Monday, January 13, 2025

 

New method forecasts computation, energy costs for sustainable AI models




North Carolina State University





The process of updating deep learning/AI models when they face new tasks or must accommodate changes in data can have significant costs in terms of computational resources and energy consumption. Researchers have developed a novel method that predicts those costs, allowing users to make informed decisions about when to update AI models to improve AI sustainability.

“There have been studies that focused on making deep learning model training more efficient,” says Jung-Eun Kim, corresponding author of a paper on the work and an assistant professor of computer science at North Carolina State University. “However, over a model’s life cycle, it will likely need to be updated many times. One reason is that, as our work here shows, retraining an existing model is much more cost effective than training a new model from scratch.

“If we want to address sustainability issues related to deep learning AI, we must look at computational and energy costs across a model’s entire life cycle – including the costs associated with updates. If you cannot predict what the costs will be ahead of time, it is impossible to engage in the type of planning that makes sustainability efforts possible. That makes our work here particularly valuable.”

Training a deep learning model is a computationally intensive process, and users want to go as long as possible without having to update the AI. However, two types of shifts can happen that make these updates inevitable. First, the task that the AI is performing may need to be modified. For example, if a model was initially tasked with only classifying digits and traffic symbols, you may need to modify the task to identify vehicles and humans as well. This is called a task shift.

Second, the data users provide to the model may change. For example, you may need to make use of a new kind of data, or perhaps the data you are working with is being coded in a different way. Either way, the AI needs to be updated to accommodate the change. This is called a distribution shift.

“Regardless of what is driving the need for an update, it is extremely useful for AI practitioners to have a realistic estimate of the computational demand that will be required for the update,” Kim says. “This can help them make informed decisions about when to conduct the update, as well as how much computational demand they will need to budget for the update.”

To forecast what the computational and energy costs will be, the researchers developed a new technique they call the REpresentation Shift QUantifying Estimator (RESQUE).

Essentially, RESQUE allows users to compare the dataset that a deep learning model was initially trained on to the new dataset that will be used to update the model. This comparison is done in a way that estimates the computational and energy costs associated with conducting the update.

Those costs are presented as a single index value, which can then be compared with five metrics: epochs, parameter change, gradient norm, carbon and energy. Epochs, parameter change and gradient norm are all ways of measuring the amount of computational effort necessary to retrain the model.

“However, to provide insight regarding what this means in a broader sustainability context, we also tell users how much energy, in kilowatt hours, will be needed to retrain the model,” Kim says. “And we predict how much carbon, in kilograms, will be released into the atmosphere in order to provide that energy.”

The researchers conducted extensive experiments involving multiple data sets, many different distribution shifts, and many different task shifts to validate RESQUE’s performance.

“We found that the RESQUE predictions aligned very closely with the real-world costs of conducting deep learning model updates,” Kim says. “Also, as I noted earlier, all of our experimental findings tell us that training a new model from scratch demands far more computational power and energy than retraining an existing model.”

In the short term, RESQUE is a useful methodology for anyone who needs to update a deep learning model.

“RESQUE can be used to help users budget computational resources for updates, allow them to predict how long the update will take, and so on,” Kim says.

“In the bigger picture, this work offers a deeper understanding of the costs associated with deep learning models across their entire life cycle, which can help us make informed decisions related to the sustainability of the models and how they are used. Because if we want AI to be viable and useful, these models must be not only dynamic but sustainable.”

The paper, “RESQUE: Quantifying Estimator to Task and Distribution Shift for Sustainable Model Reusability,” will be presented at the Thirty-Ninth Association for the Advancement of Artificial Intelligence (AAAI) Conference on Artificial Intelligence, which will be held Feb. 25-Mar. 4 in Philadelphia, Penn. The first author of the paper is Vishwesh Sangarya, a graduate student at NC State.

 

Safe and energy-efficient quasi-solid battery for electric vehicles and devices



Researchers develop a quasi-solid-state lithium-ion battery with improved stability, safety, and longevity



Doshisha University

New quasi-solid-state lithium-ion-battery can revolutionize the widespread application of electric vehicles and devices 

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Researchers from Doshisha University, Japan, develop a novel quasi-solid-state lithium-ion battery (LIB) with non-flammable solid and liquid electrolytes. The battery has higher ionic conductivity, improved cycle performance, and better safety than conventional LIBs.

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Credit: Ryosuke Kido from Doshisha University




Technological advances have led to the widespread use of electric devices and vehicles. These innovations are not only convenient but also environmentally friendly, offering an alternative to polluting fuel-driven machines. Lithium ion batteries (LIBs) are widely used in electrical appliances and vehicles. Commercial LIBs comprise an organic electrolyte solution, which is considered indispensable to make them energy efficient. However, ensuring safety becomes a concern and may be difficult to achieve with the rising market demand.

While solid-state batteries can help mitigate safety issues, the interface between solid electrodes and the electrolyte is not conducive to optimum lithium-ion transfer. Moreover, the expansion and shrinkage of solid electrodes can disrupt the joint interface and hamper ion transfer. Therefore, there is a need to develop efficient solid-state batteries with a stable joint interface that can enhance their safety, utility, and performance.

To overcome these challenges, a team of researchers from Japan has developed a non-flammable quasi-solid-state LIB that can overcome the limitations of conventional batteries. The study was led by Ryosuke Kido from Doshisha University and TDK Corporation, Japan, Professor Minoru Inaba and Professor Takayuki Doi from Doshisha University, and Atsushi Sano from TDK Corporation and their findings were published online on 11 October 2024, in the Journal of Energy Storage.  It has also been published in the Volume 102 on 15 November 2024.

Giving further insight into their work, Mr. Kido the main author of the paper, says, “Increasing the capacity of positive and negative electrode active materials to achieve higher energy density reduces cycle performance and safety. The flame-retardant quasi-solid-state battery we developed, combining a liquid electrolyte and a solid electrolyte, provides a safer and more durable alternative to all-solid-state batteries with high energy density.”

The new battery design includes a silicon (Si) negative electrode and a LiNi0.8Co0.1Mn0.1O2 (NCM811) positive electrode, which is considered next-generation materials for LIBs. These electrodes are separated by a solid lithium-ion conducting glass ceramic sheet (LICGC™) from OHARA. To enhance compatibility and performance, the researchers developed non-flammable, nearly saturated electrolyte solutions tailored to each electrode. The solutions used tris(2,2,2-trifluoroethyl) phosphate and methyl 2,2,2-trifluoroethyl carbonate, which were compatible with the electrodes and the solid electrolyte interface. The resulting 30 mAh-class quasi-solid-state pouch cells demonstrated excellent ionic conductivity, thermal stability, and electrochemical performance.

The researchers went on to assess the thermal stability and electrochemical performance of the quasi-solid-state LIB using electrochemical impedance spectroscopy, charge-discharge tests, and accelerating rate calorimetry (ARC). Notably, the battery demonstrated high charge/discharge capacity with good cycle performance and little change in the internal resistance. Moreover, the ARC test revealed that the Si-LICGC-NCM811 structure with the respective electrolyte solutions showed improved thermal stability and that the heat generation associated with the side reaction was very low even in the high-temperature range of around 150 °C.

Overall, the newly developed LIB has the potential to enhance the development of efficient and safer next-generation electric vehicles and cordless appliances like drones. Its widespread application can not only improve user convenience but also promote sustainable economic growth.

Mr. Kido concludes with the long-term implications of their work by saying, As the world moves toward carbon neutrality, electric vehicles have been gaining significant attention in recent years. It is vital to develop highly safe automotive batteries with extended lifespans. The quasi-solid-state battery from our study has the potential to improve the longevity of liquid-based LIBs and enhance energy density while maintaining the safety of all-solid-state batteries.”

The study represents a step toward developing next-generation energy storage solutions that balance safety, efficiency, and environmental sustainability.
 


About Ryosuke Kido from Doshisha University, Japan
Mr. Ryosuke Kido is a second-year doctoral fellow at the Faculty of Science and Engineering Department of Molecular Chemistry and Biochemistry, Doshisha University, Japan. His doctoral work is in collaboration with the Cell Engineering Section, Japan Battery Division, Energy Devices Business Group, TDK Corporation, Japan.

About Professor Takayuki Doi from Doshisha University, Japan
Takayuki Doi obtained his Ph.D. in Engineering from Kyoto University, Japan, in 2005. He joined Doshisha University, Japan, as an Associate Professor in 2013 and was promoted to full Professor in 2020. He specializes in material science, with a focus on nanomaterials, energy chemistry, inorganic compounds, and battery science. He has published over 130 papers on these topics.

Funding information
This research was partially supported by “Advanced Research Program for Energy and Environmental Technologies” from New Energy and Industrial Technology Development Organization (NEDO), Japan.

 

Love bites? Scientists identify pre-mating behaviors of whale sharks in coastal Western Australia




Murdoch University
Whale shark swimming at Ningaloo Reef 

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Researchers at Murdoch University in Western Australia have observed pre-mating behaviours in endangered whale sharks at Ningaloo Reef. For the first time, following and biting behaviours were recorded between a mature male and a smaller female, shedding light on their elusive mating rituals. These findings will support conservation efforts and understanding sex biases in whale shark populations. 

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Credit: Harry Butler Institute, Murdoch University




For the first time researchers have witnessed behaviour in the wild which could reveal critical clues about how the endangered whale shark reproduces.

Little is known about the pre-mating rituals of the elusive creature, and due to its endangered status, there has never been a more critical time to uncover them.

Annual research expeditions at Ningaloo Reef, a World Heritage Site in the north west coastal region of Western Australia, have taken place from 2009-2024 during the month of May, the peak of the seasonal aggregation of whale sharks.

During the 2024 expedition, a research team witnessed and recorded following and biting behaviours by a sexually mature male whale shark towards a smaller female.

The research team included PhD candidate Christine Barry from Murdoch University’s Harry Butler Institute and the Australian Institute of Marine Science, and one of her supervisors Dr Mark Meekan from The University of Western Australia.

In a paper published in Frontiers in Marine Science Ms Barry explores the implications of these observations.

“Following and biting are common copulation behaviours in other species within the subclass of cartilaginous fish that the whale shark belongs to,” Ms Barry said.

“This is also consistent with previous reports by fishers recounting behaviours they’d observed out on the water of sexually mature males towards females at different aggregation sites.”

While the observed interaction likely did not culminate in mating, Ms Barry said the team’s observations suggested the whale shark’s mating behaviours resembled those of many other species of shark.

The existence of these records not only expands researchers’ understanding of the whale shark’s mating behaviours, but also provide insights into sex-biases reported in whale shark populations across various coastal aggregations.

“At Ningaloo Reef, and many aggregation sites around the world, males outnumber females with a ratio of 1 female to 3 males,” Ms Barry said.

“This could explain why female whale sharks may be avoiding aggregation sites. Particularly for juvenile female sharks, the energetic costs of unwanted attention from males could imply a reason for strong male biases.”

This research opens the door for conservation efforts and further exploration into repopulation and protection of the species. Ms Barry, and PhD supervisor Dr Adrian Gleiss – senior lecturer with Murdoch University’s School of Environmental and Conservation Sciences – have been at the forefront of whale shark research.

Their research outputs have included insights into the impacts of tourism on whale sharks and the predation of baitfishes associated with Ningaloo Reef whale sharks. ENDS

 

Raw materials from nuclear waste



EU Project “MaLaR” launched under HZDR leadership




Helmholtz-Zentrum Dresden-Rossendorf

Prof. Kristina Kvashnina 

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Prof. Kristina Kvashnina

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Credit: Denis Morel/HZDR




Is permanent storage the only strategy for dealing with nuclear waste? No, says Prof. Kristina Kvashnina of the Helmholtz-Zentrum-Dresden-Rossendorf (HZDR). With the aid of new EU funding, she wants to investigate the options for recycling some elements of nuclear waste using novel separation techniques – because old nuclear fuels contain important raw materials, not just for nuclear energy. For the next three years, 2.3 million euros in funding have recently been made available for the project “MaLaR – Novel 2D-3D Materials for Lanthanide Recovery from nuclear waste”. In addition to Germany, the partners are France, Sweden and Romania.

What is supposed to be recycled are lanthanides, a group of chemical elements which include some rare earths. They are widely used, for example, in screens, batteries, magnets, contrast media and biological probes. “Lanthanides are a very rare raw material, most of which comes from China. That’s why we are trying to recycle this raw material from waste, even from nuclear waste,” explains Kvashnina, the coordinator of the MaLaR Project. The physicist belongs to HZDR’s Institute of Resource Ecology and holds a professorship at the Université Grenoble Alpes in France.

In order to recycle waste, it has to be separated. Apart from the basic safety risks associated with radioactive elements, there is a special problem with nuclear waste: The materials it contains exhibit very similar chemical reactions. “That’s why it’s very difficult to find something which only causes a reaction in one element and not in others so that you can extract just the one,” explains Kvashnina. Existing separation processes often involve dangerous chemicals, use a great deal of energy and result in additional waste streams.

Carbon materials as specific element scavengers

The MaLaR Consortium is working on an innovative procedure. The idea is to develop novel three-dimensional materials as the crucial tool for effective, environmentally friendly, sustainable separation methods. This applies both to nuclear waste and industrial waste, such as radiomedical applications. Just as in the current separation methods, the researchers are building on the principle of sorption: specific radioactive elements in liquid nuclear waste attach themselves to the neighboring solid phase of a sorbent and can thus be separated from the rest of the waste.

In recent years, studies have shown that graphene oxides – carbon-based porous materials – can significantly outperform the most important industrial sorbents or radio nuclides currently in use. Moreover, it recently emerged that certain changes in the electronic structure further increase sorption performance. In the MaLaR project, Kvashnina and her partners want to systematically explore the underlying chemical reactions and develop new materials based on graphene oxide that can serve as specific element scavengers.

Getting a grip on nuclear and industrial waste

“Our aim is to design a material with which we can initially extract individual elements from synthetic element mixtures. In the future, that could then be transferred to various applications. Admittedly, in three years we can only take the first step toward recycling, but if we are successful, applications will be within easy reach,” Kvashnina emphasizes. The impact would be enormous because the novel separation methods would not only help with the recovery of raw materials from nuclear and other industrial waste, but also with the safe final storage of highly radioactive waste, for example if isotopes with different lifetimes can be separated and then stored separately. The project explicitly aims to develop appropriate close-to-the-market technological solutions.

The MaLaR-Team can rely on its partners’ expertise in several different worlds: in 2D/3D materials development, fundamental physics and the chemistry of radioactive elements as well as the possibility of using a new in-situ method for the time-resolved investigation of the tiniest concentrations of lanthanides in radioactive materials.

“It’ll be great to spend the next few years working in this team. We can combine fundamental insights from experiments with theoretical calculations and models as well as material characterization and development,” says Kvashnina enthusiastically. As part of the project, she will also be in charge of experiments at HZDR’s Rossendorf Beamline (ROBL) at the European Synchrotron (ESRF) in Grenoble where the new materials will be tested for their chemical properties using intensive x-ray light.

Background

The MaLaR project started on January 1st, 2025. Via the European EURATOM Program, HZDR and the following partners will receive 2.3 million euros over a period of three years:

  •     Marcoule Institute in Separation Chemistry, University of Montpellier and Centre National de la Recherche Scientifique (CNRS) in France
  •     Universities of Umeå and Uppsala in Sweden
  •     University POLITEHNICA of Bucharest in Romania

At HZDR, most of the work will be conducted in an alpha-lab in Dresden-Rossendorf and at the ROBL Beamline in Grenoble.

The Helmholtz-Zentrum Dresden-Rossendorf (HZDR) performs – as an independent German research center – research in the fields of energy, health, and matter. We focus on answering the following questions:

  • How can energy and resources be utilized in an efficient, safe, and sustainable way?
  • How can malignant tumors be more precisely visualized, characterized, and more effectively treated?
  • How do matter and materials behave under the influence of strong fields and in smallest dimensions?

To help answer these research questions, HZDR operates large-scale facilities, which are also used by visiting researchers: the Ion Beam Center, the Dresden High Magnetic Field Laboratory and the ELBE Center for High-Power Radiation Sources.
HZDR is a member of the Helmholtz Association and has six sites (Dresden, Freiberg, Görlitz, Grenoble, Leipzig, Schenefeld near Hamburg) with almost 1,500 members of staff, of whom about 680 are scientists, including 200 Ph.D. candidates.