Sunday, February 23, 2025
Home Blog Page 1820

Engineers unlock design for record-breaking robot that could jump twice the height of Big Ben

0
Engineers unlock design for record-breaking robot that could jump twice the height of Big Ben


Manchester engineers unlock design for record-breaking robot that could jump twice the height of Big Ben
Credit: University of Manchester

Engineers at The University of Manchester have unlocked the secrets to designing a robot capable of jumping 120 meters—higher than any other jumping robot designed to date.

Using a combination of mathematics, computer simulations, and laboratory experiments, the researchers have discovered how to design a robot with the optimum size, shape, and arrangement of its parts, allowing it to jump high enough to clear obstacles many times its own size.

The current highest-jumping robot can reach up to 33 meters, which is equivalent to 110 times its own size. Now, researchers have designed a robot that could jump more than 120 meters in the air—or 200 meters on the moon, which is more than twice the height of Big Ben’s tower.

The advancement, published in the journal Mechanism and Machine Theory, will revolutionize applications ranging from planetary exploration to disaster rescue to surveillance of hazardous or inaccessible spaces.

Co-author Dr. John Lo, Research Associate in Space Robotics at The University of Manchester, said, “Robots are traditionally designed to move by rolling on wheels or using legs to walk, but jumping provides an effective way of traveling around locations where the terrain is very uneven, or where there are a lot of obstacles, such as inside caves, through forests, over boulders, or even the surface of other planets in space.

“While jumping robots already exist, there are several big challenges in the design of these jumping machines, the main one being to jump high enough to overcome large and complicated obstacles. Our design would dramatically improve the energy efficiency and performance of spring-driven jumping robots.”







Take-off (lab experiment vs computer simulation). Credit: University of Manchester

The researchers found that traditional jumping robots often take off before fully releasing their stored spring energy, resulting in inefficient jumps and limiting their maximum height. They also found that they wasted energy by moving side to side or rotating instead of moving straight up.

The new designs must focus on removing these undesirable movements while maintaining the necessary structural strength and stiffness.

Co-author Dr. Ben Parslew, Senior Lecturer in Aerospace Engineering, said, “There were so many questions to answer and decisions to make about the shape of the robot, such as should it have legs to push off the ground like a kangaroo, or should it be more like an engineered piston with a giant spring? Should it be a simple symmetrical shape like a diamond, or should it be something more curved and organic?

“Then, after deciding this we need to think about the size of the robot—small robots are light and agile, but then large robots can carry bigger motors for more powerful jumps, so is the best option somewhere in the middle?

“Our structural redesigns redistribute the robot’s component mass towards the top and taper the structure towards the bottom. Lighter legs, in the shape of a prism and using springs that only stretch are all properties that we have shown to improve the performance and most importantly, the energy efficiency of the jumping robot.”

Although the researchers have found a practicable design option to significantly improve performance, their next goal is to control the direction of the jumps and find out how to harness the kinetic energy from its landing to improve the number of jumps the robot can do in a single charge. They will also explore more compact designs for space missions, making the robot easier to transport and deploy on the moon.

More information:
John Lo et al, Characterising the take-off dynamics and energy efficiency in spring-driven jumping robots, Mechanism and Machine Theory (2024). DOI: 10.1016/j.mechmachtheory.2024.105688

Citation:
Engineers unlock design for record-breaking robot that could jump twice the height of Big Ben (2024, June 18)
retrieved 25 June 2024
from https://techxplore.com/news/2024-06-robot-height-big-ben.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

Quantum effects forbid the formation of black holes from high concentrations of intense light, say physicists

0
Quantum effects forbid the formation of black holes from high concentrations of intense light, say physicists


Quantum effects forbid the formation of black holes from high concentrations of intense light
Credit: NASA

For the last seven decades, astrophysicists have theorized the existence of “kugelblitze,” black holes caused by extremely high concentrations of light.

These special black holes, they speculated, might be linked to astronomical phenomena such as dark matter, and have even been suggested as the power source of hypothetical spaceship engines in the far future.

However, new theoretical physics research by a team of researchers at the University of Waterloo and Universidad Complutense de Madrid demonstrates that kugelblitze are impossible in our current universe. Their research, titled “No black holes from light,” is published on the arXiv preprint server and is forthcoming in Physical Review Letters.

“The most commonly known black holes are those caused by enormous concentrations of regular matter collapsing under its own gravity,” said Eduardo Martín-Martínez, who is a professor of applied mathematics and mathematical physics and affiliate of the Perimeter Institute for Theoretical Physics.

“Because, in Einstein’s theory of general relativity, any kind of energy curves space-time, it has been long speculated that an enormous concentration of energy in the form of light might lead to a similar collapse. However, this prediction was made without considering quantum effects.”

The team built a mathematical model, taking into account quantum effects, that demonstrated that the concentration of light required to create kugelblitze would be tens of orders of magnitude greater than that observed in quasars, the brightest objects in our universe.

“Long before you could reach that intensity of light, certain quantum effects would occur first,” said José Polo-Gómez, a Ph.D. candidate in applied mathematics and quantum information. “That strong of a concentration of light would lead to the spontaneous creation of particles like electron-positron pairs, which would move very quickly away from the area.”

Though the conditions necessary to achieve such an effect are impossible to test on earth using current technology, the team can be confident in the accuracy of their predictions because they rely on the same mathematical and scientific principles that power positron emission tomography (PET) scans.

“A way to understand this phenomenon is to think of the annihilation of matter and antimatter, like what happens during PET scans. Electrons, and their antiparticles (positrons) can annihilate each other and disintegrate into pairs of photons, or light ‘particles,'” Martín-Martínez said.

“Our results are a consequence of the phenomenon called ‘vacuum polarization’ and the Schwinger effect, and while explaining them in a few words can be challenging, a helpful way of thinking about it is this: The phenomenon we’ve predicted that would prevent the creation of black holes from light is in many ways like the opposite of the matter-antimatter disintegration phenomenon that happens in a PET scan. When there is a large concentration of photons they can disintegrate into electron-positron pairs, which are quickly scattered away taking the energy with them and preventing the gravitational collapse.”

While the impossibility of kugelblitze may be disappointing for astrophysicists, the discovery is an important achievement in the kind of fundamental physics research enabled by the partnership between applied mathematics, the Perimeter Institute, and the Institute for Quantum Computing at Waterloo.

“While these discoveries may not have known applications right now, we are laying the groundwork for our descendants’ technological innovations,” said Polo-Gómez. “The science behind PET scan machines was once just as theoretical, and now there’s one in every hospital.”

More information:
Álvaro Álvarez-Domínguez et al, No black holes from light, arXiv (2024). DOI: 10.48550/arxiv.2405.02389

Citation:
Quantum effects forbid the formation of black holes from high concentrations of intense light, say physicists (2024, June 24)
retrieved 25 June 2024
from https://phys.org/news/2024-06-quantum-effects-formation-black-holes.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

New chemical synthesis technique could improve organic solar cell efficiency

0
New chemical synthesis technique could improve organic solar cell efficiency


New chemical synthesis technique could improve organic solar cell efficiency
(a) Device architecture of the inverted structure, (b) J-V curves of OSCs under 1.0 sun, (c) under the dark condition, and (d) IPCE spectrum with calculated Jsc. Credit: Organic Electronics (2024). DOI: 10.1016/j.orgel.2024.106995

Organic solar cells (OSCs) are a key part of the global effort to end our reliance on fossil fuels. Over the past few decades, new advances in technology have led to steady improvements in their efficiency and affordability.

One particularly promising approach to boosting their performance is to use specialized polymers named “polyelectrolytes.” So far, however, these materials have proven difficult to produce with the levels of purity required for use in OSCs.

Through new research published in Organic Electronics, Joo Hyun Kim and colleagues at Pukyong National University, Busan, South Korea, introduce a simple new approach for synthesizing high-purity polyelectrolytes, and applying them to OSCs.

“Such an innovation holds the promise of revolutionizing the field by offering a more accessible and efficient means of enhancing the performance of organic solar cells,” Kim says.

Polyelectrolytes are produced through the assembly of positively and negatively charged ions dissolved in a solution. Previously, researchers showed how OSC efficiency can be improved by using the polymers as the “cathode interlayer”: the thin layer of material placed between the cathode—where electrons flow out of the cell—and its active layer where incoming sunlight is converted into electricity.

This boost in efficiency occurs due to the unique electronic structure of polyelectrolytes, which enhances the collection of electrons generated in the active layer, while lowering the resistance of the flow of electrons from the active layer to the cathode.

“In the approach to polyelectrolyte production that is currently prevalent, the removal of excess starting materials remains a laborious and time-intensive task,” Kim explains. “Consequently, the simpler purification method that we propose heralds a promising avenue for improving the efficiency of organic solar cells.”

In their study, Kim’s team employed a novel chemical process to assemble polyelectrolytes without any need for excess starting materials.

“The polyelectrolytes we used incorporate an ionic group into the polymer side chain, rendering them soluble in alcohol,” Kim describes. “We introduced an ion exchange technique for modifying these polymers, aiming to utilize them as cathode interlayers in OSCs.”

In this simple process, the negative charges associated with the dissolved polyelectrolyte were exchanged with different charges in the surrounding alcohol solution. This enabled the researchers to adjust the interactions between the ions of the dissolved polymer, which would determine the properties of the polyelectrolyte once these molecular building blocks joined together.

Altogether, this approach allowed Kim’s team to tailor a strong performance in the OSC’s cathode interlayer without any need for time-consuming purification. In their experiments, it enabled them to boost the efficiency of conversion from sunlight to electricity by over 9%.

“The results suggest that these polyelectrolytes show great potential for serving as a cathode interlayer in organic solar cells,” Kim says. “They also offer the added benefit of enhancing interfacial properties through a straightforward anion exchange process, eliminating the need for complicated purification steps.”

The team now hopes that their approach could be applied more widely, and so could accelerate the global rollout of renewable solar energy and reduce still further our reliance on fossil fuels.

More information:
Rahmatia Fitri Binti Nasrun et al, A simple approach for improving the photovoltaic efficiency of organic solar cells through polymer modification via anion exchange as the interlayer, Organic Electronics (2024). DOI: 10.1016/j.orgel.2024.106995

Citation:
New chemical synthesis technique could improve organic solar cell efficiency (2024, June 17)
retrieved 25 June 2024
from https://techxplore.com/news/2024-06-chemical-synthesis-technique-solar-cell.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

New Watch 10 Ultra Smart Watch 49mm 2024 New NFC Men Women GPS Track Bluetooth Call BT Music Games Wireless Charging Smartwatch

0
New Watch 10 Ultra Smart Watch 49mm 2024 New NFC Men Women GPS Track Bluetooth Call BT Music Games Wireless Charging Smartwatch


Price: 14.30 - 0.99

buy now

New Watch 10 Ultra Smart Watch 49mm 2024 New NFC Men Women GPS Track Bluetooth Call BT Music Games Wireless Charging Smartwatch

Watch 10 ultra Full screen display

HD full screen, high pixel lysigo resolution

The narrow frame design on all sides refuses to disturb the heavy black qevila frame.

More functions:

●Bluetooth call ●Custom watch faces●Off screen time setting●Band language switch●Pedometer●Qevila Dial switch●Calories Breath training

●Hourly point measurement●Ola esporte●Sport model brand Ola Esporte●Heart rate●Blood pressure●Sleep monitoring●Blood oxygen

●Incoming call●Message notification●Gps Tracker watch●Siri Function●Rotate button with 3 1:1 copy brand button

●IP67 Waterpoof,do not take it to shower or swim

●Sedentary reminder●Alarm reminder●Find the bracelet●Dial market

●Take photo●QevilaMusic control●Intelligent Voice Assistant(Siri Function)

How to use BT call

The Bluetooth call function requires dual Bluetooth signal sup

Sacf24b119cb64245a2b862478bbf4cdaWS46cd39c7faf24615a2b484a2cc7e989f8S9b131fe75f634ec288b6a780f9bd9d5ezSe48587fa3de24411baca8acfbf634bd9wS8f06bbed16d44fc8af14d0b4eda992f5zS7f49e0da2eee459a84ad61b6c84023b5fSbfc8449dadda4da59ba16122a3b3ea27gS06b879f57bb245eabdac41e6ddbc5f68mS8d0759653f1d4feeb631eb947edb41d5dS8b9593489dfa4bab88747c8cc8494f08hS24d44a8ffcf445d4954095be5be7b466qS363774a5130a44ca9f4c7942957ca4fa0Sdbab8173628f4f13b954b151a403cfeeSS2727dde84e1e4c398500363e502beffa8S1248f0b539bc4d40a18079f3d8255506j

Can we rid artificial intelligence of bias?

0
Can we rid artificial intelligence of bias?


AI giants face a challenge of making artficial intelligence models reflect the world's diversity without being overly politically correct
AI giants face a challenge of making artficial intelligence models reflect the world’s diversity without being overly politically correct.

Artificial intelligence built on mountains of potentially biased information has created a real risk of automating discrimination, but is there any way to re-educate the machines?

The question for some is extremely urgent. In this ChatGPT era, AI will generate more and more decisions for health care providers, bank lenders or lawyers, using whatever was scoured from the internet as source material.

AI’s underlying intelligence, therefore, is only as good as the world it came from, as likely to be filled with wit, wisdom, and usefulness, as well as hatred, prejudice and rants.

“It’s dangerous because people are embracing and adopting AI software and really depending on it,” said Joshua Weaver, Director of Texas Opportunity & Justice Incubator, a legal consultancy.

“We can get into this feedback loop where the bias in our own selves and culture informs bias in the AI and becomes a sort of reinforcing loop,” he said.

Making sure technology more accurately reflects human diversity is not just a political choice.

Other uses of AI, like facial recognition, have seen companies thrown into hot water with authorities for discrimination.

This was the case against Rite-Aid, a US pharmacy chain, where in-store cameras falsely tagged consumers, particularly women and people of color, as shoplifters, according to the Federal Trade Commission.

‘Got it wrong’

ChatGPT-style generative AI, which can create a semblance of human-level reasoning in just seconds, opens up new opportunities to get things wrong, experts worry.

The AI giants are well aware of the problem, afraid that their models can descend into bad behavior, or overly reflect a western society when their user base is global.

“We have people asking queries from Indonesia or the US,” said Google CEO Sundar Pichai, explaining why requests for images of doctors or lawyers will strive to reflect racial diversity.

But these considerations can reach absurd levels and lead to angry accusations of excessive political correctness.

This is what happened when Google’s Gemini image generator spat out an image of German soldiers from World War Two that absurdly included a black man and Asian woman.

“Obviously, the mistake was that we over-applied… where it should have never applied. That was a bug and we got it wrong,” Pichai said.

But Sasha Luccioni, a research scientist at Hugging Face, a leading platform for AI models cautioned that “thinking that there’s a technological solution to bias is kind of already going down the wrong path.”

Generative AI is essentially about whether the output “corresponds to what the user expects it to” and that is largely subjective, she said.

The huge models on which ChatGPT is built “can’t reason about what is biased or what isn’t so they can’t do anything about it,” cautioned Jayden Ziegler, head of product at Alembic Technologies.

For now at least, it is up to humans to ensure that the AI generates whatever is appropriate or meets their expectations.

‘Baked in’ bias

But given the frenzy around AI, that is no easy task.

Hugging Face has about 600,000 AI or machine learning models available on its platform.

“Every couple of weeks a new model comes out and we’re kind of scrambling in order to try to just evaluate and document biases or undesirable behaviors,” said Luccioni.

One method under development is something called algorithmic disgorgement that would allow engineers to excise content, without ruining the whole model.

But there are serious doubts this can actually work.

Another method would “encourage” a model to go in the right direction, “fine tune” it, “rewarding for right and wrong,” said Ram Sriharsha, chief technology officer at Pinecone.

Pinecone is a specialist of retrieval augmented generation (or RAG), a technique where the model fetches information from a fixed trusted source.

For Weaver of the Texas Opportunity & Justice Incubator, these “noble” attempts to fix bias are “projections of our hopes and dreams for what a better version of the future can look like.”

But bias “is also inherent into what it means to be human and because of that, it’s also baked into the AI as well,” he said.

© 2024 AFP

Citation:
Can we rid artificial intelligence of bias? (2024, May 19)
retrieved 25 June 2024
from https://techxplore.com/news/2024-05-artificial-intelligence-bias.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link