Search results for "control system"
showing 10 items of 971 documents
Modelling and cost analysis of hybrid systems for seawater desalination: Electromembrane pre-treatments for Reverse Osmosis
2019
Abstract The need to reduce energy consumption in seawater Reverse Osmosis (RO) process has pushed research towards the development of new hybrid systems in which, for example, other membrane processes can be used to pre-treat seawater. Electrodialysis (ED) and Reverse Electrodialysis (RED) can act as a pre-desalting step before seawater enters the RO unit, thus leading to an important energy saving in RO. In this work, two coupled models are proposed for the RED-RO and ED-RO systems. Each process model was validated. Then a sensitivity analysis was performed to assess the effect of the integration on the overall process cost saving. The analysis was performed by changing ED or RED voltage …
Experimental Comparison of Type-1 and Type-2 Fuzzy Logic Controllers for the Control of Level and Temperature in a Vessel
2011
Abstract The objective of this experimental study is to compare the performance of type-1 and type-2 fuzzy logic controllers on a real system where the control of liquid level and temperature are considered. By the use of genetic algorithms it is possible to optimize the fuzzy sets of each fuzzy controller assuring high control performance. The experimental results show that a better control in terms of robustness can be achieved by type-2 fuzzy logic controllers.
Control of a non-isothermal continuous stirred tank reactor by a feedback–feedforward structure using type-2 fuzzy logic controllers
2011
A control system that uses type-2 fuzzy logic controllers (FLC) is proposed for the control of a non-isothermal continuous stirred tank reactor (CSTR), where a first order irreversible reaction occurs and that is characterized by the presence of bifurcations. Bifurcations due to parameter variations can bring the reactor to instability or create new working conditions which although stable are unacceptable. An extensive analysis of the uncontrolled CSTR dynamics was carried out and used for the choice of the control configuration and the development of controllers. In addition to a feedback controller, the introduction of a feedforward control loop was required to maintain effective control…
Methods to Predict Energy Use for Lighting Systems: An Overview and an Application on a Real Case Study
2022
The study of Demand Response strategies application is widely related to the evaluation of the energy consumption. It is fundamental to optimize the design and management of the plants in the smart buildings. During the design steps, it is necessary to predict the above-mentioned energy consumption. This paper reviews some methods that can be applied to predict energy consumption related to lighting systems. In particular, three categories of methods have been analysed: methods proposed by technical standards, methods based on mathematical indices for daylight assessment, and methods based on simulation models. These methods have been described and applied by calculating the energy consumpt…
Experimental Set up of Advanced Lighting Systems for Load Shifting Strategies
2021
Shiftable and modulable loads are an essential part of smart grids in the effort for improving the efficiency of the power system and providing new ancillary services. Most of the researches considered shiftable loads and the impact on the power grid. Smart lighting systems are able to modulate their consumption while preserving the visual duty, therefore they can take part to this action. In this context, this paper presents an advanced experimental setup implemented in the SolarLab of the University of Palermo, with the aim of studying the impact on the end-user's energy consumption and on the power grid of smart lighting systems. In this light, different control strategies will be consid…
PDA -- Remote Display Interaction Framework
2008
This paper discusses the design of a PDA-driven remote display control system which was designed for a pervasive computing scenario. Our solution enables a PDA to perform as an interaction device (such as keyboard or mouse) to operate applications which are using remote displays. Our system consists of two components: one devoted to pair users and remote display according to their relative position, and one to provide the PDA with appropriate graphical interfaces and ad-hoc communication protocols. Besides a case study on the use of remote displays during a course with in our department, this paper discusses system highlights, components, and experiments as for standard multimedia and offic…
A genetic algorithm for the design of a fuzzy controller for active queue management
2003
Active queue management (AQM) policies are those\ud policies of router queue management that allow for the detection of network congestion, the notification of such occurrences to the\ud hosts on the network borders, and the adoption of a suitable control\ud policy. This paper proposes the adoption of a fuzzy proportional\ud integral (FPI) controller as an active queue manager for Internet\ud routers. The analytical design of the proposed FPI controller is\ud carried out in analogy with a proportional integral (PI) controller,\ud which recently has been proposed for AQM. A genetic algorithm is\ud proposed for tuning of the FPI controller parameters with respect\ud to optimal disturbance rej…
Non-celiac wheat sensitivity: a search for the pathogenesis of a self-reported condition
2019
A significant percentage of the general population reports gastrointestinal and non-gastrointestinal symptoms caused by wheat and/or gluten ingestion, even though they do not suffer from celiac disease (CD) or wheat allergy (WS), because they test negative both for CD-specific serology and histopathology. All patients report improvement of symptoms on a gluten-free diet. This clinical condition has been named non-celiac gluten sensitivity (NCGS). The objective of this paper was to review some studies regarding the pathogenesis of NCGS to summarize the current hypotheses about the mechanisms, which can lead to NCGS. Particular attention was given to the immunologic and the malabsorptive hypo…
Family Business Advising, Strategic Work and Unfolding Spaces
2019
The purpose of this paper is to explore the ways in which the process of advising, as well as the family firm-professional advisor relationship, can unfold over time and perform strategic work. To achieve this aim, we rely upon the experience of a family firm and its evolving relationship with an external advisor in the management accounting field. Over a period of 15 years, strategy work was performed through (and shaped by) unfolding ‘strategy spaces’ within which the advisor made use of multiple material, spatial and discursive resources. By interpreting the empirical evidence with theoretical insights from the strategy-as-practice literature, as well as from organization studies on spac…
Sistema di Controllo Interno e prevenzione delle infiltrazioni della criminalità organizzata
2019
L’intensificarsi della diffusione delle infiltrazioni della criminalità organizzata in molteplici settori rende sempre più complessa per le aziende operanti con la pubblica amministrazione, la verifica dell’affidabilità, non solo economico-patrimoniale, dei soggetti (es., partner, clienti, fornitori) con i quali interagire. L’assenza di efficaci strumenti di prevenzione e contrastato dei tentativi di infiltrazioni della criminalità organizzata nella gestione aziendale può dar luogo a sanzioni interdittive, compromettendo in modo irreversibile l’immagine e il processo di creazione di valore e tutela degli stakeholders. Muovendo da tali presupposti, il presente lavoro è teso a verificare se i…