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Optimal random access for a cognitive radio terminal with energy harvesting capability

We consider a cognitive radio scenario with an energy harvesting secondary user (SU) attempting to access a primary channel randomly. We assume multipacket reception (MPR) capability and investigate a system in which the SU may or may not exploit the primary feedback messages. The access probabilities are obtained to maximize the secondary throughput under the constraints of primary queue
Software and Communications
Agriculture and Crops

Optimization of fractional-order RLC filters

This paper introduces some generalized fundamentals for fractional-order RL β C α circuits as well as a gradient-based optimization technique in the frequency domain. One of the main advantages of the fractional-order design is that it increases the flexibility and degrees of freedom by means of the fractional parameters, which provide new fundamentals and can be used for better interpretation or

Circuit Theory and Applications
Software and Communications
Mechanical Design

On the flow anonymity problem in network coding

In this paper, we aim at protecting the privacy of the communicating parties while ensuring the authenticity of source nodes. In particular, we exploit intra-flow network coding to preserve the anonymity of communicating parties. Towards this objective, we propose an anonymity preservation scheme, namely closed group anonymity (CGA) that preserves the anonymity of the communicating parties via

Software and Communications

Cross-layer minimum-delay scheduling and maximum-throughput resource allocation for multiuser cognitive networks

A cognitive network is considered that consists of a base station (BS) communicating with multiple primary and secondary users. Each secondary user can access only one of the orthogonal primary channels. A model is considered in which the primary users can tolerate a certain average delay. A special case is also considered in which the primary users do not suffer from any delay. A novel cross

Software and Communications

Agent-based simulation of urban infrastructure asset management activities

This paper presents a case for adopting agent-based modeling (ABM) as a framework for representing the complex interactions that occur within the context of urban infrastructure management. A generic ABM is proposed with four key agents namely; assets, users, operators and politicians. For each agent a set of generic attributes, actions and behaviors are defined. A detailed behavioral model is

Mechanical Design
Innovation, Entrepreneurship and Competitiveness

Assessing lean systems using variability mapping

A new approach to assess lean manufacturing based on system's variability is proposed. The assessment utilizes a new tool called variability source mapping (VSMII) which focuses on capturing and reducing variability across the production system. The new tool offers a new metric called variability index to measure the overall variability level of the system. Based on the mapping and the new metric

Software and Communications
Innovation, Entrepreneurship and Competitiveness

Optimal random access and random spectrum sensing for an energy harvesting cognitive radio

We consider a secondary user with energy harvesting capability. We design access schemes for the secondary user which incorporate random spectrum sensing and random access, and which make use of the primary automatic repeat request (ARQ) feedback. The sensing and access probabilities are obtained such that the secondary throughput is maximized under the constraints that both the primary and

Software and Communications
Agriculture and Crops

Transmission power adaptation for cognitive radios

In cognitive radio (CR) networks, determining the optimal transmission power for the secondary users (SU) is crucial to achieving the goal of maximizing the secondary throughput while protecting the primary users (PU) from service disruption and interference. In this paper, we propose an adaptive transmission power scheme for cognitive terminals opportunistically accessing a primary channel. The

Artificial Intelligence
Circuit Theory and Applications
Software and Communications

Reduced-complexity SFBC-OFDM for vehicular channels with high mobility

Space frequency block coding with orthogonal frequency division multiplexing (SFBC-OFDM) suffers from the effect of inter-carrier interference (ICI) in doubly-selective communication channels. In this paper, a scheme is proposed in which windowing is applied to the received signal to reduce the effect of ICI to a limited number of neighboring sub-carriers. The sub-carriers holding the SFBC

Circuit Theory and Applications
Software and Communications

Formation principles and ligand dynamics of nanoassemblies of CdSe quantum dots and functionalised dye molecules

Functional dye molecules, such as porphyrins, attached to CdSe quantum dots (QDs) through anchoring meso-pyridyl substituents, form quasi-stable nanoassemblies. This fact results in photoluminescence (PL) quenching of the QDs both due to Förster resonance energy transfer (FRET) and the formation of non-radiative surface states under conditions of quantum confinement (non-FRET). The formation

Circuit Theory and Applications