bluuebunny/crossref_metadata_2025_split huggingface dataset:
Echo Doppler Frequency Compensation Analysis of Space-based Radars
Authors: Hongjian Wang , Yong Yu , Zhibin Zheng , Zhiyong Lei , Yao Wei , Gang Wu 
Published: May 2022

Abstract
Based on the geometric model between space-based radar (SBR) and the Earth, Earth’s rotation adds an additional component to the echo Doppler frequency. The result is as follows, when the orbit inclination is fixed, the crab magnitude has an offset effect on the clutter Doppler frequency, and the fluctuation of the offset value is very small, so the echo data can be uniformly compensated. However, the effect of the crab angle on the clutter Doppler frequency is two orders of magnitude larger than that of the crab magnitude and changes with time, so real-time compensation is needed. The maximum compensation interval is also related to the radar pulse repetition time and the number of accumulated pulses. Compensation interval needs to be less than 6s under a typical scene. The above conclusions lay the foundation for effective detection of SBR.
Study of bipedal locomotion considering property of toe mechanism
Authors: Nguyen Van-Tinh , Tao Ngoc-Linh , Nguyen Thanh-Trung , Bui Ngoc-Tam 
Published: May 2022

Abstract
Walking behaviour of the humanoid robot depends on many parameters of body structure, in which, the foot structure is one of the most important factors since it directly interacts with the environment in the locomotion. In this paper, joint characteristics of the robot’s foot have been investigated for our further understanding of biped motion. These properties are stiffness and damping factor of spring of passive toe joints. The subject of this paper is a small humanoid robot named Kondo KHR-3HV belonging to the Kondo Kagaku company. The foot structure of the robot consists of a big toe and a tiptoe with passive joints using torsion spring. The effect of the structure property is collected and evaluated through dynamic simulation on Adams and analysis of variance (ANOVA).
Aerodynamic Studies of Small Box-Wing Unmanned Aerial Vehicle Using CFD
Authors: Sutthison Danupol , Wongkamchang Prasatporn , Sukuprakarn Nukul 
Published: May 2022

Abstract
This paper presents a computational fluid dynamics (CFD) simulation study of a small unmanned aerial vehicle (UAV) with airfoil s3010 and 245 mm chord length at a cruising speed of 17.5 m/s, compared with the aerodynamic characteristics of a 3D conventional fixed-wing UAV from a commercial RC airplane modified with a box-wing configuration. Simulation results showed that at an angle of attack of 0°, the lift coefficient increased by 60.005%, drag coefficient increased by 58.3299% and L/D ratio increased 1.0578%. The box-wing UAV had higher lift-to-drag ratio than the fixed-wing UAV. However, weight increased by 46.5%. The fuselage shape of the box-wing UAV in this study can be redesigned to shorten the rear area for drag and weight reduction.
Experimental Study on Ignition and Combustion Characteristics of Al/NEPE Propellant
Authors: Zhuang Yuqian , Feng Yaya , Dong Longlong , Zhang Beichen , Ling Zhigang 
Published: May 2022

Abstract
In order to understand the ignition and combustion characteristics of Al particles in micron aluminized composite solid propellant under different pressures, the Al/NEPE propellant was tested on a laser ignition test system. By the means of scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and so on, the results indicate that the phenomenon of Al particles escaping from the combustion surface become more significant with the increase of pressure, and AlO gas intermediates exist during the combustion process of Al particles. The presence of oxide cap and broken agglomerates were observed and the influence of ambient pressure on size of Al agglomerates was illustrated by a laser particle size analyzer.
Numerical Investigation of Two-phase Unstable Combustion in High Temperature Rise Flame Tube
Authors: Long Wang , Ren Jiande , Cai Wenxiang , Chen Xiong 
Published: May 2022

Abstract
Intense acoustic pressure oscillation, caused by instability combustion, poses a huge challenge for the performance and the structural integrity of high temperature rise combustor. Transient process of combustion in the flame tube with three-stage axial swirler was investigated by numerical methods. Simulation results show that a wide range of velocity fluctuations appear at swirler’s outlet and recirculation zone move periodically at flame tube’s circumferential center plane, which cause the oscillation combustion.
A dual-mode hydrogen peroxide and kerosene space propulsion system pressurized by electric pumps
Authors: Zhou Chuang , Yu Nanjia , Li Tianwen , Gong Haojie 
Published: May 2022

Abstract
In this study, the performance characteristics and previous application cases of the dual-mode propulsion system (DMPS) were discussed. Besides, a dual-mode hydrogen peroxide and kerosene space propulsion system pressurized by electric pumps was proposed via the analysis of the existing problems with respect to the dual-mode propulsion system. In addition, the working process of this system was analyzed by system modeling and simulation. Further, the feasibility of DMPS was verified by exploring the working characteristics of the bipropellant main thruster and the monopropellant attitude control thruster. As per the analysis results, the DMPS proposed in this study contributed to eliminating the problems in the application of the dual-mode propulsion system at the present stage, and it also provided effective guidance in improving the performance of the propulsion system, adjusting the thrust flow rate, and making the propellant non-toxic.
Parameter optimization and simulation of lean-burn gas generator
Authors: Bo-wei JIAO , Nan-jia YU , Chuang ZHOU 
Published: May 2022

Abstract
The pre-cooling engine cools the incoming air through a pre-cooler and then makes it enter the subsequent components to work. This type of engine is one of the most important development directions in the combined power scheme. In order to accurately control the lean-burn gas temperature and oxygen concentration under different incoming flow conditions, and adjust it through the nitrogen-to-hydrogen ratio (GNGH) and oxygen-to-hydrogen ratio (GOGH). The oxygen concentration and temperature were obtained by thermal calculation and the optimal nitrogen-hydrogen ratio and oxygen-hydrogen ratio were optimized by genetic algorithm. Finally, the sensitivity analysis of the influence of nitrogen-hydrogen ratio and oxygen-hydrogen ratio on temperature and oxygen concentration was performed near the optimal point. According to the research, when α (weight coefficient) is determined, as the height increases, GNGH and GOGH decreases, and the amount of hydrogen required increases. When α > 1, the temperature term plays a major role in the optimization result. When α < 0.01, the oxygen concentration term plays a major role in the optimization result. When 0.01 < α < 1, the temperature term and oxygen concentration term are considered to have an effect on the optimization result at the same time. For the sensitivity analysis of the nitrogen-hydrogen ratio, oxygen-hydrogen ratio, temperature and oxygen concentration under different working conditions, accurate numerical results have also been obtained.
Analysis of Heavy Vehicle Research Status about Knowledge Structure and Research Hotspots Based on CiteSpace
Authors: Shao Tingting , Liu Shaohua 
Published: May 2022

Abstract
Heavy vehicle is an important carrier of cargo transportation and is always the research focus of the automotive and environment field. In this paper, the scientific metrological analysis method is used to systematically summarize the research topics and current situation of heavy vehicles. From 2000 to 2019, 1047 articles and 7259 references were investigated. The subject and subject of heavy vehicle research are determined. This paper makes an in-depth study on the phenomenon of citation burst. The research results of this paper not only provide practitioners with a deeper understanding of heavy vehicles, but also help researchers carry out relevant in-depth research.
Experimental research on carbonization of insulation and condensed particle deposition of SRJ combustion chamber
Authors: Zhao Jing-chao , Zhao Rui-jie , Cai Wen-xiang , Chen Xiong 
Published: May 2022

Abstract
Performance of boron-based solid rocket ramjet was carried out by the ground direct connection test rig. Through SEM and EDS analysis of condensed products on the insulation wall of the second combustion chamber, the change of carbonization structure of insulation and the deposition of condensed particles along the axis were researched. Experiment results show that porosity of the carbonized layer become larger and the structure becomes loose along flow direction. The deposition of condensed particles on the insulation wall is increased, and the deposition is obvious at nozzle entrance.
Research on Vertical Interconnection and Energy Conversion of Bridge Film
Authors: Li Liming , Zhang Jingxin , Li Jun 
Published: May 2022

Abstract
In this paper, a NiCr bridge film igniting component is designed. The film igniting component is fabricated by an integrated circuit process to complete the electrical connection of the bridge film igniting component and the side and bottom of the substrate. By placing the bridge film igniting component on the electrode plug, the bottom electrode is aligned with the top surface of the electrode plug upper surface to complete the connection between the bridge film igniting component and the electrode plug, and the conventionally connected wire bond is removed. Through the relationship between the adiabatic equation of the NiCr bridge film igniting component and the input electric energy, the theoretical relationship between the ignition time of the bridge film igniting Component and the input current is calculated, and the experimental test is verified.
Inner Sequential Single Solid Method for Layout Optimization of Multi-Materials
Authors: Cao Jing 
Published: May 2022

Abstract
In multiple materials layout optimization, the optimal solution is difficult to achieve due to the number of design variables being too large and the material interpolation scheme becoming complicated when using density-like method. To bypass this problem, an inner sequential single solid optimization (ISSSO) method is presented in this study. There are two types of iterations in the optimization process of this method: the inner and outer iterations. In the inner iteration, the original layout optimization of many materials is replaced with a series of single solid sub-optimizations. In each sub-optimization, only one solid is chosen to update and the rest keeps unchanged. The inner iteration stops when all the solids are updated consequently. The next loop of inner iteration starts when the current solution does not meet the requirement of convergence. The outer iteration starts only if the current inner iteration comes to an end. In the outer iteration, the new inner iterations for update of all the solid materials are carried out. The effectiveness of ISSSO method is verified by comparing the calculation results with other methods.
Study of Impingement Cooling Technology by Using Circular Pin Fins and Mist/Air Methods in Gas Turbine Combustor
Authors: Yu Zhenglei , Cao Qing , Liu Zhenze , Liu Bo 
Published: May 2022

Abstract
The gas turbine is an indispensable part of technology and it is commonly used in electric power, aviation and marine mechanical. However, the gas combustion temperature was higher than the melting point of metal, which prevents further increase in efficiency in a gas turbine. To enhance the turbine inlet temperature greatly, an advanced cooling technology has been essentially required to protect the material of high thermal components. The final numerical results are compare with each other and show the characteristics of heat transfer and pressure drop. In these investigations, different cases evaluate that the adiabatic cooling effectiveness (ηc
) indicates a downward curvature in the following descending order: circular pin fin with mist case = circular pin fin only case > normal with mist cooling case > normal with air only case. Mist/air impiangement cooling with circular pin fins not only maintain the superiorities of air cooling jets, but more effective than pin fins technique. Accordingly, renewing the air impingement cooling systems with pin fins and mist cooling seems to be more attractive. The inspire application of the circular pin fins and mist/air impingement cooling will make it a reference for designing a new cooling structure in marine gas turbine combustor.
An optimization model of cutting path and parameters for low cost and carbon emissions in a NC milling process
Authors: Yang Qingbin , Yin Ruixue , Li Chaowen , Feng Xuqing 
Published: May 2022

Abstract
Based on the analysis of the carbon emissions and the cost evaluation model for NC milling process, the impact of different tool cutting paths to carbon emissions is compared and analyzed. Taking both carbon emissions and cost of NC milling process as optimization goals, constraints are proposed based on machine parameters and processing quality requirements. The optimization model of cutting paths and parameters for low carbon emissions and cost of NC milling process is built where the spindle speeds, feed per tooth and transverse cutting depth are taken into account as optimization variables. An example is employed to validate the model. First, the cutting path of the tool is determined by experience and the cutting parameters are selected under the lowest carbon emissions and cost target. Secondly, the genetic algorithm is used to optimize the cutting paths based on the optimal cutting parameters.
Study of Direct-link Test of Oblique Detonation Engine
Authors: Chen Shuo , Ma Hu 
Published: May 2022

Abstract
Based on the shock tube wind tunnel driven by detonation, simulating the flight altitude of 30km and the incoming flow conditions of flight Mach number 9, this paper conducts a study of direct-link test of the oblique detonation engine with an oblique wedge angle of 30 degrees. The detonation process and stationing characteristics of the oblique detonation wave are analysed in detail by the engine wall pressure measurement combined with the high-speed camera for simultaneous shooting. During the test, the oblique detonation wave successfully detonates on the oblique wedge and is validly stationed. Under the collision effect of the shock waves system downstream the oblique wedge, the oblique detonation wave successfully detonates, and the oblique detonation wave spreads and develops upstream direction after the detonation, and finally, the oblique detonation wave is successfully stationed. Using shadow-graph method to observe the wave system in the combustion chamber, the typical flow field structure such as non-reactive shock wave, oblique detonation wave, transverse wave and triple point is clearly observed, and the angle of oblique detonation wave in the oblique detonation engine tested in this paper is greater than 80 degrees. The successful detonation and stationarity of oblique detonation wave in direct-link test proves the feasibility of oblique detonation wave to be applied to hypersonic propulsion.
Analysis of FSC Supercharged Engine Intake Front End
Authors: Xinyi Zheng , Wei Su 
Published: May 2022

Abstract
This paper is based on the simulation analysis of the supercharger front intake pipeline of the FSAE racing car engine. To limit engine power, the equation race requires an annular restrictor valve to be installed in the intake system with an inner diameter less than 20mm. Limiting valves have a great impact on the intake flow and engine performance. In this paper, the intake front segment is modeled, the simulation analysis is done by Fluent, and the GT-power engine simulation software is used to assist the simulation. A good intake front segment is obtained, which provides an effective method for the design of the intake front of supercharger engine.
Fast point cloud registration algorithm using parallel computing strategy
Authors: Feng-yuan SHI , Xun-jiang ZHENG , Li-hui JIANG , Di PAN , Bing LIU 
Published: May 2022

Abstract
At present, the traditional ICP (Iterative Closest Point) algorithm used by TOF (Time-Of-Flight) cameras has the problem of high time-consuming in nearest point search process, resulting in low data update rate. Therefore, based on the characteristics of the data structure of the ICP algorithm, a multi-stage pipeline acceleration system is proposed, and the point cloud registration algorithm used in this system is studied. Firstly, design multiple units to store point cloud data and serve as the main search module. Secondly, make each group of units perform parallel operations, input the stored point clouds into their respective calculation modules, select a model point, traverse all query points, and perform subtraction. Then replace the model point and repeat the process until all model points are calculated. Finally, the query point corresponding to the minimum value in each model point difference data is selected and the model point is output as a point pair to the CPU to complete the final algorithm iteration. The experimental results show that at 30000 points, a single closest point search takes 25.65ms; at 20000 points, a single closest point search takes 11.65ms; at 10000 points, a single closest point search takes 2.88ms. It basically meets the requirements of TOF camera on-orbit measurement for the stability and reliability of point cloud registration and high data update rate.
Polarization space time adaptive processing based on maximum likelihood polarization vector estimation
Authors: Zhongping HUANG , Zhiyong LEI , Zishu HE , Huiyong LI , Liang ZHANG , Haoliang SHEN 
Published: May 2022

Abstract
In airborne radar, signal to clutter plus noise ratio (SCNR) can be improved by utilizing polarization space time adaptive processing (PSTAP). The optimal output SCNR is obtained when the expected polarization-space-time (PST) vector matches the true value. The problem of polarization parameters estimation limits the potential application of PSTAP. The inaccuracy of polarization parameters estimation unevitably causes SCNR loss. In this paper, the effect of expected polarization vector on output SCNR is analyzed on the basis of PSTAP theory. In order to reduce SCNR loss introduced by polarization mismatch, an engineering PSTAP based on maximum likelihood method is proposed. Experimental data show that this method can accurately estimate the polarization parameters, improving SCNR about 2~3dB compared with the conventional STAP.
Micro-nano Satellite Phasing Maneuver Method under Microthrust Constraint
Authors: Chuang-ge WANG , Gen XU , Dan-he CHEN , Wen-he LIAO 
Published: May 2022

Abstract
The micro-thruster of micro-nano satellite cannot provide a large impulse for a single time to satisfy the requirements of the general phasing maneuver because of the constraints of thrust and the stability of attitude control system. A multi impulses phasing method is proposed based on the four impulses phasing maneuver, which satisfies the constraint of the working time of the micro thruster. In this method, a large impulse is divided into multiple small impulses, and the impulses can be re-optimized under the constraint of phasing time, which can realize the phasing maneuver of micro-nano satellites using microthrusters. The simulation results show that the error of phasing time is less than 30 s, and the phasing accuracy in two-body orbit dynamic is less than 0.2 km. Considering the perturbation and the error of the micro thruster, the phasing accuracy is less than 5 km, which meets the time limit and fuel consumption limit in phasing maneuver of the micro-nano satellite.
AIR TOUCH: Human Machine Interface Using Electromyography Signals
Authors: Sreyas S. , Kochuvila Sreeja , Vignesh S. , Pranav R. 
Published: May 2022

Abstract
Novel interactions between futuristic devices and humans in the ever-expanding digital world is gaining momentum in the current era. In this paper, a system is proposed where electromyography (EMG) signals are used to control the cursor on a PC with the movement of the hand, making effortless interaction between user and the computer. The hand movements are detected using accelerometer and EMG signals acquired using electrodes are used to classify the hand gestures. Time domain features are extracted from the EMG signals and the gestures are classified using K-Nearest Neighbor (KNN) classifier. The operation to be performed on PC is determined from the gesture with help of a suitable interface. This system is implemented to perform the positioning of the cursor and two of the most common actions of a mouse, namely, single click and double click. The system showed an accuracy of 98% in classifying the gestures.
Robotic arm for brake performance testing
Authors: Shirose Burhanuddin , Yadav Kunal , Meenatchi LS , Vedhanarayan K 
Published: May 2022

Abstract
Bikes require their brakes to be tested. There are adequately defined conditions under which these tests need to be performed: the brake pedal has to be pressed by a constant force. This force varies depending on the standardized test, but the value remains constant under each standard. No bike brake is perfect and thus has imperfections like disc thickness variation and disc misalignment. These imperfections cause judder due to which force experienced by the brakes under a specific pedal position varies too. This can create errors in tests and thus needs to be overcome for proper performance testing of brakes. “Robotic arm for brake performance testing” provides an effective solution by constantly measuring the braking force and instantly moving the brake pedal to keep the braking force constant.
The Design of an Intelligent Chatbot with Natural Language Processing Capabilities to Support Learners
Authors: Wong A 
Published: May 2022

Abstract
It would be ideal for the teacher to give individual attention to each student. However, this is infeasible as teachers only have limited time and they will be tired after long periods of consultation. Chatbots can be an effective tool to overcome this problem. A pilot was conducted on 11 Feb 2019 in which 27 students tried a chatbot prototype built by the author. The students compared the chatbot and a quiz website. The academic contents provided by the chatbot are exactly the same as the website. Over 80% of the students agreed that the chatbot is better than the quiz website in many aspects. However, about half of the students also indicated that the chatbot took them more time to complete the quiz than the quiz website. The author proposed using the Unified Theory of Acceptance and Use of Technology (UTAUT) framework to conduct more research into this area. The knowledge would allow more teachers to create chatbots in more disciplines of study so that students are more motivated to achieve the learning outcomes better.