function beta_reputation_analysis() fprintf('\n开始Beta信誉机制分析...\n'); % 创建图形窗口 figure('Position', [100, 100, 1200, 600]); % 图2a: 高信誉值场景 subplot(1, 2, 1); plot_beta_distribution(5, 2, 'a=5, b=2', 'r'); hold on; plot_beta_distribution(5, 3, 'a=5, b=3', 'b'); hold off; title('(a) 高频率可信共享'); xlabel('概率 p'); ylabel('概率密度 f(p)'); legend('Location', 'best'); grid on; % 图2b: 低信誉值场景 subplot(1, 2, 2); plot_beta_distribution(2, 5, 'a=2, b=5', 'g'); hold on; plot_beta_distribution(3, 5, 'a=3, b=5', 'm'); hold off; title('(b) 低频率可信共享'); xlabel('概率 p'); ylabel('概率密度 f(p)'); legend('Location', 'best'); grid on; sgtitle('Beta概率密度分布图(图2)', 'FontSize', 14, 'FontWeight', 'bold'); % 生成信誉值演化分析 analyze_reputation_evolution(); end function plot_beta_distribution(a, b, label_text, color) x = linspace(0, 1, 1000); y = betapdf(x, a, b); plot(x, y, 'Color', color, 'LineWidth', 2, 'DisplayName', label_text); % 计算并显示信誉值 rep_value = a / (a + b); x_pos = 0.7; y_pos = max(y) * 0.8; text(x_pos, y_pos, sprintf('Rep = %.2f', rep_value), ... 'Color', color, 'FontWeight', 'bold'); end function analyze_reputation_evolution() % 分析信誉值的动态演化 figure('Position', [100, 100, 1400, 800]); % 初始参数 initial_a = 1; initial_b = 1; num_rounds = 50; % 模拟四种不同的用户行为模式 behavior_patterns = { [0.8, 0.2], % 80%诚实,20%不诚实 [0.6, 0.4], % 60%诚实,40%不诚实 [0.4, 0.6], % 40%诚实,60%不诚实 [0.2, 0.8] % 20%诚实,80%不诚实 }; for pattern_idx = 1:4 subplot(2, 2, pattern_idx); honest_prob = behavior_patterns{pattern_idx}(1); dishonest_prob = behavior_patterns{pattern_idx}(2); % 存储信誉值演化 rep_values = zeros(num_rounds, 1); a_values = zeros(num_rounds, 1); b_values = zeros(num_rounds, 1); a = initial_a; b = initial_b; for round = 1:num_rounds % 计算当前信誉值 rep_values(round) = a / (a + b); a_values(round) = a; b_values(round) = b; % 模拟用户行为 if rand() < honest_prob a = a + 1; % 诚实共享 else b = b + 1; % 不诚实共享 end end % 绘制信誉值演化 yyaxis left; plot(1:num_rounds, rep_values, 'b-', 'LineWidth', 2); ylabel('信誉值 Rep'); ylim([0, 1]); yyaxis right; plot(1:num_rounds, a_values, 'g--', 'LineWidth', 1.5); hold on; plot(1:num_rounds, b_values, 'r--', 'LineWidth', 1.5); ylabel('累积次数'); legend('信誉值', '诚实次数', '不诚实次数', 'Location', 'best'); xlabel('交易轮次'); title(sprintf('行为模式: %.0f%%诚实, %.0f%%不诚实', ... honest_prob*100, dishonest_prob*100)); grid on; end sgtitle('信誉值动态演化分析', 'FontSize', 14, 'FontWeight', 'bold'); end %% 计算用户信誉值 function rep = calculate_reputation(a, b) % 基于Beta分布计算信誉值 % a: 成功(诚实)交易次数 % b: 失败(不诚实)交易次数 rep = a / (a + b); end %% 更新信誉参数 function [new_a, new_b] = update_reputation(a, b, is_honest) if is_honest new_a = a + 1; new_b = b; else new_a = a; new_b = b + 1; end end %% 基于信誉值的激励机制 function reward = calculate_reward(base_reward, reputation) % 根据信誉值计算奖励 % 使用非线性函数增强高信誉用户的奖励 k = 2; % 奖励系数 reward = base_reward * (1 + k * reputation^2); end %% 基于信誉值的惩罚机制 function penalty = calculate_penalty(base_penalty, reputation) % 根据信誉值计算惩罚 % 低信誉用户受到更严重的惩罚 a = 1 - reputation; % 惩罚系数 penalty = base_penalty * (1 + a); end