Security and Trust in Distributed Computation

We propose three research problems to explore the relations between trust and security in the setting of distributed computation. In the first problem, we study trust-based adversary detection in distributed consensus computation. The adversaries we consider behave arbitrarily disobeying the consensus protocol. We propose a trust-based consensus algorithm with local and global trust evaluations. The algorithm can be abstracted using a two-layer structure with the top layer running a trust-based consensus algorithm and the bottom layer as a subroutine executing a global trust update scheme. We utilize a set of pre-trusted nodes, headers, to propagate local trust opinions throughout the network. This two-layer framework is flexible in that it can be easily extensible to contain more complicated decision rules, and global trust schemes. The first problem assumes that normal nodes are homogeneous, i.e. it is guaranteed that a normal node always behaves as it is programmed. In the second and third problems however, we assume that nodes are heterogeneous, i.e, given a task, the probability that a node generates a correct answer varies from node to node. The adversaries considered in these two problems are workers from the open crowd who are either investing little efforts in the tasks assigned to them or intentionally give wrong answers to questions. In the second part of the thesis, we consider a typical crowdsourcing task that aggregates input from multiple workers as a problem in information fusion. To cope with the issue of noisy and sometimes malicious input from workers, trust is used to model workers' expertise. In a multi-domain knowledge learning task, however, using scalar-valued trust to model a worker's performance is not sufficient to reflect the worker's trustworthiness in each of the domains. To address this issue, we propose a probabilistic model to jointly infer multi-dimensional trust of workers, multi-domain properties of questions, and true labels of questions. Our model is very flexible and extensible to incorporate metadata associated with questions. To show that, we further propose two extended models, one of which handles input tasks with real-valued features and the other handles tasks with text features by incorporating topic models. Our models can effectively recover trust vectors of workers, which can be very useful in task assignment adaptive to workers' trust in the future. These results can be applied for fusion of information from multiple data sources like sensors, human input, machine learning results, or a hybrid of them. In the second subproblem, we address crowdsourcing with adversaries under logical constraints. We observe that questions are often not independent in real life applications. Instead, there are logical relations between them. Similarly, workers that provide answers are not independent of each other either. Answers given by workers with similar attributes tend to be correlated. Therefore, we propose a novel unified graphical model consisting of two layers. The top layer encodes domain knowledge which allows users to express logical relations using first-order logic rules and the bottom layer encodes a traditional crowdsourcing graphical model. Our model can be seen as a generalized probabilistic soft logic framework that encodes both logical relations and probabilistic dependencies. To solve the collective inference problem efficiently, we have devised a scalable joint inference algorithm based on the alternating direction method of multipliers. The third part of the thesis considers the problem of optimal assignment under budget constraints when workers are unreliable and sometimes malicious. In a real crowdsourcing market, each answer obtained from a worker incurs cost. The cost is associated with both the level of trustworthiness of workers and the difficulty of tasks. Typically, access to expert-level (more trustworthy) workers is more expensive than to average crowd and completion of a challenging task is more costly than a click-away question. In this problem, we address the problem of optimal assignment of heterogeneous tasks to workers of varying trust levels with budget constraints. Specifically, we design a trust-aware task allocation algorithm that takes as inputs the estimated trust of workers and pre-set budget, and outputs the optimal assignment of tasks to workers. We derive the bound of total error probability that relates to budget, trustworthiness of crowds, and costs of obtaining labels from crowds naturally. Higher budget, more trustworthy crowds, and less costly jobs result in a lower theoretical bound. Our allocation scheme does not depend on the specific design of the trust evaluation component. Therefore, it can be combined with generic trust evaluation algorithms.

ASSESSING THE LEVEL OF TECHNOLOGY INTEGRATION OF TITLE I TEACHERS IN A LARGE URBAN SCHOOL DISTRICT

By law, Title I schools employ teachers who are both competent in their subject knowledge and State certified. In addition, Title I teachers receive ongoing professional development in technology integration and are equipped with the latest innovative resources to integrate technology in the classroom. The aim is higher academic achievement and the effective use of technology in the classroom. The investment to implement technology in this large urban school district to improve student achievement has continued to increase. In order to infuse current and emerging technology throughout the curriculum, this school district needs to know where teachers have, and have not, integrated technology. Yet the level of how technology is integrated in Title I schools is unknown. This study used the Digital-Age Survey Levels of Teaching Innovation (LoTi) to assess 508 Title I teachers’ technology integration levels using three major initiatives purchased by Title I— the iPads program, the Chromebook initiative, and the interactive whiteboards program. The study used a quantitative approach. Descriptive statistics, regression analysis, and statistical correlations were used to examine the relationship between the level of technology integration and the following dependent variables: personal computer use (PCU), current instructional practices (CIP), and levels of teaching innovation (LoTi). With this information, budgetary decisions and professional development can be tailored to the meet the technology implementation needs of this district. The result of this study determined a significant relationship between the level of teaching innovation, personal computer use, and current instructional practices with teachers who teach with iPad, Chromebook, and/or interactive whiteboard. There was an increase in LoTi, PCU, and CIP scores with increasing years of experience of Title I teachers. There was also a significant relationship between teachers with 20 years or more teaching experience and their LoTi score.

Refletir sobre a língua através do jogo – um estudo com alunos do 2.º ano do ensino básico

Relatório de estágio apresentado à Escola Superior de Educação para obtenção de grau de mestre em Ensino do 1.º e do 2.º Ciclo do Ensino Básico

Programa Etnomatemática: ponderações da prática pedagógica

The aim of this present work is investigating the interest and motivation for learning, awakened in pupils when the educator practice is guided by the ethnomathematics perspective. The main question is: Can an ethnomathematic approach awaken enthusiasm in pupils, causing it to become more critic and active in building their knowledge? The methodology that guides the investigation is qualitative, based on technical arising of the ethnographic case study. Theoretical contributions that support the investigation are from the scientific methodology and from ethnomathematics. The research material is composed by: researcher’s field diary, audio recording of participant observation, interviews reports of community residents and students parents, highlighting the material produced by students. This study was developed on an 8º year of high school of rural community. During the work were prioritized the ethnomathematics concepts of the Ethnomathematic Program, which establish a link exchange, where the lecturers inserts themselves on the reality of pupils in a way that promote an appreciation of their identity and a commitment to their learning. The educator investigates and values the ideas of pupils throughout dialogues. There are challenges for the application of education with ethno mathematic perspective, pointed out by authors, listed and supplemented in the research. In this context, it is believed that the socio-cultural knowledge must be respect, and as they are understood their specialties, capabilities and characteristics, this can guide teaching practice, making significant process for pupils, providing appropriation of scientific knowledge. Analysis of research practice indicated that students, research subjects, when they decided contextual issues, with their way of life, felt appreciated. The conclusion is that, with continuous action of contextualized of school mathematics, from the recognition of the environment and of cultural identity, the educator has the opportunity of review their own participant condition, and therefore promote an enthusiasm for learning. Because a motivated pupil becomes active, since that the all project is guided in a significant theme.

A motivação na aprendizagem da matemática no pré-escolar e no 1.º ciclo

Relatório de estágio para obtenção de grau mestre em Educação pré-escolar e Ensino do 1.º ciclo do ensino básico

Caracter?sticas del perfil del aprendiz exitoso en un curso de ingl?s (EFL) virtual en el contexto Sena [recurso electr?nico]

This case study presents the general profile of the successful EFL online apprentice in the Colombian public vocational institution, SENA. This profile is described in terms of demographic, academic and cognitive aspects. The demographic profile is composed of features like sex, age, marital status and present job; the academic profile comprises information related to study habits, reasons to study English online, previous English learning experiences and type of ICT tools at home; and the cognitive profile refers to learning styles and EFL learning strategies. Four online surveys addressed to 33 successful online apprentices provide the data, which are also analyzed by means of a basic statistical description supported by Excel. The findings allow the author to conclude that the successful EFL online apprentice in SENA is basically a single person who is unemployed but has access to ICT tools to move forward in his learning process. Additionally, this apprentice has a divergent learning style who prefers the metacognitive, social and memory learning strategies for the EFL online process.

A motivação na aprendizagem da matemática no pré-escolar e no 1.º ciclo

Relatório de estágio para obtenção de grau mestre em Educação pré-escolar e Ensino do 1.º ciclo do ensino básico

Science fair project: O CLIL na educaçã pré-escolar

O ensino bilingue torna-se cada vez mais relevante no contexto Europeu. O Content and Language Integrated Learning (CLIL) apresenta-se como uma metodologia importante como podemos observar no European Profile for Language Teacher Education. Após realizar uma revisão de literatura cujo conteúdo versa sobretudo acerca os princípios orientados pelos preconizadores desta abordagem metodológica, nomeadamente Coyle (2010), Marsh (2010), Mehisto (2008), entre outros, e no sentido de tentarmos aferir a sua viabilidade, realizámos um Projeto de Investigação no qual implementámos esta abordagem pedagógica, ensinando a disciplina de ciências a grupo de alunos do Pré-escolar. Assim, neste estudo de caso, com contornos da metodologia de investigação-ação, tivemos como principal objetivo verificar a aplicabilidade do CLIL na Educação Préescolar. Com a implementação deste projeto, conseguimos perceber que a metodologia CLIL é uma abordagem metodológica eficaz, sendo que, nos permitiu concluir que mesmo na Educação Pré-escolar é possível ensinarmos uma disciplina através de uma segunda língua.

Motivação para a aprendizagem de ferramentas de utilização do arco

Relatório de Estágio para a obtenção do grau de Mestre em Ensino da Música

A motivação no processo de ensino-aprendizagem no jardim de infância e no 1.º ciclo do ensino básico

Relatório de estágio apresentado para a obtenção do grau de mestre na área de Educação Pré-Escolar e de Ensino do 1.º Ciclo do Ensino Básico

A motivação no processo de ensino-aprendizagem no jardim de infância e no 1.º ciclo do ensino básico

Relatório de estágio apresentado para a obtenção do grau de mestre na área de Educação Pré-Escolar e de Ensino do 1.º Ciclo do Ensino Básico

Emotional Skills and Promoting School Success in the 3rd Cycle: Students Perception

The perceptions about school play a central role in behavior, performance and learning outcomes. There is evidence that an improvement in emotional skills is associated with a higher school success. The aim of this paper is to know the relationship between internalizing and externalizing behaviors, emotional skills and academic success of students of the 3rd cycle of basic education. In order to promote students social and emotional skills, a pilot study in a School Grouping of the central region (Portugal) was carried out. It was made a diagnosis of disruptive behavior (ASEBA) and identified 6 children aged between 12 and 14 years old and followed by 3 focus groups with students, parents, and teachers, respectively. Six students mostly male were identified, with the predominance of externalizing behaviors and academic failure. They don’t like school and have no motivation for learning. The relationship between parents and teachers is conflictive. All parents have the utmost concern academic success and teachers perceived good practices, but without success. This program is seen in a perspective of empowerment of the educational agents to manage various environments and relationships. The results point to the importance of the systemic intervention program on the improvement of the social and emotional competences and academic achievement.

Emotional skills and promoting School Success in the 3rd cycle: students perception

Problem Statement: The perceptions about school, play a central role in behavior, performance and results. There is evidence that an improvement in emotional skills is associated with a higher success. Research Questions: What is the relationship between internalizing and externalizing behaviors, emotional skills and academic success in the 3rd cycle of basic education? Purpose of Study: To promote social and emotional skills of students, in the 3rd cycle of basic education. Research Methods: A pilot study with groups of 7th year at a school central Portugal. Made diagnosis of disruptive behavior (ASEBA) was identified 6 children aged 12 0s and 14 and followed by 3 focus groups with students, parents, and teachers respectively. Findings: 6 students mostly male were identified (70 %), with the predominance of externalizing behaviors and academic failure. Not like school (80%) and have no motivation for learning. The relationship between parents and teachers is conflituoso. 100 % of parents have the utmost concern academic success and teachers perceptional good practices, but without success. Conclusions: This program is seen in a perspective of empowerment of the various educational agents to manage various environments and relationships. The results point to the importance of the focus group in the awareness of relational problems in schools. Less adjusted change behaviors imply the involvement of all educators.