Discrete Dynamics in Nature and Society

The idea of a smart city is to connect physical objects or things with sensors, software, electronics, and Internet connectivity for data communication through the Internet of Things (IoT) devices. IoT enhances productivity and efficacy intelligently using remote management, but the risk of security and privacy increases. Cyber threats are advancing day by day, causing insufficient measures of security and confidentiality. As the hackers use the Internet, several IoT vulnerabilities are introduced, demanding new security measures in the IoT devices of the smart city. The threads concerned with IoT need to be reduced for efficient Intrusion Detection Systems (IDSs). As a result, machine learning algorithms generate correct outputs from a large and complicated dataset. The output of machine learning could be used to detect anomalies in IoT-network systems. This paper employed several machine learning classifiers and a deep learning model for intrusion detection using seven datasets of the TON_IoT telemetry dataset. The proposed IDS achieved an accuracy of 99.7% using Thermostat, GPS Tracker, Garage Door, and Modbus datasets via voting classifier.

Innovation is the core of China’s national policy and the lifeline of enterprises at the local and global market. There has been a huge amount of research on innovation and elements contributing to innovation performance; however, few of them built a theoretical model to study the correlations among organizational learning, dynamic capabilities, and innovation performance. Based on the existing studies and literature at home and abroad and considering the development status of innovative enterprises in China, this paper decomposes organizational learning into three dimensions of learning commitment, shared vision, and open-mindedness and divides dynamic capabilities into three dimensions of environmental insight capability, resource integration capability, and organizational flexibility capability. To verify the model of LDP (learning-capability-performance) and hypotheses, the authors conducted a survey in Beijing, Tianjin, Hebei, Shanghai, and Qingdao, which have ranked top in the number of innovative enterprises in China in recent years. A sample of 232 valid questionnaires were collected and validated with SPSS23.0 software. The result shows that organizational learning and its three dimensions have significant positive effects on innovation performance, while only two dimensions of dynamic capabilities, resource integration capability and organizational flexibility capability, have significant positive effects on innovation performance. The third dimension of environmental insight capability has no significant positive effects on innovation performance. The dynamic capabilities and its three dimensions play a partial intermediary role between organizational learning and innovation performance.

In this study, the panel smooth transition regression model was used for an empirical survey to investigate the dynamic effect of unemployment rate and crime rate on suicide rate under economic growth rate. The research period was from 2000 to 2019. Statistical results indicated that unemployment rate and crime rate had dynamic effects on suicide rate and that nonlinear relationships existed among them. In addition, depending on the fluctuation of dynamic value, the rise or fall of suicide rate had an asymmetrical influence on the value of unemployment rate and crime rate. Finally, when the rate of change of economic growth rate was larger than the dynamic value, the unemployment rate and crime rate had an aggressive influence on suicide rate.

The China Securities Regulatory Commission (CSRC) proposed the green channel policy for poverty alleviation Initial Public Offerings (IPOs), aiming to help poverty-stricken areas reduce poverty and increase income, but it has an impact on the business performance of the companies involved. This paper uses data from public annual reports of listed companies to construct a policy intervention group and a control group and comparatively analyzes the degree of annual performance downturn of newly listed companies in A-share from 2016 to 2017 through a counterfactual method, and the results show that the “IPO green channel” policy for poverty alleviation has an obvious negative effect on listed enterprises in poverty-stricken counties. The results show that enterprises listed via the green channel have more significant performance downturn than those listed normally during the same period. This paper suggests that the distortion of the market issuance system causes the declining of the quality of IPO firms. Finally, this paper suggests that regulators should cooperate with local governments actively to ensure the smooth implementation of the government’s poverty alleviation efforts while balancing market equity and efficiency. The SFC should take more consideration of institutional compatibility for policy output in financial poverty alleviation to avoid institutional alienation and distortion of corporate behavior.

The coalescence and interaction of two in-line two-dimensional bubbles rising in viscous ambient liquids were studied using two-dimensional simulations. A mass-conserving lattice Boltzmann model that was combined by the phase-field lattice Boltzmann equation (LBE) and the pressure-evolution lattice Boltzmann method (LBM) with a multiple-relaxation-time (MRT) collision operator was used to solve the Navier–Stokes equations for multiphase flow. Starting from the circle shape, the interfaces of bubbles during the rising processes are captured by the calculation of the conservative phase-field LBE. The influence of liquid viscosity and interface tension on the coalescence and interaction of bubbles was studied by varying the Archimedes numbers (Ar) from 1 to 300 and several Bond numbers (Bo) from 5 to 200. It was found that the bubble–bubble interaction is enhanced with the decrease of the liquid viscosity, and the outcome of the coalescence is promoted by the two vortex rings (liquid circulations) around the two bubbles. A comprehensive map of the coalescence regime was obtained. Four distinct coalescence regimes (namely, Central I, Central II, Edge, and Hug) were identified, and three critical Ar that can distinguish the above four regimes were defined. Moreover, the effects of Ar and Bo on the coalescence time and the relative velocity between the two bubbles were also investigated. The current work enhances the understanding of the coalescence and interaction of bubbles.

With the advancement of information technology, the informatization construction of internal control has evolved into crucial fundamental support for the construction of internal control in colleges and universities. The informatization construction of internal control is a systematic project of which the selection of software development mode is the key link. In this paper, a detailed analysis is carried out on the equilibrium strategy of the two parties in the game between the informatization construction department of internal control in colleges and universities as well as software development companies by establishing a game model and a software maintenance risk management model for both sides, in order to probe into the selection of the software development mode in colleges and universities. The model test and case study prove that the fully commissioned development mode is the optimal mode for the informatization construction of internal control in colleges and universities, and relevant suggestions are made. This research has provided sufficient theoretical support for the informatization construction of internal control in colleges and universities.