Search results for "network"

Wykorzystanie sztucznej sieci neuronowej do diagnostyki związków chemicznych przy pomocy ich widm w podczerwieni

2013

W artykule przedstawiono możliwości zastosowania sztucznej sieci neuronowej w identyfikacji związków chemicznych metodą tzw. „odcisku palca” oraz opisano budowę opracowanego specjalnie do tego celu narzędzia z wykorzystaniem SSN, jak też sprecyzowano wymogi, jakie muszą być spełnione do jej poprawnego funkcjonowania.

Estimation of wind velocity over a complex terrain using the Generalized Mapping Regressor

2010

Abstract Wind energy evaluation is an important goal in the conversion of energy systems to more environmentally friendly solutions. In this paper, we present a novel approach to wind speed spatial estimation on the isle of Sicily (Italy): an incremental self-organizing neural network (Generalized Mapping Regressor – GMR) is coupled with exploratory data analysis techniques in order to obtain a map of the spatial distribution of the average wind speed over the entire region. First, the topographic surface of the island was modelled using two different neural techniques and by exploiting the information extracted from a digital elevation model of the region. Then, GMR was used for automatic …

Univariate and multivariate properties of wind velocity time series

2009

We analyze the time series of hourly average wind speeds measured at 29 different stations located in Sicily, a region with a complex morphology. The investigation, performed from the univariate as well as the multivariate point of view, evidences that the statistical properties of wind at the single sites have features that are not reproduced by standard models and, thus, require specific modeling. Moreover, the synchronous evolution of wind velocity presents a cluster structure, obtained with different algorithms, that persists in the standard deviation too.

Challenges and opportunities in emerging high-density wireless networks

2020

Performance Study of IEEE 802.11 DCF and IEEE 802.11e EDCA

2008

Making IEEE 802.11 wireless access programmable

2013

In this paper, we present a modular Layer 2 architecture which makes wireless access in {IEEE}~802.11 networks programmable and thus opens the door for broader range of enhancements. We show the power of the proposed architecture by presenting a number of innovative solutions for infrastructure, direct links and mesh cases. Early prototyping results are publicly available and can be used to develop solutions not so strictly bounded by legacy access rules, to quicker and more accurately meet evolving user demands.

Learn to Cache: Machine Learning for Network Edge Caching in the Big Data Era

2018

The unprecedented growth of wireless data traffic not only challenges the design and evolution of the wireless network architecture, but also brings about profound opportunities to drive and improve future networks. Meanwhile, the evolution of communications and computing technologies can make the network edge, such as BSs or UEs, become intelligent and rich in terms of computing and communications capabilities, which intuitively enables big data analytics at the network edge. In this article, we propose to explore big data analytics to advance edge caching capability, which is considered as a promising approach to improve network efficiency and alleviate the high demand for the radio resou…

IEEE Access Special Section Editorial: Exploiting the Benefits of Interference in Wireless Networks: Energy Harvesting and Security

2018

Interference used to be viewed as a harmful factor in wireless networks, which can reduce the quality of information transmission. To combat against interference, many interference management techniques have emerged. Due to the latest research advances, interference (or noise) can also be exploited to offer some benefits to wireless networks. The first aspect is that interference in multi-user networks can be collected as a green power supply for the transceivers, known as wireless energy harvesting. Another application is that one can generate artificial noise to disrupt the adversarial eavesdropping, and guarantee the security of wireless networks. Therefore, conventional interference man…

A Double Auction Mechanism for Virtual Resource Allocation in SDN-based Cellular Network

2016

The explosively growing demands for mobile traffic service bring both challenges and opportunities to wireless net- works, among which, wireless network virtualization is proposed as the main evolution towards 5G. In this paper, we first propose a Software Defined Network (SDN) based wireless virtualization architecture for enabling multi-flow transmission in order to save capital expenses (CapEx) and operation expenses (OpEx) significantly with multiple Infrastructures Providers (InPs) and multiple Mobile Virtual Network Operators (MVNOs). We for- mulate the virtual resource allocation problem with diverse QoS requirements as a social welfare maximization problem with transaction cost. Due…

Sparsity-aware multiple relay selection in large multi-hop decode-and-forward relay networks

2016

In this paper, we propose and investigate two novel techniques to perform multiple relay selection in large multi-hop decode-and-forward relay networks. The two proposed techniques exploit sparse signal recovery theory to select multiple relays using the orthogonal matching pursuit algorithm and outperform state-of-the-art techniques in terms of outage probability and computation complexity. To reduce the amount of collected channel state information (CSI), we propose a limited-feedback scheme where only a limited number of relays feedback their CSI. Furthermore, a detailed performance-complexity tradeoff investigation is conducted for the different studied techniques and verified by Monte …