CMCC Foundation explores the ML potential for climate change risk assessment

Large amounts of data and new methods and technologies with which to analyze them. The new frontier of machine learning, a branch of artificial intelligence, at the service of climate studies, in research by the CMCC Foundation and Ca’ Foscari University of Venice

Global warming is exacerbating weather and climate extreme events. The interaction between different forms of hazards triggered by climate change will cause future cross-sectoral impacts affecting a variety of natural and human systems.

Research can improve the understanding of these interactions and dynamics, support decision-makers in managing current and future climate change risks, also thanks to an improved ability to predict expected risks and quantify their impacts.

To this end, in recent years, the scientific community has started testing new methodological approaches, technologies, and tools, among which the application of machine learning, which can help exploit the potential of large amounts and variety of environmental monitoring data available today (big data).

What are the results of the exponential increase in the application of machine learning methods for the assessment of climate-induced risks?

In the study “Exploring machine learning potential for climate change risk assessment“, a team of scientists from the CMCC Foundation and Ca’ Foscari University of Venice conducted an in-depth review of more than 1,200 articles on the subject, published in the last 20 years, highlighting the potential and limitations of machine learning in this field.

“Machine learning is a branch of artificial intelligence,” explains Federica Zennaro, a researcher at the CMCC Foundation and Ca’ Foscari University Venice and the main author of the study. “By simulating the processes of the human brain, certain mathematical algorithms can understand the relationships between a set of input data in order to predict the required output. In our research, we identified that floods and landslides are the most analyzed events through machine learning models, probably because they are the most relevant and frequent around the world.”

Moreover, the study reveals that machine learning has two major potentials that make it particularly interesting when applied to this field of study.

The first is that said algorithms can learn from data: the more data, the better algorithms learn. Thanks to its ability to analyze and process large amounts of data, machine learning allows researchers to disentangle complex relationships underlying the functioning of socio-ecological systems, exploiting the big data collected from various sources, including sensors for environmental analysis at high temporal frequency, social media, satellite data and images, and drones.

The second is that they can combine different types of data, thus enabling an assessment of the risk extent whilst taking into account all its dimensions. These include not only the triggering hazard (for example, an increase in rainfall) but also the vulnerability and exposure of the socio-economic system at stake, which are crucial factors in an evaluation of overall impacts

“For example, consider a model that is trained with detailed data on flood events over the past 20 years, including their location and information on the affected context (urban or natural). This model can project, in a scenario characterized by future climate conditions, what the probability of an event happening at a certain point will be, and calculate its risk of causing harmful impacts to society and the environment,” Zennaro explains. “Machine learning represents the future of risk assessment, but its great potential is not yet widely exploited. Our research shows that there are still few studies that use these models to develop long-term future risk scenarios (up to 2100). The vast majority of studies focus on the short term, probably influenced by the reduced availability of extended time series data capable of supporting adequate model training for long-term projections.”

The next step, explains the co-author Elisa Furlan, a researcher at the CMCC Foundation and Ca’Foscari University Venice, is to develop machine learning models that are increasingly efficient at studying and untangling the complex spatiotemporal interrelationships among different climatic, environmental, and socioeconomic variables, thereby improving understanding of the behavior of complex systems. “Under the perspective of a rising abundance of data and machine learning models’ complexity, researchers will have the possibility (and duty) to improve the understanding of climate-related risks, with the main aim of providing accurate and sound multi-risk scenarios able to drive robust adaptation planning and disaster risk reduction and management”.

UK review of academic studies finds AI could help clinicians with mechanical ventilation

Artificial intelligence could be used in the future to help guide when to use mechanical ventilation and the likelihood of complications in the ventilation of patients. This is according to the first systematic review of studies in this area, led by clinicians at Guy’s and St Thomas’ NHS Foundation Trust.

The review found 1,342 papers on AI and mechanical ventilation and looked in detail at 95 of these. They found that many were looking at the early testing of AI technology and models. One was already at the next stage of clinical trials in patients, with many technologies on the cusp of this step.

The team of academics at Guy’s and St Thomas’ and King’s College London made recommendations for further transparency, to help avoid bias and to facilitate rapid developments in this field. {module title="INSIDE STORY"} 

Artificial intelligence shows great promise in guiding treatment in many diseases. Its ability to analyze large amounts of data could help clinicians in their decision-making by calculating complex probabilities which might take clinicians a lot of time and experience.

Mechanical ventilation in particular is considered an area where AI could help, as patients put on mechanical ventilation can vary hugely, and AI may help to personalize approaches to an individual’s characteristics. They may also be used to flag to a clinician exactly when a person should be taken off or put on to ventilation.

Of the 1,342 papers found in this area, the team looked in detail at 95 particularly relevant studies, where information specifically on AI applied to mechanical ventilation in humans was presented. They made recommendations for researchers to improve work in this field. These included improving the availability of data. They also recommended better reporting of characteristics like ethnicity and gender, to help scientists assess how well findings can be generalized across wider populations.

Dr. Luigi Camporota, consultant in intensive care medicine at Guy’s and St Thomas’ said: “Our systematic review of the literature revealed an exponential increase in the rate of publications on artificial intelligence as applied to mechanical ventilation in the past few years. Despite this increased scientific and clinical interest, artificial intelligence is still very little used in mechanical ventilators.”

Dr. Jack Gallifant, from the Centre for Human and Applied Physiological Sciences at King’s College London, said: “Artificial intelligence has the potential to improve the management of mechanical ventilation therapy. Our review highlights a need for greater code and data availability, and thorough validation that, combined with smaller bias, will facilitate translation of data science into improved patient care.”

Durham University develops new simulation model that helps with COVID-19 planning in world’s largest refugee settlement

Academics and data scientists from Durham University, a public research university in Durham, England, and UN Global Pulse (UNGP) have developed an agent-based model to simulate the spread of COVID-19 in the Cox’s Bazar refugee settlement in Bangladesh.

The researchers analyzed several operational interventions by modeling the interactions of over 900,000 Rohingya refugees and found that mask-wearing is highly effective to slow the spread of COVID-19. 

Researchers also established that handling of positive cases in isolation and treatment centers have little impact on the spread of COVID-19 in comparison to home isolation for individuals with mild symptoms, mainly due to the exceptionally high population density in the settlement and many facilities being communal that poses an increased risk of coronavirus transmission. Credit: UNHCR/Amos Halder

Furthermore, at the time of the study, the simulation results indicated that the reopening of learning centers could lead to a higher infection rate in the refugee settlement, where social distancing is nearly impossible. This led the researchers to explore various mitigation strategies.

The study adapted the JUNE epidemic model to the settlement setting. The team took a scenario-based approach that focused on simulating the relative effectiveness of the above-mentioned interventions in the settlement.

The modeling followed a three-step process of (1) building a ‘digital twin’ of the Cox’s Bazar refugee settlement that (2) simulated the possible movement and interaction patterns among the residents and (3) implementation of operational interventions to simulate its effects on the spread of COVID-19 in the settlement. 

Virtual individuals were included in the model with different demographic attributes that mirrored real-world statistics. A simulation engine was designed by the researchers that captured the movement and interaction patterns of the people in the model.

Full results of the study have been published in the journal PLOS Computational Biology. 

The study findings have allowed decision-makers in the refugee settlement to set up new contingency plans for high case numbers and develop policies on the safe opening of various indoor spaces.

A mask-wearing strategy was rolled out, which included mask-making, and communication and engagement campaigns to increase correct mask usage, as the model showed how this could significantly reduce the spread of COVID-19 over time.

The model has been informed by data from UNHCR, the UN’s Refugee Agency, on geography, demographics, comorbidities, physical infrastructure, and other parameters obtained from real-world observations. 

The study results were presented in a series of reports that provided crucial insights and limitations relevant to this modeling approach to the World Health Organisation and UNHCR public health professionals operating in the settlement on the potential effectiveness of interventions to curb the spread of COVID-19.  

Chris Earney, Deputy Director of UNGP said: “The project has fulfilled its operational objectives successfully and the team is aiming to scale the model implementation further with future applications and partnerships.”

The JUNE open-source modeling framework has been developed by the researchers during the pandemic and was originally applied to simulating the spread of COVID-19 in England.

Professor Frank Krauss of Durham University said: “The work with the UN and the WHO is super-exciting and a very good example for the caliber of our Ph.D. students. It is great to see their enthusiasm, skills, and drive: this project started from zero, and within months we had a highly competitive COVID simulation for the UK, all while they also collaborated with international agencies to apply this to a completely new setting. This is nothing short of a truly excellent achievement!”               

The research conducted by UNGP has been supported by the Government of Sweden, and the William and Flora Hewlett Foundation and the Ph.D. students were supported by the UKRI-STFC grant.

HZB physicist gains new insights into topological materials for ultrafast spintronics

The laws of quantum physics rule the microcosm. They determine, for example, how easily electrons move through a crystal and thus whether the material is a metal, a semiconductor, or an insulator. Quantum physics may lead to exotic properties in certain materials: In so-called topological insulators, only the electrons that can occupy some specific quantum states are free to move like massless particles on the surface, while this mobility is completely absent for electrons in the bulk. What's more, the conduction electrons in the "skin" of the material are necessarily spin-polarized and form robust, metallic surface states that could be utilized as channels in which to drive pure spin currents on femtosecond time scales (1 fs= 10-15 s). Snapshots of the electronic structure of Sb acquired with femtosecond time-resolution. Note the changing spectral weight above the Fermi energy (EF).

These properties open up exciting opportunities to develop new information technologies based on topological materials, such as ultrafast spintronics, by exploiting the spin of the electrons on their surfaces rather than the charge. In particular, optical excitation by femtosecond laser pulses in these materials represents a promising alternative to realize highly efficient, lossless transfer of spin information. Spintronic devices utilizing these properties have the potential of superior performance, as they would allow increasing the speed of information transport up to frequencies a thousand times faster than in modern electronics.

However, many questions still need to be answered before spintronic devices can be developed. For example, the details of exactly how the bulk and surface electrons from a topological material respond to the external stimulus i.e., the laser pulse, and the degree of overlap in their collective behaviors on ultrashort time scales.

A team led by HZB physicist Dr. Jaime Sánchez-Barriga has now brought new insights into such mechanisms. The team, which has also established a Helmholtz-RSF Joint Research Group in collaboration with colleagues from Lomonosov State University, Moscow, examined single crystals of elemental antimony (Sb), previously suggested to be a topological material. "It is a good strategy to study interesting physics in a simple system because that's where we can hope to understand the fundamental principles," Sánchez-Barriga explains. "The experimental verification of the topological property of this material required us to directly observe its electronic structure in a highly excited state with time, spin, energy, and momentum resolutions, and in this way, we accessed an unusual electron dynamics," adds Sánchez-Barriga.

The aim was to understand how fast excited electrons in the bulk and on the surface of Sb react to the external energy input and to explore the mechanisms governing their response. "By controlling the time delay between the initial laser excitation and the second pulse that allows us to probe the electronic structure, we were able to build up a full time-resolved picture of how excited states leave and return to equilibrium on ultrafast time scales. The unique combination of time and spin-resolved capabilities also allowed us to directly probe the spin-polarization of excited states far out-of-equilibrium," said Dr. Oliver J. Clark.

The data show a "kink" structure in transiently occupied energy-momentum dispersion of surface states, which can be interpreted as an increase in effective electron mass. The authors were able to show that this mass enhancement plays a decisive role in determining the complex interplay in the dynamical behaviors of electrons from the bulk and the surface, also depending on their spin, following the ultrafast optical excitation.

"Our research reveals which essential properties of this class of materials are the key to systematically control the relevant time scales in which lossless spin-polarized currents could be generated and manipulated," explained Sánchez-Barriga. These are important steps on the way to spintronic devices which based on topological materials possess advanced functionalities for ultrafast information processing.

Spanish university develops a machine learning method for computational design of industrial apps without the high computational costs

The study has been selected as an outstanding publication by the academic journal Physics of Fluids Structure of the mix in the microdevice under different designs

In the field of industrial engineering, using simulations to model, predict, and even optimize the response of a system or device is widespread, as it is less expensive and less complex -and, sometimes, less dangerous- than fabricating and testing several prototypes.

This type of simulation study uses numerical methods that, depending on the problem to be addressed -for example, reducing the aerodynamic forces of an aircraft by changing its shape or using the minimum possible amount of material on elements under loading without breaking- require the simulation of a wide variety of possible combinational cases, which entails high computational costs.

The researchers from the School of Industrial Engineering of the University of Malaga in Spain Francisco Javier Granados Ortiz and Joaquín Ortega Casanova have taken a step further by developing a novel computational design optimization method that reduces these simulation costs by using artificial intelligence.

Faster and cost-efficient designs

They have developed a new methodology with Machine Learning algorithms to predict whether a combination of the design parameters of a problem will be useful or not, based on the objective pursued, and thus guide the design process.

"This method enables us to obtain faster-optimized designs by discarding simulations of little or no interest, thus saving not only physical prototype fabrication costs but also those related to simulation," explained the researchers of the Area of Fluid Mechanics. The researchers Francisco Javier Granados and Joaquin Ortega, authors of this study Particularly, this procedure has been applied to the design of a mechanical mixer that produces a significant increase in heat/mass transfer between two fluids thanks to vortex shedding, which results in an oscillating flow. "Based on the design parameters of the mixer, with our method we have verified that this flow can be controlled and achieve an efficient increase in mixing, but, at the same time, a decrease in pressure drop within it," said Ortega Casanova.