4,369 research outputs found
Internet of Things Cloud: Architecture and Implementation
The Internet of Things (IoT), which enables common objects to be intelligent
and interactive, is considered the next evolution of the Internet. Its
pervasiveness and abilities to collect and analyze data which can be converted
into information have motivated a plethora of IoT applications. For the
successful deployment and management of these applications, cloud computing
techniques are indispensable since they provide high computational capabilities
as well as large storage capacity. This paper aims at providing insights about
the architecture, implementation and performance of the IoT cloud. Several
potential application scenarios of IoT cloud are studied, and an architecture
is discussed regarding the functionality of each component. Moreover, the
implementation details of the IoT cloud are presented along with the services
that it offers. The main contributions of this paper lie in the combination of
the Hypertext Transfer Protocol (HTTP) and Message Queuing Telemetry Transport
(MQTT) servers to offer IoT services in the architecture of the IoT cloud with
various techniques to guarantee high performance. Finally, experimental results
are given in order to demonstrate the service capabilities of the IoT cloud
under certain conditions.Comment: 19pages, 4figures, IEEE Communications Magazin
Multi-user Resource Control with Deep Reinforcement Learning in IoT Edge Computing
By leveraging the concept of mobile edge computing (MEC), massive amount of
data generated by a large number of Internet of Things (IoT) devices could be
offloaded to MEC server at the edge of wireless network for further
computational intensive processing. However, due to the resource constraint of
IoT devices and wireless network, both the communications and computation
resources need to be allocated and scheduled efficiently for better system
performance. In this paper, we propose a joint computation offloading and
multi-user scheduling algorithm for IoT edge computing system to minimize the
long-term average weighted sum of delay and power consumption under stochastic
traffic arrival. We formulate the dynamic optimization problem as an
infinite-horizon average-reward continuous-time Markov decision process (CTMDP)
model. One critical challenge in solving this MDP problem for the multi-user
resource control is the curse-of-dimensionality problem, where the state space
of the MDP model and the computation complexity increase exponentially with the
growing number of users or IoT devices. In order to overcome this challenge, we
use the deep reinforcement learning (RL) techniques and propose a neural
network architecture to approximate the value functions for the post-decision
system states. The designed algorithm to solve the CTMDP problem supports
semi-distributed auction-based implementation, where the IoT devices submit
bids to the BS to make the resource control decisions centrally. Simulation
results show that the proposed algorithm provides significant performance
improvement over the baseline algorithms, and also outperforms the RL
algorithms based on other neural network architectures
Neoline from Aconitum flavum Hand
The title compound, C24H39NO6 [systematic name: (1α,6α,14α,16β)-N-ethyl-6,16-dimethoxy-4-methoxymethylaconitane-1,8,14-triol], is a C19-diterpenoid alkaloid from the roots of Aconitum flavum Hand. The molecule has an aconitane carbon skeleton with four six-membered rings and two five-membered rings. Both five-membered rings adopt envelope conformations. Two six-membered rings adopt chair conformations, whereas the other two adopt boat conformations. Intramolecular O—H⋯O and O—H⋯N and intermolecular O—H⋯O hydrogen bonds are present in the structure. In the crystal, one methyl group is disordered over two sites with an occupancy ratio of 0.70 (3):0.30 (3)
BcBIM: A Blockchain-Based Big Data Model for BIM Modification Audit and Provenance in Mobile Cloud
Building Information Modeling (BIM) is envisioned as an indispensable opportunity in the architecture, engineering, and construction (AEC) industries as a revolutionary technology and process. Smart construction relies on BIM for manipulating information flow, data flow, and management flow. Currently, BIM model has been explored mainly for information construction and utilization, but rare works pay efforts to information security, e.g., critical model audit and sensitive model exposure. Moreover, few BIM systems are proposed to chase after upcoming computing paradigms, such as mobile cloud computing, big data, blockchain, and Internet of Things. In this paper, we make the first attempt to propose a novel BIM system model called bcBIM to tackle information security in mobile cloud architectures. More specifically, bcBIM is proposed to facilitate BIM data audit for historical modifications by blockchain in mobile cloud with big data sharing. The proposed bcBIM model can guide the architecture design for further BIM information management system, especially for integrating BIM cloud as a service for further big data sharing. We propose a method of BIM data organization based on blockchains and discuss it based on private and public blockchain. It guarantees to trace, authenticate, and prevent tampering with BIM historical data. At the same time, it can generate a unified format to support future open sharing, data audit, and data provenance
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