Sunday, July 26, 2026

Smarter railways: New ultrasonic denoising method improves defect detection in heavy-haul lines

Tsinghua University Press

Multi-Feature Fusion Framework for Ultrasonic A-Scan Denoising in Heavy-Haul Railways — image:
Schematic illustration of a physics-guided multi-feature fusion framework for ultrasonic A-scan signals in heavy-haul railway inspection. The method integrates Variational Mode Decomposition (VMD), Continuous Wavelet Transform (CWT), and time-domain statistical analysis to extract features from modal, time–frequency, and waveform domains. These features are combined within an ideal binary mask (IBM) paradigm to mitigate coupled non-Gaussian noise and improve defect echo identification.
view more
Credit: Communications in Transportation Research

Heavy-haul railways play a crucial role in bulk freight transportation, particularly for coal and mineral resources. However, under long-term high-axle-load operation, rails in small-radius curve sections are subjected to intense wheel–rail interaction forces. These conditions accelerate defect formation such as head checks and bolt-hole cracks, which can ultimately lead to rail fracture if not detected in time.

Ultrasonic inspection is the primary non-destructive testing method used in heavy-haul railway maintenance. In practice, inspection vehicles collect ultrasonic A-scan signals to identify internal rail defects. However, in small-radius curves, strong flange-related structural vibrations, low-frequency disturbances, and high-frequency electrical noise are coupled together. These non-Gaussian noise components overlap spectrally and temporally with defect echoes, severely masking critical defect information.

The team published their study in Communications in Transportation Research (https://doi.org/10.26599/COMMTR.2026.9640021).

“Traditional denoising methods assume relatively simple noise characteristics,” the researchers explain. “But in real heavy-haul environments, noise is strongly coupled and non-Gaussian. Simply applying low-pass filtering or single-domain feature extraction is often insufficient.”

To address this challenge, the research team first constructed a physics-based ultrasonic A-scan signal model under noise-coupled conditions. The model explicitly characterizes defect echoes together with structural vibration noise, low-frequency irrelevant components, and high-frequency electrical noise. This modeling step provides a theoretical foundation for understanding why conventional signal processing methods fail under complex field conditions.

Based on this signal model, the team developed a multi-feature fusion filtering framework within an ideal binary mask (IBM) paradigm. The framework integrates three complementary feature extraction mechanisms: Variational Mode Decomposition (VMD)–based inter-layer correlation analysis to capture synchronized multi-mode defect responses; Continuous Wavelet Transform (CWT) time–frequency clustering to identify triangular energy ridges associated with defect echoes; Sliding-window waveform morphology analysis using kurtosis and peak-width features to discriminate impulsive defect pulses from background noise.

Rather than treating feature fusion as simple vector concatenation, the proposed method performs decision-level fusion based on physically interpretable indicators from time, frequency, and modal domains. The fused features are used to construct an indexed binary mask, which selectively preserves defect-related samples while suppressing unsupported noise components.

Field-based experiments were conducted using 285 simulated noise-contaminated defect signals derived from real inspection data. Results show that the proposed method achieves accurate defect localization in more than 90% of test cases. Compared with single-feature methods, the multi-feature fusion framework significantly reduces missed detections and large localization deviations.

From an engineering perspective, this improvement directly enhances the accuracy of B-scan image reconstruction and defect positioning. By operating at the A-scan level and preserving peak amplitude integrity, the method provides practical support for intelligent condition-based maintenance of heavy-haul railways.

The researchers note that future work will extend the framework to multi-channel ultrasonic inspection systems, where inter-channel coupled noise presents additional challenges.

DOI Link:

https://doi.org/10.26599/COMMTR.2026.9640021

About Communications in Transportation Research

Communications in Transportation Research was launched in 2021, with academic support provided by Tsinghua University and China Intelligent Transportation Systems Association. The Editors-in-Chief are Professor Xiaobo Qu, a member of the Academia Europaea from Tsinghua University, and Professor Xiaopeng (Shaw) Li from University of Wisconsin–Madison. The journal mainly publishes high-quality, original research and review articles that are of significant importance to emerging transportation systems, aiming to serve as an international platform for showcasing and exchanging innovative achievements in transportation and related fields, fostering academic exchange and development between China and the global community.

It has been indexed in SCIE, SSCI, Ei Compendex, Scopus, CSTPCD, CSCD, OAJ, DOAJ, TRID and other databases. It was selected as Q1 Top Journal in the Engineering and Technology category of the Chinese Academy of Sciences (CAS) Journal Ranking List. In 2022, it was selected as a High-Starting-Point new journal project of the “China Science and Technology Journal Excellence Action Plan”. In 2024, it was selected as the Support the Development Project of “High-Level International Scientific and Technological Journals”. The same year, it was also chosen as an English Journal Tier Project of the “China Science and Technology Journal Excellence Action Plan Phase Ⅱ”. In 2024, it received the first impact factor (2023 IF) of 12.5, ranking Top1 (1/58, Q1) among all journals in "TRANSPORTATION" category. In 2026, its 2025 IF was announced as 12.7, maintaining the Top1 position (1/66, Q1) in the same category.

From Volume 6 (2026), Communications in Transportation Research will be published by Tsinghua University Press on the SciOpen platform with the official journal website at https://www.sciopen.com/journal/2097-5023. We kindly request that all new manuscript submissions be made through the journal’s submission system at https://mc03.manuscriptcentral.com/commtr. For any submission-related inquiries, please contact the Editorial Office at commtr_e@mail.tsinghua.edu.cn.

Journal

Communications in Transportation Research

DOI

10.26599/COMMTR.2026.9640021

Article Title

Ultrasonic denoising for intelligent operation and maintenance of heavy-haul railways: Noise mechanisms and suppression methods

NRL demonstrates dual-use laser system for power beaming and counter-UAS operations

Naval Research Laboratory

WASHINGTON, D.C. – U.S. Naval Research Laboratory (NRL) scientists successfully demonstrated a dual-use laser system capable of wirelessly transmitting power over long distances and rapidly transitioning to perform defensive missions, advancing expeditionary energy and defense capabilities for future warfighters.

Sponsored by the Office of the Under Secretary of War for Acquisition & Sustainment (OUSW (A&S)) and supported by the Operational Energy Capability Improvement Fund (OECIF), the demonstration showed how a fielded laser system could provide remote power delivery while maintaining its original mission as a directed-energy defense capability. The demonstration was conducted in partnership with Boeing and the DEVCOM Ground Vehicle Systems Center (GVSC) and with collaboration across Navy, Marine Corps and Army stakeholders.

Using a trailer-mounted laser positioned across an airfield, researchers transmitted power from a standard military vehicle to specialized receivers at a remote location. The same laser system then transitioned without delay to address a simulated aerial threat, proving its ability to perform both missions without interrupting operations.

“This was not just a laboratory exercise we were building the pieces for what this capability could actually look like on the battlefield,” said NRL Electrical Engineer Alex Grede, Ph.D. “We demonstrated that the same laser used to beam power remotely can immediately transition to counter a drone threat, giving Marines and soldiers greater flexibility without changing their operational footprint.”

Unlike previous record-setting power beaming demonstrations conducted in highly controlled desert conditions, this test focused on realistic field environments and adverse atmospheric conditions, helping identify technical improvements required for operational use.

The team continued testing through severe weather, including snowfall approaching whiteout conditions, until visibility nearly disappeared, all while collecting critical data for future system refinement.

“We wanted to prove this could work where warfighters actually operate, not just in ideal conditions,” said NRL Research Physicist Justin Lorentzen. “Testing in wind, snow and real atmospheric interference gives us the data we need to improve the system and move it toward a true operational capability.”

The demonstration also highlighted the importance of joint-service collaboration. While NRL continues developing the technology for naval applications, U.S. Army operational requirements helped shape the field test, particularly for expeditionary power scenarios where replacing fuel-dependent generators could improve logistics and survivability.

“The service most likely to field this kind of capability first may be the Army, and that’s exactly why this collaboration matters,” Grede said. “We can take the expertise we’ve built at NRL and help accelerate capability development across the joint force. That’s good for the services and good for the country.”

The laser system used in the demonstration was already fielded by the U.S. Marine Corps for directed-energy applications. By pairing that proven capability with high-efficiency solar receivers and mobile vehicle power generation, the team demonstrated a practical pathway toward distributed, resilient energy delivery for forward operations.

The test also validated rapid field maintenance and ease of operation. During the event, researchers quickly repaired a key system component in the field, demonstrating system resilience and maintainability in operational conditions.

“You can’t have a system that takes months to repair or months to train someone to use,” said NRL Radar Division Military Deputy Lt. Cmdr. Brian Di Salvo. “This system showed both repairability and simplicity of operation, qualities that matter when you’re talking about real deployment with young operators in the field.”

Researchers say the next phase includes additional demonstrations with Marines, Soldiers and Sailors gathering direct user feedback and tailoring the system for operational needs.

“Our next goal is putting this capability in front of warfighters and letting them tell us how they would use it,” Grede said. “That feedback is what will help shape the next generation of power beaming systems.”

The work supports NRL’s ongoing efforts to develop scalable directed-energy technologies that improve expeditionary logistics, strengthen battlefield resilience and expand the operational reach of U.S. forces.

About the Operational Energy Capability Improvement Fund (OECIF)

The Operational Energy Capability Improvement Fund (OECIF) is DoW’s premier, joint operational energy investment program. OECIF is pre-commercialization. Through highly targeted science and technology investments, it guides and matures advanced, first-of-a-kind operational energy technologies across warfighting platforms and domains.

More information can be found at https://www.acq.osd.mil/eie/ero/inn/oecif-oepf.html

About the U.S. Naval Research Laboratory

NRL is a scientific and engineering command dedicated to research that drives innovative advances for the U.S. Navy and Marine Corps from the seafloor to space and in the information domain. NRL is located in Washington, D.C. with major field sites in Stennis Space Center, Mississippi; Key West, Florida; Monterey, California.

NRL offers several mechanisms for collaborating with the broader scientific community, within and outside of the Federal government. These include Cooperative Research and Development Agreements (CRADAs), LP-CRADAs, Educational Partnership Agreements, agreements under the authority of 10 USC 4892, licensing agreements, FAR contracts, and other applicable agreements.

For more information, contact NRL Corporate Communications at NRLPAO@us.navy.mil.

Method of Research

Experimental study

U.S. Naval Research Lab advances continuous biomanufacturing for on-demand production of critical materials

Naval Research Laboratory

WASHINGTON, D.C. – U.S. Naval Research Laboratory (NRL) scientists are developing continuous biomanufacturing technologies designed to produce critical materials more efficiently, sustainably, and closer to where they are needed, strengthening supply chain resilience and expanding future operational capabilities.

The research focuses on replacing traditional batch-based biomanufacturing methods with continuous production systems that use surface-bound microbial cells to generate valuable compounds over extended periods. The effort supports Department of War priorities in biotechnology and biomanufacturing while exploring new ways to manufacture essential materials with smaller, more adaptable systems.

“Traditional biomanufacturing often relies on large fermentation tanks that operate in batches,” said Matthew Yates, Ph.D. a research scientist in NRL’s Center for Biomolecular Science and Engineering. “Our goal is to develop systems that continuously produce molecules for weeks or months at a time while reducing energy requirements, equipment size, and operational complexity.”

Conventional biomanufacturing frequently depends on large-scale reactors that require substantial infrastructure, energy, and downtime between production runs. NRL researchers are pursuing an alternative approach that uses biofilm-based reactors, where microorganisms attach to specially designed surfaces and continuously produce target compounds as nutrients flow through the system. This design increases cell density while reducing reactor volume and energy consumption.

Technology is being developed to produce a range of materials important to both military and commercial applications. Researchers have demonstrated production pathways for lubricant precursors, munition components, active pharmaceutical ingredients, bioplastics, and single-cell proteins, all products that will support future needs of the warfighter.

“A key feature of these programs is the use of additive manufacturing to rapidly design and fabricate bioreactors. By leveraging 3D printing, we can quickly prototype, test, and modify reactor designs to optimize performance for different microorganisms and products.” Yates said.

The approach also enables future field deployment scenarios where replacement reactor components could be manufactured on-site rather than shipped from centralized facilities.

“Additive manufacturing gives us tremendous flexibility,” Yates said. “If mission requirements change, we can rapidly reconfigure reactor designs and produce new components when and where they’re needed.”

Researchers have also observed promising secondary benefits from the 3D-printed reactor systems. Early testing suggests some target molecules naturally accumulate within the reactor matrix, potentially simplifying downstream processing by combining production, separation, and concentration into a single step. If validated, this capability could further reduce manufacturing costs and improve system efficiency.

In parallel, NRL scientists are investigating marine microorganisms capable of operating in seawater and utilizing alternative feedstocks. The ability to grow production organisms without relying on freshwater resources could expand operational flexibility while reducing logistical burdens associated with traditional manufacturing processes.

The laboratory has already demonstrated a mobile, containerized biomanufacturing system that fits within a standard shipping container. Researchers envision integrating continuous production technologies into future versions of these deployable systems, enabling the manufacture of critical materials at the point of need.

“Ultimately, we want to create a platform that can produce a variety of products wherever they’re needed,” Yates said. “Whether supporting domestic manufacturing or future expeditionary operations, continuous biomanufacturing offers a pathway toward more resilient and adaptable production capabilities.”

These efforts are collaborative research initiatives involving NRL, the Air Force Research Laboratory, and the U.S. Army Combat Capabilities Development Command Chemical Biological Center. Together, the organizations are evaluating multiple production strains and products to determine how continuous biomanufacturing platforms can be optimized across a broad range of applications.

As the research progresses, NRL scientists intend to further demonstrate the scalability, versatility, and operational value of continuous biomanufacturing systems, helping lay the foundation for future domestic and point-of-need manufacturing capabilities.

About the U.S. Naval Research Laboratory
NRL is a scientific and engineering command dedicated to research that drives innovative advances for the U.S. Navy and Marine Corps from the seafloor to space and in the information domain. NRL is located in Washington, D.C. with major field sites in Stennis Space Center, Mississippi; Key West, Florida; Monterey, California.

NRL offers several mechanisms for collaborating with the broader scientific community, within and outside of the Federal government. These include Cooperative Research and Development Agreements (CRADAs), LP-CRADAs, Educational Partnership Agreements, agreements under the authority of 10 USC 4892, licensing agreements, FAR contracts, and other applicable agreements.

For more information, contact NRL Corporate Communications at NRLPAO@us.navy.mil.

MSU researchers create new tool to investigate one of regenerative biology’s biggest mysteries

Michigan State University

EAST LANSING, Mich. — Why can zebrafish regenerate damaged gut nerves while humans largely cannot?

Michigan State University researchers have developed a powerful new research tool that allows them to remove gut neurons in zebrafish and watch them regenerate in real time, helping scientists investigate one of regenerative biology’s biggest questions.

The research focuses on the enteric nervous system, often called the body‘s “second brain.“ This vast network of neurons is embedded throughout the digestive tract and contains roughly as many neurons as the spinal cord. It controls digestion, nutrient absorption and the movement of food through the gut while remaining in constant communication with the brain.

Although humans and other mammals have only a limited ability to replace damaged gut neurons, zebrafish can rebuild those neural networks within days.

“We knew zebrafish could regenerate nervous system tissue,” said Julia Ganz, associate professor in MSU’s College of Natural Science. “But we didn’t know exactly how regeneration happens in the gut nervous system.”

Using the new system, Ganz and her team selectively removed gut neurons in larval zebrafish and watched new neurons regenerate and reconnect with existing neural networks in about nine days.

“The neurons don’t just come back,” Ganz said. “They integrate into the existing nervous system and appear to resume the jobs they were performing before.”

The findings showed that the regenerated neurons not only replaced lost cells but also restored the neural connections needed for normal gut function.

More importantly, the new system gives researchers a controlled way to trigger gut nerve regeneration and investigate the cells, genes and molecular signals that make regeneration possible.

“We’re already looking at what signals play a role in this regenerative response and what cell populations are needed,” Ganz said during an interview. “Once we have a better understanding of how zebrafish accomplish this, the next step is to compare that process with mammals and figure out what’s different.”

The long-term goal is to understand why regeneration occurs so readily in zebrafish but is far more limited in mammals — knowledge that could eventually help researchers develop ways to repair damaged nerves instead of simply treating the symptoms caused by nerve loss.

“Right now, many treatments focus on managing symptoms or surgically removing damaged portions of the digestive tract,” Ganz said. “If we can understand how regeneration works in zebrafish, it may eventually help us develop ways to repair the nervous system itself.”

The findings could eventually have implications for digestive disorders, inflammatory diseases, congenital conditions involving the loss of gut nerves and other diseases that affect the enteric nervous system.

The research was published in Stem Cell Reports.

MSU has a satellite uplink/LTN TV studio and Comrex line for radio interviews upon request.

Contact: Emilie Lorditch: 810-844-1460, lorditch@msu.edu; Kim Ward: 734-224-8377, kward@msu.edu

Images

###

Michigan State University has been advancing the common good with uncommon will for more than 170 years. Among the world’s top 100 universities and a leading U.S. public research institution, MSU pushes the limits of discovery and innovation to advance the state of Michigan and the nation, and make a better, safer, healthier world for all. The university provides life-changing educational opportunities through an inclusive academic community with more than 400 programs of study and is the largest producer of talent for Michigan, educating more undergraduates than any other university in the state.

For generations, Spartans have changed lives through research and innovation. Support from federal, state and local funding helps power discoveries that improve health, strengthen communities and keep America at the forefront of innovation and competitiveness. From lifesaving cancer treatments to advances in agriculture, energy and technology, see how Michigan State University researchers are shaping a better future for Michigan and the world.

For MSU news on the web, go to MSUToday or x.com/MSUnews.