This paper investigates the joint spectrum and energy efficiency in multimanned aerial vehicle (Multi-UAV) communication network in environments beyond the fifth generation and sixth generation (B5G / 6G), with a focus on the challenges posed by redundant data. We propose a linear optimization model for bandwidth allocation that accounts for both correlated and uncorrelated data scenarios. Additionally, we enhance energy efficiency through the Augmented Lagrangian method for power control optimization. Our approach achieves superior joint spectrum and energy efficiency, with spectrum efficiency reaching 0.75 bits/Hz, outperforming other methods by effectively exploiting data correlation. Furthermore, the proposed approach demonstrates a significant improvement in energy efficiency under varying levels of source correlation, achieving up to 7 Mb/J as the correlation variance increases. These results highlight the crucial role of data correlation in optimizing joint spectrum and energy efficiency, making the proposed approach highly effective for future 6G multi-UAV networks in smart city environments, with an emphasis on reliability.
Leonhard Ziegler, Michael Grabatin, Daniela Pöhn
et al.
Abstract While self-sovereign identities (SSI) have been gaining more traction, the topic of SSI security has yet to be addressed. Especially regarding response procedures to security incidents, no prior work is available. However, incident response processes are essential to systematically respond to a security incident in a timely manner. We first evaluate the current state-of-the-art by conducting a literature survey and contacting organizations that offer SSI. The insights underpin the subject’s relevance, highlighting that incident response capabilities are just starting to be developed. Contributing to this development, we identify the challenges of building a security incident response process for SSI. Mainly, the decentralized nature inhibits the utilization of known best practices, which all focus on building a centralized incident response capability. However, even in the case of SSI, some centralized entities may exist. Therefore, we design two variants of SIR processes: one more centralized and one more decentralized. For the latter, the problem size is reduced in the first step by identifying all the stakeholders within an SSI ecosystem and then analyzing possible proactive and reactive measures each participant can access. This procedure leads to the grouping of SSI system participants into three distinct domains of incident response. For each domain, different capabilities for handling incidents are introduced depending on the involved stakeholders, their infrastructure, and their goals. To demonstrate the procedures, incident scenarios for each domain highlight the workflows during incident handling.
A theoretical framework is presented for free vibration of a flexible horizontal rectangular vessel, whether it is partially or fully filled with a fluid. The vibrational modal patterns of the vessel, whether dry or wet, are classified into symmetric and antisymmetric modes. The theoretical model conceptualizes the vessel as an unfolded plate with line supports simulating the vessel's corners. The motion of contained fluid is described using displacement potentials that adhere to the Laplace equation and fluid boundary conditions. Importantly, the proposed analytical approach accounts for the dynamic interaction between the vessel and the fluid, ensuring compatibility along their contacting surfaces. The Rayleigh-Ritz method is employed to formulate an eigenvalue problem, considering entire kinetic and strain energies of the fluid-filled vessel. The accuracy of the theoretical approach is checked by conducting finite element analyses. Remarkably, the natural frequencies obtained through commercial software align closely with the theoretical predictions for both dry and fluid-filled vessels. In instances of fully fluid-filled vessels, we can discern the presence of fluid contact at the vessel's upper plate by examining the natural frequencies and mode shapes. The proposed method offers applicability in dynamically analyzing water-filled spent fuel casks, enhancing safety during transportation.
Abstract Neuromorphic hardware enables energy-efficient computing, which is essential for a sustainable system. Recently, significant progress has been reported in neuromorphic hardware based on two-dimensional materials. However, traditional planar-integrated architectures still suffer from high energy consumption. This review systematically explores recent advances in the three-dimensional integration of two-dimensional material-based neuromorphic hardware to address these challenges. The materials, process, device physics, array, and integration levels are discussed, highlighting challenges and perspectives.
Materials of engineering and construction. Mechanics of materials, Chemistry
The increasing interconnectivity with external networks and the higher reliance on digital systems make chemical and process industries, including waste and drinking water treatment plants, more vulnerable to cyber-attacks. Historical evidence shows that these attacks have the potential to cause events with severe consequences on property, people, and the surrounding environment, posing a serious threat. While the risks deriving from the malicious manipulation of the Basic Process Control System (BPCS) and the Safety Instrumented System (SIS) in chemical and Oil&Gas facilities have been systematically analysed in the available literature, including previous works of the Authors, the analysis of the consequences of cyber-attacks to drinking water treatment plants has not been conducted to date. To fill this gap, in the present study the methodology POROS 2.0 (Process Operability Analysis of Remote manipulations through the cOntrol System) developed by the Authors was applied to a drinking water treatment plant, providing valuable insights on possible critical scenarios originated by cyber-attacks in these facilities.
Chemical engineering, Computer engineering. Computer hardware
Purposes To investigate the influence of different tamping methods on the reinforcement effect of sand dynamic compaction, this research has been done from the perspective of soil stress distribution characteristics. Methods The dynamic compaction model test was carried out in the outdoor field to monitor the vertical and radial soil pressures in the soil and falling weight acceleration during tamping process, and the displacements in the soil were analyzed by numerical simulation method. Findings It is concluded that in the construction of dynamic compaction method, the vertical soil pressure waveform is the shock wave waveform or the vibration attenuation wave shape, and the radial earth pressure waveform is the impact waveform; There are two reinforcement modes in the process of dynamic compaction, the soil under tamping point is mainly vertically compacted, while the soil side of tamping point also has significant radial compaction; At the same level of dynamic compaction, heavy falling weight is suitable for deep soil and radial soil reinforcement, while light falling weight is suitable for rapid reinforcement of shallow soil. Conclusions The research results have a certain guiding significance for the selection of tamping methods of the same energy level dynamic compaction.
Chemical engineering, Materials of engineering and construction. Mechanics of materials
The growing importance of numerical simulations in the welding industry stems from their ability to enhance structural performance and sustainability by ensuring optimal manufacturing conditions. The use of the finite element method (FEM) allows for detailed and precise calculations of the mechanical and material changes caused by the welding process. Acquiring knowledge of these parameters not only serves to augment the quality of the manufacturing process but also yields consequential benefits, such as reducing adverse effects. Consequently, the enhancement of structural performance and prolonged lifespan becomes achievable, aligning with overarching sustainability goals. To achieve this goal, this paper utilizes numerical simulations of welding processes based on experimental tests, with a specific focus on analyzing temperatures generated within the structures. In the finite element analysis (FEA), a total of 12 welding cycles were systematically modeled to align with experimental conditions, incorporating cooling intervals, preheating considerations, and the relevant section of the connecting concrete structure with studs. The outcomes of this research exemplify the potential of numerical simulation in the welding industry, demonstrating a diverse range of results achieved through FEA to enhance the quality of structures within the context of sustainability.
Chemical engineering, Computer engineering. Computer hardware
Mikhail Ivanenko, Damian Wanta, Waldemar T. Smolik
et al.
This study investigated the potential of machine-learning-based stroke image reconstruction in capacitively coupled electrical impedance tomography. The quality of brain images reconstructed using the adversarial neural network (cGAN) was examined. The big data required for supervised network training were generated using a two-dimensional numerical simulation. The phantom of an axial cross-section of the head without and with impact lesions was an average of a three-centimeter-thick layer corresponding to the height of the sensing electrodes. Stroke was modeled using regions with characteristic electrical parameters for tissues with reduced perfusion. The head phantom included skin, skull bone, white matter, gray matter, and cerebrospinal fluid. The coupling capacitance was taken into account in the 16-electrode capacitive sensor model. A dedicated ECTsim toolkit for Matlab was used to solve the forward problem and simulate measurements. A conditional generative adversarial network (cGAN) was trained using a numerically generated dataset containing samples corresponding to healthy patients and patients affected by either hemorrhagic or ischemic stroke. The validation showed that the quality of images obtained using supervised learning and cGAN was promising. It is possible to visually distinguish when the image corresponds to the patient affected by stroke, and changes caused by hemorrhagic stroke are the most visible. The continuation of work towards image reconstruction for measurements of physical phantoms is justified.
Thais N. Guerrero, Ruth M. Fisher, Ademir A. Prata
et al.
The beneficial reuse and recovery of biosolids is an attractive option instead of disposal. However, odour emissions present significant challenges to land application of biosolids, increasing operational costs and reducing community acceptance. This study aimed to assess the influence of conveying and storage conditions in wastewater treatment plants on the sensory impact from biosolids. For sensory assessment, samples of anaerobically digested biosolids were collected after centrifuge and during storage out-loading. The emissions were extracted over 15 days using a dynamic flux chamber and sensory analysis conducted using an ODP coupled to a TD-GC-MS. Odour descriptors and intensities (from 1 – weak to 4 – strong) were evaluated by expert panellists, providing insights into the sensory aspects of odour emissions. The ODP results showed variations in the number of occurrences, intensity and modified frequency of odour events across the stages of wastewater solids processing and laboratory storage. Conveying could potentially impact the release of volatile compounds due to the mechanical agitation that can aerate and disturb the structure and surface of the biosolids. On the other hand, storage can accelerate biological and chemical processes as a result of the development of anaerobic conditions leading to subsequent odour generation. The interplay between wastewater treatment processes and odour emissions is complex and requires targeted strategies. The application of sensorial analysis contributes to valuable insights into understanding and managing odour emissions in wastewater treatment plants, offering potential avenues for optimizing operational parameters to benefit biosolids reuse initiatives.
Keywords: Wastewater sludge; Anaerobic digestion; Biosolids; Beneficial reuse; Land application; Gaseous emissions; Sensory emissions; Sensory analysis; Odour detection port.
Chemical engineering, Computer engineering. Computer hardware
Abstract Capacitor mismatch problem due to process variation causes weight error, which deteriorates the linearity of SAR ADC. In this paper, a novel calibration scheme based on genetic algorithm(GA) combined with a radix‐less‐than‐2 SAR ADC is proposed to extract the weight error caused by capacitor mismatch. This is a foreground calibration scheme and no extra injections are added. The proposed GA‐based calibration scheme is simulated based on 40 nm CMOS technology. After calibration, ENOB increases from 10.19 bits to 11.46 bits, INL changes from +2.22/−2.12 LSB to +0.81/−0.80 LSB, and DNL changes from +1.79/−1.00 LSB to +0.99/−1.00LSB. As can be seen from the simulation results, the proposed calibration scheme can effectively improve the linearity deterioration caused by capacitor mismatch.
Nader Mohamed, Jameela Al-Jaroodi, Imad Jawhar
et al.
Healthcare systems are complex systems that need effective and efficient operations, optimizations, management, and control to offer reliable, high-quality, and cost-effective healthcare services. There are different approaches to improve the management of healthcare systems including utilizing the healthcare systems engineering principles. Healthcare systems engineering views a healthcare organization as a system and applies the engineering analysis and design principles to improve different aspects of healthcare services provided in that system. While this approach can provide many advantages for healthcare organizations, there are also many challenges hindering the ability of healthcare systems engineers from effectively accomplishing their mission. The initiation of the digital twin technology formed several potential methods for various industrial sectors to enhance their operations. Accordingly, they can help improve productivity, cost-effectiveness, reliability, quality, and flexibility. This paper studies how digital twins can be utilized for improving healthcare systems engineering processes and outcomes to enhance different aspects of healthcare systems. The paper discusses some of the challenges of healthcare systems engineering and how these challenges can be relaxed by utilizing digital twins. The paper also develops a conceptual framework to utilize digital twins for improving healthcare systems engineering processes and outcomes and discusses the prospects of such utilization on achieving the goals of healthcare systems engineering. In addition, the paper provides some discussions on the impact of this utilization and the future research and development projections of the employment of digital twins for healthcare systems engineering.
Matthew Dvorsky, Daniela Munalli, Mohammad Tayeb Al Qaseer
et al.
In this paper synthetic aperture radar (SAR) polarimetry techniques are applied to detect and characterize fiber misalignment in both carbon fiber sheets and glass fiber reinforced polymer (GFRP) composites. The principle behind SAR polarimetry technique to characterize fiber orientation is described, making use of the fact that carbon and glass fibers are polarizing when irradiated with a microwave signal. The difficulties in using 2D polarimetry techniques to make the 3D orientation measurements, required to characterize out-of-plane fiber misalignment, are discussed as well. Subsequently, the feasibility of a recently-developed 3D SAR polarimetry method for this purpose is demonstrated. Several carbon fiber sheet and glass fiber reinforced polymer (GFRP) samples were manufactured with both in- and out-of-plane fiber misalignment. Polarimetric SAR images of the samples were then produced to show the spatially-varying relative orientation (both in-plane and out-of-plane) of the fibers for each sample. These images can be used to both detect and characterize any fiber misalignment, successfully demonstrating the potential for SAR polarimetry as a tool for the inspection of carbon and glass fiber reinforced composites.
Instruments and machines, Electrical engineering. Electronics. Nuclear engineering
The movement and deposition of nanoparticles in supercritical carbon dioxide is a current international frontier subject. In the development of new nuclear reactors, using supercritical carbon dioxide Brayton cycle instead of traditional steam Rankine cycle can greatly improve the cycle efficiency, reduce equipment size and improve safety. In this new cycle, the movement and deposition of nanoparticles play a significant role under normal and abnormal operating conditions in nuclear power plants. Nanoparticles, due to their small particle size and higher relative surface energy, are more penetrable. When it under the thermophoresis force will emerge the thermophoresis deposition, causing collision and erosion to the pipeline. And it may be more destructive to supercritical devices or systems. To study the movement and deposition characteristics of nanoparticles in supercritical media, then further explore the factors affecting nanoparticles deposition, and find their qualitative and even quantitative relationship. This paper studies this problem from the aspects of particle size, wall temperature difference, incoming flow velocity, and so on to try to clarify the motion mechanism of nanoparticle deposition. In specific studies, stainless steel nanoparticles and supercritical carbon dioxide were selected as the objects, a 1 meter long horizontal straight pipe was taken as the flow geometric channel, based on the control single variable method, the factors affecting the thermophoresis deposition of nanoparticles were calculated and analyzed by Fluent software. According to the calculation to obtain the curve picture, the results show that the higher the fluid temperature, the greater the temperature gradient, and the greater the thermophoresis force on nanoparticles, which increases the dimensionless thermophoresis deposition velocity and the thermophoresis deposition rate. In addition, the increase of fluid temperature leads to the decrease of fluid viscosity and viscous resistance of particle movement, which also promotes the movement of particles and increases their deposition rate to a certain extent. In terms of particle size, the change of thermophoresis deposition rate caused by the change of particle size on a small scale (1100 nm) is more obvious than that on a large scale. With the increase of particle size, the thermophoresis force increases, but the increasing speed slows down. At the same time, the viscous resistance and lift increase in geometric multiples with the particle size. Under the combined action of these forces, the thermophoresis deposition efficiency decreases. The pipe diameter and flow velocity do not directly affect the thermophoresis deposition rate. The pipe diameter increases the average distance and reduces the thermophoresis gradient, while the flow velocity affects the heat transfer coefficient. In addition, the increase of external flow velocity enhances the carrying capacity of fluid, and nanoparticles are easier to be coerced out of the channel, thus reducing their thermophoresis deposition. Totally, for thermophoresis deposition, the temperature difference between the fluid and the wall is the most important factor affecting the deposition rate, and there is a positive correlation. The flow velocity, particle size, and pipe diameter are negatively correlated with deposition rate.
A Vehicular Ad-Hoc Network(VANET) is a Mobile Ad-Hoc Network(MANET) composed of mobile vehicular nodes.It does not rely on infrastructure to either establish a communication link orrealize communication. Owingto the high mobility of vehicles and limited wireless-communication resources, it is difficult for VANETs to guarantee Quality of Service(QoS).To solve this problem, this paper introduces a Software-Defined Network(SDN).In particular, amulti-constrained QoS routing algorithm suitable for Doftware-Defined Vehicular Ad-Hoc Network(SDN-VANET) is proposedthatharnessesthe advantages of SDN control and forwarding separation to ensurevehicle QoS.First, the SDN controller schedules a vehicle's service based on deadline constraints.Second, this paper proposesan Adaptive Hybrid Shuffled Frog-Leaping Algorithm(AH-SFLA).The SDN controller calculates the appropriate value of the data on the transmission link according to the QoS index and the global topology information and uses this as a benchmark to search for an optimized path.At the same time, alternative link mechanisms and QoS resource consumption thresholds are set to implement routing maintenance in order toreduce the probability of network failures.Finally, mininet-wifi and SUMO are combined to build an SDN-VANET environment, and the AH-SFLA routing algorithm is compared with the performances ofIGA and IICSFLA.The experimental results show that compared with IGA and IICSFL, AH-SFLA can improve the average end-to-end delay index by 57.74% and 46.6%, reduce the packet-loss rate by 29.9% and 18.6%, and increase the cost of standardized routing by 36.93% and 27.2%, respectively, effectively guaranteeingQoS in VANET.
A major challenge with current wearable electronics and e-textiles, including sensors, is power supply. As an alternative to batteries, energy can be harvested from various sources using garments or other textile products as a substrate. Four different energy-harvesting mechanisms relevant to smart textiles are described in this review. Photovoltaic energy harvesting technologies relevant to textile applications include the use of high efficiency flexible inorganic films, printable organic films, dye-sensitized solar cells, and photovoltaic fibers and filaments. In terms of piezoelectric systems, this article covers polymers, composites/nanocomposites, and piezoelectric nanogenerators. The latest developments for textile triboelectric energy harvesting comprise films/coatings, fibers/textiles, and triboelectric nanogenerators. Finally, thermoelectric energy harvesting applied to textiles can rely on inorganic and organic thermoelectric modules. The article ends with perspectives on the current challenges and possible strategies for further progress.
Anita J. Crompton, Kelum A. A. Gamage, Divyesh Trivedi
et al.
Due to the short path length of alpha particles in air, a detector that can be used at a distance from any potential radiological contamination reduces the time and hazard that traditional alpha detection methods incur. This would reduce costs and protect personnel in nuclear power generation and decommissioning activities, where alpha detection is crucial to full characterisation and contamination detection. Stand-off alpha detection could potentially be achieved by the detection of alpha-induced radioluminescence, especially in the ultraviolet C (UVC) wavelength range (180⁻280 nm) where natural and artificial background lighting is less likely to interfere with detection. However, such a detector would also have to be effective in the field, potentially in the presence of other radiation sources that could mask the UVC signal. This work exposed a UVC sensor, the UVTRON (Hamamatsu, Japan) and associated electronics (driver circuit, microprocessor) to sources of beta and gamma radiation in order to assess its response to both of these types of radiation, as may be found in the field where a mixed radiation environment is likely. It has been found that the UVTRON is affected by both gamma and beta radiation of a magnitude that would mask any UVC signal being detected. <sup>152</sup>Eu generated 0.01 pulses per second per Bq through beta and gamma interactions, compared to <sup>210</sup>Po, which generates 4.72 × 10<sup>−8</sup> cps per Bq from UVC radioluminescence, at 20 mm separation. This work showed that UVTRON itself is more susceptible to this radiation than the associated electronics. The results of this work have implications for the use of the UVTRON as a sensor in a stand-off detection system, highlighting the necessity for shielding from both potential gamma and beta radiation in any detector design.
A hybrid multi-mode narrow-frame antenna for WWAN/LTE metal-rimmed smartphone applications is proposed in this paper. The ground clearance is only 5 mm <inline-formula> <tex-math notation="LaTeX">$\times45$ </tex-math></inline-formula> mm, which is promising for narrow-frame smartphones. The metal rim with a small gap is connected to the system ground by three grounded patches. This proposed antenna can excite three coupled-loop modes and one slot mode. By incorporating these four modes, the proposed antenna can provide coverage for GSM850/900, DCS/PCS/UMTS2100, and LTE2300/2500 operations. Detailed design considerations of the proposed antenna are described, and both experimental and simulated results are also presented.
With the envisioned era of internet of things, all aspects of Intelligent Transportation Systems will be connected to improve transport safety, relieve traffic congestion, reduce air pollution, enhance the comfort of transportation and significantly reduce road accidents. In internet of vehicles, regular exchange of current position, direction, velocity and so on, enables mobile vehicles to predict an upcoming accident and alert the human drivers in time or proactively take precautionary actions to avoid the accident. The actualisation of this concept requires the use of channel access protocols that can guarantee reliable and timely broadcast of safety messages. This study investigates the application of network coding concept to increase content of every transmission and achieve improved broadcast reliability with less number of retransmissions. In particular, the authors proposed Code Aided Retransmission‐based Error Recovery (CARER) scheme, introduced a request‐to‐broadcast/clear‐to‐broadcast (RTB/CTB) handshake to overcome hidden node problem and reduce packets collision rate. In order to avoid broadcast storm problem associated with the use of RTB/CTB packet in a broadcast transmission, they developed a rebroadcasting metric used to successfully select a vehicle to rebroadcast the encoded message. The performance of CARER protocol is clearly shown with detailed theoretical analysis and further validated with simulation experiments.