情景感知在移动计算中的应用研究

随着移动商务的发展,情景感知在交互移动计算系统中的应用越来越广泛。为了把这一概念应用到设计的动态环境中,有必要了解什么是情景感知、情景感知的分类等概念。学者们针对情景感知概念的讨论和验证从未停止过,分析情景感知在移动计算中的应用是当前一个重要的研究方向。本文对情景感知概念及移动计算数据获取的方法提出了一些建议。     

物联网在环境监测中的感知作用研究

物联网是在互联网出现之后的又一次信息技术革命,这一革命使得网络社会形态从虚拟社会向感知社会转变。环境保护是物联网技术应用的重要领域,它是提高环境管理水平,发展战略性环保产业的重要手段。物联网的感知作用大大缩短了人与人、人与物、物与物之间的时空距离,这一技术的发展将会带来新的产业发展机遇。本文就拟从物联网的概念、应用以及它在环境监测中的感知作用角度进行探讨和阐述,以期加深对这一问题的认识程度。     

情景感知驱动的移动对象多模式轨迹预测技术综述

如何利用多源异构时空数据进行准确的轨迹预测并且反映移动对象的移动特性是轨迹预测领域的核心问题.现有的大多数轨迹预测方法是长序列轨迹模式预测模型,根据历史轨迹的特点进行预测,或将当前移动对象的轨迹位置放入时空语义场景根据历史移动对象轨迹预测位置.综述当前常用的轨迹预测模型和算法,涉及不同的研究领域.首先,阐述了多模式轨迹预测的主流工作,轨迹预测的基本模型类;其次,对不同类的预测模型进行总结,包括数学统计类、机器学习类、滤波算法,以及上述领域具有代表性的算法;再次,对情景感知技术进行了介绍,描述了不同领域的学者对情景感知的定义,阐述了情景感知技术所包含的关键技术点,诸如情景感知计算、情景获取和情景推理的不同类模型,分析了情景感知的不同分类、过滤、存储和融合以及它们的实现方法等.详细介绍了情景感知驱动的轨迹预测模型技术路线及各阶段任务的工作原理.给出了情景感知技术在真实场景中的应用,包括位置推荐,兴趣点推荐等,通过与传统算法对比,分析情景感知技术在此类应用中的优劣.详细介绍了情景感知结合LSTM (long short-term memory)技术应用于行人轨迹预测领域的新方法.最后,总结了...     

移动协同感知研究综述

移动感知网在军事、工业、医疗、交通、商业上运用极其广泛.为了进一步提高移动感知网的性能,更好地协同节点的移动感知行为,本文提出了移动协同感知技术.首先介绍了国内外近年来有关移动协同感知技术的发展情况和关键技术,包括移动协同感知模型、移动协同感知中间件、移动协同感知相关技术,然后概括归纳了技术特点,最后总结了移动协同感知技术的研究意义和发展趋势.     

移动群体感知中协作方法研究

在移动群体感知中,移动终端集成了丰富的感知设备和通信端口且分布广泛,能够收集、共享各类感知数据.然而,由于移动设备在感知能力、通信端口、移动规律等方面存在异构性,这与要收集实时、精确且覆盖全面的感知信息之间存在矛盾.为了在异构群体中收集优质的感知信息,提出了一种带有任务拆分的感知任务迁移算法(简称STOTS算法).该方法感知信息质量在感知数据覆盖率方面有所提高.     

基于RFID的无源感知机制研究综述

随着物联网技术的飞速发展与广泛部署,物联网领域的应用需求逐步从"万物互联"转变成"人-机-物"的感知融合.在众多感知技术之中,射频识别技术(radio frequency identification,RFID)作为物联网领域的核心技术之一,由于标签的轻量级、可标记、易部署等特征,成为"无源感知"的重要媒介.为深入剖析...     

以人为中心的感知

随着嵌入式技术、移动计算技术和无线传感器网络技术的发展,越来越多的可移动的通信和存储设备上嵌入了传感器,比如,手机上的方位传感器、震动传感器(实际上,手机的话筒和摄像头也是传感器),以及嵌入到MP3播放器中的脉搏传感器,等等.这些移动设备上的传感器可以采集与人们的行动、社会交往等息息相关的个人信息.此外,随着成本的下降,这些具有感知功能的移动通信设备的持有量不断提高,再加上Internet中社会网络软件的广泛使用,一类新的感知应用应运而生-以人为中心的感知(People-Centric Sensing,PCS).PCS不仅是一个新的研究领域,而且具有巨大的潜在应用价值,近几年来引起了学术界和工业界的高度关注.该文介绍了PCS的概念、特征以及重要的研究问题和挑战,并概述了PCS的研究现状.     

物联网信息感知与交互技术研究与分析

为了全面认识物联网技术,对物联网信息感知与交互技术进行研究和分析。首先简单阐述了物联网技术说明,并从数据采集技术、数据筛选技术、数据压缩技术、数据交融技术以及数据汇集技术五个方面阐述了物联网信息感知技术;然后从网络和内容的交互、用户和内容的交互以及用户和网络的交互三个方面阐述了物联网信息交互技术;最后通过物联网信息技术在日常生活中的应用分析和物联网信息技术在军事领域的应用分析两个方面说明了物联网信息技术在现实生活中的应用。     

社交网络中感知技术的研究与应用

社交网络已成为互联网上最热门的话题和网络应用亮点,它让用户组织自己的网络链接,维护各种社会关系.社交网络重要的是对个人信息的维护,对网络内他人信息的感知;在社交网络环境下,用户的信息感知程度普遍较低.探索了是否可有效调整CSCW领域中的感知概念以应用到社会网络领域.分析了感知的概念和内涵,对比了CSCW领域的群组与社交网络中的社区,研究了社交网络感知信息的形成过程,从社交网络环境和群组两个方面讨论了感知技术的应用,改善了社交网络中的通信,增强了用户之间的交互性.最后,实现了面向科研工作者的社交网络--学术社区,在学术社区中应用感知技术,帮助研究者发现科研热点或某一领域的研究群体,促进学术交流和创新.     

一种新型群智感知系统架构模型和实现方法

物联网移动群智感知模式本质是汇聚大规模普通移动个体的智能感知能力,对开放、动态、复杂物理环境进行感知,通过感知大数据的智能分析,对感知群体引导和反馈,使其持续涌现群体智能并辅助综合决策.目前的群智感知系统仍然存在个体感知欠智能、群体目标少引导、群智过程弱调控三方面的局限性.本文首先讨论了群智感知研究现状和面临的挑战;结合人机物融合、云边端协同、感算控闭环3个核心发展趋势,提出一种智能演进与反馈引导结合的新型群智感知系统架构模型Evo-CPS,并研究了该模型的实现方法;然后结合智慧出行应用场景,将所提出的理论方法进行应用验证;最后,总结全文并展望新一代群智感知研究领域的发展方向.     

Improvement of optimization algorithm in active gas/odor sensing system

In the field of gas or odor sensing, it is difficult to quantify the composition of a mixture of aromas accurately. We proposed earlier the method of active sensing for this purpose and quantification was successfully performed in principle. Here, an optimization algorithm such as the gradient descent method for quantifying the mixture composition is improved by the introduction of least-squares and singular-value decomposition methods so that the stability of the system can be improved. Better convergence is achieved after the improvement.     

认知无线电中能效优先的频谱感知算法研究

频谱感知是认知无线电的关键技术之一.针对认知无线电中降低频谱感知能耗的问题,研究了在满足一定感知性能的前提下,能效优先的频谱感知算法.首先对感知能耗最小化问题进行了建模,然后推导出目标检测概率与最小感知能耗之间的关系,接着给出了在目标检测概率要求下的最小感知能耗,最后分别对单信道和多信道场景进行了仿真,仿真结果验证了理论推导的正确性.     

Survey-based exploration of attitudes to participatory sensing tasks in location-based gaming communities

An increasing number of participatory sensing applications have been developed in recent years. However, most of them are still in the early adoption phase and count only few users as compared to the billions of devices that could be leveraged. On the other side, existing location-based games, such as geocaching or Ingress, gain in popularity and attract up to millions of users worldwide. Since the players of location-based games are already exploring their environment, one approach could be to especially address these communities in order to increase the user base of participatory sensing applications. To this end, we conduct a preliminary questionnaire-based study involving 337 participants to investigate the possible attitudes of such players towards participatory sensing applications. In particular, we analyze the potential interests of our participants in sensing tasks based on their demographics, played games, and sensing modalities. Our results show that our participants would prefer contributing to sensing tasks when integrated in geocaching. Moreover, a point-based reward system would not significantly motivate them and could even have negative consequences.     

Partial cooperative spectrum sensing schedule in cognitive network

Cognitive radio has emerged as a promising technology for maximizing the utilization efficiency of the limited spectrum resources while accommodating the increasing amount of services and applications in wireless networks. One of the most important and critical components of the cognitive radio is spectrum sensing and accordingly, detection of primary users. Considering the hardware constraints existing in cognitive devices, based on the coarse estimation of channel occupancy, partial cooperative spectrum sensing with adaptive spectrum schedule scheme is proposed to increase the possibility to discover more spectrum opportunities promptly. Simulation results show the gain of sensing performance and the energy-saving feature of partial spectrum sensing. Special security scheme is designed to protect the reliability of sensing result from the false message attack. For the scenarios tested, the proposed scheme is shown to increase opportunities by up to 15 percent.     

基于LoRa信号的行走距离和方向估计

行走追踪在真实场景中具有广泛应用,可以用于安防监控、老人看护、室内导航等场景.近年来,基于无线射频信号的非接触式行走追踪受到了研究人员的广泛关注,包括基于Wi-Fi信号、RFID信号等的行走追踪系统.然而,现有的行走追踪系统依然面临感知范围小、感知设备部署稠密等问题.在本文中,我们首次将用于物联网低功耗、远距离通信的L...     

A weighted cooperative spectrum sensing framework for infrastructure-based cognitive radio networks

Spectrum sensing plays a critical role in cognitive radio networks. A good sensing scheme can reduce the false alarm probability and the miss detection probability, and thus improves spectrum utilization. This paper presents a weighted cooperative spectrum sensing framework for infrastructure-based cognitive radio networks, to increase the spectrum sensing accuracy. The framework contains two modules. In the first module, each cognitive radio performs local spectrum sensing and computes the total error probability, which combines the false alarm probability and the miss detection probability. The total error probability and the energy signal from the primary user are then sent to the base station. In the second module, the base station makes a final decision after combining the weighted energy signals from all cognitive radios. The final decision is then broadcasted back to all cognitive radios. To reduce the computation complexity and communication overhead, the base station also instructs the cognitive radios that have large total error probabilities not to report their local sensing results. We have developed a theoretical model for the proposed framework, and derived the optimal detection threshold, as well as the minimum number of cognitive radios required to participate in cooperative sensing, subject to a given total error probability. Numerical results verify that the proposed weighted cooperative spectrum sensing framework significantly improves the sensing accuracy.     

基于压缩感知的MIMO-TDCS频谱感知方法

针对MIMO-TDCS系统频谱感知中因数据量大而较难实现的难题,提出一种利用压缩感知的MIMO-TDCS频谱感知方法.在电磁环境一致的情况下,收发两端分别用远低于乃奎斯特的采样速率对电磁环境信号进行采样,然后用正交匹配追踪算法对信号进行重构,并通过二元门限进行状态判决.实验结果证明,运用压缩感知技术能大大减少电磁环境宽带信号的快速采样和处理难度,在选取合理测量值的情况下能够准确恢复信号,进而能有效地检测和剔除干扰,达到抗干扰的目的.     

遥感专业互动网络站点的设计与建设

利用当前网络的迅捷和便利，建设以遥感课件与考试系统为特色的遥感专业网络站点，有利于遥感知识的普及和遥感专业的学习。遥感专业站点是在校园网的基础上完成了以遥感考试系统、多媒体课件教学以及遥感社区为主要内容的遥感专业网站。遥感专业站点中课件的网络化，以及站点中考试系统动态交互性以及安全性是该网站的特色和要解决的关键技术。     

A criterion for optimal design of multi-axis force sensors

This paper deals with the design of multi-axis force (also known as force/torque) sensors, as considered within the framework of optimal design theory. Optimal design procedures consists of finding the combination of design variables that extremizes some optimality criterion: provided a suitable mathematical formulation of the problem, solutions can be efficiently obtained through currently available numerical techniques. The principal goal of this paper is to identify a mathematical objective function, whose minimization corresponds to the optimization of sensor accuracy. The methodology employed is derived from linear algebra and analysis of numerical stability. An objective function which can be applied to a large class of sensor configurations is proposed. The problem of optimizing the number of basic transducers employed in a multi-component sensor is also addressed. Finally, applications of the proposed method to the design of a simple sensor as well as to the optimization of a novel, 6-axis miniaturized sensor are discussed.