PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Source-shifting metastructures composed of only one resin for location camouflaging

Novel numerical optimization methodology paves the way for acoustic camouflaging in the form of sound source-shifters

Source-shifting metastructures composed of only one resin for location camouflaging
2023-05-30
(Press-News.org) The field of transformation optics has flourished over the past decade, allowing scientists to design metamaterial-based structures that shape and guide the flow of light. One of the most dazzling inventions potentially unlocked by transformation optics is the invisibility cloak — a theoretical fabric that bends incoming light away from the wearer, rendering them invisible. Interestingly, such illusions are not restricted to the manipulations of light alone.

Many of the techniques used in transformation optics have been applied to sound waves, giving rise to the parallel field of transformation acoustics. In fact, researchers have already made substantial progress by developing the “acoustic cloak”, the analog of the invisibility cloak for sounds. While research on acoustic illusion has focused on the concept of masking the presence of an object, not much progress has been made on the problem of location camouflaging.

The concept of an acoustic source-shifter utilizes a structure that makes the location of the sound source appear different from its actual location. Such devices capable of “acoustic location camouflaging” could find applications in advanced holography and virtual reality. Unfortunately, the nature of location camouflaging has been scarcely studied, and the development of accessible materials and surfaces that would provide a decent performance has proven challenging.

Against this backdrop, Professor Garuda Fujii, affiliated with the Institute of Engineering and Energy Landscape Architectonics Brain Bank (ELab2) at Shinshu University, Japan, has now made progress in developing high-performance source-shifters. In a recent study published in the Journal of Sound and Vibration online on May 5, 2023, Prof. Fujii presented an innovative approach to designing source-shifter structures out of acrylonitrile butadiene styrene (ABS), an elastic polymer commonly used in 3D printing.

Prof. Fujii’s approach is centered around a core concept: inverse design based on topology optimization. The numerical approach builds on the reproduction of pressure fields (sound) emitted by a virtual source, i.e., the source that nearby listeners would mistakenly perceive as real. Next, the pressure fields emitted by the actual source are manipulated to camouflage the location and make it sound as if coming from a different location in space. This can be achieved with the optimum design of a metastructure that, by the virtue of its geometry and elastic properties, minimizes the difference between the pressure fields emitted from the actual and virtual sources.

Utilizing this approach, Prof. Fujii implemented an iterative algorithm to numerically determine the optimal design of ABS resin source-shifters according to various design criteria. His models and simulations had to account for the acoustic-elastic interactions between fluids (air) and solid elastic structures, as well as the actual limitations of modern manufacturing technology.

The simulation results revealed that the optimized structures could reduce the difference between the emitted pressure fields of the masked source and those of a bare source at the virtual location to as low as 0.6%. “The optimal structure configurations obtained via topology optimization exhibited good performances at camouflaging the actual source location despite the simple composition of ABS that did not comprise complex acoustic metamaterials”, remarks Prof. Fujii.

To shed more light on the underlying camouflaging mechanisms, Prof. Fujii analyzed the importance of the distance between the virtual and actual sources. He found that a greater distance did not necessarily degrade the source-shifter’s performance. He also investigated the effect of changing the frequency of the emitted sound on the performance as the source-shifters had been optimized for only one target frequency. Finally, he explored whether a source-shifter could be topologically optimized to operate at multiple sound frequencies.

While his approach requires further fine-tuning, the findings of this study will surely help advance illusion acoustics. He concludes, “The proposed optimization method for designing high-performance source-shifters will help in the development of acoustic location camouflage and the advancement of holography technology.”

The future sure sounds bright for acoustic camouflaging!

 

                                              ###

 

About Shinshu University
Shinshu University is a national university founded in 1949 located nestling under the Japanese Alps in Nagano known for its stunning natural landscapes. Our motto: "Powered by Nature - strengthening our network with society and applying nature to create innovative solutions for a better tomorrow" reflects the mission of fostering promising creative professionals and deepening the collaborative relationship with local communities, which leads up to our contribution to regional development by innovation in various fields. We’re working on providing solutions for building sustainable society through interdisciplinary research fields: material science (carbon, fiber and composites), biomedical science (for intractable diseases and preventive medicine) and mountain science, and aiming to boost research and innovation capability through collaborative projects with distinguished researchers from the world. For more information and latest news visit website or follow us on twitter (@ShinshuUni) .

END

[Attachments] See images for this press release:
Source-shifting metastructures composed of only one resin for location camouflaging Source-shifting metastructures composed of only one resin for location camouflaging 2 Source-shifting metastructures composed of only one resin for location camouflaging 3

ELSE PRESS RELEASES FROM THIS DATE:

Code-switching in intercultural communication: Japanese vs Chinese point of view

Code-switching in intercultural communication: Japanese vs Chinese point of view
2023-05-30
When people communicate, speakers and listeners use information shared by both the parties, which is referred to as ‘context.’ It is believed that there are cultural differences in the degree of reliance on this context, with Westerners having a low-context culture, i.e., they speak more directly, and Easterners having a high-context culture, i.e., they are subtle and speak less directly. Although Chinese are assumed to be in a high-context culture, Yamashina (2018) found that Chinese people are viewed as more direct speakers i.e., low-context cultural communicators ...

Trials will investigate if rock dust can combat climate crisis

Trials will investigate if rock dust can combat climate crisis
2023-05-30
Scientists at the UK Centre for Ecology & Hydrology (UKCEH) are trialling an innovative approach to mitigating climate change and boosting crop yield in mid-Wales. Adding crushed rock dust to farmland has the potential to remove and lock up large amounts of carbon dioxide from the atmosphere. In the first trial of Enhanced Rock Weathering on upland grasslands in the world, UKCEH scientists have applied 56 tonnes of finely ground basalt rock from quarries to three hectares of farmland in Plynlimon, Powys, this month and are repeating this at the same time next year. The basalt rock dust particles, which are less than 2mm in size, absorb and store carbon at faster rates ...

Women with a first normal weight offspring and a small second offspring have increased risk of cardiovascular mortality

Women with a first normal weight offspring and a small second offspring have increased risk of cardiovascular mortality
2023-05-30
A new study from the University of Bergen reveals that including offspring birthweight information from women’s subsequent births, is helpful in identifying a woman's long-term risk of dying from cardiovascular causes.  Knowledge of the association between offspring birthweight and long-term maternal cardiovascular disease (CVD) mortality is often based on first-born infants without considering women’s consecutive births. “These possible relations are also less closely studied among women with term deliveries”, ...

ENDO 2023 press conferences to highlight emerging technology and diabetes research

2023-05-30
CHICAGO—Researchers will delve into the latest research in diabetes, obesity, reproductive health and other aspects of endocrinology during the Endocrine Society’s ENDO 2023 news conferences June 15-18. The Society also will share its Hormones and Aging Scientific Statement publicly for the first time during a news conference on Friday, June 16. Reporters will have an opportunity to hear from members of the writing group that drafted the statement on the research landscape. Other press conferences will feature select abstracts that are being presented at ENDO 2023, the Endocrine Society’s annual meeting. The event is being held at McCormick Place in Chicago, Ill. ...

New tool may help spot “invisible” brain damage in college athletes

2023-05-30
An artificial intelligence computer program that processes magnetic resonance imaging (MRI) can accurately identify changes in brain structure that result from repeated head injury, a new study in student athletes shows. These variations have not been captured by other traditional medical images such as computerized tomography (CT) scans. The new technology, researchers say, may help design new diagnostic tools to better understand subtle brain injuries that accumulate over time. Experts have long known about potential risks of concussion among young athletes, particularly for those who play high-contact sports such as football, hockey, and soccer. Evidence is now mounting ...

The next generation of solar energy collectors could be rocks

The next generation of solar energy collectors could be rocks
2023-05-30
The next generation of sustainable energy technology might be built from some low-tech materials: rocks and the sun. Using a new approach known as concentrated solar power, heat from the sun is stored then used to dry foods or create electricity. A team reporting in ACS Omega has found that certain soapstone and granite samples from Tanzania are well suited for storing this solar heat, featuring high energy densities and stability even at high temperatures. Energy is often stored in large batteries when not needed, but these can be expensive and require lots of resources to manufacture. A lower-tech alternative ...

Hidden in plain sight: Windshield washer fluid is an unexpected emission source

2023-05-30
Exhaust fumes probably come to mind when considering vehicle emissions, but they aren’t the only source of pollutants released by a daily commute. In a recent ACS’ Environmental Science & Technology study, researchers report that alcohols in windshield washer fluid account for a larger fraction of real-world vehicle emissions than previous estimates have suggested. Notably, the levels of these non-fuel-derived gases will likely remain unchanged, even as more drivers transition from gas-powered ...

Humans evolved to walk with an extra spring in our step

2023-05-30
A new study has shown that humans may have evolved a spring-like arch to help us walk on two feet. Researchers studying the evolution of bipedal walking have long assumed that the raised arch of the foot helps us walk by acting as a lever which propels the body forward. But a global team of scientists have now found that the recoil of the flexible arch repositions the ankle upright for more effective walking. The effects in running are greater, which suggests that the ability to run efficiently could have been a selective pressure for a flexible arch that made walking more efficient too. This discovery could even help doctors improve ...

Bile acid receptor could be innovative target in protecting the vision of premature newborns

Bile acid receptor could be innovative target in protecting the vision of premature newborns
2023-05-30
AUGUSTA, Ga. (May 30, 2023) – It sounds like bile acid in the eye would hurt, but scientists think stimulating one of its receptors can actually help protect the vision of premature newborns. It’s called the farnesoid-X-receptor, or FXR, a bile acid receptor whose expression is significantly diminished in two key cell types affected by retinopathy of prematurity. Medical College of Georgia scientists have early evidence that targeting that receptor could provide earlier, more impactful treatments for these babies, a process that could be expedited by the fact that the drugs they ...

Study finds similar quality and cost of care for patients treated by an allopathic (M.D.) or osteopathic (D.O.) physician

2023-05-29
1. Study finds similar quality and cost of care for patients treated by an allopathic (M.D.) or osteopathic (D.O.) physician Abstract: https://www.acpjournals.org/doi/10.7326/M22-3723 Editorial: https://www.acpjournals.org/doi/10.7326/M23-1165 URL goes live when the embargo lifts An observational study of more than 329,000 Medicare admissions found that older persons receiving hospital care from an allopathic (M.D.) or an osteopathic (D.O.) physician experience similar quality and cost of care. The findings are published in Annals ...

LAST 30 PRESS RELEASES:

Antibiotic pollution disrupts the gut microbiome and blocks memory in aquatic snails 

Researchers expose new symbiosis origin theories, identify experimental systems for plant life

Q&A: How AI affects kids’ creativity

Virtual lab meetings improve undergraduate research experience and foster diversity in academia

Study shows effectiveness of updated COVID-19 vaccines wanes moderately over time, is lower against currently circulating variants

Researchers expose new ‘origin’ theories, identify experimental systems for plant life

Researchers honored for outstanding contributions to cancer care

A new Hungarian method may aid protein research

AIM algorithm enhances super-resolution microscope images in real time

Rice researchers uncover surprising role of opioid receptors in gut development

Cleveland Clinic and IBM researchers apply quantum computing methods to protein structure prediction

Blood flow makes waves across the surface of the mouse brain

More out-of-state patients seek abortions in Washington state

Researchers take step toward development of universal COVID-19 antibodies

Do epilepsy medications taken during pregnancy affect a child’s creativity?

First hints of memory problems associated with changes in the brain

Mass General Brigham study finds that memory complaints can predict biological changes in the brain

JPMorgan Chase, Argonne and Quantinuum show theoretical quantum speedup with the quantum approximate optimization algorithm

AI browser plug-ins to help consumers improve digital privacy literacy, combat manipulative design

Grant funds CU project to develop novel mechanism to expand NF1 treatments

A drying Salton Sea pollutes neighboring communities

Wild megalopolis: Study shows unexpected pockets of biodiversity pepper Los Angeles

Slugs and snails love the city, unlike other animals

Ideas that cross international borders may have powerful impact on elections

YouTube’s comments section: Political echo chamber or constructive cross-partisan forum?

Babies babble squeals and growls in clustering patterns observable from birth through the first year, suggesting this active vocal exploration is important to speech development

The sweat bee, H. rubicundus, is less sociable in Scotland than in Cornwall, but is genetically differentiated and genetically isolated too

Smartphone use may help adolescents feel better - at least in the moment, finds real-time survey of US teens

Public have no difficulty getting to grips with an extra thumb, study finds

Breakthrough in cancer prediction with nano informatics and AI

[Press-News.org] Source-shifting metastructures composed of only one resin for location camouflaging
Novel numerical optimization methodology paves the way for acoustic camouflaging in the form of sound source-shifters