Search results for "multi-channel"
showing 7 items of 7 documents
On the Performance of Channel Assembling and Fragmentation in Cognitive Radio Networks
2014
[EN] Flexible channel allocation may be applied to multi-channel cognitive radio networks (CRNs) through either channel assembling (CA) or channel fragmentation (CF). While CA allows one secondary user (SU) occupy multiple channels when primary users (PUs) are absent, CF provides finer granularity for channel occupancy by allocating a portion of one channel to an SU flow. In this paper, we investigate the impact of CF together with CA for SU flows by proposing a channel access strategy which activates both CF and CA and correspondingly evaluating its performance. In addition, we also consider a novel scenario where CA is enabled for PU flows. The performance evaluation is conducted based on…
Optimizing the MAC Protocol in Localization Systems Based on IEEE 802.15.4 Networks
2017
Radio frequency signals are commonly used in the development of indoor localization systems. The infrastructure of these systems includes some beacons placed at known positions that exchange radio packets with users to be located. When the system is implemented using wireless sensor networks, the wireless transceivers integrated in the network motes are usually based on the IEEE 802.15.4 standard. But, the CSMA-CA, which is the basis for the medium access protocols in this category of communication systems, is not suitable when several users want to exchange bursts of radio packets with the same beacon to acquire the radio signal strength indicator (RSSI) values needed in the location proce…
Mixture Hidden Markov Models for Sequence Data: The seqHMM Package in R
2019
Sequence analysis is being more and more widely used for the analysis of social sequences and other multivariate categorical time series data. However, it is often complex to describe, visualize, and compare large sequence data, especially when there are multiple parallel sequences per subject. Hidden (latent) Markov models (HMMs) are able to detect underlying latent structures and they can be used in various longitudinal settings: to account for measurement error, to detect unobservable states, or to compress information across several types of observations. Extending to mixture hidden Markov models (MHMMs) allows clustering data into homogeneous subsets, with or without external covariate…
Optical Gating of Photosensitive Synthetic Ion Channels
2011
4-oxo-4-(pyren-4-ylmethoxy) butanoic acid is used as a photolabile protecting group to show the optical gating of nanofluidic devices based on synthetic ion channels. The inner surface of the channels is decorated with monolayers of photolabile hydrophobic molecules that can be removed by irradiation, which leads to the generation of hydrophilic groups. This process can be exploited in the UV-light-triggered permselective transport of ionic species in aqueous solution through the channels. The optical gating of a single conical nanochannel and multichannel polymeric membranes is characterised experimentally and theoretically by means of current-voltage and selective permeation measurements,…
Consumers in Information Technology Enabled Service Encounters: Perceptions and Tradeoffs in Multi-Channel Interactions
2015
This study examines information technology enabled, multi-channel service context from the end-user's perspective and, more specifically, from the perspective of a consumer, in particular the extent to which the multi-channel interaction experience results in consumer satisfaction and any tradeoffs that consumers make in the evaluation of the context of service. Empirical results from our online survey with mobile consumers indicate that the variables included in the model have a direct impact on consumer satisfaction when considered individually. There are, however, tradeoffs between variables (e.g., problem-handling and record accuracy; scalability and usability of service) when considere…
LA MULTICANALITA’ NEL RETAIL BANKING: INNOVAZIONI, STRATEGIE, RISCHI
2017
Il presente lavoro intende prendere in esame i processi di innovazione tecnologica ed organizzativa nel mercato dei servizi di retail banking, con particolare riferimento all’accesso multicanale ai prodotti e servizi bancari che, inquadrandosi nei profondi cambiamenti della struttura distributiva delle banche intervenuti negli ultimi anni, rappresenta un connotato strutturale del mercato dei servizi bancari retail. Saranno, pertanto, analizzati i caratteri distintivi della multicanalità nel retail banking, le implicazioni di carattere organizzativo e strategico che simili processi evolutivi determinano nell’economia e gestione delle banche, i principali profili di rischio relativi all’impie…
Understanding the impact of digital on performing arts: a systematic literature review proposal
2023
Digital technologies have profoundly changed the cultural and creative industries. Due to the intrinsic characteristics of the performing arts sector, this digital transition has had a later impact on it. However, it has accelerated since the Covid-19 pandemic, forcing organizations to digitally transform themselves to keep in touch with their audience(s). Now that this crisis is over, many strategic and operational questions still remain unanswered. This research proposes a systematic literature review in order to establish the state of the art of the research on digitalization of the performing arts sector and to highlight the main research avenues to be explored.