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1.
星地一体化网络是卫星网络和地面网络互联,实现卫星网络和地面网络优势互补的一体化网络。随着无线通信的快速发展,卫星网络和地面网络的同频复用技术可有效提升资源利用效率,满足日益增长的无线数据业务需求。但由于无线数据业务类型的多样化和频谱资源的稀缺性,如何实现用户数据服务的服务体验质量(Quality of experience, QoE)和公平性提升也成为星地一体化网络亟待解决的关键问题。本文综合考虑信道时变性、服务体验多样性和服务公平性,提出了一种基于QoE感知的星地一体化网络资源分配策略。为此,将目标问题描述为基于时间平均的服务体验质量的网络公平效用最大化,并利用李雅普诺夫优化理论,将复杂的动态原始优化问题进一步转化并分解为3个瞬时优化子问题,每个子问题可以在每个时隙独立求解。同时,由于无线资源分配为典型的非凹混合组合优化问题,推导了一个低复杂度的两步算法来求解第三个资源分配子问题。仿真结果揭示了在不同的公平性参数下用户的长时QoE与公平性之间的折衷情况。 相似文献
2.
针对具有不完美信道状态信息的Femtocell双层网络,为了保证网络效用最大化、最小服务质量要求及Femtocell用户之间的效用公平,提出了基于议价博弈的鲁棒功率控制方案.在保证宏小区用户正常传输情况下,考虑到Femtocell家庭用户的最小服务质量要求,将Femtocell网络的鲁棒功率控制问题转化为议价博弈功率控制问题.为了保证Femtocell家庭用户之间的公平性,给出了Kalai-Smorodinsky(K-S)议价博弈解,证明了议价博弈解的存在性和唯一性,并提出了一种基于二分查找算法的分布式鲁棒功率控制方案.仿真结果表明,所提出的算法不仅具有较好的收敛性能,而且能够较好地保证用户之间的公平性. 相似文献
3.
利用模糊控制和比例积分微分(PID)控制相结合的手段对注塑机料筒温度进行了控制,同时以Matlab 6.0软件为仿真平台,对料筒温度控制进行了模拟仿真研究。实验发现,在注塑机料筒升温过程中利用CHR整定的PID控制手段和模糊控制手段,恒温过程中利用人工整定的PID控制手段,可保证快速的料筒升温响应速率和稳定的保温过程。通过实际注塑实验对该仿真结果进行了验证,在十组实验中,料筒温度误差不超过2%,产品翘曲变形量不超过0.059 mm。 相似文献
4.
Traditionally, in supervised machine learning, (a significant) part of the available data (usually 50%-80%) is used for training and the rest—for validation. In many problems, however, the data are highly imbalanced in regard to different classes or does not have good coverage of the feasible data space which, in turn, creates problems in validation and usage phase. In this paper, we propose a technique for synthesizing feasible and likely data to help balance the classes as well as to boost the performance in terms of confusion matrix as well as overall. The idea, in a nutshell, is to synthesize data samples in close vicinity to the actual data samples specifically for the less represented (minority) classes. This has also implications to the so-called fairness of machine learning. In this paper, we propose a specific method for synthesizing data in a way to balance the classes and boost the performance, especially of the minority classes. It is generic and can be applied to different base algorithms, for example, support vector machines, k-nearest neighbour classifiers deep neural, rule-based classifiers, decision trees, and so forth. The results demonstrated that (a) a significantly more balanced (and fair) classification results can be achieved and (b) that the overall performance as well as the performance per class measured by confusion matrix can be boosted. In addition, this approach can be very valuable for the cases when the number of actual available labelled data is small which itself is one of the problems of the contemporary machine learning. 相似文献
5.
The extent to which the deliberative scenario brackets socio-economic inequalities (i.e., functioning as an ideal public sphere) has been long-debating. This study empirically addresses this question in the online setting. We test whether offline advantages (i.e., economic and cultural capitals) can be translated into power in online deliberation and how their dynamic relations further influence interlocutors’ deliberation experience (i.e., perceived procedural fairness and validity claim). Power is conceptualized as network power, including prestige (indegree), leadership (outdegree), and brokering power (betweenness). A national sample of Singaporeans participated in a three-week online deliberation, and network power is measured based on the web log. The participants answered a two-wave (i.e., pre- and post-deliberation) survey to indicate individual attributes. Structural equation modeling finds that online deliberation brackets as well as reinforces offline status. Economic capital is suppressed while cultural capital translates into network power, which further influences interlocutors’ evaluation of the deliberation. 相似文献
6.
Maintenance is crucial to ensure production/output and customer satisfaction in the mining sector. The cost of maintenance of mechanised and automated mining systems is very high, necessitating efforts to enhance the effectiveness of maintenance systems and organisation. For effective maintenance planning, it is important to have a good understanding of the reliability and availability characteristics of the systems. Determining the Mean Residual Life (MRL) of systems allows organisations to more effectively plan maintenance tasks. In this paper, we use a statistical approach to estimate MRL and consider a Weibull proportional hazard model (PHM) with time-independent covariates to model the hazard function so that the operating environment could be integrated into the reliability analysis. The paper explains our methods for calculating the conditional reliability function and computing the MRL as a function of the current conditions. The model is verified and validated using data from the hydraulic system of LHD equipment in a Swedish mine. The results are useful to estimate the remaining useful life of such systems; the method can be used for maintenance planning, helping to control unplanned stoppages of highly mechanised and automated systems. 相似文献
7.
Fair bandwidth allocation (FBA) has been studied in optical burst switching (OBS) networks, with the main idea being to map the max-min fairness in traditional IP networks to the fair-loss probability in OBS networks. This approach has proven to be fair in terms of the bandwidth allocation for differential connections, but the use of the ErlangB formula to calculate the theoretical loss probability has made this approach applicable only to Poisson flows. Furthermore, it is necessary to have a reasonable fairness measure to evaluate FBA models. This article proposes an approach involving throughput-based-FBA, called TFBA, and recommends a new fairness measure that is based on the ratio of the actual throughput to the allocated bandwidth. An analytical model for the performance of the output link with TFBA is also proposed. 相似文献
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9.
PPP 模式对于社会资本参与基础设施建设项目具有积极的推动作用。然而,由于基础设施建设周期长、回报低,社会投资方将面临较高的收益风险,因此,我国大部分 PPP 项目的社会资本方为国企或国企与民企的联营体,纯粹的私人资本参与 PPP 项目的积极性并不高。为了激发私人资本参与基础设施项目建设的投资热情,当政府与不同投资方合作时,有必要基于项目参与方的公平偏好程度设置相应风险分配机制,一方面降低私人资本投资方所面临的收益风险,另一方面改变政府承担项目付费的现状,实现风险的合理分配。基于委托代理理论模拟项目收益风险分配机制,在考察投资方公平偏好的前提下,对传统的收益函数进行了调整,构建了基于公平偏好理论的 PPP 项目收益风险分配模型。通过数据分析得出,社会效益会随着投资方公平偏好的增大而增加,投资方承担风险比例亦与其公平偏好正相关 相似文献
10.