Green Noise Research Articles

Perovskite-Doped Modulated Color-Selective Photosynaptic Transistors for Target Object Recognition.

The processing of multicolor noisy images in visual neuromorphic devices requires selective absorption at specific wavelengths; however, it is difficult to achieve this because the spectral absorption range of the device is affected by the type of material. Surprisingly, the absorption range of perovskite materials can be adjusted by doping. Herein, a CdCl2 co-doped CsPbBr3 nanocrystal-based photosensitive synaptic transistor (PST) is reported. By decreasing the doping concentration, the response of the PST to short-wavelength light is gradually enhanced, and even weak light of 40 μW·cm-2 can be detected. Benefiting from the excellent color selectivity of the PST device, the device array is applied to feature extraction of target blue items and removal of red and green noise, which results in the recognition accuracy of 95% for the noisy MNIST data set. This work provides new ideas for the application of novel transistors integrating sensors and storage computing.

Erratum: "Associations of Combined Exposures to Surrounding Green, Air Pollution, and Road Traffic Noise with Cardiometabolic Diseases".

Erratum: "Associations of Combined Exposures to Surrounding Green, Air Pollution, and Road Traffic Noise with Cardiometabolic Diseases".

Robust phase retrieval with green noise binary masks

Phase retrieval with pre-defined optical masks can provide extra constraints and thus achieve improved performance. Recent progress in optimization theory demonstrates the superiority of random masks in enhancing the accuracy of phase retrieval algorithms. However, traditional approaches only focus on the randomness of the masks but ignore their non-bandlimited nature. When using these masks for phase retrieval, the intensity measurements contain many significant high-frequency components that the phase retrieval algorithm cannot take care of and thus leads to degraded performance. Based on the concept of digital halftoning, this paper proposes a green noise binary masking scheme that can significantly reduce the high-frequency contents of the masks while fulfilling the randomness requirement. The resulting intensity measurements will contain data concentrated in the mid-frequency band and around zero frequency areas which can be fully utilized in the phase retrieval optimization process. Our experimental results show that the proposed green noise binary masking scheme consistently outperforms the traditional ones when using in binary coded diffraction pattern phase retrieval systems.

Interspike interval correlations in neuron models with adaptation and correlated noise.

The generation of neural action potentials (spikes) is random but nevertheless may result in a rich statistical structure of the spike sequence. In particular, contrary to the popular renewal assumption of theoreticians, the intervals between adjacent spikes are often correlated. Experimentally, different patterns of interspike-interval correlations have been observed and computational studies have identified spike-frequency adaptation and correlated noise as the two main mechanisms that can lead to such correlations. Analytical studies have focused on the single cases of either correlated (colored) noise or adaptation currents in combination with uncorrelated (white) noise. For low-pass filtered noise or adaptation, the serial correlation coefficient can be approximated as a single geometric sequence of the lag between the intervals, providing an explanation for some of the experimentally observed patterns. Here we address the problem of interval correlations for a widely used class of models, multidimensional integrate-and-fire neurons subject to a combination of colored and white noise sources and a spike-triggered adaptation current. Assuming weak noise, we derive a simple formula for the serial correlation coefficient, a sum of two geometric sequences, which accounts for a large class of correlation patterns. The theory is confirmed by means of numerical simulations in a number of special cases including the leaky, quadratic, and generalized integrate-and-fire models with colored noise and spike-frequency adaptation. Furthermore we study the case in which the adaptation current and the colored noise share the same time scale, corresponding to a slow stochastic population of adaptation channels; we demonstrate that our theory can account for a nonmonotonic dependence of the correlation coefficient on the channel's time scale. Another application of the theory is a neuron driven by network-noise-like fluctuations (green noise). We also discuss the range of validity of our weak-noise theory and show that by changing the relative strength of white and colored noise sources, we can change the sign of the correlation coefficient. Finally, we apply our theory to a conductance-based model which demonstrates its broad applicability.

0413 The Influence of Community Environment Exposure and Individual Health Behavior on Insufficient Sleep

Abstract Introduction Short sleep duration is associated with the risk of various chronic diseases, and it has been hypothesized to influence health behaviors and environmental exposure such as green space and noise. However, little studies have explored this relationship, especially with the consideration of the integrated environment information. The purpose of this study is to examine the influence of environmental exposure and individuals’ health behavior on sleep duration. Methods We examined aggregate national-level datasets regarding health information, noise, and green space. Sleep, health behavior, and socio-demographic variables were derived from 500 cities data, and the unit of analysis was the prevalence of each variable in the census tract. The insufficient sleep was calculated by the percentage of the population who had less than 7 hours of sleep in the census block. Spatial analysis was performed for green space and noise measurement; both values were calculated within the community activity space, which is a combined area with the census urban area and census place to examine the potential activity space. Multiple linear regression analysis was performed to model the relationship. Results The final sample was 29,610 census tracts from 497 cities, and the average median age of each census tract was 36.02±7.085. 36.64% of insufficient sleep was reported from the entire sample. The model (R2=0.804) indicate that green space (β=-.053, p<.001) and natural noise (β=-.029, p<.001) has negatively associated with insufficient sleep; while, smoker (β=.374, p<.001), binge drinker (β=.105, p<.001), no leisure physical activity time (β=.111, p<.001), and artificial noise (β=.034, p<.001) has positive association with insufficient sleep. Conclusion The results indicate that a better environment source in the community mitigates the insufficient sleep population as well as individual health behavior. Further studies are needed, however, to fully disentangle the association between sleep duration and sleep quality associated with other environmental exposure. Support N/A

A Framework for Green Concrete Noise Barrier Materials using Palm Oil Clinker

Noise pollution from traffic is an increasing environmental problem worldwide. The most popular mitigation measure is the control of path by means of construction of noise barriers. Current concrete barrier incorporated with perforated surface infilled with non-mineral fibre sound absorbing material on the highway side are the commonly found. The disadvantage of this type is it’s easily damaged and the non-mineral fibre is so dreadful to human health. On the other hand, palm oil clinker (POC) is a by-product waste material produced in palm oil mills, are currently dump in open land or landfill sites, which leads to environmental problems. POC is internally porous and if it replaces the aggregate in porous concrete it may absorb sound better than standard porous concrete which is the most important characteristic for noise barrier development. This paper discusses how the palm oil clinker substitution will make concrete noise barrier material to be labelled as green and sustainable. A framework for developing green noise barrier made of palm oil clinker concrete will also be presented and discussed.

Associations of Surrounding Green, Air Pollution and Traffic Noise with General and Mental Health

Background: Several studies showed indications that mental health is affected by environmental exposures.Objectives: To evaluate the effects of combined exposure to surrounding green, air pollution...

Green Space, Noise and Air Pollution and Mortality in Barcelona

Background/Aim: Relatively few studies have evaluated simultaneously the relationship between green space, air pollution and noise and mortality in urban setting We conducted a study to evaluate the relationship between green space, noise and air pollution and all cause mortality in Barcelona using a large patient database with individual level mortality and covariate data. Methods: Both men and women of 18 years and above registered on January 1 2010 by the Sistema d'Informació pel Desenvolupament de la Investigació en Atenció Primària (SIDIAP) were included in the cohort and followed up until 31 December 2014 or until death. SIDIAP is a primary care computerized medical records of a representative sample of 0.8 million people in Barcelona. We used different definitions of green space (greenness and access to green space), noise maps and air pollution estimates from land use regression modeling. From the SIDIAP database we extracted Individual level covariate data such as age, gender, country of origin, smoking status, and BMI. For each year of study on a census track level we also obtained MEDEA social economic status (SES), urbanity level, and built environment measures. We used Cox proportional hazards regres¬sion models [hazard ratios (HRs)] with time-dependent exposures and age as the time scale to estimate associations between green space, noise and air pollution and all cause mortality. Results: Initial results show independent effects of the exposures with an increase in mortality with increasing levels of noise and air pollution and a decrease in in mortality with increasing levels of green space. Risk estimates were similar to previous studies where only one exposure was examined. Conclusions: The study provides evidence for policy making, specifically for urban planning and management, environment and health.

Onset of colored-noise-induced chaos in the generalized Duffing system

The effects of colored noise, red noise and green noise, on the onset of chaos are investigated theoretically and confirmed numerically in the generalized Duffing system with a fractional-order deflection. Analytical predictions concerning the chaotic thresholds in the parameter space are derived by using the stochastic Melnikov method combined with the mean-square criterion. To qualitatively confirm the analytical results, numerical simulations obtained from the mean largest Lyapunov exponent are used as test beds. We show that colored noise can induce chaos, and the effects for the case of red noise on the onset of chaos differ from those for the case of green noise. The most noteworthy result of this work is the formula, which relates the chaotic thresholds among red, green and white noise, holds for noise-induced chaos in the Duffing system. We also show that Gaussian white noise can induce chaos more easily than colored noise.

Acoustic evaluation of modular greenery noise barriers

Green noise barriers have become an alternative means of reducing urban traffic noise. In this paper, the acoustic performance of a modular greenery noise barrier is evaluated. In situ measurements of noise reflection were performed using an experimental prototype to estimate the sound absorption coefficients. These coefficients were found to have values of approximately 0.7, higher than those previously found in laboratory measurements for a similar system with a lower vegetation density. The obtained values were input into software for predicting environmental noise to analyse the expected performance of such barriers, particularly in the case of a pair of parallel barriers. A comparison with the results for reflective barriers indicates a significant improvement in sound attenuation of up to 4dBA. The values are similar and even superior to results reported by other authors regarding the effectiveness of absorptive treatments applied to parallel barriers, and furthermore, the proposed barriers offer an aesthetic element for environmental integration.

A minimal Munsell value error based laser printer model

The image printed by laser printer may be nonlinearly distorted by dot gain and dot loss. In this case, printer model is usually built to suppress this nonlinear distortion and to make sure the printout result is the same as input image. The parameters of the printer model which will directly affect the printout result are key. In this paper, the chroma or density values of printout result is changed into Munsell value, and optimal parameters of printer model are calculated via the calculation of minimal error between Munsell value and input gray value. And then the minimal-Munsell-value-error-based laser printer model (MMVEBLPM) is established and applied in the green noise halftone method. Experimental results showed that the optimal parameters can be calculated fast and the nonlinear distortion of laser printer is suppressed significantly with the proposed model.

A Review on the Acoustical Properties of Natural and Synthetic Noise Absorbents

Background and aims: Nowadays, artificial insulators such as fiberglass and rock wool are used as sound absorbers in developing countries. The present study is performed to introduce new sound absorbing materials used in developed countries and discuss their acoustical characteristics. It also aims to look at the efficiency of sound absorber natural materials (green materials) as an alternative to commercial materials with a synthetic base used in different places. Methods: In order to identify new porous absorbents, their mechanism of action and various applications, a search was conducted by using keywords such as “Sound Absorbent”, “Natural Noise Absorbent” and “Passive Absorber” in PubMed, Scopus, Science Direct, ProQuest, Springer, Web of Knowledge, Magiran, SID, IranMedex and Google Scholar. We selected 48 review and original research papers that were about natural and recycled absorbents. Results: Most recent research includes production and optimization of sound absorbers using natural and recycled materials. The aim of all of these researches was producing green absorber materials in accordance with environmental regulations. In order to properly use these materials, in addition to knowing the benefits and suitability of absorbers for use in the intended environment, the effective factors in sound absorption such as fiber size, air flow resistance, porosity, curve, thickness and density of absorbers were considered. Conclusion: In comparison to old absorbents, new materials are safer and lighter and enjoy a more efficient technology. It seems like environmental friendly, degradable, recyclable and green noise absorbents will play on important role in the market of noise absorbents in the future. Also because of the place and different uses of absorbent materials, specialists should consider the limitations of the environment and the acoustic characteristics of the absorbents.

Effect of the green noise on the phase-locked-loop frequency-control system

The operation of the phase-locked-loop frequency-control system under the action of low-passfiltered broadband stationary noise (green noise) is considered. In order to analyze such systems, an averaging method that takes into account the external noise in a zeroth-order approximation has been constructed. Notions of an effective potential and correction process have been introduced and their role in the development of the dynamics of the system has been determined. A numerical experiment has been performed, which confirms the theoretical conclusions.

Parametrically controlled stochastically seeded clustered halftones: design strategies and applications

We present a stochastically seeded, clustered halftoning method with parametric control of dot shapes as well as seed placement adaption to local image structure. While the literature on other randomly structured screens (blue noise, green noise, and stochastic halftoning) is quite extensive, there is very little discussion on optimization of dot shape for robustness or preferred tile appearance. The parametric control presented here can enable an imaging engineer to optimize robustness for a given printing system. The halftoning method that we introduce defines dot centers as seeds that are placed typically in a random, high spatial frequency configuration. Spot functions are defined about these randomly placed seeds, where the spot function allows control of dot cluster growth, touch points, cluster angle, and eccentricity. The spot function can also be applied to regular and irregular polygonal halftone tiling. The adaptability of the seed placement provided by the halftoning method allows for better edge rendition than conventional isotropic methods and enables the implementation of data-embedding techniques. The resulting monochromatic screens can be seamlessly integrated with novel successive filling techniques in order to provide dot-off-dot vector halftoning capabilities.

Test and Analysis of Noise Reduction Effect for Different Heights and Distances of Sound Barrier

Based on the comparative analysis on the low-noise road surface, noise reduction green belts, noise barriers and other noise reduction methods, the sound barrier is put forward as an important method for reducing the city road traffic noise. The noise reduction effects for different heights and different distances of the sound barrier are tested and analyzed through noise and vibration test and analysis system, the following conclusions can be drawn. At the same heights from the ground, the father the test points away from the noise barrier, the higher the sound pressure level will be; At the same distances from the sound barrier, the nearer the test points from the ground, the smaller the sound pressure level will be; All of the sound pressure level curves have basically the same variation trend and the main noise frequency band is from 160 to 1600Hz; In the high frequency range which is greater than 1600Hz, the sound pressure level decrease significantly, indicating that the sound barrier has better noise reduction effect for high frequency range. The results provide the basis for the design of the sound barriers.

Focus on lasers and imaging

Focus on lasers and imaging

Green Noise or Green Value? Measuring the Effects of Environmental Certification on Office Values

This study investigates the price effects of environmental certification on commercial real estate assets. It is argued that there are likely to be three main drivers of price differences between certified and noncertified buildings. These are additional occupier benefits, lower holding costs for investors and a lower risk premium. Drawing upon the CoStar database of U.S. commercial real estate assets, hedonic regression analysis is used to measure the effect of certification on both rent and price. The results suggest that, compared to buildings in the same submarkets, eco‐certified buildings have both a rental and sale price premium.

The influence of moisture and recycled porous medium on the acoustical properties of soil substratum used on green noise barriers and absorbing building facades.

This work investigates the acoustical and related non-acoustical properties of soil substratum that is used on vegetative noise barriers and green walls. The following effects are studied in the laboratory: (i) soil moisture content, (ii) soil blending with porous recycled materials, and (iii) multi-layering of soil with porous recycled materials. The acoustic absorption and surface impedance measurements are carried out using a standard 100-mm impedance tube. The flow resistivity measurements are carried out using a calibrated flow resistivity apparatus having the diameter of 100 mm. Samples of soil substratum are prepared in a specially designed sample holder that enables accurate control of the moisture content, porosity, material compaction, and soil density. The observed experimental data are used to validate the theoretical predictions which are based on a model that requires the knowledge of the flow resistivity, porosity, tortuosity, and pore size distribution of soil and recycled porous media.

Green Noise Digital Halftoning With Multiscale Error Diffusion

Multiscale error diffusion (MED) is superior to conventional error diffusion algorithms as it can eliminate directional hysteresis completely and possesses a good blue noise characteristic. However, due to its filter design, it is not suitable for systems with poor isolated dot generation and instable dot gain. In this paper, we propose a MED algorithm to produce halftones of desirable green noise characteristics. This algorithm allows one to adjust the desirable cluster size freely through a single parameter and supports a linear relationship between the cluster size and the input gray level. With a close-to-isotropic diffusion filter, the algorithm can effectively remove pattern artifacts, eliminate directional artifacts and preserve original image details. Analysis and simulation results show that it provides better performance in terms of various aspects including dot distribution, anisotropy and output image quality as compared with other conventional green noise error diffusion algorithms.

Operation of a synchronization system in the presence of green pulse noise

It is analytically shown that, under the action of green pulse noise on a synchronization system, the phase-locking effect is retained; however, the width of the phase-locking zone significantly depends on the pulse amplitude, whereas the character of statistics of times of random-pulse occurrences affects only slightly the synchronization process.