bluuebunny/crossref_metadata_2025_split huggingface dataset:
The interplay between the dark matter axion and primordial black holes
Authors: Mazde Kratika , Visinelli Luca 
Published: January 2023

Abstract
If primordial black holes (PBHs) had come to dominate the energy density of the early Universe when oscillations in the axion field began, we show that the relic abundance and expected mass range of the QCD axion would be greatly modified. Since the QCD axion is a potential candidate for dark matter (DM), we refer to it as the DM axion. We predominantly explore PBHs in the mass range (106 - 5× 108)g. We investigate the relation between the relic abundance of DM axions and the parameter space of PBHs. We numerically solve the set of Boltzmann equations, that governs the cosmological evolution during both radiation and PBH-dominated epochs, providing the bulk energy content of the early Universe. We further solve the equation of motion of the DM axion field to obtain its present abundance. Alongside non-relativistic production mechanisms, light QCD axions are generated from evaporating PBHs through the Hawking mechanism and could make up a fraction of the dark radiation (DR). If the QCD axion is ever discovered, it will give us insight into the early Universe and probe into the physics of the PBH-dominated era. We estimate the bounds on the model from DR axions produced via PBH evaporation and thermal decoupling, and we account for isocurvature bounds for the period of inflation where the Peccei-Quinn symmetry is broken. We assess the results obtained against the available CMB data and we comment on the forecasts from gravitational wave searches. We briefly state the consequences of PBH accretion and the uncertainties this may further add to cosmology and astroparticle physics modeling.
Multi-field Cuscuton cosmology
Authors: Mansoori Seyed Ali Hosseini , Molaee Zahra 
Published: January 2023

Abstract
In this paper, we first introduce a multi-field setup of Cuscuton gravity in a curved
field space manifold. Then, we show that this model allows for a regular bouncing cosmology and it
does not lead to ghosts or other instabilities at the level of perturbations. More precisely, by
decomposing the scalar fields perturbations into the tangential and normal components with respect
to the background field space trajectory, the entropy mode perpendicular to the background
trajectory is healthy which directly depends on the signature of the field-space metric, whereas
the adiabatic perturbation tangential to the background trajectory is frozen. In analogy with the
standard Cuscuton theory equipped with an extra dynamical scalar field, the adiabatic field does
not have its own dynamics, but it modifies the dynamics of other dynamical fields like entropy
mode in our scenario. Finally, we perform a Hamiltonian analysis of our model in order to count
the degrees of freedom propagated by dynamical fields.
Integrated simulation analysis of the HL-2M high-parameter hybrid scenario
Authors: Zhong Y. , Yang G. , Gong X. , Yu P. , Tan Q. , Huang Q. , Zheng P. , Yin L. , Yang T. , Gao Z. , Wang Z. , Xu M. 
Published: January 2023

Abstract
On the basis of the OMFIT integrated simulation platform and the parameters of the HL-2M device, a hybrid scenario with a typical safety factor q profile is simulated using the joint injection method of neutral beam and electron cyclotron wave with a normalized toroidal beta (β
N) of 2.39. At the same time, by analyzing the effect of impurity concentration (Z
eff) and pedestal density (n
e,ped) on confinement, a higher parameters hybrid scenario is obtained, with β
N reaching 3.118. The research results indicate that the turbulent stabilization effect caused by Z
eff gradually decreases from strong to weak with the increase of Z
eff, whereas the radiation power loss increases linearly as Z
eff increases. Consequently, there exists an optimal Z
eff value for optimal confinement. In addition, it is found that the optimal Z
eff value decreases with the increase of n
e,ped. The research results are crucial for the HL-2M device to accomplish the 1 MA advanced scenario discharge target, and they serve as a reference for future impurity seeding experiments.
Temperature Prediction for Subway Station Based on LSTM-SVR Algorithm with Multi Period Characteristics
Authors: Li Youwen , Chu Hongjian , Cai Yilei 
Published: January 2023

Abstract
By analyzing the timing characteristics of historical temperature data of the subway sensors, aiming at the problem of poor accuracy of a single temperature prediction model, combined with the long-term trend, multi period and irregular change characteristics of the temperature data, this paper proposes a combined prediction model based on the Long Short-Term Memory network (LSTM) and Support Vector Regression (SVR) theory, the prediction mean error of LSTM-SVR is lower than single model, which can predict the temperature of subway station with high accuracy, so as to provide a basis for controlling air-conditioning and ventilation equipment, also saving energy and reducing consumption.
Research on Moving Object Detection based on Camshift Algorithm and Kalman Filter
Authors: Liu Liping , Wu Guangli , Yang Zhilong 
Published: January 2023

Abstract
The key content of video image processing and analysis is the detection and tracking of moving objects, and it is also the focus and important research field of computer vision. It has important applications in unmanned operation, defense industry, human-computer interaction, image processing and other fields. In this paper, under the development environment of Spyder and Opencv, the autonomous adaptability of Camshift tracking algorithm is combined with kalman filter algorithm, so the moving target detection and tracking in video monitoring is realized by using python language.
Research on Effectiveness Evaluation Method of Expressway Toll Station Based on Entropy Method and TOPSIS Method
Authors: Zhang Chunsheng , Han Fuqing , Wu Youquan , Huang Junfei , Zeng Renfen , Lin Di , Yin Lingyu , Li Dan , Li Zhi , Liu Mengzhu 
Published: January 2023

Abstract
The effectiveness of expressway toll station is the core part to characterize the quality of its toll service, but there are few studies on the effectiveness evaluation of toll station in China. This paper studied the effectiveness evaluation method of toll station based on entropy method and TOPSIS method. After putting forward an evaluation index system, the entropy method was used to determine the weight value of each index, and then the TOPSIS method was used to calculate the comprehensive score. In the application process, YOLOv5 target detection algorithm was used to calculate the index values obtained in real time in the monitoring video, make accurate and objective evaluation on the effectiveness of the toll station, and provide a basis for intelligent management of toll station.
Ionosphere Delay Extraction in GNSS using DSP Algorithm
Authors: Li Qianxia , Xia Linyuan , Huang Qiuhua , Lin Hong , Zhu Hongyu , Wu Jinhua , Cai Yuezhen , Zhang Xiao , Song Xuejin 
Published: January 2023

Abstract
With multiple GNSS availability and wider applications, many positioning modes like SPS, DGNSS, RTK and PPP have been developed to cover these flexible employments. Currently, some intricate influences such as ionosphere delays and environmental interference have caused obvious impacts to accurate positioning, and they are therefore formed highlighted research points for worldwide researchers and scholars. To deal with the ionosphere delay, this submission has proposed an intrinsic approach to identify and extract the ionospheric disturbance from GNSS observations in which Digital Signal Process (DSP) is employed to form an adaptive band pass filter for combined observations in the form of either code minus phase (CMP) or double differential (DD) carrier phase. Related mechanism for identification and extraction of the ionosphere delay using DSP are introduced and analyzed. We have also discussed the separation of ionosphere delay with multipath caused by signal reflections from nearby surroundings when deformation monitoring is conducted on some restricted environments. Effects achieved by DSP have been verified combining with typical SPS and carrier based relative positioning conducted in Guangzhou metro construction sites. Results exhibit that the suggested standalone approach to extract ionosphere delays is an innovative technical frame to achieve accurate positioning regardless of assistant messages from base stations or satellite navigation broadcast.
Study on Fire Extinguishment Performance of Water Mist System in a Utility Tunnel
Authors: Yang Quan , Li Yanfeng , Xu Chenliang , Liu Huiqiang , Tian Wei 
Published: January 2023

Abstract
The power cable fire in an utility tunnel is difficult to control due to its characteristics of narrow and long structure, cable layer arrangement, and variable fire locations. Water mist system is one of commonly used method for fire control. This paper studied the fire extinguishing efficiency of high-pressure water mist system in utility tunnel by large eddy simulation (LES). In order to compare the fire extinguishing effect of the water mist system, two working conditions are designed, that is, the utility tunnel with water mist system and without water mist system. Results have shown that continuously operating of high-pressure water mist system can extinguish cable fires effectively. The cooling effect of the water mist is obvious and it can control fire development or extinguished fire. The temperature of utility tunnel would be reduced so as to prevent the structure from being destroyed.
Experimental Study on Dynamic Shear Modulus and Damping Ratio of Loess Considering Disturbance
Authors: Liu Songbiao , Liu Nina , Li Jun , Fei Fei 
Published: January 2023

Abstract
Loess is a special kind of Quaternary sediment. The sub-stable skeleton formed by fine grains and salt crystals makes the loess with great risk of catastrophic changes under dynamic action. In order to study the influence of the natural structure of loess on its dynamic properties, the test was conducted on the loess at the near-fault site of the Lishan piedmont fault to analyze the influence of soil structure disturbance on the dynamic properties of loess. The test adopts dynamic triaxial test system. The results show that the soil structure disturbance has a large effect on the dynamic shear modulus of the loess, while it has little effect on the damping ratio. Under low confining pressure, the maximum dynamic shear modulus of original loess is smaller than that of remodeled loess. Under the high confining pressure, the original loess is larger than the remodeled loess. When the confining pressure is 400 kPa, the maximum dynamic shear modulus of the original loess is 93.28 MPa, which is 53.8% larger than that of the remodeled loess. When the dynamic strain reaches 0.15%, the difference between the damping ratio of the remodeled loess and the original loess is less than 0.04, and it can concluded that the soil structure disturbance has little effect on the loess in the Lishan piedmont fault.
Research on Quality Management and Countermeasures of Fabricated Building Construction Based on SWOT Theory
Authors: Gao Jia , Zhu Jiwei , Wang Xin , Zhao Jie 
Published: January 2023

Abstract
With the rapid development of science and technology, the construction industry is showing the trend of informatization. BIM has emerged to bring vitality into the construction industry. This paper introduces the application of BIM software in various phases and the mainstream BIM software at home and abroad, and conducts a comparative study on each BIM software from the design phase, construction phase and operation and maintenance phase, analyses the advantages and disadvantages of each software, and helps relevant practitioners to quickly choose the appropriate software according to their needs.
Numerical Simulation on Train Length Effect on Smoke Propagation in a Stopped Train Fire
Authors: Shuangliu  , Li Yanfeng , Li Jiaxin 
Published: January 2023

Abstract
It is important to keep fire safety for subway system especially for subway tunnel. This paper selects a 2.2 km tunnel of Beijing subway as the research object, and studies fire scenario for a stopped train with natural ventilation. The multi-scale method where a three-dimensional field model and a one-dimensional network model are combined is used to simulate smoke propagation in a tunnel fire. The effects of train length on the smoke propagation, temperature and visibility distribution are analyzed. The results show that during the initial period of 120s, the influence of train length on temperature distribution, visibility distribution and smoke distribution is not obvious. However, after 120s period, smoke distribution becomes more concentrated with the increase of train length, and the impact of stack effect is more obvious. For a shorter train, the concentration of smoke is higher. The temperature distribution inside the 60 m train is higher than those of 120m and 160m trains.
Effect of Molding Methods on Free-Thaw Durability of Pervious Concrete
Authors: Li Qiuxiang , Zheng Jie , Fu Mingfu 
Published: January 2023

Abstract
Pervious concrete is one of the most important new materials in the sustainable development of infrastructure construction, and has been widely studied and developed by the industry. Through freeze-thaw test, dynamic elastic modulus test, mass test and strength test, the durability of pervious concrete with different molding methods was studied. The test results show that the mass loss rate and strength decline rate of the pervious concrete controlled by the pervious rate are the lowest after 25 cycles of freezing and thawing, marshall compacted pervious concrete has the lowest loss rate of dynamic elastic modulus, and plug-in concrete has the lowest durability. Finally, the mix proportion of pervious concrete with optimal target porosity by rotary compaction is suggested.
The Study on Deformation Characteristics and Stiffness Degradation of Loess near Active Faults
Authors: Fei Fei , Liu Nina , Gao Shuai , Huang Zhuo 
Published: January 2023

Abstract
In order to explore the deformation characteristics and stiffness degradation of loess near active faults under subway loading, a series of dynamic triaxial tests were utilized to model the effect of subway loading on loess near active faults. The cumulative plastic strain characteristics and stiffness degradation laws of loess under different dynamic stress amplitudes and different loading frequencies are obtained, and the cumulative plastic strain and stiffness degradation indices are fitted using empirical formulas and degradation models, respectively. The results show that the growth rate of cumulative plastic strain and the attenuation degree of stiffness degradation index are large under large dynamic stress amplitude and low loading frequency. And the empirical formula accurately fits the cumulative plastic strain curve, and the correlation coefficient is more than 0.9. Furthermore, the degradation model fits the stiffness degradation index curve well, and the degradation parameter increases with increasing dynamic stress amplitude and decrease with increasing frequency. The findings of the study can be used to guide the construction and safe operation of subway tunnels that traverse active faults.
Research on Ground Surface Settlement of Curved Pipe Jacking Based on Numerical Simulation
Authors: Wu Qixing , Deng Dian , Chen Xuehua , Zhou Lihong , Liu Guodong , Song Huihui 
Published: January 2023

Abstract
The construction disturbance caused by pipe jacking is an index that must be strictly controlled in the project. With the wide application of curved pipe jacking in urban underground construction, predicting its ground surface settlement characteristics has become an increasingly important research topic. Based on finite element numerical simulation, a three-dimensional model of curved pipe jacking was established to simulate the construction stage. Compared with the straight pipe jacking, the normal component of jacking force is set in the outer tunnel of the curved pipe jacking to simulate the extrusion of the outer soil caused by the corner of the pipe joint, and the surface settlement characteristics of the curved pipe jacking are explored by changing the pressure value. The research results show that the surface settlement of the curved pipe jacking conforms to the normal distribution as a whole. Compared with the linear pipe jacking, the surface settlement is not symmetrical about the design axis of the tunnel. With the increase of the pressure outside the tunnel, the maximum settlement value of the surface and the difference between the two sides of the axis increase. Compared with the Peck formula, the width of the settling tank of the curved pipe jacking is larger, the convergence rate outside the width of the settling tank is slower, and the settlement trend is more in line with the Verruijt formula. The calculation formula is modified by axis offset distance and ovalization coefficient and modified formula can better reflect the measured engineering data. The research results can provide guidance and reference for the prediction and control of surface settlement of curved pipe jacking.
Waveform Similarity Comparison Protection Scheme for Multi terminal Distribution Network Based on Fault Self-synchronization and 5G Communication
Authors: Jiang Shuai , Li Zhongqing , Xiao Shuyu , Chen Lei , Li Zhao 
Published: January 2023

Abstract
With the wide access of distributed new energy, how to quickly identify and accurately isolate the fault of distribution network is a key technical problem to be solved in the industry. Due to the numerous branches of the distribution network, the imperfect data acquisition network, and the transmission error of the transformer, there is an urgent need for new means to cope with the synchronization problem of data acquisition in different locations. To solve the above problems, firstly, the characteristics of multi terminal distribution network in case of fault are analyzed, and the automatic synchronization of protection data is realized by detecting the abrupt points of signals at different locations; Secondly, the information of each node in the distribution network is transmitted to the substation in real time through the 5G network, and the decision-making center connects the distribution lines with multiple branches for information synthesis to form a double ended line form that is convenient for calculation and comparison; On this basis, through the tanimoto waveform similarity algorithm, the correlation coefficients of current waveforms at both ends of each line are compared to determine whether they have failed, and finally a new scheme of fast protection for multi terminal distribution network suitable for distributed new energy access is formed. By building the distribution network model in PSCAD/EMTDC, the effectiveness of the proposed protection scheme under various fault scenarios is verified. Compared with the traditional over-current protection scheme, it has faster action speed and higher reliability, and has good practical value.
Experimental Study on Strength Anisotropy of Loess in Near-Fault Area
Authors: Lin Wei , Huang Zhuo , Tian Kaifei 
Published: January 2023

Abstract
The anisotropy of loess has been widely studied. However, most studies only consider the difference in soil quality and do not consider the impact of special areas. In addition, the conclusions of scholar researches are differences, and not representative. With the development of underground engineering construction, the direction of principal stress of loess is no longer just vertical, and the study of loess anisotropy has become a key issue. Therefore, this study takes the loess near-fault area of the Lishan piedmont fault as the research object, the differences of shear strength parameters in different directions were studied by routine triaxial shear test. The results show that the anisotropy of loess in this area is obviously different, which is greater than that of loess in other sites. The difference mainly reflect in the cohesion. The cohesion of the sample of the θ=90° is 1.62 times that of the sample of the θ=0° about. The difference of saturated loess is decreases, and the difference of cohesion is about 30%. The results provide a reference for the construction of the underground engineering for this areas, the engineering construction should pay attention to the difference in the strength and deformation on different directions of the loess.
Mesh Division Method of Large Span Spatial Structure based on Free-Form Surface
Authors: Liu Kai , Wang Zhuangzhuang , Hong Cheng , Li Xingang , Tu Bin 
Published: January 2023

Abstract
All Free-form architecture has novel and unique shapes, complex and diverse changes, and has become the trend of modern architectural development with its rich shape changes and soft lines. The traditional grid layout method is not applicable to the grid division of free-form surfaces, and how to divide a smooth and beautiful grid is a hot research problem for large-span spatial structures. In response to the above problems, after investigating the current scientific research results at home and abroad, our team proposes a meshing method using the 3D software Rhino platform to solve the problems of uneven meshing of free-form surfaces and low intelligence, and to divide a smooth and beautiful mesh.
Research on the Cloud Platform for Urban Rail Transit based on Track Inspection Vehicle
Authors: Shi Yufeng , Wu Gaohua , Li Dan , Wang Xutong , Yu Dachuan 
Published: January 2023

Abstract
The aim of this paper was to improve the automation of track inspection, data utilization rate, informationization of maintenance dispatch. We designed a track inspection vehicle based on multi-sensor information fusion, then gave the method of coordinate transformation and data fusion. And then researched the service of data displaying, data management and data analysis, proposed the system architecture and network topology, realized the system deployment on the cloud. And then demonstrated stability by comparing the results of two machine tests, and proved accuracy by comparing the results of machine tests with manual tests. The result shows that it had a high accuracy and stability. At last, designed the reserve of cloud platform function extension, discussed the method of data analysis. Research shows that, the track inspection vehicle can measure the track geometric parameter. The application of cloud platform technology can reduce the cost of operation, simplify the function extension. The research result has a positive impact on solving the current problem of track inspection, improving passenger comfort and ensuring safe operation.
TrEKBQA:Traversing Knowledge Graph Embedding for Multi-hop Knowledge Base Question Answering
Authors: Shi Xiujin , Hu Jun , Sun Naiwen , Yu Shoujian 
Published: January 2023

Abstract
Recent research apply KG embedding to multi-hop Knowledge Base Question Answering(KBQA) to predict missing links, however, it is often affected by the skewed distribution of nodes in the knowledge graph, resulting in poor generalization of the model. Therefore, we propose a method TrEKBQA based on traversing the knowledge graph embedding space for multi-hop KBQA, which performs path traversal in the KG embedding space instead of KG itself for link prediction to complete the knowledge graph, thus improving the accuracy of multi-hop KBQA.TrEKBQA model complex relationships using correlations between individual links and longer paths connecting the same pair of entities to traverse the KG embedding space to mitigate the effects of biased distribution of nodes and improve the performance of link prediction. In the pre-processing process, TrEKBQA uses the PRN algorithm to extract subgraphs related to the problem entity to reduce the number of target entities. Through experiments on multiple benchmark datasets, we demonstrate the effectiveness of TrEKBQA on KBQA tasks.