Aurelia Butler

A new theory of economic decision-making from Mina Mahmoudi, a lecturer in the Department of Economics at Rensselaer Polytechnic Institute, offers an explanation as to why humans, in general, make decisions that are simply adequate, not optimal.
In research published today in the Review of Behavioral Economics, Dr. Mahmoudi theorizes an aspect of relative thinking explaining people may use ratios in their decision-making when they should only use absolute differences. The inverse is also possible.
To explain this behavioral anomaly, Dr. Mahmoudi has developed a ratio-difference theory that gives weight to both ratio and difference comparisons. This theory seeks to more accurately capture the manner by which a boundedly rational decision-maker might operationally distinguish whether one alternative is better than another.
“Effectively solving some economic problems requires one to think in terms of differences while others require one to think in terms of ratios,” Dr. Mahmoudi said. “Because both types of thinking are necessary, it is reasonable to think people develop and apply both types. However, it is also reasonable to expect that people misapply the two types of thinking, especially when less experienced with the context.”
Past studies have shown that when given the opportunity to save, for example, $5 on a $25 item or a $500 item, people in general would put in more effort to save the money on the lower-cost product than the more expensive item. They believe they are getting a better deal because the ratio of cost to savings is higher. In fact, the $5 saved is the same for both items and the perfect, or optimal choice, would be to look at the absolute savings and work equally hard to save each $5. People should use differences to solve this problem, but many seem to make unreasonable decisions because they apply ratio thinking.
“Understanding how the cognitive and motivational characteristics of human beings and the operating procedures of organizations influence the working of economic systems is of critical importance,” Dr. Mahmoudi said. “Many economic behaviors such as imitation occur and many economic institutions like inventories exist because people cannot maximize or because markets are not in equilibrium. Our model provides an example of a behavior that occurs because people cannot maximize.”
This model can be applied to a variety of behavioral economic experiments in the gambling industry and financial markets among others.
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Materials provided by Rensselaer Polytechnic Institute. Original written by Jeanne Hedden Gallagher. Note: Content may be edited for style and length. More

Recently, electric vehicles (EVs) are seen everywhere, from passenger cars, buses, to taxis. EVs have the advantage of being eco-friendly and having low maintenance costs; but their owners must remain wary of fatal accidents in case the battery runs out or reaches the end of its life. Therefore, precise capacity and lifespan predictions for the lithium-ion batteries — commonly used in EVs — are vital.
A POSTECH research team led by Professor Seungchul Lee, and Ph.D. candidate Sung Wook Kim (Department of Mechanical Engineering) collaborated with Professor Ki-Yong Oh of Hanyang University to develop a novel artificial intelligence (AI) technology that can accurately predict the capacity and lifespan of lithium-ion batteries. This research breakthrough, which considerably improved the prediction accuracy by merging physical domain knowledge with AI, has recently been published in Applied Energy, an international academic journal in the energy field.
There are two methods of predicting the battery capacity: a physics-based model, which simplifies the intricate internal structure of batteries, and an AI model, which uses the electrical and mechanical responses of batteries. However, the conventional AI model required large amounts of data for training. In addition, when applied to untrained data, its prediction accuracy was very low, which desperately called for the emergence of a next-generation AI technology.
To effectively predict battery capacity with less training data, the research team combined a feature extraction strategy that differs from conventional methods with physical domain knowledge-based neural networks. As a result, the battery prediction accuracy for testing batteries with various capacities and lifespan distributions improved by up to 20%. Its reliability was ensured by confirming the consistency of the results. These outcomes are anticipated to lay the foundation for applying highly dependable physical domain knowledge-based AI to various industries.
Professor Lee of POSTECH remarked, “The limitations of data-based AI have been overcome using physics knowledge. The difficulty of building big data has also been alleviated thanks to the development of the differentiated feature extraction technique.”
Professor Oh of Hanyang University added, “Our research is significant in that it will contribute in propagating EVs to the public by enabling accurate predictions of remaining lifespan of batteries in next-generational EVs.”
This study was supported by the Institute of Civil Military Technology Cooperation and the National Research Foundation of Korea.
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Materials provided by Pohang University of Science & Technology (POSTECH). Note: Content may be edited for style and length. More

Sensors are a constant feature of our everyday lives. Although they often go unperceived, sensors provide critical information essential to modern healthcare, security, and environmental monitoring. Modern cars alone contain over 100 sensors and this number will only increase.
Quantum sensing is poised to revolutionise today’s sensors, significantly boosting the performance they can achieve. More precise, faster, and reliable measurements of physical quantities can have a transformative effect on every area of science and technology, including our daily lives.
However, the majority of quantum sensing schemes rely on special entangled or squeezed states of light or matter that are hard to generate and detect. This is a major obstacle to harnessing the full power of quantum-limited sensors and deploying them in real-world scenarios.
In a paper published today, a team of physicists at the Universities of Bristol, Bath and Warwick have shown it is possible to perform high precision measurements of important physical properties without the need for sophisticated quantum states of light and detection schemes.
The key to this breakthrough is the use of ring resonators — tiny racetrack structures that guide light in a loop and maximize its interaction with the sample under study. Importantly, ring resonators can be mass manufactured using the same processes as the chips in our computers and smartphones.
Alex Belsley, Quantum Engineering Technology Labs (QET Labs) PhD student and lead author of the work, said: “We are one step closer to all integrated photonic sensors operating at the limits of detection imposed by quantum mechanics.”
Employing this technology to sense absorption or refractive index changes can be used to identify and characterise a wide range of materials and biochemical samples, with topical applications from monitoring greenhouse gases to cancer detection.
Associate Professor Jonathan Matthews, co-Director of QET Labs and co-author of the work, stated: “We are really excited by the opportunities this result enables: we now know how to use mass manufacturable processes to engineer chip scale photonic sensors that operate at the quantum limit.”
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Materials provided by University of Bristol. Note: Content may be edited for style and length. More

Researchers at the Niels Bohr Institute, University of Copenhagen, have improved the coherence time of a previously developed quantum membrane dramatically. The improvement will expand the usability of the membrane for a variety of different purposes. With a coherence time of one hundred milliseconds, the membrane can for example store sensitive quantum information for further processing in a quantum computer or network. The result has now been published in Nature Communications.
The quantum drum is now connected to a read-out unit
As a first step, the team of researchers has combined the membrane with a superconducting microwave circuit, which enables precise readouts from the membrane. That is, it has become “plugged in,” as required for virtually any application. With this development, the membrane can be connected to various other devices that process or transmit quantum information.
Cooling the quantum drum system to reach quantum ground state
Since the temperature of the environment determines the level of random forces disturbing the membrane, it is imperative to reach a sufficiently low temperature to prevent the quantum state of motion from being washed out. The researchers achieve this by means of a helium-based refrigerator. With the help of the microwave circuit, they can then control the quantum state of the membrane motion. In their recent work, the researchers could prepare the membrane in the quantum ground state, meaning that its motion is dominated by quantum fluctuations. The quantum ground state corresponds to an effective temperature of 0,00005 degrees above the absolute zero, which is −273.15 °C.
Applications for the plugged in quantum membrane are many
One could use a slightly modified version of this system that can feel forces from both microwave and optical signals to build a quantum transducer from microwave to optics. Quantum information can be transported at room temperature in optical fibers on kilometers without perturbations. On the other hand, the information is typically processed inside a cooling unit, capable of reaching sufficiently low temperatures for superconducting circuits like the membrane to operate. Connecting these two systems — superconducting circuits to optical fibers — could therefore enable the construction of a quantum internet: several quantum computers linked together with optical fibers. No computers have infinite space, so the possibility of distributing computational capabilities to connected quantum computers, would greatly enhance the capacity to solve complicated problems.
Gravity — not well understood in quantum mechanics, but crucial — can now be explored
The role of gravity in the quantum regime is a yet unanswered, fundamental question in physics. This is yet another place where the high coherence time of the membranes demonstrated here may be applied for study. One hypothesis in this area is that gravity has the potential to destroy some quantum states with time. With a device as big as the membrane, such hypotheses may be tested in the future.
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Materials provided by University of Copenhagen – Faculty of Science. Note: Content may be edited for style and length. More

Photonics researchers have introduced a novel method to control a light beam with another beam through a unique plasmonic metasurface in a linear medium at ultra-low power. This simple linear switching method makes nanophotonic devices such as optical computing and communication systems more sustainable requiring low intensity of light.
All-optical switching is the modulation of signal light due to control light in such a way that it possesses the ON/OFF conversion function. In general, a light beam can be modulated with another intense laser beam in the presence of a nonlinear medium.
The switching method developed by the researchers is fundamentally based on the quantum optical phenomenon known as Enhancementof Index of Refraction (EIR).
“Our work is the first experimental demonstration of this effect on the optical system and its utilization for linear all-optical switching. The research also enlightens the scientific community to achieve loss-compensated plasmonic devices operating at resonance frequencies through extraordinary enhancement of refractive index without using any gain media or nonlinear processes,” says Humeyra Caglayan, Associate Professor (tenure track) in Photonics at Tampere University.
Optical switching enabled with ultrafast speed
High-speed switching and low-loss medium to avoid the strong dissipation of signal during propagation are the basis to develop integrated photonic technology where photons are utilized as information carriers instead of electrons. To realize on-chip ultrafast all-optical switch networks and photonic central processing units, all-optical switching must have ultrafast switching time, ultralow threshold control power, ultrahigh switching efficiency, and nanoscale feature size. More

The second century Alexandrian astronomer and mathematician Claudius Ptolemy had a grand ambition. Hoping to make sense of the motion of stars and the paths of planets, he published a magisterial treatise on the subject, known as the Almagest. Ptolemy created a complex mathematical model of the universe that seemed to recapitulate the movements of the celestial objects he observed.
Unfortunately, a fatal flaw lay at the heart of his cosmic scheme. Following the prejudices of his day, Ptolemy worked from the premise that the Earth was the center of the universe. The Ptolemaic universe, composed of complex “epicycles” to account for planet and star movements, has long since been consigned to the history books, though its conclusions remained the scientific dogma for over 1200 years.
The field of evolutionary biology is no less subject to misguided theoretical approaches, sometimes producing impressive models that nevertheless fail to convey the true workings of nature as it shapes the dizzying assortment of living forms on Earth.
A new study examines mathematical models designed to draw inferences about how evolution operates at the level of populations of organisms. The study concludes that such models must be constructed with the greatest care, avoiding unwarranted initial assumptions, weighing the quality of existing knowledge and remaining open to alternate explanations.
Failure to apply strict procedures in null model construction can lead to theories that seem to square with certain aspects of available data derived from DNA sequencing, yet fail to correctly elucidate underlying evolutionary processes, which are often highly complex and multifaceted.
Such theoretical frameworks may offer compelling but ultimately flawed pictures of how evolution actually acts on populations over time, be these populations of bacteria, shoals of fish, or human societies and their various migrations during prehistory. More

Atoms do weird things when forced out of their comfort zones. Rice University engineers have thought up a new way to give them a nudge.
Materials theorist Boris Yakobson and his team at Rice’s George R. Brown School of Engineering have a theory that changing the contour of a layer of 2D material, thus changing the relationships between its atoms, might be simpler to do than previously thought.
While others twist 2D bilayers — two layers stacked together — of graphene and the like to change their topology, the Rice researchers suggest through computational models that growing or stamping single-layer 2D materials on a carefully designed undulating surface would achieve “an unprecedented level of control” over their magnetic and electronic properties.
They say the discovery opens a path to explore many-body effects, the interactions between multiple microscopic particles, including quantum systems.
The paper by Yakobson and two alumni, co-lead author Sunny Gupta and Henry Yu, of his lab appears in Nature Communications.
The researchers were inspired by recent discoveries that twisting or otherwise deforming 2D materials bilayers like bilayer graphene into “magic angles” induced interesting electronic and magnetic phenomena, including superconductivity. More