6 research outputs found
Renegotiation Strategy of Public-Private Partnership Projects with Asymmetric Information—An Evolutionary Game Approach
The characteristics of public-private partnerships (PPPs) determine that renegotiation is inevitable. Moreover, the strategic choice of the government and investors during renegotiation is critical for the project to continue. Previous studies suggested that the government’s decision-making mistakes and investors’ opportunism during renegotiation are the significant reasons for project failures. However, most of the research focused on the behavioral decision of one party while few have applied evolutionary game theory to study the mutual influence of the strategy choices of both parties involved. To address this issue, this paper established an evolutionary game model of the government’s and investors’ renegotiation strategies, and analyzed the evolutionary stability strategy and related parameters. The results showed that the government’s selection of strategy is based on two values, i.e., the buyback cost and the difference between subsidy cost and the expected social benefit of the project in the future. The higher the expected social benefit, the higher the probability that the government chooses to maintain the project. Besides, investors’ strategy is mainly determined by speculative net benefit and financial status. The probability of investors’ opportunism is positively correlated with the speculative net benefit and negatively correlated with the project benefit of non-opportunism. In addition, cooperative benefits created by reasonable participation in the project will effectively restrict opportunistic behaviors, and the interactive behavior of both game players will move toward the optimal portfolio strategy. This study can provide relevant management suggestions for avoiding excessive subsidies and restraining opportunistic behaviors, which are conducive to the sustainable development of PPP projects
CLE against SOA with Better Data Security Storage to Cloud 5G
Cloud 5G and Cloud 6G technologies are strong backbone infrastructures to provide high data rate and data storage with low latency for preserving QoS (Quality of Service) and QoE (Quality of Experience) in applications such as driverless vehicles, drone-based deliveries, smart cities and factories, remote medical diagnosis and surgery, and artificial-intelligence-based personalized assistants. There are many techniques to support the aforementioned applications, but for privacy preservation of Cloud 5G, the existing methods are still not sufficient. Public key encryption (PKE) scheme is an important means to protect user data privacy in Cloud 5G. Currently, the most common PKE used in Cloud 5G is CCA or CPA secure ones. However, its security level maybe not enough. SOA security is a stronger security standard than CPA and CCA. Roughly speaking, PKE with SOA security means that the adversary is allowed to open a subset of challenger ciphertexts and obtains the corresponding encrypted messages and randomness, but the unopended messages and randomness remain secure in the rest of the challenger ciphertexts. Security against SOA in PKEs has been a research hotspot, especially with the wide discussion in Cloud 5G. We revisited the SOA-CLE and proposed a new security proof, which is more concise and user friendly to understand privacy preservation in Cloud 5G applications
Effects of food wastes based on different components on digestibility and energy recovery in hydrogen and methane co-production
This study was conducted for four organic fractions (carbohydrates, proteins, cellulose, lipids) at an inoculum concentration of 30 % and a total solid (TS) of 8 % to investigate the effect of the main components of food waste on the performance of the two-stage anaerobic digestion. The results showed that the gas phase products were closely related to the composition of the substrate, with the carbohydrate and lipid groups showing the best hydrogen (154.91 ± 2.39mL/gVS) and methane (381.83 ± 12.691mL/gVS) production performance, respectively. However, the increased protein content predisposes the system to inhibition of gas production, which is mutually supported by changes in the activity of dehydrogenase and coenzyme F420. Butyric acid (53.19 %) dominated the liquid phase products in both stages, indicating that all four organic fractions were butyric acid-based fermentation and that the final soluble chemical oxygen demand degradation reached 72.97 %–82.86 %. The carbohydrate and cellulose groups achieved the best energy recovery performance, with conversion rates exceeding 65 %. The above results can provide a useful reference for the resource utilization of food waste