Fast and accurate prediction of sound radiation of Contra-Rotating Open Rotors(CRORs)is an essential element of design methods of low-noise open rotor propulsion systems.In the present work,a previous frequency-domain...Fast and accurate prediction of sound radiation of Contra-Rotating Open Rotors(CRORs)is an essential element of design methods of low-noise open rotor propulsion systems.In the present work,a previous frequency-domain model is extended to predict CROR noise.It builds explicitly the relationship between harmonic loadings and corresponding tonal noise,by which the influential parameters to noise generation can be clearly understood.The real distribu-tions of steady and unsteady blade loadings are calculated by the Nonlinear Harmonic(NLH)method.In the present hybrid approach,both the CFD and acoustic modules are solved in the fre-quency domain.To assess the accuracy of the developed method,the loading noise of a CROR is calculated and compared against results by using the time-domain FW-H module of NUMECA.The predicted sound directivities by the two methods are in good agreements.The present acoustic model in the frequency domain is proven to be accurate and have high efficiency in far-field noise prediction and data processing.Furthermore,the characteristics of the CROR interaction tonal noise are analyzed and discussed.展开更多
Basing upon the tonality analytic method, the present paper aims at： （1） Drawing attention to the subordination of the minor key vs. the major key in the chord classification, using the same methodology; and （2） ...Basing upon the tonality analytic method, the present paper aims at： （1） Drawing attention to the subordination of the minor key vs. the major key in the chord classification, using the same methodology; and （2） Showing the differences for the major key and the minor （harmonic） key in the classification of chords, as an aspect of importance for interpreting a piece＇s tonal structure diagram. The relations between chords appearing in the major and minor （harmonic） key will be shown by applying the comparisons of： （1） third-based chords; and （2） degrees in the C major and A minor keys, on which the same diatonic chords appear.展开更多
A monitoring of multiple physical parameters in a moderate seismic area in Western Piedmont (NW Italy) and the simultaneous observation of the behaviour of numerous species of domestic and wild animals gave in a perio...A monitoring of multiple physical parameters in a moderate seismic area in Western Piedmont (NW Italy) and the simultaneous observation of the behaviour of numerous species of domestic and wild animals gave in a period of over twenty years the possibility to distinguish the unusual animal behaviours due to local earthquake nucleation from other causes. In particular, the observation of the body and vocal language of dogs (Canis familiaris) in the same area has permitted not only to specify the different meanings of vocal language in connection to their body language, but also to classify the minimum elements into a vocal language that is linked together by tonal and rhythmical sequences of sounds that form a semantic lexicon. The usage of the same tonal and rhythmical vocal sequences in similar or identical situations, which are experienced by different groups of dogs, induces us to verify whether it could be possible to link particular vocal sequences to precise physical anomalies before earthquakes. The individuation of physical anomalies due to an earthquake nucleation or due to a hydro-geological destabilization, is possible thanks to a continuous long-term monitoring of some parameters. Moreover, the complexity of the vocal language of dogs increases if the dogs live in an area with a law population density. Then the correlation between some vocal sequences and some seismic precursors is better if dogs live free in yard or on farms, if they are in good health, and if they can establish a strong social relation of group. When dogs live closed in yards of houses that are far apart, they communicate with each other with an amazing vocal language, full of questions and answers, imitations of sequences, and information about situations that may be harmful to them.展开更多
Musical analysis enables us to study the various elements of a musical work, for example texture, m dynamics, or harmony （including tonality）. Thanks to musical analysis we are able to trace the compos technique, or...Musical analysis enables us to study the various elements of a musical work, for example texture, m dynamics, or harmony （including tonality）. Thanks to musical analysis we are able to trace the compos technique, or assess the artistic value of given work. In addition to traditional, descriptive methods of e it ody, onal music analysis, we can observe in 20th century the development of methods based on science （mathematics, otherwise statistics）. Such methodologies allow us to obtain a strict understanding of the structure of musical pieces Applying mathematical methods for musical analysis seems very reasonable in relation to the output of Frederic Chopin, due to large originality of the elements of musical pieces of this composer. Present paper was written as a result of research related to the applying of numerical method of analysis for exploring the tonal structure of Chopin＇s works. The author＇s research method enables a strict analysis of the chord＇s domination that can be classified under given key （range）--taking into consideration the harmonic functions. By the method of analysis we can get charts that depict whole diatonic vertical music material of the given piece. The main objective of the present study is to describe observations on the high uniqueness in the tonal construction of selected Chopin＇s mazurkas, especially, when compared to the miniatures of other composers of the first half of the 19th century and previously analyzed Chopin＇s pieces： etudes, preludes, and songs.展开更多
Valeo, involved in engine cooling fan system design for many years, is interested in noise prediction tools for axial fans. Thus, this paper describes a two-part study of tonal noise computation. The first part deals ...Valeo, involved in engine cooling fan system design for many years, is interested in noise prediction tools for axial fans. Thus, this paper describes a two-part study of tonal noise computation. The first part deals with the prediction of tonal noise using analytical models. As for the second part, it describes a hybrid approach for predicting tonal noise where the sources are extracted from an Unsteady Reynolds-Averaged Naviers-Stocks （URANS） simulation and then propagated into the far, free field using the Ffowcs Williams and Hawkings＇ acoustic analogy. The computational domain is meshed with 46 million polyhedral elements and the simulation takes into account the exact geometry of the rotor blades, the stator blades and the shroud. The results from the first part show that analytical models can be used for comparisons between different fan geometries, but are unable to provide accurate noise predictions compared to experimental results. The simulation shows non-periodic blade loading over a whole fan revolution, and different blade loading between the blades. This introduces some bias in the assessment of the acoustic performance of the fan. Overall, the results from the hybrid method are in accordance with the experimental results.展开更多
This study explores the intricate symbiotic relationship between the Cantonese tonal system and Cantonese opera through an interdisciplinary lens of linguistics and musicology.Cantonese,with its complex tonal architec...This study explores the intricate symbiotic relationship between the Cantonese tonal system and Cantonese opera through an interdisciplinary lens of linguistics and musicology.Cantonese,with its complex tonal architecture and unique phonetic characteristics,serves not only as a communicative medium but as a structural blueprint for the melodic and rhythmic composition of Cantonese opera.Through historical tracing,phonological analysis,and performative interpretation,the paper examines how tonal contours directly shape vocal techniques,emotional expression,and narrative cadence within the opera tradition.The research further investigates how socio-cultural factors—ranging from regional identity,migration,and colonial modernity to contemporary digital transmission—have mediated the evolution and resilience of this art form.By demonstrating how linguistic tone and musical tune co-construct aesthetic experience and cultural memory,the paper offers a new theoretical model for understanding language-music co-evolution in tonal cultures.This inquiry not only affirms Cantonese opera’s role as a living archive of regional identity but also proposes strategies for its revitalization amidst the shifting conditions of modernity and globalization.展开更多
为了避免航空发动机涡轮部件成为未来超扇发动机低噪声设计的瓶颈之一,有必要开展涡轮气动噪声的声学特征和控制方法研究。本文采用经过实验验证的流场/声场混合计算方法,以轴向间距减半的GE E3最后1.5级低压涡轮(转-静-转构型)为研究对...为了避免航空发动机涡轮部件成为未来超扇发动机低噪声设计的瓶颈之一,有必要开展涡轮气动噪声的声学特征和控制方法研究。本文采用经过实验验证的流场/声场混合计算方法,以轴向间距减半的GE E3最后1.5级低压涡轮(转-静-转构型)为研究对象,对基准静叶下不同叶片排之间产生的尾迹干涉单音噪声和位势干涉单音噪声的声场特征,以及复合锯齿静叶对气动效率和单音噪声的影响进行了数值分析。结果表明:位势干涉单音噪声成为与尾迹干涉单音噪声同等量级的主导声源之一,并且同一展向位置的位势作用强度受到尾迹干涉强度的直接影响。此外,复合锯齿静叶具备同时改善气动效率和降低涡轮单音噪声的能力,最大效率收益为锯齿振幅A/波长W=1.5时的0.0234%,此时1.5级低压涡轮前三阶谐波单音噪声总声功率级的降噪收益为2.5 d B。因此,复合锯齿静叶在未来超扇发动机中可以作为控制多级低压涡轮噪声的有效手段之一。展开更多
A method based on ensemble empirical mode decomposition (EEMD) is proposed for accurately detecting the time varying pitch of speech in tonal languages. Unlike frame-, event-, or subspace-based pitch detectors, the ti...A method based on ensemble empirical mode decomposition (EEMD) is proposed for accurately detecting the time varying pitch of speech in tonal languages. Unlike frame-, event-, or subspace-based pitch detectors, the time varying information of pitch within the short duration, which is of crucial importance in speech processing of tonal languages, can be accurately extracted. The Chinese Linguistic Data Consortium (CLDC) database for Mandarin Chinese was employed as standard speech data for the evaluation of the effectiveness of the method. It is shown that the proposed method provides more accurate and reliable results, particularly in estimating the tones of non-monotonically varying pitches like the third one in Mandarin Chinese. Also, it is shown that the new method has strong resistance to noise disturbance.展开更多
Quadrisyllabic words and phrases with normal stress of Mandarin were used to study the tonal coarticulation. It was firstly found that the F0perturbation at the starting-point and the ending-point of the F0 curve in e...Quadrisyllabic words and phrases with normal stress of Mandarin were used to study the tonal coarticulation. It was firstly found that the F0perturbation at the starting-point and the ending-point of the F0 curve in each syllable caused by tonal coarticulation is larger than the intrinsic F0 difference of vowels at the starting-point and the ending-point of it. As for the tonal coarticulation, it was discovered that tonal coarticulation in word and phrase with normal stress is different to that in the nonsense sequence with even stress, and in word and phrase with normal stress, the tonal coarticulatory effects are unidirectional, and the carryover effect does not extend to the ending-point of tone-section of the following syllable and the anticipatory effect does not extend to the starting-point of tone-section of the preceding one, and the F0 perturbation by tonal coarticulation has its pattern.展开更多
The present paper reports a comparison of experimental SPL spectral data related to the tonal noise generated by axial-flow fans.A nine blade rotor has been operated at free discharge conditions and in four geometrica...The present paper reports a comparison of experimental SPL spectral data related to the tonal noise generated by axial-flow fans.A nine blade rotor has been operated at free discharge conditions and in four geometrical configurations in which different kinds of tonal noise generating mechanisms are present:large-scale inlet turbulent structures,tip-gap flow,turbulent wakes,and rotor-stator interaction.The measurements have been taken in a hemi-anechoic chamber at constant rotational speed and,in order to vary the acoustic source strength,during low angular acceleration,linear speed ramps.In order to avoid erroneous quantitative evaluations if the acoustic propagation effects are not considered,the acoustic response functions of the different test configurations have been computed by means of the spectral decomposition method.Then,the properties of the tonal noise generating mechanisms have been studied.To this aim,the constant-Strouhal number SPL,obtained by means of measurements taken during the speed ramps,have been compared with the propagation function.Finally,the analysis of the phase of the acoustic pressure has allowed to distinguish between random and deterministic tonal noise generating mechanisms and to collect information about the presence of important propagation effects.展开更多
The relations of intensity Just Noticeable Difference (JND) to intensity for tone bursts maybe,depend on signal durations according to Jont B.Allen's [J. Acoust. Soc. Am. 102 3, 1997, 3628--3646.]. The intensity j...The relations of intensity Just Noticeable Difference (JND) to intensity for tone bursts maybe,depend on signal durations according to Jont B.Allen's [J. Acoust. Soc. Am. 102 3, 1997, 3628--3646.]. The intensity just noticeable differences for tone bursts with durations of 1 ms, 10 ms, 100 ms, 1000 ms, 5000 ms and 10000 ms were measured at different intensity levels of 20 dB, 30 dB, 40 dB, 50 dB, 60 dB, 70 dB, 80 dB, 90 dB, 100 dB. The data show that variance of Weber fraction (△I/I) with intensity is distinct from Riesz's result and SPIN theory, and that the relations between Weber fraction and intensity for signals of different durations are similar in spite of Weber fraction decreasing to asymptote with signal duration increasing. This means the difference of pulse measurement of intensity JND from Riesz's result and SPIN theory does not arise from the limited signal duration of pulse method and provides new cue for hearing research.展开更多
王建中手稿中的《八声音阶及其在近现代音乐中的使用》一文,是他阅读大量西方音乐作品和有关八声音阶理论研究文献后所作的梳理与总结,展现出一位中国作曲家在20世纪八九十年代学习西方现代音乐及后调性理论的经历。这份文稿虽参考了范...王建中手稿中的《八声音阶及其在近现代音乐中的使用》一文,是他阅读大量西方音乐作品和有关八声音阶理论研究文献后所作的梳理与总结,展现出一位中国作曲家在20世纪八九十年代学习西方现代音乐及后调性理论的经历。这份文稿虽参考了范登图恩(Pieter C.van den Toorn)与安托克莱茨(Elliot Antokoletz)的专著,但却有自己的见解。其后,王建中于1994年创作的钢琴独奏《情景》作为他关于八声音阶研究的实践性成果,则反映出了西方八声音阶理论对中国现代音乐创作的影响。展开更多
基金co-supported by the National Natural Science Foundation of China(Nos.52022009,51790514)the National Science and Technology Major Project,China(No.2017-II-003-0015)the Key Laboratory Foundation,China(No.2021-JCJQ-LB-062-0102).
文摘Fast and accurate prediction of sound radiation of Contra-Rotating Open Rotors(CRORs)is an essential element of design methods of low-noise open rotor propulsion systems.In the present work,a previous frequency-domain model is extended to predict CROR noise.It builds explicitly the relationship between harmonic loadings and corresponding tonal noise,by which the influential parameters to noise generation can be clearly understood.The real distribu-tions of steady and unsteady blade loadings are calculated by the Nonlinear Harmonic(NLH)method.In the present hybrid approach,both the CFD and acoustic modules are solved in the fre-quency domain.To assess the accuracy of the developed method,the loading noise of a CROR is calculated and compared against results by using the time-domain FW-H module of NUMECA.The predicted sound directivities by the two methods are in good agreements.The present acoustic model in the frequency domain is proven to be accurate and have high efficiency in far-field noise prediction and data processing.Furthermore,the characteristics of the CROR interaction tonal noise are analyzed and discussed.
文摘Basing upon the tonality analytic method, the present paper aims at： （1） Drawing attention to the subordination of the minor key vs. the major key in the chord classification, using the same methodology; and （2） Showing the differences for the major key and the minor （harmonic） key in the classification of chords, as an aspect of importance for interpreting a piece＇s tonal structure diagram. The relations between chords appearing in the major and minor （harmonic） key will be shown by applying the comparisons of： （1） third-based chords; and （2） degrees in the C major and A minor keys, on which the same diatonic chords appear.
文摘A monitoring of multiple physical parameters in a moderate seismic area in Western Piedmont (NW Italy) and the simultaneous observation of the behaviour of numerous species of domestic and wild animals gave in a period of over twenty years the possibility to distinguish the unusual animal behaviours due to local earthquake nucleation from other causes. In particular, the observation of the body and vocal language of dogs (Canis familiaris) in the same area has permitted not only to specify the different meanings of vocal language in connection to their body language, but also to classify the minimum elements into a vocal language that is linked together by tonal and rhythmical sequences of sounds that form a semantic lexicon. The usage of the same tonal and rhythmical vocal sequences in similar or identical situations, which are experienced by different groups of dogs, induces us to verify whether it could be possible to link particular vocal sequences to precise physical anomalies before earthquakes. The individuation of physical anomalies due to an earthquake nucleation or due to a hydro-geological destabilization, is possible thanks to a continuous long-term monitoring of some parameters. Moreover, the complexity of the vocal language of dogs increases if the dogs live in an area with a law population density. Then the correlation between some vocal sequences and some seismic precursors is better if dogs live free in yard or on farms, if they are in good health, and if they can establish a strong social relation of group. When dogs live closed in yards of houses that are far apart, they communicate with each other with an amazing vocal language, full of questions and answers, imitations of sequences, and information about situations that may be harmful to them.
文摘Musical analysis enables us to study the various elements of a musical work, for example texture, m dynamics, or harmony （including tonality）. Thanks to musical analysis we are able to trace the compos technique, or assess the artistic value of given work. In addition to traditional, descriptive methods of e it ody, onal music analysis, we can observe in 20th century the development of methods based on science （mathematics, otherwise statistics）. Such methodologies allow us to obtain a strict understanding of the structure of musical pieces Applying mathematical methods for musical analysis seems very reasonable in relation to the output of Frederic Chopin, due to large originality of the elements of musical pieces of this composer. Present paper was written as a result of research related to the applying of numerical method of analysis for exploring the tonal structure of Chopin＇s works. The author＇s research method enables a strict analysis of the chord＇s domination that can be classified under given key （range）--taking into consideration the harmonic functions. By the method of analysis we can get charts that depict whole diatonic vertical music material of the given piece. The main objective of the present study is to describe observations on the high uniqueness in the tonal construction of selected Chopin＇s mazurkas, especially, when compared to the miniatures of other composers of the first half of the 19th century and previously analyzed Chopin＇s pieces： etudes, preludes, and songs.
文摘Valeo, involved in engine cooling fan system design for many years, is interested in noise prediction tools for axial fans. Thus, this paper describes a two-part study of tonal noise computation. The first part deals with the prediction of tonal noise using analytical models. As for the second part, it describes a hybrid approach for predicting tonal noise where the sources are extracted from an Unsteady Reynolds-Averaged Naviers-Stocks （URANS） simulation and then propagated into the far, free field using the Ffowcs Williams and Hawkings＇ acoustic analogy. The computational domain is meshed with 46 million polyhedral elements and the simulation takes into account the exact geometry of the rotor blades, the stator blades and the shroud. The results from the first part show that analytical models can be used for comparisons between different fan geometries, but are unable to provide accurate noise predictions compared to experimental results. The simulation shows non-periodic blade loading over a whole fan revolution, and different blade loading between the blades. This introduces some bias in the assessment of the acoustic performance of the fan. Overall, the results from the hybrid method are in accordance with the experimental results.
文摘This study explores the intricate symbiotic relationship between the Cantonese tonal system and Cantonese opera through an interdisciplinary lens of linguistics and musicology.Cantonese,with its complex tonal architecture and unique phonetic characteristics,serves not only as a communicative medium but as a structural blueprint for the melodic and rhythmic composition of Cantonese opera.Through historical tracing,phonological analysis,and performative interpretation,the paper examines how tonal contours directly shape vocal techniques,emotional expression,and narrative cadence within the opera tradition.The research further investigates how socio-cultural factors—ranging from regional identity,migration,and colonial modernity to contemporary digital transmission—have mediated the evolution and resilience of this art form.By demonstrating how linguistic tone and musical tune co-construct aesthetic experience and cultural memory,the paper offers a new theoretical model for understanding language-music co-evolution in tonal cultures.This inquiry not only affirms Cantonese opera’s role as a living archive of regional identity but also proposes strategies for its revitalization amidst the shifting conditions of modernity and globalization.
文摘为了避免航空发动机涡轮部件成为未来超扇发动机低噪声设计的瓶颈之一,有必要开展涡轮气动噪声的声学特征和控制方法研究。本文采用经过实验验证的流场/声场混合计算方法,以轴向间距减半的GE E3最后1.5级低压涡轮(转-静-转构型)为研究对象,对基准静叶下不同叶片排之间产生的尾迹干涉单音噪声和位势干涉单音噪声的声场特征,以及复合锯齿静叶对气动效率和单音噪声的影响进行了数值分析。结果表明:位势干涉单音噪声成为与尾迹干涉单音噪声同等量级的主导声源之一,并且同一展向位置的位势作用强度受到尾迹干涉强度的直接影响。此外,复合锯齿静叶具备同时改善气动效率和降低涡轮单音噪声的能力,最大效率收益为锯齿振幅A/波长W=1.5时的0.0234%,此时1.5级低压涡轮前三阶谐波单音噪声总声功率级的降噪收益为2.5 d B。因此,复合锯齿静叶在未来超扇发动机中可以作为控制多级低压涡轮噪声的有效手段之一。
基金supported by the National Natural Science Foundation of China (No. 10574070)the State Key Laboratory Foundation of China (No. 9140C240207060C24)
文摘A method based on ensemble empirical mode decomposition (EEMD) is proposed for accurately detecting the time varying pitch of speech in tonal languages. Unlike frame-, event-, or subspace-based pitch detectors, the time varying information of pitch within the short duration, which is of crucial importance in speech processing of tonal languages, can be accurately extracted. The Chinese Linguistic Data Consortium (CLDC) database for Mandarin Chinese was employed as standard speech data for the evaluation of the effectiveness of the method. It is shown that the proposed method provides more accurate and reliable results, particularly in estimating the tones of non-monotonically varying pitches like the third one in Mandarin Chinese. Also, it is shown that the new method has strong resistance to noise disturbance.
文摘Quadrisyllabic words and phrases with normal stress of Mandarin were used to study the tonal coarticulation. It was firstly found that the F0perturbation at the starting-point and the ending-point of the F0 curve in each syllable caused by tonal coarticulation is larger than the intrinsic F0 difference of vowels at the starting-point and the ending-point of it. As for the tonal coarticulation, it was discovered that tonal coarticulation in word and phrase with normal stress is different to that in the nonsense sequence with even stress, and in word and phrase with normal stress, the tonal coarticulatory effects are unidirectional, and the carryover effect does not extend to the ending-point of tone-section of the following syllable and the anticipatory effect does not extend to the starting-point of tone-section of the preceding one, and the F0 perturbation by tonal coarticulation has its pattern.
基金Università di Genova for the financial support to the present work
文摘The present paper reports a comparison of experimental SPL spectral data related to the tonal noise generated by axial-flow fans.A nine blade rotor has been operated at free discharge conditions and in four geometrical configurations in which different kinds of tonal noise generating mechanisms are present:large-scale inlet turbulent structures,tip-gap flow,turbulent wakes,and rotor-stator interaction.The measurements have been taken in a hemi-anechoic chamber at constant rotational speed and,in order to vary the acoustic source strength,during low angular acceleration,linear speed ramps.In order to avoid erroneous quantitative evaluations if the acoustic propagation effects are not considered,the acoustic response functions of the different test configurations have been computed by means of the spectral decomposition method.Then,the properties of the tonal noise generating mechanisms have been studied.To this aim,the constant-Strouhal number SPL,obtained by means of measurements taken during the speed ramps,have been compared with the propagation function.Finally,the analysis of the phase of the acoustic pressure has allowed to distinguish between random and deterministic tonal noise generating mechanisms and to collect information about the presence of important propagation effects.
文摘The relations of intensity Just Noticeable Difference (JND) to intensity for tone bursts maybe,depend on signal durations according to Jont B.Allen's [J. Acoust. Soc. Am. 102 3, 1997, 3628--3646.]. The intensity just noticeable differences for tone bursts with durations of 1 ms, 10 ms, 100 ms, 1000 ms, 5000 ms and 10000 ms were measured at different intensity levels of 20 dB, 30 dB, 40 dB, 50 dB, 60 dB, 70 dB, 80 dB, 90 dB, 100 dB. The data show that variance of Weber fraction (△I/I) with intensity is distinct from Riesz's result and SPIN theory, and that the relations between Weber fraction and intensity for signals of different durations are similar in spite of Weber fraction decreasing to asymptote with signal duration increasing. This means the difference of pulse measurement of intensity JND from Riesz's result and SPIN theory does not arise from the limited signal duration of pulse method and provides new cue for hearing research.
文摘王建中手稿中的《八声音阶及其在近现代音乐中的使用》一文,是他阅读大量西方音乐作品和有关八声音阶理论研究文献后所作的梳理与总结,展现出一位中国作曲家在20世纪八九十年代学习西方现代音乐及后调性理论的经历。这份文稿虽参考了范登图恩(Pieter C.van den Toorn)与安托克莱茨(Elliot Antokoletz)的专著,但却有自己的见解。其后,王建中于1994年创作的钢琴独奏《情景》作为他关于八声音阶研究的实践性成果,则反映出了西方八声音阶理论对中国现代音乐创作的影响。
