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Noise pollution from road traffic was evaluated in a large city in Latin America based on in situ measurements taken at 174 points and on noise maps. The noise maps were calculated using Predictor 7810 version 8.11 software, based...
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Noise pollution from road traffic was evaluated in a large city in Latin America based on in situ measurements taken at 174 points and on noise maps. The noise maps were calculated using Predictor 7810 version 8.11 software, based on the prediction model of the international standard ISO 9613. Three distinct areas in the city of Campo Grande (Brazil) were evaluated: 1) Commercial sector, 2) Mixed sector (commercial and residential), and 3) Residential sector. The noise maps indicate the presence of noise pollution in the Commercial and Mixed sectors, as well as the fact that parts of the Residential sector are noise polluted but that it still has large areas where the noise limit of 55dB(A) is respected.
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We study an entangled distributed quantum sensing scheme based on an array of d Mach-Zehnder interferometers (MZIs) for the estimation of relative phase shifts. The scheme uses d coherent states and a single squeezed-vacuum state ...
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We study an entangled distributed quantum sensing scheme based on an array of d Mach-Zehnder interferometers (MZIs) for the estimation of relative phase shifts. The scheme uses d coherent states and a single squeezed-vacuum state that is distributed among the MZIs by a quantum circuit (QC). The protocol can be optimized analytically: it overcomes the shot-noise limit and reaches the Heisenberg limit with respect to the average total number of probe particles, n(T) , for the estimation of arbitrary linear combinations of the d phases. We compare the entangled strategy with a separable one that uses d coherent and d squeezed-vacuum states and the same n(T) . The entangled strategy benefits for a substantial reduction of resource overhead and can achieve a maximum gain equal to d when using the same total squeezed-light intensity as the separable strategy. Interestingly, the entangled strategy using a single squeezed-vacuum state can reach the same sensitivity as the separable strategy that uses d copies of the same state. Finally, given a random choices of the QC, we identify the optimal linear combination of the phases that can be estimated with maximum sensitivity. Our scheme paves the ways for a variety of applications in distributed quantum sensing with photonic and atomic interferometers.
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It is shown that the addition of down-converted photon pairs to coherent laser light enhances the N-photon phase sensitivity due to the quantum interference between components of the same total photon number. Since most of the pho...
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It is shown that the addition of down-converted photon pairs to coherent laser light enhances the N-photon phase sensitivity due to the quantum interference between components of the same total photon number. Since most of the photons originate from the coherent laser light, this method of obtaining non-classical N-photon states is much more efficient than methods based entirely on parametrically down-converted photons. Specifically, it is possible to achieve an optimal phase sensitivity of about delta phi(2) = 1/N-3/2, equal to the geometric mean of the standard quantum limit and the Heisenberg limit, when the average number of down-converted photons contributing to the N-photon state approaches root N/2.
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We consider the problem of estimating the phase of squeezed vacuum states within a Bayesian framework. We derive bounds on the average Holevo variance for an arbitrary number N of uncorrelated copies. We find that it scales with t...
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We consider the problem of estimating the phase of squeezed vacuum states within a Bayesian framework. We derive bounds on the average Holevo variance for an arbitrary number N of uncorrelated copies. We find that it scales with the mean photon number n, as dictated by the Heisenberg limit, i.e., as n(-2), only for N>4. For N 收起
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This paper summarizes results, trends and needs of contemporary research on community noise effects. In the first part (status), the following topics are outlined: the changing concept of noise; annoyance; disturbances of communic...
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This paper summarizes results, trends and needs of contemporary research on community noise effects. In the first part (status), the following topics are outlined: the changing concept of noise; annoyance; disturbances of communication, recreation, cognitive performance, sleep and health; comparison of the effects of different noise sources; effects of abrupt noise level changes; and scientific support for noise limit proposals. The second part (tendencies) shows recent developments of noise research with respect to following topics: effects of visual information on annoyance; wind turbines; monetary valuation of quietness in residential areas; tradeoffs between noisy and quiet places; psychology as a means for reducing noise effects; sound-scapes; effects of combined noise sources; and effect-related indicators of noisy situations. The third part (desiderata) contains a list of topics which need further consideration in the near future.
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The planned provisions of the new Noise Directive to protect employees drawn up in 2001 are analysed and evaluated on the basis of the existing Directive. Although the new Noise Directive provides for a number of major changes, th...
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The planned provisions of the new Noise Directive to protect employees drawn up in 2001 are analysed and evaluated on the basis of the existing Directive. Although the new Noise Directive provides for a number of major changes, the basic problems of noise control at the workplace are not dealt with.
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In this paper concurrent design of Schottky diode based limiter and low noise amplifier (LNA), based on noise matching, is investigated to achieve minimum noise figure (NF) of the receiver chain. In design procedure of the LNA, th...
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In this paper concurrent design of Schottky diode based limiter and low noise amplifier (LNA), based on noise matching, is investigated to achieve minimum noise figure (NF) of the receiver chain. In design procedure of the LNA, the noise figure is minimum, gain at central frequency is 14.5 dB, and limiter structure tolerates up to 5 W continuous wave input power. In the proposed concurrent design, a pass-band filter is applied at the LNA output to attenuate undesired out-of-band signals. In the proposed design, the limiter-LNA is implemented with a 0.25 mu m gate length AlGaAs/InGaAs pHEMT process. Measured noise figure of chain is 2.7 dB and average gain over 8.5-9.5 GHz frequency range and the gain at 9 GHz center frequency are 10 dB and 14.5 dB respectively. The performance results of proposed matching network are compared with traditional 50 omega matching networks in limiter-LNA with identical circuit specifications.
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Environmental noise in urban areas is known to cause functional abnormalities reflected in human health and behavior. In developing countries such as Brazil, public schools are exposed to high levels of noise due in part to poor i...
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Environmental noise in urban areas is known to cause functional abnormalities reflected in human health and behavior. In developing countries such as Brazil, public schools are exposed to high levels of noise due in part to poor infrastructure, especially with regard to noise attenuation. In schools exposed to noise levels above the limits specified by regulations and international guidelines, students and teachers are at greater risk of health problems, and performance may be compromised. In this study we evaluated the impact of environmental noise on children and teachers at three public schools (a kindergarten, an elementary school, and a high school) in a Northeast Brazilian metropolis, with emphasis on noise generated by street, above ground rail and air traffic. Environmental noise maps were generated and teachers were administered questionnaires focusing on the impact of noise pollution on health and performance. The study was intended to subsidize efforts at urban planning and public policy making by measuring actual noise levels and probing their possible effects. As shown by our results, public schools are in urgent need of noise attenuation measures, and enforcement of noise emission regulations for public transportation needs to be more emphatic.
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Environmental noise and vibration annoyance - especially from road transportation networks - is widely accepted as an end-point of environmental assessment that can be taken as a basis for evaluating the impact and annoyance cause...
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Environmental noise and vibration annoyance - especially from road transportation networks - is widely accepted as an end-point of environmental assessment that can be taken as a basis for evaluating the impact and annoyance caused to the exposed population. This paper presents the results of a comprehensive monitoring program for environmental noise and vibration from ELEFSINA (ATHENS) - KORINTHOS (an upgraded three-lane motorway crossing the famous Korinthos canal with a total length of 63 km), as well as the resulting appropriate noise action plan, including adequate mitigation measures for environmental road noise abatement. In the framework of this monitoring program, 40 locations were selected for airborne noise monitoring (various indices as L_A eq (08:00-20:00), L_A 10(18 h), L_(den), L_(night)) and 24 locations for vibration (ground borne noise both in dB(A) and peak vibration velocity - PPV in mm/s) monitoring covering all sensitive uses as per residential buildings, educational uses, churches, etc. A full assessment of all measured results and the noise mapping assessment was also executed. This assessment aimed at the implementation of appropriate noise barriers with synthetic axes, upon which the total aesthetical and acoustic adaptation was based to fulfill the need for adequate noise protection criteria and full aesthetic consistency of the final outcome with the built-up surrounding landscape. In conclusion, some 9,000 m2 of semi-transparent noise barriers are already under construction. Environmental noise and vibration monitoring programs are proven to be a crucial parameter in sustainability assessments of inter- and semi-urban road networks.
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Many residents suffer from traffic-generated noise. Traffic is the most prevailing source ofnoise in cities. With the number of vehicles increasing and traffic intensity growing, the awareness ofenvironment pollution issues necess...
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Many residents suffer from traffic-generated noise. Traffic is the most prevailing source ofnoise in cities. With the number of vehicles increasing and traffic intensity growing, the awareness ofenvironment pollution issues necessitates a search for noise reduction possibilities. Noise is justly considered as one of the key ecological problems in many cities andresidential areas. Naujasodiiai residential area located by Highway A2 Vilnius—Panevezyswas selected for the investigation. The highest noise level in the daytime, 70-71 dBA, wasrecorded in the measurement locations A2—A3 at a 7.5 m distance from Highway A2Vilnius—Panevezys. Data of the spread of noise level indicates that higher levels of noiseare recorded on the edges of the residential area. The measured level of traffic-generatednoise in the residential area shows that the equivalent noise level limits are exceeded onlywithin 30 m distance from the highway. This is mainly predetermined by the absence ofnoise reduction barriers. The spread of noise is partly subdued in the central part of theresidential area by an embankment, running along the highway, planted with bushes andtrees. The equivalent noise level measured at the height of 4.0 m in the living environmentof NaujasodZiai residential area was around 1-2 dB bigger than at the height of 1.5 m. Themost efficient way of reducing the noise is to install a noise-reduction wall on an embank-ment and to construct industrial-purpose buildings, e. shields, in the industrial zone infront of the residential area as well as to plant the slopes of the embankment.
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