Research

22 pages, 916 KiB

Open AccessArticle

Comparative Performance Evaluation of an Accuracy-Enhancing Lyapunov Solver

by Vasile Sima

Information 2019, 10(6), 215; https://doi.org/10.3390/info10060215 - 19 Jun 2019

Cited by 2 | Viewed by 3038

Lyapunov equations are key mathematical objects in systems theory, analysis and design of control systems, and in many applications, including balanced realization algorithms, procedures for reduced order models, Newton methods for algebraic Riccati equations, or stabilization algorithms. A new iterative accuracy-enhancing solver for [...] Read more.

Lyapunov equations are key mathematical objects in systems theory, analysis and design of control systems, and in many applications, including balanced realization algorithms, procedures for reduced order models, Newton methods for algebraic Riccati equations, or stabilization algorithms. A new iterative accuracy-enhancing solver for both standard and generalized continuous- and discrete-time Lyapunov equations is proposed and investigated in this paper. The underlying algorithm and some technical details are summarized. At each iteration, the computed solution of a reduced Lyapunov equation serves as a correction term to refine the current solution of the initial equation. The best available algorithms for solving Lyapunov equations with dense matrices, employing the real Schur(-triangular) form of the coefficient matrices, are used. The reduction to Schur(-triangular) form has to be done only once, before starting the iterative process. The algorithm converges in very few iterations. The results obtained by solving series of numerically difficult examples derived from the SLICOT benchmark collections for Lyapunov equations are compared to the solutions returned by the MATLAB and SLICOT solvers. The new solver can be more accurate than these state-of-the-art solvers and requires little additional computational effort. Full article

(This article belongs to the Special Issue ICSTCC 2018: Advances in Control and Computers)

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29 pages, 415 KiB

Open AccessArticle

Optimal Control of Virus Spread under Different Conditions of Resources Limitations

by Paolo Di Giamberardino and Daniela Iacoviello

Information 2019, 10(6), 214; https://doi.org/10.3390/info10060214 - 19 Jun 2019

Viewed by 2957

Abstract

The paper addresses the problem of human virus spread reduction when the resources for the control actions are somehow limited. This kind of problem can be successfully solved in the framework of the optimal control theory, where the best solution, which minimizes a [...] Read more.

The paper addresses the problem of human virus spread reduction when the resources for the control actions are somehow limited. This kind of problem can be successfully solved in the framework of the optimal control theory, where the best solution, which minimizes a cost function while satisfying input constraints, can be provided. The problem is formulated in this contest for the case of the HIV/AIDS virus, making use of a model that considers two classes of susceptible subjects, the wise people and the people with incautious behaviours, and three classes of infected, the ones still not aware of their status, the pre-AIDS patients and the AIDS ones; the control actions are represented by an information campaign, to reduce the category of subjects with unwise behaviour, a test campaign, to reduce the number of subjects not aware of having the virus, and the medication on patients with a positive diagnosis. The cost function considered aims at reducing patients with positive diagnosis using as less resources as possible. Four different types of resources bounds are considered, divided into two classes: limitations on the instantaneous control and fixed total budgets. The optimal solutions are numerically computed, and the results of simulations performed are illustrated and compared to put in evidence the different behaviours of the control actions. Full article

(This article belongs to the Special Issue ICSTCC 2018: Advances in Control and Computers)

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17 pages, 974 KiB

Open AccessFeature PaperArticle

Optimal Resource Allocation to Reduce an Epidemic Spread and Its Complication

by Paolo Di Giamberardino and Daniela Iacoviello

Information 2019, 10(6), 213; https://doi.org/10.3390/info10060213 - 13 Jun 2019

Cited by 8 | Viewed by 3357

Abstract

Mathematical modeling represents a useful instrument to describe epidemic spread and to propose useful control actions, such as vaccination scheduling, quarantine, informative campaign, and therapy, especially in the realistic hypothesis of resources limitations. Moreover, the same representation could efficiently describe different epidemic scenarios, [...] Read more.

Mathematical modeling represents a useful instrument to describe epidemic spread and to propose useful control actions, such as vaccination scheduling, quarantine, informative campaign, and therapy, especially in the realistic hypothesis of resources limitations. Moreover, the same representation could efficiently describe different epidemic scenarios, involving, for example, computer viruses spreading in the network. In this paper, a new model describing an infectious disease and a possible complication is proposed; after deep-model analysis discussing the role of the reproduction number, an optimal control problem is formulated and solved to reduce the number of dead patients, minimizing the control effort. The results show the reasonability of the proposed model and the effectiveness of the control action, aiming at an efficient resource allocation; the model also describes the different reactions of a population with respect to an epidemic disease depending on the economic and social original conditions. The optimal control theory applied to the proposed new epidemic model provides a sensible reduction in the number of dead patients, also suggesting the suitable scheduling of the vaccination control. Future work will be devoted to the identification of the model parameters referring to specific epidemic disease and complications, also taking into account the geographic and social scenario. Full article

(This article belongs to the Special Issue ICSTCC 2018: Advances in Control and Computers)

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17 pages, 1109 KiB

Open AccessFeature PaperArticle

Electronic Identification for Universities: Building Cross-Border Services Based on the eIDAS Infrastructure

by Diana Berbecaru, Antonio Lioy and Cesare Cameroni

Information 2019, 10(6), 210; https://doi.org/10.3390/info10060210 - 12 Jun 2019

Cited by 17 | Viewed by 4546

Abstract

The European Union (EU) Regulation 910/2014 on electronic IDentification, Authentication, and trust Services (eIDAS) for electronic transactions in the internal market went into effect on 29 September 2018, meaning that EU Member States are required to recognize the electronic identities issued in the [...] Read more.

The European Union (EU) Regulation 910/2014 on electronic IDentification, Authentication, and trust Services (eIDAS) for electronic transactions in the internal market went into effect on 29 September 2018, meaning that EU Member States are required to recognize the electronic identities issued in the countries that have notified their eID schemes. Technically speaking, a unified interoperability platform—named eIDAS infrastructure—has been set up to connect the EU countries’ national eID schemes to allow a person to authenticate in their home EU country when getting access to services provided by an eIDAS-enabled Service Provider (SP) in another EU country. The eIDAS infrastructure allows the transfer of authentication requests and responses back and forth between its nodes, transporting basic attributes about a person, e.g., name, surname, date of birth, and a so-called eIDAS identifier. However, to build new eIDAS-enabled services in specific domains, additional attributes are needed. We describe our approach to retrieve and transport new attributes through the eIDAS infrastructure, and we detail their exploitation in a selected set of academic services. First, we describe the definition and the support for the additional attributes in the eIDAS nodes. We then present a solution for their retrieval from our university. Finally, we detail the design, implementation, and installation of two eIDAS-enabled academic services at our university: the eRegistration in the Erasmus student exchange program and the Login facility with national eIDs on the university portal. Full article

(This article belongs to the Special Issue ICSTCC 2018: Advances in Control and Computers)

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17 pages, 1094 KiB

Open AccessArticle

Optimization and Security in Information Retrieval, Extraction, Processing, and Presentation on a Cloud Platform

by Adrian Alexandrescu

Information 2019, 10(6), 200; https://doi.org/10.3390/info10060200 - 05 Jun 2019

Cited by 7 | Viewed by 4410

Abstract

This paper presents the processing steps needed in order to have a fully functional vertical search engine. Four actions are identified (i.e., retrieval, extraction, presentation, and delivery) and are required to crawl websites, get the product information from the retrieved webpages, process that [...] Read more.

This paper presents the processing steps needed in order to have a fully functional vertical search engine. Four actions are identified (i.e., retrieval, extraction, presentation, and delivery) and are required to crawl websites, get the product information from the retrieved webpages, process that data, and offer the end-user the possibility of looking for various products. The whole application flow is focused on low resource usage, and especially on the delivery action, which consists of a web application that uses cloud resources and is optimized for cost efficiency. Novel methods for representing the crawl and extraction template, for product index optimizations, and for deploying and storing data in the cloud database are identified and explained. In addition, key aspects are discussed regarding ethics and security in the proposed solution. A practical use-case scenario is also presented, where products are extracted from seven online board and card game retailers. Finally, the potential of the proposed solution is discussed in terms of researching new methods for improving various aspects of the proposed solution in order to increase cost efficiency and scalability. Full article

(This article belongs to the Special Issue ICSTCC 2018: Advances in Control and Computers)

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14 pages, 1069 KiB

Open AccessArticle

Evaluation of Sequence-Learning Models for Large-Commercial-Building Load Forecasting

by Cristina Nichiforov, Grigore Stamatescu, Iulia Stamatescu and Ioana Făgărăşan

Information 2019, 10(6), 189; https://doi.org/10.3390/info10060189 - 01 Jun 2019

Cited by 16 | Viewed by 3815

Abstract

Buildings play a critical role in the stability and resilience of modern smart grids, leading to a refocusing of large-scale energy-management strategies from the supply side to the consumer side. When buildings integrate local renewable-energy generation in the form of renewable-energy resources, they [...] Read more.

Buildings play a critical role in the stability and resilience of modern smart grids, leading to a refocusing of large-scale energy-management strategies from the supply side to the consumer side. When buildings integrate local renewable-energy generation in the form of renewable-energy resources, they become prosumers, and this adds more complexity to the operation of interconnected complex energy systems. A class of methods of modelling the energy-consumption patterns of the building have recently emerged as black-box input–output approaches with the ability to capture underlying consumption trends. These make use and require large quantities of quality data produced by nondeterministic processes underlying energy consumption. We present an application of a class of neural networks, namely, deep-learning techniques for time-series sequence modelling, with the goal of accurate and reliable building energy-load forecasting. Recurrent Neural Network implementation uses Long Short-Term Memory layers in increasing density of nodes to quantify prediction accuracy. The case study is illustrated on four university buildings from temperate climates over one year of operation using a reference benchmarking dataset that allows replicable results. The obtained results are discussed in terms of accuracy metrics and computational and network architecture aspects, and are considered suitable for further use in future in situ energy management at the building and neighborhood levels. Full article

(This article belongs to the Special Issue ICSTCC 2018: Advances in Control and Computers)

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19 pages, 9755 KiB

Open AccessArticle

Gain Adaptation in Sliding Mode Control Using Model Predictive Control and Disturbance Compensation with Application to Actuators

by Benedikt Haus, Paolo Mercorelli and Harald Aschemann

Information 2019, 10(5), 182; https://doi.org/10.3390/info10050182 - 25 May 2019

Cited by 7 | Viewed by 3461

Abstract

In this contribution, a gain adaptation for sliding mode control (SMC) is proposed that uses both linear model predictive control (LMPC) and an estimator-based disturbance compensation. Its application is demonstrated with an electromagnetic actuator. The SMC is based on a second-order model of [...] Read more.

In this contribution, a gain adaptation for sliding mode control (SMC) is proposed that uses both linear model predictive control (LMPC) and an estimator-based disturbance compensation. Its application is demonstrated with an electromagnetic actuator. The SMC is based on a second-order model of the electric actuator, a direct current (DC) drive, where the current dynamics and the dynamics of the motor angular velocity are addressed. The error dynamics of the SMC are stabilized by a moving horizon MPC and a Kalman filter (KF) that estimates a lumped disturbance variable. In the application under consideration, this lumped disturbance variable accounts for nonlinear friction as well as model uncertainty. Simulation results point out the benefits regarding a reduction of chattering and a high control accuracy. Full article

(This article belongs to the Special Issue ICSTCC 2018: Advances in Control and Computers)

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15 pages, 1006 KiB

Open AccessArticle

A High Throughput Hardware Architecture for Parallel Recursive Systematic Convolutional Encoders

by Gabriele Meoni, Gianluca Giuffrida and Luca Fanucci

Information 2019, 10(4), 151; https://doi.org/10.3390/info10040151 - 24 Apr 2019

Cited by 1 | Viewed by 3232

Abstract

During the last years, recursive systematic convolutional (RSC) encoders have found application in modern telecommunication systems to reduce the bit error rate (BER). In view of the necessity of increasing the throughput of such applications, several approaches using hardware implementations of RSC encoders [...] Read more.

During the last years, recursive systematic convolutional (RSC) encoders have found application in modern telecommunication systems to reduce the bit error rate (BER). In view of the necessity of increasing the throughput of such applications, several approaches using hardware implementations of RSC encoders were explored. In this paper, we propose a hardware intellectual property (IP) for high throughput RSC encoders. The IP core exploits a methodology based on the ABCD matrices model which permits to increase the number of inputs bits processed in parallel. Through an analysis of the proposed network topology and by exploiting data relative to the implementation on Zynq 7000 xc7z010clg400-1 field programmable gate array (FPGA), an estimation of the dependency of the input data rate and of the source occupation on the parallelism degree is performed. Such analysis, together with the BER curves, provides a description of the principal merit parameters of a RSC encoder. Full article

(This article belongs to the Special Issue ICSTCC 2018: Advances in Control and Computers)

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10 pages, 276 KiB

Open AccessArticle

Youla–Kučera Parametrization with no Coprime Factorization—Single-Input Single-Output Case

by Kazuyoshi Mori

Information 2019, 10(4), 120; https://doi.org/10.3390/info10040120 - 31 Mar 2019

Cited by 3 | Viewed by 2900

Abstract

We present a generalization of the Youla—Kučera parametrization to obtain all stabilizing controllers for single-input and single-output plants. This uses three parameters and can be applied to plants that may not admit coprime factorizations. In this generalization, at most two rational expressions of [...] Read more.

We present a generalization of the Youla—Kučera parametrization to obtain all stabilizing controllers for single-input and single-output plants. This uses three parameters and can be applied to plants that may not admit coprime factorizations. In this generalization, at most two rational expressions of plants are required, while the Youla–Kučera parametrization requires precisely one rational expression. Full article

(This article belongs to the Special Issue ICSTCC 2018: Advances in Control and Computers)

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