基于网络等级特征与VMS的交叉巢式Logit模型

基于等级特征与可变信息板(VMS)研究了交叉巢式Logit(CNL)模型及网络交通流分配。综合幂函数与指数函数表示方法给出新的信息效用衰减因子,结合道路等级特征表示VMS对车流的影响系数及CNL模型的分配系数;给出等级结构道路网络的随机用户均衡条件下的交叉巢式Logit路径选择模型及其等价数学规划,并设计网络流分配算法。通过实例网络的计算与分析,得到一些有意义的结论:等级结构越显著的路网总出行时间费用越低且其分散参数(θ)弹性绝对值越大;对具有较强随机性的实际路网,若增加一定的确定性则节省更多网络总出行时间;道路网络中设置了VMS时总出行时间受分散参数的影响更小。     

Evolution of cooperation in the spatial public goods game with the third-order reputation evaluation

In this letter, in order to deeply explore the role of individual reputation in the evolutionary game dynamics, we present a new third-order reputation evaluation model to discuss the evolution of cooperation in the spatial public goods game. In the current model, we should not only consider the strategy (cooperation, C or defection, D) of a focal player, but also take his own reputation and his opponent's reputation status into account. Among them, the individual reputation will be divided into being good and bad according to the specified threshold, and the good player will be endowed with the more influential strategy transfer ability, which further helps to create the clusters of cooperative and good players within the population and then fosters the cooperation. A large plethora of experimental simulation results indicate that four rules under the third-order reputation mechanism can lead to the promotion of cooperation when compared to the traditional public goods game model. The current work is conductive to a better understanding of the persistence and emergence of collective cooperation in real-world systems.     

Evolution of global cooperation and ethnocentrism in group-structured populations

Global cooperation becomes more and more important in times of increased environmental awareness. However, exploiting out-group members allows ethnocentrism to be advantageous over global cooperation. The debate on which strategy, global cooperation or ethnocentrism, is more likely to persist with the increasing trend of globalization, is ongoing from the evolutionary perspective. To shed some light on this issue, we explore the influences of global migration and leadership on the emergence of global cooperation and ethnocentrism. It is found that global migration can enhance ethnocentrism while has little effect on global cooperation. Interestingly, the enforcement of leadership, under which leaders punish defectors, can facilitate global cooperation such that it accounts for a higher fraction than ethnocentrism in equilibrium state.     

Role of memory effect in the evolution of cooperation based on spatial prisoner's dilemma game

We investigate the impact of memory effect on the evolution of cooperation in the spatial prisoner's dilemma game, in which each player will record his own strategies during the previous M game rounds (here, M is also named as the memory length). At each time step, each individual will update his current strategy according to the Fermi-like probability which will be multiplied by a pre-factor, and this factor will be correlated with the fraction of previous strategy states identical with the individual strategy to be updated. The numerical simulation results demonstrate that the memory length will largely influence the cooperation level at the stationary state, and it is clearly shown that the intermediate value of M will optimally favor the emergence of cooperation and the dynamical evolution, and characteristic patterns also support these conclusions. In addition, we depict the full cooperation phase diagrams and find that the cooperation region will be broadened under the case of moderate M values. The current results also indicate that the limited memory may be enough for us to design the effective promotion mechanism and further understand the emergency of cooperation taking place upon many networked populations.     

Cooperative Dynamics in Lattice-Embedded Scale-Free Networks

We investigate cooperative behaviors of lattice-embeddedscale-free networking agents in the prisoner's dilemma game model byemploying two initial strategy distribution mechanisms, which are specificdistribution to the most connected sites (hubs) and random distribution. Ourstudy indicates that the game dynamics crucially depends on the underlyingspatial network structure with different strategy distribution mechanism.The cooperators' specific distribution contributes to an enhanced level ofcooperation in the system compared with random one, and cooperation isrobust to cooperators' specific distribution but fragile to defectors' specific distribution. Especially, unlike the specific case, increasing heterogeneity of network does not always favor the emergence of cooperation under random mechanism. Furthermore, we study the geographical effects and find that the graphically constrained network structure tends to improve the evolution of cooperation in random case and in specific one for a large temptation to defect.     

ATIS和道路收费下的混合随机用户均衡的效率损失

在ATIS作用下的交通网络中,用户在交通信息的接受程度上是异质的;考虑到装有ATIS的用户并不总是遵循ATIS的建议,因此,引入信息遵从率这一参数,将所有用户分为三类:安装并遵从信息、安装但不遵从信息和不安装的用户;均按照随机用户均衡的方式进行择路,但对出行时间有不同的感知。同时考虑存在道路收费的情形下,用户在时间价值上是异质的。综合考虑交通信息与道路收费的影响,基于用户两方面的异质性,对其进行合理分类,构建了多用户多准则的混合随机均衡模型及其等价的变分不等式;当收费不作为系统总成本的一部分时,建立了时间准则与费用准则下的系统最优模型;在此基础之上,分别研究了两种准则下混合均衡相对于系统最优的效率损失,给出了效率损失上界,并进一步分析了效率损失上界与各参数间的关系;交通管理者可以从道路收费策略的实施、信息诱导系统的完善等角度进行路网的改造和优化设计。     

一种基于用户识别特征模型的中医药健康养老信息推送算法

通过分析传统协同过滤算法的优缺点,设计构建用户识别特征模型,并提出基于用户识别特征模型的协同过滤算法,将经典协同过滤算法与基于用户识别特征模型的协同过滤算法进行比较试验,分析基于用户识别特征模型的协同过滤算法相对于经典协同算法的优势,进而证明其能够在中医药健康养老信息的推送过程中提高效率。     

Multiuser detection for the uplink of clustered 5G systems with universal frequency reuse

With 5G (Fifth generation) cellular communications, systems have to be able to cope with a massive increase of mobile devices and services and simultaneously improve the system’s spectral efficiency, as well as dealing with high interference levels. Base Station (BS) cooperation architectures jointly with block transmission techniques, such as OFDM (Orthogonal Frequency Division Multiplexing) for the downlink and SC-FDE (Single-Carrier with Frequency-Domain Equalization) for the uplink, are proven to be suitable for broadband wireless transmission systems. In BS cooperation systems MTs (Mobile Terminals) in adjacent cells share the same physical channel allowing the reducing of the frequency reuse and improving the spectral efficiency of cellular systems. In this paper we present a set of multiuser detection techniques for the uplink transmission in clustered architectures based on the C-RAN (Centralized-Radio Access Network) concept. We consider BS cooperation systems employing a universal frequency reuse approach. Our performance results demonstrate that by employing clustered techniques for the detection procedure it is possible to reduce substantially the signal processing complexity and the side information that must be transmitted by the backhaul structure.     

面向移动用户的矢量地图数据压缩方法

随着第4代移动通信技术（4G）的普及以及4核和8核CPU手机的出现,无线网络数据传输能力和移动终端性能得到了大幅提高.移动用户的广泛参与使得地理信息的采集和上传下载数据巨量,致使有限的带宽传输速率与海量信息传输需求存在矛盾.针对移动用户对空间数据的高压缩率和高失真度容忍率的需求,提出了一种新的矢量地图数据压缩方法,通过去除冗余点、平移坐标轴和转换数据类型3个步骤,可2次压缩数据.测试结果显示,该方法的综合压缩率接近70%,可有效降低无线网络数据传输负荷,节约移动终端的存储空间.     

产品追溯中基于多企业合作模式的制造过程编码研究

通过对多企业合作模式下制造过程编码的需求和信息要素分析, 以产品制造信息追溯为目的, 基于层级分类思路, 提出了类—级—层的编码结构模型, 制定了编码规则及编码属性, 并以QR Code二维码的形式进行表达, 支持产品的信息追溯.