Hierarchical Data Aggregation with Data Offloading Scheme for Fog Enabled IoT Environment

Fog computing is a promising technology that has been emerged to handle the growth of smart devices as well as the popularity of latency-sensitive and location-awareness Internet of Things (IoT) services. After the emergence of IoT-based services, the industry of internet-based devices has grown. The number of these devices has raised from millions to billions, and it is expected to increase further in the near future. Thus, additional challenges will be added to the traditional centralized cloud-based architecture as it will not be able to handle that growth and to support all connected devices in real-time without affecting the user experience. Conventional data aggregation models for Fog enabled IoT environments possess high computational complexity and communication cost. Therefore, in order to resolve the issues and improve the lifetime of the network, this study develops an effective hierarchical data aggregation with chaotic barnacles mating optimizer (HDAG-CBMO) technique. The HDAG-CBMO technique derives a fitness function from many relational matrices, like residual energy, average distance to neighbors, and centroid degree of target area. Besides, a chaotic theory based population initialization technique is derived for the optimal initial position of barnacles. Moreover, a learning based data offloading method has been developed for reducing the response time to IoT user requests. A wide range of simulation analyses demonstrated that the HDAG-CBMO technique has resulted in balanced energy utilization and prolonged lifetime of the Fog assisted IoT networks.     

无线传感器网络数据融合技术研究

无线传感器网络是一种新兴前沿技术,其巨大的应用前景受到学术界和工业界的高度重视。无线传感器网络节点能量和计算资源严重受限,数据融合技术是减少网络能耗、降低数据冲突、降低传输时延的重要方法。本文首先分析数据融合的重要性;其次针对数据融合的功能分类阐述现有的数据融合方法,并分析存在的问题;最后对数据融合技术的未来发展进行了展望。     

基于Paillier算法的智能电网数据聚合与激励方案

针对智能电网数据聚合和激励存在的隐私泄露问题,基于Paillier算法设计智能电网数据聚合和激励方案。采用超递增序列构造多维数据,并利用同态Paillier密码技术加密结构化数据。在云计算中心直接对用户与电网管理中心之间的密文数据进行聚合,添加与密钥相关的哈希运算消息认证码防止密文数据被篡改,并由电网管理中心解密后获得原始数据的聚合结果。此外,通过引入区块链和环签名实现高效匿名的光伏发电奖励和电网管理中心与用户之间的双向匿名,利用批验证算法降低计算成本。分析结果表明,在保障数据完整性和用户匿名性前提下,该方案可实现高效安全的智能电网数据聚合和激励。     

雾辅助智能电网中容错隐私保护数据聚合方案

针对雾辅助智能电网数据收集过程中存在的隐私泄露问题,本文提出一种新的支持容错的隐私保护数据聚合方案.首先,结合BGN同态加密算法和Shamir秘密共享方案确保电量数据的隐私性.同时,基于椭圆曲线离散对数困难问题构造高效的签名认证方法保证数据的完整性.特别地,方案具有两种容错措施,当部分智能电表数据无法正常发送或部分云服务器遭受攻击而无法工作时,方案仍然能够进行聚合统计.安全分析证明了方案满足智能电网的安全需求;性能实验表明,与已有方案相比,本文方案计算和通信性能更优.     

Metropolitan intelligent surveillance systems for urban areas by harnessing IoT and edge computing paradigms

Recent technological advances led to the rapid and uncontrolled proliferation of intelligent surveillance systems (ISSs), serving to supervise urban areas. Driven by pressing public safety and security requirements, modern cities are being transformed into tangled cyber‐physical environments, consisting of numerous heterogeneous ISSs under different administrative domains with low or no capabilities for reuse and interaction. This isolated pattern renders itself unsustainable in city‐wide scenarios that typically require to aggregate, manage, and process multiple video streams continuously generated by distributed ISS sources. A coordinated approach is therefore required to enable an interoperable ISS for metropolitan areas, facilitating technological sustainability to prevent network bandwidth saturation. To meet these requirements, this paper combines several approaches and technologies, namely the Internet of Things, cloud computing, edge computing and big data, into a common framework to enable a unified approach to implementing an ISS at an urban scale, thus paving the way for the metropolitan intelligent surveillance system (MISS). The proposed solution aims to push data management and processing tasks as close to data sources as possible, thus increasing performance and security levels that are usually critical to surveillance systems. To demonstrate the feasibility and the effectiveness of this approach, the paper presents a case study based on a distributed ISS scenario in a crowded urban area, implemented on clustered edge devices that are able to off‐load tasks in a “horizontal” manner in the context of the developed MISS framework. As demonstrated by the initial experiments, the MISS prototype is able to obtain face recognition results 8 times faster compared with the traditional off‐loading pattern, where processing tasks are pushed “vertically” to the cloud.     

无线传感器网络数据融合路由算法的改进

无线传感器网络能量有限,数据融合能通过合并冗余数据减少传输数据量,但其本身的代价不可忽略。针对该问题,研究数据融合代价和数据传输代价对数据融合路由的影响,在基于决策数据融合技术AFST中,对直传数据采用动态最短路径(DSPT)算法,动态识别网络环境和数据特征变化,以最小的代价调整路由。实验与分析结果表明,当网络结构发生变化时,DSPT算法比SPT算法效率更高、更节能。     

智能电网中家域网安全数据汇聚与调度方法研究

智能电网中通信网络的安全是实施智能电网的一个重要环节。用户信息的隐私保护是智能电网安全服务的一个主要任务。智能电网中用户信息隐私保护主要围绕智能电表数据的机密性和匿名性展开。本文以家域网作为智能电网通信网络的一个基本数据汇聚与调度单元,提出了一种安全的网内数据汇聚与调度方法,从而保证了智能家居设备的用电信息的机密性和匿名性。采用NS-2对本文提出的网内方法进行了仿真研究。仿真结果表明,本文提出的网内数据汇聚与调度方法与传统方法相比具有较高的实用性。     

基于大数据聚合的电力用户行为实时云监测方法

为提升电力用户行为监测效果及准确性,判断电力用户异常行为,提出一种基于大数据聚合的电力用户行为实时云监测方法。该方法将基础设施及终端等获取的电力用户行为大数据储存至数据层的关系数据库内,处理层调用数据层存储电力用户行为大数据,采用大数据处理技术,通过数据降维、清洗以及标准化处理后,提升电力用户行为大数据质量;应用层采用改进流数据聚类算法,通过用户及簇典型曲线提取、曲线相似度度量,实现用户用电行为异常监测,并通过显示层云展现监测结果。实验结果证明,该方法的数据聚类质量高,可以有效获取电力用户行为监测结果,判断电力用户是否存在异常行为,具备较高监测准确性。     

一种异构集群中能量高效的大数据处理算法

集群的能量消耗已经超过了其本身的硬件购置费用,而大数据处理需要大规模的集群耗费大量时间,因此如何进行能量高效的大数据处理是数据拥有者和使用者亟待解决的问题,也是对能源和环境的一个巨大挑战.现有的研究一般通过关闭部分节点以减少能量消耗,或者设计新的数据存储策略以便实施能量高效的数据处理.通过分析发现即便使用最少的节点也存在很大的能源浪费,而新的数据存储策略对于已经部署好的集群会造成大规模的数据迁移,消耗额外的能量.针对异构集群下I/O密集型的大数据处理任务,提出一种新的能量高效算法MinBalance,将问题分为节点选择和负载均衡两个步骤.在节点选择阶段采用4种不同的贪心策略,充分考虑到节点的异构性,尽量选择最合适的节点进行任务处理;在负载均衡阶段对选择的节点进行负载均衡,以减少各个节点因为等待而造成的能量浪费.该方法具有通用性,不受数据存储策略的影响.实验表明MinBalance方法在数据集较大的情况下相对于传统关闭部分节点的方法可以减少超过60%的能量消耗.