Data Mining Practical Machine Learning Tools and Techniques

In the last years, wireless sensor networks (WSNs) have gained increasing attention from both the research community and actual users. As sensor nodes are generally battery-powered devices, the critical aspects to face concern how to reduce the energy consumption of nodes, so that the network lifetime can be extended to reasonable times. In this paper we first break down the energy consumption for the components of a typical sensor node, and discuss the main directions to energy conservation in WSNs. Then, we present a systematic and comprehensive taxonomy of the energy conservation schemes, which are subsequently discussed in depth. Special attention has been devoted to promising solutions which have not yet obtained a wide attention in the literature, such as techniques for energy efficient data acquisition. Finally we conclude the paper with insights for research directions about energy conservation in WSNs.

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Energy conservation in wireless sensor networks: A survey

For 100 years, there has been no change in the basic structure of the electrical power grid. Experiences have shown that the hierarchical, centrally controlled grid of the 20th Century is ill-suited to the needs of the 21st Century. To address the challenges of the existing power grid, the new concept of smart grid has emerged. The smart grid can be considered as a modern electric power grid infrastructure for enhanced efficiency and reliability through automated control, high-power converters, modern communications infrastructure, sensing and metering technologies, and modern energy management techniques based on the optimization of demand, energy and network availability, and so on. While current power systems are based on a solid information and communication infrastructure, the new smart grid needs a different and much more complex one, as its dimension is much larger. This paper addresses critical issues on smart grid technologies primarily in terms of information and communication technology (ICT) issues and opportunities. The main objective of this paper is to provide a contemporary look at the current state of the art in smart grid communications as well as to discuss the still-open research issues in this field. It is expected that this paper will provide a better understanding of the technologies, potential advantages and research challenges of the smart grid and provoke interest among the research community to further explore this promising research area.

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Smart Grid Technologies: Communication Technologies and Standards

The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.

[서평]「Applied Cryptography」

Sphere Packings, Lattices and Groups

A new optical correlator containing a tapped delay line with thousands of taps is described This enables ultra-high resolution correlation We apply this to monitoring quality-of-signal by correlating the received, degraded bits with an un-degraded signal The strength of the correlation signal, which is all-optical, is proportional to the quality Dispersion and attenuation can be evaluated in less than 100 ps at 40Gb/s, and jitter and noise in less than 100 ns This is a significant improvement over minutes or even hours for bit-error-rate measurements Simulations show good correspondence to eye-diagram measurements, the conventional (but slow) way to measure signal quality If a network node can know the quality of all its links in real-time, it can re-route signals around poor links, and provide restoration and protection as well The key to all this is an optical correlator with a very large number of taps in its internal tapped delay line Our device uses a White cell and a fixed micro-mirror array In a White cell, light bounces back and forth between three spherical mirrors Multiple beams circulate in the same cell without interfering and are each refocused to a unique pattern of spots We make the spots land on the micro-mirror array to switch between cells of slightly different lengths Our current design provides 6550 possible delays for thousands of light beams, using only ten mirrors, a lens, and the micro-mirror array We have developed two routing and protection protocols to exploit having this real-time information available to the network

All-optical quality-of-signal monitoring in real time

Broadband satellite constellation networks will be required to carry all types of IP traffic, real time interactive traffic as well as nonreal time traffic, warranting the need for appropriate QoS for these different traffic flows. In this paper we investigate advantages of employing constraint-based routing using MPLS in a multilayered hierarchical satellite constellation. Bandwidth availability or residual bandwidth on a satellite link is taken into account when setting up routes for high priority real-time traffic e.g. VoIP, which is sensitive to delay and jitter. Also to protect the VoIP traffic from being swamped by bursty best-effort traffic we propose to have a separate queue for high priority traffic. The performance of the prioritized load balancing routing algorithm on a multi-layered satellite network is simulated and analyzed.

Routing of VoIP traffic in multilayered satellite networks

Wireless Sensor Networks (WSN) are a sensing, computing and communication infrastructure that are able to observe and respond to phenomena in the natural environment and in our physical and cyber infrastructure. The sensors themselves can range from small passive micro sensors to larger scale, controllable weather-sensing platforms. In this work, we investigate how the sensor network performs in the case when the sink node moves using different radio models. We consider good put and depletion metrics to evaluate the performance of WSN. We compare the simulation results when the sink node is mobile and stationary considering lattice topology and AODV protocol. The simulation results have shown that in case of mobile sink, the good put of TwoRayGround radio model is better than Shadowing. However, the consumed energy of Shadowing model is better than TwoRayGround model.

Impact of Mobile Sink for Wireless Sensor Networks Considering Different Radio Models

The growing interest in applications that demand certain end-to-end performance guarantees and the introduction of imaging and video sensors have posed additional challenges. Transmission of data in such cases requires both energy and QoS aware network management in order to ensure efficient usage of the sensor resources and effective access to the gathered measurements. In this paper we present LEAS, a Lightweight Energy-efficient Scheduling Scheme, a novel power management and routing scheme for heterogeneous wireless sensor networks.

LEAS: A Load-Aware Energy-Efficient Adaptive Scheduling for Heterogeneous Wireless Sensor Networks

Sensor networks are a sensing, computing and communication infrastructure that are able to observe and respond to phenomena in the natural environment and in our physical and cyber infrastructure. The sensors themselves can range from small passive micro-sensors to larger scale, controllable weather-sensing platforms. In this work, we investigate how the sensor network performs in the case when the sink node moves. We consider as a metrics for evaluation goodput and Routing Efficiency (RE). We compare the simulation results when the sink node is mobile and stationary considering lattice topology using AODV protocol. The simulation results have shown that for the case of mobile sink, the goodput is better when the number of nodes is 16. However, when the number of nodes are 100 and 256, the goodput of mobile sink is worse than stationary sink when the values Tr is larger than 1pps. For both stationary and mobile sinks, the RE increases with the increase of number of sensor nodes, but the RE of mobile sink is better than the stationary sink.

Arjan Durresi

Papers

All-optical quality-of-signal monitoring in real time

Routing of VoIP traffic in multilayered satellite networks

Impact of Mobile Sink for Wireless Sensor Networks Considering Different Radio Models

LEAS: A Load-Aware Energy-Efficient Adaptive Scheduling for Heterogeneous Wireless Sensor Networks

Impact of mobile sink forwireless sensor networks considering goodput and routing efficiency metrics