bluuebunny/crossref_metadata_2025 huggingface dataset:
Linguistic categories, language description and linguistic typology – An overview
Authors: Alfieri Luca , Arcodia Giorgio Francesco , Ramat Paolo
Published: December 2020

In this paper we propose a critical discussion of the rationale for this volume. After a short introduction (Section 1), an outline of the long-standing opposition between language particular description and universal grammar in the history of the language sciences is provided (Section 2). This opposition indeed represents the substrate on which our ‘comparative concepts debate’ is based: a summary of the debate, both in the form it had in the lingtyp mailing list (January / February 2016) and in the subsequent monographic issue of Linguistic Typology 2016, is offered in Section 3 and Section 4. Some critical consideration on the debate and on its relation with the various branches of linguistics are presented in Section 5. An overview of the papers included in the volume closes this introduction (Section 6).
Greater decrements in neuromuscular function following interval compared to continuous eccentric cycling
Authors: Green David James , Thomas Kevin , Howatson Glyn
Published: December 2020

Our aim was to determine the demands and consequences of a single session of continuous (CONT) or interval (INT) eccentric cycling. Fourteen healthy males performed ‘work‐matched’ CONT and INT eccentric cycling in a cross over design. Measures of maximal voluntary contraction (MVC), resting twitch force, voluntary activation (VA), muscle soreness and creatine kinase (CK) were taken at baseline, immediately post, and 24, 48 and 72 h post the first exercise bout. The second bout was used to characterise within session demands. Decreases in MVC (INT 19%, CONT 13%), twitch force (INT 31%, CONT 18%), and VA (INT 10%, CONT 6%) were observed immediately post session (p < 0.05). Reductions in twitch force were greater after INT (p < 0.05) and lasted 48 h. Muscle soreness was greater following INT, versus CONT (p < 0.05), although no differences in CK were observed. Metabolic demands (% of V̇O2peak and [BLa]) were greater during INT vs. CONT (32 ± 6% 28 ± 6%; p < 0.001), [BLa] (1.0 ± 0.4 vs. 0.8 ± 0.2 mmol·L−1; p < 0.001) and RPE (12 ± 1 vs. 11 ± 1; p < 0.001), respectively. Total time under tension was 48% greater in CONT compared to INT (p < 0.001), whereas average torque (during exercise) was 40% greater during INT compared to CONT (p < 0.001). Interval eccentric cycling exacerbates muscle soreness, decrements in muscle function and lengthens recovery compared to a work matched continuous bout, which is attributable to increased force rather than time under tension.
The NLRP3–inflammasome as a sensor of organelle dysfunction
Authors: Seoane Paula I. , Lee Bali , Hoyle Christopher , Yu Shi , Lopez-Castejon Gloria , Lowe Martin , Brough David
Published: December 2020

Diverse pathogen- and damage-associated stresses drive inflammation via activation of the multimolecular NLRP3–inflammasome complex. How the effects of diverse stimuli are integrated by the cell to regulate NLRP3 has been the subject of intense research, and yet an accepted unifying hypothesis for the control of NLRP3 remains elusive. Here, we review the literature on the effects of NLRP3-activating stimuli on subcellular organelles and conclude that a shared feature of NLRP3-activating stresses is an organelle dysfunction. In particular, we propose that the endosome may be more important than previously recognized as a signal-integrating hub for NLRP3 activation in response to many stimuli and may also link to the dysfunction of other organelles. In addition, NLRP3–inflammasome-activating stimuli trigger diverse posttranslational modifications of NLRP3 that are important in controlling its activation. Future research should focus on how organelles respond to specific NLRP3-activating stimuli, and how this relates to posttranslational modifications, to delineate the organellar control of NLRP3.
Propagation properties and radiation force of circular Airy Gaussian vortex beams in strongly nonlocal nonlinear medium*
Authors: Liu Xinyu , Sun Chao , Deng Dongmei
Published: December 2020

We study the abruptly autofocusing and autodefocusing properties of the circular Airy Gaussian vortex (CAiGV) beams in strongly nonlocal nonlinear medium for the first time through numerical simulations. The magnitude of topological charges and the position of the vortex could change not only the light spot pattern but also the intensity contrast. Meanwhile, we can change the position of the autofocusing and autodefocusing planes by changing the parameter of the incident beam. Furthermore, we can control the peak intensity contrast through choosing properly the truncation factor. As for the radiation force, we study the gradient and the scattering forces of CAiGV beams on Rayleigh dielectric sphere. Our analyses demonstrate that the radiation force can be enhanced by choosing proper parameters of CAiGV beams.
Phase transition of asymmetric diblock copolymer induced by nanorods of different properties*
Authors: Guo Yu-Qi
Published: December 2020

We investigate the microphase transition of asymmetric diblock copolymer induced by nanorods of different properties using cell dynamics simulation and Brown dynamics. The results show the phase diagram and representative nanostructures of the diblock copolymer nanocomposite. Various structures such as sea-island structure (SI), sea-island and lamellar structure (SI-L), and lamellar structure (L) are observed in the phase diagram. The system undergoes phase transition from SI-L to SI or from L to SI with increasing length of A-like sites for all numbers of nanorods except 10 and 300, and from SI to L with increasing number of nanorods for all lengths of A-like sites. Notably, the polymer system transforms from a tilted layered structure to a parallel lamellar, perpendicular lamellar, and subsequently sea-island structure with increasing length of A-like sites for a rod number of 240. To gain more detailed insight into these structural formation mechanisms, we analyze the evolution kinetics of the system with various lengths of A-like sites of the rods. The pattern evolution and domain growth of the ordered parallel/perpendicular lamellar structure are also investigated. Furthermore, the effects of the wetting strength, rod-rod interaction, polymerization degree, and length of nanorods on the self-assembled structure of asymmetric diblock copolymer/nanorods are studied. Our simulations provide theoretical guidance on the construction of complex-assembled structures and the design of novel functional materials.
Influence of an inserted bar on the flow regimes in the hopper*
Authors: Peng Yi , Zhang Sheng , Wang Mengke , Yang Guanghui , Wan Jiangfeng , Chen Liangwen , Yang Lei
Published: December 2020

We investigated the influence of an inserted bar on the hopper flow experimentally. Three geometrical parameters, size of upper outlet D
1, size of lower outlet D
0, and the height of bar H, are variables here. With varying H we found three regimes: one transition from clogging to a surface flow and another transition from a surface flow to a dense flow. For the dense flow, the flow rate follows Beverloo’s law and there is a saturation of inclination of free surface θ. We plotted the velocity field and there is a uniform linear relation between the particle velocity and depth from the free surface. We also found that the required value of D
1 to guarantee the connectivity of flow is little smaller than D
0. For the transition from a surface flow to a dense flow, there is a jump of flow rate and the minimum θ for flowing is two degrees larger than the repose angle.
Exact solution of the Gaudin model with Dzyaloshinsky–Moriya and Kaplan–Shekhtman–Entin–Wohlman–Aharony interactions*
Authors: Wen Fa-Kai , Zhang Xin
Published: December 2020

We study the exact solution of the Gaudin model with Dzyaloshinsky–Moriya and Kaplan–Shekhtman–Entin–Wohlman–Aharony interactions. The energy and Bethe ansatz equations of the Gaudin model can be obtained via the off-diagonal Bethe ansatz method. Based on the off-diagonal Bethe ansatz solutions, we construct the Bethe states of the inhomogeneous XXX Heisenberg spin chain with the generic open boundaries. By taking a quasi-classical limit, we give explicit closed-form expression of the Bethe states of the Gaudin model. From the numerical simulations for the small-size system, it is shown that some Bethe roots go to infinity when the Gaudin model recovers the U(1) symmetry. Furthermore, it is found that the contribution of those Bethe roots to the Bethe states is a nonzero constant. This fact enables us to recover the Bethe states of the Gaudin model with the U(1) symmetry. These results provide a basis for the further study of the thermodynamic limit, correlation functions, and quantum dynamics of the Gaudin model.
Novel Si/SiC heterojunction lateral double-diffused metal–oxide semiconductor field-effect transistor with p-type buried layer breaking silicon limit*
Authors: Duan Baoxing , Huang Xin , Song Haitao , Wang Yandong , Yang Yintang
Published: December 2020

A novel silicon carbide (SiC) on silicon (Si) heterojunction lateral double-diffused metal–oxide semiconductor field-effect transistor with p-type buried layer (PBL Si/SiC LDMOS) is proposed in this paper for the first time. The heterojunction has breakdown point transfer (BPT) characteristics, and the BPT terminal technology is used to increase the breakdown voltage (BV) of Si/SiC LDMOS with the deep drain region. In order to further optimize the surface lateral electric field distribution of Si/SiC LDMOS with the deep drain region, the p-type buried layer is introduced in PBL Si/SiC LDMOS. The vertical electric field is optimized by Si/SiC heterojunction and the surface lateral electric field is optimized by the p-type buried layer, which greatly improves the BV of device and alleviates the relationship between BV and specific on-resistance (R
on,sp). Through TCAD simulation, when the drift region length is 20 μm, the BV is significantly improved from 249 V for the conventional Si LDMOS to 440 V for PBL Si/SiC LDMOS, increased by 77%; And the BV is improved from 384 V for Si/SiC LDMOS with the deep drain region to 440 V for the proposed structure, increased by 15%. The figure-of-merit (FOM) of the Si/SiC LDMOS with the deep drain region and PBL Si/SiC LDMOS are 4.26 MW/cm2 and 6.37 MW/cm2, respectively. For the PBL Si/SiC LDMOS with the drift length of 20 μm, the maximum FOM is 6.86 MW/cm2. The PBL Si/SiC LDMOS breaks conventional silicon limit.
Dynamics analysis in a tumor-immune system with chemotherapy*
Authors: Liu Hai-Ying , Yang Hong-Li , Yang Lian-Gui
Published: December 2020

An ordinary differential equation (ODE) model of tumor growth with the effect of tumor-immune interaction and chemotherapeutic drug is presented and studied. By analyzing the existence and stability of equilibrium points, the dynamic behavior of the system is discussed elaborately. The chaotic dynamics can be obtained in our model by equilibria analysis, which show the existence of chaos by calculating the Lyapunov exponents and the Lyapunov dimension of the system. Moreover, the action of the infusion rate of the chemotherapeutic drug on the resulting dynamics is investigated, which suggests that the application of chemotherapeutic drug can effectively control tumor growth. However, in the case of high-dose chemotherapeutic drug, chemotherapy-induced effector immune cells damage seriously, which may cause treatment failure.
Investigation of cavitation bubble collapse in hydrophobic concave using the pseudopotential multi-relaxation-time lattice Boltzmann method*
Authors: Shan Minglei , Yang Yu , Zhao Xuemeng , Han Qingbang , Yao Cheng
Published: December 2020

The interaction between cavitation bubble and solid surface is a fundamental topic which is deeply concerned for the utilization or avoidance of cavitation effect. The complexity of this topic is that the cavitation bubble collapse includes many extreme physical phenomena and variability of different solid surface properties. In the present work, the cavitation bubble collapse in hydrophobic concave is studied using the pseudopotential multi-relaxation-time lattice Boltzmann model (MRT-LB). The model is modified by involving the piecewise linear equation of state and improved forcing scheme. The fluid–solid interaction in the model is employed to adjust the wettability of solid surface. Moreover, the validity of the model is verified by comparison with experimental results and grid-independence verification. Finally, the cavitation bubble collapse in a hydrophobic concave is studied by investigating density field, pressure field, collapse time, and jet velocity. The superimposed effect of the surface hydrophobicity and concave geometry is analyzed and explained in the framework of the pseudopotential LBM. The study shows that the hydrophobic concave can enhance cavitation effect by decreasing cavitation threshold, accelerating collapse and increasing jet velocity.
“Surface-line-point”—analysis of the development of artificial intelligence in the Yangtze River Delta
Authors: Liang Yao , Hu Yuewei
Published: December 2020

Artificial intelligence technology is booming all over the world, profoundly affecting the social and economic development model and people’s lifestyle. The Yangtze River Delta urban agglomeration, which has a very high strategic position in the country’s modernization and comprehensive opening up, is an important support for China’s participation in international competition and a gathering place for China’s cutting-edge technology. The Yangtze River Delta has become the leader of my country’s artificial intelligence technology and industry by virtue of its advantageous geographical location, active economic development, high-density talent pool and years of development and accumulation in the field of artificial intelligence. From “surface-line-point”, the article analyzes the advantages and disadvantages of the rapid development of artificial intelligence in the Yangtze River Delta; combines the education industry to analyze the integration of artificial intelligence and education and possible bottlenecks; conforms to the trend of the times and shows the new Internet celebrities of programming world—python.
The Application Research of Artificial Intelligence and Big Data Analysis Technology in University Foreign Language Teaching
Authors: Zhang Xinyan
Published: December 2020

In recent years, with the development of computer linguistics and artificial intelligence technology in the field of English education, the research methods and technical means of artificial intelligence big data analysis have been introduced into the research and practice of foreign language teaching. As a new element, artificial intelligence big data analysis provides a new approach and research perspective for foreign language teaching. In order to solve the problems of foreign language teaching resources sharing, optimizing teaching resources, improve the efficiency of foreign language topic teaching, and improving the interaction between teachers and students, based on the theoretical and practical research of foreign language teaching in colleges and universities, this paper uses artificial intelligence and big data technology, firstly classifies the artificial intelligence system of foreign language teaching in colleges and universities, secondly, it classifies the information technology of artificial intelligence in high school. The ability of information storage and information processing in college foreign language teaching is analyzed theoretically in computer language. The software and hardware design of the artificial intelligence information integrated system of college foreign language teaching is carried out. The results show that: relying on the design of the storage module and system server, the hardware design of the system is realized, and the software design of the system is realized based on the system running environment design and database design. Finally, the paper puts forward the countermeasures and suggestions for the development of AI in foreign language teaching.
Research on classification of spiral galaxies and stars based on convolutional neural network
Authors: Xu Zhaoyan , Hu Tao , Peng Zhongqi
Published: December 2020

In astronomy, the shape of galaxies can often reflect the course of its evolution, and can further reveal the development law of the universe. With the progress and development of observation technology, image data has grown explosively, and the efficiency of traditional manual astronomical image classification is far from enough. Image classification based on machine learning effectively solves the problem of low efficiency of artificial classification, but in the face of massive data sets, the classification effect of traditional machine learning is often not as good as deep learning. In this paper, relevant concepts based on neural network image classification algorithm are introduced. Then, according to the characteristics of the mainstream CNN (convolutional neural network) model, the design and optimization of the custom RS CNN model are completed. Finally, the custom RS CNN is used to conduct classification experiments on spiral galaxies and stars.
Hardware Trojan detection research based on MLP
Authors: Ding Qiao , Yin Shizhuang , Liu Lijun , Wang Chao
Published: December 2020

In view of the variety of Hardware Trojan (HT) and the difficulty of obtaining unknown Trojan characteristics in side-channel signals by conventional methods. In this paper, MLP was selected to establish the network model by means of supervised learning, the method took supervised learning ways to build neural network model for feature extraction and discrimination of side channel information. A verification system was set up based on FPGA to obtain side-channel information. The results show that the detection rate of the MLP is more than 1% higher than that of the traditional support vector machine (SVM) method when detecting the hardware Trojan horse with the parent circuit area of 2%.
Bert-based Siamese Network for Semantic Similarity
Authors: Feifei Xu , Shuting Zheng , Yu Tian
Published: December 2020

As a key technology in the field of natural language processing, text matching is widely used in many tasks such as question answering systems, search, recommendation, and advertising. Aiming at the insufficient feature extraction capabilities of traditional Siamese-based text matching methods, a fast matching method based on large-scale pre-training model BSSM (BERT based Siamese Semantic Model) is proposed. The proposed method uses a pre-training model to encode two texts separately, which interact the representation vectors of the two texts to obtain attention weights and generate new representation vectors, so that the new and old representation vectors can be pooled and aggregated, and finally two representation vectors are concatenated in some strategy and sent to the prediction layer for prediction. Experimental results on the AFQMC and LCQMC datasets show that the proposed method not only improves the accuracy rate, but also improves the computational efficiency.
Explore the development direction of mobile communication network optimization
Authors: Feng Yuan
Published: December 2020

Based on the purpose of promoting the better development of mobile communication network, this paper makes a simple discussion on this topic, puts forward optimization methods and technologies, and looks forward to the future development direction. First of all, the development status of mobile communication network is analyzed. Secondly, taking mobile communication 4G network as an example, the key technologies and methods of network optimization are discussed. Finally, combined with the development of mobile communication network, the development direction of network optimization is prospected. People’s requirements for mobile communication network services are constantly improving, and the exploration of network optimization is always on-going. We should focus on the modernization of mobile communication network.
CNN-based Image Recognition and Processing Technology Development of Airborne Display and Control System
Authors: He Jinsong , Li Xiaojun , Xiao Jia
Published: December 2020

The test system is designed for the MDU unit of the airborne display and control subsystem, and the test software is developed based on LabVIEW. The CNN image recognition and processing technology is used to realize the image recognition and test functions of the MDU unit. The image data collection system collects 8 channels of analog signals, converts the data collected in each channel, and then outputs the whole image, so as to obtain a complete frame of image information, combined with the threshold shrinkage and the two coefficients of noise pollution by judging the degree of noise pollution image noise reduction processing, image text recognition processing based on CNN and image CNN model training. Experimental results show that the test system can successfully realize the functions of recognition, analysis, detection and processing of displayed images.
Performance analysis of data fusion schemes in cooperative spectrum sensing for cognitive radio networks
Authors: Chen Gaoyu , Wang Haijun , Wan Runze
Published: December 2020

In the actual communication environment, the accuracy of spectrum detection is easily affected by the uncertainty factors such as multipath fading, shadow effect, hidden terminal, channel signal-to-noise ratio, and noise variance fluctuation. Cooperative spectrum sensing technology makes full use of the spatial gain generated by sensor nodes in different geographical locations, and obtains more accurate combination decision results than single node decision. In cooperative sensing, fusion center (FC) will analyze and process the collected local detection statistics or sensing results according to a certain data fusion rule, and make the final decision on the current channel state according to the fusion results. Data fusion strategy plays an important role in perception results and system reliability. In this paper, we summarize several conventional data fusion schemes in cooperative spectrum sensing for cognitive radio networks and conduct performance analysis.
Optimization communication for BFS based on 1D-partition
Authors: Liu Chengyao
Published: December 2020

Parallel Breadth First Search (BFS) is a famous algorithm in Graph500, a benchmark function for evaluating data-intensive applications on supercomputers. For parallel breadth first search (BFS) algorithms on large-scale distributed memory systems, the cost of communication is usually much higher than the arithmetic cost, which limits the scalability of the algorithm. However, the specific communication model of Graph500 brings challenges to computing in large-scale graphs. First, we use an adjustment method to delete redundant data in messages. Second, a data compression method was used to further reduce comm-unication. Evaluation results show that the performance of this method is more efficient than graph500 benchmark.
Research on the Scenario-based Development Strategy of Live Broadcast in the Era of Mobile Internet
Authors: Guo Wei , Zhang Bo
Published: December 2020

Based on the change of information transmission form and interactive mode, this paper will introduce the concept of scene-based precise communication in the network live broadcast Based on the analysis of the current situation of the network live broadcast platform, this paper focuses on the construction of the network live broadcast scene from the aspects of technology, content and users The ultimate goal of scene analysis is to understand the logic and habits of users’ behavior, and to better serve the audience.
Application of PLC technology in electrical automatic control
Authors: Zhipeng Lin , Xuejiao Lv , Jiwei Ma
Published: December 2020

at present, the development of electrical engineering automation has been very mature, in which the progress and breakthrough of PLC technology is very significant, and its value and role in electrical automation control are becoming more and more critical. In this paper, the application of PLC technology in electrical automatic control is further explored, and the application of PLC technology in electrical automatic control is analyzed in detail.
Modeling and simulation of three-phase 6/4 switched reluctance motor speed control system
Authors: Bian Huihui , Chen Hua , Wang Ronghua
Published: December 2020

To improve the response ability of the motor and reduce the torque ripple, we take the three-phase 6/4 SRM as the research object, according to the structure and characteristics of the SRM speed control system, the SRM speed and current double closed-loop control system are established and the current chopping control mode is adopted to change the motor speed. According to the mathematical model of SRM, then the model of each module of the speed control system is established by Matlab/Simulink. The simulation and performance analysis are carried out. The results show that the simulation model double closed loop control method can improve the system response ability, improve the stability of the motor and reduce the torque ripple.
Design of temperature control system for infant radiant warmer based on Kalman filter-fuzzy PID
Authors: Jin Aiguo , Wu Haixiao , Zhu Haosheng , Hua Hua , Hu Yanhai
Published: December 2020

In order to improve the dynamic and static performance of the temperature control system of the baby radiant warmer, a Kalman filter-fuzzy PID (KFPID)algorithm is proposed on the basis of the ordinary incremental PID control algorithm. The system uses STM32 as the main controller. The temperature data is collected by the TLV2548 analog-to-digital conversion chip, and the feedback data is filtered by Kalman filter, and the bed surface of the warming table is controlled by the fuzzy PID control algorithm. After the simulation of Matlab, it can be seen that compared with the traditional PID temperature control algorithm, the KFPID algorithm has the characteristics of short adjustment time and almost zero overshoot, and the steady-state error is smaller when dealing with the same interference noise.
Design of Frequency Reconfigurable Antenna for WLAN/Bluetooth/WiMAX
Authors: Liu Guijie , Cao Liping , Wang Liang , Liu Xiaoni , Du Fengjuan , Li Yuanyuan , Liu Yali , Sun Xubao
Published: December 2020

A reconfigurable frequency antenna which can be switched in two frequency bands is designed. The antenna is composed of a rectangular patch, a diode switch and a rectangular ground plate, and the size is 30×30×1.6mm3. The antenna changes the length of the branch through the diode switch to achieve the antenna model conversion. Simulation results show that the antenna S11<-10dB in the two frequency bands of 2.32∼2.60GHz and 3.27∼3.60GHz, covering WLAN (2.4∼2.48GHz), Bluetooth (2.4∼2.483GHz) and WiMAX (3.4∼3.6 GHz) communication frequency bands.
Design simulation and analysis of deep-sea transducer
Authors: Su Wei , Yu Yanting , Zhang Chao , Sun Yang , Gong Jinlong
Published: December 2020

Aiming at the design limitations of current deep-sea transducers, this paper designs and manufactures a deep-sea transducer based on the theoretical analysis of the characteristics of the piezo ring. This transducer is potted and vulcanized into a solid structure with sound-permeable rubber. As a result, not only the deep water pressure resistance is achieved, but also the operating frequency range is broadened by the high-low order coupling vibration between the piezo ring and the sound-permeable rubber. The influences of the main parameters on the electroacoustic characteristics of the transducer are analyzed in detail by FEM. Prototypes are developed subsequently. The measured results show that the simulation and measured results have high consistency. The maximum working depth of the transducer can reach 10000 m, and the beam direction is omnidirectional in the upper hemisphere. In the frequency range of 7∼20 kHz, the transmitter voltage response is higher than 120dB, and the receiver sensitivity is greater than -200dB. This research indicates that the transducer has excellent deep-water characteristic and transmit-receive performance.
Advances in industrial robots programming applying gestural guidance techniques
Authors: Padilla A F , Peña C A , Moreno-Contreras G G
Published: December 2020

In this article, artificial vision is presented as an application for the generation of trajectories through the capture of an operator’s movements using a structured light camera (Kinect) and applying a recognition algorithm to the body’s joints, a three-dimensional representation is made of the skeleton, taking as points of interest the articulation of the left hand to generate the gestural commands and the right hand to indicate the path that the robot must execute. Simulation results are obtained through a development environment where the kinematic model of the robot is incorporated, this indicates that it is possible to generate a trajectory through the human body using artificial vision.
Analysis of the intensity of electromagnetic radiation for the estimation of vegetation cover
Authors: Pelaez D A , Gualdron O E , Castellanos L
Published: December 2020

The remote monitoring of electromagnetic radiation allows to differentiate the behavior of five different wavelengths that are shown as images in their respective visible and non-visible light spectral, these are subjected to a processing in which it is calculated for each pixel using the red band and near infrared the normalized difference vegetation index, with which a multispectral orthophoto mosaic is generated which is later analyzed with the objective of estimate the quantity and quality of vegetation of 15 hectares of different properties in the municipality of Tuta in the department of Boyacá, Colombia, that they possess with a high productive potential and in which the process of information acquisition was carried out before and after proceeding with the implementation of crops with a previous agroecological model, Later, a statistical analysis was carried out using polynomial trend models, and this remote inspection system identified that the behavior of radiation intensities at different wavelengths is associated with variable vegetation densities and, indirectly, with the presence of water stress and the quality of the shrubs and plants.
Computer sciences applied to the sustainability of projects
Authors: Velásquez-Pérez T , Castro-Silva H F , Quijano-Brand L F
Published: December 2020

Computer science incorporates information theory that is a fundamental element in project management. Achieving the conservation of the current resources for future generations has become an increasingly important and urgent challenge for our society. Thus, the sustainability topic becomes more valid on the agenda of governments and organizations. This cross-section empirical study presents partial results of the perception of a representative sample of engineering project managers in Colombia about the implementation of sustainability elements in the management of these projects, established in the sustainable project management maturity model. The results applying information science, indicate a greater orientation towards the aspects of product sustainability than the project process and in general that in the studied context, the economic dimension significantly predominates over social and environmental aspects.
Development of a three-bladed horizontal axis wind turbine with active control by using a programmable logic controller
Authors: Barrera J , Durán C
Published: December 2020

For the increasing the physical efficiency, useful life and avoid accidents in wind turbines, it is very useful to implement a pitch control on the blades that help as an aerodynamic brake and orientation in the base to follow the wind direction. The main goal of this paper was to develop a digital controller on the wind turbine blades that allows to keep the constant angular velocity and monitor the orientation of the wind. A computer-aided design software was developed for allowing the aerodynamic analysis by using Solid Works® software based on a flow simulation tool. On the other hand, a MATLAB model was created employing Simulink tool and the Simscape toolbox with typical data from a 2MW wind turbine whereas the electrical and mechanical dynamics and control feedback were calculated having as input parameters the wind direction and speed. Consequently, a prototype was designed in 3D which was implemented to make the different tests. For lab experimentation, a fuzzy control algorithm was developed in structured control language and then implemented using the S7-1200 PLC. The trials with programmable logic controller and the fuzzy algorithm were satisfactory, which could be a basis for the optimization of the performance of a three-bladed horizontal axis wind turbine.
Novel integrated agricultural land management approach provides sustainable biomass feedstocks for bioplastics and supports the UK’s ‘net-zero’ target
Authors: Ni Yuanzhi , Richter Goetz M , Mwabonje Onesmus N , Qi Aiming , Patel Martin K , Woods Jeremy
Published: December 2020

We investigate the potential in producing biodegradable bio-plastics to support the emergent ‘net-zero’ greenhouse gas (GHG) emissions targets in the UK. A ‘cradle to grave’ life cycle assessment was developed to evaluate GHG mitigation potentials of bio-based polybutylene succinate plastics produced from wheat straw-only (single feedstock) or wheat straw plus Miscanthus (mixed feedstocks) agricultural supply systems. For scenarios using mixed feedstocks, significant carbon mitigation potentials were identified at catchment and national levels (emission reduction of 30 kg CO2eq kg−1 plastic compared to petroleum-based alternatives), making the system studied a significant net carbon sink at marginal GHG abatement costs of £0.5–14.9 t−1 CO2eq. We show that an effective ‘net-zero’ transition of the UK’s agricultural sector needs spatially explicit, diversified and integrated cropping strategies. Such integration of perennial bio-materials into food production systems can unlock cost-effective terrestrial carbon sequestration. Research & Development and scale-up will lower costs helping deliver a sustainable bioeconomy and transition to ‘net-zero’.
Residential environments across Denmark have become both denser and greener over 20 years
Authors: Samuelsson Karl , Chen Tzu-Hsin Karen , Antonsen Sussie , Brandt S Anders , Sabel Clive , Barthel Stephan
Published: December 2020

Despite much attention in the literature, knowledge about the dynamics surrounding urban densification and urban greening is still in dire need for architects, urban planners and scientists that strive to design, develop, and regenerate sustainable and resilient urban environments. Here, we investigate countrywide patterns of changes in residential density and residential nature at high spatial resolution over a time period of >20 years (1995–2016), combining a dataset of address-level population data covering all of Denmark (>2 million address points) with satellite image-derived normalised difference vegetation index (NDVI) data. Our results show that many residential environments across Denmark have witnessed simultaneous densification and greening since the mid-1990s. In fact, the most common change within 500 m neighbourhoods around individual address points is of joint increases in population and NDVI (28%), followed by increasing NDVI with stable population figures (21%). In contrast, only 8% of neighbourhoods around address points have seen a decline in either population or NDVI. Results were similar in low- middle- and high-density environments, suggesting that trends were driven by climate change but also to some degree enabled by urban planning policies that seek to increase rather than decrease nature in the cities.
Heat treatment effect on structural and elastic characteristics of a single-component abrasive tool
Authors: Polyanchikova M Yu , Nosenko V A , Kozhevnikova A A
Published: December 2020

The article presents the results of a research of elastic properties of a bondless single-component abrasive tool (SCAT) after sintering. The method of determining the modulus of elongation and porosity based on theoretical and experimental data is used. The dependency between the modulus of elongation and porosity, as well as experimental formulas indicating these dependencies, are presented. Based on the experimental and calculated data on the magnitude of the modulus of elongation, depending on the sintering temperature and the size of the abrasive grains in the initial abrasive compound, empirical dependencies of the elastic characteristics are determined in order to predict the production of a bondless tool with predetermined properties.
Unbalances formation of the textured wheel at preparation to grinding process
Authors: Gusev Vladimir
Published: December 2020

The entrance factors of grinding processes of materials, affecting dynamic activity of a technological system, define exit indicators of processes: operation productivity, geometrical and physic-mechanical indicators of quality of the processed blanket, etc. One of such dominating factors is unbalance of quickly rotating grinding wheel, which role continuously increases in connection with a current trend of increase of cutting speed. Formation of the main vector of unbalances of the textured grinding wheel during his preparation to work is analysed. The mathematical model of unbalances, caused by errors of production of abrasive cutting elements, their assembly with the metal case, installation of the tool on a spindle, and also by uneven removal of abrasive material in the course of its first editing, is developed. On the basis of the established mathematical model the numerical values of unbalances of the textured grinding tool are defined and the recommendations, providing values of the main vector of the imbalances, regulated by the standard, are developed. The results of researches are necessary for high-quality design of the textured grinding wheels, intended for grinding of responsible surfaces.
Efficiency of the continuous editing process grinding circles
Authors: Salova D P , Denisenko A F , Salov P M , Grishin R G
Published: December 2020

Conducted experimental studies have shown the high efficiency of using continuous dressing and its varieties - cleaning during grinding. The conditions that ensure the minimum wear of the ruling and working circles for various processing conditions are determined. It is established that the minimum wear of the circles takes place at a relative speed of the working and ruling circles, close to zero. At the same time, the productivity of the dressing process and the processing efficiency are practically not reduced. It is shown that the greatest efficiency of continuous dressing takes place when grinding materials that are prone to adhesive setting with the components of the abrasive wheel. Recommendations are given on choosing the ligament and firmness of the ruling circles. The mechanisms of wear of the circles at various slip coefficients are established. Ensuring the angle of intersection between the circles, as a rule, increases the efficiency of the process, in addition, reduces vibration in the editing system. An increase in the angle of crossing over 10° increases the wear of the circles. The use of continuous cleaning reduces wear on the working circle and does not distort its macro profile. It was found that the ruling circles with an abrasive, which was created using the technology of self-propagating high-temperature synthesis (SHS), have greater wear resistance than circles of a similar characteristic from elbor, but inferior to diamond.
Mathematical model of allowance removal at nonabrasive processing of bearing details
Authors: Reshetnikov M K , Davidenko O Y , Shpilev V V , Zakharchenko M Y
Published: December 2020

To increase the durability of the bearing, it is necessary to achieve a profile shape of the groove of the bearing close to that obtained during running-in. This effect allows you to achieve a method of non-abrasive tuning of the raceways of the rings of roller bearings. To study the effectiveness of this method, it is necessary at the initial stage to build a mathematical model of metal removal from the treated surface. To derive the mathematical model, we used the energy theory of friction, the theory of elasticity, and the physical theory of similarity. After the conclusion of the model, you can see which factors have the greatest impact on the efficiency of the process of non-abrasive tuning of the raceways of the roller bearing rings.
Numerical simulation of turning contact temperatures with varying material yield strength and tool wear
Authors: Unyanin A N , Finageev P R
Published: December 2020

The results of numerical simulation the main component of cutting forces and temperatures at the contact zones of the face of the cutter with chip and flank with the workpiece depending on the tool wear and physico-mechanical properties of the workpiece material. The values of fluctuations in the cutting force and contact temperatures are determined depending on the variation of the stress yield of the workpiece material during machining of the workpieces material when processing workpieces made of steel 45 and steel 12KH18N10T are established. The degree of influence of tool wear on the flank on cutting forces and contact temperatures is determined.
Unified approach to developing analytical models of different grinding processes based on basic cutting process model
Authors: Akintseva A V , Pereverzev P P , Prokhorov A V , Kononov S N
Published: December 2020

The appearance of modern CNC grinding machines allowed concentrating multipass and multistage processing of different workpiece surfaces by means of using different grinding types and different tool types. Meanwhile, the processing of different surfaces is carried out with different allowances and accuracy requirements and performed according to the specified stepwise cycles of the feeds control. As a result, there is a difficult task of quick and reliable calculation of the optimal feed cycles and other cutting modes for different types of processing of different surfaces with various grinding conditions. The solution to this problem is developing of mathematical models that link processing accuracy with cutting modes and other technological conditions of the processing. The development of such models should begin with the creation of a complex of the cutting forces` models for each grinding type. This article describes a method for deriving generalized analytical model of the cutting force for the different grinding types which is based on the functional interrelation between the intensity of the metal removal performed by the wheel and elementary volumes of metal deformable in the shear zone. The complex of the cutting forces models for different grinding types, obtained by means of using this technique, establishes functional interrelation of the cutting force with cutting modes, strength properties of the treated material, kinematics of the grinding process, geometry of the cutting zone, characteristics and geometric parameters of the grinding wheel, etc. It should also be noted that the developed models cover the majority of production conditions and they are wide-range in terms of the main technological parameters (dimensions of the treated surfaces, allowances, tolerance grades, etc.).
Development of a control system for large-sized products to improve product quality in mechanical engineering
Authors: Sinitsa M O , Komshin A S
Published: December 2020

The paper considers the problems of monitoring the metrological support of overall parts in mechanical engineering. The decision to implement the control of large products such as ship’s shaft. In addition, an algorithm for analyzing control results using the Matlab program to assess the state of the object of study is proposing.
Development of the algorithm for modelling autoclave curing conditions and calculation of temperature fields into elements of sandwich structures
Authors: Morozov B B , Nasonov F A , Bukharov S V
Published: December 2020

To study the distribution of temperature fields into a large-sized combined parts, it is necessary to devote a great attention for all the design features. A specimen for investigation the “behavior” of the material in different zones of a typical PCM panel must simultaneously contain both a monolithic and sandwich part of the structure.
Profiles’ classifier of hot-rolled rolling
Authors: Belskiy S M , Pimenov V A , Shkarin A N
Published: December 2020

The geometric parameters describing the features of the cross-sectional profile of the hot-rolled strips do not give a complete picture of the flatness acquired by the cold-rolled strips rolled from these strips. An additional analysis showed that there are four characteristic classes of cross-sectional profiles of hot rolled strips that have a significant effect on the shape of the strips during cold rolling, three of which negatively affect the flatness of the cold rolled strips. The cross-sectional profiles of hot-rolled strips with a concave middle part and (or) marginal thickenings lead to the appearance of edge waviness, peak-like cross-sectional profiles cause central warping. Therefore, the actual task is to determine the factual shape of cross-sectional profile. Sixth order polynomials were used to digitalize and parameterize hot-rolled profile. As a result, we developed analytic function of the transverse profile, which keeps important information about its near-edge areas and features in the middle part. To assign a specific cross-sectional profile of a hot-rolled strip to one of four characteristic classes of cross-sections, mathematical software was developed, called a classifier, and implemented with the programming environment R. To classify the profiles of the hot-rolled cross-section according to characteristic classes, a linear discriminant method was used as a machine learning method analysis. The result is an adequate mathematical model for recognizing the shape of the cross-sectional profile.
Tool Performance Under Ultrasonic Reaming
Authors: Agapov S I , Sidyakin Y I , Olshtynsky S N
Published: December 2020

The widespread adoption of ultrasonic processing methods was hindered by the lack of reliable ultrasonic heads. Currently, in connection with the widespread production of piezoceramic transducers of various shapes and sizes, it has become possible to abandon bulky magnetostrictive transducers requiring individual cooling. The creation of light piezoceramic heads and their implementation in production is associated with targeted comprehensive studies to determine the magnitude and direction of ultrasonic vibrations, the influence of technological factors on the surface roughness and accuracy of the obtained holes. This processing method is especially important in aircraft engine building, where the issue of obtaining quality holes is particularly acute. Difficulties in the processing of holes by reaming are associated with the low machinability of the used steels and alloys in aircraft engine construction. The cutting edges wear out at the intersection of the intake cone and the calibrating part the more intensively, the higher the processing conditions. The process of holes reaming is one of the most difficult and critical stages of machining, on which the quality and the final result of the machined parts depend. This paper describes the experiment and gives experimental data on the influence of the magnitude and direction of ultrasonic vibrations on the resistance of a cutting tool, as well as the effect of wear on surface roughness and accuracy of machined holes. The research has established a significant advantage of ultrasonic reaming in terms of surface roughness, the accuracy of holes, and the resistance of the cutting tool in workpieces made of difficult-to-process materials.