Search results for "heterogeneous"
showing 10 items of 460 documents
Towards a software-defined Network Operating System for the IoT
2015
The heterogeneity characterizing the Internet of Things (IoT) landscape can be addressed by leveraging network operating systems (NOS)s. Current NOS solutions have been developed for traditional infrastructured networks: they do not take the specific features of fundamental IoT components such as wireless sensor and actuator networks into account. Accordingly, in this paper an innovative integrated network operating system for the IoT which is obtained as the evolution of the Open Network Operating System (ONOS) is proposed. This has been appropriately extended to enhance the recently proposed SDN-WISE platform for supporting SDN in wireless sensor networks and let it interact with standard…
Toward Unified Control of Networks of Switches and Sensors Through a Network Operating System
2018
Wireless sensor networks (WSNs) are an integral part of an Internet of Things (IoT) ecosystem. In fact, a typical IoT service deployment considers an integrated network of switches and sensors (as well as actuators). In order to manage this heterogeneous network infrastructure, the use of software defined networking (SDN) technologies is anticipated. However, existing SDN-enabling technologies consider only isolated networks and there has been no concrete solution that treats the whole network in a unified way. In this paper, a network operating system is proposed as a way to address the above issue. Starting from the open network operating system, which currently supports only OpenFlow net…
Wireless MAC Processor Networking: A Control Architecture for Expressing and Implementing High-Level Adaptation Policies in WLANs
2013
The current proliferation of unplanned wireless local area networks (WLANs) is creating the need for implementing different adaptation strategies to improve network performance under mutating and evolving interference scenarios. In this article, we envision a new solution for expressing and implementing high-level adaptation policies in WLANs, in contrast to the current approaches based on vendor-specific implementations. We exploit the hardware abstraction interface recently proposed by the wireless medium access control (MAC) processor (WMP) architecture and some flow-control concepts similar to the Openflow model for defining MAC adaptation policies. A simple control architecture for dis…
Virtual Resource Allocation for Wireless Virtualized Heterogeneous Network with Hybrid Energy Supply
2022
In this work, two novel virtual user association and resource allocation algorithms are introduced for a wireless virtualized heterogeneous network with hybrid energy supply. In the considered system, macro base stations (MBSs) are supplied by the grid power and small base stations (SBSs) have the energy harvesting capability in addition to the grid power supplement. Multiple infrastructure providers (InPs) own the physical resources, i.e., BSs and radio resources. The Mobile Virtual Network Operators (MVNOs) are able to recent these resources from the InPs and operate the virtualized resources for providing services to different users. In particular, aiming to maximize the overall utility …
Structural contagion and vulnerability to unexpected liquidity shortfalls
2012
This paper assumes that financial fluctuations are the result of the dynamic interaction between liquidity and solvency conditions of individual economic units. The framework is an extention of Sordi and Vercelli (2012) designed as an heterogeneous agent model which proceeds through discrete time steps within a finite time horizon. The interaction at the micro-level between economic units monitors the spread of contagion and systemic risk, producing interesting complex dynamics. The model is analysed by means of numerical simulations and systemic risk modelling, where local interaction of units is captured and analysed by the bilateral provision of liquidity among units. The behaviour and e…
Oxygen isotopic exchange: A useful tool for characterizing oxygen conducting oxides
2005
International audience; The 18O/16O isotope exchange depth profile technique (IEDP) followed by SIMS characterizations was applied to dense membranes of pure ionic conductors and mixed ionic/electronic conducting materials. It is a very useful tool since we obtain in both cases data concerning the oxygen diffusion in the bulk and the oxygen exchange at the surface of the materials. Comparisons were done, including results concerning the role of the surface with regards to the oxygen reduction reaction. Detailed experimental and analytical processes are given.
Oxidative degradation properties of Co-based catalysts in the presence of ozone
2007
Four series of cobalt-based catalysts, such as bare Co3O4 and CoO, CoOx-CeO2 mixed oxides, CoOx supported over alumina and alumina-baria and CoMgAl and CoNiAl hydrotalcites have been synthesized and investigated for the oxidative degradation of phenol in the presence of ozone. Characterizations were obtained by several techniques in order to investigate the nature of cobalt species and their morphological properties, depending on the system. Analyses by XRD, BET, TPR, UV-visible diffuse reflectance spectroscopy and TG/DT were performed. The CoNiAl hydrotalcite exhibits, after 4 h of reaction, the highest phenol ozonation activity followed by Co(3 wt%)/Al2O3-BaO and CoMgAl. The samples Co(1 …
Surrogate-assisted evolutionary biobjective optimization for objectives with non-uniform latencies
2018
We consider multiobjective optimization problems where objective functions have different (or heterogeneous) evaluation times or latencies. This is of great relevance for (computationally) expensive multiobjective optimization as there is no reason to assume that all objective functions should take an equal amount of time to be evaluated (particularly when objectives are evaluated separately). To cope with such problems, we propose a variation of the Kriging-assisted reference vector guided evolutionary algorithm (K-RVEA) called heterogeneous K-RVEA (short HK-RVEA). This algorithm is a merger of two main concepts designed to account for different latencies: A single-objective evolutionary a…
Classification of Brain Tumors
1989
In 1914, L. Bruns stated in Krause’s General Surgery of Brain Disorders that brain tumors include all neoplasias growing within the cranium and that they comprise three groups: (1) true tumors, (2) infectious granulomas, and (3) parasites. Current usage is more precise and is limited to the first of Bruns’ categories. Even so, brain tumors constitute a large and very heterogeneous group. A taxonomic approach to classification is necessary if we are to make sense of an initially disorganized set of observations, compare the findings of different observers, and attempt a prognostic evaluation.
Neuroendocrine Neoplasms (NENs)
2021
Neuroendocrine neoplasms (NENs) represent a rare and heterogeneous group of malignancies which can develop in many different sites of our body. They originate from the cells of the diffuse neuroendocrine system. Gastroenteropancreatic NENs were classified in four categories, including NETs G1 (WD with 20% Ki-67), and NECs (PD with >20% Ki-67) in accordance with the 2019 WHO classification (IARC WHO Classification of the digestive system tumors, on 11th July 2019). Lung NENs, in accordance with the latest WHO classification, 2015 edition, are distinguished in small cell lung cancer (SCLC), large cell neuroendocrine carcinoma (LCNEC), atypical carcinoid (AC), and typical carcinoid (TC).