bluuebunny/crossref_metadata_2025_split huggingface dataset:
The MSPTDfast photoplethysmography beat detection algorithm: design, benchmarking, and open-source distribution
Authors: Charlton Peter H , Argüello Prada Erick Javier , Mant Jonathan , Kyriacou Panayiotis A 
Published: February 2025

Abstract
Objective: Photoplethysmography is widely used for physiological monitoring, whether in clinical devices such as pulse oximeters, or consumer devices such as smartwatches. A key step in the analysis of photoplethysmogram (PPG) signals is detecting heartbeats. The MSPTD algorithm has been found to be one of the most accurate PPG beat detection algorithms, but is less computationally efficient than other algorithms. Therefore, the aim of this study was to develop a more efficient, open-source implementation of the MSPTD algorithm for PPG beat detection, named MSPTDfast (v.2). Approach: Five potential improvements to MSPTD were identified and evaluated on four datasets. MSPTDfast (v.2) was designed by incorpo- rating each improvement which on its own reduced execution time whilst maintaining a high F1-score. After internal validation, MSPTDfast (v.2) was benchmarked against state-of-the-art beat detection algorithms on four additional datasets. Main results: MSPTDfast (v.2) incorporated two key improvements: pre-processing PPG signals to reduce the sampling frequency to 20 Hz; and only calculating scalogram scales corresponding to heart rates >30 bpm. During internal validation MSPTDfast (v.2) was found to have an execution time of between approximately one-third and one-twentieth of MSPTD, and a comparable F1-score. During benchmarking MSPTDfast (v.2) was found to have the highest F1-score alongside MSPTD, and amongst one of the lowest execution times with only MSPTDfast (v.1), qppgfast and MMPD (v.2) achieving shorter execution times. Significance: MSPTDfast (v.2) is an accurate and efficient PPG beat detection algorithm, available in an open-source Matlab toolbox.
Effective secondary electron yields for different surface materials in capacitively coupled plasmas
Authors: Beckfeld Florian , Masheyeva Ranna , Derzsi Aranka , Schulenberg David Alexander , Korolov Ihor , Bock Claudia , Schulze Julian , Donkó Zoltán 
Published: February 2025

Abstract
Processes at the plasma boundaries, including the electrodes, can significantly influence plasma properties, among them the plasma density, the flux-energy distribution of various particle species, etc. The emission of secondary electrons, in particular, can lead to ionization avalanches, which strongly increase the plasma density and change the discharge operation mode as a function of the operating conditions. Using reliable values to characterize the efficiency of such processes is indispensable for accurate numerical modeling. There is, however, a lack of such data for surface coefficients for arbitrary combinations of the plasma species and electrode materials and surface conditions. In this work, we investigate the α- to γ-mode mode transition induced by changes of the operating conditions (voltage, pressure) in capacitively coupled argon plasmas for different electrode surface materials (copper, nickel, gold, aluminum, and stainless steel) and target the determination of the effective in-situ secondary electron emission coefficient, γ∗. The first is accomplished by phase-resolved optical emission spectroscopy applied to measure the spatio-temporal distribution of the electron-impact excitation rate from the ground state into a high-threshold-energy level of a tracer gas (neon). The studies are conducted for pressures between 50 Pa - 200 Pa and voltage amplitudes ranging from 150 V - 350 V at a driving frequency of 13.56 MHz. A mode transition from the α- to the γ-mode is shown to take place at different pressures for different materials. The combination of these measurements with particle-in-cell / Monte Carlo collision simulations employing a range of γ∗ values allows the determination of the effective 'in-situ' electron yield for the given set of operating conditions. The simulations also shed light on the contributions of the various species, argon ions, metastable atoms, and vacuum-ultraviolet photons to electron emission from the electrodes. The findings suggest that for precise modeling individual secondary electron yields specific to different electrode surface materials should be used and multiple species should be included in the models that describe secondary electron emission at the electrodes.
A high rectification efficiency Dual Fin Si0.7Ge0.3/Si/Si0.7Ge0.3 Quantum Well Channel Structure FinFET for 2.45 GHz micropower microwave wireless energy harvesting
Authors: Ren Jiazhi , Song Jian-Jun , Zhang Yuchen 
Published: February 2025

Abstract
In wireless energy harvesting systems, the performance of rectifier diodes directly determines the upper limit of rectification efficiency. Schottky diodes and MOSFETs are currently the most widely used rectifier devices, but their performance is unsatisfactory in micro-power density input environments. To address this, this paper proposes and designs a high rectification efficiency FinFET model for 2.45 GHz micro-power microwave wireless energy harvesting using Sentaurus TCAD software simulation. When selecting 16 nm gate length, 6 nm fin width, and 53 nm fin height as the basic structural parameters of the FinFET device, the device’s subthreshold swing approaches the ideal value of 60 mV/dec, significantly enhancing the switching speed. Furthermore, a dual-fin structure is adopted to maintain excellent subthreshold swing characteristics and achieve a substantial increase in drive current strength. Finally, a dual-fin strained Si quantum well channel SiGe-OI FinFET structure is proposed to reduce the adverse effects of interfacial scattering on carrier mobility while introducing stress into the channel region to further enhance carrier mobility. The improvement in rectification efficiency is verified by constructing a half-wave rectifier circuit with filter capacitors via the Mixmode module. The rectification efficiencies reach 4.94% and 21.41% when the input power is -20 dBm and -10 dBm, respectively, which are 7 times and 3.4 times higher than conventional near-zero-threshold-voltage Si-based MOS devices under the same conditions.
Enhancing Electromagnetic Tracking: A Hybrid Pose Calculation Algorithm and a Novel Transmitting Coil Calibration Approach
Authors: Wen Shihan , Feng Yuke , Lai Jiacheng , Shi Jianqiao , Yang Rongqian 
Published: February 2025

Abstract
Medical electromagnetic tracking technology offers significant benefits in puncture and interventional surgeries by effectively mitigating obstacles. Traditional optimization-based algorithms for pose estimation in electromagnetic localization often converge to local optima and exhibit slow iterative convergence, which limits their accuracy and efficiency. To address these issues, we propose an enhanced pose estimation algorithm that integrates advanced optimization techniques for receiver sensors.The algorithm successfully converged to the global optimal solution in all test cases and no local optimal solution problem occurred in certain volume, which enables rapid real-time tracking of multiple coils simultaneously, outperforming traditional methods. Furthermore, we have developed a novel calibration method for transmission coils that corrects manufacturing-induced errors in size, position, and orientation. These innovations achieved system positional accuracy of 2.64 mm and directional accuracy of 1.33 degrees within a tracking volume of 350$ \times$ 350 $\times$ 350 $\text{mm}^3$.
The state-of-the-art of invasive brain-computer interfaces in humans: a systematic review and individual patient meta-analysis
Authors: Lim Mervyn Jun Rui , Lo Jack Yu Tung , Tan Yong Yi , Lin Hong-Yi , Wang Yu Hang , Tan Dewei , Wang Eugene , Naing Ma Yin Yin , Ng Joel Jia Wei , Jefree Ryan Ashraf Bin , Yeo Tseng Tsai 
Published: February 2025

Abstract
Objective&#xD;Invasive brain-computer interfaces (iBCIs) have evolved significantly since the first neurotrophic electrode was implanted in a human subject three decades ago. Since then, both hardware and software advances have increased the iBCI performance to enable tasks such as decoding conversations in real-time and manipulating external limb prostheses with haptic feedback. In this systematic review, we aim to evaluate the advances in iBCI hardware, software and functionality and describe challenges and opportunities in the iBCI field.&#xD;Approach&#xD;Medline, EMBASE, and Cochrane databases were searched from inception until 13 April 2024. Primary studies reporting the use of iBCI in human subjects to restore function were included. Endpoints extracted include iBCI electrode type, iBCI implantation, decoder algorithm, iBCI effector, testing and training methodology and functional outcomes. Narrative synthesis of outcomes was done with a focus on hardware and software development trends over time. Individual patient data (IPD) was also collected and an IPD meta-analysis was done to identify factors significant to iBCI performance.&#xD;Main results&#xD;93 studies involving 214 patients were included in this systematic review. The median task performance accuracy for cursor control tasks was 76.00% (Interquartile range [IQR] = 21.2) , for motor tasks was 80.00% (IQR = 23.3), and for communication tasks was 93.27% (IQR = 15.3). Current advances in iBCI software include use of recurrent neural network architectures as decoders, while hardware advances such as intravascular stentrodes provide a less invasive alternative for neural recording. Challenges include the lack of standardized testing paradigms for specific functional outcomes and issues with portability and chronicity limiting iBCI usage to laboratory settings.&#xD;Significance&#xD;Our systematic review demonstrated the exponential rate at which iBCIs have evolved over the past two decades. Yet, more work is needed for widespread clinical adoption and translation to long-term home-use.&#xD;
The design method of a high-rigidity support platform based on a multi-load optimization model
Authors: Zhao Yanyan 
Published: February 2025

Abstract
This paper presents a platform design method based on a multi-condition optimization model. This method primarily considers the stiffness of the platform to resist translational deformation in three orthogonal directions, as well as its ability to resist rotational deformation along the vertical axis. Additionally, the fundamental frequency of the platform is taken into account, treating all these loads as input loads for multi-load optimized design in the topology optimization process. Considering that the platform’s main load-bearing structure is assembled from a steel frame, the beam element was selected for finite element analysis and optimization design. The optimization method used was the Solid Isotropic Material with Penalization (SIMP) method. The optimization efficiency is determined by the number of beams, which is usually less than 1000. Therefore, the optimization efficiency of the proposed method is very high. This method was validated through case studies. The results showed that it can yield a concept design configuration of a platform in a few minutes, and the performance under comprehensive working conditions has been greatly improved.
Research and exploration of rubber band ejection system for small vehicles
Authors: Liu Chengge 
Published: February 2025

Abstract
With the widespread use of small unmanned aerial vehicles, there is a growing need to improve takeoff efficiency and takeoff accuracy. The shift from the traditional rocket-boosted takeoff method to a more flexible launch method has become critical. Rapid response, simplicity of launch, flexibility of location, and low cost become necessary for new launch methods. In this thesis, we have developed a system for launching a small flying vehicle using the rubber strap ejection technique. The system mainly consists of a rotating lifting base platform, an ejection system, and a small vehicle. We analyze the various parts of the ejection system in detail, including the sliding table, the energy storage structure, the trigger, and the buffer structure, and design and test a small vehicle. Experimental results show that this rubber ejection system provides stable, accurate launches that excel in repeatability and efficiency. Specifically, the system demonstrates excellent launch stability, reliability, and launch repeatability, proving its potential in a variety of real-world application scenarios. Demonstrating robust performance and a wide range of applications, this rubber ejection system provides a new, efficient solution for launching small vehicles.
Analysis of the causes of cracks in the cladding layer of the extraction tower
Authors: Deng Cong , Liu Jiayue , Luo Weijian , Li Xufeng , Yang Ruizeng 
Published: February 2025

Abstract
Pressure class special equipment is essential to the operation of a petrochemical production plant. Any failure in this equipment can lead to disastrous consequences. Therefore, during maintenance, it is crucial for technicians to quickly identify equipment problems, analyze their causes, and address them promptly to ensure safe operation. This paper takes a phenol acetone plant (PA) extraction tower as an example, for the penetration test found in the cladding cracks, to carry out background investigation, macro-inspection, spectral analysis, hardness testing, ferrite testing, and metallurgical testing. After comprehensive analysis, it is believed that the surface crack of the cladding layer is caused by chloride stress corrosion cracking, which is caused by improper welding process in the manufacturing process, resulting in large residual stress and intergranular sensitization of 300 series stainless steel. At the same time, according to the actual situation of the site, opinions on disposal and suggestions for subsequent use are given, which provides a reference for the inspection and testing of similar equipment.
Processing performance and regular of 6061 aluminum alloy by longitudinal-torsional ultrasonic milling
Authors: Zhao Yu , Wu Chenjun , Li Xuewei 
Published: February 2025

Abstract
The application of ultrasonic vibration-assisted cutting in machining is also increasing. In order to provide practical guidelines for industrial applications, a single-factor experimental method was employed to compare the surface morphology and surface roughness of 6061 aluminum alloy processed by longitudinal-torsional ultrasonic machining and conventional machining in end milling and side milling. The influence of ultrasonic amplitude on surface quality was systematically analyzed. The experimental results indicate that the surface morphology of both longitudinal-torsional ultrasonic end milling and side milling exhibit similar regular fish-scale-like textures. In contrast, the surface of conventional end milling exhibited arc-shaped concave-convex scratches, while the surface morphology of conventional side milling displayed irregular wavy textures. The surface roughness of longitudinal-torsional ultrasonic end milling is higher than that of conventional end milling, whereas the surface roughness of longitudinal-torsional ultrasonic side milling is lower than that of conventional side milling. Overall, the surface quality achieved through ultrasonic side milling is superior to that of conventional side milling.
Microstructures and properties optimization of Co-Ni based superalloy manufactured by direct laser energy deposition laser process
Authors: Wen Mingyue , Ren Hanwen , Li Wen 
Published: February 2025

Abstract
Superalloy is widely used in the hot-section parts of the aero-engines due to its excellent performance at elevated temperatures. In this paper, a new Co-Ni based superalloy was designed and printed using direct laser energy deposition (DLED), and 17 groups of depositions with different process parameters were set. This paper discusses the effects of process parameters on the deposition metals’ morphologies, microstructures, and mechanical properties, and figures out the process parameter for the DLED formation of Co-Ni based superalloy, with the best microstructure quality and mechanical properties.
NVH performance optimization of an electric vehicle compressor bracket
Authors: Ruan Xianzhen , Sun Lingling , Yao Mengliang , Ye Xiang , Xu Zichen 
Published: February 2025

Abstract
Electric vehicle compressor bracket is a key component that affects the noise, vibration, and harshness (NVH) performance of the vehicle. This paper first uses Hypermesh software to model and mesh the compressor bracket system, and uses modal analysis and frequency response analysis to determine the natural frequency and maximum vibration mode position of the bracket system; secondly, an optimization scheme is proposed for the defective position of the bracket; finally, the vibration isolation rate test verifies the improvement effect of the bracket optimization scheme, and the results show that the vibration isolation rate of the new scheme has been significantly improved. The innovation of this study is that frequency response analysis was combined with structural optimization to systematically optimize and experimentally verify the NVH performance of the compressor support system for the first time. The research method of this paper can provide a certain reference for solving such problems.
Prediction model for lifting performance in deep-sea mining based on flow patterns
Authors: Chen Hailong , Jiang Pan , Xiong Ting , Tang Dingding 
Published: February 2025

Abstract
Utilizing the momentum theorem, flow pattern analysis, and the drift flux method, a comprehensive theoretical model for air lifting in gas-liquid-solid transportation within deep-sea mining has been developed. The results indicate that as the gas mass flow rates increase, there is an initial rapid rise in the particle mass flow rates, followed by stabilization. Concurrently, lifting efficiency shows an initial increase before declining, peaking at lower gas mass flow rates. Increasing the riser diameter or immersion ratio, as well as deepening the air injection port, significantly enhances both the particle mass flow rates and lifting efficiency, while expanding the range of highly efficient gas mass flow rates to improve system lifting capacity. This suggests that under high immersion rates or with larger injection port depths, an air lifting system can utilize a higher gas mass flow rate to enhance production capacity. This study not only provides effective theoretical support for air lifting systems in deep-sea mining but also introduces novel concepts and avenues for further research and engineering practice in related fields.
Research and analysis of AP1000 nuclear fan belt fracture fault
Authors: Li Shuaishuai , Wang Yang , Qu Tianzuo , Ou Ruiheng , Wang Dalin , Meng Weiyan 
Published: February 2025

Abstract
Belt breakage faults often occur in the supply fan of the radioactive waste building in the nuclear power plant. To avoid affecting the normal operation of the fan, the regular replacement frequency of the fan belt was shortened, but the breakage still occurred. Through testing and analysis of belts produced by different manufacturers, a detailed and in-depth analysis was conducted from different perspectives, and corresponding conclusions were drawn. At the same time, follow-up action suggestions were also provided, providing a good reference for improving the operational reliability of similar fans.
Effect of assembly misalignment and weld crack on the maximum pressure of pipeline in-service repair
Authors: Wu Mingchang , Xu Yan , Guo Lei , Huang Liangliang , Lu Yongxin 
Published: February 2025

Abstract
The influence of assembly misalignment and welding crack on the maximum pressure in pipeline repair was investigated using numerical simulation methods in this work. The result indicated that the pipeline doesn’t need to be depressurized when welding misalignment is less than or equal to 5mm for the calculated X70 and X80 pipelines. Besides, when the specifications of X80 pipe was 1219×22 mm, the crack depth to pipe diameter was 0.20~0.40, the crack depth to crack length was 0.20~0.80, and the repair pressure level was the highest, with a range of 8.2~11.4 MPa. The maximum repair pressure was distributed with a range of 7.1~9.5 MPa when the thickness of the pipe decreased to 18.4 mm. The pipeline maximum repair pressure increased with the increase in pipe wall thickness. The maximum repair pressure was up to 14 MPa when the pipeline specification was Φ1016-26.2.
Study on the parameters of DLC coating preparation process based on COMSOL
Authors: Li Tianyi 
Published: February 2025

Abstract
The process of preparing DLC coatings by vacuum evaporation was simulated using COMSOL software. The distance between the evaporation source and the substrate, as well as the temperature of the evaporation source, were changed, and the influence of these parameters on the quality of the coating was analyzed. The results of the simulation experiment indicate that the coating prepared by vacuum evaporation has the thickest center and thinner edges compared to the center. Appropriately increasing the distance between the evaporation source and the substrate material can improve the uniformity of the coating; Raising the temperature has a significant impact on accelerating the sedimentation rate.
Measurement and calibration of discrete element parameters for extruded floating feed pellets and ABS plastic
Authors: Wang Liang , Ji Mingdong , Zheng Yuanhong , Zheng Yuqing 
Published: February 2025

Abstract
In the design and optimization of pneumatic feeding equipment for industrialized recirculating aquaculture systems (RAS), it is essential to simulate the separating and air-blowing process of floating feed pellets through the engineering discrete element model (EDEM). To improve the accuracy of the discrete element model (DEM), both computational simulations and physical tests were performed to adjust the relevant values. A DEM for feed pellets was created by sampling and measuring their inherent characteristics (density, Poisson ratio, and shear modulus) along with interaction parameters (restitution coefficient, and both static and rolling friction coefficients among pellets and between pellets and ABS). The restitution, static friction, and rolling resistance coefficients between puffed floating feed pellets and ABS plastic were calibrated via collision-rebound, inclined plane sliding, and rolling tests. Their calibrated values were 0.533, 0.331, and 0.069, respectively.
Analysis of aerodynamic loads in equipment compartments of high-speed trains
Authors: Xia Nanling , He Yanjing , Zhang Yongchang 
Published: February 2025

Abstract
This paper studied the pressure distribution on the side wall and bottom of the CH3 train equipment compartment at a speed of 300km/h under aerodynamic loading through numerical simulation. The results show that negative pressure exists on the surface of the equipment compartment, and the pressure at the downstream position is higher than that at the upstream position. With the development of the flow field at the downstream position of the bottom and side wall of the equipment compartment, the pressures in the head and middle equipment compartments gradually stabilize, while the pressure in the tail equipment compartment decreases. In addition, the pressure increase at the bottom of the equipment compartment is more pronounced than that at the sidewalls. The pressure change trends of the sidewalls at different heights are similar, but the higher the height above the ground, the greater the pressure fluctuation. The lateral and bottom pressure distributions in the equipment compartment of the train are more likely to be affected by the location of the equipment compartment. This study provides an important reference for the aerodynamic design and safety of the equipment compartment of high-speed trains, lays a basic steady state foundation for the study of other influencing factors.