Application of decision logic trees and game-tree structures in analysis of automatic transmission gearboxes

Introduction (problem statement and relevance). The graphs, logic and game-tree structures methods have been used in mechanics. The purpose of modeling an automatic gearbox with graphs can be versatile, namely: determining the transmission ratio of individual gears, analyzing the speed and acceleration of individual rotating elements.The purpose of the study. The article presents the application of decision trees in the analysis of automatic gearboxes modeled with the Hsu graph.Methodology and research methods. The paper presents a method of generating game tree structures that allow to change the values of decision parameters in the issues of decision making and knowledge generation. Specifying the rank of importance, in which order you should change individual items to active, allows you to detect the so-called redundant or temporarily redundant components for a given gear currently under consideration.Scientific novelty and results. At each stage of optimization, a tree is generated, selecting the optimal decisions. Then, vertices can be added to the tree that represent the optimal responses of the system to changes in arithmetic construction parameters.Practical significance. The most important in this regard will be the selection of the optimal programming environment with the possibility of installing the program in laboratory

An efficient AI-based method to play the Mahjong game with the knowledge and game-tree searching strategy

The Mahjong game has widely been acknowledged to be a difficult problem in the field of imperfect information games. Because of its unique characteristics of asymmetric, serialized and multi-player game information, conventional methods of dealing with perfect information games are difficult to be applied directly on the Mahjong game. Therefore, AI (artificial intelligence)-based studies to handle the Mahjong game become challenging. In this study, an efficient AI-based method to play the Mahjong game is proposed based on the knowledge and game-tree searching strategy. Technically, we simplify the Mahjong game framework from multi-player to single-player. Based on the above intuition, an improved search algorithm is proposed to explore the path of winning. Meanwhile, three node extension strategies are proposed based on heuristic information to improve the search efficiency. Then, an evaluation function is designed to calculate the optimal solution by combining the winning rate, score and risk value assessment. In addition, we combine knowledge and Monte Carlo simulation to construct an opponent model to predict hidden information and translate it into available relative probabilities. Finally, dozens of experiments are designed to prove the effectiveness of each algorithm module. It is also worthy to mention that, the first version of the proposed method, which is named as KF-TREE, has won the silver medal in the Mahjong tournament of 2019 Computer Olympiad.

Modeling and Simulation of Cultural Communication Based on Evolutionary Game Theory

In the process of cultural dissemination, the dissemination of false information will have a negative impact on the entire environment. In this case, it is an effective method to regulate the behavior of cultural dissemination participants. Based on the community network structure and the improved classic network communication model, this paper constructs the susceptible-infected-recovered (SIR) model for the grassroots communication of engineering safety culture and discusses the law of grassroots transmission of engineering safety culture. The communication process is simulated, and it is concluded that a good engineering safety culture will be the first to be covered by low-level engineering safety culture in the process of dissemination. With a modularity coefficient of 0.5 as the boundary, it will affect the scale of good safety culture in different directions; the dissemination infection rate of low-level engineering safety culture changes in the same direction with the speed and scale of transmission; the maximum transmission scale of low-level engineering safety culture does not decrease with the increase of the initial value of the susceptible state. When the initial value of the immune state is 15%, the low-level safety culture scale is the lowest value of 0.135, which is the low initial value of employees with low-level engineering safety culture and is more conducive to control its maximum spread. It also puts forward management recommendations for the subjects and objects of the grassroots dissemination of engineering safety culture. This paper transforms cultural communication into an evolutionary game model, uses a game tree to describe it, and analyzes that the model has a Nash equilibrium point by adding a penalty function to the income matrix. This model can encourage cultural communication participants to take honest behaviors, effectively restrain the transmission of false information, and promote a virtuous circle of cultural communication.

Application of the Dependency Graph Method in the Analysis of Automatic Transmission Gearboxes

The current article discusses the use of the dependency graph method to design and analyze automatic transmissions. Different goals may be served by modeling an automatic transmission using graphs. The most important of them are: determining the gear ratios for gears and the analysis of speed and acceleration of the rotating elements. Game tree-structure methods can be used to analyze the functional schemes of the selected gears. This paper describes the method of generating a system of kinematics equations for signal dependency graphs. This allows the generalization and extension of the algorithmic approach, and also further analyses and syntheses, such as checking the isomorphism of the proposed solutions and determining the validity of the structure and the operational parameters of the analyzed gears.

A game strategy model in the digital curling system based on NFSP

The digital curling game is a two-player zero-sum extensive game in a continuous action space. There are some challenging problems that are still not solved well, such as the uncertainty of strategy, the large game tree searching, and the use of large amounts of supervised data, etc. In this work, we combine NFSP and KR-UCT for digital curling games, where NFSP uses two adversary learning networks and can automatically produce supervised data, and KR-UCT can be used for large game tree searching in continuous action space. We propose two reward mechanisms to make reinforcement learning converge quickly. Experimental results validate the proposed method, and show the strategy model can reach the Nash equilibrium.

Insufficient declines in new HIV infection rates amidst high scores in HIV testing and awareness: ‘a game theory simulation’

Aim Substantial progress has been made towards the 90–90–90 global targets; however, the pace at which new infections are declining remains undesirable to meet the UNAIDS 2020 global targets of below 500,000 new infections annually. We discussed the possibility of continued HIV incidence amidst remarkable scores in the 90–90–90 global targets. Subject and methods A game theory simulation was used to explain micro-level sexual interactions in situations of imperfect information on each partner’s HIV status. A non-cooperative sex game tree was constructed following the Harsanyi transformation in two scenarios; scenario one: a player assigns higher subjective probability that the partner is HIV negative; and in scenario two: a player assigns higher subjective probability that the partner is HIV positive. Subjective expected utilities were computed using hypothetical payoffs. Results Accepting unprotected sex is a pure strategy for both players in scenario 1. Player2 is likely to acquire HIV/AIDS. Accepting protected sex is a mixed strategy equilibrium for both players in scenario 2. Player2 is likely to avoid HIV infection. Conclusion Choice for safe or risky sex is a function of subjective probabilities individuals attach to their partners being infected or uninfected. More efforts towards addressing factors affecting individual probability distributions on riskiness of their sexual partners is required, especially for young women in Sub-Saharan Africa.

Implementation of Subgame-Perfect Cooperative Agreement in an Extensive-Form Game

A novel approach to sustainable cooperation called subgameperfect core (S-P Core) was introduced by P. Chander and M. Wooders in 2020 for n-person extensive-form games with terminal payoffs. This solution concept incorporates both subgame perfection and cooperation incentives and implies certain distribution of the total players' payoff at the terminal node of the cooperative history. We use in the paper an extension of the S-P Core to the class of extensive games with payoffs defined at all nodes of the game tree that is based on designing an appropriate payoff distribution procedure β and its implementation when a game unfolds along the cooperative history. The difference is that in accordance with this so-called β-subgameperfect core the players can redistribute total current payoff at each node in the cooperative path. Moreover, a payoff distribution procedure from the β-S-P Core satisfies a number of good properties such as subgame efficiency, non-negativity and strict balance condition. In the paper, we examine different properties of the β-S-P Core, introduce several refinements of this cooperative solution and provide examples of its implementation in extensive-form games. Finally, we consider an application of the β-S-P Core to the symmetric discrete-time alternating-move model of fishery management.

Earthquake induced crises: game tree approached risk communication and lessons learnt

Earthquakes, large or even moderate, are often followed by secondary phenomena, such as landslides, tsunamis, fires and technological disasters, leading to cascading effects that may, in turn, cause severe repercussions. Before, during and after the occurrence of these events, risk communication, currently evolved to codified legislation, is a crucial factor. Policy selection in the present study is approached by the application of the risk game tree and its formation. The events studied here in view of policy making have occurred both in the historical and the instrumental era, to account for different level of exposure and anthropogenic hazards, in Greece (1894 Atlanti, 1953 Kefallinia series, 2003 and 2015 Lefkas), Italy (1976 Friuli), Japan (2011 Tōhoku) and Slovenia (1917 Brežice). In all case studies the whole disaster management cycle is examined, i.e. mitigation, preparedness, response and recovery. Disaggregation of earthquake-related direct and cascading effects, as well as risk communication are taken into account and ethical challenges are posed both to scientists and policy makers.