Search results for "Telecommunication"
showing 10 items of 1769 documents
An Efficient and Secure Multidimensional Data Aggregation for Fog-Computing-Based Smart Grid
2021
International audience; The secure multidimensional data aggregation (MDA) has been widely investigated in smart grid for smart cities. However, previous proposals use heavy computation operations either to encrypt or to decrypt the multidimensional data. Moreover, previous fault-tolerant mechanisms lead to an important computation cost, and also a high communication cost when considering a separate identification phase. In this article, we propose an efficient and secure MDA scheme, named ESMA. Unlike existing schemes, the multidimensional data in ESMA are structured and encrypted into a single Paillier ciphertext and thereafter, the data are efficiently decrypted. For privacy preserving, …
Automatic building of a visual interface for content-based multiresolution retrieval of paleontology images
2001
In this article we present research work in the field of content-based image retrieval in large databases applied to the paleontology image database of the Universite´ de Bourgogne, Dijon, France, called ‘‘TRANS’TYFIPAL.’’ Our indexing method is based on multiresolution decomposition of database images using wavelets. For each family of paleontology images we try to find a model image that represents it. The K-means automatic classification algorithm divides the space of parameters into several clusters. A model image for each cluster is computed from the wavelet transform of each image of the cluster. Then a search tree is built to offer users a graphic interface for retrieving images. So …
File system scalability with highly decentralized metadata on independent storage devices
2016
This paper discusses using hard drives that integrate a key-value interface and network access in the actual drive hardware (Kinetic storage platform) to supply file system functionality in a large scale environment. Taking advantage of higher-level functionality to handle metadata on the drives themselves, a serverless system architecture is proposed. Skipping path component traversal during the lookup operation is the key technique discussed in this paper to avoid performance degradation with highly decentralized metadata. Scalability implications are reviewed based on a fuse file system implementation. Peer Reviewed
Wireless energy and information transmission in FSO and RF-FSO links
2018
We propose and analyze a wireless energy and information transmission scheme in free-space optical (FSO) links. The results are presented for both quasi-static and fast-fading conditions. We derive closed-form expressions for throughput, outage probability, and optimal power allocation optimizing the system throughput/outage probability. Finally, we complement the FSO link with an additional radio frequency (RF) link to create a hybrid RF-FSO system and reduce the system outage probability. The results show that joint implementation of the RF and FSO links leads to considerable performance improvement, compared to the cases with only FSO-based communication.
Some Results Using Different Approaches to Merge Visual and Text-Based Features in CLEF’08 Photo Collection
2009
This paper describes the participation of the MIRACLE team at the ImageCLEF Photographic Retrieval task of CLEF 2008. We succeeded in submitting 41 runs. Obtained results from text-based retrieval are better than content-based as previous experiments in the MIRACLE team campaigns [5, 6] using different software. Our main aim was to experiment with several merging approaches to fuse text-based retrieval and content-based retrieval results, and it happened that we improve the text-based baseline when applying one of the three merging algorithms, although visual results are lower than textual ones.
[MIII(bpym)(CN)4]−: a suitable building block to design ferrimagnetic cyano-bridged heterobimetallic chains (M = Fe, Cr; bpym = 2,2′-bypyrimidine)
2008
Two cyano-bridged M(III)Mn(III) [M = Fe () and Cr ()] ferrimagnetic chains are reported; exhibits metamagnetism with two critical fields of 1250 G and 2.0 T which correspond to the overcoming by the applied dc field of the inter- and intrachain magnetic interactions, respectively.
Tunable and Large-Scale Model Network StarPEG-DNA Hydrogels
2021
The use of DNA as a building block in synthetic polymer hydrogels promises high levels of programmability regarding sol/gel temperatures, tunable bond lifetimes, biocompatibility, and interaction w...
Improving Collective I/O Performance Using Non-volatile Memory Devices
2016
Collective I/O is a parallel I/O technique designed to deliver high performance data access to scientific applications running on high-end computing clusters. In collective I/O, write performance is highly dependent upon the storage system response time and limited by the slowest writer. The storage system response time in conjunction with the need for global synchronisation, required during every round of data exchange and write, severely impacts collective I/O performance. Future Exascale systems will have an increasing number of processor cores, while the number of storage servers will remain relatively small. Therefore, the storage system concurrency level will further increase, worseni…
Joint Distribution of Polarization-Multiplexed UWB and WiMAX Radio in PON
2009
[EN] In this paper, the feasibility of the joint distribution of ultra-wideband (UWB) and WIMAX wireless using polarization multiplexing as a coexistence technique is proposed and experimentally demonstrated within the framework of passive optical networks (PON). Four single- and orthogonal-polarization multiplexing schemes are studied targeting to reduce the mutual interference when UWB and WiMAX are distributed jointly through standard single-mode fiber (SSMF) without transmission impairments compensation techniques and amplification. Experimental results indicate successful transmission up to 25 km, in SSMF exceeding the range in typical PON deployments. The radio link penalty introduced…
Control points deployment in an Intelligent Transportation System for monitoring inter-urban network roadway
2022
Abstract The constant evolution of transportation systems and traffic in developing countries is nowadays confronted with a problem of road safety and therefore of a high accident rate, especially in the context of inter-urban road transport. In this work, we propose a communication architecture for an Intelligent Transport System (ITS) to provide surveillance in an inter-urban transport network in the context of developing countries. We introduce two types of control points: Relay Control Points (RCP) and Treatment Control Points (TrCP). We also designed two multi-objective models for the deployment of these points. In order to ensure good coverage, to minimize the cost of installation and…