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1.
This paper considers a multi-user wireless communication network supported by a multiple-antenna base station (BS), where the users who are located sufficiently close to the BS employ wireless energy harvesting (EH) to replenish their energy needs. The objective of this work is to design an efficient beamforming to maximize the minimum throughput among all the information users (IUs), subject to EH constraints. In this regard, transmit time-switching approach is employed, where energy and information are transmitted over different fractions of a time-slot. To achieve efficient EH, a conjugate beamforming (matched filtering) is applied. To design efficient information beamforming for max–min throughput optimization, conventional zero-forcing (ZF) beamforming can be adopted, however, it will not suppress multi-user interference if the number of users is greater than the number of antennas at the BS. To this end, different from the existing works which employ regularized zero-forcing (RZF) beamforming, this work proposes a new generalized zero-forcing (GZF) beamforming, which promises better max–min throughput compared to that achieved by the RZF beamforming. A new path-following algorithm is developed to achieve max–min throughput optimization by GZF beamforming, which is based on a simple convex quadratic program over each iteration.  相似文献   
2.
Recently, measuring the complexity of body movements during sleep has been proven as an objective biomarker of various psychiatric disorders. Although sleep problems are common in children with autism spectrum disorder (ASD) and might exacerbate ASD symptoms, their objectivity as a biomarker remains to be established. Therefore, details of body movement complexity during sleep as estimated by actigraphy were investigated in typically developing (TD) children and in children with ASD. Several complexity analyses were applied to raw and thresholded data of actigraphy from 17 TD children and 17 children with ASD. Determinism, irregularity and unpredictability, and long-range temporal correlation were examined respectively using the false nearest neighbor (FNN) algorithm, information-theoretic analyses, and detrended fluctuation analysis (DFA). Although the FNN algorithm did not reveal determinism in body movements, surrogate analyses identified the influence of nonlinear processes on the irregularity and long-range temporal correlation of body movements. Additionally, the irregularity and unpredictability of body movements measured by expanded sample entropy were significantly lower in ASD than in TD children up to two hours after sleep onset and at approximately six hours after sleep onset. This difference was found especially for the high-irregularity period. Through this study, we characterized details of the complexity of body movements during sleep and demonstrated the group difference of body movement complexity across TD children and children with ASD. Complexity analyses of body movements during sleep have provided valuable insights into sleep profiles. Body movement complexity might be useful as a biomarker for ASD.  相似文献   
3.
The identification of emergent structures in complex dynamical systems is a formidable challenge. We propose a computationally efficient methodology to address such a challenge, based on modeling the state of the system as a set of random variables. Specifically, we present a sieving algorithm to navigate the huge space of all subsets of variables and compare them in terms of a simple index that can be computed without resorting to simulations. We obtain such a simple index by studying the asymptotic distribution of an information-theoretic measure of coordination among variables, when there is no coordination at all, which allows us to fairly compare subsets of variables having different cardinalities. We show that increasing the number of observations allows the identification of larger and larger subsets. As an example of relevant application, we make use of a paradigmatic case regarding the identification of groups in autocatalytic sets of reactions, a chemical situation related to the origin of life problem.  相似文献   
4.
Zhiyuan Lin 《中国物理 B》2021,30(8):80501-080501
We build a double quantum-dot system with Coulomb coupling and aim at studying connections among the entropy production, free energy, and information flow. By utilizing concepts in stochastic thermodynamics and graph theory analysis, Clausius and nonequilibrium free energy inequalities are built to interpret local second law of thermodynamics for subsystems. A fundamental set of cycle fluxes and affinities is identified to decompose two inequalities by using Schnakenberg's network theory. Results show that the thermodynamic irreversibility has energy-related and information-related contributions. A global cycle associated with the feedback-induced information flow would pump electrons against the bias voltage, which implements a Maxwell demon.  相似文献   
5.
地上生物量(AGB)是作物长势评价及产量预测的重要指标,因此快速准确地估算AGB至关重要。由于传统植被指数(VIs)估算多生育期的AGB存在饱和现象,因此,利用VIs结合基于离散小波转换(DWT)的影像小波分解(IWD)技术提取的高频信息和连续小波转换(CWT)技术提取的小波系数,探究VIs,VIs+IWD和VIs+CWT对于AGB的估算能力。首先,基于无人机平台分别获取马铃薯现蕾期、块茎形成期、块茎增长期、淀粉积累期的数码影像和成像高光谱影像以及地面实测的AGB数据。其次,利用数码影像通过IWD技术提取3种高频信息和利用高光谱反射率数据通过CWT技术提取小波系数以及构建6种高光谱植被指数。然后,将植被指数、高频信息和小波系数分别与AGB进行相关性分析,并挑选出不同尺度下相关系数绝对值较高的前10波段。最后,以VIs,VIs+IWD和VIs+CWT这3种变量分别使用偏最小二乘回归(PLSR)方法构建AGB估算模型,并对比不同模型估算AGB的效果。结果表明: (1)每个生育期选取的6种植被指数、3种高频信息和10种小波系数与AGB的相关性均达到0.01显著水平,整个生育期相关性均呈现先升高后降低的趋势,其中以小波系数得到的相关性最高、高频信息次之,植被指数最低。(2)对比分析每个生育期的3种估算模型,以VIs+CWT为输入变量的估算效果最好,VIs+IWD的估算效果次之,而VIs的估算效果最差,说明基于小波分析构建的模型适用性较广、稳定性较强。(3)每个生育期分别以3种变量利用PLSR方法构建的AGB估算模型均在块茎增长期达到最高精度(VIs:建模R2=0.70,RMSE=98.88 kg·hm-12,NRMSE=11.63%;VIs+IWD:建模R2=0.78,RMSE=86.45 kg·hm-12,NRMSE=10.17%;VIs+CWT:建模R2=0.85,RMSE=74.25 kg·hm-12,NRMSE=9.27%)。通过VIs分别结合IWD和CWT技术利用PLSR建模方法,可以提高AGB估算精度,为农业指导管理提供可靠参考。  相似文献   
6.
本文在碳交易机制下,考虑制造商之间存在竞争且减排成本系数为低碳制造商私有信息的情况,分别构建信息完全对称和信息非对称情形下的供应链模型,对低碳制造商减排率和产品销售价格进行决策。通过引入由批发价和成本共担组成的联合契约,促使低碳制造商传递真实的减排成本信息,并通过算例对碳交易价格和减排成本系数等进行灵敏度分析。研究发现:引入联合契约能够使得信息非对称下的供应链利润基本达到集中决策水平;碳交易价格的增加会激励制造商积极减排、降低碳排放总量、提高供应链利润;低碳制造商减排成本系数的降低有助于减少碳排放量、增加产品市场需求、实现供应链利润增长。  相似文献   
7.
Previous hotel performance studies neglected the role of information entropy in feedback processes between input and output management. This paper focuses on this gap by exploring the relationship between hotel performance at the industry level and the capability of learning by doing and adopting best practices using a sample of 153 UK hotels over a 10-year period between 2008–2017. Besides, this research also fills a literature gap by addressing the issues of measuring hotel performance in light of negative outputs. In order to achieve this, we apply a novel Modified slack-based model for the efficiency analysis and Least Absolute Shrinkage and Selection Operator to examine the influence of entropy related variable on efficiency score. The Results indicate that less can be learnt from inputs than from outputs to improve efficiency levels and resource allocation is more balanced than cash flow and liquidity. The findings suggest that market dynamics explains the cash flow generation potential and liquidity. We find that market conditions are increasingly offering the opportunities for learning and improving hotel efficiency. The results report that the distinctive characteristic of superior performance in hotel operations is the capability to match the cash flow generation potential with market opportunities.  相似文献   
8.
We quantify the nonclassicality of multimode bosonic field states by adopting an information-theoretic approach involving the Wigner-Yanase skew information. The fundamental properties of the quantifier such as convexity, superadditivity, monotonicity, and conservation relations are revealed. The quantifier is illustrated by a variety of typical examples, and applications to the quantification of nonclassical correlations are discussed. Various extensions are indicated.  相似文献   
9.
Meta-learning, or “learning to learn”, refers to techniques that infer an inductive bias from data corresponding to multiple related tasks with the goal of improving the sample efficiency for new, previously unobserved, tasks. A key performance measure for meta-learning is the meta-generalization gap, that is, the difference between the average loss measured on the meta-training data and on a new, randomly selected task. This paper presents novel information-theoretic upper bounds on the meta-generalization gap. Two broad classes of meta-learning algorithms are considered that use either separate within-task training and test sets, like model agnostic meta-learning (MAML), or joint within-task training and test sets, like reptile. Extending the existing work for conventional learning, an upper bound on the meta-generalization gap is derived for the former class that depends on the mutual information (MI) between the output of the meta-learning algorithm and its input meta-training data. For the latter, the derived bound includes an additional MI between the output of the per-task learning procedure and corresponding data set to capture within-task uncertainty. Tighter bounds are then developed for the two classes via novel individual task MI (ITMI) bounds. Applications of the derived bounds are finally discussed, including a broad class of noisy iterative algorithms for meta-learning.  相似文献   
10.
针对在线评价的发布时间、获得的“有用”的投票数以及是否被贴上“砖家”点评标签对在线评价信息可信度和消费者购买决策具有重要影响,提出一种基于在线评价信息且考虑评价信息可信度及消费者类型的酒店排序方法。首先,将不同类型消费者群体给出的在线评价信息转换成考虑在线评价信息可信度的区间中智数;其次,依据区间中智数距离测度公式确定针对目标群体的各消费者群体权重,进而依据INLNPA集成算子集结各消费者群体评价信息确定针对目标群体的酒店-属性决策矩阵;再次,依据区间中智集熵测度方法确定各属性权重,在此基础上,基于VIKOR方法得到针对目标群体的酒店排序结果;最后,通过一个实例分析说明该方法的有效性和可行性。  相似文献   
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