Lisandro Lovisolo

Rio de Janeiro State University | UERJ · Departamento de Eletrônica e Telecomunicações (DETEL)

The Compressive Sensing (CS) framework explores signal sparsity to reduce the amount of data to transmit or store. In it, signal projections on sensing vectors are used to measure the signal, the set of sensing vectors compose the sensing matrix. Usually, one constructs the sensing matrix to be incoherent to a basis in which the signal is sparse. I...

Noise and artifacts affect strongly the quality of the electrocardiogram (ECG) in long-term ECG monitoring (LTM), making some of its parts impractical for diagnosis. The clinical severity of noise defines a qualitative quality score according to the manner clinicians make the interpretation of the ECG, in contrast to assess noise from a quantitativ...

Millimeter-wave communication systems design requires accurate path-loss (PL) prediction, which is critical to determining coverage area and system capacity. In this work, four machine learning (ML) algorithms are proposed for PL prediction in an indoor environment for 5G millimeter-wave frequencies, from 26.5 to 40 GHz. They are artificial neural...

Power line infrastructure is available almost everywhere. Positioning systems aim to estimate where a device or target is. Consequently, there may be an opportunity to use power lines for positioning purposes. This survey article reports the different efforts, working principles, and possibilities for implementing positioning systems relying on pow...

Due to the COVID-19 pandemic, there was a growing interest in society in the area of epidemiology. In this context, emerged the initiative COVID-19: Observatorio Fluminense (COVID19RJ), which is managed by a group of independent researchers affliated with different Brazilian institutions. COVID19RJ publishes trend and monitoring graphs of the COVID...

Chaotic vibrations may appear in nonlinear energy harvesting systems, which can be problematic when using the recovered power, as it may require an extra expenditure of energy to rectify the voltage signal or reduce the harvesting process efficiency when charging the battery. Both cases can derail the energy harvester’s functionality. An alternativ...

Implementing finite impulse response (FIR) adaptive filters by employing the sums of signed-powers-of-two (SOPOT) arithmetic may lead to simpler hardware and consequently reduced power consumption. In this paper, one evaluates the effects of SOPOT arithmetic on the adaptive filter’s recursion algorithms. The filters’ coefficients and algorithms...

Due to the COVID-19 pandemic, there was a growing interest in society in the area of epidemiology. In this context, emerged the initiative COVID-19: Observatório Fluminense (COVID19RJ), which is managed by a group of independent researchers affiliated with different Brazilian institutions. COVID19RJ publishes trend and monitoring graphs of the COVI...

Sparse component analysis techniques have been successfully applied to the separation of speech sources. This paper presents an efficient algorithm based on the matching pursuit approach to deal with multichannel records. The proposed algorithm explicitly employs spatial constraints among different channels to express mixed signals as linear combin...

In this work, the use of adaptive filters for reducing forecast errors produced by a Regional Climate Model (RCM) is investigated. Seasonal forecasts are compared against the reanalysis data provided by the National Centers for Environmental Prediction. The reanalysis is used to train adaptive filters based on the Recursive Least Squares algorithm...

Prior to the 21st century, positioning technologies had limited applications including air traffic control, air and sea navigation, satellite communications and related military uses. Today, positioning technologies have deeply merged with daily life and enabled many novel sensors, systems and services. For example, navigation systems are the enabl...

A Informação do Estado do Canal (CSI – Channel State Information}) está disponível em redes sem-fio IEEE 802.11. A CSI traz informação sobre o estado do canal/ambiente de propagação: as amplitudes e fases das subportadoras OFDM. Neste trabalho, empregamos a CSI para detecção de risco de queda em ambientes hospitalares. A CSI é empregado para detect...

Este trabalho aborda a comunicação sem fio para uma frota de veículos de superfície não tripulados (Unmanned Surface Vehicles, USVs) em ambiente aquático. Para realizar a comunicação neste cenário desafiador, propõe-se um protocolo de aplicação que opera sobre uma rede Wi-Fi em modo ad hoc combinado com o protocolo de roteamento AODV (Ad-hoc On-dem...

A pandemia de COVID-19 despertou um interesse coletivo na sociedade sobre esse tema, especi-almente entre cidadãos que não são especialistas em epidemiologia. Neste contexto, a iniciativa COVID-19: Observatório Fluminense, grupo de pesquisadores independentes afiliados a diferentes instituições brasilei-ras, elaborou um código educacional chamado E...

Single frequency networks (SFN) are being widely adopted for different communication services. SFNs employ transmitters operating at the same frequency band and the locations of transmitter stations must be selected to improve coverage while under different constraints. In general, choosing the locations of the transmitters to vouch for the coverag...

The so-called sum-of-powers-of-two arithmetic has the advantage of using simple shift and thus avoiding multiplications operations. In this work, we provide a feasible RLS adaptive filter algorithm employing the SOPOT representation. This reduces the computational burden of the RLS algorithm. Therefore, leading to a reduction in the power consumpti...

In this short report, we bring some data-driven analyses of COVID-19 mortality in Brazil. The impact of COVID-19 is evaluated by comparing the 2019 and 2020 civilian death records. There is evidence of a considerable excess of deaths since the pandemic started with respect to the previous year. In some states, it is clear that not all excess of dea...