摘要 :
This paper reviews the current state of loudspeaker-based spatial sound reproduction methods from technical perspective as well as perceptual perspective. A nomenclature is developed that allows for a strict separation between the...
展开
This paper reviews the current state of loudspeaker-based spatial sound reproduction methods from technical perspective as well as perceptual perspective. A nomenclature is developed that allows for a strict separation between these two perspectives. The physical fundamentals, practical realization, and results from perceptual studies are discussed for a number of well-established and emerging reproduction techniques. Further, the paper outlines novel approaches to spatial sound evaluation in terms of perceived quality and provides a comparison of current approaches.
收起
摘要 :
A sound field recording and reproduction method that exploits prior information on the locations of sound sources to be reproduced is proposed. Current methods do not take such prior information into consideration in the transform...
展开
A sound field recording and reproduction method that exploits prior information on the locations of sound sources to be reproduced is proposed. Current methods do not take such prior information into consideration in the transformation from the signals received by microphones into the driving signals of loudspeakers. The proposed method for planar and linear arrays of microphones and loudspeakers optimizes spatial basis functions and their coefficients, which represent the driving signals of loudspeakers, on the basis of the maximum a posteriori (MAP) estimation approach, leading to higher reproduction accuracy above the spatial Nyquist frequency when there are fewer microphones than loudspeakers, i.e., super-resolution in sound field recording and reproduction. Numerical simulations show that the reproduction accuracy at frequencies above the spatial Nyquist frequency was maintained using the proposed method even when there was a mismatch between actual and prior locations of the sound sources to be reproduced.
收起
摘要 :
The purpose of this study is to evaluate the usefulness of SF ASSR (Sound-Field Auditory Steady State Response) when comparing to hearing thresholds and typical ASSR. A total of seventy-five subjects (75 ears) were participated an...
展开
The purpose of this study is to evaluate the usefulness of SF ASSR (Sound-Field Auditory Steady State Response) when comparing to hearing thresholds and typical ASSR. A total of seventy-five subjects (75 ears) were participated and divided by four groups according to their hearing thresholds; 18(28 ears) for normal-hearing, 10(10 ears) for mild sensorineural hearing loss (SNHL), 13(13 ears) for moderate SNHL, 13(13 ears) for moderate-to- severe SNHL, and 11(11 ears) for severe SNHL. Results showed that there were highly significant correlations in all test frequencies (0.5, 1, 2, 4 kHz) between the pure-tone audiogram and thresholds obtained from two kinds of ASSR measurements, especially in moderate and moderate-to-severe SNHL groups. However, normal hearing and mild SNHL groups revealed no correlation among three measurements, while showing lower correlation coefficient. The pattern of results suggests that as hearing sensitivity is higher (or poor), the higher correlation among three tests were revealed.
收起
摘要 :
The total-field/scattered-field (TF/SF) formulation is widely used to initiate incident waves for scattering problems in finite-difference time-domain (FDTD) simulations. An important aspect of the TF/SF formulation is the calcula...
展开
The total-field/scattered-field (TF/SF) formulation is widely used to initiate incident waves for scattering problems in finite-difference time-domain (FDTD) simulations. An important aspect of the TF/SF formulation is the calculation of incident fields at the TF/SF boundary by methods that account for the numerical nature of the incident wave in the FDTD grid. Failure to do so can lead to high levels of field leakage errors across the TF/SF boundary. This paper presents an improved analytic time-domain method for accurately computing incident fields in the TF/SF formulation. Using analytic field expressions with higher-order dispersion and polarization compensations, the proposed method compensates for 1) the FDTD numerical dispersion; and 2) the lack of orthogonality between the frequency-dependent field polarizations and the wavevector, which was not accounted for in existing analytic time-domain methods. The higher-order compensations result in further suppression of field leakage errors in the SF region. In addition to exciting a plane wave, the proposed method can be employed to excite an incident beam. To demonstrate this, numerical experiments that source both 3-D plane wave and focused beam into a free space FDTD grid are presented and compared with existing methods.
收起
摘要 :
Data drive decisions. In this age of globalization, society's thirst for information is nearly unquenchable. All sectors of modern society, from education and research to manufacturing and commerce, require real-time data for effe...
展开
Data drive decisions. In this age of globalization, society's thirst for information is nearly unquenchable. All sectors of modern society, from education and research to manufacturing and commerce, require real-time data for effective decision making. Even the efficiency of everyday tasks such as automobile travel is enhanced by data from continuous satellite positioning systems to keep us on the right track.
收起
摘要 :
In this work, a new model has been proposed for the finite-difference time-domain analysis (FDTD) of sub-structure coupling problems. By stretching the total-field/scattered-field (TF/SF) boundary and the perfect electric conducto...
展开
In this work, a new model has been proposed for the finite-difference time-domain analysis (FDTD) of sub-structure coupling problems. By stretching the total-field/scattered-field (TF/SF) boundary and the perfect electric conductor (PEC) plane into the convolution PML (CPML) layers, the coupling of sub-structures loaded on infinite planes induced by plane waves can be simulated. The validity of the proposed model has been approved from the comparison of the results obtained from the proposed model with the analytical and the open region results. The CPML performances of this model are compared in different parameters, furthermore the optimal constructive parameters of the CPML have been chosen for the high-resolution simulation of the proposed model, which can help for development of optimal sub-structure coupling.
收起
摘要 :
While PBS reforms have preoccupied pharmacists' attention over the last two years, the focus has been mainly on the administration of the program and the business impact from a pharmacy perspective. While this is a sound approach ...
展开
While PBS reforms have preoccupied pharmacists' attention over the last two years, the focus has been mainly on the administration of the program and the business impact from a pharmacy perspective. While this is a sound approach in the remaining days before 1 August, I ask that my colleagues, and their staff, focus attention on the impact to patients, with a key overarching aim of preserving the good name of pharmacy with the public.
收起
摘要 :
The paper compares geoelectric models obtained through lateral logging data and the results of NTEMS curves interpretation, while indicating their similarities and differences. It also provides an example of using a lateral loggin...
展开
The paper compares geoelectric models obtained through lateral logging data and the results of NTEMS curves interpretation, while indicating their similarities and differences. It also provides an example of using a lateral logging model when carrying out a detailed inversion - stratification of a thick layer confined to the production interval of the subsalt complex into separate geoelectric subhorizons.
收起
摘要 :
Conventional heterostructure field-effect transistors (HFETs) have a high gate leakage current due to the gate electrode being in contact with the exposed channel layer and with the carrier-providing layer on the mesa sidewall. In...
展开
Conventional heterostructure field-effect transistors (HFETs) have a high gate leakage current due to the gate electrode being in contact with the exposed channel layer and with the carrier-providing layer on the mesa sidewall. In this study, we use a new step-free (SF) air-bridge gate structure to reduce the gate leakage and improve the breakdown voltage. The proposed structure does not increase any MASKs as compared with the conventional process. In addition, this new structure promises a gate-source capacitance smaller than those of conventional heterostructure FET devices. Consequently, the high-frequency performance of the HFETs using the proposed structure can be improved.
收起
原文获取