Flexible Solution Research Articles

A Versatile Board for Event-Driven Data Acquisition.

Event-driven data acquisition is used to capture information from fast transient phenomena typically requiring a high sampling speed. This is an important requirement in the ITER Neutral Beam Test Facility for the development of one of the heating systems of the ITER nuclear fusion experiment. The Red Pitaya board has been chosen for this project because of its versatility and low cost. Versatility is provided by the hosted Zynq System on Chip (SoC), which allows full configuration of the module architecture and the OpenSource architecture of Red Pitaya. Price is an important factor, because the boards are installed in a hostile environment where devices can be damaged by EMI and radiation. A flexible solution for event-driven data acquisition has been developed in the Zynq SoC and interfaced to the Linux-based embedded ARM processor. It has been successfully adopted in a variety of data acquisition applications in the test facility.

“The Greatest Benefit Is to Think Differently”: Experiences of Developing and Using a Web-Based Tool for Decision-Making under Deep Uncertainty for Adaptation to Sea Level Rise in Municipalities

The need for handling the deep uncertainty surrounding the future climate has led to various novel and robust approaches for decision-making under deep uncertainty (DMDU) when adapting to climate change. Here, an online and self-explanatory web-based tool was developed and tested with civil servants from five municipalities in Sweden challenged by rising sea levels. The municipalities used the tool by themselves and were then interviewed about the usability of the tool, the perceived urgency of climate change adaptation, and the possibilities for municipalities for handling the flexible solutions that are at the core of DMDU. Results were that the civil servants reported that the urgency of climate change adaptation has increased, that the tool changed their perspectives compared to traditional planning methods, and that changes in laws and regulations to accommodate decisions about flexible solutions were recommended.

Self-supervised few-shot learning for real-time traffic sign classification

Although supervised approaches for traffic sign classification have demonstrated excellent performance, they are limited to classifying several traffic signs defined in the training dataset. This prevents them from being applied to different domains, i.e., different countries. Herein, we propose a self-supervised approach for few-shot learning-based traffic sign classification. A center-awareness similarity network is designed for the traffic sign problem and trained using an optical flow dataset. Unlike existing supervised traffic sign classification methods, the proposed method does not depend on traffic sign categories defined by the training dataset. It applies to any traffic signs from different countries. We construct a Korean traffic sign classification (KTSC) dataset, including 6000 traffic sign samples and 59 categories. We evaluate the proposed method with baseline methods using the KTSC, German traffic sign, and Belgian traffic sign classification datasets. Experimental results show that the proposed method extends the ability of existing supervised methods and can classify any traffic sign, regardless of region/country dependence. Furthermore, the proposed approach significantly outperforms baseline methods for patch similarity. This approach provides a flexible and robust solution for classifying traffic signs, allowing for accurate categorization of every traffic sign, regardless of regional or national differences.

A Novel Approach to Dynamic Line Rating Calculation

In order to adjust the electric power network to today’s trends—such as the charging of electric vehicles, design of the Internal Electricity Market (IEM), headway of renewable energy sources, etc.—the demand for flexible network solutions is increasingly significant. Dynamic line rating (DLR) technology offers a flexible solution for the uprating of overhead lines. Moreover, the DLR methodology can be used in a wider system approach in order to establish a line management system, including functions such as ice prevention subsystems or the real-time tracking of clearances. Therefore, the extension possibilities and operational features of DLR-based systems have been extensively researched in the last few years, which is also confirmed by the high number of pilot projects funded for research and development on the topic of DLR. The key question during the implementation of a DLR system is the obtainable operational safety of such a system. This mainly depends on the installation places of the field equipment and the accuracy of the line rating calculation models. The aim of this article is the comparison of the so far available international line rating calculation models and also to propose another way for the determination of the real-time line rating. Moreover, laboratory measurements and case studies are presented for the confirmation of the proposed model’s reliability.

Development of a multilayer film for the first US Food and Drug Administration cleared aseptically-produced intravenous solution bags with a short history of key medical device milestones

Flexible intravenous solution containers (IV bags) were introduced to the marketplace in the early 1970s. These new containers were designed to replace glass IV bottles and were quickly adopted widely for delivering medical solutions to patients throughout the world. The 40 years during which commercially available IV solutions in glass bottles were used, the healthcare industry grew dramatically with better patient outcomes while also reducing operational costs. These early developments then led to the rapid expansion of new medical devices that have been further developed to improve healthcare and reduce overall costs of the products and devices. It is not an exaggeration to suggest that the medical device industry was founded on the development of the flexible poly (vinyl chloride) (PVC) plastic IV tubing and bag. After the IV bag product lines grew to serve many markets, a new unmet need was discovered for an aseptically produced premixed drug container. This article will review how a new film was developed and used to produce the required aseptically made IV premixed drug product. It was, after the Food and Drug Administration (FDA) gave “clearance to market”, a ground-breaking product, never before thought possible for the highly FDA-regulated and controlled industry.

Boosting general-purpose stream processing with reconfigurable hardware

Reconfigurable devices such as field-programmable gate arrays (FPGAs) offer flexible solutions to workload acceleration with high energy efficiency. Despite such a potential advantage, they often reveal hard to program by application programmers. High-level synthesis languages have been developed to provide higher-level abstractions, allowing the developers to define the FPGA behavior using an imperative programming approach based on C/C++ languages. However, such approaches still leave the developer with the responsibility to harness the low-level optimizations required to develop efficient FPGA programs. Along this line, this paper introduces FSPX, a framework helping programmers to develop FPGA-accelerated data stream processing (DSP) applications. The approach provides a high-level Python API to develop the data-flow graph of operators, which is automatically translated into an efficient Vitis source code targeting Xilinx devices. The execution of the bitstreams implementing two benchmark applications showcases the efficiency of using FPGAs for DSP workloads. In general, FSPX provides, with a reasonable time-to-solution, higher performance compared with state-of-the-art DSP frameworks.

Anthropomorphic Soft Hand: Dexterity, Sensing, and Machine Learning

Humans possess dexterous hands that surpass those of other animals, enabling them to perform intricate, complex movements. Soft hands, known for their inherent flexibility, aim to replicate the functionality of human hands. This article provides an overview of the development processes and key directions in soft hand evolution. Starting from basic multi-finger grippers, these hands have made significant advancements in the field of robotics. By mimicking the shape, structure, and functionality of human hands, soft hands can partially replicate human-like movements, offering adaptability and operability during grasping tasks. In addition to mimicking human hand structure, advancements in flexible sensor technology enable soft hands to exhibit touch and perceptual capabilities similar to humans, enhancing their performance in complex tasks. Furthermore, integrating machine learning techniques has significantly promoted the advancement of soft hands, making it possible for them to intelligently adapt to a variety of environments and tasks. It is anticipated that these soft hands, designed to mimic human dexterity, will become a focal point in robotic hand development. They hold significant application potential for industrial flexible gripping solutions, medical rehabilitation, household services, and other domains, offering broad market prospects.

Versatile photonic molecule switch in multimode microresonators

Harnessing optical supermode interaction to construct artificial photonic molecules has uncovered a series of fundamental optical phenomena analogous to atomic physics. Previously, the distinct energy levels and interactions in such two-level systems were provided by coupled microresonators. The reconfigurability is limited, as they often require delicate external field stimuli or mechanically altering the geometric factors. These highly specific approaches also limit potential applications. Here, we propose a versatile on-chip photonic molecule in a multimode microring, utilizing a flexible regulation methodology to dynamically control the existence and interaction strength of spatial modes. The transition between single/multi-mode states enables the “switched-off/on” functionality of the photonic molecule, supporting wider generalized applications scenarios. In particular, “switched-on” state shows flexible and multidimensional mode splitting control in aspects of both coupling strength and phase difference, equivalent to the a.c. and d.c. Stark effect. “Switched-off” state allows for perfect low-loss single-mode transition (Qi ~ 10 million) under an ultra-compact bend size (FSR ~ 115 GHz) in a foundry-based silicon microring. It breaks the stereotyped image of the FSR-Q factor trade-off, enabling ultra-wideband and high-resolution millimeter-wave photonic operations. Our demonstration provides a flexible and portable solution for the integrated photonic molecule system, extending its research scope from fundamental physics to real-world applications such as nonlinear optical signal processing and sixth-generation wireless communication.

Measurement of Transient Overvoltages by Capacitive Electric Field Sensors.

The accurate measurement and the investigation of electromagnetic transients are becoming more important, especially with the increasing integration of renewable energy sources into the power grid. These sources introduce new transient phenomena due to the extensive use of power electronics. To achieve this, the measurement devices must have a broadband response capable of measuring fast transients. This paper presents a capacitive electric field sensor-based measurement system to measure transient overvoltages in high-voltage substations. The concept and design of the measurement system are first presented. Then, the design and concept are validated using tests performed in a high-voltage laboratory. Afterwards, two different calibration techniques are discussed: the simplified method (SM) and the coupling capacitance compensation (CCC) method. Finally, three recorded transients are evaluated using the calibration methods. The investigation revealed that the SM tends to overestimate the maximum overvoltage, highlighting the CCC method as a more suitable approach for calibrating transient overvoltage measurements. This measurement system has been validated using various measurements and can be an efficient and flexible solution for the long-term monitoring of transient overvoltages in high-voltage substations.

Role of Renewables in Energy Storage Economic Viability in the Western Balkans

Given the growing shares of renewable energy sources in the grids, the interest in energy storage systems has increased. The role of pumped hydro energy storage systems as flexible solutions for managing peak and off-peak prices from nuclear and fossil power plants in previous systems is now revitalized in the liberalized systems, with a volatile generation of wind and solar energy. Thus, understanding of the patterns behind the economics of energy storage is crucial for the further integration of energy storage in the grids. In this paper, the factors that impact the economic viability of energy storage in electricity markets are analyzed. The method of approach used in this study considers the electricity market price distribution, full load hours, the total costs of energy storage, and linear regression analysis. Using revenues from arbitraging a 10-megawatt (MW) pumped hydro storage system in the Western Balkans, resulting from the electricity market price distribution and the analysis of the total costs of storage, an econometric model is created. This model shows the impacting factors of energy storage development in the context of the rising renewables sector. Research shows that the previous hypothesis about the integration of energy storage systems in proportion to the increase in shares of renewables in the grids is incorrect. There is a significant correlation between energy storage revenues, the dependent variable, and the independent variables of hydro, wind, and solar generation. The conducted analysis indicates the future arbitraging opportunities of pumped hydro energy storage systems and provides useful insights for energy storage investors and policymakers. During the transitional period, until the deployment of renewables changes the effects of fossil power plants, energy storage price arbitrage is profitable and desirable for 500, 1000, and 2000 full load hours in the Western Balkan region. Despite the need for flexibility, with more renewables in the grids, large-scale energy storage systems will not be economically viable in the long run because of “revenue cannibalization”.

Crescent Antennas as Sensors: Case of Sensing Brain Pathology.

Microstrip crescent antennas offer compactness, conformability, low profile, high sensitivity, multi-band operability, cost-effectiveness and ease of fabrication in contrast to bulky, rigid horn, helical and Vivaldi antennas. This work presents crescent sensors for monitoring brain pathology associated with stroke and atrophy. Single- and multi-element crescent sensors are designed and validated by software simulations. The fabricated sensors are integrated with glasses and experimentally evaluated using a realistic brain phantom. The performance of the sensors is compared in terms of peak gain, directivity, radiation performance, flexibility and detection capability. The crescent sensors can detect the pathologies through the monitoring of backscattered electromagnetic signals that are triggered by dielectric variations in the affected tissues. The proposed sensors can effectively detect stroke and brain atrophy targets with a volume of 25 mm3 and 56 mm3, respectively. The safety of the sensors is examined through the evaluation of Specific Absorption Rate (peak SAR < 1.25 W/Kg, 100 mW), temperature increase within brain tissues (max: 0.155 °C, min: 0.115 °C) and electric field analysis. The results suggest that the crescent sensors can provide a flexible, portable and non-invasive solution to monitor degenerative brain pathology.

An Integrated Gesture Framework of Smart Entry Based on Arduino and Random Forest Classifier

Gesture-based systems have emerged as a prominent breakthrough in the field of smart access control, effectively integrating security measures with user comfort. This study presents a novel gesture detection framework for smart entry systems that combines the computational capabilities of a Random Forest Classifier with the practicality of Arduino-based hardware. Central to methodology is the utilization of MediaPipe, an advanced computer vision library, to extract hand motion landmarks from live video streams. The selected landmarks function as a comprehensive dataset for training a Random Forest Classifier, which has been specifically chosen due to its high level of accuracy and efficiency in managing intricate classification jobs. The model exhibits outstanding competence in the categorization of gestures in real-time, attaining high levels of accuracy that are crucial for ensuring dependable entrance control. The Arduino microcontroller plays a vital role in the execution of the entry mechanism as it serves as the intermediary between the gesture detection software and the tangible entry control hardware. The incorporation of gesture recognition technology facilitates a cohesive and prompt user experience, wherein identified motions are directly converted into input commands. The system's practical use is demonstrated through a series of detailed tests, which highlight its dependability and efficiency across diverse climatic circumstances. The findings underscore the system's capacity as a flexible and safe solution for contactless access in many environments, including both private homes and highly protected establishments. Furthermore, the study makes a substantial contribution to the larger domain of human-computer interaction by showcasing the practicality of advanced gesture detection systems in many everyday contexts. The suggested framework presents a novel approach to smart entry systems and also paves the way for further investigation in the domains of smart home automation and interactive systems. In these areas, gesture-based interfaces have the potential to deliver user experiences that are both intuitive and efficient.

Emergency power supply enabling solar PV integration with battery storage and wireless interface

ABSTRACT This paper presents a detailed investigation of an emergency power supply that enables solar photovoltaic (PV) power integration with a battery energy storage system (BESS) and a wireless interface. Through the utilisation of solar PV-based generation and BESS with wireless/contactless power transmission, the proposed method offers an easy-to-setup and flexible alternative solution for the emergency power supply (EPS) for household appliances and wireless electric vehicle (EV) charging for all weather conditions. During bad weather conditions, the battery acts as the main power supply and can be charged from the solar PV panel and during rainy days, it can be charged from the grid by the proposed wireless interface for emergency use. The proposed system is analysed by mathematical modelling, focusing on the interface of the solar PV, BESS, and load, with inductive power transfer (IPT) as a wireless power transfer (WPT) method. The simulation and a scaled-down experimental prototype are built to demonstrate that the proposed system enables wireless power transfer with PV and BESS, and easy installation can be achieved by just placing the primary charging coil of the proposed power supply close to the wireless charging pad that is available in the existing system for e.g. EV charging. The results show that the load voltage is kept constant at 48 V against the varying input characteristic of the solar panel which is the solar irradiance ranging from 20% to 100% and output characteristics of the load of the proposed integrated system with variation of 20–50%, respectively. Moreover, the wireless power transfer efficiency across the inductive coils is maintained at about 97% under these variations.

The use of containers as a constructive method in buildings: a viable and sustainable alternative

With the increase in environmental concern, alternatives for the use of resources that are less harmful to the environment have been explored, including materials and construction methods. In this context, there is a growing search for new construction processes, especially container buildings, which have gained popularity and acceptance in society, being applied in both commercial and residential contexts. The main attractions for those interested in acquiring a container construction are the reduction of costs and the shortening of the execution time of the work. This is due to the minimization of waste generated during construction and the recycling of metal boxes, which would otherwise remain useless in ports. This advantage goes beyond the economic benefits, contributing to adding sustainable value to the project. This paper aims to discuss the feasibility analysis of the use of containers as a sustainable and financially advantageous proposal compared to conventional methods of structural construction for housing. Through a literature review, evidence of the feasibility and reuse of shipping containers for housing purposes is presented, exploring viable alternatives for the use of waste. The comparative study is based on the parameters established by the National System of Research on Costs and Indices of Civil Construction – SINAPI. The steps include the initial survey of all the improvements and adaptations necessary to provide housing conditions, considering standards of acoustic comfort, lighting, and ventilation. The results indicate that the reuse of the container results in savings of approximately 10% compared to masonry construction. Therefore, this approach has numerous advantages, being a financially viable, fast, and flexible solution for new architectural arrangements, in addition to incorporating architectural innovations aligned with environmental awareness.

Fast-reconfigurable frequency comb generation based on AlGaAsOI waveguide with electro-optic time lens

Tunable optical frequency combs offer a flexible solution for specific applications such as dual-comb spectroscopy, optical communications and microwave photonics, delivering improved precision, compatibility, and performance. However, previously, there has been a trade-off between reconfigurability and system simplicity in comb generation. Here, we present a fast-switched repetition rate frequency comb system that utilizes an electro-optic modulation time-lens technique with a high third-order nonlinear AlGaAsOI waveguide. Only one stage of modulator is used in the time-lens system which significantly reduces the complexity of the overall system. Our system allows for tuning of the center wavelength from 1542 nm to 1556 nm, as well as independent adjustment of the repetition rates from 18 GHz to 26.5 GHz, enabling fast-switching capabilities. Additionally, our system exhibits a high pump-to-comb conversion efficiency of up to 67.9%. It also demonstrates robustness to temperature changes and environmental instability. All the involved devices can be integrated onto a single chip, making this comb suitable for various applications.

Dynamic control of reflection from a metasurface with distinct modulating mechanisms

Dynamic control of the reflection from an object is much of importance in microwave engineering. In the past the tunable absorbers are usually employed to realize this goal and have been widely discussed. In this work, we propose a metasurface to offer a more flexible solution to dynamically control the reflection property. The proposed metasurface can be independently modulated by three distinct physical mechanisms. Apart from the absorption mechanism as the conventional tunable absorbers, the reflectivity of the proposed metasurface can be dynamically controlled by modulating the phase distribution profiles in the space as well as the time domains. Such flexibly dynamic reflection controlling ability is demonstrated by a series of experimental measurements. Results indicate that the tuning level of the reflectivity is more than 10 dB in a broad frequency band for the three distinct mechanisms. The proposal may find promising application in various fields, such as wireless communications and the stealth technology.

An Optical Signal Simulator for the Characterization of Photoplethysmographic Devices.

(1) Background: An optical simulator able to provide a repeatable signal with desired characteristics as an input to a photoplethysmographic (PPG) device is presented in order to compare the performance of different PPG devices and also to test the devices with PPG signals available in online databases. (2) Methods: The optical simulator consists of an electronic board containing a photodiode and LEDs at different wavelengths in order to simulate light reflected by the body; the PPG signal taken from the chosen database is reproduced by the electronic board, and the board is used to test a wearable PPG medical device in the form of earbuds. (3) Results: The PPG device response to different average and peak-to-peak signal amplitudes is shown in order to assess the device sensitivity, and the fidelity in tracking the actual heart rate is also investigated. (4) Conclusions: The developed optical simulator promises to be an affordable, flexible, and reliable solution to test PPG devices in the lab, allowing the testing of their actual performances thanks to the possibility of using PPG databases, thus gaining useful and significant information before on-the-field clinical trials.

Mathematical programming model for cost-optimized and environmentally sustainable supply chain design

Sustainability is becoming increasingly important as a topic in general supply chains and cold chains. This study addresses the critical need for an integrated and comprehensive approach to supply chain design that simultaneously maximizes cost efficiency and incorporates environmental sustainability, focusing specifically on cold chains. Prior research has identified a gap in existing studies, highlighting the absence of an overarching framework from the logistics providers’ perspective. Our novel mathematical programming model introduces a unique strategy that carefully balances environmental concerns and cost optimization, addressing the shortcomings found in previous works. By integrating variables related to distribution, transportation, and inventory management, the model aims to minimize overall expenses and environmental impact, specifically regarding energy consumption and carbon emissions. We formulate and solve the optimization problem through rigorous mathematical programming, offering a flexible solution applicable to various logistics scenarios. The results demonstrate a significant reduction in overall expenses and environmental effects, providing logistics providers with a powerful tool for informed decision-making and sustainable supply chain management. This research contributes to the evolving field of supply chain sustainability by presenting a practical and effective model for maximizing cost savings while promoting environmental responsibility. The study concludes with compelling statistics, revealing a noteworthy decrease in overall expenses by €25 128 146.73 (100.25%) and environmental impact by 17 359.39 (100.04%). The outcomes show a notable decrease in general expenses and environmental effects, giving logistics providers a strong instrument for wise choices and sustainable supply chain management.

Dynamic Traffic Grooming Based on Virtualization-Plane-Aided Optimization for Elastic Optical Satellite Networks

With the increase in global wireless traffic, the use of large-scale satellite networking to provide ubiquitous access is one of the essential trends of future 6G network development. Elastic optical satellite networks (EOSNs) are widely considered a flexible solution for future satellite communication. However, with the continuous proliferation of network devices and users, the growing disparity between user demands and the limited bandwidth and capacity of the network is becoming increasingly noticeable. This has led to issues such as constrained network resource utilization and resource fragmentation. Therefore, EOSNs must efficiently address the challenge of allocating scarce bandwidth resources. Effective traffic grooming methods will be applied to EOSNs to solve the problem of bandwidth shortage. This paper proposed a dynamic traffic grooming algorithm based on virtualization-plane-aided optimization (DTG-VPO) to facilitate the bandwidth allocation for EOSNs. Firstly, the nodes of the alternative paths were graded, and the weights of the subsequent hop links were modified. Then, the path was evaluated using link weights, alternative paths were selected in the virtual and physical topologies, respectively, and a path set was constructed. Finally, a resource block evaluation parameter was designed to quantify the quality of candidate resource blocks and rank them. A series of simulations have evaluated the traffic-blocking probability and wavelength utilization under different traffic loads. The link resource was more fully utilized compared with other traffic grooming algorithms. The blocking probability can be reduced by 75%, while wavelength utilization can be improved by 8.1%.

How to exploit Augmented Reality (AR) technology in patient customized surgical tools: a focus on osteotomies

In orthopedic surgery and maxillofacial there is a growing use of augmented reality (AR) as a technology to increase the visual perception of the surgeon in the operating room. The objective of this review is to analyze the state of the art in the use of AR for osteotomies, highlighting the advantages and the most-known open issues to be addressed in the future research. Scopus, Web of Science, Pubmed and IEEE Xplore databases have been explored with a keyword search, setting the time limits from January 2017 to January 2023, inclusive. Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines has been used in this review, focusing on anatomical districts, real-virtual environment interaction, advantaged and limitations of existing AR-based applications. 49 articles met the inclusion criteria and have been selected in the final analysis. For the sake of clarity, works have been grouped according to the anatomical district, but also the real-virtual environment interaction methodology was reported, as well as information regarding accuracy assessment. A Quality Function Deployment (QFD) has been used to assess the AR-based solutions with regards to the more traditional freehand (FH) and Patient Specific Template (PST) approaches. Finally, some suggestions to foster the AR-based solution adoption in osteotomies treatment have been drawn, considering the highlighted advantages and limitations of this technology. The AR resulted to meet the surgeons’ needs more than other traditional approaches. Among the emerged advantages, AR can lead to a better surgical field accessibility, more flexible solutions and lower the management effort. Nonetheless, future research should address some well-known issues, among which the calibration time, the robustness of the tracking, and the HMDs discomfort.