the indoor noise levels reduced significantly to the level under 35 dB(A) (Pwindows had significant influence on the indoor noise levels (Pwindow, when the sound insulation windows were closed, the indoor noise levels reduced 18.8 dB(A) and 8.3 dB(A) in residential rooms facing North 4th ring road side and campus side, respectively. The results indicated that installation of insulation windows had significant noise reduction effects on street residential buildings especially on the rooms facing major traffic roads. Installation of the sound insulation windows has significant preventive effects on indoor noise in the street residential building.

  17. Dispersive detection of radio-frequency-dressed states

    Science.gov (United States)

    Jammi, Sindhu; Pyragius, Tadas; Bason, Mark G.; Florez, Hans Marin; Fernholz, Thomas

    2018-04-01

    We introduce a method to dispersively detect alkali-metal atoms in radio-frequency-dressed states. In particular, we use dressed detection to measure populations and population differences of atoms prepared in their clock states. Linear birefringence of the atomic medium enables atom number detection via polarization homodyning, a form of common path interferometry. In order to achieve low technical noise levels, we perform optical sideband detection after adiabatic transformation of bare states into dressed states. The balanced homodyne signal then oscillates independently of field fluctuations at twice the dressing frequency, thus allowing for robust, phase-locked detection that circumvents low-frequency noise. Using probe pulses of two optical frequencies, we can detect both clock states simultaneously and obtain population difference as well as the total atom number. The scheme also allows for difference measurements by direct subtraction of the homodyne signals at the balanced detector, which should technically enable quantum noise limited measurements with prospects for the preparation of spin squeezed states. The method extends to other Zeeman sublevels and can be employed in a range of atomic clock schemes, atom interferometers, and other experiments using dressed atoms.

  18. Investment strategy due to the minimization of portfolio noise level by observations of coarse-grained entropy

    Science.gov (United States)

    Urbanowicz, Krzysztof; Hołyst, Janusz A.

    2004-12-01

    Using a recently developed method of noise level estimation that makes use of properties of the coarse-grained entropy, we have analyzed the noise level for the Dow Jones index and a few stocks from the New York Stock Exchange. We have found that the noise level ranges from 40% to 80% of the signal variance. The condition of a minimal noise level has been applied to construct optimal portfolios from selected shares. We show that the implementation of a corresponding threshold investment strategy leads to positive returns for historical data.

  19. The Usability of Noise Level from Rock Cutting for the Prediction of Physico-Mechanical Properties of Rocks

    Science.gov (United States)

    Delibalta, M. S.; Kahraman, S.; Comakli, R.

    2015-11-01

    Because the indirect tests are easier and cheaper than the direct tests, the prediction of rock properties from the indirect testing methods is important especially for the preliminary investigations. In this study, the predictability of the physico-mechanical rock properties from the noise level measured during cutting rock with diamond saw was investigated. Noise measurement test, uniaxial compressive strength (UCS) test, Brazilian tensile strength (BTS) test, point load strength (Is) test, density test, and porosity test were carried out on 54 different rock types in the laboratory. The results were statistically analyzed to derive estimation equations. Strong correlations between the noise level and the mechanical rock properties were found. The relations follow power functions. Increasing rock strength increases the noise level. Density and porosity also correlated strongly with the noise level. The relations follow linear functions. Increasing density increases the noise level while increasing porosity decreases the noise level. The developed equations are valid for the rocks with a compressive strength below 150 MPa. Concluding remark is that the physico-mechanical rock properties can reliably be estimated from the noise level measured during cutting the rock with diamond saw.

  20. Assessment of ambient noise levels in the urban residential streets of Eastern Alexandria, Egypt.

    Science.gov (United States)

    Zaki, Gehan R

    2012-12-01

    Street of Alexandria have numerous unplanned, mixed, and noisy activities that may interfere with public health and comfort. The aim of this study was to assess A-weighted ambient noise levels in urban residential streets of Eastern Alexandria, Egypt, from September 2010 to January 2011, with the objective of recommending corrective actions to minimize high noise levels. A descriptive cross-sectional study was carried out, in which A-weighted ambient noise levels were measured on the basis of 24-h periods, using Ono sokki la-5120--precision integrating sound level meter, from September 2010 to January 2011. The measurements were taken on three streets, which were selected using stratified random sampling. Seven measurement sites, along the three streets under study, were selected by site visits according to predetermined criteria. A-weighted ambient noise levels (LAeq) were the highest [70.7 (24.2) dB] on high-traffic-density and high-human-activity streets followed by streets with moderate and low traffic density and human activity [67.5 (31.3) and 62.8 (38.2) dB], respectively. It varied significantly depending on means of transportation (road traffic, train, and/or tram) and human activities (parking lots, shops, and/or street merchants). The A-weighted ambient noise levels on urban residential streets of Eastern Alexandria, Egypt, exceeded the Egyptian National Standards during the three periods of the day (daytime, evening, and night), except in some relatively quiet locations during the night. Consequently, remedial actions to reduce noise levels were recommended.

  1. The Effect of the Cholesterol Levels on Noise-Induced Hearing Loss.

    Science.gov (United States)

    Demir, Mehmet Gokhan; Aydin, Sedat

    2018-01-01

    Introduction  Noise-induced hearing loss (NIHL), which is one of the most common occupational diseases among industrialized populations, is associated with longstanding exposure to high levels of noise. The pathogenesis of NIHL is not clear, but some genes and their activity at the tissue level have been investigated. Hypercholesterolemia, which can disturb the microcirculation, can be one of the underlying pathologies in hearing loss. Objective  To investigate the relationship between NIHL and hypercholesterolemia. Methods  The study group was selected among workers who had an occupational exposure of 85 dB of noise for at least 10 years. The audiologic assessment was recorded at seven frequencies (500 Hz, 1,000 Hz, 2,000 Hz, 3,000 Hz, 4,000 Hz, 6,000 Hz and 8,000 Hz). A total of 456 workers were included in the study and divided into two groups: the control group (252 patients) and the NIHL group (204 patients). After the audiologic measurement, blood samples were taken and investigated for blood cholesterol levels. According to these results, the groups were compared. Results  Both groups were similarly distributed regarding age and occupational exposure time ( p  > 0.05). We could not detect any association between cholesterol levels and noise-induced hearing loss ( p   0.05). Conclusion  Noise-induced hearing loss is still a common occupational problem that can be prevented by hearing conservation programs and occupational health and safety training. Still, we know little about the relationship between NIHL and hypercholesterolemia. According to our findings, we cannot detect any relationship. Controlled studies and studies with human individuals can be made possible in the future with diagnostic innovations in tissue imaging and tissue microcircular sampling.

  2. A survey of acoustic conditions and noise levels in secondary school classrooms in England.

    Science.gov (United States)

    Shield, Bridget; Conetta, Robert; Dockrell, Julie; Connolly, Daniel; Cox, Trevor; Mydlarz, Charles

    2015-01-01

    An acoustic survey of secondary schools in England has been undertaken. Room acoustic parameters and background noise levels were measured in 185 unoccupied spaces in 13 schools to provide information on the typical acoustic environment of secondary schools. The unoccupied acoustic and noise data were correlated with various physical characteristics of the spaces. Room height and the amount of glazing were related to the unoccupied reverberation time and therefore need to be controlled to reduce reverberation to suitable levels for teaching and learning. Further analysis of the unoccupied data showed that the introduction of legislation relating to school acoustics in England and Wales in 2003 approximately doubled the number of school spaces complying with current standards. Noise levels were also measured during 274 lessons to examine typical levels generated during teaching activities in secondary schools and to investigate the influence of acoustic design on working noise levels in the classroom. Comparison of unoccupied and occupied data showed that unoccupied acoustic conditions affect the noise levels occurring during lessons. They were also related to the time spent in disruption to the lessons (e.g., students talking or shouting) and so may also have an impact upon student behavior in the classroom.

  3. HIDE & SEEK: End-to-end packages to simulate and process radio survey data

    Science.gov (United States)

    Akeret, J.; Seehars, S.; Chang, C.; Monstein, C.; Amara, A.; Refregier, A.

    2017-01-01

    As several large single-dish radio surveys begin operation within the coming decade, a wealth of radio data will become available and provide a new window to the Universe. In order to fully exploit the potential of these datasets, it is important to understand the systematic effects associated with the instrument and the analysis pipeline. A common approach to tackle this is to forward-model the entire system-from the hardware to the analysis of the data products. For this purpose, we introduce two newly developed, open-source Python packages: the HI Data Emulator (HIDE) and the Signal Extraction and Emission Kartographer (SEEK) for simulating and processing single-dish radio survey data. HIDE forward-models the process of collecting astronomical radio signals in a single-dish radio telescope instrument and outputs pixel-level time-ordered-data. SEEK processes the time-ordered-data, removes artifacts from Radio Frequency Interference (RFI), automatically applies flux calibration, and aims to recover the astronomical radio signal. The two packages can be used separately or together depending on the application. Their modular and flexible nature allows easy adaptation to other instruments and datasets. We describe the basic architecture of the two packages and examine in detail the noise and RFI modeling in HIDE, as well as the implementation of gain calibration and RFI mitigation in SEEK. We then apply HIDE &SEEK to forward-model a Galactic survey in the frequency range 990-1260 MHz based on data taken at the Bleien Observatory. For this survey, we expect to cover 70% of the full sky and achieve a median signal-to-noise ratio of approximately 5-6 in the cleanest channels including systematic uncertainties. However, we also point out the potential challenges of high RFI contamination and baseline removal when examining the early data from the Bleien Observatory. The fully documented HIDE &SEEK packages are available at http://hideseek.phys.ethz.ch/ and are published

  4. Does the acceptable noise level (ANL) predict hearing-aid use?

    DEFF Research Database (Denmark)

    Olsen, Steen Østergaard; Brännström, K Jonas

    2014-01-01

    OBJECTIVE: It has been suggested that individuals have an inherent acceptance of noise in the presence of speech, and that different acceptance of noise results in different hearing-aid (HA) use. The acceptable noise level (ANL) has been proposed for measurement of this property. It has been...... claimed that the ANL magnitude can predict hearing-aid use patterns. Many papers have been published reporting on different aspects of ANL, but none have challenged the predictive power of ANL. The purpose of this study was to discuss whether ANL can predict HA use and how more reliable ANL results can...... reviewed journals as well as a number of papers from trade journals, posters and oral presentations from audiology conventions. CONCLUSIONS: An inherent acceptance of noise in the presence of speech may exist, but no method for precise measurement of ANL is available. The ANL model for prediction of HA use...

  5. Noise level in a neonatal intensive care unit in Santa Marta - Colombia.

    Science.gov (United States)

    Garrido Galindo, Angélica Patricia; Camargo Caicedo, Yiniva; Velez-Pereira, Andres M

    2017-09-30

    The environment of neonatal intensive care units is influenced by numerous sources of noise emission, which contribute to raise the noise levels, and may cause hearing impairment and other physiological and psychological changes on the newborn, as well as problems with care staff. To evaluate the level and sources of noise in the neonatal intensive care unit. Sampled for 20 consecutive days every 60 seconds in A-weighting curves and fast mode with a Type I sound level meter. Recorded the average, maximum and minimum, and the 10th, 50th and 90th percentiles. The values are integrated into hours and work shift, and studied by analysis of variance. The sources were characterized in thirds of octaves. The average level was 64.00 ±3.62 dB(A), with maximum of 76.04 ±5.73 dB(A), minimum of 54.84 ±2.61dB(A), and background noise of 57.95 ±2.83 dB(A). We found four sources with levels between 16.8-63.3 dB(A). Statistical analysis showed significant differences between the hours and work shift, with higher values in the early hours of the day. The values presented exceed the standards suggested by several organizations. The sources identified and measured recorded high values in low frequencies.

  6. Detection of anomalies in radio tomography of asteroids: Source count and forward errors

    Science.gov (United States)

    Pursiainen, S.; Kaasalainen, M.

    2014-09-01

    The purpose of this study was to advance numerical methods for radio tomography in which asteroid's internal electric permittivity distribution is to be recovered from radio frequency data gathered by an orbiter. The focus was on signal generation via multiple sources (transponders) providing one potential, or even essential, scenario to be implemented in a challenging in situ measurement environment and within tight payload limits. As a novel feature, the effects of forward errors including noise and a priori uncertainty of the forward (data) simulation were examined through a combination of the iterative alternating sequential (IAS) inverse algorithm and finite-difference time-domain (FDTD) simulation of time evolution data. Single and multiple source scenarios were compared in two-dimensional localization of permittivity anomalies. Three different anomaly strengths and four levels of total noise were tested. Results suggest, among other things, that multiple sources can be necessary to obtain appropriate results, for example, to distinguish three separate anomalies with permittivity less or equal than half of the background value, relevant in recovery of internal cavities.

  7. Origin of solar radio waves

    International Nuclear Information System (INIS)

    Olmr, J.

    1977-01-01

    Solar radiowave radiation amounts to about 10 -7 of the total solar radiation. The solar atmosphere emits radiation of different wavelengths from a fraction of nanometer to kilometer waves. The solar radiowaves are of thermal origin and except for neutral hydrogen emission and solid body radio emission their emission always results from free electrons. The radiowave radiation active components were classified in several types, such as noise storms, flashes, flares, continuum, and flashes lasting for several minutes. The respective types are discussed and their origins shown. The mechanisms are described permitting the formation of radio waves of nonthermal origin, i.e., plasma oscillations, gyromagnetic emission, synchrotron and Cherenkov radiations. (J.P.)

  8. Signal Detection for QPSK Based Cognitive Radio Systems using Support Vector Machines

    Directory of Open Access Journals (Sweden)

    M. T. Mushtaq

    2015-04-01

    Full Text Available Cognitive radio based network enables opportunistic dynamic spectrum access by sensing, adopting and utilizing the unused portion of licensed spectrum bands. Cognitive radio is intelligent enough to adapt the communication parameters of the unused licensed spectrum. Spectrum sensing is one of the most important tasks of the cognitive radio cycle. In this paper, the auto-correlation function kernel based Support Vector Machine (SVM classifier along with Welch's Periodogram detector is successfully implemented for the detection of four QPSK (Quadrature Phase Shift Keying based signals propagating through an AWGN (Additive White Gaussian Noise channel. It is shown that the combination of statistical signal processing and machine learning concepts improve the spectrum sensing process and spectrum sensing is possible even at low Signal to Noise Ratio (SNR values up to -50 dB.

  9. The Analysis of Low Noise Protection Barriers Influence on Tram Traffic Noise Levels

    Directory of Open Access Journals (Sweden)

    Ahac Maja

    2013-07-01

    Full Text Available The paper describes the analysis of tram traffic noise situation in residential areas in the vicinity of Drzic Avenue, one of the major routes between the northern and southern part of the Croatian capital city Zagreb, and the effect of low barriers placed by the tracks on tram noise mitigation. In order to evaluate the effect of planned protection measure, noise models were produced and verified with short-term field measurements. Calculations were conducted by means of noise prediction software, using European interim noise prediction method and 3D model of analyzed area. Finally, the results of noise calculations for existing tram traffic situation and planned measure of protection are presented on noise maps.

  10. Exploring three faint source detections methods for aperture synthesis radio images

    Science.gov (United States)

    Peracaula, M.; Torrent, A.; Masias, M.; Lladó, X.; Freixenet, J.; Martí, J.; Sánchez-Sutil, J. R.; Muñoz-Arjonilla, A. J.; Paredes, J. M.

    2015-04-01

    Wide-field radio interferometric images often contain a large population of faint compact sources. Due to their low intensity/noise ratio, these objects can be easily missed by automated detection methods, which have been classically based on thresholding techniques after local noise estimation. The aim of this paper is to present and analyse the performance of several alternative or complementary techniques to thresholding. We compare three different algorithms to increase the detection rate of faint objects. The first technique consists of combining wavelet decomposition with local thresholding. The second technique is based on the structural behaviour of the neighbourhood of each pixel. Finally, the third algorithm uses local features extracted from a bank of filters and a boosting classifier to perform the detections. The methods' performances are evaluated using simulations and radio mosaics from the Giant Metrewave Radio Telescope and the Australia Telescope Compact Array. We show that the new methods perform better than well-known state of the art methods such as SEXTRACTOR, SAD and DUCHAMP at detecting faint sources of radio interferometric images.

  11. Adaptive nonlocal means filtering based on local noise level for CT denoising

    International Nuclear Information System (INIS)

    Li, Zhoubo; Trzasko, Joshua D.; Lake, David S.; Blezek, Daniel J.; Manduca, Armando; Yu, Lifeng; Fletcher, Joel G.; McCollough, Cynthia H.

    2014-01-01

    Purpose: To develop and evaluate an image-domain noise reduction method based on a modified nonlocal means (NLM) algorithm that is adaptive to local noise level of CT images and to implement this method in a time frame consistent with clinical workflow. Methods: A computationally efficient technique for local noise estimation directly from CT images was developed. A forward projection, based on a 2D fan-beam approximation, was used to generate the projection data, with a noise model incorporating the effects of the bowtie filter and automatic exposure control. The noise propagation from projection data to images was analytically derived. The analytical noise map was validated using repeated scans of a phantom. A 3D NLM denoising algorithm was modified to adapt its denoising strength locally based on this noise map. The performance of this adaptive NLM filter was evaluated in phantom studies in terms of in-plane and cross-plane high-contrast spatial resolution, noise power spectrum (NPS), subjective low-contrast spatial resolution using the American College of Radiology (ACR) accreditation phantom, and objective low-contrast spatial resolution using a channelized Hotelling model observer (CHO). Graphical processing units (GPU) implementation of this noise map calculation and the adaptive NLM filtering were developed to meet demands of clinical workflow. Adaptive NLM was piloted on lower dose scans in clinical practice. Results: The local noise level estimation matches the noise distribution determined from multiple repetitive scans of a phantom, demonstrated by small variations in the ratio map between the analytical noise map and the one calculated from repeated scans. The phantom studies demonstrated that the adaptive NLM filter can reduce noise substantially without degrading the high-contrast spatial resolution, as illustrated by modulation transfer function and slice sensitivity profile results. The NPS results show that adaptive NLM denoising preserves the

  12. [Comfort and noise level in infants with helmet interface].

    Science.gov (United States)

    Medina, A; Alvarez Fernández, P; Rey Galán, C; Álvarez Mendiola, P; Álvarez Blanco, S; Vivanco Allende, A

    2015-10-01

    To evaluate comfort and noise intensity using the COMFORT scale in infants who receive respiratory support with a helmet interface. An observational descriptive study was conducted on all infants (1 to 12 months of age) admitted to a PICU from November 1st 2013 to March 31st 2014 and who received non-invasive ventilation with a helmet interface. Tolerance to the interface was assessed by use of the COMFORT scale. The intensity of the noise to which the infants were exposed was measured with a TES1350A HIBOK 412 sound-level meter. Three measurements were made every day. Twenty seven patients with bronchiolitis (median age: 54 days; range: 10 to 256) were included. Median COMFORT score in the first day was 21 points (14 - 28). An increase in patient comfort was found with a gradual decrease in the scores, with a maximum reduction of 22% from the first hours (score of 22) to the fifth day (score of 18). The minimum sound intensity registered was 42dB, and the maximum was 78dB. Background noise intensity was associated with noise intensity in the helmet. No differences were observed in COMFORT score and noise intensity between ventilator devices. Helmet interface was well tolerated by infants. COMFORT score results are an indicator that infants were comfortable or very comfortable. The measured noise intensity was in the safe range permitted by World Health Organization. Copyright © 2014 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.

  13. Noise exposure and hearing impairment among Chinese restaurant workers and entertainment employees in Hong Kong.

    Science.gov (United States)

    Lao, Xiang Qian; Yu, Ignatius Tak Sun; Au, Dennis Kin Kwok; Chiu, Yuk Lan; Wong, Claudie Chiu Yi; Wong, Tze Wai

    2013-01-01

    Noise-induced hearing loss (NIHL) is a major concern in the non-manufacturing industries. This study aimed to investigate the occupational noise exposure and the NIHL among Chinese restaurant workers and entertainment employees working in the service industry in Hong Kong. This cross-sectional survey involved a total of 1,670 participants. Among them, 937 were randomly selected from the workers of Chinese restaurants and 733 were selected from workers in three entertainment sectors: radio and television stations; cultural performance halls or auditoria of the Leisure and Cultural Services Department (LCSD); and karaoke bars. Noise exposure levels were measured in the sampled restaurants and entertainment sectors. Each participant received an audiometric screening test. Those who were found to have abnormalities were required to take another diagnostic test in the health center. The "Klockhoff digit" method was used to classify NIHL in the present study. The main source of noise inside restaurants was the stoves. The mean hearing thresholds showed a typical dip at 3 to 6 KHz and a substantial proportion (23.7%) of the workers fulfilled the criteria for presumptive NIHL. For entertainment sectors, employees in radio and television stations generally had higher exposure levels than those in the halls or auditoria of the LCSD and karaoke bars. The mean hearing thresholds showed a typical dip at 6 KHz and a substantial proportion of the employees fulfilled the criteria for presumptive NIHL (38.6%, 95%CI: 35.1-42.1%). Being male, older, and having longer service and daily alcohol consumption were associated with noise-induced hearing impairment both in restaurant workers and entertainment employees. Excessive noise exposure is common in the Chinese restaurant and entertainment industries and a substantial proportion of restaurant workers and entertainment employees suffer from NIHL. Comprehensive hearing conservation programs should be introduced to the service industry

  14. Interplanetary radio storms. 2: Emission levels and solar wind speed in the range 0.05-0.8 AU

    Science.gov (United States)

    Bougeret, J. L.; Fainberg, J.; Stone, R. G.

    1982-01-01

    Storms of interplanetary type III radio bursts (IP storms) are commonly observed in the interplanetry medium by the ISEE-3 radio instrument. This instrument has the capability of accurately determining the arrival direction of the radio emission. At each observing frequency, the storm radio sources are tracked as they cross the line-of-sight to the Sun. Usng a simple model, the emission levels are determined at a number of radio frequencies for four separate storms. The IP storm radiation is found to occur in regions of enhanced density at levels of 0.05 to 0.8 AU. The density in these enhancements falls off faster than R(-2). The solar wind speed in the storm region is also measured. The analysis is consistent with steady conditions in the storm region during a few days around the central meridian passage of the storm. The comparison with average in situ density measurements compiled from the HELIOS 1-2 observations favors type III storm burst radio emission at the harmonic of the local plasma frequency.

  15. The impact of noise level on students' learning performance at state elementary school in Medan

    Science.gov (United States)

    Buchari, Matondang, Nazaruddin

    2017-06-01

    This study was conducted to determine the level and impact of noise on pupils' learning performance that was observed through a survey at State Elementary School (SDN 060882), which is located on the corner of Abdullah Lubis Street and Pattimura Medan Street. The study was done by measuring the noise level using the Threshold Limit Value (TLV) by taking 24 locations as the measurement points. The results indicated that the noise levels exceeded the standard TLV >55 dBA as regulated in the Decree of the Minister of Environment No. KEP/48/MENLH/11/1996. According to the data processing, the noise level at school was 70.79 dBA. The classrooms were classified into noisy zones based on the Noise Mapping. Those in Red Zone which noise level were in the range of (69-75 dBA) were Class IIIa, Class IVb, and Class VI. In addition, those in Yellow Zone which were in the range of (65-69 dBA) were Class II, Class IIIa, Class IVa and Class V. The noise brought the physiological impact in the forms of dizziness that had the highest percentage of 22% and emotional and uncomfortable feeling of 21%; the communication impact of teacher's explanation disturbance of 22%; and Pupils' learning performance was evidenced to decline of 22%. Some improvements are suggested to reduce the noise such as the reposition of windows, acoustic material to cover the classrooms' wall, and bamboo trees or grasses as the barried around the school area.

  16. Wavelet Denoising of Radio Observations of Rotating Radio Transients (RRATs): Improved Timing Parameters for Eight RRATs

    Science.gov (United States)

    Jiang, M.; Cui, B.-Y.; Schmid, N. A.; McLaughlin, M. A.; Cao, Z.-C.

    2017-09-01

    Rotating radio transients (RRATs) are sporadically emitting pulsars detectable only through searches for single pulses. While over 100 RRATs have been detected, only a small fraction (roughly 20%) have phase-connected timing solutions, which are critical for determining how they relate to other neutron star populations. Detecting more pulses in order to achieve solutions is key to understanding their physical nature. Astronomical signals collected by radio telescopes contain noise from many sources, making the detection of weak pulses difficult. Applying a denoising method to raw time series prior to performing a single-pulse search typically leads to a more accurate estimation of their times of arrival (TOAs). Taking into account some features of RRAT pulses and noise, we present a denoising method based on wavelet data analysis, an image-processing technique. Assuming that the spin period of an RRAT is known, we estimate the frequency spectrum components contributing to the composition of RRAT pulses. This allows us to suppress the noise, which contributes to other frequencies. We apply the wavelet denoising method including selective wavelet reconstruction and wavelet shrinkage to the de-dispersed time series of eight RRATs with existing timing solutions. The signal-to-noise ratio (S/N) of most pulses are improved after wavelet denoising. Compared to the conventional approach, we measure 12%–69% more TOAs for the eight RRATs. The new timing solutions for the eight RRATs show 16%–90% smaller estimation error of most parameters. Thus, we conclude that wavelet analysis is an effective tool for denoising RRATs signal.

  17. Wavelet Denoising of Radio Observations of Rotating Radio Transients (RRATs): Improved Timing Parameters for Eight RRATs

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, M.; Schmid, N. A.; Cao, Z.-C. [Lane Department of Computer Science and Electrical Engineering West Virginia University Morgantown, WV 26506 (United States); Cui, B.-Y.; McLaughlin, M. A. [Department of Physics and Astronomy West Virginia University Morgantown, WV 26506 (United States)

    2017-09-20

    Rotating radio transients (RRATs) are sporadically emitting pulsars detectable only through searches for single pulses. While over 100 RRATs have been detected, only a small fraction (roughly 20%) have phase-connected timing solutions, which are critical for determining how they relate to other neutron star populations. Detecting more pulses in order to achieve solutions is key to understanding their physical nature. Astronomical signals collected by radio telescopes contain noise from many sources, making the detection of weak pulses difficult. Applying a denoising method to raw time series prior to performing a single-pulse search typically leads to a more accurate estimation of their times of arrival (TOAs). Taking into account some features of RRAT pulses and noise, we present a denoising method based on wavelet data analysis, an image-processing technique. Assuming that the spin period of an RRAT is known, we estimate the frequency spectrum components contributing to the composition of RRAT pulses. This allows us to suppress the noise, which contributes to other frequencies. We apply the wavelet denoising method including selective wavelet reconstruction and wavelet shrinkage to the de-dispersed time series of eight RRATs with existing timing solutions. The signal-to-noise ratio (S/N) of most pulses are improved after wavelet denoising. Compared to the conventional approach, we measure 12%–69% more TOAs for the eight RRATs. The new timing solutions for the eight RRATs show 16%–90% smaller estimation error of most parameters. Thus, we conclude that wavelet analysis is an effective tool for denoising RRATs signal.

  18. Noise levels in neonatal intensive care unit and use of sound absorbing panel in the isolette.

    Science.gov (United States)

    Altuncu, E; Akman, I; Kulekci, S; Akdas, F; Bilgen, H; Ozek, E

    2009-07-01

    The purposes of this study were to measure the noise level of a busy neonatal intensive care unit (NICU) and to determine the effect of sound absorbing panel (SAP) on the level of noise inside the isolette. The sound pressure levels (SPL) of background noise, baby crying, alarms and closing of isolette's door/portholes were measured by a 2235-Brüel&Kjaer Sound Level Meter. Readings were repeated after applying SAP (3D pyramidal shaped open cell polyurethane foam) to the three lateral walls and ceiling of the isolette. The median SPL of background noise inside the NICU was 56dBA and it decreased to 47dBA inside the isolette. The median SPL of monitor alarms and baby crying inside the isolette were not different than SPL measured under radiant warmer (p>0.05). With SAP, the median SPL of temperature alarm inside the isolette decreased significantly from 82 to 72dBA, monitor alarm from 64 to 56dBA, porthole closing from 81 to 74dBA, and isolette door closing from 80 to 68dBA (pnoise produced by baby crying when SAP was used in the isolette (79dBA vs 69dBA, respectively) (pnoise. The noise level in our NICU is significantly above the universally recommended levels. Being inside the isolette protects infants from noise sources produced outside the isolette. However, very high noises are produced inside the isolette as well. Sound absorbing panel can be a simple solution and it attenuated the noise levels inside the isolette.

  19. Evaluation of noise pollution level in the operating rooms of hospitals: A study in Iran.

    Science.gov (United States)

    Giv, Masoumeh Dorri; Sani, Karim Ghazikhanlou; Alizadeh, Majid; Valinejadi, Ali; Majdabadi, Hesamedin Askari

    2017-06-01

    Noise pollution in the operating rooms is one of the remaining challenges. Both patients and physicians are exposed to different sound levels during the operative cases, many of which can last for hours. This study aims to evaluate the noise pollution in the operating rooms during different surgical procedures. In this cross-sectional study, sound level in the operating rooms of Hamadan University-affiliated hospitals (totally 10) in Iran during different surgical procedures was measured using B&K sound meter. The gathered data were compared with national and international standards. Statistical analysis was performed using descriptive statistics and one-way ANOVA, t -test, and Pearson's correlation test. Noise pollution level at majority of surgical procedures is higher than national and international documented standards. The highest level of noise pollution is related to orthopedic procedures, and the lowest one related to laparoscopic and heart surgery procedures. The highest and lowest registered sound level during the operation was 93 and 55 dB, respectively. Sound level generated by equipments (69 ± 4.1 dB), trolley movement (66 ± 2.3 dB), and personnel conversations (64 ± 3.9 dB) are the main sources of noise. The noise pollution of operating rooms are higher than available standards. The procedure needs to be corrected for achieving the proper conditions.

  20. EVALUATION OF THE ENVIRONMENTAL NOISE LEVELS IN ABUJA MUNICIPALITY USING MOBILE PHONES.

    Science.gov (United States)

    Ibekwe, T; Folorunso, D; Ebuta, A; Amodu, J; Nwegbu, M; Mairami, Z; Liman, I; Okebaram, C; Chimdi, C; Durogbola, B; Suleiman, H; Mamven, H; Baamlong, N; Dahilo, E; Gbujie, I; Ibekwe, P; Nwaorgu, O

    2016-12-01

    Noise remains a nuisance which impacts negatively on the physical, social and psychological wellbeing of man. It aggravates chronic illnesses like hypertension and other cardiopulmonary diseases. Unfortunately, increased activities from industrialization and technological transfers/drifts have tumultuously led to increased noise pollution in most of our fast growing cities today and hence the need for concerted efforts in monitoring and regulating our environmental noise. To assess the equivalent noise level (Leq) in Abuja municipality and promote a simple method for regular assessment of Leq within our environment. This is a cross-sectional community based study of the environmental Leq of Abuja municipality conducted between January 2014 and January 2016. The city was divided into 12 segments including residential, business and market areas via the Abuja Geographic Information System. The major markets were captured separately on a different scale. Measurements were taken with the mobile phone softwares having validated this with Extech 407730 digital sound level meter, serial no Z310135 . Leq(A) were measured at different points and hours of the day and night. The average Leq(A) were classified according to localities and compared with WHO standard safety levels. LeqD ranged 71-92dB(A); 42-79dB(A) and 69-90dB(A) in business/ parks, residential and market places respectively. The Night measurements were similar 18dB(A)-56dB(A) and the day-night Leq(A)=77.2dB(A) and 90.4dB(A) for residential and business zones. The night noise levels are satisfactory but the day and day-night levels are above the recommended tolerable values by WHO and therefore urgently call for awareness and legislative regulations.

  1. Noise levels of a track-laying tractor during field operations in the vineyard

    Directory of Open Access Journals (Sweden)

    Pietro Catania

    2013-09-01

    Full Text Available Noise in agriculture is one of the risk factors to be taken into account in the assessment of the health and safety of workers; in particular, it is known that the tractor is a source of high noise. The Italian Low Decree 81/2008 defined the requirements for assessing and managing noise risk identifying a number of procedures to be adopted at different noise levels to limit workers exposure. This paper concerns the analysis of the noise risk arising from the use of a tracklaying tractor during field operations carried out in the vineyard. The objective of this study was to evaluate the noise level that comes close to the ear of the operator driving the tractor measuring the values of equivalent sound level (Leq(A and peak sound pressure (LCpk. We considered four options related to the same tractor coupled with the following tools to perform some farming operations: rototilling, chisel plough, flail mowers and vibro farmer. We considered three test conditions: T1 in flat (slope 0%, T2 uphill and T3 downhill (both 30% slope. The instrument used for the measurements is a precision integrating portable sound level meter, class 1, model HD2110L by Delta OHM, Italy. Each survey lasted 2 minutes, with an interval of measurement equal to 0.5 s. The tests were performed in compliance with the standards ISO 9612 and ISO 9432. The results show that the measured sound levels exceed the limits allowed by the regulations in almost all the test conditions; values exceeding the threshold limit of 80 dB(A were recorded coming up to a maximum value of 92.8 dB(A for flail mowers in test T1. When limits imposed by the regulations are exceeded, the operator is obliged to wear the appropriate Personal Protective Equipment.

  2. Assessment and analysis of noise levels in and around Ib river coalfield, Orissa, India.

    Science.gov (United States)

    Mohapatra, Haraprasad; Goswami, Shreerup

    2012-05-01

    Heavy earth moving machineries, different capacities of dumpers and loaders, blasting and drilling make the mining environment noisy. A study was carried out to assess the noise level in different opencast projects in and around Belpahar and Brajarajnagar areas of Ib river coalfield. Noise assessment was carried out in various residential, commercial and industrial places. The noise levels, especially L(eq) values of different wheel loaders, dumpers, shovel and crusher units were also assessed and were more than permissible limit (90dB) in some of their operating conditions. Sound ressure level measurements while drilling into coal and overburden at Lakhanpur opencast project yielded noise levels (L(eq)) of 81.33 to 96.2 dB. Thus, these L(eq) values of drilling machines in most of the operating conditions were above permissible limit. The average noise intensities (6 a.m.-10 p.m.: 51.6-60.875dB and 10 p.m.-6 a.m.: 42.6-49.8dB) and L(eq) values (6 a.m.-10 p.m.: 50.9-67.0dB and 10 p.m.-6 a.m.: 40.8-53.3dB) during both day and night time of the residential areas around the Ib river coalfield were in close proximity or beyond the permissible limit. The L(eq) values at some of the commercial and industrial places were beyond (6 a.m.-10 p.m.: 61.6-88.3 dB and 10 p.m.-6 a.m.: 55.4-64.8dB) permissible limit. However, in most of the cases, the L(max) noise values were more (6 a.m.-10 p.m.: 68.5-91.4 dB and 10 p.m.-6 a.m.: 69.3-76.4dB) than the permissible limit. Analysis of variance was also computed for heavy earth moving machineries in different operating conditions and also for different residential, commercial and industrial places to infer the level of significance. The difference of noise intensity produced by different wheel loaders at Lakhanpur and Lilari opencast projects, drilling machines at Lakhanpur opencast project, 50 tons capacity dumpers at various conditions of Ib river coalfield within the same operating condition was significant at both 5% and 1% levels

  3. Experimental Results on the Level Crossing Intervals of the Phase of Sine Wave Plus Noise

    Science.gov (United States)

    Youssef, Neji; Munakata, Tsutomu; Mimaki, Tadashi

    1993-03-01

    Experimental study was made on the level crossing intervals of a phase process of a sine wave plus narrow-band Gaussian noise. Since successive level crossings of phase do not necessarily occur alternately in the upward and downward direction due to the phase jump beyond 2π, the usual definitions of the probability densities of the level crossing intervals for continuous random processes are not applicable in the case of the phase process. Therefore, the probability densities of level crossing intervals of phase process are newly defined. Measurements of these densities were performed for noise having lowpass spectra of Gaussian and 7th order Butterworth types. Results are given for various values of the signal-to-noise power ratio and of the crossing level, and compared with corresponding approximation developed under the assumption of quasi-independence. The validity of the assumption depends on the spectrum shape of the noise.

  4. Hybrid Scheduling/Signal-Level Coordination in the Downlink of Multi-Cloud Radio-Access Networks

    KAUST Repository

    Douik, Ahmed

    2016-03-28

    In the context of resource allocation in cloud- radio access networks, recent studies assume either signal-level or scheduling-level coordination. This paper, instead, considers a hybrid level of coordination for the scheduling problem in the downlink of a multi-cloud radio- access network, so as to benefit from both scheduling policies. Consider a multi-cloud radio access network, where each cloud is connected to several base-stations (BSs) via high capacity links, and therefore allows joint signal processing between them. Across the multiple clouds, however, only scheduling-level coordination is permitted, as it requires a lower level of backhaul communication. The frame structure of every BS is composed of various time/frequency blocks, called power- zones (PZs), and kept at fixed power level. The paper addresses the problem of maximizing a network-wide utility by associating users to clouds and scheduling them to the PZs, under the practical constraints that each user is scheduled, at most, to a single cloud, but possibly to many BSs within the cloud, and can be served by one or more distinct PZs within the BSs\\' frame. The paper solves the problem using graph theory techniques by constructing the conflict graph. The scheduling problem is, then, shown to be equivalent to a maximum- weight independent set problem in the constructed graph, in which each vertex symbolizes an association of cloud, user, BS and PZ, with a weight representing the utility of that association. Simulation results suggest that the proposed hybrid scheduling strategy provides appreciable gain as compared to the scheduling-level coordinated networks, with a negligible degradation to signal-level coordination.

  5. Noise level in intensive care units of a public university hospital in Santa Marta (Colombia).

    Science.gov (United States)

    Garrido Galindo, A P; Camargo Caicedo, Y; Vélez-Pereira, A M

    2016-10-01

    To evaluate the noise level in adult, pediatric and neonatal intensive care units of a university hospital in the city of Santa Marta (Colombia). A descriptive, observational, non-interventional study with follow-up over time was carried out. Continuous sampling was conducted for 20 days for each unit using a type i sound level meter, filter frequency in A weighting and Fast mode. We recorded the maximum values, the 90th percentile as background noise, and the continuous noise level. The mean hourly levels in the adult unit varied between 57.40±1.14-63.47±2.13dBA, with a maximum between 71.55±2.32-77.22±1.94dBA, and a background noise between 53.51±1.16-60.26±2.10dBA; in the pediatric unit the mean hourly levels varied between 57.07±3.07-65.72±2.46dBA, with a maximum of 68.69±3.57-79.06±2.34dBA, and a background noise between 53.33±3.54-61.96±2.85dBA; the neonatal unit in turn presented mean hourly values between 59.54±2.41-65.33±1.77dBA, with a maximum value between 67.20±2.13-77.65±3.74dBA, and a background noise between 55.02±2.03-58.70±1.95dBA. Analysis of variance revealed a significant difference between the hourly values and between the different units, with the time of day exhibiting a greater influence. The type of unit affects the noise levels in intensive care units, the pediatric unit showing the highest values and the adult unit the lowest values. However, the parameter exerting the greatest influence upon noise level is the time of day, with higher levels in the morning and evening, and lower levels at night and in the early morning. Copyright © 2015 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  6. Rat hippocampal alterations could underlie behavioral abnormalities induced by exposure to moderate noise levels.

    Science.gov (United States)

    Uran, S L; Aon-Bertolino, M L; Caceres, L G; Capani, F; Guelman, L R

    2012-08-30

    Noise exposure is known to affect auditory structures in living organisms. However, it should not be ignored that many of the effects of noise are extra-auditory. Previous findings of our laboratory demonstrated that noise was able to induce behavioral alterations that are mainly related to the cerebellum (CE) and the hippocampus (HC). Therefore, the aim of this work was to reveal new data about the vulnerability of developing rat HC to moderate noise levels through the assessment of potential histological changes and hippocampal-related behavioral alterations. Male Wistar rats were exposed to noise (95-97 dB SPL, 2h daily) either for 1 day (acute noise exposure, ANE) or between postnatal days 15 and 30 (sub-acute noise exposure, SANE). Hippocampal histological evaluation as well as short (ST) and long term (LT) habituation and recognition memory assessments were performed. Results showed a mild disruption in the different hippocampal regions after ANE and SANE schemes, along with significant behavioral abnormalities. These data suggest that exposure of developing rats to noise levels of moderate intensity is able to trigger changes in the HC, an extra-auditory structure of the Central Nervous System (CNS), that could underlie the observed behavioral effects. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. The effects of noise-bandwidth, noise-fringe duration, and temporal signal location on the binaural masking-level difference.

    Science.gov (United States)

    Yasin, Ifat; Henning, G Bruce

    2012-07-01

    The effects of forward and backward noise fringes on binaural signal detectability were investigated. Masked thresholds for a 12-ms, 250-Hz, sinusoidal signal masked by Gaussian noise, centered at 250 Hz, with bandwidths from 3 to 201 Hz, were obtained in N(0)S(0) and N(0)S(π) configurations. The signal was (a) temporally centered in a 12-ms noise burst (no fringe), (b) presented at the start of a 600-ms noise burst (backward fringe), or (c) temporally centered in a 600-ms noise burst (forward-plus-backward fringe). For noise bandwidths between 3 and 75 Hz, detection in N(0)S(0) improved with the addition of a backward fringe, improving further with an additional forward fringe; there was little improvement in N(0)S(π). The binaural masking-level difference (BMLD) increased from 0 to 8 dB with a forward-plus-backward fringe as noise bandwidths increased to 100 Hz, increasing slightly to 10 dB at 201 Hz. This two-stage increase was less pronounced with a backward fringe. With no fringe, the BMLD was about 10-14 dB at all bandwidths. Performance appears to result from the interaction of across-time and across-frequency listening strategies and the possible effects of gain reduction and suppression, which combine in complex ways. Current binaural models are, as yet, unable to account fully for these effects.

  8. Predictive modelling of noise level generated during sawing of rocks ...

    Indian Academy of Sciences (India)

    This paper presents an experimental and statistical study on noise level generated .... hardness were determined according to related ISRM (1981) suggested methods. Thin section ..... tistical Package for the Social Sciences). Additionally, the ...

  9. The effect of solar radio bursts on the GNSS radio occultation signals

    Science.gov (United States)

    Yue, Xinan; Schreiner, William S.; Kuo, Ying-Hwa; Zhao, Biqiang; Wan, Weixing; Ren, Zhipeng; Liu, Libo; Wei, Yong; Lei, Jiuhou; Solomon, Stan; Rocken, Christian

    2013-09-01

    radio burst (SRB) is the radio wave emission after a solar flare, covering a broad frequency range, originated from the Sun's atmosphere. During the SRB occurrence, some specific frequency radio wave could interfere with the Global Navigation Satellite System (GNSS) signals and therefore disturb the received signals. In this study, the low Earth orbit- (LEO-) based high-resolution GNSS radio occultation (RO) signals from multiple satellites (COSMIC, CHAMP, GRACE, SAC-C, Metop-A, and TerraSAR-X) processed in University Corporation for Atmospheric Research (UCAR) were first used to evaluate the effect of SRB on the RO technique. The radio solar telescope network (RSTN) observed radio flux was used to represent SRB occurrence. An extreme case during 6 December 2006 and statistical analysis during April 2006 to September 2012 were studied. The LEO RO signals show frequent loss of lock (LOL), simultaneous decrease on L1 and L2 signal-to-noise ratio (SNR) globally during daytime, small-scale perturbations of SNR, and decreased successful retrieval percentage (SRP) for both ionospheric and atmospheric occultations during SRB occurrence. A potential harmonic band interference was identified. Either decreased data volume or data quality will influence weather prediction, climate study, and space weather monitoring by using RO data during SRB time. Statistically, the SRP of ionospheric and atmospheric occultation retrieval shows ~4% and ~13% decrease, respectively, while the SNR of L1 and L2 show ~5.7% and ~11.7% decrease, respectively. A threshold value of ~1807 SFU of 1415 MHz frequency, which can result in observable GNSS SNR decrease, was derived based on our statistical analysis.

  10. Children's speech recognition and loudness perception with the Desired Sensation Level v5 Quiet and Noise prescriptions.

    Science.gov (United States)

    Crukley, Jeffery; Scollie, Susan D

    2012-12-01

    To determine whether Desired Sensation Level (DSL) v5 Noise is a viable hearing instrument prescriptive algorithm for children, in comparison with DSL v5 Quiet. In particular, the authors compared children's performance on measures of consonant recognition in quiet, sentence recognition in noise, and loudness perception when fitted with DSL v5 Quiet and Noise. Eleven children (ages 8 to 17 years) with stable, congenital sensorineural hearing losses participated in the study. Participants were fitted bilaterally to DSL v5 prescriptions with behind-the-ear hearing instruments. The order of prescription was counterbalanced across participants. Repeated measures analysis of variance was used to compare performance between prescriptions. Use of the Noise prescription resulted in a significant decrease in consonant perception in Quiet with low-level input, but no difference with average-level input. There was no significant difference in sentence-in-noise recognition between the two prescriptions. Loudness ratings for input levels above 72 dB SPL were significantly lower with the noise prescription. Average-level consonant recognition in quiet was preserved and aversive loudness was alleviated by the Noise prescription relative to the quiet prescription, which suggests that the DSL v5 Noise prescription may be an effective approach to managing the nonquiet listening needs of children with hearing loss.

  11. Possible mechanism of solar noise storm generation in meter wavelength

    International Nuclear Information System (INIS)

    Genkin, L.G.; Erukhimov, L.M.; Levin, B.N.

    1989-01-01

    Fluctuation plasma mechanism of noise storm generation is proposed. The sporadic formation of density irregularities in plasma (Langmuir) turbulence region is shown to be the result of thermal stratification of plasma. The noise storm type 1 bursts in their typical parameters are like radio emission due to plasma turbulence conversion on this structures

  12. Spectrum sensing algorithm based on autocorrelation energy in cognitive radio networks

    Science.gov (United States)

    Ren, Shengwei; Zhang, Li; Zhang, Shibing

    2016-10-01

    Cognitive radio networks have wide applications in the smart home, personal communications and other wireless communication. Spectrum sensing is the main challenge in cognitive radios. This paper proposes a new spectrum sensing algorithm which is based on the autocorrelation energy of signal received. By taking the autocorrelation energy of the received signal as the statistics of spectrum sensing, the effect of the channel noise on the detection performance is reduced. Simulation results show that the algorithm is effective and performs well in low signal-to-noise ratio. Compared with the maximum generalized eigenvalue detection (MGED) algorithm, function of covariance matrix based detection (FMD) algorithm and autocorrelation-based detection (AD) algorithm, the proposed algorithm has 2 11 dB advantage.

  13. Evaluation of the environmental noise levels in Abuja Municipality ...

    African Journals Online (AJOL)

    Objectives: To assess the equivalent noise level (Leq) in Abuja municipality and promote a simple method for regular assessment of Leq within our environment. Methods: This is a cross-sectional community based study of the environmental Leq of Abuja municipality conducted between January 2014 and January 2016.

  14. In vitro comparison of noise levels produced by different CPAP generators.

    Science.gov (United States)

    Kirchner, Lieselotte; Wald, Martin; Jeitler, Valerie; Pollak, Arnold

    2012-01-01

    Minimization of noise exposure is an important aim of modern neonatal intensive care medicine. Binasal continuous positive airway pressure (CPAP) generators are among the most important sources of continuous noise in neonatal wards. The aim of this study was to find out which CPAP generator creates the least noise. In an experimental setup, two jet CPAP generators (Infant Flow® generator and MediJet®) and two conventional CPAP generators (Bubble CPAP® and Baby Flow®) were compared. Noise production was measured in decibels in an A-weighted scale [dB(A)] in a closed incubator at 2 mm lateral distance from the end of the nasal prongs. Reproduction of constant airway pressure and air leak was achieved by closure of the nasal prongs with a type of adhesive tape that is semipermeable to air. The noise levels produced by the four generators were significantly different (p CPAP® and 55 dB(A) for the Baby Flow®. Conventional CPAP generators work more quietly than the currently available jet CPAP generators. Copyright © 2011 S. Karger AG, Basel.

  15. Receiver system for radio observation of high-energy cosmic ray air showers and its behaviour in self trigger mode

    International Nuclear Information System (INIS)

    Kroemer, Oliver

    2008-04-01

    The observation of high-energy cosmic rays is carried out by indirect measurements. Thereby the primary cosmic particle enters into the earth's atmosphere and generates a cosmic ray air shower by interactions with the air molecules. The secondary particles arriving at ground level are detected with particle detector arrays. The fluorescence light from the exited nitrogen molecules along the shower axis is observed with reflector telescopes in the near-ultraviolet range. In addition to these well-established detection methods, the radio observation of the geosynchrotron emission from cosmic ray air showers is investigated at present as a new observation method. Geosynchrotron emission is generated by the acceleration of the relativistic electron-positron-pairs contained in the air shower by Lorentz forces in the earth's magnetic field. At ground level this causes a single pulse of the electric field strength with a continuous frequency spectrum ranging from a few MHz to above 100 MHz. In this work, a suitable receiver concept is developed based on the signal properties of the geosynchrotron emission and the analysis of the superposed noise and radio frequency interferences. As the required receiver system was not commercially available, it was designed in the framework of this work and realised as system including the antenna, the receiver electronics and suitable data acquisition equipment. In this concept considerations for a large scale radio detector array have already been taken into account, like low power consumption to enable solar power supply and cost effectiveness. The result is a calibrated, multi-channel, digital wideband receiver for the complete range from 40 MHz to 80 MHz. Its inherent noise and RFI suppression essentially results from the antenna directional characteristic and frequency selectivity and allows effective radio observation of cosmic ray air showers also in populated environment. Several units of this receiver station have been deployed

  16. A direct method for calculating instrument noise levels in side-by-side seismometer evaluations

    Science.gov (United States)

    Holcomb, L. Gary

    1989-01-01

    The subject of determining the inherent system noise levels present in modem broadband closed loop seismic sensors has been an evolving topic ever since closed loop systems became available. Closed loop systems are unique in that the system noise can not be determined via a blocked mass test as in older conventional open loop seismic sensors. Instead, most investigators have resorted to performing measurements on two or more systems operating in close proximity to one another and to analyzing the outputs of these systems with respect to one another to ascertain their relative noise levels.The analysis of side-by-side relative performance is inherently dependent on the accuracy of the mathematical modeling of the test configuration. This report presents a direct approach to extracting the system noise levels of two linear systems with a common coherent input signal. The mathematical solution to the problem is incredibly simple; however the practical application of the method encounters some difficulties. Examples of expected accuracies are presented as derived by simulating real systems performance using computer generated random noise. In addition, examples of the performance of the method when applied to real experimental test data are shown.

  17. Noiseonomics: the relationship between ambient noise levels in the sea and global economic trends.

    Science.gov (United States)

    Frisk, George V

    2012-01-01

    In recent years, the topic of noise in the sea and its effects on marine mammals has attracted considerable attention from both the scientific community and the general public. Since marine mammals rely heavily on acoustics as a primary means of communicating, navigating, and foraging in the ocean, any change in their acoustic environment may have an impact on their behavior. Specifically, a growing body of literature suggests that low-frequency, ambient noise levels in the open ocean increased approximately 3.3 dB per decade during the period 1950-2007. Here we show that this increase can be attributed primarily to commercial shipping activity, which in turn, can be linked to global economic growth. As a corollary, we conclude that ambient noise levels can be directly related to global economic conditions. We provide experimental evidence supporting this theory and discuss its implications for predicting future noise levels based on global economic trends.

  18. Effects of a traffic noise background on judgements of aircraft noise

    Science.gov (United States)

    Powell, C. A.; Rice, C. G.

    1974-01-01

    A study was conducted in which subjects judged aircraft noises in the presence of road traffic background noise. Two different techniques for presenting the background noises were evaluated. For one technique, the background noise was continuous over the whole of a test session. For the other, the background noise was changed with each aircraft noise. A range of aircraft noise levels and traffic noise levels were presented to simulate typical indoor levels.

  19. Effect of background noise on neuronal coding of interaural level difference cues in rat inferior colliculus.

    Science.gov (United States)

    Mokri, Yasamin; Worland, Kate; Ford, Mark; Rajan, Ramesh

    2015-07-01

    Humans can accurately localize sounds even in unfavourable signal-to-noise conditions. To investigate the neural mechanisms underlying this, we studied the effect of background wide-band noise on neural sensitivity to variations in interaural level difference (ILD), the predominant cue for sound localization in azimuth for high-frequency sounds, at the characteristic frequency of cells in rat inferior colliculus (IC). Binaural noise at high levels generally resulted in suppression of responses (55.8%), but at lower levels resulted in enhancement (34.8%) as well as suppression (30.3%). When recording conditions permitted, we then examined if any binaural noise effects were related to selective noise effects at each of the two ears, which we interpreted in light of well-known differences in input type (excitation and inhibition) from each ear shaping particular forms of ILD sensitivity in the IC. At high signal-to-noise ratios (SNR), in most ILD functions (41%), the effect of background noise appeared to be due to effects on inputs from both ears, while for a large percentage (35.8%) appeared to be accounted for by effects on excitatory input. However, as SNR decreased, change in excitation became the dominant contributor to the change due to binaural background noise (63.6%). These novel findings shed light on the IC neural mechanisms for sound localization in the presence of continuous background noise. They also suggest that some effects of background noise on encoding of sound location reported to be emergent in upstream auditory areas can also be observed at the level of the midbrain. © 2015 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  20. Modeling Speech Level as a Function of Background Noise Level and Talker-to-Listener Distance for Talkers Wearing Hearing Protection Devices

    Science.gov (United States)

    Bouserhal, Rachel E.; Bockstael, Annelies; MacDonald, Ewen; Falk, Tiago H.; Voix, Jérémie

    2017-01-01

    Purpose: Studying the variations in speech levels with changing background noise level and talker-to-listener distance for talkers wearing hearing protection devices (HPDs) can aid in understanding communication in background noise. Method: Speech was recorded using an intra-aural HPD from 12 different talkers at 5 different distances in 3…

  1. Hearing impairment among workers exposed to excessive levels of noise in ginning industries

    Directory of Open Access Journals (Sweden)

    Kamalesh J Dube

    2011-01-01

    Full Text Available Cotton ginning workers have a risk of hearing loss due to excessive noise levels at the workplace environment. In this study, estimates of typical sound levels prevailing at the workplace environment and its effects on hearing ability of the exposed workers were made among cotton ginning workers. Data on self-reported health status was collected by a questionnaire survey at 10 cotton ginning industries located at Jalgaon district of Maharashtra state, India. The cotton ginning workers were exposed to continuous noise levels between 89 and 106 dBA. The hearing ability of the subjects was accessed by pure tone audiometry. The results of audiometry show mild, moderate and moderately severe degree of hearing impairment among the cotton ginning workers. The data generated during the study show that hearing loss was significantly associated with period of exposure to the workplace noise (P <0.0001. The prevalence of audiometric hearing impairment defined as a threshold average greater than 25 dB hearing level was 96% for binaural low-frequency average, 97% for binaural mid frequency average and 94% for binaural high-frequency average in the cotton ginning workers. We recommend the compulsory use of personal protective equipment like ear plug by the cotton ginning workers at the workplace environment. A regular maintenance of ginning and pressing machineries will avoid the emission of excessive noise at the workplace environment of cotton gins. A regular periodic medical examination is necessary to measure the impact of workplace noise on the health of cotton ginning workers.

  2. Noise level and MPEG-2 encoder statistics

    Science.gov (United States)

    Lee, Jungwoo

    1997-01-01

    Most software in the movie and broadcasting industries are still in analog film or tape format, which typically contains random noise that originated from film, CCD camera, and tape recording. The performance of the MPEG-2 encoder may be significantly degraded by the noise. It is also affected by the scene type that includes spatial and temporal activity. The statistical property of noise originating from camera and tape player is analyzed and the models for the two types of noise are developed. The relationship between the noise, the scene type, and encoder statistics of a number of MPEG-2 parameters such as motion vector magnitude, prediction error, and quant scale are discussed. This analysis is intended to be a tool for designing robust MPEG encoding algorithms such as preprocessing and rate control.

  3. Noise-induced annoyance from transportation noise: short-term responses to a single noise source in a laboratory.

    Science.gov (United States)

    Kim, Jaehwan; Lim, Changwoo; Hong, Jiyoung; Lee, Soogab

    2010-02-01

    An experimental study was performed to compare the annoyances from civil-aircraft noise, military-aircraft noise, railway noise, and road-traffic noise. Two-way within-subjects designs were applied in this research. Fifty-two subjects, who were naive listeners, were given various stimuli with varying levels through a headphone in an anechoic chamber. Regardless of the frequency weighting network, even under the same average energy level, civil-aircraft noise was the most annoying, followed by military-aircraft noise, railway noise, and road-traffic noise. In particular, penalties in the time-averaged, A-weighted sound level (TAL) of about 8, 5, and 5 dB, respectively, were found in the civil-aircraft, military-aircraft, and railway noises. The reason could be clarified through the high-frequency component and the variability in the level. When people were exposed to sounds with the same maximum A-weighted level, a railway bonus of about 3 dB was found. However, transportation noise has been evaluated by the time-averaged A-weighted level in most countries. Therefore, in the present situation, the railway bonus is not acceptable for railway vehicles with diesel-electric engines.

  4. Effects of traffic noise on tree frog stress levels, immunity, and color signaling.

    Science.gov (United States)

    Troïanowski, Mathieu; Mondy, Nathalie; Dumet, Adeline; Arcanjo, Caroline; Lengagne, Thierry

    2017-10-01

    During the last decade, many studies have focused on the detrimental effects of noise pollution on acoustic communication. Surprisingly, although it is known that noise exposure strongly influences health in humans, studies on wildlife remain scarce. In order to gain insight into the consequences of traffic noise exposure, we experimentally manipulated traffic noise exposure as well as the endocrine status of animals to investigate physiological and phenotypic consequences of noise pollution in an anuran species. We showed that noise exposure increased stress hormone level and induced an immunosuppressive effect. In addition, both traffic noise exposure and stress hormone application negatively impacted H. arborea vocal sac coloration. Moreover, our results suggest profound changes in sexual selection processes because the best quality males with initial attractive vocal sac coloration were the most impacted by noise. Hence, our study suggests that the recent increases in anthropogenic noise worldwide might affect a broader range of animal species than previously thought, because of alteration of visual signals and immunity. Generalizing these results to other taxa is crucial for the conservation of biodiversity in an increasingly noisy world. © 2017 Society for Conservation Biology.

  5. Comparison of the Effect of Noise Levels on Stress Response in Two Different Operation Groups in an Orthopedic Surgery Room

    Directory of Open Access Journals (Sweden)

    Hasibe Baytan Yildiz

    2016-09-01

    Full Text Available Aim: The aim of this randomized, single-blinded study was to evaluate the effects of noise on hemodynamic and neuroendocrine stress response by measuring the level of noise in the surgery rooms of patients undergoing knee operations under neuroaxial anesthesia. Gerec ve Yontem: We compared patient responses from two groups of patients: those undergoing knee operations in a surgery room where the noise level (measured in decibels is high, and those undergoing meniscus operations in a surgery room with lower noise levels. The STAI, the State-Trait Anxiety Inventory (STAI-1, and the anxiety test (STAI-2wereperformed at preoperative and postoperative periods. 20 ml of blood sample was taken for basal, intraoperative 30th minute, and postoperative 1st hour measurements. Systolic, diastolic, and mean arterial blood pressures were found to be higher in the high noise level group. ACTH levels were increased during the early postoperative period and became normal during the late postoperative period in the high noise level group whereas ACTH levels were significantly decreased in the low-noise level group. Basal cortisol levels were significantly higher in the high noise level group. HCRP, an inflammatory response mediator was found to be decreased in both groups. Early and late blood glucose levels were significantly higher in the high noise group. There was a greater increase in early and late blood glucose levels in the high noise group. In the postoperative period, although the state-trait anxiety inventory (STAI-2 levels being higher in patients subject to noisier environment determines how people feel independent of the conditions and state they are in, this result made us consider that the noise the patients were subjected to in the intraoperative period may cause a stress response. Discussion: As a result we believe that standard noise levels should be achieved by reducing the factors causing high noise levels in the operating room. This will

  6. Evaluation of noise pollution in oil extracting region of Lavan and the effect of noise enclosure on noise abatement

    Directory of Open Access Journals (Sweden)

    F. Golbabaei

    2007-09-01

    Full Text Available Background and aims   Overexposure to industrial noise pollution induce hearing loss workers. Occupational hearing loss may cause interference whit oral communication, so it may  increase the risk of occupational accidents in workplace as well as affects whit social activities.  This study was conducted on Lavan Island, are of oil extracting regions in the south of Iran. The  object of this study was to evaluate noise pollution and determining the effect of noise enclosure  on noise abatement.   Methods   The noise sources were recognized and noise pressure level was measured by CEL- 440. Noise dose of the exposed workers in high level noise area were measured by CEL 272.   Results   Major noise sources were gas turbines, diesel generators, compressors, fans and gas containing pips, noise contour map revealers that noise level were higher than the recommended national exposure limit. The results of workers noise dose show that their noise exposure were  higher than the recommended value, (p<0.001. Finally, by using the results of noise frequency  analysis of different noise sources, the noise pressure level of each sources was determined in   terms of enclosing them.   Conclusion   By enclosing the noise sources, noise pressure levels can be lowered douse to  acceptable levels but limitation of applying enclosure should be regarded.  

  7. A Survey of the Relationship Between Noised Pollution, Honey and Vitamin E and Plasma Level of Blood Sexual Hormones in Noise-Exposed Rats

    Directory of Open Access Journals (Sweden)

    Kenani

    2015-02-01

    Full Text Available Background This study was conducted to examine the efficacy of honey and vitamin E on fertilization capacity of noise-exposed rats by assessing whether the plasma sexual hormones levels i.e. follicle stimulating hormone (FSH, luteinizing hormone (LH and testosterone are altered in relation with noise stress. Objectives Therefore, this study aimed to evaluate the effects of honey and vitamin E on the levels of sex hormones and male fertilization capacity of noise-exposed rats. Materials and Methods This study targeted 24 male rats that were randomly divided into four equal groups including the control group that were not exposed to noise and experimental groups 1, 2 and 3 that were the untreated, honey treated and vitamin E treated groups, respectively; all of which were exposed to noise for 50 days. Next, in order to measure serum sexual hormones, blood samples of experimental and control groups were taken and analyzed. Also in order to investigate the fertility capacity of rats, the male rats of all groups were coupled with female rats. Results The results showed that in the male rats exposed to the noise stress, the levels of FSH and LH rose and the testosterone secretion fell sharply compared to not exposed rats. Additionally, the continuing effects of noise stress injury could reduce the weight of the fetus and the number of live fetuses and survival rate of the fetus. However, honey and vitamin E improved serum testosterone concentration, while declined plasma FSH and LH secretion in noise-exposed rats and enhanced fertility rate by increasing the rate of healthy alive fetuses. Conclusions It seems that noise pollution has harmful effects on the fertility of males. Also these findings may suggest the use of a natural curative approach rather than pharmaceutical drugs to optimize both neuroendocrine gonadal axis and testicular integrity induced by pathogenesis stress, and enhance fertility capacity in men.

  8. Sources and levels of background noise in the NASA Ames 40- by 80-foot wind tunnel

    Science.gov (United States)

    Soderman, Paul T.

    1988-01-01

    Background noise levels are measured in the NASA Ames Research Center 40- by 80-Foot Wind Tunnel following installation of a sound-absorbent lining on the test-section walls. Results show that the fan-drive noise dominated the empty test-section background noise at airspeeds below 120 knots. Above 120 knots, the test-section broadband background noise was dominated by wind-induced dipole noise (except at lower harmonics of fan blade-passage tones) most likely generated at the microphone or microphone support strut. Third-octave band and narrow-band spectra are presented for several fan operating conditions and test-section airspeeds. The background noise levels can be reduced by making improvements to the microphone wind screen or support strut. Empirical equations are presented relating variations of fan noise with fan speed or blade-pitch angle. An empirical expression for typical fan noise spectra is also presented. Fan motor electric power consumption is related to the noise generation. Preliminary measurements of sound absorption by the test-section lining indicate that the 152 mm thick lining will adequately absorb test-section model noise at frequencies above 300 Hz.

  9. A method of background noise cancellation for SQUID applications

    International Nuclear Information System (INIS)

    He, D F; Yoshizawa, M

    2003-01-01

    When superconducting quantum inference devices (SQUIDs) operate in low-cost shielding or unshielded environments, the environmental background noise should be reduced to increase the signal-to-noise ratio. In this paper we present a background noise cancellation method based on a spectral subtraction algorithm. We first measure the background noise and estimate the noise spectrum using fast Fourier transform (FFT), then we subtract the spectrum of background noise from that of the observed noisy signal and the signal can be reconstructed by inverse FFT of the subtracted spectrum. With this method, the background noise, especially stationary inferences, can be suppressed well and the signal-to-noise ratio can be increased. Using high-T C radio-frequency SQUID gradiometer and magnetometer, we have measured the magnetic field produced by a watch, which was placed 35 cm under a SQUID. After noise cancellation, the signal-to-noise ratio could be greatly increased. We also used this method to eliminate the vibration noise of a cryocooler SQUID

  10. 36 CFR 3.15 - What is the maximum noise level for the operation of a vessel?

    Science.gov (United States)

    2010-07-01

    ... level for the operation of a vessel? 3.15 Section 3.15 Parks, Forests, and Public Property NATIONAL PARK... level for the operation of a vessel? (a) A person may not operate a vessel at a noise level exceeding... vessel is being operated in excess of the noise levels established in paragraph (a) of this section may...

  11. Performance Enhancement of Optical CDMA by Differential-Phase Method for Radio-over-Fiber Transmissions

    Directory of Open Access Journals (Sweden)

    Hsu-Chih Cheng

    2013-01-01

    Full Text Available The study proposes the differential-phase optical code-division multiple-access (OCDMA network for radio-over-fiber (RoF transmissions, and the characteristics are numerically analyzed. The network coder/decoders (codecs are structured on the basis of arrayed-waveguide-grating (AWG routers with complementary Walsh-Hadamard (CWH signature codes. In the proposed system, the network requires only two AWG routers to accomplish spectral encoding of radio base station (RBS and decoding of control station for the complementary keying, thus resulting in a simpler and low cost system. Performance analyses are evaluated with the dominant noise of phase-induced intensity noise (PIIN in spectral code OCDMA network. By the proposed AWG-based OCDMA with the differential-phase scheme, it is possible to establish interference-free and low crosstalk beat noise RoF systems.

  12. modelling traffic noise level on roadside traders at wurukum market

    African Journals Online (AJOL)

    HOD

    . This leads to poor planning and traffic control strategies within the town to reduce ... embark on a study to assess the level of noise pollution .... industrial products such as cement, fuel, timber, water, waste, etc ... used for a manual traffic count.

  13. Levels And Spectra Of Aircraft Noise And People\\'s Reactions In ...

    African Journals Online (AJOL)

    A study of sound levels and spectral distribution as well as people\\'s reactions to aircraft noise in three Nigerian international airports have been conducted. The study comprised physical measurements and social survey. Results show that maximum octave band pressure levels (BPLs) for Margaret Ekpo, Port Harcourt and ...

  14. A RADIO-LOUD MAGNETAR IN X-RAY QUIESCENCE

    International Nuclear Information System (INIS)

    Levin, Lina; Bailes, Matthew; Bhat, N. D. Ramesh; Burke-Spolaor, Sarah; Van Straten, Willem; Bates, Samuel; Kramer, Michael; Stappers, Ben; Burgay, Marta; D'Amico, Nichi; Milia, Sabrina; Possenti, Andrea; Johnston, Simon; Keith, Michael; Rea, Nanda

    2010-01-01

    As part of a survey for radio pulsars with the Parkes 64 m telescope, we have discovered PSR J1622-4950, a pulsar with a 4.3 s rotation period. Follow-up observations show that the pulsar has the highest inferred surface magnetic field of the known radio pulsars (B ∼3 x 10 14 G), and it exhibits significant timing noise and appears to have an inverted spectrum. Unlike the vast majority of the known pulsar population, PSR J1622-4950 appears to switch off for many hundreds of days and even in its on-state exhibits extreme variability in its flux density. Furthermore, the integrated pulse profile changes shape with epoch. All of these properties are remarkably similar to the only two magnetars previously known to emit radio pulsations. The position of PSR J1622-4950 is coincident with an X-ray source that, unlike the other radio pulsating magnetars, was found to be in quiescence. We conclude that our newly discovered pulsar is a magnetar-the first to be discovered via its radio emission.

  15. Noise exposure and hearing impairment among Chinese restaurant workers and entertainment employees in Hong Kong.

    Directory of Open Access Journals (Sweden)

    Xiang Qian Lao

    Full Text Available BACKGROUND: Noise-induced hearing loss (NIHL is a major concern in the non-manufacturing industries. This study aimed to investigate the occupational noise exposure and the NIHL among Chinese restaurant workers and entertainment employees working in the service industry in Hong Kong. METHODS: This cross-sectional survey involved a total of 1,670 participants. Among them, 937 were randomly selected from the workers of Chinese restaurants and 733 were selected from workers in three entertainment sectors: radio and television stations; cultural performance halls or auditoria of the Leisure and Cultural Services Department (LCSD; and karaoke bars. Noise exposure levels were measured in the sampled restaurants and entertainment sectors. Each participant received an audiometric screening test. Those who were found to have abnormalities were required to take another diagnostic test in the health center. The "Klockhoff digit" method was used to classify NIHL in the present study. RESULTS: The main source of noise inside restaurants was the stoves. The mean hearing thresholds showed a typical dip at 3 to 6 KHz and a substantial proportion (23.7% of the workers fulfilled the criteria for presumptive NIHL. For entertainment sectors, employees in radio and television stations generally had higher exposure levels than those in the halls or auditoria of the LCSD and karaoke bars. The mean hearing thresholds showed a typical dip at 6 KHz and a substantial proportion of the employees fulfilled the criteria for presumptive NIHL (38.6%, 95%CI: 35.1-42.1%. Being male, older, and having longer service and daily alcohol consumption were associated with noise-induced hearing impairment both in restaurant workers and entertainment employees. CONCLUSION: Excessive noise exposure is common in the Chinese restaurant and entertainment industries and a substantial proportion of restaurant workers and entertainment employees suffer from NIHL. Comprehensive hearing

  16. Laser Noise and its Impact on the Performance of Intensity-Modulation with Direct-Detection Analog Photonic Links

    National Research Council Canada - National Science Library

    Urick, Vincent J; Devgan, Preetpaul S; McKinney, Jason D; Dexter, James L

    2007-01-01

    The equations for radio-frequency gain, radio-frequency noise figure, compression dynamic range and spurious-free dynamic range are derived for an analog photonic link employing intensity modulation and direct detection...

  17. Radio frequency plasma nitriding of aluminium at higher power levels

    International Nuclear Information System (INIS)

    Gredelj, Sabina; Kumar, Sunil; Gerson, Andrea R.; Cavallaro, Giuseppe P.

    2006-01-01

    Nitriding of aluminium 2011 using a radio frequency plasma at higher power levels (500 and 700 W) and lower substrate temperature (500 deg. C) resulted in higher AlN/Al 2 O 3 ratios than obtained at 100 W and 575 deg. C. AlN/Al 2 O 3 ratios derived from X-ray photoelectron spectroscopic analysis (and corroborated by heavy ion elastic recoil time of flight spectrometry) for treatments preformed at 100 (575 deg. C), 500 (500 deg. C) and 700 W (500 deg. C) were 1.0, 1.5 and 3.3, respectively. Scanning electron microscopy revealed that plasma nitrided surfaces obtained at higher power levels exhibited much finer nodular morphology than obtained at 100 W

  18. Measurement of the Low Frequency Noise of MOSFETs under Large Signal RF Excitation

    NARCIS (Netherlands)

    van der Wel, A.P.; Klumperink, Eric A.M.; Nauta, Bram

    2002-01-01

    A measurement technique [1] is presented that allows measurement of MOSFET low frequency (LF) noise under large signal RF (Radio Frequency) excitation. Measurements indicate that MOSFETS exhibit a reduction in LF noise when they are cycled from inversion to accummulation and that this reduction does

  19. Direction of Radio Finding via MUSIC (Multiple Signal Classification) Algorithm for Hardware Design System

    Science.gov (United States)

    Zhang, Zheng

    2017-10-01

    Concept of radio direction finding systems, which use radio direction finding is based on digital signal processing algorithms. Thus, the radio direction finding system becomes capable to locate and track signals by the both. Performance of radio direction finding significantly depends on effectiveness of digital signal processing algorithms. The algorithm uses the Direction of Arrival (DOA) algorithms to estimate the number of incidents plane waves on the antenna array and their angle of incidence. This manuscript investigates implementation of the DOA algorithms (MUSIC) on the uniform linear array in the presence of white noise. The experiment results exhibit that MUSIC algorithm changed well with the radio direction.

  20. Solar radio continuum storms and a breathing magnetic field model. Final report

    International Nuclear Information System (INIS)

    1975-01-01

    Radio noise continuum emissions observed in metric and decametric wave frequencies are, in general, associated with actively varying sunspot groups accompanied by the S-component of microwave radio emissions. These continuum emission sources, often called type I storm sources, are often associated with type III burst storm activity from metric to hectometric wave frequencies. This storm activity is, therefore, closely connected with the development of these continuum emission sources. It is shown that the S-component emission in microwave frequencies generally precedes, by several days, the emission of these noise continuum storms of lower frequencies. In order for these storms to develop, the growth of sunspot groups into complex types is very important in addition to the increase of the average magnetic field intensity and area of these groups. After giving a review on the theory of these noise continuum storm emissions, a model is briefly considered to explain the relation of the emissions to the storms

  1. Quasi-periodic oscillations and noise in low-mass X-ray binaries

    International Nuclear Information System (INIS)

    Van der Klis, M.

    1989-01-01

    The phenomenology of quasi-periodic oscillations (QPOs) and noise in low-mass X-ray binaries (LMXBs) is discussed. Signal analysis aspects of QPO and noise are addressed along with the relationship between LMXBs and millisecond radio pulsars. The history and prehistory of QPOs and noise in LMXBs are examined. Universal noise components and normal and flaring branch QPOs in Z sources are described and the phenomenology of Z sources is discussed. Bright LMXBs known as atoll sources are considered, as are nonpersistently bright LMXBs accreting pulsars and black hole candidates. 162 refs

  2. Radio-adaptation: cellular and molecular features of a response to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Rigaud, O.

    1998-01-01

    It is well established that sublethal doses of DNA damaging agents induce protective mechanisms against a subsequent high dose treatment ; for instance, the phenomenon of radio-adaptation in the case of ionizing radiations. Since the early observation described in 1984, numerous studies have confirmed the radio-adaptive response in terms of reduction of chromosomal breaks for varied biological models in vitro and in vivo. Evidence for an adaptive response against the induction of gene mutations and the lethal effect is clearly demonstrated. This paper reviews the experimental results describing various aspects of these adaptive responses expressed on these different biological end-points. The molecular mechanism underlying radio-adaptation still remains nuclear. The development of this phenomenon requires de novo synthesis of transcripts and proteins during the time interval between the two doses. Some data are consistent with the hypotheses that these gene products would be involved in the activation of DNA repair pathways and antioxidant systems. However, a major question still remains unanswered; indeed, it is not clear whether or not the radio-adaptation could affect the estimation of cancer risk related with low level exposure to ionizing radiation, a major concern in radioprotection. Until such data are available, it is yet unwise to evoke the beneficial effects of radio-adaptation. (authors)

  3. Effect of external pressure environment on the internal noise level due to a source inside a cylindrical tank

    Science.gov (United States)

    Clevenson, S. A.; Roussos, L. A.

    1984-01-01

    A small cylindrical tank was used to study the effect on the noise environment within a tank of conditions of atmospheric (sea level) pressure or vacuum environments on the exterior. Experimentally determined absorption coefficients were used to calculate transmission loss, transmissibility coefficients and the sound pressure (noise) level differences in the interior. The noise level differences were also measured directly for the two exterior environments and compared to various analytical approximations with limited agreement. Trend study curves indicated that if the tank transmission loss is above 25 dB, the difference in interior noise level between the vacuum and ambient pressure conditions are less than 2 dB.

  4. Determination of Noise Level and Its Sources in the Neonatal Intensive Care Unit and Neonatal Ward

    Directory of Open Access Journals (Sweden)

    Mahdi Jahangir Blourchian

    2015-12-01

    Full Text Available Background: In Neonatal intensive care units (NICU different sound intensities and frequencies are produced from different sources, which may exert undesirable physiological effects on the infants. The aim of this study was to determine the noise level and its sources in the NICU and neonatal ward of Al-Zahra Hospital of Rasht, Iran. Methods: In this descriptive cross-sectional study, the intensity of the sounds generated by the internal and external sources in the NICU and neonatal ward was measured using a sound level meter device. The sound produced by each of the sources was individually calculated. Data were analyzed performing descriptive and analytical statistics, using SPSS version 19. Results: The mean noise levels in six rooms and a hallway during morning, afternoon and night shifts with the electromechanical devices turned on were 61.67±4.5, 61.32±4.32 and 60.71±4.56 dB, respectively. Moreover, with the devices tuned off the mean noise levels during morning, afternoon and evening shifts were 64.97±2.6, 60.6±1.29 and 57.91±4.73 dB, respectively. The differences between the mean noise levels in the neonatal wards (standard noise level=45 dB during each shift with the electromechanical devices turned on and off were statistically significant (P=0.002 and P

  5. BROADBAND RADIO POLARIMETRY AND FARADAY ROTATION OF 563 EXTRAGALACTIC RADIO SOURCES

    International Nuclear Information System (INIS)

    Anderson, C. S.; Gaensler, B. M.; Feain, I. J.; Franzen, T. M. O.

    2015-01-01

    We present a broadband spectropolarimetric survey of 563 discrete, mostly unresolved radio sources between 1.3 and 2.0 GHz using data taken with the Australia Telescope Compact Array. We have used rotation-measure synthesis to identify Faraday-complex polarized sources, those objects whose frequency-dependent polarization behavior indicates the presence of material possessing complicated magnetoionic structure along the line of sight (LOS). For sources classified as Faraday-complex, we have analyzed a number of their radio and multiwavelength properties to determine whether they differ from Faraday-simple polarized sources (sources for which LOS magnetoionic structures are comparatively simple) in these properties. We use this information to constrain the physical nature of the magnetoionic structures responsible for generating the observed complexity. We detect Faraday complexity in 12% of polarized sources at ∼1′ resolution, but we demonstrate that underlying signal-to-noise limitations mean the true percentage is likely to be significantly higher in the polarized radio source population. We find that the properties of Faraday-complex objects are diverse, but that complexity is most often associated with depolarization of extended radio sources possessing a relatively steep total intensity spectrum. We find an association between Faraday complexity and LOS structure in the Galactic interstellar medium (ISM) and claim that a significant proportion of the Faraday complexity we observe may be generated at interfaces of the ISM associated with ionization fronts near neutral hydrogen structures. Galaxy cluster environments and internally generated Faraday complexity provide possible alternative explanations in some cases

  6. Relationship between lighting and noise levels and productivity of the occupants in automotive assembly industry.

    Science.gov (United States)

    Akbari, Jafar; Dehghan, Habibollah; Azmoon, Hiva; Forouharmajd, Farhad

    2013-01-01

    Work environment affects human productivity and his performance. The aims of this study were to investigate the effects of lighting and noise levels on human productivity in the automotive assembly industry. Subjects were 181 workers from different parts of an automobile assembly industry. Illuminance (Lx) at the height of 30 inches from the surface of work station and noise (dBA) were locally measured. Also human productivity by the Goldsmith and Hersey scale (1980) was measured. Data were analyzed by using SPSS v20 Pearson correlation coefficient. The results showed that the relationship between noise level and human productivity is negative and significant (P productivity (P > 0.05). Based on the results, in assembly tasks, noise has a negative impact on human productivity, and lighting does not affect this. So, in order to increase employee productivity, noise control and reduction to less than the standard values (less than 85 dB) is necessary.

  7. Relationship between Lighting and Noise Levels and Productivity of the Occupants in Automotive Assembly Industry

    Directory of Open Access Journals (Sweden)

    Jafar Akbari

    2013-01-01

    Full Text Available Work environment affects human productivity and his performance. The aims of this study were to investigate the effects of lighting and noise levels on human productivity in the automotive assembly industry. Method. Subjects were 181 workers from different parts of an automobile assembly industry. Illuminance (Lx at the height of 30 inches from the surface of work station and noise (dBA were locally measured. Also human productivity by the Goldsmith and Hersey scale (1980 was measured. Data were analyzed by using SPSS v20 Pearson correlation coefficient. Results. The results showed that the relationship between noise level and human productivity is negative and significant (, , but there was no significant relationship between lighting and human productivity (. Conclusion. Based on the results, in assembly tasks, noise has a negative impact on human productivity, and lighting does not affect this. So, in order to increase employee productivity, noise control and reduction to less than the standard values (less than 85 dB is necessary.

  8. Noise exposure levels for musicians during rehearsal and performance times.

    Science.gov (United States)

    McIlvaine, Devon; Stewart, Michael; Anderson, Robert

    2012-03-01

    The purpose of this study was to determine daily noise doses and 8-hour time weighted averages for rock band musicians, crew members, and spectators during a typical rehearsal and performance using both Occupational Safety and Health Administration (OSHA) and National Institute of Occupational Safety and Health (NIOSH) measurement criteria. Personal noise dosimetry was completed on five members of a rock band during one 2-hr rehearsal and one 4-hr performance. Time-weighted averages (TWA) and daily dose values were calculated using both OSHA and NIOSH criteria and compared to industry guidelines for enrollment in hearing conservation programs and the use of hearing protection devices. TWA values ranged from 84.3 to 90.4 dBA (OSHA) and from 90.0 to 96.4 dBA (NIOSH) during the rehearsal. The same values ranged from 91.0 to 99.7 dBA (OSHA) and 94.0 to 102.8 dBA (NIOSH) for the performance. During the rehearsal, daily noise doses ranged from 45.54% to 106.7% (OSHA) and from 317.74% to 1396.07% (NIOSH). During the performance, doses ranged from 114.66% to 382.49% (OSHA) and from 793.31% to 5970.15% (NIOSH). The musicians in this study were exposed to dangerously high levels of noise and should be enrolled in a hearing conservation programs. Hearing protection devices should be worn, especially during performances. The OSHA measurement criteria yielded values significantly more conservative than those produced by NIOSH criteria. Audiologists should counsel musician-patients about the hazards of excessive noise (music) exposure and how to protect their hearing.

  9. Radio drama adaptations: an approach towards an analytical methodology

    NARCIS (Netherlands)

    Huwiler, E.

    2010-01-01

    This article establishes a methodology with which radio drama pieces can be analysed. It thereby integrates all features the art form has to offer: voices, music, noises, but also technical features like cutting and mixing contribute to the narrative that is being told. This approach emphasizes the

  10. A Q-band two-beam cryogenic receiver for the Tianma Radio Telescope

    Science.gov (United States)

    Zhong, Wei-Ye; Dong, Jian; Gou, Wei; Yu, Lin-Feng; Wang, Jin-Qing; Xia, Bo; Jiang, Wu; Liu, Cong; Zhang, Hui; Shi, Jun; Yin, Xiao-Xing; Shi, Sheng-Cai; Liu, Qing-Hui; Shen, Zhi-Qiang

    2018-04-01

    A Q-band two-beam cryogenic receiver for the Tianma Radio Telescope (TMRT) has been developed, and it uses the independently-developed key microwave and millimeter-wave components operating from 35 to 50GHz with a fractional bandwidth of 35%. The Q-band receiver consists of three parts: optics, cold unit assembly and warm unit assembly, and it can receive simultaneously the left-handed and right-handed circularly polarized waves. The cold unit assembly of each beam is composed of a feed horn, a noise injection coupler, a differential phase shifter, an orthomode transducer and two low-noise amplifiers, and it works at a temperature range near 20 K to greatly improve the detection sensitivity of the receiving system. The warm unit assembly includes four radio-frequency amplifiers, four radio-frequency high-pass filters, four waveguide biased mixers, four 4–12 GHz intermediate-frequency amplifiers and one 31–38 GHz frequency synthesizer. The measured Q-band four-channel receiver noise temperatures are roughly 30–40 K. In addition, the single-dish spectral line and international very long baseline interferometry (VLBI) observations between the TMRT and East Asia VLBI Network at the Q-band have been successfully carried out, demonstrating the advantages of the TMRT equipped with the state-of-the-art Q-band receiver.

  11. 24-26  GHz radio-over-fiber and free-space optics for fifth-generation systems.

    Science.gov (United States)

    Bohata, Jan; Komanec, Matěj; Spáčil, Jan; Ghassemlooy, Zabih; Zvánovec, Stanislav; Slavík, Radan

    2018-03-01

    This Letter outlines radio-over-fiber combined with radio-over-free-space optics (RoFSO) and radio frequency free-space transmission, which is of particular relevance for fifth-generation networks. Here, the frequency band of 24-26 GHz is adopted to demonstrate a low-cost, compact, and high-energy-efficient solution based on the direct intensity modulation and direct detection scheme. For our proof-of-concept demonstration, we use 64 quadrature amplitude modulation with a 100 MHz bandwidth. We assess the link performance by exposing the RoFSO section to atmospheric turbulence conditions. Further, we show that the measured minimum error vector magnitude (EVM) is 4.7% and also verify that the proposed system with the free-space-optics link span of 100 m under strong turbulence can deliver an acceptable EVM of <9% with signal-to-noise ratio levels of 22 dB and 10 dB with and without turbulence, respectively.

  12. EGRET Unidentified Source Radio Observations and Performance of Receiver Gain Calibration

    International Nuclear Information System (INIS)

    Niinuma, Kotaro; Asuma, Kuniyuki; Kuniyoshi, Masaya; Matsumura, Nobuo; Takefuji, Kazuhiro; Kida, Sumiko; Takeuchi, Akihiko; Ichikawa, Hajime; Sawano, Akihiro; Yoshimura, Naoya; Suzuki, Shigehiro; Nakamura, Ryosuke; Nakayama, Yu; Daishido, Tsuneaki

    2006-01-01

    Last year, we have developed the receiver gain calibration system by using Johnson-Nyquist noise, for accuracy flux measurement, because we have been starting radio identification program of transient radio sources, blazars and radio counterpart of The Energetic Gamma Ray Experiment Telescope (EGRET) unidentified γ-ray sources in Waseda Nasu Pulsar Observatory. It is shown that there are a few low correlation data between receiver gain and ambient temperature around receiver for anything troubles of receiver, because we can detect gain and ambient temperature through a day by developed system. Estimated fluctuations of daily data of steady sources decrease by removing low correlation data before analysing. As the result of our analysis by using above system, radio counterpart of EGRET identified source showed fading light-curve for a week

  13. EUV and Magnetic Activities Associated with Type-I Solar Radio Bursts

    Science.gov (United States)

    Li, C. Y.; Chen, Y.; Wang, B.; Ruan, G. P.; Feng, S. W.; Du, G. H.; Kong, X. L.

    2017-06-01

    Type-I bursts ( i.e. noise storms) are the earliest-known type of solar radio emission at the meter wavelength. They are believed to be excited by non-thermal energetic electrons accelerated in the corona. The underlying dynamic process and exact emission mechanism still remain unresolved. Here, with a combined analysis of extreme ultraviolet (EUV), radio and photospheric magnetic field data of unprecedented quality recorded during a type-I storm on 30 July 2011, we identify a good correlation between the radio bursts and the co-spatial EUV and magnetic activities. The EUV activities manifest themselves as three major brightening stripes above a region adjacent to a compact sunspot, while the magnetic field there presents multiple moving magnetic features (MMFs) with persistent coalescence or cancelation and a morphologically similar three-part distribution. We find that the type-I intensities are correlated with those of the EUV emissions at various wavelengths with a correlation coefficient of 0.7 - 0.8. In addition, in the region between the brightening EUV stripes and the radio sources there appear consistent dynamic motions with a series of bi-directional flows, suggesting ongoing small-scale reconnection there. Mainly based on the induced connection between the magnetic motion at the photosphere and the EUV and radio activities in the corona, we suggest that the observed type-I noise storms and the EUV brightening activities are the consequence of small-scale magnetic reconnection driven by MMFs. This is in support of the original proposal made by Bentley et al. ( Solar Phys. 193, 227, 2000).

  14. Combination therapy using antioxidants and low level laser therapy (LLLT) on noise induced hearing loss (NIHL)

    Science.gov (United States)

    Chang, So-Young; Lim, Sung Kyu; Lee, Min young; Chung, Phil-Sang; Jung, Jae-Yun; Rhee, Chung-Ku

    2016-02-01

    One of the most common factors that cause hearing disorders is noise trauma. Noise is an increasing hazard and it is pervasive, which makes it difficult to take precautions and prevent noise-induced hearing loss (NIHL). The prevalence of hearing loss among factory workers to be 42 %[1]. Ocupational noise induced hearing loss (ONIHL) continues to be a significant occupational hazard. ONIHL is permanent and may cause significant disability, for which there currently exists no cure, but is largely preventable. More than 30 million Americans are potentially exposed to hazardous noise levels in occupations such as transportation, construction, and coal mining, as well as recreationally. In the mainstream setting, exposure avoidance strategies aimed to reduce the incidence of ONIHL remain the focus of public health and occupational medicine approaches[2]. In military conditions this is most often caused by such things as explosions, blasts, or loud noises from vehicles ranging from 100 to 140 dB[3] and military weapons generating approximately 140-185 dB peak sound pressure levels[4].

  15. Estimation of MIMO channel capacity from phase-noise impaired measurements

    DEFF Research Database (Denmark)

    Pedersen, Troels; Yin, Xuefeng; Fleury, Bernard Henri

    2008-01-01

    Due to the significantly reduced cost and effort for system calibration time-division multiplexing (TDM) is a commonly used technique to switch between the transmit and receive antennas in multiple-input multiple-output (MIMO) radio channel sounding. Nonetheless, Baum et al. [1], [2] have shown t...... matrix. It is shown by means of Monte Carlo simulations assuming a measurementbased phase noise model, that the MIMO channel capacity can be estimated accurately for signal to noise ratios up to about 35 dB......Due to the significantly reduced cost and effort for system calibration time-division multiplexing (TDM) is a commonly used technique to switch between the transmit and receive antennas in multiple-input multiple-output (MIMO) radio channel sounding. Nonetheless, Baum et al. [1], [2] have shown...... that phase noise of the transmitter and receiver local oscillators, when it is assumed to be a white Gaussian random process, can cause large errors of the estimated channel capacity of a low-rank MIMO channel when the standard channel matrix estimator is used. Experimental evidence shows that consecutive...

  16. Tracking Solar Type II Bursts with Space Based Radio Interferometers

    Science.gov (United States)

    Hegedus, Alexander M.; Kasper, Justin C.; Manchester, Ward B.

    2018-06-01

    The Earth’s Ionosphere limits radio measurements on its surface, blocking out any radiation below 10 MHz. Valuable insight into many astrophysical processes could be gained by having a radio interferometer in space to image the low frequency window for the first time. One application is observing type II bursts tracking solar energetic particle acceleration in Coronal Mass Ejections (CMEs). In this work we create a simulated data processing pipeline for several space based radio interferometer (SBRI) concepts and evaluate their performance in the task of localizing these type II bursts.Traditional radio astronomy software is hard coded to assume an Earth based array. To circumvent this, we manually calculate the antenna separations and insert them along with the simulated visibilities into a CASA MS file for analysis. To create the realest possible virtual input data, we take a 2-temperature MHD simulation of a CME event, superimpose realistic radio emission models from the CME-driven shock front, and propagate the signal through simulated SBRIs. We consider both probabilistic emission models derived from plasma parameters correlated with type II bursts, and analytical emission models using plasma emission wave interaction theory.One proposed SBRI is the pathfinder mission SunRISE, a 6 CubeSat interferometer to circle the Earth in a GEO graveyard orbit. We test simulated trajectories of SunRISE and image what the array recovers, comparing it to the virtual input. An interferometer on the lunar surface would be a stable alternative that avoids noise sources that affect orbiting arrays, namely the phase noise from positional uncertainty and atmospheric 10s-100s kHz noise. Using Digital Elevation Models from laser altimeter data, we test different sets of locations on the lunar surface to find near optimal configurations for tracking type II bursts far from the sun. Custom software is used to model the response of different array configurations over the lunar year

  17. Entropy-Based Method of Choosing the Decomposition Level in Wavelet Threshold De-noising

    Directory of Open Access Journals (Sweden)

    Yan-Fang Sang

    2010-06-01

    Full Text Available In this paper, the energy distributions of various noises following normal, log-normal and Pearson-III distributions are first described quantitatively using the wavelet energy entropy (WEE, and the results are compared and discussed. Then, on the basis of these analytic results, a method for use in choosing the decomposition level (DL in wavelet threshold de-noising (WTD is put forward. Finally, the performance of the proposed method is verified by analysis of both synthetic and observed series. Analytic results indicate that the proposed method is easy to operate and suitable for various signals. Moreover, contrary to traditional white noise testing which depends on “autocorrelations”, the proposed method uses energy distributions to distinguish real signals and noise in noisy series, therefore the chosen DL is reliable, and the WTD results of time series can be improved.

  18. Effects of road traffic background noise on judgments of individual airplane noises. Ph.D. Thesis

    Science.gov (United States)

    Powell, C. A.

    1979-01-01

    Two laboratory experiments were conducted to investigate the effects of road-traffic background noise on judgments of individual airplane flyover noises. In the first experiment, 27 subjects judged a set of 16 airplane flyover noises in the presence of traffic-noise sessions of 30-min duration consisting of the combinations of 3 traffic-noise types and 3 noise levels. In the second experiment, 24 subjects judged the same airplane flyover noises in the presence of traffic-noise sessions of 10-min duration consisting of the combinations of 2 traffic-noise types and 4 noise levels. In both experiments the airplane noises were judged less annoying in the presence of high traffic-noise levels than in the presence of low traffic-noise levels.

  19. A statistical background noise correction sensitive to the steadiness of background noise.

    Science.gov (United States)

    Oppenheimer, Charles H

    2016-10-01

    A statistical background noise correction is developed for removing background noise contributions from measured source levels, producing a background noise-corrected source level. Like the standard background noise corrections of ISO 3741, ISO 3744, ISO 3745, and ISO 11201, the statistical background correction increases as the background level approaches the measured source level, decreasing the background noise-corrected source level. Unlike the standard corrections, the statistical background correction increases with steadiness of the background and is excluded from use when background fluctuation could be responsible for measured differences between the source and background noise levels. The statistical background noise correction has several advantages over the standard correction: (1) enveloping the true source with known confidence, (2) assuring physical source descriptions when measuring sources in fluctuating backgrounds, (3) reducing background corrected source descriptions by 1 to 8 dB for sources in steady backgrounds, and (4) providing a means to replace standardized background correction caps that incentivize against high precision grade methods.

  20. Reducing visitor noise levels at Muir Woods National Monument using experimental management.

    Science.gov (United States)

    Stack, David W; Peter, Newman; Manning, Robert E; Fristrup, Kurt M

    2011-03-01

    Noise impacts resources and visitor experience in many protected natural areas, and visitors can be the dominant source of noise. This experimental study tested the efficacy and acceptability of signs asking visitors to be quiet at Muir Woods National Monument, California. Signs declaring a "quiet zone" (at the park's Cathedral Grove) or a "quiet day" (throughout the park) were posted on a randomized schedule that included control days (no signs). Visitor surveys were conducted to measure the cognitive and behavioral responses of visitors to the signs and test the acceptability of these management practices to visitors. Visitors were highly supportive of these management practices and reported that they consciously limited the amount of noise they produced. Sound level measurements showed substantial decreases on days when signs were posted. © 2011 Acoustical Society of America

  1. Radio stars observed in the LAMOST spectral survey

    Science.gov (United States)

    Zhang, Li-Yun; Yue, Qiang; Lu, Hong-Peng; Han, Xian-Ming L.; Zhang, Yong; Shi, Jian-Rong; Wang, Yue-Fei; Hou, Yong-Hui; Zi-Huang, Cao

    2017-09-01

    Radio stars have attracted astronomers’ attention for several decades. To better understand the physics behind stellar radio emissions, it is important to study their optical behaviors. The LAMOST survey provides a large database for researching stellar spectroscopic properties of radio stars. In this work, we concentrate on their spectroscopic properties and infer physical properties from their spectra, such as stellar activity and variability. We mined big data from the LAMOST spectral survey Data Release 2 (DR2), published on 2016 June 30, by cross-matching them with radio stars from FIRST and other surveys. We obtained 783 good stellar spectra with high signal to noise ratio for 659 stars. The criteria for selection were positional coincidence within 1.5‧‧ and LAMOST objects classified as stars. We calculated the equivalent widths (EWs) of the Ca ii H&K, Hδ, Hγ, Hβ, Hα and Ca ii IRT lines by integrating the line profiles. Using the EWs of the Hα line, we detected 147 active stellar spectra of 89 objects having emissions above the Hα continuum. There were also 36 objects with repeated spectra, 28 of which showed chromospheric activity variability. Furthermore, we found 14 radio stars emitting noticeably in the Ca ii IRT lines. The low value of the EW8542/EW8498 ratio for these 14 radio stars possibly alludes to chromospheric plage regions.

  2. EPICS based low-level radio frequency control system in LIPAc

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, Julio, E-mail: julio.calvo@ciemat.es [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Ciemat (Spain); Rivers, Mark L. [Department of Geophysical Sciences and Center for Advanced Radiation Sources, The University of Chicago (United States); Patricio, Miguel A. [Departamento de Informatica, Universidad Carlos III de Madrid (Spain); Ibarra, Angel [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Ciemat (Spain)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer The system proposed can control amplitude and phase of each cavity. Black-Right-Pointing-Pointer Rapid diagnostics are refreshed in milliseconds. Black-Right-Pointing-Pointer Increasing control parameters will not increase consumed time neither complexity. Black-Right-Pointing-Pointer IQ demodulation can be achieved thanks to the transformed values at driver level. - Abstract: The IFMIF-EVEDA (International Fusion Materials Irradiation Facility - Engineering Validation and Engineering Design Activity) linear accelerator, known as Linear IFMIF Prototype Accelerator (LIPAc), will be a 9 MeV, 125 mA continuous wave (CW) deuteron accelerator prototype to validate the technical options of the accelerator design for IFMIF. The primary mission of such facility is to test and verify materials performance when subjected to extensive neutron irradiation of the type encountered in a fusion reactor to prepare for the design, construction, licensing and safe operation of a fusion demonstration reactor (DEMO). The radio frequency (RF) power system of IFMIF-EVEDA consists of 18 RF chains working at 175 MHz with three amplification stages each. The low-level radio frequency (LLRF) controls the amplitude and phase of the signal to be synchronized with the beam and it also controls the resonance frequency of the cavities. The system is based on a commercial compact peripheral component interconnect (cPCI) field programmable gate array (FPGA) board, provided by Lyrtech and controlled by a Windows host PC. For this purpose, it is mandatory to communicate the cPCI FPGA board from EPICS Channel Access [1]. A software architecture on EPICS framework in order to control and monitor the LLRF system is presented.

  3. Evaluation of noise pollution in urban traffic hubs—Noise maps and measurements

    International Nuclear Information System (INIS)

    Fiedler, Paulo Eduardo Kirrian; Zannin, Paulo Henrique Trombetta

    2015-01-01

    A study was made of some of the main traffic hubs in a Latin American metropolis, in order to determine the presence or absence of noise by means of noise measurements and acoustic mapping. To characterize noise in the evaluated road stretches, 232 measurements were taken at different points. The Predictor software package was used for the noise mapping calculations. Noise sensitive areas, e.g., hospitals, were identified in the evaluated road stretches. Noise maps were calculated for two hospitals, showing the current levels of noise that reach their facades. Hypothetical scenarios were simulated by making changes in the composition of traffic and total number of vehicles, and an assessment was made of the potential influence of these modifications in reducing the noise levels reaching the facades of the buildings in question. The simulations indicated that a 50% reduction in total traffic flow, or a 50% reduction in heavy vehicle traffic flow, would reduce the noise levels by about 3 dB(A). - Highlights: • Evaluation of noise pollution in urban traffic hubs • Street systems • Environmental noise impacts • Noise mapping

  4. Evaluation of noise pollution in urban traffic hubs—Noise maps and measurements

    Energy Technology Data Exchange (ETDEWEB)

    Fiedler, Paulo Eduardo Kirrian; Zannin, Paulo Henrique Trombetta, E-mail: paulo.zannin@pesquisador.cnpq.br

    2015-02-15

    A study was made of some of the main traffic hubs in a Latin American metropolis, in order to determine the presence or absence of noise by means of noise measurements and acoustic mapping. To characterize noise in the evaluated road stretches, 232 measurements were taken at different points. The Predictor software package was used for the noise mapping calculations. Noise sensitive areas, e.g., hospitals, were identified in the evaluated road stretches. Noise maps were calculated for two hospitals, showing the current levels of noise that reach their facades. Hypothetical scenarios were simulated by making changes in the composition of traffic and total number of vehicles, and an assessment was made of the potential influence of these modifications in reducing the noise levels reaching the facades of the buildings in question. The simulations indicated that a 50% reduction in total traffic flow, or a 50% reduction in heavy vehicle traffic flow, would reduce the noise levels by about 3 dB(A). - Highlights: • Evaluation of noise pollution in urban traffic hubs • Street systems • Environmental noise impacts • Noise mapping.

  5. Environmental impact assessment - baseline noise survey and noise impact assessment for Aurora Mine

    International Nuclear Information System (INIS)

    Yee, S.

    1996-01-01

    A noise impact assessment was conducted at Syncrude's proposed Aurora Mine site to comply with Alberta Energy and Utilities Board (AEUB) Noise Control Directive ID 94-4. Noise assessments were conducted near a major noise source, i.e. the hydraulic and electric shovels. Noise levels at 50 meters away from the source varied from 72.3 to 79.7 dBA. The worst case noise level was 75 dBA measured at 100 meters away from a hydraulic shovel. This assessment was used to calculate the predicted design sound level from a noise source at the nearest or most impacted occupied dwelling. Two cabins located near the access road and along Kearl Lake respectively, were identified as the most impacted and nearest dwellings to the mine site. The predicted sound level at one cabin was 43 dBA, and 55 dBA at the other. Fort McKay was also assessed because it is the nearest community to the mine site. The sound level at Fort McKay was predicted to be 34 dBA. These results indicate that the sound level from Aurora Mine is not in compliance with the AEUB Noise Control Directive. Attenuation measures are required to reduce the noise to acceptable level at Cabin A and B. Predicted sound level at Fort McKay is lower than the permitted sound level

  6. Prospective cohort study on noise levels in a pediatric cardiac intensive care unit.

    Science.gov (United States)

    Garcia Guerra, Gonzalo; Joffe, Ari R; Sheppard, Cathy; Pugh, Jodie; Moez, Elham Khodayari; Dinu, Irina A; Jou, Hsing; Hartling, Lisa; Vohra, Sunita

    2018-04-01

    To describe noise levels in a pediatric cardiac intensive care unit, and to determine the relationship between sound levels and patient sedation requirements. Prospective observational study at a pediatric cardiac intensive care unit (PCICU). Sound levels were measured continuously in slow A weighted decibels dB(A) with a sound level meter SoundEarPro® during a 4-week period. Sedation requirement was assessed using the number of intermittent (PRNs) doses given per hour. Analysis was conducted with autoregressive moving average models and the Granger test for causality. 39 children were included in the study. The average (SD) sound level in the open area was 59.4 (2.5) dB(A) with a statistically significant but clinically unimportant difference between day/night hours (60.1 vs. 58.6; p-value noise levels were > 90 dB. There was a significant association between average (p-value = 0.030) and peak sound levels (p-value = 0.006), and number of sedation PRNs. Sound levels were above the recommended values with no differences between day/night or open area/single room. High sound levels were significantly associated with sedation requirements. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Analysing Self Interference Cancellation in Full Duplex Radios

    DEFF Research Database (Denmark)

    Mahmood, Nurul Huda; Shafique Ansari, Imran; Berardinelli, Gilberto

    2016-01-01

    Full duplex communication promises a theoretical $100\\%$ throughput gain by doubling the number of simultaneous transmissions. Such compelling gains are conditioned on perfect cancellation of the self interference power resulting from simultaneous transmission and reception. Generally, self...... interference power is modelled as a noise-like constant level interference floor. However, experimental validations have shown that the self interference power is in practice a random variable depending on a number of factors such as the surrounding wireless environment and the degree of interference...... cancellation. In this study, we derive an analytical model for the residual self interference power, and demonstrate various applications of the derived model in analysing the performance of a Full Duplex radio. In general, full duplex communication is found to provide only modest throughput gains over half...

  8. Noise suppression in duct

    International Nuclear Information System (INIS)

    Ahmed, A.; Barfeh, M.A.G.

    2001-01-01

    In air-conditioning system the noise generated by supply fan is carried by conditioned air through the ductwork. The noise created in ductwork run may be transmission, regenerative and ductborne. Transmission noise is fan noise, regenerative noise is due to turbulence in flow and ductborne noise is the noise radiating from duct to surroundings. Some noise is attenuated in ducts also but if noise level is high then it needs to be attenuated. A simple mitre bend can attenuate-noise. This principle is extended to V and M-shape ducts with inside lining of fibreglass, which gave maximum attenuation of 77 dB and 62 dB respectively corresponding to 8 kHz frequency as compared to mitre, bend giving maximum 18 dB attenuation. Sound level meter measured sound levels with octave band filter and tests were conducted in anechoic room. A V-shape attenuator can be used at fan outlet and high frequency noise can be minimized greatly. (author)

  9. Reduced impact of induced gate noise on inductively degenerated LNAs in deep submicron CMOS technologies

    DEFF Research Database (Denmark)

    Rossi, P.; Svelto, F.; Mazzanti, A.

    2005-01-01

    Designers of radio-frequency inductively-degenerated CMOS low-noise-amplifiers have usually not followed the guidelines for achieving minimum noise figure. Nonetheless, state-of-the- art implementations display noise figure values very close to the theoretical minimum. In this paper, we point out...... that this is due to the effect of the parasitic overlap capacitances in the MOS device. In particular, we show that overlap capacitances lead to a significant induced-gate-noise reduction, especially when deep sub-micron CMOS processes are used....

  10. Equivalent noise level response to number of vehicles: a comparison between a high traffic flow and low traffic flow highway in Klang Valley, Malaysia

    OpenAIRE

    Halim, Herni; Abdullah, Ramdzani

    2014-01-01

    HIGHLIGHTS Highway traffic noise is a serious problem in Malaysia Heavy traffic flow highway recorded higher noise level compared to low traffic flow Noise level stabilized at certain number of vehicles on the road i.e above 500 vehicles. Although much research on road traffic noise has found that noise level increase are influenced by driver behavior and source-receiver distance, little attention has been paid to the relationship between noise level and total number of vehicles...

  11. Radio-frequency shot-noise measurement in a magnetic tunnel junction with a MgO barrier

    International Nuclear Information System (INIS)

    Rehman, Mushtaq; Park, Junghwan; Song, Woon; Chong, Yonuk; Lee, Yeonsub; Min, Byoungchul; Shin, Kyungho; Ryu, Sangwan; Khim, Zheong

    2010-01-01

    We measured the noise power of a magnetic tunnel junction in the frequency range of 710 ∼ 1200 MHz. A low-noise cryogenic HEMT amplifier was used to measure the small noise signal at a high frequency with wide bandwidth. The MgO-barrier tunnel junction showed large tunnel magnetoresistance ratio of 215% at low temperature, which indicates electronic transport through the tunnel barrier without any significant spin-flip scattering. In the bias-dependent noise measurement, however, the zero-bias shot noise was enhanced compared to the value expected from a perfect tunnel barrier or the value observed from a good Al-AlO x -Al tunnel junction. We assume that this enhanced noise comes from inelastic tunneling processes through the barrier, which may be related to the observed zero-bias anomaly in the differential resistance of the tunnel junctions. We present a simple phenomenological model for how the inelastic scattering process can enhance the zero-bias noise in a tunnel junction.

  12. Tracking electric field exposure levels through radio frequency dosimetry

    International Nuclear Information System (INIS)

    Ewing, P.D.; Moore, M.R.; Rochelle, R.W.; Thomas, R.S.; Hess, R.A.; Hoffheins, B.S.

    1991-01-01

    The radio-frequency (rf) dosimeter developed by the Oak Ridge National Laboratory is a portable, pocket-sized cumulative-dose recording device designed to detect and record the strengths and durations of electric fields present in the work areas of naval vessels. The device measures an integrated dose and records the electric fields that exceed the permissible levels set by the American National Standards Institute. Features of the rf dosimeter include a frequency range of 30 MHz to 10 GHz and a three-dimensional sensor. Data obtained with the rf dosimeter will be used to determine the ambient field-strength profile for shipboard personnel over an extended time. Readings are acquired and averaged over a 6-min period corresponding to the rise time of the core body temperature. These values are stored for up to 6 months, after which the data are transferred to a computer via the dosimeter's serial port. The rf dosimeter should increase knowledge of the levels of electric fields to which individuals are exposed. 5 refs., 4 figs

  13. Classification of Partial Discharge Measured under Different Levels of Noise Contamination.

    Directory of Open Access Journals (Sweden)

    Wong Jee Keen Raymond

    Full Text Available Cable joint insulation breakdown may cause a huge loss to power companies. Therefore, it is vital to diagnose the insulation quality to detect early signs of insulation failure. It is well known that there is a correlation between Partial discharge (PD and the insulation quality. Although many works have been done on PD pattern recognition, it is usually performed in a noise free environment. Also, works on PD pattern recognition in actual cable joint are less likely to be found in literature. Therefore, in this work, classifications of actual cable joint defect types from partial discharge data contaminated by noise were performed. Five cross-linked polyethylene (XLPE cable joints with artificially created defects were prepared based on the defects commonly encountered on site. Three different types of input feature were extracted from the PD pattern under artificially created noisy environment. These include statistical features, fractal features and principal component analysis (PCA features. These input features were used to train the classifiers to classify each PD defect types. Classifications were performed using three different artificial intelligence classifiers, which include Artificial Neural Networks (ANN, Adaptive Neuro-Fuzzy Inference System (ANFIS and Support Vector Machine (SVM. It was found that the classification accuracy decreases with higher noise level but PCA features used in SVM and ANN showed the strongest tolerance against noise contamination.

  14. Modelo AHP-VIKOR para handoff espectral en redes de radio cognitiva

    Directory of Open Access Journals (Sweden)

    César Hernández

    2015-07-01

    Full Text Available This paper proposed a hybrid algorithm for spectrum allocation in cognitive radio networks based on two algorithms, analytical hierarchical process (AHP and multi-criteria optimization and compromise solution (VIKOR, for improving the performance of mobility spectrum of secondary users in cognitive radio networks. To evaluate the level of performance of the proposed algorithm, a comparative analysis between the proposed AHP-VIKOR, Grey Relational Analysis (GRA and a random allocation of spectrum (Random algorithm, is performed. The first two algorithms work with the same decision criteria: probability of channel availability, estimated time availability, signal-to-interference-plus-noise ratio and bandwidth. Unlike related work, benchmarking was validated through a trace of real spectral occupation data, captured in the GSM frequency band, which models the actual behavior of licensed users. For performance evaluation five metric were used, handoff failed average cumulative number, handoff average cumulative number, average bandwidth, delay and throughput average cumulative. The results of the comparative analysis with the other two algorithms show that the AHP-VIKOR algorithm proposed provides the best performance in spectral mobility.

  15. ON THE USE OF SHOT NOISE FOR PHOTON COUNTING

    Energy Technology Data Exchange (ETDEWEB)

    Zmuidzinas, Jonas, E-mail: jonas@caltech.edu [Division of Physics, Mathematics, and Astronomy, California Institute Institute of Technology, Pasadena, CA 91125 (United States)

    2015-11-01

    Lieu et al. have recently claimed that it is possible to substantially improve the sensitivity of radio-astronomical observations. In essence, their proposal is to make use of the intensity of the photon shot noise as a measure of the photon arrival rate. Lieu et al. provide a detailed quantum-mechanical calculation of a proposed measurement scheme that uses two detectors and conclude that this scheme avoids the sensitivity degradation that is associated with photon bunching. If correct, this result could have a profound impact on radio astronomy. Here I present a detailed analysis of the sensitivity attainable using shot-noise measurement schemes that use either one or two detectors, and demonstrate that neither scheme can avoid the photon bunching penalty. I perform both semiclassical and fully quantum calculations of the sensitivity, obtaining consistent results, and provide a formal proof of the equivalence of these two approaches. These direct calculations are furthermore shown to be consistent with an indirect argument based on a correlation method that establishes an independent limit to the sensitivity of shot-noise measurement schemes. Furthermore, these calculations are directly applicable to the regime of interest identified by Lieu et al. Collectively, these results conclusively demonstrate that the photon-bunching sensitivity penalty applies to shot-noise measurement schemes just as it does to ordinary photon counting, in contradiction to the fundamental claim made by Lieu et al. The source of this contradiction is traced to a logical fallacy in their argument.

  16. Wideband CMOS low noise amplifier including an active balun

    NARCIS (Netherlands)

    Blaakmeer, S.C.; Klumperink, Eric A.M.; Leenaerts, D.M.W.; Nauta, Bram

    2007-01-01

    An inductorless LNA with active balun is proposed for multi-standard radio applications between 100MHz and 6GHz [1]. It exploits a combination of a common-gate (CG) stage and an common-source (CS) stage with replica biasing to maximize balanced operation, while simultaneously canceling the noise and

  17. Active Noise Control for Dishwasher noise

    Science.gov (United States)

    Lee, Nokhaeng; Park, Youngjin

    2016-09-01

    The dishwasher is a useful home appliance and continually used for automatically washing dishes. It's commonly placed in the kitchen with built-in style for practicality and better use of space. In this environment, people are easily exposed to dishwasher noise, so it is an important issue for the consumers, especially for the people living in open and narrow space. Recently, the sound power levels of the noise are about 40 - 50 dBA. It could be achieved by removal of noise sources and passive means of insulating acoustical path. For more reduction, such a quiet mode with the lower speed of cycle has been introduced, but this deteriorates the washing capacity. Under this background, we propose active noise control for dishwasher noise. It is observed that the noise is propagating mainly from the lower part of the front side. Control speakers are placed in the part for the collocation. Observation part of estimating sound field distribution and control part of generating the anti-noise are designed for active noise control. Simulation result shows proposed active noise control scheme could have a potential application for dishwasher noise reduction.

  18. Acceptable noise level (ANL) with Danish and non-semantic speech materials in adult hearing-aid users

    DEFF Research Database (Denmark)

    Olsen, Steen Østergaard; Lantz, Johannes; Nielsen, Lars Holme

    2012-01-01

    The acceptable noise level (ANL) test is used for quantification of the amount of background noise subjects accept when listening to speech. This study investigates Danish hearing-aid users' ANL performance using Danish and non-semantic speech signals, the repeatability of ANL, and the association...

  19. Entropy as a measure of the noise extent in a two-level quantum feedback controlled system

    Institute of Scientific and Technical Information of China (English)

    Wang Tao-Bo; Fang Mao-Fa; Hu Yao-Hua

    2007-01-01

    By introducing the von Neumann entropy as a measure of the extent of noise, this paper discusses the entropy evolution in a two-level quantum feedback controlled system. The results show that the feedback control can induce the reduction of the degree of noise, and different control schemes exhibit different noise controlling ability, the extent of the reduction also related with the position of the target state on the Bloch sphere. It is shown that the evolution of entropy can provide a real time noise observation and a systematic guideline to make reasonable choice of control strategy.

  20. Mean and Extreme Radio Properties of Quasars and the Origin of Radio Emission

    Science.gov (United States)

    Richards, Gordon T.; Kratzer, R.

    2014-01-01

    We explore the evolution of the fraction of radio loud quasars and the mean radio properties of quasars. Although any quasar has only a ~10% chance of being radio loud and the average quasar has a radio luminosity of ~4x10^30 ergs/s/Hz, these properties are strong functions of not only luminosity, redshift, black hole mass, and accretion rate, but also the strength of the accretion disk wind (as characterized by CIV emission line properties). Quasars with higher optical luminosity and/or lower redshift have a higher than average probability of being radio loud, but their median radio luminosity (relative to optical) is much lower than average. We find that, while radio properties of quasars generally cannot be predicted from their optical properties, objects where one expects a strong radiation line driven wind (based on emission line features) have virtually no chance of being radio loud. The redder quasars are in the optical, the more radio flux (relative to optical) they have; this trend holds even for quasars that are not expected to be significantly dust reddened/extincted in the optical. Finally, we consider the radio properties of quasars in the framework of models which describe the radio loud extrema as being due to particularly high spin resulting from second generation mergers and in the context of star formation at lower levels of radio flux. This work was supported by NSF AAG grant 1108798.

  1. Nanosecond-level time synchronization of autonomous radio detector stations for extensive air showers

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Messina, S.; Scholten, O.; van den Berg, A.M.

    To exploit the full potential of radio measurements of cosmic-ray air showers at MHz frequencies, a detector timing synchronization within 1 ns is needed. Large distributed radio detector arrays such as the Auger Engineering Radio Array (AERA) rely on timing via the Global Positioning System (GPS)

  2. Listen to the noise: noise is beneficial for cognitive performance in ADHD.

    Science.gov (United States)

    Söderlund, Göran; Sikström, Sverker; Smart, Andrew

    2007-08-01

    Noise is typically conceived of as being detrimental to cognitive performance. However, given the mechanism of stochastic resonance, a certain amount of noise can benefit performance. We investigate cognitive performance in noisy environments in relation to a neurocomputational model of attention deficit hyperactivity disorder (ADHD) and dopamine. The Moderate Brain Arousal model (MBA; Sikström & Söderlund, 2007) suggests that dopamine levels modulate how much noise is required for optimal cognitive performance. We experimentally examine how ADHD and control children respond to different encoding conditions, providing different levels of environmental stimulation. Participants carried out self-performed mini tasks (SPT), as a high memory performance task, and a verbal task (VT), as a low memory task. These tasks were performed in the presence, or absence, of auditory white noise. Noise exerted a positive effect on cognitive performance for the ADHD group and deteriorated performance for the control group, indicating that ADHD subjects need more noise than controls for optimal cognitive performance. The positive effect of white noise is explained by the phenomenon of stochastic resonance (SR), i.e., the phenomenon that moderate noise facilitates cognitive performance. The MBA model suggests that noise in the environment, introduces internal noise into the neural system through the perceptual system. This noise induces SR in the neurotransmitter systems and makes this noise beneficial for cognitive performance. In particular, the peak of the SR curve depends on the dopamine level, so that participants with low dopamine levels (ADHD) require more noise for optimal cognitive performance compared to controls.

  3. Noise exposure in movie theaters: a preliminary study of sound levels during the showing of 25 films.

    Science.gov (United States)

    Warszawa, Anna; Sataloff, Robert T

    2010-09-01

    The harmful effects of noise exposure during leisure-time activities are beginning to receive some scrutiny. We conducted a preliminary study to investigate the noise levels during the showings of 25 different films. During each screening, various sound measurements were made with a dosimeter. The movies were classified on the basis of both their Motion Picture Association of America (MPAA) rating and their genre, and the size of the theater and the size of the audience were taken into consideration in the final analysis. Our findings suggest that the sound levels of many movies might be harmful to hearing, although we can draw no definitive conclusions. We did not discern any relationship between noise levels and either MPAA rating or genre. Further studies are recommended.

  4. Current Background Noise Sources and Levels in the NASA Ames 40- by 80-Foot Wind Tunnel: A Status Report

    Science.gov (United States)

    Allen, Christopher S.; Jaeger, Stephen; Soderman, Paul; Koga, Dennis (Technical Monitor)

    1999-01-01

    Background noise measurements were made of the acoustic environment in the National Full-Scale Aerodynamics Complex 40- by 80-Foot Wind Tunnel (40x80) at NASA Ames Research Center. The measurements were acquired subsequent to the 40x80 Aeroacoustic Modernization Project, which was undertaken to improve the anechoic characteristics of the 40x80's closed test section as well as reduce the levels of background noise in the facility. The resulting 40x80 anechoic environment was described by Soderman et. al., and the current paper describes the resulting 40x80 background noise, discusses the sources of the noise, and draws comparisons to previous 40x80 background noise levels measurements. At low wind speeds or low frequencies, the 40x80 background noise is dominated by the fan drive system. To obtain the lowest fan drive noise for a given tunnel condition, it is possible in the 40x80 to reduce the fans' rotational speed and adjust the fans' blade pitch, as described by Schmidtz et. al. This idea is not new, but has now been operationally implemented with modifications for increased power at low rotational speeds. At low to mid-frequencies and at higher wind speeds, the dominant noise mechanism was thought to be caused by the surface interface of the previous test section floor acoustic lining. In order to reduce this noise mechanism, the new test section floor lining was designed to resist the pumping of flow in and out of the space between the grating slats required to support heavy equipment. In addition, the lining/flow interface over the entire test section was designed to be smoother and quieter than the previous design. At high wind speeds or high frequencies, the dominant source of background noise in the 40x80 is believed to be caused by the response of the in-flow microphone probes (required by the nature of the closed test section) to the fluctuations in the freestream flow. The resulting background noise levels are also different for probes of various

  5. Sources of the Radio Background Considered

    Energy Technology Data Exchange (ETDEWEB)

    Singal, J.; /KIPAC, Menlo Park /Stanford U.; Stawarz, L.; /KIPAC, Menlo Park /Stanford U. /Jagiellonian U., Astron. Observ.; Lawrence, A.; /Edinburgh U., Inst. Astron. /KIPAC, Menlo Park /Stanford U.; Petrosian, V.; /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., Appl. Phys. Dept.

    2011-08-22

    We investigate possible origins of the extragalactic radio background reported by the ARCADE 2 collaboration. The surface brightness of the background is several times higher than that which would result from currently observed radio sources. We consider contributions to the background from diffuse synchrotron emission from clusters and the intergalactic medium, previously unrecognized flux from low surface brightness regions of radio sources, and faint point sources below the flux limit of existing surveys. By examining radio source counts available in the literature, we conclude that most of the radio background is produced by radio point sources that dominate at sub {mu}Jy fluxes. We show that a truly diffuse background produced by elections far from galaxies is ruled out because such energetic electrons would overproduce the observed X-ray/{gamma}-ray background through inverse Compton scattering of the other photon fields. Unrecognized flux from low surface brightness regions of extended radio sources, or moderate flux sources missed entirely by radio source count surveys, cannot explain the bulk of the observed background, but may contribute as much as 10%. We consider both radio supernovae and radio quiet quasars as candidate sources for the background, and show that both fail to produce it at the observed level because of insufficient number of objects and total flux, although radio quiet quasars contribute at the level of at least a few percent. We conclude that the most important population for production of the background is likely ordinary starforming galaxies above redshift 1 characterized by an evolving radio far-infrared correlation, which increases toward the radio loud with redshift.

  6. Methods For an Acceptable Traffic Noise Level Design

    Directory of Open Access Journals (Sweden)

    Zlatko Sviben

    2004-07-01

    Full Text Available Road noise disturbance on rough roads by means of loudnesssensor caused by wideband signal components with a significantimpact of tonal effects on smooth roads and in specificactions in driving lead to the annoyance of drivers. A systemicapproach has been applied for the sound quality estimation ofphysical properties of various noise sources and structuralvibroacoustic car properties and its components as an integratedparameter in car design for the purpose of the developmentand vehicle noise reduction. Simulation of the most importantcharacteristics of listening impressions was performedby modem systems of signal analysis together with the presentationof loudness, sharpness, and roughness as essential quantities.Optimization of the noise control measuring regarding vehiclesound was obtained by means of a simulation system withthe capability of the real time original sound filtering. Structuralanalysis was performed as an acoustic modal analysis on therear part and the car interior with the quantitative analysis ofsport and luxury car sounds. The possibility of active noise controlwas studied and examples are given for an application ofpsychoacoustic tools for car sound quality design. Sound qualitywas obtained by an observation of certain aspects, which areempirically or theoretically connected with the design. An experimentalsound synthesis with psychometrical measuring wasapplied. The sound quality of car interior is presented takinginto consideration the criteria of objectivity, reliability and validity.

  7. Ambient Noise Levels in Acute Neonatal Intensive Care Unit of a Tertiary Referral Hospital

    OpenAIRE

    Sonia R. B D'Souza; Leslie Edward Lewis; Vijay Kumar; Ramesh Bhat Y; Jayashree Purkayastha; Hari Prakash

    2017-01-01

    Background: Advances in neonatal care have resulted in improved survival of neonates admitted to the intensive care of the Neonatal Intensive Care Unit (NICU). However, the NCU may be an inappropriate milieu, with presence of overwhelming stimuli, most potent being the continuous presence of noise in the ambience of the NICU. Aim and Objectives: To determine and describe the ambient noise levels in the acute NICU of a tertiary referral hospital. Material and Methods...

  8. Radio/FADS/IMU integrated navigation for Mars entry

    Science.gov (United States)

    Jiang, Xiuqiang; Li, Shuang; Huang, Xiangyu

    2018-03-01

    Supposing future orbiting and landing collaborative exploration mission as the potential project background, this paper addresses the issue of Mars entry integrated navigation using radio beacon, flush air data sensing system (FADS), and inertial measurement unit (IMU). The range and Doppler information sensed from an orbiting radio beacon, the dynamic pressure and heating data sensed from flush air data sensing system, and acceleration and attitude angular rate outputs from an inertial measurement unit are integrated in an unscented Kalman filter to perform state estimation and suppress the system and measurement noise. Computer simulations show that the proposed integrated navigation scheme can enhance the navigation accuracy, which enables precise entry guidance for the given Mars orbiting and landing collaborative exploration mission.

  9. The impact of electrode materials on 1/f noise in piezoelectric AlN contour mode resonators

    Science.gov (United States)

    Kim, Hoe Joon; Jung, Soon In; Segovia-Fernandez, Jeronimo; Piazza, Gianluca

    2018-05-01

    This paper presents a detailed analysis on the impact of electrode materials and dimensions on flicker frequency (1/f) noise in piezoelectric aluminum nitride (AlN) contour mode resonators (CMRs). Flicker frequency noise is a fundamental noise mechanism present in any vibrating mechanical structure, whose sources are not generally well understood. 1 GHz AlN CMRs with three different top electrode materials (Al, Au, and Pt) along with various electrode lengths and widths are fabricated to control the overall damping acting on the device. Specifically, the use of different electrode materials allows control of thermoelastic damping (TED), which is the dominant damping mechanism for high frequency AlN CMRs and largely depends on the thermal properties (i.e. thermal diffusivities and expansion coefficients) of the metal electrode rather than the piezoelectric film. We have measured Q and 1/f noise of 68 resonators and the results show that 1/f noise decreases with increasing Q, with a power law dependence that is about 1/Q4. Interestingly, the noise level also depends on the type of electrode materials. Devices with Pt top electrode demonstrate the best noise performance. Our results help unveiling some of the sources of 1/f noise in these resonators, and indicate that a careful selection of the electrode material and dimensions could reduce 1/f noise not only in AlN-CMRs, but also in various classes of resonators, and thus enable ultra-low noise mechanical resonators for sensing and radio frequency applications.

  10. Unlocking radio broadcasts

    DEFF Research Database (Denmark)

    Skov, Mette; Lykke, Marianne

    2012-01-01

    This poster reports the preliminary results of a user study uncovering the information seeking behaviour of humanities scholars dedicated to radio research. The study is part of an interdisciplinary research project on radio culture and auditory resources. The purpose of the study is to inform...... the design of information architecture and interaction design of a research infrastructure that will enable future radio and audio based research. Results from a questionnaire survey on humanities scholars‟ research interest and information needs, preferred access points, and indexing levels are reported....... Finally, a flexible metadata schema is suggested, that includes both general metadata and highly media and research project specific metadata....

  11. Do hearing threshold levels in workers of the furniture industry reflect their exposure to noise?

    Directory of Open Access Journals (Sweden)

    Małgorzata Pawlaczyk-Łuszczyńska

    2016-06-01

    Full Text Available Background: The aim of the study was to analyze the hearing status of employees of a furniture factory with respect to their exposure to noise and the presence of additional risk factors of noise-induced hearing loss (NIHL. Material and Methods: Noise measurements, questionnaire survey and assessment of hearing, using pure tone audiometry, were carried out in 50 male workers, aged 20–57 years, directly employed in the manufacture of furniture. The actual workers’ hearing threshold levels (HTLs were compared with the predictions calculated according to PN-ISO 1999:2000 based on age, gender and noise exposure. Results: Workers under study were exposed to noise at daily noise exposure levels of 82.7–94.8 dB (mean: 90.9 dB for a period of 3–14 years. In all subjects, mean HTL at 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz did not exceed 25 dB. Nevertheless, high frequency notches were found in 11% of audiograms. The actual workers’ HTLs at 3000–6000 Hz were similar to those predicted using PN-ISO 1999:2000. There were statistical significant differences between HTLs in subgroups of people with higher (> 78 mm Hg and lower (≤ 78 mm Hg diastolic blood pressure, smokers and non-smokers, and those working with organic solvents. Hearing loss was more evident in subjects affected by the additional risk factors specified above. Conclusions: The results confirm the need to consider, in addition to noise, also some other NIHL risk factors, such as tobacco smoking, elevated blood pressure, and co-exposure to organic solvents when estimating the risk of NIHL and developing the hearing conservation programs for workers. Med Pr 2016;67(3:337–351

  12. [Do hearing threshold levels in workers of the furniture industry reflect their exposure to noise?].

    Science.gov (United States)

    Pawlaczyk-Łuszczyńska, Małgorzata; Dudarewicz, Adam; Czaja, Norman; Bortkiewicz, Alicja

    The aim of the study was to analyze the hearing status of employees of a furniture factory with respect to their exposure to noise and the presence of additional risk factors of noise-induced hearing loss (NIHL). Noise measurements, questionnaire survey and assessment of hearing, using pure tone audiometry, were carried out in 50 male workers, aged 20-57 years, directly employed in the manufacture of furniture. The actual workers' hearing threshold levels (HTLs) were compared with the predictions calculated according to PN-ISO 1999:2000 based on age, gender and noise exposure. Workers under study were exposed to noise at daily noise exposure levels of 82.7-94.8 dB (mean: 90.9 dB) for a period of 3-14 years. In all subjects, mean HTL at 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz did not exceed 25 dB. Nevertheless, high frequency notches were found in 11% of audiograms. The actual workers' HTLs at 3000-6000 Hz were similar to those predicted using PN-ISO 1999:2000. There were statistical significant differences between HTLs in subgroups of people with higher (> 78 mm Hg) and lower (≤ 78 mm Hg) diastolic blood pressure, smokers and non-smokers, and those working with organic solvents. Hearing loss was more evident in subjects affected by the additional risk factors specified above. The results confirm the need to consider, in addition to noise, also some other NIHL risk factors, such as tobacco smoking, elevated blood pressure, and co-exposure to organic solvents when estimating the risk of NIHL and developing the hearing conservation programs for workers. Med Pr 2016;67(3):337-351. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  13. The Concept of 'Radio Music'

    DEFF Research Database (Denmark)

    Fjeldsøe, Michael

    2016-01-01

    , educational and didactic effort which would enlighten all of society. For a while it seemed that radio music was considered a genre of its own. To fulfil its function, radio music had to consider technical limitations as well as the educational level and listening modes of the new mass audience. Public radio......, as discussed by Kurt Weill and Paul Hindemith, was at first greeted with great expectations, but soon a more realistic attitude prevailed. Weill, himself a radio critic as well, composed Der Lindberghflug (1929) as a piece of ‘radio music theatre’, but then changed some of its features in order to turn...... it into a didactical play for amateurs, a so-called Lehrstück. The article will present the concept of ‘radio music’ developed within German Neue Sachlichkeit and discuss the relevance of such a concept for current research in the field of radio and music....

  14. The Cost-Effectiveness of Lowering Permissible Noise Levels Around U.S. Airports

    Directory of Open Access Journals (Sweden)

    Boshen Jiao

    2017-12-01

    Full Text Available Aircraft noise increases the risk of cardiovascular diseases and mental illness. The allowable limit for sound in the vicinity of an airport is 65 decibels (dB averaged over a 24-h ‘day and night’ period (DNL in the United States. We evaluate the trade-off between the cost and the health benefits of changing the regulatory DNL level from 65 dB to 55 dB using a Markov model. The study used LaGuardia Airport (LGA as a case study. In compliance with 55 dB allowable limit of aircraft noise, sound insulation would be required for residential homes within the 55 dB to 65 dB DNL. A Markov model was built to assess the cost-effectiveness of installing sound insulation. One-way sensitivity analyses and Monte Carlo simulation were conducted to test uncertainty of the model. The incremental cost-effectiveness ratio of installing sound insulation for residents exposed to airplane noise from LGA was $11,163/QALY gained (95% credible interval: cost-saving and life-saving to $93,054/QALY gained. Changing the regulatory standard for noise exposure around airports from 65 dB to 55 dB comes at a very good value.

  15. Development of a radio-detection array for the observation of UHE neutrino-induced showers

    Energy Technology Data Exchange (ETDEWEB)

    Ardouin, Daniel [SUBATECH, IN2P3-CNRS, University of Nantes, E. Mines Nantes, Nantes (France)], E-mail: Daniel.ardouin@univ-nantes.fr; Charrier, Didier; Lautridou, Pascal [SUBATECH, IN2P3-CNRS, University of Nantes, E. Mines Nantes, Nantes (France); Martineau-Huynh, Olivier [LPNHE, IN2P3-CNRS, University of Paris VI, Paris (France); Ravel, Olivier [SUBATECH, IN2P3-CNRS, University of Nantes, E. Mines Nantes, Nantes (France); Wu Xiangping; Zhao Meng [NAOC, Beijing (China)

    2009-06-01

    The recent demonstration by the CODALEMA collaboration of the ability of the radio-detection technique for the characterization of ultra-high-energy cosmic-rays (UHECR) calls for the use of this powerful method for the observation of UHE neutrinos. For this purpose, an adaptation of the already existing 21CM-Array (CMA) in China, is presently under achievement. In an exceptionally low electromagnetic noise level, 10160 log-periodic 50-200 MHz antennas sit along two high-altitude valleys, surrounded by mountain chains. This layout results in 30-60 km effective rock thicknesses for {nu} interactions with low incidence trajectories along the direction of two 4-6 km baselines. We will present first in-situ radio measurements demonstrating that this environment shows particularly favourable physical conditions for the observation of electromagnetic decay signals of {tau}'s leptons originating from the interaction of 10{sup 17-20} eV {nu}{sub {tau}} neutrinos.

  16. Development of a radio-detection array for the observation of UHE neutrino induced showers

    Energy Technology Data Exchange (ETDEWEB)

    Ardouin, D.; Charrier, D.; Lautridou, P.; Ravel, O. [Nantes Univ., E.Mines, SUBATECH, IN2P3-CNRS, 44 (France); Martineau-Huynh, O. [Paris-6 Univ., LPNHE, IN2P3-CNRS, 75 (France). Lab. de Physique Nucleaire et de Hautes Energies; Xiang-Ping, Wu; Meng, Zhao [NAOC, Beijing (China)

    2008-07-01

    The recent demonstration by the CODALEMA Collaboration of the ability of the radio-detection technique for the characterization of ultra-high energy cosmic-rays (UHECR) calls for the use of this powerful method for the observation of UHE neutrinos. For this purpose, an adaptation of the already existing 21CM-Array in China, is presently under achievement. In an exceptionally low electromagnetic noise level, 10160 log-periodic 50-200 MHz antennas sit along two high altitude valleys, surrounded by mountain chains. This lay-out results in 30-60 km effective rock thicknesses for {nu} interactions with low incidence trajectories along the direction of two 4-6 km baselines. We will present first in-situ radio measurements demonstrating that this environment shows particularly favourable physical conditions for the observation of electromagnetic decay signals of {tau}'s leptons originating from the interaction of 10{sup 17-20} eV {nu}{sub {tau}} neutrinos. (authors)

  17. Traffic noise in Hyderabad city, part-II. vehicular contribution to road traffic noise

    International Nuclear Information System (INIS)

    Sheikh, G.H.

    2001-01-01

    The results of a road traffic noise survey carried out in Hyderabad city showed that the levels of traffic noise in the City are alarmingly high and much beyond the comfortable limits. There, in order to investigate the level of the noise emitted by different types of vehicles plying on the city roads and to assess their individual contribution to high level traffic noise, studies have been carried out on the measurement of noise emitted by motorcycles, buses, auto-rickshaws, and motor vehicle horns as they normally move on the city roads. The data collected has been analyzed for L/sub v99/, L/sub v90/, L/sub v50/, L/sub v10/ and L/sub v1/ and results are discussed with reference to the existing motor vehicle rules in Pakistan and motor vehicle noise emission limits set by the EEC and other developed countries. Some suggestion have also been made to limit high level traffic noise. (author)

  18. Noiseonomics: The relationship between ambient noise levels in the sea and global economic trends

    OpenAIRE

    Frisk, George V.

    2012-01-01

    In recent years, the topic of noise in the sea and its effects on marine mammals has attracted considerable attention from both the scientific community and the general public. Since marine mammals rely heavily on acoustics as a primary means of communicating, navigating, and foraging in the ocean, any change in their acoustic environment may have an impact on their behavior. Specifically, a growing body of literature suggests that low-frequency, ambient noise levels in the open ocean increas...

  19. Chicago transit authority train noise exposure.

    Science.gov (United States)

    Phan, Linh T; Jones, Rachael M

    2017-06-01

    To characterize noise exposure of riders on Chicago Transit Authority (CTA) trains, we measured noise levels twice on each segment of 7 of the 8 CTA train lines, which are named after colors, yielding 48 time-series measurements. We found the Blue Line has the highest noise levels compared to other train lines, with mean 76.9 dBA; and that the maximum noise level, 88.9 dBA occurred in the tunnel between the Chicago and Grand stations. Train segments involving travel through a tunnel had significantly higher noise levels than segments with travel on elevated and ground level tracks. While 8-hr doses inside the passenger cars were not estimated to exceed occupational exposure limits, train operators ride in a separate cab with operational windows and may therefore have higher noise exposures than riders. Despite the low risk of hearing loss for riders on CTA trains, in part because transit noise accounts for a small part of total daily noise exposure, 1-min average noise levels exceeded 85 dBA at times. This confirms anecdotal observations of discomfort due to noise levels, and indicates a need for noise management, particularly in tunnels.

  20. Noise in the operating room

    DEFF Research Database (Denmark)

    Hasfeldt-Hansen, Dorthe; Lærkner, Eva Ann; Birkelund, Regner

    2010-01-01

    Because noise is a general stressor, noise in the OR should be avoided whenever possible. This article presents the results of a review of the research literature on the topic of noise in the OR. A systematic literature search was conducted. Eighteen relevant articles were identified...... and categorized as follows: noise levels, noise sources, staff performances, and patient’s perception of noise. Each study was assessed according to the strength of the evidence and the quality of the study. Noise levels in the OR in general exceed recommended levels, and the noise sources are related...... to equipment and staff behavior. The main effect of noise on staff performances is related to impaired communication, resulting in a negative effect on patient safety. The literature on patients’ perception of noise is both limited and inconsistent, and more research on this topic is needed....

  1. Feedback damping of a microcantilever at room temperature to the minimum vibration amplitude limited by the noise level.

    Science.gov (United States)

    Kawamura, Y; Kanegae, R

    2016-06-17

    Cooling the vibration amplitude of a microcantilever as low as possible is important to improve the sensitivity and resolutions of various types of scanning type microscopes and sensors making use of it. When the vibration amplitude is controlled to be smaller using a feed back control system, it is known that the obtainable minimum amplitude of the vibration is limited by the floor noise level of the detection system. In this study, we demonstrated that the amplitude of the thermal vibration of a microcantilever was suppressed to be about 0.15 pmHz(-1/2), which is the same value with the floor noise level, without the assistance of external cryogenic cooling. We think that one of the reason why we could reach the smaller amplitude at room temperature is due to stiffer spring constant of the lever, which leads to higher natural frequency and consequently lower floor noise level. The other reason is considered to be due to the increase in the laser power for the diagnostics, which lead to the decrease in the signal to noise ratio determined by the optical shot noise.

  2. Anthropogenic noise alters bat activity levels and echolocation calls

    OpenAIRE

    Bunkley, Jessie P.; McClure, Christopher J.W.; Kleist, Nathan J.; Francis, Clinton D.; Barber, Jesse R.

    2015-01-01

    Negative impacts from anthropogenic noise are well documented for many wildlife taxa. Investigations of the effects of noise on bats however, have not been conducted outside of the laboratory. Bats that hunt arthropods rely on auditory information to forage. Part of this acoustic information can fall within the spectrum of anthropogenic noise, which can potentially interfere with signal reception and processing. Compressor stations associated with natural gas extraction produce broadband nois...

  3. Ulysses radio and plasma wave observations in the jupiter environment.

    Science.gov (United States)

    Stone, R G; Pedersen, B M; Harvey, C C; Canu, P; Cornilleau-Wehrlin, N; Desch, M D; de Villedary, C; Fainberg, J; Farrell, W M; Goetz, K; Hess, R A; Hoang, S; Kaiser, M L; Kellogg, P J; Lecacheux, A; Lin, N; Macdowall, R J; Manning, R; Meetre, C A; Meyer-Vernet, N; Moncuquet, M; Osherovich, V; Reiner, M J; Tekle, A; Thiessen, J; Zarka, P

    1992-09-11

    The Unified Radio and Plasma Wave (URAP) experiment has produced new observations of the Jupiter environment, owing to the unique capabilities of the instrument and the traversal of high Jovian latitudes. Broad-band continuum radio emission from Jupiter and in situ plasma waves have proved valuable in delineating the magnetospheric boundaries. Simultaneous measurements of electric and magnetic wave fields have yielded new evidence of whistler-mode radiation within the magnetosphere. Observations of aurorallike hiss provided evidence of a Jovian cusp. The source direction and polarization capabilities of URAP have demonstrated that the outer region of the lo plasma torus supported at least five separate radio sources that reoccurred during successive rotations with a measurable corotation lag. Thermal noise measurements of the lo torus densities yielded values in the densest portion that are similar to models suggested on the basis of Voyager observations of 13 years ago. The URAP measurements also suggest complex beaming and polarization characteristics of Jovian radio components. In addition, a new class of kilometer-wavelength striated Jovian bursts has been observed.

  4. Noise Budget and Interstellar Medium Mitigation Advances in the NANOGrav Pulsar Timing Array

    Science.gov (United States)

    Dolch, T.; NANOGrav Collaboration; Chatterjee, S.; Cordes, J. M.; Demorest, P. B.; Ellis, J. A.; Jones, M. L.; Lam, M. T.; Lazio, T. J. W.; Levin, L.; McLaughlin, M. A.; Palliyaguru, N. T.; Stinebring, D. R.

    2018-02-01

    Gravitational wave (GW) detection with pulsar timing arrays (PTAs) requires accurate noise characterization. The noise of our Galactic-scale GW detector has been systematically evaluated by the Noise Budget and Interstellar Medium Mitigation working groups within the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) collaboration. Intrinsically, individual radio millisecond pulsars (MSPs) used by NANOGrav can have some degree of achromatic red spin noise, as well as white noise due to pulse phase jitter. Along any given line-of-sight, the ionized interstellar medium contributes chromatic noise through dispersion measure (DM) variations, interstellar scintillation, and scattering. These effects contain both red and white components. In the future, with wideband receivers, the effects of frequency-dependent DM will become important. Having anticipated and measured these diverse sources of detector noise, the NANOGrav PTA remains well-poised to detect low-frequency GWs.

  5. Estimation of a noise level using coarse-grained entropy of experimental time series of internal pressure in a combustion engine

    International Nuclear Information System (INIS)

    Litak, Grzegorz; Taccani, Rodolfo; Radu, Robert; Urbanowicz, Krzysztof; HoIyst, Janusz A.; Wendeker, MirosIaw; Giadrossi, Alessandro

    2005-01-01

    We report our results on non-periodic experimental time series of pressure in a single cylinder spark ignition engine. The experiments were performed for different levels of loading. We estimate the noise level in internal pressure calculating the coarse-grained entropy from variations of maximal pressures in successive cycles. The results show that the dynamics of the combustion is a non-linear multidimensional process mediated by noise. Our results show that so defined level of noise in internal pressure is not monotonous function of loading

  6. The effect of traffic noise on the hearing level of people on Karachi streets

    International Nuclear Information System (INIS)

    Jawed, I.; Musani, A.; Mahmood, R.; Khambaty, W.Y.; Asim, M.

    2010-01-01

    To study the effects of traffic noise on hearing ability of subjects prone to traffic noise exposure. Method: A hospital based prospective study was performed comprising of 200 selected subjects significantly exposed to traffic noise. These included rickshaw drivers, traffic constables and shopkeepers in central business area. All subjects were questioned according to a Performa after which ENT examination was carried out followed by Pure Tone Audiometer y. Results: Hearing impairment showed correlation with the duration of job when analyzed by linear regression analysis with correlation coefficient r=0.36 (p<0.001), Hearing impairment was 33.81+0.42 dB according to the duration of job (in years). Conclusion: Subjects are perceptually exposed to potentially damaging sound pressure level in the metropolis of Karachi. It was observed that audio logically consistent noise induced hearing loss was found to be 0.42 dB per octave from 500 Hz to 2000 Hz per year of duration of job. (author)

  7. Measuring changes in ambient noise levels from the installation and operation of a surge wave energy converter in the coastal ocean

    Energy Technology Data Exchange (ETDEWEB)

    Haxel, Joe H [Oregon State Univ., Newport, OR (United States); Henkel, Sarah K [Oregon State Univ., Newport, OR (United States)

    2017-10-18

    Ecosystem impacts resulting from elevated underwater noise levels generated by anthropogenic activities in the coastal ocean are poorly understood and remain difficult to address as a result of a significant gap in knowledge for existing nearshore sound levels. Ambient noise is an important habitat component for marine mammals and fish that use sound for essential functions such as communication, navigation, and foraging. Questions surrounding the amplitudes, frequency distributions, and durations of noise emissions from renewable wave energy conversion (WEC) projects during their construction and operation present concerns for long-term consequences in marine habitats. Oregon’s dynamic nearshore environment presents significant challenges for passive acoustic monitoring that include flow noise contamination from wave orbital motions, turbulence from breaking surf, equipment burial, and fishing pressure from sport and commercial crabbers. This project included 2 techniques for passive acoustic data collection: 1) campaign style deployments of fixed hydrophone lander stations to capture temporal variations in noise levels and 2) a drifting hydrophone system to record spatial variations within the project site. The hydrophone lander deployments were effective and economically feasible for enabling robust temporal measurements of ambient noise levels in a variety of sea state conditions. Limiting factors for the fixed stations included 1) a flow shield mitigation strategy failure in the first deployment resulting in significant wideband data contamination and 2) flow noise contamination of the unshielded sensors restricting valuable analysis to frequencies above 500 Hz for subsequent deployments. Drifting hydrophone measurements were also effective and economically feasible (although logistically challenging in the beginning of the project due to vessel time constraints) providing a spatial distribution of sound levels, comparisons of noise levels in varying levels

  8. Maximizing noise energy for noise-masking studies.

    Science.gov (United States)

    Jules Étienne, Cédric; Arleo, Angelo; Allard, Rémy

    2017-08-01

    Noise-masking experiments are widely used to investigate visual functions. To be useful, noise generally needs to be strong enough to noticeably impair performance, but under some conditions, noise does not impair performance even when its contrast approaches the maximal displayable limit of 100 %. To extend the usefulness of noise-masking paradigms over a wider range of conditions, the present study developed a noise with great masking strength. There are two typical ways of increasing masking strength without exceeding the limited contrast range: use binary noise instead of Gaussian noise or filter out frequencies that are not relevant to the task (i.e., which can be removed without affecting performance). The present study combined these two approaches to further increase masking strength. We show that binarizing the noise after the filtering process substantially increases the energy at frequencies within the pass-band of the filter given equated total contrast ranges. A validation experiment showed that similar performances were obtained using binarized-filtered noise and filtered noise (given equated noise energy at the frequencies within the pass-band) suggesting that the binarization operation, which substantially reduced the contrast range, had no significant impact on performance. We conclude that binarized-filtered noise (and more generally, truncated-filtered noise) can substantially increase the energy of the noise at frequencies within the pass-band. Thus, given a limited contrast range, binarized-filtered noise can display higher energy levels than Gaussian noise and thereby widen the range of conditions over which noise-masking paradigms can be useful.

  9. Power distribution and substrate noise coupling investigations on the behavioral level for photon counting imaging readout circuits

    International Nuclear Information System (INIS)

    Lundgren, Jan; Abdalla, Suliman; O'Nils, Mattias; Oelmann, Bengt

    2007-01-01

    In modern mixed-signal system design, there are increasing problems associated with noise coupling caused by switching digital parts to sensitive analog parts. As a consequence, there is a growing necessity to understand these problems. In order to avoid costly design iterations, noise coupling simulations should be initiated as early as possible in the design chain. The problems associated with on-chip noise coupling have been discovered in photon counting pixel detector readout systems, where the level of integration of analog and digital circuits is very high on a very small area, and it would appear that these problems will continue to increase for future system designs in this field. This paper deals with the functionality of utilizing behavioral level models for simulating noise coupling in these readout systems. The methods and models are described and simulation results are shown for a photon counting pixel detector readout system

  10. Honey and Vitamin E Restore the Plasma Level of Gonadal Hormones and Improve the Fertilization Capacity in Noise-Stressed Rats

    Directory of Open Access Journals (Sweden)

    Rajabzadeh Asghar

    2015-04-01

    Full Text Available Objective: Noise as a natural teratogenic factor affects the body systems including the reproductive organ to reduce the fertility rate and fetus health. Honey and vitamin E as natural antioxidants protects the sperm released from the reproductive system. This study was conducted to examine the efficacy of honey and vitamin E on fertilization capacity in noise-exposed rats by assessing plasma sexual hormones levels i.e., follicle-stimulating hormone (FSH, luteinizing hormone (LH, and testosterone, altered in relation with noise stress. Materials and Methods: This study was targeted the 24 male rats that randomly were divided into four equal groups including one control group (unexposed to noise stress and three experimental groups pre-induced with noise stress for 50 days and then divided as: no treated, honey and vitamin E treated groups, respectively. Then, the blood samples of experimental and control groups were taken, and the serum level of the sexual hormones was analyzed. Finally, to investigate the fertility capacity of rats, the male rats of all groups were coupled with the female ones. Results: Our results showed that FSH and LH level in noise stressed male rats raised, and the testosterone secretion decreased compared to the control group. Moreover, noise stress injury could reduce weight and the survival rate of the fetus. However, the honey and vitamin E improved the testosterone concentration, declined the plasma FSH and LH level in noise - exposed rats and enhanced the fertility rate. Conclusion: These findings may also spell out a natural curative approach rather than pharmaceutical drugs to optimize of neuroendocrine gonadal axis and testicular integrity induced by pathogenesis stress, i.e., noise and enhance the male fertility capacity.

  11. WHO Environmental Noise Guidelines for the European Region: A Systematic Review on Environmental Noise and Annoyance

    Directory of Open Access Journals (Sweden)

    Rainer Guski

    2017-12-01

    Full Text Available Background: This paper describes a systematic review and meta-analyses on effects of environmental noise on annoyance. The noise sources include aircraft, road, and rail transportation noise as well as wind turbines and noise source combinations. Objectives: Update knowledge about effects of environmental noise on people living in the vicinity of noise sources. Methods: Eligible were published studies (2000–2014 providing comparable acoustical and social survey data including exposure-response functions between standard indicators of noise exposure and standard annoyance responses. The systematic literature search in 20 data bases resulted in 62 studies, of which 57 were used for quantitative meta-analyses. By means of questionnaires sent to the study authors, additional study data were obtained. Risk of bias was assessed by means of study characteristics for individual studies and by funnel plots to assess the risk of publication bias. Main Results: Tentative exposure-response relations for percent highly annoyed residents (%HA in relation to noise levels for aircraft, road, rail, wind turbine and noise source combinations are presented as well as meta-analyses of correlations between noise levels and annoyance raw scores, and the OR for increase of %HA with increasing noise levels. Quality of evidence was assessed using the GRADE terminology. The evidence of exposure-response relations between noise levels and %HA is moderate (aircraft and railway or low (road traffic and wind turbines. The evidence of correlations between noise levels and annoyance raw scores is high (aircraft and railway or moderate (road traffic and wind turbines. The evidence of ORs representing the %HA increase by a certain noise level increase is moderate (aircraft noise, moderate/high (road and railway traffic, and low (wind turbines. Strengths and Limitations: The strength of the evidence is seen in the large total sample size encompassing the included studies (e

  12. Occupational Noise Reduction in CNC Striping Process

    Science.gov (United States)

    Mahmad Khairai, Kamarulzaman; Shamime Salleh, Nurul; Razlan Yusoff, Ahmad

    2018-03-01

    Occupational noise hearing loss with high level exposure is common occupational hazards. In CNC striping process, employee that exposed to high noise level for a long time as 8-hour contributes to hearing loss, create physical and psychological stress that reduce productivity. In this paper, CNC stripping process with high level noises are measured and reduced to the permissible noise exposure. First condition is all machines shutting down and second condition when all CNC machine under operations. For both conditions, noise exposures were measured to evaluate the noise problems and sources. After improvement made, the noise exposures were measured to evaluate the effectiveness of reduction. The initial average noise level at the first condition is 95.797 dB (A). After the pneumatic system with leakage was solved, the noise reduced to 55.517 dB (A). The average noise level at the second condition is 109.340 dB (A). After six machines were gathered at one area and cover that area with plastic curtain, the noise reduced to 95.209 dB (A). In conclusion, the noise level exposure in CNC striping machine is high and exceed the permissible noise exposure can be reduced to acceptable levels. The reduction of noise level in CNC striping processes enhanced productivity in the industry.

  13. Noise levels of toys for children between the ages of birth and 3 ...

    African Journals Online (AJOL)

    Noise-induced hearing loss (NIHL) in children is a growing area of concern for ... Sound intensity or loudness, measured as sound pressure level (SPL) in a logarithmic decibel ..... Focus needs to be placed on increasing parents' awareness of ...

  14. The Assessment of Noise Exposure and Noise Annoyance at a Petrochemical Company

    Directory of Open Access Journals (Sweden)

    S. Farhang Dehghan

    2013-12-01

    .Conclusion: Based on the obtained results of investigating the noise level (objective exposure as well as the noise annoyance (subjective exposure at the studied company, it is necessary to adopt the management –technical noise reduction measures at manufacturing sectors as the personal noise exposure and environmental noise exposure and also noise personal exposure of administrative staff can be decreased.

  15. DSP-Enabled Radio Astronomy: Towards IIIZW35 Reconquest

    Directory of Open Access Journals (Sweden)

    Alain Lecacheux

    2005-09-01

    Full Text Available In radio astronomy, the radio spectrum is used to detect weak emission from celestial sources. By spectral averaging, observation noise is reduced and weak sources can be detected. However, more and more observations are polluted by man-made radio frequency interferences (RFI. The impact of these RFIs on power spectral measurement ranges from total saturation to subtle distortions of the data. To some extent, elimination of artefacts can be achieved by blanking polluted channels in real time. With this aim in view, a complete real-time digital system has been implemented on a set of FPGA and DSP. The current functionalities of the digital system have high dynamic range of 70 dB, bandwidth selection facilities ranging from 875 kHz to 14 MHz, high spectral resolution through a polyphase filter bank with up to 8192 channels with 49 152 coefficients and real-time time-frequency blanking with a robust threshold detector. This receiver has been used to reobserve the IIIWZ35 astronomical source which has been scrambled by a strong satellite RFI for several years.

  16. The effect of extending high-frequency bandwidth on the acceptable noise level (ANL) of hearing-impaired listeners.

    Science.gov (United States)

    Johnson, Earl; Ricketts, Todd; Hornsby, Benjamin

    2009-01-01

    This study examined the effects of extending high-frequency bandwidth, for both a speech signal and a background noise, on the acceptable signal-to-noise ratio (SNR) of listeners with mild sensorineural hearing loss through utilization of the Acceptable Noise Level (ANL) procedure. In addition to extending high-frequency bandwidth, the effects of reverberation time and background noise type and shape were also examined. The study results showed a significant increase in the mean ANL (i.e. participants requested a better SNR for an acceptable listening situation) when high-frequency bandwidth was extended from 3 to 9 kHz and from 6 to 9 kHz. No change in the ANL of study participants was observed as a result of isolated modification to reverberation time or background noise stimulus. An interaction effect, however, of reverberation time and background noise stimulus was demonstrated. These findings may have implications for future design of hearing aid memory programs for listening to speech in the presence of broadband background noise.

  17. Acceptable noise level (ANL) with Danish and non-semantic speech materials in adult hearing-aid users

    DEFF Research Database (Denmark)

    Olsen, Steen Østergaard; Lantz, Johannes; Nielsen, Lars Holme

    2012-01-01

    The acceptable noise level (ANL) test is used for quantification of the amount of background noise subjects accept when listening to speech. This study investigates Danish hearing-aid users' ANL performance using Danish and non-semantic speech signals, the repeatability of ANL, and the association...... between ANL and outcome of the international outcome inventory for hearing aids (IOI-HA)....

  18. Space Telecommunications Radio System STRS Cognitive Radio

    Science.gov (United States)

    Briones, Janette C.; Handler, Louis M.

    2013-01-01

    Radios today are evolving from awareness toward cognition. A software defined radio (SDR) provides the most capability for integrating autonomic decision making ability and allows the incremental evolution toward a cognitive radio. This cognitive radio technology will impact NASA space communications in areas such as spectrum utilization, interoperability, network operations, and radio resource management over a wide range of operating conditions. NASAs cognitive radio will build upon the infrastructure being developed by Space Telecommunication Radio System (STRS) SDR technology. This paper explores the feasibility of inserting cognitive capabilities in the NASA STRS architecture and the interfaces between the cognitive engine and the STRS radio. The STRS architecture defines methods that can inform the cognitive engine about the radio environment so that the cognitive engine can learn autonomously from experience, and take appropriate actions to adapt the radio operating characteristics and optimize performance.

  19. Estimation of directivity and sound power levels emitted by aircrafts during taxiing, for outdoor noise prediction purpose

    NARCIS (Netherlands)

    Asensio, C.; Pavón, I.; Ruiz, M.; Pagan Munoz, Raul; Recuero, M.

    2007-01-01

    Integrated noise model (INM) is the most internationally used software to calculate noise levels near airports. Take off, landing or pass by operations can be modeled by INM, but it does not consider aircrafts taxiing, which, in some cases, can be important to accurately evaluate and reduce

  20. Possible earthquake precursors revealed by LF radio signals

    Directory of Open Access Journals (Sweden)

    P. F. Biagi

    2001-01-01

    Full Text Available Among radio signals, low frequency (LF radio signals lie in the band between 30–300 kHz. Monitoring equipment with the ability to measure the electric strength of such signals at field sites, were designed and assembled in Italy. From 1993 onwards, the electric field strength of the MCO (216 kHz, France broadcasting station has been collecting measurements at two sites in central Italy that were chosen according to very low noise levels. At the end of 1996, radio signals from the CLT (189 kHz, Italy and CZE (270 kHz, Czech Republic broadcasting stations were included in the measurements. Meteorological data from central Italy were also collected over the same time period in order to study the influence of weather conditions on the experimental measurements. During the monitoring period, we observed some evident attenuation of the electric field strength in some of the radio signals at some of the receivers. The duration of the attenuation observed was several days, so it could possibly be related to particular meteorological conditions. On the other hand, this phenomenon might represent precursors of moderate (3.0 M 3.5 earthquakes that occurred near the receivers (within 50 km along the transmitter-receiver path. In this case, it is possible that the pre-seismic processes could have produced irregularities in the troposphere, such as ducts, reflecting layers and scattering zones, so that some local troposphere defocusing of the radio signals might have occurred. These observations were related only to moderate earthquakes and in these cases, suitable meteorological conditions were probably needed to observe the effect. Between February – March 1998, we observed at one measuring site, a significant increase in the CZE electric field strength. Unfortunately, we could not use the data of the other receiver in this case, due to frequent interruptions in the data set. The increase might have been a precursor of the strong seismic sequence (M = 5

  1. Phase noise in RF and microwave amplifiers.

    Science.gov (United States)

    Boudot, Rodolphe; Rubiola, Enrico

    2012-12-01

    Understanding amplifier phase noise is a critical issue in many fields of engineering and physics, such as oscillators, frequency synthesis, telecommunication, radar, and spectroscopy; in the emerging domain of microwave photonics; and in exotic fields, such as radio astronomy, particle accelerators, etc. Focusing on the two main types of base noise in amplifiers, white and flicker, the power spectral density of the random phase φ(t) is Sφ(f) = b(0) + b(-1)/f. White phase noise results from adding white noise to the RF spectrum in the carrier region. For a given RF noise level, b(0) is proportional to the reciprocal of the carrier power P(0). By contrast, flicker results from a near-dc 1/f noise-present in all electronic devices-which modulates the carrier through some parametric effect in the semiconductor. Thus, b(-1) is a parameter of the amplifier, constant in a wide range of P(0). The consequences are the following: Connecting m equal amplifiers in parallel, b(-1) is 1/m times that of one device. Cascading m equal amplifiers, b(-1) is m times that of one amplifier. Recirculating the signal in an amplifier so that the gain increases by a power of m (a factor of m in decibels) as a result of positive feedback (regeneration), we find that b(-1) is m(2) times that of the amplifier alone. The feedforward amplifier exhibits extremely low b(-1) because the carrier is ideally nulled at the input of its internal error amplifier. Starting with an extensive review of the literature, this article introduces a system-oriented model which describes the phase flickering. Several amplifier architectures (cascaded, parallel, etc.) are analyzed systematically, deriving the phase noise from the general model. There follow numerous measurements of amplifiers using different technologies, including some old samples, and in a wide frequency range (HF to microwaves), which validate the theory. In turn, theory and results provide design guidelines and give suggestions for CAD and

  2. High levels of absorption in orientation-unbiased, radio-selected 3CR Active Galaxies

    Science.gov (United States)

    Wilkes, Belinda J.; Haas, Martin; Barthel, Peter; Leipski, Christian; Kuraszkiewicz, Joanna; Worrall, Diana; Birkinshaw, Mark; Willner, Steven P.

    2014-08-01

    A critical problem in understanding active galaxies (AGN) is the separation of intrinsic physical differences from observed differences that are due to orientation. Obscuration of the active nucleus is anisotropic and strongly frequency dependent leading to complex selection effects for observations in most wavebands. These can only be quantified using a sample that is sufficiently unbiased to test orientation effects. Low-frequency radio emission is one way to select a close-to orientation-unbiased sample, albeit limited to the minority of AGN with strong radio emission.Recent Chandra, Spitzer and Herschel observations combined with multi-wavelength data for a complete sample of high-redshift (1half the sample is significantly obscured with ratios of unobscured: Compton thin (22 24.2) = 2.5:1.4:1 in these high-luminosity (log L(0.3-8keV) ~ 44-46) sources. These ratios are consistent with current expectations based on modelingthe Cosmic X-ray Background. A strong correlation with radio orientation constrains the geometry of the obscuring disk/torus to have a ~60 degree opening angle and ~12 degree Compton-thick cross-section. The deduced ~50% obscured fraction of the population contrasts with typical estimates of ~20% obscured in optically- and X-ray-selected high-luminosity samples. Once the primary nuclear emission is obscured, AGN X-ray spectra are frequently dominated by unobscured non-nuclear or scattered nuclear emission which cannot be distinguished from direct nuclear emission with a lower obscuration level unless high quality data is available. As a result, both the level of obscuration and the estimated instrinsic luminosities of highly-obscured AGN are likely to be significantly (*10-1000) underestimated for 25-50% of the population. This may explain the lower obscured fractions reported for optical and X-ray samples which have no independent measure of the AGN luminosity. Correcting AGN samples for these underestimated luminosities would result in

  3. The impact of electrode materials on 1/f noise in piezoelectric AlN contour mode resonators

    Directory of Open Access Journals (Sweden)

    Hoe Joon Kim

    2018-05-01

    Full Text Available This paper presents a detailed analysis on the impact of electrode materials and dimensions on flicker frequency (1/f noise in piezoelectric aluminum nitride (AlN contour mode resonators (CMRs. Flicker frequency noise is a fundamental noise mechanism present in any vibrating mechanical structure, whose sources are not generally well understood. 1 GHz AlN CMRs with three different top electrode materials (Al, Au, and Pt along with various electrode lengths and widths are fabricated to control the overall damping acting on the device. Specifically, the use of different electrode materials allows control of thermoelastic damping (TED, which is the dominant damping mechanism for high frequency AlN CMRs and largely depends on the thermal properties (i.e. thermal diffusivities and expansion coefficients of the metal electrode rather than the piezoelectric film. We have measured Q and 1/f noise of 68 resonators and the results show that 1/f noise decreases with increasing Q, with a power law dependence that is about 1/Q4. Interestingly, the noise level also depends on the type of electrode materials. Devices with Pt top electrode demonstrate the best noise performance. Our results help unveiling some of the sources of 1/f noise in these resonators, and indicate that a careful selection of the electrode material and dimensions could reduce 1/f noise not only in AlN-CMRs, but also in various classes of resonators, and thus enable ultra-low noise mechanical resonators for sensing and radio frequency applications.

  4. The Influence of Geography and Geology on Seismic Background Noise Levels Across the United States as Revealed by the Transportable Array

    Science.gov (United States)

    Anthony, R. E.; Ringler, A. T.; Holland, A. A.; Wilson, D. C.

    2017-12-01

    The EarthScope USArray Transportable Array (TA) has now covered the US with 3-component broadband seismometers at approximately 70 km station spacing and deployment durations of approximately 2 years. This unprecedented coverage, combined with high-quality and near homogenous installation techniques, offers a novel dataset in which to characterize spatially varying levels of background seismic noise across the United States. We present background noise maps in period bands of interest to earthquake and imaging seismology across the US (lower 48 states and Alaska). Early results from the contiguous 48 states demonstrate that ambient noise levels within the body wave period band (1-5 s) vary by > 20 dB (rel. 1 (m/s2)2/Hz) with the highest noise levels occurring at stations located within sedimentary basins and lowest within the mountain ranges of the Western US. Additionally, stations around the Great Lakes observe heightened noise levels in this band beyond the aforementioned basin amplification. We attribute this observation to local swell activity in the Great Lakes generating short-period microseism signals. This suggests that lake-generated microseisms may be a significant source of noise for Alaskan deployments situated in close proximity to lakes to facilitate float plane access. We further investigate how basin amplification and short-period lake microseism signals may noticeably impact detection and signal-to-noise of teleseismic body wave signals during certain time periods. At longer-periods (> 20 s), we generally observe larger noise levels on the horizontal components of stations situated in basins or on soft sediment, likely caused by locally induced tilt of the sensor. We will present similar analysis from the initial Alaska TA dataset to quantitatively assess how utilization of posthole sensors affects signal-to-noise for the long-period horizontal wavefield.

  5. Perencanaan dan analisis kehandalan sistem komunikasi radio microwave tampak pandang pada pita frekuensi 12750-13250 MHz [Planning and analysis of the reliability of line of sight microwave radio communication system on 12750-13250 MHz band

    Directory of Open Access Journals (Sweden)

    Ahmad Hasyim

    2016-12-01

    Full Text Available Propagasi gelombang radio dapat diartikan sebagai proses perambatan gelombang radio dari pemancar ke penerima. Gelombang ini akan merambat melalui udara bebas menuju antena penerima dan mengalami redaman di sepanjang lintansannya,  redaman perangkat dan saluran transmisi, sehingga ketika sampai di antena penerima, energi sinyal sudah sangat lemah. Line of sight    (LOS merupakan salah satu jenis propagasi di mana diantara stasiun pengirim dan stasiun penerima  tidak terdapat penghalang. Kendala geografis dan kelengkungan bumi menyebabkan adanya keterbatasan untuk transmisi line of sight, namun masalah ini secara umum dapat dikurangi melalui perencanaan, perhitungan dan penggunaan teknologi tambahan. Dalam perencanaan sistem komunikasi radio, kinerja LOS perlu direncanakan cadangan daya akibat fluktuasi sinyal serta analisis kehandalannya. Sistem radio gelombang mikro digital antar titik yang menggunakan  frekuensi 13 GHz dengan modulasi 16 QAM, bit rate 140 MBps,dan  noise figure 0,7 dB memerlukan daya pancar -4,488 dBm, fading margin sebesar 85,51 dB dan kehandalannya sebesar 99,9999999%.*****Radio wave propagation can be defined as the process of propagation of radio waves from the transmitter to the receiver. These waves will propagate through free air towards the receiver antena with experienced curbs along the tracks, so when it arrive at the receiver antena, the signal energy is very slow. Line of sight (LOS is one kind of propagation where no obstacles found between the transmitter and the receiver station. Geographical constraints and the curvature of the earth bring limitations to the line of sight transmission, but this problem can generally be reduced through planning, calculation and use of additional technologies. In a radio communication system planning, LOS performance needs to be planned caused by signal fluctuations and reliability. Digital microwave point to point radio systems using 13 GHz of spectrum, 16 QAM of

  6. Radio and γ -Ray Variability in the BL Lac PKS 0219−164: Detection of Quasi-periodic Oscillations in the Radio Light Curve

    Energy Technology Data Exchange (ETDEWEB)

    Bhatta, Gopal, E-mail: gopalbhatta716@gmail.com [Astronomical Observatory of the Jagiellonian University, ul. Orla 171, 30-244 Kraków (Poland); Mt. Suhora Observatory, Pedagogical University, ul. Podchorazych 2, 30-084 Kraków (Poland)

    2017-09-20

    In this work, we explore the long-term variability properties of the blazar PKS 0219−164 in the radio and the γ -ray regime, utilizing the OVRO 15 GHz and the Fermi /LAT observations from the period 2008–2017. We found that γ -ray emission is more variable than the radio emission implying that γ -ray emission possibly originated in more compact regions while the radio emission represented continuum emission from the large-scale jets. Also, in the γ -ray, the source exhibited spectral variability, characterized by the softer-when-brighter trend, a less frequently observed feature in the high-energy emission by BL Lacs. In radio, using Lomb–Scargle periodogram and weighted wavelet z -transform, we detected a strong signal of quasi-periodic oscillation (QPO) with a periodicity of 270 ± 26 days with possible harmonics of 550 ± 42 and 1150 ± 157 day periods. At a time when detections of QPOs in blazars are still under debate, the observed QPO with high statistical significance (∼97%–99% global significance over underlying red-noise processes) and persistent over nearly 10 oscillations could make one of the strongest cases for the detection of QPOs in blazar light curves. We discuss various blazar models that might lead to the γ -ray and radio variability, QPO, and the achromatic behavior seen in the high-energy emission from the source.

  7. Aircrafts' taxi noise. Sound power level and directivity frequency band results

    NARCIS (Netherlands)

    Asensio, C.; Pavón, I.; Ruiz, M.; Pagan Munoz, Raul; Recuero, M.

    2009-01-01

    When noise mapping airports, the main noise sources are take offs and landings. But aircrafts' taxi noise can also be important, and should be considered, for instance when there are residential buildings near the airport's terminal. Main prediction tools, like Integrated Noise Model (INM), do not

  8. Changing noise levels in a high CO2/lower pH ocean

    Science.gov (United States)

    Brewer, P. G.; Hester, K. C.; Peltzer, E. T.; Kirkwood, W. J.

    2008-12-01

    We show that ocean acidification from fossil fuel CO2 invasion and from increased respiration/reduced ventilation, has significantly reduced ocean sound absorption and thus increased ocean noise levels in the kHz frequency range. Below 10 kHz, sound absorption occurs due to well known chemical relaxations in the B(OH)3/B(OH)4- and HCO3-/CO32- systems. The pH dependence of these chemical relaxations results in decreased sound absorption (α = dB/km) as the ocean becomes more acidic from increased CO2 levels. The scale of surface ocean pH change today from the +105 ppmv change in atmospheric CO2 is about - 0.12 pH, resulting in frequency dependent decreases in sound absorption that now exceed 12% over pre- industrial. Under reasonable projections of future fossil fuel CO2 emissions and other sources a pH change of 0.3 units or more can be anticipated by mid-century, resulting in a decrease in α by almost 40%. Increases in water temperature have a smaller effect but also contribute to decreased sound absorption. Combining a lowering of 0.3 pH units with an increase of 3°C, α will decrease further to almost 45%. Ambient noise levels in the ocean within the auditory range critical for environmental, military, and economic interests are set to increase significantly due to the combined effects of decreased absorption and increasing sources from mankind's activities. Incorporation of sound absorption in modeling future ocean scenarios (R. Zeebe, personal communication) and long-term monitoring possibly with the aid of modern cabled observatories can give insights in how ocean noise will continue to change and its effect on groups such as marine mammals which communicate in the affected frequency range.

  9. Rydberg-atom based radio-frequency electrometry using frequency modulation spectroscopy in room temperature vapor cells.

    Science.gov (United States)

    Kumar, Santosh; Fan, Haoquan; Kübler, Harald; Jahangiri, Akbar J; Shaffer, James P

    2017-04-17

    Rydberg atom-based electrometry enables traceable electric field measurements with high sensitivity over a large frequency range, from gigahertz to terahertz. Such measurements are particularly useful for the calibration of radio frequency and terahertz devices, as well as other applications like near field imaging of electric fields. We utilize frequency modulated spectroscopy with active control of residual amplitude modulation to improve the signal to noise ratio of the optical readout of Rydberg atom-based radio frequency electrometry. Matched filtering of the signal is also implemented. Although we have reached similarly, high sensitivity with other read-out methods, frequency modulated spectroscopy is advantageous because it is well-suited for building a compact, portable sensor. In the current experiment, ∼3 µV cm-1 Hz-1/2 sensitivity is achieved and is found to be photon shot noise limited.

  10. Background noise levels and correlation with ship traffic in the Gulf of Catania

    Science.gov (United States)

    Viola, Salvatore; Buscaino, Giuseppa; Caruso, Francesco; Chierici, Francesco; Embriaco, Davide; Favali, Paolo; Giovanetti, Gabriele; Grammauta, Roasario; Larosa, Giuseppina; Pavan, Gianni; Pellegrino, Carmelo; Pulvirenti, Sara; Riccobene, Giorgio; Sciacca, Virginia; Simeone, Francesco; Beranzoli, Laura; Marinaro, Giuditta

    2015-04-01

    In the last decades the growing interest in the evaluation of the underwater acoustic noise for studies in the fields of geology, biology and high-energy physics is driving the scientific community to collaborate towards a multidisciplinary approach to the topic. In June 2012 in the framework of the European project EMSO, a multidisciplinary underwater observatory, named NEMO-SN1, was installed 25 km off-shore the port of Catania, at a depth of 2100 m and operated until May 2013 by INFN (Istituto Nazionale di Fisica Nucleare) and INGV (Istituto Nazionale di Geofisica e Vulcanologia). NEMO-SN1 hosted aboard geophysical, oceanographic and acoustic sensors: among these a seismic hydrophone model SMID DT-405D(V). In this work, conducted within the activity of the SMO project, the results on the evaluation of the underwater acoustic pollution in the Gulf of Catania through SMID DT-405D(V) recordings are presented. The seismic hydrophone provided a data set of about 11 months of continuous (24/7) recordings. Underwater sounds have been continuously digitized at a sampling frequency of 2 kHz and the acquired data have been stored in 10min long files for off-line analysis. To describe one-year background noise levels, the mean integrated acoustic noise was measured every second (sampling frequency 2000, NFFT 2048) in the 1/3 octave bands with centre frequency 63 Hz and for each 10 minutes-long file the 5th, the 50th and the 98th percentiles were calculated. Measured noise was correlated with the shipping traffic in the area, thanks to the data provided by an AIS receiver installed at the INFN-Laboratori Nazionali del Sud. An acoustic noise increment was measured in coincidence with the passing of crafts in the area and it was possible to identify the characteristic spectrum of each ship. A simple model for the estimation of the acoustic noise induced by the ships passing through the area was developed. The model was applied by using AIS data acquired during the operation

  11. Longitudinal changes in hearing threshold levels of noise-exposed construction workers

    NARCIS (Netherlands)

    Leensen, Monique C. J.; Dreschler, Wouter A.

    2015-01-01

    Longitudinal analysis of audiometric data of a large population of noise-exposed workers provides insight into the development of noise-induced hearing loss (NIHL) as a function of noise exposure and age, particularly during the first decade of noise exposure. Data of pure-tone audiometry of 17,930

  12. Noise characterization of oil and gas operations.

    Science.gov (United States)

    Radtke, Cameron; Autenrieth, Daniel A; Lipsey, Tiffany; Brazile, William J

    2017-08-01

    In cooperation with The Colorado Oil and Gas Conservation Commission, researchers at Colorado State University performed area noise monitoring at 23 oil and gas sites throughout Northern Colorado. The goals of this study were to: (1) measure and compare the noise levels for the different phases of oil and gas development sites; (2) evaluate the effectiveness of noise barriers; and (3) determine if noise levels exceeded the Colorado Oil and Gas Conservation Commission noise limits. The four phases of oil and gas development include drilling, hydraulic fracturing, completion and production. Noise measurements were collected using the A- and C-weighted sound scales. Octave band analysis was also performed to characterize the frequency spectra of the noise measurements.  Noise measurements were collected using noise dosimeters and a hand-held sound-level meter at specified distances from the development sites in each cardinal direction. At 350 ft (107 m), drilling, hydraulic fracturing, and completion sites without noise barriers exceeded the maximum permissible noise levels for residential and commercial zones (55 dBA and 60 dBA, respectively). In addition, drilling and hydraulic fracturing sites with noise barriers exceeded the maximum permissible noise level for residential zones (55 dBA). However, during drilling, hydraulic fracturing, and completion operations, oil producers are allowed an exception to the noise permissible limits in that they only must comply with the industrial noise limit (80 dBA). It is stated in Rule 604.c.(2)A. that: "Operations involving pipeline or gas facility installation or maintenance, the use of a drilling rig, completion rig, workover rig, or stimulation is subject to the maximum permissible noise levels for industrial zones (80dBA)." [8] Production sites were within the Colorado Oil and Gas Conservation Commission permissible noise level criteria for all zones. At 350 ft (107 m) from the noise source, all drilling

  13. The Radio Synchrotron Background: Conference Summary and Report

    Science.gov (United States)

    Singal, J.; Haider, J.; Ajello, M.; Ballantyne, D. R.; Bunn, E.; Condon, J.; Dowell, J.; Fixsen, D.; Fornengo, N.; Harms, B.; Holder, G.; Jones, E.; Kellermann, K.; Kogut, A.; Linden, T.; Monsalve, R.; Mertsch, P.; Murphy, E.; Orlando, E.; Regis, M.; Scott, D.; Vernstrom, T.; Xu, L.

    2018-03-01

    We summarize the radio synchrotron background workshop that took place 2017 July 19–21 at the University of Richmond. This first scientific meeting dedicated to the topic was convened because current measurements of the diffuse radio monopole reveal a surface brightness that is several times higher than can be straightforwardly explained by known Galactic and extragalactic sources and processes, rendering it by far the least well understood photon background at present. It was the conclusion of a majority of the participants that the radio monopole level is at or near that reported by the ARCADE 2 experiment and inferred from several absolutely calibrated zero-level lower frequency radio measurements, and unanimously agreed that the production of this level of surface brightness, if confirmed, represents a major outstanding question in astrophysics. The workshop reached a consensus on the next priorities for investigations of the radio synchrotron background.

  14. Radio systems engineering a tutorial approach

    CERN Document Server

    Santos, Héctor J De Los; Ponte, Juan

    2015-01-01

    This book is intended for readers who already have knowledge of devices and circuits for radio-frequency (RF) and microwave communication and are ready to study the systems engineering-level aspects of modern radio communications systems. The authors provide a general overview of radio systems with their components, focusing on the analog parts of the system and their non-idealities. Based on the physical functionality of the various building blocks of a modern radio system, block parameters are derived, which allows the examination of their influence on the overall system performance. The dis

  15. Critical Low-Noise Technologies Being Developed for Engine Noise Reduction Systems Subproject

    Science.gov (United States)

    Grady, Joseph E.; Civinskas, Kestutis C.

    2004-01-01

    NASA's previous Advanced Subsonic Technology (AST) Noise Reduction Program delivered the initial technologies for meeting a 10-year goal of a 10-dB reduction in total aircraft system noise. Technology Readiness Levels achieved for the engine-noise-reduction technologies ranged from 4 (rig scale) to 6 (engine demonstration). The current Quiet Aircraft Technology (QAT) project is building on those AST accomplishments to achieve the additional noise reduction needed to meet the Aerospace Technology Enterprise's 10-year goal, again validated through a combination of laboratory rig and engine demonstration tests. In order to meet the Aerospace Technology Enterprise goal for future aircraft of a 50- reduction in the perceived noise level, reductions of 4 dB are needed in both fan and jet noise. The primary objectives of the Engine Noise Reduction Systems (ENRS) subproject are, therefore, to develop technologies to reduce both fan and jet noise by 4 dB, to demonstrate these technologies in engine tests, and to develop and experimentally validate Computational Aero Acoustics (CAA) computer codes that will improve our ability to predict engine noise.

  16. Tracking of Nonstationary Noise Based on Data-Driven Recursive Noise Power Estimation

    NARCIS (Netherlands)

    Erkelens, J.S.; Heusdens, R.

    2008-01-01

    This paper considers estimation of the noise spectral variance from speech signals contaminated by highly nonstationary noise sources. The method can accurately track fast changes in noise power level (up to about 10 dB/s). In each time frame, for each frequency bin, the noise variance estimate is

  17. Abstract Radio Resource Management Framework for System Level Simulations in LTE-A Systems

    DEFF Research Database (Denmark)

    Fotiadis, Panagiotis; Viering, Ingo; Zanier, Paolo

    2014-01-01

    This paper provides a simple mathematical model of different packet scheduling policies in Long Term Evolution- Advanced (LTE-A) systems, by investigating the performance of Proportional Fair (PF) and the generalized cross-Component Carrier scheduler from a theoretical perspective. For that purpose......, an abstract Radio Resource Management (RRM) framework has been developed and tested for different ratios of users with Carrier Aggregation (CA) capabilities. The conducted system level simulations confirm that the proposed model can satisfactorily capture the main properties of the aforementioned scheduling...

  18. Neural indices of phonemic discrimination and sentence-level speech intelligibility in quiet and noise: A P3 study.

    Science.gov (United States)

    Koerner, Tess K; Zhang, Yang; Nelson, Peggy B; Wang, Boxiang; Zou, Hui

    2017-07-01

    This study examined how speech babble noise differentially affected the auditory P3 responses and the associated neural oscillatory activities for consonant and vowel discrimination in relation to segmental- and sentence-level speech perception in noise. The data were collected from 16 normal-hearing participants in a double-oddball paradigm that contained a consonant (/ba/ to /da/) and vowel (/ba/ to /bu/) change in quiet and noise (speech-babble background at a -3 dB signal-to-noise ratio) conditions. Time-frequency analysis was applied to obtain inter-trial phase coherence (ITPC) and event-related spectral perturbation (ERSP) measures in delta, theta, and alpha frequency bands for the P3 response. Behavioral measures included percent correct phoneme detection and reaction time as well as percent correct IEEE sentence recognition in quiet and in noise. Linear mixed-effects models were applied to determine possible brain-behavior correlates. A significant noise-induced reduction in P3 amplitude was found, accompanied by significantly longer P3 latency and decreases in ITPC across all frequency bands of interest. There was a differential effect of noise on consonant discrimination and vowel discrimination in both ERP and behavioral measures, such that noise impacted the detection of the consonant change more than the vowel change. The P3 amplitude and some of the ITPC and ERSP measures were significant predictors of speech perception at segmental- and sentence-levels across listening conditions and stimuli. These data demonstrate that the P3 response with its associated cortical oscillations represents a potential neurophysiological marker for speech perception in noise. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Radio quite site qualification for the Brasilian Southern Space Observatory by monitoring the low frequency 10-240 MHz Eletromagnetic Spectrum

    Science.gov (United States)

    da Rosa, Guilherme Simon; Schuch, Nelson Jorge; Espindola Antunes, Cassio; Gomes, Natanael

    The monitoring of the level of the radio interference in the Site of the Brazilian Southern Space Observatory - SSO/CRS/CIE/INPE - MCT, (29S, 53W), São Martinho da Serra, RS, in south a of Brazil, aims to gather spectral data for the Observatory's Site qualification as a radio quite site for installation of Radio Astronomy instrumentation, free of radio noise. The determination of the radio interference level is being conducted by using a spectrum analyzer and Omni directional antennas remotely controlled through a GPIB interface, via IEEE 488 bus, and programs written in C language. That procedure allows the scanning of the Electromagnetic Spectrum power over the examined frequency range from 10 - 240MHz. The methodology for these tests was to amplify the radio signal from the antenna by a block amplifier. Subsequently, the received signals are evaluated by the spectrum analyzer. A dedicated PC computer is used for the control and data acquisition, with the developed software. The data are instantly stored in digital format and remotely transferred via VNC software from the SSO-Observatory Site to the Radio Frequency and Telecommunication Laboratory at the Southern Regional Space Research Center - CRS/CIE/INPE - MCT, in Santa Maria, RS, for analysis and storage on the radio interference data base for long period. It is compared the SSO's Electromagnetic Spectrum data obtained since the beginning of the 1990's decade, before the Site constructions, with the current observed data. Some radio transmissions were found in the observed frequency range due to some local FMs, mostly between 93.5 MHz to 105.7 MHz, which were observed in previous monitoring. A good evidence of the site quality is the fact that the power of the Electromagnetic Spectrum is much lower than that measured at the Radio Frequency and Telecommunication Laboratory, in Santa Maria, RS, where the signals do not exceed -60 dB. On the Site of the SSO, due to the low power observed, weak radio signals

  20. Sea Ice Deformation State From Synthetic Aperture Radar Imagery - Part II: Effects of Spatial Resolution and Noise Level

    DEFF Research Database (Denmark)

    Dierking, Wolfgang; Dall, Jørgen

    2008-01-01

    C- and L-band airborne synthetic aperture radar (SAR) imagery acquired at like- and cross-polarization over sea ice under winter conditions is examined with the objective to study the discrimination between level ice and ice deformation features. High-resolution low-noise data were analysed...... in the first paper. In this second paper, the main topics are the effects of spatial resolution and signal-to-noise ratio. Airborne, high-resolution SAR scenes are used to generate a sequence of images with increasingly coarser spatial resolution from 5 m to 25 m, keeping the number of looks constant....... The signal-to-noise ratio is varied between typical noise levels for airborne imagery and satellite data. Areal fraction of deformed ice and average deformation distance are determined for each image product. At L-band, the retrieved values of the areal fraction get larger as the image resolution is degraded...

  1. Predetermining acceptable noise limits of EXAFS spectra in the limit of stochastic noise

    International Nuclear Information System (INIS)

    Hu, Yung-Jin; Booth, Corwin H

    2009-01-01

    The effect of stochastic noise on Extended X-ray Absorption Fine Structure (EXAFS) data measurement, analysis, and fitting is discussed. Stochastic noise reduces the ability to uniquely fit a calculated model to measured EXAFS data. Such noise can be reduced by common methods that increase the signal-to-noise ratio; however, these methods are not always practical. Therefore, predetermined, quantitative knowledge of the level of acceptable stochastic noise when fitting for a particular model system is essential in maximizing the chances of a successful EXAFS experiment and minimizing wasted beamtime. This paper outlines a method to estimate, through simulation, the acceptable level of stochastic noise in EXAFS spectra that still allows a successful test of a proposed model compound.

  2. A search for fast radio bursts associated with gamma-ray bursts

    International Nuclear Information System (INIS)

    Palaniswamy, Divya; Wayth, Randall B.; Trott, Cathryn M.; Tingay, Steven J.; Reynolds, Cormac; McCallum, Jamie N.

    2014-01-01

    The detection of seven fast radio bursts (FRBs) has recently been reported. FRBs are short duration (∼1 ms), highly dispersed radio pulses from astronomical sources. The physical interpretation for the FRBs remains unclear but is thought to involve highly compact objects at cosmological distance. It has been suggested that a fraction of FRBs could be physically associated with gamma-ray bursts (GRBs). Recent radio observations of GRBs have reported the detection of two highly dispersed short duration radio pulses using a 12 m radio telescope at 1.4 GHz. Motivated by this result, we have performed a systematic and sensitive search for FRBs associated with GRBs. We have observed five GRBs at 2.3 GHz using a 26 m radio telescope located at the Mount Pleasant Radio Observatory, Hobart. The radio telescope was automated to rapidly respond to Gamma-ray Coordination Network notifications from the Swift satellite and slew to the GRB position within ∼140 s. The data were searched for pulses up to 5000 pc cm –3 in dispersion measure and pulse widths ranging from 640 μs to 25.60 ms. We did not detect any events ≥6σ. An in depth statistical analysis of our data shows that events detected above 5σ are consistent with thermal noise fluctuations only. A joint analysis of our data with previous experiments shows that previously claimed detections of FRBs from GRBs are unlikely to be astrophysical. Our results are in line with the lack of consistency noted between the recently presented FRB event rates and GRB event rates.

  3. Application of the kurtosis statistic to the evaluation of the risk of hearing loss in workers exposed to high-level complex noise.

    Science.gov (United States)

    Zhao, Yi-Ming; Qiu, Wei; Zeng, Lin; Chen, Shan-Song; Cheng, Xiao-Ru; Davis, Robert I; Hamernik, Roger P

    2010-08-01

    Develop dose-response relations for two groups of industrial workers exposed to Gaussian or non-Gaussian (complex) types of continuous noises and to investigate what role, if any, the kurtosis statistic can play in the evaluation of industrial noise-induced hearing loss (NIHL). Audiometric and noise exposure data were acquired on a population (N = 195) of screened workers from a textile manufacturing plant and a metal fabrication facility located in Henan province of China. Thirty-two of the subjects were exposed to non-Gaussian (non-G) noise and 163 were exposed to a Gaussian (G) continuous noise. Each subject was given a general physical and an otologic examination. Hearing threshold levels (0.5-8.0 kHz) were age adjusted (ISI-1999) and the prevalence of NIHL at 3, 4, or 6 kHz was determined. The kurtosis metric, which is sensitive to the peak and temporal characteristics of a noise, was introduced into the calculation of the cumulative noise exposure metric. Using the prevalence of hearing loss and the cumulative noise exposure metric, a dose-response relation for the G and non-G noise-exposed groups was constructed. An analysis of the noise environments in the two plants showed that the noise exposures in the textile plant were of a Gaussian type with an Leq(A)8hr that varied from 96 to 105 dB whereas the exposures in the metal fabrication facility with an Leq(A)8hr = 95 dB were of a non-G type containing high levels (up to 125 dB peak SPL) of impact noise. The kurtosis statistic was used to quantify the deviation of the non-G noise environment from the Gaussian. The dose-response relation for the non-G noise-exposed subjects showed a higher prevalence of hearing loss for a comparable cumulative noise exposure than did the G noise-exposed subjects. By introducing the kurtosis variable into the temporal component of the cumulative noise exposure calculation, the two dose-response curves could be made to overlap, essentially yielding an equivalent noise

  4. Increased noise levels have different impacts on the anti-predator behaviour of two sympatric fish species.

    Directory of Open Access Journals (Sweden)

    Irene K Voellmy

    Full Text Available Animals must avoid predation to survive and reproduce, and there is increasing evidence that man-made (anthropogenic factors can influence predator-prey relationships. Anthropogenic noise has been shown to have a variety of effects on many species, but work investigating the impact on anti-predator behaviour is rare. In this laboratory study, we examined how additional noise (playback of field recordings of a ship passing through a harbour, compared with control conditions (playback of recordings from the same harbours without ship noise, affected responses to a visual predatory stimulus. We compared the anti-predator behaviour of two sympatric fish species, the three-spined stickleback (Gasterosteus aculeatus and the European minnow (Phoxinus phoxinus, which share similar feeding and predator ecologies, but differ in their body armour. Effects of additional-noise playbacks differed between species: sticklebacks responded significantly more quickly to the visual predatory stimulus during additional-noise playbacks than during control conditions, while minnows exhibited no significant change in their response latency. Our results suggest that elevated noise levels have the potential to affect anti-predator behaviour of different species in different ways. Future field-based experiments are needed to confirm whether this effect and the interspecific difference exist in relation to real-world noise sources, and to determine survival and population consequences.

  5. A study on the contribution of body vibrations to the vibratory sensation induced by high-level, complex low-frequency noise

    Directory of Open Access Journals (Sweden)

    Yukio Takahashi

    2011-01-01

    Full Text Available To investigate the contribution of body vibrations to the vibratory sensation induced by high-level, complex low-frequency noise, we conducted two experiments. In Experiment 1, eight male subjects were exposed to seven types of low-frequency noise stimuli: two pure tones [a 31.5-Hz, 100-dB(SPL tone and a 50-Hz, 100-dB(SPL tone] and five complex noises composed of the pure tones. For the complex noise stimuli, the sound pressure level of one tonal component was 100 dB(SPL and that of another one was either 90, 95, or 100 dB(SPL. Vibration induced on the body surface was measured at five locations, and the correlation with the subjective rating of the vibratory sensation at each site of measurement was examined. In Experiment 2, the correlation between the body surface vibration and the vibratory sensation was similarly examined using seven types of noise stimuli composed of a 25-Hz tone and a 50-Hz tone. In both the experiments, we found that at the chest and the abdomen, the rating of the vibratory sensation was in close correlation with the vibration acceleration level (VAL of the body surface vibration measured at each corresponding location. This was consistent with our previous results and suggested that at the trunk of the body (the chest and the abdomen, the mechanoreception of body vibrations plays an important role in the experience of the vibratory sensation in persons exposed to high-level low-frequency noise. At the head, however, no close correlation was found between the rating of the vibratory sensation and the VAL of body surface vibration. This suggested that at the head, the perceptual mechanisms of vibration induced by high-level low-frequency noise were different from those in the trunk of the body.

  6. Audience noise in concert halls during musical performances

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Marie, Pierre; Brunskog, Jonas

    2012-01-01

    functions of the sound pressure levels were obtained in octave bands, which were fitted with three Gaussian distribution curves. The Gaussian distribution curve with the lowest mean value corresponds to a mixture of the technical background noise and audience generated noise, which is named the mixed...... background noise. Finally, the audience noise distribution is extracted by energy subtraction of the technical background noise levels measured in an empty condition from the mixed background noise levels. As a single index, L-90 of the audience noise distribution is named the audience noise level. Empirical...... prediction models were made using the four orchestra concert halls, revealing that the audience noise level is significantly correlated with the technical background noise level. It is therefore concluded that a relaxation of the current background noise recommendations for concert halls is not recommended...

  7. Audience noise in concert halls during musical performances

    DEFF Research Database (Denmark)

    Marie, Pierre; Jeong, Cheol-Ho; Brunskog, Jonas

    2012-01-01

    functions of the sound pressure levels were obtained in octave bands, which were fitted with three Gaussian distribution curves. The Gaussian distribution curve with the lowest mean value corresponds to a mixture of the technical background noise and audience generated noise, which is named the mixed...... background noise. Finally, the audience noise distribution is extracted by energy subtraction of the technical background noise levels measured in an empty condition from the mixed background noise levels. As a single index, L90 of the audience noise distribution is named the audience noise level. Empirical...... prediction models were made using the four orchestra concert halls, revealing that the audience noise level is significantly correlated with the technical background noise level. It is therefore concluded that a relaxation of the current background noise recommendations for concert halls is not recommended....

  8. Music, radio and mediatization

    DEFF Research Database (Denmark)

    Michelsen, Morten; Krogh, Mads

    2016-01-01

    of mediatization where media as such seem to be ascribed agency. Instead, we consider historical accounts of music–radio in order to address the complex nonlinearity of concrete processes of mediatization as they take place in the multiple meetings between a decentred notion of radio and musical life.......Mediatization has become a key concept for understanding the relations between media and other cultural and social fields. Contributing to the discussions related to the concept of mediatization, this article discusses how practices of radio and music(al life) influence each other. We follow Deacon......’s and Stanyer’s advice to supplement the concept of mediatization with ‘a series of additional concepts at lower levels of abstraction’ and suggest, in this respect, the notion of heterogeneous milieus of music–radio. Hereby, we turn away from the all-encompassing perspectives related to the concept...

  9. THE BRAKING INDEX OF A RADIO-QUIET GAMMA-RAY PULSAR

    Energy Technology Data Exchange (ETDEWEB)

    Clark, C. J.; Pletsch, H. J.; Allen, B.; Aulbert, C.; Beer, C.; Bock, O.; Cuéllar, A.; Eggenstein, H. B.; Fehrmann, H.; Machenschalk, B.; Nieder, L. [Albert-Einstein-Institut, Max-Planck-Institut für Gravitationsphysik, D-30167 Hannover (Germany); Wu, J.; Guillemot, L.; Kramer, M. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Camilo, F. [SKA South Africa, Pinelands, 7405 (South Africa); Johnson, T. J. [College of Science, George Mason University, Fairfax, VA 22030 (United States); Kerr, M., E-mail: colin.clark@aei.mpg.de [CSIRO Astronomy and Space Science, Australia Telescope National Facility, Epping, NSW 1710 (Australia)

    2016-11-20

    We report the discovery and timing measurements of PSR J1208−6238, a young and highly magnetized gamma-ray pulsar, with a spin period of 440 ms. The pulsar was discovered in gamma-ray photon data from the Fermi Large Area Telescope (LAT) during a blind-search survey of unidentified LAT sources, running on the distributed volunteer computing system Einstein@Home . No radio pulsations were detected in dedicated follow-up searches with the Parkes radio telescope, with a flux density upper limit at 1369 MHz of 30 μ Jy. By timing this pulsar’s gamma-ray pulsations, we measure its braking index over five years of LAT observations to be n = 2.598 ± 0.001 ± 0.1, where the first uncertainty is statistical and the second estimates the bias due to timing noise. Assuming its braking index has been similar since birth, the pulsar has an estimated age of around 2700 years, making it the youngest pulsar to be found in a blind search of gamma-ray data and the youngest known radio-quiet gamma-ray pulsar. Despite its young age, the pulsar is not associated with any known supernova remnant or pulsar wind nebula. The pulsar’s inferred dipolar surface magnetic field strength is 3.8 × 10{sup 13} G, almost 90% of the quantum-critical level. We investigate some potential physical causes of the braking index deviating from the simple dipole model but find that LAT data covering a longer time interval will be necessary to distinguish between these.

  10. THE BRAKING INDEX OF A RADIO-QUIET GAMMA-RAY PULSAR

    International Nuclear Information System (INIS)

    Clark, C. J.; Pletsch, H. J.; Allen, B.; Aulbert, C.; Beer, C.; Bock, O.; Cuéllar, A.; Eggenstein, H. B.; Fehrmann, H.; Machenschalk, B.; Nieder, L.; Wu, J.; Guillemot, L.; Kramer, M.; Camilo, F.; Johnson, T. J.; Kerr, M.

    2016-01-01

    We report the discovery and timing measurements of PSR J1208−6238, a young and highly magnetized gamma-ray pulsar, with a spin period of 440 ms. The pulsar was discovered in gamma-ray photon data from the Fermi Large Area Telescope (LAT) during a blind-search survey of unidentified LAT sources, running on the distributed volunteer computing system Einstein@Home . No radio pulsations were detected in dedicated follow-up searches with the Parkes radio telescope, with a flux density upper limit at 1369 MHz of 30 μ Jy. By timing this pulsar’s gamma-ray pulsations, we measure its braking index over five years of LAT observations to be n = 2.598 ± 0.001 ± 0.1, where the first uncertainty is statistical and the second estimates the bias due to timing noise. Assuming its braking index has been similar since birth, the pulsar has an estimated age of around 2700 years, making it the youngest pulsar to be found in a blind search of gamma-ray data and the youngest known radio-quiet gamma-ray pulsar. Despite its young age, the pulsar is not associated with any known supernova remnant or pulsar wind nebula. The pulsar’s inferred dipolar surface magnetic field strength is 3.8 × 10 13 G, almost 90% of the quantum-critical level. We investigate some potential physical causes of the braking index deviating from the simple dipole model but find that LAT data covering a longer time interval will be necessary to distinguish between these.

  11. Electronic noise in CT detectors: Impact on image noise and artifacts.

    Science.gov (United States)

    Duan, Xinhui; Wang, Jia; Leng, Shuai; Schmidt, Bernhard; Allmendinger, Thomas; Grant, Katharine; Flohr, Thomas; McCollough, Cynthia H

    2013-10-01

    The objective of our study was to evaluate in phantoms the differences in CT image noise and artifact level between two types of commercial CT detectors: one with distributed electronics (conventional) and one with integrated electronics intended to decrease system electronic noise. Cylindric water phantoms of 20, 30, and 40 cm in diameter were scanned using two CT scanners, one equipped with integrated detector electronics and one with distributed detector electronics. All other scanning parameters were identical. Scans were acquired at four tube potentials and 10 tube currents. Semianthropomorphic phantoms were scanned to mimic the shoulder and abdominal regions. Images of two patients were also selected to show the clinical values of the integrated detector. Reduction of image noise with the integrated detector depended on phantom size, tube potential, and tube current. Scans that had low detected signal had the greatest reductions in noise, up to 40% for a 30-cm phantom scanned using 80 kV. This noise reduction translated into up to 50% in dose reduction to achieve equivalent image noise. Streak artifacts through regions of high attenuation were reduced by up to 45% on scans obtained using the integrated detector. Patient images also showed superior image quality for the integrated detector. For the same applied radiation level, the use of integrated electronics in a CT detector showed a substantially reduced level of electronic noise, resulting in reductions in image noise and artifacts, compared with detectors having distributed electronics.

  12. Drone noise

    Science.gov (United States)

    Tinney, Charles; Sirohi, Jayant; University of Texas at Austin Team

    2017-11-01

    A basic understanding of the noise produced by single and multirotor drones operating at static thrust conditions is presented. This work acts as an extension to previous efforts conducted at The University of Texas at Austin (Tinney et al. 2017, AHS Forum 73). Propeller diameters ranging from 8 inch to 12 inch are examined for configurations comprising an isolated rotor, a quadcopter configuration and a hexacopter configuration, and with a constant drone pitch of 2.25. An azimuthal array of half-inch microphones, placed between 2 and 3 hub-center diameters from the drone center, are used to assess the acoustic near-field. Thrust levels, acquired using a six degree-of-freedom load cell, are then used to correlate acoustic noise levels to aerodynamic performance for each drone configuration. The findings reveal a nearly logarithmic increase in noise with increasing thrust. However, for the same thrust condition, considerable noise reduction is achieved by increasing the number of propeller blades thereby reducing the blade passage frequency and both the thickness and loading noise sources that accompany it.

  13. AAFE man-made noise experiment project. Volume 1: Introduction experiment definition and requirements

    Science.gov (United States)

    1974-01-01

    An experiment was conducted to measure and map the man-made radio frequency emanations which exist at earth orbital altitudes. The major objectives of the program are to develop a complete conceptual experiment and developmental hardware for the collection and processing of data required to produce meaningful statistics on man-made noise level variations as functions of time, frequency, and geographic location. A wide dispersion measurement receiver mounted in a spacecraft operating in a specialized orbit is used to obtain the data. A summary of the experiment designs goals and constraints is provided. The recommended orbit for the spacecraft is defined. The characteristics of the receiver and the antennas are analyzed.

  14. Noise levels of toys for children between the ages of birth and 3 ...

    African Journals Online (AJOL)

    Design. A quantitative, non-experimental, descriptive research design was employed for this study. Subjects. Twenty toys, 5 from each of 4 categories, were chosen from a popular toy store in ... the noise levels of toys on the packaging and adherence to ASTM International standards for toy manufacturers are recommended.

  15. Noise Pollution in Turkish Elementary Schools: Evaluation of Noise Pollution Awareness and Sensitivity Training

    Science.gov (United States)

    Bulunuz, Nermin

    2014-01-01

    This study investigates noise pollution levels in two elementary schools. Also, "noise level awareness and sensitivity training" was given for reducing noise pollution, and the effects and results of this training were evaluated. "Sensitivity" training was given to 611 students and 48 teachers in a private and a public school.…

  16. Estimation of background noise level on seismic station using statistical analysis for improved analysis accuracy

    Science.gov (United States)

    Han, S. M.; Hahm, I.

    2015-12-01

    We evaluated the background noise level of seismic stations in order to collect the observation data of high quality and produce accurate seismic information. Determining of the background noise level was used PSD (Power Spectral Density) method by McNamara and Buland (2004) in this study. This method that used long-term data is influenced by not only innate electronic noise of sensor and a pulse wave resulting from stabilizing but also missing data and controlled by the specified frequency which is affected by the irregular signals without site characteristics. It is hard and inefficient to implement process that filters out the abnormal signal within the automated system. To solve these problems, we devised a method for extracting the data which normally distributed with 90 to 99% confidence intervals at each period. The availability of the method was verified using 62-seismic stations with broadband and short-period sensors operated by the KMA (Korea Meteorological Administration). Evaluation standards were NHNM (New High Noise Model) and NLNM (New Low Noise Model) published by the USGS (United States Geological Survey). It was designed based on the western United States. However, Korean Peninsula surrounded by the ocean on three sides has a complicated geological structure and a high population density. So, we re-designed an appropriate model in Korean peninsula by statistically combined result. The important feature is that secondary-microseism peak appeared at a higher frequency band. Acknowledgements: This research was carried out as a part of "Research for the Meteorological and Earthquake Observation Technology and Its Application" supported by the 2015 National Institute of Meteorological Research (NIMR) in the Korea Meteorological Administration.

  17. Cavitation noise from butterfly valves

    International Nuclear Information System (INIS)

    Rahmeyer, W.J.

    1982-01-01

    Cavitation in valves can produce levels of intense noise. It is possible to mathematically express a limit for a design level of cavitation noise in terms of the cavitation parameter sigma. Using the cavitation parameter or limit, it is then possible to calculate the flow conditions at which a design level of cavitation noise will occur. However, the intensity of cavitation increases with the upstream pressure and valve size at a constant sigma. Therefore, it is necessary to derive equations to correct or scale the cavitation limit for the effects of different upstream pressures and valve sizes. The following paper discusses and presents experimental data for the caviation noise limit as well as the cavitation limits of incipient, critical, incipient damage, and choking cavitation for butterfly valves. The main emphasis is on the design limit of caviation noise, and a noise level of 85 decibels was selected as the noise limit. Tables of data and scaling exponents are included for applying the design limits for the effects of upstream pressure and valve size. (orig.)

  18. Radio as the Voice of God: Peace and Tolerance Radio Programming’s Impact on Norms

    Directory of Open Access Journals (Sweden)

    Daniel P. Aldrich

    2012-12-01

    Full Text Available Observers have argued that radio programming can alter norms, especially through hate radio designed to increase animosity between groups. This article tests whether or not radio programming under the Countering Violent Extremism (CVE policy framework can reduce potential conflict and increase civic engagement and positive views of foreign nations. Data from surveys of more than 1,000 respondents in Mali, Chad, and Niger illuminate the ways in which peace and tolerance programming changed perspectives and altered behavior in statistically significant ways. Results show that individuals exposed to multi-level U.S. government programming were more likely to listen to peace and tolerance radio. Further, bivariate, multivariate regression, and propensity score matching techniques show that individuals who listened more regularly to such programs participated more frequently in civic activities and supported working with the West to combat terrorism (holding constant a number of potential confounding economic, demographic, and attitudinal factors. However, higher levels of radio listening had no measurable impact on opposition to the use of violence in the name of Islam or opposition to the imposition of Islamic law. Further, data indicate that women and men have responded to programming in measurably different ways. These mixed results have important implications for current and future “soft-side” programs for countering violent extremism.

  19. Road traffic noise: self-reported noise annoyance versus GIS modelled road traffic noise exposure.

    Science.gov (United States)

    Birk, Matthias; Ivina, Olga; von Klot, Stephanie; Babisch, Wolfgang; Heinrich, Joachim

    2011-11-01

    self-reported road traffic noise annoyance is commonly used in epidemiological studies for assessment of potential health effects. Alternatively, some studies have used geographic information system (GIS) modelled exposure to road traffic noise as an objective parameter. The aim of this study was to analyse the association between noise exposure due to neighbouring road traffic and the noise annoyance of adults, taking other determinants into consideration. parents of 951 Munich children from the two German birth cohorts GINIplus and LISAplus reported their annoyance due to road traffic noise at home. GIS modelled road traffic noise exposure (L(den), maximum within a 50 m buffer) from the noise map of the city of Munich was available for all families. GIS-based calculated distance to the closest major road (≥10,000 vehicles per day) and questionnaire based-information about family income, parental education and the type of the street of residence were explored for their potential influence. An ordered logit regression model was applied. The noise levels (L(den)) and the reported noise annoyance were compared with an established exposure-response function. the correlation between noise annoyance and noise exposure (L(den)) was fair (Spearman correlation r(s) = 0.37). The distance to a major road and the type of street were strong predictors for the noise annoyance. The annoyance modelled by the established exposure-response function and that estimated by the ordered logit model were moderately associated (Pearson's correlation r(p) = 0.50). road traffic noise annoyance was associated with GIS modelled neighbouring road traffic noise exposure (L(den)). The distance to a major road and the type of street were additional explanatory factors of the noise annoyance appraisal.

  20. Aircraft and background noise annoyance effects

    Science.gov (United States)

    Willshire, K. F.

    1984-01-01

    To investigate annoyance of multiple noise sources, two experiments were conducted. The first experiment, which used 48 subjects, was designed to establish annoyance-noise level functions for three community noise sources presented individually: jet aircraft flyovers, air conditioner, and traffic. The second experiment, which used 216 subjects, investigated the effects of background noise on aircraft annoyance as a function of noise level and spectrum shape; and the differences between overall, aircraft, and background noise annoyance. In both experiments, rated annoyance was the dependent measure. Results indicate that the slope of the linear relationship between annoyance and noise level for traffic is significantly different from that of flyover and air conditioner noise and that further research was justified to determine the influence of the two background noises on overall, aircraft, and background noise annoyance (e.g., experiment two). In experiment two, total noise exposure, signal-to-noise ratio, and background source type were found to have effects on all three types of annoyance. Thus, both signal-to-noise ratio, and the background source must be considered when trying to determine community response to combined noise sources.

  1. Recommendation of maximum allowable noise levels for offshore wind power systems; Empfehlung von Laermschutzwerten bei der Errichtung von Offshore-Windenergieanlagen (OWEA)

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Stefanie [Umweltbundesamt, Dessau-Rosslau (Germany). Fachgebiet II 2.3

    2011-05-15

    When offshore wind farms are constructed, every single pile is hammered into the sediment by a hydraulic hammer. Noise levels at Horns Reef wind farm were in the range of 235 dB. The noise may cause damage to the auditory system of marine mammals. The Federal Environmental Office therefore recommends the definition of maximum permissible noise levels. Further, care should be taken that no marine mammals are found in the immediate vicinity of the construction site. (AKB)

  2. Enhancing the management of the noise level using six sigma method: a case study on the machining industry

    Science.gov (United States)

    Rimantho, D.; Hanantya, M. W.

    2017-12-01

    The hearing disorder is caused by noises in the workplace, it has been a concern for numerous researchers. This study aims to improve the performance of the management of the noise level by applying the six sigma method. Data collection is done directly by using a sound level meter. In addition, several key informants also used in order to gather information related to the problem. The results showed the values of Cp and Cpk on the entire department are still below the recommended value. Moreover, the results also showed the potential failure (DPMO) approximately 115,260.6 and equivalent to the Sigma value is approximately 2.70. Furthermore, the highest value of the RPN in FMEA analysis is the workers not wear factor of earplug which is about 56. Thus, it is necessary to make enhancements to the process of managing the noise level in the framework of continuous improvement.

  3. The effect of hearing aid signal-processing schemes on acceptable noise levels: perception and prediction.

    Science.gov (United States)

    Wu, Yu-Hsiang; Stangl, Elizabeth

    2013-01-01

    The acceptable noise level (ANL) test determines the maximum noise level that an individual is willing to accept while listening to speech. The first objective of the present study was to systematically investigate the effect of wide dynamic range compression processing (WDRC), and its combined effect with digital noise reduction (DNR) and directional processing (DIR), on ANL. Because ANL represents the lowest signal-to-noise ratio (SNR) that a listener is willing to accept, the second objective was to examine whether the hearing aid output SNR could predict aided ANL across different combinations of hearing aid signal-processing schemes. Twenty-five adults with sensorineural hearing loss participated in the study. ANL was measured monaurally in two unaided and seven aided conditions, in which the status of the hearing aid processing schemes (enabled or disabled) and the location of noise (front or rear) were manipulated. The hearing aid output SNR was measured for each listener in each condition using a phase-inversion technique. The aided ANL was predicted by unaided ANL and hearing aid output SNR, under the assumption that the lowest acceptable SNR at the listener's eardrum is a constant across different ANL test conditions. Study results revealed that, on average, WDRC increased (worsened) ANL by 1.5 dB, while DNR and DIR decreased (improved) ANL by 1.1 and 2.8 dB, respectively. Because the effects of WDRC and DNR on ANL were opposite in direction but similar in magnitude, the ANL of linear/DNR-off was not significantly different from that of WDRC/DNR-on. The results further indicated that the pattern of ANL change across different aided conditions was consistent with the pattern of hearing aid output SNR change created by processing schemes. Compared with linear processing, WDRC creates a noisier sound image and makes listeners less willing to accept noise. However, this negative effect on noise acceptance can be offset by DNR, regardless of microphone mode

  4. Nanosecond-level time synchronization of autonomous radio detector stations for extensive air showers

    Science.gov (United States)

    The Pierre Auger Collaboration

    2016-01-01

    To exploit the full potential of radio measurements of cosmic-ray air showers at MHz frequencies, a detector timing synchronization within 1 ns is needed. Large distributed radio detector arrays such as the Auger Engineering Radio Array (AERA) rely on timing via the Global Positioning System (GPS) for the synchronization of individual detector station clocks. Unfortunately, GPS timing is expected to have an accuracy no better than about 5 ns. In practice, in particular in AERA, the GPS clocks exhibit drifts on the order of tens of ns. We developed a technique to correct for the GPS drifts, and an independent method is used to cross-check that indeed we reach a nanosecond-scale timing accuracy by this correction. First, we operate a ``beacon transmitter'' which emits defined sine waves detected by AERA antennas recorded within the physics data. The relative phasing of these sine waves can be used to correct for GPS clock drifts. In addition to this, we observe radio pulses emitted by commercial airplanes, the position of which we determine in real time from Automatic Dependent Surveillance Broadcasts intercepted with a software-defined radio. From the known source location and the measured arrival times of the pulses we determine relative timing offsets between radio detector stations. We demonstrate with a combined analysis that the two methods give a consistent timing calibration with an accuracy of 2 ns or better. Consequently, the beacon method alone can be used in the future to continuously determine and correct for GPS clock drifts in each individual event measured by AERA.

  5. Nanosecond-level time synchronization of autonomous radio detector stations for extensive air showers

    International Nuclear Information System (INIS)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E.J.; Al Samarai, I.; Albuquerque, I.F.M.; Allekotte, I.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.

    2016-01-01

    To exploit the full potential of radio measurements of cosmic-ray air showers at MHz frequencies, a detector timing synchronization within 1 ns is needed. Large distributed radio detector arrays such as the Auger Engineering Radio Array (AERA) rely on timing via the Global Positioning System (GPS) for the synchronization of individual detector station clocks. Unfortunately, GPS timing is expected to have an accuracy no better than about 5 ns. In practice, in particular in AERA, the GPS clocks exhibit drifts on the order of tens of ns. We developed a technique to correct for the GPS drifts, and an independent method is used to cross-check that indeed we reach a nanosecond-scale timing accuracy by this correction. First, we operate a ''beacon transmitter'' which emits defined sine waves detected by AERA antennas recorded within the physics data. The relative phasing of these sine waves can be used to correct for GPS clock drifts. In addition to this, we observe radio pulses emitted by commercial airplanes, the position of which we determine in real time from Automatic Dependent Surveillance Broadcasts intercepted with a software-defined radio. From the known source location and the measured arrival times of the pulses we determine relative timing offsets between radio detector stations. We demonstrate with a combined analysis that the two methods give a consistent timing calibration with an accuracy of 2 ns or better. Consequently, the beacon method alone can be used in the future to continuously determine and correct for GPS clock drifts in each individual event measured by AERA

  6. Triple play service under the impact of nonstationary noise in a DSL system: an Amazon approach

    Science.gov (United States)

    de Souza, Lamartine V.; Cardoso, Diego; Silva, Marcelino; Seruffo, Marcos; Francês, Carlos R. L.; Costa, João C. W. A.; Castro, Agostinho L. S.; Cavalcante, Gervásio; Rius i Riu, Jaume

    2007-09-01

    The Brazilian Amazon has sui generis characteristics that affect strongly the communication technologies, such as high humidity and temperature. These characteristics cause impact in the existent infrastructure, especially in twisted-pair copper lines. At the moment, new services are based on multimedia applications, as voice over internet protocol (VoIP), video on demand (VoD), and internet protocol television (IPTV). Such services use digital broadband networks such as ADSL2+ (Asymmetric Digital Subscriber Line) to transmit the data. Broadband services require data rates which can only be achieved by using relatively high spectrum frequencies. At high frequencies the DSL signal is more susceptible to external noise sources, such as radio frequency interference and impulsive noise. For this purpose, an experimental setup has been built at UFPA that consists of noise generator, traffic generator, real cables, modems and DSLAM (digital subscriber line access multiplexer). This paper aims at characterizing how the noise impacts on triple play services for a broadband system using a DSL loop on Amazon environment. The objective of the noise impact experimentation is to observe the behavior of a DSL system under more realistic but controlled line conditions. Metrics as lost packet, jitter, latency, and throughput are used to characterize the triple play service in a DSL loop under the noise impact. Through the real experiments and controlled loop conditions, this paper allow identify, from application level point of view, how robust DSL system is in respect to noise occurrence. Additionally, it is described a methodology for noise impact measurements using a DSL system.

  7. Noise annoyance from wind turbines a review

    International Nuclear Information System (INIS)

    Pedersen, Eja

    2003-08-01

    This study summarises present knowledge on noise perception and annoyances from wind turbines in areas were people live or spend recreation time. There are two main types of noise from a wind turbine: mechanical noise and aerodynamic noise. The aerodynamic noise emits from the rotor blades passing the air. It has a swishing character with a modulation that makes it noticeable from the background noise. This part of the wind turbine noise was found to be the most annoying. Field studies performed among people living in the vicinity of wind turbines showed that there was a correlation between sound pressure level and noise annoyance, but annoyance was also influenced by visual factors such as the attitude to wind turbines' impact on the landscape. Noise annoyance was found at lower sound pressure levels than in studies of annoyance from traffic noise. There is no scientific evidence that noise at levels created by wind turbines could cause health problems other than annoyance. No studies on noise from wind turbines in wilderness areas have been found, but the reaction to other noise sources such as aircraft have been studied. In recreational areas, the expectation of quietness is high among visitors, but wind turbines are, in contrary to aircraft, stationary and could be avoided by recreationists. The visual impact of wind turbines might though be the dominant source of annoyance. Regulations on noise from wind turbines are based on different principles. Some states, e.g. Denmark, have a special legislation concerning wind turbines, while others, like Sweden, have used recommendations originally developed for a different noise source. The noise level could either be absolute, as in Germany, or related to the background noise level as in France. This background noise level could be standardised, measured or related to wind speed

  8. Noise in strong laser-atom interactions: Phase telegraph noise

    International Nuclear Information System (INIS)

    Eberly, J.H.; Wodkiewicz, K.; Shore, B.W.

    1984-01-01

    We discuss strong laser-atom interactions that are subjected to jump-type (random telegraph) random-phase noise. Physically, the jumps may arise from laser fluctuations, from collisions of various kinds, or from other external forces. Our discussion is carried out in two stages. First, direct and partially heuristic calculations determine the laser spectrum and also give a third-order differential equation for the average inversion of a two-level atom on resonance. At this stage a number of general features of the interaction are able to be studied easily. The optical analog of motional narrowing, for example, is clearly predicted. Second, we show that the theory of generalized Poisson processes allows laser-atom interactions in the presence of random telegraph noise of all kinds (not only phase noise) to be treated systematically, by means of a master equation first used in the context of quantum optics by Burshtein. We use the Burshtein equation to obtain an exact expression for the two-level atom's steady-state resonance fluorescence spectrum, when the exciting laser exhibits phase telegraph noise. Some comparisons are made with results obtained from other noise models. Detailed treatments of the effects ofmly jumps, or as a model of finite laser bandwidth effects, in which the laser frequency exhibits random jumps. We show that these two types of frequency noise can be distinguished in light-scattering spectra. We also discuss examples which demonstrate both temporal and spectral motional narrowing, nonexponential correlations, and non-Lorentzian spectra. Its exact solubility in finite terms makes the frequency-telegraph noise model an attractive alternative to the white-noise Ornstein-Uhlenbeck frequency noise model which has been previously applied to laser-atom interactions

  9. Combat aircraft noise

    Science.gov (United States)

    Sgarbozza, M.; Depitre, A.

    1992-04-01

    A discussion of the characteristics and the noise levels of combat aircraft and of a transport aircraft in taking off and landing are presented. Some methods of noise reduction are discussed, including the following: operational anti-noise procedures; and concepts of future engines (silent post-combustion and variable cycle). Some measurement results concerning the noise generated in flight at great speeds and low altitude will also be examined. Finally, the protection of the environment of French air bases against noise will be described and the possibilities of regulation examined.

  10. Wideband Balun-LNA with Simultaneous Output Balancing, Noise-Canceling and Distortion-Canceling

    NARCIS (Netherlands)

    Blaakmeer, S.C.; Klumperink, Eric A.M.; Leenaerts, D.M.W.; Nauta, Bram

    2008-01-01

    An inductorless low-noise amplifier (LNA) with active balun is proposed for multi-standard radio applications between 100 MHz and 6 GHz. It exploits a combination of a common-gate (CGH) stage and an admittance-scaled common-source (CS) stage with replica biasing to maximize balanced operation, while

  11. The Mitigation of Radio Noise from External Sources at Receiving Sites

    Science.gov (United States)

    2007-05-01

    53 3.1.7 Underground Distribution Lines...available newer models were preferred for laboratory measurements of time- stable signals and noise. 9 An ELF Engineering Model 7200B 3-Axis... communications terminal was located about 1 km from an HF and VHF receiving site. The satellite terminal was equipped with an Uninterruptible Power Supply (UPS

  12. Influence of military low-level flight noise on the inner ear of guinea pigs. Der Einfluss von militaerischem Tieffluglaerm auf das Innenohr des Meerschweinchens

    Energy Technology Data Exchange (ETDEWEB)

    Gehrig, W.; Meyer, P.; Kuhl, K.D.; Schmidt, R.; Gruetzmacher, W. (Greifswald Univ. (Germany). HNO-Klinik); Ising, H. (BGA, Berlin (Germany). Inst. fuer Wasser-, Boden- und Lufthygiene); Ishi, K.; Merker, H.J. (Freie Univ. Berlin (Germany). Inst. fuer Anatomie)

    1992-03-01

    The influence of different rises in noise level and - in cases of the repeated passage of aircraft - the impact of varying intervals between the events was to be investigated. The experimental animals used were pigmented guinea pigs of 250 to 500 grammes body weight. The auditory thresholds were measured on the anaesthesized animals by derivation of the acoustically evoked brain stem potentials from the EEGs. For the noise exposure of the animals, two types of military low-level flight noise were used: one flight overhead with a rise in noise level of 7.5 dB/s, and a second one with 75 dB/s.-unlike other cases of damage to the inner ear through noise, the damage sustained in this case was not restricted to the basal convolution but was observed in all four cochlear convolutions. This suggests a particularity of the harmful effect of low-level flight noise, which it is planned to follow up in the future. (orig./MG).

  13. Noise-induced hearing loss: a recreational noise perspective.

    Science.gov (United States)

    Ivory, Robert; Kane, Rebecca; Diaz, Rodney C

    2014-10-01

    This review will discuss the real-world risk factors involved in noise-induced hearing loss as a result of common and popular recreational activities prone to mid and high levels of noise exposure. Although there are currently no interventional measures available to reverse or mitigate preexisting hearing loss from noise, we discuss the vital importance of hearing loss prevention from noise exposure avoidance and reduction. Despite a seeming understanding of the effects of noise exposure from various recreational activities and devices, a large percentage of the general public who is at risk of such noise-induced hearing loss still chooses to refrain from using hearing protection instruments. While occupational exposures pose the greatest traditional risk to hearing conservation in selected workers, recreational risk factors for noise-induced hearing loss may be more insidious in overall effect given the indifferent attitude of much of the general public and particularly our youths toward hearing protection during recreational activities. Active counseling regarding the consequences of excessive noise exposure and the potential benefits to hearing from usage of hearing protection instruments is critical to providing best possible care in the hearing health professions.

  14. Davis Canyon noise analysis: Revision 2

    International Nuclear Information System (INIS)

    1985-11-01

    A study was performed as part of the Civilian Radioactive Waste Management Program to quantify the level and effect of noise from the various major phases of development of the proposed potentially acceptable nuclear waste repository site at Davis Canyon, Utah. This report contains the results of a predictive noise level study for the site characterization, repository construction, and repository operational phases. Included herein are graphic representations of energy averaged sound levels, and of audibility levels representing impact zones expected during each phase. Sound levels from onsite and offsite activity including traffic on highways and railroad routes are presented in isopleth maps. A description of the Environmental Noise Prediction Model used for the study, the study basis and methodologies, and actual modeling data are provided. Noise and vibration levels from blasting are also predicted and evaluated. Protective noise criteria containing a margin of safety are used in relation to residences, schools, churches, noise-sensitive recreation areas, and noise-sensitive biological resources. Protective ground motion criteria for ruins and delicate rock formation in Canyonlands National Park and for human annoyance are used in the evaluation of blasting. The evaluations provide the basis for assessing the noise impacts from the related activities at the proposed repository. 45 refs., 21 figs., 15 tabs

  15. Noise Pollution and Health Effects

    Directory of Open Access Journals (Sweden)

    Geravandi

    2015-01-01

    Full Text Available Background Noise pollution is of particular importance due to the physical and psychological effects on humans. Noise is a stressor that affects the autonomic nervous system and the endocrine system. Noise is also a threat to marine and terrestrial ecosystems. Health risks from noise are correlated with road traffic. In other words, noise health effects are the health consequences of elevated sound levels. Objectives This study aims to determine the effect of noise pollution (near roadways on health issues in Ahvaz, Iran. Materials and Methods In this cross-sectional study, equivalent sound pressure level were measured by sound level meters TES-1353 in 75 locations around 4 roadways, which had a high load of traffic in Ahvaz City during day time. During the study, 820 measurements were recorded at measuring stations, for 7 days per week with 1-hour interval between each measurement. Statistical analysis was carried out by SPSS software. Results According to the research findings, the equivalent sound pressure levels in all stations were 76.28 ± 3.12 dB (Mean ± SD. According to sound measurements and the survey questionnaire, noise pollution is higher than EPA (US Environmental Protection Agency and Iran standard level. Based on result of this study the worst noise health effects were the nervousness and sleep quality during 2012. Conclusions According to the results of this study, with increasing load of traffic, there is an increasing need for proper consideration plans to control noise pollution and prevent its effects.

  16. Noise, impulse noise, and other physical factors: combined effects on hearing.

    Science.gov (United States)

    Pekkarinen, J

    1995-01-01

    In most of the epidemiologic studies conducted during the last 20 years, impulse noise caused increased risk of hearing loss in comparison to continuous noise with the same acoustical energy. The interaction between noise exposure (broadband at 100 dB(A)) and hand-arm vibration (125 Hz at 2 ms-2 acceleration level) has been proven for people having vibration-induced white finger symptoms. This interaction is evidenced as a permanent hearing loss. However, why the interaction is seen only in people with VWF is not known. The mechanisms may be related to individual susceptibility, and hypotheses are given on the role of the autonomous nervous system regulating the peripheral vascular reaction. Whole-body vibration (2-10 Hz, at 10 ms-2 level) seems to increase the TTS when noise (broadband at 90 dB(A)) is present. This effect is more pronounced at higher temperatures. The hypothermia protects hearing against the effects of noise in animal studies. The interaction between noise and temperature decrease seems obvious in animal studies. Exercise has both increased and decreased the TTS during noise exposure. The effects have been successfully explained as the depression of the stapedius reflex. Thus, less protection against noise is provided for the inner ear in exercise conditions. The increase of the blood temperature also has been suggested to increase noise-induced TTS during exercise. Electromagnetic fields have been found to cause acoustical interactions in the inner ear. Animal studies and human studies have given contradictory results on the effects of magnetic coil devices on hearing. The MR imaging devices produce noise levels of 82-93 dB, which is not sufficient to produce the risk of permanent hearing loss when short exposure durations are taken into consideration. More systematic research is needed with accurately defined electromagnetic characteristics to reveal the potential interactions. The interactions seem to exist, but relatively high levels and

  17. Performance evaluation and optimization of multiband phase-modulated radio over IsOWC link with balanced coherent homodyne detection

    Science.gov (United States)

    Zong, Kang; Zhu, Jiang

    2018-04-01

    In this paper, we present a multiband phase-modulated (PM) radio over intersatellite optical wireless communication (IsOWC) link with balanced coherent homodyne detection. The proposed system can provide the transparent transport of multiband radio frequency (RF) signals with higher linearity and better receiver sensitivity than intensity modulated with direct detection (IM/DD) system. The expressions of RF gain, noise figure (NF) and third-order spurious-free dynamic range (SFDR) are derived considering the third-order intermodulation product and amplifier spontaneous emission (ASE) noise. The optimal power of local oscillator (LO) optical signal is also derived theoretically. Numerical results for RF gain, NF and third-order SFDR are given for demonstration. Results indicate that the gain of the optical preamplifier and the power of LO optical signal should be optimized to obtain the satisfactory performance.

  18. Compressed Sensing Methods in Radio Receivers Exposed to Noise and Interference

    DEFF Research Database (Denmark)

    Pierzchlewski, Jacek

    , there is a problem of interference, which makes digitization of radio receivers even more dicult. High-order low-pass lters are needed to remove interfering signals and secure a high-quality reception. In the mid-2000s a new method of signal acquisition, called compressed sensing, emerged. Compressed sensing...... the downconverted baseband signal and interference, may be replaced by low-order lters. Additional digital signal processing is a price to pay for this feature. Hence, the signal processing is moved from the analog to the digital domain. Filtering compressed sensing, which is a new application of compressed sensing...

  19. Comparison of clinical parameters and environmental noise levels between regular surgery and piezosurgery for extraction of impacted third molars.

    Science.gov (United States)

    Chang, Hao-Hueng; Lee, Ming-Shu; Hsu, You-Chyun; Tsai, Shang-Jye; Lin, Chun-Pin

    2015-10-01

    Impacted third molars can be extracted by regular surgery or piezosurgery. The aim of this study was to compare clinical parameters and device-produced noise levels between regular surgery and piezosurgery for the extraction of impacted third molars. Twenty patients (18 women and 2 men, 17-29 years of age) with bilateral symmetrical impacted mandibular or maxillary third molars of the same level were included in this randomized crossover clinical trial. The 40 impacted third molars were divided into a control group (n = 20), in which the third molar was extracted by regular surgery using a high-speed handpiece and an elevator, and an experimental group (n = 20), in which the third molar was extracted by piezosurgery using a high-speed handpiece and a piezotome. The clinical parameters were evaluated by a self-reported questionnaire. The noise levels produced by the high-speed handpiece and piezotome were measured and compared between the experimental and control groups. Patients in the experimental group had a better feeling about tooth extraction and force delivery during extraction and less facial swelling than patients in the control group. However, there were no significant differences in noise-related disturbance, extraction period, degree of facial swelling, pain score, pain duration, any noise levels produced by the devices under different circumstances during tooth extraction between the control and experimental groups. The piezosurgery device produced noise levels similar to or lower than those of the high-speed drilling device. However, piezosurgery provides advantages of increased patient comfort during extraction of impacted third molars. Copyright © 2014. Published by Elsevier B.V.

  20. Decreased Hippocampal 5-HT and DA Levels Following Sub-Chronic Exposure to Noise Stress: Impairment in both Spatial and Recognition Memory in Male Rats.

    Science.gov (United States)

    Haider, Saida; Naqvi, Fizza; Batool, Zehra; Tabassum, Saiqa; Perveen, Tahira; Saleem, Sadia; Haleem, Darakhshan Jabeen

    2012-01-01

    Mankind is exposed to a number of stressors, and among them noise is one which can cause intense stress. High levels of background noise can severely impair one's ability to concentrate. The present study was aimed to investigate the effect of sub-chronic noise stress on cognitive behavior and hippocampal monoamine levels in male rats. The study was performed on 12 male Wistar rats, divided into two groups; the control and noise-exposed. The rats in the test group were subjected to noise stress, 4h daily for 15 days. Cognitive testing was performed by the Elevated Plus Maze test (EPM) and Novel Object Recognition test (NOR). HPLC-EC was used to determine hippocampal monoamine levels and their metabolites. The data obtained revealed a significant decrease in hippocampal serotonin (5-hydroxytryptamine; 5-HT) and dopamine (DA) levels, whereas turnover ratios of 5-HT and DA were significantly increased compared to the controls. Rats exposed to noise exhibited a significant decrement in spatial memory. A significantly decreased recognition index of rats exposed to noise as compared to the control was also observed in the NOR test. Results of the present findings suggest the role of decreased hippocampal 5-HT and DA in the impairment of cognitive function following noise exposure.

  1. Chronic exposure to low frequency noise at moderate levels causes impaired balance in mice.

    Directory of Open Access Journals (Sweden)

    Haruka Tamura

    Full Text Available We are routinely exposed to low frequency noise (LFN; below 0.5 kHz at moderate levels of 60-70 dB sound pressure level (SPL generated from various sources in occupational and daily environments. LFN has been reported to affect balance in humans. However, there is limited information about the influence of chronic exposure to LFN at moderate levels for balance. In this study, we investigated whether chronic exposure to LFN at a moderate level of 70 dB SPL affects the vestibule, which is one of the organs responsible for balance in mice. Wild-type ICR mice were exposed for 1 month to LFN (0.1 kHz and high frequency noise (HFN; 16 kHz at 70 dB SPL at a distance of approximately 10-20 cm. Behavior analyses including rotarod, beam-crossing and footprint analyses showed impairments of balance in LFN-exposed mice but not in non-exposed mice or HFN-exposed mice. Immunohistochemical analysis showed a decreased number of vestibular hair cells and increased levels of oxidative stress in LFN-exposed mice compared to those in non-exposed mice. Our results suggest that chronic exposure to LFN at moderate levels causes impaired balance involving morphological impairments of the vestibule with enhanced levels of oxidative stress. Thus, the results of this study indicate the importance of considering the risk of chronic exposure to LFN at a moderate level for imbalance.

  2. [Relationship between the Mandarin acceptable noise level and the personality traits in normal hearing adults].

    Science.gov (United States)

    Wu, Dan; Chen, Jian-yong; Wang, Shuo; Zhang, Man-hua; Chen, Jing; Li, Yu-ling; Zhang, Hua

    2013-03-01

    To evaluate the relationship between the Mandarin acceptable noise level (ANL) and the personality trait for normal-hearing adults. Eighty-five Mandarin speakers, aged from 21 to 27, participated in this study. ANL materials and the Eysenck Personality Questionnaire (EPQ) questionnaire were used to test the acceptable noise level and the personality trait for normal-hearing subjects. SPSS 17.0 was used to analyze the results. ANL were (7.8 ± 2.9) dB in normal hearing participants. The P and N scores in EPQ were significantly correlated with ANL (r = 0.284 and 0.318, P 0.05). Listeners with higher ANL were more likely to be eccentric, hostile, aggressive, and instabe, no ANL differences were found in listeners who were different in introvert-extravert or lying.

  3. The Radio JOVE Project - Shoestring Radio Astronomy

    Science.gov (United States)

    Thieman, J.; Flagg, R.; Greenman, W.; Higgins, C.; Reyes, F.; Sky, J.

    2010-01-01

    Radio JOVE is an education and outreach project intended to give students and other interested individuals hands-on experience in learning radio astronomy. They can do this through building a radio telescope from a relatively inexpensive kit that includes the parts for a receiver and an antenna as well as software for a computer chart recorder emulator (Radio Skypipe) and other reference materials

  4. Effectiveness of radio spokesperson's gender, vocal pitch and accent and the use of music in radio advertising

    Directory of Open Access Journals (Sweden)

    Josefa D. Martín-Santana

    2015-07-01

    Full Text Available The aim of this study is to analyze how certain voice features of radio spokespersons and background music influence the advertising effectiveness of a radio spot from the cognitive, affective and conative perspectives. We used a 2 × 2 × 2 × 2 experimental design in 16 different radio programs in which an ad hoc radio spot was inserted during advertising block. This ad changed according to combinations of spokesperson's gender (male–female, vocal pitch (low–high and accent (local–standard. In addition to these independent factors, the effect of background music in advertisements was also tested and compared with those that only had words. 987 regular radio listeners comprised the sample that was exposed to the radio program we created. Based on the differences in the levels of effectiveness in the tested voice features, our results suggest that the choice of the voice in radio advertising is one of the most important decisions an advertiser faces. Furthermore, the findings show that the inclusion of music does not always imply greater effectiveness.

  5. Continuous monitoring of noise levels in the Gulf of Catania (Ionian Sea). Study of correlation with ship traffic.

    Science.gov (United States)

    Viola, S; Grammauta, R; Sciacca, V; Bellia, G; Beranzoli, L; Buscaino, G; Caruso, F; Chierici, F; Cuttone, G; D'Amico, A; De Luca, V; Embriaco, D; Favali, P; Giovanetti, G; Marinaro, G; Mazzola, S; Filiciotto, F; Pavan, G; Pellegrino, C; Pulvirenti, S; Simeone, F; Speziale, F; Riccobene, G

    2017-08-15

    Acoustic noise levels were measured in the Gulf of Catania (Ionian Sea) from July 2012 to May 2013 by a low frequency (<1000Hz) hydrophone, installed on board the NEMO-SN1 multidisciplinary observatory. NEMO-SN1 is a cabled node of EMSO-ERIC, which was deployed at a water depth of 2100m, 25km off Catania. The study area is characterized by the proximity of mid-size harbors and shipping lanes. Measured noise levels were correlated with the passage of ships tracked with a dedicated AIS antenna. Noise power was measured in the frequency range between 10Hz and 1000Hz. Experimental data were compared with the results of a fast numerical model based on AIS data to evaluate the contribution of shipping noise in six consecutive 1/3 octave frequency bands, including the 1/3 octave frequency bands centered at 63Hz and 125Hz, indicated by the Marine Strategy Framework Directive (2008/56/EC). Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. THE NANOGRAV NINE-YEAR DATA SET: EXCESS NOISE IN MILLISECOND PULSAR ARRIVAL TIMES

    Energy Technology Data Exchange (ETDEWEB)

    Lam, M. T.; Jones, M. L.; McLaughlin, M. A.; Pennucci, T. T. [Department of Physics, West Virginia University, White Hall, Morgantown, WV 26506 (United States); Cordes, J. M.; Chatterjee, S. [Department of Astronomy and Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY 14853 (United States); Arzoumanian, Z. [Center for Research and Exploration in Space Science and Technology and X-Ray Astrophysics Laboratory, NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States); Crowter, K.; Fonseca, E.; Gonzalez, M. E. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Demorest, P. B. [National Radio Astronomy Observatory, P.O. Box 0, Socorro, NM, 87801 (United States); Dolch, T. [Department of Physics, Hillsdale College, 33 E. College Street, Hillsdale, MI 49242 (United States); Ellis, J. A [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena CA, 91109 (United States); Ferdman, R. D. [Department of Physics, McGill University, 3600 rue Universite, Montreal, QC H3A 2T8 (Canada); Jones, G. [Department of Physics, Columbia University, 550 W. 120th Street, New York, NY 10027 (United States); Levin, L. [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Madison, D. R.; Ransom, S. M. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Nice, D. J. [Department of Physics, Lafayette College, Easton, PA 18042 (United States); Shannon, R. M., E-mail: michael.lam@mail.wvu.edu [CSIRO Astronomy and Space Science, Australia Telescope National Facility, Box 76, Epping NSW 1710 (Australia); and others

    2017-01-01

    Gravitational wave (GW) astronomy using a pulsar timing array requires high-quality millisecond pulsars (MSPs), correctable interstellar propagation delays, and high-precision measurements of pulse times of arrival. Here we identify noise in timing residuals that exceeds that predicted for arrival time estimation for MSPs observed by the North American Nanohertz Observatory for Gravitational Waves. We characterize the excess noise using variance and structure function analyses. We find that 26 out of 37 pulsars show inconsistencies with a white-noise-only model based on the short timescale analysis of each pulsar, and we demonstrate that the excess noise has a red power spectrum for 15 pulsars. We also decompose the excess noise into chromatic (radio-frequency-dependent) and achromatic components. Associating the achromatic red-noise component with spin noise and including additional power-spectrum-based estimates from the literature, we estimate a scaling law in terms of spin parameters (frequency and frequency derivative) and data-span length and compare it to the scaling law of Shannon and Cordes. We briefly discuss our results in terms of detection of GWs at nanohertz frequencies.

  7. Noise pollution in Lahore and the solution

    International Nuclear Information System (INIS)

    Ahmad, K.

    1999-01-01

    The main objective of the study is to know the current status of noise levels in Lahore as compared to NEQS . Sound Level Meter model 211 FS Quest Electronics with a 50-120 dBA selectable range was used in the current investigation. Study relates to road traffic noise, aircraft noise at city airports, rail traffic noise, noise levels in urban centers and occupational noise. Investigation revealed that nine main commercial centers, six public hospital and ten educational institution of Lahore had values higher than NEQS (85 dBA). Maximum noise producing vehicles on Lahore roads are scooter producing a noise of 90, 86 and 87 dBA. There are forty airports in operation in the country and the aircraft being used has higher noise level varying from 16 to 120 dBA. Based on age and length of service permanent hearing damage has been observed in skilled industrial workers. Risk from hearing damage of industrial workers can be reduced by the use of some form of ear protection. Ear plugs can reduce noise levels by 15 to 35 dBA according to their design and fit. Industrial noise from heavy machinery can be reduced by anti-vibration mountings. Noisy work area in industry should be either isolated or surrounded by baffles. The most appealing approach to reduce noise problems in communities due to aircraft operation is reduction of the noise generated by the aircraft and land use planning. (author)

  8. Effects of acoustic treatment on the interior noise levels of a twin-engine propeller aircraft - Experimental flight results and theoretical predictions

    Science.gov (United States)

    Beyer, T. B.; Powell, C. A.; Daniels, E. F.; Pope, L. D.

    1984-01-01

    In-flight noise level measurements were made within two cabin configurations of a general aviation business aircraft. The Fairchild Merlin IVC twin-engine aircraft was tested with bare walls and fiberglass insulation and in an executive trim configuration. Narrow-band and octave format data were subjected to analyses which permitted identification of the blade passage harmonics (BPH). Cabin noise level reductions (insertion losses) due to added insulation varied with position in the cabin, the BPH number, cabin pressure, and engine torque. The measurements were closely predicted using the propeller aircraft interior noise (PAIN) mode.

  9. Development of a multichannel RF field detector for the low-level RF control of the free-electron laser at Hamburg

    International Nuclear Information System (INIS)

    Hoffmann, Matthias

    2008-10-01

    Modern free electron lasers produce synchrotron radiation with constantly shortening wavelengths of up to 6 nm and pulse widths of up to 100 fs. That requires a constantly increasing stability of the beam energy and arrival time of the electron beam at the undulator entrance which is situated at the end of the accelerator. At the same time, the increasing speed of digital signal processing and data acquisition facilitates new possibilities for the digital radio frequency control and field detection. In this thesis the development of a multichannel radio frequency field detector for the low level radio frequency (LLRF) control of the superconducting cavities of the Free-Electron Laser at Hamburg (FLASH) is described. The applied method of IF sampling is state of the technology and is utilized in many areas of digital communication. It is evaluated concerning its applicability for the LLRF control. Analytical and numerical investigations of the noise behavior and transport in the control loop have been accomplished to define the requirements for the measurement accuracy of the field detector that was to be developed. Therefore, simplified models of the noise behavior of each system component of the control loop, e.g. amplifier, radio frequency mixer and analog-to-digital converter, were established and subsequently assorted to a the model of the control loop. Due to the application of the vector-sum control, where several separately measured field vectors are added to a vector-sum, requirements concerning the allowable compression error of the detector nonlinearity were defined. These were investigated by analytical and numerical methods, as well. Requirements for the hardware that was to be developed were compiled from the simulation results. For the development of the field detector, a modular and EMC-compatible concept with a high-level passive front-end for an improvement of the signal-to-noise ratio was chosen. The following tests in the lab delivered the

  10. Development of a multichannel RF field detector for the low-level RF control of the free-electron laser at Hamburg

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Matthias

    2008-10-15

    Modern free electron lasers produce synchrotron radiation with constantly shortening wavelengths of up to 6 nm and pulse widths of up to 100 fs. That requires a constantly increasing stability of the beam energy and arrival time of the electron beam at the undulator entrance which is situated at the end of the accelerator. At the same time, the increasing speed of digital signal processing and data acquisition facilitates new possibilities for the digital radio frequency control and field detection. In this thesis the development of a multichannel radio frequency field detector for the low level radio frequency (LLRF) control of the superconducting cavities of the Free-Electron Laser at Hamburg (FLASH) is described. The applied method of IF sampling is state of the technology and is utilized in many areas of digital communication. It is evaluated concerning its applicability for the LLRF control. Analytical and numerical investigations of the noise behavior and transport in the control loop have been accomplished to define the requirements for the measurement accuracy of the field detector that was to be developed. Therefore, simplified models of the noise behavior of each system component of the control loop, e.g. amplifier, radio frequency mixer and analog-to-digital converter, were established and subsequently assorted to a the model of the control loop. Due to the application of the vector-sum control, where several separately measured field vectors are added to a vector-sum, requirements concerning the allowable compression error of the detector nonlinearity were defined. These were investigated by analytical and numerical methods, as well. Requirements for the hardware that was to be developed were compiled from the simulation results. For the development of the field detector, a modular and EMC-compatible concept with a high-level passive front-end for an improvement of the signal-to-noise ratio was chosen. The following tests in the lab delivered the

  11. Noise-based Stego-ECC

    Directory of Open Access Journals (Sweden)

    Rahardjo Budi

    2014-03-01

    Full Text Available A novel method of inserting noise into stream of ciphered text is proposed. The goal of inserting noise is to increase the level of uncertainty, thus making it harder for an attacker to detect data and noise. This form of steganography is implemented using Elliptic Curve Cryptography (ECC. The process of embedding the noise to the message in the encryption process and removing the noise from the message in the decryption process is proposed in this work by modifying ElGamal to allow auto detection of data and noise.

  12. Traffic noise control of a city

    International Nuclear Information System (INIS)

    Ahmed, A.; Khan, J.A.; Lakhani, A.H.; Hyder, F.G.; Shamsuddin, S.A.

    2003-01-01

    Long exposure to noise due to traffic affects our health and comfort. A noise level up to 45 dB is acceptable for the buildings in the city. A traffic noise study was conducted in Karachi at places of high traffic flow. The noise level was between 75-85 dB. Residential and commercial buildings had sound level up to 79 dB. Reducing vehicle noise by using proper muffler and acoustic treatment should first control traffic noise. Then noise can be reduced by 10-15 dB by constructing barriers of wood or concrete along roadside. Barrier height for sound attenuation can be found from Fresnel Number. The barrier reduces noise better if width at the top is increased and an inward bend of 60 degree is placed at the top. Where feasible a 4-5 meter high concrete barrier is recommended otherwise the nearby buildings from the road should be insulated and acoustically treated. (author)

  13. A computer simulation of an adaptive noise canceler with a single input

    Science.gov (United States)

    Albert, Stuart D.

    1991-06-01

    A description of an adaptive noise canceler using Widrows' LMS algorithm is presented. A computer simulation of canceler performance (adaptive convergence time and frequency transfer function) was written for use as a design tool. The simulations, assumptions, and input parameters are described in detail. The simulation is used in a design example to predict the performance of an adaptive noise canceler in the simultaneous presence of both strong and weak narrow-band signals (a cosited frequency hopping radio scenario). On the basis of the simulation results, it is concluded that the simulation is suitable for use as an adaptive noise canceler design tool; i.e., it can be used to evaluate the effect of design parameter changes on canceler performance.

  14. Radio resource management in multi-tier cellular wireless networks

    CERN Document Server

    Hossain, Ekram; Niyato, Dusit

    2013-01-01

    Providing an extensive overview of the radio resource management problem in femtocell networks, this invaluable book considers both code division multiple access femtocells and orthogonal frequency-division multiple access femtocells. In addition to incorporating current research on this topic, the book also covers technical challenges in femtocell deployment, provides readers with a variety of approaches to resource allocation and a comparison of their effectiveness, explains how to model various networks using Stochastic geometry and shot noise theory, and much more.

  15. Radio astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Nagnibeda, V.G.

    1981-01-01

    The history of radio astronomical observations at the Astronomical Observatory of Leningrad State University is reviewed. Various facilities are described, and methods and instruments used are discussed. Some results are summarized for radio observations of the sun, including observations of local sources of solar radio emission, the absolute solar radio flux, and radio emission from filaments and prominences.

  16. Aircrafts' taxi noise emission

    NARCIS (Netherlands)

    Asensio, C.; Pagan Munoz, Raul; López, J.M.

    2008-01-01

    An investigation has been conducted, with the objective of creating a database of inputs that can be used with noise prediction software, to evaluate noise of aircraft taxing movements and community noise exposure levels. The acoustic consultant can use these data with any of the software packages,

  17. Cochlea hair cell rescue after a noise-induced hearing loss using a low level laser therapy (LLLT)

    Science.gov (United States)

    Rhee, Chung-Ku; Bahk, Chan Woong; Jung, Jae Yun; Ahn, Jin-Chul; Suh, Myung-Whan

    2011-03-01

    Aim: To see the effect of LLLT on noise-induced hearing loss. Methods: Eleven rats were exposed to noise (120 dB, 16 kHz, 6 h) and left ears were irradiated at 60J/cm2, 830 nm laser for 12 days. Right ears were control. Hearing levels were measured at frequencies of 4, 8, 12, 16, 32 kHz before noise exposure and after 12th irradiations. Results: The initial hearing levels were 26.5+/-4.7, 24.5+/-5.0, 24.0+/-5.2, 24.0+/-3.2, 24.5+/-5.5 dB SPL. After noise exposure, thresholds were 63.5+/-15.1, 64+/-16.8, 71.5+/-11.3, 73.5+/-15.6, 67.5+/-14.4 dB SPL in 4, 8, 12, 16, 32 kHz. After 12th irradiation, thresholds of treated ears recovered significantly 21+/-4.2, 20+/-3.5, 24+/-11.9, 24+/-12.9, 21+/-2.2 dB SPL and that of the untreated right ears measured 36.3+/-22.9, 45+/-15.8, 66.3+/-22.9, 50+/-16.8, 43.8+/-21.4 dB SPL. Conclusion: LLLT may promote recovery of hearing after noiseinduced hearing loss.

  18. The 136 MHZ/400 MHz earth station antenna-noise temperature prediction program for RAE-B

    Science.gov (United States)

    Taylor, R. E.; Fee, J. J.; Chin, M.

    1972-01-01

    A simulation study was undertaken to determine the 136 MHz and 400 MHz noise temperature of the ground network antennas which will track the RAE-B satellite during data transmission periods. Since the noise temperature of the antenna effectively sets the signal-to-noise ratio of the received signal, a knowledge of SNR will be helpful in locating the optimum time windows for data transmission during low noise periods. Antenna noise temperatures will be predicted for selected earth-based ground stations which will support RAE-B. Telemetry data acquisition will be at 400 MHz; tracking support at 136 MHz will be provided by the Goddard Range and Range Rate (RARR) stations. The antenna-noise temperature predictions will include the effects of galactic-brightness temperature, the sun, and the brightest radio stars. Predictions will cover the ten-month period from March 1, 1973 to December 31, 1973.

  19. DEEP SPITZER OBSERVATIONS OF INFRARED-FAINT RADIO SOURCES: HIGH-REDSHIFT RADIO-LOUD ACTIVE GALACTIC NUCLEI?

    International Nuclear Information System (INIS)

    Norris, Ray P.; Mao, Minnie; Afonso, Jose; Cava, Antonio; Farrah, Duncan; Oliver, Seb; Huynh, Minh T.; Mauduit, Jean-Christophe; Surace, Jason; Ivison, R. J.; Jarvis, Matt; Lacy, Mark; Maraston, Claudia; Middelberg, Enno; Seymour, Nick

    2011-01-01

    Infrared-faint radio sources (IFRSs) are a rare class of objects which are relatively bright at radio wavelengths but very faint at infrared and optical wavelengths. Here we present sensitive near-infrared observations of a sample of these sources taken as part of the Spitzer Extragalactic Representative Volume Survey. Nearly all the IFRSs are undetected at a level of ∼1 μJy in these new deep observations, and even the detections are consistent with confusion with unrelated galaxies. A stacked image implies that the median flux density is S 3.6μm ∼ 0.2 μJy or less, giving extreme values of the radio-infrared flux density ratio. Comparison of these objects with known classes of object suggests that the majority are probably high-redshift radio-loud galaxies, possibly suffering from significant dust extinction.

  20. Evaluation of Noise Exposure Secondary to Wind Noise in Cyclists.

    Science.gov (United States)

    Seidman, Michael D; Wertz, Anna G; Smith, Matthew M; Jacob, Steve; Ahsan, Syed F

    2017-11-01

    Objective Determine if the noise levels of wind exposure experienced by cyclists reach levels that could contribute to noise-induced hearing loss. Study Design Industrial lab research. Setting Industrial wind tunnel. Subjects and Methods A commercial-grade electric wind tunnel was used to simulate different speeds encountered by a cyclist. A single cyclist was used during the simulation for audiometric measurements. Microphones attached near the ears of the cyclist were used to measure the sound (dB sound pressure level) experienced by the cyclist. Loudness levels were measured with the head positioned at 15-degree increments from 0 degrees to 180 degrees relative to the oncoming wind at different speeds (10-60 mph). Results Wind noise ranged from 84.9 dB at 10 mph and increased proportionally with speed to a maximum of 120.3 dB at 60 mph. The maximum of 120.3 dB was measured at the downwind ear when the ear was 90 degrees away from the wind. Conclusions Wind noise experienced by a cyclist is proportional to the speed and the directionality of the wind current. Turbulent air flow patterns are observed that contribute to increased sound exposure in the downwind ear. Consideration of ear deflection equipment without compromising sound awareness for cyclists during prolonged rides is advised to avoid potential noise trauma. Future research is warranted and can include long-term studies including dosimetry measures of the sound and yearly pre- and postexposure audiograms of cyclists to detect if any hearing loss occurs with long-term cycling.

  1. Upper-limit on the Advanced Virgo output mode cleaner cavity length noise

    Science.gov (United States)

    Bonnand, R.; Ducrot, M.; Gouaty, R.; Marion, F.; Masserot, A.; Mours, B.; Pacaud, E.; Rolland, L.; Was, M.

    2017-09-01

    The Advanced Virgo detector uses two monolithic optical cavities at its output port to suppress higher order modes and radio frequency sidebands from the carrier light used for gravitational wave detection. These two cavities in series form the output mode cleaner. We present a measured upper limit on the length noise of these cavities that is consistent with the thermo-refractive noise prediction of 8×10-16~m~Hz-1/2 at 15 Hz. The cavity length is controlled using Peltier cells and piezo-electric actuators to maintain resonance on the incoming light. A length lock precision of 3.5×10-13 m is achieved. These two results are combined to demonstrate that the broadband length noise of the output mode cleaner in the 10-60 Hz band is at least a factor 10 below other expected noise sources in the Advanced Virgo detector design configuration.

  2. A study investigating sound sources and noise levels in neonatal ...

    African Journals Online (AJOL)

    Background. Exposure to noise in the neonatal intensive care unit (NICU) has the potential to affect neonatal auditory development, sleep patterns and physiological stability, thus impacting on developmental progress. Objectives. This study aimed to identify noise sources in three NICUs in Johannesburg, South Africa, and ...

  3. SELECTED PROBLEMS OF PROTECTION AGAINST ROAD TRAFFIC NOISE

    Directory of Open Access Journals (Sweden)

    Władysław Gardziejczyk

    2015-11-01

    Full Text Available The paper presents factors for assessment of road traffic noise level and possible actions towards the minimization of excessive noise in the roadway neighborhood. Changes of equivalent sound level values were analyzed in relation to traffic intensity, categorization and vehicles speed. In relation to measures reducing noise level in roadway’s surroundings particular attention was given to anti-noise protections and tyre/noise reduction. Acoustic effectiveness of specific solutions was showed based on chosen examples. It was proved that when admissible noise level is slightly exceeded the need for noise barrier use may be replaced by a proper design and maintenance of road pavement or by enforcement of speed limit.

  4. Effect of training data size and noise level on support vector machines virtual screening of genotoxic compounds from large compound libraries.

    Science.gov (United States)

    Kumar, Pankaj; Ma, Xiaohua; Liu, Xianghui; Jia, Jia; Bucong, Han; Xue, Ying; Li, Ze Rong; Yang, Sheng Yong; Wei, Yu Quan; Chen, Yu Zong

    2011-05-01

    Various in vitro and in-silico methods have been used for drug genotoxicity tests, which show limited genotoxicity (GT+) and non-genotoxicity (GT-) identification rates. New methods and combinatorial approaches have been explored for enhanced collective identification capability. The rates of in-silco methods may be further improved by significantly diversified training data enriched by the large number of recently reported GT+ and GT- compounds, but a major concern is the increased noise levels arising from high false-positive rates of in vitro data. In this work, we evaluated the effect of training data size and noise level on the performance of support vector machines (SVM) method known to tolerate high noise levels in training data. Two SVMs of different diversity/noise levels were developed and tested. H-SVM trained by higher diversity higher noise data (GT+ in any in vivo or in vitro test) outperforms L-SVM trained by lower noise lower diversity data (GT+ in in vivo or Ames test only). H-SVM trained by 4,763 GT+ compounds reported before 2008 and 8,232 GT- compounds excluding clinical trial drugs correctly identified 81.6% of the 38 GT+ compounds reported since 2008, predicted 83.1% of the 2,008 clinical trial drugs as GT-, and 23.96% of 168 K MDDR and 27.23% of 17.86M PubChem compounds as GT+. These are comparable to the 43.1-51.9% GT+ and 75-93% GT- rates of existing in-silico methods, 58.8% GT+ and 79% GT- rates of Ames method, and the estimated percentages of 23% in vivo and 31-33% in vitro GT+ compounds in the "universe of chemicals". There is a substantial level of agreement between H-SVM and L-SVM predicted GT+ and GT- MDDR compounds and the prediction from TOPKAT. SVM showed good potential in identifying GT+ compounds from large compound libraries based on higher diversity and higher noise training data.

  5. The Analysis of Closed-form Solution for Energy Detector Dynamic Threshold Adaptation in Cognitive Radio

    Directory of Open Access Journals (Sweden)

    R. Bozovic

    2017-12-01

    Full Text Available Spectrum sensing is the most important process in cognitive radio in order to ensure interference avoidance to primary users. For optimal performance of cognitive radio, it is substantial to monitor and promptly react to dynamic changes in its operating environment. In this paper, energy detector based spectrum sensing is considered. Under the assumption that detected signal can be modelled according to an autoregressive model, noise variance is estimated from that noisy signal, as well as primary user signal power. A closed-form solution for optimal decision threshold in dynamic electromagnetic environment is proposed and analyzed.

  6. Ambient seismic noise levels: A survey of the permanent and temporary seismographic networks in Morocco, North Africa

    Science.gov (United States)

    El Fellah, Y.; Khairy Abd Ed-Aal, A.; El Moudnib, L.; Mimoun, H.; Villasenor, A.; Gallart, J.; Thomas, C.; Elouai, D.; Mimoun, C.; Himmi, M.

    2013-12-01

    Abstract The results, of a conducted study carried out to analyze variations in ambient seismic noise levels at sites of the installed broadband stations in Morocco, North Africa, are obtained. The permanent and the temporary seismic stations installed in Morocco of the Scientific Institute ( IS, Rabat, Morocco), institute de Ciencias de la Tierra Jaume almera (ICTJA, Barcelona, Spain) and Institut für Geophysik (Munster, Germany) were used in this study. In this work, we used 23 broadband seismic stations installed in different structural domains covering all Morocco from south to north. The main purposes of the current study are: 1) to present a catalog of seismic background noise spectra for Morocco obtained from recently installed broadband stations, 2) to assess the effects of experimental temporary seismic vault construction, 3) to determine the time needed for noise at sites to stabilize, 4) to establish characteristics and origin of seismic noise at those sites. We calculated power spectral densities of background noise for each component of each broadband seismometer deployed in the different investigated sites and then compared them with the high-noise model and low-noise Model of Peterson (1993). All segments from day and night local time windows were included in the calculation without parsing out earthquakes. The obtained results of the current study could be used forthcoming to evaluate permanent station quality. Moreover, this study could be considered as a first step to develop new seismic noise models in North Africa not included in Peterson (1993). Keywords Background noise; Power spectral density; Model of Peterson; Scientific Institute; Institute de Ciencias de la Tierra Jaume almera; Institut für Geophysik

  7. Adaptation of the deoxyglucose method for use at cellular level: histological processing of the central nervous system for high resolution radio-autography

    International Nuclear Information System (INIS)

    Des Rosiers, M.H.; Descarries, Laurent

    1978-01-01

    Vascular perfusion of all products required for primary fixation, postfixation, dehydration and embedding of nervous tissue in Epon permits radio-autographic detection of radioactivity accumulated in the central nervous system after intravenous injection of [ 3 H]deoxyglucose. This histological technique should allow application of the deoxyglucose method at cellular if not subcellular level, since a high proportion of the tracer appears to be retained in situ in specimens adequately preserved for light and electron microscope radio-autography [fr

  8. New solution for transport and industrial noise protection through reflective noise barriers

    Directory of Open Access Journals (Sweden)

    Kralov Ivan

    2017-01-01

    Full Text Available A new solution for protection of transportation and industrial noise through reflective noise barriers is proposed and investigated in this study. The new solution combines the advantages of the known barriers and has its own advantages in addition. The preliminary results show a very good level of noise reduction for this type of barriers.

  9. Evaluation of noise levels in manufacturing sectors in Thika district ...

    African Journals Online (AJOL)

    Noise is considered as any unwanted sound that may adversely affect the health and wellbeing of individuals or populations exposed. This study assessed the magnitude of occupational noise exposures to workers in different manufacturing sectors in Thika District‐Kenya. Systematic random sampling was used to select 8 ...

  10. A descriptive study of noise in the neonatal intensive care unit: ambient levels and perceptions of contributing factors.

    Science.gov (United States)

    Darcy, Ashley E; Hancock, Lauren E; Ware, Emily J

    2008-10-01

    To examine the baseline acoustic environment in several mid-Atlantic region neonatal intensive care units (NICUs) and investigate the perceived factors contributing to noise levels in these NICUs. Quantitative data were collected from 3 urban, mid-Atlantic level IIIB and level IIIC NICUs. Qualitative data were collected via interview from 2 RNs employed in each of the study NICUs. This was an exploratory descriptive study utilizing a mixed-methods approach. A quantitative method was used for sound-level data collection, and a qualitative method was utilized during interviews with nurses to examine perceptions of factors contributing to noise. Ambient sound levels, measured in decibels, were taken at 5-minute intervals over a 2-hour period during both day and night shifts in a central location at each NICU. In addition, nurses were interviewed using a standardized interview questionnaire, and these interviews were then reviewed to determine themes regarding perceived factors contributing to sound levels. Hourly mean sound levels in each NICU ranged from 53.9 dB to 60.6 dB, with no statistically significant difference between noise levels recorded on day shift versus night shift, and no statistically significant difference among sites. Qualitative data showed that nurses' believed day shift to be louder than night shift and many perceived their own NICU as "pretty quiet." Key contributing factors to increased sound levels were stated as monitors or alarms, performing invasive procedures, presence of family, nurses or doctors giving report or rounds, and ringing phones. Noise levels were found to be above the American Academy of Pediatrics-recommended 45-dB level and often louder than the 50-dB level, which should not be exceeded more than 10% of the time. The recommended impulse maximum of 65 dB was also exceeded. Environmental Protection Agency recommendations for hospitals include sound levels no louder than 35 dB on night shift; this standard was also violated

  11. A descriptive study of noise in the neonatal intensive care unit. Ambient levels and perceptions of contributing factors.

    Science.gov (United States)

    Darcy, Ashley E; Hancock, Lauren E; Ware, Emily J

    2008-06-01

    To examine the baseline acoustic environment in several mid-Atlantic region neonatal intensive care units (NICUs) and investigate the perceived factors contributing to noise levels in these NICUs. Quantitative data were collected from 3 urban, mid-Atlantic level IIIB and level IIIC NICUs. Qualitative data were collected via interview from 2 RNs employed in each of the study NICUs. This was an exploratory descriptive study utilizing a mixed-methods approach. A quantitative method was used for sound-level data collection, and a qualitative method was utilized during interviews with nurses to examine perceptions of factors contributing to noise. Ambient sound levels, measured in decibels, were taken at 5-minute intervals over a 2-hour period during both day and night shifts in a central location at each NICU. In addition, nurses were interviewed using a standardized interview questionnaire, and these interviews were then reviewed to determine themes regarding perceived factors contributing to sound levels. Hourly mean sound levels in each NICU ranged from 53.9 dB to 60.6 dB, with no statistically significant difference between noise levels recorded on day shift versus night shift, and no statistically significant difference among sites. Qualitative data showed that nurses' believed day shift to be louder than night shift and many perceived their own NICU as "pretty quiet." Key contributing factors to increased sound levels were stated as monitors or alarms, performing invasive procedures, presence of family, nurses or doctors giving report or rounds, and ringing phones. Noise levels were found to be above the American Academy of Pediatrics--recommended 45-dB level and often louder than the 50-dB level, which should not be exceeded more than 10% of the time. The recommended impulse maximum of 65 dB was also exceeded. Environmental Protection Agency recommendations for hospitals include sound levels no louder than 35 dB on night shift; this standard was also violated

  12. On the prediction of impact noise, V: The noise from drop hammers

    Science.gov (United States)

    Richards, E. J.; Carr, I.; Westcott, M.

    1983-06-01

    In earlier papers in this series, the concepts of "acceleration" and "ringing" noise have been studied in relation to impact machines, and values of radiation efficiency have been obtained for the various types of structural components. In the work reported in this paper the predicted and measured noise radiation from a drop hammer, both in full-scale and in {1}/{3}- scale model form, were examined. It is found that overall noise levels ( Leq per event) can be predicted from vibration measurements to within ± 1·5 dB, and to within ±2·5 dB in one-third octave bands. In turn this has permitted noise reduction techniques to be examined by studies of local component vibration levels rather than overall noise, a method which provides considerable enlightenment at the design stage. It is shown that on one particular drop hammer, the noise energy is shared surprisingly uniformly over four or five sources, and that when these have been reduced, the overall noise reduction is severely limited by the "acceleration" noise from the "tup" or "hammer" itself. As this is difficult to eliminate without a basic change in forging technology, it follows that "tup" enclosure or modification of the sharpness of the final "hard" impact are the only means available for any serious noise reduction. Also indicated is the reliability of using model techniques, suitably scaled in frequency and impulse magnitude, in developing machinery with impact characteristics.

  13. Noise-reducing designs of machines and structures

    Indian Academy of Sciences (India)

    an increase in the levels of noise pollution almost everywhere. The harmful effects of noise are well-known. Exposure to high noise levels can cause hearing loss. Noise can also result in other ill effects such as general annoyance, loss of sleep, headache, stress, constriction of blood vessels and deterioration in work ...

  14. High levels of sound pressure: acoustic reflex thresholds and auditory complaints of workers with noise exposure

    Directory of Open Access Journals (Sweden)

    Alexandre Scalli Mathias Duarte

    2015-08-01

    Full Text Available INTRODUCTION: The clinical evaluation of subjects with occupational noise exposure has been difficult due to the discrepancy between auditory complaints and auditory test results. This study aimed to evaluate the contralateral acoustic reflex thresholds of workers exposed to high levels of noise, and to compare these results to the subjects' auditory complaints.METHODS: This clinical retrospective study evaluated 364 workers between 1998 and 2005; their contralateral acoustic reflexes were compared to auditory complaints, age, and noise exposure time by chi-squared, Fisher's, and Spearman's tests.RESULTS: The workers' age ranged from 18 to 50 years (mean = 39.6, and noise exposure time from one to 38 years (mean = 17.3. We found that 15.1% (55 of the workers had bilateral hearing loss, 38.5% (140 had bilateral tinnitus, 52.8% (192 had abnormal sensitivity to loud sounds, and 47.2% (172 had speech recognition impairment. The variables hearing loss, speech recognition impairment, tinnitus, age group, and noise exposure time did not show relationship with acoustic reflex thresholds; however, all complaints demonstrated a statistically significant relationship with Metz recruitment at 3000 and 4000 Hz bilaterally.CONCLUSION: There was no significance relationship between auditory complaints and acoustic reflexes.

  15. Background noise levels measured in the NASA Lewis 9- by 15-foot low-speed wind tunnel

    Science.gov (United States)

    Woodward, Richard P.; Dittmar, James H.; Hall, David G.; Kee-Bowling, Bonnie

    1994-01-01

    The acoustic capability of the NASA Lewis 9 by 15 Foot Low Speed Wind Tunnel has been significantly improved by reducing the background noise levels measured by in-flow microphones. This was accomplished by incorporating streamlined microphone holders having a profile developed by researchers at the NASA Ames Research Center. These new holders were fabricated for fixed mounting on the tunnel wall and for an axially traversing microphone probe which was mounted to the tunnel floor. Measured in-flow noise levels in the tunnel test section were reduced by about 10 dB with the new microphone holders compared with those measured with the older, less refined microphone holders. Wake interference patterns between fixed wall microphones were measured and resulted in preferred placement patterns for these microphones to minimize these effects. Acoustic data from a model turbofan operating in the tunnel test section showed that results for the fixed and translating microphones were equivalent for common azimuthal angles, suggesting that the translating microphone probe, with its significantly greater angular resolution, is preferred for sideline noise measurements. Fixed microphones can provide a local check on the traversing microphone data quality, and record acoustic performance at other azimuthal angles.

  16. Noise and Hearing Loss Prevention

    Science.gov (United States)

    ... message, please visit this page: About CDC.gov . NOISE AND HEARING LOSS PREVENTION Language: English (US) Español ( ... when hazardous noise levels cannot be adequately reduced. Noise and Hearing Loss on the NIOSH Science Blog ...

  17. Environmental propagation of noise in mines and nearby villages: A study through noise mapping

    Directory of Open Access Journals (Sweden)

    Veena D Manwar

    2016-01-01

    Full Text Available Background: Noise mapping being an established practice in Europe is hardly practiced for noise management in India although it is mandatory in Indian mines as per guidelines of the Directorate General of Mines Safety (DGMS. As a pilot study, noise mapping was conducted in an opencast mine with three different models; one based on the baseline operating conditions in two shifts (Situation A, and two other virtual situations where either production targets were enhanced by extending working hours to three shifts (Situation B or only by increased mechanization and not changing the duration of work (Situation C. Methods: Noise sources were categorized as point, line, area, and moving sources. Considering measured power of the sources, specific meteorological and geographical parameters, noise maps were generated using Predictor LimA software. Results: In all three situations, Lden values were 95 dB(A and 70–80 dB(A near drill machine and haul roads, respectively. Noise contours were wider in Situation C due to increase in frequency of dumpers. Lden values near Shovel 1 and Shovel 2 under Situation B increased by 5 dB and 3 dB, respectively due to expansion of working hours. In Situation C, noise levels were >82 dB(A around shovels. Noise levels on both sides of conveyor belts were in the range of 80–85 dB(A in Situations A and C whereas it was 85–90 dB(A in Situation B. Near crusher plants, it ranged from 80 to 90 dB(A in Situations A and C and between 85 and 95 dB(A in Situation B. In all situations, noise levels near residential areas exceeded the Central Pollution Control Board (CPCB limits, i.e., 55 dB(A. Conclusions: For all situations, predicted noise levels exceeded CPCB limits within the mine and nearby residential area. Residential areas near the crusher plants are vulnerable to increased noise propagation. It is recommended to put an acoustic barrier near the crusher plant to attenuate the noise propagation.

  18. Development of the Phase-up Technology of the Radio Telescopes: 6.7 GHz Methanol Maser Observations with Phased Hitachi 32 m and Takahagi 32 m Radio Telescopes

    Science.gov (United States)

    Takefuji, K.; Sugiyama, K.; Yonekura, Y.; Saito, T.; Fujisawa, K.; Kondo, T.

    2017-11-01

    For the sake of high-sensitivity 6.7 GHz methanol maser observations, we developed a new technology for coherently combining the two signals from the Hitachi 32 m radio telescope and the Takahagi 32 m radio telescope of the Japanese Very long baseline interferometer Network (JVN), where the two telescopes were separated by about 260 m. After the two telescopes were phased as a twofold larger single telescope, the mean signal-to-noise ratio (S/N) of the 6.7 GHz methanol masers observed by the phased telescopes was improved to 1.254-fold higher than that of the single dish, through a very long baseline interferometry (VLBI) experiment on the 50 km baseline of the Kashima 34 m telescope and the 1000 km baseline of the Yamaguchi 32 m telescope. Furthermore, we compared the S/Ns of the 6.7 GHz maser spectra for two methods. One is a VLBI method and the other is the newly developed digital position switching that is a similar technology to that used in noise-canceling headphones. Finally, we confirmed that the mean S/N of method of the digital position switching (ON-OFF) was 1.597-fold higher than that of the VLBI method.

  19. Radio stars

    International Nuclear Information System (INIS)

    Hjellming, R.M.

    1976-01-01

    Any discussion of the radio emission from stars should begin by emphasizing certain unique problems. First of all, one must clarify a semantic confusion introduced into radio astronomy in the late 1950's when most new radio sources were described as radio stars. All of these early 'radio stars' were eventually identified with other galactic and extra-galactic objects. The study of true radio stars, where the radio emission is produced in the atmosphere of a star, began only in the 1960's. Most of the work on the subject has, in fact, been carried out in only the last few years. Because the real information about radio stars is quite new, it is not surprising that major aspects of the subject are not at all understood. For this reason this paper is organized mainly around three questions: what is the available observational information; what physical processes seem to be involved; and what working hypotheses look potentially fruitful. (Auth.)

  20. Wind seismic noise introduced by external infrastructure: field data and transfer mechanism

    Science.gov (United States)

    Martysevich, Pavel; Starovoyt, Yuri

    2017-04-01

    Background seismic noise generated by wind was analyzed at six co-located seismic and infrasound arrays with the use of the wind speed data. The main factors affecting the noise level were identified as (a) external structures as antenna towers for intrasite communication, vegetation and heavy solar panels fixtures, (b) borehole casing and (c) local lithology. The wind-induced seismic noise peaks in the spectra can be predicted by combination of inverted pendulum model for antenna towers and structures used to support solar panels, free- or clamped-tube resonance of the borehole casing and is dependent on the type of sedimentary upper layer. Observed resonance frequencies are in agreement with calculated clamped / free tube modes for towers and borehole casings. Improvement of the seismic data quality can be achieved by minimizing the impact of surrounding structures close to seismic boreholes. The need and the advantage of the borehole installation may vanish and appear to be even not necessary at locations with non-consolidated sediments because the impact of surrounding structures on seismic background may significantly deteriorate the installation quality and therefore the detection capability of the array. Several IMS arrays where the radio telemetry antennas are used for data delivery to the central site may benefit from the redesign of the intrasite communication system by its substitute with the fiber-optic net as less harmful engineering solution.

  1. Adjusting phenotypes by noise control.

    Directory of Open Access Journals (Sweden)

    Kyung H Kim

    2012-01-01

    Full Text Available Genetically identical cells can show phenotypic variability. This is often caused by stochastic events that originate from randomness in biochemical processes involving in gene expression and other extrinsic cellular processes. From an engineering perspective, there have been efforts focused on theory and experiments to control noise levels by perturbing and replacing gene network components. However, systematic methods for noise control are lacking mainly due to the intractable mathematical structure of noise propagation through reaction networks. Here, we provide a numerical analysis method by quantifying the parametric sensitivity of noise characteristics at the level of the linear noise approximation. Our analysis is readily applicable to various types of noise control and to different types of system; for example, we can orthogonally control the mean and noise levels and can control system dynamics such as noisy oscillations. As an illustration we applied our method to HIV and yeast gene expression systems and metabolic networks. The oscillatory signal control was applied to p53 oscillations from DNA damage. Furthermore, we showed that the efficiency of orthogonal control can be enhanced by applying extrinsic noise and feedback. Our noise control analysis can be applied to any stochastic model belonging to continuous time Markovian systems such as biological and chemical reaction systems, and even computer and social networks. We anticipate the proposed analysis to be a useful tool for designing and controlling synthetic gene networks.

  2. Optimal Height Calculation and Modelling of Noise Barrier

    Directory of Open Access Journals (Sweden)

    Raimondas Grubliauskas

    2011-04-01

    Full Text Available Transport is one of the main sources of noise having a particularly strong negative impact on the environment. In the city, one of the best methods to reduce the spread of noise in residential areas is a noise barrier. The article presents noise reduction barrier adaptation with empirical formulas calculating and modelling noise distribution. The simulation of noise dispersion has been performed applying the CadnaA program that allows modelling the noise levels of various developments under changing conditions. Calculation and simulation is obtained by assessing the level of noise reduction using the same variables. The investigation results are presented as noise distribution isolines. The selection of a different height of noise barriers are the results calculated at the heights of 1, 4 and 15 meters. The level of noise reduction at the maximum overlap of data, calculation and simulation has reached about 10%.Article in Lithuanian

  3. Noise-invariant Neurons in the Avian Auditory Cortex: Hearing the Song in Noise

    Science.gov (United States)

    Moore, R. Channing; Lee, Tyler; Theunissen, Frédéric E.

    2013-01-01

    Given the extraordinary ability of humans and animals to recognize communication signals over a background of noise, describing noise invariant neural responses is critical not only to pinpoint the brain regions that are mediating our robust perceptions but also to understand the neural computations that are performing these tasks and the underlying circuitry. Although invariant neural responses, such as rotation-invariant face cells, are well described in the visual system, high-level auditory neurons that can represent the same behaviorally relevant signal in a range of listening conditions have yet to be discovered. Here we found neurons in a secondary area of the avian auditory cortex that exhibit noise-invariant responses in the sense that they responded with similar spike patterns to song stimuli presented in silence and over a background of naturalistic noise. By characterizing the neurons' tuning in terms of their responses to modulations in the temporal and spectral envelope of the sound, we then show that noise invariance is partly achieved by selectively responding to long sounds with sharp spectral structure. Finally, to demonstrate that such computations could explain noise invariance, we designed a biologically inspired noise-filtering algorithm that can be used to separate song or speech from noise. This novel noise-filtering method performs as well as other state-of-the-art de-noising algorithms and could be used in clinical or consumer oriented applications. Our biologically inspired model also shows how high-level noise-invariant responses could be created from neural responses typically found in primary auditory cortex. PMID:23505354

  4. Noise-invariant neurons in the avian auditory cortex: hearing the song in noise.

    Science.gov (United States)

    Moore, R Channing; Lee, Tyler; Theunissen, Frédéric E

    2013-01-01

    Given the extraordinary ability of humans and animals to recognize communication signals over a background of noise, describing noise invariant neural responses is critical not only to pinpoint the brain regions that are mediating our robust perceptions but also to understand the neural computations that are performing these tasks and the underlying circuitry. Although invariant neural responses, such as rotation-invariant face cells, are well described in the visual system, high-level auditory neurons that can represent the same behaviorally relevant signal in a range of listening conditions have yet to be discovered. Here we found neurons in a secondary area of the avian auditory cortex that exhibit noise-invariant responses in the sense that they responded with similar spike patterns to song stimuli presented in silence and over a background of naturalistic noise. By characterizing the neurons' tuning in terms of their responses to modulations in the temporal and spectral envelope of the sound, we then show that noise invariance is partly achieved by selectively responding to long sounds with sharp spectral structure. Finally, to demonstrate that such computations could explain noise invariance, we designed a biologically inspired noise-filtering algorithm that can be used to separate song or speech from noise. This novel noise-filtering method performs as well as other state-of-the-art de-noising algorithms and could be used in clinical or consumer oriented applications. Our biologically inspired model also shows how high-level noise-invariant responses could be created from neural responses typically found in primary auditory cortex.

  5. Noise-invariant neurons in the avian auditory cortex: hearing the song in noise.

    Directory of Open Access Journals (Sweden)

    R Channing Moore

    Full Text Available Given the extraordinary ability of humans and animals to recognize communication signals over a background of noise, describing noise invariant neural responses is critical not only to pinpoint the brain regions that are mediating our robust perceptions but also to understand the neural computations that are performing these tasks and the underlying circuitry. Although invariant neural responses, such as rotation-invariant face cells, are well described in the visual system, high-level auditory neurons that can represent the same behaviorally relevant signal in a range of listening conditions have yet to be discovered. Here we found neurons in a secondary area of the avian auditory cortex that exhibit noise-invariant responses in the sense that they responded with similar spike patterns to song stimuli presented in silence and over a background of naturalistic noise. By characterizing the neurons' tuning in terms of their responses to modulations in the temporal and spectral envelope of the sound, we then show that noise invariance is partly achieved by selectively responding to long sounds with sharp spectral structure. Finally, to demonstrate that such computations could explain noise invariance, we designed a biologically inspired noise-filtering algorithm that can be used to separate song or speech from noise. This novel noise-filtering method performs as well as other state-of-the-art de-noising algorithms and could be used in clinical or consumer oriented applications. Our biologically inspired model also shows how high-level noise-invariant responses could be created from neural responses typically found in primary auditory cortex.

  6. Architectures for radio over fiber transmission of high-quality video and data signals

    DEFF Research Database (Denmark)

    Lebedev, Alexander

    with a constraint on complexity. For wireless personal area networks distribution, we explore the notion of joint optimization of physical layer parameters of a fiber-wireless link (optical power levels, wireless transmission distance) and the codec parameters (quantization, error-resilience tools) based...... on the peak signal-to-noise ratio as an objective video quality metric for compressed video transmission. Furthermore, we experimentally demonstrate uncompressed 1080i highdefinition video distribution in V-band (50–75 GHz) and W-band (75–110 GHz) fiber-wireless links achieving 3 m of wireless transmission...... efficient wired/wireless backhaul of picocell networks. Gigabit signal transmission is realized in combined fiber-wireless-fiber link enabling simultaneous backhaul of dense metropolitan and suburban areas. In this Thesis, we propose a technique to combat periodic chromatic dispersion-induced radio...

  7. SINR balancing in the downlink of cognitive radio networks with imperfect channel knowledge

    KAUST Repository

    Hanif, Muhammad Fainan

    2010-01-01

    In this paper we consider the problem of signal-to-interference-plus-noise ratio (SINR) balancing in the downlink of cognitive radio (CR) networks while simultaneously keeping interference levels at primary user (PU) receivers (RXs) below an acceptable threshold with uncertain channel state information available at the CR base-station (BS). We optimize the beamforming vectors at the CR BS so that the worst user SINR is maximized and transmit power constraints at the CR BS and interference constraints at the PU RXs are satisfied. With uncertainties in the channel bounded by a Euclidean ball, the semidefinite program (SDP) modeling the balancing problem is solved using the recently developed convex iteration technique without relaxing the rank constraints. Numerical simulations are conducted to show the effectiveness of the proposed technique in comparison to known approximations.

  8. High Dynamic Range RF Front End with Noise Cancellation and Linearization for WiMAX Receivers

    Directory of Open Access Journals (Sweden)

    J.-M. Wu

    2012-06-01

    Full Text Available This research deals with verification of the high dynamic range for a heterodyne radio frequency (RF front end. A 2.6 GHz RF front end is designed and implemented in a hybrid microwave integrated circuit (HMIC for worldwide interoperability for microwave access (WiMAX receivers. The heterodyne RF front end consists of a low-noise amplifier (LNA with noise cancellation, an RF bandpass filter (BPF, a downconverter with linearization, and an intermediate frequency (IF BPF. A noise canceling technique used in the low-noise amplifier eliminates a thermal noise and then reduces the noise figure (NF of the RF front end by 0.9 dB. Use of a downconverter with diode linearizer also compensates for gain compression, which increases the input-referred third-order intercept point (IIP3 of the RF front end by 4.3 dB. The proposed method substantially increases the spurious-free dynamic range (DRf of the RF front end by 3.5 dB.

  9. The impact of a noise reduction quality improvement project upon sound levels in the open-unit-design neonatal intensive care unit.

    Science.gov (United States)

    Liu, W F

    2010-07-01

    To decrease measured sound levels in the neonatal intensive care unit through implementation of human factor and minor design modification strategies. Prospective time series. Two open-unit-design neonatal centers. Implementation of a coordinated program of noise reduction strategies did not result in any measurable improvement in levels of loudness or quiet. Two centers, using primarily human behavior noise reduction strategies, were unable to demonstrate measurable improvements in sound levels within the occupied open-unit-design neonatal intensive care unit.

  10. Event reconstruction using the radio-interferometric technique in the frame of AERA

    Energy Technology Data Exchange (ETDEWEB)

    Rogozin, Dmytro [Institut fuer Experimentelle Kernphysik, Karlsruher Institut fuer Technologie (KIT) (Germany); Collaboration: Pierre-Auger-Collaboration

    2016-07-01

    It is a well-known fact that there is coherent radio emission induced by extensive air-showers. This fact is exploited in the Auger Engineering Radio Array (AERA), the radio extension of the Pierre Auger Observatory. This is a unique radio experiment due to its world-largest size of 17 km{sup 2}, and due to its precise nanosecond timing calibration. These features become crucial for detection of highly inclined air-showers with their very large foot-prints, and for the ability to apply interferometric reconstruction techniques. The standard reconstruction techniques typically treat all radio stations as separate detectors. Nevertheless there is a possibility to do an interferometric analysis. This means combining all detected signals from all antennas in a specific way. In this talk we present a beam-forming interferometric technique and its application to AERA. According to the definition of the beam-forming quantities one can expect its correlation with the shower parameters such as energy of the primary particle and distance to the shower maximum. At the first step, Monte-Carlo simulations of AERA events including the noise from measured events were used to test these dependencies. The results and the future perspectives of this method are discussed with a particular emphasis on very inclined air-showers where the aforementioned correlations are assumed to be strongest.

  11. Richton Dome noise analysis: Revision 2

    International Nuclear Information System (INIS)

    1985-11-01

    A study was performed as part of the Civilian Radioactive Waste Management Program to quantify the level and effect of noise from the various major phases of development of the proposed potentially acceptable nuclear waste repository site at Richton Dome, Mississippi. This report contains the results of a predictive noise level study for the site characterization, repository construction, and repository operational phases. Included herein are graphic representations of energy averaged day/night sound levels representing impact zones expected during each phase. Sound levels from onsite and offsite activity including traffic on highways and railroad routes are presented in isopleth maps. A description of the Environmental Noise Prediction Model used for the study, the study basis and methodologies, and actual modeling data are provided. Noise and vibration levels from blasting are also predicted and evaluated. Protective noise criteria containing a margin of safety are used for persons in relation to residences, schools, churches, and agricultural areas. Protective ground motion criteria for residential dwelling and for human annoyance are used in the evaluation. The evaluation provides the bases for assessing the noise impacts from the related activities at the proposed repository. 24 refs., 8 figs., 8 tabs

  12. The 136 MHz/400 MHz earth station antenna-noise temperature prediction program documentation for RAE-B

    Science.gov (United States)

    Chin, M.

    1972-01-01

    A simulation study to determine the 136 MHz and 400 MHz noise temperature of the ground network antennas which will track the RAE-B satellite during data transmission periods is described. Since the noise temperature of the antenna effectively sets the signal-to-noise ratio (SNR) of the received signal, a knowledge of SNR will be helpful in locating the optimum time windows for data transmission during low-noise periods. Antenna-noise temperatures at 136 MHz and 400 MHz will be predicted for selected earth-based ground stations which will support RAE-B. The antenna-noise temperature predictions will include the effects of galactic-brightness temperature, the sun, and the brightest radio stars. Predictions will cover the ten-month period from March 1, 1973 to December 31, 1973. The RAE-B mission will be expecially susceptible to SNR degradation during the two eclipses of the Sun occurring in this period.

  13. Traffic Noise Assessment at Residential Areas in Skudai, Johor

    Science.gov (United States)

    Sulaiman, F. S.; Darus, N.; Mashros, N.; Haron, Z.; Yahya, K.

    2018-03-01

    Vehicles passing by on roadways in residential areas may produce unpleasant traffic noise that affects the residents. This paper presents the traffic noise assessment of three selected residential areas located in Skudai, Johor. The objectives of this study are to evaluate traffic characteristics at selected residential areas, determine related noise indices, and assess impact of traffic noise. Traffic characteristics such as daily traffic volume and vehicle speed were evaluated using automatic traffic counter (ATC). Meanwhile, noise indices like equivalent continuous sound pressure level (LAeq), noise level exceeded 10% (L10) and 90% (L90) of measurement time were determined using sound level meter (SLM). Besides that, traffic noise index (TNI) and noise pollution level (LNP) were calculated based on the measured noise indices. The results showed an increase in noise level of 60 to 70 dBA maximum due to increase in traffic volume. There was also a significant change in noise level of more than 70 dBA even though average vehicle speed did not vary significantly. Nevertheless, LAeq, TNI, and LNP values for all sites during daytime were lower than the maximum recommended levels. Thus, residents in the three studied areas were not affected in terms of quality of life and health.

  14. Measured Noise from Small Unmanned Aerial Vehicles

    Science.gov (United States)

    Cabell, Randolph; McSwain, Robert; Grosveld, Ferdinand

    2016-01-01

    Proposed uses of small unmanned aerial vehicles (UAVs), including home package delivery, have the potential to expose large portions of communities to a new noise source. This paper discusses results of flyover noise measurements of four small UAVs, including an internal combustion-powered model airplane and three battery-powered multicopters. Basic noise characteristics of these vehicles are discussed, including spectral properties and sound level metrics such as sound pressure level, effective perceived noise level, and sound exposure level. The size and aerodynamic characteristics of the multicopters in particular make their flight path susceptible to atmospheric disturbances such as wind gusts. These gusts, coupled with a flight control system that varies rotor speed to maintain vehicle stability, create an unsteady acoustic signature. The spectral variations resulting from this unsteadiness are explored, in both hover and flyover conditions for the multicopters. The time varying noise, which differs from the relatively steady noise generated by large transport aircraft, may complicate the prediction of human annoyance using conventional sound level metrics.

  15. Novel Acoustic Feedback Cancellation Approaches In Hearing Aid Applications Using Probe Noise and Probe Noise Enhancement

    DEFF Research Database (Denmark)

    Guo, Meng; Jensen, Søren Holdt; Jensen, Jesper

    2012-01-01

    . In many cases, this bias problem causes the cancellation system to fail. The traditional probe noise approach, where a noise signal is added to the loudspeaker signal can, in theory, prevent the bias. However, in practice, the probe noise level must often be so high that the noise is clearly audible...... and annoying; this makes the traditional probe noise approach less useful in practical applications. In this work, we explain theoretically the decreased convergence rate when using low-level probe noise in the traditional approach, before we propose and study analytically two new probe noise approaches...... the proposed approaches much more attractive in practical applications. We demonstrate this through a simulation experiment with audio signals in a hearing aid acoustic feedback cancellation system, where the convergence rate is improved by as much as a factor of 10....

  16. Profiling Saturn's rings by radio occultation

    International Nuclear Information System (INIS)

    Marouf, E.A.; Tyler, G.L.; Rosen, P.A.

    1986-01-01

    The development of reconstruction algorithms that correct for diffraction effects in radio occultation measurements is described. The reciprocal Fresnel transform relationship between the complex amplitude of the observed coherent signal and the complex microwave transmittance of the rings is derived using the Huygens-Fresnel formulation of the diffraction problem. The effects of the finite data segment width, the uncertainties in the Fresnel scale, systematic phase errors in the kernel of the inverse transform, reference oscillator instabilities, and random noise measurements on the resolution of the reconstructed transmittance are analyzed. Examples of reconstructed opacity profiles for some regions of Saturn's rings derived by applying the reconstruction theory to Voyager 1 at Saturn data are presented. 35 references

  17. First radio astronomy from space - RAE

    International Nuclear Information System (INIS)

    Kaiser, M.L.

    1987-01-01

    The spacecraft design, instrumentation, and performance of the Radio Astronomy Explorer (RAE) satellites (RAE-1 launched to earth orbit in 1968 and RAE-2 launched to lunar orbit in 1972) are reviewed and illustrated with drawings, diagrams, and graphs of typical data. Consideration is given to the three pairs of antennas, the Ryle-Vonberg and burst radiometers, and problems encountered with antenna deployment and observing patterns. Results summarized include observations of type III solar bursts, the spectral distribution of cosmic noise in broad sky regions, Jupiter at low frequencies, and auroral kilometric radiation (AKR) from the earth. The importance of avoiding the AKR bands in designing future space observatories is stressed. 11 references

  18. Innovative Technique for Noise Reduction in Spacecraft Doppler Tracking for Planetary Interior Studies

    Science.gov (United States)

    Notaro, V.; Armstrong, J. W.; Asmar, S.; Di Ruscio, A.; Iess, L.; Mariani, M., Jr.

    2017-12-01

    Precise measurements of spacecraft range rate, enabled by two-way microwave links, are used in radio science experiments for planetary geodesy including the determination of planetary gravitational fields for the purpose of modeling the interior structure. The final accuracies in the estimated gravity harmonic coefficients depend almost linearly on the Doppler noise in the link. We ran simulations to evaluate the accuracy improvement attainable in the estimation of the gravity harmonic coefficients of Venus (with a representative orbiter) and Mercury (with the BepiColombo spacecraft), using our proposed innovative noise-cancellation technique. We showed how the use of an additional, smaller and stiffer, receiving-only antenna could reduce the leading noise sources in a Ka-band two-way link such as tropospheric and antenna mechanical noises. This is achieved through a suitable linear combination (LC) of Doppler observables collected at the two antennas at different times. In our simulations, we considered a two-way link either from NASA's DSS 25 antenna in California or from ESA's DSA-3 antenna in Malargüe (Argentina). Moreover, we selected the 12-m Atacama Pathfinder EXperiment (APEX) in Chile as the three-way antenna and developed its tropospheric noise model using available atmospheric data and mechanical stability specifications. For an 8-hour Venus orbiter tracking pass in Chajnantor's winter/night conditions, the accuracy of the simulated LC Doppler observable at 10-s integration time is 6 mm/s, to be compared to 23 mm/s for the two-way link. For BepiColombo, we obtained 16.5 mm/s and 35 mm/s, respectively for the LC and two-way links. The benefits are even larger at longer time scales. Numerical simulations indicate that such noise reduction would provide significant improvements in the determination of Venus's and Mercury's gravity field coefficients. If implemented, this noise-reducing technique will be valuable for planetary geodesy missions, where the

  19. Reorganization of auditory map and pitch discrimination in adult rats chronically exposed to low-level ambient noise

    Directory of Open Access Journals (Sweden)

    Weimin eZheng

    2012-09-01

    Full Text Available Behavioral adaption to a changing environment is critical for an animal’s survival. How well the brain can modify its functional properties based on experience essentially defines the limits of behavioral adaptation. In adult animals the extent to which experience shapes brain function has not been fully explored. Moreover, the perceptual consequences of experience-induced changes in the brains of adults remain unknown. Here we show that the tonotopic map in the primary auditory cortex of adult rats living with low-level ambient noise underwent a dramatic reorganization. Behaviorally, chronic noise-exposure impaired fine, but not coarse pitch discrimination. When tested in a noisy environment, the noise-exposed rats performed as well as in a quiet environment whereas the control rats performed poorly. This suggests that noise-exposed animals had adapted to living in a noisy environment. Behavioral pattern analyses revealed that stress or distraction engendered by the noisy background could not account for the poor performance of the control rats in a noisy environment. A reorganized auditory map may therefore have served as the neural substrate for the consistent performance of the noise-exposed rats in a noisy environment.

  20. Mapping of radio frequency electromagnetic field exposure levels in outdoor environment and comparing with reference levels for general public health.

    Science.gov (United States)

    Cansiz, Mustafa; Abbasov, Teymuraz; Kurt, M Bahattin; Celik, A Recai

    2018-03-01

    In this study, radio frequency electromagnetic field exposure levels were measured on the main streets in the city center of Diyarbakır, Turkey. Measured electric field levels were plotted on satellite imagery of Diyarbakır and were compared with exposure guidelines published by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Exposure measurements were performed in dense urban, urban and suburban areas each day for 7 consecutive days. The measurement system consisted of high precision and portable spectrum analyzer, three-axis electric field antenna, connection cable and a laptop which was used to record the measurement samples as a data logger. The highest exposure levels were detected for two places, which are called Diclekent and Batıkent. It was observed that the highest instantaneous electric field strength value for Batıkent was 7.18 V/m and for Diclekent was 5.81 V/m. It was statistically determined that the main contributor band to the total exposure levels was Universal Mobile Telecommunications System band. Finally, it was concluded that all measured exposure levels were lower than the reference levels recommended by ICNIRP for general public health.

  1. Towards a better understanding of helicopter external noise

    Science.gov (United States)

    Damongeot, A.; Dambra, F.; Masure, B.

    The problem of helicopter external noise generation is studied taking into consideration simultaneously the multiple noise sources: rotor rotational-, rotor broadband -, and engine noise. The main data are obtained during flight tests of the rather quiet AS 332 Super Puma. The flight procedures settled by ICAO for noise regulations are used: horizontal flyover at 90 percent of the maximum speed, approach at minimum power velocity, take-off at best rate of climb. Noise source levels are assessed through narrow band analysis of ground microphone recordings, ground measurements of engine noise and theoretical means. With the perceived noise level unit used throughout the study, relative magnitude of noise sources is shown to be different from that obtained with linear noise unit. A parametric study of the influence of some helicopter parameters on external noise has shown that thickness-tapered, chord-tapered, and swept-back blade tips are good means to reduce the overall noise level in flyover and approach.

  2. Noise-Induced Hearing Loss - A Preventable Disease? Results of a 10-Year Longitudinal Study of Workers Exposed to Occupational Noise.

    Science.gov (United States)

    Frederiksen, Thomas W; Ramlau-Hansen, Cecilia H; Stokholm, Zara A; Grynderup, Matias B; Hansen, Åse M; Kristiansen, Jesper; Vestergaard, Jesper M; Bonde, Jens P; Kolstad, Henrik A

    2017-01-01

    To survey current, Danish industrial noise levels and the use of hearing protection devices (HPD) over a 10-year period and to characterise the association between occupational noise and hearing threshold shift in the same period. Furthermore, the risk of hearing loss among the baseline and the follow-up populations according to first year of occupational noise exposure is evaluated. In 2001-2003, we conducted a baseline survey of noise- and hearing-related disorders in 11 industries with suspected high noise levels. In 2009-2010, we were able to follow up on 271 out of the 554 baseline workers (49%). Mean noise levels per industry and self-reported HPD use are described at baseline and follow-up. The association between cumulative occupational noise exposure and hearing threshold shift over the 10-year period was assessed using linear regression, and the risk of hearing loss according to year of first occupational noise exposure was evaluated with logistic regression. Over the 10-year period, mean noise levels declined from 83.9 dB(A) to 82.8 dB(A), and for workers exposed >85 dB(A), the use of HPD increased from 70.1 to 76.1%. We found a weak, statistically insignificant, inverse association between higher ambient cumulative noise exposure and poorer hearing (-0.10 dB hearing threshold shift per dB-year (95% confidence interval (CI): -0.36; 0.16)). The risk of hearing loss seemed to increase with earlier first year of noise exposure, but odds ratios were only statistically significant among baseline participants with first exposure before the 1980s (odds ratio: 1.90, 95% CI: 1.11; 3.22). We observed declining industrial noise levels, increased use of HPD and no significant impact on hearing thresholds from current ambient industrial noise levels, which indicated a successful implementation of Danish hearing conservation programs.

  3. Noise levels in a neonatal intensive care unit in the Cape metropole ...

    African Journals Online (AJOL)

    Introduction. Continuous noise exposure is potentially harmful to infants\\' auditory systems and wellbeing. Although the effects of noise on infants in a neonatal intensive care unit (NICU) have been well researched overseas, limited studies have been conducted in South Africa. Aim. To conduct a detailed noise assessment ...

  4. Type of activity and order of experimental conditions affect noise annoyance by identifiable and unidentifiable transportation noise.

    Science.gov (United States)

    White, Kim; Bronkhorst, Adelbert W; Meeter, Martijn

    2018-04-01

    Previous studies have shown that identifiability of sound sources influence noise annoyance levels. The aim of the present experiment was to additionally study the effects of actively performing a task versus a less active pastime on noise annoyance. This was done by asking participants to perform a task (task condition) or read a magazine of their choice (no-task condition), while listening to identifiable and unidentifiable samples of transportation noise at varying sound exposure levels (55-85 ASEL). Annoyance was higher for identifiable samples (recordings) than for unidentifiable transformed samples (with equal spectral energy and envelope). Although there was no main effect of activity type on noise annoyance, for the transformed samples, an interaction was found between activity type and sound exposure levels: annoyance started lower in the no-task condition, but rose more steeply with ascending exposure levels than was the case during task performance (large effect). When assessing order effects, it was found that annoyance was higher when the task condition came first, especially for lower sound exposure levels (large effects). It is therefore concluded that the type of activity and the condition order do influence noise annoyance but in interaction with exposure levels, the type of noise and habituation.

  5. Physiologic correlates to background noise acceptance

    Science.gov (United States)

    Tampas, Joanna; Harkrider, Ashley; Nabelek, Anna

    2004-05-01

    Acceptance of background noise can be evaluated by having listeners indicate the highest background noise level (BNL) they are willing to accept while following the words of a story presented at their most comfortable listening level (MCL). The difference between the selected MCL and BNL is termed the acceptable noise level (ANL). One of the consistent findings in previous studies of ANL is large intersubject variability in acceptance of background noise. This variability is not related to age, gender, hearing sensitivity, personality, type of background noise, or speech perception in noise performance. The purpose of the current experiment was to determine if individual differences in physiological activity measured from the peripheral and central auditory systems of young female adults with normal hearing can account for the variability observed in ANL. Correlations between ANL and various physiological responses, including spontaneous, click-evoked, and distortion-product otoacoustic emissions, auditory brainstem and middle latency evoked potentials, and electroencephalography will be presented. Results may increase understanding of the regions of the auditory system that contribute to individual noise acceptance.

  6. Noise from wind turbines

    International Nuclear Information System (INIS)

    Andersen, B.; Larsen, P.

    1993-01-01

    Denmark has 3200 wind turbines with an installed maximum capacity of 418MW. The most important Danish research projects into wind turbine noise and the main results are listed. These date from 1983. Two comprehensive studies are currently in progress. The first is an analytical and empirical investigation of aerodynamic noise from wind turbine rotors and has so far dealt mainly with tip noise. The measurement method, using a hard board mounted microphone on the ground near the turbine, is described. Four different tip designs have been tested. Some examples of reference sound power level spectra for three of the designs are presented. During the past two years a computerbased data acquisition system has been used for real-time determination of sound power levels. The second study, which has just commenced, is on annoyance from wind turbine noise. It will include noise measurements, masking calculations and a social survey on the perceived nuisance. (UK)

  7. The first radio astronomy from space - RAE

    Science.gov (United States)

    Kaiser, M. L.

    1987-01-01

    The spacecraft design, instrumentation, and performance of the Radio Astronomy Explorer (RAE) satellites (RAE-1 launched to earth orbit in 1968 and RAE-2 launched to lunar orbit in 1972) are reviewed and illustrated with drawings, diagrams, and graphs of typical data. Consideration is given to the three pairs of antennas, the Ryle-Vonberg and burst radiometers, and problems encountered with antenna deployment and observing patterns. Results summarized include observations of type III solar bursts, the spectral distribution of cosmic noise in broad sky regions, Jupiter at low frequencies, and auroral kilometric radiation (AKR) from the earth. The importance of avoiding the AKR bands in designing future space observatories is stressed.

  8. Noise in CdZnTe detectors

    International Nuclear Information System (INIS)

    Luke, P. N.; Amman, M.; Lee, J. S.; Manfredi, P. F.

    2000-01-01

    Noise in CdZnTe devices with different electrode configurations was investigated. Measurements on devices with guard-ring electrode structures showed that surface leakage current does not produce any significant noise. The parallel white noise component of the devices appeared to be generated by the bulk current alone, even though the surface current was substantially higher. This implies that reducing the surface leakage current of a CdZnTe detector may not necessarily result in a significant improvement in noise performance. The noise generated by the bulk current is also observed to be below full shot noise. This partial suppression of shot noise may be the result of Coulomb interaction between carriers or carrier trapping. Devices with coplanar strip electrodes were observed to produce a 1/f noise term at the preamplifier output. Higher levels of this 1/f noise were observed with decreasing gap widths between electrodes. The level of this 1/f noise appeared to be independent of bias voltage and leakage current but was substantially reduced after certain surface treatments

  9. Nonlinearity effect of electro-optical modulator response in double spread CDMA radio-over-fiber transmissions

    Science.gov (United States)

    Huang, Jen-Fa; Yen, Chih-Ta; Li, Tzung-Yen

    2008-07-01

    This study presents a double-spread code-division multiple-access (CDMA) scheme for radio-over-fiber (RoF) transmissions. The network coder/decoders (codecs) are implemented using arrayed-waveguide grating (AWG) routers coded with maximal-length sequence ( M-sequence) codes. The effects of phase-induced intensity noise (PIIN) and multiple-access interference (MAI) on the system performance are evaluated numerically for different values of the optical modulation index (OMI) during the nonlinear electro-optical modulator (EOM) response. At low OMI optical device noise is dominant, but at high OMI nonlinear effect becomes significant. Numerical result shows that the system performance is highly sensitive to the OMI. Therefore, specifying an appropriate value of the OMI is essential in optimizing the system performance. The influence of the degree of polarization (DOP) in the system is also discussed. By employing the scrambler in front of the balanced photo-detector, the system performance can be enhanced. The high-performance, low-cost characteristics of the double-spread CDMA render the scheme an ideal solution for radio-CDMA wireless system cascaded with optical CDMA network.

  10. No impact on P-gp level in radio-resistant Mcf-7 cells

    International Nuclear Information System (INIS)

    Madhu, L.N.; Rao, Shama; Sarojini, B.K.

    2016-01-01

    Cancer has become the leading cause of human death worldwide. One possible cause for therapeutic failure is that residual tumor cells are reminiscent of stem cells, which ultimately give rise to secondary tumors or distant metastasis. The property of resistance to radiation therapy or chemotherapy might be the major clinical criterion to characterize 'cancer stem cells (CSCs)'. In the process of radiotherapy, the radiosensitive cancer will become a radioresistant one. Such radio-resistance cells might also show the characters of multi drug resistance (MRD) properties which may affect the chemotherapy process. The present study was carried out to know the expression level of P-gp, a MRD protein in radioresistance breast cancer cells. The study conducted by exposing the MCF-7 cells to 4Gy of gamma radiation

  11. The recommendations of the noise working group

    International Nuclear Information System (INIS)

    Legerton, M.L.

    1997-01-01

    In 1993 the DTI set up a Working Group to define a framework which can be used to measure and rate the noise from wind turbines. The final report of the Noise Working Group is now available for publication. The advice on the setting of noise limits for wind farms is largely unaltered from the preliminary recommendations presented at the 17th BWEA Annual Conference [1]. This paper recaps on those recommendations and provides additional information on the measurement procedures to be used with the recommendations on noise limits. The paper describes the measurement of the existing background noise climate on which the limits are based and the procedure to be used for the measurement of turbine noise levels in the investigation of complaints. The noise limits are rated noise levels in that they can include a penalty for tones present in the noise. The level of penalty depends upon the audibility of the tone and measurement procedure for determining audibility and the associated penalty system are also described. (author)

  12. Transmit Antenna Selection for Power Adaptive Underlay Cognitive Radio with Instantaneous Interference Constraint

    KAUST Repository

    Hanif, Muhammad

    2017-03-31

    The high hardware cost associated with multiple antennas at the secondary transmitter of an underlay cognitive radio (CR) can be reduced by antenna selection. This paper analyzes different power adaptive transmit antenna selection (TAS) schemes for an underlay CR, which ensure that the instantaneous interference caused by the secondary transmitter to the primary receiver is below a predetermined level. We consider the optimal continuous power adaptive TAS and present a low-complexity antenna and power level selection scheme, named sequential antenna and power level selection scheme (SAPS), for discrete power adaptation. Exact statistical characterizations of the signal-to-interference plus noise ratio at the secondary receiver are derived for the considered schemes. Based on the newly derived statistics, we prove that the considered schemes achieve the highest diversity order equaling the number of antennas at the secondary transmitter. Further, we also derive a closed-form expression of the ergodic capacity for the underlay CR with SAPS scheme. Finally, we show that the proposed scheme outperforms existing schemes in terms of ergodic capacity.

  13. Assessment of traffic noise levels in urban areas using different soft computing techniques.

    Science.gov (United States)

    Tomić, J; Bogojević, N; Pljakić, M; Šumarac-Pavlović, D

    2016-10-01

    Available traffic noise prediction models are usually based on regression analysis of experimental data, and this paper presents the application of soft computing techniques in traffic noise prediction. Two mathematical models are proposed and their predictions are compared to data collected by traffic noise monitoring in urban areas, as well as to predictions of commonly used traffic noise models. The results show that application of evolutionary algorithms and neural networks may improve process of development, as well as accuracy of traffic noise prediction.

  14. A Literature Survey of Noise Pollution.

    Science.gov (United States)

    Shih, H. H.

    Physically, noise is a complex sound that has little or no periodicity. However, the essential characteristic of noise is its undesirability. Thus, noise can be defined as any annoying or unwanted sound. In recent years, the rapid increase of noise level in our environment has become a national public health hazard. Noise affects man's state of…

  15. GPK heading machines with noise suppression means. [USSR

    Energy Technology Data Exchange (ETDEWEB)

    Geshlin, L.A.; Anenberg, G.I.

    1981-11-01

    Chain conveyor is the main noise pollution source of the GPK heading machine. When the conveyor forms a straight line its noise level ranges from 100 to 106 dB and when bent at a 30 degree angle the noise level is from 102 to 107 dB. The mean noise level in the two positions is 103 and 105 dB respectively. The Donetsk Research Scientific Institute for Occupational Hygiene has developed a system for noise suppression using rubber elements which are particularly efficient when the conveyor is bent. Rubber elements also reduce mechanical vibrations of the chain. Design of the modernized conveyors is shown in three schemes. Operational tests show that use of rubber suppresses noise by 5 to 10 dB, and on the average by 8 dB. Noise level measured at the operator's working place amounts to 89 dB. The noise pollution control measures developed by the Institute are economical and do not exceed 1% of the conveyor price.

  16. Radio stars

    International Nuclear Information System (INIS)

    Hjellming, R.M.; Gibson, D.M.

    1985-01-01

    Studies of stellar radio emission became an important field of research in the 1970's and have now expanded to become a major area of radio astronomy with the advent of new instruments such as the Very Large Array in New Mexico and transcontinental telescope arrays. This volume contains papers from the workshop on stellar continuum radio astronomy held in Boulder, Colorado, and is the first book on the rapidly expanding field of radio emission from stars and stellar systems. Subjects covered include the observational and theoretical aspects of stellar winds from both hot and cool stars, radio flares from active double star systems and red dwarf stars, bipolar flows from star-forming regions, and the radio emission from X-ray binaries. (orig.)

  17. Effect of cigarette smoking on noise-induced hearing loss in workers exposed to occupational noise in China.

    Science.gov (United States)

    Tao, Liyuan; Davis, Robert; Heyer, Nicholas; Yang, Qiuling; Qiu, Wei; Zhu, Liangliang; Li, Nan; Zhang, Hua; Zeng, Lin; Zhao, Yiming

    2013-01-01

    Excessive exposure to high noise level environments has the potential to cause noise-induced hearing loss (NIHL), and cigarette smoking has also been shown to have a potential adverse effect on hearing. The aim of this study was to determine whether smoking interacts with noise in the development of hearing loss, and if so, the extent of the contribution from smoking on NIHL. A cross-sectional study was designed to assess the effect of smoking on NIHL in 517 male workers (non-smokers: N = 199; smokers: N = 318) exposed to a high-level industrial noise environment in China. Shift-long temporal waveforms of the noise that workers were exposed to for evaluation of noise exposures, and audiometric threshold measures were obtained on all selected subjects. The subjects used hearing protection devices only within the last 1-2 years. The results suggest that smoking has an adverse effect on NIHL in workers exposed to high level industrial noise, i.e., the median high frequency hearing thresholds were significantly greater in smokers than non-smokers exposed to noise for more than 10 years. This effect was observed at 4.0 and 6.0 kHz. Smoking did not have an adverse effect on NIHL in workers exposed to noise less than 10 years. Multivariate regression analysis revealed that the odds ratio (OR) for high frequency hearing loss (i.e., hearing threshold greater than 40 dB at 4.0 kHz) were 1.94 for smokers in comparison to non-smokers. The results suggest that: (1) smokers have a higher risk of developing high frequency hearing loss than non-smokers with a similar occupational noise exposure, and (2) the interaction between cigarette smoking and high-level noise exposure may be additive. There is a need to develop and analyze a larger database of workers with well-documented exposures and smoking histories for better understanding of the effect of smoking on NIHL incurred from high-level industrial noise exposures. A better understanding of the role of smoking may lead to its

  18. Computer model for estimating electric utility environmental noise

    International Nuclear Information System (INIS)

    Teplitzky, A.M.; Hahn, K.J.

    1991-01-01

    This paper reports on a computer code for estimating environmental noise emissions from the operation and the construction of electric power plants that was developed based on algorithms. The computer code (Model) is used to predict octave band sound power levels for power plant operation and construction activities on the basis of the equipment operating characteristics and calculates off-site sound levels for each noise source and for an entire plant. Estimated noise levels are presented either as A-weighted sound level contours around the power plant or as octave band levels at user defined receptor locations. Calculated sound levels can be compared with user designated noise criteria, and the program can assist the user in analyzing alternative noise control strategies

  19. Noise Reduction Effect of Multiple-Sampling-Based Signal-Readout Circuits for Ultra-Low Noise CMOS Image Sensors

    Directory of Open Access Journals (Sweden)

    Shoji Kawahito

    2016-11-01

    Full Text Available This paper discusses the noise reduction effect of multiple-sampling-based signal readout circuits for implementing ultra-low-noise image sensors. The correlated multiple sampling (CMS technique has recently become an important technology for high-gain column readout circuits in low-noise CMOS image sensors (CISs. This paper reveals how the column CMS circuits, together with a pixel having a high-conversion-gain charge detector and low-noise transistor, realizes deep sub-electron read noise levels based on the analysis of noise components in the signal readout chain from a pixel to the column analog-to-digital converter (ADC. The noise measurement results of experimental CISs are compared with the noise analysis and the effect of noise reduction to the sampling number is discussed at the deep sub-electron level. Images taken with three CMS gains of two, 16, and 128 show distinct advantage of image contrast for the gain of 128 (noise(median: 0.29 e−rms when compared with the CMS gain of two (2.4 e−rms, or 16 (1.1 e−rms.

  20. IRAS observations of radio-quiet and radio-loud quasars

    Science.gov (United States)

    Neugebauer, G.; Soifer, B. T.; Miley, G.; Habing, H. J.; Young, E.; Low, F. J.; Beichman, C. A.; Clegg, P. E.; Harris, S.; Rowan-Robinson, M.

    1984-01-01

    Observations from 12 to 100 microns are presented of two radio-quiet and three radio-loud quasars. Over this wavelength range, all five have grossly similar continuum energy distributions. The continua of the radio-loud quasars are consistent with synchrotron radiation. There is an indication, however, of excess 100 micron emission in the two radio-quiet quasars.

  1. Traffic noise in Hyderabad city. part I: road traffic noise

    International Nuclear Information System (INIS)

    Shaikh, G.H.; Shaikh, Q.

    2000-01-01

    Traffic noise survey was conducted at 20 sites in different areas and localities in Hyderabad city and each site noise data was collected continuously from 0800 to 2000 h. The data was analyzed for L/sub A99/, L/sub A90/, L/sub A50/, L/sub 10/ and L/sub A1/, and approximate values of L/sub Aeq12h/ were evaluated for each site. The results are discussed with reference to some criteria for community annoyance and means and ways to limit high-level traffic noise are suggested. (author)

  2. Wide-band residual phase-noise measurements on 40-GHz monolithic mode-locked lasers

    DEFF Research Database (Denmark)

    Larsson, David; Hvam, Jørn Märcher

    2005-01-01

    We have performed wide-band residual phase-noise measurements on semiconductor 40-GHz mode-locked lasers by employing electrical waveguide components for the radio-frequency circuit. The intrinsic timing jitters of lasers with one, two, and three quantum wells (QW) are compared and our design......-QW laser. There is good agreement between the measured results and existing theory....

  3. Noise characteristics of U. S. synchrotron radiation sources

    International Nuclear Information System (INIS)

    Powers, L.

    1986-01-01

    Noise characteristics of the U. S. x-ray synchrotron sources are compared in the 0--2.5-kHz region. In general, little difference is found in the characteristic frequencies of the noise on focused and unfocused beamlines of a particular source, but the magnitude and white-noise levels differ. The National Synchrotron Light Source shows the least characteristic noise and the noise that is observed is small in magnitude (2--3 times the white-noise level)

  4. Search for EAS radio-emission at the Tien-Shan shower installation at a height of 3340 m above sea level

    Science.gov (United States)

    Beisenova, A.; Boos, E.; Haungs, A.; Sadykov, T.; Salihov, N.; Shepetov, A.; Tautayev, Y.; Vildanova, L.; Zhukov, V.

    2017-06-01

    The complex EAS installation of the Tien Shan mountain cosmic ray station which is situated at a height of 3340 m above sea level includes the scintillation and Cherenkov detectors of charged shower particles, an ionization calorimeter and a set of neutron detectors for registering the hadronic component of the shower, and a number of underground detectors of the penetrative EAS component. Now it is intended to expand this installation with a promising method for detecting the radio-emission generated by the particles of the developing shower. The facility for radio-emission detection consists of a three crossed dipole antennae, one being set vertically, and another two - mutually perpendicularly in a horizontal plane, all of them being connected to a three-channel radio-frequency amplifier of German production. By the passage of an extensive air shower, which is defined by a scintillation shower detector system, the output signal of antenna amplifier is digitized by a fast multichannel DT5720 ADC of Italian production, and kept within computer memory. The further analysis of the detected signal anticipates its operation according to a special algorithm and a search for the pulse of radio-emission from the shower. A functional test of the radio-installation is made with artificial signals which imitate those of the shower, and with the use of a N1996A type wave analyzer of Agilent Technologies production. We present preliminary results on the registration of extensive air shower emission at the Tien Shan installation which were collected during test measurements held in Summer 2016.

  5. Acoustics of fish shelters: background noise and signal-to-noise ratio.

    Science.gov (United States)

    Lugli, Marco

    2014-12-01

    Fish shelters (flat stones, shells, artificial covers, etc., with a hollow beneath) increase the sound pressure levels of low frequency sounds (noise ratio (SNR) in the nest. Background noise amplification by the shelter was examined under both laboratory (stones and shells) and field (stones) conditions, and the SNR of tones inside the nest cavity was measured by performing acoustic tests on stones in the stream. Stone and shell shelters amplify the background noise pressure levels inside the cavity with comparable gains and at similar frequencies of an active sound source. Inside the cavity of stream stones, the mean SNR of tones increased significantly below 125 Hz and peaked at 65 Hz (+10 dB). Implications for fish acoustic communication inside nest enclosures are discussed.

  6. Noise study in laboratories with exhaust fans

    International Nuclear Information System (INIS)

    Shaikh, G.H.; Hashmi, R.; Shareef, A.

    2005-01-01

    Noise study has been carried out in 25 laboratories fitted with exhaust fans. We have studied A- Weighted equivalent sound pressure levels (dB(A) LAeJ and equivalent octave band sound pressure levels (dB L/sub eq/ in each of the laboratories surveyed. The data collected has been analyzed for Preferred Speech Interference Levels (PSIL). The results show that the interior noise levels in these laboratories vary from 59.6 to 72.2 dB(A) L/sub Aeq/, which are very high and much beyond the interior noise limits recommended for laboratories. Some ways and means to limit emission of high-level noise from exhaust fans are also discussed. (author)

  7. Detecting signatures of cosmological recombination and reionization in the cosmic radio background

    Science.gov (United States)

    Subrahmanyan, Ravi; Shankar Narayana Rao, Udaya; Sathyanarayana Rao, Mayuri; Singh, Saurabh

    2015-08-01

    Evolution of the baryons during the Epochs of cosmological Recombination and Reionization has left traces in the cosmic radio background in the form of spectral distortions (Sunyaev & Chluba 2008 Astron. Nachrichten, 330, 657; Pritchard & Loeb 2012 Rep Prog Phys 75(8):086901). The spectral signature depends on the evolution in the ionization state in hydrogen and helium and on the spin temperature of hydrogen. These probe the physics of energy release beyond the last scattering surface at redshifts exceeding 1090 and the nature of the first sources and gas evolution down to redshift about 6. The spectral distortions are sensitive to the nature of the first stars, ultra-dwarf galaxies, accreting compact objects, and the evolving ambient radiation field: X-rays and UV from the first sources. Detection of the all-sky or global spectral distortions in the radio background is hence a probe of cosmological recombination and reionization.We present new spectral radiometers that we have purpose designed for precision measurements of spectral distortions at radio wavelengths. New antenna elements include frequency independent and electrically small fat-dipole (Raghunathan et al. 2013 IEEE TAP, 61, 3411) and monopole designs. Receiver configurations have been devised that are self-calibratable (Patra et al. 2013 Expt Astron, 36, 319) so that switching of signal paths and of calibration noise sources provide real time calibration for systematics and receiver noise. Observing strategies (Patra et al. arXiv:1412.7762) and analysis methods (Satyanarayana Rao et al. arXiv:1501.07191) have been evolved that are capable of discriminating between the cosmological signals and the substantially brighter foregrounds. We have also demonstrated the value of system designs that exploit advantages of interferometer detection (Mahesh et al. arXiv:1406.2585) of global spectral distortions.Finally we discuss how the Square Kilometer Array stations may be outfitted with precision spectral

  8. 1/f noise in graphene nanopores

    International Nuclear Information System (INIS)

    Heerema, S J; Schneider, G F; Rozemuller, M; Vicarelli, L; Zandbergen, H W; Dekker, C

    2015-01-01

    Graphene nanopores are receiving great attention due to their atomically thin membranes and intrinsic electrical properties that appear greatly beneficial for biosensing and DNA sequencing. Here, we present an extensive study of the low-frequency 1/f noise in the ionic current through graphene nanopores and compare it to noise levels in silicon nitride pore currents. We find that the 1/f noise magnitude is very high for graphene nanopores: typically two orders of magnitude higher than for silicon nitride pores. This is a drawback as it significantly lowers the signal-to-noise ratio in DNA translocation experiments. We evaluate possible explanations for these exceptionally high noise levels in graphene pores. From examining the noise for pores of different diameters and at various salt concentrations, we find that in contrast to silicon nitride pores, the 1/f noise in graphene pores does not follow Hooge’s relation. In addition, from studying the dependence on the buffer pH, we show that the increased noise cannot be explained by charge fluctuations of chemical grou