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SSRN 2024年

作者： da Silva, Gabriel Caetano Gomes Ribeiro Naveira-Cotta, Carolina Palma Lisboa, Kleber Marques Cotta, Renato M. Su, Jian Nuclear Engineering Program COPPE Universidade Federal do Rio de Janeiro Rio de Janeiro RJ Brazil Mechanical Engineering Program POLI & COPPE Universidade Federal do Rio de Janeiro Rio de Janeiro RJ Brazil Universidade Federal Fluminense Niterói RJ Brazil Navy Research Institute IPqM General Directorate of Nuclear and Technological Development DGDNTM Brazilian Navy and AMAZUL S.A. Rio de Janeiro Brazil

despite the proven feasibility and cost-effectiveness of nuclear desalination in small modular reactors (SMRs), the exclusive use of waste heat for this purpose remains virtually unexplored. This work investigates coupling an SMR (NuScale) to a direct contact membrane distillation (DCMD) desalination plant with heat recovery and feed recycle. Both the reactor waste heat and the low-pressure (LP) steam extraction from the reactor turbine were considered as heat sources. The DCMD hollow fiber module was modeled as a porous medium with satisfactory accuracy. Key parameters affecting system performance, identified through factorial analysis, include membrane porosity, module length, feed superficial velocity, and fiber inner radius. Single and multiobjective optimization analyses revealed the feasibility of producing up to 3,810 m3/d of water without any reactor power loss, and up to 8,832 m3/d, with a 2.28 MWe power loss, using steam extraction. DCMD demonstrated competitiveness, especially when the reactor's primary purpose is electricity generation. © 2024, The Authors. All rights reserved.

关键词： Waste heat

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Baseline Drifting Correction for Automated MTWA Measurements

Baseline Drifting Correction for Automated MTWA Measurements

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Computers in Cardiology (CinC)

作者： T Winkert P R Benchimol-Barbosal J Nadal Biomedical Engineering Program COPPE Institute Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil Hospital Universitário Pedro Ernesto Universidade do Estado do Rio de Janeiro Rio de Janeiro Brazil

To reduce the incidence of sudden cardiac death (SCD), risk stratification markers have a relevant role. Microvolt T-wave alternans (MTWA) is a marker of SCD risk, defined as T-wave amplitude variation in the ECG. Usually, MTWA tests are carried out in noisy environments when interferences are expected. Baseline drifting correction methods may distort ECG signals, compromising MTWA analysis. This work assesses the impact of baseline drifting removal (BLDR) by two approaches. Signals with controlled baseline drifting, respiratory fluctuations and MTWA were analyzed. The classical BLDR approach (CA) estimates baseline signals using ECG fiducial points. The time-space cancellation approach (TSC) uses only T-wave information to assemble a vector with T-wave amplitudes, calculated by the difference between the maximum T-wave value and its endpoint. The squared coherence between the spectrum from each approach and the spectrum of the ECG without baseline drifting was calculated. At the alternation frequency (0.5 cycles-per-beat) a higher coherence occurred with TSC (0.57) as compared to CA (0.19). Results indicate that CA adds a distortion to the ECG, compromising MTWA. Conversely, the TSC approach preserves MTWA oscillations and has the potential to improve MTWA quantification.

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Optimizing in-band network telemetry problem

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Procedia Computer Science 2024年 239卷 2074-2081页

作者： Thierno Bocar N’Diaye Marcelo Caggiani Luizelli Jules degila Luciana Salete Buriol Institut de Mathematiques et Sciences Physiques Universite d’Abomey-Calavi (UAC) Benin Graduate Program in Electrical Engineering Universidade Federal do Pampa (UNIPAMPA) Brazil Graduate Program in Computing Universidade Federal do Rio Grande do Sul (UFRGS) Brazil

In-band network telemetry is a powerful framework for network monitoring. It allows the collection of telemetry data in real-time and provides network-wide visibility. However, depending on the routing of network flows and which telemetry data are collected, the network-wide visibility and the performance of monitoring applications may decrease. In this paper, we present the in-band network telemetry problem and extend the existing mathematical optimization models of the problem by proposing a new model that computes the routing of network flows. Results show that the new model outperforms existing models in term of network coverage and monitoring applications performance. The results of this work can be useful for network managers and enterprises to gain real-time insights into network performance.

关键词： Network monitoring Monitoring application Optimization In-band network telemetry Network flows routes

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Very Simple Method to Produce Superhydrophobic Stainless Steel Surfaces at Room Temperature

SSRN

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SSRN 2023年

作者： Wysard, Mauro Meliga Campos, Rodrigo Bezerra Vasconcelos de Souza, Eduardo Alencar da Costa, Marcelo Eduardo Huguenin Maia de Souza Camargo, Sérgio Alvaro Metallurgical and Materials Engineering Program COPPE Universidade Federal do Rio de Janeiro UFRJ Rio de Janeiro Brazil Physics Department Pontifícia Universidade Católica do Rio de Janeiro PUC-Rio Rio de Janeiro Brazil Nanotechnology Engineering Program COPPE Universidade Federal do Rio de Janeiro UFRJ P.O Box 68505 Rio de Janeiro Brazil

In this work, super-hydrophobic and self-cleaning AISI 347 stainless steel surfaces were obtained by a fast and simple room-temperature process comprising mild HCl, H2O2 and FeCl3 etching solutions followed by PECVD deposition of a fluorocarbon film using 1,1,1,2-tetrafluorethane (C2H2F4) as a precursor. The chemical etching process produces a hierarchical surface topography of micro-cavities separated by walls covered by nano-particles that resulted in interfacial contact liquid/solid area ratio as low as only 3.6%. This structure results from the continuous nucleation of iron oxide nanoparticles provided by the high supply of iron ions from the solution and the low temperature of the process that disfavors the growth of the nanoparticles. Low surface energy (25.4 mJ/m2) fluorocarbon coatings were obtained by tuning the rf power supplied to the plasma to achieve a balance between etching/ion bombardment and deposition processes and resulted in a dense and interconnected, yet highly fluorinated material. Contact angle measurements showed that the hydrophobicity of the films is directly associated with their chemical properties. Their good mechanical properties (maximum hardness 1.1 GPa and elastic modulus 9.7 GPa) are similar to sputtered PTFE films. The developed process results in superhydrophobic and self-cleaning surfaces with contact angles of up to 1640 and sliding angles of 30. Preliminary anodic polarization and CaCO3 fouling tests pointed out these surfaces as promising candidates for anti-fouling applications. © 2023, The Authors. All rights reserved.

关键词： Temperature

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A cryptographic system based on automata for Networked Automation systems abstracted as Discrete-Event systems

A cryptographic system based on automata for Networked Autom...

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IEEE International Conference on Automation Science and engineering (CASE)

作者： Marcos V. Moreira Publio M. M. Lima Lilian K. Carvalho Felipe G. Cabral COPPE - Electrical Engineering Program Universidade Federal do Rio de Janeiro Cidade Universitária Rio de Janeiro RJ Brazil Department of Automation and Systems Federal University of Santa Catarina Florianópolis SC Brazil

ISBN: (数字)9798350358513

ISBN: (纸本)9798350358520

One of the main concerns about implementing Networked Automation systems is ensuring its security against cyber-attacks. In this paper, we consider that the Networked Automation System is abstracted as a Discrete-Event System, and we consider cyber-attacks where a malicious agent eavesdrops on a communication channel with the objective of gathering information about the system’s behavior. To protect the information transmitted in the attacked channel, we propose a cryptographic system that uses Mealy automata to represent the encryption and decryption functions. One of the main advantages of representing cryptographic systems using automata is that they can be easily implemented on programmable Logic Controllers, yielding to fast encryption and decryption of the transmitted message.

关键词： Automation Computer aided software engineering programmable logic devices Automata Rotors Communication channels Encryption Discrete-event systems Complexity theory Cyberattack

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Toward a Computer-Supported Remote Serendipity: Understanding the Role of Collaboration in Remote Innovation

Toward a Computer-Supported Remote Serendipity: Understandin...

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IEEE International Conference on systems, Man and Cybernetics

作者： Aline Coutinho Carlos Eduardo Barbosa Marcos Antonio de Almeida Jano Moreira de Souza Program of Systems and Computer Engineering (PESC) COPPE Universidade Federal do Rio de Janeiro (UFRJ) Rio de Janeiro RJ Brazil Centro de Análises de Sistemas Navais Marinha do Brasil Praça Barão de Ladário - Ilha das Cobras Rio de Janeiro RJ Brazil

ISBN: (数字)9781665410205

ISBN: (纸本)9781665410212

Since 2016, the demand for remote work has grown by nearly 400%, with 3.5 million remote job vacancies posted, and it is expected to continue to grow in the coming years. Therefore, one of the challenges in advancing remote work is fostering innovation, particularly serendipity, in a remote workforce. This fortunate discovery can pave the way for technological advancements, new business strategies, or even scientific revolutions. However, creating moments of serendipity in a remote work environment is a significant challenge. Thus, finding the right approach to stimulate serendipity in a remote work environment is an ever-evolving challenge. Therefore, this work aims to understand the possibilities of serendipity that collaboration tools used in remote work can support. The methodology used for this work was a Rapid Review. First, we explore the factors related to serendipity in physical offices, for which we identified twenty-three elements. Next, we compiled 38 strategies for remote work that were found to promote serendipity, which we organized in a framework for better observation. Our findings can serve as a starting point for designing new tools and identifying existing software and tools that already play a supportive role.

关键词： Technological innovation Reviews Pandemics Employment Virtual environments Solids Remote working Software Object recognition Guidelines

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Evaluation of materials for confection of phantoms to mimetize acoustic properties of tendons

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Research on Biomedical engineering 2021年第1期37卷 47-52页

作者： Gomes, Gabriela Beatriz de Matheo, Lucas Lobianco da Silva, Flavia Fernandes Ferreira Maggi, Luis Eduardo von Krüger, Marco Antônio de Albuquerque Pereira, Wagner Coelho Programa de Engenharia Biomédica COPPE Universidade Federal do Rio de Janeiro Rio de JaneiroRJ Brazil Biomedical Engineering Program COPPE Federal University of Rio de Janeiro Rio de JaneiroRJ Brazil Programa de Pós-Graduação em Ciências da Saúde na Amazônia Ocidental Universidade Federal do Acre Rio BrancoAC Brazil Graduate Program in Health Sciences in the Western Amazon Federal University of Acre Rio BrancoAC Brazil

Background: The tendon is a structure found in different parts of the human body. Damages within tendons cause movement deficit and discomfort, which requires medical and therapeutic treatment. One useful tool is the therapeutic ultrasound;however, fine adjustment is required to avoid further lesions to the patient. Aiming at enhancing the resources for the research in the study of therapeutic ultrasound and the knowledge regarding its application to tendons, the objective of this work is to evaluate materials to prepare ultrasonic phantoms that mimic the acoustic properties of the tendons. Materials and methods: The acoustic characterization of a pig tendon and three PVCP-based phantoms were made. The transmission-reception method was used, and the propagation speed and attenuation of each phantom were calculated. Results: The tendon showed an attenuation of 4.8 ± 1.7 dB cm−1 and propagation speed of 1497.5 ± 21.6 m s−1. The attenuation of the phantoms varied from 1.3 ± 1.2 to 4.0 ± 1.0 dB cm−1 and velocity from 1509.9 ± 31.8 to 1519.8 ± 26.7 m s−1. Conclusions: We concluded that among the materials used, it was possible to find values statistically similar to this animal tendon in the PVCP phantom with 15% glycerin and 10% PVC powder. Complementary studies with other materials and protocols are needed to mimic other values found in the literature. © 2020, Sociedade Brasileira de Engenharia Biomedica.

关键词： Ultrasonics

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Comparison of body sway measured by a markerless low-cost motion sensor and by a force plate

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Research on Biomedical engineering 2021年第3期37卷 507-517页

作者： Gonzalez, Diego Ramon Gonçalves Imbiriba, Luis Aureliano Jandre, Frederico Caetano Biomedical Engineering Program Universidade Federal do Rio de Janeiro Av Horacio Macedo 2030 Centro de Tecnologia Bl.H sala H-327 Cidade Universitária Rio de JaneiroRJCEP 21941-914 Brazil Nova FriburgoRJ Brazil School of Physical Education and Sports Universidade Federal do Rio de Janeiro Rio de JaneiroRJ Brazil

Purpose: The measurement of body sway is the standard method in the assessment of postural balance. Although the usual technique involves the record of center of pressure (CoP), it may also be done by the measurement of center of mass (CoM). This study compared the CoM estimated from joint positions reported by the Microsoft Kinect v2 (CoMk) to the CoP tracked with a force plate and CoM obtained from CoP (CoMp). Methods: The signals of CoP and CoM of forty-six subjects in medial–lateral and anterior–posterior direction were acquired during quiet standing with eyes open or closed, on stable (floor) or unstable (foam pad) surface. Stabilometric parameters (sway area, velocity, range, RMS value, and the frequency band which contain 80% of the signal energy) based on CoP and CoM were calculated to evaluate the performance among conditions. The Spearman correlation coefficient (rs) between parameters based on all measurements was also computed. Results: Five parameters of CoP were able to distinguish differences among all four conditions, four parameters of CoMp, and three of CoMk. Sway area, range, and RMS values from CoP and CoMk presented high correlation (rs > 0.7), velocity showed high or moderate correlation (0.3 s s © 2021, Sociedade Brasileira de Engenharia Biomedica.

关键词： Motion analysis

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Experimental Evaluation of a Checklist-Based Inspection Technique to Verify the Compliance of Software systems with the Brazilian General Data Protection Law

arXiv

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arXiv 2023年

作者： Cerqueira, Diego André de Mello, Rafael Maiani Travassos, Guilherme Horta Systems Engineering and Computer Science Graduate Program Federal University of Rio de Janeiro Brazil Computing Institute Federal University of Rio de Janeiro Brazil

Background/Context: Recent laws to ensure the security and protection of personal data establish new software requirements. Consequently, new technologies are needed to guarantee software quality under the perception of privacy and protection of personal data. Therefore, we created a checklist-based inspection technique (LGPDCheck) to support the identification of defects in software artifacts based on the principles established by the Brazilian General Data Protection Law (LGPD). Objective/Aim: To evaluate the effectiveness and efficiency of LGPDCheck for verifying privacy and data protection (PDP) in software artifacts compared to ad-hoc techniques. Method: To assess LGPDCheck and ad-hoc techniques experimentally through a quasi-experiment (two factors, five treatments). The data will be collected from IoT-based health software systems built by software engineering students from the federal University of rio de janeiro. The data analyses will compare results from ad-hoc and LGPDCheck inspections, the participant's effectiveness and efficiency in each trial, defects' variance and standard deviation, and time spent with the reviews. The data will be screened for outliers, and normality and homoscedasticity will be verified using the Shapiro-Wilk and Levene tests. Nonparametric or parametric tests, such as the Wilcoxon or Student's t-tests, will be applied as appropriate. © 2023, CC BY-NC-ND.

关键词： Data privacy

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Generative AI Impact on the Future of Work: Insights from Software development

Generative AI Impact on the Future of Work: Insights from So...

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IEEE International Conference on systems, Man and Cybernetics

作者： Caroline Da Conceição Lima Herbert Salazar Yuri Lima Carlos Eduardo Barbosa Matheus Argôlo Alan Lyra Jano Moreira de Souza Program of Systems and Computer Engineering (PESC) COPPE Universidade Federal do Rio de Janeiro (UFRJ) Rio de Janeiro - RJ Brazil Centro de Analises de Sistemas Navais Marinha do Brasil Praca Barao de Ladario - Ilha das Cobras Rio de Janeiro - RJ Brazil

ISBN: (数字)9781665410205

ISBN: (纸本)9781665410212

Recent Artificial Intelligence advancements raise concerns about the future of work, particularly technological unemployment. Studies show automation's impact, but tools like ChatGPT disrupt even traditionally secure professions like programming. In this study, we reevaluate AI's effects using a method to assess the impact of Generative AI technologies on occupations to understand the potential effects of Generative AI systems on software development work. Valuable insights were obtained by gathering the view of a group of workers, primarily composed of developers who are starting their careers, regarding the impact of these technologies on the tasks they perform to provide a comprehensive understanding of the implications of Generative AI for software development. Results show that all programming tasks performed by these workers would experience some impact by Generative AI -65% of the tasks being considerably impacted, 12% moderately impacted, and 18% minimally impacted. This analysis highlights the substantial influence of Generative AI technologies on software development, mainly affecting those in the early stages of their career. The results of this work contribute to the academic community with valuable information. Policymakers can also use this information, as this work provides a comprehensive view of the impacts of Generative AI on software developers, considering their direct impact on job tasks.

关键词： Automation Generative AI engineering profession Chatbots Software Unemployment programming profession Cybernetics Software development management

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