313 research outputs found

    Long-Range Communications in Unlicensed Bands: the Rising Stars in the IoT and Smart City Scenarios

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    Connectivity is probably the most basic building block of the Internet of Things (IoT) paradigm. Up to know, the two main approaches to provide data access to the \emph{things} have been based either on multi-hop mesh networks using short-range communication technologies in the unlicensed spectrum, or on long-range, legacy cellular technologies, mainly 2G/GSM, operating in the corresponding licensed frequency bands. Recently, these reference models have been challenged by a new type of wireless connectivity, characterized by low-rate, long-range transmission technologies in the unlicensed sub-GHz frequency bands, used to realize access networks with star topology which are referred to a \emph{Low-Power Wide Area Networks} (LPWANs). In this paper, we introduce this new approach to provide connectivity in the IoT scenario, discussing its advantages over the established paradigms in terms of efficiency, effectiveness, and architectural design, in particular for the typical Smart Cities applications

    Platforms and Protocols for the Internet of Things

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    Building a general architecture for the Internet of Things (IoT) is a very complex task, exacerbated by the extremely large variety of devices, link layer technologies, and services that may be involved in such a system. In this paper, we identify the main blocks of a generic IoT architecture, describing their features and requirements, and analyze the most common approaches proposed in the literature for each block. In particular, we compare three of the most important communication technologies for IoT purposes, i.e., REST, MQTT, and AMQP, and we also analyze three IoT platforms: openHAB, Sentilo, and Parse. The analysis will prove the importance of adopting an integrated approach that jointly addresses several issues and is able to flexibly accommodate the requirements of the various elements of the system. We also discuss a use case which illustrates the design challenges and the choices to make when selecting which protocols and technologies to use

    Golden Modulation: a New and Effective Waveform for Massive IoT

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    This paper considers massive Internet of Things systems, especially for LoW Power Wide Area Networks, that aim at connecting billions of low-cost devices with multi-year battery life requirements. Current systems for massive Internet of Things exhibit severe problems when trying to pursue the target of serving a very large number of users. In this paper, a novel asynchronous spread spectrum modulation, called Golden Modulation, is introduced. This modulation provides a vast family of equivalent waveforms with very low cross-interference even in asynchronous conditions, hence enabling natural multiuser operation without the need for inter-user synchronization or for interference cancellation receivers. Thanks to minimal interference between waveforms, coupled with the absence of coordination requirements, this modulation can accommodate very high system capacity. The basic modulation principles, relying on spectrum spreading via direct Zadoff-Chu sequences modulation, are presented and the corresponding theoretical bit error rate performance in an additive white Gaussian noise channel is derived and compared by simulation with realistic Golden Modulation receiver performance. The demodulation of the Golden Modulation is also described, and its performance in the presence of uncoordinated multiple users is characterized.Comment: This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

    Field evaluation of two point-of-care tests for syphilis among men who have sex with men, Verona, Italy

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    Objectives: The incidence of HIV and syphilis among men who have sex with men (MSM) in Europe has recently increased. Rapid point-of-care tests (POCTs) for syphilis can improve access to screening. The purpose of this study was to evaluate the performance of two syphilis POCTs compared with laboratory tests among MSM. Methods: The study was undertaken in Verona, Italy. Asymptomatic MSM, potentially exposed to syphilis, were enrolled prospectively. The POCTs evaluated were SD Bioline Syphilis 3.0 and Chembio DPP Syphilis Screen & Confirm Assay on both serum and fingerprick blood. The results of the POCTs were read by the naked eye by two independent readers and their concordance assessed. Results: A total of 289 MSM were enrolled in the study. Based on laboratory tests, 35 MSM (12.1%) were TPPA-positive alone and 16 (5.5%) were both Treponema pallidum particle agglutination test (TPPA) and rapid plasma reagin (RPR)-positive. The specificities of both POCTs were above 99% on both serum and fingerstick blood specimens, while sensitivities varied considerably. The sensitivity of the SD Bioline test was lower on fingerprick blood (51.4% and 54.3%, readers 1 and 2, respectively) compared with that on serum (80.0% and 82.9%). In contrast, the Chembio test exhibited similar sensitivity values for serum and fingerprick samples (57.7% and 64.0% on serum vs 65.4% and 69.2% on fingerprick for the treponemal component; 63.6% on both samples by both readers for the non-treponemal component). The positive predictive value ranged between 100% and 93.9% for the treponemal component of both syphilis POCTs, but was lower (76.3%-100%)%) for the non-treponemal component of the Chembio POCT. The negative predictive value surpassed 90% for both tests on both samples. The agreement between readers was very high (>99%). Conclusion: The diagnostic performance of the syphilis POCTs was lower than expected; however, considering the prevalence of syphilis among MSM, POCTs should be recommended to improve syphilis detection among MSM

    Compact Quantum Random Number Generator with Silicon Nanocrystals Light Emitting Device Coupled to a Silicon Photomultiplier

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    A small-sized photonic quantum random number generator, easy to be implemented in small electronic devices for secure data encryption and other applications, is highly demanding nowadays. Here, we propose a compact configuration with Silicon nanocrystals large area light emitting device (LED) coupled to a Silicon photomultiplier to generate random numbers. The random number generation methodology is based on the photon arrival time and is robust against the non-idealities of the detector and the source of quantum entropy. The raw data show high quality of randomness and pass all the statistical tests in national institute of standards and technology tests (NIST) suite without a post-processing algorithm. The highest bit rate is 0.5 Mbps with the efficiency of 4 bits per detected photon

    Potencial de Geração de Biogás a Partir da Suplementação de Óleo de Babaçu em Dejetos de Animais

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    O presente trabalho objetiva avaliar o comportamento e o potencial de geração de biogás através do blend de dejetos de bovinos, suínos e aves quando suplementado com óleo de babaçu. O uso de oleaginosas para fins energéticos em comunidades isoladas que não possuem acesso às redes convencionais de distribuição de energia elétrica está sendo bastante discutido, uma vez que há vasta disponibilidade destas biomassas na Região Amazônica e poucas atividades econômicas sustentáveis em torno da mesma. O estudo foi desenvolvido no Laboratório de Biorreatores do Centro Universitário UNIVATES, sendo a avaliação da geração de biogás realizada através de um dispositivo baseado no deslocamento de fluidos e na equação combinada dos gases ideais, enquanto o teor de metano contido no biogás foi verificado através de um sensor específico para este fim, denominado Advanced Gasmitter. Os resultados obtidos demonstram que a aplicação de óleo de babaçu (OB) em resíduos agrícolas melhora o rendimento de biogás e de metano, sendo que o tratamento suplementado com 7,5% de OB o qual obteve melhor desempenho

    An unusual pathological finding of chronic lymphocitic leukemia and adenocarcinoma of the prostate after transurethral resection for complete urinary retention: case report

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    BACKGROUND: We describe a patient who underwent transurethral resection of the prostate for urinary obstructive symptoms and had histological findings of adenocarcinoma of the prostate with prostatic localization of chronic lymphocitic leukemia (CLL).The contemporary presence of CLL, adenocarcinoma of the prostate and residual prostatic gland after transurethral resection has never been reported before and the authors illustrate how they managed this unusual patient. CASE PRESENTATION: A 79-years-old white man, presented with acute urinary retention, had a peripheral blood count with an elevated lymphocytosis (21.250/mL) with a differential of 65.3% lymphocytes and the prostate-specific antigen (PSA) value was 3.38 ng/mL with a percent free PSA of 8.28%. The transrectal ultrasound (TRUS) indicated an isoechonic and homogenic enlarged prostate of 42 cm(3 )and the abdomen ultrasound found a modest splenomegaly and no peripheral lymphadenophaty. The patient underwent transurethral resection of the prostate and had a pathological finding of adenocarcinoma in the prostate with a Gleason Score 4 (2+2) of less than 5% of the material (clinical stage T1a), associated with a diffused infiltration of chronic lymphocitic leukemia elements. CONCLUSIONS: The incidental finding of a prostatic localization of a low-grade non-Hodgkin's lymphoma does not modify eventually further treatments for neither prostate cancer nor lymphoma. The presence of a low-grade and low-stage lymphoma, confirmed by a hematological evaluation, and the simultaneous evidence of an adenocarcinoma after transurethral resection of the prostate for acute urinary retention do not require any immediate treatment due to its long-term survival rate and the follow-up remains based on periodical PSA evaluation and complete blood count

    Field evaluation of two point-of-care tests for syphilis among men who have sex with men, Verona, Italy.

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    OBJECTIVES: The incidence of HIV and syphilis among men who have sex with men (MSM) in Europe has recently increased. Rapid point-of-care tests (POCTs) for syphilis can improve access to screening. The purpose of this study was to evaluate the performance of two syphilis POCTs compared with laboratory tests among MSM. METHODS: The study was undertaken in Verona, Italy. Asymptomatic MSM, potentially exposed to syphilis, were enrolled prospectively. The POCTs evaluated were SD Bioline Syphilis 3.0 and Chembio DPP Syphilis Screen & Confirm Assay on both serum and fingerprick blood. The results of the POCTs were read by the naked eye by two independent readers and their concordance assessed. RESULTS: A total of 289 MSM were enrolled in the study. Based on laboratory tests, 35 MSM (12.1%) were TPPA-positive alone and 16 (5.5%) were both Treponema pallidum particle agglutination test (TPPA) and rapid plasma reagin (RPR)-positive. The specificities of both POCTs were above 99% on both serum and fingerstick blood specimens, while sensitivities varied considerably. The sensitivity of the SD Bioline test was lower on fingerprick blood (51.4% and 54.3%, readers 1 and 2, respectively) compared with that on serum (80.0% and 82.9%). In contrast, the Chembio test exhibited similar sensitivity values for serum and fingerprick samples (57.7% and 64.0% on serum vs 65.4% and 69.2% on fingerprick for the treponemal component; 63.6% on both samples by both readers for the non-treponemal component). The positive predictive value ranged between 100% and 93.9% for the treponemal component of both syphilis POCTs, but was lower (76.3%-100%)%) for the non-treponemal component of the Chembio POCT. The negative predictive value surpassed 90% for both tests on both samples. The agreement between readers was very high (>99%). CONCLUSION: The diagnostic performance of the syphilis POCTs was lower than expected; however, considering the prevalence of syphilis among MSM, POCTs should be recommended to improve syphilis detection among MSM

    Gestão de Resíduos Sólidos de uma Empresa de Aglomerados - um Olhar para Sustentabilidade

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    O objetivo principal deste trabalho é identificar quais tipos de resíduos sólidos provenientes das indústrias moveleiras podem ser potencializados para reaproveitamento na fabricação de novas chapas de aglomerado e/ou para geração de energia. Para tanto, foram identificadas as principais indústrias de móveis que utilizam como matéria prima o MDP e MDF junto ao SINDMÓVEIS de Bento Gonçalves. O método utilizado foi de pesquisa aplicada quanto aos fins e pesquisa documental, bibliográfica e estudo de caso quanto aos meios. O trabalho buscou quantificar e evidenciar o aproveitamento destes resíduos como matérias-primas alternativas tanto na produção de novas chapas de aglomerado como para geração de energia (biomassa). Os resultados obtidos mostram que há grande quantidade de resíduos gerados no polo moveleiro de Bento Gonçalves, onde, comparando-os com a quantidade de resíduos de matérias-primas virgens utilizadas na empresa de aglomerados, o aproveitamento destes resíduos alternativos reduziria consideravelmente o consumo de florestas plantadas
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