Anhui University of Finance and Economics

About: Anhui University of Finance and Economics is a education organization based out in Bengbu, China. It is known for research contribution in the topics: China & Hopf bifurcation. The organization has 933 authors who have published 1070 publications receiving 11500 citations. The organization is also known as: AUFE.

Capacity of Nakagami- $m$ Fading Channel With BPSK/QPSK Modulations

Abstract: In this letter, we develop a recurrence formula for the capacity of Nakagami- $m$ fading channel with BPSK/QPSK modulations when channel state information is available at the receiver. For each fading parameter $m$ , a simply constructed series representation with a fast-convergence rate can be obtained through the recurrence formula. The series expansion provides a numerically efficient way to calculate the capacity for both Rayleigh and Nakagami- $m$ fading channels. The simulation results show that the recurrence formula is a good alternative for estimating the capacity of Nakagami fading channel.

Complexity analysis of cold chain transportation in a vaccine supply chain considering activity inspection and time-delay

Abstract: The development of COVID-19 vaccine is highly concerned by all countries in the world. So far, many kinds of COVID-19 vaccines have entered phase III clinical trial. However, it is difficult to deliver COVID-19 vaccines efficiently and safely to the areas affected by the epidemic. This paper focuses on vaccine transportation in a supply chain model composed of one distributor and one retailer (clinic or hospital), in which the distributor procures COVID-19 vaccines from the manufacturer and then resells them to the retailer. Distributor detects the activity level of the vaccines, and retailer is responsible for transportation of the vaccines. Firstly, we establish a difference equations model with time-delay. Secondly, we investigate the impact of time-delay on the stability of vaccine supply chain. In addition, we explore the influence of decision adjustment speed of the distributor (or retailer) on the stability of vaccine supply chain. Finally, we verify the theoretical results by a two-dimensional bifurcation diagram, the largest Lyapunov exponent, entropy, and domain of attraction. The results show that when the decision delay-time or the adjustment speed of decision variables exceeds a certain threshold, it brings a negative impact on the stability of vaccine supply chain system. The stability domain of the system shrinks as customers’ sensitivity to cold chain transportation decreases and by contrast expends as customers’ sensitivity to vaccine prices decreases. When the vaccine supply chain is in a state of chaos, the effect of external control over the system is superior to that of internal control over the system.

Delay-induced Hopf bifurcation of an SVEIR computer virus model with nonlinear incidence rate

Abstract: We are concerned with the Hopf bifurcation of an SVEIR computer virus model with time delay and nonlinear incident rate. First of all, by analyzing the associated characteristic equation we obtain sufficient conditions for its local stability and the existence of a Hopf bifurcation. Directly afterward, by means of the normal form theory and the center manifold theorem we derive explicit formulas that determine the direction of the Hopf bifurcation and the stability of the bifurcated periodic solutions. Finally, we carry out numerical simulations to illustrate and verify the theoretical results.

Prediction of Fish Migration Caused by Ocean Warming Based on SARIMA Model

Abstract: Herring and mackerel are two of the most important pillars of Scottish fisheries. In recent years, global warming has caused a gradual rise in ocean temperatures. In order to survive and reproduce, herring and mackerel populations will migrate. This will have a huge impact on Scotland’s fisheries. Therefore, we need to predict the relocation of fish stocks in advance, make timely adjustments to the fishing range, and minimize the loss of the fishing industry. In this article, we subdivide the research target sea area into 39 regions, establish the optimal SARIMA model for each region based on the collected seawater temperature time series data, and take region 13 and region 15 as examples to fit the ARIMA (3, 3, 1) (1, 2, 1) and ARIMA (2, 3, 1) (0, 2, 1) models with a period of 12. The results show that the SARIMA model fits well in all regions and predicts the temperature changes in the studied sea area from 2021 to 2050. Finally, according to the predicted sea temperature in different periods, the migration position of the fish school is predicted.