Some factors influencing the intelligibility of the enhanced whisper in the joint time-frequency domain are evaluated. Specifically, both the spectrum density and different regions of the enhanced spectrum are analyze...Some factors influencing the intelligibility of the enhanced whisper in the joint time-frequency domain are evaluated. Specifically, both the spectrum density and different regions of the enhanced spectrum are analyzed. Experimental results show that for a spectrum of some density, the joint time-frequency gain-modification based speech enhancement algorithm achieves significant improvement in intelligibility. Additionally, the spectrum region where the estimated spectrum is smaller than the clean spectrum, is the most important region contributing to intelligibility improvement for the enhanced whisper. The spectrum region where the estimated spectrum is larger than twice the size of the clean spectrum is detrimental to speech intelligibility perception within the whisper context.展开更多
AIMTo investigate factors, including psychosocial factors, associated with alcoholic use relapse after liver transplantation (LT) for alcoholic liver disease (ALD).METHODSThe clinical records of 102 patients with ALD ...AIMTo investigate factors, including psychosocial factors, associated with alcoholic use relapse after liver transplantation (LT) for alcoholic liver disease (ALD).METHODSThe clinical records of 102 patients with ALD who were referred to Nagoya University Hospital for LT between May 2003 and March 2015 were retrospectively evaluated. History of alcohol intake was obtained from their clinical records and scored according to the High-Risk Alcoholism Relapse scale, which includes duration of heavy drinking, types and amount of alcohol usually consumed, and previous inpatient treatment history for alcoholism. All patients were assessed for eligibility for LT according to comprehensive criteria, including Child-Pugh score, Model for End-Stage Liver Disease score, and psychosocial criteria.RESULTSOf the 102 patients with ALD referred for LT, seven (6.9%) underwent LT. One (14.3%) of these seven patients returned to heavy drinking, but that patient was able to successfully quit drinking following an immediate intervention, consisting of psychotherapeutic education and supportive psychotherapy, by a psychiatrist. A comparison between the transplantation/registration (T/R) group, consisting of the seven patients who underwent LT and 10 patients listed for deceased donor LT, and 50 patients who did not undergo LT and were not listed for deceased donor LT (non-T/R group), showed statistically significant differences in duration of abstinence period (P < 0.01), duration of heavy drinking (P < 0.05), adherence to medical treatment (P < 0.01), and declaration of abstinence (P < 0.05).CONCLUSIONPatients with ALD referred for LT require comprehensive evaluation, including evaluation of psychosocial criteria, to prevent alcoholic recidivism.展开更多
Radio is all about dreams. This old and tired medium now fights with new media as it is with its old enemy television. Radio has a big impact on dreams. It gives you the sound and makes you dream. Once you get used to...Radio is all about dreams. This old and tired medium now fights with new media as it is with its old enemy television. Radio has a big impact on dreams. It gives you the sound and makes you dream. Once you get used to this media you start dreaming. If you used to listen radio more, you get in dependence with it. So this day dreaming change to lifeless dreaming. This article gives an evaluation of how radio audience can shape audience future dreams with dependence theory. The paper starts with a conceptual explanation of dependence theory and goes on with a survey done in Turkey to 101 radio listeners. The survey investigates on how people like listening the radio and what makes them enjoy radio. The survey assumes that people listening to radio and getting depended on it start changing the behaviors and habits of listeners. This behavior change effects listeners future dreams and the audience take radio as a model. The paper shows by using the dependence theory that radio listeners take the radio they love as model and use it to build their future business dreams.展开更多
The article presents a new approach to the tasks of noise assessment and reduction in the urbanized environment endangered by road noise sources. It was proposed to include the acoustic quality model in the currently ...The article presents a new approach to the tasks of noise assessment and reduction in the urbanized environment endangered by road noise sources. It was proposed to include the acoustic quality model in the currently applied quantitative noise assessment in the management of urbanized environment. In particular, this model takes into account subjective features of sound quality, i.e.: loudness, sharpness, roughness, and fluctuation strength as well as noise mmoya^ce assessment obtained in laboratory conditions. The proposed way can be used in estimating investment costs of an acoustic barrier at the design stage展开更多
A codec is a device or computer program for encoding or decoding a digital data stream or signal. Codec is a portmanteau of coder-decoder. According to different technical principles of audio compression, audio compre...A codec is a device or computer program for encoding or decoding a digital data stream or signal. Codec is a portmanteau of coder-decoder. According to different technical principles of audio compression, audio compression coding methods have their own characteristics. This paper considers that the coding quality is high and the digital rate is also high. In addition, according to the compressed data whether exists information loss, data compression coding can also be divided into two forms, which is lossless compression and lossy compression. Lossy compression method also called compression method for the amount of information. Lossy compression is always larger, widely used in audio compression. It is also familiar to us. However, for the more critical to the quality of people, especially the music enthusiast, lossy compression of audio files often cannot meet their quality on the requirements, and it is very necessary and lossless compression. Firstly, this paper has designed and executed tests to compare the performance ofcodecs by using my methodology. Then, it has analysed the results. Finally, there are conclusions on the relative merits of the codecs selected and some recommendations.展开更多
In order to improve the Mandarin vowel pronunciation quality assessment, a nox/el formant feature was proposed and applied to formant classification for Chinese Mandarin vowel pronunciation quality evaluation. Formant...In order to improve the Mandarin vowel pronunciation quality assessment, a nox/el formant feature was proposed and applied to formant classification for Chinese Mandarin vowel pronunciation quality evaluation. Formant candidates of each frame were plotted on the time-frequency plane to form a bitmap, and its Gabor feature was extracted to represent the formant trajectory. The feature was then classified by using GMM model and the classification posterior probability was mapped to pronunciation quality grade. The experiments of comparing the Gabor transformation based formant trajectory feature with several other kinds of traditionally used features show that with this method, a human-machine scoring correlation coefficient (CC) of 0.842 can be achieved, which is better than the result of 0.832 by traditional speech recognition techniques. At the same time, considering that the long-term information of formant classification and the short-term information of speech recognition technique are complementary to each other, it is investigated to combine their results with linear or nonlinear methods to further improve the evaluation performance. As a result, experiments on PSK show that the best CC of 0.913, which is very close to the correlation of inter-human rating of 0.94, is gotten by using neural network.展开更多
Through the establishment of music teaching effect evaluation model and the multimedia courseware evaluation model, which can effectively avoid the influence of subjective evaluation, the evaluation process will be si...Through the establishment of music teaching effect evaluation model and the multimedia courseware evaluation model, which can effectively avoid the influence of subjective evaluation, the evaluation process will be simple and objective. Through the issuance of assessment questionnaire, each index is divided into four grades of excellent, good, poor, according to percentile scoring, the score of every index multiply corresponding weight, and then addition, and finally we can obtain the evaluation results.展开更多
Our study was carried out to assess the level of noise generated and ground vibrations induced during blasting operations at the Ewekoro limestone quarry in Nigeria.To achieve this objective,vibro monitor equipment wa...Our study was carried out to assess the level of noise generated and ground vibrations induced during blasting operations at the Ewekoro limestone quarry in Nigeria.To achieve this objective,vibro monitor equipment was used to take readings related to noise generated and ground vibrations during all blasting operations that took place in the quarry for a period of one month.As well,a digital camera was used to take photographs of residential structures within villages near the quarry.The results obtained indicate that the ground vibration readings fall between 0.5 mm/s and 2.1 mm/s and the noise generated during the blasting operations between 82 dB and 89 dB.These readings when compared with the limits set by FEPA(Federal Environmental Protection Agency) of 5.0 mm/s and 150 dB) all fall within the permissible limits.However the photographs of most structures near the quarry reveal cracks and dilapidated building walls.Recommendations are made on how to sustain and improve current blasting techniques.展开更多
Multidimensional Scale Evaluation Rules as a performer in the field of learning assessment is feasible, but for each dimension settings, level settings and value setting need to be developed according to the actual ra...Multidimensional Scale Evaluation Rules as a performer in the field of learning assessment is feasible, but for each dimension settings, level settings and value setting need to be developed according to the actual raters, object evaluation, the focus of the evaluation. Scores of overall dimensions use variance analysis, and the results show a significant difference. In sub-dimension score comparison, the high group and low group both got higher scores in the degree of difficulty performing works and read music accuracy. The high group and low group are different on dimensions of the lowest score. Total scores in the scale of multi-dimensional evaluation of rules are positively correlated on the scores on the improvising horizontal dimension, but the correlation is not very high level, that is not all students who is better in playing levels, and they can get higher scores on the improvising horizontal dimension. Using multi-dimensional scale scores and teacher direct evaluation rules score are significantly different for student achievement.展开更多
Objective To observe the effects on the range of motion (ROM) of ankle joint and muscular spasm of the lower limbs treated with Chinese massage for promoting the Governor Vessel, benefiting the kidney and strengthen...Objective To observe the effects on the range of motion (ROM) of ankle joint and muscular spasm of the lower limbs treated with Chinese massage for promoting the Governor Vessel, benefiting the kidney and strengthening the spleen combined with music therapy in infantile cerebral palsy (CP). Methods In 286 cases of spasmodic CP, 7 kinds of Chinese massage were adopted, named massage on acupoints to promote circulation of the Governor Vessel, massage for strengthening the spleen and benefiting qi, spine-pinching therapy, segmental massage, foot massage, massage for promoting the recovery of muscle strength and massage for promoting ROM of joints. Chinese massage was applied in musical background. Buddha music and five-element music of Chinese medicine (music of the Heart, Liver and Kidney Meridians) were optioned. The treatment was given once or twice a day and 30 days made one course. The angles of femoral adductor and dorsal flexion of foot as well as the score of composite spasticity scale (CSS) were observed before and after treatment so that the therapeutic effect was assessed. Results In 30 days of treatment, 106 cases (37. 1%) were effective markedly, 172 cases (60. 1%) effective and 8 cases (2.8%) failed. The angle of dorsal flexion of foot was (105.64± 12.66)° and (76.58± 9.89)° before and after treatment respectively; the angle of femoral adductor was (119.89±25.47)° and (158.99± 18.66)° before and after treatment respectively; the score of CSS was (12.39±2.56) and (7. 069 ± 2.97) before and after treatment respectivel, there was significant difference before and after treatment (all P〈0.01). Conclusion Chinese massage for promoting the Governor Vessel, benefiting the kidney and strengthening the spleen combined with music therapy brings the extremely active effect into play on the recovery of sitting, kneeling, standing and walking for children with CP.展开更多
This study investigates how raters make their scoring decisions when assessing tape-mediated speaking test performance. 24 Chinese EFL teachers were trained before scoring analytically five sample tapes selected from ...This study investigates how raters make their scoring decisions when assessing tape-mediated speaking test performance. 24 Chinese EFL teachers were trained before scoring analytically five sample tapes selected from TEM4-Oral, a national EFL speaking test designed for college English major sophomores in China. The raters' verbal reports concerning what they were thinking about while making their scoring decisions were audio-recorded and collected during and immediately after each assessment. Post-scoring interviews were used as supplements to the probe of the scoring process. A qualitative analysis of the data showed that the raters tended to give weight to the content, to punish both grammar and pronunciation errors and to reward the use of impressive and uncommon words. Moreover, the whole decision-making process was proved to be cyclic in nature. A flow chart describing the cyclic process of hypothesis forming and testing was then proposed and discussed.展开更多
When pointed V-notches weaken structural components, local stresses are singular and their intensities are expressed in terms of the notch stress intensity factors (NSIFs). These parameters have been widely used for...When pointed V-notches weaken structural components, local stresses are singular and their intensities are expressed in terms of the notch stress intensity factors (NSIFs). These parameters have been widely used for fatigue assessments of welded struc- tures under high cycle fatigue and sharp notches in plates made of brittle materials subjected to static loading. Fine meshes are required to capture the asymptotic stress distributions ahead of the notch tip and evaluate the relevant NSIFs. On the other hand, when the aim is to determine the local Strain Energy Density (SED) averaged in a control volume embracing the point of stress singularity, refined meshes are, not at all, necessary. The SED can be evaluated from nodal displacements and regular coarse meshes provide accurate values for the averaged local SED. In the present contribution, the link between the SED and the NSIFs is discussed by considering some typical welded joints and sharp V-notches. The procedure based on the SED has been also proofed to be useful for determining theoretical stress concentration factors of blunt notches and holes. In the second part of this work an application of the strain energy density to the fatigue assessment of A17075 notched plates is presented. The experimental data are taken from the recent literature and refer to notched specimens subjected to different shot peening treatments aimed to increase the notch fatigue strength with respect to the parent material.展开更多
To aim at design requirements of high lift-to-drag ratio as well as high volumetric efficiency of next generation hypersonic airplanes,a body-wing-blending configuration with double flanking air inlets layout is prese...To aim at design requirements of high lift-to-drag ratio as well as high volumetric efficiency of next generation hypersonic airplanes,a body-wing-blending configuration with double flanking air inlets layout is presented.Moreover,a novel forebody design methodology which by rotating and assembling two waverider-based surfaces is firstly introduced in this paper.Some typical configurations are designed and their aerodynamic performances are evaluated by computational fluid dynamics.The results for forebodies analysis show that large volumetric efficiency,high lift-to-drag ratio,and uniformly distributed flowfield at the inlet cross section can be assured simultaneously.Furthermore,results of numerical simulation of four integrated configurations with various leading edge shapes,including three power-law curves and a cosine curve clearly show the advantage of high lift-to-drag ratio.Besides,the high pressure generated by the side wall of the airframe can be partly captured by the reasonably designed wings in the condition of small flight attack angle.Then the order of lift-to-drag ratio of four configurations at 0 degree flight attack angle is completely different from the condition of 4-degree flight attack angle.This result demonstrates that the curve shape of the leading edge is very important for the lift-to-drag ratio of the aircraft,and it should be further optimized under the cruising attack angle in future work.展开更多
The cocktail party problem,i.e.,tracing and recognizing the speech of a specific speaker when multiple speakers talk simultaneously,is one of the critical problems yet to be solved to enable the wide application of au...The cocktail party problem,i.e.,tracing and recognizing the speech of a specific speaker when multiple speakers talk simultaneously,is one of the critical problems yet to be solved to enable the wide application of automatic speech recognition(ASR) systems.In this overview paper,we review the techniques proposed in the last two decades in attacking this problem.We focus our discussions on the speech separation problem given its central role in the cocktail party environment,and describe the conventional single-channel techniques such as computational auditory scene analysis(CASA),non-negative matrix factorization(NMF) and generative models,the conventional multi-channel techniques such as beamforming and multi-channel blind source separation,and the newly developed deep learning-based techniques,such as deep clustering(DPCL),the deep attractor network(DANet),and permutation invariant training(PIT).We also present techniques developed to improve ASR accuracy and speaker identification in the cocktail party environment.We argue effectively exploiting information in the microphone array,the acoustic training set,and the language itself using a more powerful model.Better optimization ob jective and techniques will be the approach to solving the cocktail party problem.展开更多
This paper is concerned with a three-species competitive model with both white noises and Levy noises. We first carry out the almost complete parameters analysis for the model and establish the critical value between ...This paper is concerned with a three-species competitive model with both white noises and Levy noises. We first carry out the almost complete parameters analysis for the model and establish the critical value between persistence in the mean and extinction for each species. The sufficient criteria for stability in distribution of solutions are obtained. Finally, numerical simulations are carried out to verify the theoretical results.展开更多
基金The National Natural Science Foundation of China(No.61301295,61273266,61301219,61201326,61003131)the Natural Science Foundation of Anhui Province(No.1308085QF100,1408085MF113)+2 种基金the Natural Science Foundation of Jiangsu Province(No.BK20130241)the Natural Science Foundation of Higher Education Institutions of Jiangsu Province(No.12KJB510021)the Doctoral Fund of Anhui University
文摘Some factors influencing the intelligibility of the enhanced whisper in the joint time-frequency domain are evaluated. Specifically, both the spectrum density and different regions of the enhanced spectrum are analyzed. Experimental results show that for a spectrum of some density, the joint time-frequency gain-modification based speech enhancement algorithm achieves significant improvement in intelligibility. Additionally, the spectrum region where the estimated spectrum is smaller than the clean spectrum, is the most important region contributing to intelligibility improvement for the enhanced whisper. The spectrum region where the estimated spectrum is larger than twice the size of the clean spectrum is detrimental to speech intelligibility perception within the whisper context.
文摘AIMTo investigate factors, including psychosocial factors, associated with alcoholic use relapse after liver transplantation (LT) for alcoholic liver disease (ALD).METHODSThe clinical records of 102 patients with ALD who were referred to Nagoya University Hospital for LT between May 2003 and March 2015 were retrospectively evaluated. History of alcohol intake was obtained from their clinical records and scored according to the High-Risk Alcoholism Relapse scale, which includes duration of heavy drinking, types and amount of alcohol usually consumed, and previous inpatient treatment history for alcoholism. All patients were assessed for eligibility for LT according to comprehensive criteria, including Child-Pugh score, Model for End-Stage Liver Disease score, and psychosocial criteria.RESULTSOf the 102 patients with ALD referred for LT, seven (6.9%) underwent LT. One (14.3%) of these seven patients returned to heavy drinking, but that patient was able to successfully quit drinking following an immediate intervention, consisting of psychotherapeutic education and supportive psychotherapy, by a psychiatrist. A comparison between the transplantation/registration (T/R) group, consisting of the seven patients who underwent LT and 10 patients listed for deceased donor LT, and 50 patients who did not undergo LT and were not listed for deceased donor LT (non-T/R group), showed statistically significant differences in duration of abstinence period (P < 0.01), duration of heavy drinking (P < 0.05), adherence to medical treatment (P < 0.01), and declaration of abstinence (P < 0.05).CONCLUSIONPatients with ALD referred for LT require comprehensive evaluation, including evaluation of psychosocial criteria, to prevent alcoholic recidivism.
文摘Radio is all about dreams. This old and tired medium now fights with new media as it is with its old enemy television. Radio has a big impact on dreams. It gives you the sound and makes you dream. Once you get used to this media you start dreaming. If you used to listen radio more, you get in dependence with it. So this day dreaming change to lifeless dreaming. This article gives an evaluation of how radio audience can shape audience future dreams with dependence theory. The paper starts with a conceptual explanation of dependence theory and goes on with a survey done in Turkey to 101 radio listeners. The survey investigates on how people like listening the radio and what makes them enjoy radio. The survey assumes that people listening to radio and getting depended on it start changing the behaviors and habits of listeners. This behavior change effects listeners future dreams and the audience take radio as a model. The paper shows by using the dependence theory that radio listeners take the radio they love as model and use it to build their future business dreams.
文摘The article presents a new approach to the tasks of noise assessment and reduction in the urbanized environment endangered by road noise sources. It was proposed to include the acoustic quality model in the currently applied quantitative noise assessment in the management of urbanized environment. In particular, this model takes into account subjective features of sound quality, i.e.: loudness, sharpness, roughness, and fluctuation strength as well as noise mmoya^ce assessment obtained in laboratory conditions. The proposed way can be used in estimating investment costs of an acoustic barrier at the design stage
文摘A codec is a device or computer program for encoding or decoding a digital data stream or signal. Codec is a portmanteau of coder-decoder. According to different technical principles of audio compression, audio compression coding methods have their own characteristics. This paper considers that the coding quality is high and the digital rate is also high. In addition, according to the compressed data whether exists information loss, data compression coding can also be divided into two forms, which is lossless compression and lossy compression. Lossy compression method also called compression method for the amount of information. Lossy compression is always larger, widely used in audio compression. It is also familiar to us. However, for the more critical to the quality of people, especially the music enthusiast, lossy compression of audio files often cannot meet their quality on the requirements, and it is very necessary and lossless compression. Firstly, this paper has designed and executed tests to compare the performance ofcodecs by using my methodology. Then, it has analysed the results. Finally, there are conclusions on the relative merits of the codecs selected and some recommendations.
基金Project(61062011)supported by the National Natural Science Foundation of ChinaProject(2010GXNSFA013128)supported by the Natural Science Foundation of Guangxi Province,China
文摘In order to improve the Mandarin vowel pronunciation quality assessment, a nox/el formant feature was proposed and applied to formant classification for Chinese Mandarin vowel pronunciation quality evaluation. Formant candidates of each frame were plotted on the time-frequency plane to form a bitmap, and its Gabor feature was extracted to represent the formant trajectory. The feature was then classified by using GMM model and the classification posterior probability was mapped to pronunciation quality grade. The experiments of comparing the Gabor transformation based formant trajectory feature with several other kinds of traditionally used features show that with this method, a human-machine scoring correlation coefficient (CC) of 0.842 can be achieved, which is better than the result of 0.832 by traditional speech recognition techniques. At the same time, considering that the long-term information of formant classification and the short-term information of speech recognition technique are complementary to each other, it is investigated to combine their results with linear or nonlinear methods to further improve the evaluation performance. As a result, experiments on PSK show that the best CC of 0.913, which is very close to the correlation of inter-human rating of 0.94, is gotten by using neural network.
文摘Through the establishment of music teaching effect evaluation model and the multimedia courseware evaluation model, which can effectively avoid the influence of subjective evaluation, the evaluation process will be simple and objective. Through the issuance of assessment questionnaire, each index is divided into four grades of excellent, good, poor, according to percentile scoring, the score of every index multiply corresponding weight, and then addition, and finally we can obtain the evaluation results.
文摘Our study was carried out to assess the level of noise generated and ground vibrations induced during blasting operations at the Ewekoro limestone quarry in Nigeria.To achieve this objective,vibro monitor equipment was used to take readings related to noise generated and ground vibrations during all blasting operations that took place in the quarry for a period of one month.As well,a digital camera was used to take photographs of residential structures within villages near the quarry.The results obtained indicate that the ground vibration readings fall between 0.5 mm/s and 2.1 mm/s and the noise generated during the blasting operations between 82 dB and 89 dB.These readings when compared with the limits set by FEPA(Federal Environmental Protection Agency) of 5.0 mm/s and 150 dB) all fall within the permissible limits.However the photographs of most structures near the quarry reveal cracks and dilapidated building walls.Recommendations are made on how to sustain and improve current blasting techniques.
文摘Multidimensional Scale Evaluation Rules as a performer in the field of learning assessment is feasible, but for each dimension settings, level settings and value setting need to be developed according to the actual raters, object evaluation, the focus of the evaluation. Scores of overall dimensions use variance analysis, and the results show a significant difference. In sub-dimension score comparison, the high group and low group both got higher scores in the degree of difficulty performing works and read music accuracy. The high group and low group are different on dimensions of the lowest score. Total scores in the scale of multi-dimensional evaluation of rules are positively correlated on the scores on the improvising horizontal dimension, but the correlation is not very high level, that is not all students who is better in playing levels, and they can get higher scores on the improvising horizontal dimension. Using multi-dimensional scale scores and teacher direct evaluation rules score are significantly different for student achievement.
文摘Objective To observe the effects on the range of motion (ROM) of ankle joint and muscular spasm of the lower limbs treated with Chinese massage for promoting the Governor Vessel, benefiting the kidney and strengthening the spleen combined with music therapy in infantile cerebral palsy (CP). Methods In 286 cases of spasmodic CP, 7 kinds of Chinese massage were adopted, named massage on acupoints to promote circulation of the Governor Vessel, massage for strengthening the spleen and benefiting qi, spine-pinching therapy, segmental massage, foot massage, massage for promoting the recovery of muscle strength and massage for promoting ROM of joints. Chinese massage was applied in musical background. Buddha music and five-element music of Chinese medicine (music of the Heart, Liver and Kidney Meridians) were optioned. The treatment was given once or twice a day and 30 days made one course. The angles of femoral adductor and dorsal flexion of foot as well as the score of composite spasticity scale (CSS) were observed before and after treatment so that the therapeutic effect was assessed. Results In 30 days of treatment, 106 cases (37. 1%) were effective markedly, 172 cases (60. 1%) effective and 8 cases (2.8%) failed. The angle of dorsal flexion of foot was (105.64± 12.66)° and (76.58± 9.89)° before and after treatment respectively; the angle of femoral adductor was (119.89±25.47)° and (158.99± 18.66)° before and after treatment respectively; the score of CSS was (12.39±2.56) and (7. 069 ± 2.97) before and after treatment respectivel, there was significant difference before and after treatment (all P〈0.01). Conclusion Chinese massage for promoting the Governor Vessel, benefiting the kidney and strengthening the spleen combined with music therapy brings the extremely active effect into play on the recovery of sitting, kneeling, standing and walking for children with CP.
文摘This study investigates how raters make their scoring decisions when assessing tape-mediated speaking test performance. 24 Chinese EFL teachers were trained before scoring analytically five sample tapes selected from TEM4-Oral, a national EFL speaking test designed for college English major sophomores in China. The raters' verbal reports concerning what they were thinking about while making their scoring decisions were audio-recorded and collected during and immediately after each assessment. Post-scoring interviews were used as supplements to the probe of the scoring process. A qualitative analysis of the data showed that the raters tended to give weight to the content, to punish both grammar and pronunciation errors and to reward the use of impressive and uncommon words. Moreover, the whole decision-making process was proved to be cyclic in nature. A flow chart describing the cyclic process of hypothesis forming and testing was then proposed and discussed.
基金supported by the Italian Research Program(Grant No.CPDA100715)entitled"Static and fatigue behaviour of structural notched components subjected to tension and torsion under small or large scale yielding"the Italian PRIN project(Grant No.2009Z55NWC_001)
文摘When pointed V-notches weaken structural components, local stresses are singular and their intensities are expressed in terms of the notch stress intensity factors (NSIFs). These parameters have been widely used for fatigue assessments of welded struc- tures under high cycle fatigue and sharp notches in plates made of brittle materials subjected to static loading. Fine meshes are required to capture the asymptotic stress distributions ahead of the notch tip and evaluate the relevant NSIFs. On the other hand, when the aim is to determine the local Strain Energy Density (SED) averaged in a control volume embracing the point of stress singularity, refined meshes are, not at all, necessary. The SED can be evaluated from nodal displacements and regular coarse meshes provide accurate values for the averaged local SED. In the present contribution, the link between the SED and the NSIFs is discussed by considering some typical welded joints and sharp V-notches. The procedure based on the SED has been also proofed to be useful for determining theoretical stress concentration factors of blunt notches and holes. In the second part of this work an application of the strain energy density to the fatigue assessment of A17075 notched plates is presented. The experimental data are taken from the recent literature and refer to notched specimens subjected to different shot peening treatments aimed to increase the notch fatigue strength with respect to the parent material.
基金supported by the National Natural Science Foundation of China (Grant No. 90916013)the guidance and help from Academician Li Tian and peer reviewers are gratefully acknowledged
文摘To aim at design requirements of high lift-to-drag ratio as well as high volumetric efficiency of next generation hypersonic airplanes,a body-wing-blending configuration with double flanking air inlets layout is presented.Moreover,a novel forebody design methodology which by rotating and assembling two waverider-based surfaces is firstly introduced in this paper.Some typical configurations are designed and their aerodynamic performances are evaluated by computational fluid dynamics.The results for forebodies analysis show that large volumetric efficiency,high lift-to-drag ratio,and uniformly distributed flowfield at the inlet cross section can be assured simultaneously.Furthermore,results of numerical simulation of four integrated configurations with various leading edge shapes,including three power-law curves and a cosine curve clearly show the advantage of high lift-to-drag ratio.Besides,the high pressure generated by the side wall of the airframe can be partly captured by the reasonably designed wings in the condition of small flight attack angle.Then the order of lift-to-drag ratio of four configurations at 0 degree flight attack angle is completely different from the condition of 4-degree flight attack angle.This result demonstrates that the curve shape of the leading edge is very important for the lift-to-drag ratio of the aircraft,and it should be further optimized under the cruising attack angle in future work.
基金supported by the Tencent and Shanghai Jiao Tong University Joint Project
文摘The cocktail party problem,i.e.,tracing and recognizing the speech of a specific speaker when multiple speakers talk simultaneously,is one of the critical problems yet to be solved to enable the wide application of automatic speech recognition(ASR) systems.In this overview paper,we review the techniques proposed in the last two decades in attacking this problem.We focus our discussions on the speech separation problem given its central role in the cocktail party environment,and describe the conventional single-channel techniques such as computational auditory scene analysis(CASA),non-negative matrix factorization(NMF) and generative models,the conventional multi-channel techniques such as beamforming and multi-channel blind source separation,and the newly developed deep learning-based techniques,such as deep clustering(DPCL),the deep attractor network(DANet),and permutation invariant training(PIT).We also present techniques developed to improve ASR accuracy and speaker identification in the cocktail party environment.We argue effectively exploiting information in the microphone array,the acoustic training set,and the language itself using a more powerful model.Better optimization ob jective and techniques will be the approach to solving the cocktail party problem.
基金The work is supported by National Science Foundation of China (No. 11472298), the Fundamental Research Funds for the Central Universities (No. ZXH2012K004), the National Science Foundation of Tianjin City (No. 13JCQNJC04400) and the NNSF of P. R. China (No. 11401574).
文摘This paper is concerned with a three-species competitive model with both white noises and Levy noises. We first carry out the almost complete parameters analysis for the model and establish the critical value between persistence in the mean and extinction for each species. The sufficient criteria for stability in distribution of solutions are obtained. Finally, numerical simulations are carried out to verify the theoretical results.