ISSN 0253-2778

CN 34-1054/N

2022 Vol. 52, No. 11

2022-11 Contents
2022, 52(11): 1-2.
2022-11 Abstract
2022, 52(11): 1-2.
Chemistry ;Engineering & Materials
Robust transfer-printing method for perovskite films and nanostructures
Peiyuan Pang, Guichuan Xing
2022, 52(11): 1. doi: 10.52396/JUSTC-2022-0139
Metal halide perovskites, as a promising semiconductor material, have been successfully used in electroluminescent devices because of their desirable characteristics, such as good conductivity, high color purity, tunable bandgap, low cost and solution process ability. In the past few years, significant progress has been made in the development of high-efficiency perovskite light-emitting diodes (PeLEDs). These efficient PeLEDs are mainly achieved by sophisticated spin-coating methods, which can easily control the perovskite's composition, film thickness, morphology and crystallinity. However, with the continuous development of PeLEDs, commercial production problems have to be solved, such as large area production, high resolution patterning and substrate diversity, which are difficult for the current spin-coating process.
Accessibility percolation on N-ary trees
Zhishui Hu, Jinwen Wu, Liang Dong
2022, 52(11): 2. doi: 10.52396/JUSTC-2022-0059
Consider a rooted $ N $-ary tree. To each of its vertices, we assign an independent and identically distributed continuous random variable. A vertex is called accessible if the assigned random variables along the path from the root to it are increasing. We study the number $C_{N,\,k}$ of accessible vertices of the first $ k $ levels and the number $ C_N $ of accessible vertices in the $ N $-ary tree. As $ N\rightarrow \infty $, we obtain the limit distribution of $C_{N,\, \beta N}$ as $ \beta $ varies from $ 0 $ to $ +\infty $ and the joint limiting distribution of $(C_{N}, C_{N,\,\alpha N+t \sqrt{\alpha N}})$ for $0 < \alpha\leqslant 1$ and $ t\in \mathbb{R} $. In this work, we also obtain a weak law of large numbers for the longest increasing path in the first $ n $ levels of the $ N $-ary tree for fixed $ N $.
A new deep reinforcement learning model for dynamic portfolio optimization
Weiwei Zhuang, Cai Chen, Guoxin Qiu
2022, 52(11): 3. doi: 10.52396/JUSTC-2022-0072
There are many challenging problems for dynamic portfolio optimization using deep reinforcement learning, such as the high dimensions of the environmental and action spaces, as well as the extraction of useful information from a high-dimensional state space and noisy financial time-series data. To solve these problems, we propose a new model structure called the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) method with multi-head attention reinforcement learning. This new model integrates data processing methods, a deep learning model, and a reinforcement learning model to improve the perception and decision-making abilities of investors. Empirical analysis shows that our proposed model structure has some advantages in dynamic portfolio optimization. Moreover, we find another robust investment strategy in the process of experimental comparison, where each stock in the portfolio is given the same capital and the structure is applied separately.
Socially responsible donation decision analysis in a supply chain under government subsidy
Dongxu Du, Feng Yang, Manman Wang
2022, 52(11): 4. doi: 10.52396/JUSTC-2022-0017
As an important form for firms to demonstrate social responsibility, socially responsible donation (SRD) is becoming increasingly widespread and attracting more attention. It is important to encourage firms to effectively undertake social responsibilities and improve social welfare. Recently, it has become very popular for firms to demonstrate their social responsibility through SRD campaigns. With the aim of solving the decision-making problem of a retailer-led socially responsible supply chain considering government subsidy, this study established a three-stage Stackelberg game model. By analyzing the impact of pricing and donation decisions on operations and management, either with or without government subsidy, we found that to achieve better performance, retail firms will choose to implement donation activities. However, it is not the case that the higher the donation, the better the performance. In addition, there is a gap: without government subsidy, social welfare is not optimal when members’ performance in the supply chain is maximized, and more donations are needed to maximize social welfare. This study proves that government subsidy can encourage supply chain members to generate more donations, while improving the performance of the supply chain and social welfare. We propose an optimal subsidy rate to eliminate the gap and maximize social welfare. We also analyze the impact of external parameters, including the cost parameter and consumer preference level, on the equilibrium results. Finally, we extend this research to provide management insights for businesses under uncertain market sizes and centralized decision-making scenarios.
Preinstalled application policies of smart device firms
Ningxin Lei, Jie Wu, Mingjun Li, Xiang Ji
2022, 52(11): 5. doi: 10.52396/JUSTC-2022-0012
Recent technological advancements in smart devices have paved the way for a booming mobile commerce industry. As smart device vendors launch products with a rich variety of business applications, it is critical for all stakeholders to understand the attitudes of different vendors toward preinstalled applications in the smart device industry. We address this issue by exploring an analytical model for preinstalled application policies. Specifically, we study how to choose an optimal policy in a market with hypercritical consumers who have disutility from preinstalled applications, and expert consumers who have removal knowledge. The results show that, as marginal preinstallation income increases, firms tend to force more consumer segments to use preinstalled applications. By comparing monopolistic and competitive situations, we find that the advantages of the policy change are different, and competitive firms prefer to adopt more stringent policies than monopolistic firms when the marginal preinstallation income is smaller. The initiative of expert consumers introduced new findings to the research. The increase in such consumers may lead to an increase in the profits of monopolistic firms when they adopt a preinstallation policy with a low removal threshold, but this has no impact on the profits of competitive firms. Additionally, an increase in such consumers will lead competitive firms to choose to bundle applications when the marginal preinstallation income is smaller and the impact on monopolistic firms’ policy decisions is morecomplex.
Evolutionary game analysis of low-carbon behavior credit supervision of logistics enterprises
Yu Dong, Rui Zhen, Tingting Yang
2022, 52(11): 6. doi: 10.52396/JUSTC-2022-0070
Based on the low-carbon obligation fulfillment of Chinese logistics enterprises, this study constructs a tripartite evolutionary game model to analyze the evolutionary process of the interaction between the local government, logistics enterprises and the public in the process of low-carbon behavior credit supervision. Then using Netlogo software, a parameter simulation experiment is conducted to determine the optimal policy for improving the effect of supervision. The results are as follows: ① The combined influence of the local government and the public can effectively change the strategic choice of enterprises and promote the low-carbon behavior of enterprises. ② In terms of improving the effect of supervision, reducing the cost of government supervision would have a highly significant effect, and reducing the cost of the public would be counterproductive. ③ Increasing the government subsidies to enterprises and the government’s fines to enterprises both have a significant effect, and the effect of improving the former is better. However, increasing the severity of higher-level governments punishing local governments will reduce the stability of the system. ④ Supervision can be more effective by increasing the public’s impact on enterprises’ earnings rather than by increasing government subsidies to the public.