Showing papers by "Applied Science Private University published in 1976"

First Passage Probability for Nonlinear Oscillators

Abstract: An approximate method of calculating the probability that a nonlinear oscillator will fail within a specified interval of time is developed, where failure is assumed to occur at the instant the response amplitude first exceeds a critical level. It is shown for oscillators driven by white noise that the energy envelope of the response process is well represented as a one-dimensional Markov process. From the appropriate Fokker-Planck equation of this process simple differential equations for the moments of the time to failure are derived, and integrated numerically in certain cases. In the case of an oscillator with linear damping but a nonlinear spring of the power law type, a complete analytical solution is found in terms of hypergeometric functions. A comparison with digital simulation results indicates that the proposed theory yields a lower bound from the mean time to failure which is close when the damping is very light.

The effect of cooling rate on the performance of thermoluminescent dosimeter crystals (TLD-100) and LiF crystals

Abstract: A detailed study has been made of the effect of cooling rate on (a) the thermoluminescent sensitivity of TLD-100 and Harshaw pure LiF, and (b) the Mg++V associated pair concentration in TLD-100. The thermoluminescence of TLD-100 at the lower cooling rates appears to be strongly affected by precipitation of a second phase, whereas changes at higher cooling rates appear to be a consequence of Mg++V clustering. In particular there is evidence to show that peaks II and III are probably associated with the same trapping centre and that this is the Mg++V pair.

Implications of Charge-Coupled Devices for Pattern Recognition

Abstract: The use of charge-coupled devices (CCD's) for pattern recognition applications is discussed. In particular, it is suggested that the new CCD technology may satisfy the large memory, fast processing speed, low cost, small size, and low power requirements which could make practical many pattern processing systems which until now have not been feasible. Specific implementations are suggested along with estimates of processing times.

A fuzzy set characterization of interaction in scientific research

Abstract: There is increasing interest in an empirical analysis of the system of scientific literature with a view toward improved information retrieval systems and science policy development. Many studies have sought to identify various aspects of the developmental structure of science via this system. The research has relied heavily on the citation or referencing structure with little attention directed toward the study and formalization of the citation relation itself. Fuzzy set theory is shown to be an appropriate approach to the formalization of this relation. The set of references is viewed as a static, partial representation of the total collection of eligible entities and individuals which were involved in the socio-intellectual interactions that contributed to the development of the paper. It is also shown that fuzzy sets of journals can be derived.

Memory Versus Error Characteristics for Inexact Representations of Linear Orders

Abstract: This paper addresses the following question. A computer system is presented with a very long list of ordered items and files a summarized description of the data to facilitate answering queries about the order of the items in the list. What is the minimum storage space required to guarantee that the fraction of incorrect answers remains below a specified level?

DNA Fiber Autoradiography of Tobacco Mesophyll Protoplasts

Abstract: DNA fiber autoradiography was successfully applied to protoplasts isolated from tobacco leaf mesophyll. After an incubation period of 37 h, DNA began to be labeled with 3H-thymidine. These cells, with regenerated thin cell walls, were then effectively disrupted in a lytic solution containing sodium dodecyl sulfate. DNA fiber autoradiography confirmed that the mean replicon size of this plant is approximately 60 μ in good agreement with the values reported previously in animal cells.

Methods for ultrasonic imaging of the heart

Abstract: Ultrasound imaging of the heart is divided into one-dimensional methods currently in use, preliminary techniques which have been developed for two-dimensional static and motion imaging, those techniques currently under development for two-dimensional motion imaging, and goals which appear achievable and which would appear to lead to an ultimate cardiac diagnostic system. The primary current one-dimensional display of cardiac ultrasound data is range as a function of time. This provides dynamic information about cardiac structures lying within a relatively narrow ultrasonic beam but fails to show the coordinated motion of entire structures under study and depicts movements which occur across the beam as intermittently appearing echo complexes. Preliminary approaches employing mechanical assemblies which contain either moving transducers or rotating reflectors have been used to show feasibility of motion imaging. Systems currently under development for two-dimensional motion imaging of the heart use mechanical or electronic beam scanning or multielement arrays for real-time presentations or use ECG-based sampling and computer processing for image construction and data processing. Achievable goals for future development include the simultaneous imaging of solid structures of the heart as well as quantitative display of blood flow data in a motion format and in three dimensions with specific indications of tissue and flow macrostructure.