The Norwegian Façade Insulation Study: the efficacy of façade insulation in reducing noise annoyance due to road traffic

The ergodic propriety of a room has strong effects on its reverberation. If the room is ergodic, the reverberation can be broken up in two steps: a deterministic process followed by a stochastic one. The late reverberation can be then modeled by a reverberation algorithm instead of more computationally consuming methods. In this study, the free path temporal distribution obtained by ray-tracing is used as an indicator of the room's mixing: the energetic average of the path lengths is computed at each time step. Ergodic rooms are thus characterized by rapidly convergent distributions. The free path value becomes independent of time. On the other hand, path selection mechanism and orbits are observed in non-ergodic rooms. The transition time from the deterministic process to the stochastic one is also studied through the evaluation of the room's time constant. It is shown that its value depends only on the mean free path and the boundaries scattering value. An empirical expression is obtained which agrees well with simulations carried out in a concert hall. This transition time from a deterministic model to a stochastic one can be used to speed up the acoustical predictions and auralizations in ergodic rooms.     

Measurements and analyses of infrasound noise field in the atmosphere

Methods for measuring and analyzing the infrasound noise field inthe atmosphere have been expounded.A set of space correlation radii of noisecorresponding to wind speed 4m/s has been obtained,which can be takenas the tentative basis for an acoustical array design.At the same time,thewind speed-sound pressure relation curves have been measured and calcu-lated,and the anti-jamming ability of the array receiving infrasonic signals isobtained.     

Determining the efficacy of a nanotechnology media product in enhancing children’s engagement with nanotechnology

Public engagement in nanotechnology media products can lead to a greater interest in understanding of nanotechnology. A study was undertaken to determine middle school student engagement in Nanooze, a magazine featuring nanotechnology research that has been developed for a young adult audience. Teachers at 116 Detroit middle schools distributed two issues of the magazine to their students, and surveys were collected from 870 students after reading the magazines. Results suggest that the majority of students liked reading the magazine and learned something about nanotechnology. Engagement in nanotechnology led to understanding of nanotechnology. The Nanooze magazine was an effective medium for engaging middle school students in learning about nanotechnology.     

Receiving response of towed line array to the noise of the tow ship in shallow water

The receiving response of towed line array to the noise radiated from the tow ship is investigated through normal mode modeling and computer simulation.The phenomenon that the maximum output of the towed line array is away from the endfire direction towards the tow ship is explained.The result is important for the understanding of the phenomenon and also for the application research concerning the suppression of the noise from the tow ship as well as adequate application of towed array techniques in shallow water.     

Spatial coherences of the sound pressure and the particle velocity in underwater ambient noise

The spatial coherences were investigated between the sound pressure and the three orthogonal components of the particle velocity in underwater ambient noise. Based on the ray theory, integral expression was derived for the spatial coherence matrix of the sound pressure and the particle velocity in a stratified ocean with dipole noise sources homogenously distributed on the surface. The integrand includes a multiplying factor of the vertical directivity of the noise intensity, and the layered ocean environment affects the spatial coherences via this directivity factor. For a shallow water environment and a semi-infinite homogenous medium, the coherence calculation results were given. It was showed that the sound speed profile and the sea bottom could not be neglected in determining the spatial coherences of the ambient noise vector field.     

The effects of pitch and duration on the perception of the neutral tone in standard Chinese

The research aim is to investigate that how pitch and duration affect the perception of the neutral tone in standard Chinese and that which one of the two factors is more important. A psycho-acoustic experiment was conducted, in which the listening stimuli consisted of 15 groups of disyllabic words, and the pitches and durations of the two syllables in each of the words were artificially controlled. Thirty-three standard Chinese native speakers participated in a forced-choice task to judge if the second syllables of the words they heard carried the neutral tone or the normal tones. The results of the experiment indicated that, (1) the effects of both pitch and duration on the perception of the neutral tone are significant; (2) the effect of pitch is larger than that of duration; (3) both the F0 values of the high point in the pitch contour and the pitch contour pattern have influence on the perception. The results of the experiment were correspondent to some extent to those of the previous acoustic analyses on the neutral tone. The diversity between the results of the presented perceptual study and those of the acoustical studies implies that the acoustic features of the neutral tone that exist in natural speech while do not affect the perception may be phonologically redundant.     

Advances in optoelectronics in europe—the RACE and ESPRIT programmes

EditorialSpecial issue

Advances in optoelectronics in europe—the RACE and ESPRIT programmes     

Angular dependence of shot noise in the presence of Rashba spin–orbit coupling in semiconductor spintronics junctions

We investigate spin-dependent current and shot noise, taking into account the Rashba spin–orbit coupling (RSOC) effect in double diluted magnetic semiconductor (DMS) barrier resonant tunneling diodes. The calculation is based on an effective mass approach. The magnetization of DMS is calculated by the mean-field approximation in low magnetic field. The spin-splitting of DMS depends on the sp–d exchange interaction. We also examine the dependence of transport properties of CdTe/CdMnTe heterostructures on applied voltage and relative angle between the magnetization of two DMS layers. It is found that the RSOC has great different influence on the transport properties of tunneling electrons with spin-up and spin-down, which have different contributions to the current and the shot noise. Also, we can see that the RSOC enhances the spin polarization of the system, which makes the nanostructure a good candidate for new spin filter devices. Thus, these numerical results may shed light on the next applications of quantum multilayer systems and make them a good choice for future spintronics devices.     

Effects of traffic noise on pupils''''behavior in classroom

Noise surveys in this country reported that a large number ofclassrooms in primary and secondary schools in the urban areas were dis-turbed by environmental noise,particulariy by traffic noise.A series ofpsychological tests were conducted to identify pupils'behavior in aclassroom under different noise levels within the range of 40 to 70 dBA.Statistical analysis results were obtained by using Relational Data Analy-sis System(RDAS)software.According to the t-test and single factor vari-ance analysis of the results,significant differences of the pupils'behaviorin the classroom have been observed when the percentile exceeded soundlevel either L_(50) exceeds 50 dBA or L_(10) exceeds 55 dBA,or the equivalentcontinuous sound level L_(eq) exceeds 50 dBA.The same conclusion hasbeen drawn from the average percentages of syllable articulation under different noise levels in a classroom which were the results of tests made inacdordance with the procedure described in the National Standard.Themaximum acceptable noise     

Active control of intermittent noise in a room

I.IntroductionThereverberantnoisesmaybereducedwithanactivenoisecontrol(ANC)systcmformedbyacornermicrophonc-amplifier-1oudspcakersystemina.oom.lllThismeth-odbascdonthenormalmodccancelingprincip1chasalreadybeenclarifiedbothinthco-ryandexperimcnts,andthclimitationandpotcntialityofitsapp1icationalsodiscussedinapreviouspaper.Thediscussionsinthepastlimitedmost1ytothesteadyconditionofnoiscfield,andthisisextendedtothetransientcondihoninthcprcsentwork,viz.thein-llucnceofthecornerANCsystemwhenthenois…     

Measurement and simulation of partial discharge in oil-paper insulation under the combined AC–DC voltage

Depending on unique operation characteristics for voltage applied on valve side winding of the converter transformers, it is extraordinarily significant to study the partial discharge (PD) behavior with oil-paper insulation under combined AC–DC voltage. Therefore, this paper investigated PD inception characteristics by pulse current methods with needle-plate electrode system under combined AC–DC voltage. Furthermore, 3D electric field distributions versus combined AC–DC voltage in different ratios were calculated by Finite Element Analysis (FEA). An experimental conclusion was drew that AC partial discharge inception voltage (PDIV) in pure oil would decrease linearly with the DC component increasing but the inception voltage with oil-paper insulation appeared to be independent of DC voltage and dependent of AC voltage. And 3D electric field distribution deduced from simulation provided a supplementary proof on the experimental results. Moreover, high speed photography was used to capture emitted light produced by discharge, estimate streamer velocity (1.8 km/s) and record streamer initiation and propagation process in oil gap. Previous studies have shown that the prebreakdown phenomena involving the generation and propagation of vapor channels through the oil could be divided into a three-stage process.     

Effect of external noise on the dynamical localization of two coupling electrons in quantum dot array

The effect of external noise, which is characterized by an Ornstein--Uhlenbeck process, on the dynamical localization of two coupling electrons in a quantum dot array under the action of an ac electric field is studied. A numerical solution of the stochastic equations is obtained by averaging over stochastic trajectories. The results show that the external noise may destroy the dynamical localization, but the anti-noise capacity of the system is stronger when the two electrons are localized at the ends of the quantum dot array.     

Experimental studies on the impact of ASE noise of single-channel optical amplifiers in central office applications

We identified the amplified spontaneous emission-amplified spontaneous emission (ASE-ASE) beat noise from the semiconductor optical amplifier, which has been overlooked in previous studies, as a cause of severe system penalties when it was used to provide single-channel amplification in a dynamic central office environment through experimental studies. Our results pointed out that the ASE-ASE beat noise of the optical amplifier, other than its gain and noise figure, has to be considered to correctly predict its performance in these new applications.     

Security analysis of the “Ping–Pong” quantum communication protocol in the presence of collective-rotation noise

Environmental noise is inevitable in non-isolated systems. It is, therefore, necessary to analyze the security of the “Ping–Pong” protocol in a noisy environment. An excellent model for collective-rotation noise is introduced, and information theoretical methods are applied to analyze the security of this protocol. If noise level ε   is lower than 11%, an eavesdropper can gain some, but not all, information freely without being detected. Otherwise, the protocol becomes insecure. We conclude that the use of ‘Ping–Pong’ protocol as a quantum secure direct communication (QSDC) protocol is quasi-secure, as declared by the original author when ε?11%$\epsilon ?11\text{\%}$.     

Stress perception of Chinese disyllabic words in utterance

A perceptual experiment was conducted on the stress of 1,898 Chinese disyllabic words in 300 sentences taken from the Chinese speech corpus of Microsoft Research Asia. The analyses revealed (1) that the perceptual stress location in utterance was influenced by the prosodic boundary where a word stood; (2) that -the perceptual stress degree of a syllable was positively correlated with the pitch of the syllable and the duration as well, while the correlation coefficient between the stress degree and the pitch was larger than that between the stress degree and the duration; (3) that the pitch and the duration was not correlated if there was no pause following a word, but weakly and positively correlated if there was a pause; (4) that tone pattern of a syllable showed an effect on stress perception. The results of the experiment indicate that the perceptual characteristics of word stress in utterance are quite different from those in isolated words.     

Stress perception of Chinese disyllabic workds in utterance

A perceptual experiment was conducted on the stress of 1,898 Chinese disyllabic words in 300 sentences taken from the Chinese speech corpus of Microsoft Research Asia.The analyses revealed(1) that the perceptual stress location in utterance was influenced by the prosodic boundary where a word stood;(2)that the perceptual stress degree of a syllable was positively correlated with the pitch of the syllable and the duration as well,while the correlation coefficient between the stress degree and the pitch was larger than that between the stress degree and the duration;(3) that the pitch and the duration was not correlated if there was no pause following a word,but weakly and positively correlated if there was a pause;(4) that tone pattern of a syllable showed an effect on stress perception.The results of the experiment indicate that the perceptual characteristics of word stress in utterance are quite different from those in isolated workds.     

Research on perception of juncturebetween syllables in Chinese

1IntroductionXUYi[l]classifiesjuncturesofChineseinfourcategories'inner-syllablejuncture,between-syllablejuncture,rhythmjuncture,andpausejuncture.Amongthefourcategories,theinner-syllablejunctureisthestrongestone,thebetween-syllablejunctureisthesecond,andtheothertwokindsofjuncturesareweaker.SincemonosyllablesusuallyareadoptedasChinesesyntheticunits,theinner-syllablejuncturehasbeenpreservedinsyllables.Thereforetheinfiuenceofbetween-syllablejunctureonperceptionofnaturalnessofsynthesisChineseisth…     

A snapshot of young adults’ noise exposure reveals evidence of ‘Binge Listening’

There have been several previous studies into daily noise exposure levels in modern urban communities, which typically report mean noise exposure levels (L_Aeq) for adults between 73 and 79 dB. In this study, rather than focus on group mean exposures across a wide age range, individual patterns of noise exposure over 4- and 5-day periods were examined in a group of 45 young adults aged 18–35 years. The main objective of the study was to determine the extent to which young adults exhibit a ‘binge listening’ pattern of noise exposure, i.e., high weekend leisure noise vs. low weekday work noise exposure. A secondary objective was to identify the types of activities that generate the highest noise exposures. The results showed that although most participants (60%) were exposed to low daily noise levels, 33% of participants exhibited a ‘binge listening’ exposure pattern characterized by one or two high-noise days, usually a Friday, Saturday or Sunday, preceded or followed by much quieter days. The most notable high-noise activities were playing an instrument solo or in a band; attending a nightclub; and attending a pop concert, each of which recorded average noise levels greater than 100 dB. Future research is needed to determine whether ‘binge listening’ is more or less harmful than the chronic exposure presupposed in traditional risk models, however, under the equal-energy principle, repeated ‘binge’ noise exposures from weekend visits to nightclubs, live music events and other high-noise events represent a significant risk to long-term hearing health.