bluuebunny/crossref_metadata_2025 huggingface dataset:
Lessons learned from the COVID-19 pandemic—what Occupational Safety and Health can bring to Public Health
Authors: Godderis Lode , Lerouge Loic , Samant Yogindra , Noone Peter
Published: January 2023

We strive to increase public (PH) and occupational health (OSH) inter-linkages by building a collaborative framework. Besides Covid-19 pandemic, recent approaches such as Human Exposome and Total Worker Health TM, have led to a shift to improving health of working population and consequently the total population. These health objectives can be best realised through primary care actors in specific contexts. Work, school, home and leisure are the four multi-stakeholder contexts in which health and healthcare (goal-oriented care) objectives needs to be set and defined. PH policy makers need to establish a shared decision-making process involving employees, employers and OSH representatives to set PH goals and align with OSH goals. The policy making process in OSH can serve as a potential way forward, as the decisions and policies are being decided centrally in consultation with social partners and governments. This process can then be mirrored on company level to adopt and implement.
Syntactic complexity in legal translated texts and the use of plain English: a corpus-based study
Authors: Lin Xiaowen , Afzaal Muhammad , Aldayel Hessah Saleh
Published: January 2023

This study compared the linguistic difficulty of legal translated texts with the syntactic complexity of native English legal writings in order to demonstrate the statistically significant differences between the two big datasets. The study applies features of the syntactic complexity of sentences within legal text translations that translated texts are less complicated than their original counterparts. It provides an example of how easy plain English translation in legal communication might result in understandable target writings. The findings of the legal translation of the people of three regions reveal striking patterns in terms of syntactic complexity and legal communication in plain English, which are consistent with previous research. Complex nominal and hypotactic structures result in a high number of propositions per sentence, placing a high demand on the cognitive processing abilities of those who read and understand the text. The statistics show considerable differences among the three locations and various forms of company law corpora. The study is the first large-scale quantitative analysis of the accessibility of legal jargon compared to other forms of English, emphasizing the efficacy of plain-language initiatives in legal translations.
Ultra-fast semi-empirical quantum chemistry for high-throughput computational campaigns with Sparrow
Authors: Bosia Francesco , Zheng Peikun , Vaucher Alain , Weymuth Thomas , Dral Pavlo O. , Reiher Markus
Published: January 2023

Semi-empirical quantum chemical approaches are known to compromise accuracy for the feasibility of calculations on huge molecules. However, the need for ultrafast calculations in interactive quantum mechanical studies, high-throughput virtual screening, and data-driven machine learning has shifted the emphasis toward calculation runtimes recently. This comes with new constraints for the software implementation as many fast calculations would suffer from a large overhead of the manual setup and other procedures that are comparatively fast when studying a single molecular structure, but which become prohibitively slow for high-throughput demands. In this work, we discuss the effect of various well-established semi-empirical approximations on calculation speed and relate this to data transfer rates from the raw-data source computer to the results of the visualization front end. For the former, we consider desktop computers, local high performance computing, and remote cloud services in order to elucidate the effect on interactive calculations, for web and cloud interfaces in local applications, and in world-wide interactive virtual sessions. The models discussed in this work have been implemented into our open-source software SCINE Sparrow.
Flow characteristics within an interior subchannel of a 61-pin wire-wrapped hexagonal rod bundle with a porous blockage
Authors: Menezes Craig , Melsheimer Trevor , Pyle Dalton W. , Kinsky Matthew , Hassan Yassin A.
Published: January 2023

Potential accumulation of undesirable debris in a subchannel of a Liquid Metal Fast Reactor (LMFR) hexagonal fuel bundle presents accident conditions, which are crucial to investigate. Very limited experimental research persists in the literature to understand the fluid dynamics effects of partially blocked subchannels due to the presence of porous blockages. It is imperative to comprehend flow regime-dependent fluid response in the vicinity of porous blockages to predict and counter abnormal conditions in an LMFR rod assembly. The presented experimental research investigates flow-field characteristics in a 61-pin wire-wrapped rod assembly with a three-dimensional (3D) printed porous blockage medium in an interior subchannel at Reynolds numbers (Re) of 350, 5000, and 14 000. Time-resolved velocimetry measurements were acquired yielding first- and second-order Reynolds decomposition flow statistics—revealing important fluid response upstream and downstream of the porous blockage. Profiles of velocities, velocity fluctuations, Reynolds stresses, and vorticities uncovered the downstream blockage perturbation effects. Spatial cross-correlations of the velocity fluctuations displayed eddy structure elongations and quantified eddy integral scale lengths. A time-frequency analysis of the velocity fluctuations further detailed the mechanisms of flow instabilities via power spectral analysis. The application of a one-dimensional continuous wavelet transform revealed complex Re-dependent flow and characterized the temporal turbulence occurrences—caused by the trailing edge effects of the porous blockage. This research provides unique and novel experimental analyses on flow regime-dependent fluid physics due to a porous blockage medium and provides data sets vital for computational model benchmarking and development, toward the enhancement of LMFR rod bundle designs.
Benchmarking two-body contributions to crystal lattice energies and a range-dependent assessment of approximate methods
Authors: Sargent Caroline T. , Metcalf Derek P. , Glick Zachary L. , Borca Carlos H. , Sherrill C. David
Published: January 2023

Using the many-body expansion to predict crystal lattice energies (CLEs), a pleasantly parallel process, allows for flexibility in the choice of theoretical methods. Benchmark-level two-body contributions to CLEs of 23 molecular crystals have been computed using interaction energies of dimers with minimum inter-monomer separations (i.e., closest contact distances) up to 30 Å. In a search for ways to reduce the computational expense of calculating accurate CLEs, we have computed these two-body contributions with 15 different quantum chemical levels of theory and compared these energies to those computed with coupled-cluster in the complete basis set (CBS) limit. Interaction energies of the more distant dimers are easier to compute accurately and several of the methods tested are suitable as replacements for coupled-cluster through perturbative triples for all but the closest dimers. For our dataset, sub-kJ mol−1 accuracy can be obtained when calculating two-body interaction energies of dimers with separations shorter than 4 Å with coupled-cluster with single, double, and perturbative triple excitations/CBS and dimers with separations longer than 4 Å with MP2.5/aug-cc-pVDZ, among other schemes, reducing the number of dimers to be computed with coupled-cluster by as much as 98%.
Increasing depth reduces macrophyte coverage but increasing transparency promotes composition turnover through environmental thresholds
Authors: Canalli Yasmin M. , Soares Bruno E. , Sakuragui Cassia M.
Published: January 2023

Context Environmental filters modify the coverage and frequency patterns of macrophyte communities. Aims We characterised the thresholds in depth and transparency at which the macrophyte distribution shifted in an Atlantic Forested wetland. Methods Macrophyte communities were characterised in 150 plots divided into 6 transects. Key results Threshold indicator taxa analysis (TITAN) indicated that free-floating life forms respond negatively to depth and transparency increase. Rooted-floating species responded negatively to an increase in depth and transparency; by contrast, submerged species responded positively to increased transparency. Conclusion TITAN also highlighted that the entire macrophyte community responded negatively to increased depth but exhibited a synchronous turnover among species responding positively and negatively to transparency. Implications Our results demonstrated that macrophyte responses to increasing depth and transparency are non-linear and depend on species life forms.
A scoring system for cochlear implant candidate selection using artificial intelligence
Authors: Abousetta Alaa , El Kholy Wafaa , Hegazy Mona , Kolkaila Enaas , Emara Afaf , Serag Shayma , Fathalla Ahmed , Ismail Omnia
Published: January 2023

Objective:

Cochlear implant (CI) candidate selection is a lengthy, complicated process that entails subjective judgment on the interaction of multiple pre-operative variables. It is assumed that setting a scoring system for the process of CI candidate selection would help in precise and reliable decision making. This would also provide a tool that would help in providing a better quality of life for CI patients.

Methods:

Retrospective cohort study was held out in three post-CI rehabilitation centers. A total of 100 children records were analyzed with two statistical methods; conventional and Artificial Intelligence (AI) using Machine Learning. Language age deficit, phonological deficit, and social deficit were invented as new measures of CI performance; used to represent the developmental delay of those children in a single numeric value (in months).

Results:

Artificial Intelligence analysis surpassed conventional statistical methods for the prediction of the outcome measures of post-CI performance. This was clearly expressed using linear regression models. The AI classification model validation for predictive accuracy of language age deficit, phonological deficit, and social deficit were 56.66%, 88.11%, and 40.46% respectively.

Conclusion:

The production of a preliminary CI scoring model used for prediction of performance of patients was achieved. More data should be collected and fed to the software in order to improve its performance.
Discussion for the enhanced understanding of the photoelectric effect
Authors: Jho Hunkoog , Lee Bongwoo , Ji Youngrae , Ha Sangwoo
Published: January 2023

The photoelectric effect is a crucial phenomenon that contributed to the emergence of modern physics. Even, it is widely used in various fields of physics, such as spectroscopy, image sensing, and particle physics. Albeit its significance in physics, most of the textbooks illuminate a limited perspective focusing on the particle nature of light. This study aims to provide a more productive account of the photoelectric effect from a holistic viewpoint relevant to various fields of physics. This study examines the various fields of physics, from electromagnetics to modern physics, including quantum mechanics such as Fermi–Dirac statistics and light quantum theory. We also suggest extending the quantum mechanics to consider factors influencing the photoelectric effect experiment, such as both anode and cathode materials, geometric considerations of apparatus, and various kinds of interaction between quantum particles. To understand the mechanism of the photoelectric effect deeply, students should be aware of various fields of physics and connect them. The discussions in this study provide more productive ways of understanding the photoelectric effect.
Implementing the learning assistant model in European higher education
Authors: Odden Tor Ole B , Lauvland Anders , Bøe Maria Vetleseter , Henriksen Ellen Karoline
Published: January 2023

The learning assistant (LA) model is a widely used and researched model for institutional and course transformation towards research-based instructional strategies (RBIS). The LA model leverages learning assistants, pedagogically trained students, to facilitate student learning in active learning environments. However, although the LA model has shown significant results when implemented in university contexts in the United States, there has as yet been little documentation of similar implementation or results in European higher education. In this study, we present the results of a three-semester design-based research project to implement the LA Model in a Scandinavian physics department. The three core elements of the LA model (pedagogical training, course content meetings, and teaching in active learning environments) were implemented and iteratively refined, with necessary adjustments due to the specific institutional and cultural contexts documented. Throughout all three semesters, data was collected on how participation in the LA model affected LAs’ buy-in to RBIS using focus groups, pre/post surveys, and teaching observations. A thematic analysis of these data showed that participation in the LA model helped ensure LA buy-in to both the interactive engagement methods and goal of cultivating conceptual understanding that underlie most RBIS, and that the combination of teaching practice and pedagogical training seminars were key to this buy-in. We argue that these results demonstrate the potential usefulness of the LA model for creating institutional and cultural change in European higher education.
Below- and near-threshold harmonic generation from multiple orbitals
Authors: Long Jie , Chen Yuhang , Zhu Xiaosong , He Lixin , Lan Pengfei , Lu Peixiang
Published: January 2023

We report an unexplored observation of multi-orbital contribution in the below- and near-threshold harmonic generation of aligned molecules. A typical pump–probe configuration is used in our experiments. By scanning the time delay and crossing angle of polarization directions between the pump and probe pulses, we find that the harmonic yield in this region exhibits abnormal intensity-dependent modulation patterns. Further comparison and analysis show that this observation can be interpreted as due to the contribution of deeper-lying molecular orbitals, which are much more prominent than in the above-threshold region and can overall surpass the contribution of the highest occupied molecular orbital, leading to reversed modulation patterns. The particular importance of the deeper-lying orbitals in this regime is closely related to the multi-photon excitation pathways involved in the generation process. Our work will advance further investigations on the mechanism of below- and near-threshold harmonic generation.
CDMAM in digital mammography: contrast threshold measurements, achievable values and relation with dose
Authors: Trindade Hugo , Barreira Marisa
Published: January 2023

The main goal of this study is to characterise threshold contrast values and average glandular dose (AGD) in mammography examinations, as well as their relationship with acceptable (minimum quality values) and achievable (desirable quality values) values from the fourth edition of the EUREF protocol. Therefore, data from 84 mammography units from six different manufacturers comprising 15 different models were gathered across Portugal during 2020 and 2021. The contrast measurements were obtained with a CDMAM 4.0 phantom. Within the tested units, six failed to comply with the acceptable EUREF values for threshold contrast and 5% achieved all levels of desirable contrast. Only 3% of the units presented values above an achievable AGD level of 2.4 mGy for an equivalent breast thickness of 60 mm. As these acceptable and achievable values are used as a guideline for the setup of dose and image quality of mammography units, the obtained results demonstrate that clinical images are being produced with an AGD much lower than the achievable dose values. As a result, contrast threshold values are close to the minimum quality values, which could result in images with less diagnostic data, compromising the justification of x-ray exams. Results proved that there is a possibility for an increase in AGD to give achievable image standards. Higher levels of radiation dose correlated with better image quality, and consequently higher diagnostic confidence could be consistent with the optimisation principle for radiation protection.
Structural and dynamical studies of CH–π bonded CH4–C6H6 dimer by ultrafast intermolecular Coulombic decay
Authors: Zhou Jiaqi , Jia Shaokui , Xue Xiaorui , Hao Xintai , Zeng Qingrui , Wang Xing , Ren Xueguang
Published: January 2023

The inner-valence ionization and fragmentation dynamics of CH4–C6H6 dimer induced by 200 eV electron impact is studied utilizing a multi-particle coincidence momentum spectroscopy. The three-dimensional momentum vectors and kinetic energy release (KER) of the CH4
++C6H6
+ ion pairs are obtained by coincident momentum measurement. Our analysis on the absolute cross sections indicates that the intermediate dication CH4
+–C6H6
+ is preferentially produced by the removal of an inner-valence electron from CH4 or C6H6 and subsequent relaxation of ultrafast intermolecular Coulombic decay followed by two-body Coulomb explosion. Combining with ab initio molecular dynamics (AIMD) simulations, the real-time fragmentation dynamics including translational, vibrational and rotational motions are presented as a function of propagation time. The revealed fragmentation dynamics are expected to have a potential implication for crystal structure imaging with various radiation sources.
Actively controlled anode auxiliary gate super-junction insulated gate bipolar transistor with extremely low
Eoff
Authors: Li Luping , Li Zehong , Chen Peng , Yang Yuanzhen , Rao Qiansheng , Wang Tongyang , Zhao Yishang , Yang Yang , Ren Min
Published: January 2023

When dealing with the super-junction insulated gate bipolar transistor (SJ-IGBT), due to its unipolar/bipolar mixed conduction mechanism, the approaches to improve its

V

on

–

E

off

are not exactly the same as for non-SJ IGBTs. In the pursuit of extremely low

E

off

, a planar auxiliary anode gate SJ-IGBT (AAG-SJ-IGBT) is proposed based on a 650 V SJ-IGBT to realize a unipolar turn-off as observed in SJ-MOSFETs accompanied by fast switching and extremely low

E

off

. The planar auxiliary anode gate provides similar effects but better feasibility than conventional trench ones. Sentaurus TCAD simulation results for the proposed AAG-SJ-IGBT indicate a 69% smaller

t

doff

and a 54% lower

E

off

than the FP-SJ-IGBT, and its

V

on

–

E

off

is significantly optimized from cathode-improved SJ-IGBTs. The analysis of carrier and current density reveals the static and dynamic characteristics of the AAG-SJ-IGBT and the principle for excellent

V

on

–

E

off

trade-off.
Pressure sensing of Ga2O3 thin film
Authors: Liu Zeng , Zhang Shaohui , Zhang Maolin , Fang Junpeng , Du Ling , Zhang Jian , Xu Chang , Guo Yufeng , Tang Weihua
Published: January 2023

In this paper, a Ga2O3-based pressure sensor is introduced via metalorganic chemical vapor deposition thin film growth technique. As an important semiconductor materials, it could achieve some functional electronics and optoelectronics, while Ga2O3-based pressure sensor is less investigated, inspite of that the natural property endows it the possibility. Here, the fabricated Ga2O3-based pressure sensor displayed decent sensing performance responding to various pressures. Under pressure of 5 kPa, the current increase two of orders with respect to the current without any additional pressure. Moreover, the response/release times were 0.18 s/0.15 s, 0.27 s/0.21 s, 0.32 s/0.23 s, and 0.38 s/0.24 s under different pressures of 1, 5, 10 and 20 kPa. In all, this work provides a possible route for constructing smart pressure sensor based on functional Ga2O3 along with good sensing behaviors.
Direct observations of π-leaps of superconducting phase differences in π-junction-based SQUIDs
Authors: Takeshita Yuto , Li Feng , Higashi Masayuki , Tanaka Masamitsu , Yamashita Taro , Fujimaki Akira
Published: January 2023

We directly observed π-leaps of superconducting phase differences in π-junction-based superconducting quantum interference devices (SQUIDs). The SQUIDs studied here are formed by introducing a π-junction to a conventional-junction (0-junction)-based direct current (DC)-SQUID, which is referred to as the 0-0-π SQUID. Either clockwise or counter-clockwise-circulating currents flow spontaneously in the 0-0-π SQUID because of a π-phase shift of the π-junction. In other words, the 0-0-π SQUID has a bistable state corresponding to the directions of circulating currents. π-leaps are generated by transiting between the two states of the bistable state. π-leaps are an ultra-fast phenomenon and are difficult to observe as they are. We prepared a half-flux quantum (HFQ)-SQUID that comprised two 0-0-π SQUIDs. π-leaps are reflected in a static characteristic, that is, a modulation pattern of the critical current in the HFQ-SQUID. We formed π-junctions with the PdNi layer on 0-junction-based circuits supplied by the National Institute of Advanced Industrial Science and Technology. The modulation pattern of the HFQ-SQUID had a period corresponding to π-leaps as expected, although some microstructures were observed. We demonstrated that the microstructures originated from the asymmetry inside each 0-0-π SQUID by analyzing the relationship between the phase change of 0-0-π SQUIDs and the modulation patterns.
Optically pumped magnetometer with high spatial resolution magnetic guide for the detection of magnetic droplets in a microfluidic channel
Authors: Jofre Marc , Romeu Jordi , Jofre-Roca Luis
Published: January 2023

Quantum sensors provide unprecedented magnetic field detection sensitivities, enabling these to extend the common magnetometry range of applications and environments of operation. In this framework, many applications also require high spatial resolution magnetic measurements for biomedical research, environmental monitoring and industrial production. In this regard, optically pumped magnetometers (OPMs) are considered as prominent candidates, but are impaired in size with micrometer scale magnetic particles, e.g. magnetic droplets. In order to address this limitation, here we study the effects of adding a micrometer-to-millimeter magnetic guide to a miniature OPM. This device is applied to detect Fe3O4 magnetic droplets flowing at rates up to 25 drop. s−1 in a microfluidic channel. The computed spatial resolution is 300 µm and the measured signal-to-noise ratio is larger than 15 dB for the different sizes of considered magnetic droplets.
Radiative symmetry breaking, cosmic strings and observable gravity waves in 𝖴(1)𝖱 symmetric 𝖲𝖴(5) × 𝖴(1)χ
Authors: Ahmed Waqas , Zubair Umer
Published: January 2023

We implement shifted hybrid inflation in the framework of supersymmetric SU(5) × U(1)χ GUT model which provides a natural solution to the monopole problem appearing in the spontaneous symmetry breaking of SU(5). The U(1)χ symmetry is radiatevely broken after the end of inflation at an intermediate scale, yielding topologically stable cosmic strings. The Planck's bound on the gravitational interaction strength of these strings, characterized by GNμs
are easily satisfied with the U(1)χ symmetry breaking scale which depends on the initial boundary conditions at the GUT scale. The dimension-5 proton lifetime for the decay p → K
+
ν̅, mediated by color-triplet Higgsinos is found to satisfy current Super-Kamiokande bounds for SUSY breaking scale M
SUSY ≳ 12.5 TeV. We show that with minimal Kähler potential, the soft supersymmetry breaking terms play a vital role in bringing the scalar spectral index n_s within the Planck's latest bounds, although with small tensor modes r ≲ 2.5 × 10-6 and SU(5) gauge symmetry breaking scale in the range (2 × 1015≲ Mα
≲ 2 × 1016) GeV. By employing non-minimal terms in the Kähler potential, the tensor-to-scalar ratio approaches observable values (r ≲ 10-3) with the SU(5) symmetry breaking scale Mα
≃ 2 × 1016 GeV.
Freeze-in dark matter perturbations are adiabatic
Authors: Racco D. , Riotto A.
Published: January 2023

We show that the large-scale perturbations in the dark matter generated by the freeze-in mechanism are only of adiabatic nature.
The freeze-in mechanism is not at odds with the current stringent constraints on isocurvature perturbations.
The interplay between the dark matter axion and primordial black holes
Authors: Mazde Kratika , Visinelli Luca
Published: January 2023

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.