Athens International Airport ＂Eleftherios Venizelos＂ （AIA） is considered a pioneer international Public-Private Partnership, being the first major int. airport constructed with the participation of the private sec...Athens International Airport ＂Eleftherios Venizelos＂ （AIA） is considered a pioneer international Public-Private Partnership, being the first major int. airport constructed with the participation of the private sector with the BOOT method （Build, Own, Operate, and Transfer）. AIA＇s 1st day of operation was in March 2001 and the aircraft traffic on 2006 reached 191.000 movements ＆ 15.1 million passengers. According to the European Directive 49/2002 and the Joint Ministerial Decision 13586/724-28/3/06, Athens International Airport （AIA） is included in the category of＂large airports＂ and it consequently comes under the authority of the above mentioned legislation on the evaluation and management of environmental noise. A complete Study on Aircraft Noise [1], according to the European Directive 49/2002 [2] and Joint Ministerial Decision 13586/724-28/3/06 was undertaken under the auspices of the Ministry of Environment, Energy ＆ Climate Change, the Hellenic Civil Aviation Authority, and AIA S.A. In this article the following results are presented： （1） The 2006 Strategic Noise Map （SNM） of both indicators Lden and Lnight based on the ECAC.CEAC Doc 29 methodology ＂Report on Standard Method of Computing Noise Contours around Civil Airports＂, 1997 [3], （2） A statistical analysis of predicted vs measured noise levels based on the existing Noise Monitoring System, （3） Effects from the removal of marginally accepted chapter 3 aircraft, （4） A complete evaluation of results regarding calculation of area/land uses and number of individuals living in residences inside blocks exposed in various levels of noise, and （5） A full evaluation of Noise Action Plans （NAP） regrouping existing and foreseen actions FOR 2006 ＆ 2011 scenarios, especially regarding among others, noise abatement procedures, a comprehensive noise insulation legal framework.展开更多
In this paper, we conduct research on the accurate computer music composition mode under the basic background of big data. From the perspective of music theory, in terms of micro notes jump within a certain range, wil...In this paper, we conduct research on the accurate computer music composition mode under the basic background of big data. From the perspective of music theory, in terms of micro notes jump within a certain range, will not cause discomfort, notes there are upward at the same time, the downward makes the whole piece will not boring. From the macroscopic, the nature of the chord with internal connection between motivation and motivation as support, at the same time, the whole range can maintain in a certain range, making sound effects is can let a person feel cheerful. Computer science first occupied is music in the music sound production and the propagation of position as it is mainly used for digital audio clips and automated synthesis. But there is a certain distance away from the traditional concept of composition. Therefore, our research proposes the innovative perspective to deal with the issues for achieving the better performance.展开更多
A flow resonance accompanied by the emission of acoustic tones occurs in an over-expanded convergent-divergent(C-D) nozzle when operated at comparatively low pressure ratios. This phenomenon is distinguished from conv...A flow resonance accompanied by the emission of acoustic tones occurs in an over-expanded convergent-divergent(C-D) nozzle when operated at comparatively low pressure ratios. This phenomenon is distinguished from conventional screech tones and is referred to as "transonic tones". In contrast to screech tones, the peak resonant frequency for transonic tones increases with pressure ratio; the peak sound pressure level exceeds 110 d B. In this study, we investigated the basic characteristics of transonic resonance and tones using a circular C-D nozzle in an anechoic room. The effects of the boundary layer trip were also evaluated using a tripping wire for the suppressing transonic resonance and tones. The results of acoustic measurements show that several predominant peaks correspond to transonic tones. However, the boundary layer trip inside the nozzle effectively eliminated these tones and suppressed the unsteadiness of the flow inside the nozzle.展开更多
Vocal communication is a crucial aspect of animal behavior. The mechanism which most mam- mals use to vocalize relies on three anatomical components. First, air overpressure is generated in- side the lower vocal tract...Vocal communication is a crucial aspect of animal behavior. The mechanism which most mam- mals use to vocalize relies on three anatomical components. First, air overpressure is generated in- side the lower vocal tract. Second, as the airstream goes through the glottis, sound is produced via vocal fold vibration. Third, this sound is further filtered by the geometry and length of the upper vocal tract. Evidence from mammalian anatomy and bioacoustics suggests that some of these three components may covary with an animal＇s body size. The framework provided by acoustic al- Iometry suggests that, because vocal tract length （VTL） is more strongly constrained by the growth of the body than vocal fold length （VFL）, VTL generates more reliable acoustic cues to an animal＇s size. This hypothesis is often tested acoustically but rarely anatomically, especially in pinnipeds. Here, we test the anatomical bases of the acoustic allometry hypothesis in harbor seal pups Phoca vitulina. We dissected and measured vocal tract, vocal folds, and other anatomical features of 15 harbor seals post-mortem. We found that, while VTL correlates with body size, VFL does not. This suggests that, while body growth puts anatomical constraints on how vocalizations are filtered by harbor seals＇ vocal tract, no such constraints appear to exist on vocal folds, at least during puppy- hood. It is particularly interesting to find anatomical constraints on harbor seals＇ vocal tracts, the same anatomical region partially enabling pups to produce individually distinctive vocalizations.展开更多
文摘Athens International Airport ＂Eleftherios Venizelos＂ （AIA） is considered a pioneer international Public-Private Partnership, being the first major int. airport constructed with the participation of the private sector with the BOOT method （Build, Own, Operate, and Transfer）. AIA＇s 1st day of operation was in March 2001 and the aircraft traffic on 2006 reached 191.000 movements ＆ 15.1 million passengers. According to the European Directive 49/2002 and the Joint Ministerial Decision 13586/724-28/3/06, Athens International Airport （AIA） is included in the category of＂large airports＂ and it consequently comes under the authority of the above mentioned legislation on the evaluation and management of environmental noise. A complete Study on Aircraft Noise [1], according to the European Directive 49/2002 [2] and Joint Ministerial Decision 13586/724-28/3/06 was undertaken under the auspices of the Ministry of Environment, Energy ＆ Climate Change, the Hellenic Civil Aviation Authority, and AIA S.A. In this article the following results are presented： （1） The 2006 Strategic Noise Map （SNM） of both indicators Lden and Lnight based on the ECAC.CEAC Doc 29 methodology ＂Report on Standard Method of Computing Noise Contours around Civil Airports＂, 1997 [3], （2） A statistical analysis of predicted vs measured noise levels based on the existing Noise Monitoring System, （3） Effects from the removal of marginally accepted chapter 3 aircraft, （4） A complete evaluation of results regarding calculation of area/land uses and number of individuals living in residences inside blocks exposed in various levels of noise, and （5） A full evaluation of Noise Action Plans （NAP） regrouping existing and foreseen actions FOR 2006 ＆ 2011 scenarios, especially regarding among others, noise abatement procedures, a comprehensive noise insulation legal framework.
文摘In this paper, we conduct research on the accurate computer music composition mode under the basic background of big data. From the perspective of music theory, in terms of micro notes jump within a certain range, will not cause discomfort, notes there are upward at the same time, the downward makes the whole piece will not boring. From the macroscopic, the nature of the chord with internal connection between motivation and motivation as support, at the same time, the whole range can maintain in a certain range, making sound effects is can let a person feel cheerful. Computer science first occupied is music in the music sound production and the propagation of position as it is mainly used for digital audio clips and automated synthesis. But there is a certain distance away from the traditional concept of composition. Therefore, our research proposes the innovative perspective to deal with the issues for achieving the better performance.
文摘A flow resonance accompanied by the emission of acoustic tones occurs in an over-expanded convergent-divergent(C-D) nozzle when operated at comparatively low pressure ratios. This phenomenon is distinguished from conventional screech tones and is referred to as "transonic tones". In contrast to screech tones, the peak resonant frequency for transonic tones increases with pressure ratio; the peak sound pressure level exceeds 110 d B. In this study, we investigated the basic characteristics of transonic resonance and tones using a circular C-D nozzle in an anechoic room. The effects of the boundary layer trip were also evaluated using a tripping wire for the suppressing transonic resonance and tones. The results of acoustic measurements show that several predominant peaks correspond to transonic tones. However, the boundary layer trip inside the nozzle effectively eliminated these tones and suppressed the unsteadiness of the flow inside the nozzle.
文摘Vocal communication is a crucial aspect of animal behavior. The mechanism which most mam- mals use to vocalize relies on three anatomical components. First, air overpressure is generated in- side the lower vocal tract. Second, as the airstream goes through the glottis, sound is produced via vocal fold vibration. Third, this sound is further filtered by the geometry and length of the upper vocal tract. Evidence from mammalian anatomy and bioacoustics suggests that some of these three components may covary with an animal＇s body size. The framework provided by acoustic al- Iometry suggests that, because vocal tract length （VTL） is more strongly constrained by the growth of the body than vocal fold length （VFL）, VTL generates more reliable acoustic cues to an animal＇s size. This hypothesis is often tested acoustically but rarely anatomically, especially in pinnipeds. Here, we test the anatomical bases of the acoustic allometry hypothesis in harbor seal pups Phoca vitulina. We dissected and measured vocal tract, vocal folds, and other anatomical features of 15 harbor seals post-mortem. We found that, while VTL correlates with body size, VFL does not. This suggests that, while body growth puts anatomical constraints on how vocalizations are filtered by harbor seals＇ vocal tract, no such constraints appear to exist on vocal folds, at least during puppy- hood. It is particularly interesting to find anatomical constraints on harbor seals＇ vocal tracts, the same anatomical region partially enabling pups to produce individually distinctive vocalizations.
