Journal articles: 'PM noise'

1

Hati, A., C. W. Nelson, and D. A. Howe. "Reducing oscillator PM noise from AM–PM noise correlation." Electronics Letters 50, no. 17 (August 2014): 1195–97. http://dx.doi.org/10.1049/el.2014.2210.

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Hati, Archita, Craig W. Nelson, and David A. Howe. "Oscillator PM Noise Reduction From Correlated AM Noise." IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 63, no. 3 (March 2016): 463–69. http://dx.doi.org/10.1109/tuffc.2016.2521614.

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Hati, Archita, Craig Nelson, and David Howe. "PM noise measurement at W-band." IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 61, no. 12 (December 2014): 1961–66. http://dx.doi.org/10.1109/tuffc.2014.006647.

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ABO-ELNOR, OSSAMA, and ALI ABOU-ELNOUR. "EFFECTS OF CIRCUIT ELEMENTS AND HARMONIC OSCILLATION POWER ON FUNDAMENTAL PM NOISE POWER OF FET OSCILLATOR." Fluctuation and Noise Letters 07, no. 03 (September 2007): L289—L298. http://dx.doi.org/10.1142/s0219477507003945.

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Analytical expressions for the PM noise in FET oscillators are derived in terms of the FET equivalent circuit elements and the passive circuitry. Efficient methods to reduce the PM noise in fundamental and in harmonic modes are suggested and implemented. The effects of the different FET equivalent circuit parameters on large-signal, small-signal, and noise behavior of FET oscillators are investigated. Finally, the effects of harmonic signal on the output noise power and on the phase noise at both fundamental and harmonic frequencies are determined.

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Hu, Wei Wei, Chang Ming Wang, and Ai Jun Zhang. "Application of Weighted Projection PM Algorithm in Estimation of DOA." Applied Mechanics and Materials 300-301 (February 2013): 746–49. http://dx.doi.org/10.4028/www.scientific.net/amm.300-301.746.

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In order to improve the decreasing resolution ability of Propagator Method (PM) algorithm under the environments like low signal noise ratio and small number of snapshots, a new weighted projection PM algorithm is proposed in this paper. This algorithm orthogonalizes noise subspace to get a new one, gains the signal subspace with the relationship between it and noise subspace, and weights the signal subspace and noise subspace with values gained by projecting integral value of steering vector in the field around the signals to each element of subspace. Simulation results show that the proposed method can keep computation simple, and also can decrease signal noise ratio threshold and snapshots threshold, so it has the better resolution ability and higher precision in snapshot deficient and low signal noise ratio scenario.

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Hati, Archita, David Howe, Fred Walls, and David Walker. "Merits of PM noise measurement over noise figure: a study at microwave frequencies." IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 53, no. 10 (October 2006): 1889–94. http://dx.doi.org/10.1109/tuffc.2006.121.

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Yan, Zheping, Di Wu, Jiajia Zhou, and Lichao Hao. "Recursive Subspace Identification of AUV Dynamic Model under General Noise Assumption." Mathematical Problems in Engineering 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/547539.

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A recursive subspace identification algorithm for autonomous underwater vehicles (AUVs) is proposed in this paper. Due to the advantages at handling nonlinearities and couplings, the AUV model investigated here is for the first time constructed as a Hammerstein model with nonlinear feedback in the linear part. To better take the environment and sensor noises into consideration, the identification problem is concerned as an errors-in-variables (EIV) one which means that the identification procedure is under general noise assumption. In order to make the algorithm recursively, propagator method (PM) based subspace approach is extended into EIV framework to form the recursive identification method called PM-EIV algorithm. With several identification experiments carried out by the AUV simulation platform, the proposed algorithm demonstrates its effectiveness and feasibility.

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Bailly, Christophe, Gildas Guilly, Diana Mavrudieva, and Patrick Lombard. "Multi-physics noise optimization in fuel pump PM motor." International Journal of Applied Electromagnetics and Mechanics 59, no. 3 (March 21, 2019): 873–80. http://dx.doi.org/10.3233/jae-171115.

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Gupta, Amitava Sen, and F. L. Walls. "Investigations of spurs and PM noise after frequency division." Measurement Science and Technology 15, no. 10 (August 21, 2004): 1982–85. http://dx.doi.org/10.1088/0957-0233/15/10/006.

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Hati, Archita, Craig W. Nelson, and David A. Howe. "Vibration-induced PM and AM noise in microwave components." IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 56, no. 10 (October 2009): 2050–59. http://dx.doi.org/10.1109/tuffc.2009.1288.

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Nelson, Craig W., and David A. Howe. "A Sub-Sampling Digital PM/AM Noise Measurement System." NCSLI Measure 7, no. 3 (September 2012): 70–73. http://dx.doi.org/10.1080/19315775.2012.11721610.

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Paull, Naomi, Daniel Krix, Fraser Torpy, and Peter Irga. "Can Green Walls Reduce Outdoor Ambient Particulate Matter, Noise Pollution and Temperature?" International Journal of Environmental Research and Public Health 17, no. 14 (July 14, 2020): 5084. http://dx.doi.org/10.3390/ijerph17145084.

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Green walls have previously demonstrated the capacity to reduce particulate matter (PM), noise pollution, and temperature conditions in manipulative experiments and computational models. There is, however, minimal evidence that green walls can influence ambient environmental conditions, especially taking into account the variable environmental conditions encountered in situ. The aim of this paper was to determine if green walls have a quantitative effect on ambient air quality in an urban environment. Ambient PM, noise, and temperature were recorded at 12 green wall and adjacent reference wall locations across a dense urban centre, over a 6-month period. The results indicated that PM levels and temperature did not significantly differ between the green wall and reference wall sites. Ambient noise at the green wall sites, however, was significantly lower than at the reference wall locations. It is suggested that mechanically assisted, or ‘active’ green wall systems may have a higher PM and temperature reduction capacity, and if so, they will be more valuable for installation in situ compared to standard passive systems, although this will require further research.

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Wang, Yonghua, Shengfu Liu, Haiquan Wu, Chengchun Zhang, Jinkai Xu, and Huadong Yu. "On-demand optimize design of sound-absorbing porous material based on multi-population genetic algorithm." e-Polymers 20, no. 1 (March 24, 2020): 122–32. http://dx.doi.org/10.1515/epoly-2020-0014.

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AbstractPorous material (PM) shows good sound absorption performance, however, the sound absorbing property of PM with different parameters are greatly different. In order to match the most suitable absorbing materials with the most satisfactory sound-absorbing performance according to the noise spectrum in different practical applications, multi-population genetic algorithm is used in this paper to optimize the parameters of porous sound absorbing structures that are commonly used according to the actual demand of noise reduction and experimental verification. The results shows that the optimization results of multi-population genetic algorithm are obviously better than the standard genetic algorithm in terms of sound absorption performance and sound absorption bandwidth. The average acoustic absorption coefficient of PM can reach above 0.6 in the range of medium frequency, and over 0.8 in the range of high frequency through optimization design. At a mid-to-high frequency environment, the PM has a better sound absorption effect and a wider frequency band than that of micro-perforated plate. However, it has a poor sound absorption effect at low frequency. So it is necessary to select suitable sound absorption material according to the actual noise spectrum.

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苗, 本萱. "One-Dimensional Stochastic Wave Equations Driven by Poisson White Noise." Pure Mathematics 11, no. 04 (2021): 552–61. http://dx.doi.org/10.12677/pm.2021.114068.

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Zannin, Paulo Henrique Trombetta, Ferdinado Quadros, Felipe Luz De Oliveira, and Eriberto Oliveira Do Nascimento. "Evaluation of Environmental Noise Generated by Household Waste Collection Trucks." Journal of Environmental Assessment Policy and Management 20, no. 04 (December 2018): 1850010. http://dx.doi.org/10.1142/s1464333218500102.

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This paper discusses a specific source of noise, which is generated by household waste collection trucks. Two areas in the city of Curitiba were chosen for evaluation, one of them a densely populated residential neighborhood and the other in downtown Curitiba. A noise map was created for each area. The evaluation, which was carried out in the daytime in the residential area and at night in the downtown area, revealed noise levels exceeding the limits established by Curitiba Municipal Law No. 10625. The regular use of utility vehicles that generate high noise levels, such as garbage trucks, during nighttime hours in residential areas is thus not sustainable from the standpoint of noise protection laws. Nighttime hours in Curitiba are 10[Formula: see text]pm to 7[Formula: see text]am, but nighttime garbage collection begins at 7[Formula: see text]pm and goes on until 4[Formula: see text]am. Therefore, changes in this schedule are advisable, given the noise impact caused by garbage collection trucks.

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Thompson, Jonathan E. "Improved Measurement Performance for the Sharp GP2Y1010 Dust Sensor: Reduction of Noise." Atmosphere 12, no. 6 (June 16, 2021): 775. http://dx.doi.org/10.3390/atmos12060775.

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Sharp GP2Y1010 dust sensors are increasingly being used within distributed sensing networks and for personal monitoring of exposure to particulate matter (PM) pollution. These dust sensors offer an easy-to-use solution at an excellent price point; however, the sensors are known to offer limited dynamic range and poor limits of detection (L.O.D.), often >15 μg m−3. The latter figure of merit precludes the use of this inexpensive line of dust sensors for monitoring PM2.5 levels in environments within which particulate pollution levels are low. This manuscript presents a description of the fabrication and circuit used in the Sharp GP2Y1010 dust sensor and reports several effective strategies to minimize noise and maximize limits of detection for PM. It was found that measurement noise is primarily introduced within the photodiode detection circuitry, and that electromagnetic interference can influence dust sensor signals dramatically. Through optimization of the external capacitor and resistor used in the LED drive circuit—and the inter-pulse delay, electromagnetic shielding, and data acquisition strategy—noise was reduced approximately tenfold, leading to a projected noise equivalent limit of detection of 3.1 μg m−3. Strategies developed within this manuscript will allow improved limits of detection for these inexpensive sensors, and further enable research toward unraveling the spatial and temporal distribution of PM within buildings and urban centers—as well as an improved understanding of effect of PM on human health.

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Du, Yongqian, Wei Hu, Guifang Li, and Shibin Liu. "Modeling and Analysis of the Nonideality of LO Pulse Overlap for Multi-Phase Passive Mixer First RF Frontend." Journal of Circuits, Systems and Computers 28, no. 05 (May 2019): 1950086. http://dx.doi.org/10.1142/s0218126619500865.

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Multi-phase passive mixer (PM) first RF frontend has regained great concern for its satisfactory noise performance comparable to LNA-first frontend. Moreover, the re-configurable impedance, bi-directional signal transparency and bi-directional impedance translation performance enable a splendid application future for the multi-phase PM-first RF frontend. However, it still suffers from quite a few nonidealities, among which the adjacent Local Oscillator (LO) pulse overlap is the remaining nonideality lacking deep research, and how the LO pulse overlap decays the impedance matching and noise performance of multi-phase PM-first RF frontend remains unclear. In this work, an accurate model is, for the first time, established and analyzed to reveal how the LO pulse overlap decays the impedance matching and noise performance of multi-phase PM-first RF frontend. The analytical and simulation results demonstrate that the impedance matching will be drastically deteriorated because of LO overlap, and when LO pulse overlap exceeds 2% the impedance matching will be collapsed, while the noise figure (NF) is deteriorated by 3.1 dB when LO overlap ranges from 0% to 2%. Moreover, even a chocking inductor technique and a technique by introducing a synchronous phase-shifted signal have been proposed to suppress the LO overlap, the gain and noise performance can be deteriorated or the power and chip area cost are big. To address this question, a LO pulse overlap suppression technique is proposed furthermore by introducing an overlap safeguard factor (OLSF) in this work. The additional impedance smaller than 2[Formula: see text][Formula: see text] in the main signal path makes the OLSF scheme beneficial for noise and gain improvement, and the proposed OLSF scheme is power, area (0.04[Formula: see text]mm[Formula: see text] and cost efficient compared with existing LO overlap suppression techniques.

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KIMURA, Kento, Aravind THARAYIL NARAYANAN, Kenichi OKADA, and Akira MATSUZAWA. "An AM-PM Noise Mitigation Technique in Class-C VCO." IEICE Transactions on Electronics E98.C, no. 12 (2015): 1161–70. http://dx.doi.org/10.1587/transele.e98.c.1161.

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Gruson, Yannick, Vincent Giordano, Ulrich L. Rohde, Ajay K. Poddar, and Enrico Rubiola. "Cross-Spectrum PM Noise Measurement, Thermal Energy, and Metamaterial Filters." IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 64, no. 3 (March 2017): 634–42. http://dx.doi.org/10.1109/tuffc.2016.2645719.

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Nelson, L. M., C. W. Nelson, and F. L. Walls. "Relationship of AM to PM noise in selected RF oscillators." IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 41, no. 5 (September 1994): 680–84. http://dx.doi.org/10.1109/58.308503.

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Rubiola, E., V. Giordano, and J. Groslambert. "Double correlating interferometer scheme for measuring PM and AM noise." Electronics Letters 34, no. 1 (1998): 93. http://dx.doi.org/10.1049/el:19980129.

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Kamble, Rahul K. "Traffic Intersections Noise Levels and Daily Noise Exposure in Chandrapur City, Central India." Indonesian Journal of Environmental Management and Sustainability 3, no. 3 (September 30, 2019): 80–92. http://dx.doi.org/10.26554/ijems.2019.3.3.80-92.

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Noise level monitoring was carried out at nine important traffic intersections of the Chandrapur city to ascertain noise levels and daily noise exposure. A pre-calibrated mini sound level meter was used for noise measurement. Observations were recorded for 24 hours and noise level during the day, night and for 24-hours was computed. Maximum noise level during daytime was 84.27 dB(A) at Bangali camp square; whereas, minimum 79.23 dB(A) at Priyadarshani square. In case of nighttime maximum 85.90 dB(A) was at Warora naka square and minimum 70.06 dB(A) at the Jatpura gate. Minimum noise level during 24-hours was at Bagla square 84.34 dB(A) and maximum 91.14 dB(A) at Warora naka square. Noise level during day and night were above the Indian noise standard for the commercial area. The Bangali camp square was identified as the most ear-splitting square during daytime and Warora naka square at nighttime and for 24-hours also. Peak noise was recorded from 10.00 am to 11.00 am and 3.00 pm to 7.00 pm. Vehicular noise, horns, and improper road design contributed significantly to noise levels at traffic intersections. Daily noise exposure analysis by Health and Safety Executive, UK software revealed Bangali camp square and Ramnagar police station square’s daily noise exposure for 0.25 hour was maximum 70 LEP,d and minimum at Gandhi square and Bagla square 65 LEP,d. Noise levels indicated no immediate effect for hearing loss. Control measures for reduction of noise levels at traffic intersections have also been proposed.

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Howe, D. A., and J. R. Ostrick. "100-GHz cooled amplifier residual pm and am noise measurements, noise figure, and jitter calculations." IEEE Transactions on Microwave Theory and Techniques 51, no. 11 (November 2003): 2235–42. http://dx.doi.org/10.1109/tmtt.2003.818934.

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Nchama, Gustavo Asumu Mboro, Angela Leon Mecias, and Mariano Rodriguez Ricard. "Perona-Malik Model with Diffusion Coefficient Depending on Fractional Gradient via Caputo-Fabrizio Derivative." Abstract and Applied Analysis 2020 (August 1, 2020): 1–15. http://dx.doi.org/10.1155/2020/7624829.

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The Perona-Malik (PM) model is used successfully in image processing to eliminate noise while preserving edges; however, this model has a major drawback: it tends to make the image look blocky. This work proposes to modify the PM model by introducing the Caputo-Fabrizio fractional gradient inside the diffusivity function. Experiments with natural images show that our model can suppress efficiently the blocky effect. Also, our model has good performance in visual quality, high peak signal-to-noise ratio (PSNR), and lower value of mean absolute error (MAE) and mean square error (MSE).

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Sumega, Martin, Pavol Rafajdus, and Marek Stulrajter. "Current Harmonics Controller for Reduction of Acoustic Noise, Vibrations and Torque Ripple Caused by Cogging Torque in PM Motors under FOC Operation." Energies 13, no. 10 (May 16, 2020): 2534. http://dx.doi.org/10.3390/en13102534.

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This article presents an effective algorithm to reduce acoustic noise, vibrations and torque ripple caused by cogging torque in three-phase Permanent Magnet (PM) motors under Field Oriented Control (FOC) operation. Cogging torque profile is suitably included into q-axis current reference, which must be then precisely tracked in order to mitigate acoustic noise, vibrations, torque ripple and speed ripple caused by cogging torque. Conventional FOC structure has been extended by a Current Harmonics Controller (CHC) to achieve precise control of dq current harmonics for all operation speeds, which is crucial to reduce impact of cogging torque and increase performance of electric drive with PM motor. Effectiveness of proposed control technique is experimentally verified by vibrations and acoustic noise measurements.

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Wang, Zhong-Min, Yixin Zhou, Fraser W. Gaspar, and Asa Bradman. "Using low cost open-face passive samplers to sample PM concentration and elemental composition in childcare facilities." Environmental Science: Processes & Impacts 22, no. 7 (2020): 1502–13. http://dx.doi.org/10.1039/d0em00075b.

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Nie, Yao, Chunyan Feng, Huan Wu, Fangfang Liu, Caili Guo, and Maosheng Fu. "Phase Noise Cancelation Based on Polarization Modulation for Massive MIMO-OFDM Systems." International Journal of Antennas and Propagation 2019 (March 13, 2019): 1–14. http://dx.doi.org/10.1155/2019/6574827.

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In massive multiple-input multiple-output (MIMO) systems, phase noise introduced by oscillators can cause severe performance loss. It leads to common phase error and intercarrier interference in massive MIMO-OFDM uplink. To solve the issue, a novel phase noise cancelation scheme based on polarization modulation for the massive MIMO-OFDM system is proposed. We first introduce the polarization modulation (PM) exploited in massive MIMO-OFDM uplink. Then, by exploiting the zero-forcing detection, we analyze the asymptotically ICI and the distribution of the transformed noise under different XPD values. Furthermore, we demonstrate that phase noise can be asymptotically canceled and only the transformed additive white Gaussian noise exists as the number of antennas at the base station is very large. Moreover, we derive the instantaneous signal-to-noise ratio (SNR) on each subcarrier and analyze the ergodic capacity. To increase the ergodic capacity performance further, a joint modulation scheme combining the PM and 2PSK is proposed and the ergodic capacity performance of the joint modulation is discussed. The simulation results show that the proposed scheme can effectively mitigate phase noise and achieve a higher ergodic capacity.

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Goeren, Danielle, Sherley John, Katie Meskill, Laura Iacono, Stacy Wahl, and Kerri Scanlon. "Quiet Time: A Noise Reduction Initiative in a Neurosurgical Intensive Care Unit." Critical Care Nurse 38, no. 4 (August 1, 2018): 38–44. http://dx.doi.org/10.4037/ccn2018219.

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BACKGROUND High noise levels in intensive care units are common. Increased noise levels can lead to sleep deprivation, increased pain perception, and delirium. The most common cause of reducible noise in intensive care units often is attributed to staff conversations. OBJECTIVES In January 2015, the neurosurgical intensive care unit staff identified noise as a problem, referencing complaints from other disciplines and family members. Quiet times from 3 am to 5 am and from 3 pm to 5 pm were agreed upon. An improvement plan was developed with a goal to decrease noise levels by 10 decibels in 6 months. METHODS Using a decibel meter, noise data were collected in 4 locations every 30 minutes during the chosen times for 8 days. Quiet time was implemented 1 week after staff, patient, and family education was completed. Decibel data were collected and evaluated after 60 days. RESULTS There were statistically significant reductions in noise levels at nurses’ station left (P = .04) and the bed 9 entrance (P = .02). Noise levels were lower, but not significantly so, for nurses’ station right (P = .12) and the bed 4 entrance (P = .06). Noise levels during quiet time decreased to an average of 10 to 15 decibels lower than baseline data. CONCLUSIONS Sharing baseline data was effective to heighten noise awareness. During quiet time, limiting conversations, eliminating environmental noise, and dimming the lights as a reminder to be quiet are 3 simple strategies that can be implemented to lessen noise.

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Suh, Inwon, and Patrick Roblin. "Model Comparison for $1/f$ Noise in Oscillators With and Without AM to PM Noise Conversion." IEEE Transactions on Microwave Theory and Techniques 59, no. 12 (December 2011): 3129–45. http://dx.doi.org/10.1109/tmtt.2011.2170086.

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Osejos-Merino, Miguel A., Martin V. Merino-Conforme, Monserrate C. Merino-Conforme, Medardo A. Saltos-Bury, and Rocío J. Cano-Andrade. "Acoustic pollution and its incidence in population health around bus station perimeter in Jipijapa city – Ecuador." Polo del Conocimiento 3, no. 11 (November 26, 2018): 353. http://dx.doi.org/10.23857/pc.v3i11.800.

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<p style="text-align: justify;">This research entitled: " Acoustic pollution and its incidence in population health around bus station perimeter in Jipijapa city - Ecuador. " was carried out during 2017. The methodology used in this work was: observation prior determination of monitoring place, the application of survey, tabulation and interpretation of results. The monitoring was done during the two-month period. The monitoring was carried out on working days (Monday and Tuesday) and non-working (Sunday) at three key points of the perimeter of the bus station. Point 1 (front), point 2 (entry), point 3 (exit). After having monitored the noise pollution, the results were: The highest level of noise was presented in the month of June on Monday afternoon rush hours (12:30 pm to 1:00 pm) at point 1 (front side) ) of the perimeter of the terrestrial terminal with a maximum monthly average of 79.8 decibels dB (A). The month of July presented a higher level of noise pollution in point 1, with a maximum monthly average of 79.9 decibels dB (A), these levels exceed the permissible limits that is 55 decibels dB (A) in a mixed commercial zone according to TULSMA. The main source that generates noise is the horn of rural and provincial buses, cars, motorcycles with defective exhaust pipes, motor vehicles in poor condition, among others. The possible damages caused by the exposure of noise pollution in inhabitants of this area with physiological and psychological effects are: headache, stress, irritability and aggressiveness, hearing loss, nervous system alterations. In addition, the respondents said they do not agree that drivers make unnecessary noises with the horn of their vehicles and agree that noise control standards should be applied; the noise that bothers most is generated by the buses. It also presents a proposal that contributes to finding solutions in noise pollution and its effects on the health of the inhabitants.</p>

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Cho, Hyuntae, and Yunju Baek. "Practical Particulate Matter Sensing and Accurate Calibration System Using Low-Cost Commercial Sensors." Sensors 21, no. 18 (September 14, 2021): 6162. http://dx.doi.org/10.3390/s21186162.

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Air pollution is a social problem, because the harmful suspended materials can cause diseases and deaths to humans. Specifically, particulate matters (PM), a form of air pollution, can contribute to cardiovascular morbidity and lung diseases. Nowadays, humans are exposed to PM pollution everywhere because it occurs in both indoor and outdoor environments. To purify or ventilate polluted air, one need to accurately monitor the ambient air quality. Therefore, this study proposed a practical particulate matter sensing and accurate calibration system using low-cost commercial sensors. The proposed system basically uses noisy and inaccurate PM sensors to measure the ambient air pollution. This paper mainly deals with three types of error caused in the light scattering method: short-term noise, part-to-part variation, and temperature and humidity interferences. We propose a simple short-term noise reduction method to correct measurement errors, an auto-fitting calibration for part-to-part repeatability to pinpoint the baseline of the signal that affects the performance of the system, and a temperature and humidity compensation method. This paper also contains the experiment setup and performance evaluation to prove the superiority of the proposed methods. Based on the evaluation of the performance of the proposed system, part-to-part repeatability was less than 2 μg/m3 and the standard deviation was approximately 1.1 μg/m3 in the air. When the proposed approaches are used for other optical sensors, it can result in better performance.

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Rubiola, E., V. Giordano, and J. Groslambert. "Improved interferometric method to measure near-carrier AM and PM noise." IEEE Transactions on Instrumentation and Measurement 48, no. 2 (April 1999): 642–46. http://dx.doi.org/10.1109/19.769677.

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饶, 维亚. "Stability of Solutions for Stochastic Volterra-Levin Equations Driven by α-Stable Noise." Pure Mathematics 09, no. 10 (2019): 1187–94. http://dx.doi.org/10.12677/pm.2019.910145.

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Tan, Chao, Ruijie Fu, Chenguang Wu, and Xinglin Li. "A Linearized Model of FID Signal for Increasing Proton Magnetometer Precision." Measurement Science Review 20, no. 3 (June 1, 2020): 115–25. http://dx.doi.org/10.2478/msr-2020-0014.

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AbstractA linearized model of frequency measurement for the Free Induction Decay (FID) signal is proposed to increase the Proton Magnetometer (PM) precision. First, the nonlinear model of frequency measurement is set up according to the characteristic of the FID signal. Then, according to the error analysis of the MCFM method, the model is linearized on the condition of precision requirement. Furthermore, to reduce the nonlinear error caused by approximate treatment and the trigger time error caused by the random noise, the Least Squares (LS) method is adopted to estimate the slope of the linearized model, and the frequency to be measured is the inverse of the slope. Finally, a PM Prototype is made to verify the effectiveness of the proposed method. Experimental results show that the precision of frequency measurement is obviously increased if the proposed method is adopted for the noised sine signal. Moreover, the RMSD and the NPSD of magnetic-field measurement are about 0.13 nT and 80 pT/Hz1/2, respectively if the proposed method is adopted by PM, which is better than the comparison method.

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Yu, Jimin, Rumeng Zhai, Shangbo Zhou, and LiJian Tan. "Image Denoising Based on Adaptive Fractional Order with Improved PM Model." Mathematical Problems in Engineering 2018 (2018): 1–11. http://dx.doi.org/10.1155/2018/9620754.

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In order to improve the image quality, in this paper, we propose an improved PM model. In the proposed model, we introduce two novel diffusion coefficients and a residual error term and replace the integer differential operator with the fractional differential operator in the PM model. The diffusion coefficients can be used effectively for edge detection and noise removal. The residual error term can help to prevent image distortion. Fractional order differential operator has a good characteristic that it can enhance image texture information while removing image noise. Additionally, in the two new diffusion coefficients, a novel method is proposed for automatically setting parameter k, and it does not need to do any experiments to get the value of k. For the computing fractional order diffusion coefficient, we employ the discrete Fourier transform, and an iterative scheme is carried out in the frequency domain. In the proposed model, not only is the integer differential operator replaced with the fractional differential operator, but also the order of the fractional differentiation is determined adaptively with the local variance. Comparing with some existing models, the experimental results show that the proposed algorithm can not only better suppress noise, but also better preserve edge and texture information. Moreover, the running time is greatly reduced.

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Lebrusán, Irene, and Jamal Toutouh. "Using Smart City Tools to Evaluate the Effectiveness of a Low Emissions Zone in Spain: Madrid Central." Smart Cities 3, no. 2 (June 1, 2020): 456–78. http://dx.doi.org/10.3390/smartcities3020025.

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Population concentration in cities brings new risks as an increase in pollution, which causes urban health problems. In order to address this problem, traffic reduction measures are being implemented as pedestrianization areas; they are the definition of Low Emissions Zones (LEZs). When the effectiveness of these types of measures is in doubt, smart city tools provide data that can be used to scientifically asses their impact. This article analyzes the situation of Madrid Central (Spain), a LEZ subject to controversy. We apply statistical and regression analyses to evaluate the effectiveness of this measure to reduce air pollution and outdoor noise. According to the results, this LEZ was able to significantly reduce NO 2 , PM 2.5 , and PM 10 concentration locally, having the same positive impact in the rest of the city. In terms of noise, this measure was able to mitigate background noise levels generated by road traffic.

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Alam, Pervez, Kafeel Ahmad, Afzal Husain Khan, Nadeem A. Khan, and Mohammad Hadi Dehghani. "2D and 3D mapping of traffic induced noise near major roads passing through densely populated residential area of South Delhi, India." PLOS ONE 16, no. 3 (March 24, 2021): e0248939. http://dx.doi.org/10.1371/journal.pone.0248939.

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Noise monitoring and mapping is the critical processes to ensure that the noise level does not reach the harmful levels and provides noise exposure level details. 2-D and 3-D noise mapping has been carried out at pre-selected critical locations of major roads passing through densely populated residential areas, namely, Mathura Road, Lodhi Road, Lala Lajpat Rai Road, and Ring road, along with significant intersections, viz. Moolchand, Ashram, Sabz Burj, and Lodhi road. The monitoring has been performed during the day and night’s peak traffic hours using Sound Level Meter (SLM) Larson & Davis 831as per standard procedure. Then after, 2-D and 3-D noise maps have been prepared, visualized, and analyzed by soundPLAN (acoustic) and MapInfo Pro (Desktop GIS). The maximum noise level is observed at Ashram Chowk [81.1 dB (A)] at 8 pm; however, the minimum noise level is found to be at Lala Lajpat Rai Road [76.4dB (A)] at 7 pm. Monitoring results of noise level show non-compliance of regulatory standards for day time and night time. 2-D noise maps revealed that the noise level is maximum at the centerline of the road and decreases either side with the distance, and remains above the permissible limits at all locations. However, the 3-D noise maps show horizontal as well as vertical noise levels at all locations. The 3-D noise maps also revealed a noise level of 70 dB (A) up to a height of 6.096m at the Ashram Chowk and Moolchand intersection. However, a noise level of 65 dB (A) has been observed at the height of 5.486m at Lala Lajpat Rai Marg and Sabz Burj. This study will explore noise levels in both horizontal and vertical directions near roads surrounded by high-rise buildings. It will help the decision-makers take remedial measures.

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Jafarzadeh, M., H. Rangani Jahromi, and M. Amniat-Talab. "Effects of partial measurements on quantum resources and quantum Fisher information of a teleported state in a relativistic scenario." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 476, no. 2239 (July 2020): 20200378. http://dx.doi.org/10.1098/rspa.2020.0378.

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We address the teleportation of single- and two-qubit quantum states, parametrized by weight θ and phase ϕ parameters, in the presence of the Unruh effect experienced by a mode of a free Dirac field. We investigate the effects of the partial measurement (PM) and partial measurement reversal (PMR) on the quantum resources and quantum Fisher information (QFI) of the teleported states. In particular, we discuss the optimal behaviour of the QFI, quantum coherence (QC) as well as fidelity with respect to the PM and PMR strength and examine the effect of the Unruh noise on optimal estimation. It is found that, in the single-qubit scenario, the PM (PMR) strength at which the optimal estimation of the phase parameter occurs is the same as the PM (PMR) strength with which the teleportation fidelity and the QC of the teleported single-qubit state reaches its maximum value. On the other hand, generalizing the results to two-qubit teleportation, we find that the encoded information in the weight parameter is better protected against the Unruh noise in two-qubit teleportation than in the one-qubit scenario. However, extraction of information encoded in the phase parameter is more efficient in single-qubit teleportation than in the two-qubit version.

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Mestoui, Jamal, Mohammed El Ghzaoui, Serghini Elaage, Abdelmounim Hmamou, and Jaouad Foshi. "CE-OFDM-CDMA Phase Modulation for 5G System." International Journal of Mathematical, Engineering and Management Sciences 6, no. 4 (July 18, 2021): 1100–1114. http://dx.doi.org/10.33889/ijmems.2021.6.4.065.

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In the present work, we propose a novel modulation scheme for 5G wireless communication system. Our contribution is to combine PM-OFDM (Phase Modulation Orthogonal Frequency Division Multiplexing) and CDMA (Code Division Multiple Access) to exploit their distinctive advantages. On the one hand, PM-OFDM is an effective technique to combat multipath fading effects. On the other hand, CDMA can serve multiple users who are using the same resources of time/frequency. The aim is to make a combination of PM-OFDM and CDMA techniques. In this paper, the OFDM-CDMA scheme and its PAPR (Peak-to-Average Power Ratio) statistics are reviewed. In this paper, the proposed scheme PM-OFDM-CDMA is described and its performances in terms of PAPR, power spectral density, and BER (Bit Error Rate) are analyzed. Moreover, MMSE (Minimum Mean Square Error) equalizer is used to avoid multipath and noise effects simultaneously. The simulation through AWGN (Additive white Gaussian noise) and Rayleigh channels is performed using MATLAB. From the simulation results, we observed that PM-OFDM-CDMA is an efficient technique in terms of energy consumption (PAPR = 0dB). Besides, CE-OFDM-CDMA offers high spectral efficiency with low BER due to its low PAPR. In CE-OFDM-CDMA method, the shape of the spectrum varies according to the value of the modulation index h. The band occupied by the spectrum increases with the value of h. Therefore, CE-OFDM-CDMA could be considered as a suitable technique for 5G applications.

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Wang, Meng, Minqiu Liu, Yewang Chen, Deqin Ouyang, Junqing Zhao, Jihong Pei, and Shuangchen Ruan. "Stable noise-like pulse generation in all-PM mode-locked Tm-doped fiber laser based on NOLM." Chinese Optics Letters 19, no. 9 (2021): 091402. http://dx.doi.org/10.3788/col202119.091402.

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Zuidema, Christopher, Sinan Sousan, Larissa V. Stebounova, Alyson Gray, Xiaoxing Liu, Marcus Tatum, Oliver Stroh, Geb Thomas, Thomas Peters, and Kirsten Koehler. "Mapping Occupational Hazards with a Multi-sensor Network in a Heavy-Vehicle Manufacturing Facility." Annals of Work Exposures and Health 63, no. 3 (January 22, 2019): 280–93. http://dx.doi.org/10.1093/annweh/wxy111.

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Abstract Due to their small size, low-power demands, and customizability, low-cost sensors can be deployed in collections that are spatially distributed in the environment, known as sensor networks. The literature contains examples of such networks in the ambient environment; this article describes the development and deployment of a 40-node multi-hazard network, constructed with low-cost sensors for particulate matter (SHARP GP2Y1010AU0F), carbon monoxide (Alphasense CO-B4), oxidizing gases (Alphasense OX-B421), and noise (developed in-house) in a heavy-vehicle manufacturing facility. Network nodes communicated wirelessly with a central database in order to record hazard measurements at 5-min intervals. Here, we report on the temporal and spatial measurements from the network, precision of network measurements, and accuracy of network measurements with respect to field reference instruments through 8 months of continuous deployment. During typical production periods, 1-h mean hazard levels ± standard deviation across all monitors for particulate matter (PM), carbon monoxide (CO), oxidizing gases (OX), and noise were 0.62 ± 0.2 mg m−3, 7 ± 2 ppm, 155 ± 58 ppb, and 82 ± 1 dBA, respectively. We observed clear diurnal and weekly temporal patterns for all hazards and daily, hazard-specific spatial patterns attributable to general manufacturing processes in the facility. Processes associated with the highest hazard levels were machining and welding (PM and noise), staging (CO), and manual and robotic welding (OX). Network sensors exhibited varying degrees of precision with 95% of measurements among three collocated nodes within 0.21 mg m−3 for PM, 0.4 ppm for CO, 9 ppb for OX, and 1 dBA for noise of each other. The median percent bias with reference to direct-reading instruments was 27%, 11%, 45%, and 1%, for PM, CO, OX, and noise, respectively. This study demonstrates the successful long-term deployment of a multi-hazard sensor network in an industrial manufacturing setting and illustrates the high temporal and spatial resolution of hazard data that sensor and monitor networks are capable of. We show that network-derived hazard measurements offer rich datasets to comprehensively assess occupational hazards. Our network sets the stage for the characterization of occupational exposures on the individual level with wireless sensor networks.

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Kannan, R., G. Latha, and M. Prashanthi Devi. "Circadian Rhythm of Ambient Noise Off the Southeast Coast of India." Fluctuation and Noise Letters 16, no. 04 (November 21, 2017): 1750037. http://dx.doi.org/10.1142/s0219477517500377.

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An ambient noise system consisting of a vertical linear hydrophone array was deployed in the shallow waters off Chennai, southeast coast of India from 1 August to 16 September 2013 to record ambient ocean noise of frequencies up to 10[Formula: see text]kHz. Biological sounds, which are broadband, short duration signals resulting from Terapon theraps, a native species, are a prominent feature of the ocean soundscape. Terapon activity peaks at 8[Formula: see text]pm and 11[Formula: see text]pm, and its presence is not observed after 12 midnight in both the months. In the other period, the ambient noise fluctuation is due to wind and vessel traffic. Hence, the present study focuses on the description of the ambient noise fluctuation over two 12[Formula: see text]h periods, i.e., 12 midnight–12 noon considered as period I, and 12 noon–12 midnight as period II in order to show the circadian rhythm of ambient noise. In this study area, Terapon vocalization reached 25[Formula: see text]dB above the ambient noise level and it dominates the short-term spectra records in the 0.4–4[Formula: see text]kHz range. All Terapon signals had daily patterns of sound production with highest levels of activity after dusk during the study period. The result shows that the circadian rhythm of ambient noise is mainly of biological sound generated by Terapon and it is reported first time in the shallow waters off the southeast coast of India.

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Ferre-Pikal, E., and F. H. Savage. "Up-converted 1/f PM and AM noise in linear HBT amplifiers." IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 55, no. 8 (August 2008): 1698–704. http://dx.doi.org/10.1109/tuffc.2008.855.

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Suzuki, Kazuhiko, Sadao Yamazaki, and Eisaku Oho. "PM-17 Noise removal for SEM images using a convolutional neural network." Microscopy 68, Supplement_1 (November 1, 2019): i43. http://dx.doi.org/10.1093/jmicro/dfz097.

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Djurhuus, Torsten, Viktor Krozer, Jens Vidkjær, and Tom K. Johansen. "AM to PM noise conversion in a cross-coupled quadrature harmonic oscillator." International Journal of RF and Microwave Computer-Aided Engineering 16, no. 1 (2005): 34–41. http://dx.doi.org/10.1002/mmce.20129.

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Chang, Ray-I., and Chi-Cheng Chuang. "Comparing LR, GP, BPN, RBF and SVR for Self-Learning Pattern Matching in WSN Indoor Localization." International Journal of Applied Metaheuristic Computing 3, no. 3 (July 2012): 49–62. http://dx.doi.org/10.4018/jamc.2012070104.

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It is a challenging issue to apply WSN (Wireless Sensor Network) to achieve accurate location information. PM (Pattern Matching), known as one of the most famous localization methods, has the drawback of requiring high initialization effort to predict/train MF (Matching Function). In this paper, the authors propose SPM (Self-learning PM) to improve not only the localization accuracy but also the initialization effort of PM. SPM applies a divide-and-conquer self-learning scheme to reduce the number of training patterns in training. Additionally, it introduces a Bayesian filtering scheme to remove the noise signal caused by multipath effects so as to enhance localization accuracy accordingly. This paper applies different training methods (linear regression, Gaussian process, backpropagation network, radial basis function, and support vector regression) to evaluate the performances of SPM and PM in a complicated indoor environment. Experiments show that SPM is better than PM for all training methods applied. SPM can use up to 72% fewer training patterns than PM to achieve the same localization accuracy. If the same number of training patterns is utilized, SPM can achieve up to 58% higher localization accuracy than PM.

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Yang, Haechang, Sanghoon Shin, Dongmin Seo, Jaewon Park, and Sungkyu Seo. "Detection of Particulate Matters with a Field-Portable Microscope Using Side-Illuminated Total Internal Reflection." Sensors 21, no. 8 (April 13, 2021): 2745. http://dx.doi.org/10.3390/s21082745.

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Field-portable observation and analysis of particulate matter (PM) is required to enhance healthy lives. Various types of the PM measurement methods are in use; however, each of these methods has significant limitations in that real time measurement is impossible, the detection system is bulky, or the measurement accuracy is insufficient. In this work, we introduce an optical method to perform a fast and accurate PM analysis with a higher-contrast microscopic image enabled by a side-illuminated total internal reflection (TIR) technique to be implemented in a compact device. The superiority of the proposed method was quantitatively demonstrated by comparing the signal-to-noise ratio of the proposed side-illuminated TIR method with a traditional halogen lamp-based transmission microscope. With the proposed device, signal-to-noise ratios (SNRs) for microbeads (5~20 µm) and ultrafine dust particles (>5 µm) increased 4.5~17 and 4~10 dB, respectively, compared to the conventional transmission microscope. As a proof of concept, the proposed method was also applied to a low-cost commercial smartphone toy microscope enabling field-portable detection of PMs. We believe that the proposed side-illuminated TIR PM detection device holds significant advantages over other commonly used systems due to its sufficient detection capability along with simple and compact configuration as well as low cost.

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Chakraborty, Meenakshi, and Taraprasad Chattopadhyay. "A Novel Scheme for UDWDM-PON Broadband Access Network Using Injection-Locked Phase-to-Intensity Modulation Converter." Journal of Optical Communications 40, no. 4 (October 25, 2019): 369–77. http://dx.doi.org/10.1515/joc-2017-0085.

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Abstract In this paper, we have proposed and analyzed a novel cost-effective ultradense wavelength division multiplexed (UDWDM) passive optical network (PON) which uses phase modulation (PM) of the optical carriers in the optical line terminal (OLT) in order to achieve inherent noise immunity in the network. In the demodulation of the optical PM signal at the optical network unit (ONU), we have proposed to use a simple injection–locked Fabry–Perot (FP) laser diode (LD) for achieving PM to intensity modulation (IM) converter which is followed by a photodiode to recover the specific channel information. A detailed analysis of PM–IM conversion in an injection–locked FPLD has been carried out and the viability of the proposed scheme has been established. The proposed UDWDM–PON which is a broadband access network is cost-effective and long reach.

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Silvaggio, Rosalba, Salvatore Curcuruto, Enrico Mazzocchi, Francesco Borchi, Chiara Bartalucci, Lapo Governi, Monica Carfagni, et al. "LIFE Monza: comparison between ante and post-operam noise and air quality monitoring activities in a Noise Low Emission Zone." Noise Mapping 7, no. 1 (September 26, 2020): 171–91. http://dx.doi.org/10.1515/noise-2020-0015.

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AbstractLIFE MONZA project (Methodologies fOr Noise low emission Zones introduction And management) aims at defining an easy-replicable method for the identification and management of the Noise Low Emission Zones (Noise LEZ), urban areas subject to traffic restrictions, usually introduced in order to ensure compliance with the air pollutants limit values, prescribed by the European Directive on ambient air quality 2008/50/EC, whose impacts and potential benefits regarding noise issues have been taken into account, tested and analysed in a pilot area of the city of Monza, located in North Italy. Noise LEZ has been established in Libertà district, introducing infrastructural interventions carried out by the municipality (top-down actions) and encouraging an active involvement of the citizens, in the definition of a more sustainable lifestyle (bottom-up actions). The analysis of potential effects on noise reduction due to the Noise LEZ can contribute to the implementation of the EU Directive 2002/49/EC, related to the assessment and management of environmental noise (Environmental Noise Directive – END), which introduces noise action plans, designed to manage noise issues and their effects, suggesting the adoption of urban and mobility planning. Noise and air quality monitoring activities have been carried out in pilot area in ante and post-operam conditions. The monitoring methods, the measurement techniques, the analysis procedures, able to describe the effects due to Noise LEZ establishment, for both the main environmental issues are reported in this paper, as proposals to be applied in other different contexts. Results of monitoring activities highlight a reduction of noise, in term of sound pressure levels, between ante and post-operam, during the day and particularly during the night period, and it is essentially due to the interventions realised. The effect of the Noise LEZ on air pollution seems to be negligible for combustion related pollutant and carbon fractions of PM, due both to the moderate spatial effects of the measures undertaken and confounding factors due to concomitant emission sources and meteorology.

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Monazzam, Mohammad Reza, Elham Karimi, Parvin Nassiri, Lobat Taghavi, and Samaneh Karbalaei. "Outdoor Noise Pollution Mapping Case Study: A District of Tehran." Fluctuation and Noise Letters 13, no. 04 (October 20, 2014): 1450027. http://dx.doi.org/10.1142/s0219477514500278.

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The main objective of this study was to investigate the noise levels at different land uses of District 14 in Tehran. For this purpose, a total number of 91 sampling stations were selected. Afterwards, the equivalent sound pressure level in each station was measured at three occasions of morning (7–9 am), noon (12–3 pm), and evening (5–8 pm). Based on the conformability requirement of each land uses, noise levels was divided in three zones wherein the land uses are exposed to different noise levels was estimated. The obtained results indicated that 8.79% of 78 land uses (residential, recreational and medical) in the Zone 1 were exposed to acceptable range of sound pressure level while the rest suffers from unacceptable noise levels. Among 10 land uses of Zone 2 (commercial–residential), 2.19% were within the acceptable range and 8.78% were in unacceptable range. None of the three land uses in Zone 3 were within the acceptable range. Accordingly, the Zone 3 was recognized to be in a critical condition. In other words, about 88.99% of the total and uses in the Zone 3 is exposed to unaccepted able noise level. Comparing with the standard equivalent sound pressure level of 55 dB(A) presented, the residential land use with the equivalent sound pressure level of 19.27 dB(A) accounted for the highest standard deviation. This is due to proximity of most of the residential areas to the crowded highways and streets.

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Journal articles on the topic 'PM noise'

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