bluuebunny/crossref_metadata_2025 huggingface dataset:
Edge-Weighted Consensus-Based Formation Control with Collision Avoidance for Mobile Robots Based on Multi-Strategy Mutation Differential Evolution
Authors: Hernandez-Barragan Jesus , Hernandez Tonatiuh , Rios Jorge D. , Perez-Cisneros Marco , Alanis Alma Y.
Published: August 2023

An edge-weighted consensus-based formation control strategy is presented for mobile robots. In the edge-weighted strategy, a desired formation pattern is achieved by adjusting gain weights related to the distance between robots. Moreover, the edge-weighted formation control exploits the properties of weighted graphs to allow the formation to rotate and adapt its shape to avoid collision among robots. However, formation patterns are commonly defined by biases with respect to the centroid of the consensus rather than gain weights. This work proposes to optimize the gain weights in edge-weighted graphs, given a formation pattern in terms of biases. A multi-strategy mutation differential evolution algorithm is introduced to solve the optimization problem. Simulation and real-world experiments are performed considering multi-robot systems composed of differential drive robots. Additionally, the experimental setup includes Turtlebot3® Waffle Pi robots and an OptiTrack® motion capture system for control purposes. The experimental results verify the effectiveness of the proposed approach.
Spatio-Temporal Coherence of mmWave/THz Channel Characteristics and Their Forecasting Using Video Frame Prediction Techniques
Authors: Prosvirov Vladislav , Ali Amjad , Khakimov Abdukodir , Koucheryavy Yevgeni
Published: August 2023

Channel state information in millimeter wave (mmWave) and terahertz (THz) communications systems is vital for various tasks ranging from planning the optimal locations of BSs to efficient beam tracking mechanisms to handover design. Due to the use of large-scale phased antenna arrays and high sensitivity to environmental geometry and materials, precise propagation models for these bands are obtained via ray-tracing modeling. However, the propagation conditions in mmWave/THz systems may theoretically change at very small distances, that is, 1 mm–1 μm, which requires extreme computational effort for modeling. In this paper, we first will assess the effective correlation distances in mmWave/THz systems for different outdoor scenarios, user mobility patterns, and line-of-sight (LoS) and non-LoS (nLoS) conditions. As the metrics of interest, we utilize the angle of arrival/departure (AoA/AoD) and path loss of the first few strongest rays. Then, to reduce the computational efforts required for the ray-tracing procedure, we propose a methodology for the extrapolation and interpolation of these metrics based on the convolutional long short-term memory (ConvLSTM) model. The proposed methodology is based on a special representation of the channel state information in a form suitable for state-of-the-art video enhancement machine learning (ML) techniques, which allows for the use of their powerful prediction capabilities. To assess the prediction performance of the ConvLSTM model, we utilize precision and recall as the main metrics of interest. Our numerical results demonstrate that the channel state correlation in AoA/AoD parameters is preserved up until approximately 0.3–0.6 m, which is 300–600 times larger than the wavelength at 300 GHz. The use of a ConvLSTM model allows us to accurately predict AoA and AoD angles up to the 0.6 m distance with AoA being characterized by a higher mean squared error (MSE). Our results can be utilized to speed up ray-tracing simulations by selecting the grid step size, resulting in the desired trade-off between modeling accuracy and computational time. Additionally, it can also be utilized to improve beam tracking in mmWave/THz systems via a selection of the time step between beam realignment procedures.
Physics-Informed Neural Networks and Functional Interpolation for Solving the Matrix Differential Riccati Equation
Authors: Drozd Kristofer , Furfaro Roberto , Schiassi Enrico , D’Ambrosio Andrea
Published: August 2023

In this manuscript, we explore how the solution of the matrix differential Riccati equation (MDRE) can be computed with the Extreme Theory of Functional Connections (X-TFC). X-TFC is a physics-informed neural network that uses functional interpolation to analytically satisfy linear constraints, such as the MDRE’s terminal constraint. We utilize two approaches for solving the MDRE with X-TFC: direct and indirect implementation. The first approach involves solving the MDRE directly with X-TFC, where the matrix equations are vectorized to form a system of first order differential equations and solved with iterative least squares. In the latter approach, the MDRE is first transformed into a matrix differential Lyapunov equation (MDLE) based on the anti-stabilizing solution of the algebraic Riccati equation. The MDLE is easier to solve with X-TFC because it is linear, while the MDRE is nonlinear. Furthermore, the MDLE solution can easily be transformed back into the MDRE solution. Both approaches are validated by solving a fluid catalytic reactor problem and comparing the results with several state-of-the-art methods. Our work demonstrates that the first approach should be performed if a highly accurate solution is desired, while the second approach should be used if a quicker computation time is needed.
Non-Aggressive Adaptive Routing in Traffic
Authors: Prasad Madhushini Narayana , Dimitrov Nedialko , Nikolova Evdokia
Published: August 2023

Routing a person through a traffic road network presents a tension between selecting a fixed route that is easy to navigate and selecting an aggressively adaptive route that minimizes travel time. In this paper, we propose a novel routing framework that strikes a balance between adaptability and simplicity. Specifically, we propose to create non-aggressive adaptive routes that seek the best of both these extremes in the navigation world. These selected routes still adapt to changing traffic conditions, but we limit the number of adjustments made en route. This framework improves the driver experience by providing a continuum of options between saving travel time and reducing navigation stress. We design strategies to model single and multiple route adjustments, and investigate numerous techniques to solve these models for better route selection. To alleviate the intractability of handling real-life traffic data, we devise efficient algorithms with easily computable lower and upper bounds. We finally perform computational experiments on our algorithms to demonstrate the benefits of limited adaptability in terms of reducing the travel time.
Spindle Cell Rhabdomyosarcoma of the Inguinal Region Mimicking a Complicated Hernia in the Adult—An Unexpected Finding
Authors: Grigorean Valentin Titus , Serescu Radu , Anica Andrei , Coman Violeta Elena , Bedereag Ştefan Iulian , Sfetea Roxana Corina , Liţescu Mircea , Pleşea Iancu Emil , Florea Costin George , Burleanu Cosmin , Erchid Anwar , Coman Ionuţ Simion
Published: August 2023

Rhabdomyosarcoma is a rare tumor that is diagnosed mostly in children and adolescents, rarely in adults, representing 2–5% of all soft tissue sarcomas. It has four subtypes that are recognized: embryonal (50%), alveolar (20%), pleomorphic (20%), and spindle cell/sclerosing (10%). The diagnosis of rhabdomyosarcoma is based on the histological detection of rhabdomyoblasts and the expression of muscle-related biomarkers. Spindle cell/sclerosing rhabdomyosarcoma consists morphologically of fusiform cells with vesicular chromatin arranged in a storiform pattern or long fascicles, with occasional rhabdomyoblasts. Also, dense, collagenous, sclerotic stroma may be seen more commonly in adults. We present a rare case of an adult who presented to the hospital with a tumor in the left inguinal area, was first diagnosed with a left strangulated inguinal hernia and was operated on as an emergency, although the diagnosis was ultimately a spindle cell rhabdomyosarcoma of the inguinal region.
The Interplay of Raloxifene and Sonochemical Bio-Oss in Early Maxillary Sinus Bone Regeneration: A Histological and Immunohistochemical Analysis in Rabbits
Authors: de Souza Santos Anderson Maikon , dos Santos Pereira Rodrigo , Montemezzi Pietro , Mello-Machado Rafael Coutinho , Okamoto Roberta , Sacco Roberto , Noronha Lisboa-Filho Paulo , Messora Michel Reis , Mourão Carlos Fernando , Hochuli-Vieira Eduardo
Published: August 2023

The study aimed to assess the efficacy of using Raloxifene with ultrasonic processing to enhance Bio-Oss®, a bone graft substitute, for maxillary sinus bone height reconstruction. A total of 24 rabbit maxillary sinuses were distributed into three groups, each receiving different treatments: Bio-Oss® only, sonicated Bio-Oss, and sonicated Bio-Oss® with Raloxifene. Surgical procedures and subsequent histomorphometric and immunohistochemistry analyses were conducted to evaluate the bone formation, connective tissue, and remaining biomaterial, as well as the osteoblastic differentiation and maturation of collagen fibers. Results indicated that the sonicated Bio-Oss® and Bio-Oss® groups showed similar histological behavior and bone formation, but the Raloxifene group displayed inflammatory infiltrate, low bone formation, and disorganized connective tissue. The statistical analysis confirmed significant differences between the groups in terms of bone formation, connective tissue, and remaining biomaterial. In conclusion, the study found that while sonicated Bio-Oss® performed comparably to Bio-Oss® alone, the addition of Raloxifene led to an unexpected delay in bone repair. The findings stress the importance of histological evaluation for accurate bone repair assessment and the necessity for further investigation into the local application of Raloxifene. Future research may focus on optimizing bone substitutes with growth factors to improve bone repair.
Extracellular Production of Glutathione by Recombinant Escherichia coli K-12
Authors: Suzuki Hideyuki , Nishida Kazuki , Nakamura Tatsuya
Published: August 2023

The goal of this study was to produce a sufficient amount of glutathione in the fermentation medium without the addition of cysteine. This would simplify and reduce the cost of its purification. In addition to reducing the cost of cysteine, it also avoids the inhibition of bacterial growth by cysteine. The gshA, gshB, and cysE genes of Escherichia coli were cloned under the control of the strong T5 promoter of the pQE-80L plasmid and introduced into an E. coli strain knocked out for the genes encoding γ-glutamyltranspeptidase and the GsiABCD glutathione transporter, which are responsible for the recycling of excreted glutathione. The overexpression of the gshA and gshB genes, genes for γ-glutamylcysteine synthetase and glutathione synthetase, and the cysEV95R D96P gene, a gene for serine acetyltransferase with the V95R D96P mutation that makes it insensitive to cysteine, were effective on glutathione production. Na2S2O3 was a good sulfur source for glutathione production, while the addition of Na2SO4 did not affect the glutathione production. With the addition of 50 mM glutamic acid and 75 mM glycine, but without the addition of cysteine, to the simplified SM1 medium, 4.6 mM and 0.56 mM of the reduced and oxidized glutathione, respectively, were accumulated in the extracellular space after 36 h of batch culture. This can eliminate the need to extract glutathione from the bacterial cells for purification.
Bloodstream Infections: Comparison of Diagnostic Methods and Therapeutic Consequences between a Hospital in a Resource-Limited Setting and Two French Hospitals
Authors: Eid Racha , Zahar Jean-Ralph , Ait Ali Chahrazed , Mizrahi Assaf , Ibrahim Racha , Banh Emeline , Halouani Habib , Jauréguy Françoise , Pilmis Benoit , Saliba Rindala
Published: August 2023

In recent years, the diagnosis of bloodstream infections has been complemented by rapid microbiological methods, unattainable to most clinical laboratories in resource-limited settings. We evaluated the impact of their shortage on antibiotic therapy adequacy. We conducted a prospective multicenter cohort study including 150 adult Gram-negative bacilli bacteremia episodes, evenly distributed across three university hospitals: one in Lebanon, a resource-limited setting, and two in France, a resource-rich setting. Previous colonization by multidrug-resistant organisms (MDRO) was significantly more prevalent among the Lebanese than the French group of patients (16/50 vs. 5/100; p < 0.01). Bloodstream infections by carbapenemase-producing Enterobacterales and other MDRO were higher among the Lebanese than the French group of patients (25/50 vs. 12/100; p < 0.01). For the French group, rapid identification of species and mechanisms of resistance significantly shortened turnaround time for definitive laboratory diagnosis and increased antibiotic therapy adequacy. No statistically significant differences were noted in targeted antibiotic therapy between the two groups. This study suggests that, in settings where bacterial resistance is prevalent, rapid microbiological methods have not provided any additional value. The clinical and economic impact of rapid microbiological methods will likely depend on local CPE, VRE, and other MDRO epidemiology and are areas for future research.
Isolation and Characterization of the Acadevirus Members BigMira and MidiMira Infecting a Highly Pathogenic Proteus mirabilis Strain
Authors: da Silva Jéssica Duarte , Bens Lene , Santos Adriele J. do Carmo , Lavigne Rob , Soares José , Melo Luís D. R. , Vallino Marta , Dias Roberto Sousa , Drulis-Kawa Zuzanna , de Paula Sérgio Oliveira , Wagemans Jeroen
Published: August 2023

Proteus mirabilis is an opportunistic pathogen and is responsible for more than 40% of all cases of catheter-associated urinary tract infections (CAUTIs). Healthcare-associated infections have been aggravated by the constant emergence of antibiotic-resistant bacterial strains. Because of this, the use of phages to combat bacterial infections gained renewed interest. In this study, we describe the biological and genomic features of two P. mirabilis phages, named BigMira and MidiMira. These phages belong to the Acadevirus genus (family Autographiviridae). BigMira and MidiMira are highly similar, differing only in four missense mutations in their phage tail fiber. These mutations are sufficient to impact the phages’ depolymerase activity. Subsequently, the comparative genomic analysis of ten clinical P. mirabilis strains revealed differences in their antibiotic resistance profiles and lipopolysaccharide locus, with the latter potentially explaining the host range data of the phages. The massive presence of antimicrobial resistance genes, especially in the phages’ isolation strain P. mirabilis MCS, highlights the challenges in treating infections caused by multidrug-resistant bacteria. The findings reinforce BigMira and MidiMira phages as candidates for phage therapy purposes.
A New Fluorescent Probe for Hydrogen Sulfide Detection in Solution and Living Cells
Authors: Feng Wei , Xiao Qicai , Wang Lu , Yang Yuanyong
Published: August 2023

Since Hydrogen Sulfide (H2S) was recognized as a gas transmitter, its detection and quantification have become a hot research topic among chemists and biologists. In this area, fluorescent probes have shown great advantages: fast and strong response, low detection limit and easy manipulation. Here we developed a new fluorescent probe that detected H2S selectively among various bioactive and inorganic salts. This probe was based on the core structure of fluorescein and reacted with H2S through azide-reduction. Great linearity was achieved correlating fluorescence intensity and H2S concentrations in solution. The detection of H2S in cancer cells was also achieved.
Treatment of Organic and Sulfate/Sulfide Contaminated Wastewater and Bioelectricity Generation by Sulfate-Reducing Bioreactor Coupling with Sulfide-Oxidizing Fuel Cell
Authors: Kieu Thi Quynh Hoa , Nguyen Thi Yen , Do Chi Linh
Published: August 2023

A wastewater treatment system has been established based on sulfate-reducing and sulfide—oxidizing processes for treating organic wastewater containing high sulfate/sulfide. The influence of COD/SO42− ratio and hydraulic retention time (HRT) on removal efficiencies of sulfate, COD, sulfide and electricity generation was investigated. The continuous operation of the treatment system was carried out for 63 days with the optimum COD/SO42− ratio and HRT. The result showed that the COD and sulfate removal efficiencies were stable, reaching 94.8 ± 0.6 and 93.0 ± 1.3% during the operation. A power density level of 18.0 ± 1.6 mW/m2 was obtained with a sulfide removal efficiency of 93.0 ± 1.2%. However, the sulfide removal efficiency and power density decreased gradually after 45 days. The results from scanning electron microscopy (SEM) with an energy dispersive X-ray (EDX) show that sulfur accumulated on the anode, which could explain the decline in sulfide oxidation and electricity generation. This study provides a promising treatment system to scale up for its actual applications in this type of wastewater.
High Value-Added Reutilization of Waste-Printed Circuit Boards Non-Metallic Components in Sustainable Polymer Composites
Authors: Hu Dechao , Zeng Xianghong , Lin Yinlei , Chen Yongjun , Chen Wanjuan , Jia Zhixin , Lin Jing
Published: August 2023

The reutilization non-metallic components from a waste-printed circuit board (WPCB) has become one of the most significant bottlenecks in the comprehensive reuse of electronic wastes due to its low value and complex compositions, and it has received great attention from scientific and industrial researchers. To effectively address the environmental pollution caused by inappropriate recycling methods, such as incineration and landfill, extensive efforts have been dedicated to achieving the high value-added reutilization of WPCB non-metals in sustainable polymer composites. In this review, recent progress in developing sustainable polymer composites based on WPCB non-metallic components was systematically summarized. It has been demonstrated that the WPCB non-metals can serve as a promising reinforcing and functional fillers to significantly ameliorate some of the physical and chemical properties of polymer composites, such as excellent mechanical properties, enhanced thermal stability, and flame retardancy. The recovery strategies and composition of WPCB non-metals were also briefly discussed. Finally, the future potentials and remaining challenges regarding the reutilization of WPCB non-metallic components are outlined. This work provides readers with a comprehensive understanding of the preparation, structure, and properties of the polymer composites based on WPCB non-metals, providing significant insights regarding the high value-added reutilization of WPCB non-metals of electronic wastes.
Antiradical and Antioxidant Activity of Compounds Containing 1,3-Dicarbonyl Moiety: An Overview
Authors: Bērziņa Laima , Mieriņa Inese
Published: August 2023

Free radicals and oxidants may cause various damages both to the lifeworld and different products. A typical solution for the prophylaxis of oxidation-caused conditions is the usage of various antioxidants. Among them, various classes are found—polyphenols, conjugated polyalkenes, and some sulfur and nitrogen derivatives. Regarding the active site in the molecules, a widely discussed group of compounds are 1,3-dicarbonyl compounds. Among them are natural (e.g., curcumin and pulvinic acids) and synthetic (e.g., 4-hydroxy coumarins, substituted Meldrum’s acids) compounds. Herein, information about various compounds containing the 1,3-dicarbonyl moiety is covered, and their antiradical and antioxidant activity, depending on the structure, is discussed.
Coordinatively Unsaturated Nickel Nitroxyl Complex: Structure, Physicochemical Properties, and Reactivity toward Dioxygen
Authors: Fujisawa Kiyoshi , Kataoka Taisei , Terashima Kohei , Kurihara Haruka , de Santis Gonçalves Felipe , Lehnert Nicolai
Published: August 2023

For its important roles in biology, nitrogen monoxide (·NO) has become one of the most studied and fascinating molecules in chemistry. ·NO itself acts as a “noninnocent” or “redox active” ligand to transition metal ions to give metal–NO (M–NO) complexes. Because of this uncertainty due to redox chemistry, the real description of the electronic structure of the M–NO unit requires extensive spectroscopic and theoretical studies. We previously reported the Ni–NO complex with a hindered N3 type ligand [Ni(NO)(L3)] (L3− denotes hydrotris(3-tertiary butyl-5-isopropyl-1-pyrazolyl)borate anion), which contains a high-spin (hs) nickel(II) center and a coordinated 3NO−. This complex is very stable toward dioxygen due to steric protection of the nickel(II) center. Here, we report the dioxygen reactivity of a new Ni–NO complex, [Ni(NO)(I)(L1″)], with a less hindered N2 type bis(pyrazolyl)methane ligand, which creates a coordinatively unsaturated ligand environment about the nickel center. Here, L1″ denotes bis(3,5-diisopropyl-1-pyrazolyl)methane. This complex is also described as a hs-nickel(II) center with a bound 3NO−, based on spectroscopic and theoretical studies. Unexpectedly, the reaction of [Ni(NO)(I)(L1″)] with O2 yielded [Ni(κ2-O2N)(L1″)2](I3), with the oxidation of both 3NO− and the I− ion to yield NO2− and I3−. Both complexes were characterized by X-ray crystallography, IR, and UV–Vis spectroscopy and theoretical calculations.
ROS1-Rearranged Lung Adenocarcinoma: From Molecular Genetics to Target Therapy
Authors: Testa Ugo , Castelli Germana , Pelosi Elvira
Published: August 2023

Non-small-cell lung cancer (NSCLC) is a heterogeneous group of diseases accounting for 80–85% of lung cancers. A molecular subset of NSCLC (1–2.5%) harboring molecular rearrangements of the tyrosine kinase gene ROS1 is defined as ROS1-positive and is almost exclusively diagnosed in patients with lung adenocarcinoma histology, predominantly nonsmokers. ROS1 is constitutively activated by molecular rearrangements and acts as a main driver of lung carcinogenesis. These findings have provided a strong rationale for the clinical use of tyrosine kinase inhibitors that target ROS1; these inhibitors block ROS1-positive NSCLC and provide clinical benefit. Crizotinib was introduced as a first-line treatment for ROS1-positive NSCLCs, with 75–80% of patients responding and a PFS of about 20 months. More recently developed ROS1-TKIs, such as entrectinib, lorlatinib, taletrectinib, repotrectinib and NVL-520, are active against some resistant ROS1 mutants appearing during crizotinib therapy and more active against brain metastases, frequent in ROS1-positive NSCLC. The development of resistance mechanisms represents a great limitation for the targeted treatment of ROS1-positive NSCLCs with TKIs.
Joining Forces against Antibiotic Resistance: The One Health Solution
Authors: Cella Eleonora , Giovanetti Marta , Benedetti Francesca , Scarpa Fabio , Johnston Catherine , Borsetti Alessandra , Ceccarelli Giancarlo , Azarian Taj , Zella Davide , Ciccozzi Massimo
Published: August 2023

Antibiotic resistance is a significant global health concern that affects both human and animal populations. The One Health approach acknowledges the interconnectedness of human health, animal health, and the environment. It emphasizes the importance of collaboration and coordination across these sectors to tackle complex health challenges such as antibiotic resistance. In the context of One Health, antibiotic resistance refers to the ability of bacteria to withstand the efficacy of antibiotics, rendering them less effective or completely ineffective in treating infections. The emergence and spread of antibiotic-resistant bacteria pose a threat to human and animal health, as well as to the effectiveness of medical treatments and veterinary interventions. In particular, One Health recognizes that antibiotic use in human medicine, animal agriculture, and the environment are interconnected factors contributing to the development and spread of antibiotic resistance. For example, the misuse and overuse of antibiotics in human healthcare, including inappropriate prescribing and patient non-compliance, can contribute to the selection and spread of resistant bacteria. Similarly, the use of antibiotics in livestock production for growth promotion and disease prevention can contribute to the development of antibiotic resistance in animals and subsequent transmission to humans through the food chain. Addressing antibiotic resistance requires a collaborative One Health approach that involves multiple participants, including healthcare professionals, veterinarians, researchers, and policymakers.
Effects of Transition from Closed-Book to Open-Book Assessment on Students’ Scores in a Pharmacokinetics Course
Authors: Mehvar Reza , Beuttler Richard
Published: August 2023

Closed-book summative assessment of student learning, common in pharmacy education, is challenging to administer in a remote setting due to the need for costly and intrusive monitoring technology. Therefore, open-book assessments without monitoring have been considered an alternative in remote settings. The present study investigated the effects of the transition from in-person closed-book to remote open-book format on the students’ scores in different assessment categories in a Pharmacokinetics course. The students’ performances in the transition cohort (Transition, n = 96) during the in-person and remote periods were compared with those of an in-person cohort (Control, n = 85) during the same periods. Assessments included take-home assignments, daily quizzes, and progress/final examinations. Whereas the take-home assignments were open-book for cohorts and periods, the quizzes and examinations were open-book only for the Transition cohort during the remote period. Only the quiz/examination questions that were identical for both cohorts were included in the analysis. Statistical analysis by a linear, mixed-effects model indicated that the transition did not have any significant impact on the scores of students in the assignments, which were open-book for both cohorts and both periods. However, there were significant increases in the Transition cohort’s scores (mean ± SE) during the remote open-book period in both quizzes (+8.4 ± 1.9%) and examination (+6.8 ± 1.5%) questions, compared with the Control cohort who had in-person closed-book assessments. These differences amounted to Cohen’s d-effect sizes of 0.61 and 0.59 for the quiz and examination questions, respectively. It is concluded that when the questions are similar, the students’ scores in pharmacokinetic assessments are higher (medium effect size) in a remote open-book format compared with the in-person closed-book format.
Assessment of Cognitive Behavioral Characteristics in Intelligent Systems with Predictive Ability and Computing Power
Authors: Kubryak Oleg V. , Kovalchuk Sergey V. , Bagdasaryan Nadezhda G.
Published: August 2023

The article proposes a universal dual-axis intelligent systems assessment scale. The scale considers the properties of intelligent systems within the environmental context, which develops over time. In contrast to the frequent consideration of the “mind” of artificial intelligent systems on a scale from “weak” to “strong”, we highlight the modulating influences of anticipatory ability on their “brute force”. In addition, the complexity, the ”weight“ of the cognitive task and the ability to critically assess it beforehand determine the actual set of cognitive tools, the use of which provides the best result in these conditions. In fact, the presence of ”common sense“ options is what connects the ability to solve a problem with the correct use of such an ability itself. The degree of ”correctness“ and ”adequacy“ is determined by the combination of a suitable solution with the temporal characteristics of the event, phenomenon, object or subject under study. The proposed approach can be applied in the evaluation of various intelligent agents in different contexts including AI and humans performing complex domain-specific tasks with high uncertainty.
BiGRU-Based Adaptive Receiver for Indoor DCO-OFDM Visible Light Communication
Authors: Huang Yi , Han Dahai , Zhang Min , Zhu Yanwen , Wang Liqiang
Published: August 2023

Nonlinear devices and channel interference can significantly impact the received signal in visible light communication (VLC). While recent research has explored receiver recovery using deep learning, existing approaches often involve replacing traditional channel estimation and equalization modules with neural network models. However, these models introduce additional data processing steps after fast Fourier transform (FFT), leading to increased complexity. To address these challenges, this study introduces a novel direct time-domain waveform equalization approach using a bidirectional gated recurrent unit (BiGRU) neural network for indoor VLC employing direct current (DC)-biased orthogonal frequency division multiplexing (DCO-OFDM). Unlike previous methods, our proposed scheme utilizes time-domain waveform data from photodiode outputs for direct balancing, harnessing the potent nonlinear processing capabilities of the BiGRU model. We first analyze the nonlinear processing capacity of the BiGRU model and subsequently compare the performance of different receiving methods on a constructed indoor visible-light communication platform. Experimental results demonstrate that the BiGRU-based approach exhibits low complexity and exceptional nonlinear channel learning capabilities. Notably, the proposed method outperforms other strategies in terms of bit error rate without the need for pilot signals. These findings validate the potential of the BiGRU-based DCO-OFDM receiving scheme as a promising solution for future VLC systems.
Robust Topological Edge States in C6 Photonic Crystals
Authors: Borges-Silva Daniel , Costa Carlos Humberto Oliveira , Bezerra Claudionor Gomes
Published: August 2023

The study of photonic crystals has emerged as an attractive area of research in nanoscience in the last years. In this work, we study the properties of a two-dimensional photonic crystal composed of dielectric rods. The unit cell of the system is composed of six rods organized on the sites of a C6 triangular lattice. We induce a topological phase by introducing an angular perturbation ϕ in the pristine system. The topology of the system is then determined by using the so-called k.p perturbed model. Our results show that the system presents a topological and a trivial phase, depending on the sign of the angular perturbation ϕ. The topological character of the system is probed by evaluating the electromagnetic energy density and analyzing its distribution in the real space, in particular on the maximal Wyckoff points. We also find two edge modes at the interface between the trivial and topological photonic crystals, which present a pseudospin topological behavior. By applying the bulk-edge correspondence, we study the pseudospin edge modes and conclude that they are robust against defects, disorder and reflection. Moreover, the localization of the edge modes leads to the confinement of light and the interface behaves as a waveguide for the propagation of electromagnetic waves. Finally, we show that the two edge modes present energy flux propagating in opposite directions, which is the photonic analogue of the quantum spin Hall effect.
Thermo-Mechanical Numerical Analysis of Stress and Damage Distribution within the Surrounding Rock of Underground Coal Gasification Panels
Authors: Wang Pengfei , Deng Jingen , Liu Wei , Xiao Qiangzhong , Lv Qian , Zhang Yan , Hou Youlin
Published: August 2023

Underground coal gasification (UCG) is a promising technology for extracting synthesis gas from coal seams through in situ gasification. This study aims to investigate the thermo-mechanical behavior and integrity of the surrounding rock in the gasification vicinity to facilitate safe and efficient UCG operations. Rock property testing experiments are conducted under varying temperature conditions, revealing significant temperature dependencies for the thermal and mechanical parameters. A thermo-mechanical coupling model is developed to analyze the stress and damage distribution near the gasification chamber. The influence of the temperature dependency of stress states and failure risks during the gasification process is evaluated. In addition, the effects of panel orientation, chamber width, maintaining duration, operating temperature and operating pressure on the failure behavior of the gasification surrounding rocks are illustrated through parametric analysis. The findings have practical implications for the design and assessment of UCG processes, enhancing the safety and efficiency of coal gasification operations.
Energy Variation Features during the Isothermal Adsorption of Coal under High-Temperature and High-Pressure Conditions
Authors: Jing Tongling , Tao Chuanqi , Wang Yanbin , Miao Huan , Xi Mingyu , Zhao Xingchen , Fu Haiyang
Published: August 2023

This paper aims to describe methane adsorption in coal under the conditions of high temperature and high pressure, as well as quantitatively decipher the change rule of energy in the isothermal adsorption process. The isothermal adsorption test was carried out with four groups of middle-rank coals from the Linxing area with different degrees of metamorphism. The impacts of the degree of deterioration of coal, temperature, and pressure on adsorption were analyzed with regard to the adsorption amount, adsorption potential, and adsorption space. Additionally, the energy change during the adsorption of methane by the coal was considered. The results show that the coal adsorption capacity hinges on the degree of deterioration of the coal, as well as the pressure and temperature. Additionally, the impact of temperature upon coal methane adsorption under depth conditions is highlighted. Like the adsorption space, the adsorption potential is an important parameter used to quantitatively characterize the adsorption ease and adsorption capacity; furthermore, the adsorption potential of millipores exceeds that of mesopores, as they are capable of offering a larger specific surface area for adsorption. The total decrease in the surface free energy during adsorption increases as the pressure increases; simultaneously, the increase rate is fast and then slow. The total decrease in the above-described free energy diminishes as the temperature escalates. Under the same pressure, the total decrease in the aforementioned free energy increases as the reflectance of the specular body of the coal increases. The decrease in the aforementioned free energy at each point of pressure lessens as the pressure grows; notably, when the pressure is comparatively low, the reduction is very fast. As the pressure escalates continuously, the decrease speed is slow. Regarding the effect of pressure and temperature upon adsorption, the adsorption gas volume of coal exists in a conversion depth from 1200 m to 1500 m; at the same time, the impact of pressure upon adsorption is dominant up to this depth. Additionally, beyond this depth, temperature gradually comes to have the greatest impact on adsorption.
Effect of LiCl Electrolyte Concentration on Energy Storage of Supercapacitor with Multilayered Ti3C2Tx MXene Electrodes Synthesized by Hydrothermal Etching
Authors: Tsyganov Alexey , Shindrov Alexander , Vikulova Maria , Zheleznov Denis , Gorokhovsky Alexander , Gorshkov Nikolay
Published: August 2023

The development of new electrode materials for electrochemical systems for various purposes is a significant and in-demand task of scientific research. Layered transition metal carbides and nitrides, known as MXenes, show great potential for use as electrodes in electrochemical energy storage devices operating in aqueous electrolytes. In this work, a multilayer Ti3C2Tx MXene was obtained from a Ti3AlC2 precursor and studied as the electrode material of a symmetrical supercapacitor with an aqueous LiCl electrolyte. The formation of the MXene structure was confirmed by the data from X-ray phase analysis and scanning electron microscopy. The X-ray diffraction pattern showed the disappearance of the main reflections related to the Ti3AlC2 phase and the shift of the reflection peak (002) from 9.4° to 6.7°, which indicated successful etching of the Al layers from the Ti3AlC2 precursor. At electrolyte concentrations of 1, 5, 10, and 20 M, the supercapacitors demonstrated high specific capacitances of 105, 120, 126, and 151 F·g−1 at a scan rate of 5 mV·s−1. In addition, an increase in the LiCl concentration contributed to the expansion of the potential window from 0.7 to 1 V. It was shown that the contribution of the surface capacitance to the total capacitance of the electrode is about 40% and depends little on the scan rate. In addition, the symmetrical supercapacitor with 5 M electrolyte showed good cyclic stability with capacitance retention of 88% over 10,000 cycles. The parameters of the main components of the physical processes of supercapacitors based on Ti3C2Tx were determined by the method of impedance spectroscopy.
Inside Late Bronze Age Settlements in NE Romania: GIS-Based Surface Characterization of Ashmound Structures Using Airborne Laser Scanning and Aerial Photography Techniques
Authors: Brașoveanu Casandra , Mihu-Pintilie Alin , Brunchi Radu-Alexandru
Published: August 2023

The identification and delineation, through aerial photography, of the archaeological structures that present temporal resolution, as well as their characterization based on high-resolution LiDAR (Light Detection and Ranging)-derived DEMs (Digital Elevation Models) are modern techniques widely used in the archaeological prospecting of various landscapes. In this study, we present an application of Airborne Laser Scanning (ALS) and aerial photography (AP) techniques, used in order to compute geomorphometric indices specific to the ashmound structures of Late Bronze Age (LBA) archaeological sites that are visible on the soil surface. The necessity of determining the ashmounds’ geoarchaeological description stems from the fact that despite the majority of archaeologists weighing in on the subject, there is still no accepted explanation regarding their initial functionality. Thus, we believe that the GIS-based high-resolution characterization of 200 ashmound features identified in 21 Noua Culture (NC) archaeological sites will contribute to a better understanding of the ashmounds’ functionality and evolution in the heterogeneous landscape of the study area (NE Romania). Therefore, various shape indices, such as the area (A), perimeter (P), length (L), form factor (RF), circularity ratio (RC), and elongation ratio (RE) were computed for microlevel characterizations of the visible ashmounds’ structures. Additionally, LiDAR-derived DEMs with a 0.5 m resolution were used to generate more surface characteristics such as the slope (S) and hypsometric indices (HI). The outcomes indicate that the ashmounds have relatively diverse shapes (an RF range from 0.37 to 0.77; a RC range from 0.79 to 0.99; a RE range from 0.68 to 0.99), and the micro-relief slightly varies from positive to negative landforms (HI range from 0.34 to 0.61) depending on the erosion intensity (S range from 1.17° to 19.69°) and anthropogenic impact (e.g., current land use and agriculture type). Furthermore, each morphometric parameter is an indicator for surface processes, aiding in the identification of the geomorphologic and surface-erosion aspects that affect the archaeological remains, contributing to the assessment of the conservation status of the ashmound structures within the current landscape configuration. In this regard, this article presents and discusses the remote sensing (RS) techniques used, as well as the morphometric data obtained, exploring the implications of our findings for a better characterization of the NC in Romania.
Modeling Signal-to-Noise Ratio of CMOS Image Sensors with a Stochastic Approach under Non-Stationary Conditions
Authors: Cherniak Gil , Nemirovsky Jonathan , Nemirovsky Amikam , Nemirovsky Yael
Published: August 2023

A stochastic model for characterizing the conversion gain of Active Pixel Complementary metal–oxide–semiconductor (CMOS) image sensors (APS), assuming stationary conditions was recently presented in this journal. In this study, we extend the stochastic approach to non-stationary conditions. Non-stationary conditions occur in gated imaging applications. This new stochastic model, which is based on fundamental physical considerations, enlightens us with new insights into gated CMOS imaging, regardless of the sensor. The Signal-to-Noise Ratio (SNR) is simulated, allowing optimized performance. The conversion gain should be determined under stationary conditions.
Multimodal Approach for Pilot Mental State Detection Based on EEG
Authors: Alreshidi Ibrahim , Moulitsas Irene , Jenkins Karl W.
Published: August 2023

The safety of flight operations depends on the cognitive abilities of pilots. In recent years, there has been growing concern about potential accidents caused by the declining mental states of pilots. We have developed a novel multimodal approach for mental state detection in pilots using electroencephalography (EEG) signals. Our approach includes an advanced automated preprocessing pipeline to remove artefacts from the EEG data, a feature extraction method based on Riemannian geometry analysis of the cleaned EEG data, and a hybrid ensemble learning technique that combines the results of several machine learning classifiers. The proposed approach provides improved accuracy compared to existing methods, achieving an accuracy of 86% when tested on cleaned EEG data. The EEG dataset was collected from 18 pilots who participated in flight experiments and publicly released at NASA’s open portal. This study presents a reliable and efficient solution for detecting mental states in pilots and highlights the potential of EEG signals and ensemble learning algorithms in developing cognitive cockpit systems. The use of an automated preprocessing pipeline, feature extraction method based on Riemannian geometry analysis, and hybrid ensemble learning technique set this work apart from previous efforts in the field and demonstrates the innovative nature of the proposed approach.
An Analysis of the Convergence Problem of a Function in Functional Norms by Applying the Generalized Nörlund-Matrix Product Operator
Authors: Srivastava Hari , Nigam Hare , Nandy Swagata
Published: August 2023

In this paper, we analyze the convergence problems of function g of Fourier series in Besov and generalized Zygmund norms using generalized Nörlund-Matrix (Np,qA) means of Fourier series. Convergence results are also compared by means of applications.
Auditing Accessibility of Pavements and Points of Interest in Urban Areas: The ‘Seek & Go’ Tool
Authors: Achillas Charisios , Aidonis Dimitrios , Tsolakis Naoum , Tsampoulatidis Ioannis , Mourouzis Alexandros , Bialas Christos , Koritsoglou Kyriakos
Published: August 2023

In recent years, accessibility has become a topic of great interest on a global scale across the scientific, business, and policy sectors. There are two primary reasons for this growing trend. Firstly, accessibility serves as a vital indicator reflecting the social performance of communities, and the public is increasingly aware of critical social issues such as accessibility. Secondly, accessibility is essential for the sustainable development of regions and civil settings, facilitating inclusion and business growth. In this regard, information and communications technologies can play a crucial role in facilitating the accessibility of spaces by disabled people. Numerous digital tools and smart applications are already available to serve this purpose. This study presents a novel digital tool called ‘Seek & Go’, a comprehensive aid application designed specifically for disabled individuals. The app features a GPS navigation system that caters to pedestrians with disabilities and unique accessibility requirements. The present study documents the models underlying the development of ‘Seek & Go’, discusses technical aspects of the application, and presents user experience insights.
The Thread of Trauma: A Critical Analysis of the Criminal Legal System
Authors: Slovinsky Tammi L.
Published: August 2023

A thread of trauma weaves throughout the U.S. criminal legal system, beginning with individual childhood experiences that are situated within families, communities, and systems that are embedded in structural oppression, thereby increasing the risk of initial and subsequent traumas. The criminal legal system, where individuals who experience prior trauma are more likely to be system-involved, exposes racial minority youths especially to further trauma. This thread also impacts criminal legal system professionals who bear witness to the indirect trauma of victims and people who have harmed, which is often manifested in secondary and vicarious trauma symptoms, while may also cause them to grapple with their own prior trauma. The author offers a critical theory of trauma based on Bronfenbrenner’s ecological framework, first by examining select scholarly research on individual-, relationship-, community-, and system-level trauma, including trauma within the criminal legal system. The system is then examined through the lens of critical race theory, which both explains the persistence of oppression within the system and provides a path to reform by centering on the lived experiences of those most impacted. The author then applies the concepts of secondary and vicarious trauma, psychological safety, and institutional betrayal to explore original research on the impacts of working sex crimes on prosecutors. Finally, implications for system- and organizational-level change and recommendations for future research are offered, including the meaningful engagement of individuals with lived experiences in the development, implementation, and evaluation of victim-centered, trauma-informed, and culturally responsive programs and services.
Triggers and Halts of Professional Mobility in Public Companies: A Case Study of the Romanian Forest Administration
Authors: Iosifescu Vasile , Drăgoi Marian
Published: August 2023

This research tried to identify the most important factors that motivate or hinder forest engineers in commuting between their household and the regional office of the National Forest Administration, or prompt them to relocate their entire family to Bucharest, where the headquarters of the NFA is located, in seeking promotion in the professional hierarchy. A survey, administered as a Google form, was designed to carry out analysis of independent benefits, opportunities, costs, and risks. The decision process was designed as an analytic hierarchy process, and each one of these factors was a separate analytic hierarchy process. We found that forest engineers tend to be very conservative when it comes to changing their professional position from the forest district to the NFA regional office or NFA top management. On the one hand, the professional opportunities to promote upwards do not compensate for the fringe benefits gained at the forest district level, while the costs of living in a larger city outweigh the benefits, even though the house rent is paid by the employer.