Computers Math

Imagine you want to carry a large, heavy box up a flight of stairs. You might spread your fingers out and lift that box with both hands, then hold it on top of your forearms and balance it against your chest, using your whole body to manipulate the box.
Humans are generally good at whole-body manipulation, but robots struggle with such tasks. To the robot, each spot where the box could touch any point on the carrier’s fingers, arms, and torso represents a contact event that it must reason about. With billions of potential contact events, planning for this task quickly becomes intractable.
Now MIT researchers found a way to simplify this process, known as contact-rich manipulation planning. They use an AI technique called smoothing, which summarizes many contact events into a smaller number of decisions, to enable even a simple algorithm to quickly identify an effective manipulation plan for the robot.
While still in its early days, this method could potentially enable factories to use smaller, mobile robots that can manipulate objects with their entire arms or bodies, rather than large robotic arms that can only grasp using fingertips. This may help reduce energy consumption and drive down costs. In addition, this technique could be useful in robots sent on exploration missions to Mars or other solar system bodies, since they could adapt to the environment quickly using only an onboard computer.
“Rather than thinking about this as a black-box system, if we can leverage the structure of these kinds of robotic systems using models, there is an opportunity to accelerate the whole procedure of trying to make these decisions and come up with contact-rich plans,” says H.J. Terry Suh, an electrical engineering and computer science (EECS) graduate student and co-lead author of a paper on this technique.
Joining Suh on the paper are co-lead author Tao Pang PhD ’23, a roboticist at Boston Dynamics AI Institute; Lujie Yang, an EECS graduate student; and senior author Russ Tedrake, the Toyota Professor of EECS, Aeronautics and Astronautics, and Mechanical Engineering, and a member of the Computer Science and Artificial Intelligence Laboratory (CSAIL). The research appears this week in IEEE Transactions on Robotics.
Learning about learning
Reinforcement learning is a machine-learning technique where an agent, like a robot, learns to complete a task through trial and error with a reward for getting closer to a goal. Researchers say this type of learning takes a black-box approach because the system must learn everything about the world through trial and error. More

For many patients, the internet serves as a powerful tool for self-education on medical topics. With ChatGPT now at patients’ fingertips, researchers from Brigham and Women’s Hospital, a founding member of the Mass General Brigham healthcare system, assessed how consistently the artificial intelligence chatbot provides recommendations for cancer treatment that align with National Comprehensive Cancer Network (NCCN) guidelines. Their findings, published in JAMA Oncology, show that in approximately one-third of cases, ChatGPT 3.5 provided an inappropriate (“non-concordant”) recommendation, highlighting the need for awareness of the technology’s limitations.
“Patients should feel empowered to educate themselves about their medical conditions, but they should always discuss with a clinician, and resources on the Internet should not be consulted in isolation,” said corresponding author Danielle Bitterman, MD, of the Department of Radiation Oncology and the Artificial Intelligence in Medicine (AIM) Program of Mass General Brigham. “ChatGPT responses can sound a lot like a human and can be quite convincing. But, when it comes to clinical decision-making, there are so many subtleties for every patient’s unique situation. A right answer can be very nuanced, and not necessarily something ChatGPT or another large language model can provide.”
The emergence of artificial intelligence tools in health has been groundbreaking and has the potential to positively reshape the continuum of care. Mass General Brigham, as one of the nation’s top integrated academic health systems and largest innovation enterprises, is leading the way in conducting rigorous research on new and emerging technologies to inform the responsible incorporation of AI into care delivery, workforce support, and administrative processes.
Although medical decision-making can be influenced by many factors, Bitterman and colleagues chose to evaluate the extent to which ChatGPT’s recommendations aligned with the NCCN guidelines, which are used by physicians at institutions across the country. They focused on the three most common cancers (breast, prostate and lung cancer) and prompted ChatGPT to provide a treatment approach for each cancer based on the severity of the disease. In total, the researchers included 26 unique diagnosis descriptions and used four, slightly different prompts to ask ChatGPT to provide a treatment approach, generating a total of 104 prompts.
Nearly all responses (98 percent) included at least one treatment approach that agreed with NCCN guidelines. However, the researchers found that 34 percent of these responses also included one or more non-concordant recommendations, which were sometimes difficult to detect amidst otherwise sound guidance. A non-concordant treatment recommendation was defined as one that was only partially correct; for example, for a locally advanced breast cancer, a recommendation of surgery alone, without mention of another therapy modality. Notably, complete agreement in scoring only occurred in 62 percent of cases, underscoring both the complexity of the NCCN guidelines themselves and the extent to which ChatGPT’s output could be vague or difficult to interpret.
In 12.5 percent of cases, ChatGPT produced “hallucinations,” or a treatment recommendation entirely absent from NCCN guidelines. These included recommendations of novel therapies, or curative therapies for non-curative cancers. The authors emphasized that this form of misinformation can incorrectly set patients’ expectations about treatment and potentially impact the clinician-patient relationship.
Going forward, the researchers are exploring how well both patients and clinicians can distinguish between medical advice written by a clinician versus a large language model (LLM) like ChatGPT. They are also prompting ChatGPT with more detailed clinical cases to further evaluate its clinical knowledge.
The authors used GPT-3.5-turbo-0301, one of the largest models available at the time they conducted the study and the model class that is currently used in the open-access version of ChatGPT (a newer version, GPT-4, is only available with the paid subscription). They also used the 2021 NCCN guidelines, because GPT-3.5-turbo-0301 was developed using data up to September 2021. While results may vary if other LLMs and/or clinical guidelines are used, the researchers emphasize that many LLMs are similar in the way they are built and the limitations they possess.
“It is an open research question as to the extent LLMs provide consistent logical responses as oftentimes ‘hallucinations’ are observed,” said first author Shan Chen, MS, of the AIM Program. “Users are likely to seek answers from the LLMs to educate themselves on health-related topics — similarly to how Google searches have been used. At the same time, we need to raise awareness that LLMs are not the equivalent of trained medical professionals.” More

Scientists from Nanyang Technological University, Singapore (NTU Singapore) have developed a flexible battery as thin as a human cornea, which stores electricity when it is immersed in saline solution, and which could one day power smart contact lenses.
Smart contact lenses are high-tech contact lenses capable of displaying visible information on our corneas and can be used to access augmented reality. Current uses include helping to correct vision, monitoring wearers’ health, and flagging and treating diseases for people with chronic health conditions such as diabetes and glaucoma. In the future, smart contact lenses could be developed to record and transmit everything a wearer sees and hears to cloud-based data storage.
However, to reach this future potential a safe and suitable battery needs to be developed to power them. Existing rechargeable batteries rely on wires or induction coils that contain metal and are unsuitable for use in the human eye, as they are uncomfortable and present risks to the user.
The NTU-developed battery is made of biocompatible materials and does not contain wires or toxic heavy metals, such as those in lithium-ion batteries or wireless charging systems. It has a glucose-based coating that reacts with the sodium and chloride ions in the saline solution surrounding it, while the water the battery contains serves as the ‘wire’ or ‘circuitry’ for electricity to be generated.
The battery could also be powered by human tears as they contain sodium and potassium ions, at a lower concentration. Testing the current battery with a simulated tear solution, the researchers showed that the battery’s life would be extended an additional hour for every twelve-hour wearing cycle it is used. The battery can also be charged conventionally by an external power supply.
Associate Professor Lee Seok Woo, from NTU’s School of Electrical and Electronic Engineering (EEE), who led the study, said: “This research began with a simple question: could contact lens batteries be recharged with our tears? There were similar examples for self-charging batteries, such as those for wearable technology that are powered by human perspiration.
“However, previous techniques for lens batteries were not perfect as one side of the battery electrode was charged and the other was not. Our approach can charge both electrodes of a battery through a unique combination of enzymatic reaction and self-reduction reaction. Besides the charging mechanism, it relies on just glucose and water to generate electricity, both of which are safe to humans and would be less harmful to the environment when disposed, compared to conventional batteries.”
Co-first author Dr Yun Jeonghun, a research fellow from NTU’s EEE said: “The most common battery charging system for smart contact lenses requires metal electrodes in the lens, which are harmful if they are exposed to the naked human eye. Meanwhile, another mode of powering lenses, induction charging, requires a coil to be in the lens to transmit power, much like wireless charging pad for a smartphone. Our tear-based battery eliminates the two potential concerns that these two methods pose, while also freeing up space for further innovation in the development smart contact lenses.” More

Parents are spending considerable amounts of energy thinking about and mitigating the risks associated with their kids using mobile phones and the internet.
The impacts of too much screen time on children’s physical and mental health, development and education are common concerns among parents.
New research by the University of South Australia suggests that mums in particular are experiencing a “relentless and intense” mental load linked to their children’s digital use.
UniSA researcher Dr Fae Heaselgrave calls this additional burden “digital care work,” which involves mothers monitoring their children’s digital activity, familiarising themselves with social media platforms and coming up with strategies to manage their kids’ media use.
“At a societal level, we already know that the use of mobile phones, laptops, and computers in the home is more prevalent than ever. Families in Australia own on average almost eight digital devices, with children owning up to three devices each,” she says.
“What we don’t know as much about is the effect children’s digital media use has on a mother’s role. Digital care work — which is an extension of the wider unpaid care role mothers provide in the home — is more often the domain of women, as mothers tend to be the primary caregiver.
“This means the increased use of digital devices is having a bigger impact on mums in terms of demanding more time, energy and mental and cognitive work, which can also affect their career choices and paid work patterns.”
In a series of interviews with Adelaide mothers of children aged 9 to 16, Dr Heaselgrave found that digital care work intensifies modern mothering by requiring an additional investment of time and energy to monitor children’s digital media use. More

A new study led by Dr. Xuekun Lu from Queen Mary University of London in collaboration with an international team of researchers from the UK and USA has found a way to prevent lithium plating in electric vehicle batteries, which could lead to faster charging times. The paper was published in the journal Nature Communications.
Lithium plating is a phenomenon that can occur in lithium-ion batteries during fast charging. It occurs when lithium ions build up on the surface of the battery’s negative electrode instead of intercalating into it, forming a layer of metallic lithium that continues growing. This can damage the battery, shorten its lifespan, and cause short-circuits that can lead to fire and explosion.
Dr. Xuekun Lu explains that lithium plating can be significantly mitigated by optimizing the microstructure of the graphite negative electrode. The graphite negative electrode is made up of randomly distributed tiny particles, and fine-tuning the particle and electrode morphology for a homogeneous reaction activity and reduced local lithium saturation is the key to suppress lithium plating and improve the battery’s performance.
“Our research has revealed that the lithiation mechanisms of graphite particles vary under distinct conditions, depending on their surface morphology, size, shape and orientation. It largely affects the lithium distribution and the propensity of lithium plating,” said Dr. Lu. “Assisted by a pioneering 3D battery model, we can capture when and where lithium plating initiates and how fast it grows. This is a significant breakthrough that could have a major impact on the future of electric vehicles.”
The study provides new insights into developing advanced fast charging protocols by improving the understanding of the physical processes of lithium redistribution within graphite particles during fast charging. This knowledge could lead to an efficient charging process while minimising the risk of lithium plating.
In addition to faster charging times, the study also found that refining the microstructure of the graphite electrode can improve the battery’s energy density. This means that electric cars could travel further on a single charge.
These findings are a major breakthrough in the development of electric vehicle batteries. They could lead to faster-charging, longer-lasting, and safer electric cars, which would make them a more attractive option for consumers. More

In the form of DNA, nature shows how data can be stored in a space-saving and long-term manner. Bioinformatics specialists are developing DNA chips for computer technology. Researchers show how a combination of molecular biology, nanotechnology, novel polymers, electronics and automation, coupled with systematic development, could make DNA data storage useful for everyday use possible in a few years.
The hereditary molecule DNA can store a great deal of information over long periods of time in a very small space. For a good ten years, scientists have therefore been pursuing the goal of developing DNA chips for computer technology, for example for the long-term archiving of data. Such chips would be superior to conventional silicon-based chips in terms of storage density, longevity, and sustainability.
Four recurring basic building blocks are found in a DNA strand. A specific sequence of these blocks can be used to encode information, just as nature does. To build a DNA chip, the correspondingly coded DNA must be synthesised and stabilised. If this works well, the information is preserved for a very long time — researchers assume several thousand years. The information can be retrieved by automatically reading out and decoding the sequence of the four basic building blocks.
What challenges have to be overcome
“The fact that digital DNA data storage with high capacity and a long lifespan is feasible has been demonstrated several times in recent years,” says Professor Thomas Dandekar, head of the Chair of Bioinformatics at Julius-Maximilians-Universität (JMU) Würzburg. “But the storage costs are high, close to 400,000 US dollars per megabyte, and the information stored in the DNA can only be retrieved slowly. It takes hours to days, depending on the amount of data.”
These challenges must be overcome to make DNA data storage more applicable and marketable. Suitable tools for this are light-controlled enzymes and protein network design software. Thomas Dandekar and his chair team members Aman Akash and Elena Bencurova discuss this in a recent review in the journal Trends in Biotechnology.
Dandekar’s team is convinced that DNA has a future as a data store. In the journal, the JMU researchers show how a combination of molecular biology, nanotechnology, novel polymers, electronics and automation, coupled with systematic development, could make DNA data storage useful for everyday use possible in a few years. More

An innovative bimanual robot displays tactile sensitivity close to human-level dexterity using AI to inform its actions.
The new Bi-Touch system, designed by scientists at the University of Bristol and based at the Bristol Robotics Laboratory, allows robots to carry out manual tasks by sensing what to do from a digital helper.
The findings, published in IEEE Robotics and Automation Letters, show how an AI agent interprets its environment through tactile and proprioceptive feedback, and then control the robots’ behaviours, enabling precise sensing, gentle interaction, and effective object manipulation to accomplish robotic tasks.
This development could revolutionise industries such as fruit picking, domestic service, and eventually recreate touch in artificial limbs.
Lead author Yijiong Lin from the Faculty of Engineering, explained: “With our Bi-Touch system, we can easily train AI agents in a virtual world within a couple of hours to achieve bimanual tasks that are tailored towards the touch. And more importantly, we can directly apply these agents from the virtual world to the real world without further training.
“The tactile bimanual agent can solve tasks even under unexpected perturbations and manipulate delicate objects in a gentle way.”
Bimanual manipulation with tactile feedback will be key to human-level robot dexterity. However, this topic is less explored than single-arm settings, partly due to the availability of suitable hardware along with the complexity of designing effective controllers for tasks with relatively large state-action spaces. The team were able to develop a tactile dual-arm robotic system using recent advances in AI and robotic tactile sensing. More

Whenever the precision of a measurement approaches the uncertainty limit defined by quantum mechanics, the outcomes of the measurement depend on the dynamics of the interactions with the meter used to determine a physical property of the system. This finding may explain why quantum experiments often produce conflicting results and may contradict basic assumptions regarding physical reality.
Two quantum physicists from Hiroshima University recently analyzed the dynamics of a measurement interaction, where the value of a physical property is identified with a quantitative change in the meter state. This is a difficult problem, because quantum theory does not identify the value of a physical property unless the system is in a so-called “eigenstate” of that physical property, a very small set of special quantum states for which the physical property has a fixed value. The researchers solved this fundamental problem by combining information about the past of the system with information about its future in a description of the dynamics of the system during the measurement interaction, demonstrating that the observable values of a physical system depend on the dynamics of the measurement interaction by which they are observed.
The team published the results of their study on July 31 in Physical Review Research.
“There is much disagreement about the interpretation of quantum mechanics because different experimental results cannot be reconciled with the same physical reality,” said Holger Hofmann, professor in the Graduate School of Advanced Science and Engineering at Hiroshima University in Hiroshima, Japan.
“In this paper, we investigate how quantum superpositions in the dynamics of the measurement interaction shape the observable reality of a system seen in the response of a meter. This is a major step towards explaining the meaning of “superposition” in quantum mechanics,” said Hofmann.
In quantum mechanics, a superposition describes a situation in which two possible realities seem to co-exist, even though they can be distinguished clearly when an appropriate measurement is performed. The analysis of the team’s study suggests that superpositions describe different kinds of reality when different measurements are performed. The reality of an object depends on the object’s interactions with its surroundings.
“Our results show that the physical reality of an object cannot be separated from the context of all its interactions with the environment, past, present and future, providing strong evidence against the widespread belief that our world can be reduced to a mere configuration of material building blocks,” said Hofmann. More