bluuebunny/crossref_metadata_2025 huggingface dataset:
Features of digital transformation in the construction industry
Authors: Kudryavtseva V A , Nikishina O V , Vasileva N V
Published: July 2020

The introduction and development of digital technologies and innovations is one of the necessary elements for the long-term and effective functioning of most sectors of the economy, not only in Russia, but also in the world. The construction sector accounts for a significant portion of Russia’s GDP. Therefore, the issue of introducing digital and innovative technologies is quite acute. In order to develop a mechanism for digital transformation of the construction sector, special attention should be paid to the possible maximum coverage of business processes existing in construction. Since the synergistic effect of the introduction of digital technologies in the construction sector will be to increase the competitiveness of construction organizations in the construction market. The formation and development of the concept of digital transformation of the construction industry is one of the necessary elements for the full implementation of the digital economy of the state.
A model for managing the development of low-rise housing construction using the method of discursive design
Authors: Bezrukikh O A , Pinchuk T O , Latysheva S V
Published: July 2020

In the Russian Federation, the housing problem is one of the strategic and top-priority goals of the state’s social and economic policy. The indicators of housing supply prove that low-rise buildings created by means of large-panel housing construction technology can become a solution to the housing problem in the Russian Federation. Today, the technology of large-panel housing construction has opened up completely new prospects for the construction sector, combining all the advantages of industrial mass technology and providing originality and individuality of architectural solutions. In this context, switching from institutional to personal discursive design will help to increase the investment attractiveness of low-rise construction projects.
Analysis of the DuPont model of the construction industry in the Baikal region
Authors: Filatov E A , Bunkovsky V I
Published: July 2020

In the context of globalization, the role of the investment component in the dynamics of economic development is significantly increased. The DuPont model allows you to determine which factors caused the change in profitability or to make a factor analysis of the return on equity. The object of the study is construction companies (construction of residential and non-residential buildings) in the Baikal region of the Russian Federation (Irkutsk region, Republic of Buryatia, Zabaikalsky Krai). The article describes the methods of factor analysis developed by Filatov E. A., which make it possible to make an accessible and relatively simple conclusion about changes in the financial position of the enterprise, as well as to assess the degree of influence of factors on changes in the studied indicator. The purpose of this article is to generalize and systematize the theoretical and methodological foundations of factor analysis in a form that is accessible to specialists in the field of economics and management. The article should contribute to the formation of a basis for managers and economists to develop economic thinking, understanding the essence of economic processes and phenomena occurring within the framework of economic entities, and most importantly – the development of skills for their quantitative assessment, economic interpretation and search for reserves to improve the efficiency of functioning. The article was carried out within the framework of the scientific project of the Inc SB RAS no. XI.174.1.4 ‘Activation of the internal development potential of regions of resource specialization (on the example of the Baikal region)’
On legal regulation of investment of financial resources of the compensation fundscreated by self-regulatory construction organizations
Authors: Kuryshova I V , Timofeeva A A
Published: July 2020

The article deals with the issues of legal regulation of investment offinancial resources of compensation fundscreated by self-regulatory organizations, identifies features of this process in the construction industry of the Russian Federation, analyzes methods of investing financial resources of compensation funds in modern Russian reality. The shortcomings of the investment policy are identified, conclusions about the need to improve legal regulation in the Russian legislationare drawn.
Organization of investment support for entrepreneurial activity in energy construction
Authors: Ryutin V S , Matveeva M V
Published: July 2020

Process of reforming and forming a new model of the heat energy market in Russia is associated with the increasing role of interaction between private business and the state in the development of Russian energy sector and achieving energy security. Due to the long overdue need to attract private investment to the industry, the issues of investing activities financing of heat supply organizations are relevant and of great research interest. The article analyzes the effectiveness of the state policy on attracting private investment in the heat supply industry and builds a model for optimizing sources of financing for investment activities of heat supply enterprises.
Determinants of the housing engineering entrepreneurship
Authors: Kogan A B
Published: July 2020

Current specifics of entrepreneurship in the field of apartment buildings construction (AB) and the impact of modern financing rules set on it, written in the relevant Federal Law are highlighted in the article. The purpose of the discussion is to develop the method foundations for analyzing the financial boundaries of housing (MFAFBH). The author’s opinion is based on the results of monitoring facts and expert opinions, texts’ analysis of normative acts, averaged requirements of banks for AB projects, methods of equivalent mathematical transformations, calculations according to special dynamic financial models of AB projects (MFPAB), principles of financial decision-making, laws of the primary market real estate (PRMRE), conjuncture of the Novosibirsk PRMRE. The fundamentals of MFAFBH were developed, the MFPAB was compiled for one of the typical apartment buildings in Novosibirsk, the boundary price of housing under construction was calculated, below this prize any AB project could not receive funding, i.e. construction would be impossible. The MFAFBH proposed by the author, can be applied to any region of the country, to forecast housing construction volumes on its basis, to develop and take measures, to manage this field of activity.
Development of a risk assessment methodology for the implementation of investment projects of a construction organization
Authors: Nizamova G Z , Gayfullina M M , Musina D R , Yu Tumanova A , Battalova A A
Published: July 2020

The article considers the risks of implementing an investment project in the construction sector. The purpose of the study is to develop a methodological approach to assessing the risks of implementing investment projects of a construction organization. The object of the study is an investment project of a construction company. The subject of the study is the risks associated with the implementation of the investment project of a construction organization. Research methodology-methods of logical analysis, grouping and comparison, generalization were used. Using the method of expert assessment, an integral indicator of risk assessment is proposed. The main results and conclusions of the study: a risk management algorithm is proposed, a system of external and internal risks for the implementation of investment projects in the construction sector is formed within the algorithm, which allows to identify market and investment risks of the project. A method for assessing the risks of investment projects in the construction sector, based on expert assessment, is proposed. It allows to quantify and rank the impact of risks on the implementation of an investment project of a construction organization, as well as to calculate the integral level of risk for the implementation of investment projects of a construction organization.
Concept of logistics processes in the activity of a construction company in the implementation of innovative construction projects
Authors: Pinchuk T O , Chuvashova N V
Published: July 2020

The main objective of the study is the study and analysis of logistics processes in the activities of construction companies. During the study, methods were used to analyze existing approaches to the management of the logistics system in construction, as well as methods for the effective management of material and technical support. It was revealed that, based on the prevailing conditions, the mission of the logistics center is the introduction of an effective logistics system to ensure construction, which supports the growth of construction volumes by uninterrupted supply of construction materials to Group A. The main goal is to reduce construction time by implementing MRP2 and just-in-time concepts and a cost-effectiveness strategy. It can be concluded that logistics considers the movement of material flows in a company as a single and interconnected process, regardless of which unit controls these flows at the moment. Moreover, logistics technology involves close interaction with other departments at various stages of work with external contractors.
Alternatives of judicial economic disputes settlement in investment and construction sphere
Authors: Yu Yaskova N , Zaitseva L I
Published: July 2020

Modern state of construction industry signifies the necessity of coping with technological backwardness, accrued misbalances, low productiveness of construction business and also its persistent unprofitability and high level of conflict character of construction participants. Actual rise of economic interests contradictions caused by a more complicated character of projects, increase of social burden on construction business induced by inconsistent and even fragmentary measures of public regulation has led to enormous number of economic disputes. Bankruptcy caseload of investment and construction companies is at the highest possible level nowadays. Not only small and middle-sized business but also large companies cannot withstand modern challenges pressure. In this connection there is a huge field for elaboration of dispute resolution methods. Shifting towards project financing strengthens inner contradictions in the industry and also causes conflict of interests with banks. Decline of assets quality, increase of unfinished construction volume, loss of partners, withdrawal of turnover capital, waste of staff, enlargement of shadow economy segment – these are just the part of consequences which should be overcome immediately. Systemic possible solutions deal with the use of the whole specter of disputes resolution methods. Foreign experience, for example Belarusian one, proves that non-judicial methods are more flexible, rational, diverse and acceptable for parties in conflict. The most important thing is that these methods of settling differences have negotiating nature and let the parties find decisions with a high potential of practical fulfillment (not just winning the case in court). Experts expressed different opinions on the issue of conciliation procedure organizational form. The main requirement for arising disputes in investment and construction projects is an uninterrupted process and prevention of bankruptcies: debtors, contractors, subcontractors and construction shareholders. Participants of conference came to the conclusion that certain pilot projects promoting diverse disputes settlement procedures in investment and construction should be launched
Low-rise housing – a new tool for the development of the rental real estate market
Authors: Yu Gorbachevskaya E
Published: July 2020

The article deals with the development of such a segment of the residential real estate market as low-rise construction. The study analyzes existing approaches and concepts for implementing investment and construction projects in the low-rise housing segment. According to the results of the analysis, it is concluded that this segment is developing in the direction of “business” and “elite” in most of the Russian territories. The “comfort” segment is allocated only 8% of the total volume of implemented projects. According to the authors, the increase in the volume of low-rise construction in the “comfort” and “economy” class segment can become one of the main tools for solving the housing problem in the country and achieving the benchmarks indicated in the corresponding strategies. The study also considers possible options for building suburban areas by density, and it is determined that high-density low-rise housing can become relevant for “comfort” and “economy” class, and the main method of construction is large-panel housing construction. As a result of studying the collected analytical and technical information, methodological recommendations were developed for organizing mass low-rise construction of high-density low-rise housing in the comfort and economy segments. The potential advantages of the housing under consideration allow us to overcome the factors that hinder the development of rental housing, from which it is concluded that the developed recommendations are applicable not only for projects intended for sale to property, but also for renting to middle-income families.
Specifics of construction in Eastern Siberia in 2015-2019
Authors: Kaigorodova N V , Rudykh L G
Published: July 2020

The article is devoted to the specifics of Eastern Siberia construction industry development in 2015-2019. Questions about a place of a building branch in structure of economy of region are actualized, data on priority directions of building in the investigated period are resulted, influence of bank sphere, mortgage crediting is specified, reasons of recession of the market of working trades are described, a degree of development of building in region is revealed. The article describes the current state and trends in the construction industry of Eastern Siberia for the last five years. The comparison of large-panel and reinforced concrete house-building is given, the advantages and disadvantages of each type of residential building construction are analyzed. The specificity of resource base of construction materials is noted, the reason of high cost of construction objects in the region, starting from complicated climatic conditions and finishing with economically expensive transport logistics is specified. The prospects for the development of other construction directions than civil construction are presented. The conclusions of the article reflect the specific character of the construction complex in Eastern Siberia in 2015-2019, which is expressed by the high demand of the population for the purchase of housing, the availability of a sufficient number of enterprises on the housing construction market, a wide mineral base for the production of construction materials.
Specifics of construction in China in 2019-2020
Authors: Rudykh L G
Published: July 2020

China is currently building entire cities, and new settlements are rapidly being built. It is important to note that the ideology of construction has undergone significant changes. if earlier the high rate of construction was due to a large number of cheap labor, and the quality suffered, today the emphasis is on the quality of construction work and materials. For this purpose, China has trained specialists-professionals who have received the best education and passed training in construction companies in different countries of the world, so today Chinese young engineers can teach their foreign colleagues how to innovate in the field of construction. The successful development of the construction industry is facilitated by strict state control, and the fact that almost all construction equipment of modern samples is produced by China itself and does not depend on foreign investment. This, in turn, contributes to an increase in sales of construction vehicles to other countries. Today, after many years of development of construction industrialization, BIM technologies have become widespread, which has determined the acceleration of the growth of modular and industrial development. It is no secret that the Chinese economy is developing rapidly. Of course, effective development of the economy, industry and agriculture is impossible without the development of construction, services and infrastructure.
Study on the Transverse Elastic Vibration Equation and the Generalized Aerodynamic Force of Space Vehicle
Authors: Peng-fei Guo , Zheng-xue Li , Jian-hui Wu , Wei Dong , Wang-hua Fei
Published: July 2020

In order to avoid divergence of space vehicle attitude, structural elastic movements should be taken into consideration in the control system design. Space vehicle structure generally has a large length-diameter ratio, the corresponding rolling and longitudinal modal with higher natural frequency has a slight impact on the design of the control system, while the transverse elastic modal with lower natural frequency including pitching and yawing should be paid more attention in the design of space vehicle control system. In this paper, the influence of elastic vibration on the design of attitude control system of space vehicle is analyzed firstly. Then the transverse elastic vibration equation of spacecraft and the calculation method of generalized aerodynamic force are studied. Furthermore, the equation of elastic vibration considering the coupling effect of aerodynamic force between pitching and yawing control channels is proposed and the engineering calculation method of generalized aerodynamic force for typical stations in spacecraft is improved. The research results can provide significant reference for the design of the new generation of spacecraft control system.
Aerodynamic Analysis of a Gull-inspired Flapping Wing Glider
Authors: Bie Dawei , Zuo Shiyu , Li Huadong , Shao Haoyuan , Li Daochun
Published: July 2020

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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 < .001). Those who were independent in medication management outperformed assisted and dependent counterparts (p’s < .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

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.
Clozapine in the treatment of refractory schizophrenia: a practical guide for healthcare professionals
Authors: Flanagan R J , Lally J , Gee S , Lyon R , Every-Palmer S
Published: July 2020

Background

Clozapine remains the only medication licensed for treating refractory schizophrenia. However, it remains underutilized in part due to concerns regarding adverse events.

Sources of data

Published literature.

Areas of agreement

Common adverse events during clozapine treatment include sedation, hypersalivation, postural hypotension, dysphagia, gastrointestinal hypomotility, weight gain, diabetes mellitus and dyslipidaemia. Rare but serious events include agranulocytosis, cardiomyopathy, myocarditis, pneumonia, paralytic ileus and seizure.

Areas of controversy

It remains unclear how best to minimize clozapine-induced morbidity/mortality (i) during dose titration, (ii) from hypersalivation and (iii) from gastrointestinal hypomotility. It is also unclear how clozapine pharmacokinetics are affected by (i) gastrointestinal hypomotility, (ii) systemic infection and (iii) passive exposure to cigarette smoke. Whether monthly haematological monitoring needs to continue after 12 months of uninterrupted therapy is also a subject of debate.

Growing points

There is a need for better management of serious clozapine-related adverse events in addition to agranulocytosis. There is also a need for better education of patients and carers, general practitioners, A&E and ITU staff and others of the problems posed in using clozapine safely.

Areas timely for developing research

There is a need for more research on assessing clozapine dosage (i) as patients get older, (ii) with respect to exposure to cigarette smoke and (iii) optimizing response if adverse events or other factors limit dosage.
Local and Landscape-Scale Features Influence Bumble Bee (Hymenoptera: Apidae) Bycatch in Bertha Armyworm Mamestra configurata (Lepidoptera: Noctuidae) Pheromone-Baited Monitoring Traps
Authors: Grocock Nicholas L , Evenden Maya L
Published: July 2020

The bertha armyworm (BAW) Mamestra configurata Walker is a significant pest of canola Brassica napus L. (Brassicales: Brassicaceae) in western Canada. Its activity is monitored through a large network of pheromone-baited monitoring traps as a part of the Prairie Pest Monitoring Network across the Canadian Prairies. The unintentional bycatch of bee pollinators in pheromone-baited traps targeting moth pests occurs in many agroecosystems and may have repercussions for biodiversity and pollination services of wild plants and managed crops. We conducted field experiments to determine the abundance and diversity of bees attracted to green-colored BAW pheromone-baited traps across the canola growing regions of Alberta, Canada. A higher species diversity and more bumble bees were captured in BAW pheromone-baited than in unbaited control traps. Bombus rufocinctus Cresson (Hymenoptera: Apidae) was the most commonly captured species. Few other wild bees or honey bees Apis mellifera L. (Hymenoptera: Apidae) were captured during this study. Additionally, we evaluated the influence of local and landscape-level habitat features on bee bycatch. Local flowering plant abundance improved overall model fit but did not directly impact bee bycatch. The proportion of natural and seminatural habitat, and especially forested area, in the area surrounding monitoring traps affected bee bycatch. Both local and landscape-scale factors were important in this study and often have combined effects on bee communities. This study provides recommendations to reduce the bycatch of beneficial bee pollinators in a large-scale pheromone-baited monitoring network.
Infection with SARS-CoV-2 in primary care health care workers assessed by antibody testing
Authors: Lackermair Korbinian , William Frederic , Grzanna Noelle , Lehmann Elke , Fichtner Stephanie , Kucher Hans Bernd , Wilhelm Karl , Estner Heidi
Published: July 2020

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a pandemic threat of public health during the last month causing more than 10 million infections and 500 000 deceased patients worldwide. Nevertheless, data about risk of infection for health care workers are sparse.

Methods

In a large primary care facility, 151 workers underwent SARS-CoV-2 immunoglobulin G (IgG) testing. In addition, participants had to complete a survey regarding symptoms and their individual risk of infection.

Results

Symptoms suspicious for COVID-19 occurred in 72%, fever in 25% of all subjects. Four workers (2.6%, 95% confidence interval 0.8–7.1%) had a positive SARS-CoV-2 antibody testing. None of these was free from COVID-19 suspicious symptoms. Source of infection was presumably professional in three of four individuals.

Conclusion

Our systematic analysis of SARS-CoV-2 infection in a cohort of health care workers in a large outpatient centre revealed an apparently low rate of 2.6% past SARS-CoV-2 infections. Relative risk for infection following health care profession cannot be derived as data about infection rates in the corresponding general population are lacking.