一种新型的认知无线电合作频谱感知算法*

为了提高认知无线电频谱感知性能,同时考虑到不同认知用户SU(Secondary User)具有不同的感知贡献和谈判力量,该文利用合作博弈理论提出了一种新的基于认知无线电的合作频谱感知非对称纳什谈判算法ANBS(Asymmetric Nash Bargaining Solution),该算法充分考虑到了每一个认知用户的感知可信度不尽相同的情况。仿真结果表明,与NBS(Nash Bargaining Solution)等算法相比,该算法不仅具有更强的合理性和可靠性,而且使系统整体感知性能得到了较大提高。     

Cooperative power-aware scheduling in grid computing environments

Energy usage and its associated costs have taken on a new level of significance in recent years. Globally, energy costs that include the cooling of server rooms are now comparable to hardware costs, and these costs are on the increase with the rising cost of energy. As a result, there are efforts worldwide to design more efficient scheduling algorithms. Such scheduling algorithm for grids is further complicated by the fact that the different sites in a grid system are likely to have different ownerships. As such, it is not enough to simply minimize the total energy usage in the grid; instead one needs to simultaneously minimize energy usage between all the different providers in the grid. Apart from the multitude of ownerships of the different sites, a grid differs from traditional high performance computing systems in the heterogeneity of the computing nodes as well as the communication links that connect the different nodes together. In this paper, we propose a cooperative, power-aware game theoretic solution to the job scheduling problem in grids. We discuss our cooperative game model and present the structure of the Nash Bargaining Solution. Our proposed scheduling scheme maintains a specified Quality of Service (QoS) level and minimizes energy usage between all the providers simultaneously; energy usage is kept at a level that is sufficient to maintain the desired QoS level. Further, the proposed algorithm is fair to all users, and has robust performance against inaccuracies in performance prediction information.     

Game-theoretic static load balancing for distributed systems

In this paper, we present a game theoretic approach to solve the static load balancing problem for single-class and multi-class (multi-user) jobs in a distributed system where the computers are connected by a communication network. The objective of our approach is to provide fairness to all the jobs (in a single-class system) and the users of the jobs (in a multi-user system). To provide fairness to all the jobs in the system, we use a cooperative game to model the load balancing problem. Our solution is based on the Nash Bargaining Solution (NBS) which provides a Pareto optimal solution for the distributed system and is also a fair solution. An algorithm for computing the NBS is derived for the proposed cooperative load balancing game. To provide fairness to all the users in the system, the load balancing problem is formulated as a non-cooperative game among the users who try to minimize the expected response time of their own jobs. We use the concept of Nash equilibrium as the solution of our non-cooperative game and derive a distributed algorithm for computing it. Our schemes are compared with other existing schemes using simulations with various system loads and configurations. We show that our schemes perform near the system optimal schemes and are superior to the other schemes in terms of fairness.     

Joint Quality Enhancement and Power Control for Wireless Visual Sensor Networks based on the Nash Bargaining Solution

We propose a cooperative method for resource allocation with power control in a multihop Direct Sequence Code Division Multiple Access Wireless Visual Sensor Network (WVSN). Typical multihop WVSNs consist of visual sensors that record different scenes and relay nodes that retransmit video data until the base station is reached. The error prone wireless environment contributes to the end-to-end video quality degradation. Moreover, the limited battery life span of the network nodes poses challenges on the management of power consumption. The different resource requirements of the WVSN nodes necessitate a quality-driven and power-aware resource allocation mechanism. We formulate the joint Quality Enhancement and Power Control problem based on a utility function that reflects both the benefit in terms of video quality and the cost in terms of transmission power. This function is employed by the Nash Bargaining Solution, which achieves higher fairness in terms of end-to-end video quality among all nodes. For the fairness assessment, a new metric is introduced. The experiments demonstrate the effectiveness of the proposed approach and explain the video quality-power consumption tradeoff as well as the resulting fairness-power consumption tradeoff.     

MEC中资源分配与卸载决策联合优化策略

针对移动边缘计算(MEC)中用户任务处理时延与能耗过高的问题,提出了“云-边-端”三层MEC计算卸载结构下的资源分配与卸载决策联合优化策略。首先,考虑系统时延与能耗,将优化问题规划为系统总增益(任务处理时延与能耗相对减少的加权和)最大化问题;其次,为用户任务设置优先级,并根据任务数据量初始化卸载决策方案;然后,采用均衡传输性能的信道分配算法为卸载任务分配信道资源,对于卸载至同一边缘服务器上的任务以最大化资源收益为目标进行资源竞争,实现计算资源最优配置;最后,基于博弈论证明优化问题为关于卸载决策的势函数,即存在纳什均衡,并利用迭代增益值比较法得到了纳什均衡下的卸载决策方案。仿真结果表明,所提联合优化策略在满足用户处理时延要求的情况下最大化系统总增益,有效地提高了计算卸载的性能。     

基于协作博弈的ZigBee能量优化路由算法

针对 ZigBee网络节点协作过程中,由于工作任务不均衡导致能耗不均问题,从带有竞价的博弈角度提出了基于协作博弈的ZigBee网络能量优化路由算法。首先建立了ZigBee路由博弈的系统模型以及能耗模型;其次,针对ZigBee网络节点建立了基于斯坦克贝格博弈的ZigBee协作博弈模型,分析了协作博弈的近似纳什均衡解,给出了优化的路由算法流程描述;最后的OPNET仿真实验表明,改进的路由算法能够在节点失效数目、能量消耗以及生存时间上得到了一定的改善。     

Energy-efficient power allocation for selfish cooperative communication networks using bargaining game

In commercial networks,user nodes operating on batteries are assumed to be selfish to consume their energy solely to maximize their own benefits,e.g.,data rates.In this paper,we propose a bargaining game to perform the power allocation for the selfish cooperative communication networks.In our system,two partner nodes can act as a source as well as a relay for each other,and each node is with an energy constraint to transmit one frame.Consider a selfish node is willing to seek cooperative transmission only if the data rate achieved through cooperation will not lower than that achieved through noncooperation by using the same amount of energy.The energy-efficient power allocation problem can be modeled as a cooperative game.We proved that there exists a unique Nash bargaining solution (NBS) for the game by verifying that the game is indeed a bargaining problem.Thus,the two objectives,i.e.,system efficiency and user fairness specified in the selfish networks can be achieved.Simulation results show that the NBS scheme is efficient in that the performance loss of the NBS scheme to that of the maximal overall rate scheme is small while the maximal-rate scheme is unfair.The simulation results also show that the NBS result is fair in that both nodes could experience better performance than they work independently and the degree of cooperation of a node only depends on how much contribution its partner can make to improve its own performance.     

无线传感器网络基于议价解的合作策略

针对无线传感器网络（WSN）的合作多样性问题,对结合节点能耗和吞吐量的对称合作模式进行了讨论。基于Raiffa-Kalai-Smorodinsky议价解（RBS）,将对称合作问题转换成议价问题,提出了一种提高网络传输效率的WSN对称合作策略。分析了由[n]传感器节点和一个sink 组成的对称合作模型,并在此基础上,讨论了RBS最优带宽分配策略的实现过程。仿真结果表明,该对称合作策略可以大大提高传感器节点的传输效率。     

一种基于合作博弈论的自动驾驶车道变更模型

提出一个新颖的车道变更模型,采用合作博弈方法激励车辆参与合作。首次将合作博弈理论应用到车道变更领域,设计用于两车变道的纳什讨价还价变道模型,然后扩展为三车的合作博弈变道模型,并求出变道模型的纳什讨价还价解和夏普利值。为了进一步激励车辆参与合作,在收益分配方案中加入支付补偿部分来实现整体收益的可转移性,从而取得模型的解。实验结果表明,采用合作博弈后车辆的整体收益得到了大幅增加,同时每个参与车辆的个人收益也增加了。     

Game Theoretic subcarrier and power allocation for wireless OFDMA networks

This paper proposes a bargaining game theoretic resource(including the subcarrier and the power) allocation scheme for wireless orthogonal frequency division multiple access(OFDMA) networks.We define a wireless user s payoff as a function of the achieved data-rate.The fairness resource allocation problem can then be modeled as a cooperative bargaining game.The objective of the game is to maximize the aggregate payoffs for the users.To search for the Nash bargaining solution(NBS) of the game,a suboptimal subcarrier allocation is performed by assuming an equal power allocation.Thereafter,an optimal power allocation is performed to maximize the sum payoff for the users.By comparing with the max-rate and the max-min algorithms,simulation results show that the proposed game could achieve a good tradeoff between the user fairness and the overall system performance.     

一种新的多目标优化策略机制及其应用

在博弈问题中很多学习机制只能使Agent收敛到Nash均衡解，不能很好地满足实际需要。将博弈问题转化为多目标优化问题，提出了一种新的多目标优化策略机制——保留受控策略机制，并将其应用到囚徒困境问题中得到比Nash均衡更有意义的Pareto最优解，在自博弈实验中取得了较高的满意度。实验结果表明,该策略机制求解Pareto最优解的有效性。     

A goal programming based energy efficient resource allocation in data centers

We study the multi-objective problem of mapping independent tasks onto a set of data center machines that simultaneously minimizes the energy consumption and response time (makespan) subject to the constraints of deadlines and architectural requirements. We propose an algorithm based on goal programming that effectively converges to the compromised Pareto optimal solution. Compared to other traditional multi-objective optimization techniques that require identification of the Pareto frontier, goal programming directly converges to the compromised solution. Such a property makes goal programming a very efficient multi-objective optimization technique. Moreover, simulation results show that the proposed technique achieves superior performance compared to the greedy and linear relaxation heuristics, and competitive performance relative to the optimal solution implemented in Linear Interactive and Discrete Optimizer (LINDO) for small-scale problems.     

基于博弈论的能量均衡路由算法

针对传感器网络能量不均衡且网络性能易受自私节点影响的问题,利用博弈论的思想,构建了均衡能耗的博弈模型(EBGM)。该算法从激励节点合作行为出发,引入能量关注因子,摒除传统博弈算法以剩余能量作为调整转发意愿的唯一标准,转而根据节点现有能量比例与邻居能量比例的差异程度进行调节。对EBGM模型进行理论分析,证明了纳什均衡点的存在性,且其能够趋于帕累托最优。仿真结果表明,EBGM模型能够促进节点合作行为、均衡能量开销、延长网络的整体生存周期。     

Characterization of the iterative application of makespan heuristics on non-makespan machines in a heterogeneous parallel and distributed environment

Heterogeneous computing (HC) is the coordinated use of different types of machines, and networks to process a diverse workload in a manner that will maximize the combined performance and/or cost effectiveness of the system. Heuristics for allocating resources in an HC system are based on some optimization criterion. A common optimization criterion is to minimize the completion time of the machine that finishes last (makespan). In this study, we consider an iterative approach that repeatedly runs a mapping heuristic to minimize the makespan of the considered machines and tasks. For each successive iteration, the makespan machine of the previous iteration and the tasks assigned to it are removed from the set of considered machines and tasks. This study focuses on understanding the different mathematical characteristics of resource allocation heuristics that cause them to behave differently when combined with this iterative approach. This paper has three main contributions. The first contribution is the study of an iterative technique used in conjunction with resource allocation heuristics. The second contribution is the definition and mathematical characterization of “iteration invariant” heuristics. The third contribution is to determine the characteristics of a heuristic that will cause the mapping to change across iterations.     

Robust static allocation of resources for independent tasks under makespan and dollar cost constraints

Heterogeneous computing (HC) systems composed of interconnected machines with varied computational capabilities often operate in environments where there may be inaccuracies in the estimation of task execution times. Makespan (defined as the completion time for an entire set of tasks) is often the performance feature that needs to be optimized in such systems. Resource allocation is typically performed based on estimates of the computation time of each task on each class of machines. Hence, it is important that makespan be robust against errors in computation time estimates. In this research, the problem of finding a static mapping of tasks to maximize the robustness of makespan against the errors in task execution time estimates given an overall makespan constraint is studied. Two variations of this basic problem are considered: (1) where there is a given, fixed set of machines, (2) where an HC system is to be constructed from a set of machines within a dollar cost constraint. Six heuristic techniques for each of these variations of the problem are presented and evaluated.     

Cooperative network design: A Nash bargaining solution approach

The Network Design problem has received increasing attention in recent years. Previous works have addressed this problem considering almost exclusively networks designed by selfish users, which can be consistently suboptimal. This paper addresses the network design issue using cooperative game theory, which permits to study ways to enforce and sustain cooperation among users. Both the Nash bargaining solution and the Shapley value are widely applicable concepts for solving these games. However, the Shapley value presents several drawbacks in this context.For this reason, we solve the cooperative network design game using the Nash bargaining solution (NBS) concept. More specifically, we extend the NBS approach to the case of multiple players and give an explicit expression for users’ cost allocations. We further provide a distributed algorithm for computing the Nash bargaining solution. Then, we compare the NBS to the Shapley value and the Nash equilibrium solution in several network scenarios, including real ISP topologies, showing its advantages and appealing properties in terms of cost allocation to users and computation time to obtain the solution.Numerical results demonstrate that the proposed Nash bargaining solution approach permits to allocate costs fairly to users in a reasonable computation time, thus representing a very effective framework for the design of efficient and stable networks.     

Bargaining game theoretic power control in selfish cooperative relay networks

Wireless cooperative communications require appropriate power allocation (PA) between the source and relay nodes. In selfish cooperative communication networks, two partner user nodes could help relaying information for each other, but each user node has the incentive to consume his power solely to decrease its own symbol error rate (SER) at the receiver. In this paper, we propose a fair and efficient PA scheme for the decode-and-forward cooperation protocol in selfish cooperative relay networks. We formulate this PA problem as a two-user cooperative bargaining game, and use Nash bargaining solution (NBS) to achieve a win-win strategy for both partner users. Simulation results indicate that the NBS is fair in that the degree of cooperation of a user only depends on how much contribution its partner can make to decrease its SER at the receiver, and efficient in the sense that the SER performance of both users could be improved through the game.     

Multi-objective Task Scheduling to Minimize Energy Consumption and Makespan of Cloud Computing Using NSGA-II

The utilization of cloud services has significantly increased due to the easiness in accessibility, better performance, and decrease in the high initial cost. In general, cloud users anticipate completing their tasks without any delay, whereas cloud providers yearn for reducing the energy cost, which is one of the major costs in the cloud service environment. However, reducing energy consumption increases the makespan and leads to customer dissatisfaction. So, it is essential to obtain a set of non-domination solutions for these multiple and conflicting objectives (makespan and energy consumption). In order to control the energy consumption efficaciously, the Dynamic Voltage Frequency Scaling system is incorporated in the optimization procedure and a set of non-domination solutions are obtained using Non-dominated Sorting Genetic Algorithm (NSGA-II). Further, the Artificial Neural Network (ANN), which is one of the most successful machine learning algorithms, is used to predict the virtual machines based on the characteristics of tasks and features of the resources. The optimum solutions obtained using the optimization process with the support of ANN and without the support of ANN are presented and discussed.     

Coordination mechanisms for selfish scheduling

In machine scheduling, a set of jobs must be scheduled on a set of machines so as to minimize some global objective function, such as the makespan, which we consider in this paper. In practice, jobs are often controlled by independent, selfishly acting agents, which each select a machine for processing that minimizes the (expected) completion time. This scenario can be formalized as a game in which the players are job owners, the strategies are machines, and a player’s disutility is the completion time of its jobs in the corresponding schedule. The equilibria of these games may result in larger-than-optimal overall makespan. The price of anarchy is the ratio of the worst-case equilibrium makespan to the optimal makespan. In this paper, we design and analyze scheduling policies, or coordination mechanisms, for machines which aim to minimize the price of anarchy of the corresponding game. We study coordination mechanisms for four classes of multiprocessor machine scheduling problems and derive upper and lower bounds on the price of anarchy of these mechanisms. For several of the proposed mechanisms, we also prove that the system converges to a pure-strategy Nash equilibrium in a linear number of rounds. Finally, we note that our results are applicable to several practical problems arising in communication networks.     

协作式云资源博弈分配

针对用户对云资源的异构性需求和竞争问题,提出了一种协作式资源分配博弈策略。建立了资源分配的协作式博弈模型,定义了协作博弈的用户效用函数和评估函数,证明了在该效用函数下协作博弈存在唯一Nash均衡,并讨论了用户组建联盟对协作特征函数和整体效用的影响。实验结果表明,在该协作博弈策略下,个体用户通过组建联盟集体出价的方式,能够为联盟用户带来更大效用,以收敛方式实现Pareto改进。