Search results for "NETWORKS"

A Multi-Scale Analysis to Measure Ecological Impact of LUCC in a Built Environment

2015

International audience; In human-dominated environments, efforts to preserve ecological connectivity between animal species habitats is an important issue. These areas are indeed concern by anthropogenic pressures leading to rapid land use and land cover changes (LUCC). This is particularly the case of urban fringes, affected by many changes (e.g. urban sprawl) specifically for several decades.Of all the methods to model the ecological networks connectivity, landscape graphs provide a relevant approach, which interest for decision support in land-use planning has already been highlighted (Foltête et al., 2014). This approach allows to represent ecological networks in a simplified way as gra…

Urban Services to Ecosystems - Green Infrastructure Benefits from the Landscape to the Urban Scale

2021

The aim of this book is to bring together multidisciplinary research in the field of green infrastructure design, construction and ecology. The main core of the volume is constituted by contributions dealing with green infrastructure, vegetation science, nature-based solutions and sustainable urban development. The green infrastructure and its ecosystem services, indeed, are gaining space in both political agendas and academic research. However, the attention is focused on the services that nature is giving for free to and for human health and survival. What if we start to see things from another perspective? Our actions shall converge for instance to turn man-made environment like cities f…

A 3D Deep Neural Network for Liver Volumetry in 3T Contrast-Enhanced MRI.

2020

 To create a fully automated, reliable, and fast segmentation tool for Gd-EOB-DTPA-enhanced MRI scans using deep learning. Datasets of Gd-EOB-DTPA-enhanced liver MR images of 100 patients were assembled. Ground truth segmentation of the hepatobiliary phase images was performed manually. Automatic image segmentation was achieved with a deep convolutional neural network. Our neural network achieves an intraclass correlation coefficient (ICC) of 0.987, a Sørensen-Dice coefficient of 96.7 ± 1.9 % (mean ± std), an overlap of 92 ± 3.5 %, and a Hausdorff distance of 24.9 ± 14.7 mm compared with two expert readers who corresponded to an ICC of 0.973, a Sørensen-Dice coefficient of 95.2 ± 2.8 %, and…

A comparative analysis of two immersive virtual reality systems in the integration and visualization of natural hand interaction

2022

AbstractIt is generally accepted that the use of natural interaction provides a positive impact in Virtual Reality (VR) applications. Therefore, it is important to understand what is the best way to integrate and visualize this feature in VR. For this reason, this paper presents a comparative study of the integration of natural hand interaction in two immersive VR systems: a Cave Audio Visual Experience (CAVE) system –where users’ real hands are visible– and a non-see-through Head-Mounted Display (HMD) system –where only a virtual representation of the hands is possible–. In order to test the suitability of using this type of interaction in a CAVE and compare it to an HMD, we raise six rese…

Hyvinvointinäkökulmia HOPS-ohjaukseen

2011

Handover management in heterogenous mobile and wireless networks

2015

Since 1990, networking and mobile technologies have made a phenomenal unprecedented progress. This progress has been experienced on multiple fronts in parallel; especially on the application level and the user's needs one. This rapid evolution of the technology imposed a need for the existence of heterogeneous environments where the coverage is ensured throughout the different available networks. The challenge with such architecture would be to provide the user with the ability to navigate through the different available networks in a transparent and seamless fashion. However, the navigation among different types of networks is commonly referred to as vertical Handover. The IEEE 802.21 stan…

Handover and Uplink Power Control Performance in the 3.84 Mcps TDD mode of UTRA Network

2003

In this article we consider the performance of the 3.84 Mcps time-division duplex (TDD) mode of UTRA (Universal Terrestrial Radio Access) network. We emphasize two of the radio resource management algorithms, handover and uplink power control, whose role in the overall system performance is studied extensively. First, a handover algorithm used in WCDMA (Wideband Code Division Multiple Access) standard is considered in a TDD-mode operation. This gives rise to a careful setting of different handover parameters, and the evaluation of the effects to the system performance. Secondly, the specified uplink power control algorithm is considered. Since it is based on several user-made measurements w…

Optimized Handover Algorithm Based on Stackelberg Games in CBTC Systems for Urban Rail Transit

2014

Communications Based Train Control (CBTC) systems have become indispensable for train operation to improve the safety and efficiency of train running to the utmost extent at present. In this paper, the problem of train handover in wireless LAN of CBTC systems for urban rail transit was taken into consideration, which was formulated as a market competition with Stackelberg games and cooperative diversity to obtain the reasonable resource allocation for trains. Under the environment of continuous train-to-wayside communications with high reliability, the successful train handover probability was analyzed in detail. Firstly, the relay triggering during handover was introduced, and the price st…

A fog-assisted system to defend against Sybils in vehicular crowdsourcing

2022

Technological advancements in vehicular transportation systems have led to the growth of novel paradigms, in which vehicles and infrastructures collaborate to infer high-level knowledge about phenomena of interest. Vehicular Social Network (VSN) is one such paradigm in which vehicular network entities are considered as part of an Online Social Network (OSN), paving the way for new services derived from social context. Although vehicular crowdsourcing has tremendous benefits, its deployment in real systems requires to solve important challenges including defense against Sybil attacks. This paper proposes a novel fog-assisted system that uses SybilDriver to minimize the presence of Sybil enti…

Spectrum cartography techniques, challenges, opportunities, and applications: A survey

2021

The spectrum cartography finds applications in several areas such as cognitive radios, spectrum aware communications, machine-type communications, Internet of Things, connected vehicles, wireless sensor networks, and radio frequency management systems, etc. This paper presents a survey on state-of-the-art of spectrum cartography techniques for the construction of various radio environment maps (REMs). Following a brief overview on spectrum cartography, various techniques considered to construct the REMs such as channel gain map, power spectral density map, power map, spectrum map, power propagation map, radio frequency map, and interference map are reviewed. In this paper, we compare the pe…