bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aerodynamic Analysis of a Gull-inspired Flapping Wing Glider
Authors: Bie Dawei , Zuo Shiyu , Li Huadong , Shao Haoyuan , Li Daochun 
Published: July 2020

Abstract
This paper provided a gull-inspired flapping wing micro aerial vehicle (FMAV) concept followed with aerodynamic analysis. The FMAV supposed to implement both flapping and gliding mode during the flight to enlarge the endurance. A cambered airfoil is employed for wing cross section different with the traditional flat plate. Aerodynamic analysis is proposed through 3D computational fluid dynamics (CFD) method to get the lift characteristic of two different modes. Result shows that the FMAV is able to generate the lift force up to 5 N with an angle of attack 6 degrees and flight speed 6 m/s without flapping, which proves that the FMAV is able to achieve gliding in specific circumstance. Flapping motion is able to produce a higher lift during the flight. Comparison of the lift performance under a specific condition shows that the average lift generated with flapping is 65.3% higher than gliding mode. Research also found that the effect of airfoil camber on lift generation with flapping is not always positive, further analysis is needed when employs a cambered wing in design of FMAVs.
Research on TCH and RDH of Glide Path Equipment
Authors: Jiaquan Ye , fei Liang , Xiaojia Yang , Yuankai Li 
Published: July 2020

Abstract
There is a certain difference between the RDH obtained from the flight inspection and the TCH calculated from geometry terrain. The problem is always neglected and someone attribute the cause of poor RDH to equipment issues, actually equipment is a problem, but the electromagnetic environment is also a very important factor overlooked by owner. When the electromagnetic environment around glide path antenna is worse, the difference of TCH and RDH is even larger, and even cannot meet the requirements for safe operation. This article study the calculation method of the actual measured RDH, revealing fundamental reason of the difference, and further explaining the importance of protecting the electromagnetic environment of the instrument landing system,.providing analysis ideas and solutions for equipment construction and maintenance engineers.
Research on Evolution Process and Control Method of External Shapes in the Life-cycle of Modern Civil Jets
Authors: Jin Ding , Wang Yue 
Published: July 2020

Abstract
External shape is a key property of aircraft. With the wide application of digital technology, various external shapes are produced in different states and different uses in the life-cycle of modern civil jets. If these external shapes are not clearly distinguished, they might be used improperly. Therefore, in this paper, various shapes in the full life-cycle of modern civil jets are defined, and the evolution process of these external shapes is researched. Based on the control of these external shapes, some advanced management methods are put forward, which have been successfully applied in civil jet development in China, and effectively improve the efficiency of civil jet product development.
Aerodynamic Analysis and Drag-reduction Design for Ultra-low-orbit Satellite
Authors: Yu Shao-ting , Fan Cai-zhi 
Published: July 2020

Abstract
When the satellite is operating at an orbital height of 120-300km, aerodynamic drag becomes the most important factor affecting ultra-low orbital attenuation and attitude disturbance. Based on the theory of free-molecular flow, the model of aerodynamic drag of a panel in free-molecular flow is established firstly, and then the influence of the angle of attack, adaptation coefficient, and the molecular velocity ratio on the drag coefficient of the panel is analysed. Finally, A reduced drag design method for a ultra-low-orbit satellite is proposed based on the analysis results. And it is validated by the simulation results. The approaches presented in this paper can be applied to aerodynamic design and calculation of ultra-low-orbit satellites.
Effect of Obstacle’s Length-to-Height Ratio on Aerodynamic Quantities of Rarefied Hypersonic Flow
Authors: Wang L , Fang S 
Published: July 2020

Abstract
The DSMC method was used to calculate and analyse the flow field structure and the surface aerodynamic quantities when the hypersonic rarefied gas flow passing obstacle at a height of 70km. The changes of surface aerodynamic quantities such as skin friction coefficient, heat transfer coefficient, and pressure coefficient when the length-to-height ratio of the rectangular obstacle is 1/1, 1/2, 1/3, and 1/4 are analysed. The results show that under the above aspect ratio of the obstacle, a recirculation region is formed at each corner of the obstacle. A bow shock will be formed on the windward side of the obstacle, and with the increase of the obstacle’s height, the bow shock will be superimposed on the separated shock wave in front. A strong expansion wave will be formed on the backside of the obstacle, which affects the downstream flow field structure and aerodynamic quantities. When the obstacle’s height increases, the maximum value of the aerodynamic quantities on each surface of the obstacle will increase significantly. It is calculated that the quantities such as heat transfer coefficient and pressure coefficient reach the maximum at the convex point of the windward surface.
Experimental Study on Hysteresis Characteristics of Fluorosilicone Rubber Damper
Authors: Yang Qiang , Zhou Yunlai 
Published: July 2020

Abstract
This study tested the hysteresis characteristics of the damper for determining the damping characteristics. Firstly, dampers with four kinds of hardness, such as 20HA, 30HA, 40HA and 50HA, were obtained by vulcanization. Then hysteresis loops of the dampers were tested by cyclic loading method with displacement of ±0.5mm, ±1.0mm and ±1.2mm. The relationship between stiffness of dampers and hardness was obtained, and it was found that the stiffness of dampers changed quadratically with rubber hardness. The ellipse method is used to calculate the damping factor of the damper. The damping factor of the damper varies with the change of loading displacement and rubber hardness.
Dynamical Analysis for the INS Vibration Control System Used in UAV
Authors: Duan Yuxing , Li Xiao , Su Bo , Wang Xin , Yang Qiang 
Published: July 2020

Abstract
A six-degree-of-freedom mechanical dynamic model and its equations of the damping system are established for the offset installation environment of the UAV. The influence parameters of the damping system on the vibration coupling state is studied based on the model. And the optimal parameters of the damping system are obtained by doing the mechanical dynamic calculation. And then the vibration isolator of the UAV strap-down inertial measurement unit is designed and manufactured. Finally, the damping system was tested and verified on the shaking table and in the flight environment of the UAV. It is shown that the damping system could implement the tri-axial equal rigid design when the shaft-to-radius stiffness of the isolator is about 0.8. And the experiments also prove this point. The damping system weakens the coupling problem of the strap-down inertial measurement unit effectively, and it reaches the quasi-decoupled state. The amplitude of the acceleration decreases by more than 50% after vibration isolation.
Experimental Study and Application Prospect Analysis of Truss Heat Pipes for Space Optical Cameras
Authors: Chunmei Shen , Shikui Luo , Jin Cui , Tao Yang , Zhao Liu , Zhenming Zhao , Feng Yu 
Published: July 2020

Abstract
To meet the application requirements of space optical cameras, the concept of a truss heat pipe is proposed in this paper. This truss heat pipe is composed of multiple (two or more) heat pipe shells with inner capillary wicks connected to each other by special joints with additional inner capillary wicks. It can be assembled into a variety of truss structures according to the layout requirements of the structure. Truss heat pipes can be used as the supporting structure of space optical cameras and can simultaneously efficiently transfer heat and maintain an even temperature, conserving the thermal control resources of space optical cameras. The function and performance of truss heat pipes were verified through tests of a single T-joint prototype and a multi T-joint prototype. Two truss heat pipes were then applied to the thermal management of a space optical camera. The thermal vacuum test results show that as the supporting structure of the front lens barrel heat shields, the two truss heat pipes can transfer heat from the space optical camera heat source to the front lens barrel heat shield both efficiently and evenly. This indicates that truss heat pipes can meet the requirements of the structure-thermal integrated design and thermal management of space optical cameras. As a new thermal control technology and product, truss heat pipes have the potential for broad applications in many aerospace fields in the future.
Numerical Study of Shock Train in the Isolator of Scramjet Engine
Authors: Fang Jing , Xian Yao Xiao , Lin Fang Guan 
Published: July 2020

Abstract
The isolator of scramjet engine has to separate the combustor from the inlet so that the scramjet can keep working stably. The steady-state flow field structure, the shock train shape and the starting position of the symmetrical model of isolator under different backpressure ratio are obtained by numerical simulation of commercial software fluent. Using the user-defined function to simulate the pressure fluctuation caused by the irregular heat release in the combustion chamber, the motion of the shock train in the isolation section is obtained. It is found that the start position of the shock train is larger than that of the steady state simulation, which provides a reference for the design of the combustion chamber.
The Research on Indirect Modular Adaptable Design Platform on Part Design of Civil Aircraft
Authors: Cheng Bing 
Published: July 2020

Abstract
Based on the traditional modular design and the module division concept of virtual flexible modules in generalized modular design, this paper proposes a design method of indirect modular design. It suggests a way to achieve modular design of products without obvious serialization and hierarchical characteristics integrating modular platform and parameterized platform. The division and application of geometric parameters and numerical parameters of civil aircraft fuselage frame are taken as an example to show how it works. The indirect module is constructed on the basis of the framework model, and the lines and surfaces of the framework model are used as driving parameters. The design idea of adaptable design platform based on indirect modular design is also presented in this paper. The similar modules of the parameterized family modules can be designed quickly by driving the geometric parameters and numerical parameters separately. It makes faster and more accurate response to customer needs.
Research on Virtual Assembly Simulation System for Aircraft Flight Control System Based on Unity3D
Authors: Wang Yan , Zhou Zhangning , Zhou Puli , Li Bo 
Published: July 2020

Abstract
Based on Unity3d’s digital assembly simulation technology, this paper designs a virtual assembly simulation system for the flight control system of a certain aircraft nose. Firstly, the structure tree division of the flight control system assembly model based on modular decomposition is studied. Secondly, a virtual assembly simulation system for the assembly operation of the flight control system is designed and implemented by Unity3D. Finally, the system verified the virtual assembly operation of the flight control system of the aircraft nose through the laboratory platform. The assembly guidance and interaction functions of the flight control system are initially realized by this simulation system.
Analysis on Aerodynamic Performance of Single-skinned Parawing in the Hypersonic Rarefied flow
Authors: Rao Q J , Fang S Z , Zhang S 
Published: July 2020

Abstract
In consideration of the serious aerodynamic heating and overload in the return process of the space vehicles, a single-skinned parawing suitable for the whole return process is proposed, which uses lift deceleration to realize flexible reentry. A three-dimensional steady numerical simulation of the single-skinned parawing with different leading edge sweep angles was conducted by using the direct simulation Monte Carlo method, and the effects of different Mach numbers and altitudes on the aerodynamic performance of the parawing were studied in the hypersonic rarefied atmosphere. The results show that with the increase of the leading edge sweep angle, the aerodynamic performance of the parawing decreases obviously, but the ability of stall resistant is improved. The lift-drag ratio decreases monotonously with the increase of Mach number and altitude. The effect of Mach number on lift-drag ratio is not obvious, but the effect of altitude is more obvious. The maximum lift-drag ratio of parawing is 0.45 at 90 km, but only about 0.1 at 110 km. The peak heat flux always appears near the head, which will decreases obviously by decreasing the flight speed or increasing the flight altitude.
Unmanned Aerial Vehicle Flying Qualities Flight Test Evaluation Technique in Approaching and Landing Phase
Authors: Jing Li , Qi Shenjun , Wang Feng 
Published: July 2020

Abstract
Unmanned Aerial Vehicle (UAV) flying qualities in approaching and landing phase relates directly to flight safety. In this paper, autonomous control mode and remote piloted control mode were introduced for analysing approaching and landing flying qualities firstly. Then evaluation criteria about landing flying qualities of these two control modes were proposed according to characteristics and design requirements of UAV and manned aircraft flying qualities specifications. For autonomous control mode, control accuracy and transient response were the main contents of evaluation, but for remote piloted control mode, flight test evaluation method was given in order to lower risk and improve safety, which includes modified Cooper-Harper Rating Scale, closed-loop ground simulation, simulated approaching and landing flight test in low altitude and simulated remote piloted control landing flight test. Finally, flight test was carried out to demonstrate the validity of evaluation criteria and method which is useful and meaningful for UAV landing flying qualities evaluation.
Optimization of UAV Flight Control Algorithm and Flight Simulation in Two-dimension
Authors: Xu Xiao , Li Jie , Yang Chengwei , Wang Ziquan , Xiong Jin , Liu Chang 
Published: July 2020

Abstract
Large-scale Unmanned Aerial Vehicle (UAV) groups flight simulation in two-dimensional planes is commonly applied to UAV cluster mission planning algorithm design. In this paper, an UAV control algorithm optimized for two-dimensional planes is designed. The tandem structure of closed loops, as well as the control laws of L1 and Total Energy Control System (TECS), are transplanted to an UAV model that is simplified to a moving particle of a two-dimensional space, and UAV flight simulation is performed based on the flight control algorithm. Compared with the traditional 3D space flight simulation, it can save hardware resources and improve the simulation efficiency. Compare with the flight simulation based on the geometric method, on the premise of maintaining the dynamics basis, the trajectory and dynamics curves are closer to the actual flight results in 3D space, and the dynamics data onto the entire flight can be recorded. It has been verified that 50 UAVs need only 0.8s to perform 100 square-area snake-like search simulation experiments, and the fitting degree of the UAV’s flight curve to the three-dimensional space is greater than 80%. The two-dimensional plane flight control algorithm and flight simulation proposed in this paper provide a new simulation method for the design of UAV cluster mission planning algorithms, therefore can help promote the development of the subject.
Aerodynamic Performance Analysis of a Curved-channel ABLE Airfoil in Supersonic Continuous and Hypersonic Rarefied Flows
Authors: Zhang S , Fang S Z , Guo J 
Published: July 2020

Abstract
An airfoil, equipped with a curved-channel ABLE, is a good alternative to increase the lift-to-drag ratio. For this purpose, a curved-channel artificial blunted leading edge (ABLE) was applied to several supersonic/hypersonic symmetrical airfoils to analyse the aerodynamic performance in low-altitude supersonic continuous flow and high-altitude hypersonic rarefied flow during the process of re-entry into the atmosphere. The compressible Navier–Stokes equations were solved using the finite volume method to analyse the aerodynamic performance and determine the optimal curved-channel ABLE airfoil for supersonic continuous flow. Thereafter, the drag reduction and lift increment efficiency of the optimal ABLE airfoil were analysed in the hypersonic rarefied flow. The variation in the aerodynamic performance of the ABLE airfoil with the Knudsen number and freestream Mach number was determined using the direct simulation Monte Carlo (DSMC) method. The results showed that with suitable ABLE configuration and parameter values, the concept of ABLE can help reduce the drag coefficient, improve the lift coefficient, and obtain a better lift-to-drag ratio in both continuous and rarefied flows without considerable aerothermal penalty. However, the drag reduction effect of the curved-channel airfoil in the rarefied flow is much lower than that in the continuous flow, because of the lower proportion of the wave drag in the total drag, and the overall aerodynamic performance is significantly deteriorated because of the rarefaction effect of the atmosphere.
Error Analysis of High Precision Two-way Time Difference Measurement in Satellite-ground Links
Authors: Shuaihe Gao , Yuqi Liu , Lishu Guo , Leyuan Sun , Zhou Chen , Song Kun 
Published: July 2020

Abstract
High precision time difference measurement between satellite and earth is an important part of space-based time-frequency system application in the future. With the on-orbit operation of high-precision atomic clocks, the accuracy of satellite-ground time difference measurement link has become the bottleneck of space-based time-frequency distribution. In this paper, the basic principle of two-way time difference measurement is derived. The system error and equipment error involved are analyzed, and the error control strategy is given. The above work will provide engineering guidance for high-precision two-way time difference measurement in the design of satellite-ground links.
An integrated 3D fluidic device with bubble guidance mechanism for long-term primary and secondary cell recordings on multi-electrode array platform
Authors: Konduri Anil Krishna , Deepak C S , Purohit S , Narayan K S 
Published: July 2020

Abstract
A 3D fluidic device (3D-FD) is designed and developed with the capability of auto bubble guidance via a helical pathway in a 3D geometry. This assembly is integrated to a multi-electrode array (MEA) to maintain secondary cell lines, primary cells and primary retinal tissue explants of chick embryos for continuous monitoring of the growth and electrophysiology recording. The ability to maintain the retinal tissue explant, extracted from day 14 (E-14) and day 21 (E-21) chick embryos in an integrated 3D-FD MEA for long duration (>100 h) and study the development is demonstrated. The enhanced duration of monitoring offered by this device is due to the controlled laminar flow and the maintenance of a stable microenvironment. The spontaneous electrical activity of the retina, including the spike recordings from the retinal ganglion layer, was monitored over a long duration. Specifically, the spiking activity in embryonic chick retinas of different days (E-14 to 21) is studied, and the presence of light-stimulated firings along with a distinct electroretinogram for E-21 mature retina provides the evidence of a stable microenvironment over a sustained period.
The rheological performance of aqueous ceramic ink described based on the modified Windhab model
Authors: Wang Yongqing , Yang Wenjing , Wang Qikun , Liu Kun , Wang Chao , Chang Qibing 
Published: July 2020

Abstract
The good stability is the pre-requirement for ceramic ink in ink-jetted printing technology. The aqueous ceramic ink owning a significant shear-thinning effect is proposed using guar gum as additive agent. Due to the shear-thinning effect, the ink in static state has a high viscosity, which contributes to keep the ink stable. At the same time, the ink in spray state has a very low viscosity to meet the requirement of spraying. To describe this rheological performance, the Windhab model is modified, in which the correction term η

α
is added into η
∞. The term η

α
is related to the concentration of guar gum and the solid content of the aqueous ceramic ink. A slip model is proposed to understand the interaction between pigment particles and guar molecules.
The Clinical Utility and Ecological Validity of the Medication Management Ability Assessment in Older Adults with and without Dementia
Authors: Margolis Seth A , Hallowell Emily S , Davis Jennifer D , Kenney Lauren E , Tremont Geoffrey N 
Published: July 2020

Abstract

Objective
Older adults are susceptible to medication nonadherence, which may signify functional decline. Thus, performance-based proxies of medication-taking behavior may help diagnose dementia. We assessed the Medication Management Ability Assessment’s (MMAA) clinical utility and ecological validity.

Method
This was a retrospective chart review of 180 outpatients (age = 72 ± 8 years) who completed the MMAA during clinical evaluations. Forty-seven were cognitively normal (CN), 103 had mild cognitive impairment (MCI), and 30 had dementia. Most (136) were independent in medication management, whereas 28 were assisted and 16 were dependent. Kruskal–Wallis tests assessed whether MMAA scores differed by diagnosis and independence. Receiver operating characteristic (ROC) analyses identified diagnostic cut-offs. Classification accuracy estimates were derived.

Results
MMAA performance differed across diagnosis as expected (p’s &lt; .001). Those who were independent in medication management outperformed assisted and dependent counterparts (p’s &lt; .001). Assisted and dependent cases were no different. At a cut-off = 23, the MMAA was good-to-strong in distinguishing dementia from CN cases (Sn = 0.96, Sp = 0.83), dementia from MCI (Sn = 0.70, Sp = 0.83), and dementia from functionally unimpaired cases (Sn = 0.78, Sp = 0.83). At a cut-off = 27, it had good sensitivity but weaker specificity when distinguishing both MCI and all cognitively impaired patients (MCI and dementia) from CN cases (Sn = 0.81, Sp = 0.66 and Sn = 0.81, Sp = 0.72, respectively).

Conclusions
The MMAA has ecological validity and clinical utility in identifying dementia. Its inclusion in neuropsychological practice may be especially useful when medication mismanagement is suspected.
PAFway: pairwise associations between functional annotations in biological networks and pathways
Authors: Mahjoub Mahiar , Ezer Daphne 
Published: July 2020

Abstract

Motivation
Large gene networks can be dense and difficult to interpret in a biologically meaningful way.

Results
Here, we introduce PAFway, which estimates pairwise associations between functional annotations in biological networks and pathways. It answers the biological question: do genes that have a specific function tend to regulate genes that have a different specific function? The results can be visualized as a heatmap or a network of biological functions. We apply this package to reveal associations between functional annotations in an Arabidopsis thaliana gene network.

Availability and implementation
PAFway is submitted to CRAN. Currently available here: https://github.com/ezer/PAFway.

Supplementary information
Supplementary data are available at Bioinformatics online.