Computers Math

Inspired by the effortless way humans handle objects without seeing them, a team led by engineers at the University of California San Diego has developed a new approach that enables a robotic hand to rotate objects solely through touch, without relying on vision.
Using their technique, the researchers built a robotic hand that can smoothly rotate a wide array of objects, from small toys, cans, and even fruits and vegetables, without bruising or squishing them. The robotic hand accomplished these tasks using only information based on touch.
The work could aid in the development of robots that can manipulate objects in the dark.
The team recently presented their work at the 2023 Robotics: Science and Systems Conference.
To build their system, the researchers attached 16 touch sensors to the palm and fingers of a four-fingered robotic hand. Each sensor costs about $12 and serves a simple function: detect whether an object is touching it or not.
What makes this approach unique is that it relies on many low-cost, low-resolution touch sensors that use simple, binary signals — touch or no touch — to perform robotic in-hand rotation. These sensors are spread over a large area of the robotic hand.
This contrasts with a variety of other approaches that rely on a few high-cost, high-resolution touch sensors affixed to a small area of the robotic hand, primarily at the fingertips. More

Researchers have created a quantum superposition state in a semiconductor nanostructure that might serve as a basis for quantum computing. The trick: two optical laser pulses that act as a single terahertz laser pulse.
A German-Chinese research team has successfully created a quantum bit in a semiconductor nanostructure. Using a special energy transition, the researchers created a superposition state in a quantum dot — a tiny area of the semiconductor — in which an electron hole simultaneously possessed two different energy levels. Such superposition states are fundamental for quantum computing. However, excitation of the state would require a large-scale free-electron laser that can emit light in the terahertz range. Additionally, this wavelength is too long to focus the beam on the tiny quantum dot. The German-Chinese team has now achieved the excitation with two finely tuned short-wavelength optical laser pulses.
The team headed by Feng Liu from Zhejiang University in Hangzhou, together with a group led by Dr. Arne Ludwig from Ruhr University Bochum and other researchers from China and the UK, report their findings in the journal “Nature Nanotechnology,” published online on 24 July 2023.
Lasers trigger the radiative Auger process
The team made use of the so-called radiative Auger transition. In this process, an electron recombines with a hole, releasing its energy partly in the form of a single photon and partly by transferring the energy to another electron. The same process can also be observed with electron holes — in other words, missing electrons. In 2021, a research team succeeded for the first time in specifically stimulating the radiative Auger transition in a semiconductor.
In the current project, the researchers showed that the radiative Auger process can be coherently driven: they used two different laser beams with intensities in a specific ratio to each other. With the first laser, they excited an electron-hole pair in the quantum dot to create a quasiparticle consisting of two holes and an electron. With a second laser, they triggered the radiative Auger process to elevate one hole to a series of higher energy states.
Two states simultaneously
The team used finely tuned laser pulses to create a superposition between the hole ground state and the higher energy state. The hole thus existed in both states simultaneously. Such superpositions are the basis for quantum bits, which, unlike conventional bits, exist not only in the states “0” and “1,” but also in superpositions of both.
Hans-Georg Babin produced the high-purity semiconductor samples for the experiment at Ruhr University Bochum under the supervision of Dr. Arne Ludwig at the Chair for Applied Solid State Physics headed by Professor Andreas Wieck. In the process, the researchers increased the ensemble homogeneity of the quantum dots and ensured the high purity of the structures produced. These measures facilitated the performance of the experiments by the Chinese partners working with Jun-Yong Yan and Feng Liu. More

Researchers at Monash University have designed a new co-training AI algorithm for medical imaging that can effectively mimic the process of seeking a second opinion.
Published recently in Nature Machine Intelligence, the research addressed the limited availability of human annotated, or labelled, medical images by using an adversarial, or competitive, learning approach against unlabelled data.
This research, by Monash University faculties of Engineering and IT, will advance the field of medical image analysis for radiologists and other health experts.
PhD candidate Himashi Peiris of the Faculty of Engineering, said the research design had set out to create a competition between the two components of a “dual-view” AI system.
“One part of the AI system tries to mimic how radiologists read medical images by labelling them, while the other part of the system judges the quality of the AI-generated labelled scans by benchmarking them against the limited labelled scans provided by radiologists,” said Ms Peiris.
“Traditionally radiologists and other medical experts annotate, or label, medical scans by hand highlighting specific areas of interest, such as tumours or other lesions. These labels provide guidance or supervision for training AI models.
“This method relies on the subjective interpretation of individuals, is time-consuming and prone to errors and extended waiting periods for patients seeking treatments.”
The availability of large-scale annotated medical image datasets is often limited, as it requires significant effort, time and expertise to annotate many images manually. More

Fast data transmissions could be delivered in homes and offices through light-emitting diodes (LED) bulbs, complementing existing communication technologies and networks.
The future’s new internet technologies are being rapidly refined by academics and LED-based communication links are expected to be extensively used in numerous emerging services and scenarios, including Light-fidelity (Li-Fi), underwater communications, moderate- to high-speed photonic interconnects and various ‘Internet of Things’ (IoT) devices.
A new study led by the University of Surrey and University of Cambridge has investigated how to release high-speed photonic sources using metal-halide perovskites. These are semiconductors being researched with LEDs for their excellent optoelectronic properties and low-cost processing methods.
Dr Wei Zhang, lead corresponding author of the study and associate professor at University of Surrey’s Advanced Technology Institute, said:
“Billions of IoT connected devices have the potential to add significant value to industry and the global economy. In this market costs and compatibility are often prioritised over data transmission speed and scientists are looking for alternative ways to reduce energy consumption per bit and improve compactness while simultaneously working on improving the speed of data connection.
“In our study we have made a huge leap forward and shown how metal-halide perovskites could provide a cost-efficient and powerful solution to make LEDs which have enormous potential to increase their bandwidths into the gigahertz levels. The insights gained from this research will undoubtedly shape the future of data communication.
“Moreover, our investigations will accelerate the development of high-speed perovskite photodetectors and continuous wave pumped perovskite lasers, thus opening up new avenues for advancements in optoelectronic technologies.”
Hao Wang, co-first author and Ph.D. student at the University of Cambridge, said:
“We provided the first study to elucidate the mechanisms behind achieving high-speed perovskite LEDs, which represents a significant step toward the realisation of perovskite light sources for next-generation data communications. The ability to achieve solution-processed perovskite emitters on silicon substrates also paves the way for their integration with micro-electronics platforms, presenting new opportunities for seamless integration and advancement in the field of data communications.”
The research published in the journal Nature Photonics was a collaborative project with the support over 10 laboratories and research institutes from Oxford, Cambridge, Bath, Warwick, UCL, EMPA and UESTC. More

The University of Bristol-led study, published today in The Proceedings of the National Academy of Sciences (PNAS), demonstrates how to make conductive, biodegradable wires from designed proteins. These could be compatible with conventional electronic components made from copper or iron, as well as the biological machinery responsible for generating energy in all living organisms.
The miniscule wires are the size of transistors on silicon chips or one thousandth of the breadth of the finest human hair. They are made completely of natural amino acids and heme molecules, found in proteins such as hemoglobin, which transports oxygen in red blood cells. Harmless bacteria were used for their manufacture, eliminating the need for potentially complex and environmentally damaging procedures commonly used in the production of synthetic molecules.
Lead author Ross Anderson, Professor of Biological Chemistry at the University of Bristol, said: “While our designs take inspiration from the protein-based electronic circuits necessary for all life on Earth, they are free from much of the complexity and instability that can prevent the exploitation of their natural equivalents on our own terms. We can also build these minute electronic components to order, specifying their properties in a way that is not possible with natural proteins.”
Leading experts in biomolecular engineering and simulation worked together to produce this unique new method of designing tailor-made proteins with tuneable electronic properties.
The multidisciplinary team used advanced computational tools to design simple building blocks that could be combined into longer, wire-like protein chains for conducting electrons. They were able to visualise the structures of these wires using protein X-ray crystallography and electron cryo-microscopy (cryo-EM), techniques which allow structures to be viewed in the finest detail. Pushing the technical boundaries of cryo-EM, images of the smallest individual protein ever studied were obtained with this technique.
Ultimately, these nanoscale designer wires have the potential to be used in a wide range of applications, including biosensors for the diagnosis of diseases and detection of environmental pollutants.
It is also hoped this invention will form the foundation of new electrical circuits for creating tailor-made catalysts for green industrial biotechnology and artificial photosynthetic proteins for capturing solar energy. More

If you find the computer security guidelines you get at work confusing and not very useful, you’re not alone. A new study highlights a key problem with how these guidelines are created, and outlines simple steps that would improve them — and probably make your computer safer.
At issue are the computer security guidelines that organizations like businesses and government agencies provide their employees. These guidelines are generally designed to help employees protect personal and employer data and minimize risks associated with threats such as malware and phishing scams.
“As a computer security researcher, I’ve noticed that some of the computer security advice I read online is confusing, misleading or just plain wrong,” says Brad Reaves, corresponding author of the new study and an assistant professor of computer science at North Carolina State University. “In some cases, I don’t know where the advice is coming from or what it’s based on. That was the impetus for this research. Who’s writing these guidelines? What are they basing their advice on? What’s their process? Is there any way we could do better?”
For the study, researchers conducted 21 in-depth interviews with professionals who are responsible for writing computer security guidelines for organizations including large corporations, universities and government agencies.
“The key takeaway here is that the people writing these guidelines try to give as much information as possible,” Reaves says. “That’s great, in theory. But the writers don’t prioritize the advice that’s most important. Or, more specifically, they don’t deprioritize the points that are significantly less important. And because there is so much security advice to include, the guidelines can be overwhelming — and the most important points get lost in the shuffle.”
The researchers found that one reason security guidelines can be so overwhelming is that guideline writers tend to incorporate every possible item from a wide variety of authoritative sources.
“In other words, the guideline writers are compiling security information, rather than curating security information for their readers,” Reaves says. More

Excess heat from electronic or mechanical devices is a sign or cause of inefficient performance. In many cases, embedded sensors to monitor the flow of heat could help engineers alter device behavior or designs to improve their efficiency. For the first time, researchers exploit a novel thermoelectric phenomenon to build a thin sensor that can visualize heat flow in real time. The sensor could be built deep inside devices where other kinds of sensors are impractical. It is also quick, cheap and easy to manufacture using well-established methods.
According to the law of conservation of energy, energy is never created or destroyed but only changes form from one to another depending on the interaction between the entities involved. All energy eventually ends up as heat. For us that can be a useful thing, for example, when we want to heat our homes in winter; or detrimental, when we want to cool something down, or get the most out of a battery-driven application. In any case, the better we can manage the thermal behavior of a device, the better we can engineer around this inevitable effect and improve the efficiency of the device in question. However, this is easier said than done, as knowing how heat flows inside some complex, miniature or hazardous device is something ranging from the difficult to the impossible, depending on the application.
Inspired by this problem, Project Associate Professor Tomoya Higo and Professor Satoru Nakatsuji from the Department of Physics at the University of Tokyo, and their team, which included a corporate partnership, set out to find a solution. “The amount of heat conducted through a material is known as its heat flux. Finding new ways to measure this could not only help improve device efficiency, but also safety, as batteries with poor thermal management can be unsafe, and even health, as various health or lifestyle issues can relate to body heat,” said Higo. “But finding a sensor technology to measure heat flux, while also satisfying a number of other conditions, such as robustness, cost efficiency, ease of manufacture and so on, is not easy. Typical thermal diode devices are relatively large and only give a value for temperature in a specific area, rather than an image, of the heat flux across an entire surface.”
The team explored the way a heat flux sensor consisting of certain special magnetic materials and electrodes behaves when there are complex patterns of heat flow. The magnetic material based on iron and gallium exhibits a phenomenon known as the anomalous Nernst effect (ANE), which is where heat energy is unusually converted to an electrical signal. This is not the only magnetic effect that can turn heat into power, though. There is also the Seebeck effect, which can actually create more electrical power, but it requires a large bulk of material, and the materials are brittle so hard to work with. ANE, on the other hand, allowed the team to engineer their device on an incredibly thin and malleable sheet of plastic.
“By finding the right magnetic and electrode materials and then applying them in a special repeating pattern, we created microscopic electronic circuits that are flexible, robust, cheap and easy to produce, and most of all are very good at outputting heat flux data in real time,” said Higo. “Our method involves rolling a thin sheet of clear, strong and lightweight PET plastic as a base layer, with magnetic and electrode materials sputtered onto it in thin and consistent layers. We then etch our desired patterns into the resultant film, similar to how electronic circuits are made.”
The team designed the circuits in a particular kind of way to boost ANE whilst also suppressing the Seebeck effect, as this actually interferes with the data-gathering potential of ANE. Previous attempts to do this were unsuccessful in any way that could be easily scaled up and potentially commercialized, making this sensor the first of its kind.
“I envisage seeing downstream applications such as power generation or data centers, where heat impedes efficiency. But as the world becomes more automated, we might see these kinds of sensors in automated manufacturing environments where they could improve our ability to predict machine failures, certain safety issues, and more,” said Nakatsuji. “With further developments, we might even see internal medical applications to help doctors produce internal heat maps of specific areas of the body, or organs, to aid in imaging and diagnosis.” More

A University of Otago study has added weight to the evidence that watching too much television as a child can lead to poor health in adulthood.
The research, led by Professor Bob Hancox, of the Department of Preventive and Social Medicine, and published this week in the journal Pediatrics, found that children who watched more television were more likely to develop metabolic syndrome as an adult.
Metabolic syndrome is a cluster of conditions including high blood pressure, high blood sugar, excess body fat, and abnormal cholesterol levels that lead to an increased risk of heart disease, diabetes and stroke.
Using data from 879 participants of the Dunedin study, researchers found those who watched more television between the ages of 5 and 15 were more likely to have these conditions at age 45.
Television viewing times were asked at ages 5, 7, 9, 11, 13 and 15. On average, they watched just over two hours per weekday.
“Those who watched the most had a higher risk of metabolic syndrome in adulthood,” Professor Hancox says.
“More childhood television viewing time was also associated with a higher risk of overweight and obesity and lower physical fitness.”
Boys watched slightly more television than girls and metabolic syndrome was more common in men, than women (34 percent and 20 per cent respectively). The link between childhood television viewing time and adult metabolic syndrome was seen in both sexes however, and may even be stronger in women. More