147 research outputs found
LIPIcs, Volume 251, ITCS 2023, Complete Volume
LIPIcs, Volume 251, ITCS 2023, Complete Volum
LIPIcs, Volume 274, ESA 2023, Complete Volume
LIPIcs, Volume 274, ESA 2023, Complete Volum
High-Density Solid-State Memory Devices and Technologies
This Special Issue aims to examine high-density solid-state memory devices and technologies from various standpoints in an attempt to foster their continuous success in the future. Considering that broadening of the range of applications will likely offer different types of solid-state memories their chance in the spotlight, the Special Issue is not focused on a specific storage solution but rather embraces all the most relevant solid-state memory devices and technologies currently on stage. Even the subjects dealt with in this Special Issue are widespread, ranging from process and design issues/innovations to the experimental and theoretical analysis of the operation and from the performance and reliability of memory devices and arrays to the exploitation of solid-state memories to pursue new computing paradigms
A Survey on the Communication Protocols and Security in Cognitive Radio Networks
A cognitive radio (CR) is a radio that can change its transmission parameters based on the perceived availability of the spectrum bands in its operating environment. CRs support dynamic spectrum access and can facilitate a secondary unlicensed user to efficiently utilize the available underutilized spectrum allocated to the primary licensed users. A cognitive radio network (CRN) is composed of both the secondary users with CR-enabled radios and the primary users whose radios need not be CR-enabled. Most of the active research conducted in the area of CRNs has been so far focused on spectrum sensing, allocation and sharing. There is no comprehensive review paper available on the strategies for medium access control (MAC), routing and transport layer protocols, and the appropriate representative solutions for CRNs. In this paper, we provide an exhaustive analysis of the various techniques/mechanisms that have been proposed in the literature for communication protocols (at the MAC, routing and transport layers), in the context of a CRN, as well as discuss in detail several security attacks that could be launched on CRNs and the countermeasure solutions that have been proposed to avoid or mitigate them. This paper would serve as a good comprehensive review and analysis of the strategies for MAC, routing and transport protocols and security issues for CRNs as well as would lay a strong foundation for someone to further delve onto any particular aspect in greater depth
Development of a microfluidic device for gaseous formaldehyde sensing = Développement d\u27un dispositif microfluidique pour la détection de formaldéhyde à l\u27état gazeux
Formaldehyd (HCHO) ist eine chemische Verbindung, die bei der Herstellung einer großen Zahl von Haushaltsprodukten verwendet wird.Charakteristisch ist seine hohe Flüchtigkeit aufgrund einer niedrigen Siedetemperatur (). Daher ist HCOH fast überall als Luftschadstoff in Innenräumen vorhanden. Die Miniaturisierung analytischer Systeme zu Handheld-Gerät hat das Potenzial, nicht nur effizientere, sondern auch empfindlichere Instrumente für die Echtzeitüberwachung dieses gefährlichen Luftschadstoffs zu ermöglichen.
Die vorliegende Doktorarbeit präsentiert die Entwicklung eines Mikrofluidik-Geräts für die Erfassung von HCHO basierend auf der Hantzsch-Reaktion.Hierbei wurde der Schwerpunkt auf die Komponente für Fluoreszenzdetektion gelegt.
Es wurde eine umfangreiche Literaturrecherche durchgeführt, die es erlaubt, den Stand der Technik auf dem Gebiet der Miniaturisierung des Fluoreszenzsensors zusammenzufassen. Auf Grund dieser Studie wurde ein modulares Fluoreszenzdetektionskonzept vorgeschlagen, das um einen CMOS-Bildsensor (CIS) herum entwickelt wurde. Zwei dreischichtige Fluidikzellenkonfigurationen (Konfiguration 1: Quarz - SU-8 3050 - Quarz und Konfiguration 2: Silizium - SU-8 3050 - Quarz) wurden in Betracht gezogen und parallel unter den gleichen experimentellen Bedingungen getestet. Die Verfahren der Mikrofabrikation der fluidischen Zellen wurden detailliert beschrieben, einschließlich des Integrationsprozesses der Standardkomponenten und der experimentellen Verfahren.
Der CIS-basierte Fluoreszenzdetektor bewies seine Leistungsfähigkeit, eine anfängliche HCHO-Konzentration von 10 µg/L vollständig in 3,5-Diacetyl-1,4-dihydrolutidin (DDL- derivatisiert) sowohl für die Quarz- als auch für die Silizium-Fluidikzellen zu detektieren. Beide Systemewiesenein Abfragevolumen von 3,5 µL auf. Ein offensichtlich höheres Signal-Rausch-Verhältnis (SNR) wurde für die Silizium-Fluidzelle () im Vergleich zur Quarz-Fluidzelle () beobachtet. Die Verstärkung der Signalintensität in der Silizium-Fluidzelle ist wahrscheinlich auf den Silizium-Absorptionskoeffizienten bei der Anregungswellenlänge zurückzuführen,. Dieser Koeffizient ist ungefähr fünfmal höher als der Absorptionskoeffizient bei der Fluoreszenzemissionswellenlänge
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HCHO wird aufgrund seiner relativ hohen Konstanten für das Henry-Gesetz sehr schnell in ein flüssiges Reagenz aufgenommen. Somit hängt die Auswahl des molekularen Einfangverfahrens (Schwallströmung, Ringströmung oder membranbasierte Strömungswechselwirkung) von derLeistungsfähigkeit des Fluoreszenzdetektors ab. Ein vorläufiges Konzept, das auf der Verwendung einer Gas-Flüssigkeitsmembran-basierten Wechselwirkung zum ständigen Abfangen des gasförmigen HCHO basiert, wurde eingeführt. Hierzu wurden kompatible Materialien und Herstellungsmethoden identifiziert. Darüber hinaus wurden CFD-Simulationen durchgeführt, um die Mikrokanallänge unter verschiedenen hydrodynamischen Bedingungen abzuschätzen, die für eine vollständige HCHO-Derivatisierung erforderlich sind.
Eine Verbesserung und Vereinfachung auf der Grundlage von sehrnempfindlichen Fluoreszenzdetektoren mit niedrigen Detektionsgrenzen könnte zukünftig basierend z. B. auf Schwallströmung oder Ringströmung möglich sein
Relações entre iniciação científica e aspectos socioeducacionais, acadêmicos e profissionais de egressos da Universidade Federal do Paraná
Orientador: Prof. Dr. Cícero Aparecido BezerraCoorientadora: Prof.ª Dr.ª Rafaela Mantovani FontanaTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Sociais Aplicadas, Programa de Pós-Graduação em Gestão da Informação. Defesa : Curitiba, 04/05/2022Inclui referênciasResumo: A Iniciação Científica (IC) propicia o contato prematuro de discentes com o ambiente científico das universidades e possui papel estratégico na formação de alunos e na renovação de recursos humanos qualificados, seja para a pesquisa ou mesmo para o mercado de trabalho. Esta tese tem como objetivo analisar alunos egressos da Universidade Federal do Paraná (UFPR) entre os anos de 2005 a 2020, considerando caracerísticas dos escopos socioeducacional, acadêmico, científico e profissional, estabelecendo comparações e verificando diferenças conforme a participação na atividade de IC. Parte-se do pressuposto que a IC não exerce diferença na vida profissional do estudante, limitando os ganhos da atividade para a área científica, com ingresso na pós-graduação e publicação de artigos. Metodologicamente, o estudo possui natureza quantitativa, com dados coletados de múltiplas fontes. Informações socioeducacionais, acadêmicas e de participações em IC foram obtidas das próprias bases da UFPR - Sistema Integrado de Ensino (SEI), Núcleo de Concursos (NC) e Sistema de Iniciação Científica e Tecnológica (SICT). Para informações científicas de ingresso em pós-graduação e publicações, foram colhidos dados da plataforma Currículo Lattes, enquanto os dados profissionais foram selecionados da Relação Anual de Informações Sociais (RAIS). Para atingir o objetivo do estudo, técnicas estatísticas bivariadas e análise de correspondência múltipla foram empregadas em 37.516 egressos da UFPR - 8.133 com IC, 29.383 sem IC - de modo a identificar as características e diferenças entre os grupos IC x Sem IC, e validar protocolo de pesquisa e tese apresentadas. Os resultados apontaram que: i) no escopo socioeducacional, egressos que participaram da IC foram ligeiramente mais jovens; predominantemente do sexo feminino; demonstraram menor interesse em participar de atividades profissionais em tempo integral durante o curso; e apresentaram melhor desempenho no vestibular; não houve qualquer diferença para variáveis de cota ou raça; ii) no âmbito acadêmico, egressos com IC possuíram carga horária do curso maior; estiveram associados a cursos do turno matutino; e figuraram de maneira mais intensa nas áreas de Ciências Sociais Aplicadas e Ciências da Saúde; e também apresentaram maior índice de rendimento acadêmico; ii) no escopo científico, os egressos com IC apresentaram maior encaminhamento para cursos de pós-graduação stricto sensu e lato sensu, e médias maiores para todas as variáveis de publicações analisadas, tanto durante a graduação como após este período; iv) nas variáveis profissionais, houve maior empregabilidade ao longo dos anos para egressos sem IC; ao observar a empregabilidade para a área de docência, os percentuais foram maiores para os alunos IC; em todas as variáveis envolvendo a remuneração, não houve padrão que pudesse postar um grupo de maneira favorável ou mesmo de destaque em relação ao outro. Os resultados fortalecem a ideia de que os benefícios propiciados pela IC se encontram principalmente para a área científica dos estudantes egressos, com destaque no encaminhamento para a pós-graduação e publicações.Abstract: Undergraduate Research (UR) provides early contact of the students with the scientific environment of the universities and plays a strategic role in the training of students and the renewal of qualified human resources, whether for research or even for the labor market. This thesis aims to analyze students from the Federal University of Parana (UFPR) between the years 2005 to 2020, considering characteristics of the socio-educational, academic, scientific and professional scopes, establishing comparisons and verifying differences according to the participation in the UR activity. It is assumed that UR makes no difference in the student's academic and professional life, limiting the gains from the activity for the scientific area, with admission to graduate studies and publication of articles. Methodologically, the study has a quantitative nature, where data were collected from multiple sources. Socio-educational, academic and participation information in UR were collected from the UFPR's own bases - Integrated Teaching System (SEI), Contests Center (NC) and Scientific and Technological Initiation System (SICT). For graduate scientific information and publications, data were collected from the Curriculum Lattes platform, while professional data were selected from the Annual Social Information List (RAIS). To achieve the objective of the study, bivariate statistical techniques and multiple correspondence analysis were used in the 37,516 undergraduates of UFPR - 8.133 with UR, 29.383 without UR - in order to identify the characteristics and differences between the UR students gruoup vs No UR students grouo, and validate the research protocol and thesis presented. The results showed that: i) in the socio-educational scope, graduates who participated in the IC were slightly younger; predominantly female; showed less interest in participating in full-time professional activities during the course; and showed better performance in the entrance exam; there was no difference for quota or race variables; ii) in the academic sphere, graduates with UR had a higher course load; were associated with morning shift courses; and figured more intensely in the areas of Applied Social Sciences and Health Sciences; and also had a higher academic performance index; iii) in the scientific scope, UR graduates showed greates fowarding to stricto sensu and lato sensu graduate courses, and higher averages for all variables of analyzed publications, both during graduation and after this period; iv) in the professional variables, there was greater employability over the years for graduates without UR; when observing the employability for teaching in higher education, the percentages were higher for UR students; in all variables involving remuneration, there was no pattern that could place a group in a favorable way or even prominently in relation to the other. The results strengthen the idea that the benefits provided by the UR are mainly for the scientific area of the graduating st dents, with emphasis on the referral to postgraduate studies and publications
Toward a new generation of photonic devices based on the integration of metal oxides in silicon technology
[ES] La búsqueda de nuevas soluciones e ideas innovadoras en el campo de la fotónica de silicio mediante la integración de nuevos materiales con prestaciones únicas es un tema de alta actualidad entre la comunidad científica en fotónica y con un impacto potencial muy alto. Dentro de esta temática, esta tesis pretende contribuir hacia una nueva generación de dispositivos fotónicos basados en la integración de óxidos metálicos en tecnología de silicio. Los óxidos metálicos elegidos pertenecen a la familia de óxidos conductores transparentes (TCO), concretamente el óxido de indio y estaño (ITO) y el óxido de cadmio (CdO), y materiales de cambio de fase (PCM) como el dióxido de vanadio (VO2). Dichos materiales se caracterizan especialmente por una variación drástica de sus propiedades optoelectrónicas, tales como la resistividad o el índice de refracción, frente a un estímulo externo ya sea en forma de temperatura, aplicación de un campo eléctrico o excitación óptica. De esta forma, nuestro objetivo es diseñar, fabricar y demostrar experimentalmente nuevas soluciones y dispositivos clave tales como dispositivos no volátiles, desfasadores y dispositivos con no linealidad óptica. Tales dispositivos podrían encontrar potencial utilidad en diversas aplicaciones que comprenden las comunicaciones ópticas, redes neuronales, LiDAR, computación, cuántica, entre otros. Las prestaciones clave en las que se pretende dar un salto disruptivo son el tamaño y capacidad para una alta densidad de integración, el consumo de potencia, y el ancho de banda.[CA] La recerca de noves solucions i idees innovadores al camp de la fotònica de silici mitjançant la integració de nous materials amb prestacions úniques és un tema d'alta actualitat entre la comunitat científica en fotònica i amb un impacte potencial molt alt. D'aquesta temàtica, aquesta tesi pretén contribuir cap a una nova generació de dispositius fotònics basats en la integració d'òxids metàl·lics en tecnologia de silici. Els òxids metàl·lics elegits pertanyen a la família d'òxids conductors transparents (TCO), concretament l'òxid d'indi i estany (ITO) i l'òxid de cadmi (CdO), i materials de canvi de fase (PCM) com el diòxid de vanadi (VO2). Aquests materials es caracteritzen especialment per una variació dràstica de les propietats optoelectròniques, com ara la resistivitat o l'índex de refracció, davant d'un estímul extern ja siga en forma de temperatura, aplicació d'un camp elèctric o excitació òptica. D'aquesta manera, el nostre objectiu és dissenyar, fabricar i demostrar experimentalment noves solucions i dispositius clau com ara dispositius no volàtils, desfasadors i dispositius amb no-linealitat òptica. Aquests dispositius podrien trobar potencial utilitat en diverses aplicacions que comprenen les comunicacions òptiques, xarxes neuronals, LiDAR, computació, quàntica, entre d'altres. Les prestacions clau en què es pretén fer un salt disruptiu són la grandària i la capacitat per a una alta densitat d'integració, el consum de potència i l'amplada de banda.[EN] The search for new solutions and innovative ideas in the field of silicon photonics through the integration of new materials featuring unique optoelectronic properties is a hot topic among the photonics scientific community with a very high potential impact. Within this topic, this thesis aims to contribute to a new generation of photonic devices based on the integration of metal oxides in silicon technology. The chosen metal oxides belong to the family of transparent conducting oxides (TCOs), namely indium tin oxide (ITO) and cadmium oxide (CdO), and phase change materials (PCMs) such as vanadium dioxide (VO2). These materials are characterized by a drastic variation of their optoelectronic properties, such as resistivity or refractive index, in response to an external stimulus either in the form of temperature, application of an electric field, or optical excitation. Therefore, our objective is to design, fabricate and experimentally demonstrate new solutions and key devices such as non-volatile devices, phase shifters, and devices with optical nonlinearity. Such devices could find potential utility in several applications, including optical communications, neural networks, LiDAR, computing, and quantum. The key features in which we aim to take a leapfrog are footprint and capacity for high integration density, power consumption, and bandwidth.This work is supported in part by grants ACIF/2018/172 funded by Generaliltat Valenciana, and FPU17/04224 funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”.Parra Gómez, J. (2022). Toward a new generation of photonic devices based on the integration of metal oxides in silicon technology [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/19088
Proceedings of the 9th Arab Society for Computer Aided Architectural Design (ASCAAD) international conference 2021 (ASCAAD 2021): architecture in the age of disruptive technologies: transformation and challenges.
The ASCAAD 2021 conference theme is Architecture in the age of disruptive technologies: transformation and challenges. The theme addresses the gradual shift in computational design from prototypical morphogenetic-centered associations in the architectural discourse. This imminent shift of focus is increasingly stirring a debate in the architectural community and is provoking a much needed critical questioning of the role of computation in architecture as a sole embodiment and enactment of technical dimensions, into one that rather deliberately pursues and embraces the humanities as an ultimate aspiration
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