Dissertationen zum Thema „FIDO2“

En cette ère numérique, l’utilisation des documents papier s’avère peu pratique et inefficace, ce qui motive les sociétés à évoluer vers l’utilisation des documents électroniques (ou e-docs). Ce désir d’innover vers une opération sans papier peut améliorer l’efficacité et la qualité des services d’administrations publiques ou privées de manière à accélérer leurs activités et en même temps mieux satisfaire les besoins des clients. Cependant, cette pratique a créé des nouveaux besoins, tels que la signature numérique réelle de documents. Dans ce mémoire, nous avons proposé un nouveau schéma de signature numérique utilisant FIDO2, qui se trouve être une nouvelle norme d’authentification sécurisée en ligne basée sur la signature numérique. Le fait que FIDO2 soit un standard libre permet aux développeurs de logiciel et de matériel d’implémenter plus facilement leurs propres produits. Cela nous a inspiré à l’utiliser pour une fin de signature numérique, l’idée étant de remplacer le défi envoyé par le serveur avec le hash de e-docs et de l’envoyer à l’appareil du signataire afin que ce dernier signe avec sa clé privée. Comme dans le cas de l’infrastructure à clé publique, chaque utilisateur possédait une paire de clés, c’est-à-dire une clé privée et une clé publique. Un signataire doit confirmer son identification biométrique (empreinte digitale, reconnaissance faciale, voix, etc.) ou son code PIN pour accéder à la clé privée stockée localement sur son appareil et signer un document. Au cours de notre recherche, nous avons effectué plusieurs tests avec différents équipements (PC, USB FIDO, Smartphone) ainsi que différentes OS (Android, iOS, Windows). Les résultats de nos tests nous montrent que nous pouvons utiliser FIDO2 pour signer un document électronique. Cette nouvelle approche proposée peut être utilisée pour une signature face à face (en locale) ou à distance (en ligne). Le prototype développé pour la mise en œuvre de notre approche a été validé auprès d’usagers types (membres clients et conseillers) dans une entreprise.<br>In this digital era, the use of paper documents is impractical and inefficient, which motivates companies to move towards the use of electronic documents (or e-docs). This desire to innovate towards a paperless operation can improve the efficiency and quality of public or private administration services so as to speed up their activities and at the same time better meet customer needs. However, this practice has created new needs, such as the actual digital signature of documents. In this thesis, we have proposed a new digital signature scheme using FIDO2, which happens to be a new standard for secure online authentication based on digital signatures. The fact that FIDO2 is a free standard makes it easier for software and hardware developers to implement their own products. This inspired us to use it a digital signature purpose, the idea being, to replace the challenge sent by the server with the hash of e-docs and send it to the signer’s device so that the latter signs with his private key. As with public key infrastructure, each user had a key pair, that is, a private key and a public key. A signatory must confirm their biometric identification (fingerprint, facial recognition, voice, etc.) or PIN code to access the private key stored locally on their device and sign a document. During our research, we carried out several tests with different equipment (PC, USB FIDO, Smartphone) as well as different OS (Android, iOS, Windows). The results of our tests show us that we can use FIDO2 to sign an electronic document. This proposed new approach can be used for a face-to-face (local) or remote (online) signature. The prototype developed for the implementation of our approach has been validated with typical users (member-clients and advisers) in a company.

The use of passwords for user authentication has significant shortcomings. As society becomes more dependent on the internet and web services, we need to find a replacement authentication method that users are willing to use. WebAuthn is one potential technology for password replacement. Recent studies have shown that users enjoy the usability of WebAuthn and hardware tokens as a password replacement but don't want to carry them around. Meanwhile, little to no research involves the use of software tokens. I carried out a user study of WebAuthn and roaming software tokens when used as a password replacement. We were able to learn if the shortcoming of WebAuthn and hardware tokens were remedied by the use of smart phones as software tokens. Software tokens have similiar usability to hardware tokens and are more usable than passwords. Users continued fearing loss of access to their account when using software tokens. Users were less worried about carrying an extra device but replaced that fear with the fear of a dead battery or a broken phone.

Cieľom systému Excalibur je presunúť autentifikáciu od hesiel používaných v súčastnosti ku bezheslovej budúcnosti. Zámerom tejto práce je integrácia systému Excalibur s webovými bezheslovými protokolmi SAML a FIDO2.    Štandard SAML bol integrovaný do systému Excalibur a úspešne otestovaný s niekoľkými známymi aplikáciami. Excalibur má na starosti samotnú autentifikáciu a manažment používateľov a SAML je použitý na predanie týchto informácii aplikáciam tretích strán.   FIDO2 je, na druhú stranu, kompletný autentifikačný štandard, ktorý môže byť do systému Excalibur integrovaný viacerými spôsobmi. Ako najsľubnejší spôsob sa javí výmena autentifikačného mechanizmu systému Excalibur za FIDO2, ale slabá podpora štandardu a chýbajúce funkcie to zatiaľ nedovoľujú.

"The National Aeronautics and Space Administration (NASA) plans to send a human exploration team to Mars within the next 25 years. In support of this effort Hamilton Standard Space Systems International (HSSSI), current manufacturers of the Space Shuttle spacesuit, began exploring alternative solutions for supporting an astronaut during a Martian surface exploration. A design concept was developed by HSSSI to integrate a minimally equipped Martian spacesuit with a robotic support cart capable of providing life support assistance, communications, and independent navigational functions. To promote NASA's visionary efforts and increase university relations, HSSSI partnered with Worcester Polytechnic Institute (WPI) to develop a proof-of-concept robotic support cart system, FIDOE - Fully Independent Delivery of Expendables. As a proof-of-concept system, the primary goal of this project was to demonstrate the feasibility of current technologies utilized by FIDOE's communication and controls system for future Martian surface explorations. The primary objective of this project was to procure selected commercial-off-the-shelf components and configure these components into a functional robotic support cart. The design constraints for this project, in addition to the constraints imposed by the Martian environment and HSSSI's Martian spacesuit, were a one-year time frame and a $20,000 budget for component procurement. This project was also constrained by the protocols defined by the NASA demonstration test environment. The final design configuration comprised of 37 major commercial off-the-shelf components and three individual software packages that integrated together to provide FIDOE's communications and control capabilities. Power distribution was internally handled through a combination of a main power source and dedicated power supplies. FIDOE also provided a stowage area for handling assisted life support systems and geological equipment. The proof-of-concept FIDOE system proved that the current technologies represented by the selected components are feasible applications for a Mars effort. Specifically, the FIDOE system demonstrated that the chosen technologies can be integrated to perform assisted life support and independent functions. While some technologies represented by the proof-of-concept system may not adequately address the robustness issues pertaining to the Mars effort, e.g., voice recognition and power management, technology trends indicate that these forms of technology will soon become viable solutions to assisting an astronaut on a Martian surface exploration."

Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2007.<br>Title from electronic title page (viewed Dec. 18, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Music." Discipline: Music; Department/School: Music.

Objetivo: Evaluar el rendimiento del APPS para la predicción de mortalidad a los 28 días en pacientes con diagnóstico de síndrome de distrés respiratorio agudo en una unidad de cuidados intensivos en una clínica privada peruana. Diseño: Cohorte retrospectiva. Se recolectarán los datos de manera retrospectiva de pacientes atendidos desde el 6 de Marzo de 2020 hasta Mayo de 2021, periodo comprendido dentro de la pandemia por SARS-CoV-2 en el Perú.

Odours are emitted from numerous sources and can form a natural part of the environment. The sources of odour range from natural to industrial sources and can be perceived by the community dependant upon a number of factors. These factors include frequency, intensity, duration, offensiveness and location (FIDOL). Or in other words how strong an odour is, at what level it becomes detectable, how long it can be smelt for, whether or not the odour is an acceptable or unacceptable smell as judged by the receptor (residents) and where the odour is smelt. Intensive livestock operations cover a wide range of animal production enterprises, with all of these emitting odours. Essentially, intensive livestock in Queensland, and a certain extent Australia, refers to piggeries, feedlots and intensive dairy and poultry operations. Odour emissions from these operations can be a significant concern when the distance to nearby residents is small enough that odour from the operations is detected. The distance to receptors is a concern for intensive livestock operations as it may hamper their ability to develop new sites or expand existing sites. The piggery industry in Australia relies upon anaerobic treatment to treat its liquid wastes. These earthen lagoons treat liquid wastes through degradation via biological activity (Barth 1985; Casey and McGahan 2000). As these lagoons emit up to 80 per cent of the odour from a piggery (Smith et al., 1999), it is imperative for the piggery industry that odour be better quantified. Numerous methods have been adopted throughout the world for the measurement of odour including, trained field sniffers, electronic noses, olfactometry and electronic methods such as gas chromatography. Although these methods all have can be used, olfactometry is currently deemed to be the most appropriate method for accurate and repeatable determination of odour. This is due to the standardisation of olfactometry through the Australian / New Zealand Standard for Dynamic Olfactometry and that olfactometry uses a standardised panel of "sniffers" which tend to give a repeatable indication of odour concentration. This is important as often, electronic measures cannot relate odour back to the human nose, which is the ultimate assessor of odour. The way in which odour emission rates (OERs) from lagoons are determined is subject to debate. Currently the most commonly used methods are direct and indirect methods. Direct methods refer to placing enclosures on the ponds to measure the emissions whereas indirect methods refer to taking downwind samples on or near a pond and calculating an emission rate. Worldwide the odour community is currently divided into two camps that disagree on how to directly measure odour, those who use the UNSW wind tunnel or similar (Jiang et al., 1995; Byler et al., 2004; Hudson and Casey 2002; Heber et al., 2000; Schmidt and Bicudo 2002; Bliss et al., 1995) or the USEPA flux chamber (Gholson et al., 1989; Heber et al., 2000; Feddes et al., 2001; Witherspoon et al., 2002; Schmidt and Bicudo 2002; Gholson et al., 1991; Kienbusch 1986). The majority of peer reviewed literature shows that static chambers such as the USEPA flux chamber under predict emissions (Gao et al., 1998b; Jiang and Kaye 1996) and based on this, the literature recommends wind tunnel type devices as the most appropriate method of determining emissions (Smith and Watts 1994a; Jiang and Kaye 1996; Gao et al., 1998a). Based on these reviews it was decided to compare the indirect STINK model (Smith 1995) with the UNSW wind tunnel to assess the appropriateness of the methods for determining odour emission rates for area sources. The objective of this project was to assess the suitability of the STINK model and UNSW wind tunnel for determining odour emission rates from anaerobic piggery lagoons. In particular determining if the model compared well with UNSW wind tunnel measurements from the same source; the overall efficacy of the model; and the relationship between source footprint and predicted odour emission rate.

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No. of bitstreams: 1 silva_hra_me_jabo.pdf: 1516889 bytes, checksum: bfa8ae71c54b032d16f1d405cbf9c519 (MD5) Previous issue date: 2016-07-27<br>Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)<br>Avaliaram-se os efeitos de diferentes concentrações do óxido nitroso (N2O) e oxigênio, sobre os índices de lactato sérico, glicemia e características do hemograma, em suínos anestesiados com propofol e mantidos em ventilação espontânea ou controlada a pressão associada ou não à PEEP. Para isso, 48 animais machos ou fêmeas, foram distribuídos aleatoriamente em seis grupos, denominados, GN10 (FiO2 a 90% e N2O a 10%), GA10 (FiO2 a 90% e ar comprimido a 10%), GN30 (FiO2 a 70% e N2O a 30%), GA30 (FiO2 a 70% e ar comprimido a 30%), GN50 (FiO2 a 50% e N2O a 50%) e GA50 (FiO2 a 50% e ar comprimido a 50%). Empregou-se, como medicação pré-anestésica azaperona (2 mg/kg por via intramuscular), indução anestésica com propofol (dose efeito) bem como manutenção anestésica (0,5 mg/kg/min). Após a intubação o traqueotubo foi acoplado ao aparelho de anestesia inalatória para fornecimento das misturas de gases preconizadas para cada grupo. Após 100 minutos da indução anestésica, foi administrado por via intravenosa rocurônio (0,6 mg/kg IV), seguido de infusão contínua (0,6 mg/kg/hora) e inciou-se a ventilação controlada a pressão (15 cmH2O). A primeira amostra sanguínea foi coletada 20 minutos decorridos da aplicação da azaperona e imediatamente antes da indução anestésica (M0). Após 40 minutos, nova amostra de sangue foi obtida (M1), seguida de mais três colheitas decorridos 100, 175 e 220 minutos da indução da anestesia, tempos estes que coincidiram com o início da ventilação mecânica (M2), início da PEEP (M3) e final do experimento (M4), respectivamente. Todas as amostras foram acondicionadas em microtubos contendo Fluoreto de Na ou EDTA. Os dados foram submetidos à análise de variância (ANOVA) para avaliar e comparar os valores médios, utilizando o procedimento de Tukey, sendo considerado significativo valor de P<0,05. Os resultados revelaram diferenças estatísticas entre momentos e entre grupos nas variáveis hematológicas (Ht, He, Hb, plaquetas, Leucócitos Totais, EOS, NB, NS, Linf) glicemia e lactato.<br>This study evaluated the effects of different concentrations of nitrous oxide (N2O) and oxygen, on seric level of lactate, glycemia and hematological dynamic, in propofol-anesthetized pigs under spontaneous breathing or in pressure-controlled ventilation with or without PEEP. For this, forty eight animals, males or females, were randomly divided into six groups: GN10 (FiO2 = 90% and N2O = 10%), GA10 (FiO2 = 80% and air = 10%), GN30 (FiO2 = 70% and N2O = 30%), GA30 (FiO2 = 70% and air = 30%), GN50 (FiO2 = 50% and N2O = 50%), GA50 (FiO2 = 50% and air = 50%). Azaperone was administered (2.0 mg/kg IM) as premadication. The induction was performed with propofol at sufficient doses to endotracheal intubation and for the maintenance of anesthesia, the same anesthesic were used (0.5 mg/kg/min). After 100 minutes of the induction, were administered rocuronium (0.6 mg/kg IV) followed by continuous infusion (0.6 mg/kg/h) and started mechanical ventilation (15 cmH2O). Were coleted blood samples in the first moment (M0), twenty minutes after azaperone administration. After forty minutes new blood sample were obtained (M1), followed by three more harvest past 100, 175 and 220 minutes after anesthesia induction (M2, M3 and M4 respectively). The samples were condition in microtubes with sodium fluoride or EDTA. Repeated measures analyses of variance was the statistical method used to evaluate pair wise comparisons of mean were mode, using Tukey’s procedure. A P value <0,05 was considered significant. Among the main changes were between groups and moments in HT, RBC, HGB, platelets, WBC, EOS, NS, Lymph, glucose blood and lactate.<br>FAPESP: 2013/25655-0

Orientador: Newton Nunes<br>Banca: Danielli Parrilha de Paula<br>Banca: Roberto Thiesen<br>Resumo: Com esse estudo procurou-se avaliar comparativamente a anestesia total intravenosa pelo propofol e a anestesia geral inalatória pelo isofluorano e determinar qual modalidade anestésica foi mais vantajosa à dinâmica cardiorrespiratória, bem como sobre parâmetros intracranianos, em suínos recebendo FiO2 de 0,5 sob ventilação espontânea. Para tanto foram utilizados 16 animais machos ou fêmeas, distribuídos aleatoriamente em dois grupos de igual número: GI (Isofluorano e FiO2=0,5) e GP (Propofol e FiO2=0,5). Para todos os suínos, empregou-se como medicação pré-anestésica azaperona (2 mg/kg). Em ambos os grupos, os animais foram induzidos com propofol pela via intravenosa, na dose necessária para intubação orotraqueal. No grupo GI, após a intubação orotraqueal dos animais, o vaporizador foi ajustado para 1,5 CAM. No grupo GP, a manutenção anestésica foi realiza com propofol na taxa de 0,5 mg/kg/min. Em ambos os grupos, os parâmetros hemodinâmicos, ventilatórios e intracranianos foram avaliados 40 minutos após a indução da anestesia (M0), seguida de novas mensurações em intervalos de 15 minutos (de M15 a M60). Os resultados das variáveis paramétricas foram analisados pelo software SAS 9.1 (2010). De todos os parâmetros avaliados, houve diferença entre grupos nas variáveis respiratórias (PvO2, Hbv, ETCO2, f, Vt e Tins), cardiovasculares (PAS e IRPT) e intracranianos (PIC, PPC e TIC). Com relação aos momentos dentro do mesmo grupo, houve diferença no GI para as variáveis respiratória... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: The aim of the present study was to compare the cardiorrespiratory dynamics as well as the intracranial parameters of piglets anesthetized with either total intravenous anesthesia with propofol or inhalation anesthesia with isoflurane and receiving FiO2 of 0,5 and kept under spontaneous ventilation. To that purpose, sixteen animals, males or females, were randomly divided into two groups: GI (Isoflurane and FiO2=0,5) and GP (Propofol and FiO2=0,5). For all pigs, azaperone (2 mg/kg) was used as premedication. In both groups, the animals were induced with intravenous administration of propofol, at the required dose for endotracheal intubation. In GI, after endotracheal intubation, the vaporizer was adjusted to 1.5 MAC. In GP, the maintenance of anesthesia was performed with constant rate infusion of propofol, at rate of 0,5 mg/kg/min. In both groups, hemodynamic, ventilatory and intracranial parameters were evaluated 40 minutes after anesthetic induction (M0), followed by 15-minutes intervals (M15 to M60). The results of parametric variables were analyzed by SAS 9.1 software (2010). In all parameters, there were differences between groups in the respiratory (PvO2, Hbv, PETCO2, f, Vt and Tins), cardiovascular (SBP and TPRI) and intracranial variables (ICP, CPP and ICT). Regarding moments in the same group, there were differences in GI in the respiratory (PaCO2, pH, PvO2, ETCO2, Vm, PAO2 and P(A-a)O2) and intracranial variables (TIC). In GP, significantly differed the pH, PvCO2, ... (Complete abstract click electronic access below)<br>Mestre

Minor utgör ett hot mot civilbefolkningen men även personal i fredsfrämjande insatser riskerar att skadas av minorna under patruller i insatsområdet. Idag används minhunden i Försvarsmakten för att lokaliera minor i kombination med minpik och metalldetektor. Hunden har sina begränsningar och har under flera perioder varit på väg att fasas ut till förmån för tekniken. Minans doftbild, minhunden och den elektroniska nosen beskrivs och mynnar ut i en analys där för-/nackdelar presenteras och därefter diskuteras. Den militära nyttan i den militära kontexten, insats med undsättningsstyrka (MRT) utgör ramverk i uppsatsen. Vid en undsättningsinsats med MRT är det av största vikt att minorna kan lokaliseras, märkas ut och undvikas. Hunden har förmåga till lokalisering av minor vilket den elektroniska nosen Fido saknar. Minornas doftbild överlappar varandra. Fido kan inte särskilja minorna från varandra utan endast bekräfta förekomst i ett område vilket inte bidrar till den militära nyttan när en fri väg ska sökas fram till en skadeplats.<br>Landmines pose a threat to the civilian population but personnel in peacekeeping operations could also be harmed by landmines during patrols in the area. Today the Swedish Armed Forces use mine detection dogs to locate landmines. The mine detection dogs are used in combination with prodders and metal detectors. The dogs have their limitations and there have been several attempts to phase them out and replace them with technology. Substances detected by dogs and electronic noses, the mine detection dog and the electronic dog nose Fido are described and incorporated in an analysis where advantages/disadvantages are presented and then discussed. Military utility in a military context constitute the frame of the essay. The military context is an operation with a mine rescue team to rescue an injured person in a mine field. In a rescue operation with a mine rescue team the most important thing is to locate, mark and avoid the landmines. The dog can locate landmines but the electronic nose Fido cannot. The chemical signatures from the landmines overlap each other making it difficult for Fido to pinpoint the exact location. Fido can confirm the presence of landmines in an area which does not have military utility during mine rescue team operations to find a free path and rescue an injured person out from a minefield.

INTRODUÇÃO: O desenvolvimento de colapso pulmonar (atelectasia) durante anestesia geral com ventilação mecânica é frequente, podendo determinar hipoxemia e contribuir para desenvolvimento de outras complicações pós-operatórias, como infecção e síndrome do desconforto respiratório agudo (SDRA). O uso de fração inspirada de oxigênio (FIO2) baixa e de pressão expiratória final positiva (PEEP) podem reduzir a quantidade de pulmão atelectasiado. Existem poucos dados experimentais sobre a cinética do desenvolvimento da atelectasia no intraoperatório em diferentes ajustes de FIO2 e PEEP no decorrer do tempo. A Tomografia de impedância elétrica (TIE) do tórax permite uma análise contínua e não invasiva da função pulmonar, bem como da quantificação do colapso e pode ser usada no intraoperatório. OBJETIVOS: a) avaliar, em animais com pulmões sadios durante anestesia geral, o efeito do uso de uma PEEP individualizada escolhida através da TIE (\"PEEP titulada\"), na formação de colapso; b) analisar a magnitude e a cinética de desenvolvimento do colapso pulmonar no decorrer do período de uma hora em dois valores de FIO2 (0,4 e 1) e dois valores de PEEP (3 cmH2O e valor da PEEP titulada) através da TIE e Tomografia computadorizada (TC); c) analisar mecânica, ventilação regional e aeração pela TIE e troca gasosa nos diferentes períodos do estudo. MÉTODOS: Nove animais (suínos) com pulmão normal foram submetidos à manobra de titulação da PEEP para escolha da PEEP que determina colapso pulmonar mínimo (colapso menor que 3% determinado pela TIE, denominada \"PEEP titulada\") e posteriormente ventilados com volume corrente de 6ml/Kg em quatro ajustes, em sequência randomizada, por um período de 1 hora: FIO2 0,4 e PEEP 3, FIO2 0,4 e PEEP titulada, FIO2 1 e PEEP 3 e FIO2 1 e PEEP titulada. O colapso, ventilação regional e aeração foram medidos continuamente, através da TIE assim como dados da mecânica. Mensuramos troca gasosa e aeração pulmonar pela TC em 3 momentos em cada período do estudo (baseline, 5 e 50 minutos). RESULTADOS: A PEEP titulada foi de 11,6 ±1,4 cm H2O. Houve colapso progressivo no decorrer do tempo nos 4 grupos estudados tendo sido maior na PEEP 3 que na PEEP titulada. A medida do colapso pela TIE não foi influenciada pela FIO2 utilizada, ao contrário da mensuração pela TC na qual o colapso foi maior na FIO2 de 1. Houve queda da complacência pulmonar e aumento da pressão de distensão no decorrer do tempo, maiores na PEEP 3, sem influência da FIO2. Na região dorsal, a TIE evidenciou redução da ventilação (delta Z) na PEEP 3, sem influência da FIO2, e, também, redução da aeração (mínimo Z) que foi maior na PEEP 3 e na FIO2 de 1. Houve queda da relação PaO2/FIO2 e aumento do shunt e mistura venosa na PEEP 3. Não houve alterações hemodinâmicas clinicamente relevantes durante o estudo. CONCLUSÕES: Houve colapso progressivo no decorrer do tempo, sendo maior na PEEP 3 que na PEEP titulada. O colapso aferido pela TC foi maior na FIO2 de 1 do que na 0,4 para uma mesma PEEP, diferente da TIE cuja estimativa de colapso não foi diferente. Paralelamente houve queda da complacência pulmonar, aumento da pressão de distensão e redução da ventilação dorsal, maiores na PEEP 3 e sem influência da FIO2. A queda da aeração estimada pela TIE foi maior na PEEP 3, sendo que nas duas PEEP a aeração foi menor na FIO2 de 1<br>INTRODUCTION: The development of pulmonary collapse (atelectasis) during general anesthesia with mechanical ventilation is frequent, which can determine hypoxemia and contribute to the development of other postoperative complications, such as infection and acute respiratory distress syndrome (ARDS). The use of low fraction of inspired oxygen (FIO2) and positive end expiratory pressure (PEEP) may reduce the amount of collapsed lung. There are few experimental data on the kinetics of intraoperative atelectasis development in different FIO2 and PEEP adjustments over time. Electrical impedance tomography (EIT) of the thorax allows a continuous and noninvasive analysis of pulmonary function as well as the quantification of pulmonary atelectasis and can be used intraoperatively. OBJECTIVES: a) to evaluate, in animals with healthy lungs during general anesthesia, the effect of the use of an individualized PEEP chosen through EIT (titrated PEEP), in the formation of collapse; b) to analyze the magnitude and development kinetics of pulmonary collapse during the one-hour period in two values of FIO2 (0.4 and 1) and two PEEP values (3 cmH2O and titrated PEEP value) through EIT and computed tomography (CT); c) to analyze mechanics, regional ventilation and aeration by EIT and gas exchange in the different periods of the study. METHODS: Nine animals (swine) with normal lung were submitted to a PEEP titration maneuver to select PEEP that determines minimal pulmonary collapse (collapse of less than 3% determined by EIT, called \"titrated PEEP\") and then ventilated with a tidal volume of 6ml / kg in four adjustments, in a randomized sequence, for a period of 1 hour: FIO2 0.4 and PEEP 3, FIO2 0.4 and titrated PEEP, FIO2 1 and PEEP 3 and FIO2 1 and titrated PEEP. The collapse, regional ventilation and aeration were measured continuously through EIT as well as mechanics data. We also measured gas exchange and aeration by CT at 3 times in each study period (baseline, 5 e 50 minutes). RESULTS: The titrated PEEP was 11.6 ±1.4 cm H2O. There was a progressive collapse over time in the 4 groups studied, having been higher in PEEP 3 than in titrated PEEP. The measurement of EIT collapse was not influenced by the FIO2 used, as opposed to the CT measurement in which the collapse was greater in the FIO2 1. There was a decrease in pulmonary compliance and an increase in drive pressure over time, higher in PEEP 3, without influence of FIO2. In the dorsal region, EIT showed a decrease in ventilation, as measured by delta Z, in PEEP 3, with no influence of FIO2; there was also reduction of aeration, measured by the minimum Z, higher in PEEP 3 and FIO2 of 1. There was a decrease in the PaO2 / FIO2 ratio and increased in shunt and venous admixture in PEEP 3. There was no clinically relevant change in hemodynamics during the study. CONCLUSIONS: There was a greater collapse in PEEP 3 than in titrated PEEP over time. Collapse measured by CT was higher in FIO2 of 1 than 0.4 for the same PEEP, different from EIT estimates of collapse which was not different. Beside the collapse, there were decrease in compliance, increase in driving pressure and reduction of dorsal ventilation, higher in PEEP 3 without FIO2 influence. The decrease of aeration estimated by EIT was higher in PEEP 3 and for both PEEP values aeration was lower with FIO2 of 1

El uso de la ventilación no invasiva (VNI) en pacientes con fracaso respiratorio hipoxémico debido a neumonía es controvertido, alcanzando elevadas tasas de fracaso en el Síndrome de Distrés Respiratorio Agudo (SDRA). Recientemente, el cociente SpO2/FiO2 (SF) se ha equiparado al cociente paO2/FiO2 (PF) para la valoración del SDRA. Determinamos en una cohorte de pacientes, diagnosticados de neumonía y tratados con VNI, si el cociente SF es una variable con valor predictor de fracaso durante las primeras horas y clasificamos mediante dicho cociente el SDRA según la última definición de Berlín (leve, moderado, grave) para identificar aquellos pacientes de mayor riesgo. La tasa global de éxito de la VNI fue del 77%. Tanto el cociente SF como la FC a las 2h se identificaron como factores predictores independientes de fracaso. El diagnóstico de SDRA mediante el cociente SF, podría utilizarse para identificar a una población más susceptible de fracaso.<br>The use of non-invasive ventilation (NIV) in patients with hypoxemic acute respiratory failure (ARF) due to pneumonia is discussed. The most frequent cause of ARF was pneumonia and acute respiratory distress syndrome (ARDS) was the main cause of treatment failure. A good correlation between SF ratio (SpO2/FiO2) and PF ratio (paO2/FiO2) was recently confirmed. We aimed to evaluate if the SF ratio is a reliable predictive factor for NIV failure in pediatric patients with moderate hypoxemic ARF due to pneumonia and could classify ARDS according to the recent Berlin definition (mild, moderate and severe) to identify high-risk children. Our NIV success rate was 77%. SF ratio and heart rate at two hours were found to be independent predictors of NIV failure. The diagnosis of ARDS based on the SF ratio was not identified as an independent NIV outcome predictor. However, it may be useful in classifying high-risk children.

How are pets being used as status symbols to display social position and wealth? This paper seeks to theoretically examine pet owners and their use of animals to convey a message of social status, position and wealth. This will be done through an application of theoretical constructs by Veblen, Marx, and Bourdieu and applications to concepts of consumerism, status, commodities and distinction. While the human-animal relationship has been investigated in terms of the human benefits of physical and mental health, stress reduction, child surrogacy, loneliness reduction and more, there have been fewer investigations of pets as social status symbols. This thesis creates a more inclusive theoretical approach to commodities being used as status symbols. After a historical look at how the function of pets has evolved in relation to humans, the more inclusive theory is applied to real world examples of pets in modern affluent societies such as pet luxury items, designer breeds, market segmentation, and mass availability of those products.

碩士<br>國立臺灣大學<br>電子工程學研究所<br>104<br>With the popularity of mobile phones and tablets, more and more people surf the Internet with mobile devices. When users log in a website, in contrast to using traditional PCs, typing the password is very troublesome on mobile phones. However, the most commonly used authentication is still password-based. Thus, users usually record their password on browsers or apps after the first login. These security issues become apparent on mobile devices. Apart from using ”password”, there are several authentication solutions with higher security. For example, adding one-time password or hardware token for two-factor authentication are good choices. Most of those solutions are not adopted because of the cumbersome steps. FIDO Alliance is formed to address the problems of password and authentication. They develop specification of password-less solution. With biometric device, the ecosystem oflogin is secure and convenient. Users only need to pass identity verification,then they can successfully log in. There are few open resources related to standard published by FIDO except to the official documents. In this thesis, we implement the client part sothat more people can refer to it and pay attention to this issue.

碩士<br>國立臺灣大學<br>電子工程學研究所<br>104<br>Many internet services grow fast in recent decades, such as e-mail, electronic payment and e-commerce. The services bring people a more convenient shopping way. However, the services also come with more security concerns. The level of the security was traditionally only decided by the complexity of a user’s password. To enhance the security, the 2-step verification was introduced. The 2-step verification is to deliver a set of the verification code to the users, and let the users to pass the code back to the server for the identity verification. The common ways for doing the 2-step verification include by SMS, by authenticator application, and by email. As all the ways listed above rely on the operation of other services, FIDO (Fast Identity Online) Alliance [1] proposed a new way called U2F (Universal Second Factor) [2] for the 2-step verification. The U2F verification was based on ECDSA (Elliptic Curve Digital Signature Algorithm) [3] and did not need a user to get the verification code from any other way. This thesis is focus on the implementation of the U2F verification from the server side and the analysis of the verification’s performance.

A oxigenoterapia é amplamente utilizada e tem um papel muito importante no tratamento da hipoxémia. Em Portugal, uma auditoria concluiu que metade dos doentes internados nas enfermarias de Medicina Interna está sob oxigenoterapia. No entanto, foram encontrados vários erros na sua prescrição colocando em risco os doentes. A prescrição por objetivo de intervalo de SpO2, apesar de recomendada nas guidelines da British Thoracic Society, representava ainda a minoria das prescrições. Sendo certo que à prescrição de oxigenoterapia por objetivo de intervalo SpO2 está associado um maior workload por parte dos profissionais de saúde, um dispositivo de ajuste automático de débito ou FiO2 com base em parâmetros clínicos definidos pelo médico, poderia melhorar a eficácia desta terapêutica. Os dispositivos experimentais testados e comparados a métodos convencionais de administração de O2 demonstraram uma maior eficácia em manter a SpO2 dentro dos valores alvo, redução do tempo em hipoxémia, redução do tempo em hiperoxemia, poupança do O2 utilizado, bem como melhor utilização do tempo por parte dos profissionais de saúde. Estes sistemas foram estudados em lactentes e doentes com Doença Pulmonar Obstrutiva Crónica (DPOC) não existindo equipamento testado em ambiente de patologia aguda em doentes adultos. Para além disso, outra limitação prende-se com o facto de só terem sido testados com cânula nasal, havendo, segundo as últimas orientações, situações nas quais outros dispositivos de administração de O2 são mais adequados. Estes sistemas não podem substituir o profissional de saúde. Caberá sempre ao médico determinar o mecanismo que produz a hipoxémia e atuar em conformidade, definindo um intervalo de SpO2 alvo e um intervalo de FiO2 alvo, de acordo com a clínica. Outras questões importantes a ter em conta na implementação de um sistema de oxigenoterapia como o descrito são a ergonomia e a segurança do doente.<br>Oxygen is one of the most widely used drugs being the primary treatment of hypoxemia. Data from a recent audit in Portugal, reported that around 50% of hospitalized patients in Internal medicine wards were receiving oxygen, at any given time. However several errors were found in oxygen therapy procedures, jeopardizing the patients. British Thoracic Society (BTS) recommends that oxygen should be prescribed to a target saturation range rather than prescribing a fixed dose of oxygen or fraction of inspired oxygen. Although recommended, oxygen therapy prescriptions by target SpO2 range were still a minority in portuguese wards. Oxygen Therapy prescription by target SpO2 is associated with an increased workload. An automated O2 flow regulator based on SpO2 readings could improve the adherence. There are some experimental devices that were compared to standard oxygen therapy. These devices showed improvement in maintaining SpO2 in the target range, better O2 savings and reduced workload. Patients also spent less time in hypoxemia, hyperoxemia. These devices were tested in infants and COPD patients. No device was tested in acute setting. Automated systems can’t replace the physician. It will always be up to the doctor to determine the cause behind hypoxaemia and act accordingly, choosing a SpO2 target range and a FiO2 range. Patient safety and comfort should be major concerns.