Interactive Joint Transfer of Energy and Information

In some communication networks, such as passive RFID systems, the energy used to transfer information between a sender and a recipient can be reused for successive communication tasks. In fact, from known results in physics, any system that exchanges information via the transfer of given physical resources, such as radio waves, particles and qubits, can conceivably reuse, at least part, of the received resources. This paper aims at illustrating some of the new challenges that arise in the design of communication networks in which the signals exchanged by the nodes carry both information and energy. To this end, a baseline two-way communication system is considered in which two nodes communicate in an interactive fashion. In the system, a node can either send an "on" symbol (or "1"), which costs one unit of energy, or an "off" signal (or "0"), which does not require any energy expenditure. Upon reception of a "1" signal, the recipient node "harvests", with some probability, the energy contained in the signal and stores it for future communication tasks. Inner and outer bounds on the achievable rates are derived. Numerical results demonstrate the effectiveness of the proposed strategies and illustrate some key design insights.Comment: 29 pages, 11 figures, Submitted in IEEE Transactions on Communications. arXiv admin note: substantial text overlap with arXiv:1204.192

Joint Interference Alignment and Bi-Directional Scheduling for MIMO Two-Way Multi-Link Networks

By means of the emerging technique of dynamic Time Division Duplex (TDD), the switching point between uplink and downlink transmissions can be optimized across a multi-cell system in order to reduce the impact of inter-cell interference. It has been recently recognized that optimizing also the order in which uplink and downlink transmissions, or more generally the two directions of a two-way link, are scheduled can lead to significant benefits in terms of interference reduction. In this work, the optimization of bi-directional scheduling is investigated in conjunction with the design of linear precoding and equalization for a general multi-link MIMO two-way system. A simple algorithm is proposed that performs the joint optimization of the ordering of the transmissions in the two directions of the two-way links and of the linear transceivers, with the aim of minimizing the interference leakage power. Numerical results demonstrate the effectiveness of the proposed strategy.Comment: To be presented at ICC 2015, 6 pages, 7 figure

Determining a piston's top dead center (TDC) in an automobile using installed piezoelectric on a vibrating beam

Smart structures and MEMS are considered important field recently, due to the importance and high capabilities in measurement and the power of reaction and response to changes of the surroundings. This research concerns two fields of practical vision in the automotive industry and discuss the energy recycled industrial vibrations. The goal is to use the PVDF piezoelectric elements in car flywheel for energy harvesting, and compare and replace it with the revolution sensor. This research is totally based on empirical tests data and the result that the use of piezoelectric polymer sensors can harvest energy, was find performing far better than inductive sensors.Keywords: Piezoelectric element; Vibration energy harvesting; smart structures; Revolution sensor; Flywhee

Evaluation of the effects of isotretinoin for treatment of acne on corneal sensitivity

Purpose: To determine the effect of isotretinoin on corneal sensitivity in acne patients. Methods: Fifty patients (13 men and 37 women) with a mean age of 23.24 ± 3.4 years were selected among patients receiving isotretinoin (1.0 mg/kg) for acne according to inclusion criteria. The Cochet-Bonnet esthesiometer was used to measure corneal sensitivity (in mm filament length) two times (the measurements were done immediately before starting the medication, then 3 months after that), including 3 measurements each time, between 11 a.m. and 1 p.m. by an experienced operator. The average of the 3 measurements in each time was recorded as the final value. One-way analysis of variance and Chi square were used for quantitative and qualitative comparison of corneal sensitivity before and after isotretinoin use, respectively. Results: The mean corneal sensitivity was 5.54 ± 0.05 before medication consumption which decreased to 5.41 ± 0.05 after isotretinoin treatment for 3 months (P < 0.005). After controlling the effect of age and sex, the decrease of corneal sensitivity was markedly significant (P = 0.003) as decreased corneal sensitivity was more pronounced at higher ages and in female gender. In non-parametric evaluation, corneal sensitivity was categorized as substantial (5.5�6 mm), intermediate (4.5�5.5 mm), and low (3.5�4.5). About 72 of the participants had substantial corneal sensitivity before drug consumption, which decreased to 60 after 3 months of treatment. Conclusions: According to the results of this study, corneal sensitivity decreases after three months of treatment with isotretinoin. This decrease is more pronounced at higher ages and in women. © 2018 Iranian Society of Ophthalmolog

Gathering Sensor Data in Home Networks with IPFIX

Abstract. New developments in military, health and home areas call for new approaches for data acquisition in real-time. Such application areas frequently include challenging requirements for collection, process-ing and analysis of environmental data. Wireless Sensor Networks can collect such environmental data efficiently. Collected sensor node data needs to be transmitted in an efficient way due to limitations of sensor node resources in battery power and available bandwidth. In this paper, we present a method for efficient transmission of sensor measurement data using the IETF standard IPFIX. We show that its template based design is suitable for efficient transmission of senor data with low band-width consumption. In this paper, we present the protocol and its imple-mentation in Wireless Sensor Networks (WSNs). Additionally, a header compression scheme is introduced which further reduces communication cost during data transmission.

Authenticated key agreement mediated by a proxy re-encryptor for the Internet of Things

International audienceThe Internet of Things (IoT) is composed of a wide range of heterogeneous network devices that communicate with their users and the surrounding devices. The secure communications between these devices are still essential even with little or no previous knowledge about each other and regardless of their resource capabilities. This particular context requires appropriate security mechanisms which should be wellsuited for the heterogeneous nature of IoT devices, without pre-sharing a secret key for each secure connection. In this work, we first propose a novel symmetric cipher proxy re-encryption scheme. Such a primitive allows a user to delegate her decryption rights to another with the help of a semi-trusted proxy, but without giving this latter any information on the transmitted messages and the user's secret keys. We then propose AKAPR, an Authenticated Key Agreement mediated by a Proxy Re-encryptor for IoT. The mechanism permits any two highly resource-constrained devices to establish a secure communication with no prior trust relationship. AKAPR is built upon our proposed proxy re-encryption scheme. It has been proved by ProVerif to provide mutual authentication for participants while preserving the secrecy of the generated session key. In addition, the scheme benefits from the lightness of our proxy re-encryption algorithm as it requires no expensive cryptographic operations such as pairing or modular exponentiatio

3D numerical modeling of a new thermo-inductive NDT using pulse mode and pulsed phase methods

Thermo-inductive testing is a new technique used for health inspection on different components of automotive and aeronautic industries. Defect detection is based on the modification of induced eddy current and temperatures due to the presence of defects. The temperature change propagated at the surface of the specimen can then be detected by an infrared camera. In this work, a 3D numerical model of this technique is developed and applied to aeronautic materials. Results obtained are compared with the infrared thermography method to demonstrate the relevance of the new technique

3D Modeling and Optimization of a C-Shape Permanent Magnet Synchronous Generator for Wind Power Plants

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Electromagnetic and Thermal Modeling of Composite Materials Using Multilayer Shell Elements

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