bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Pitkinian public: representation in the eyes of citizens
Authors: Lavi Liron , Treger Clareta , Rivlin-Angert Naama , Sheafer Tamir , Waismel-Manor Israel , Shenhav Shaul , Harsgor Liran , Shamir Michal 
Published: June 2024

AbstractDemocracy is backsliding in Europe and around the world as citizens’ trust in elected representatives and institutions wanes. Representation theories and studies have mostly centred on the representatives, rather than the represented. But how do citizens perceive political representation? Are their perceptions of any consequence at all? In this paper, we set forth a framework of representation in the eyes of citizens, based on Pitkin’s classic concept of representation in conjunction with Weissberg’s distinction between dyadic and collective representations. We use Israel as a proof of concept for our theoretical framework, employing an original set of survey items. We find that, in keeping with Pitkin’s framework, citizens perceive representation as multidimensional and depreciate the descriptive and symbolic—the standing-for—dimensions. Furthermore, citizens’ democratic attitudes are shaped by collective representation by the parliament rather than by dyadic representation by an elected representative. We conclude with a call for a greater focus on representation from the citizens’ standpoint.
Ethane under pressure revisited using x-ray diffraction, Raman spectroscopy, infrared absorption, and ab initio calculations up to 150 GPa
Authors: Toraille Loïc , Weck Gunnar , Geneste Grégory , Pépin Charles , Garbarino Gaston , Loubeyre Paul 
Published: June 2024

Ethane (C2H6) is anticipated to be the most stable compound within the carbon–hydrogen system under the 100 GPa pressure range. Nevertheless, the properties of ethane under pressure are still poorly documented. Here, we present a comprehensive study of the structural and vibrational properties of C2H6 in a diamond anvil cell at pressures up to 150 GPa. To obtain detailed data, ethane single-crystal was grown in a helium pressure-transmitting medium. Utilizing single-crystal x-ray diffraction, the distortion mechanism between the tetragonal and monoclinic phases, occurring over the 3.2–5.2 GPa pressure range, is disclosed. Subsequently, no phase transition is observed up to 150 GPa. The accurately measured compression curve is compared to various computational approximations. The vibrational modes measured by Raman spectroscopy and infrared absorption are well identified, and their evolution is well reproduced by ab initio calculations. In particular, an unusual anticrossing phenomenon occurs near 40 GPa between a rocking and a stretching mode, likely attributable to intermolecular interactions through hydrogen bonding.
Enhancement of electron–phonon coupling due to increased magnetism and applied hydrostatic pressure in FeSe
Authors: Ouyang Xiao-Fang , Song Ze-Yi , Zhang Yu-Zhong 
Published: June 2024

Abstract
Inspired by the parabolic trend of the superconducting transition temperature (Tc
) of bulk FeSe under hydrostatic pressure, we investigated the effect of magnetism and hydrostatic pressure on the electron–phonon coupling (EPC) in FeSe using density-functional perturbation theory. We found that both magnetism and hydrostatic pressure enhanced EPC. The enhancement of the EPC is mainly attributed to phonon softening and deformation potential induced by magnetism, rather than Fermi surface nesting. Furthermore, we investigated the effect of spin fluctuations on superconductivity by applying the random phase approximation method. A possible application of our results to the phase diagram of FeSe under hydrostatic pressure was discussed, and we demonstrated that when EPC and spin fluctuations are both considered, a parabolic superconducting Tc
may be obtained, providing a plausible explanation for the phase of FeSe under hydrostatic pressure.
Impact of media information and reinfection in a COVID-19 dynamical model: emergence of periodic orbits through Hopf bifurcation
Authors: Devi Arpita , Gupta Praveen Kumar 
Published: June 2024

Abstract
In the current study, we investigate an SIRI compartmental model of COVID-19 incorporating the effect of social media and TV advertisements on the disease transmission of COVID-19 in the presence of reinfection. We have performed basic analysis on the model and studied the basic reproduction number

R

0

. The proposed model admits two disease-free equilibria and upto four endemic equilibria under certain parametric restrictions. We have performed local stability analyses via the Routh-Hurwitz criterion. Global asymptotic stability is established for the unique endemic equilibrium, when it exists, via the geometric approach. We have also scrutinized the proposed model for occurrence of the bifurcation phenomena and found that both forward and backward bifurcation transpires for a certain set of parameters. Simultaneously, the proposed model also displays saddle-node bifurcation. When

R

0

>
1

, the possibility of numerous endemic equilibria exists. These numerous equilibria exhibit oscillations through Hopf bifurcation leading to rich and complicated dynamics. The model is found to show hysteresis. Effect of levels of media and reinfection on the infected compartment is demonstrated and sensitivity analysis of influential model parameters is carried out. Data fitting is carried out to validate the proposed model by comparison of real data in India and the proposed model. Lastly, numerical simulations are executed for several examples to provide analytical and epidemiological understanding into model behaviour.
Machine learning and time-series decomposition for phase extraction and symbol classification in CV-QKD
Authors: Alsaui Abdulmohsen , Alghofaili Yousef , Venkitesh Deepa 
Published: June 2024

Abstract
The predictability of phase estimation and symbol classification using machine learning (ML) for experimental continuous-variable quantum key distribution (CV-QKD) is investigated. ML outperforms standard techniques, with up to 2.3% enhancement in the symbol accuracy, showcasing classical noise impact. The time-series decomposition method upper-bounds the predictable space due to shot noise. Ultimately, a 1 kbits/s secret key rate is achieved at 20 km for a 1.8 pW symbol power.
Ultrathin absorber with independently tunable dual-resonances for terahertz sensing
Authors: Verma Vikrant , Varshney Gaurav 
Published: June 2024

Abstract
A technique is implemented for the generation and alteration of two independently tunable resonance peaks in a graphene based ultrathin absorber structure designed for the terahertz spectrum. The proposed structure is a multi-layered stacked arrangement of two resonator layers of graphene grown over the top of two isolated dielectric (SiO2) substrate layers shielded by a gold metal reflector at the bottom. The structure exhibits very low thickness profile and can be implemented with a thickness equivalent to λ/19.6 where λ is the free space wavelength. Two patterned graphene layers contributes to two independently tunable narrowband/near-perfect absorption peaks at 9.56 THz and 10.96 THz. This polarisation insensitive absorber structure also exhibits frequency ratio tunability of higher order mode with respect to lower order mode by distinctly/separately varying the Fermi level of graphene layers. The response is stable for a wider angle of wave incidence up to 70°. Its narrowband response makes it a suitable candidate to be utilized as biosensor for refractive index sensing.
An Autonomous Navigation Method for Planetary Rover Based on Multi-modal Fusion and Multi-factor Graph Optimization
Authors: Zheng Bo , Cao Tao , Hu Tao , Qian Zhouyuan , Wang Shisun , Han Fei 
Published: June 2024

Abstract
Planetary surface is a complex unstructured environment with strong light, strong shadows, weak textures and numerous obstacles. There is no GPS signal support and satellite networking support on the planetary surface. The limited computer and sensor capabilities of planetary rover have a significant gap from the ground autonomous driving configuration, which presents a great challenge to the autonomous navigation methods of planetary rover. Extreme lighting conditions will increase the camera mismatching rate, and poor texture will increase the lidar matching error, which will reduce the estimation accuracy. Moreover, camera and lidar produce great motion distortion in the rugged terrain and bumpy environment, which leads to a large increase in the cumulative error of odometer. Camera and lidar are not suitable as the main sensor of SLAM algorithm in unstructured environment because they are sensitive to the change of environment. Therefore, an autonomous navigation method for planetary rover based on multi-modal fusion and multi-factor graph optimization is presented in this paper. The IMU (Inertial Measurement Unit) odometer node is added to the lidar odometer and visual odometer thread, and the IMU is taken as the central node to build a multi-factor graph optimization model. A multi-factor graph optimization model and a strong adaptive constraint strategy with reasonable weights are constructed. The pose estimation of other sensors is used to constrain IMU bias, meanwhile historical rut tracking, obstacle contour matching and skyline feature matching are introduced. Finally, motion prediction is achieved in the IMU odometer node. Simulation results and field tests show that this method can effectively cope with the unstructured environment on planetary surface, which achieves adaptive and robust autonomous navigation of planetary rover.
Simulation of fatigue crack initiation life under compressive loading based on material meso-characteristics
Authors: Zhai Yahao 
Published: June 2024

Abstract
The fatigue problem under compressive loading is common in the key components of aeroengine. Most of the fatigue life prediction methods studied in the past are macroscopic phenomenological methods based on a large amount of experimental data. Due to the difficulty in carrying out the fatigue test under compressive loading, the S-N curve or Manson-Coffin formula commonly used on the fatigue life prediction of material under compressive stress were obtained through fatigue tests under conditions where the average stress was greater than or equal to zero. Although the average stress can be corrected by some formulas, whether the life estimation formulas fitted by those fatigue test data are applicable to the fatigue life analysis with average stress less than zero has not been solved in engineering. And there were few studies on the influence of compressive stress on fatigue life at home and abroad. On the basis of Tanaka-Mura fatigue crack initiation theory, a mesoscopic model suitable for fatigue characteristic analysis under compressive loading was established in this article. The model verified the feasibility in predicting the fatigue initiation life using test data of 7075-T651 aluminum alloy under the compressive fatigue load.
Research on optimal design method of dynamic stress parameters of helical gear based on orthogonal experimental design
Authors: Ke Chen , Huan Liu , Suliang Yang , Zheyuan Liu , Xindang He 
Published: June 2024

Abstract
Aiming at the reliability optimization design problem of two-grade helical cylindrical gear transmission system, the UG parameterized model based on expression and ADAMS dynamic simulation model under real working conditions are integrated in ISIGHT platform, and the distribution law of peak contact force on the tooth surface of helical gear pair in the transmission system at different meshing times is obtained. Considering the uncertainty of material properties, load conditions and geometric parameters, the sample set was generated according to the orthogonal experimental design method, and the Kriging approximation model was established. On this basis, the contact strength reliability of helical gear was analyzed. The mathematical model of meshing efficiency reliability optimization of helical gear pair was established and solved by Hooke-Jeeves Direct Search method. The results show that the meshing efficiency and reliability of the optimized helical gear pair are improved, and the peak value of the contact force is obviously reduced.
Random Vibration Characteristics and Vibration Suppression of an Aero-engine Inlet Rake Fabricated by Laser Powder Bed Fusion
Authors: Niu Hongwei 
Published: June 2024

Abstract
The inlet rake is generally installed in aero-engine during rig and flight test for flow field pressure and temperature measuring. There are usually complex flow channels and pipelines inside the rake to extract air flow to the sensor. The laser powder bed fusion(L-PBF) technique was applied in rake fabrication recently due to its progressive layer stacking molding procedure. However, the difference of thermoforming method between L-PBF and the traditional casting process leads to the mechanical property disparities of the material. In this work, the determinants of random vibration response of the inlet rake manufactured by L-PBF with GH4169 powder were studied individually. The stiffness and yield property of the material were investigated by the specimen tensile test, which indicates higher elasticity modulus and yield stress comparing to the ones by castling or forging process. The damping ratio of the inlet rake was obtained through stress attenuation characteristics experiment and analysis under stepwise excitation. The stress distribution and resonance margin of the inlet rake under the aero-engine random vibration spectrum were simulated by finite element modal and random vibration analysis. The results showed that the damping ratio of the L-PBF inlet rake is much smaller than engineering recommendations, and the resonance margin is insufficient. Thus, the stress level of the inlet rake was very high, especially in the blade root section, quite close to the yield limit of the material. To solve this problem, the vibration suppression methods of the inlet rake were studied from the perspective of structural design optimization and damping ratio increasing. Through the rational design of the resonance margin and addition of vibration damping structure, the vibration stress of inlet rake was significantly suppressed. As the result, the rake was installed in the inlet during the aero-engine rig test for flow field pressure and temperature measurement successfully.
Low-frequency broadband vibration isolation study of inertial amplification Meta-lattice sandwich structure
Authors: Zhang Zhilin , Li Hao , Li Bing 
Published: June 2024

Abstract
In the pursuit of excellent mechanical properties, the realization of lightweight structure has attracted great attention from researchers in recent years. To reduce the mass of structures while providing them with low-frequency, broadband vibration damping and multifunctional integration capabilities, this paper presents the use of a Meta-lattice sandwich structure designed using the inertial amplification mechanism. By utilizing a combination of Bloch boundary conditions and the finite element method, we calculated the band gap of the metamaterial structure through finite element software. Afterwards, we examined the impact of the internal structural dimensions and the angle of the internal core truss on the bandgap of the metamaterial structure, as well as their effects on the load-bearing performance. The results demonstrate that the implementation of the concept of inertial amplification achieves low-frequency broadband vibration damping while decreasing the overall mass of the structure, while also retaining good load-bearing performance.
Experimental and Simulation Study on Low-velocity Impact Damage of Composite Laminates under Temperature Environment
Authors: Huanhuan Liang , Hongwei Niu , Ye Wang , Xiewen Sun 
Published: June 2024

Abstract
The composite material casing of aero-engine operates in different temperature environments and is inevitably impacted by external objects during use. The resin matrix composite materials are sensitive to temperature, which leads to more complex damage propagation and failure modes of materials under temperature environment. The influence of temperature environment on low-velocity impact damage of composite materials needs to be studied. In this paper, the T300/QY8911 composite laminates were subjected to low-velocity impact test and simulation study under three different temperature environments of 20°C, 120°C, and 180°C. The impact damage detection was carried out by visual inspection and ultrasonic C-scan to analyze the influence of temperature on the damage of composite laminates. Finite element simulation analysis was also conducted on the gradual expansion process of impact damage of composite laminates under different temperature environments to predict the impact damage area of laminates. The results show that the main damage forms are matrix cracking and delamination and the temperature has a significant effect on the low-velocity impact damage of composite laminates. Under the same impact energy, the length of the back crack and the cracking damage of the matrix of the laminate decreases as the temperature increases; the impact damage area and the delamination damage of the laminate increases as the temperature increases.
Integrated dynamics and control of space multi-joint robotic arm
Authors: Zhang Xianliang , Wang Peiji , Guo Zhongjin , Zhao Xiaodong , Li Tongxing 
Published: June 2024

Abstract
This paper presents research on the integrated dynamics and control methods of a multi-joint robotic arm system installed on a spatial inertial platform. An integrated recursive dynamic model of the posture of the multi-joint robotic arm is established by using the method of dual quaternions. This model can succinctly describe the position and attitude relationships among the joints of the robotic arm. Based on this model, a sliding mode variable structure controller is designed, which can achieve convergence of position and attitude errors even in the presence of external disturbances. The designed controller is validated through simulations, the results of which demonstrate satisfactory control performance, offering reference value for practical engineering applications.
Study on the effect of high temperature on the mechanical properties of composites plates containing initial defects
Authors: Dai Yaguang , Li Guowei , Zhao Meiying , Huang Heyuan 
Published: June 2024

Abstract
In this study, against the background of the high temperature environment faced by hypersonic vehicles, an in-depth study is carried out to investigate the influence of temperature on the mechanical properties of reinforced wall plates of composites containing initial defects. First, the in-plane shear mechanical property data and failure morphology of two groups of specimens of T1100/5405 composites at different test temperatures (25°C, 150°C) were obtained through experimental tests. The tests show that high temperature accelerates the damage failure process of the wall plate structure, the shear capacity of the wall plate is weakened, and the ultimate load decreases by 26.06%. Secondly, a numerical model based on the CZM and the CDM of the composite is established, and the accuracy of the model is verified by combining with the test results. The work carried out in this paper has certain engineering application value for the design of composite structures for hypersonic vehicles.
Dynamic deformation reconstruction of propulsion system pipe based on inverse finite element method
Authors: Mei Mengmei , Huang He , Zheng Zhe , Wu Ziyan , Cheng Hongchuan 
Published: June 2024

Abstract
Pipes are necessary components of the propulsion system. The water hammer effect is easy to provoke severe vibration of the pipe, which is harmful to the safety of the propulsion system. Therefore, it is necessary to monitor the health status of the propulsion system pipe in real time. In this paper, the FSI analysis is adopted to study the water hammer pressure and pipe vibration response caused by valve closure in RPV system. The iFEM algorithm is performed to invert the dynamic deformation of the pipe in real time. Four sensor layout schemes are considered, and the influence of sensor layout on the reconstruction accuracy based on the iFEM algorithm is discussed. It is concluded that the iFEM algorithm is very promising for the dynamic deformation reconstruction of the pipe.
A Fault Diagnosis Method for Rectifier-Filter Circuit Integrating EEMD Algorithm and Transformer Network
Authors: Wang Fu , He Pan , Zhou Chengning , Yang Taibo , Niu Jiang , Liu Caixue 
Published: June 2024

Abstract
Rectifier-filter circuit, as a critical component of the drive circuit in instrumentation and control systems of nuclear power plants, can convert the 50 Hz AC into the smooth DC. Thus, it plays a vital role in the power control of reactors. However, the weak waveform anomalies of soft faults in the rectifier-filter circuit make fault feature extraction difficult. Therefore, in this article, an ensemble empirical modal decomposition (EEMD) algorithm is employed to decompose the signal mode components in the monitor data of the rectifier-filter circuit. The weak waveform anomalies are indirectly enhanced by the IMF and residual components. Subsequently, the Transformer network is utilized to construct the feature extractor. With the advantage of multi-head attention (MHA) mechanism in the Transformer network, the multi-directional, multi-scale, and highly sensitive long-range time-dependent features in the EEMD feature data are extracted. Then, a deep Softmax classifier is adopted to reduce the dimensionality and diagnose the soft faults of the rectifier-filter circuit. Finally, a fault simulation model of the rectifier-filter circuit is constructed and the condition monitor data are collected. The effectiveness and diagnosis accuracy of the proposed method are verified by a real case experiment and some comparative methods.
Control Moment Gyroscope Anomaly Detection Based on Sparse Autoencoder
Authors: Zheng Yuxue , Dou Haijun , Cui Hutao , Xu Minqiang 
Published: June 2024

Abstract
The Control Moment Gyroscope (CMG) is an important executing part of spacecraft, and its anomaly detection has a key influence on the reliability of spacecraft. With the rapid growth of the number of spacecraft and telemetry data, data-driven spacecraft anomaly detection methods have received extensive attention, and such methods may become an important means of spacecraft anomaly detection. However, at present, the spacecraft is faced with the problem of unknown anomalies and lack of abnormal data during orbit. To solve this problem, a sparse autoencoder (SAE) based CMG anomaly detection method was proposed, which takes the telemetry signal of CMG as the object and lacks the sample of anomalous telemetry signal in training data. Firstly, data sample selection and processing were carried out to normalize the data of each telemetry value. Secondly, the SAE model was constructed, and the model was trained with the training set data. Then the sample reconstruction error of the test set was calculated to complete the anomaly detection of the CMG. Finally, it was compared with the traditional artificial threshold monitoring method. The results indicated that the CMG anomaly detection method based on SAE can effectively detect the anomaly samples of the CMG telemetry data, and has better anomaly detection performance than the traditional artificial threshold monitoring method.