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Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objective] Thermal, light, and sound environment tests and simulation experiments are an important part of the experimental teaching of building physics. However, most current experimental projects are old in content, and the influence of sound and light environment is often ignored in comfort evaluation. Therefore, students' active participation in learning and the overall coordination of indoor comfort experiments are not ideal. To solve the aforementioned problems, this paper uses human factor technology to evaluate the light and thermal environment of the subjects in the learning state from the perspective of learning efficiency and comfort. Through this teaching experiment, students can learn the design and data analysis method of orthogonal experiments and master the basic theoretical knowledge of building thermal optics, the use of relevant experimental instruments, and the measurement method of indoor light and thermal environment parameters. Students are guided to experience different light and thermal environments, and physiological parameters are used to explore their influence on comfort and learning efficiency. Finally, the best light and thermal environment for comfort and learning efficiency is comprehensively proposed. [Methods] In this paper, the evaluation methods of traditional learning performance index and four physiological parameters on learning efficiency, including heart rate variability, brainwave α rhythm engagement, cognitive engagement, and pupil diameter, were studied. The orthogonal experimental conditions of L9 (34) with four factors of temperature, humidity, illumination, and color temperature and three levels were set. The experimental results were analyzed by a range analysis method. An indoor thermal comfort tester and an illuminometer were used to collect light and thermal environment data. Among the four physiological parameters, cognitive engagement was measured by the n-back cognitive task, whereas the others were measured by the human factor data acquisition instrument. After conducting pre-experiment testing on the feasibility of the experimental scheme, students can be organized to conduct experimental teaching in small groups. The whole teaching experiment can be divided into two parts, namely, experiment preparation and formal experiment. The preparation process included laboratory explanation and instrument wearing, whereas the formal experiment included environmental adaptation, cognitive tasks, and physiological measurements in nine working conditions. Since this experiment belongs to experimental teaching, it should be mainly guided by teachers to conduct independent experiments. Teachers should fully explain and properly demonstrate operations in the preparation stage of the experiment to ensure that students can independently and smoothly carry out the experiment under the condition of the teacher's help in switching working conditions. After the completion of the experiment, the recorded experimental data were analyzed, the relationship between comfort and indoor photothermal environment and the relationship between learning efficiency and indoor photothermal environment were obtained, and the conclusion of the best indoor light and thermal environment was obtained. [Results] The experimental results showed the following: 1) The temperature approached 22 °C, the humidity approached 40%, and the illuminance approached 300 Lx. The subjects were most comfortable when the color temperature approached 3 300 K. 2) The temperature approached 18 °C, the humidity approached 40%, and the illuminance approached 500 Lx. When the color temperature approaches 5 300 K, the learning efficiency is at its highest. [Conclusions] The subjects' learning efficiency is higher in the cold light environment with lower temperature and brighter light, and they are more relaxed in the warm light environment with appropriate temperature and dimmer light. At the same time, for different learning situations, the emphasis on light and thermal environments is also different. For example, in a brighter environment (i.e., illuminance approaching 750 Lx), subjects pay more attention; subjects were less likely to fatigue under neutral light (i.e., color temperature approaching 4 500 K). [ABSTRACT FROM AUTHOR]

[Objective] The Smart Factory curriculum integrates disciplines such as computer science, automation, and information technology, emphasizing hands-on practice and skill development. However, traditional teaching methods often focus on theoretical knowledge regarding interactivity and participation and fail to promptly incorporate teaching content related to new technologies and equipment. This course develops a practical teaching strategy that encourages students to participate in factory demand research. By simulating real factory environments and production processes, this method introduces the latest technological achievements, namely the multi-agent reinforcement learning task supervisor, into smart warehouse system case studies, thereby enhancing students' skills and innovation. [Methods] To address challenges in path planning and real-time delivery sequence adjustment for multi-load warehouse robots operating in dynamic environments, we propose a comprehensive policy that integrates local path planning, dynamic obstacle avoidance, and real-time delivery cost evaluation. This paper models a warehouse environment and captures its layout, shelf positions, aisle widths, and potential obstacle locations to frame multi-objective delivery as a traveling salesman problem. To ensure safe navigation, the robot tasks were divided into movement, obstacle avoidance, and collision avoidance. In complex warehouse environments, robots frequently execute multiple behaviors concurrently. We introduce a null-space behavioral control algorithm to manage conflicts, where behaviors are projected into null spaces based on their assigned priorities to form composite behaviors. Priorities are determined by a multi-agent reinforcement learning task supervisor, who uses composite behavior velocities as actions for the deep reinforcement learning algorithm and the robot positions as states. Through continuous interaction with the environment during the learning process and offline training, the supervisor develops a priority selection policy. Furthermore, the delivery sequence for warehouse robots is dynamically adjusted using a scoring evaluation mechanism. This mechanism updates the selection of target delivery points in real time to minimize transportation costs. This policy ensures that each warehouse robot safely delivers multiple items over the shortest possible distance while avoiding collisions, thereby providing an optimal solution for commodity delivery in warehouse systems. [Results] This simulation compared the effectiveness of a reinforcement learning task supervisor to a multi-agent reinforcement version in a warehouse environment. Although warehouse robots equipped with a reinforcement learning task supervisor can navigate paths and avoid obstacles, frequent priority switches result in longer paths. By contrast, warehouse robots utilizing a multi-agent reinforcement learning task supervisor, enhanced by a scoring evaluation mechanism, can intelligently adjust the delivery sequence based on path length costs and optimize path selection through goal-oriented learning. This approach not only reduces transportation path lengths but also effectively shortens dynamic obstacle avoidance distances and waiting times due to refined obstacle and collision avoidance behavior designs. More stable priority switching significantly enhances delivery flexibility, decreases path lengths, and alleviates traffic congestion. [Conclusions] Considering the course characteristics and teaching challenges of smart factories, this paper presents a simulation teaching scheme for multi-warehouse robot path planning tailored to smart factories. It addresses challenges in multi-objective delivery and multi-task conflicts by using a scoring evaluation mechanism to dynamically update delivery sequences of target points, optimize robot transportation paths, and improve the overall efficiency of warehouse system operations. This teaching scheme leverages Python software platforms for model experiments, enhances practical teaching resources, and employs virtual simulations to compensate for hardware deficiencies. By evaluating different solutions, students gain a deeper understanding of smart factory requirements and enhance their problem-solving skills. [ABSTRACT FROM AUTHOR]

[Objective] Most gas combustion devices used in university laboratories are custom-built. Given the widespread use of mixed gases, both the devices and experiments pose significant risks. Inadequate consideration of safety during the design, manufacture, and operation of these devices increases the likelihood of explosion accidents, which can result in severe injuries and property damage. Therefore, engineering control measures should be implemented to reduce the risk of such accidents. [Methods] This paper proposes using the Le Chatelier formula to estimate the explosion limits of combustible mixed gases. It emphasizes creating a flammability diagram for combustible gas--inert gas--oxygen mixtures and presents the combustion and explosion characteristics of mixed gases with varying volume fractions under standard temperature and pressure conditions. This approach offers a quantitative method for mitigating explosion risks by incorporating inert gases into combustion experiments. Additionally, the paper classifies combustion devices into two categories: normal pressure burners and deflagration/detonation devices. [Results] A comparison of the two types of devices reveals that deflagration/detonation devices pose a higher safety risk. When preparing and handling combustible mixed gases in these devices, special attention should be given to the impact parts of the device during gas flow, as these components are more prone to abnormal temperature increases. This paper estimates the temperature after adiabatic compression of commonly used combustible gases, such as methane and oxygen, and suggests that adiabatic compression in the negative pressure state of impact parts may lead to accidental combustion and explosion. Moreover, the explosion hazards associated with gas combustion devices are discussed from several perspectives, including the explosion temperatures and pressures of commonly used combustible gases in the laboratory and the effects of explosion overpressure on human health. [Conclusions] From the standpoint of inherent safety, the following recommendations are proposed: 1 Relatively safe combustible gases should be chosen for experimental schemes whenever possible. Inert gases should be selected based on their inerting capacity. Normal-pressure burners should be chosen, or the volume of the combustion chamber and gas mixing tank in deflagration/ detonation devices should be minimized as much as feasible. 2 Experimental devices should be equipped with appropriate valves, impact parts should be minimized, and a status monitoring and control system should be used to promptly address abnormal situations. Additionally, filters, flame arresters, pressure relief valves, and other necessary safety features should be installed. 3 The laboratory environment must meet the requirements for combustion experiments. Devices with explosion potential should be isolated. The room should be equipped with combustible gas detection and alarm systems, adequate ventilation, explosion-proof electrical equipment, and complete emergency supplies. 4 The configuration and proper use of personal protective equipment should be standardized. By implementing a comprehensive set of explosion prevention and control measures, accidents can be prevented, their progression can be managed, their consequences can be mitigated, and the overall safety of combustion experiments can be improved. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to reduce the repeated work intensity of drilling personnel and the risks faced by high-risk environments during oilfield exploitation, an intelligent manipulator is introduced into the drilling platform, and a dynamic target tracking control method of the manipulator based on deep reinforcement learning is proposed in this paper. In this paper The digital twin of the manipulator is constructed in the virtual drilling simulation environment, and multi-agent parallel training is carried out using the machine learning agents(ML-Agents) framework and proximal policy optimization(PPO) algorithm. The ideal training algorithm model is deployed to the virtual manipulator on the virtual drilling platform, and the virtual and real manipulator can track the dynamic target synchronously through serial communication. The experimental results indicate that synchronous tracking of dynamic targets with virtual and real robotic arms is feasible and accurate, providing a new approach for the digital twin application in the oil and gas industry. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objective] Laboratory grounding indicates strong professionalism and is mainly implemented in laboratory infrastructure construction and renovation processes, which are quite easy to neglect. The core objectives of the research were to delve into the significance and complexities of proper grounding in university laboratory settings, which included examining the roles of grounding in enhancing safety, protecting equipment, and maintaining the accuracy of the experimental results. This study raised awareness of the often overlooked but critical aspects of grounding in laboratories. [Methods] To achieve the aforementioned objectives, this paper first discussed the various types of grounding required in a laboratory setting and then reviewed the essential functions, such as protection against electric shocks, prevention of electromagnetic interference, stabilization of equipment operation, and dissipation of static electricity. The protective function of grounding, i.e., to prevent electric shocks and damage to equipment by diverting currents to the earth, was highlighted. The importance of grounding in shielding sensitive electronic devices from electromagnetic interference and its vital improvement of the signal-to-noise ratio of precision instruments, which could compromise the quality and reliability of data obtained from experiments, was also underscored. Risk analysis was conducted to illustrate the potential consequences of improper grounding, including power instability, increased likelihood of electrocution, fire and explosion hazards, damage to instruments, and data distortion. This study proposed the implementation of a comprehensive grounding design strategy for the Analysis & Testing Center at North China Electric Power University, which might mitigate these risks. This comprehensive grounding design strategy involved the use of local equipotential bonding boxes, complex grounding networks, and specific engineering techniques to reduce ground resistance to meet the stringent requirements of high-precision instruments. [Results] Implementing grounding strategies at the Analysis & Testing Center resulted in a significant reduction in ground resistance by employing advanced grounding techniques. In this study, a deep hole was drilled by adding conductive materials. A ground resistance of <0.5 Ω was achieved. This result not only satisfied the strict criteria set for sensitive equipment but also contributed to a safer working environment and more accurate data collection. Laboratory checklists converted the professional issues into actionable confirm items, such as "Yes or No". The use of the laboratory checklists in the ongoing management of the grounding system ensured its continued effectiveness, highlighting the importance of regular maintenance and monitoring. [Conclusion] In conclusion, this study emphasized the indispensable role of effective grounding in university laboratories. Proper grounding not only safeguards personnel and equipment from electrical hazards but also enhances the reliability of scientific research by minimizing data inaccuracies caused by electromagnetic interference. The research advocated for a more refined and systematic approach to grounding management that incorporates professional knowledge and regular inspection routines and proposed that universities should prioritize grounding education and training for laboratory staff to foster a culture of safety and precision. The success of the grounding system at the Analysis & Testing Center serves as a practical example for other institutions seeking to improve their laboratory grounding practices and refine laboratory safety management. [ABSTRACT FROM AUTHOR]

[Objective] Experimental teaching is a crucial pathway for cultivating the innovative research thinking and engineering practice abilities of undergraduate students. Integrating these innovative research results into undergraduate comprehensive experiments is essential to maintaining their cutting-edge and innovative nature. Benefiting from the quantum confinement effect, quantum dots (QDs) exhibit gain thresholds that are insensitive to temperature and gain wavelengths that are broadly tunable with size. Near-infrared QD lasers have wide-ranging applications in optical communications, on-chip photonic interconnects, and emerging quantum information technologies. However, the multiple degeneracies of the lowest quantized states in lead salt (PbS and PbSe) QDs, along with their biological toxicity, have significantly hindered the development of near-infrared colloidal QD coherent light sources. Drawing from innovative research, this study has designed a comprehensive teaching experiment focused on environmentally friendly near-infrared QD lasers. [Methods] This experiment aims to cultivate the abilities of students and adopts a student-centered, heuristic, and interactive teaching method. Students are tasked with independently designing and building an experimental platform based on industry challenges. Ultrafast transient absorption spectroscopy is employed to track the establishment and relaxation of optical gain in environmentally friendly Ag2Se QDs, determining their gain wavelength, threshold, and lifetime. A two-level model is then established to analyze the influence of the degeneracy of the lowest quantized states on the optical gain threshold. Subsequently, the characteristics of amplified spontaneous emission are measured using pulsed stripe photoexcitation experiments, and the net modal gain is evaluated using a one-dimensional optical amplification model by altering the pump stripe length. Finally, based on the optical gain characteristics of the QDs and the single-mode operation conditions of the laser, students design a low-threshold single-mode near-infrared QD laser and fabricate it using a self-assembly method. [Results] The experimental results demonstrated that, with appropriate inspiration and guidance from teachers, students can thoroughly analyze the optical gain properties of Ag2Se QDs and, based on this, develop a single-mode laser with an emission wavelength in the second near-infrared window, a threshold below 200 μJ·cm-2, and a linewidth narrower than 1 nm. A questionnaire assessing the effectiveness of the experimental teaching showed that 100% of the students believed the experiment enhanced their comprehensive abilities. In particular, 96.7% of students recognized an improvement in their innovative capabilities, 93.4% acknowledged the experiment's role in developing their ability to analyze and solve problems, and 95.1% affirmed that their scientific literacy and engineering practice abilities had been improved. This experiment has sparked student enthusiasm for innovation and substantially improved their comprehensive abilities. After completing this experiment, many students have continued to engage in scientific research by participating in teachers' research projects, achieving remarkable success in innovation and entrepreneurship competitions, as well as academic contests, and publishing multiple high-quality papers. [Conclusions] In this study, the authors have integrated the innovative research achievement of environmentally friendly near-infrared QD lasers into undergraduate comprehensive experiments, carefully designing the experiment's objectives, content, and implementation. This experiment, which focuses on the forefront of global technology, is characterized by its advanced, innovative, and challenging nature. It is highly relevant to the curriculum of optoelectronics-related majors and helps cultivate the ability of students to flexibly apply knowledge to analyze and solve problems. Through a complete research and development process involving literature research, scheme design, optical gain characteristic analysis, and laser development, the research literacy and practical innovation abilities of students are significantly enhanced, laying a solid foundation for participation in scientific research and product development. This experiment is worthy of further refinement and promotion. [ABSTRACT FROM AUTHOR]

[Objective] Unconventional oil and gas reservoirs are characterized by poor physical properties and complex stress conditions. Hydraulic fracturing is essential for improving the efficiency of exploring and developing these resources. Traditional indoor hydraulic fracturing experiments typically simulate crack propagation under a single stress state, failing to capture the crack morphology under the complex stresses of actual formations and natural fracture disturbances. [Methods] In this paper, a full-diameter core hydraulic fracturing ultrasonic testing device with independent axial stress loading has been developed. This experimental device includes multiple sets of independent pressure systems and acoustic emission data acquisition systems, allowing it to simulate various complex stress conditions found in real formations. It detects rock failure characteristics through acoustic emissions and records the response during fracture initiation and propagation in real time. Experiments focused on natural fracture stability and hydraulic fracturing under complex stress conditions were carried out on cores with natural frequencies at angles of 30°, 45°, and 60° using the instrument. Custom-designed rock samples were used to explore fracture propagation laws under varying conditions, offering a new method for simulating reservoir hydraulic fracturing effects under complex stress. [Results] The experimental results indicate the following: (1) The amplitude of acoustic emission signals is positively correlated with crack formation characteristics. A sudden increase in acoustic emission signals demonstrates the pressure point where cracks begin to destabilize; (2) Cores with 45° natural fractures exhibit the least stability. Fracture occurs at a pressure of 14.1 MPa, with prominent acoustic emission characteristics. By contrast, 30° and 60° natural fractures mainly result in shear and partial tensile fractures after instability; (3) Induced stress interference causes the fracture path to shift as hydraulic fractures approach. With increasing natural fracture angles, fracture offset becomes more obvious, leading to two major acoustic emission signal events. [Conclusions] The full-diameter core hydraulic fracturing ultrasonic detection device, equipped with independently controlled axial stress loading, addresses the challenges of predicting hydraulic fracturing effects under complex formation conditions. By combining artificial core samples with stress differential control, the device offers new insights into artificial fracture propagation mechanisms and acoustic emission fracture monitoring technologies. By utilizing artificial rock sample preparation, an axial stress loading system, a water pressure loading system, and an acoustic emission data acquisition system, it is possible to conduct fracture propagation experiments under various complex stress conditions. At the same time, according to the characteristics of the experimental device, the experimental design of other reservoir reconstruction challenges can be carried out. The device can also be upgraded and optimized. This setup effectively clarifies the hydraulic fracturing effects in actual reservoirs with complex stress, providing a foundation for reservoir stimulation strategies. [ABSTRACT FROM AUTHOR]

[Objective] Visual simultaneous localization and mapping (VSLAM) is invaluable in applications like autonomous driving, underground robot exploration, and robot search and rescue operations. However, traditional VSLAM struggles in dim dynamic environments, prompting researchers to develop specialized algorithms for such environments. Despite these efforts, many existing VSLAM algorithms often fail to meet real-time requirements. [Methods] In this study, a real-time VSLAM algorithm for dim dynamic scenes is proposed. First, this study uses an algorithm based on the Retinex theory to enhance the brightness of input red green blue(RGB) images. Because images captured by the red green blue-depth(RGB-D) cameras cannot directly obtain illumination maps, this study transforms the illumination solving problem into an optimization problem. By developing an illumination cost function and taking its derivative, the derivative is yielded as zero, and a photometric graph is obtained. Second, this paper adds an object detection thread on top of ORB-SLAM3 using YOLO to identify targets labeled "person." Next, feature points in the YOLO detection frame are prefiltered using the Lucas-Kanade(LK) optical flow method. Further, the position of the feature point in the next frame is predicted using this method. If the distance between the actual and predicted positions is greater than the preset threshold, the feature point is set as a dynamic feature point, and the other feature points are set as static feature points. Additionally, Gaussian distribution analysis is used for secondary judgment. By analyzing the standard deviation of the depth of feature points in the YOLO box, the variance and standard deviation ratio of their depth that are greater than and less than the standard deviation are calculated, and the distribution of feature points is estimated. These metrics are compared against thresholds, and different thresholds are selected for subsequent standardized scores. Finally, the standardized score for each preset static feature point is calculated to evaluate the degree of deviation from the original data point, yielding a mean of 0 and a standard deviation of 1. In static scenes, the depth values of most feature points should be relatively consistent, and even if there are some deep changes, these changes should be distributed around a mean. The depth value of dynamic feature points may significantly deviate from the mean value of static feature points in the boundary box, resulting in higher standardization scores and larger square values than the set thresholds. Through this judgment method, all dynamic feature points are successfully selected and culled. [Results and Conclusions] Test results on the TUM and Bonn public datasets show that the proposed algorithm reduces the absolute trajectory error by at least 86.93% in high dynamic environments and 27.61% in low dynamic environments compared with ORB-SLAM3. Among similar VSLAM algorithm types, the proposed algorithm offers faster processing speeds while maintaining high precision and achieves a good balance between accuracy and real-time performance. The actual scene verification shows the excellent performance of the proposed algorithm in dim scenes. In summary, through advanced image processing and accurate dynamic point culling, the proposed algorithm addresses the shortcomings of traditional VSLAM algorithms and achieves accurate positioning in dim dynamic environments. [ABSTRACT FROM AUTHOR]

[Objective] Current target tracking systems and algorithms for unmanned aerial vehicle (UAV) detection, designed for fixed optoelectronic equipment with a single field of view, perform well for non-moving targets but fall short in tracking accuracy and real-time requirements for small, moving UAV targets. To facilitate accurate and expeditious tracking of "low, slow, and small" UAVs in complex urban low-altitude environments, this paper proposes an automatic anti-UAV tracking system that incorporates the DSST(discriminative scale space tracker)-KCF(kernel correlation filter) algorithm. [Methods] The system comprises two principal components: The dual-light image acquisition unit and the display control unit. The gimbal camera, which is equipped with infrared and visible light cameras, handles image acquisition. The computer-based display control unit processes real-time images, calculates gimbal control parameters, and displays UAV images. These units are interconnected via gigabit Ethernet for efficient commands and image uploads and downloads. The system initially captures low-altitude images through the dual-optical unit, which are processed in real time using the fusion DSST-KCF algorithm. The proposed algorithm combines the high real-time performance of the KCF algorithm with the high performance of the DSST algorithm to achieve high real-time performance and target scale adaptation. It includes position and scale filters. The position filter uses a cyclic matrix to train the position filter, which subsequently predicts the target position in the subsequent frame. The scale filter, trained on a loop matrix data set, extracts features from the target position center at 33 scales to determine the tracking frame size. Finally, the DSST-KCF-gimbal control strategy maintains the UAV centered in the field of view, ensuring continuous and effective tracking of the target. This algorithm balances multi-scale variations while simultaneously enhancing real-time performance. [Results] The proposed system was tested for real-time UAV tracking in a campus environment. Results demonstrate that the improved algorithm enhances the detection success rate by 31.51% on average and tracking accuracy by 43% on average compared to the original KCF algorithm. By integrating this enhanced algorithm with gimbal control, the tracking system achieves autonomous and stable tracking in real-world conditions. It also maintains stable tracking at a distance of 2.3 km, an altitude of 100 m, and a velocity of 5 m/s, each frame is processed in less than 20 ms. [Conclusions] The test results demonstrate the effectiveness of the proposed system in tracking UAVs across both complex and simple backgrounds, offering high real-time performance and adaptability to different environments. It is also particularly well-suited for tracking small, moving targets in complex urban low-altitude scenarios. [ABSTRACT FROM AUTHOR]

[Objective] Clearance between motion pairs is commonly observed in mechanisms due to manufacturing errors in components, assembly requirements, and wear of the mechanisms. When the mechanism operates at high speeds with large loads and small cross-sectional areas, components are susceptible to elastic deformation. This elastic deformation, combined with the clearance in motion pairs, significantly restricts the motion accuracy of the entire mechanism, leading to chaotic behavior and ultimately reducing its stability and reliability. Therefore, it is essential to investigate the influence of the coupling effect between the clearance of the motion pair and the flexible component on the motion state of the mechanism. [Methods] This paper proposes a chaos identification method for a rigid-flexible coupling experimental teaching platform with revolute clearance joints. First, a revolute clearance joint model was established based on the three-state model of "contact-separation-collision." In addition, a flexible beam element model was created using the absolute node coordinate method. Following this, a dynamic model of the rigid-flexible coupling six-link experimental platform with revolute clearance joints was established using the Lagrange multiplier method. Finally, both qualitative and quantitative identifications of chaotic phenomena in the six-link experimental platform were conducted using phase diagrams, Poincaré maps, and maximum Lyapunov exponents. The nonlinear characteristics of the rigid experimental platform with clearance and the rigid-flexible coupling experimental platform with clearance were compared and analyzed. Additionally, the effects of different clearance values, driving speeds, and friction coefficients on the nonlinear characteristics of the experimental teaching platform were studied. [Results] The results obtained using methods such as phase diagrams, Poincaré maps, and maximum Lyapunov exponents indicate that compared with the rigid experimental teaching platform mechanism with revolute clearance, the vibration frequency of the rigid-flexible coupling experimental teaching platform mechanism with revolute clearance is higher, leading to reduced stability and more pronounced chaotic phenomena. The chaotic behavior at the clearance of the revolute pair intensifies with an increase in clearance size and driving speed, whereas it weakens as the friction coefficient increases. [Conclusions] The coupling effect between the clearance of the motion pair and the flexibility of the component reduces the stability of the mechanism, leading to the emergence of chaos. The chaos identification method based on the experimental teaching of rigid-flexible coupling with revolute clearance proposed in this article can effectively distinguish the motion states of the mechanism. This method provides a systematic and comprehensive theoretical foundation for the study of nonlinear dynamics in high-precision, high-performance multilink mechanisms. This not only enhances students' ability to analyze and practice the nonlinear characteristics of mechanisms but also increases the diversity, intuitiveness, and engagement of the teaching process, ultimately improving the quality of education. [ABSTRACT FROM AUTHOR]

[Objective] Recently, underground space disasters have occurred with increasing frequency, highlighting the urgent need for a comprehensive, multidimensional support system for emergency communication. A key task in emergency communication for underground spaces is the rapid reorganization of communication networks to relay disaster information in real time. Unmanned aerial vehicles(UAVs), with their flexible deployment, unmanned operation, and all-terrain mobility, can play a vital role in emergency rescue efforts. In the event of disasters such as fires, collapses, or floods, UAVs can quickly access affected areas and establish stable ad-hoc networks using their onboard communication devices. UAVs can promptly transmit the collected disaster information back to the rescue center, thereby enhancing the efficiency of rescue operations. However, while extensive research has been conducted on UAV applications in low-altitude areas, further development is necessary for their use in underground spaces. Particularly, there is a lack of research on experimental platforms that integrate scientific research and teaching. This gap has resulted in a disconnect between the educational content and real-world scenarios. Therefore, establishing a scenario-based teaching and practice platform for emergency communication networks in underground spaces is essential. By enhancing practical teaching content, we can effectively guide students in learning modern emergency communication network technologies, ensuring a strong connection between theoretical instruction and real-world applications. [Methods] In this paper, we employ hypergraph theory to abstract the rapidly changing network topology into a dynamically evolving hypergraph, modeling the evolution of interference relations through the insertion and deletion of superedges. Specifically, we reformulate the dynamic channel selection problem in UAV communication networks as a hypergraph coloring problem. To adapt to the dynamic network topology, we leverage reinforcement learning theory to enhance the traditional hypergraph coloring algorithm and develop a dynamic hypergraph coloring algorithm. Additionally, when the topology of the UAV communication network changes, the traditional greedy algorithm requires recalculation at each time slot, whereas the Q-learning algorithm can quickly converge based on prior learning. Building on this discussion, we propose a dynamic channel selection algorithm based on the Q-learning framework, which can adjust the learning rate parameters according to the rate of topological changes. [Results] To validate the effectiveness of our proposed algorithm, we conduct extensive simulation experiments to observe how the proportion of link conflicts in the network changes with varying algorithm iterations and UAV flight speeds. Additionally, we analyze the changes in average throughput across different network sizes, comparing the Q-learning algorithm to the greedy algorithm. The simulation results demonstrate that our algorithm can dynamically adjust the learning rate parameters based on the topological change rate of the UAV communication networks, achieving an optimal trade-off between algorithm performance and convergence speed. And the network performance of this algorithm is better than that of the greedy algorithm. [Conclusions] In conclusion, we utilize hypergraph theory to design an adaptive channel selection algorithm based on the Q-learning framework and establish a simulation experiment platform using ns-3 simulation software. Specifically, we employ the ns-3 platform to create a network simulation experiment for an underground space emergency scenario, helping students apply their theoretical knowledge of communication networks to practical engineering contexts. This work lays a solid foundation for developing a simulation teaching platform for UAV emergency communication networks within the interdisciplinary integration of electronic information science and emergency management. [ABSTRACT FROM AUTHOR]

[Objective] As automated drilling technologies become more prevalent, the demand for data communication while drilling has significantly risen, leading to increased requirements for downhole data communication systems. Currently, pressure wave data communication, which utilizes mud as the transmission medium, is the leading technology in these systems. The core component of these systems is the mud pressure wave generator (MPWG), which produces pressure wave signals with specific phases by adjusting the flow area of the mud through the operation of a rotary valve. Therefore, phase modulation of pressure wave signals and the control method of the rotary valve are critical technologies for the MPWG. Unlike conventional phase modulation methods, the phase of the pressure wave signal cannot change abruptly. Additionally, the drilling mud scours the rotary valve, introducing torque disturbances that make it challenging for the valve to accurately reach the desired position, ultimately reducing the quality of the pressure wave signal. [Methods] To tackle the issues of phase modulation of pressure wave signals and rotary valve position control, this paper proposes a lower sideband constant envelope smooth phase modulation method for pressure signals. Under the condition of maintaining a constant pressure wave amplitude, we introduce a parameter called the adjustable symbol transition time ratio (ASTTR) to achieve smooth phase modulation, along with a lower-sideband modulation method designed to reduce power consumption. Following this, a rotary valve position control system for the MPWG is designed. The speed and position controllers are designed using the active disturbance rejection control algorithm to ensure accurate tracking of the rotary valve position setpoint, even in the presence of external disturbance torques. Finally, a testing device is developed that integrates torque loading, parameter tuning, and data management functions to validate the proposed methods. This device allows for teaching experiments and testing of the MPWG to be conducted without the need for hydraulic circulation. [Results] Two experiments were conducted using the testing device. In Experiment 1, the valve control performance was evaluated under constant and fluctuating torque disturbances. The transmitted symbols of the MPWG are {0, 1, 0, 0, 1, 1}, the symbol period is 0.333 s, and the carrier frequency is 18π rad/s. When the ASTTR is set to 1, the position control errors under constant and fluctuating torque disturbances are 0.039 rad and 0.040 rad, respectively. When the ASTTR is set to 0.5, the position control errors are 0.059 rad and 0.058 rad under constant and fluctuating torque disturbances, respectively. The test results indicated that smooth phase modulation was successfully achieved. Moreover, a larger ASTTR, which facilitates smoother changes in the position setpoint, corresponds to smaller position tracking errors. Additionally, the tracking errors for the same position setpoint under different torque disturbances are similar, indicating that the control system performs effectively in the presence of torque disturbances. In Experiment 2, the power consumption of conventional double-sideband modulation is compared to that of the proposed lower-sideband modulation. The average power consumption for double-sideband modulation was 35.2 W, whereas the average power consumption for the proposed method is 32.6 W, demonstrating a 7.4% reduction in power consumption. [Conclusions] The experimental results demonstrate that the proposed method effectively achieves smooth phase modulation of pressure wave signals and disturbance rejection control of the rotary valve. Furthermore, the proposed method and experimental device exhibit multidisciplinary integration characteristics, enhancing students' ability to address real-world complex engineering problems. [ABSTRACT FROM AUTHOR]

[Objective] With the rapid development of the Internet of Things and network communication technology, cryptography has advanced significantly. Current hash function software can process multiple messages in parallel, making hash functions widely applicable for file tamper-proofing and software installation verification on mobile phones. However, existing hash function software often suffers from low speed and throughput, which hinders the processing of large-scale data in Internet of Things applications. Algorithm hardware can efficiently process large-scale data through algorithm adaptation and path optimization. Consequently, this experiment designs a hardware circuit for the SM3 cryptographic hash algorithm using Verilog hardware description language (HDL) to enhance the speed and throughput of the algorithm, thereby addressing the demand for high-speed hashing algorithms in Internet of Things applications. [Methods] This paper examines the speed and throughput of hash algorithm hardware using various optimization technologies and loop expansion methods. By comparing different techniques, the experiment presents an optimized SM3 hash algorithm. The Verilog HDL code implements the hardware circuit for the SM3 cryptographic hash algorithm, which is simulated using ModelSim by Mentor Graphics Corporation. According to the simulation results from the static sequence, the experiment identifies the critical path of the hardware. Leveraging this static sequence analysis, the study employs loop expansion technology and the conditional-select adder (CSA) to enhance processing speed and shorten the critical path. Furthermore, the FPGA is used to implement the hardware system experimentally and conduct a sequence test to evaluate throughput. According to the experimental results, the hardware incorporates the two-in-one structure loop expansion technology, which reduces two-step calculations to one step. As a result, the number of iterations for compression decreases from 64 to 32. This structure significantly improves calculation efficiency and reduces processing time. Additionally, this experiment proposes a CSA tree topology in the critical path to minimize logic delay without compromising accuracy. [Results] The experimental results for the hardware circuit of the SM3 cryptographic hash algorithm indicated that: 1) The initial and optimized delays were 6.006 ns and 5.525 ns, respectively, according to the simulation results from ModelSim. This represents a reduction in delay of 0.481 ns for the hardware circuit. 2) The proposed CSA tree topology in the optimized hardware system reduced logic delay by 8.01% experimentally, further enhancing overall calculation speed and efficiency. 3) The two-in-one loop expansion technology implemented in the optimized hardware system increased throughput from 822.4 Mb/s to 1 069.5 Mb/s, achieving an improvement rate of 30%. [Conclusions] By incorporating the two-in-one structure loop expansion technology and the CSA tree topology, the hardware circuit for the SM3 cryptographic hash algorithm in this experiment shortens the critical path and reduces logic delay. As a result, calculation speed and efficiency are greatly enhanced. The presented hardware circuit achieves high speed and throughput, enabling the processing of large-scale data without time expansion. Overall, this study significantly contributes to the processing of large-scale data in the Internet of Things and network communication technology. [ABSTRACT FROM AUTHOR]

[Objective] The deposition of Cl-containing harmful salts on the surface of service materials critically influences their corrosion process. The Qinshan Nuclear Power Station, located near the sea, has encountered corrosion issues due to the deposition of these harmful salts. Although researchers have conducted numerous in-depth studies on the corrosion behavior and mechanisms of materials in nuclear power plants, only limited literature addresses the deposition patterns of harmful salts on the surfaces of nuclear-grade materials. [Methods] A field environmental investigation was conducted to understand nuclear material corrosion in salty environments, and then a harmful salt solution for salt spray deposition experiments was formulated based on the investigation results following the ASTM standard. To investigate the deposition patterns of harmful salts on the surface of spent fuel storage canister materials, this solution was used for salt spray deposition on nuclear-grade materials. Tests were conducted at 90 °C to simulate the coastal service environment of the Qinshan Nuclear Power Station. [Results] The analysis of seawater composition revealed that the seawater near the Qinshan Nuclear Power Station is diluted by freshwater, as it is located near the Yangtze River estuary. Despite this dilution, a comparison with the global average sodium content of seawater indicated that the seawater near the Qinshan Nuclear Power Station retains the typical characteristics of normal seawater. The design results for the harmful salt solution indicated that, based on the total chloride content of substitute ocean water according to the ASTM D1141-98 standard (2021 edition), the concentration of each compound in the seawater near the Qinshan Nuclear Power Station must be multiplied by 4.075 26 for amplification. This adjustment allows the formulation of a harmful salt simulation solution for salt spray deposition that complies with ASTM standards. The experimental results of harmful salt deposition on the surface of nuclear-grade material at 90 °C indicated the following: By setting the sedimentation rate of the salt spray at 1.75 mL/(h·80 cm2) and establishing a single salt spray period as "1 min of salt spray followed by 15 min of standing," one salt spray period was necessary for the average harmful salt concentration on the surface of the sample to reach 0.1 g/m² (using thin slice samples measuring 100 mmx100 mmx 0.1 mm). To achieve a concentration of 1.0 g/m², 12 salt spray cycles were required (using flat samples measuring 50 mmx25 mmx2 mm). Finally, 112 salt spray cycles were needed to reach a concentration of 10.0 g/m² (also using flat samples measuring 50 mmx25 mmx2 mm). [Conclusions] The seawater near the Qinshan Nuclear Power Station retains the characteristics of normal seawater. This paper proposes a laboratory design concept and serves as a reference for evaluating the service life and performance of materials used in nuclear power plants operating in actual service environments. [ABSTRACT FROM AUTHOR]

[Objective] Gabion is widely used in slope stabilization, revetment engineering, subgrade reinforcement, and other applications. However, its use in tunnel lining remains underexplored. Owing to its unique multiporosity, which provides excellent deformation capacity and notable bearing strength, gabion shows promising potential for managing the notable deformations and high ground stresses encountered in tunnel surrounding rock. Therefore, studying the static mechanical behavior of tunnel lining components made with gabion is of practical importance. [Methods] This paper presents a simplified molding technique for gabion components and a custom-designed test loading apparatus. Additionally, a numerical modeling methodology specifically tailored for gabion components in tunnel lining is introduced based on discrete element calculations. Next, a comparative analysis is conducted to examine the influence of two key parameters--the strength of the gabion mesh and the effective modulus of the stone filling--on the variation in static mechanical characteristics of tunnel lining components constructed with gabion. This study provides valuable insights into the performance of gabion-based tunnel linings. [Results] 1) The failure of the gabion component in tunnel lining mainly occurs through instability, with only minor cases of wire breakage and stone-filling fracture. Throughout the loading process, the load-displacement curve of the component exhibits notable fluctuations driven by the ongoing interaction between the internal stone filling and the gabion mesh. The overall load-displacement curve increases and then decreases. Despite considerable deformation, the component maintains a high bearing capacity at the end of loading. 2) The tensile strength of the gabion mesh has little effect on the deformation modulus during the initial deformation stage under static load but has more impact on the peak load. The higher the tensile strength of the gabion mesh, the greater the displacement and peak strength at peak load. Under varying tensile strength conditions, the differences in peak load displacement and peak strength reached 28.9% and 25.2%, respectively, because when the tensile strength of the gabion mesh is higher, the component is more resistant to failure, allowing a more effective interaction between the stone filling and the gabion mesh. 3) Compared with the tensile strength of the gabion mesh, the effective modulus of stone filling has a pronounced impact on the component performance. As the effective modulus of the stone filling increases, the postpeak decline in the load-displacement curve becomes more prominent. During the loading process, the energy consumption of the component, peak loading strength, and effective modulus of the stone filling exhibit a distinct piecewise relationship, characterized by an initial increase followed by stabilization. [Conclusions] This experiment provides clear guidance for students conducting static loading mechanical model tests on gabion-constructed tunnel lining components, enhancing the effectiveness of experimental teaching. [ABSTRACT FROM AUTHOR]

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Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)