Helical springs serve as vibration isolators in virtually any suspension system. Various exact and approximate methods may be employed to determine the eigenfrequencies of vibrations of these structural elements and their dynamic transfer functions. The method of boundary integral equations is a meaningful alternative to obtain exact solutions of problems of the time-harmonic dynamics of elastic springs in the framework of Bernoulli-Euler beam theory. In this paper, the derivations of the Green's matrix, of the Somigliana's identities, and of the boundary integral equations are presented. The vibrational power transmission in an infinitely long spring is analyzed by means of the Green's matrix. The eigenfrequencies and the dynamic transfer functions are found by solving the boundary integral equations. In the course of analysis, the essential features and advantages of the method of boundary integral equations are highlighted. The reported analytical results may be used to study the time-harmonic motion in any wave guide governed by a system of linear differential equations in a single spatial coordinate along its axis.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1121/1.3543985 | DOI Listing |
Ann N Y Acad Sci
January 2025
Institute for Earth System Science and Remote Sensing, Leipzig University, Leipzig, Germany.
Vegetation is often viewed as a consequence of long-term climate conditions. However, vegetation itself plays a fundamental role in shaping Earth's climate by regulating the energy, water, and biogeochemical cycles across terrestrial landscapes. It exerts influence by consuming water resources through transpiration and interception, lowering atmospheric CO concentration, altering surface roughness, and controlling net radiation and its partitioning into sensible and latent heat fluxes.
View Article and Find Full Text PDFJ Cataract Refract Surg
January 2025
Yokohama Sky Building Eye Clinic, 2-19-12 Takashima, Yokohama, Nishi-ku, Kanagawa, 220-0011, Japan.
Purpose: To compare the refractive accuracy of the Barrett True axial length (BTAL) formula, newly integrated into ARGOS, with that of the Barrett Universal II (BUII) formula calculated using axial length (AL) from IOL Master 700.
Setting: Private clinics in Kanagawa, Japan.
Design: Retrospective observational study.
Microbiol Mol Biol Rev
January 2025
General Microbiology, Technische Universität Dresden, Dresden, Germany.
SUMMARYThe development of multicellularity represents a key evolutionary transition that is crucial for the emergence of complex life forms. Although multicellularity has traditionally been studied in eukaryotes, it originates in prokaryotes. Coordinated aggregation of individual cells within the confines of a colony results in emerging, higher-level functions that benefit the population as a whole.
View Article and Find Full Text PDFJ Imaging
January 2025
Center for Pattern Recognition and Machine Intelligence, Concordia University, Montreal, QC H3G 1M8, Canada.
This paper is devoted to numerical algorithms based on harmonic transformations with two goals: (1) face boundary formulation by blending techniques based on the known characteristic nodes and (2) some challenging examples of face resembling. The formulation of the face boundary is imperative for face recognition, transformation, and combination. Mapping between the source and target face boundaries with constituent pixels is explored by two approaches: cubic spline interpolation and ordinary differential equation (ODE) using Hermite interpolation.
View Article and Find Full Text PDFJ Imaging
January 2025
School of Computer Science and Engineering, University of Westminster, London W1W 6UW, UK.
The early and precise identification of a brain tumour is imperative for enhancing a patient's life expectancy; this can be facilitated by quick and efficient tumour segmentation in medical imaging. Automatic brain tumour segmentation tools in computer vision have integrated powerful deep learning architectures to enable accurate tumour boundary delineation. Our study aims to demonstrate improved segmentation accuracy and higher statistical stability, using datasets obtained from diverse imaging acquisition parameters.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!