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Search Results (269)

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19 pages, 10416 KiB  
Article
A Comparative Study of the Latest Editions of China–Japan–US Green Building Evaluation Standards
by Qiyuan Wang, Weijun Gao, Yuan Su and Yinqi Zhang
Buildings 2024, 14(11), 3698; https://doi.org/10.3390/buildings14113698 - 20 Nov 2024
Viewed by 214
Abstract
The Green Building Evaluation Standard (ESGB) has become an important support for China’s building sector in realizing the “double carbon” goal. However, there remains a lack of comprehensive research on the historical evolution and development status of the ESGB. This study firstly analyzes [...] Read more.
The Green Building Evaluation Standard (ESGB) has become an important support for China’s building sector in realizing the “double carbon” goal. However, there remains a lack of comprehensive research on the historical evolution and development status of the ESGB. This study firstly analyzes the updating logic and development strategy of the three versions of the ESGB, then compares the differences between ESGB 2019, CASBEE-NC 2014, and LEED O+M v4.1 from the perspective of the index system, and further examines the current international application status of the ESGB. The results show that LEED focuses on decarbonization and ecological protection, while CASEBB focuses on the concept of humanization and positively influences the local real estate market, and ESGB 2019 contains more health and comfort considerations than its previous version and is close to the internationally advanced level in terms of provision setting and international application. This study offers valuable insights into the potential for further refinement of green building standards in China and highlights areas for future research, including enhancing the ESGB’s adaptability and integration with emerging technologies to promote global sustainable development. Full article
(This article belongs to the Special Issue Low-Carbon Urban Development and Building Design)
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<p>Indicator changes in ESGB 2014.</p>
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<p>Indicator changes in ESGB 2019.</p>
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<p>School building of the University of Kitakyushu (Source: The University of Kitakyushu Official Website).</p>
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27 pages, 9590 KiB  
Review
Posterior Retroperitoneal Laparoscopic Adrenalectomy: An Anatomical Essay and Surgical Update
by Bogdan Ovidiu Feciche, Vlad Barbos, Alexandru Big, Daniel Porav-Hodade, Alin Adrian Cumpanas, Silviu Constantin Latcu, Flavia Zara, Alina Cristina Barb, Cristina-Stefania Dumitru, Talida Georgiana Cut, Hossam Ismail and Dorin Novacescu
Cancers 2024, 16(22), 3841; https://doi.org/10.3390/cancers16223841 - 15 Nov 2024
Viewed by 309
Abstract
Posterior retroperitoneal laparoscopic adrenalectomy (PRLA) has emerged as a revolutionary, minimally invasive technique for adrenal gland surgery, offering significant advantages over traditional open approaches. This narrative review aims to provide a comprehensive update on PRLA, focusing on its anatomical foundations, surgical technique, and [...] Read more.
Posterior retroperitoneal laparoscopic adrenalectomy (PRLA) has emerged as a revolutionary, minimally invasive technique for adrenal gland surgery, offering significant advantages over traditional open approaches. This narrative review aims to provide a comprehensive update on PRLA, focusing on its anatomical foundations, surgical technique, and clinical implications. We conducted an extensive review of the current literature and surgical practices to elucidate the key aspects of PRLA. The procedure leverages a unique “backdoor” approach, accessing the adrenal glands through the retroperitoneum, which necessitates a thorough understanding of the posterior abdominal wall and retroperitoneal anatomy. Proper patient selection, meticulous surgical planning, and adherence to key technical principles are paramount for successful outcomes. In this paper, the surgical technique is described step by step, emphasizing critical aspects such as patient positioning, trocar placement, and adrenal dissection. PRLA demonstrates reduced postoperative pain, shorter hospital stays, and faster recovery times compared to open surgery, while maintaining comparable oncological outcomes for appropriately selected cases. However, the technique presents unique challenges, including a confined working space and the need for surgeons to adapt to a posterior anatomical perspective. We conclude that PRLA, in the right clinical setting, offers a safe and effective alternative to traditional adrenalectomy approaches. Future research should focus on expanding indications and refining techniques to further improve patient outcomes. Full article
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<p>Histological architecture of the adrenal glands (hematoxylin–eosin, 100×).</p>
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<p>Illustration of bilateral adrenal gland vascularization: anterior view, coronal section.</p>
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<p>Abdominal parietal anatomy illustration, focusing on the right posterior and antero-lateral walls, in an axial L2 section of a prone patient, superior view. *—Anterior layer of thoracolumbar fascia (marked in green); **—middle layer of thoracolumbar fascia (marked in light blue); ***—posterior layer of thoracolumbar fascia (marked in deep blue).</p>
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<p>Posterior abdominal wall anatomy illustration: right side, posterior view, coronal section.</p>
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<p>Illustration of the right retroperitoneal cavity, with highlighted fascial layers and compartmentation into retroperitoneal spaces: 1—anterior pararenal space (in green); 2—perirenal space (in pink); 3—posterior pararenal space (in blue); *—anterior perirenal fascia (Gerota’s fascia); **—posterior perirenal fascia (Zuckerkandl’s fascia); ***—lateroconal fascia; ****—posterior parietal peritoneum.</p>
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<p>Prone jackknife positioning for posterior retroperitoneal laparoscopic adrenalectomy. *—Central 10 mm trocar; **—medial 5 mm trocar; ***—lateral 5 mm trocar; blue circle—optional additional 5 mm trocar, at times necessary for retraction.</p>
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<p>Comparative illustrations of trocar placement for posterior retroperitoneal laparoscopic adrenalectomy on the right side: (<b>a</b>) Axial section, prone position, superior view (from the head of the patient). (<b>b</b>) Coronal section, prone position, posterior perspective (from the surgeon’s perspective).</p>
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<p>Right posterior retroperitoneal laparoscopic adrenalectomy, with the characteristic junction between the central right adrenal vein and the inferior vena cava highlighted by the green circle: (<b>a</b>) live surgery image; (<b>b</b>) illustration.</p>
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<p>Left posterior retroperitoneal laparoscopic adrenalectomy, with the characteristic junction between the central left adrenal vein and the left inferior phrenic vein highlighted by the yellow circle: (<b>a</b>) illustration; (<b>b</b>) live surgery image.</p>
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16 pages, 4667 KiB  
Article
State Estimation for Quadruped Robots on Non-Stationary Terrain via Invariant Extended Kalman Filter and Disturbance Observer
by Mingfei Wan, Daoguang Liu, Jun Wu, Li Li, Zhangjun Peng and Zhigui Liu
Sensors 2024, 24(22), 7290; https://doi.org/10.3390/s24227290 - 14 Nov 2024
Viewed by 440
Abstract
Quadruped robots possess significant mobility in complex and uneven terrains due to their outstanding stability and flexibility, making them highly suitable in rescue missions, environmental monitoring, and smart agriculture. With the increasing use of quadruped robots in more demanding scenarios, ensuring accurate and [...] Read more.
Quadruped robots possess significant mobility in complex and uneven terrains due to their outstanding stability and flexibility, making them highly suitable in rescue missions, environmental monitoring, and smart agriculture. With the increasing use of quadruped robots in more demanding scenarios, ensuring accurate and stable state estimation in complex environments has become particularly important. Existing state estimation algorithms relying on multi-sensor fusion, such as those using IMU, LiDAR, and visual data, often face challenges on non-stationary terrains due to issues like foot-end slippage or unstable contact, leading to significant state drift. To tackle this problem, this paper introduces a state estimation algorithm that integrates an invariant extended Kalman filter (InEKF) with a disturbance observer, aiming to estimate the motion state of quadruped robots on non-stationary terrains. Firstly, foot-end slippage is modeled as a deviation in body velocity and explicitly included in the state equations, allowing for a more precise representation of how slippage affects the state. Secondly, the state update process integrates both foot-end velocity and position observations to improve the overall accuracy and comprehensiveness of the estimation. Lastly, a foot-end contact probability model, coupled with an adaptive covariance adjustment strategy, is employed to dynamically modulate the influence of the observations. These enhancements significantly improve the filter’s robustness and the accuracy of state estimation in non-stationary terrain scenarios. Experiments conducted with the Jueying Mini quadruped robot on various non-stationary terrains show that the enhanced InEKF method offers notable advantages over traditional filters in compensating for foot-end slippage and adapting to different terrains. Full article
(This article belongs to the Section Sensors and Robotics)
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<p>Test environments.</p>
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<p>Foot slipping scenarios of a quadruped robot during ground contact.</p>
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<p>Estimation of foot contact probability during unstable contact events, with (<b>a</b>) representing right front leg and (<b>b</b>) left rear leg.</p>
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<p>The position estimates of the quadruped robot in the X, Y, and Z directions on different terrains, with (<b>a</b>–<b>c</b>) depicting the position estimate for rugged slope terrain, (<b>d</b>–<b>f</b>) for shallow grass terrain, and (<b>g</b>–<b>i</b>) for deep grass terrain.</p>
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<p>The position estimates of the quadruped robot in the X, Y, and Z directions on different terrains, with (<b>a</b>–<b>c</b>) depicting the position estimate for rugged slope terrain, (<b>d</b>–<b>f</b>) for shallow grass terrain, and (<b>g</b>–<b>i</b>) for deep grass terrain.</p>
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<p>Pitch and roll angle estimation of the quadruped robot on different terrains, with (<b>a</b>,<b>d</b>) depicting the estimate for rugged slope terrain, (<b>b</b>,<b>e</b>) for shallow grass terrain, and (<b>c</b>,<b>f</b>) for deep grass terrain.</p>
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<p>Pitch and roll angle estimation of the quadruped robot on different terrains, with (<b>a</b>,<b>d</b>) depicting the estimate for rugged slope terrain, (<b>b</b>,<b>e</b>) for shallow grass terrain, and (<b>c</b>,<b>f</b>) for deep grass terrain.</p>
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24 pages, 4837 KiB  
Article
Improved Grey Wolf Algorithm: A Method for UAV Path Planning
by Xingyu Zhou, Guoqing Shi and Jiandong Zhang
Drones 2024, 8(11), 675; https://doi.org/10.3390/drones8110675 - 14 Nov 2024
Viewed by 420
Abstract
The Grey Wolf Optimizer (GWO) algorithm is recognized for its simplicity and ease of implementation, and has become a preferred method for solving global optimization problems due to its adaptability and search capabilities. Despite these advantages, existing Unmanned Aerial Vehicle (UAV) path planning [...] Read more.
The Grey Wolf Optimizer (GWO) algorithm is recognized for its simplicity and ease of implementation, and has become a preferred method for solving global optimization problems due to its adaptability and search capabilities. Despite these advantages, existing Unmanned Aerial Vehicle (UAV) path planning algorithms are often hindered by slow convergence rates, susceptibility to local optima, and limited robustness. To surpass these limitations, we enhance the application of GWO in UAV path planning by improving its trajectory evaluation function, convergence factor, and position update method. We propose a collaborative UAV path planning model that includes constraint analysis and an evaluation function. Subsequently, an Enhanced Grey Wolf Optimizer model (NI–GWO) is introduced, which optimizes the convergence coefficient using a nonlinear function and integrates the Dynamic Window Approach (DWA) algorithm into the model based on the fitness of individual wolves, enabling it to perform dynamic obstacle avoidance tasks. In the final stage, a UAV path planning simulation platform is employed to evaluate and compare the effectiveness of the original and improved algorithms. Simulation results demonstrate that the proposed NI–GWO algorithm can effectively solve the path planning problem for UAVs in uncertain environments. Compared to Particle Swarm Optimization (PSO), Artificial Bee Colony (ABC), GWO, and MP–GWO algorithms, the NI–GWO algorithm can achieve the optimal fitness value and has significant advantages in terms of average path length, time, number of collisions, and obstacle avoidance capabilities. Full article
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<p>Content block diagram of UAV co-operative path planning model based on improved grey wolf algorithm.</p>
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<p>The UAV path planning diagram.</p>
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<p>Different flight formations for a swarm of UAVs: (<b>a</b>) v-shaped; (<b>b</b>) echelon; (<b>c</b>) diamond-shaped.</p>
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<p>Schematic diagram of path planning for the <span class="html-italic">m</span>-th UAV.</p>
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<p>Schematic diagram of pitch and heading angles for the <span class="html-italic">m</span>-th UAV.</p>
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<p>Variation curve of convergence factor.</p>
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<p>NI–GWO algorithm flowchart.</p>
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<p>Detail of differences between GWO and NI–GWO algorithms.</p>
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<p>Fitness value graphs for UAV path planning: (<b>a</b>) 3 UAVs; (<b>b</b>) 5 UAVs; (<b>c</b>) 7 UAVs.</p>
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<p>Fitness value graphs for UAV path planning: (<b>a</b>) 11 no-fly zones; (<b>b</b>) 15 no-fly zones; (<b>c</b>) 19 no-fly zones.</p>
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<p>Average fitness value.</p>
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<p>UAV path planning results: (<b>a</b>) v-shaped formation; (<b>b</b>) echelon formation; (<b>c</b>) diamond-shaped formation.</p>
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<p>UAV path planning dynamic obstacle avoidance results: (<b>a</b>) three UAVs; (<b>b</b>) five UAVs.</p>
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<p>UAV paths planned by different algorithms: (<b>a</b>) path planning trajectory of the ABC algorithm; (<b>b</b>) path planning trajectory of the PSO algorithm; (<b>c</b>) path planning trajectory of the GWO algorithm; (<b>d</b>) path planning trajectory of the MP–GWO algorithm; (<b>e</b>) path planning trajectory of the NI–GWO algorithm.</p>
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17 pages, 2693 KiB  
Article
Ultra-Short-Term Wind Power Forecasting Based on the MSADBO-LSTM Model
by Ziquan Zhao and Jing Bai
Energies 2024, 17(22), 5689; https://doi.org/10.3390/en17225689 - 14 Nov 2024
Viewed by 315
Abstract
To address the challenges of the strong randomness and intermittency of wind power generation that affect wind power grid integration, power system scheduling, and the safe and stable operation of the system, an improved Dung Beetle Optimization Algorithm (MSADBO) is proposed to optimize [...] Read more.
To address the challenges of the strong randomness and intermittency of wind power generation that affect wind power grid integration, power system scheduling, and the safe and stable operation of the system, an improved Dung Beetle Optimization Algorithm (MSADBO) is proposed to optimize the hyperparameters of the Long Short-Term Memory neural network (LSTM) for ultra-short-term wind power forecasting. By applying Bernoulli mapping for population initialization, the model’s sensitivity to wind power fluctuations is reduced, which accelerates the algorithm’s convergence speed. Incorporating an improved Sine Algorithm (MSA) into the forecasting model for this nonlinear problem significantly improves the position update strategy of the Dung Beetle Optimization Algorithm (DBO), which tends to be overly random and prone to local optima. This enhancement boosts the algorithm’s exploration capabilities both locally and globally, improving the rapid responsiveness of ultra-short-term wind power forecasting. Furthermore, an adaptive Gaussian–Cauchy mixture perturbation is introduced to interfere with individuals, increasing population diversity, escaping local optima, and enabling the continued exploration of other areas of the solution space until the global optimum is ultimately found. By optimizing three hyperparameters of the LSTM using the MSADBO algorithm, the prediction accuracy of the model is greatly enhanced. After simulation validation, taking winter as an example, the MSADBO-LSTM predictive model achieved a reduction in the MAE metric of 40.6% compared to LSTM, 20.12% compared to PSO-LSTM, and 3.82% compared to DBO-LSTM. The MSE decreased by 45.4% compared to LSTM, 40.78% compared to PSO-LSTM, and 16.62% compared to DBO-LSTM. The RMSE was reduced by 26.11% compared to LSTM, 23.05% compared to PSO-LSTM, and 8.69% compared to DBO-LSTM. Finally, the MAPE declined by 79.83% compared to LSTM, 31.88% compared to PSO-LSTM, and 29.62% compared to DBO-LSTM. This indicates that the predictive model can effectively enhance the accuracy of wind power forecasting. Full article
(This article belongs to the Section A3: Wind, Wave and Tidal Energy)
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<p>Structure of an LSTM neural network unit.</p>
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<p>Scatter plot and histogram of the Bernoulli mapping.</p>
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<p>Comparison of convergence curves for each algorithm.</p>
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<p>Comparison of convergence curves for each algorithm.</p>
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<p>Flowchart of the MSADBO-LSTM model.</p>
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<p>Spearman correlation coefficient matrix.</p>
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<p>Comparison of ultra-short-term wind power forecasting models (summer).</p>
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<p>Comparison of ultra-short-term wind power forecasting models (winter).</p>
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34 pages, 3921 KiB  
Article
Soft Actor-Critic Approach to Self-Adaptive Particle Swarm Optimisation
by Daniel von Eschwege and Andries Engelbrecht
Mathematics 2024, 12(22), 3481; https://doi.org/10.3390/math12223481 - 7 Nov 2024
Viewed by 523
Abstract
Particle swarm optimisation (PSO) is a swarm intelligence algorithm that finds candidate solutions by iteratively updating the positions of particles in a swarm. The decentralised optimisation methodology of PSO is ideally suited to problems with multiple local minima and deceptive fitness landscapes, where [...] Read more.
Particle swarm optimisation (PSO) is a swarm intelligence algorithm that finds candidate solutions by iteratively updating the positions of particles in a swarm. The decentralised optimisation methodology of PSO is ideally suited to problems with multiple local minima and deceptive fitness landscapes, where traditional gradient-based algorithms fail. PSO performance depends on the use of a suitable control parameter (CP) configuration, which governs the trade-off between exploration and exploitation in the swarm. CPs that ensure good performance are problem-dependent. Unfortunately, CPs tuning is computationally expensive and inefficient. Self-adaptive particle swarm optimisation (SAPSO) algorithms aim to adaptively adjust CPs during the optimisation process to improve performance, ideally while reducing the number of performance-sensitive parameters. This paper proposes a reinforcement learning (RL) approach to SAPSO by utilising a velocity-clamped soft actor-critic (SAC) that autonomously adapts the PSO CPs. The proposed SAC-SAPSO obtains a 50% to 80% improvement in solution quality compared to various baselines, has either one or zero runtime parameters, is time-invariant, and does not result in divergent particles. Full article
(This article belongs to the Special Issue Heuristic Optimization and Machine Learning)
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<p>Comparison of reward landscapes. (<b>a</b>) Absolute reward (Equation (<a href="#FD23-mathematics-12-03481" class="html-disp-formula">23</a>)). (<b>b</b>) Relative reward (Equation (<a href="#FD25-mathematics-12-03481" class="html-disp-formula">25</a>)). (<b>c</b>) Relative change (Equation (<a href="#FD26-mathematics-12-03481" class="html-disp-formula">26</a>)).</p>
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<p>Control parameter values for baseline. (<b>a</b>) Constant CP (note that plots for <math display="inline"><semantics> <msub> <mi>c</mi> <mn>1</mn> </msub> </semantics></math> and <math display="inline"><semantics> <msub> <mi>c</mi> <mn>2</mn> </msub> </semantics></math> coincides); (<b>b</b>) Time-variant CP; (<b>c</b>) Random CP.</p>
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<p>Stable particles for baseline.</p>
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<p>Infeasible particles for baseline.</p>
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<p>Particle velocity vectors for baseline.</p>
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<p>Swarm diversity for baseline.</p>
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<p>Control parameter values for SAC.</p>
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<p>Stable particles for SAC.</p>
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<p>Stable particles for SAC.</p>
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<p>Infeasible particles for SAC.</p>
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<p>Particle velocities for SAC.</p>
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<p>Swarm diversity (log) for SAC.</p>
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<p>Control parameter values for SAC (velocity clamped).</p>
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<p>Stable particles for SAC (velocity clamped).</p>
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<p>Infeasible particles for SAC (velocity clamped).</p>
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<p>Particle velocities for SAC (velocity clamped).</p>
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<p>Particle velocities for SAC (velocity clamped).</p>
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<p>Swarm diversity (log) for SAC (velocity clamped).</p>
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14 pages, 300 KiB  
Review
An Update on Recent Clinical Trial Data in Bloodstream Infection
by Adam G. Stewart, Peter Simos, Pirathaban Sivabalan, Laura Escolà-Vergé, Katherine Garnham and Burcu Isler
Antibiotics 2024, 13(11), 1035; https://doi.org/10.3390/antibiotics13111035 - 1 Nov 2024
Viewed by 681
Abstract
Bloodstream infections (BSIs) remain a significant source of morbidity and mortality globally, exacerbated by an ageing population and rising antimicrobial resistance (AMR). This review offers an updated evaluation of randomized clinical trials (RCTs) in BSI management from 2018 onwards, focusing on the evolving [...] Read more.
Bloodstream infections (BSIs) remain a significant source of morbidity and mortality globally, exacerbated by an ageing population and rising antimicrobial resistance (AMR). This review offers an updated evaluation of randomized clinical trials (RCTs) in BSI management from 2018 onwards, focusing on the evolving landscape of diagnostics and treatment. New rapid diagnostic technologies and shorter antimicrobial courses have transformed clinical practice, reducing the time to appropriate therapy and hospital stays. Several RCTs demonstrated that rapid phenotypic and genotypic tests shorten the time to optimal therapy, especially when paired with antimicrobial stewardship. Ongoing trials are investigating novel antimicrobial regimens and the safety of early oral switch strategies, particularly for Gram-positive and Gram-negative BSIs. Recent RCTs on Staphylococcus aureus BSI (SAB) and multidrug-resistant Gram-negative bacteria highlight advances in treatment but emphasize the need for further study into the efficacy of combination therapies and the utility of rapid diagnostics in different healthcare settings. The review also explores challenges in trail design, with adaptive and pragmatic appropriates improving the efficacy of clinical trials. Finally, this paper identifies gaps in the research, including the need for further investigation into oral step-down therapy, optimal durations, and the role of rapid diagnostics in resource-limited settings. Full article
(This article belongs to the Section Antibiotic Therapy in Infectious Diseases)
14 pages, 804 KiB  
Opinion
Scientific and Regulatory Lessons Learnt on Building a Chemistry, Manufacturing, and Controls (CMC) Package for COVID-19 Variant Vaccine Updates in the EU—A Regulator’s Perspective
by Ragini Shivji, Elena Grabski and Veronika Jekerle
Vaccines 2024, 12(11), 1234; https://doi.org/10.3390/vaccines12111234 - 29 Oct 2024
Viewed by 956
Abstract
During the COVID-19 pandemic, eight COVID-19 vaccines were authorised in the European Union (EU); as a result of emerging SARS-CoV-2 variants and waning immunity, some of these have been adapted to broaden the immunity against circulating variants. The pace at which variants emerge [...] Read more.
During the COVID-19 pandemic, eight COVID-19 vaccines were authorised in the European Union (EU); as a result of emerging SARS-CoV-2 variants and waning immunity, some of these have been adapted to broaden the immunity against circulating variants. The pace at which variants emerge challenges the technical feasibility to make adapted vaccines available in a suitable timeframe and in sufficient quantities. Despite the current absence of a clear-cut seasonal spread for COVID-19, the EU regulatory approach thus far is a pragmatic approach following a pathway similar to that of seasonal influenza. This approach currently requires chemistry, manufacturing, and controls (CMC—the design, development and consistent manufacture of a specified medicinal product of good quality) and non-clinical data (from product laboratory and animal studies), as well as demonstrating that updated vaccines induce an immune response that can predict clinical efficacy and safety in humans. For CMC data, COVID-19 mRNA vaccine adaptations generally made use of the same formulation, control strategy, manufacturing process, and inclusion of registered manufacturing sites for the drug product; therefore assessment was generally streamlined. The experience gained from the vaccine adaptations, combined with a continuous early regulator-developer scientific discussion, permits increasingly greater predictability for timing and positive regulatory outcomes. Here, we review key aspects of the quality control and manufacture of updating COVID-19 vaccines to protect against new variants. Although most experience has been gained with mRNA vaccines, we note that investment in the streamlining of manufacturing processes for recombinant protein vaccines would facilitate future strain updates/adaptations thereby safeguarding availability of different COVID-19 vaccine types, which is considered of value for public health. We also reflect on the challenges and opportunities in establishing more predictable regulatory mechanisms for future COVID-19 vaccine adaptions and more widely for future vaccines containing rapidly evolving pathogens with the potential to cause health threats. Full article
(This article belongs to the Section Epidemiology)
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<p>Previously EU authorised COVID-19 vaccines and the corresponding targeted SARS-CoV-2 strains *. * Information correct as of 19 June 24. Note that not all vaccines nor all variant presentations may still be authorised [<a href="#B2-vaccines-12-01234" class="html-bibr">2</a>].</p>
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<p>Regulatory review processes used for major changes to EU COVID-19 vaccine marketing authorisations (MAs). * Indicative estimates; eventual timelines dependent on quality of initial submission and responses to questions during the procedure. ** RR = Rolling review, review of packages of data as they become available from ongoing studies before the actual start of the regulatory procedure.</p>
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18 pages, 5004 KiB  
Article
Adaptive Fault-Tolerant Tracking Control for Multi-Joint Robot Manipulators via Neural Network-Based Synchronization
by Quang Dan Le and Erfu Yang
Sensors 2024, 24(21), 6837; https://doi.org/10.3390/s24216837 - 24 Oct 2024
Viewed by 594
Abstract
In this paper, adaptive fault-tolerant control for multi-joint robot manipulators is proposed through the combination of synchronous techniques and neural networks. By using a synchronization technique, the position error at each joint simultaneously approaches zero during convergence due to the constraints imposed by [...] Read more.
In this paper, adaptive fault-tolerant control for multi-joint robot manipulators is proposed through the combination of synchronous techniques and neural networks. By using a synchronization technique, the position error at each joint simultaneously approaches zero during convergence due to the constraints imposed by the synchronization controller. This aspect is particularly important in fault-tolerant control, as it enables the robot to rapidly and effectively reduce the impact of faults, ensuring the performance of the robot when faults occur. Additionally, the neural network technique is used to compensate for uncertainty, disturbances, and faults in the system via online updating. Firstly, novel robust synchronous control for a robot manipulator based on terminal sliding mode control is presented. Subsequently, a combination of the novel synchronous control and neural network is proposed to enhance the fault tolerance of the robot manipulator. Finally, simulation results for a 3-DOF robot manipulator are presented to demonstrate the effectiveness of the proposed controller in comparison to traditional control techniques. Full article
(This article belongs to the Section Sensors and Robotics)
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<p>The orthogonal neural network. (<b>a</b>) Single output, (<b>b</b>) multiple outputs.</p>
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<p>Three-degrees-of-freedom (DOF) Staubli TX60L robot manipulator in MATLAB/Simulink with active joints.</p>
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<p>Tracking trajectory errors [<a href="#B18-sensors-24-06837" class="html-bibr">18</a>]. (<b>a</b>) Joint 1, (<b>b</b>) joint 2, (<b>c</b>) joint 3.</p>
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<p>Synchronization performance. (<b>a</b>) Conventional TSMC, (<b>b</b>) PFTC S-TSMC, (<b>c</b>) PFTC NN-S-TSMC.</p>
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<p>The online update weights of the neural network.</p>
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18 pages, 7033 KiB  
Article
Advancement of Finite Element Method Solver Used in Dam Safety Monitoring System by Interpolation of Pore Pressure and Temperature Values
by Snezana Vulovic, Marko Topalovic, Miroslav Zivkovic, Dejan Divac and Vladimir Milivojevic
Appl. Sci. 2024, 14(21), 9680; https://doi.org/10.3390/app14219680 - 23 Oct 2024
Viewed by 503
Abstract
In this paper, we focused on the advancement of Dam Monitoring Software that incorporates the Finite Element Method (FEM), as these large infrastructure constructions are crucial for ensuring a dependable water supply, irrigation, flood control, renewable electric energy generation, and safe operation, which [...] Read more.
In this paper, we focused on the advancement of Dam Monitoring Software that incorporates the Finite Element Method (FEM), as these large infrastructure constructions are crucial for ensuring a dependable water supply, irrigation, flood control, renewable electric energy generation, and safe operation, which is of utmost importance to any country. However, the material properties and geotechnical environments of dams can change (deteriorate) over time, while the standards and legal norms that govern them become more and more rigorous, so in order to accurately assess the state of a dam and detect any concerning behavior, the software must be updated as well. The custom-developed FEM solver, unlike many commercial alternatives, is adaptable and can be reconfigured to function within a Dam Monitoring System. In this paper, we present the procedure for interpolating numerical values at measurement points, when the position of the measurement point does not align with the node of the element, allowing for additional instrument locations to be added to the monitored system without the need for remeshing the numerical model. This procedure is used to compare the actual pore pressures and temperature values of the concrete dam structure with the prediction of the numerical model, and the agreement is much greater with the new interpolation algorithm in comparison to the nearest nodal values, with the average relative difference for pore pressure reduced from 8.89% to 8.10%, justifying this implementation. Full article
(This article belongs to the Special Issue Applied Computational Fluid Dynamics and Thermodynamics)
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<p>The HPP Djerdap.</p>
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<p>The FEM model of the overflow dam and power plant of HPP Djerdap.</p>
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<p>The position of the FEM model of the overflow dam and power plant of HPP Djerdap.</p>
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<p>Measuring devices on lamella ten of HPP Djerdap: thermometers (<b>a</b>), manometers and piezometers (<b>b</b>).</p>
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<p>Tetrahedral element with 10 nodes and arbitrary position of measuring point.</p>
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<p>Algorithm for calculation of local coordinates.</p>
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<p>FEM model of dam with highlighted elements of measured points.</p>
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<p>Part of PIJEZ.DAT file.</p>
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<p>A flow chart of the PAKV/PAKT/PAKS programs.</p>
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<p>DMS flow chart: (<b>a</b>) interpolation algorithm function within DMS, (<b>b</b>) genetic algorithm used for neural network training.</p>
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<p>Flow chart of wrapper of PAKV. code.</p>
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<p>Flow chart of condition algorithm: (<b>a</b>) PAKV and (<b>b</b>) PAKT.</p>
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<p>Measured potential vs. numerical potential values.</p>
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<p>Measured temperature vs. numerical values at the measured point T60 and T84.</p>
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<p>Measured temperature vs. numerical values at the measured point T87 and T90.</p>
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<p>Potential field: (<b>a</b>) 2D cross section; (<b>b</b>) cut section in 3D model.</p>
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31 pages, 18130 KiB  
Article
Research on Cattle Behavior Recognition and Multi-Object Tracking Algorithm Based on YOLO-BoT
by Lei Tong, Jiandong Fang, Xiuling Wang and Yudong Zhao
Animals 2024, 14(20), 2993; https://doi.org/10.3390/ani14202993 - 17 Oct 2024
Viewed by 825
Abstract
In smart ranch management, cattle behavior recognition and tracking play a crucial role in evaluating animal welfare. To address the issues of missed and false detections caused by inter-cow occlusions and infrastructure obstructions in the barn environment, this paper proposes a multi-object tracking [...] Read more.
In smart ranch management, cattle behavior recognition and tracking play a crucial role in evaluating animal welfare. To address the issues of missed and false detections caused by inter-cow occlusions and infrastructure obstructions in the barn environment, this paper proposes a multi-object tracking method called YOLO-BoT. Built upon YOLOv8, the method first integrates dynamic convolution (DyConv) to enable adaptive weight adjustments, enhancing detection accuracy in complex environments. The C2f-iRMB structure is then employed to improve feature extraction efficiency, ensuring the capture of essential features even under occlusions or lighting variations. Additionally, the Adown downsampling module is incorporated to strengthen multi-scale information fusion, and a dynamic head (DyHead) is used to improve the robustness of detection boxes, ensuring precise identification of rapidly changing target positions. To further enhance tracking performance, DIoU distance calculation, confidence-based bounding box reclassification, and a virtual trajectory update mechanism are introduced, ensuring accurate matching under occlusion and minimizing identity switches. Experimental results demonstrate that YOLO-BoT achieves a mean average precision (mAP) of 91.7% in cattle detection, with precision and recall increased by 4.4% and 1%, respectively. Moreover, the proposed method improves higher order tracking accuracy (HOTA), multi-object tracking accuracy (MOTA), multi-object tracking precision (MOTP), and IDF1 by 4.4%, 7%, 1.7%, and 4.3%, respectively, while reducing the identity switch rate (IDS) by 30.9%. The tracker operates in real-time at an average speed of 31.2 fps, significantly enhancing multi-object tracking performance in complex scenarios and providing strong support for long-term behavior analysis and contactless automated monitoring. Full article
(This article belongs to the Section Cattle)
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<p>Schematic diagram of the cowshed. Camera 1, positioned near the entrance of the barn, is responsible for collecting behavioral data of the cattle in the blue area. Camera 2, located farther from the entrance, is responsible for collecting behavioral data of the cattle in the red area.</p>
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<p>Examples of cattle data in different activity areas: (<b>a</b>) morning scene, (<b>b</b>) well-lit environment, (<b>c</b>) light interference, (<b>d</b>) night scene, (<b>e</b>) outdoor activity area, and (<b>f</b>) indoor activity area. The time in the top-left corner of the image represents the capture time of the data.</p>
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<p>Analysis of the cattle behavior dataset: (<b>a</b>) analysis of cattle behavior labels, and (<b>b</b>) distribution of cattle count in each image.</p>
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<p>iRMB structure and C2f-iRMB structure.</p>
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<p>ADown downsampling structure.</p>
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<p>DyHead structure.</p>
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<p>Dynamic convolution. The “*” represents element-wise multiplication of each convolution output with its attention weight.</p>
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<p>The improved YOLOv8n network architecture.</p>
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<p>Flowchart for multi-object tracking of cattle.</p>
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<p>Schematic representation of the tracking process leading to object loss due to occlusion: The red solid line denotes the detection frame, while the yellow dashed line represents the predicted frame.</p>
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<p>Ablation experiment results.</p>
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<p>Comparison of algorithm improved cattle instance detection. In scenario 1, standing cattle are mistakenly detected as walking; in scenario 2, some behavioral features of lying cattle are missed and walking behavior is repeatedly detected; and in scenario 3, some features of walking behavior are missed.</p>
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<p>Variation curve of re-identification model accuracy.</p>
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<p>Comparison of the improved results of replacing DIoU, (<b>a</b>,<b>c</b>) denote the tracking results of the original algorithm, and (<b>b</b>,<b>d</b>) denote the tracking results of the improved algorithm. The green circle indicates the part of the target extending beyond the detection box, while the red circle indicates the detection box containing extra background information.</p>
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<p>Comparison between before and after the tracking algorithm improvement at frame 50, frame 652, and frame 916, respectively. The white dotted line in the image indicates the untracked object.</p>
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<p>Comparison between before and after the tracking algorithm improvement at frame 22, frame 915, and frame 1504, respectively. The white dotted line in the image indicates the untracked object.</p>
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<p>Performance comparison of tracking algorithms.</p>
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<p>Tracking results for multiple tracking algorithms. White dashed lines in the image indicate untracked objects, while red dashed lines indicate incorrectly tracked objects. The time in the top-left corner of the image represents the capture time of the data.</p>
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<p>Behavioral duration data from the herd are displayed in one minute, focusing on the incidence of the behavior (<b>a</b>) and the number of individual cattle (<b>b</b>). Expanded to the entire 10 min video (<b>c</b>) to fully demonstrate behavioral changes in the herd over time.</p>
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<p>Time series statistics for each cattle over a one-minute period. Four cattle with both active and quiet behavior were specifically chosen to demonstrate these variations. The numbers 2, 4, 7, and 10 indicate the scaling of the selected cattle IDS assigned by the model in the initial frame.</p>
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15 pages, 22303 KiB  
Article
Innovation Adaptive UKF Train Location Method Based on Kinematic Constraints
by Xiaoping Li and Jianbin Zhang
Electronics 2024, 13(19), 3958; https://doi.org/10.3390/electronics13193958 - 8 Oct 2024
Viewed by 561
Abstract
To address the issue of reduced positioning accuracy caused by satellite signal interruptions when trains pass through long tunnels, a novel train positioning method based on an innovative adaptive unscented Kalman filter (UKF) under kinematic constraints is proposed. This method aims to improve [...] Read more.
To address the issue of reduced positioning accuracy caused by satellite signal interruptions when trains pass through long tunnels, a novel train positioning method based on an innovative adaptive unscented Kalman filter (UKF) under kinematic constraints is proposed. This method aims to improve the accuracy of the location of trains during operation. By considering the dynamic characteristics of the train, a dynamic kinematic-constrained inertial navigation system (INS)/odometer (ODO) combination positioning system is established. This system utilizes kinematic constraints to correct the accumulated errors of the INS. Additionally, the algorithm incorporates real-time estimation of the measurement noise covariance using innovation sequences. The updated adaptive estimation algorithm is applied within the UKF framework for nonlinear filtering, forming the innovative adaptive UKF algorithm. At each time step, the difference between the ODO sensor data and the INS output is used as the measurement input for the innovative adaptive UKF algorithm, enabling global estimation. This process ultimately yields the actual positioning result for the train. Simulation results demonstrate that the innovative adaptive UKF train positioning method, incorporating kinematic constraints, effectively mitigates the impact of satellite signal interruptions. Compared with the traditional INS/ODO positioning method, the innovative adaptive UKF method reduces position errors by 34.35% and speed errors by 36.33%. Overall, this method enhances navigation accuracy, minimizes train positioning errors, and meets the requirements of modern train positioning systems. Full article
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<p>INS/ODO train combination positioning system with dynamic kinematic constraints.</p>
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<p>Flow chart of the innovative adaptive UKF information fusion algorithm.</p>
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<p>Train’s operational longitude–latitude trajectory.</p>
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<p>Comparison of train position errors using different algorithms.</p>
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<p>Comparison of train velocity errors of different algorithms.</p>
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<p>Comparison of position errors of two positioning methods.</p>
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<p>Comparison of velocity errors of two positioning methods.</p>
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17 pages, 1968 KiB  
Article
A Dual Role for the Dorsolateral Prefrontal Cortex (DLPFC) in Auditory Deviance Detection
by Manon E. Jaquerod, Ramisha S. Knight, Alessandra Lintas and Alessandro E. P. Villa
Brain Sci. 2024, 14(10), 994; https://doi.org/10.3390/brainsci14100994 - 29 Sep 2024
Viewed by 884
Abstract
Background: In the oddball paradigm, the dorsolateral prefrontal cortex (DLPFC) is often associated with active cognitive responses, such as maintaining information in working memory or adapting response strategies. While some evidence points to the DLPFC’s role in passive auditory deviance perception, a detailed [...] Read more.
Background: In the oddball paradigm, the dorsolateral prefrontal cortex (DLPFC) is often associated with active cognitive responses, such as maintaining information in working memory or adapting response strategies. While some evidence points to the DLPFC’s role in passive auditory deviance perception, a detailed understanding of the spatiotemporal neurodynamics involved remains unclear. Methods: In this study, event-related optical signals (EROS) and event-related potentials (ERPs) were simultaneously recorded for the first time over the prefrontal cortex using a 64-channel electroencephalography (EEG) system, during passive auditory deviance perception in 12 right-handed young adults (7 women and 5 men). In this oddball paradigm, deviant stimuli (a 1500 Hz pure tone) elicited a negative shift in the N1 ERP component, related to mismatch negativity (MMN), and a significant positive deflection associated with the P300, compared to standard stimuli (a 1000 Hz tone). Results: We hypothesize that the DLPFC not only participates in active tasks but also plays a critical role in processing deviant stimuli in passive conditions, shifting from pre-attentive to attentive processing. We detected enhanced neural activity in the left middle frontal gyrus (MFG), at the same timing of the MMN component, followed by later activation at the timing of the P3a ERP component in the right MFG. Conclusions: Understanding these dynamics will provide deeper insights into the DLPFC’s role in evaluating the novelty or unexpectedness of the deviant stimulus, updating its cognitive value, and adjusting future predictions accordingly. However, the small number of subjects could limit the generalizability of the observations, in particular with respect to the effect of handedness, and additional studies with larger and more diverse samples are necessary to validate our conclusions. Full article
(This article belongs to the Section Behavioral Neuroscience)
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<p>Schematic representation of the co-localization of the 8 light detectors (red circles) and 22 light sources (blue squares) over prefrontal and premotor areas of the cerebral cortex and the 64-channel EEG setup according to the International 10/20 system.</p>
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<p>(<b>A</b>) Grand–average waveforms of the ERPs evoked by standard (dashed blue) and deviant (red) tones (mean<math display="inline"><semantics> <mrow> <mtext> </mtext> <mo>±</mo> <mtext> </mtext> <mn>2</mn> <mtext> </mtext> <mo>×</mo> </mrow> </semantics></math> SEM) at locations corresponding to 9 sets of electrodes along the antero-posterior and mesio-lateral axis. Four ERP components (N1, N2, P3a, and P3b) were identified. (<b>B</b>) Topographic maps of the consistency of differential activations (contrast analysis between deviant and standard tone conditions) for N1, N2, P3a, and P3b ERP components. The contour lines connect the points with the same value of consistency of differential activation.</p>
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<p>Differential activations in the event–related optical signals (EROS) following a contrast analysis (<span class="html-italic">deviant tone</span> &gt; <span class="html-italic">standard tone</span>, Z-score <math display="inline"><semantics> <mrow> <mo>&gt;</mo> <mn>2.575</mn> </mrow> </semantics></math>, n &gt; 10. (<b>A</b>) Raw EROS data analysis. The upper panels show the axial projection of the Z-score surface maps (computed across subjects) on a template MRI for the contrast analysis at 88, 120, and <math display="inline"><semantics> <mrow> <mn>320</mn> <mtext> </mtext> <mi>ms</mi> </mrow> </semantics></math> after stimulus onset. The Talairach coordinates <span class="html-italic">x</span> and <span class="html-italic">y</span> of the voxels with the greatest differential activation are indicated with the corresponding Brodmann area (BA) and nearest cortical gyri. The corresponding Talairach <span class="html-italic">z</span> coordinate is on the cortical surface. The lower panels show the corresponding EROS grand–average curves (mean <math display="inline"><semantics> <mrow> <mo>±</mo> <mtext> </mtext> <mn>2</mn> <mtext> </mtext> <mo>×</mo> <mtext> </mtext> </mrow> </semantics></math>SEM), from <math display="inline"><semantics> <mrow> <mn>100</mn> <mtext> </mtext> <mi>ms</mi> </mrow> </semantics></math> before stimulus onset to <math display="inline"><semantics> <mrow> <mn>600</mn> <mtext> </mtext> <mi>ms</mi> </mrow> </semantics></math> after stimulus onset. of the peak voxel and its direct neighboring voxels during the deviant (red) and the standard (dashed blue) tones conditions. An arrow indicates the timing of the greatest differential activation with a sign (n.s.) not significant and (*) <math display="inline"><semantics> <mrow> <mi>p</mi> <mo>&lt;</mo> <mrow> <mn>0.05</mn> </mrow> </mrow> </semantics></math>, for the significance level of the differential activation at the peak latency with multiple comparison correction within the associated ROI. (<b>B</b>) Standardized EROS data analysis. The upper panels show the axial projection of the new Z-score surface maps (computed across subjects) on a template MRI recomputed following the standardization procedure described in the Methods <a href="#sec2dot4-brainsci-14-00994" class="html-sec">Section 2.4</a>, for the contrast analysis at 88, 128, and <math display="inline"><semantics> <mrow> <mn>320</mn> <mtext> </mtext> <mi>ms</mi> </mrow> </semantics></math> after stimulus onset. At <math display="inline"><semantics> <mrow> <mn>88</mn> <mtext> </mtext> <mi>ms</mi> </mrow> </semantics></math>, no voxel of the differential activation reached the threshold level Z-score <math display="inline"><semantics> <mrow> <mo>&gt;</mo> <mn>2.575</mn> </mrow> </semantics></math>, n &gt; 10. At 128 and <math display="inline"><semantics> <mrow> <mn>320</mn> <mtext> </mtext> <mi>ms</mi> </mrow> </semantics></math> after stimulus onset, the Z-score of the differential activations was above the threshold level and remained significant (<math display="inline"><semantics> <mrow> <mi>p</mi> <mo>&lt;</mo> <mrow> <mn>0.05</mn> </mrow> </mrow> </semantics></math>) even after multiple comparison correction within the associated ROI.</p>
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25 pages, 2232 KiB  
Article
Hybrid Multi-Objective Chameleon Optimization Algorithm Based on Multi-Strategy Fusion and Its Applications
by Yaodan Chen, Li Cao and Yinggao Yue
Biomimetics 2024, 9(10), 583; https://doi.org/10.3390/biomimetics9100583 - 25 Sep 2024
Viewed by 624
Abstract
Aiming at the problems of chameleon swarm algorithm (CSA), such as slow convergence speed, poor robustness, and ease of falling into the local optimum, a multi-strategy improved chameleon optimization algorithm (ICSA) is herein proposed. Firstly, logistic mapping was introduced to initialize the chameleon [...] Read more.
Aiming at the problems of chameleon swarm algorithm (CSA), such as slow convergence speed, poor robustness, and ease of falling into the local optimum, a multi-strategy improved chameleon optimization algorithm (ICSA) is herein proposed. Firstly, logistic mapping was introduced to initialize the chameleon population to improve the diversity of the initial population. Secondly, in the prey-search stage, the sub-population spiral search strategy was introduced to improve the global search ability and optimization accuracy of the algorithm. Then, considering the blindness of chameleon’s eye turning to find prey, the Lévy flight strategy with cosine adaptive weight was combined with greed strategy to enhance the guidance of random exploration in the eyes’ rotation stage. Finally, a nonlinear varying weight was introduced to update the chameleon position in the prey-capture stage, and the refraction reverse-learning strategy was used to improve the population activity in the later stage so as to improve the ability of the algorithm to jump out of the local optimum. Eighteen functions in the CEC2005 benchmark test set were selected as an experimental test set, and the performance of ICSA was tested and compared with five other swarm intelligent optimization algorithms. The analysis of the experimental results of 30 independent runs showed that ICSA has stronger convergence performance and optimization ability. Finally, ICSA was applied to the UAV path-planning problem. The simulation results showed that compared with other algorithms, the paths generated by ICSA in different terrain scenarios are shorter and more stable. Full article
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<p>The variation curve of cosine adaptive factor <span class="html-italic">c<sub>t</sub></span>.</p>
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<p>The variation curve of nonlinear varying weight <span class="html-italic">ω<sub>t</sub></span>.</p>
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<p>Schematic diagram of refraction reverse learning.</p>
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<p>The flowchart of ICSA algorithm.</p>
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<p>Convergence curves of test functions (<span class="html-italic">N</span> = 30).</p>
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<p>Convergence curves of test functions (<span class="html-italic">N</span> = 30).</p>
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<p>Convergence curves of test functions (<span class="html-italic">N</span> = 30).</p>
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<p>UAV 3D path planning (<span class="html-italic">N</span> = 100).</p>
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<p>Total cost function convergence curve.</p>
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17 pages, 1797 KiB  
Article
Central Difference Variational Filtering Based on Conjugate Gradient Method for Distributed Imaging Application
by Wen Ye, Fubo Zhang and Hongmei Chen
Remote Sens. 2024, 16(18), 3541; https://doi.org/10.3390/rs16183541 - 23 Sep 2024
Viewed by 518
Abstract
The airborne distributed position and orientation system (ADPOS), which integrates multi-inertia measurement units (IMUs), a data-processing computer, and a Global Navigation Satellite System (GNSS), serves as a key sensor in new higher-resolution airborne remote sensing applications, such as array SAR and multi-node imaging [...] Read more.
The airborne distributed position and orientation system (ADPOS), which integrates multi-inertia measurement units (IMUs), a data-processing computer, and a Global Navigation Satellite System (GNSS), serves as a key sensor in new higher-resolution airborne remote sensing applications, such as array SAR and multi-node imaging loads. ADPOS can provide reliable, high-precision and high-frequency spatio-temporal reference information to realize multinode motion compensation with the various nonlinear filter estimation methods such as Central Difference Kalman Filtering (CDKF), and modified CDKF. Although these known nonlinear models demonstrate good performance, their noise estimation performance with its linear minimum variance estimation criterion is limited for ADPOS. For this reason, in this paper, Central Difference Variational Filtering (CDVF) based on the variational optimization process is presented. This method adopts the conjugate gradient algorithm to enhance the estimation performance for mean correction in the filtering update stage. On one hand, the proposed method achieves adaptability by estimating noise covariance through the variational optimization method. On the other hand, robustness is implemented under the minimum variance estimation criterion based on the conjugate gradient algorithm to suppress measurement noise. We conducted a real ADPOS flight test, and the experimental results show that the accuracy of the slave motion parameters has significantly improved compared to the current CDKF. Moreover, the compensation performance shows a clear enhancement. Full article
(This article belongs to the Special Issue Array and Signal Processing for Radar)
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<p>The CDVF flowchart.</p>
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<p>Flight airplane.</p>
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<p>Flight experiment trajectory(the red lines reprent the imaging area).</p>
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<p>Attitude estimation comparison.</p>
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<p>Velocity estimation comparison.</p>
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<p>Position estimation comparison.</p>
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<p>2D imaging.</p>
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<p>3D imaging after compensation.</p>
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