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IEEE International Conference on Automation Science and engineering (CASE)

作者： Patrícia C. Mayer Felipe G. Cabral Públio M. M. Lima Marcos V. Moreira Audine Subias Yannick Pencolé Department of Automation and Systems Federal University of Santa Catarina Florianópolis SC Brazil COPPE - Electrical Engineering Program Universidade Federal do Rio de Janeiro Cidade Universitária Rio de Janeiro RJ Brazil LAAS-CNRS INSA University of Toulouse France LAAS-CNRS CNRS University of Toulouse France

ISBN: (数字)9798350358513

ISBN: (纸本)9798350358520

Cyber-physical systems (CPSs) are composed of computational and physical components that interact to achieve a desired behavior for a given system. These systems are widely used in industrial applications and have guaranteed a solid improvement in productivity. However, their high connectivity also makes them more vulnerable to cyber-attacks, and thus, strategies to increase and/or guarantee the privacy of classified information are mandatory. On the other hand, the availability of system information, known as utility, to trustworthy agents is fundamental to operating large-scale CPSs efficiently, which establishes a trade-off between the privacy of information against malicious agents and the utility of data to legitimate receivers. In this paper, we explore the utility problem for CPSs abstracted as Discrete-Event Systems (DESs), where the intended receiver must know useful information about the system to achieve a desired goal. In this context, we consider that this information is the ability to be sure when a given property of interest is satisfied before the system evolves to a state where this property is no longer valid. To this end, we propose a new utility notion called Property-Based Transparency (PT), and a method for verifying whether a system is transparent with respect to the desired property. In addition, we discuss PT’s applicability in two domains and present how it relates to the notion of current-state opacity and fault diagnosis of DES.

关键词： Fault diagnosis Productivity Privacy Data privacy Computer aided software engineering Receivers Cyber-physical systems Solids Discrete-event systems Cyberattack

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Event-based cryptography for automation networks of cyber-physical systems using the stream cipher ChaCha20

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IFAC-PapersOnLine 2022年第28期55卷 58-65页

作者： Públio M. Lima Carlos K.P. da Silva Claudio M. de Farias Lilian K. Carvalho Marcos V. Moreira COPPE - Electrical Engineering Program Universidade Federal do Rio de Janeiro Cidade Universitária Ilha do Fundão Rio de Janeiro 21.945-970 RJ Brazil COPPE - PESC Universidade Federal do Rio de Janeiro Cidade Universitária Ilha do Fundão Rio de Janeiro 21.945-970 RJ Brazil

In this paper, we consider Cyber-Physical Systems (CPS) in a Discrete-Event Systems (DES) framework, and consider cyber attacks in the automation network of the CPS, where a malicious agent eavesdrops communication channels with the objective to gather information about the system behavior. We propose a cryptographic scheme to be applied in an automation network which cipher events without altering the size or structure of the transmitted data. In addition, the proposed cryptographic scheme leads to small communication delays, which makes it suitable for application in automation networks. We call this scheme event-based cryptography, where an event is defined as any change in the binary signals transmitted in the network. In order to do so, we propose a method for the codification of events as event vectors, which is suitable for encryption. We also propose the use of a stream cipher called ChaCha20, which is known to have a high resistance to cryptanalysis. A simulated example is used to illustrate the application of the proposed event-based cryptography, and to make a comparison with the RSA cipher, a public-key cipher widely used in Information Technology.

关键词： Cyber-Security Cryptography Cyber-Physical Systems Discrete-Event Systems

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Blind estimation of reverberation time by neural networks 23

Blind estimation of reverberation time by neural networks

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23rd International Congress on Acoustics: Integrating 4th EAA Euroregio, ICA 2019

作者： Prates, Rodrigo L. Petraglia, Mariane R. Torres, Julio C.B. Petraglia, Antonio Program of Electrical Engineering COPPE Federal University of Rio de Janeiro Brazil

ISBN: (纸本)9783939296157

In this paper we investigate a procedure for blind estimation of room reverberation time, that is, without a priori knowledge of the room impulse response. A neural network based method is proposed, which is robust to noise and to abrupt variations over time of the acquired signal. The input features of the neural network are calculated in the frequency domain, where training samples are generated in the Mel scale. A competent network architecture (i.e., with appropriate number and type of hidden layers and number of neurons comprising each layer), as well as the best training algorithm and regularization technique, are investigated. The use of cross-entropy error during training gives better results than those obtained by mean squared error. Comparative results are presented, considering two previously proposed blind methods: a deep neural network technique and a spectral decay distribution method. © 2019 Proceedings of the International Congress on Acoustics. All rights reserved.

关键词： Neural Network Power Spectral Density Reverberation Time

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Development of an Escherichia coli optical biosensor with computational validation 5

Development of an Escherichia coli optical biosensor with co...

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5th International Conference on Applications of Optics and Photonics, AOP 2022

作者： Dante, A. Silva, P.H. Lopes, R. Allil, A. Sbano, A. Esteves, M.E. Silva, M. Werneck, M. Allil, R. Departamento 1Integrated Micro and Nanotechnologies Group International Iberian Nanotechnology Laboratory Braga Portugal Photonics and Instrumentation Laboratory Electrical Engineering Program Universidade Federal Do Rio de Janeiro COPPE/UFRJ RJ Brazil Instituto Nacional de Metrologia Qualidade e Tecnologia Duque de Caxias Rio de Janeiro Brazil Instituto Oswaldo Cruz - IOC/Fiocruz Rio de Janeiro Brazil Instituto de Biodiversidade e Sustentabilidade -NUPEM/UFRJ- Rio de Janeiro Macaé Brazil

The biosensor consists of an optical sensing system and an optoelectronic data acquisition system. The sensor's optical system consists of a biochemically functionalized polymer optical fiber (POF-Plastic Optical Fiber) based on Field Evanescent technology. The Evanescent Field technique has been widely adopted in sensing and in this project, it was obtained by bending the fiber in a "U"shape, aiming to increase the sensitivity of the biosensor, through the contact of the curved sensor part with the sample biological. A data acquisition system was developed through an optoelectronic project aiming to increase the sensitivity when compared to a commercial equipment acquisition system. This work presents a biosensor for the detection of Escherichia coli based on an evanescent field with a polymer optical fiber linked to the analog signal acquisition system through an optoelectronic system developed. The interaction investigation of antibodies and antigens in Escherichia coli for computational methods was carried out in order to obtain information about the action of the antibody and in future steps applied in the validation of the diagnostic method. © Published under licence by IOP Publishing Ltd.

关键词： Escherichia coli

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Visual Relationship Classification With Negative-Sample Mining

Visual Relationship Classification With Negative-Sample Mini...

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IEEE International Conference on Image Processing

作者： Roberto de M. Estevão Filho José Gabriel R.C. Gomes Leonardo de O. Nunes Electrical Engineering Program Federal University of Rio de Janeiro COPPE Microsoft Advanced Technology Labs Brazil

ISBN: (数字)9781728163956

ISBN: (纸本)9781728163963

This paper introduces the application of a visual relationship classifier as a standalone system that is meant to be used with external detectors. Through these lens, we propose a training scheme that uses unannotated pairs of objects as negative samples in order to improve precision. The proposed network architecture incorporates common techniques presented in related state-of-the-art solutions with a novel positional encoding scheme. We evaluate the proposed training method and architecture on the Open Images dataset and improve mAP from 34.6% to 78.2% when considering all possible object pairings in each image. For a case where only ground-truth pairs are considered, our method presents a small decrease, from 91.0% to 88.8% mAP.

关键词： Visualization Feature extraction Task analysis Encoding Training Object detection Detectors

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DME Interference Mitigation for GNSS Receivers via Nonnegative Matrix Factorization

DME Interference Mitigation for GNSS Receivers via Nonnegati...

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General Assembly and Scientific Symposium, URSI

作者： Felipe Barboza da Silva Ediz Cetin Wallace Alves Martins School of Engineering Macquarie University Sydney NSW Australia Electrical Engineering Program (PEE/Coppe) Federal University of Rio de Janeiro (UFRJ) Rio de Janeiro RJ Brazil Interdisciplinary Centre for Security Reliability and Trust (SnT) University of Luxembourg Luxembourg

In this work a nonnegative matrix factorization based approach is proposed to mitigate the impact of interference due to distance measurement equipment (DME) signals in global navigation satellite system (GNSS) receivers. The proposed approach operates by separating the DME and GNSS signals, and the results show that it outperforms the traditional pulse-blanking based techniques in terms of acquisition and carrier-to-noise ratio metrics without discarding any of the received signal samples.

关键词： Global navigation satellite system Simulation Interference Receivers Hardware Distance measurement Proposals

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User Selection based on Inter-channel Interference for Massive MIMO under Line-of-sight Propagation

User Selection based on Inter-channel Interference for Massi...

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General Assembly and Scientific Symposium, URSI

作者： Rafael S. Chaves Ediz Cetin Markus V. S. Lima Wallace A. Martins Electrical Engineering Program (PEE/Coppe) Federal University of Rio de Janeiro (UFRJ) Rio de Janeiro RJ Brazil School Engineering Macquarie University Sydney NSW Australia Interdisciplinary Centre for Security Reliability and Trust (SnT) University of Luxembourg (UniLu) Luxembourg

Massive multiple-input multiple-output (MIMO) is seen as a key enabler for next-generation wireless communication systems. Increased throughput afforded by massive MIMO, however, may severely degrade when the number of users served by a single base station increases, calling for user scheduling algorithms. To deal with this problem, a new user selection algorithm, called inter-channel interference-based selection (ICIBS), is proposed. ICIBS drops those users that induce the highest interference to the remaining users. Simulations show that selecting users with ICIBS significantly improves the throughput, outperforming state-of-the-art user selection algorithms.

关键词： Wireless communication Base stations Scheduling algorithms Line-of-sight propagation Massive MIMO Interference Throughput

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An Electronic Drive for a Switched Reluctance Motor Using a DSC 15

An Electronic Drive for a Switched Reluctance Motor Using a ...

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15th IEEE Brazilian Power Electronics Conference and 5th IEEE Southern Power Electronics Conference, COBEP/SPEC 2019

作者： Da Fonseca, Brayan Sobral Andres Santisteban, Jose COPPE - Universidade Federal Do Rio de Janeiro Graduate Program in Electrical Engineering Rio de Janeiro Brazil Universidade Federal Fluminense Graduate Program in Electrical and Telecommunications Engineering - PPGEET Niterói Brazil

ISBN: (纸本)9781728141800

With the technological advances using electronic circuits based on microprocessors, the drive and control of electrical machines in electromechanical systems have become increasingly efficient. In this paper, for an axial magnetic flux reluctance motor, for which it is not possible to supply its energy directly from the utility, the developing of an electronic drive and its control is described. Unlike other alternatives, a development module, named DSC (Digital Signal Controller), which is based on a modern microcontroller, allows the reduction of discrete components, like operational amplifiers, and wires. The workbench comprises a three-phase power converter that is equipped with high-speed semiconductor switches, current sensors, voltage sensors and an USB interface to allow communication with a computer. The effectiveness of this approach is verified through open loop and closed loop experimental tests, where the waveforms of the trigger pulses generated by the DSC, the motor currents and their speed were monitored. © 2019 IEEE.

关键词： Reluctance motors

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Neutral Current's Effect on Four-Wire Voltage Source Converter Control Systems

Neutral Current's Effect on Four-Wire Voltage Source Convert...

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Brazilian Power Electronics Conference, COBEP

作者： Paulo F. Silva Claudionor F. Nascimento Amilcar F. Q. Gonçalves Alex F. Silva Alfeu J. Sguarezi Filho Oumar Diene Federal University of São Carlos São Carlos SP Brazil Federal University of ABC Santo Andre SP Brazil COPPE-Electrical Engineering Program Federal University of Rio de Janeiro Rio de Janeiro SP Brazil

ISBN: (纸本)9781665421300

With the expansion of sustainable sources (e.g., solar and wind) in the energy matrix, the use of three-phase fourwire Voltage Source Converters (VSCs) enables the insertion of DC energy generated into AC electrical grids. The connection of single-phase loads in three-phase four-wire systems can generate negative- and zero-sequence components due to unbalanced voltage. This study examines the effects of neutral current on the control systems proportional-resonant controller of three-phase four-wire VSCs in the topology of the split-capacitor, in which the neutral conductor is connected to the midpoint. The modeling of the proposed topology, and simulation analysis will also be studied. The results from the simulation confirmed the analyzes carried out through the proposed modeling.

关键词： Wind energy generation Analytical models Wind energy Simulation Control systems Conductors Topology

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CONFIDENTIALITY OF CYBER-PHYSICAL SYSTEMS USING EVENT-BASED CRYPTOGRAPHY

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IFAC-PapersOnLine 2020年第2期53卷 1735-1740页

作者： Públio M. Lima Lilian K. Carvalho Marcos V. Moreira COPPE - Electrical Engineering Program Universidade Federal do Rio de Janeiro Cidade Universitária Ilha do Fundão Rio de Janeiro 21.945-970 RJ Brazil

One of the most important challenges for the application of cyber-physical systems (CPS) in smart industries is ensuring its security against cyber attacks. In this paper, we consider that the CPS is abstracted as a Discrete-Event System (DES), and we consider cyber attacks where the intruder eavesdrops the sensor communication channel to detect the occurrence of a sequence in the secret behavior of the system. In order to prevent the attacker from getting information from the sensor channel, we introduce a new cryptographic scheme based on events called event-based cryptography. We also define the property of confidentiality of DES, present a necessary and sufficient condition for ensuring this property, and propose a verification test.

关键词： Cyber-security Cyber-physical systems Network communication Discrete-event systems Automata Confidentiality Encryption

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