rss_2.0Applied Mathematics and Nonlinear Sciences FeedSciendo RSS Feed for Applied Mathematics and Nonlinear Sciences Mathematics and Nonlinear Sciences 's Cover of software-defined network experimental teaching scheme based on virtualised Environment<abstract><title style='display:none'>Abstract</title><p>Aiming to address the shortage of experimental resources, the high cost of large-scale deployment of hardware experimental environment and the difficulty for students to get started in the software-defined network (SDN) course, this article proposes an SDN experimental teaching scheme based on the virtualised environment, and gives a specific experimental scheme design. The scheme utilises virtualisation technology to build a SDN experimental environment quickly, uses a lightweight network simulation platform – that goes by the name of Mininet – to build the SDN network and uses open-source controller Floodlight for centralised control of the SDN network. The scheme is mainly divided into three phases: basic, improvement and synthesis. In the basic phase, experimental projects mainly include the study of SDN basic concepts and the use of relevant tools; in the improvement phase, experimental projects mainly include the use of SDN flow table, group table, etc; in the synthetic phase, we design two innovative experimental projects that use computational intelligence technology to achieve efficient load balancing and accurate malicious attack detection. The difficulty of each phase is increasing. The constantly evolving levels of difficulty allow the individual needs of students with different levels to be met, thereby improving the effect of SDN experimental teaching and cultivating innovative SDN talents.</p></abstract>ARTICLE2021-05-25T00:00:00.000+00:00The Comprehensive Diagnostic Method Combining Rough Sets and Evidence Theory<abstract><title style='display:none'>Abstract</title><p>To solve the difficulties in practice caused by the subjectivity, relativity and evidence combination focus element explosion during the process of solving the uncertain problems of fault diagnosis with evidence theory, this paper proposes a fault diagnosis inference strategy by integrating rough sets with evidence theory along with the theories of information fusion and mete-synthesis. By using rough sets, redundancy of characteristic data is removed and the unrelated essential characteristics are extracted, the objective way of basic probability assignment is proposed, and an evidence synthetic method is put forward to solve high conflict evidence. The method put forward in this paper can improve the accuracy rate of fault diagnosis with the redundant and complementary information of various faults by synthesizing all evidences with the rule of the composition of evidence theory. Besides, this paper proves the feasibility and validity of experiments and the efficiency in improving fault diagnosis.</p></abstract>ARTICLE2021-05-25T00:00:00.000+00:00Travelling wave solutions to the proximate equations for LWSW<abstract><title style='display:none'>Abstract</title><p>By feat of Maple 17 and a subsidiary ordinary differential equation, a new extension algebraic method is chosen to construct the travelling wave solutions to the proximate equation set involving an arbitrary parameter for long waves over shallow-water. Multiple triangle periodic solutions and new Jacobi elliptic function solutions are obtained. This procedure is applicable to other nonlinear partial differential equations as well.</p></abstract>ARTICLE2021-05-25T00:00:00.000+00:00Value Creation of Real Estate Company Spin-off Property Service Company Listing<abstract><title style='display:none'>Abstract</title><p>The paper took 12 groups of parent companies and subsidiaries as the samples, in which the property service companies, spun from the real estate companies, have successfully on the capital market. The research showed that the average abnormal return (AAR) of real estate companies’ stocks was positive on the first announcement date of possible spin-off listing, while the cumulative average abnormal return (CAAR) remained positive for 21 days during the (–11, 9) days around the first announcement of possible spin-off and listing. Further, the changes in operating performance of real estate companies and property service companies were analysed after the successful spin-off for 3 consecutive years, compared with the year before the spin-off and listing. The results showed that after the spin-off and listing, real estate companies and property service companies have greatly improved their performance. Therefore, the fact that real estate companies spun off property service companies created positive values for shareholders.</p></abstract>ARTICLE2021-05-26T00:00:00.000+00:00Research on management and control strategy of E-bikes based on attribute reduction method<abstract><title style='display:none'>Abstract</title><p>The sports characteristics of E-bikes increase the conflict between traffic participants. In this paper, the criteria of E-bike traffic conflict are given according to time distance. Based on the rough set theory, the redundant rule reduction method is developed, and the following conclusions are drawn: 1. Signal lights and video monitoring points have little effect on alleviating the traffic conflict between e-vehicles and motor vehicles; 2. Setting isolation facilities, non-motor vehicle lanes and traffic police can effectively reduce the traffic conflict. The results show that this method can effectively analyse the main influencing factors of traffic conflict.</p></abstract>ARTICLE2021-05-26T00:00:00.000+00:00Impact of Web Page House Listing Cues on Internet Rental<abstract><title style='display:none'>Abstract</title><p>Based on a questionnaire survey combining the stimulus-organism-response (S-O-R) theory with the cues theory, this paper establishes hypotheses and uses partial least squares structural equation modelling (PLS-SEM) to study and analyse the impact of web page house listing cues on Internet rental from the perspective of users. The results indicate that: (1) the relevant cues of Internet renting platforms are effective and worthy of attention, (2) the subjective arousal of the tenants triggers their behavioural changes to a large extent, and (3) the sensitivity of the tenants’ behavioural approaches to their feelings is greater than their purchasing intentions. In the context of the rapid development of the online market, understanding the user's response to target information is essential to promote the optimisation of the Internet rental platform, to improve the efficiency of online housing selection, and to encourage healthy development of the rental housing market.</p></abstract>ARTICLE2021-05-27T00:00:00.000+00:00Entrepreneur's Passion and Entrepreneurial Opportunity Identification: A Moderated Mediation Effect Model<abstract><title style='display:none'>Abstract</title><p>Based on the theory of entrepreneurial cognition, we examined the relationship between entrepreneurial passion and opportunity identification, and the moderating roles of environmental complexity and mediating role of entrepreneurial contextual knowledge in this relationship. Results from 246 entrepreneurs supported the hypothesis that both their entrepreneurial passion and their entrepreneurial contextual knowledge would be positively related to opportunity identification, and these relationships would be moderated by environmental complexity. Further, environmental complexity enhanced the relationship between entrepreneurial passion and opportunity identification, and also amplified the relationship between contextual knowledge and opportunity identification. The results suggest that the effect of entrepreneurs’ passion on opportunity identification depends on the level of the individual's contextual knowledge and environmental complexity.</p></abstract>ARTICLE2021-05-25T00:00:00.000+00:00Research progress in the mining technology of the slowly inclined, thin to medium thick phosphate rock transition from open-pit to underground mine<abstract><title style='display:none'>Abstract</title><p>This paper takes the deep ore body of Yunnan Phosphate Group Co. Ltd, the largest open-pit chemical mining enterprise in China, as the research background, and systematically introduces the technical problems recognised by many Chinese researchers in the past eight years on the open-pit to underground mining of gently inclined thin to medium-thick ore bodies with a soft interlayer. It shows that the mining of open-pit transferred to underground is a complex engineering system, and the underground stope surrounding rock and overlying strata present a nonlinear failure process. Through mining process innovation, mining method innovation and improvement, research was undertaken on new processes and technologies for phosphorus mining under complex conditions. The relevant research results not only have important economic value and academic significance for Yunnan Phosphate Group Co. Ltd. but also have important guidance and impetus to the exploitation of a large number of similar phosphate resources in China.</p></abstract>ARTICLE2021-05-25T00:00:00.000+00:00Analysis on the influence factors of college students about the willingness to work in rural e-commerce<abstract><title style='display:none'>Abstract</title><p>In recent years, rural e-commerce has been actively improving, but the contradiction between talent demand and supply has become increasingly prominent. This article combines the four dimensions of personal characteristics, professional attitude, family background and external environment to conduct empirical research on willingness to engage in rural e-commerce among e-commerce major students. The results show that the willingness to engage in rural e-commerce is generally low, which influences internship experience, academic planning, salary expectations, career perception, family attitudes, school guidance and public opinion.</p></abstract>ARTICLE2021-05-25T00:00:00.000+00:00The sloshing law of liquid surface for ground rested circular RC tank under unidirectional horizontal seismic action<abstract><title style='display:none'>Abstract</title><p>The dynamic characteristics and liquid sloshing of a circular tank are analysed using ADINA software through seismic response analyses. The maximum sloshing wave height for the circular tank under unidirectional horizontal seismic action is developed. The calculation method involves three parameters such as tank radius, seismic coefficient and dynamic coefficient. The dynamic coefficient of liquid sloshing is determined corresponding to the long-period seismic design <italic>β</italic> spectrum with a 5% damping ratio using basic sloshing period. The established method can guide the seismic design of liquid-containing structures. The established method of calculating sloshing wave height is compared with those in the American code.</p></abstract>ARTICLE2021-05-25T00:00:00.000+00:00Predicting stock high price using forecast error with recurrent neural network<abstract><title style='display:none'>Abstract</title><p>Stock price forecasting is an eye-catching research topic. In previous works, many researchers used a single method or combination of methods to make predictions. However, accurately predicting stock prices is very difficult. To improve the predicting precision, in this study, an innovative prediction approach was proposed by recurrent substitution of forecast error into the historical neural network model through three steps. According to the historical data, the initial predicted value of the next day is obtained through the neural network. Then, the prediction error of the next day is obtained through the neural network according to the historical prediction error. Finally, the initial predicted value and the prediction error are added to obtain the final predicted value of the next day. We use recurrent neural network prediction methods, such as Long Short-Term Memory Network Model and Gated Recurrent Unit, which are popular in the recent neural network study. In the simulations, the past stock prices of China from June 2010 to August 2017 are used as training data, and those from September 2017 to April 2018 are used as test data. The experimental findings demonstrate that the proposed method with forecast error gives a more accurate prediction result for the stock’s high price on the next day, which indicates that the performance of the proposed one is superior to that of the traditional models without forecast error.</p></abstract>ARTICLE2021-05-25T00:00:00.000+00:00Energy-saving design of office buildings considering light environment and thermal environment<abstract><title style='display:none'>Abstract</title><p>The energy consumption of office buildings is analysed, and the influential factors to be considered in architectural design that affect the light and heat environment of office buildings are summarised. The original building model was established by Ecotect, and variable methods were adopted to simulate the influence of different influencing factors on the light and thermal environment, and to quantitatively evaluate the importance of different factors on energy consumption of buildings. This analysis provides an important basis for optimised energy saving design, and finally puts forward the optimal design strategy for energy saving, so as to build harmonious light and heat architectural environment.</p></abstract>ARTICLE2021-05-14T00:00:00.000+00:00An empirical investigation of physical literacy-based adolescent health promotion<abstract><title style='display:none'>Abstract</title><p>A reexamination of the health problems of Chinese adolescents based on the concept of physical literacy (PL) was necessary. Through the use of follow-up data collected from the China Education Panel Survey 2014–2015, the main factors affecting the health of adolescents were identified, and possible explanations were investigated after cluster and inductive analyses were conducted. The results showed that (1) the 10 main factors identified as affecting adolescent health promotion are in line with the four main elements of PL (emotional, cognitive, social and physical elements) and (2) the three major categories of influencing factors identified through a cluster analysis were aligned with the three main factors of PL (endogeneity, fundamentality and permeability). These findings suggest that the factors influencing adolescent health promotion are closely associated with PL. The study results can provide empirical evidence for adolescent health promotion research and a reference for the development of evidence-based PL training models.</p></abstract>ARTICLE2021-05-25T00:00:00.000+00:00A prediction model of urban counterterrorism based on stochastic strategy<abstract><title style='display:none'>Abstract</title><p>With ever increasing complexity and intelligence of the modern cities, protecting key public facilities and important targets from any damage is a major challenge for the security sector. In all types of anti-terrorism prediction models, the prediction of attack behaviour is indispensable. Therefore, the attack behaviour model plays an important role in the anti-terrorism security system. This paper builds the attacker’s behaviour model, and carries out the prediction about the possible attack behaviour by the attacker model based on random strategy. According to the attack strategies, analysis and construction of the attack tree and attack graph are carried out based on the state-based stochastic model. The paper describes the security system in detail taking use of the state-based stochastic model method, so as to clarify the state distribution and the transfer relationship between the states of various security resources after threatened by attacks. At the same time, this paper applies the state-based stochastic model to establish the attacker model through the impact of attack on the security system.</p></abstract>ARTICLE2021-05-25T00:00:00.000+00:00Walking model and planning algorithm of the over-obstacle pipe climbing robot<abstract><title style='display:none'>Abstract</title><p>Effective inspection of pipelines is of significant importance in the industry. In order to reduce human labour, risk and expenses in this area, robots can be applied. The pipe robot should perform not only the linear motion in the axial direction but also the rotary motion in the circumferential direction while working. Meanwhile, in order to achieve reasonable performance and efficiency, these robots should have high enough normal linear motion velocity. They should be able to cross a pipe in one direction to another pipe in a different direction to achieve the over-obstacle function. In this study, a double-joint wheeled robot model is established to fulfil the actions of fast walking, rotation around the pipe and over-obstacle on spatial pipes. Based on the expected position on the pipe for the robot constructed by the proposed model, the precise starting position and control synthesis of the axial and circumferential velocities are initially determined. In order to study the velocity synthesis more accurately, the pipe is unfolded along the axial direction to transform the spatial motion into a plane motion. A novel spatial distribution form of driving wheels is proposed. In addition, based on the initial position of the straight, T-shaped, L-shaped, two-axis ‘+’-shaped and spatial three-axis ‘+’-shaped pipes, the posture adjustment of the robot prior, during and after the over-obstacle is investigated. Furthermore, the corresponding planning algorithms are established.</p></abstract>ARTICLE2021-05-25T00:00:00.000+00:00Research on the countermeasures of cultivating the competence of born after 2000 college student cadres<abstract><title style='display:none'>Abstract</title><p>With the passage of time, the ‘born after 2000’ student group has stepped into the university campus and gradually become the main force of the college student cadre team. It has brought many new challenges while playing a huge role. The ‘born after 2000’ student group has distinctive group characteristics under the brand of the times, such as strong self-consciousness, rich material conditions and diverse network behaviour. The management of the college student cadre team needs to make new changes based on the characteristics of the ‘born after 2000’ student group. Therefore, from the perspective of competence, this paper combines the characteristics of the ‘born after 2000’ student group with the competence training and carries out countermeasures research on the competence cultivation of ‘born after 2000’ college student cadres from the four aspects of selection and appointment, education and training, supervision and assessment, reward and incentive, to solve the practical problems in the cultivation of college student cadres under the new situation, and provides some reference for the future-related theoretical research and educational practice.</p></abstract>ARTICLE2021-05-25T00:00:00.000+00:00About one method of calculation in the arbitrary curvilinear basis of the Laplace operator and curl from the vector function<abstract><title style='display:none'>Abstract</title><p>A simple algorithm for calculating Christoffel symbols, a covariant projection of the result of the Laplace operator's action on the vector, vector curl and other similar operations in an arbitrary oblique base are proposed. For an arbitrary base with ortho <italic>e<sub>i</sub></italic> is found the expressions of vector projections (Δ<bold>A</bold>)<sub><italic>i</italic></sub> and (<italic>rot</italic><bold>A</bold>)<sub><italic>i</italic></sub>, where <italic>A</italic> is a counter variant vector. Examples of orthonormal bases are considered and general expressions for (Δ<bold>A</bold>)<sub><italic>i</italic></sub> and (<italic>rot</italic><bold>A</bold>)<sub><italic>i</italic></sub> for the bases are also given. As a demonstration of the working capacity of the common formulas obtained, detailed calculations of (Δ<bold>A</bold>)<sub><italic>i</italic></sub> and (<italic>rot</italic><bold>A</bold>)<sub><italic>i</italic></sub> as an example are made in cases of spherical and cylindrical coordinate systems.</p></abstract>ARTICLE2021-05-14T00:00:00.000+00:00Research of urban waterfront space planning and design based on children-friendly idea<abstract><title style='display:none'>Abstract</title><p>The natural environment is vital for the healthy growth of children. The absence of exposure to Nature in cities is an important cause of physical and psychological health problems in children. With the objective of a healthy growth environment for children, this paper states the active role of the urban waterfront space, analyses the relationship between children and urban waterfront space, summarises the characteristics of children’s outdoor activities, proposes the principle and methods of planning and designing a children-friendly urban waterfront space, and provides some improved design strategies.</p></abstract>ARTICLE2021-05-14T00:00:00.000+00:00Combustion stability control of gasoline compression ignition (GCI) under low-load conditions: A review<abstract><title style='display:none'>Abstract</title><p>With greater energy pressure and stricter emission standards, increasing power output and reducing emissions of engines are simultaneously required. To achieve this, considerable researches are motivated. In recent years, key and representative developments in the field of high-efficiency and clean engines have been carried out. Among them, a low temperature combustion concept called gasoline compression ignition (GCI) is widely considered by universities and research institutions around the world, since it has the potential to achieve ultra-low NO<sub><italic>X</italic></sub> and soot emissions while maintaining high thermal efficiency. However, GCI combustion mode has certain issues to be solved, such as combustion instability under low-load conditions. Therefore, this paper reviews the experimental, computational and optical studies on the combustion stability control of GCI combustion mode during low loads and describes the recent progress to improve combustion stability as well as points out the future work finally.</p></abstract>ARTICLE2021-04-26T00:00:00.000+00:00Research on relationship between tourism income and economic growth based on meta-analysis<abstract><title style='display:none'>Abstract</title><p>In recent years, with the rapid growth of Chinese economy, the domestic tourism industry has gradually formed. Many scholars on the relationship between the tourism income and economic growth has carried on the empirical research and the most found that tourism income promote economic growth. The study uses the method of meta-analysis to study the relationship between tourism income and economic growth in major cities, and then analyzes the relationship between domestic tourism income and economic growth. Through literature retrieval, extract contains 409 sample sizes 21 valid documents, it is found that the tourism income and economic growth significantly correlated, analyzing the relation between the two different methods and no significant influence on the relation between regional differences. This study provides a way to promote economic growth.</p></abstract>ARTICLE2018-10-03T00:00:00.000+00:00en-us-1