bluuebunny/crossref_metadata_2025_split huggingface dataset:
EGFET-based pH Sensor coupled with Low-cost Electrochemical Screen-printed Electrodes
Authors: Alvarez-Serna Bryan E , Ramírez-Chavarría Roberto G 
Published: April 2021

Abstract
In this paper, we present an attractive EGFET-based pH sensor that integrates a n-channel metal-oxide-semiconductor field-effect transistor (MOSFET) as the transducer and low-cost electrochemical screen-printed electrodes (SPE) as the sensitive element. Our sensor is based on a metallic silver/silver-chloride (Ag/AgCl) reference electrode and an indium-tin-oxide (ITO) sensitive electrode, operating in the pH range of 2 to 9. Results show that the proposed sensor can measure pH with acceptable sensitivity and resolution.
Overview of speech keyword recognition technology
Authors: Li Sixuan , Li Guanyu , Han Jiao , Zhi Tiankai 
Published: April 2021

Abstract
Since the 1990s, speech keyword recognition technology has gradually separated from speech recognition technology and officially become an important branch of speech recognition technology. In this paper, several speech keyword recognition technologies are studied and reviewed, including sample recognition methods, filler model methods, basic speech recognition systems based methods, neural network classifiers and end-to-end methods. Finally, the development prospect and advanced technology of speech keyword recognition will be discussed.
Analysis on Wireless Charging Technology of Electric Vehicle
Authors: Fang Deng , Yuanqing Zhang , Qiusheng Liu , Jianhe Xie , Jian Wang 
Published: April 2021

Abstract
With the progress of science and technology and the development of the times, people’s living standards are gradually improving, and the use of travel tools is becoming more and more frequent. However, due to the lack of fuel resources in China and the great environmental pollution caused by the use of fuel resources, the country is vigorously promoting the development of new energy to alleviate the domestic oil crisis, among which electric energy is the most widely used energy. Enterprises can use power resources to realize wireless charging technology of electric vehicles. As far as the wireless charging technology currently studied in China is concerned, many technologies are not perfect, which can not meet the needs of people and enterprises for the performance of the wireless charging automobile industry. Therefore, according to the problems existing in the development of the current wireless charging technology, this paper makes relevant analysis.
Application of Digital Twins in Port System
Authors: Yao Haiyuan , Wang Dachuan , Su Mengchao , Qi Yue 
Published: April 2021

Abstract
This article reviewed the concept, development history, technical characteristics, and application directions of the digital twin, concluding the port’s characteristics as an international trade hub window, and the construction decision-making problems faced by the government in management, and proposed the application of digital twins in the field of port construction and operation, which should focus on the needs of port digitization and integrated management, especially set up the research on infrastructure construction, data integration, information model construction, application service platform expansion, etc., then established a spatiotemporal correlation index system for infrastructure, simulate port construction and operation processes, to realize port’ infrastructure elements virtualized, real-time monitoring, and management collaborated. The full scene visualizes the port development process and ability to ensure the adaptation, thereby promoting the cost reduction and efficiency improvement of the entire logistics chain and value chain.
Numerical solution of Showalter–Sidorov and Cauchy problems of ion–acoustic waves propagation mathematical model
Authors: Bychkov E V , Zamyshlyaeva A A 
Published: April 2021

Abstract
The paper deals with the problem of numerical investigation of semilinear mathematical model of ion-acoustic waves propagation in plasma. The research is based on the previous study of solvability of the Cauchy problem for an abstract semilinear Sobolev type equation of higher order. The theory of relatively polynomially bounded operator pencils, the theory of differentiable Banach manifolds, and the phase space method are used for analytical study of the model. Projectors splitting spaces into direct sums of subspaces are constructed. Given equation is reduced to a system of two equations. One of them determines the phase space of the initial equation, and its solution is a function with values from the eigenspace of the operator at the highest time derivative. The solution of the second equation is the function with values from the image of the projector. Moreover, in the second section, the sufficient conditions for the solvability of the abstract problem under study are presented. These results are applied to the mathematical model of ion-acoustic waves in plasma which is based on the fourth-order equation with a singular operator at the highest time derivative. Reducing the matematical model to an abstract problem, we obtain sufficient conditions for the existence of unique solution. The results of analytical investigation of the Showalter – Sidorov problem which is more natural for Sobolev type equations are also presented in this section. The Galerkin method is used for numerical study of the model. An algorithm for the numerical solution of the Showalter – Sidorov problem for the model of ion-acoustic waves in plasma is described in the last section.
On a hyperbolic system of equations in the problem of unsteady fluid motion
Authors: Grazhdantseva E Y , Solodusha S V 
Published: April 2021

Abstract
We consider a nonlinear system of the first-order partial differential equations with constant coefficients admitting a solution of the traveling wave type. Such systems are used in applied research to describe the dynamics of unsteady water movement in a pressure pipeline. In this paper, we propose methods for obtaining exact solutions in the case of an inhomogeneous equation of fluid motion under restrictions on the right-hand side in the form of a function. A special feature of the present research is reduction of the problem under study to the equations integrable in elementary functions.
Integro-differential equation with fractional order Caputo operators and spectral parameters
Authors: Yuldashev T K 
Published: April 2021

Abstract
The questions of unique solvability of a boundary value problem for an integro-differential equation with two Caputo fractional operators and spectral parameters are considered. The fractional Caputo operator’s order is bigger than one and smaller than two. Using the method of Fourier series, countable systems of ordinary fractional integro-differential equations with degenerate kernel is obtained. Further, is used a method of degenerate kernel. To determine arbitrary integration constants, a system of algebraic equations is obtained. From this system the regular and irregular values of the spectral parameters were calculated. The solution of the problem under consideration is obtained in the form of Fourier series. The unique solvability of the problem for regular values of spectral parameters is proved. In proofing of the convergence of Fourier series the properties of the Mittag-Leffler function, Cauchy-Schwarz inequality and Bessel inequality are used. We also studied the continuous dependence of the solution of the problem on small parameter for regular values of spectral parameters. The results obtained in this paper are formulated as a theorem.
On one boundary control problem of string vibrations with given velocity of points at an intermediate moment of time
Authors: Barseghyan V R , Solodusha S V 
Published: April 2021

Abstract
The boundary control problem for the string vibration equation with given initial and final conditions, with the given velocity of the string points at an intermediate moment of time is considered. It is controlled by displacement of one end while the other end is fixed. A constructive approach for constructing the boundary control action is proposed, which is applied for given functions.
On approximate controllability of a class of degenerate fractional order distributed systems
Authors: Fedorov V E , Gordievskikh D M , Filin N V 
Published: April 2021

Abstract
The approximate controllability issues for a class of control systems, whose dynamics is described by an equation in a Banach space with a linear degenerate operator at the Riemann — Liouville fractional derivative, is investigated. Under the condition of p-boundedness of the pair of operators in the equation the control system is reduced to subsystems on two mutually complement subspaces. It was shown that the approximate controllability of the whole system is equivalent to the approximate controllability of the two subsystems. Criteria of the approximate controllability for the system and two subsystems are obtained. Analogous results are got on the approximate controllability for free time and for systems of the same form with a finite-dimensional input. The obtained criteria were applied to the investigation of the approximate controllability for a distributed system with polynomials of a differential with respect to the spatial variables self-adjoint elliptic operator and for a system of the Scott-Blair — Oskolkov type.
Approximate optimal synthesis of operational control systems for dynamic objects based on quasilinearization and sufficient optimality conditions
Authors: Khrustalev M M , Sizykh V N , Daneev A V 
Published: April 2021

Abstract
A new approach to the analytical design of linear and nonlinear integrated automatic control systems (ACS) of a real (accelerated) time scale, based on the joint use of dynamic programming technologies and the quasilinearization method, is presented. For continuous dynamic systems, the foundations of the theory of nonlinear synthesis in a degenerate (synergetic) formulation are given.
Discrete maximum principle in systems with a delay in control
Authors: Mardanov M J , Malik S T 
Published: April 2021

Abstract
In the paper, we consider a discrete optimal control problem with a delay in control. Taking into account the specificity of this problem, we offer a new research method. The essence of this method is that unlike previously known ones here we assume that the set of admissible speeds satisfies convexity type conditions at the moment t + h, but not at t, where h is time delay in the system. The discrete analog of Pontryagin’s maximum principle is obtained under weakened assumptions. An example showing the content-richness of the obtained result is given.
The method of parameterization in the quadratic optimal control problem
Authors: Srochko V A , Antonik V G , Aksenyushkina E V 
Published: April 2021

Abstract
In the framework of control parameterization method the optimization problem with respect to linear phase system with quadratic functional is considered. Approximation of the control is obtained in the class of piecewise constant functions. It is formed as a linear combination of a special set of support functions. Coefficients of this combination are variables of the finite-dimensional problem. To effectively solve this problem explicit expressions for the functional with respect to parameters of approximations are obtained. As a result the quadratic mathematical programming problem is formulated.
Mechanisms of polymorphic systematization of bioecological data within the BaikalIntelli platform for organizing computational models of population dynamics
Authors: Kedrin V S , Arguchintsev A V , Dobrinets I M 
Published: April 2021

Abstract
A conceptual model of the BaikalIntelli platform for universal storage, input and processing of arbitrary spatio-temporal databases of bioecological parameters is proposed. Information technologies that allow implementing the basic functionality of the universal metamechanism of data systematization are considered. The platform mechanism has been tested on the example of entering quantitative data of different types of oligochaetes, one of the mass groups of invertebrates of Lake Baikal. Web interface for the database “Spatio-temporal variability of oligochaete populations in the area of industrial wastewater discharge of the Baikal pulp and paper mill” is developed on the base of JavaScript.
Modelling of turbulent structure of plasma inhomogeneity according to decameter data transionospheric sensing
Authors: Afanasiev N T , Trofimov E A , Chudaev S O 
Published: April 2021

Abstract
A method for determining the parameters of the thin turbulent structure of a large-scale ionospheric irregularity from the trajectory characteristics of decametre radio signals emitted from the spacecraft is proposed. The spatial parameters of large-scale heterogeneity are determined by the results of numerical synthesis of the distance-frequency characteristics of radio signals. The statistical moments of signals’ trajectory characteristics at various operating frequencies, obtained by analytically solving stochastic ray equations, are used to diagnose the thin structure of the irregularity.
Reduced mathematical model of the flow in a deep extended natural channel
Authors: Nadolin K A 
Published: April 2021

Abstract
A slightly curved open stationary channel flow is considered. It is assumed that the flow bed is given by a sufficiently smooth function, and the flow itself is long and deep, i.e. the length of the section under consideration is much longer than its width and depth, which, in turn, have similar dimensions. Using the previously developed technique for obtaining reduced mathematical models for channel flows, it is possible, at constant viscosity, to reduce the solution of a complex three-dimensional problem to solving a sequence of standard two-dimensional problems on cross-sections.
The addition of ethylhydrazine to α,β- and β,γ-unsaturated ketones: a quantum-chemical modeling
Authors: Gnatovsky G R , Orel V B , Vitkovskaya N M 
Published: April 2021

Abstract
The reactivity of α,β- and β,γ-unsaturated ketones with respect to the nucleophilic attack by ethylhydrazine in one of the key stages of the formation of 4,5-dihydropyrazole has been studied. It is shown that the addition of the terminal nitrogen atom of ethylhydrazine to the carbonyl group of β,γ- and α,γ-unsaturated ketones with the formation of β,γ- and α,β-unsaturated hydrazones is energetically preferable with the participation of two water molecules. At the same time, the addition of the internal nitrogen of ethylhydrazine to the double C=C bond of the α,β-unsaturated ketone (which is preferable in the presence of one water molecule) to give β-ethylhydrazinyl ketone occurs with a lower activation barrier and is thermodynamically more favorable than the addition to the C=O bond.
Acetylene vs ketones on the route to base-promoted assembly of furans or 6,8-dioxabicyclo[3.2.1]octanes and cyclopentenols: a quantum-chemical study
Authors: Orel V B , Vitkovskaya N M 
Published: April 2021

Abstract
The electronic characteristics of substrates (α,β-unsaturated ketones) and reagents (carbanions of ketones and ethynide ions), as well as thermodynamic and kinetic characteristics both their interaction and the formation of final products have been evaluated using the B2PLYP/6-311+G**//B3LYP/6-31+G* and B3LYP/6-311++G**//B3LYP/6-31+G* quantum-chemical approaches. Reactivity indices that adequately describe the electrophilic and nucleophilic properties of the substrates and reagents are proposed. It has been shown that, regardless of the nature of substrates and reagents, the formation of cyclopentenols and furans is thermodynamically favorable, while the presence of bulky substituents leads to an increase in energy during the formation of 6,8-dioxabicyclo[3.2.1]octanes and explains in this case their absence in products. The calculated activation barriers of the competing reactions of the nucleophilic addition of ethynide ions and ketone carbanions to the double C=C bond of α,β-unsaturated ketones are correlated with the observed reaction direction and the proposed reactivity indices.
Research on transformer fault diagnosis based on genetic algorithm optimized neural network
Authors: Zhang Lei , Zeng Xianwen 
Published: April 2021

Abstract
Aiming at the problem of transformer fault diagnosis in power system, a fault diagnosis method based on genetic algorithm optimization BP neural network is proposed. The BP neural network structure was established based on the traditional three-ratio fault diagnosis method. The concentration of dissolved gas in transformer oil was taken as the input value of the neural network, and the fault working state of transformer was taken as the output value. The established neural network is used to diagnose transformer faults. In order to avoid BP neural network falling into the problem of local optimal value, the weights and thresholds of the neural network are optimized by genetic algorithm. By using the genetic algorithm toolbox in Matlab to establish the genetic algorithm network structure, the transformer fault data as input for the performance of the neural network test. The results show that the neural network optimized by genetic algorithm has a high classification effect on transformer fault types, and the neural network optimized by genetic algorithm has a higher diagnostic efficiency and accuracy than BP neural network.
Research on Docker Cluster Scheduling Based on Self-define Kubernetes Scheduler
Authors: Zheng Gengsheng , Fu Yao , Wu Tingting 
Published: April 2021

Abstract
To address the issue that native scheduler in kubernetes cannot realize load balancing and cannot give full play to the overall performance of the cluster, we put forward a scheduling strategy based on Docker cluster of self-define kubernetes scheduler. The kubernetes scheduler can improve the native kubernetes scheduling strategy using optimized predicate algorithm model and priority algorithm model. Moreover, it can also be used to conduct contrast experiment between the native scheduling strategy of kubernetes and that of self-define kubernetes scheduler. It is in VMware Workstation environment where Centos system is installed, and where Docker container service and kubernetes container orchestration engine are deployed to establish Docker container cluster. Experimental results show that cluster scheduling strategy of the self-define kubernetes scheduler is better than the native one, because it can save more system resources to improve the fairness of the cluster scheduling and the scheduling efficiency.
The Non-negative Inverse Eigenvalue Problem for Tridiagonal Matrix, Circulant Matrix and Symmetric Matrix
Authors: Zhu Pengyu , Yong Yingjing , Guo Zhifeng , Ren Baicheng 
Published: April 2021

Abstract
The Non-negative Inverse Eigenvalue Problem (NIEP) is a sub-problem extracted from inverse eigenvalue problem with a long history from 1930s determining the sufficient and necessary conditions in order that, &#x03C3;={
λ

1,…,
λ
n
}to be the spectrum of an entry wise non-negative n x n matrix. There had been many excellent researchers and scholars who contributed to discover many practical theories. The following of this paper would be then separated into two parts to further analyze the NIEP. In the first section of the paper, some important preexisting conclusions would be demonstrated and the groups’ understanding of these indispensable theories would be expressed. In the second section, three special and wildly used matrix, including tridiagongal matrix, circulant matrix, and symmetric matrix would be considered. The solution of the NIEP of these matrices done by the group would be expressed.
Mapping XML to RDF: An algorithm based on element classification and aggregation
Authors: Liu Yuchun , Hong Zhiyu 
Published: April 2021

Abstract
Many data in Web are exchanged and stored in XML. RDF achieves rapid response and reasoning by aggregating a large amount of knowledge. It has been widely used in intelligent field as a way of data organization. Building RDF based on XML is the focus of this article. This paper analyzes the tree structure of XML, divides the XML elements into three sub-models according to the structure, then aggregates and classifies XML elements, and abstracts the aggregates into three abstract structure models, and finally proposes related mapping rules. Based on the optimization of existing methods, this paper proposes an XML-to-RDF mapping algorithm based on element classification and aggregation, which is reflected in three aspects: optimized mapping rules to ensure the completeness and accuracy of data content and semantics; proposed general algorithms for different types of XML; identified equivalent elements of XML and solved the problem of RDF data redundancy caused by such equivalent elements.
Regulatory Approaches of Cross-border Data Flow in the Big Data Era: China’s Choice
Authors: Yang Xi 
Published: April 2021

Abstract
Cross-border data flow is characterized by multi-direction and rapid dynamic gridding in the big data era. Accordingly, these characteristics necessitate effective regulation for crossborder data flows. The US and the European Union (EU) follow their respective regulatory models for cross-border data flows by considering each one’s economic, political, and historical traditions. The “geographically based” policy of data flows, characterized as internal and external, is the basic position adopted by the EU on cross-border data flows. Although the US regulatory path favors (in principle) the free flow of data across borders, this country actually adopts data protectionism for data involving critical technologies and security areas. Given the political system differences among China, the EU, and the US, China can learn from the experiences of the US and the EU, actively seek value balance between data regulation and free flow, construct its own regulatory model, and establish a diversified data management system. Lastly, China should also actively participate in the international regulation competition on cross-border data flows, thereby giving the country a voice in the international arena.
Multi-dimensional QoS Cloud Computing Task Scheduling Strategy Based on Improved Ant Colony Algorithm
Authors: Ge Junwei , Yu Dehua , Fang Yiqiou 
Published: April 2021

Abstract
This paper proposed a multi-dimensional QoS cloud computing task scheduling algorithm based on improved ant colony algorithm, considering QoS demand of users and load balancing of cloud platform comprehensively. First, this paper defines a QoS model composed of the completion time and execution cost of tasks, and defines the cloud platform load balancing constraint function. Secondly, in view of the shortcomings of ant colony algorithm such as slow convergence speed and easy to fall into local optimum, the pheromone update method and expected heuristic function are improved, and the pheromone strength is dynamically changed. Finally, the simulation is carried out in cloudsim and compared with the ACS algorithm and the MMAS algorithm. Experimental results show that the algorithm in this paper is better than these two algorithms in terms of user satisfaction and cloud platform load.