255 research outputs found
On Prediction Properties of Kriging: Uniform Error Bounds and Robustness
Kriging based on Gaussian random fields is widely used in reconstructing
unknown functions. The kriging method has pointwise predictive distributions
which are computationally simple. However, in many applications one would like
to predict for a range of untried points simultaneously. In this work we obtain
some error bounds for the (simple) kriging predictor under the uniform metric.
It works for a scattered set of input points in an arbitrary dimension, and
also covers the case where the covariance function of the Gaussian process is
misspecified. These results lead to a better understanding of the rate of
convergence of kriging under the Gaussian or the Mat\'ern correlation
functions, the relationship between space-filling designs and kriging models,
and the robustness of the Mat\'ern correlation functions
ENHANCING POINT-TO-POINT PERFORMANCE IN LOW-POWER AND LOSSY NETWORKS BASED ON GROUP AD HOC ON-DEMAND DISTANCE VECTOR AND PROJECTED DESTINATION ADVERTISEMENT OBJECT
Techniques are described herein for enhancing the performance of Point-to-Point (P2P) performance in Low-power and Lossy Networks (LLNs) based on Ad-hoc On-demand Distance Vector (AODV) and Projected Destination Advertisement Object (P-DAO). These techniques may restrict the flooding range of AODV and reduce the computational complexity of P-DAO
NOVEL SECURED INTER-PERSONAL AREA NETWORK GROUP MANAGEMENT IN LOW-POWER AND LOSSY NETWORKS
Low-power and Lossy Network (LLN) environments may comprise, possibly among other things, different personal area networks (PANs) resulting in, for example, node communication challenges across or between PANs. To address these types of challenges, techniques are presented herein that support a novel secure group management method to self-solve the inter-PAN problem that is both low-cost and customer-friendly. Aspects of the techniques presented herein encompass establishing a secure node-to-node (N2N) communication link between involved inter-PAN nodes, automatically looking for the relay neighbors between different PANs (as the inter-PAN node can help with forwarding the local the Routing Protocol for LLN (RPL) messages), automatically propagating the group information and maintaining the local RPL tree between the inter-PAN nodes, etc. Aspects of the techniques presented herein employ, among other things, spreading PAN advertisement (PA) messages with group and hop information to identify a feasible routing path, using the Extensible Authentication Protocol-Tunneled Transport Layer Security (EAP-TTLS) protocol to establish a secure transport tunnel, automatically unicasting a destination-oriented directed acyclic graph (DODAG) Information Solicitation (DIS) message to join the group tree, etc. Under aspects of the techniques presented herein an application server need not know the topology of a network
AN ACCELERATED PEER-TO-PEER (P2P) COMMUNICATION METHOD FACILITATED BY REUSING EXISTING P2P PATHS FOR LOW-POWER AND LOSSY NETWORKS
The Wireless Smart Utility Networks (Wi-SUN) alliance promotes interoperable wireless standards-based solutions for Internet of Things (IoT) deployments, such as distributed automation (DA). For some applications, such as smart utility or smart city applications, it is desirable to provide optimized peer-to-peer (P2P) routing. However, for P2P traffic within a Destination Oriented Directed Acyclic Graph (DODAG), packets either have to be routed through a root in a non-storing mode or through a common ancestor in a storing mode. Techniques herein provide for locally reusing and distributing projected directed advertisement object (P-DAO) tracks. For example, when a node receives a P-DAO track from the root, the node advertises the P-DAO track to its neighbors so that they may reuse the track. Before a node sends a P-DAO request (PDR) to the root, the node first broadcasts a polling to its neighbors to look for an existing P-DAO track that can be reused
IMPROVING THE PERFORMANCE OF DATA STREAMS IN LOSSY AND LOW-POWER NETWORKS
Presented herein are techniques to enhance the performance of data streams in Connected Grid Mesh (CG-Mesh) networks
DIFFERENTIATED RETRANSMISSION IN WIRELESS MESH NETWORKS
Techniques are described herein for enabling diverse retries at a lower layer based on possibilities provided by routing operations. An anycast model is used to indicate a set of next hops and forwarding interfaces that enable indicating raw constraints such as bounded latency to perform a transmission
RATE ADAPTION TECHNIQUES FOR LOW-POWER AND LOSSY NETWORKS (LLNS) BASED ON LOSS DIFFERENTIATION AND SAMPLE RATE
Proposed herein is a complete solution to choose the appropriate PHY mode for delivering packets between nodes based on loss differentiation and sample rate. With the proper PHY mode selection, the described techniques are capable of distinguishing between fading and collision as the source of poor network performance, which can greatly assist in decreasing the latency of frames in low-power and lossy networks (LLNs)
BLOCK ACKNOWLEDGEMENT MECHANISM FOR SPEEDING UP NODE-TO-NODE TRAFFIC IN LOW-POWER AND LOSSY NETWORKS
The Wireless Smart Utility Network (Wi-SUN) Alliance promotes interoperability for large scale wireless mesh networks (WMNs). Such Low-Power and Lossy Networks (LLNs) are widely used in industrial Internet of Things (IoT) settings. In order to improve throughput in node-to-node (N2N) communications for Wi-SUN based wireless nodes, techniques are presented herein that support the addition of a Block Acknowledgement (BA) mechanism to the Wi-SUN protocol. Such a mechanism may, among other things, eliminate a significant acknowledgement (ACK) confirmation overhead when a pair of nodes are using an Extended Directional Frame Exchange (EDFE) mode or an Adaptive Modulation (AM) mode to overcome radio interference
Improving Data Center Energy Efficiency Using a Cyber-physical Systems Approach: Integration of Building Information Modeling and Wireless Sensor Networks
AbstractThe increase in data center operating costs is driving innovation to improve their energy efficiency. Previous research has investigated computational and physical control intervention strategies to alleviate the competition between energy consumption and thermal performance in data center operation. This study contributes to the body of knowledge by proposing a cyber-physical systems (CPS) approach to innovatively integrate building information modeling (BIM) and wireless sensor networks (WSN). In the proposed framework, wireless sensors are deployed strategically to monitor thermal performance parameters in response to runtime server load distribution. Sensor data are collected and contextualized in reference to the building information model that captures the geometric and functional characteristics of the data center, which will be used as inputs of continuous simulations aiming to predict real-time thermal performance of server working environment. Comparing the simulation results against historical performance data via machine learning and data mining, facility managers can quickly pinpoint thermal hot zones and actuate intervention procedures to improve energy efficiency. This BIM-WSN integration also facilitates smarter power management by capping runtime power demand within peak power capacity of data centers and alerting power outage emergencies. This paper lays out the BIM-WSN integration framework, explains the working mechanism, and discusses the feasibility of implementation in future work
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