摘要:

The reproduction of messages, selected from defined information sources, was studied in a multichannel listening task. Standardization of message procedures was controlled independently of standardization of message nomenclature. It is shown that the standardization of procedures or nomenclature is an effective determinant of message reproduction. And, the joint standardization of both nomenclature and procedure is more effective than either alone.

ISSN:0001-4966    

DOI:10.1121/1.1909386

出版商:Acoustical Society of America    

年代:1958

数据来源: AIP

摘要:

An approximate expression is derived for the disturbance in a one‐dimensional wave guide resulting from an expanding spherical wave which is loosely coupled to the wave guide at all points along its length. For the case of a slender rod immersed in a fluid, curves are presented showing axial strain for three ratios of rod velocity to fluid velocity.

ISSN:0001-4966    

DOI:10.1121/1.1909388

出版商:Acoustical Society of America    

年代:1958

数据来源: AIP

摘要:

A simple derivation of the force which acts on a body placed in sound field is given. The tensor properties of the force are exhibited, but it is also shown that for a rigid body the force may be derived from the scalar pressure alone. It is shown how the time average force is determined by the momentum lost by the sound wave during the collision with the body. Using this result, the force is related to the scattering amplitude, and a simple expression in terms of the phase shifts is given.The connection between the force and the scattering cross section is examined. A force factorκ = K̄z/(12ρ0k2σsc)is defined. It is shown that κ = 1 for plane scatterers perpendicular incidence. A simple general formula for the force in the limit of short wavelengths is derived. It is shown that neither for very long wavelengths nor for very short ones is κ in general equal to 1.The case of a rigid sphere is treated in detail. Curves are shown for the force and for the force factor κ.

ISSN:0001-4966    

DOI:10.1121/1.1909390

出版商:Acoustical Society of America    

年代:1958

数据来源: AIP

摘要:

The paper presents a résumé of a theoretical study of the problem of flexural vibrations of the wails of orthogonally stiffened cylindrical shells. Frequency equations are given for the stiffened shells. In addition an experimental method of verifying the theory is described. Experimentally determined frequencies for an isotropic as well as two different designs of orthogonally stiffened shells are given in tables. The experimental and corresponding theoretical results are discussed.A peculiar dip in the frequency spectrum which was discovered by Arnold and Warburton for uniform isotropic shells is shown to exist theoretically and is verified experimentally for stiffened shells. In addition, there is shown to be a bias in the excitability of the modes of vibration as determined experimentally. The reason for this phenomenon is discussed.The principal axes of stiffness are in the longitudinal and transverse directions for the shells under study. In one case the axis of maximum stiffness is in the longitudinal direction and in the other case it is in the transverse direction. As the stiffness tensor is the same for the two cases, except for orientation, an opportunity is provided for examining the effect of rotating the stiffness axes through 90°.

ISSN:0001-4966    

DOI:10.1121/1.1909392

出版商:Acoustical Society of America    

年代:1958

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1909394

出版商:Acoustical Society of America    

年代:1958

数据来源: AIP