Search results for " architect"

A random-walk benchmark for single-electron circuits

2021

Mesoscopic integrated circuits aim for precise control over elementary quantum systems. However, as fidelities improve, the increasingly rare errors and component crosstalk pose a challenge for validating error models and quantifying accuracy of circuit performance. Here we propose and implement a circuit-level benchmark that models fidelity as a random walk of an error syndrome, detected by an accumulating probe. Additionally, contributions of correlated noise, induced environmentally or by memory, are revealed as limits of achievable fidelity by statistical consistency analysis of the full distribution of error counts. Applying this methodology to a high-fidelity implementation of on-dema…

Context-Aware RF-Energy Harvesting for IoT Networks

2021

Energy Harvesting plays a crucial role in improving the operational lifetime of IoT devices. The deployment of dedicated RF-transmitters helps in sufficient energy propagation to the sensor nodes of IoT networks. Also, energy harvesting using the deployment of such RF-transmitters is a challenging issue. In this work, two methods are proposed for the optimal placement of RF-transmitters for efficient energy harvesting in wireless sensor networks. The proposed context-aware RF-energy harvesting considers different network performance parameters such as energy-hole information, and data routing information. RF-transmitter deployment is achieved using network connectivity information in the fi…

Design and evaluation of prosody-based non-speech audio feedback for physical training application

2011

Abstract Methodological support for the design of non-speech user interface sounds for human–computer interaction is still fairly scarce. To meet this challenge, this paper presents a sound design case which, as a practical design solution for a wrist-computer physical training application, outlines a prosody-based method for designing non-speech user interface sounds. The principles used in the design are based on nonverbal communicative functions of prosody in speech acts, exemplifying an interpersonal approach to sonic interaction design. The stages of the design process are justified with a theoretical analysis and three empirical sub-studies, which comprise production and recognition t…

Fusion Architectures for Word-Based Audiovisual Speech Recognition

2020

Grammars++ for modelling information in text

1999

Abstract Grammars provide a convenient means to describe the set of valid instances in a text database. Flexibility in choosing a grammar can be exploited to provide information modelling capability by designing productions in the grammar to represent entities and relationships of interest to database applications. Additional constraints can be specified by attaching predicates to selected nonterminals in the grammar. When used for database definition, grammars can provide the functionality that users have come to expect of database schemas. Extended grammars can also be used to specify database manipulation, including query, update, view definition, and index specification.

The role of the Access Point in Wi-Fi networks with selfish nodes

2009

In Wi-Fi networks, mobile nodes compete for accessing the shared channel by means of a random access protocol called Distributed Coordination Function (DCF), which is long term fair. But recent drivers allow users to configure protocol parameters differently from their standard values in order to break the protocol fairness and obtain a larger share of the available bandwidth at the expense of other users. This motivates a game theoretical analysis of DCF. Previous studies have already modeled access to a shared wireless channel in terms of non-cooperative games among the nodes, but they have mainly considered ad hoc mode operation. In this paper we consider the role of the Access Point (AP…

A Cluster based Sensor-Selection Scheme for Energy-Efficient Agriculture Sensor Networks

2021

Improving the energy-efficiency of remotely deployed sensor nodes in agriculture wireless networks is very challenging due to a lack of access to energy grid. Network clustering and limiting the amount of sensor data are among the various methods to improve the lifetime of these sensor nodes. In this work, an optimal sensor-selection scheme is proposed to improve the Quality of Service in clustered agriculture networks. the proposed method selects a limited number of sensor nodes to be active in each cluster. It considers the estimator performance while selecting limited sensor nodes for environmental monitoring. the optimal sensor-selection process considers the information of remaining en…

An adaptive cooperative MAC mechanism in multi-hop wireless networks

2010

In this paper, we propose a novel adaptive cooperative MAC mechanism that is specifically designed for two-hop cooperative communications where source and destination cannot hear each other directly. The proposed scheme employs an efficient adaptive relay selection algorithm such that the number of relay nodes is optimized for each cooperative transmission to maximize cooperation benefits and effectively avoid potential collisions with other transmissions. In order to determine the optimal number of relays we apply a training sequence in Hello message exchange, which provides us with a channel status indicator combining both bit-level and flow-level information. Numerical results show that …

A contention-based multiple access protocol in cooperative wireless networks

2010

Cooperative communication has emerged as a promising technique to enhance system performance in wireless networks. This paper proposes a contention-based cooperative multiple medium access control protocol by means of multiple retransmissions of the same packet from different relay nodes. The proposed scheme exploits cooperative communication capability not only from time diversity derived from multiple temporal transmissions but also spatial diversity derived from distributed multiple relays. A Markov chain is introduced to analyze the throughput performance of the proposed cooperative scheme. The performance evaluation of the protocol is validated and compared with non-cooperative ARQ pro…

An improvement of NFC-SEC with signed exchanges for an e-prescription-based application

2013

International audience; In the context of an aging population, drug intake can be a potential source of errors leading to death in some cases. Almost all of these errors are unintentional and come from incorrect prescriptions, unsuitable dosages for the patient or incompatibility with other treatments. To limit these risks which are especially important in the elderly or pre-dependency, we propose a secure system for drug treatment through the NFC (Near Field Communication) contact-less communication technology. The proposed system provides security mechanisms such as integrity, authentication, encryption and non-repudiation. To ensure this security, an extension of the international standa…