Showing papers on "Degrees of freedom published in 1975"
970 citations
TL;DR: The human vocal cord is treated as an elastic material capable of propagating compressional, shear, and surface waves and a mathematical formulation for commonly observed vibrational modes is developed.
Abstract: The human vocal cord is treated as an elastic material capable of propagating compressional, shear, and surface waves. A mathematical formulation for commonly observed vibrational modes is developed. This includes horizontal as well as vertical tissue displacements. Current vocal cord models are discussed and evaluated in terms of their ability to describe adequately the vibrational degrees of freedom of the cords.Subject Classification: 70.20.
78 citations
TL;DR: In this paper, a curved-shell finite element of triangular shape is described which is based on conventional shell theory expressed in terms of surface coordinates and displacements Each of the three surface displacement components is independently represented by a two-dimensional polynomial of constrained-quintic order giving the element a total of 54 degrees of freedom.
55 citations
39 citations
38 citations
TL;DR: Curves are presented which enable the user to apply impact dampers to these types of continuous systems and show the amount of the isolation to be expected for values of significant system parameters.
Abstract: A study has been made of the application of impact dampers to two types of continuous systems, a simply supported and a clamped beam. Previous efforts have included the effect of impact dampers on single degree of freedom and other systems with finite numbers of degrees of freedom. Experimental models were tested in the laboratory and finite element computer programs were developed to calculate response. Results from calculations agree favorably with experimental tests. Further, results from the first few natural modes also compare reasonably with data published on systems with finite number of degrees of freedom. Curves are presented which enable the user to apply impact dampers to these types of continuous systems. Curves show the amount of the isolation to be expected for values of significant system parameters.
20 citations
TL;DR: In this paper, two different viewpoints of possible intersections between potential energy surfaces of the same symmetry for polyatomic systems are considered and extended to the general framework of complex nuclear coordinates, and the results of ab initio calculations for complex nuclear coordinate systems yield a surface of n -1 complex dimensions, where n is the number of nuclear degrees of freedom.
16 citations
TL;DR: In this paper, the use of triangular elements in finite-element analyses was considered and a strain energy function was proposed to enable solutions to be obtained at strains well beyond those of linear classical elasticity theory.
Abstract: For a highly incompressible material the use of triangular elements in plane-strain finite-element analyses restricts the number of degrees of freedom. A computer programme is developed which uses quadrilateral elements, and various methods of reducing computation time are employed. A strain-energy function is proposed which will enable solutions to be obtained at strains well beyond those of linear classical elasticity theory.
16 citations
TL;DR: In this article, the problem of the degrees of freedom of an optical image in coherent light, in the presence of noise, is investigated in the case where the image is not perfectly aplanatic.
Abstract: The problem of the degrees of freedom of an optical image in coherent light, in the presence of noise, is investigated in the case where the image is not perfectly aplanatic. In particular, we examine the case where the image of a unit (line) source at a distance x from the axis differs from the image of an axial source by a quadratic phase factor.
14 citations
01 Jun 1975
11 citations
TL;DR: In this paper, spontaneous break-down of a symmetry leads to the appearance of hypercharge and a strongly broken SU2×U1 with local octet representations and hence implies only SU3 multiplets with triality zero.
Abstract: Spontaneous break-down of a symmetry shows that this symmetry has operator and constantc-number aspects. The separation of these two parts gives rise to an appearance of new degrees of freedom which are relevant for large distances—for a small quantitative break-down—and become irrelevant for small distances. These probably general features will be illustrated for the case of an isospinSU2 fermion theory. In this model the spontaneous break-down ofSU2 leads to the appearance of hypercharge and a strongly brokenSU2×U1 with local octet representations and hence implies onlySU3 multiplets with triality zero.
TL;DR: In this article, it has been suggested that for a sample number of thirty and more the values of t should be 2.0 when the probability (P) is 0.05.
Abstract: SPECIFIC values from tables of statistical distributions that vary with degrees of freedom and probability (for example Student's t, χ2, correlation (r) or variance ratio (F)) are often included as input data, even to large detailed statistical packages1,2. Alternatively, the complete tables are held in store. The former makes the program less flexible while the latter uses store inefficiency and is impractical for desk-top computers. A common alternative practice is to use approximate values; thus for example it has been suggested3 that for a sample number of thirty and more the values of t should be 2.0 when the probability (P) is 0.05. This value for t(30–∞)is within ±2% of the true value and was considered ‘a close approximation [suitable] for most purposes’.
TL;DR: In this paper, the authors describe three applications of the degrees of freedom in the design of a unity-rank state feedback matrix for pole assignment in a multivariable system, including sensitivity reduction of closed-loop poles and restrictions on the magnitudes of feedback gains and control inputs.
Abstract: The letter describes three applications of the degrees of freedom in the design of a unity-rank state feedback matrix for pole assignment in a multivariable system. These include sensitivity reduction of closed-loop poles and restrictions on the magnitudes of feedback gains and control inputs. The method is illustrated by a numerical example.
TL;DR: In this paper, the Thirring model with internal degrees of freedom and the Schwinger model were studied and exact solutions for a large class of two-dimensional models describing the interaction of massless vector and spinor fields were constructed.
Abstract: One studies in some detail the Thirring model with internal degrees of freedom and the Schwinger model. By using this analysis it is shown how to construct exact solutions for a large class of two-dimensional models describing the interaction of massless vector and spinor fields.
Journal Article•
TL;DR: In this article, the authors presented probability-of-detection curves for a slowly fluctuating target exhibiting chi-square characteristics with less than two degrees of freedom, which is known as the Weinstock target model.
Abstract: tember 1975. This paper presents probability-of-detection curves for a slowly fluctuating target exhibiting chi-square characteristics with less than two degrees of freedom. Each graph covers the range from 1 to 100 pulses being noncoherently integrated (N) after being converted to video by a square-law detector. Additional graphs for rapidly fluctuating targets are not presented (or required) for reasons that will become apparent later in this paper. These graphs, identified as \"Meyer plots,\" are in the same format as those previously published by the authors, but for different target models [1 ] . The plots offer a convenient means of determining probability of detection PD' given any practical Fehlner false-alarm number n', average single-pulse signal-to-noise ratio x, and number of pulses (individual signal returns) noncoherently integratod N. The previously published plots were for the five standard target models, all of which have chi-square density functions with one or more duo-degrees of freedom (k > 1). The target models for which data are now being presented have chi-square density functions with 0.7, 0.4, 0.2, and 0.1 duo-degrees of freedom. These values of k encompass the range of values of 0.3 S k < 0.7, defining what are often identified as the Weinstock target models [2]. Sixteen plots are presented, one each for the above four values of k in combination with four valties of Fehlner's false-alarm number n'104, 106, 108, and 1010. An example is presented which demonstrates that by cross plotting, using the curves presented and those already available, many target and propagation characteristics can be accounted for. Also presented is a review of the chisquare target model and some information on how the new curves were generated.
01 Jan 1975
TL;DR: The equivalence between the description of the many-body finite nuclear system in terms of traditional Feynman diagrams involving only the Fermion degrees of freedom and of Fermions and phonons degree of freedom is proved for a general two-body residual interaction as discussed by the authors.
Abstract: The equivalence between the description of the many-body finite nuclear system in terms of traditional Feynman diagrams involving only the Fermion degrees of freedom and of Feynman diagrams involving Fermions and phonons degrees of freedom is proved for a general two-body residual interaction. 7 figures. (auth)
01 Jun 1975
TL;DR: In gaseous CCl4 at 20 to 30 °C, the probability that a binary collision effects an energy transfer between the translational and the vibrational degrees of freedom is 3.8 · 10−3, in liquid CC14 at the same temperature it is close to 2.6 · 10 −3.
Abstract: In gaseous CCl4 at 20 to 30 °C, the probability that a binary collision effects an energy transfer between the translational and the vibrational degrees of freedom is 3.8 · 10−3, in liquid CC14 at the same temperature it is close to 2.6 · 10−3. The ratio of these experimental values corresponds exactly to that predicted from the theoretical relationship:P
liquid/Pgas = (1 +S
η/T) · exp(−ɛ/kT).
TL;DR: Ruben as discussed by the authors generalized these results to include odd and even degrees of freedom by replacing the Poisson probabilities by chi-squara densities and provided an alternative proof of Ruben's results.
Abstract: Ruben (1974a) has obtained infinite series expressions for the distribution function (and its complement) of noncentral chi-square with even degrees of freedom. The tarms of these series are products of Poisson probabilities and the distribution function (or its complement) of central chi-square with even degrees of freedom and with the noncentrality parameter as argument. An alternative proof of Ruben’s results is provided here. At the same time the results are generalized to include odd as well as even degrees of freedom by replacing the Poisson probabilities by chi-squara densities. A recursion is given for the terms of the series.
TL;DR: The expansion theorem for the twisted product associated with the Weyl form of CCR for n degrees of freedom was generalized to involve tempered distributions in this paper, where the expansion theorem was extended to include tempered distributions.
Abstract: The expansion theorem for the twisted product associated with the Weyl form of CCR for n degrees of freedom is generalized to involve tempered distributions.
Patent•
23 Sep 1975
TL;DR: A pivot joint having at least four degrees of freedom is defined in this paper, which includes a tubular member having a longitudinal slot formed in its wall, a sphere disposed inside the tubular members in both slidable and rotatable engagement with its inner wall surface, and a post having one end which is narrower than the slot and which extends through the slot.
Abstract: A pivot joint having at least four degrees of freedom, which includes a tubular member having a longitudinal slot formed in its wall, a sphere disposed inside the tubular member in both slidable and rotatable engagement with its inner wall surface, and a post having one end which is narrower than the slot and which extends through the slot and is secured to the sphere.
01 Jan 1975
TL;DR: The number of degrees of freedom of a vibrating system can be defined as the number of independent co-ordinates required to specify its configuration at any instant and particular attention will be paid to the treatment of two-degree-of-freedom vibrations.
Abstract: The number of degrees of freedom of a vibrating system can be defined as the number of independent co-ordinates required to specify its configuration at any instant. As a natural development from the single-degree-of-freedom systems analysed in the previous chapter, particular attention will be paid to the treatment of two-degree-of-freedom vibrations. The methods developed can then be extended to the multi-degree-of-freedom cases.