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The present study focuses on the impact of exterior traffic noises on sound environment evaluation in office spaces, considering their interaction with interior noises. There were three interior noise conditions: silence, air-conditioner noise, and irrelevant speech noise. Six exterior traffic noises (road, maglev, tram, metro, conventional inter-city train, and high-speed train) were merged with interior noise clips to create the combined noise stimuli. Forty subjects participated in the experiment to assess the acoustic environment in office spaces exposed to multiple noises. The results showed that both interior and exterior noise significantly affected acoustic comfort and noise disturbance. As for the exterior traffic noise, both the traffic noise source and the noise level were found to be influential on both attributes. More temporally fluctuating traffic noises, such as high-speed train noise, were found to have a greater negative effect on subjective evaluations. Meanwhile, the interior noise source was also found to influence evaluations of the sound environment. Compared to the single traffic noise condition, irrelevant speech noise significantly increased the negative impact of traffic noises, while the air-conditioner noise had a neutral effect. In addition, participants in offices with speech noise were less sensitive to the traffic noise level. [ABSTRACT FROM AUTHOR]

Aiming at the problem that linear time-varying noise may have a negative impact on the existing zeroing neural network model to solve TVQP problem, resulting in slow convergence and low accuracy of the model, a double integral enhancement zeroing neural network was proposed.To solve the problem of linear time-varying interference of the noise, the double integral was introduced based on the original ZNN design formula, and a activation function was designed to eliminate the effects of linear time-varying noise.Theoretical analysis proved that the DIEZNN model had convergence and good noise suppression ability.The experimental results show that compared with the traditional gradient neural network and other variable ZNN models, the proposed DIEZNN model has faster convergence and higher accuracy, and can effectively solve the linear time-varying noise.

The present study focuses on the impact of exterior traffic noises on sound environment evaluation in office spaces, considering their interaction with interior noises. There were three interior noise conditions: silence, air-conditioner noise, and irrelevant speech noise. Six exterior traffic noises (road, maglev, tram, metro, conventional inter-city train, and high-speed train) were merged with interior noise clips to create the combined noise stimuli. Forty subjects participated in the experiment to assess the acoustic environment in office spaces exposed to multiple noises. The results showed that both interior and exterior noise significantly affected acoustic comfort and noise disturbance. As for the exterior traffic noise, both the traffic noise source and the noise level were found to be influential on both attributes. More temporally fluctuating traffic noises, such as high-speed train noise, were found to have a greater negative effect on subjective evaluations. Meanwhile, the interior noise source was also found to influence evaluations of the sound environment. Compared to the single traffic noise condition, irrelevant speech noise significantly increased the negative impact of traffic noises, while the air-conditioner noise had a neutral effect. In addition, participants in offices with speech noise were less sensitive to the traffic noise level.

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When evaluating the intelligibility of speech distorted by noise and reverberation, direct or indirect methods of measuring the speech transmission index are used. However, it remains insufficiently studied how significantly differ the results of measurements obtained by direct and indirect methods. To find an answer to this question, the use of a multicomponent test signal consisting of four "elementary" signals separated by pauses is proposed in this paper. As "elementary" signals, it is proposed to use a maximum-length sequence, a speech shaped maximum-length sequence, a speech shaped stationary noise, and a speech shaped amplitude-modulated noise. Use of amplitude-modulated noise allows estimating speech transmission index by a direct method. Other "elementary" signals make it possible to estimate speech transmission index by two variants of indirect method. The proposed algorithms and corresponding computer programs were tested on trial signal models, while the consistency of the obtained results with the results of previous studies was revealed. The results of the signal models studies show that both considered variants of the indirect speech transmission index measurement method lead to underestimated results compared to the direct method. For one of the variants of the indirect method, the value of the estimate bias is 0.03–0.04, regardless of the interfering conditions. For another variant of the indirect method, the estimate bias varies from 0.01 to 0.18, depending on the interference conditions. [ABSTRACT FROM AUTHOR]

Abstract Background Poor acoustic conditions at home can have negative health impact. The aim was to investigate home environment factors and medical symptoms associated with noise disturbance. Methods All adults (≥18 y) registered in selected apartments in Sweden were invited to participate in a questionnaire survey including medical questions and personal factors. Totally 5775 adults participated (response rate 46%). Information on home environment was obtained through an indoor environment questionnaire. Two-level logistic regression models (individual, municipality) were performed to estimate associations. Results Totally 11.9% reported noise disturbance in general at home. Noise disturbance from voice/radio/TV/music/similar sounds from neighbours (13.2%), scraping sound/footsteps/thumping from neighbours (16.5%) and road traffic (16.1%) were common. Younger age and smoking were related to more noise disturbance and more medical symptoms. Noise disturbance was related to tiredness, headache and difficulty concentrating (OR = 1.70–8.19). Renting the apartment (OR = 2.53) and living above ground floor (OR = 1.37) were related to more noise disturbance in general. Living in newer buildings (constructed from 1986 to 2005) was related to less noise disturbance in general (OR = 0.40–0.59). A warmer climate (OR = 1.95), higher municipality population density (OR = 1.24), a longer living time (OR = 1.34), construction year (1961–1975) (OR = 2.42), renting (OR = 1.80–2.32), living above ground floor (OR = 1.45) and having a bathroom fan (OR = 1.84) were associated with increased noise disturbance from neighbours. Factors associated with increased noise disturbance from installations or ventilation/fans/heat pumps included a warmer climate, higher municipality population density, construction year (1961–1995), renting and any mechanical ventilation. Higher municipality population density, construction year (especially 1961–1985) and renting were associated with more noise disturbance from traffic (OR = 1.77–3.92). Renting the apartment (OR = 1.73) and living above ground floor (OR = 1.60) were related to more severe traffic noise disturbances. Noise disturbance in general was partly a mediator of the effects of old buildings, renting the apartment and lack of mechanical ventilation on medical symptoms (% of total effect mediated by noise disturbance: 19–44.8%). Conclusions Noise disturbance can be associated medical symptoms. Younger age, smoking, a warmer climate, higher municipality population density and different building factors (e.g. renting the apartment, construction period 1961–1985) can be associated with noise disturbance.

Obiectives: Underground geomagnetic positioning is a new method for emergency refuge and rescue. Its geomagnetic matching probability and accuracy will be affected by the richness and stability of the matching area. There is a problem of low probability of geomagnetic matching in some areas where the geomagnetic space changes gently. Methods: A convolution enhancement operator of the underground is constructed, named convolution enhancement algorithms(CEA), which is used to convolution enhancement processing of geomagnetic data in underground matching area and geomagnetic vector of the target moving track, so as to remove the noise of measured geomagnetic data and enhance the richness of geomagnetic information. CEA operator is a kind of convolution sharpening of geomagnetic features with column quantization, is the modification of Laplace, High Pass and Sobel operators of image convolution, which is suitable for underground strip area. The simulation test of mean-square-error algorithm （MSD） geomagnetic matching before and after the convolution of CEA operator is carried out, which data is the geomagnetic data of 4 tunnels in a gold mine. Results and Conclusions: The test results show that the statistical parameters of geomagnetic data fluctuate obviously after convolution by three CEA operators. The variation of geomagnetic data features before and after convolution by the High Pass operator is small, the variation of geomagnetic standard deviation and geomagnetic roughness is small, and the correlation coefficient sometimes even weakens. The information entropy of geomagnetic data before and after convolution by the Sobel operator is increased, which cannot keep the consistency of geomagnetic map trend, appears alienation. The Laplace operator has obvious enhance effect, which keeps the change of the original geomagnetic map, increases the difference degree of the data and reduces their correlation. Especially in the matching test of 600 nT noise, the convolution processing of Laplace operator can reduce the impact of noise on geomagnetic positioning disturbance, improve the probability and accuracy of geomagnetic matching positioning, and show strong robustness, which is suitable for data preprocessing model of underground geomagnetic matching. [ABSTRACT FROM AUTHOR]

Hospitals include a variety of different spaces with different requirements and levels of sensitivity to noise but also different activities and equipment that can cause high noise levels. In this article, noise disturbance in hospitals is studied with reference to a case study in a maternity ward. The analysis is carried out by means of sound insulation measurements between bedrooms and between bedroom and corridor. Equivalent sound pressure level measurements were carried out continuously for two days and nights. The number of awakening events is examined for each hour of the two nights. In addition, the results of a questionnaire conducted on more than 100 patients are reported. The results of the study show that the main cause of noise disturbance is activity in the corridors and that this kind of disturbance is usually repeated throughout the night. This is made more critical by the poor acoustic performance of the doors, but also by the habit of keeping doors open or half-open to allow doctors to always control patients. The article proposes some possible solutions to reduce noise intrusion from the corridor to the rooms. [ABSTRACT FROM AUTHOR]

Current and proposed human development throughout high northern latitudes must assess and try to mitigate impacts on caribou and reindeer (Rangifer tarandus) herds. Sound created by development can be far-reaching, and determining the potential impacts of noise on wildlife can inform landscape use. To advance our understanding of Rangifer 's potential response to anthropogenic noise, we must first understand what they can hear. Using domestic reindeer from the Large Animal Research Station at the University of Alaska Fairbanks, we performed a Brainstem Auditory Evoked Response to estimate auditory thresholds of the species. We assessed the central auditory response and tested the sensitivity in 6 female reindeer of various ages. Prior to our work, the lowest audible frequency for the species was reported to be 63 Hz in previous studies. We identified an auditory threshold lower limit of 30 Hz in our study subjects and quantified reindeer sensitivity thresholds (dB peSPL) to frequencies ranging from 30 to 16,000 Hz. Our results indicate that anthropogenic sounds previously thought to be beyond the hearing range of Rangifer —such as seismic exploration—are likely to be audible to the species, and therefore have the potential to affect their soundscape. We compared our findings on Rangifer hearing with new measurements of anthropogenic sounds recorded on passive acoustic monitors distributed throughout northern Alaska, as well as biological sounds produced by the Rangifer themselves (e.g., vocalizations and sesamoid clicks produced by the ankles). All classes of anthropogenic sound fall within the threshold range that we identified for Rangifer. Our findings have important implications for the assessment of environmental impacts within Rangifer range and will inform future soundscape ecology research. [Display omitted] [ABSTRACT FROM AUTHOR]

Background and aims: The ceramics industry is one of the key industries in the economic development of any country. This industry has a large share of Iranchr('39')s non-oil exports so that in recent years it has consistently placed Iranchr('39')s position in the production and export of this product among other developing countries. However, there are many harmful factors in these industries, which threaten the physical and mental health of workers, the most important of which are environmental hazards, cooling, heating, vibration, noise pollution, and so on. Noise pollution is very important in the ceramics industry, as in other industries. According to research, about 600 million people worldwide and 30 million people in the United States face more than 85 dB noise in their workplace. According to the report, about 2 million workers are reported in Iran, according to a report by the Health Ministrychr('39')s Workplace Health Center. Also, according to the National Institute of Occupational Safety and Health (NIOSH), 14 percent of the total workforce is working in environments with noise levels above 90 dB. Consequently, exposure to noise in the world, including Iran, is a problem in the workplace. In addition, according to studies in the ceramics industry, it can be concluded that exposure to noise is high for the employees of the industry so that the study results Kargar et al. Found that about 45% of the ceramic industrychr('39')s employees are exposed to noise above the permitted level. As a result, personal exposure to noise will be of particular importance to employees in the industry, based on the results of past exposure research. Hair can work with noise in the workplace, except for hearing loss Hypertension, cardiovascular disease, gastrointestinal, behavioral, mental and sleep disorders. On the other hand, acoustic disturbance is a new topic that has been considered by researchers recently as one of the negative effects on onechr('39')s health and comfort. The most common subjective response is measurable, and its effects may include physiological responses, central nervous system responses, and biochemical changes. These failures include various areas such as memory, distraction, forgetfulness, inadvertent errors. Also, due to interference with daily activities can cause serious harm to the person. As a result, the present study investigated acoustic annoyance as the most common measurable subjective response among people exposed to noise and cognitive impairment as an indicator of onechr('39')s ability to perform tasks that he or she is naturally capable of performing in a ceramic industry. At the same time, it is intended to examine the relationship between sound pressure level values ​​with acoustic annoyance scores and cognitive failure. Methods: This descriptive-analytical study was conducted in the ceramics industry in 1998. To determine individual exposure to noise, we first examined the production sections and the annual results of the sound measurements, and then the loudspeakers were identified. In this study, the sample size was calculated using Cohenchr('39')s sampling formula with 80% confidence interval of 95% confidence level of 96 persons. Under 50 years of age, congenital hearing impairment, lack of sleep medications and CNS overdose, depression, and lack of a second job were considered. Thus, at the end of this study, after eliminating some of the study population, 50 workers were exposed and 50 administrative staff were placed in the control group. Also, volunteers were asked about the importance of the research subject. Then, to complete the questionnaires used in the study, a research session was held with the presence of the research population. Then the questionnaires were distributed to the individuals and their observation was completed. given. DOS 1354 TES was used to measure the sound pressure level. At the same time, the subjects completed a demographic questionnaire, noise annoyance and cognitive impairment (CFQ) questionnaire. Measurement was done in two groups of exposure and control. The TES-1356 calibrator was manufactured in Taiwan to obtain the exact results of the equipment used before each measurement. In accordance with ISO 9612 standard, a dosimeter microphone was installed on their collar at a distance of 10-30 cm from the outer ear canal. At the end, exposure dose calculations were performed, as production workers were exposed to the same noise levels during the shift, and a two-hour dosimetry was performed and generalized to the equivalent of the 8-hour balance calculations. There are four components that have the first component of distraction (2 items), memory problems (7 items), inadvertent errors (7 items), lack of recall of names (2 items). The acoustic annoyance questionnaire consists of three parts. These three sections include: The first part is heavily rated for workplace noise, the second and third are respectively for workplace noise disturbance and for determining the situations people experience throughout the day, such as fatigue, lethargy, loss of concentration, and so on checked. The questionnaire is divided into 0 to 10 levels of annoyance, with zero being non-annoying and 10 being excessive annoyance. The data were confirmed. Mann-Whitney test was used to analyze marital status with sound pressure level, acoustic distress and cognitive impairment. In addition, Spearman test was used to correlate the parameters of sound pressure level, acoustic annoyance and cognitive failure. The level of 0.05 was considered as the significant level. Results: The results of this study showed that 50% of the study population was 27-33 years old, 45% had a 3 to 5 year work experience, 64% were married and only 9% had university education. Qualitative in both exposure and control groups showed that there was no significant difference between work experience, marital status and education but there was a significant difference in age variable (p

The method presented in this work intends to analyze drum brake design parameters of a light duty automotive drum brake system. The main objective of this work is to correlate brake materials and unstability parameters to identify which condition will effectively reduce squeal propensity. The methodology involves (a) the finite-element method of the brake components, namely, drum, shoes, and frictional linings, (b) static calculations to get a pre-stress state around which (c) is computed the complex eigenvalues of the system. Hence, positive real parts indicate dynamic instabilities which are explored by varying parameters, namely, the modulus of elasticity of the materials and the friction coefficient at the contact of the shoes with the drum. According to calculations, it was observed that there exist a given range of values for Young's modulus and friction coefficient that are favorable to reduce drum brake squeal occurrence. In addition, the method proposed delivered results that match with brake squeal literature. [ABSTRACT FROM AUTHOR]

Background: Poor acoustic conditions at home can have negative health impact. The aim was to investigate home environment factors and medical symptoms associated with noise disturbance.Methods: All adults (≥18 y) registered in selected apartments in Sweden were invited to participate in a questionnaire survey including medical questions and personal factors. Totally 5775 adults participated (response rate 46%). Information on home environment was obtained through an indoor environment questionnaire. Two-level logistic regression models (individual, municipality) were performed to estimate associations.Results: Totally 11.9% reported noise disturbance in general at home. Noise disturbance from voice/radio/TV/music/similar sounds from neighbours (13.2%), scraping sound/footsteps/thumping from neighbours (16.5%) and road traffic (16.1%) were common. Younger age and smoking were related to more noise disturbance and more medical symptoms. Noise disturbance was related to tiredness, headache and difficulty concentrating (OR = 1.70-8.19). Renting the apartment (OR = 2.53) and living above ground floor (OR = 1.37) were related to more noise disturbance in general. Living in newer buildings (constructed from 1986 to 2005) was related to less noise disturbance in general (OR = 0.40-0.59). A warmer climate (OR = 1.95), higher municipality population density (OR = 1.24), a longer living time (OR = 1.34), construction year (1961-1975) (OR = 2.42), renting (OR = 1.80-2.32), living above ground floor (OR = 1.45) and having a bathroom fan (OR = 1.84) were associated with increased noise disturbance from neighbours. Factors associated with increased noise disturbance from installations or ventilation/fans/heat pumps included a warmer climate, higher municipality population density, construction year (1961-1995), renting and any mechanical ventilation. Higher municipality population density, construction year (especially 1961-1985) and renting were associated with more noise disturbance from traffic (OR = 1.77-3.92). Renting the apartment (OR = 1.73) and living above ground floor (OR = 1.60) were related to more severe traffic noise disturbances. Noise disturbance in general was partly a mediator of the effects of old buildings, renting the apartment and lack of mechanical ventilation on medical symptoms (% of total effect mediated by noise disturbance: 19-44.8%).Conclusions: Noise disturbance can be associated medical symptoms. Younger age, smoking, a warmer climate, higher municipality population density and different building factors (e.g. renting the apartment, construction period 1961-1985) can be associated with noise disturbance. [ABSTRACT FROM AUTHOR]

Multiple whale-watching vessels may operate around cetaceans at any one time, and targeted animals may experience underwater noise effects. We hypothesised that the cumulative noise of two vessels with low source levels (SLs) will elicit lower behavioural disturbance in short-finned pilot whales (Globicephala macrorhynchus) compared to a single vessel with a higher SL. We measured the behaviour of whales during 26 controls (stationary vessel >300 m) and 44 treatments off Tenerife (Canary Islands, Spain). Treatments consisted of vessel approaches mimicking whale-watch scenarios (distance ∼60 m, speed 1.5 kn). Approaches with two simultaneous vessels, with maximum cumulative mid and low-frequency (0.2–110 kHz) weighted source levels (SLs MF-LF) 137–143 dB, did not affect mother-calf pairs' resting, nursing, diving, respiration rate or inter-breath interval. However, a louder single vessel approach with twin petrol engines at SLs MF - LF 139–151 dB significantly decreased the proportion of time resting for the mother. The results suggest that if a single or two vessels are present, if the cumulative SL is < 143 dB, the behavioural disturbance on the whales will be negligible. By examining noise effects from multiple vessels on the behaviour of pilot whales, the importance of incorporating a noise threshold into whale-watching guidelines was emphasised. • Multiple whale-watching vessels operate around cetaceans at a time and there may be cumulative noise effects. • Noise disturbance reduces communication, resting and nursing rates of toothed whales. • The overall vessel noise level, regardless of number of vessels, drives behavioural responses in targeted individuals. • It is recommended to incorporate a noise emission threshold to reduce noise effects on cetaceans. [ABSTRACT FROM AUTHOR]

Students can be disturbed by background noise while working in an open-plan study environment. To improve the acoustic quality of open-plan study environments a study was done on the influence of different sound scenarios on students working on a typical student task, “studying for an exam”. Three sound scenarios and a quiet reference sound scenario were developed, based on the sound environment of a real open-plan study environment, with a varying number of talkers in the background and different reverberation times of the study environment. Seventy students worked on a set of tasks simulating a “studying for an exam” task while being exposed to the sound scenarios. This task comprises a reading comprehension task with text memory by delayed answering questions about the text, with additional tasks being performed in the gap between studying the text and retrieving. These additional tasks are a mental arithmetic task and a logical reasoning task. Performance, self-estimated performance and disturbance of students were measured. No significant effect of the sound scenarios was found on performance of students working on the reading comprehension task with text memory and the mental arithmetic task. However, a significant effect of sound was found on performance of students working on the logical reasoning task. Furthermore, a significant effect of the sound scenarios was found on self-estimated performance and perceived disturbance for all tasks from which the reading comprehension task with text memory was the most disturbed task. It is argued that the absence of a detrimental sound effect on the performance of students working on a reading comprehension task with text memory is a result of focusing due to task engagement and task difficulty, both aspects working as a “shield against distraction”.

Exposure to noise generated from traffic has led to significant annoyance and sleep deprivation in people. Continuous exposure to traffic noise can lead to mental instability and reduce the learning rate of children. Many cases of cardiovascular diseases, sleep disturbance, and cognitive impairment have been reported as a result of traffic noise. With increasing population of cars, health problems resulting from traffic noise will continue to increase and it is of utmost priority to abate this noise. Noise abatement is one of the most effective strategies in reducing noise level for communities close to roadways, although it is also one of the major cost drivers in highway projects to reduce noise. Extensive noise modeling is required to determine the feasibility of abatement choices; however, traffic noise models usually do not interact with highway geometries in selecting optimized noise abatement options. The Traffic Noise Model (TNM) developed by Federal Highway Administration (FHWA) was used to compute highway traffic noise and evaluate the effect of noise abatements. A parametric study was conducted on a total of 23,093 scenarios generated to examine ten major variables influencing roadway noise level. A noise prediction model was developed using multiple regression analysis incorporating parameters such as roadway geometry (horizontal offsets and elevation differences), barrier height, receiver height, traffic volume, roadway section, road-surface material, barrier types, speed and roadway section. This model can be used to examine possible noise mitigation strategies to make the best decision at design stage of a roadway.

Hospitals include a variety of different spaces with different requirements and levels of sensitivity to noise but also different activities and equipment that can cause high noise levels. In this article, noise disturbance in hospitals is studied with reference to a case study in a maternity ward. The analysis is carried out by means of sound insulation measurements between bedrooms and between bedroom and corridor. Equivalent sound pressure level measurements were carried out continuously for two days and nights. The number of awakening events is examined for each hour of the two nights. In addition, the results of a questionnaire conducted on more than 100 patients are reported. The results of the study show that the main cause of noise disturbance is activity in the corridors and that this kind of disturbance is usually repeated throughout the night. This is made more critical by the poor acoustic performance of the doors, but also by the habit of keeping doors open or half-open to allow doctors to always control patients. The article proposes some possible solutions to reduce noise intrusion from the corridor to the rooms.

A non-contact mode atomic force microscope with chaotic dynamics may exposed to unknown faults, disturbances or uncertain parameters that are not always be compensated using classical control methods. Therefore, a fault tolerant controller must be designed for accurate tracking of the tip-position of the end-effector. In this paper, first, an unscented Kalman filter is designed for joint estimation of the states and parameters for an atomic force microscopy under process noise. The velocity of the end-effector, sample height and unknown fault are simultaneously estimated by measuring the tip position of randomly excited microscopy. Second, unscented Kalman filtering based model predictive controller is proposed for the accurate tracking of the tip-position. To prevent the disadvantage of the model-based controller design, an uncertainty or unknown fault function of the system is estimated by unscented Kalman filter such that the unmodeled dynamics of the system are compensated while the control signal is produced. Note that the controller voltage being applied to the microscopy is produced based on the estimated states and parameters of the atomic force microscopy. The numerical applications present that satisfactory tracking performance for tip position is obtained by the proposed fault tolerant controller such that extended Kalman filtering-based tracking results are also compared and discussed. [ABSTRACT FROM AUTHOR]

In this paper, an inverse control scheme based on the novel dynamic network (multi-dimensional Taylor network (MTN)) is proposed for the real-time tracking control of nonlinear time-varying systems with noise disturbances. Utilized in this scheme are the three MTNs: the adaptive model identifier for system modeling, the adaptive inverse controller for inverse modeling, and the adaptive nonlinear filter for eliminating the noise disturbances, whose weights are modified by the variable forgetting factor recursive least squares (VFF-RLS), back propagation through model (BPTM), normalized least mean square (NLMS) algorithms, respectively. To avoid "compromise", this scheme is designed into a structure wherein controlling the object dynamic response and eliminating the noise disturbances are implemented in two relatively independent processes. Furthermore, the weight-elimination algorithm is introduced for choice of effective regression items to avoid the dimension explosion, thus overcoming the shortcoming that the number of middle nodes needs to be determined before using the traditional neural network. After a certain number of training, the more streamlined MTNs are observed to contribute to satisfying the real-time requirements of software implementation and engineering application. To ensure that MTN inverse control is strict in theory, the general conditions for the existence of single-input/single-output (SISO) nonlinear inverse systems are identified. Simulation of the MTN inverse control is conducted to confirm the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

In this paper, the global stochastic synchronization in finite time is discussed for discontinuous semi-Markovian switching neural networks with mixed time-varying delays under stochastic disturbance based on event-triggered non-fragile control scheme. By applying the novel hybrid controller, which is composed of the event-triggered controller, the non-fragile controller and the switching state-feedback controller, the global stochastic synchronization goals in finite time are achieved. Under Filippov differential inclusion framework, based on non-smooth analysis theory, general free-weighting matrix method, Lyapunov–Krasovskii functional approach and inequality analysis technique, the global stochastic synchronization conditions in finite time are addressed in terms of linear matrix inequalities. Moreover, the expressions about the upper bound of stochastic settling time are explicitly developed. Finally, two numerical examples are provided to illustrate the feasibility of the proposed control scheme and the validity of theoretical results. [ABSTRACT FROM AUTHOR]

The influence of fluctuating road traffic noise on perceived disturbance during a reading task as well as on performance, inside a living room with closed windows, is presented in this paper. Sixteen 2-min sound sequences were created combining two variables: the number of events (four levels varying from one to four car pass-bys) and the peak emergence above the background noise (four levels with a 5 dB(A) step) keeping limited variations of LAmax, 1s. The noise impact was evaluated through a reading task of texts synchronized with the sound sequences, for participants classified into fast or slow readers, and sensitive or non-sensitive to noise. The comprehension rate of the texts decreases as the background sound level increases. The reading speed decreases during the rising front of a peak, and goes back to its former regular reading speed during the descending front of the peak. This slowdown during the rising front reaches 14% for slow readers. The declared disturbance is higher for slow readers compared to fast readers, and higher for noise sensitive persons compared to non-sensitive persons. The influence of the acoustic indicators on the reading disturbance is very small compared to the influence of personal factors. There is even no influence of the number of events on this disturbance.

Background: Noise as one of the common hazardous factors in the work environments, causes adverse effects on the mental health of individuals in addition to physical problems. This study was conducted to measure the exposure of workers to noise in a construction workshop and assess its association with noise disturbance. Methods: A total of 96 employees of a construction workshop were considered in this study and were divided into four working groups: executive, administrative, supervisory and machinery. Noise exposure of workers assessed according to ISO 9612: 2009. The noise disturbance questionnaire was also completed by participants. Results: The results obtained from the noise exposure measurement showed that the mean of equivalent sound level in employees of administration section was 82.28, in administrative section was 66.52, in supervisory section was 76.43 and in machinery section was 78.45 dB. The results of noise disturbance showed that 25% of workers rated noise in the work environment as very disturbing. The results of regression analysis showed that the type of occupation associated with disturbance of subjects with correlation coefficient of 0.413. Conclusion: According to the results of dosimetry and self-reported disturbance, the noise exposure level and noise disturbance of work environment due to sound sources are high. Administrative solutions need to be provided to reduce the exposure of workers to noise.

Several studies have shown so far that poor acoustics inside classrooms negatively affects the teaching and learning processes, especially at the lowest grades of education. However, the extent to which noise exposure or excessive reverberation affect well-being of children at school in their early childhood is still unanswered, as well as their awareness of noise disturbance. This work is a pilot study to investigate to which extent classroom acoustics affects the perceived well-being and noise disturbance in first graders. About 330 pupils aged from 6 to 7 years participated in the study. They belonged to 20 classes of 10 primary schools located in Torino (Italy), where room acoustic measurements were performed and where noise level was monitored during classes. The school buildings and the classrooms were balanced between socioeconomic status and acoustic conditions. Trained experimenters administered questionnaires in each class, where pupils answered all together during the last month of the school year (May). Questions included the happiness scale, subscales assessing self-esteem, emotional health, relationship at home and with friends, enjoyment of school, intensity and noise disturbance due to different sound sources, and quality of voice. The findings of the study suggest that long reverberation times, which are associated with poor classroom acoustics as they generate higher noise levels and degraded speech intelligibility, bring pupils to a reduced perception of having fun and being happy with themselves. Furthermore, bad classroom acoustics is also related to an increased perception of noise intensity and disturbance, particularly in the case of traffic noise and noise from adjacent school environments. Finally, happy pupils reported a higher perception of noise disturbance under bad classroom acoustic conditions, whereas unhappy pupils only reported complaints in bad classroom acoustics with respect to the perception of pleasances with himself or herself and of fitting in at school. Being a mother tongue speaker is a characteristic of children that brings more chances of attending classes in good acoustics, of being less disturbed, and of having more well-being, and richer districts presented better acoustic conditions, in turn resulting in richer districts also revealing a greater perception of well-being.

Robust and efficient low signal-to-noise ratio (SNR) single pixel infrared (IR) target detection has been a key technique in IR searching and tracking system. However, there exist two critical difficulties, i.e. noise disturbance and low contrast between target and background, influencing detection accuracy. A novel IR target detection method is proposed to overcome those difficulties, by utilising the point-spread character. Specifically, a point-spread indicator is advocated to protect the potential target with the median filter to suppress the noise. Afterwards, a two-step enhancement model is built to increase the contrast value between target region and surrounding background effectively. In the first step, a point-spread local contrast method is proposed to enhance targets and suppress background. In the second step, a high boost filter is introduced to further enhance the target. In addition, an adaptive segmentation method is exploited to extract targets from the enhanced image. Experimental results on testing sequences demonstrate that this method outperforms the other state-of-the-art methods in single pixel IR target detection with higher detection rate, lower false alarm rate and less time consuming.

Context: It is widely accepted that wildlife is subjected to detrimental human noise within urban landscapes but little is known about how the intensity of land use changes soundscapes. Objectives: The objective of this research was to produce quantitative associations between characteristics of ambient soundscapes and land use intensity. These relations were used to examine the 2 kHz demarcation between anthrophony and biophony and compare the impact of different sized contributing areas on ambient soundscape characteristics. Methods: This study related the surrounding land use intensity of 67 sites in north central Florida (USA) to several metrics describing their recorded soundscapes. Land use intensity was measured remotely at three scales using the landscape development intensity index (LDI). Results: The analysis revealed that the LDI index had a statistically significant effect on soundscape characteristics after controlling for important factors such as climate, season, and attenuation due to hard ground. The trends between LDI and soundscape confirmed that human generated sounds are loud, continuous, and occupy low frequencies. The evenness of the sound distribution decreased with landscape intensity and LDI correlated significantly with sound below 3 kHz. Land use intensity within a 100 and 500-m radius contributing area were most closely related to soundscape metrics. Conclusions: LDI is a tool with the potential to predict the extent and intensity of anthropogenic noise disturbance on wildlife from remote sensing data. The utility of this tool allows for widespread application to identify and mitigate conflicts in the acoustic realm between human noise and wildlife. [ABSTRACT FROM AUTHOR]

Several studies have shown so far that poor acoustics inside classrooms negatively affects the teaching and learning processes, especially at the lowest grades of education. However, the extent to which noise exposure or excessive reverberation affect well-being of children at school in their early childhood is still unanswered, as well as their awareness of noise disturbance. This work is a pilot study to investigate to which extent classroom acoustics affects the perceived well-being and noise disturbance in first graders. About 330 pupils aged from 6 to 7 years participated in the study. They belonged to 20 classes of 10 primary schools located in Torino (Italy), where room acoustic measurements were performed and where noise level was monitored during classes. The school buildings and the classrooms were balanced between socioeconomic status and acoustic conditions. Trained experimenters administered questionnaires in each class, where pupils answered all together during the last month of the school year (May). Questions included the happiness scale, subscales assessing self-esteem, emotional health, relationship at home and with friends, enjoyment of school, intensity and noise disturbance due to different sound sources, and quality of voice. The findings of the study suggest that long reverberation times, which are associated with poor classroom acoustics as they generate higher noise levels and degraded speech intelligibility, bring pupils to a reduced perception of having fun and being happy with themselves. Furthermore, bad classroom acoustics is also related to an increased perception of noise intensity and disturbance, particularly in the case of traffic noise and noise from adjacent school environments. Finally, happy pupils reported a higher perception of noise disturbance under bad classroom acoustic conditions, whereas unhappy pupils only reported complaints in bad classroom acoustics with respect to the perception of pleasances with himself or herself and of fitting in at school. Being a mother tongue speaker is a characteristic of children that brings more chances of attending classes in good acoustics, of being less disturbed, and of having more well-being, and richer districts presented better acoustic conditions, in turn resulting in richer districts also revealing a greater perception of well-being. [ABSTRACT FROM AUTHOR]

This paper addresses the frequency restoration and accurate load power sharing problem of ac microgrids with massive penetration of distributed generators (DG) under time-delay communication in noisy environments. Existing distributed control methods commonly assume ideal communication among DGs. However, the channels are prone to additive noises and time delays, while each DG obtains noisy and delayed measurements of the states of its neighbors due to environmental noises and communication delays. The proposed distributed cooperative control strategy will achieve frequency restoration and accurate load power sharing among DGs through a sparse communication network subject to time delays and noise disturbances. The theoretical concepts and necessary conditions for stability and robust performance of the proposed distributed cooperative control strategy are outlined by the Lyapunov-Krasovskii functional method and stochastic differential equation theory. Furthermore, the proposed control strategy is implemented through sparse communication networks and thus, satisfies the plug-and-play feature of the future smart grid. Simulation results on an islanded microgrid test system are provided to reveal the effectiveness of the proposed control method to provide accurate proportional power sharing in the MATLAB/SimPowerSystems Toolbox. [ABSTRACT FROM AUTHOR]

Previous research has shown that semantic-based tasks are negatively influenced by semantic aspects in background speech. Collaboration is an important task in open-plan study environments and is a semantic task which might be disrupted by background speech. Therefore, the aim of this study was to analyze the influence of irrelevant background speech on student-collaboration. Participants worked in pairs to solve spot-the-difference puzzles, by using the 'DiapixUK' collaboration task, while they were exposed to different background sound scenarios. The composed sound scenarios varied in semantic content (mother tongue and foreign language background speech) and reverberation time (short vs long), the latter affecting speech intelligibility. Although a longer reverberation time decreases the intelligibility of background speech and a foreign language decreases meaningfulness of speech, no significant changes in performance were found. On the other hand, the data show an increased perceived disturbance for a longer reverberation time, which we interpret as an increased difficulty of interpersonal communication in the collaboration task due to the increased level of the background speech. The quiet reference condition was the most preferred sound condition which is in line with both the effect of a low background sound level and the absence of semantic interference. [ABSTRACT FROM AUTHOR]

Robust and efficient low signal-to-noise ratio (SNR) single pixel infrared (IR) target detection has been a key technique in IR searching and tracking system. However, there exist two critical difficulties, i.e. noise disturbance and low contrast between target and background, influencing detection accuracy. A novel IR target detection method is proposed to overcome those difficulties, by utilising the point-spread character. Specifically, a point-spread indicator is advocated to protect the potential target with the median filter to suppress the noise. Afterwards, a two-step enhancement model is built to increase the contrast value between target region and surrounding background effectively. In the first step, a point-spread local contrast method is proposed to enhance targets and suppress background. In the second step, a high boost filter is introduced to further enhance the target. In addition, an adaptive segmentation method is exploited to extract targets from the enhanced image. Experimental results on testing sequences demonstrate that this method outperforms the other state-of-the-art methods in single pixel IR target detection with higher detection rate, lower false alarm rate and less time consuming. [ABSTRACT FROM AUTHOR]

Noise formation is one of the most important factors taken into consideration in the studies conducted in aviation areas. This paper reviews the flow area studied on the 3D NACA0015 blade profile using different turbulence models as SST k-ro, Smagorinsky-Lilly, WALE, and WMLES to calculate the unstable flow field. In addition, the effect of mesh number and time step on the results was analyzed by using CFD program. The mesh files used in the analysis are prepared with the Pointwise program. We inserted the time-dependent flow field variables in Ffowcs-Williams and Hawkings (FW-H) equations as an input and Sound Pressure Level (SPL) values will be computed for different turbulence models from the microphone which is positioned in the computational domain to investigate the effect of augmentation of unsteady 3D airfoil region noise level. The calculated results will be compared with each other and with the experimental data available in the open literature. In the analysis, the Sound Pressure Level (SPL) effect of mesh number was investigated by using different 3 mesh numbers being 2 million, 3 million, and 4 million. In addition, to analyze the effect of the time step on the Sound Pressure Level (SPL), analyzes were made using 2 different time steps being 10-4 and 10-5; and the results were compared with each other. As results; calculated Cp values are slightly lower than the experimental value. This difference could be due to the higher Reynolds number of the experimental data. The result obtained from the comparison of the different turbulence models used is the most suitable choice is Smagorinsky-Lilly model for the use of LES method in the study of the mean sound pressure related to the unsteady 3D airfoil. Also, the results obtained from the analysis with the increase in the number of mesh and the reduction of the time step were found to be closer to the experimental data. [ABSTRACT FROM AUTHOR]

In this letter, a new scheme based on Born iterative method is proposed to solve the inverse scattering problems with noise disturbance. By controlling the balance factor in the new scheme, the convergence speed of the inversion algorithm is improved while ensuring that the inversion has a stable solution. This means that a new degree of freedom in deciding the performance of the inversion algorithm is proposed and can be controlled by the researcher. This letter discusses the significance of the balance factor and its impact on the performance of the algorithm. Besides, the method for choosing an appropriate balance factor is introduced. Finally, the effectiveness of the new scheme is verified by numerical analysis. [ABSTRACT FROM AUTHOR]

This paper deals with the global stochastic finite-time synchronization in probability for discontinuous semi-Markovian switching neural networks with time delays and noise disturbance. Firstly, the formula for calculating the global stochastic settling time of semi-Markovian switching nonlinear system with Brown motion is developed. Secondly, the novel state-feedback controllers, which include discontinuous factors and integral terms, are designed to realize the global stochastic finite-time synchronization goal. Under Filippov stochastic differential inclusion framework, by applying Lyapunov–Krasovskii functional approach, stochastic analysis theory, inequality analysis technique and the developed stochastic finite-time stability theorem, the global stochastic finite-time synchronization conditions are addressed in terms of linear matrix inequalities (LMIs). Moreover, the expressions about the upper bound of stochastic settling time are explicitly proposed. In addition, the relativity among the obtained results is analytically interpreted. Finally, two numerical examples are provided to demonstrate the validity of the proposed design methods and theoretical results. [ABSTRACT FROM AUTHOR]

Bistable structures have two stable equilibrium positions and can be utilized to maintain a static shape with no energy consumption. This paper focuses on the minimum energy required for performing snap-through of a bistable structure subjected to noise disturbance. This paper uses the Duffing-Holmes equation as a one-degree-of-freedom representative model of a bistable structure. This equation is numerically solved to calculate the energy required for cross-well oscillation under different system and forcing conditions. The paper shows how the energy required for cross-well transfer varies as a function of damping ratio and frequency ratio at specific harmonic force amplitude when the system is externally disturbed with a band-limited noise signal. A magneto-elastic bistable beam is fabricated and tested to validate the used mathematical model. Various nondimensional parameters are used to highlight interesting phenomena. The relationships between signal-to-noise ratio (SNR), dynamic-to-static force ratio, and damping ratio to the response behavior are shown. It is found that the domain of low energy regions decreases by increasing the level of noise. Additionally, underactuated bistable and linear systems behave similarly for high levels of noise. This paper specifically identifies the critical force ratio, which allows for snap-through as a function of critical nondimensional system parameters. [ABSTRACT FROM AUTHOR]

The finite-time stochastic synchronization of time-delay neural networks with noise disturbance is investigated according to finite-time stability theory of stochastic differential equation. Via constructing suitable Lyapunov function and controllers, finite-time stochastic synchronization is realized and sufficient conditions are derived. By analyzing the synchronization progress, factors affecting the convergence speed are given and feasible suggestions are proposed to improve the convergence rate. Finally, numerical simulations are given to verify the theoretical results. [ABSTRACT FROM AUTHOR]

Many of the drugs used for chemotherapy treatments are known to be ototoxic, and can result in permanent hearing threshold shifts. The degree of ototoxic damage can be influenced by many factors including dosage, duration of exposure, genetics, and coadministration with other ototoxic agents. Cisplatin is known for its ototoxic effects on hearing thresholds, particularly in the high frequencies. Recent studies have indicated a synergistic relationship between Cisplatin administration and moderate to high noise level exposure starting between 70-85 dB SPL. This study measured the noise levels in the Portland Veteran′s Affairs Medical Center′s outpatient chemotherapy clinic. Average (LAeq) and peak (LCpeak) noise measures were recorded every minute from 7 am until 6 pm on the two busiest clinic days. Patients, visitors, and staff members filled out anonymous surveys regarding their reactions to noise levels. Cumulative noise levels were not at levels known to interact with Cisplatin for a significant period of time. Noise measurement analysis indicated that levels were at or above 70 dB SPL for less than ten minutes during the 11-hour recording window. The patient and visitor surveys indicated that both groups were unbothered by noise in the clinic. However, most staff members were bothered by or concerned about noise levels, and many felt that it caused stress and difficulty communicating on the phone.

Several studies have presented the effects of environmental noise in and around buildings and communities in which people live and work. In particular, the noise introduced into a building is mostly evaluated using the A weighted sound pressure level ( L Aeq ) as the only parameter to determine the perceived disturbance. Nevertheless, if noise is produced by activities or sources characterised by a low frequency contribution, the measurement of L Aeq underestimates the real disturbance, in particular during sleeping time. The international literature suggests methods to evaluate the low-frequency noise contribution to annoyance separately from the A weighted sound pressure level; almost all of the proposed methods are based on exceeding a threshold limit. This paper tests international criteria, by applying them in real-life indoor noise situations, and then analysing, comparing and contrasting results. Based on the result of the procedure above, a new criterion consisting of a single threshold is proposed, which simplifies the procedures in case of low-frequency components, but could be used for any situation. [ABSTRACT FROM AUTHOR]

This paper investigates the passivity problem for a class of uncertain stochastic fuzzy nonlinear systems with mixed delays and nonlinear noise disturbances by employing an improved free-weighting matrix approach. The fuzzy system is based on the Takagi–Sugeno model that is often used to represent the complex nonlinear systems in terms of fuzzy sets and fuzzy reasoning. To reflect more realistic dynamical behaviors of the system, the parameter uncertainties, the stochastic disturbances, and nonlinearities are considered, where the parameter uncertainties enter into all the system matrices, the stochastic disturbances are given in the form of a Brownian motion. The mixed delays comprise both discrete and distributed time-varying delays. By taking the relationship among the time delays, their lower and upper bounds into account, some less conservative linear-matrix-inequality-based delay-dependent passivity criteria are obtained without ignoring any useful terms in the derivative of Lyapunov functional. Finally, numerical examples are given to demonstrate the effectiveness and merits of the proposed methods. [ABSTRACT FROM AUTHOR]

The sound produced by human-made machinery (technophony) is known to exert negative effects on animal communication and well-being. Mining is an important economic activity in Brazil, which is often conducted close to forested areas and produces a diffuse noise. In this study, the impact of such noise on biophony (biological sounds) was investigated by characterizing and comparing the soundscapes of two different sites (close versus distant from an open-cast mine) in the same Atlantic forest fragment, matched for habitat type, in Southeast Brazil. Six automated recorders were installed at each site and were programmed to record continuously during seven consecutive days every two months between October 2012 and August 2013. Technophony and biophony values were derived from power spectra and the Acoustic Complexity Index (ACI). Mann–Whitney U tests demonstrated that the biophony exhibited a switch in daily dynamics, resulting in a statistically higher biophony during the day at the site close to the mine and a higher biophony during the night at the site far from the mine. Potential species richness was found to be higher at the site that was distant from the mine. The species composition and spectral characteristics of the calls were also found to differ between the two sites. These results provide the first investigation of potential disturbances caused by mining noise on biophony, demonstrating that it can cause alterations in the temporal dynamics and daily patterns of animal sounds, which are symptoms of altered behaviors or variations in community-species composition. These findings suggest remarkable insights that should be taken into consideration in the regulating of the use of natural areas for mining. [ABSTRACT FROM AUTHOR]

A simple and effective stepping on-time adjustment (SOTA) method with status judgment for interleaved multichannel critical mode (CRM) boost-type power factor correction (PFC) converters is proposed. The boost-type PFC converter with CRM operation is commonly used for ac-dc conversion because of its circuit simplicity and high efficiency. The interleaved multichannel PFC converter becomes the trend for high-power applications. However, conventional interleaved methods are complicated and difficult to implement when more than two channels are required. Also, noise disturbances or on-time mismatching can easily lead to continuous conduction mode operation which will increase current distortion, reduce power conversion efficiency, or even damage the converter. The proposed SOTA method with status judgment can greatly simplify the control complexity of the interleaved multichannel operation. A prototype 600-W three-channel interleaved CRM boost PFC converter is built to verify the performance of the proposed SOTA method. [ABSTRACT FROM AUTHOR]

Background Robotic haptic guidance is the most commonly used robotic training strategy to reduce performance errors while training. However, research on motor learning has emphasized that errors are a fundamental neural signal that drive motor adaptation. Thus, researchers have proposed robotic therapy algorithms that amplify movement errors rather than decrease them. However, to date, no study has analyzed with precision which training strategy is the most appropriate to learn an especially simple task. Methods In this study, the impact of robotic training strategies that amplify or reduce errors on muscle activation and motor learning of a simple locomotor task was investigated in twenty two healthy subjects. The experiment was conducted with the MAgnetic Resonance COmpatible Stepper (MARCOS) a special robotic device developed for investigations in the MR scanner. The robot moved the dominant leg passively and the subject was requested to actively synchronize the non-dominant leg to achieve an alternating stepping-like movement. Learning with four different training strategies that reduce or amplify errors was evaluated: (i) Haptic guidance: errors were eliminated by passively moving the limbs, (ii) No guidance: no robot disturbances were presented, (iii) Error amplification: existing errors were amplified with repulsive forces, (iv) Noise disturbance: errors were evoked intentionally with a randomly-varying force disturbance on top of the no guidance strategy. Additionally, the activation of four lower limb muscles was measured by the means of surface electromyography (EMG). Results Strategies that reduce or do not amplify errors limit muscle activation during training and result in poor learning gains. Adding random disturbing forces during training seems to increase attention, and therefore improve motor learning. Error amplification seems to be the most suitable strategy for initially less skilled subjects, perhaps because subjects could better detect their errors and correct them. Conclusions Error strategies have a great potential to evoke higher muscle activation and provoke better motor learning of simple tasks. Neuroimaging evaluation of brain regions involved in learning can provide valuable information on observed behavioral outcomes related to learning processes. The impacts of these strategies on neurological patients need further investigations. [ABSTRACT FROM AUTHOR]