bluuebunny/crossref_metadata_2025 huggingface dataset:
Hyperuniformity in cyclically driven glasses
Authors: Mitra Saheli , Parmar Anshul D S , Leishangthem Premkumar , Sastry Srikanth , Foffi Giuseppe
Published: March 2021

We present a numerical investigation of the density fluctuations in a model glass under cyclic shear deformation conditions. We demonstrate that in our model glass, the compressibility is suppressed in inherently minimally energetic structures, showing a hyperuniform trend at a density which is below the critical jamming density. At low shear amplitudes, i.e. below the yield amplitude, the system reaches an absorbent steady state in which density fluctuations are suppressed, revealing the clear fingerprint of hyperuniformity up to a finite length scale. The opposite scenario is observed above the yield amplitude, where density fluctuations are strongly enhanced. We demonstrate that the transition to this state is accompanied by a spatial phase separation into two distinct hyperuniform regions, as a consequence of shear band formation at amplitudes greater than the yield amplitude.
A Real-time Pothole Detection Based on Deep Learning Approach
Authors: Yik Yeoh Keng , Alias Nurul Ezaila , Yusof Yusmeeraz , Isaak Suhaila
Published: March 2021

Today, the number of vehicles using the road including highways and single carriage way is increasing. road structure safety monitoring system that is safe for road users and also important to ensure long-term vehicle safety and prevent accidents due to road damage such as potholes, landslides and uneven roads. Most news reports of road accidents are also caused by potholes that are almost 10-30 cm deep, coupled with heavy rainfall that reduces visibility among drivers, significant damage to the suspension system to the vehicle or unnecessary traffic congestion. In this paper, deep learning detection with YOLOv3 algorithm is proposed apart from researches ranging from accelerometer detection, image processing or machine learning based detection as it is easier to develop and provide more accurate results. After pothole has been detected in real-time webcam, the location will be logged and displayed using Google Maps API for visualization. a total of 330 sets of data were sampled for the implementation of the pothole detection training model. As the results, the model provided 65.05 mAP and 0.9 % precision rate and 0.41 recall rate. The limitation of YOLOv3 algorithm detection can be improve further using GPU with higher specification performances and can sample 1000 to 10,000 datasets. The proposed algorithm provides acceptably high precision and efficient pothole monitoring solution under different scenarios for the users and may benefit the public and the government to monitor pothole in real-time.
Progressive low/high-resolution Space Attention Fusion Network for Single Image Super-Resolution
Authors: Zhong Chengzu , Zhou Yue
Published: March 2021

The general single image super-resolution methods mainly extract features from the high-resolution (HR) space by the pre-upscaling step at the beginning of the network or from the low-resolution (LR) space before the post-upscaling step at the end of the network. The former way requires high computation as well as misleading the network by wrong artificial priors. The latter way cannot learn mapping well by only conducting simple operations in HR space. In this paper, we aim to utilize the features from LR and HR space more efficiently and propose the novel network, which applies a frequency-slicing mechanism to divide features into LR and HR space, a direction-aware fusion residual group to extract distinctive features in LR space and an attention fusion module to recalibrate features in HR space. The experimental results demonstrate that our model is superior to the state-of-the-art methods upon quantitative metrics and visual quality.
A Document Image Dataset for Quality Assessment
Authors: Li Zhenghao , Yang Cihui , Shen Qingyun , Wen Shiping
Published: March 2021

Mobile device plays an very important role in capturing document image. However, the quality of the captured image is influenced by many factors, such as device quality and shooting conditions. In this context, it is necessary to automatically assess the quality of captured document image. Although there has a lot of work in the filed of image quality assessment (IQA), insufficient attention has been paid to the establishment of document images dataset. Thus, we propose a large dataset of document images containing 19,943 images which are collected by mobile devices. During the process of image acquisition, many factors such as light intensity, distortion type, document material are considered. After capturing images, multiple volunteers participated in the evaluation and collection of Mean Opinion Score (MOS) of the document images. We use two no-reference image quality assessment algorithms to test the proposed dataset. The experimental results show the validity of our dataset and the reliability of MOS. The proposed dataset can be used in the field of image quality assessment and Optical Character Recognition.
Fast Semantic Segmentation Model PULNet and Lawn Boundary Detection Method
Authors: Li Xiaoxia , Chen Jingjing , Ye Yuanzheng , Wang Shunli , Wang Xueyuan
Published: March 2021

To quickly and accurately identify the lawn area and boundary positions of different scenes, environments, and seasons, we propose a new semantic segmentation model PULNet and lawn boundary detection methods. Firstly, the ResNet50 network is improved to expand its effective receptive field, a Pooling pyramid (P) and an Upsampling dimensionality reduction structure (U) is constructed based on the Dilated_ResNet50 network. Secondly, a fast and accurate PULNet semantic segmentation network is proposed integrating the image Local detail information structure (L). Finally, an Eight-neighbor coding method is designed to accurately locate the border of the lawn. Experiments on the ADE20K dataset obtained the mean Intersection over Union (mIoU) and mean Pixel Accuracy (mPA) 32.86% and 75.65% respectively. The average speed is 82.7 frames per second on a platform with GTX 1080Ti GPU. Compared with the Fully Convolutional Network (FCN) the mIoU and mPA are increased by 3.47% and 4.33% respectively, and the speed is 11 times higher. The proposed method can be used for fast and accurate lawn semantic segmentation and boundary detection.
Research on Android Multi-classification Based on Text
Authors: Zhang Hua , Qin Jiawei , Wang Yan , Ma Yuan , Yao Li , Lei Jun
Published: March 2021

In recent years, more and more malicious applications have appeared on mobile application platforms, and they are often disguised as social, communication, and game applications. If we classify applications by category when detecting malware, which can improve the accuracy of malware detection. Classification of applications’ categories requires a large number of high-quality samples, but labels of applications’ categories are vary widely in different app stores, and samples of the same function type cannot be obtained quickly and efficiently. This thesis proposes a method for constructing a multi-classification model by using the text content of application description information, and guiding the classification of application by the category of application description. This method collects the description of an application in different app stores, predicts the category of the description through the classification model, and obtains the application category by voting. The model is based on CNN and RNN, and its F1-score is about 3% higher than the text classification model such as textCNN, LSTM. Its training prediction time and memory consumption are only 6% higher than that of textCNN and LSTM models. We named it CRNN, this thesis constructs a data set that can be used for application classification. The data set is classified using application description to obtain each application description and its category.
Stock Price Prediction Based on an Energy-Efficient Spiking-LSTM Hardware Accelerator
Authors: Wu Yuancong , Liu Y , Chen T P
Published: March 2021

Inspired by the way the human brain thinks, the neuromorphic system applies the principles of biological brains to computer architecture, providing low-energy, distributed, and massively parallel advantages for brain-inspired systems. This work presents an energy-efficient spiking long short-term memory (sLSTM) neural network hardware accelerator for sequence prediction applications, containing 256 neurons and 64k synapses in 0.96 mm
2 area. The sLSTM model can process time-dependent data and realize long-term and short-term memory to forget, memorize selectively. A leaky integrate and fire (LIF) neuron model is proposed to characterize the stimulation of neuronal membrane potentials using simple digital logic circuit without any multipliers, which extremely reduces the power consumption of the hardware system. Accordingly, the chip achieved an energy efficiency of 10.3 uj@50 MHz per sample and a predicting accuracy of about 93.2% in sLSTM neural network model using the stock price of Google from Yahoo finance, based on the modified LIF neuron.
Multi-objective Route Planning of Museum Guide based on an Improved NSGA-II Algorithm
Authors: Xu Yuhan , Guo Qing , Tan Aopin , Xu Liying , Tu Yiwei , Liu Shuang
Published: March 2021

Museums have become a hot spot of tourism. However, the uneven distribution of passenger flow makes it difficult for tourists to find out the shortest and most comfortable tour route. The multi-objective route planning strategy is proposed for the design of museum tour route. This paper presents an improved version of the NSGA-II algorithm, named adaptive 2-opt_integerated non-dominated sorting genetic (AONSGA) algorithm. Based on NSGA-II algorithm, the adaptive probability and 2-opt local search strategy is introduced. Then the computation results on benchmark multi-objective problems show that the AONSGA algorithm has better convergence and diversity performance than the NSGA-II. Whereafter, taking the Palace Museum as an example, a map is established and AONSGA is applied to carry out multi-objective guide route planning. Finally, according to different requirements of tourists, three kinds of specific schemes of the guide route in the Palace Museum are recommended.
An Adaptive Synchronverter for Ensuring Fault Ride Through Capability of Grid-Connected Solar Power System
Authors: Yap Kah Yung , Sarimuthu Charles R. , Lim Joanne Mun-Yee
Published: March 2021

In recent years, the grid-connected solar power system has grown tremendously because of its cost-effectiveness and environmental friendliness. However, its interface to the existing power grid introduces frequency and voltage instability due to its lack of rotating mass and inertia response, unlike a conventional synchronous machine. To alleviate the limitations, a novel adaptive synchronverter is proposed to equip with fault ride through in a grid-connected solar power system. It enables continuous electricity generation even under overloading, voltage sag or short circuit fault. MATLAB®/Simulink simulations are conducted, and it is validated by emulated hardware by Typhoon® Hardware-in-the-loop (HIL) 402 real-time simulation. The results validated that the fault ride through capability enables the synchronverter to stay connected in short periods of lower electric network voltage.
Smoothing of Power Consumption in Air Conditioning Systems with Ice Storage: A Receding-Horizon Optimization Approach
Authors: Hu Wenbo , Guo Song , Huo Weiqiang , Cui Cui , Feng Pengpai , Li Wenqing , Zhu Liangliang
Published: March 2021

The peak of power load brings great challenges to the safety, stability, and economical operation of the modern power system. Building air conditioning refrigeration is one of the main reasons for the peak load. In this paper, we make use of an ice storage tank to smooth the air conditioning load as far as possible so as to achieve the purpose of peak filling. A mathematical model of quadratic programming is established to characterize the trade-off between the lowest energy storage cost and smoothness via a receding-horizon optimization approach. Numerical examples are given to analyze the relationship between ice storage cost and peak filling effect.
Applying the Method of Categorical Analysis for Conceptual Design of an Automated Control System of a Group of Unmanned Aerial Vehicles
Authors: Nikiforov A , Kliushnikov I
Published: March 2021

Conceptual design of automated control systems (ACS) is an important stage in their development and making. The miscalculations admitted during this stage, as a rule, couldn’t be compensated for in the subsequent stages of the project. At the same time, despite the great importance of this stage, nowadays there is no well-developed theory of conceptual design for ACS making and improvement. In generally, it all comes down to either using the prototype, or the talent and insight of the designer. In this article an attempt was made to develop a methodology for the conceptual design of ACS. A template for creating parametric concept of ACS with its subsequent detail through the use of the method of the categorical analysis is proposed. A method allows to form a fairly complete information space of control, taking into account all possible information interactions between groups of parameters based on the generated sequence of categorical subsets of the control process with their subsequent interpretation is described. An example of method using is demonstrated for development of the ACS concept by a group of unmanned aerial vehicles. A constructive scheme of control information, including data groups and relationships between them, is considered. An interpretation of categorical subsets, an example of detailing and data of the state of the control object and the definition of some information transformation procedures for one of the formed subsets are proposed.
Construction Automatic Positioning System of a Moving Object Based on the Readings of Bluetooth Beacons and Modified Multelateration Method
Authors: Astafiev Alexandr , Zhiznyakov Arcady , Demidov Anton , Makarov Mikhail
Published: March 2021

The article discusses the solution to the problem positioning a movable mobile object in a controlled area. The proposed solution is based on the construction of a sensor network from Bluetooth Low Energy radio beacons in the controlled area. The interaction of the mobile device and the sensor network is proposed to be carried out via a Bluetooth communication channel of specification not lower than 5.0 by obtaining the values of the RSSI signal levels of each radio beacon. The room has its own absolute coordinate plane. According to the multilateration method, each triplet of beacons forms its own relative coordinate plane. The developed algorithm also considers the issue of converting relative coordinates to absolute ones. At the end of the study, a description is given of an experimental study on positioning a mobile phone in a 5 by 10-meter room.
Modulated Mathematical Formulation of MSE for Assessment of a Positioning System in Live-status
Authors: baidhani Abbas Al
Published: March 2021

In wireless sensor network (WSN), It is a substantial affair to obtain a convenient assessment metric for evaluating created positioning systems. Mean square error (MSE) is one of very paramount assessment metrics utilized for such problem. The conventional mathematical formula of MSE such as the built in MSE function in matlab is utilized only when the real and measured values of the position are available, which means utilizing the MSE is potential only after building the system not while building it. In this paper, for positioning purpose, we offer a mathematical derivation of an MSE formulation based on least square (LS) approach for three-dimensional positioning system without utilizing the real and measured position. The created MSE uses only the measured distance between anchor nodes and a mobile station, that needs its position to be calculated. The formed MSE has the ability to assess a positioning system online based only on the estimated distances, and then the user can modulate his system until obtaining a system ambidextrous to match the requested positioning accuracy. The derived MSE has accuracy 100 % equals to the conventional mathematical formulation such as the built in matlab MSE function.
Validation of An Elbow Position Super-Twisting Sliding-Mode Controller for Upper-Limb Exosuit Using A Soft Position Sensor
Authors: Pont-Esteban D , Contreras-González A F , Samper-Escudero J L , Sáez-Sáez F J , Ferre M , Sánchez-Urán M á
Published: March 2021

Flexible exoskeletons, also known as exosuits, are robotic wearable devices intended to help healthy and unhealthy subjects in different tasks, such as daily life activities, load lifting or rehabilitation. A position control is required to assure stability and compliance in all assisted movements. In this paper, the authors propose the use of a flexible position sensor based on differential capacitance measurement as position feedback for the elbow joint in the flexible exoskeleton LUXBIT. This exosuit is controlled in position by a super-twisting sliding mode controller (SMC), which is robust against disturbances. Different movements involved in rehabilitation therapies are performed over three healthy subjects in order to evaluate the exosuit performance using this motion sensor. The measures given by the flexible sensor are compared to the ones obtained by OptiTrack motion capture system, which are used as ground truth.
Application of Supply Chain Management at Drugs Flow in an Italian Hospital District
Authors: Improta Giovanni , Scala Arianna , Trunfio Teresa Angela , Guizzi Guido
Published: March 2021

The globalization has pushed to change the organization of every companies, even the hospitals. The principal phenomenon in that period and fundamental today again, has been the Supply Chain Management (SCM), with which the company is no longer seen as an isolated entity but active part in an extremely complex supply network. In fact, the only way to guarantee the competitiveness of businesses in the new world economy is through the cooperation and the integration between customers and suppliers. The present work analyses the drugs flow of three Italian hospital: the Cardarelli Hospital in Campobasso, the Veneziale located in Isernia and the San Timoteo site in Termoli. The data was provided by MOLISE DATA SPA that collected the information from all ASREM with particular interest in the already mentioned hospitals. Particularly, will be highlight, using simulation model, the benefits deriving from the implementation of a new Supply Chain, creating a collaboration along the entire logistics-production chain. Thanks to a more efficient management of drugs will get a reduction of business costs and an improvement of the health services offered.
An Innovative Business Model for a Multi-echelon Supply Chain Inventory Management Pattern
Authors: Cesarelli G , Scala A , Vecchione D , Ponsiglione AM , Guizzi G
Published: March 2021

Nowadays, companies are experimenting novel organizational solutions to efficiently operate in uncertain and highly dynamic scenarios. As a potential solution, this paper proposes a new business model for a multi-echelon Supply Chain inventory management pattern. Specifically, an inventory model with proactive lateral transshipments was developed and subsequently tested carrying out 288 experiments with the aim of assessing transshipments impact on the performance of a two-echelon Supply Chain. The final goal was to investigate the potential reduction of the overall cost of the enterprise and, conversely, whether this approach could promote significant improvements in the level of service, achievable through a more efficient management of resources. The analyses and simulations indicate the use of large batches and/or low-cost products did not demand the necessity of transshipment events. These preliminary findings could be potentially validated and tested in the future considering more complex networks or multiple products.
Optical Transmission Network Evolution Scheme of VC-OTN
Authors: Qiang Hao , Tu Mingliang , Che Yue , Tang Xianfeng
Published: March 2021

With the evolution of operator network, the optical transmission network (OTN) technology which integrates the cross-function of Virtual Container (VC) has become a hot research topic. In this paper, the application scheme of VC-OTN technology including network structure planning, network evolution steps and protection scheme in transmission network is proposed. The pilot project proves that the proposed scheme can significantly guide the operator network construction.
Joint DBF and SAO Parallel Filtering Based on Multithread Load Balancing
Authors: Ma Hao , Hu Dong , Li Yi
Published: March 2021

This paper presents a joint parallel loop filtering algorithm based on multi-thread load balancing in HEVC decoding, which implements the parallel processing of deblocking filtering (DBF) and sample adaptive compensation (SAO). Because of the diversity of video, the texture of different regions in an image is also different, which leads to various CTU partition methods. Therefore, the number of the boundary to be filtered is greatly different, resulting the computation load among multiple threads unbalanced in parallel processing. To solve this problem, an area division scheme is proposed, which divides the image into multiple areas, and the number of boundaries to be filtered in each area is similar. Then, the mapping relationship table is used to allocate these areas to multiple threads for parallel processing, so as to achieve the load balancing among the filtering threads. Finally, the cache technology is used to combine DBF and SAO to reduce the delay between them and improve the overall parallelism of the loop filter. Experimental results show that the performance of the proposed load balancing joint filtering algorithm is 8.15% higher than the previous scheme.
Ranging-Measurements-Based Maneuver Detection Method for Space Target Tracking
Authors: Li Zhao , Wang Yidi , Zheng Wei
Published: March 2021

Maneuver detection is crucial to improve the performance of space target tracking. A real-time maneuver detection method based on ranging measurements is proposed in this paper. The prediction residual of ranging measurement is selected as the test statistics. Then the maneuver and the outliers can be distinguished by setting multiple hypothesis tests. The traditional strong tracking filters can be improved by applied this detection method. The superiority of the proposed method is verified by a simulation case. Simulation results demonstrate that the new method can provide higher tracking accuracy than the traditional methods when the maneuver and the outliers both exist, and the maneuver and the outliers can be detected exactly.
Physical World to Virtual Reality – Motion Capture Technology in Dance Creation
Authors: Zhen Wu , Luan Lian
Published: March 2021

After more than 100 years of development, motion capture technology has been advanced greatly. In the initial stage, the motion capture technology was only capable of capturing a rough range of body movements. But now it is sensitive enough to capture the movement of the whole body. Motion capture technology has also been developed into different types: optical and non-optical systems including inertial, magnetic, and mechanical. There are also hybrid and depth sensing camera-based systems. Nowadays, with the combination of the technology and arts, computer software and internet technology have become a new territory for dance performance. Motion capture plays an increasingly important role in dance creation. Meanwhile, the combination of motion capture and virtual reality technology enables the audience to freely choose different viewing angles and moving positions in a totally virtual space, which can present stronger sense of tension and cultivate more immersive experience than live dance performances do. On the Internet, virtual reality dance theaters connect dance performers and audiences from different geographical spaces. The virtual reality dance heaters build up virtual performance venues, paralleling with the real theater performance in the physical world.
Using CNN to Predict the Resolution Status of Bug Reports
Authors: Arshad Muhammad Ali , Zhiqiu Huang
Published: March 2021

Bug tracking systems (BTS) are a resource for receiving bug reports that help to improve software applications. They usually contain reports reported by the end-users or developers. Bug Reports contain some suggestions, complaints, etc. The problem is that every submitted bug report is not accepted to implement. Mostly bug reports are rejected because they are incomplete, duplicate, expired, etc. while only a few are accepted to implement. But the developers have to check every bug report manually that needs many resources (i.e. labour, money, time). In this study, we proposed a convolutional neural network (CNN) based approach to automatically classify bug reports as accepted and rejected. Results show that the proposed approach achieves the highest performance as compared to closely related works.
Security Issues in Multi-hop Device-to-device Communication Networks - Secure Routing Protocols Solution
Authors: Lv Yimin
Published: March 2021

As one of the key technologies of fifth-generation mobile communication, device-to-device communication technology can not only realize direct communication between neighboring devices, but also reduce the delay of local services provided to users and increase the communication rate. Nevertheless, the special structure of the device-to-device communication network makes it more vulnerable to attacks from inside and outside the network. This paper summarizes the security issues faced by device-to-device communication networks, analysis the secure routing designed for different types of attacks, and discusses future research directions.
Support Outsourcing Unsigncryption and Member Revocation Identity-based Proxy Signcryption Scheme with Drone Environment
Authors: Yang Xiaodong , Xi Wanting , Ren Ningning , Wang Jiaqi , Li Meijuan
Published: March 2021

The identity-based signcryption scheme combines the advantages of the signcryption scheme and the identity-based cryption scheme, which has high calculation and communication efficiency and easy key management. In order to effectively solve the problems of high latency and data information privacy during the secure transmission of drone data to cloud servers, we propose an identity-based proxy signcryption scheme that supports outsourcing decryption and member revocation. The complex bilinear pairing calculation is outsourced to the cloud server to reduce the user’s computing overhead. When an illegal user wants to access the data, the illegal user’s identity value ID will be put into the revocation list and the update private key algorithm is executed to generate an update password for the unrevoked user Key, revoked users lose the ability to decrypt because they cannot obtain the updated key that matches them. The identity-based signcryption scheme protected by the proxy can satisfy unforgeability and forward security. Finally, the comparison results show that this solution is superior to previous work in terms of function and calculation time.
A Note on Eigenvalue of Matrices over The Symmetrized Max-Plus Algebra
Authors: Ariyanti Gregoria
Published: March 2021

Max-plus algebra is the structure that doesn’t have an inverse of additive. Therefore, there exists an equation that doesn’t have a solution. For example, equation 3 ®x=2 has no solution because there is no x such that max(3,x) = 2. The max-plus will have an inverse element of addition if that structure is extended to the symmetrized max-plus algebra. The expansion into a larger system is the same as the expansion of the natural number into an integer number. This paper describes the necessary or sufficient condition of the eigenvalue of matrices over the symmetrized max-plus algebra using the linear balance systems A®xV b with V as a balance relation.
Past, Present and Future Development in Mathematical Modeling for Low Temperature Thermochemical Treatments of Stainless Steels for Enhanced Surface Properties
Authors: Fanya Annissa , Haruman Esa
Published: March 2021

Research development on mathematical modeling for thermochemical treatment especially in low temperature started from the empirical-based research which focused on conducting many experimental studies to gather metallurgical data. Several thermochemical treatments have been developed experimentally using various process parameters such as temperature, treatment time and gas compositions to understand the effect of certain factors towards the resultant layer. The availability of these experimental data was a crucial factor to obtain precise simulation of the diffusion process by thermochemical treatments in the stainless steels which can reduce the trials and errors of the experimental woks. However, the lack of the metallurgical data remains an obstacle to correlate the empirical and simulation-based research. The recent additive manufacturing research area is also an attractive challenge to generate a mathematical-based simulation of thermochemical treatments of additive manufactured specimen. In this paper, a historical review in connection with modeling development in low temperature thermochemical treatments is presented including the suggested future works to attain commercial software availability in progressive industrial development.
Challenges and New Research Directions to the Development of Smart Cities: Systems-of-Systems Perspective
Authors: Mansoori Saeed Al
Published: March 2021

Cities play a pivotal role in the global economy as they are the hubs of trade, industry as well as social and cultural activities. Nowadays, more than 50% of the world’s population live in cities and this number is steadily rising throughout the upcoming few years leading to a highly significant change in the world’s demography. This remarkable growth in urbanization will make cities struggling to provide the basic services to their citizens and will encounter enormous challenges such as traffic congestion, more pollution, excessive energy consumption, extreme water usage, more waste, etc. Consequently, a smart mechanism needs to be implemented in-place to effectively manage the natural resources and assets within cities to ensure the sustainability of services and to provide a high quality of life to residents. Hence, the concept of smart cities has been introduced and becomes one of the most focal and hottest research areas in recent years. Generally, smart city is a combination of urban systems that are interconnected to each other using Information and Communication Technology (ICT) along with Internet of Things (IoT). The shift from a single system to systems of systems would accelerate the development of various sectors including healthcare, education, transportation, economy, energy, housing, etc. Nevertheless, this transfer is extremely challenging due to various aspects related to infrastructure concerns, data storage, subsystems integration as well as managing data in decision support systems (DSS) for end-users. This paper elaborates on the current state-of-the-art in the Systems of Systems Engineering in the context of smart cities. In addition, it highlights some of the smart cities long-term challenges, potential solutions along with new research directions.
Twitter Text Data from #Covid-19: Analysis of Changes in Time Using Exploratory Sentiment Analysis
Authors: Probierz Eryka , Galuszka Adam , Dzida Tomasz
Published: March 2021

The aim of this study is to analyse the characteristics of polish Covid-19-focused twitter posts identified via Covid-19 hashtags. The use of the popular service gives us an opportunity to monitor changing trends in users’ opinions, and changing focus of the most popular topics in the Covid-19-oriented tweets. As part of the analysis, an exploratory sentimental analysis was used to identify the main topics, emotional characteristics, and possible changes over time in the tweeter statements. The emotional characterization of the statements allowed to classify them as negative, neutral or positive. The analysis used wide range of classical text mining, sentiment analysis and latent semantic analysis methods. The use of the methods allowed obtaining the most accurate picture of the tweets. The obtained results indicate the importance of social media in creating opinions.
Innovation Feedback Kalman Filter
Authors: Wang Zhida , Chen Yangyang , Xue Lin , Li Jianguo
Published: March 2021

The conventional Kalman filter demands complete knowledge of the actual filter model, which is usually inaccessible in practical problems. When dealing with the filtering problem with uncertainty, any improper prediction of the uncertainty may degrade the filtering performance and even lead to divergence phenomenon. In this paper, the innovation feedback Kalman filter, which introduces the innovation feedback controller to the Kalman filter equations, is newly proposed on the basis of automatic control theory to address the filtering problem with uncertainty and is different from other filtering methods. By studying the estimate error equations, the estimate bias is extracted and its propagation mechanism is formulated. The estimate bias propagation equations reveal that eliminating the estimate bias essentially equivalents to an output regulation problem with uncertain exosystem. And a concise yet effective innovation feedback controller is subsequently given as an example. The proposed method is applied to one-dimension target tracking scenario and its high estimation accuracy performance and good stability are simulated through a comparative analysis with the ideal filtering results.
Strong rainbow disconnection in graphs
Authors: Bai Xuqing , Li Xueliang
Published: March 2021

Let G be a nontrivial edge-colored connected graph. A rainbow edge-cut is an edge-cut R of G, and all edges of R have different colors in G. For two different vertices u and v of G, a u-v-edge-cut is an edge-cut separating them. An edge-colored graph G is called strong rainbow disconnected if for every two distinct vertices u and v of G, there exists a both rainbow and minimum u-v-edge-cut in G, and such an edge-coloring is called a strong rainbow disconnection coloring (srd-coloring for short) of G. For a connected graph G, the strong rainbow disconnection number (srd-number for short) of G, denoted by srd(G), is the minimum number of colors required to make G strong rainbow disconnected. In this paper, we first characterize the graphs with m edges satisfing srd(G) = k for each k ∈ {1, 2, m}, respectively, and we also show that the srd-number of a nontrivial connected graph G is equal to the maximum srd-number in the blocks of G. Secondly, we study the srd-numbers for the complete k-partite graphs, k-edge-connected k-regular graphs and grid graphs. Finally, we prove that for a connected graph G, computing srd(G) is NP-hard. In particular, we prove that it is NP-complete to decide if srd(G) = 3 for a connected cubic graph. We also show that the following problem is NP-complete: given an edge-colored (with an unbounded number of colors) connected graph G, check whether the given coloring makes G strong rainbow disconnected.
Big Data Cloud Storage Optimization Scheme based on PSO Algorithm
Authors: Cheng Jie , Liu Songyan , Sheng Wei , Sun Yi
Published: March 2021

PSO algorithm, as one of the best swarm intelligence algorithms, has a strong optimization ability. It has obvious advantages to apply PSO algorithm to the optimization of resource scheduling strategy of cloud computing platform. Through the research on the application of PSO algorithm in cloud computing, effective methods are provided for the improvement of efficiency of cloud computing platform. This paper analyzes and studies the application of PSO algorithm optimized by cloud model in business scheduling of big data cloud storage platform.
Interface State in One-dimensional Acoustic Resonator System with Inversion Symmetry Breaking
Authors: Huang Shan , Fan Lei , He Ye , Chen Xiao-an
Published: March 2021

Topological sonic crystals are artificial periodic structures that support robust edge or interface state. Most previous studies on interface state in one-dimensional system heavily rely on Su-Schrieffer-Heeger (SSH) model, which modulates inter and intra hopping strength to yield a nontrivial topological phase. Whether it is possible to achieve interface states by connecting two trivial phases remains a question. To this point, in this paper, we propose a novel method of breaking the inversion symmetry of diatomic and elaborate the underlying mechanism using a spring-mass model. Instead of modulating spring stiffness corresponding to hopping strength which is intrinsically requested in the SSH model, we perturb the masses to break inversion symmetry while springs remain unchanged. Although breaking inversion symmetry in diatomic does not lead to a nontrivial phase, it is found that the interface state would still emerge within the chain formed by connecting two different configurations. Subsequently, this mechanism is applied to a one-dimensional acoustic resonator system connecting two different configurations to realize interface state. Simulation results reveal that acoustic wave has strongly localized at predicted interface frequency. Our study provides a novel approach of producing interface states in the one-dimensional acoustic system.
A MCDM-Based Meta-Heuristic Approach for U-shaped Disassembly Line Balancing Problem
Authors: Wang Yifeng , Xie Yang , Ren Yaping , Zhang Chaoyong
Published: March 2021

Since the rapid development of technology advancement and accelerated upgrading rate of mechanical, electrical, and electronic equipment, dealing with the recovery, recycling, and remanufacturing of end-of-life (EOL) products are of increasing importance. The disassembly line balancing problem (DLBP) aims at addressing such concern in the most efficient and effective manner. In this paper, a meta-heuristic approach involving both multi-criterion decision making (MCDM) and variable neighborhood search (VNS) is proposed to the U-shaped layout of the disassembly line. Following the MCDM method combining fuzzy set theory, grey relational analysis, and Choquet fuzzy integral, an improved VNS approach with a specially designed decoding method is utilized to balance a U-shaped line with three hierarchical objectives. Finally, computational experiments validate the effectiveness of the proposed approach.
Research on Multi-point Continuous Electromyography Control Algorithm and Its System for Multi-Finger Dexterous Hand
Authors: Huang Pengcheng , Lin Xue , Xiao Jianzhang , Wang Guifeng
Published: March 2021

As the application field of robots expands from industry to agriculture, medical rehabilitation and service industries, its working environment becomes dynamic and not good. The end effectors of robots also need to be more flexible to adapt to changing operating objects. Based on the existing research of our group, a multi-finger dexterous hand included two kinds of bending joints is designed which used human hand as the prototype and combined with the characteristics of human hand joint movement. The EMG signal is proposed as the control source to improve the diversity and flexibility of dexterous hand movement. In the link of EMG signal processing algorithm, EMG signal feature value of the independent and complete action is discretized to form a continuous characteristic parameter curve. And multi-point continuous myoelectric control which is used to characterize the action process can be realized. The real-time adjustment of the driving air pressure is realized by the control system. And the system can control the different action forms of multi-finger dexterous hand. Finally, the relative error of proposed control algorithm and its system was verified to be about 3.23% by the joint position control test.
Analysis of Empirical Research Methods of Rehabilitation Landscape
Authors: Luo Jia , Liu Hanxin
Published: March 2021

In modern times, the natural environment has attracted people’s attention as a resource for maintaining people’s physical and mental health. Nature and health involve many different disciplines. In the landscape disciplines, it is called “rehabilitation landscape”. Rehabilitation landscape is important to the mind and physiology of individuals there are also many scientific research results for new types of gardens. On this basis, this paper analyzes the current empirical research methods of rehabilitation landscape from the perspective of subject and object by combing the development process of rehabilitation landscape, and points out its shortcomings, analyzes its future development trend, and finally proposes future empirical research. The method should have a more rigorous and systematic research structure, strengthen the grasp of the research essence, and promote the formation of an evaluation system with optimized practical significance.
Experiments of Water Quality Monitoring and Sediment Pollution Release in Shamao River
Authors: Lu Qihui , Xu Yuqi , Xu Kunpeng , Xia Wenjun , Liu Junxia , Liu Yanxiang
Published: March 2021

The Shamao River is an urban river in Wuhan Economic Development District, which water body is under heavy polluted. A whole year water quality monitoring was carried out in 2019, and the corresponding results showed that the water quality of Shamao river was lower than class V bad water quality. The sediment and overlying water samples were collected. Qualified and analyzed pollution indicators, including COD, ammonia nitrogen (NH3-N) and total phosphorus (TP). The influence of pollutant in water released from sediment was analyzed through laboratory water column simulation experiment. It was found that there was no correlation between concentrations of COD, NH3-N in sediment and corresponding concentrations in overlying water samples. The amount of total phosphorus (TP) in water samples are related to the amount of sediments. Simulated sediment pollution releasing experiments showed that the COD in sediment had weak effect on water quality. The releasing of nitrogen and phosphorus from the sediment increased with time, caused the secondary pollution of the water body.
The Applicability of the Current Thermal Climate Zones for Building Energy-Saving Design of China
Authors: Bai Lujian , Song Bing , Yang Liu
Published: March 2021

Climate has a great impact on the thermal performance of buildings. This study aims to provide a theoretical foundation for developing climate classification for building energy-saving in China. The current thermal climate zoning mothed was evaluated by using the mean deviation to assess its applicability on guiding building energy-saving design in China by using the latest weather data measured from 1988 to 2017. The analysis results indicate that current thermal climate zones cannot present the difference in atmospheric moisture and solar radiation in different regions. The current cold zone is unable to reveal the discrepancy of the monthly average temperature of hottest month in different regions. To provide an adequate guidance for the energy efficient design of HVAC systems as well as for passive building design, the main zoning criteria should be revised and the climate indices relating to air humidity and solar radiation should be considered in the future.
Effect of magnetic water on strength properties of concrete
Authors: Ibrahim Enaam M , Abbas Zena K
Published: March 2021

The research’s main goal is to investigate the effects of using magnetic water in concrete mixes with regard to various mechanical properties such as compressive, flexural, and splitting tensile strength. The concrete mix investigated was designed to attain a specified cylinder compressive strength (30 MPa), with mix proportions of 1:1.8:2.68 cement to sand to crushed aggregate. The cement content was about 380 kg/m3, with a w/c ratio equal to 0.54, sand content of about 685 kg/m3, and gravel content of about 1,020 kg/m3. Magnetic water was prepared via passing ordinary water throughout a magnetic field with a magnetic intensity of 9,000 Gauss. The strength test results showed an encouraging improvement in the fresh and hardened concrete properties. The percentage increases in compressive strength of 12.16, 10.16, and 8.62% at 7, 28, and 90 days, respectively, compared particularly well with the control mix containing tap water, with consistent flexural trends and splitting tensile strengths.
Behaviour of Rubberized Concrete Beams in Shear
Authors: Al-Quraishi Hussein , Abdulazeez Aseel , Abdulkhudhur Raad
Published: March 2021

The shear strength of concrete beams manufactured from a mix including fine pieces of waste tire rubber (rubberised concrete) have been studied in several experimental programmes, with results showing a reduction in shear strength when using rubberised concrete instead of conventional concrete. In much of the recent research in this area. The main goal of the current investigation was thus to determine the extent of such reduction and to find ways to compensate for this reduction by the addition of steel fibre. A total of eight rubberised concrete beams of (140 mm width, 240 mm height, and 1240 mm length) were tested experimentally with replacement ratios by volume fraction of coarse and fine aggregate volume with fine tire waste of 0%, 25%, and 50% investigated. Additions of, 0%, 0.5% and 1.5% steel fibre content were also made to the rubberised concretes, in an attempt to test improvements in the resulting shear strength. A four-points load testing configuration was used for testing the specimens. The compressive strength of the rubberised concrete, volume fraction of steel fibres, longitudinal reinforcement ratio, replacement ratio of conventional aggregate by fine waste rubber, and shear span to depth ratio were the variables considered in this investigation, with the load-deformation behaviour and ultimate load investigated through experimental work. The test results showed that an increase in replacement ratio from 25% to 50% reduced the shear strength by 3.4%, while adding 0.5% steel fibre to the rubberised concrete increased the shear strength by 7.4% as compared with that of conventional strength concrete specimens without steel fibre. Overall, the shear modes of failure in rubberised concrete were similar to those of conventional concrete.