Accumulation Distribution of the Investigated Long-Term-Savings Product by Number of ClientsNotes. The number of clients in our sample declines with the increase in accumulated funds (over all the accounts). Amounts are in new Israeli shekels (NIS). The exchange rate at the time of the investigation was about NIS 3.5 = USD 1. Credit: Management Science (2024). DOI: 10.1287/mnsc.2022.02489
New study shows that retirees are more likely to cash out smaller retirement accounts instead of turning them into steady income streams, even though they might do the opposite with larger accounts. This choice can hurt their long-term financial security, leaving them with less stable income in retirement. For financial companies, this behavior has implications in their ability to manage assets liabilities risks (ALM).
A new study by Dr. Abigail Hurwitz and Prof. Orly Sade from Hebrew University, forthcoming in Management Science, sheds light on how retirees manage their savings across multiple accounts and its impact on their payout decisions at retirement. Titled Is One Plus One Always Two?
Insuring Longevity Risk While Having Multiple Savings Accounts, the research explores how individuals with more than one retirement savings account choose between annuitization—insuring themselves against longevity risk—and cashing out their savings in a lump sum.
Drawing on proprietary data from a leading Israeli insurance company, accompanied by a laboratory experiment and an online experimental survey, the study highlights a critical trend: smaller accounts are much more likely to be cashed out than larger ones.
The researchers use occupation as a proxy for wealth and find that individuals with higher expected wages are more likely to annuitize their savings but less likely to annuitize smaller accounts. This behavior, according to Hurwitz and Sade, is not merely about income but also the diversification of savings across multiple accounts.
“We discovered that the composition of multiple accounts influences annuitization decisions, especially for smaller versus larger accounts,” said Dr. Abigail Hurwitz. “This can have significant implications for retirees, particularly regarding their long-term financial security.”
The study uses both administrative data and a series of experiments to analyze this phenomenon. An online survey and a laboratory experiment revealed that retirees are less likely to annuitize small accounts due to mental accounting, a concept that leads individuals to treat money differently depending on how it is categorized or allocated.
A supplementary survey conducted with financial experts indicated that these professionals were less influenced by the distribution of funds across accounts and were more inclined to consider the entire portfolio.
The study’s findings are far-reaching, particularly for financial institutions managing pension funds. “Our results suggest that financial institutions should consider the size distribution of accounts when forecasting annuitization behavior and longevity risk,” said co-author Prof. Orly Sade. “It is vital for asset and liability management strategies, especially as these decisions directly impact the future reserves required for annuity providers.”
This research provides crucial insights into how retirees manage their savings and make annuitization decisions, highlighting significant implications for both financial institutions and policymakers.
More information:
Abigail Hurwitz et al, Is One Plus One Always Two? Insuring Longevity Risk While Having Multiple Savings Accounts, Management Science (2024). DOI: 10.1287/mnsc.2022.02489
Citation:
Small accounts, big decisions: How multiple savings impact retirement payout choices (2024, September 25)
retrieved 25 September 2024
from https://phys.org/news/2024-09-small-accounts-big-decisions-multiple.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.
The block diagram of the Floquet-engineered dual-signaling wireless communication framework. At the transmitter end, the system generates both a modulated THz-range signal and a reference THz signal with a frequency matching that of the carrier signal. Meanwhile, the receiver is equipped with two 2DSQWs to detect both the modulated signal and the reference signal. Credit: Kosala Herath, Ampalavanapillai Nirmalathas, Sarath D. Gunapala and Malin Premaratne
As computing technology advances, we have shifted from using large, single-chip processors to systems made up of smaller, specialized chips called “chiplets.” These chiplets work together to boost processing power and efficiency.
This transition is crucial because we’ve reached the physical limits of how many transistors can fit on a single chip. As transistors shrink, problems such as overheating and power inefficiency become more severe.[1] Using multiple chiplets in one system can increase computing power without facing these physical constraints.
The challenge of communication between chiplets
Traditionally, communication within a chip has been managed by a system called Network-on-Chip (NoC), which acts like a data highway. This method becomes inefficient as systems get more complex, especially with multiple chiplets. Data has to travel farther across more grid points, slowing communication and increasing energy consumption.
When we scale this approach to various chiplets, we create what’s known as Network-in-Package (NiP). However, the same issues—delays, energy inefficiency, and limited scalability—still exist as wired connections dominate data transfer.
To solve these problems, researchers are exploring wireless communication at the chip level. Instead of relying on wires, chiplets could communicate wirelessly using tiny antennas.
Terahertz (THz) frequencies, electromagnetic waves between infrared and microwave, offer high-speed data transfer, making them ideal for this application. However, THz signals are highly noise-sensitive, disrupting communication and making it harder to decode transmitted data.
Floquet engineering: Improving signal detection
Our research addresses this issue with Floquet engineering, a technique from quantum physics that helps control electron behavior in a material when exposed to high-frequency signals.[2,3,4] This technique makes the system more responsive to certain frequencies, improving the detection and decoding of THz wireless signals, even in noisy conditions.
We applied this method to a two-dimensional semiconductor quantum well (2DSQW)—a very thin layer of semiconductor material that restricts electron movement to two dimensions. This setup enhances the system’s ability to detect THz signals, even when noise interference is high. Our research is published in the IEEE Journal on Selected Areas in Communications.
Dual-signaling architecture for more accurate communication
To further improve noise handling, we developed a dual-signaling architecture, where two receivers work together to monitor signals. This setup allows the system to adjust a key parameter, called reference voltage, based on the noise levels detected. This real-time adjustment significantly improves signal decoding accuracy.
Our simulations showed that this dual-signaling system reduces error rates compared to traditional single-receiver systems, ensuring reliable communication in noisy environments—a critical requirement for chip-scale wireless communication.
By overcoming the challenges of noise and signal degradation, our dual-signaling technique marks a key advancement in developing high-speed, noise-resistant wireless communication for chiplets. This innovation brings us closer to creating more efficient, scalable, and adaptable computing systems for the technologies of tomorrow.
This story is part of Science X Dialog, where researchers can report findings from their published research articles. Visit this page for information about Science X Dialog and how to participate.
More information:
Kosala Herath et al, A Dual-Signaling Architecture for Enhancing Noise Resilience in Floquet Engineering-Based Chip-Scale Wireless Communication, IEEE Journal on Selected Areas in Communications (2024). DOI: 10.1109/JSAC.2024.3399206
1 Malin Premaratne and Govind P. Agrawal, Theoretical foundations of nanoscale quantum devices, Cambridge University Press (2021). DOI: 10.1017/9781108634472
2 Kosala Herath et al, Generalized model for the charge transport properties of dressed quantum Hall systems, Physical Review B (2022). DOI: 10.1103/PhysRevB.105.035430
3 Kosala Herath et al, Floquet engineering of dressed surface plasmon polariton modes in plasmonic waveguides, Physical Review B (2022). DOI: 10.1103/PhysRevB.106.235422
4 Kosala Herath et al, A Floquet engineering approach to optimize Schottky junction-based surface plasmonic waveguides, Scientific Reports (2023). DOI: 10.1038/s41598-023-37801-x
Bios:
Kosala Herath received the B.Sc. degree (Hons.) in electronic and telecommunication engineering from the University of Moratuwa, Sri Lanka, in 2018. He is currently pursuing the Ph.D. degree with the Department of Electrical and Computer System Engineering, Monash University, Australia. From 2018 to 2020, he was with WSO2 Inc. His research interests include nanoplasmonics, non-equilibrium many-body quantum systems, chip-scale wireless communication systems, and quantum computing.
Ampalavanapillai Nirmalathas received the Ph.D. degree in electrical and electronic engineering from The University of Melbourne. He is currently the Acting Dean with the Faculty of Engineering and Information Technology, the Lead of the Wireless Innovation Laboratory (WILAB), and a Professor of electrical and electronic engineering with The University of Melbourne. His current research interests include microwave photonics, optical-wireless network integration, broadband networks, photonic reservoir and edge computing, and scalability of telecom and internet services. Since 2021, he has been the Chair of the IEEE Photonics Society’s Future Technologies Task Force. From 2020 to 2021, he was the Co-Chair of the IEEE Future Networks Initiative’s Optics Working Group. He is also the Deputy Co-Chair of the National Committee on Information and Communication Sciences of the Australia Academy of Sciences.
Sarath D. Gunapala received the Ph.D. degree in physics from the University of Pittsburgh, Pittsburgh, PA, USA, in 1986. Since then, he has studied infrared properties of III–V compound semiconductor heterostructures and the development of quantum well infrared photodetectors for infrared imaging at AT&T Bell Laboratories. In 1992, he joined NASA’s Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA, where he is currently the Director of the Center for Infrared Photodetectors. He is also a Senior Research Scientist and a Principal Member of the Engineering Staff with the NASA Jet Propulsion Laboratory. He has authored more than 300 publications, including several book chapters on infrared imaging focal plane arrays, and holds 26 patents.
Malin Premaratne earned several degrees from the University of Melbourne, including a B.Sc. in mathematics, a B.E. in electrical and electronics engineering (with first-class honors), and a PhD in 1995, 1995, and 1998, respectively. He has been leading the research program in high-performance computing applications to complex systems simulations at the Advanced Computing and Simulation Laboratory, Monash University, Clayton, since 2004. Currently, he serves as the Vice President of the Academic Board of Monash University and is a Full Professor. In addition to his work at Monash University, Professor Premaratne is also a Visiting Researcher at several prestigious institutions, including the Jet-Propulsion Laboratory at Caltech, the University of Melbourne, the Australian National University, the University of California Los Angeles, the University of Rochester New York, and Oxford University. He has published more than 250 journal papers and two books and has served as an associate editor for several leading academic journals, including IEEE Photonics Technology Letters, IEEE Photonics Journal and Advances in Optics and Photonics. Professor Premaratne’s contributions to the field of optics and photonics have been recognized with numerous fellowships, including the Fellow of the Optical Society of America (FOSA), the Society of Photo-Optical Instrumentation Engineers USA (FSPIE), the Institute of Physics U.K. (FInstP), the Institution of Engineering and Technology U.K. (FIET) and The Institute of Engineers Australia (FIEAust).
Citation:
From quantum to wireless: Enhancing chip-scale communication with terahertz tech (2024, September 25)
retrieved 25 September 2024
from https://techxplore.com/news/2024-09-quantum-wireless-chip-scale-communication.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.
The Dartmouth-led study analyzed ice core data from Greenland and a 700-foot core members of the research team extracted from Denali National Park and Preserve in 2013. The Denali ice core contains a millennium of climate data in the form of gas bubbles, particulates, and compounds trapped in the ice. Credit: Mike Waszkiewicz
A Dartmouth-led study on ice cores from Alaska and Greenland found that air pollution from the burning of fossil fuels reaches the remote Arctic in amounts large enough to alter its fundamental atmospheric chemistry. The findings illustrate the long reach of fossil fuel emissions and provide support for the importance of clean-air rules, which the team found can reverse the effect.
The impact of pollution on the Arctic began as soon as widespread fossil fuel usage took hold during the industrial era, according to a report in Nature Geoscience. The researchers detected this footprint in an unexpected place—they measured declines in an airborne byproduct of marine phytoplankton activity known as methanesulfonic acid, or MSA, captured in the ice cores when air pollution began to rise.
Phytoplankton are key species in ocean food webs and carbon cycles are considered a bellwether of the ocean’s response to climate change. MSA has been used by scientists as an indicator of reduced phytoplankton productivity and, thus, of an ocean ecosystem in distress.
But the Dartmouth-led team reports that MSA also plummets in environments high in emissions generated by burning fossil fuels, even if phytoplankton numbers are stable. Their models showed that these emissions cause the initial molecule that phytoplankton produce—dimethyl sulfide—to turn into sulfate instead of MSA, leading to a deceptive drop in MSA levels.
The researchers found precipitous drops in MSA that coincided with the start of industrialization. When Europe and North America began burning large amounts of fossil fuels in the mid-1800s, MSA began to plummet in Greenland ice cores. Then, nearly a century later, the same biomarker plummeted in ice cores from Alaska around the time when East Asia underwent large-scale industrialization.
“Our study is a stark example of how air pollution can substantially alter atmospheric chemistry thousands of miles away. The pollution emitted in Asia or Europe was not contained there,” says Jacob Chalif, first author of the study and a graduate student in the lab of senior author Erich Osterberg, an associate professor of earth sciences at Dartmouth.
“By releasing all this pollution into the world, we’re fundamentally altering atmospheric processes,” Chalif says. “The fact that these remote areas of the Arctic see these undeniable human imprints shows that there’s literally no corner of this planet we haven’t touched.”
The new study solves a yearslong marine mystery surrounding the significance of MSA, says Osterberg, who led the extraction of a 700-foot ice core from Denali National Park and Preserve that the researchers used in their analysis. Osterberg collected the core in 2013 with study co-authors and professors Cameron Wake at the University of New England, and Karl Kreutz and Dartmouth alumnus Dominic Winski ’09—who also received his Ph.D. from Dartmouth in 2018—at the University of Maine.
The Denali core contains a millennium of climate data in the form of gas bubbles, particulates, and compounds trapped in the ice, including MSA, which is a common target in ice-core analysis. For centuries, MSA in the Denali core underwent minor fluctuations, “until the mid-20th century when it falls off a table,” Osterberg says.
Researchers in Osterberg’s ICE Lab, initially led by study co-author and Dartmouth alumnus David Polashenski ’17, started investigating what the precipitous drop in MSA levels indicated about the North Pacific. Osterberg and study co-author Bess Koffman, a professor at Colby College who was a postdoctoral fellow at Dartmouth, later tested numerous theories to explain why Denali MSA declined.
Like the Greenland study, they first considered whether the MSA drop was evidence for a crash in marine productivity, “but nothing added up,” Osterberg says. “It was a mystery.”
Chalif picked up the project around the time when study co-author and Dartmouth alumna Ursula Jongebloed ’18, now a graduate student at the University of Washington, was re-evaluating a 2019 study on ice cores in Greenland reporting that MSA there underwent a steady drop beginning in the 1800s. That study tied the decline to a crash in phytoplankton populations in the subarctic Atlantic due to a slowdown in ocean currents.
But Jongebloed’s work led to a study published last year reporting that declines in MSA found in the Greenland ice cores are not the result of the marine ecosystem crashing. Instead, they could be caused by pollution preventing the creation of MSA in the first place.
Chalif and Jongebloed connected at a conference in Switzerland in 2022 and discussed the Greenland and Denali MSA records.
“We rethought all of our prior assumptions,” Chalif says. “We knew that the declining MSA at Denali wasn’t due to marine productivity, so we knew some kind of change in atmospheric chemistry must be involved.”
They discussed the possible effect of nitrate pollution, which is commonly emitted through burning fossil fuels. Chalif started digging into the impact of nitrate on MSA that same evening.
“Pretty much to the year, when MSA declines at Denali, nitrate skyrockets. A very similar thing happened in Greenland,” Chalif says. “At Denali, MSA is relatively flat for 500 years, no notable trend. Then in 1962, it plummets. Nitrate was similar, but in the opposite direction—it’s basically flat for centuries then it spikes upward. When I saw that, I had a eureka moment.”
Their results showed that air pollution from the burning of fossil fuels disperses across the Atlantic and Pacific Oceans and inhibits the production of MSA in the Arctic. In addition to ruling out widespread marine ecosystem collapse, the findings open a new door to using MSA levels to measure pollution in the atmosphere, especially in regions with no obvious emissions sources, the researchers report.
“Marine ecosystem collapse just wasn’t working as an explanation for these MSA declines, and these young scientists figured out what was really going on,” Osterberg says.
“For me, it’s a new way of understanding how pollution affects our atmosphere,” he says. “The good news is that we are not seeing the collapse of marine ecosystems we thought we were. The bad news is that air pollution is causing this.”
But the data from the Greenland core shows that the local atmosphere began to stabilize when European and American air pollution became more regulated, Osterberg says. MSA rebounded in the 1990s as levels of nitrogen pollution dropped. That’s because nitrogen oxides, the type of pollution that affects MSA, dissipate within a few days, unlike carbon dioxide that lingers in the atmosphere for centuries.
“These data show the power of regulations to reduce air pollution, that they can have an immediate effect once you turn off the spigot,” Osterberg says. “I worry about younger people resigning to an environmental crisis because all we hear about is bad news. I think it’s important to acknowledge good news when we get it. Here, we see that regulations can work.”
More information:
Jacob I. Chalif et al, Pollution drives multidecadal decline in subarctic methanesulfonic acid, Nature Geoscience (2024). DOI: 10.1038/s41561-024-01543-w
Citation:
Ice cores show pollution’s impact on Arctic atmosphere (2024, September 25)
retrieved 25 September 2024
from https://phys.org/news/2024-09-ice-cores-pollution-impact-arctic.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.
Valery Levitas, right, and Sorb Yesudhas prepare a rotational diamond anvil cell for experiments at Argonne National Laboratory. Credit: Ryan Riley/College of Engineering
When Valery Levitas left Europe in 1999, he packed up a rotational diamond anvil cell and brought it to the United States. He and the researchers in his group are still using a much-advanced version of that pressing, twisting tool to squeeze and shear materials between two diamonds to see in situ, within the actual experiment, what happens and verify the researchers’ own theoretical predictions.
How, for example, do crystal structures change? Does that produce new, and potentially useful properties? Does the shearing change how high pressure needs to be applied to create new material phases?
It’s research “at the intersection of advanced mechanics, physics, material science, and applied mathematics,” wrote Levitas, an Iowa State University Anson Marston Distinguished Professor of Engineering and the Murray Harpole Chair in Engineering.
One of the latest findings from Levitas and his collaborators is that silicon, an important material for electronics, has unusual phase transformations when it is pressed and sheared with large and plastic, or permanent, deformations.
The journal Nature Communications recently published the findings. The corresponding authors are Levitas; and Sorb Yesudhas, an Iowa State postdoctoral research associate in aerospace engineering and the key experimentalist. Co-authors are Feng Lin, formerly of Iowa State; K.K. Pandey, formerly of Iowa State now at the Bhabha Atomic Research Centre in India; and Jesse Smith, of the High-Pressure Collaborative Access Team at Argonne National Laboratory in Illinois, where the group did in situ, X-ray diffraction experiments.
The researchers acknowledge there have been many studies of silicon’s changes under high pressure, but not of silicon under pressure and plastic shear deformation. In this case, they subjected three particle sizes of silicon—1 millionth of a meter, 30 billionths of a meter and 100 billionths of a meter—to the unique strains of the rotational diamond anvil cell.
Such “plastic strain-induced phase transformations are entirely different and promise numerous discoveries,” the researchers wrote.
One room-temperature experiment on silicon samples 100 billionths of a meter across found that pressures of 0.3 gigapascals, a common unit to measure pressure, and plastic deformations transformed silicon’s so-called “Si-I” crystal phase to “Si-II.” Under high pressure alone, that transformation starts at 16.2 gigapascals.
“Pressure is reduced by a factor of 54,” the authors wrote.
That’s a breakthrough experimental finding, Levitas said.
“One of our goals is to reduce transformation pressures,” he said. “So, we work in a region other researchers usually ignore—very low pressures.”
In addition, he said, the point of the researchers’ material deformations isn’t to change the shape or size of material samples.
“The key part is changing the microstructure,” Levitas said. “That makes the changes that produce phase transformations.”
And the different crystal lattice structures of the different phases—this paper considers seven phases of silicon—offers different properties that could be useful in real-world, industrial applications.
“Retrieving the desired nanostructured pure phases or mixture of phases (nanocomposites) with optimal electronic, optical and mechanical properties is possible with this technique,” the researchers wrote.
It’s a technique that industry could find interesting.
“Working with very high pressures for these phase transformations isn’t practical for industry,” Levitas said. “But with plastic deformations, we can get to these traditionally high-pressure phases, properties and applications at very modest pressures.”
After 20 years of thinking and theorizing about these material questions, Levitas said he expected silicon’s unusual response to the strains in the rotational diamond anvil cell.
“If I didn’t expect phase transformations at low pressures, we would have never checked,” he said. “These experiments confirm our several theoretical predictions and also open new challenges for the theory.”
More information:
Sorb Yesudhas et al, Unusual plastic strain-induced phase transformation phenomena in silicon, Nature Communications (2024). DOI: 10.1038/s41467-024-51469-5
Citation:
Unique straining affects phase transformations in silicon, a material vital for electronics (2024, September 25)
retrieved 25 September 2024
from https://techxplore.com/news/2024-09-unique-straining-affects-phase-silicon.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.
Computer monitors and a laptop display the X, formerly known as Twitter, sign-in page, July 24, 2023, in Belgrade, Serbia. Credit: AP Photo/Darko Vojinovic, File
Social media platform X on Wednesday published its first transparency report since the company was purchased by Elon Musk. The report, which details content moderation practices, shows the company has removed millions of posts and accounts from the site in the first half of the year.
X, formerly Twitter, suspended nearly 5.3 million accounts in that time, compared with the 1.6 million accounts the company reported suspending in the first half of 2022. The social media company also “removed or labeled” more than 10.6 million posts for violating platform rules—about 5 million of which it categorized as violating its “hateful conduct” policy.
Posts containing “violent content“—2.2 million—or “abuse and harassment”—2.6 million—also accounted for a large portion of content that was labeled or removed. The company does not distinguish between how many posts were removed and how many were labeled.
In an April 2023 blog post published in lieu of a transparency report, by contrast, the company said it required users to remove 6.5 million pieces of content that violated the company’s rules in the first six months of 2022, an increase of 29% from the second half of 2021.
Some have blamed Musk for turning a fun platform into one that’s chaotic and toxic. Musk has previously posted conspiracy theories and feuded with world leaders and politicians. X is currently banned in Brazil amid a dustup between Musk and a Brazilian Supreme Court judge over free speech, far-right accounts and misinformation.
To enforce their rules, X said, the company uses a combination of machine learning and human review. The automated systems either take action or surface the content to human moderators. Posts violating X’s policy accounted for less than 1% of all content on the site, the company said.
When Musk was trying to buy Twitter in 2022, he said he was doing so because it wasn’t living up to its potential as a “platform for free speech.” Since acquiring the company that October, Musk has fired much of its staff and made other changes, leading to a steady exodus of celebrities, public figures, organizations and ordinary people from the platform.
Citation:
X releases its first transparency report since Elon Musk’s takeover (2024, September 25)
retrieved 25 September 2024
from https://techxplore.com/news/2024-09-transparency-elon-musk-takeover.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.
