基于博弈理论的供应链信任稳定演化策略

考虑供应链信任演化3个不同阶段,研究供应链信任稳定演化策略。针对传统博弈的局限性,从约束机制不健全和约束机制健全两个层面进行分析,将企业选择信任的额外收益、单方面信任成本、单方面不信任额外收益、单方面不信任代价和单方面信任额外补偿引入到演化博弈矩阵中,利用演化博弈理论分析各阶段的稳定状态。为验证模型的有效性和可行性,通过数值分析,研究模型的演化动力变化,得出相应的系统相图。研究结果表明,供应链信任策略值的概率大于0.75时,合作达到稳态,供应链整体收益最大;约束机制不健全下的稳定演化策略明显优于传统博弈下的稳定演化策略,但是约束机制不健全,企业的稳定演化策略未必都是信任;供应链企业间需要健全约束机制,当约束机制健全时,信任是企业最终策略选择。     

基于系统动力学的跑道侵入风险演化博弈研究

为探究跑道侵入风险控制中机场、航空公司与行业政府的博弈策略,构建了基于支付函数矩阵的三方演化博弈模型,并运用系统动力学对演化博弈过程进行仿真分析。设置了2种仿真环境：演化博弈模型中概率突变的情景以及动态监管策略下的博弈过程,通过了模型检验及灵敏度分析。仿真结果表明：该博弈模型存在有效解,但不存在演化稳定均衡解;改进的行业政府动态监管策略条件下存在演化稳定均衡解。得出结论：行业政府实行动态监管策略,令经济制裁额度为跑道侵入风险严重度的函数,促使机场和航空公司加大跑道侵入风险的控制力度。     

远程医疗背景下社区医院和患者行为选择的演化分析

采用演化博弈理论方法,在远程医疗合作背景下,建立了社区医院和患者策略选择的演化博弈模型,分析了社区医院远程医疗合作策略和患者选择就医医院策略博弈的演化路径、演化均衡及其影响因素,并用Matlab软件对博弈演化过程进行数值仿真。研究发现,决策参数(政府对社区医院的资金支持、患者享有的医保报销比例等)取值的改变会对演化结果产生影响,并且给出了相应决策参数的确定方法。最后,根据分析结果为远程医疗的推广提出了合理性建议。     

基于互联网环境的生鲜农产品质量安全控制研究

针对生鲜农产品质量安全问题,构建了基于互联网环境下农户、龙头企业、消费者的三方演化博弈模型,探讨三方主体行为策略的演化过程以及策略选择的相互影响。通过求解稳定均衡点,分析了不同情形下生鲜农产品质量安全三方主体的演化路径,并使用Matlab进行算例分析。研究发现,生鲜农产品质量安全三方演化博弈模型存在多重演化稳定策略,且存在相应的演化稳定条件。据此提出了促使农户和龙头企业提供优质安全生鲜农产品的相关建议,为提高生鲜农产品质量安全水平提供了一个方向。     

考虑生产商风险规避的农产品绿色投资策略演化研究

针对农户与生产商绿色投资策略的选择问题，构建以农户为主导的Stackelberg博弈模型，得到双方在不同策略组合下的支付矩阵。以此为依据，运用演化博弈理论，研究农户与风险规避生产商两类异质群体绿色投资策略选择的演化过程，推演不同条件下系统的演化稳定策略，探讨双方绿色投资策略选择的演化路径及其影响因素。结果表明，面对具有绿色农产品消费偏好的消费者时，农户与生产商至少有一方会选择绿色投资策略，当双方选择合作并分担绿色投资成本时市场需求最大。此时，成本分担比例及生产商风险规避程度对两群体的策略选择演化速度、绩效水平具有显著影响。     

关于上海开展旅游医疗的可行性研究

通过一个非对称二人博弈模型,给出了医院和代理公司合作开展旅游医疗的演化稳定分析.结果显示,经过长期反复博弈,学习和策略调整的结果随着双方利润分配比例的不同而变化.当医院和代理公司独自开展旅游医疗服务的净收益均为正值时,两种类型的博弈方都采取"背叛"的策略;当博弈一方独自开展旅游医疗的净收益为正、另一方独自开展旅游医疗的净收益为负时,净收益为正的一方将选择"背叛"的策略,净收益为负的一方将采取"合作"的策略;当博弈双方独自开展旅游医疗的净收益均为负数时,演化结果是,其中一方采取"背叛"的策略,而另一方将采取"合作"的策略.     

政府奖惩激励下快递包装回收行为演化博弈与仿真分析

目的 厘清快递包装废弃物回收利益主体间的博弈关系与演化路径,解决快递包装回收率普遍较低的问题。方法 在信息不对称和有限理性的条件下,构建政府、回收商和消费者三群体间快递包装回收行为演化博弈模型。分析群体间稳定策略组合的实现条件,运用Matlab软件进行数值仿真,探究不同参数变化对三方演化路径的影响。结果 政府的奖惩力度、激励成本、收益大小是影响博弈三主体策略选择和演化稳定路径走向的关键因素。同时回收商和消费者的参与比例对政府行为选择有显著作用。结论 参与主体得益是影响其行为的关键,政府通过积极鼓励、支持和宣传,同时设立科学合理的奖惩激励政策能够明显提高快递包装回收率。     

数据采集流程认证机制的演化博弈分析

数字经济的高速发展已经受到了质疑,数据安全问题已成为各国政府数据治理的一项挑战。本文以标准视角,创新性地提出数据采集流程认证机制,界定了必要采集和非必要采集数据的概念,在构建平台企业和消费者双方博弈的基础上,利用动态演化博弈分析了双方的稳定策略与博弈路径,通过模拟仿真进一步讨论了平台企业认证成本对双方博弈路径的影响。研究结果表明：（1）平台企业“完成认证”、消费者“全部授权”是博弈理想的稳定策略;（2）平台企业初始策略选择会影响消费者的策略选择,最终形成“U型”曲线;（3）平台企业的认证成本会影响模型演化的速度和结果。研究结果为平台企业个人数据采集流程认证的建立提供了理论依据,为政府制定相关政策提供了参考,对于数字经济的健康发展具有重要的理论意义和实践价值。     

技术共享对科技型中小企业协同创新联盟稳定性的影响

技术共享有助于形成稳定的企业创新联盟。研究围绕科技型中小企业之间协同创新网络展开研究,构建企业之间基于有限理性假设的演化博弈模型。并通过研究企业之间协同创新博弈的演化路径和均衡点的位置,得到系统演化的数值解及不同初始创新概率下策略演化趋势,讨论了企业之间技术共享行为及相互影响的博弈演化过程。结果表明:参与技术共享协同创新的企业技术外化程度和吸收能力都会影响协同创新联盟技术资源的共享,并且企业选择博弈的初始意愿越接近均衡策略点,达成联盟稳定的周期越长。     

政府主导下军民融合式协同创新的演化博弈

应用演化博弈理论,从动态角度对有限理性的政府、军工企业和民营企业间的博弈行为进行分析,探讨政府主导下军民合作创新系统中双方成员的演化稳定策略,提出促进军工领域多主体最优合作的对策和建议。结果表明,协同创新系统的超额收益、研发总成本以及背叛收益等因素对双方的策略选择具有直接的影响。政府通过建立完善的激励、监督和惩罚机制,打造良好的军民融合式发展环境,发挥宏观调控作用,能够促进创新体系向帕累托最优的方向演化。     

Merging into heavy motorway traffic by young and elderly drivers

An increase in the number of Heavy Goods Vehicles on motorways may lead to additional problems in the interaction with an increased number of elderly drivers. Elderly drivers suffer from reduced information processing speed and capacity, and in general effectively compensate for this by taking more time. However, this strategy, regulating task demands by slowing down will make merging into motorway traffic actually more difficult.In an experiment performed in a driving simulator, young and elderly drivers merged into motorway traffic. Driver behaviour and mental workload were studied while the following factors were manipulated: type of traffic and density of Heavy Goods Vehicles on the main road, the length of the acceleration lane, presence of a slowly driving lead car, and presence of a driver support system that encouraged the drivers to speed up if their speed was too low.Results show that the effects of an increased number of Heavy Goods Vehicles on the main road were not more adverse for elderly than for the young participants, with the exception that elderly drivers merged at a lower speed. This lower speed could make the manoeuvre more risky in real traffic. The support system and an extended acceleration lane facilitated merging, while a slowly driving lead car impeded completion of the manoeuvre.     

The effect of chevron alignment signs on driver performance on horizontal curves with different roadway geometries

To develop a practicable and clear guideline for implementing Chevrons on China’s highways, it is necessary to understand the effect of Chevrons on driving performance in different roadway geometries.Using a driving simulator, this study tests the effect of China’s Chevrons on vehicle speed and lane position on two-lane rural highway horizontal curves with different roadway geometries.The results showed a significant effect of Chevrons on speed reduction, and this function was not significantly affected by curve radius but was statistically affected by curve direction. The speed reduction caused by Chevrons was also significant at the approach of curve, middle of curve and point of tangent. The 85th percentile speed was also markedly lower when Chevrons were present. We also found a significant effect of Chevrons in encouraging participants to drive the vehicle with a more proper lane position at the first half of curves; and this function was slightly affected by curve radius. Meanwhile, the effect of Chevrons on keeping drivers staying in a more stable lane position was also statistically significant at the second half of curves. In sharp curves, the function of Chevrons to make drivers keep a stable lane position was lost. Besides, the impact of curve direction on the function of Chevrons on lane position was always present, and drivers would drive slightly away from Chevrons.Regardless of the curve radius, China’s Chevrons at horizontal curves provide an advance warning, speed control and lane position guide for traffic on the nearside of Chevrons. Besides, combing with the function of Chevrons on preventing excessive speed and the benefit to make drivers keep a more proper lane position, China’s Chevrons appear to be of great benefit to reduce crashes (e.g., run-off-road) in curves.     

Less is more: the influence of traffic count on drinking and driving behaviour

Drinking and driving road checks are often organized with either a clear prevention or repression objective in mind. The objective of a prevention strategy is to make as many people as possible believe that police officers are enforcing drinking and driving laws and that drinking drivers will most likely be caught. As such, targeting high traffic count road sites with high-visibility road checks is a priority because it serves to increase awareness of the enforcement activity. An alternative to this prevention approach is the “repression” approach that involves targeting times and places where the highest number of drinking drivers are to be expected. Rather than attempting to affect the subjective chance of getting caught, this approach seeks to increase the objective likelihood of getting caught; the aim is to apprehend as many drinking drivers as possible. Regardless of the chosen strategy, there is a need to understand how traffic count influences drinking and driving behaviour as traffic count may play a role in a police officer's choice of sites for a road check. The objective of this paper is to shed some light on this relationship between drinking and driving behaviour and traffic count. In this paper, data from a roadside survey, carried out in British Columbia in 2003, are used. A two-level logistic regression analysis was carried out with data from 2627 drivers coming from 48 different road sites to replicate a model that was previously obtained with comparable data from a Belgian roadside survey, also carried out in 2003. The present study successfully replicated the findings of the Belgian model, substantiating that the probability for drivers to be drinking and driving significantly decreases with an increasing level of traffic count. This supports the suggestion that drinking drivers avoid high traffic count road sites. The relevance of these findings with respect to organizing preventive or repressive road checks and possible confounding variables are discussed at the end of this paper.     

Micro-simulation of vehicle conflicts involving right-turn vehicles at signalized intersections based on cellular automata

At intersection, vehicles coming from different directions conflict with each other. Improper geometric design and signal settings at signalized intersection will increase occurrence of conflicts between road users and results in a reduction of the safety level. This study established a cellular automata (CA) model to simulate vehicular interactions involving right-turn vehicles (as similar to left-turn vehicles in US). Through various simulation scenarios for four case cross-intersections, the relationships between conflict occurrences involving right-turn vehicles with traffic volume and right-turn movement control strategies are analyzed. Impacts of traffic volume, permissive right-turn compared to red-amber-green (RAG) arrow, shared straight-through and right-turn lane as well as signal setting are estimated from simulation results. The simulation model is found to be able to provide reasonable assessment of conflicts through comparison of existed simulation approach and observed accidents. Through the proposed approach, prediction models for occurrences and severity of vehicle conflicts can be developed for various geometric layouts and traffic control strategies.     

Analyzing fault and severity in pedestrian–motor vehicle accidents in China

The number of pedestrian–motor vehicle accidents and pedestrian deaths in China surged in recent years. However, a large scale empirical research on pedestrian traffic crashes in China is lacking. In this study, we identify significant risk factors associated with fault and severity in pedestrian–motor vehicle accidents. Risk factors in several different dimensions, including pedestrian, driver, vehicle, road and environmental factors, are considered. We analyze 6967 pedestrian traffic accident reports for the period 2006–2010 in Guangdong Province, China. These data, obtained from the Guangdong Provincial Security Department, are extracted from the Traffic Management Sector-Specific Incident Case Data Report. Pedestrian traffic crashes have a unique inevitability and particular high risk, due to pedestrians’ fragility, slow movement and lack of lighting equipment. The empirical analysis of the present study has the following policy implications. First, traffic crashes in which pedestrians are at fault are more likely to cause serious injuries or death, suggesting that relevant agencies should pay attention to measures that prevent pedestrians from violating traffic rules. Second, both the attention to elderly pedestrians, male and experienced drivers, the penalty to drunk driving, speeding, driving without a driver's license and other violation behaviors should be strengthened. Third, vehicle safety inspections and safety training sessions for truck drivers should be reinforced. Fourth, improving the road conditions and road lighting at night are important measures in reducing the probability of accident casualties. Fifth, specific road safety campaigns in rural areas, and education programs especially for young children and teens should be developed and promoted. Moreover, we reveal a country-specific factor, hukou, which has significant effect on the severity in pedestrian accidents due to the discrepancy in the level of social insurance/security, suggesting that equal social security level among urban and rural people should be set up. In addition, establishing a comprehensive liability distribution system for non-urban areas and roadways will be conducive to both pedestrians’ and drivers’ voluntary compliance with traffic rules.     

The effect of cycle lanes on the proximity between motor traffic and cycle traffic

An experiment collected proximity data of motor traffic overtaking cycle traffic on roads with and without cycle lanes using an instrumented bicycle. The work enhances previous research which has considered the riding position of the cyclist and whether or not the cyclist was helmeted, while controlling for vehicle type.The analysis shows that significantly wider passing distances are adopted by motorists in the condition without a 1.45 m cycle lane, with posted speed limits of 40 mph and 50 mph with a 9.5 m wide carriageway. These findings were not replicated for a similar width road with a posted speed limit of 30 mph and a 1.3 m cycle lane.The results suggest that in the presence of a cycle lane, drivers may be driving within the confines of their own marked lane with less recognition being given to the need to provide a comfortable passing distance to cycle traffic in the adjacent cycle lane.     

Influence of road markings,lane widths and driver behaviour on proximity and speed of vehicles overtaking cyclists

The proximity and speed of motor traffic passing cyclists in non-separated conditions may be so close and so great as to cause discomfort. A variety of road design and driver behaviour factors may affect overtaking speeds and distances. The investigation presented in this paper builds on previous research and fills gaps in that research by considering the presence of cycle lanes on 20 mph and 30 mph roads, different lane widths, different lane markings, vehicle type, vehicle platooning and oncoming traffic. Data were collected from a bicycle ridden a distance of one metre from the kerb fitted with an ultrasonic distance detector and forward and sideways facing cameras.     

The effects of driver training on simulated driving performance

Given that the beneficial effects of driver training on accident risk may not be an appropriate criterion measure, this study investigates whether professionally trained and experienced drivers exhibit safer driving behaviour in a simulated driving task compared with drivers without professional driver training. A sample of 54 police trained drivers and a sample of 56 non-police trained drivers were required to complete two tasks. Firstly to overtake a slow-moving bus on a hazardous stretch of single-lane road with bends and hills and secondly to follow a lead vehicle travelling at 55mph in a built-up section with a speed limit of 30mph. Results showed that in comparison with non-police trained drivers, police drivers were significantly less likely to cross the central division of the road at unsafe locations during the overtaking task and reduced their speed on approach to pedestrians at the roadside in the following task to a greater extent. Police drivers also adopted a more central lane position compared with non-police trained drivers on urban roads and at traffic lights during the following task. Driver group differences in simulated driving performance are discussed with reference to the implications for driver training assessment and skill development.     

The effect of traffic tickets on road traffic crashes

Road traffic crashes are globally a leading cause of death. The current study tests the effect of traffic tickets issued to drivers on subsequent crashes, using a unique dataset that overcomes some shortcomings of previous studies. The study takes advantage of a national longitudinal dataset at the individual level that merges Israeli census data with data on traffic tickets issued by the police and official data on involvement in road traffic crashes over seven years. The results show that the estimated probability of involvement in a subsequent fatal or severe crash was more than eleven times higher for drivers with six traffic tickets per year compared to those with one ticket per year, while controlling for various confounders. However, the majority of fatal and severe crashes involved the larger population of drivers who received up to one ticket on average per year. The current findings indicate that reducing traffic violations may contribute significantly to crash and injury reduction. In addition, mass random enforcement programs may be more effective in reducing fatal and severe crashes than targeting high-risk recidivist drivers.