Search results for "Networking & Telecommunications"
showing 10 items of 962 documents
Survey of Formal Verification Methods for Smart Contracts on Blockchain
2019
Due to the immutable nature of distributed ledger technology such as blockchain, it is of utter importance that a smart contract works as intended before employment outside test network. This is since any bugs or errors will become permanent once published to the live network, and could lead to substantial economic losses; as manifested in the infamous DAO smart contract exploit hack in 2016. In order to avoid this, formal verification methods can be used to ensure that the contract behaves according to given specifications. This paper presents a survey of the state of the art of formal verification of smart contracts. Being a relatively new research area, a standard or best practice for fo…
Predictive analysis of Cardiac Resynchronization Therapy response by means of the ECG
2016
Aims: Cardiac Resynchronization Therapy (CRT) is an effective treatment for heart failure patients with moderate to severe symptoms. Unfortunately, a significant proportion of patients (up to 35%) do not respond to CRT (patients called "non-responders"). This results in a large cost-effectiveness relation for heart failure treatment. This study aims to assess the prediction response to CRT by means of analysing the ECG. Methods: We retrospectively analysed the surface ECG and QRS previous to CRT implantation in 45 consecutive patients with dilated (27) or ischemic (18) cardiomyopathy. We extracted the QRS and then processed a measure of energy of a discrete version of the Stockwell Transfor…
Bɪ-CомDᴇт: Community Detection in Bipartite Networks
2019
Abstract Extracting hidden communities from bipartite networks witnessed a determined effort. In this respect, different streams of research relied on bipartite networks to unveil communities. In this paper, we introduce a new approach, called Bi-Comdet, that aims to an efficient community detection in bipartite networks. The main trust of the introduced approach is that it stresses on the importance of grouping two types of nodes in communities having a full connection between its nodes. The quality of the unveiled communities, is assessed through some metrics borrowed from the FCA community, to wit modularity, overlapping and stability. These metrics are then aggregated through the use of…
Health Applications Based on Molecular Communications: A Brief Review
2019
This work analyses significant cases in which applications of molecular communication systems to nano/bio-hybrid medical field represent an ideal solution for medical therapies (e.g., for the treatment of diseases such as cancer). A review of the literature reveals that biocompatibility jointly with nanocommunication can be exploited to provide effective treatment of diseases and reduce side effects considerably when compared to conventional therapy. Biocompatibility avoids the immune response rejecting drugs and does not stimulate nerves, whereas nanocommunication is a promising technology that allows accessing small and delicate body sites non-invasively. Refereed/Peer-reviewed
Learning From Errors: Detecting Cross-Technology Interference in WiFi Networks
2018
In this paper, we show that inter-technology interference can be recognized using commodity WiFi devices by monitoring the statistics of receiver errors. Indeed, while for WiFi standard frames the error probability varies during the frame reception in different frame fields (PHY, MAC headers, and payloads) protected with heterogeneous coding, errors may appear randomly at any point during the time the demodulator is trying to receive an exogenous interfering signal. We thus detect and identify cross-technology interference on off-the-shelf WiFi cards by monitoring the sequence of receiver errors (bad PLCP, bad FCS, invalid headers, etc.) and propose two methods to recognize the source of in…
CODING PARTITIONS OF REGULAR SETS
2009
A coding partition of a set of words partitions this set into classes such that whenever a sequence, of minimal length, has two distinct factorizations, the words of these factorizations belong to the same class. The canonical coding partition is the finest coding partition that partitions the set of words in at most one unambiguous class and other classes that localize the ambiguities in the factorizations of finite sequences. We prove that the canonical coding partition of a regular set contains a finite number of regular classes and we give an algorithm for computing this partition. From this we derive a canonical decomposition of a regular monoid into a free product of finitely many re…
Hardware Implementation of a Configurable Motion Estimator for Adjusting the Video Coding Performances
2012
International audience; Despite the diversity of video compression standard, the motion estimation still remains a key process which is used in most of them. Moreover, the required coding performances (bit-rate, PSNR, image spatial resolution, etc.) depend obviously of the application, the environment and the network communication. The motion estimation can therefore be adapted to fit with these performances. Meanwhile, the real time encoding is required in many applications. In order to reach this goal, we propose in this paper a hardware implementation of the motion estimator which enables the integer motion search algorithms to be modified and the fractional search and variable block siz…
Efficient formulation of Multimode Equivalent Networks for 2-D waveguide steps through Kummer's transformation
2017
In this paper we present a new and improved formulation for the Multimode Equivalent Network (MEN) representation of arbitrary waveguide junctions. In the new formulation the Kummer's transformation is used to separate the kernel into dynamic and static parts, by introducing higher order extraction terms. The main difference with respect to the old formulation is that the approximation of the kernel is more accurate and the numerical computations are more efficient. In addition to theory, both formulations are compared in terms of efficiency and convergence thereby fully validating the proposed new formulation.
Enabling Retransmissions for Achieving Reliable Multicast Communications in WSNs
2016
To ensure end-to-end reliable multicast or broadcast transmissions in IEEE 802.15.4 based wireless sensor networks WSNs) is a challenging task since no retransmission and acknowledgment mechanisms are defined in such WSNs. In this paper, we propose three retransmission enabled multicast transmission schemes in order to achieve reliable packet transmissions in such networks. Different from the legacy CSMA/CA principle, these schemes allow a sending or forwarding node to retransmit a packet if necessary and enable implicit or/and explicit acknowledgment for multicast services. Simulations are performed in order to assess the performance of these schemes in terms of number of retransmissions, …
Priority-oriented multicast transmission schemes for heterogeneous traffic in WSNs
2016
To ensure quality of service (QoS) for heterogeneous traffic in IEEE 802.15.4 based wireless sensor networks (WSNs) is a challenging task since no traffic prioritization mechanism is defined in such WSNs. In this paper, we propose two priority-oriented multicast transmission schemes to provide QoS for heterogeneous traffic in WSNs. Contrary to the legacy CSMA/CA and FIFO principles, these schemes differentiate self-generated or received traffic and give priority to delay-sensitive traffic with respect to channel access and packet scheduling. Simulations are performed in order to assess the performance of these schemes in terms of end-to-end delay, energy consumption, packet delivery ratio, …