708 research outputs found
Energy Efficient Wireless Internet Access with Cooperative Cellular Networks
No full textIn this paper we study the energy-aware cooperative management of the cellular access networks of the operators that offer service over the same area. In particular, we evaluate the amount of energy that can be saved by using all networks in high traffic conditions, but progressively switching off networks during the periods when traffic decreases, and eventually becomes so low that the desired quality of service can be obtained with just one network. When a network is switched off, its customers are allowed to roam over those networks that remain powered on. Several alternatives are studied, as regards the traffic profile, the switch-off pattern, the energy cost model, and the roaming policy. Numerical results indicate that a huge amount of energy can be saved with an energy-aware cooperative management of the networks, and suggest that, to reduce energy consumption, and thus the cost to operate the networks, new cooperative attitudes of the operators should
be encouraged with appropriate incentives, or even enforced by regulation authorities.TRUEpu
Queueing systems to study the energy consumption of a campus WLAN
No full textIn this paper we exploit simple approximate queueing models to assess the effectiveness of the approaches that have been proposed to save energy in dense wireless local area networks (WLANs), based on the activation of access points (APs) according to the user demand. In particular, we look at a portion of a dense WLAN, where several APs are deployed to provide sufficient capacity to serve a large number of active users during peak traffic hours. To increase capacity, some APs are colocated and provide identical coverage; we say that these APs belong to the same group, and they serve users in the same area. The areas covered by different AP groups only partially overlap, so that some active users can only be served by a group of APs, but a fraction of active users can be served by more groups. Due to daily variations of the number of active users accessing the WLAN, some APs can be switched off to save energy when not all the capacity is needed. A real example of this setting is provided by a floor of one building of Politecnico di Torino in Italy, where a student library is located. The approximate analytical models indicate that the energy saving achievable with the proposed approaches is quite substantial, over 40% if at least one AP for each group is always kept on, even with no traffic, to be ready to accept incoming users, and it grows to almost 60% if all APs can be switched off at night, using a separate technology to activate an AP when the first user requests association in the mornin
Energy-optimal RAN configurations for SWIPT IoT
No full textInternet of Things (IoT) devices often have batteries of limited capacity, which are not easily replaced or recharged. This implies very short device lifetimes, and calls for a very careful device configuration to achieve the optimal trade-off between performance and power consumption. SWIPT (Simultaneous Wireless Information and Power Transfer) deals with this problem by harvesting energy at IoT devices from the received RF signals. Studying the efficiency of SWIPT in dealing with the energy and data transfer demands of IoT nodes leads to a number of open issues. In this paper, we devise an analytical model based on stochastic geometry for a SWIPT radio access network with a dense population of IoT users. With our model, it is possible to accurately study the impact of the system parameters on the key system performance indicators, while accounting in a realistic manner for device performance, and for the statistics of time scheduling at base stations. This allows us to understand (not without some surprise) what are the most effective strategies to minimize energy consumption in a SWIPT network, and what is their potential for energy savings
The Energy Saving Potential of Static and Adaptive Resource Provisioning in Dense Cellular Networks
No full textDEVELOPMENT OF HIGH-VALUE-OIL-BASED SYSTEM THROUGH INNOVATIVE STRUCTURING AGENTS FOR THE NUTRITIONAL AND/OR FUNCTIONAL ENHANCEMENT OF FOOD MATRICES
No full textL'obiettivo della ricerca è quello di sviluppare un prodotto alimentare arricchito dal punto di vista nutrizionale e facilmente deglutibile, adatto a persone son esigenze specifiche. La ricerca è strutturata in quattro fasi progressive (supportate dalla collaborazione con partner industriali) per la realizzazione del prodotto finale e lo studio della interazioni a livello microstrutturale. Nella prima fase, sono state analizzate diverse tipologie di frutta secca per determinarne le proprietà nutrizionali: particolare attenzione è stata data al tocoferolo e al contenuto proteico. Per preservare le loro proprietà nutrizionali la frutta secca è stata spremuta a freddo, isolando i componenti per ottimizzarne l'incorporazione durante la formulazione degli idrogel caricati di emulsione. Questo approccio mira a utilizzare strategicamente questi componenti per massimizzare i benefici funzionali e nutrizionali durante il processo. La seconda fase si concentrerà sui sottoprodotti fibrosi della produzione di succo di agrumi, isolando in particolare la pectina dalla fibra insolubile di agrumi per sfruttarne le rispettive funzionalità. La pectina agirà come agente strutturante, mentre la fibra di agrumi servirà come emulsionante. L'interazione tra questi due componenti sarà studiata con trattamenti termici per capire come la loro sinergia contribuisca alla stabilità, alla consistenza e alla resilienza. Questa esplorazione mira a sviluppare una matrice flessibile e robusta che integri oli e altri componenti senza compromettere l'integrità strutturale complessiva. La terza fase sarà incentrata sulla valutazione reologica di emulsioni a base di fibre di agrumi in due mezzi disperdenti: acqua e purea di albicocca. Questa analisi comparativa mira a scoprire come la fibra di agrumi formi reti in ambienti diversi e come l'effetto matrice dell'albicocca migliori le proprietà dell'emulsione. I risultati chiariranno il ruolo dei componenti intrinseci della frutta nel migliorare la consistenza e la coesione strutturale, aprendo la strada ad applicazioni più ampie. Questi risultati contribuiranno ad approfondire i meccanismi alla base della stabilità e della consistenza delle emulsioni destinate all'uso alimentare. Nella fase finale, le conoscenze acquisite nelle fasi precedenti saranno sintetizzate per creare un idrogel avanzato pieno di emulsione che combina fibre di agrumi, purea di albicocca, olio di nocciola spremuto a freddo e torta sgrassata di nocciole. Questa formulazione sarà ottimizzata per la deglutibilità, la stabilità e le prestazioni tribologiche. L'olio di nocciola, ricco di tocoferoli, sarà valutato per la sua stabilità in condizioni di lavorazione, mentre la torta di nocciole migliorerà l'emulsionabilità e il rinforzo strutturale. Integrando la pectina e la fibra di agrumi, la consistenza dell'idrogel sarà modulata per ottenere una sensazione piacevole e gestibile in bocca. Questa fase si concentrerà anche sulla garanzia che il prodotto soddisfi gli standard tribologici per una facile deglutizione senza compromettere la qualità nutrizionale.Questa formulazione sarà ottimizzata per la deglutibilità, la stabilità e le prestazioni tribologiche. L'olio di nocciola, ricco di tocoferoli, sarà valutato per la sua stabilità in condizioni di lavorazione, mentre la torta di nocciole migliorerà l'emulsionabilità e il rinforzo strutturale. Integrando la pectina e la fibra di agrumi, la consistenza dell'idrogel sarà modulata per ottenere una sensazione piacevole e gestibile in bocca. Questa fase si concentrerà anche sulla garanzia che il prodotto soddisfi gli standard tribologici per una facile deglutizione senza compromettere la qualità nutrizionale. Il prodotto finale servirà come piattaforma per fornire una nutrizione mirata attraverso soluzioni testuali innovative, affrontando la duplice sfida della palatabilità e della nutrizione funzionale. Questi sforzi contribuiranno a far progredire il campo della scienza alimentare orientata alla texture, aprendo la strada ad applicazioni alimentari personalizzate, sostenibili e ricche di nutrienti.The objective of this research is to develop a nutritionally enriched and easily swallowable food product tailored for individuals requiring texture-modulated foods. The research is structured into four progressive stages (supported by collaboration with industry partners), each addressing critical components of formulation and processing. In the first stage, a detailed analysis of various nuts will be conducted to determine their nutritional properties: particular attention will be given to tocopherol profiles, and protein content. To preserve their natural synergies, the nuts will be cold-pressed, isolating components to optimize their incorporation during the formulation of emulsion-filled hydrogels. This approach aims to strategically utilize these components to maximize functional and nutritional benefits throughout the process. The second phase will focus on the fibrous byproducts of citrus juice production, specifically isolating pectin from insoluble citrus fiber to harness their respective functionalities. Pectin will act as a structuring agent, while citrus fiber will serve as an emulsifier. The interaction between these two components will be studied under thermal treatments to understand how their synergy contributes to stability, consistency, and resilience. This exploration seeks to develop a flexible and robust matrix that integrates oils and other components without compromising the overall structural integrity. The third stage will emphasize the rheological evaluation of citrus fiber-based emulsions in two dispersing media: water and apricot puree. This comparative analysis aims to uncover how citrus fiber forms networks in different environments and how apricot matrix effect enhances the emulsion properties. The results will clarify the role of fruit intrinsic components in improving texture and structural cohesion, paving the way for broader applications. These findings will contribute valuable insights into the mechanisms underpinning stability and texture in emulsions designed for food use. In the final phase, insights from the previous stages will be synthesized to create an advanced emulsion-filled hydrogel combining citrus fiber, apricot puree, cold-pressed hazelnut oil, and hazelnut defatted cake. This formulation will be optimized for swallowability, stability, and tribological performance. Hazelnut oil, rich in tocopherols, will be evaluated for its stability under processing conditions, while hazelnut cake will enhance emulsification and structural reinforcement. By integrating pectin and citrus fiber, the hydrogel's texture will be modulated for a pleasant and manageable mouthfeel. This phase will also focus on ensuring the product meets the tribological standards for easy swallowing without compromising nutritional quality. The final product will serve as a platform for delivering targeted nutrition through innovative textural solutions, addressing the dual challenges of palatability and functional nutrition. These efforts will contribute to advancing the field of texture-oriented food science while opening pathways for tailored, sustainable, and nutrient-rich food applications
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