An approach to dynamic focusing of ultrasound linear array scanners is presented, leading to the unique capability of implementing a focus that continuously tracks the return signal along the penetration depth. An electronically variable lens is obtained by a heterodyning process, in which the phases of echo signals at the array elements are equalized by mixing with suitable reference oscillations. These are generated by control of a single voltage-controlled oscillator, whose frequency is properly varied in synchronism with the delay of signal from different depths. The technique has been experimentally demonstrated by modifying the focusing processor of a conventional echographic linear scanner. Superior performances have been obtained with respect to fixed-focus operation mode. The image quality results are comparable with those of multizone-focus operation mode, in which the focus is varied over more transmit/receive cycles at the expense of lower frame rate.
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http://dx.doi.org/10.1109/58.4143 | DOI Listing |
Chaos
January 2025
College of Computer Science and Software Engineering, Shenzhen University, Guangdong 518060, China.
This paper considers the selection and optimization of drive nodes based on the controllability of multilayer networks. The intra-layer network topologies are arbitrary, and the node dynamics are linear time-invariant dynamical systems. The study focuses on the number and selection of drive nodes in a special class of drive-response networks.
View Article and Find Full Text PDFPLoS One
January 2025
College of Education for the Future, Beijing Normal University, Zhuhai, Guangdong, China.
Personalized sports training plans are essential for addressing individual athlete needs, but traditional methods often need to integrate diverse data types, limiting adaptability and effectiveness. Existing machine learning (ML) and rule-based approaches cannot dynamically generate context-specific training programs, reducing their applicability in real-world scenarios. This study aims to develop a Generative Adversarial Network (GAN)- based framework to create context-specific training plans by integrating numeric attributes (e.
View Article and Find Full Text PDFPLoS One
January 2025
School of Architecture and Urban Planning, Lanzhou Jiaotong University, Gansu, Lanzhou, China.
The built environment is an important determinant of travel demand and mode choice. Studying the relationship between the built environment and transportation usage can support and assist traffic policy interventions. Previous studies often assumed that this relationship is linear; however, the impact of the built environment on non-motorized travel efficiency may be more complex than the typically modeled linear relationships.
View Article and Find Full Text PDFEnviron Monit Assess
January 2025
Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh, India.
In recent years, heightened concern has emerged regarding the pervasive presence of microplastics in the environment, particularly in aquatic ecosystems. This concern has prompted extensive scientific inquiry into microplastics' ecological and physiological implications, including threats to biodiversity. The robust adsorption capacity of microplastic surfaces facilitates their widespread distribution throughout aquatic ecosystems, acting also as carriers of organic pollutants.
View Article and Find Full Text PDFFront Cell Infect Microbiol
January 2025
Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran.
Background: is a significant cause of healthcare-associated infections, with rising antimicrobial resistance complicating treatment. This study offers a genomic analysis of , focusing on sequence types (STs), global distribution, antibiotic resistance genes, and virulence factors in its chromosomal and plasmid DNA.
Methods: A total of 19,711 genomes were retrieved from GenBank.
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