With current state-of-the-art privacy-preserving blockchain solutions, users can submit transactions to a blockchain while maintaining full anonymity and not leaking the contents of the transaction through cryptographic techniques like zero-knowledge proofs and homomorphic encryption. However, the architecture of a blockchain consists of a decentralized network where every network participant maintains their own local copy of the blockchain and updates it upon every added transaction. As a result, the volume of blockchain transactions and the timestamp of each blockchain transaction for an application is publicly available. This is problematic for applications with time-sensitive or volume-sensitive outcomes because users may want this information to be privatized, such as not leaking the lateness of student examinations. However, this is not possible with existing blockchain research. In this thesis, we propose a blockchain system for multi-party applications that does not leak any useful information from the volume and timing metadata of the application's transactions, including maintaining the privacy of a time-sensitive or volume-sensitive outcome. We achieve this by adding sufficient noise using indistinguishable decoy transactions such that an adversary cannot deduce which transactions actually impacted the outcome of the application. This is facilitated in a manner where anyone can publicly verify the application's execution to be correct, fair, and honest. We demonstrate and evaluate our approach by implementing a Dutch auction that supports decoy bid transactions on a private Ethereum blockchain network. / Master of Science / Blockchains are distributed, append-only, digital ledgers whose current state is continuously agreed upon through the consensus of network participants and not by any centralized party. These characteristics make them unique for many applications because they enable the application to be facilitated and executed in a public, verifiable, decentralized, and tamper-proof manner. For example, Bitcoin, the most popular cryptocurrency, uses blockchains to continuously maintain a permanent, verifiable ledger of payment transactions. However, one downside of this public architecture is that the volume of transactions and the timestamp of each transaction can always be publicly observed (e.g. the timestamp of every Bitcoin payment is public). This is problematic for applications with time-sensitive or volume-sensitive outcomes because users may want this volume and timing information to be privatized, such as not leaking the lateness of student examinations which could have severe consequences like violating student privacy laws. But currently with state-of-the-art blockchain research, privatizing this information is not possible. In this thesis, we demonstrate our approach that enables these time-sensitive and volume-sensitive applications to be implemented on blockchains in a manner that can maintain the privacy of these time-sensitive or volume-sensitive outcomes without sacrificing the application's integrity or verifiability. We then demonstrate and evaluate our approach through implementing a Dutch auction that supports decoy bid transactions on a private blockchain network.

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Made available in DSpace on 2016-04-27T16:58:37Z (GMT). No. of bitstreams: 1 Fabiane Guimaraes.pdf: 590364 bytes, checksum: 94fd201e0ae358d7c02beb2a7db423f3 (MD5) Previous issue date: 2008-05-12 / Secretaria da Educação do Estado de São Paulo / In this work, the students of Education Child Schooling including studentes Education of young people and adults were interviewed on what they think about the zero, which senses atribute him. Students from different series in ages (ETHNO), to explain (MATHEMA) zero, used different technical (TICS). Using precepts of qualitative research and based on the theory of knowledge Ethnomathematics the TICS of MATHEMA were grouped into units of meaning. The zero was perceived as: a technique mathematical, a concept, a technique in the service of social and as metaphor, The work is organized into three chapters: The chapter zero brings the thinking initials, theoretical and methodological; The chapter I brings reflections on the historical zero. And finally in chapter II are the stories of students on zero / Neste trabalho, alunos da Educação Infantil ao Ensino Médio incluindo alunos da Educação de Jovens e Adultos foram entrevistados sobre o que pensavam sobre o zero, que sentidos atribuíam-lhe. Os alunos de diferentes séries e idades (ETNO), para explicar (MATEMA) o zero, utilizaram diferentes técnicas (TICA). Usando preceitos da pesquisa qualitativa e baseado na teoria do conhecimento Etnomatemática as TICA de MATEMA foram agrupadas em unidades de significado. O zero foi percebido como: uma técnica matemática, um conceito, uma técnica a serviço do social e como metáfora. O trabalho está organizado em três capítulos: O capítulo Zero traz as reflexões iniciais, teóricas e metodológicas; O capítulo I traz reflexões históricas sobre o zero; Por fim no capítulo II encontram-se os relatos dos alunos sobre o zero

In this thesis, I explored several neural network-based models to resolve the issues of zero pronoun in Chinese English translation tasks. I reviewed previous work that attempts to take the resolution as a classification task, such as determining if a candidate in a given set is the antecedent of a zero pronoun, which can be categorized as rule-based and supervised methods. Existing methods either did not take the relationship between potential zero pronoun candidates into consideration or did not fully utilize attention to zero pronoun representations. In my experiments, I investigated attention-based neural network models as well as its application in reinforcement learning environment building on an existing neural model. In particular, I integrated an LSTM-tree-based module into the attention network, which encodes syntax information for zero pronoun resolution tasks. In addition, I apply Bi-Attention layers between modules to interactively learn the syntax and semantic alignment. Furthermore, I leveraged a reinforcement learning framework to fine-tune the proposed model, and experiment with different encoding strategies, i.e., FastText, BERT, and trained RNN-based embedding. I found that attention-based model with LSTM-tree- based module, fine-tuned under reinforcement learning framework that utilized FastText embedding achieves the best performance, superior to the baseline models. I evaluated the model performance on different categories of resources, of which FastText shows great potential in encoding web blog text.

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The purpose of this investigation is to find out suitability of the solar chimney natural ventilation system in a Zero Energy Lab located at the University of North Texas campus, to figure out performance of the solar chimney. Reduction in the heating and ventilation and air conditioning energy consumption of the house has been also analyzed. The parameters which are considered for investigation are volumetric flow rate of outlet of chimney, the absorber wall temperature and glass wall temperatures. ANSYS FLUENT 14.0 has been employed for the 3-D modeling of the solar chimney. The dimensions of the solar chimney are 14’2” X 7’4” X 6’11”. The flow inside solar chimney is found to be laminar and the simulation results show that maximum outlet volumetric flow rate of about 0.12m3/s or 432 cfm is possible from chimney. The experimental velocity of chimney was found to be 0.21 m/s. Density Boussinesq approximation is considered for the modeling. Velocity and temperature sensors have been installed at inlet and outlet of the chimney in order to validate the modeling results. It is found that based on simulated volumetric flow rate that cooling load of 9.29 kwh can be saved and fan power of 7.85 Watts can be saved.

Normal coloring - an equivalent version of Petersen coloring - is a special proper 5-edge-coloring of cubic graphs. Every edge in a normally colored graph is normal, i.e. it uses together with its four neighbours either only three colors or all five colors. Jaeger conjectured that every bridgeless cubic graph has a normal coloring. This conjecture, if true, imply for example Cycle double cover conjecture. Here we solve a weakened version of Jaeger's problem. We are looking for a proper 5-edge-coloring such that at least a part of the edges is normal. We show a coloring of generalized prisms with two thirds of the edges normal and a coloring of graphs without short cycles with almost half of the edges normal. Then we propose a new approach to normal coloring - chains. We use chains to prove that there cannot be only one single mistake in an almost normally colored graph. We also prove some statements about cuts in a normally colored graph which also follow from nowhere-zero Petersen flow. Finally, we examine a four-cycle in a normally colored graph. 1

O objetivo deste trabalho é propor os modelos Zero Modificados com distribuição na família Série de Potência (ZMPS) para séries temporais com dados de contagem. O modelo ZMPS possui um amplo portfólio de distribuições para dados de contagem em que, com uma função de ligação apropriada, podemos escrever os modelos de regressão usando as distribuições ZMPS de forma semelhante ao que é feito com os modelos lineares generalizados. Em seguida, utilizamos a ideia dos modelos Generalizados Autorregressivos e de Médias Móveis (GARMA) para finalmente propor os modelos Série de Potência Zero-Modificado para Séries Temporais com dados de contagem. / The goal of this work is to propose the Zero-Modified models with Power Series distribution (ZMPS) for time series with counting data. The ZMPS model have a huge portfolio of count data distributions wherein, with an appropriate link function, we can write the regression models using the ZMPS distributions similar to what is done with generalized linear models. Then, we can use the idea of the Generalized Autoregressive and Moving Average (GARMA) models to propose the Zero-Modified Power Series models for Time Series with counting data.