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This thesis addresses the threat that personal computer faced from malware when the personal computer is connected to the Internet. Traditional host-based security approaches, such as anti-virus scanning protect the host from virus, worms, Trojans and other malwares. One of the issues of the host-based security approaches is that when the operating system is compromised by the malware, the antivirus software also becomes vulnerable. In this thesis, we present a novel approach through using an external device to enhance the host security by offloading the security solution from the host to the external device. We describe the design of the DeviceGuard framework that separate the security solution from the host and offload it to the external device, a Trusted Device. The architecture of the DeviceGuard consists of two components, the DeviceGuard application on the Trusted Device and a DeviceGuard daemon on the host. Our prototype based on Android Development Phone (ADP) shows the feasibilities and efficiency of our approach to provide security features including system file and user data integrity monitoring, secure signing and secure decryption. We use Bluetooth as the communication protocol between the host and the Trusted Device. Our experiment results indicates a practical Bluetooth throughput at about 2M Bytes per second is sufficient for short range communication between the host and the Trusted Device; Message digest with SHA-512, digital signing with 1024 bits signature and secure decryption with AES 256 bits on the Trusted device takes only the scale of 10? and 10? ms for 1K bytes and 1M bytes respectively which are also shows the feasibility and efficiency of the DeviceGuard solution. We also investigated the use of embedded system as the Trusted Device. Our solution takes advantage of the proliferation of devices, such as Smartphone, for stronger system and data security. / Master of Science

Tesis por compendio / Traditionally, Physics laboratory practices have two objectives. On the one hand, students reinforce the concepts that they have acquired in theory lessons. On the other hand, they get used to the experimental techniques. However, students sometimes consider that the practices are routine and of little interest. Several resources, based on Information and Communication Technologies, have been used to deal with this problem. The smartphones of the students themselves incorporate various sensors. Free available applications are able to control the sensors, acquire data and transmit them. The smartphones become measuring tools. The main objective of this Thesis is to propose new experiments for Physics laboratories that take advantage of this way of using smartphones. A collection of works is presented as a set of publications. The acceleration sensor enables us to study: the free and damped oscillations of the smartphone; the normal modes of a coupled two dimensional vibrating system of smartphones; and the mechanical beat. The ambient light sensor is used to analyze the efficiency of several types of optical sources; the dependence of the illuminance on the distance to the source is also studied. Finally, the microphone enables us to characterize the acoustic beat phenomenon. The new experiments are focused on university and high school students. Our surveys show the higher rating given to this type of experiences with respect to their traditional alternatives. / Tradicionalmente, el objetivo de las prácticas de laboratorio de las asignaturas de Física es doble: por una parte, que los estudiantes refuercen los conocimientos adquiridos en las clases de teoría; por otra, que se habitúen a las técnicas experimentales. Sin embargo, los alumnos consideran que en ocasiones las prácticas son rutinarias y poco interesantes. Para paliar este problema, se ha hecho uso de diversos recursos basados en las Tecnologías de la Información y las Comunicaciones. El objetivo fundamental de esta Tesis es proponer diversos experimentos de Física en los que se utilizan como herramientas de medida los sensores de que disponen los smartphones de los propios estudiantes, aprovechando las aplicaciones gratuitas existentes para el control de estos sensores y para la toma y transmisión de los datos obtenidos. Con este fin se ha realizado un conjunto de trabajos, recogidos en esta Tesis en formato de compendio de publicaciones, en los que se proponen nuevas experiencias de laboratorio de Física con smartphones. En ellas se saca partido del sensor de aceleración para el estudio de las oscilaciones libres y amortiguadas de un smartphone, de los modos de vibración de dos acoplados, y del batido mecánico; del sensor de luz ambiente para el análisis de la eficiencia de diversos tipos de fuente, y de la dependencia de la iluminancia con la distancia; y, finalmente, del micrófono para la caracterización del fenómeno del batido acústico. Las experiencias diseñadas están enfocadas a estudiantes universitarios y de educación secundaria. Las encuestas realizadas muestran la mayor califica-ción otorgada a este tipo de experiencias con respecto a sus alternativas tradicionales. / Tradicionalment, l'objectiu de les pràctiques de laboratori de les assignatures de Física és doble: d'una banda, que els estudiants reforcen els coneixements adquirits en les classes de teoria; per una altra, que s'habituen a les tècniques experimentals. No obstant això, els alumnes consideren que en ocasions les pràctiques són rutinàries i poc interessants. Per a pal¿liar aquest problema, s'ha fet ús de diversos recursos basats en les Tecnologies de la Informació i les Comunicacions. L'objectiu fonamental d'aquesta Tesi és proposar diversos experiments de Física en els quals s'utilitzen com a eines de mesura els sensors de què disposen els smartphones dels propis estudiants, aprofitant les aplicacions gratuïtes existents per al control d'aquests sensors i per a la presa i la transmissió de les dades obtingudes. Amb aquesta finalitat s'ha realitzat un conjunt de treballs, recollits en aquesta Tesi en format de compendi de publicacions, en els quals es proposen noves experiències de laboratori de Física amb smartphones. En aquestes es trau partit del sensor d'acceleració per a l'estudi de les oscil¿lacions lliures i esmorteïdes d'un smartphone, dels modes de vibració de dos acoblats, i del batut mecànic; del sensor de llum ambiente per a l'anàlisi de l'eficiència de diversos tipus de font, i de la dependència de la il¿luminancia amb la distància; i, finalment, del micròfon per a la caracterització del fenomen del batut acústic. Les experiències dissenyades estan enfocades a estudiants universitaris i d'educació secundària. Les enquestes realitzades mostren la major qualificació atorgada a aquest tipus d'experiències pel que fa a les seues alternatives tradicionals. / Giménez Valentín, MH. (2017). Aplicaciones de los sensores de los smartphones a la didáctica de la física experimental [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/83123 / Compendio

Yes / Older adults use their smartphones to learn new material but few studies examined their learning with the presence of a chatbot in a smartphone. We developed a three-week self-paced learning module on three topics (chatbot, QR scanner, Google Drive) using their smartphone. Our aims were to examine participants’ self-paced learning accuracy while exploring older adults acceptance of the chatbot. Twelve participants participated in this study (Mage: 64.75 years) for three weeks at their homes individually. Results showed that they had low accuracy for the chatbot but higher accuracy for the other two. Qualitative analyses indicated that participants disliked the chatbot and that good clarity in our instructional videos and slides may have contributed to the low acceptance for the chatbot. Our findings indicated that self-paced learning is feasible with slides and videos only, and to create more chatbot-related assessments to increase chatbot usage. / Newton Fund Institutional Links grant ID: 331745333.

Das Smartphone ist mittlerweile ein ständiger Begleiter in unserer Gesellschaft geworden. Die Nutzer fühlen sich jedoch zunehmend belästigt von zu vielen Angeboten, Informationen und Hinweisen, die sie täglich erreichen. Eine Bedarfsanpassung in Form von Personalisierung und Kontextbezug nimmt dementsprechend bei mobilen Diensten eine immer wichtigere Rolle ein. Kontextorientierung bildet heutzutage einen Schwerpunkt im Ubiquitous Computing und geht einher mit der extensiven Nutzung von Sensordaten.

A capilarização da informação no território brasileiro por meio do smartphone e suas implicações espaciais são resultado da convergência das técnicas de telefonia e internet, cuja rede expande seu alcance para atender à demanda crescente de conexão, sob a regulação de agentes públicos e privados que determinam a implementação e o uso dessas infraestruturas. Os sistemas técnicos que compõem essa rede se fundamentam em lógicas, intenções e investimentos, induzindo seu aperfeiçoamento para a produção e o consumo desses objetos e das informações que por eles fluem de forma banalizada. O papel do smartphone é de conector e ponto de acesso, e seu funcionamento presume uma lógica reticular, pela qual as redes e as distâncias não contíguas não impedem relações cotidianas. As resultantes espaciais dos movimentos de produção, consumo, distribuição e capilarização dessa rede incidem em diferentes escalas do território, sob a influência das relações interescalares e de ordens e intencionalidades de agentes envolvidos no controle dessa rede. / The information networks capillarization in Brazilian territory through the smartphone and its spatial implications are the result of the telephony and internet techniques convergence, whose network expands its reach to meet the increasing demand for connection, under the regulation of public and private agents that determine the implementation and use of these infrastructures. The technical systems that make up this network are based on logic, intentions and investments, inducing their improvement for the production and consumption of these objects and the information that they flow in a trivial way. The role of the smartphone is of connector and access point, and its operation presumes a reticular logic, in which the networks and the noncontiguous distances do not impede daily relations. The spatial results of the movements of production, consumption, distribution and capillarization of this network affect different scales of the territory, under the influence of the interscalar relations and orders and intentionalities of agents involved in the control of this network.

O objetivo do presente estudo foi verificar a acurácia diagnóstica da imagem clínica obtida pela câmera acoplada ao telefone celular, comparada ao diagnóstico clínico presencial e ao diagnóstico histopatológico em tumores palpebrais. Métodos: Pacientes sob demanda espontânea, foram recrutados. Foram incluídos pacientes encaminhados para avaliação e exérese de tumor palpebral benigno ou maligno. Avaliação presencial foi realizada constando de anamnese, avaliação externa macroscópica e biomicroscópica com estabelecimento de diagnóstico clínico. Todos os pacientes tiveram as lesões palpebrais documentadas com um smartphone Samsung S4 (imagens de 4128x 3096 pixels), salvas em formato JPEG. Todas as lesões foram ressecadas e submetidas à exame histopatológico. Três especialistas em Plástica Ocular em outro país fizeram a teleavaliação das imagens na tela de um laptop (2366x768 pixels). Verificou-se a concordância entre o padrão-ouro (histologia) e os diagnósticos presencial e à distância. Resultados: Foram avaliados 75 casos por exame presencial e por imagem. A idade média dos pacientes foi de 66,6 anos com predominância do sexo feminino (44 mulheres). As lesões ocorreram com maior frequência nas pálpebras inferiores (57 casos - 76%). O tamanho médio das lesões foi de 9,36 mm (DP 7,37). Trinta e quatro (45,33%) eram benignas e 41 (54,67%) malignas. O diagnóstico anatomopatológico maligno mais comum foi o carcinoma basocelular com 27 casos (36%) e o benigno mais comum foi o nevus com 10 casos (13,33%). Os examinadores virtuais acertaram cerca de 50% do diagnóstico histológico enquanto o presencial foi de 76%. Quanto ao diagnóstico de malignidade, o estudo mostrou alta concordância da teleavaliação (sensibilidade de 85-90%) - praticamente igual ao exame presencial - 88%. Nas lesões benignas, por telemedicina houve 74-88% de acertos (alta concordância), contra 100% de acertos no exame presencial. A acurácia média via telemedicina do diagnóstico de malignidade de lesão foi de 83% contra 93% do exame presencial. O tamanho da lesão também se relacionou positivamente com diagnóstico de malignidade tanto no exame presencial quanto na teleavaliação. Conclusões: A avaliação de lesões palpebrais usando smartphone e Telemedicina nas condições deste estudo, é viável, sendo alta a concordância para o reconhecimento de tumores palpebrais malignos. Quanto ao diagnóstico histopatológico, o exame à distância foi menos acurado que o exame presencial. Os resultados deste estudo sugerem que a avaliação de tumores palpebrais através da Telemedicina é um bom método que pode ter aplicações práticas em populações com acesso restrito a médicos especialistas, com grandes vantagens para fins de saúde pública / The objective of this study was to check the diagnostic precision of clinical image obtained by the phone camera of smartphones compared to face-toface clinical diagnosis and histopathological diagnosis of eyelid tumors. Methods Patients on spontaneous demand were recruited. We included patients referred to evaluation and resection of benign or malignant eyelid tumors. The face-to-face evaluation was done to establish the clinical diagnosis: anamnesis, external macroscopic evaluation and biomicroscopic exam. Every patient had pictures of eyelid lesions taken with a smartphone Samsung S4 (images of 4128x 3096 pixels) and saved in jpeg format. All lesions were resected and had the histologic evaluation. Three Oculoplastics experts in another city abroad performed images tele evaluation at the laptop screen with a resolution of 2366x768 pixels. We investigated concordance between the gold standard (histology) and the face-to-face and telemedicine diagnosis. Results Seventy-five lesions were evaluated face-to-face and by images. The mean age was 66.6 years, with the predominance of women (44). The lesions were more frequent at lower eyelid (57 cases- 76%). The mean size was 9.36 mm (DP 7.37). Thirty-four (45.33%) were benign and 41 (54.67) malignant. The most frequent malignant histopathological diagnosis was basal cell carcinoma with 27 cases (36%), and the benign was nevus with 10 cases (13.33%). Tele examiners answered correctly 50% of histological diagnosis, and face-to-face examiner matched 76%. The study showed a high correlation between tele evaluation and face- to- face exam at malignity diagnosis (sensibility= 85-90%, mean accuracy = 83.3% against 88% and 93%). At benign lesions, with Telemedicine, there are 74-88% of correct answers against face- to - face 100% hits. Lesion size correlated positively with malignity diagnosis at face - to- face and by telemedicine exam. Conclusions Eyelid lesion evaluation by telemedicine in this study conditions was viable. It showed high concordance to recognize malignant eyelid tumors. However, histological diagnosis was less accurate at telemedicine when compared to face - to- face exam. These results indicate that eyelid tumors evaluation by telemedicine is a suitable method. It can have practical applications in communities where experts are few, so providing advantages at public health

Den elektroniska handeln har varit på framfart i många år, den erbjuder stora potentiella affärsmöjligheter för företag. Med hjälp av internet kan företag idag erbjuda produkter och tjänster till kunder över hela världen. Elektronisk handel kan också erbjudas via mobiltelefoner, även kallat mobilhandel. Den handeln har i Sverige haft en trög tillväxt jämfört med den elektroniska, en förklaring till detta kan vara säkerhetsaspekten. Flera forskare uttrycker att det råder en osäkert hos konsumenten i transaktionsutförandet. Även fast tillväxten börjat ta fart sedan det explosionsartade användandet av smartphone kan vi fortfarande se att företag är försiktiga med att investera i den mobila försäljningskanalen. Eftersom den mobilahandeln fortfarande är relativ ny i Sverige är den också oprövad, det finns inte tillräckligt med teorier som säger hur företagen bör arbeta för att skapa en lönsam mobilkanal. Statistik visar att de flesta använder sin smartphone för att söka information, det krävs således att företag kan konvertera sina besökare till kunder. En annan problematik som vi valt att fokusera på är målgruppsanalysen, vilka är det som kan tänka sig använda sig av m-handel och vad för faktorer är viktiga för konsumenten om de handlar via mobilen. Med den utgångspunkten är vårt syfte att studera de personliga, tekniska och finansiella faktorerna som ligger till grund för en djupare förståelse av vad som påverkar konsumenters acceptans att handla/betala via mobilen. Vi vill även undersöka om det finns andra faktorer som kan dyka upp i resultatet, som kan ha en viktig betydelse relaterat till vår forskningsfråga. Studien skrivs ur ett konsumentbeteende perspektiv. Vidare bygger studien på en kvantitativ metod som vi valt att utföra med hjälp av enkäter. Det var 144st smartphone-användare som besvarade enkäten och som ligger till grund till resultatet. Våra slutsatser besvarar vår problemformulering utifrån de tre faktorer som vi valt att fokusera på. Resultatet visade att de tekniska faktorerna spelade en större roll än de två andra.

O presente estudo avaliou a relação entre aspectos demográficos, socioeconômicos e de mobilidade com o espaço de atividades de residentes de Paraisópolis, uma das maiores favelas de São Paulo, Brasil, com mais de 70.000 habitantes. Foram utilizados, para tanto, dados de GPS, coletados por smartphones, e entrevistas domiciliares. Dois indicadores espaço-temporais de acessibilidade, facilmente mensuráveis, foram extraídos da literatura para determinar, para cada indivíduo da amostra, (i) a dispersão espacial de atividades não residenciais e (ii) o afastamento de seu centroide de atividades ao local de residência. Os dados brutos coletados através de um aplicativo instalado nos smartphones, com intervalos programados de 5 minutos, durante um período de 14 dias, foram então processados para a identificação de pontos de interesse (POIs) - locais de atividades e residências - e de sua frequência de visitas (stays), constatando-se que, ao longo dos sete dias consecutivos de coleta de dados adotados neste trabalho, a amostra de 109 indivíduos visitou 673 pontos de interesse. A acessibilidade individual foi então analisada para três períodos: de forma agregada, para os dias úteis e final de semana, e de forma isolada, para cada dia pesquisado. As análises investigaram a relação dos indicadores de acessibilidade com características demográficas e socioeconômicas dos indivíduos, bem como com seus hábitos de transporte. Os resultados mostraram maior número de indivíduos que não saem de casa no final de semana (125% maior que nos dias úteis); o uso de transporte público e a presença de doenças crônicas são características comuns entre eles. Quem trabalha apresenta maior espaço de atividades nos dias úteis e no final de semana; enquanto o número de dias produtivos contribui para a dispersão e o afastamento à residência, o aumento da jornada de trabalho age em sentido contrário, provavelmente pela redução do tempo livre. O gênero também afeta a dispersão de atividades, e as mulheres apresentam menor espaço de atividades. O grau de escolaridade, o estado civil e a idade parecem influenciar ambos os indicadores, em todos os períodos analisados. Estudantes, homens e aqueles com ensino superior completo/incompleto apresentaram grandes variações dos indicadores ao longo dos dias. Finalmente, o uso de transporte público sobre pneus está associado a um espaço de atividades maior nos dias úteis; por outro lado, o acesso ao automóvel e à rede metroferroviária parece facilitar a participação em atividades não-residenciais localizadas mais longe da residência, no final de semana. / The purpose of this thesis is to analyze the activity space of residents of Paraisópolis, one of the largest slums in São Paulo, Brazil, with a population over 70,000. Two easily measured space-temporal accessibility indicators were selected from literature to assess, for each person, (i) the spatial dispersion of non-residential activities and (ii) the distance of the activities centroid to the residential location. Data of 109 individuals was collected from interviews and from respondents\' smartphones, using an app configured to record GPS locations at 5-minute intervals for a period of up to 14 days. The raw data was processed to identify activity locations (POIs - points of interest), time and frequency of visits (stays), leading to 673 POIs visited within 7 consecutive days selected for analysis. Accessibility is analyzed for daily measurements, and for data aggregated into weekdays and weekends. The analysis investigated the relation of accessibility indicators to socioeconomic and demographic characteristics of individuals as well as information on habitual transport mode. Results show a large number of individuals who do not leave home during weekends (125% higher than during weekdays); these persons have in common the presence of chronic diseases and the habitual use of public transport; lack of access to cars probably restrict the travel of these individuals. Workers have a larger activity space during both, weekdays and weekends; those who work more days in a week present higher dispersion and distance from the activities centroid to home. However, longer daily working hours decrease dispersion, probably due to reduced time availability. Gender also impacts dispersion, with women having a reduced activity space. Age, marital status and years of study seem to influence the two accessibility indicators, for both weekdays and weekend. Males, students and those with higher education present large variation in the accessibility indicators. Finally, habitual use of public transport is associated with a larger activity space during weekdays; on the other hand, access to cars and to the metro and rail network seems to facilitate nonresidential activities to be performed further from home on weekends.

The global shipments of smartphones will be more than four hundred fifty million, and it will overtake handset and become the mainstream in 2011. The fact is that there are more and more choices for customers to choose. It not only many brands, but also varieties of operating systems are provided with consumers.In this trend, is brand image still important factor that contributes to the consumers choosing the smartphones? For customers having had smartphones, how the brand image affects their loyalty? Therefore, this study attempts to find out the linear relationship between brand image and brand loyalty, In addition, it takes involvement and the operating systems into consideration. The research also intends to focus on whether the effects of the involvement adjust this or not and look for a difference of linear relationship between the two operating systems-android and ios. The scope of this research includes the customers owning smartphones in Taiwan. Moreover, the method of the study is sending on-line and paper questionnaires at the same time, and the number of the valid questionnaires is 261.In this study, brand image are divided into three perspectives by factorial analysis, functional benefits, symbolic benefits, experiential benefits. Brand loyalty consists of behavioral loyalty and attitudinal loyalty. The involvement is composed of importance, symbolic value, and risk.The research uses regression analysis to verify the linear relationship between brand image and brand loyalty. Furthermore, put brand image, brand loyalty, involvement into the regression analysis, and through multiple stepwise regression analysis to find out the factors which contribute to linear relationship. The result reveals that there is a linear relationship between the brand image and brand loyalty. In addition, linear relationship between different operating systems is also different, and especially the functional brand influences significantly on brand loyalty.