bluuebunny/crossref_metadata_2025 huggingface dataset:
High-pressure neutron diffraction study of magnetite, Fe3O4, nanoparticles
Authors: Tan Lei , Sapelkin Andrei V. , Misquitta Alston J. , Bull Craig L. , Lin He , Tian Haolai , Huang Haijun , Dove Martin T.
Published: June 2022

We use in situ high-pressure neutron powder diffraction to study elastic properties of Fe3O4 magnetite nanoparticles of different sizes. It is found that nanoparticles are elastically softer than the bulk. Apart from the smallest nanoparticle of diameter 8 nm, the atomic and magnetic structures do not change significantly with nanoparticle size or pressure. The 8 nm sample appears to take a disordered spinel structure instead of the inverse spinel structure of the bulk and larger nanoparticles, as seen in bond lengths and magnetic structures. Synchrotron x-ray total scattering was used to support this interpretation. Furthermore, this study suggests that the influence of magnetic disorder at the nanoparticle surface is significant for the size of 8 nm.
Dual-axis thrust stand for the direct characterization of electrospray performance
Authors: Gilpin Matthew R. , McGehee Will A. , Arnold N. Ivan , Natisin Michael R. , Holley Zachary A.
Published: June 2022

A dual-axis torsional thrust stand was successfully demonstrated at the Air Force Research Laboratory, enabling direct simultaneous thrust and mass loss measurement for the Air Force Electrospray Thruster Series 2 passively fed electrospray thruster. The dual-axis system is effectively two nulled torsional thrust stands sharing a single dual-axis gimbal with a thrust and mass resolution of ±0.2 µN and ±0.04 mg, respectively. The development of this system was inspired by a need for direct efficiency characterization of electrosprays via in situ mass measurements, and performance was compared to thruster masses measured pre- and post-testing using an analytical balance. Mass consumption data captured via the dual-axis stand, which is calibrated to a traceable uncertainty of 1.6%, varied between −5% and 18% as compared to analytical balance measurements throughout a multi-month testing effort highlighting the limitations in pre/post-weighing as a method for capturing propellant consumption due to absorption of atmospheric moisture when thrusters are removed from vacuum. Thrust stand tests were limited to short term operation with a daily available testing window of ∼5 h due to thrust stand drift following the 24 h cyclic temperature variations of the testing facility. A thorough investigation into the root cause of ambient thermal drift suggests that the thermal response of commercial flex-pivot bearings is directly producing spurious torques on the order of 10 μN m/°C. Additionally, unresolved charging effects on thrust stand hardware currently limit thrust stand operation to tests operating with a positive thruster polarity. Further development and long duration test stability require both a targeted investigation into flex-pivot thermal response and minimization of facility effects.
Large cavitation bubbles in the tube with a conical-frustum shaped closed end during a transient process
Authors: Wang Zhichao , Liu Shuhong , Li Bo , Zuo Zhigang , Pan Zhao
Published: June 2022

The transient process accompanied by extreme acceleration in conical sections of hydraulic systems (e.g., draft tube, diffuser) can induce large cavitation bubbles both at the closed ends and in the bulk liquid. The collapses of the large cavitation bubbles can cause severe damage to the solid walls. We conduct experiments in the tubes with different conical-frustum shaped closed ends with the “tube-arrest” method and observe bubbles generated at these two locations. For the bubbles generated at the close end of the tube, we propose the onset criteria, consisting of two universal non-dimensional parameters Ca1 and Ca2, of large cavitation bubbles separating the water column. We investigate their dynamics including the collapse time and speed. The results indicate that the larger the conical angle, the faster the bubbles collapse. For the bubbles generated in the bulk liquid, we numerically study the collapse time, the jet characteristics, and the pressure pulse at the bubble collapse. We observe a much stronger jet and pressure pulse of bubbles in tubes, comparing with a bubble near an infinite plate. Our results can provide guidance in the design and safe operation of hydraulic machinery with complex geometries, considering the cavitation during the transient process.
Variational inference of the drift function for stochastic differential equations driven by Lévy processes
Authors: Dai Min , Duan Jinqiao , Hu Jianyu , Wen Jianghui , Wang Xiangjun
Published: June 2022

In this work, we consider the nonparametric estimation problem of the drift function of stochastic differential equations driven by the α-stable Lévy process. We first optimize the Kullback–Leibler divergence between the path probabilities of two stochastic differential equations with different drift functions. We then construct the variational formula based on the stationary Fokker–Planck equation using the Lagrangian multiplier. Moreover, we apply the empirical distribution to replace the stationary density, combining it with the data information, and we present the estimator of the drift function from the perspective of the process. In the numerical experiment, we investigate the effect of the different amounts of data and different α values. The experimental results demonstrate that the estimation result of the drift function is related to both and that the exact drift function agrees well with the estimated result. The estimation result will be better when the amount of data increases, and the estimation result is also better when the α value increases.
Evaluating the impact of heat stress on milk quality in South Korea
Authors: Zhang Jing , Jeong Kyeong-Soo
Published: June 2022

Context The probability of heat stress in South Korea is gradually increasing as a consequence of climate change. Although it is known that heat stress drives persistent negative effects on the lactation of dairy cattle, there is a lack of research on the effects of heat stress on milk quality in South Korea. Aim The aim of this study was to measure the influence of the temperature–humidity index (THI) on milk quality. Methods A non-parametric regression model was used to measure the influence of the THI on milk fat and milk protein. The data used in the model were obtained from observations of farmers’ management practises. Key results The concentrations of fat and protein in milk decreased when the THI was >65. In comparison with milk fat, milk protein was more significantly affected by heat stress. Conclusions A comparison of the THI values from 2001–2009 and 2010–2020 indicated that heat stress has occurred more frequently over time in South Korea. The concentrations of fat and protein in milk decrease when the THI exceeds 65. Implications Korean dairy farmers should build facilities that provide the optimal low and relatively dry conditions needed for dairy cattle to cope with heat stress and mitigate its impact on milk quality.
The downside of metabolic diversity: Postingestive rearrangements by specialized insects
Authors: Heiling Sven , Li Jiancai , Halitschke Rayko , Paetz Christian , Baldwin Ian T.
Published: June 2022

Significance

Higher plants produce specialized metabolites to cope with biotic and abiotic challenges faced in natural environments. The diversity and complexity of specialized metabolism is often beneficial, providing functional synergisms and evolutionary stability when metabolic solutions to ecological problems are deployed as mixtures. These benefits of diversity have recently been realized in the deployment of antibiotics, insecticides, fungicides, and herbicides. However, the functional downside of metabolite diversity is rarely studied, in part because the mechanisms of post-ingestive metabolite interactions are largely unknown. Here we showed that larvae of the tobacco hornworm,Manduca sexta, rearrange key constituents of two distinct defense pathways in its wild tobacco host plant,Nicotiana attenuata, to thwart the defensive properties of both pathways.
Nontrivial band topology coupled thermoelectrics in VSe2/MoSe2 van der Waals magnetic Weyl semimetal
Authors: Mohanty Saransha , Deb Pritam
Published: June 2022

The correlation between topological and thermoelectrics promotes numerous interesting electronic phenomena and sets the stage for efficient thermopower devices. Herein, we report nontrivial band topology of 1T–VSe2/1H–MoSe2 van der Waals system and also probe its thermoelectric (TE) characteristics on the basis of first-principle calculations. The crossover of bands, which creates a close loop near Fermi level along M–K high symmetry points, gets inverted at former crossing points of bands, under spin–orbit coupling effect. The calculated Chern Number C = 1 supports the nontrivial band topology whereas the broken time reversal symmetry asserts its magnetic Weyl semimetallic behavior. The nontrivial band topology falls under the category of Type-I Weyl band crossing. We delve into the TE characteristics of the proposed topological material by employing constant relaxation time approximation. The heterostructure shows high electrical conductivity of order 106 S m−1 at both 300 K and 1200 K, and a low magnitude of Seebeck coefficient (S) value of 79.3 μV K−1 near room temperature. Such interplay between the topological phase and TE characteristics can lay foundation for next-generation topological-TE devices.
A modified dielectric dissipation factor measurement technique for transformer insulating oil
Authors: Sur Ujjal
Published: June 2022

This paper proposes a low cost mechanism to accurately measure the dissipation factor and its allied effect over transformer insulating oil. The measuring circuit is a modified De Sauty bridge network where the accurate parameter measurement can been performed. The effect of stray capacitance over dielectric loss and dissipation factor has been nullified by the application of operational amplifier in the circuit. Different samples of transformer insulating oil have been tested based on their aging and moisture content to check the reliability of the proposed measuring technique. Experimental result shows the efficacy of the proposed method when compared to existing IEC and ASTM standard procedures and commercial measuring devices. Measurement error analysis with repeatability and uncertainty calculation shows promising result and is within the acceptable limits.
Multi-sensor information fusion-based prediction of remaining useful life of nonlinear Wiener process
Authors: Wu Bin , Zeng Jianchao , Shi Hui , Zhang Xiaohong , Shi Guannan , Qin Yankai
Published: June 2022

The use of multi-sensor information fusion techniques is essential for condition monitoring and prediction in large complex systems. In this paper, a new distributed model fusion method is proposed to predict the remaining useful life (RUL) of a nonlinear Wiener process. First, the state–space model of the nonlinear Wiener process is established, based on multi-sensor monitoring, and the distributed Kalman filtering algorithm is used to filter and fuse the measurement data received from multiple sensors. Next, the parameters and degradation states of the state–space model are estimated and updated online in real time using the expectation maximum and smoothing filter algorithms. Moreover, the distribution of the system’s RUL is obtained according to the estimated state–space model considering the random failure threshold factor. Finally, numerical experiments are conducted to elucidate the accuracy of the adopted distributed fusion method, and the adaptability and effectiveness of the proposed method are verified using the FD001 data of the C-MPASS dataset as an example.
A survey on IoT-based smart agriculture to reduce vegetable and fruit waste
Authors: Pal Himanshu , Tripathi Sweta
Published: June 2022

Agriculture automation is a top focus and developing area for a number of countries right now. We are seeing a surge in demand for Internet of Things (IoT) in various industries these days. One of the most essential applications of IoT is agriculture. Today, we notice that the world’s population is quickly rising, and an agro product plays a critical part in this population’s existence. We are conscious of the fact that resources are limited. If we continue to farm in the traditional manner, it will be extremely difficult for the rising population to survive. Due to improper fertilizers, quantity of water, chemicals and huge amount of pesticides decreases the fertility of land. There is a need for smart agriculture to monitor all these factors which affect the fertility of soil. When the fertility is decreasing it will impact on the growth of fruits and vegetables. In this paper we are going to study how we can manage our resources through Internet of Things, multispectral camera, hyper spectral camera, and thermal camera and RGB camera. Plant diseases, pesticide control, weed control, proper irrigation, and water management are all problems in agriculture that can be readily solved with the various automated and control approaches stated above.
Comparison of different Classification techniques for the detection of Speech affected due to Respiratory disorders
Authors: Shrivastava Poonam , Tripathi Neeta
Published: June 2022

Respiratory disorders are one of the common chronic disorders across the world. Any malfunctioning in the respiration process affects speech as speech and respiration go hand in hand. Analysis of speech parameter variation due to respiratory disorders is a prime research area in today’s scenario. In this paper, an efficient approach using a machine learning paradigm was used to detect the speech affected due to respiratory disorders. Various speech parameters were extracted (F1, F2, F3… etc.) using PRAAT software along with MFCC and LPC coefficients. Statistically, significant features were obtained to determine the predominant parameters. The extracted features were applied to different machine learning paradigms then different classification techniques were analyzed and compared to distinguish between normal and affected speech.5-fold,10-fold cross-validation, and hold-out data division protocols were used for evaluating the classification results. To evaluate the performance of the proposed methodology, Accuracy, sensitivity, specificity, and the area under receiver operating characteristics (AUC) were used. The result demonstrates that the speech parameters (F1, F2, F3…etc.) extraction method and the LPC method achieved a significantly higher classification accuracy, sensitivity, and specificity of 100% and AUC of 1, under the holdout method. While MFCC method achieved the highest classification accuracy of 83%, sensitivity of 100%, specificity of 67%, and AUC of 0.83.
Testing some grouping methods to achieve a low error quantile estimate for high resolution (0.25° x 0.25°) precipitation data
Authors: Sahu Ramgopal T. , Verma Shashikant , Kumar Kislay , Verma Mani Kant , Ahmad Ishtiyaq
Published: June 2022

The study focuses on the estimation of a technique, a method for developing a phenomenon, to obtain a quantile with minimal or low error (AR and R-RMSE bias). To arrive at such a solution, a case study of the Mahanadi River system (Mahanadi Basin) was conducted along with the integration of various techniques available in past and present literature, to come up with a novel solution. Which could answer practical questions in water resource planning and management for addressing a wide range of problems such as meteorological draught analysis, agricultural planning, precipitation forecasting and downscaling, design of water control and conveyance structures, and land-use planning and management. A gridded rainfall data set of resolution 0.25° x 0.25° (1901 – 2017) obtained from IMD Pune is used to calculate the statistics that will be used for the regionalization of precipitation. Other attributes or variables used for regionalization are seasonality measurements and location parameters (latitude, longitude, and elevation). The L-moment statistics are computed from the time series rainfall data and the ratios of the L-coefficient of variance and the L-coefficient of skewness, i.e., the L-moment ratio, are the main components in computing quantile estimates of selected regions for effective regional frequency analysis. To determine potential scenarios for homogeneous regions, the use of seasonal extreme precipitation will serve as a basis for regionalization.
Elcare: Elderly Care With Fall Detection
Authors: Jawale Chirag Dilip , Joshi Keval Ashok , Gogate Swaroop Kusumakar , Badgujar Chetana
Published: June 2022

Continuous growth in the aged population over the years around the globe suggests advancements in medical facilities to ensure good medical health of people. The elder population is vulnerable to many medical problems as the immune system as well as the musculoskeletal system weakens with time. Falls are the major cause leading to serious medical conditions such as paralysis or even death for elders. Early fall detection can help in reducing the severity of these accidents and provide immediate medical assistance. To detect falls this paper discusses the use of pose estimation and sensor-based mobile devices. The system makes use of MediaPipe’s Pose Detection method to form a skeletal structure of the person. Exploiting the features such as drastic change in coordinate axes, angle of inclination while falling, and the sudden change in velocity during a fall helps to verify the authenticity of the fall. The sensor-based method makes use of mobile sensors and records the change in their values to decide whether the activity is a fall or not. The combination of both these methods allows for an accurate fall detection mechanism where the system finally notifies the concerned authorities via real-time feedback techniques such as text, message, or push notification.
Characterization and driving of polymer-dispersed liquid-crystal sheet for smarthome applications
Authors: Uranus Henri P.
Published: June 2022

A commercial polymer-dispersed liquid-crystal (PDLC) sheet sample was characterized for its basic optical and electrical properties under DC and AC excitation. The results give driving voltage for 90% of transmittance for the PDLC of 10 V for DC excitation, and 9.5 Vrms for 50 Hz AC excitation. The measured contrast ratio of the PDLC is 2.55 and 2.47 under DC and AC excitation, respectively, which is suitable for smart window in a smarthome application. While it has rather similar optical properties under DC and AC excitation, it has significantly different electrical properties for DC and AC excitation. The PDLC exhibits a capacitive property which has capacitance per unit area of 18.5 μF/m2, indicating that DC excitation will give benefit compared to AC excitation which will scale with area of the PDLC. Based on these results, a DC driving circuit employing boost converter was designed to make a microcontroller-compatible driving circuit. The system was then integrated into a miniature smarthome demonstrator model exhibiting contrast ratio of 2.05 under switching from 0 to 100% of duty cycle of pulse width modulation (PWM) control signal from the microcontroller executed through voice command in an internet of things (IoT) platform.
Scheduling optimization researchs considering AGV operation conflicts with different loads
Authors: Tang Li-min , Wang Jun-wang , Wu Dan
Published: June 2022

With the increase in the volume of container trading, automated container terminals have gradually become the target of the world’s largest port construction. In order to improve the efficiency of the automated AGV container terminal and gantry cranes, the possible conflicts in the horizontal AGV transportation area under different load conditions and speeds have been resolved. The problem is to create a comprehensive scheduling model that minimizes the total AGV execution time through prediction and solved by genetic algorithm. Experimental data analysis shows that after optimization, the total execution time and conflict timeout of multiple AGVs are reduced, which improves the work efficiency of AGVs.
Intelligent video surveillance of sand mining based on object detection and tracking
Authors: Gao Yueming , Lin Qinghua , Xu Chaoyang , Li Wentong
Published: June 2022

In order to improve the regulatory capability of sand mining and make full use of the video resources collected by video surveillance systems, an object detection and tracking algorithm that combines YOLOv4 and Kalman filter is proposed to identify sand dredgers. Initially, an object detection dataset of common ships is finely established through camera capture, manual and automatic annotation, and data augmentation. Then, the obtained dataset is used to train YOLOv4. The results show that the trained YOLOv4 achieves a mean Average Precision of 92.26% over all classes. Although Kalman filter does not increase the precision of YOLOv4, it supplements the association information between images in an frame stream, so as to solve the target loss problem of YOLOv4 caused by occlusion. Finally, the proposed algorithm is deployed in edge computing terminal devices to form an intelligent video surveillance system for sand dredgers. The intelligent system realizes the 24-hour real-time monitoring of sand mining, which can help to stop illegal sand mining in time, and provide strong technical support for relevant departments to fulfill their management obligations.
Database Modeling Technology Research Based on Requirement Ontology
Authors: Litao Li , Jingyu Yang
Published: June 2022

Aiming at the complexity and uncertainty of large-scale system requirements, this paper introduces the concept of ontology, through the requirement ontology model, the system requirements are formed into a unified modular unit, and each modular unit has a structured logical relationship. Finally, the structured and modularized requirement model will form a complete requirement management platform in the DOORS tool, which will realize the basis of civil aircraft requirement management and improve the capability and efficiency of civil aircraft product design.
Research on the evolution law of incidental traffic congestion based on CTM
Authors: Peng Lang , Wang Qiu-ping , Zhou Shuai-qi , Tian Zhun
Published: June 2022

This paper takes the urban road network as the research object to study the temporal and spatial characteristics and evolution mechanism of incidental traffic congestion. Firstly, the improved cell transmission model (CTM) is proposed considering the traffic flow delay phenomenon and the boundary conditions of the cell at the intersection. Secondly, considering the delay time of vehicles at the intersection, the A
* path-finding algorithm is proposed, and a dynamic path selection model based on real-time road impedance is established. Finally, combined with the improved CTM and dynamic path selection model, starting from the severity of the incident and the frequency of information induction and update, the traffic flow is simulated by MATLAB software to simulate the traffic flow in the road network under different conditions and analyze the diffusion characteristics of congestion under sudden events. The simulation results show that during the simulation time period, when the traffic capacity caused by the severity of the incident is only 1/2, 1/4 and 1/8 of the original, the maximum number of congestion cells in the network is 9, 26 and 35, and the maximum delay per unit time stepping is 290, 1.31*103 and 2.41*103 vehicles, and the total delay in the road network is 2.73*105, 7.19*105, and 1.50*106 vehicles, after 320δ, 578δ and 588δ the congestion cells in the road network completely disappear. At the information induced update time of 30s, 120s and 600s, the maximum number of congestion cells in the road network is 5, 10 and 23, the maximum number of delayed vehicles is 162, 254 and 985 vehicles - time stepping, the total delay is 1.25*105, 1.68*105 and 5.84*105 vehicles. The findings of the study can provide reference for urban road network design and traffic management.
Aerodynamic Characteristic Analysis of V-22 Tilt-Rotor Aircraft in Hover
Authors: Xu Peimin , Yang Yueyue , Zhou Jie , Zhou Guiyu
Published: June 2022

Tilt-rotor aircraft combines the vertical take-off and landing function of helicopters with the high-speed cruise function of fixed-wing aircraft, which has given rise to extensive attention in the aviation field, but the complex aerodynamic characteristics of the rotor flow field and the interference of rotor/fuselage have always been tough problems. In recent years, the continuous development of high-performance computer and the combination of high-precision CFD method and dynamic overset grid technology, make it possible to perform fine numerical simulation of tilt-rotor aircraft’s flow field. In this paper, the low-dissipation fifth-order Roe-WENO scheme and overset grid method are used to solve the unsteady N-S equation, and the hovering state of tilt-rotor aircraft is numerically simulated. The result shows: under the interference of ground effect and fountain effect, the lift coefficient of blade when the azimuth angle is 180° to 360° is obviously smaller than that when the azimuth angle is 0° to 180°. The vortex structure of the hovering flow field of V-22 tilt-rotor aircraft is mainly composed of the fountain effect recirculation zone, the tip vortex wake and the root vortex wake. The tip vortex wake develops downwards, shrinks inward and approaches the fuselage. After the root wake falls off, it converges and fuses on the surface of nacelles. The root vortex wake is strong and moves towards the front of the fuselage and the plane of symmetry.
Numerical Investigation of Round-to-Slot Holes on Film-Cooling Performance in a Turbine Vane
Authors: Huang Ying , Peng Can , Zhang Jingzhou , Zhu Xingdan
Published: June 2022

The numerical investigation of single row holes on suction surface and pressure surface of a scaled turbine guide vane is carried out. In particular, the effects of round-to-slot holes (RTSHs) on film cooling performance are illustrated. Four RTSHs with different exit-to-inlet area ratios are considered under different blowing ratios. The results show that RTSHs can suppress the normal penetration of cooling jet and broadening the lateral coverage of film layer. With the increase of slot aspect ratio, the anti-kidney vortices pair is generally strengthened, making the film cooling improvement more significantly. The film cooling improving effects of shaped holes on the pressure surface is better than that on the suction surface, particularly under high blowing ratios. A key factor affecting the bleed pressure of coolant flow is exit-inlet area ratio of RTSH. The equivalent-area RTSH achieves nearly the same discharge coefficient (Cd) as the cylindrical hole. Viewed from the comprehensive effects of the Cd and adiabatic film cooling effectiveness on shaped hole, the RTSH-3 with a slot aspect of 9 and an exit-inlet area ratio of 1.27 is suggested to be the most favorable film-hole geometry among the current shaped-holes, either on the pressure surface or on the suction surface.
Study on optical scattering detection method of bubbly wake of targets in water
Authors: Wang Yun , Gu Wei , Shen Zhiben , Shi Weihua , Wu Jianwei , Dong Liang
Published: June 2022

A method for the detection of the bubbly wake of targets in water is presented, which is based on the features of optical frequency domain of the scattering optical signal. A simulation on the optical frequency domain characteristics of the bubbly wake scattering signal is performed by statistical test method. The influence of the bubble population and the velocity distribution on the optical frequency domain characteristics is analyzed. On this basis, a test platform for the characteristics of optical frequency domain of the bubbly wake scattering signal is designed and established. The characteristics of the bubbly wake scattering signal are studied experimentally. Experimental results agree with the theoretical analysis. The results show that the amplitude and the cut-off frequency of the shift spectra will increase with the increasing bubble population and range of velocity distribution. It indicates the effectiveness of the detection method.
Effects of blade curvature on flow and heat transfer characteristics of internal cooling at trailing edge
Authors: Yan Yan , Zhu Jianqin , Cheng Zeyuan
Published: June 2022

In modern turbine blade designs, a large number of internal cooling technologies have been developed and blade curvature is one of the most important factors. This paper numerically simulates the heat transfer process of the internal cooling channel with flat plate and wall curvature at the trailing edge and analyses Nu distribution and deviation between these two structures. The results show that due to the disruptive and reorganising effects of blade curvature on the vortex structure, blade curvature strengthens the heat transfer. There are significant heat transfer differences at the individual surface of each path.
Analysis on Welding Temperature Field and Stress Field of Boring Bar of New Boring Machine
Authors: Han Liang , Song Yuning
Published: June 2022

Ansys software is used to simulate the welding process of the boring bar of the new cylinder head boring machine. The indirect coupling method is used to analyze the temperature field, then the stress field and deformation. It is found that for the double support structure, the highest temperature occurs at the outer stiffened plate of the small diameter end, and the lowest temperature occurs at both ends of the inner support structure. The deformation of the whole structure mainly comes from the axial deformation, and the maximum deformation occurs at the large diameter end of the outer rib plate. Because the role of the supporting web is to limit the large deformation of the whole structure, the structure at the small diameter end is firmer and has the ability of anti-deformation. In terms of technology, the influence caused by deformation can be compensated by the compensation design of machining amount.
Analysis of rainwater overflow in underground pipe network
Authors: Zhou Tian , Yang Fan , Liu Wei , Tan Yue
Published: June 2022

Urban rainwater pipe network is a direct way to resist urban waterlogging, and its safe and stable operation is the premise to ensure the normal operation of the city. However, in China and even around the world, the monitoring means for the operation of urban rainwater pipe network are very limited. For the occurrence and solution of urban waterlogging, it often mainly depends on the means of personnel inspection to monitor where the rainwater pipe network overflows, and then take measures. There is no effective monitoring method for the whole rainwater pipe network. Therefore, an accurate and efficient rainwater pipe network monitoring method is urgently needed. To solve the current problem of real-time monitoring of rainwater pipe network, the core problem is how to monitor the liquid level data of any pipe section of the whole rainwater pipe network in real time, so it is necessary to introduce hydrodynamic model. The traditional hydrodynamic model mainly simulates the hydraulic and hydrological, and does not simulate the rainwater pipe network, but makes a generalized estimation of the drainage of the rainwater pipe network. In addition, some hydrodynamic models for drainage pipe network are not established for the problem of rainwater pipe network monitoring. The ultrasonic liquid level gauge with real-time acquisition function is not introduced into the calculation simulation, and it does not have the ability of adaptive correction. Therefore, the traditional rainwater monitoring methods and hydrodynamic models can not fundamentally solve the problem of real-time monitoring of the whole rainwater pipe network. Using hydrodynamic model calculation, combined with rain gauge and liquid level gauge to monitor and modify model parameters, so as to intelligently monitor the whole rainwater pipe network, which can greatly improve the current monitoring level of urban rainwater pipe network and reduce the work cost of manual patrol monitoring.
Operational Effectiveness Evaluation of UAV Cluster Based on Bayesian Networks
Authors: Wang J J , zhang Y Y , Ma J , Hou J , Wang F M , Li N
Published: June 2022

This paper focuses on the requirements of operational efficiency evaluation for UAV cluster, and establishes an evaluation index system for UAV cluster operations, and establishes evaluation index system from the aspects of cooperative attack capability, autonomous reconnaissance capability, instant messaging capability, rapid planning capability and autonomous formation capability. The evaluation network model is built by using Bayesian network, and the corresponding prior and conditional probabilities are calculated. The effectiveness values of each capability are calculated and verified by experiments. This paper provides an applicable quantitative evaluation method for UAV cluster operational effectiveness evaluation.
The Positive Integer Solutions of Ternary Euler Function Equation φ(x
1
x
2
x
3) = k(φ
2(x
1) + φ
2(x
2) + φ
2 (x
3)) + l
Authors: Zheng Hui
Published: June 2022

Let φ(n) be Euler function. In this work we discuss the solvability of Euler function equation φ(x
1
x
2
x
3) = k (φ
2(x
1) + φ
2(x
2) + φ
2(x
3)) +l, and give more accurate upper bounds of all positive integer solutions of this equation with elementary method. As an application, we find all the positive integer solutions of this equation for the given k and l.
The Lagrange’s method in dynamic spacetime
Authors: He Po-shan
Published: June 2022

The Lagrange’s method is a kind of commen method in physics on motion particle. Usually, the field is nonconsevative if it had constraint condition vary in time, it lead to the Lagrange’s equaition have inhomogeneous term and many integral. The dynamic spacetime can be constraint the situation of motion of particle, because of this kind of spacetime had the gravitational wave. This paper will be discuess the form of Lagrange’s method in dynamic spacetime.
S1 attractor bifurcation analysis for a three-species cooperating model
Authors: Li Junyan , Wu Ruili
Published: June 2022

In this paper, the dynamic bifurcation of the three-species cooperating model is considered. It worth noting that the main theory of this paper is the Center manifold reduction and attractor bifurcation theory, which is developed by Ma [1,2]. The main work of this paper shows that if the algebraic multiplicity of the first eigenvalue is 2, there exists an S1 attractor bifurcation, and the number of its singular points can only be eight. Besides, we show that the simplified governing equations bifurcate to an S1 attractor, when the Control parameter λ crosses a critical value λ
0.
Acoustic Radiation Characteristics from Shell Structure for Different Depth State
Authors: Dong Lei , Li HanXu , Chen YanYu
Published: June 2022

As a naval warship, submarine is a typical complex combined system. The excitation source of its vibration has the characteristics of large amplitude and wide frequency spectrum, and the prediction of vibro-acoustic radiation needs to be carried out in a wide frequency band. How to accurately predict the vibro-acoustic radiation of submarines in the whole frequency band has become a problem of practical significance. Elastic cylindrical shell is the typical structure of underwater vehicle. Studying acoustic radiation characteristics from shell structure for different depth state has a certain significance for studying submarine acoustic stealth characteristics. As an important acoustic performance metrics, the radiation sound power of underwater structure is significant for researching vibration and sound radiation characteristics. In this article, based on the FEM and BEM method, by using ANSYS and SYSNOISE software shell structure for different depth state is modeled and its vibration and radiation characteristics are researched. Numerical calculation shows that with immersed depth increasing, the vibration response and sound radiation power from shell structure gradually tend to the ones from under free field.
The influence of structural features on the acoustic scattering characteristics of array transducers
Authors: Deng Fang-zhou
Published: June 2022

In order to study the sound scattering characteristics of array transducers on different shell structures, based on the COMSOL finite element simulation calculation method, this paper analyzes the scattered sound field characteristics of the array transducer in the single-shell structure, the single-double transition shell structure, and the double-shell structure. A quantitative comparison between the radiated sound field and the scattered sound field is made, the law of the scattered sound field is analyzed, the scattering characteristics of the array transducer under different shells are explained, and the simulation basis for the engineering application of the array transducer is provided.
The Large Deflection Solution of Circular Elastic Membrane under Composite Loads
Authors: Zhou Can , Fang Shuting , Liu Changjiang
Published: June 2022

In this paper, the large deflection problem of axisymmetric isotropic elastic membranes subjected to the composite loads is studied. The Hencky transformation is extended and the general solution of large deflection of the membranes under the composite loads is obtained. The general solution is given in different forms in different values of loads. The obtained results of the numerical values of elastic characters can be applied in practice.
Research Status and Development Trend of UAV Path Planning Algorithms
Authors: Zeng Sha , Liu Kang
Published: June 2022

This paper introduces the basic concepts of UAV track planning, the relationship between track planning and algorithms, and focuses on the analysis and induction of several commonly used algorithms at home and abroad in recent years. The advantages and disadvantages of current path planning algorithms in different application scenarios are summarized. Finally, the future development trend of UAV path planning algorithm is prospected, and it is pointed out that real-time online path planning algorithm research, multi-UAV swarm planning algorithm, perfect path planning problem model and algorithm hybrid optimization are the next research trends.
Adaptive RBF Neural Network Backstepping Control for Two-Link Robot Manipulators
Authors: Wang Chao
Published: June 2022

In this paper, an adaptive radial basis function neural network(RBFNN) backstepping controller is presented for a two-link robot manipulator in the presence of uncertainty and external interferences. RBFNNs are applied to approximate uncertain nonlinear functions, and considering the backstepping technique, an adaptive RBFNN backstepping control strategy is proposed. It is proved by the Lyapunov function that tracking errors converge to a small neighborhood of the equilibrium point and the closed-loop system variables are bounded. The simulation results demonstrate the effectiveness of the presented design method.
The Research of Asymptotic Average Shadowing Property and Pointwise Lipschitz Shadowing Property
Authors: Bei Caixia , Ji Zhanjiang
Published: June 2022

We investigated the dynamical relationship between asymptotic average shadow ing property and pointwise Lipschitz shadowing property on the sequence map and the limit map. Then, we have: (1)Suppose {gn
} strongly uniformly converge to g · gn
has asymptotic average shadowing property implies g has asymptotic average shadowing property. (2) Suppose {gn
} strongly uniformly converge to g · gn
has fine pointwise shadowing property implies g has pointwise Lipschitz shadowing property. The above results promote the theory development of asymptotic average shadowing property and pointwise Lipschitz shadowing property.
Numerical study on variable aperture extraction grids of a titanium hydride cathodic vacuum arc ion source
Authors: Wu W.B. , Zhou H.J. , Zhou Q.H. , Yang W. , Dong Y. , Yang W.Y.
Published: June 2022

Titanium hydride cathodic vacuum arc ion sources are widely
used in particle accelerators, neutron sources, etc. For the
application in neutron sources, higher H+/D+ fraction and
higher beam uniformity are preferred. In this work, to improve the
beam uniformity of a miniature titanium hydride cathodic vacuum arc
ion source, a new scheme of variable aperture extraction grids is
proposed. A 2D numerical model is developed for the investigation of
the variable aperture extraction grids. Numerical results indicate
that the extraction grid plays important roles in the titanium
hydride cathodic vacuum arc ion source that can improve the
stability of ion source. Moreover, simulated results show that the
designed variable aperture extraction grids can reduce the beam
nonuniformity to less than ±10%, while the beam nonuniformity
of the fixed aperture extraction grids are between ±22% and
±37%. Thus, the presented work can provide a potential
reference for the improvement of beam uniformity of the vacuum arc
ion sources.
Design of PLC and EPICS based control system for a deuteron RFQ
Authors: Liu S. , Wei Y.X. , Lu Y.R. , Wang Z. , Han M.Y. , Wei T.H. , Zheng P.F.
Published: June 2022

Peking University and Southwestern Institute of Physics are
jointly developing a new deuteron RFQ to study the migration and
deposition of impurities on the first wall of a tokamak
facility. This RFQ will accelerate a 10-mA deuteron beam from
40 keV up to 1.5 MeV at a duty factor of 1%. In this paper, the
detailed design of the prototype control system based on a Siemens
PLC and EPICS/CSS software environment for the RFQ accelerator is
presented. The system is composed by many kinds of sub-systems
developed using different hardware solutions. The interlock
protection mechanism is introduced into the control system. The
EPICS Archiver Appliance is used to provide the service of data
archiving and retrieval. The system has been successfully
implemented for RF conditioning and beam commissioning.
Effect of Positional Changes on Skin Landmarks in Midface Filling
Authors: Du Yuyang , Ye Yajie , Wang Qing , Li Meijia , Chen Xinyao , Li Rou , Hao Lijun , Luo Sai
Published: June 2022

Background

The design lines for midfacial filling shift upward with a patient’s position changes from upright to supine during operation. This will cause the actual filled part to deviate from the target area.

Objectives

This authors aimed to evaluate the effect of positional changes on midfacial landmarks and find the optimal body position for midface filling.

Methods

The process involved the grading and evaluation stages. The midfacial laxity of each sample in the evaluation stage was graded into minimal, moderate, and severe by the system established in the grading stage. Measured through the 3-dimensional images in each grade, the vertical distances from landmarks C, D, and E (representing the region of the tear trough, infraorbital area, and nasolabial fat pad, respectively) to the horizontal line of the inner canthus and depth of nasolabial fold at an angle of 90° were separately compared with those from the other angles (60°, 45°, 30°, and 0°) of the operating table.

Results

In the minimal midfacial laxity group, all 3 landmarks significantly moved upward when the angle decreased to 30°. However, landmark E of the moderate and severe and landmark D of the severe midfacial laxity groups both significantly moved upward when the angle decreased to 45°. The depth of the nasolabial fold at a 45° angle was significantly less than that at a 90° angle in the moderate and severe groups.

Conclusions

In midface filling, a patient’s body position should be optimally selected according to the midfacial laxity and filling area.
A yeast suppressor screen links Coa4 to the mitochondrial copper delivery pathway for cytochrome c oxidase
Authors: Swaminathan Abhinav B , Soma Shivatheja , Vicary Alison C , Zulkifli Mohammad , Kaur Harman , Gohil Vishal M
Published: June 2022

Cytochrome c oxidase (CcO) is a multimeric copper-containing enzyme of the mitochondrial respiratory chain that powers cellular energy production. The two core subunits of cytochrome c oxidase, Cox1 and Cox2, harbor the catalytic CuB and CuA sites, respectively. Biogenesis of each copper site occurs separately and requires multiple proteins that constitute the mitochondrial copper delivery pathway. Currently, the identity of all the members of the pathway is not known, though several evolutionarily conserved twin CX9C motif-containing proteins have been implicated in this process. Here, we performed a targeted yeast suppressor screen that placed Coa4, a twin CX9C motif-containing protein, in the copper delivery pathway to the Cox1 subunit. Specifically, we show that overexpression of Cox11, a copper metallochaperone required for the formation of CuB site, can restore Cox1 abundance, cytochrome c oxidase assembly, and mitochondrial respiration in coa4Δ cells. This rescue is dependent on the copper-coordinating cysteines of Cox11. The abundance of Coa4 and Cox11 in mitochondria is reciprocally regulated, further linking Coa4 to the CuB site biogenesis. Additionally, we find that coa4Δ cells have reduced levels of copper and exogenous copper supplementation can partially ameliorate its respiratory-deficient phenotype, a finding that connects Coa4 to cellular copper homeostasis. Finally, we demonstrate that human COA4 can replace the function of yeast Coa4 indicating its evolutionarily conserved role. Our work provides genetic evidences for the role of Coa4 in the copper delivery pathway to the CuB site of cytochrome c oxidase.
David Against Goliath: Direct Comparison of Handheld Bowel Sonography and Magnetic Resonance Enterography for Diagnosis of Crohn’s Disease
Authors: Rispo Antonio , de Sire Roberto , Mainenti Pier Paolo , Imperatore Nicola , Testa Anna , Maurea Simone , Ricciolino Simona , Nardone Olga Maria , Olmo Oriana , Castiglione Fabiana
Published: June 2022

Background

Diagnosis of Crohn’s disease (CD) requires ileo-colonoscopy (IC) and cross-sectional evaluation. Recently, “echoscopy” has been used effectively in several settings, although data about its use for CD diagnosis are still limited. Our aim was to evaluate the diagnostic accuracy of handheld bowel sonography (HHBS) in comparison with magnetic resonance enterography (MRE) for CD diagnosis.

Methods

From September 2019 to June 2021, we prospectively recruited consecutive subjects attending our third level IBD Unit for suspected CD. Patients underwent IC, HHBS, and MRE in random order with operators blinded about the result of the other procedures. Bivariate correlation between MRE and HHBS was calculated by Spearman coefficient (r). To test the consistency between MRE and HHBS for CD location and complications, the Cohen’s k measure was applied.

Results

Crohn’s disease diagnosis was made in 48 out of 85 subjects (56%). Sensitivity, specificity, positive predictive values, and negative predictive values for CD diagnosis were 87.50%, 91.89%, 93.33%, and 85% for HHBS; and 91.67%, 94.59%, 95.65%, and 89.74% for MRE, without significant differences in terms of diagnostic accuracy (89.41% for HHBS vs 92.94% for MRE, P = NS). Magnetic resonance enterography was superior to HHBS in defining CD extension (r = 0.67; P < .01) with a better diagnostic performance than HHBS for detecting location (k = 0.81; P < .01), strictures (k = 0.75; P < .01), abscesses (k = 0.68; P < .01), and fistulas (k = 0.65; P < .01).

Conclusion

Handheld bowel sonography and MRE are 2 accurate and noninvasive procedures for diagnosis of CD, although MRE is more sensitive in defining extension, location, and complications. Handheld bowel sonography could be used as effective ambulatory (or out-of-office) screening tool for identifying patients to refer for MRE examination due to high probability of CD diagnosis.