Maximum Fundamental Frequency Research Articles

Age gradations in vocalization and body weight in Japanese monkeys (Macaca fuscata).

449 syllables in 174 food calls of Japanese monkeys of various ages were analyzed spectrographically. The fundamental frequency bands were divided into 55 frequency modulation patterns. The percentage of harsh syllables changed with age class among adults. Although the duration of syllables did not change with age, the maximum fundamental frequency and the minimum fundamental frequency showed age-related changes. Both were distinctly decreased by 6-8 years of age and thereafter the decline was far more gradual. Body weight also increased up to 6 years of age for females and 8 years for males, thereafter stabilizing for both sexes. The matching in age-related changes between fundamental frequency and body weight indicates that it is increase in size of the vocal folds with physical growth that lowers the fundamental frequency.

EFFECT OF MODERATE HYPERBILIRUBINEMIA ON ORIENTING RESPONSES & CRY IN TERM INFANTS

Brazelton auditory orienting responses and acoustic cry patterns were evaluated in 10 moderately jaundiced term infants, (BR-15.2±2.5 mg/dl, Mean±S.D.) and 11 non-jaundiced infants (BR-4.1±1.1 mg/dl). The groups did not differ in birthweight, gestational or postnatal age, or 5 min. Apgar score. Jaundiced infants scored lower on auditory orienting items, (4.7±1.25 vs 5.64±0.55, p<0.02) and on the global orientation cluster (4.96±0.92 vs 5.9±0.53, p<0.01). Cries were recorded during blood sampling, and analyzed by computing the log magnitude spectrum in 25 msec blocks for each cry unit; summary measures were computed across the 25 msec blocks of each cry unit. In jaundiced infants, the first cry utterance showed an increase in average first formant during dysphonation (AvDF1-1876±376 Hz vs 1434±470 Hz, p<0.05), and in the summation of first formant during dysphonation (SumDF1-2102±324 Hz vs 1192±786 Hz, p<0.005). 9 of 10 jaundiced and 4 of 11 non-jaundiced infants had episodes of hyperphonation, and jaundiced infants had greater variability (S.D.) in the maximum fundamental frequency of hyperphonation (Max HFo) for the entire cry (p=0.03 for S.D. Max HFo vs non-jaundiced infants). In summary, moderate hyperbilirubinemia decreases the global capability for orienting responses, and increases the frequencies and variability of some acoustic cry characteristics in term newborns.

Optimal Forms of Shallow Cylindrical Panels With Respect to Vibration and Stability

Thin, shallow, elastic, cylindrical panels with rectangular planform are considered. We seek the midsurface form which maximizes the fundamental frequency of vibration, and the form which maximizes the buckling value of a uniform axial load. The material, surface area, and uniform thickness of the panel are specified. The curved edges are simply supported, while the straight edges are either simply supported or clamped. For the clamped case, the optimal panels have zero slope at the edges. In the examples, the maximum fundamental frequency is up to 12 percent higher than that of the corresponding circular cylindrical panel, while the buckling load is increased by as much as 95 percent. Most of the solutions are bimodal, while the rest are either unimodal or trimodal.

Optimal Forms of Shallow Shells With Circular Boundary, Part 1: Maximum Fundamental Frequency

Thin, shallow, elastic shells with given circular boundary are considered. We seek the axisymmetric shell form which maximizes the fundamental frequency of vibration. The boundary conditions, material, surface area, and uniform thickness of the shell are specified. We employ a bimodal formulation and use an iterative procedure based on the optimality condition to obtain optimal forms. Results are presented for clamped and simply supported boundary conditions. For the clamped case, the optimal forms have zero slope at the boundary. The maximum fundamental frequency is significantly higher than that for the corresponding spherical shell if the boundary is clamped, but only slightly higher if it is simply supported.

Frequency analysis of multi-span shifts

Some basic properties of receptance functions are employed to determine the stationary values of the critical frequencies of a multi-span shaft in which the position of one of the bearings can be varied. Details are given of the determination of the maximum and minimum values of the first two critical frequencies. The theory is then extended to obtain the spacing of the intermediate supports for the first critical to be a maximum. The simple result thus obtained generalizes Darnley's solution for the special case of a uniform shaft with simply-supported ends. The method is also employed to determine the maximum fundamental frequency of a beam or shaft having a freely articulating internal joint of variable position.

On the extremal fundamental frequencies of vibrating beams

Bernoulli-Euler Beams with variable cross section are optimized with respect to their fundamental frequency of transverse oscillation. The cross section is allowed to vary in a manner such that the second area moment is linearly related to the area. Using calculus of variations, the fundamental frequency is made stationary. The closed-form solution is found for all sets of homogeneous boundary conditions. In most cases, the resulting beam is uniform, however, the frequency in some cases is a minimum, others a maximum. For cantilever and free-free beams no maximum fundamental frequency exists for this type of cross section variation.

Problems of Optimal Structural Design

The paper presents a uniform method of treating a variety of problems of optimal design of sandwich structures. The design procedure consists of two steps: The integration of an optimality condition, which is a differential equation for the optimal displacement field that does not involve any design parameters, and the subsequent determination of the optimal distribution of elastic stiffness or plastic resistance from the usual differential equations of the structure. Optimal elastic design for maximum stiffness, maximum fundamental frequency, or maximum buckling load, and optimal plastic design for maximum safety are treated as examples.

Relations between Prosodic Variables and Emotions in Normal American English Utterances

Relations between a speaker's emotional states and some acoustic prosodic variables of his speech were investigated experimentally. The speaker's emotional states, as reflected in 30 utterances, were evaluated by 19 subjects on nine semantic differential scales. The utterances were also evaluated for pitch, loudness, and speed. Durational, fundamental-frequency, and amplitude characteristics of each utterance were measured. Linear correlation coefficients were computed between the acoustic variables and the listeners' judgment of the speaker's emotional states. Significant correlations were found between some of the acoustic variables (e.g., maximum fundamental frequency) and the judgments of some types of emotion. Higher correlations were found between the acoustic variables and judgments of degree of emotion. Correlation coefficients were also computed between judgments of emotion and judgments of prosodic features. Many of these correlations were significant, and higher than the correlations with the acoustic variables. The possibility of regular, but nonlinear, relations between acoustic prosodic variables of speech and perceived emotion was also investigated.

Observation of a bistable flow in a hemispherical cavity.

It can be concluded from the comparison between the experimental and theoretical results that the deflection expression (6), with the proper ratio between the parameters A, B, and C, represents a good approximation of the fundamental mode shape of the plate and can be used to obtain the fundamental frequency of the plate over a wide range of support locations. In addition, it can be used to determine the location of the supports to give the maximum fundamental frequency and the value of the maximum frequency.

Turbines

Vibration characteristics of pre-twisted composite blades are analysed using a three-noded triangular cylindrical shell element. The specific example of glass fibre reinforced plastic material is analysed with its material damping. The effect of different parameters such as pre-twist, fibre orientation, skew angle, taper ratio and aspect ratio on natural frequency and system loss factor is investigated. It is found that the maximum fundamental frequency and maximum fundamental loss factor occur at different twist angles and at different fibre orientations. The influence of taper ratio and aspect ratio on 0° and 90° fibre orientations is reported. The effect of skew angle on natural frequency and on system loss factors is seen to be low.