867 resultados para one-time passwords
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This report summarizes Iowa results of a five year, Pooled Fund study involving the Wisconsin, Iowa, and Minnesota Departments of Transportation (DOTs) designed to 1) assess the public's perceptions of the DOTs' pavement improvement strategies and 2) develop customer-based thresholds of satisfaction with pavements on rural two lane highways in each state as related to the DOTs' physical indices, such as pavement ride and condition. The primary objective was to seek systematic customer input to improve the DOTs' pavement improvement policies by 1) determining how drivers perceive the DOTs' pavements in terms of comfort and convenience but also in terms of other tradeoffs the DOTs had not previously considered, 2) determining relationships between perceptions and measured pavement condition thresholds (including a general level of tolerance of winter ride conditions in two of the states), and 3) identifying important attributes and issues that may not have been considered in the past. Secondary objectives were 1) to provide a tool for systematic customer input in the future and 2) to provide information which can help structure public information programs. A University of Wisconsin-Extension survey lab conducted the surveys under the direction of a multi-disciplinary team from Marquette University. Approximately 4500 drivers in the 3 states participated in the 3 phases of the project. Researchers conducted 6 focus groups in each state, approximately 400 statewide telephone interviews in each state and 700-800 targeted telephone interviews in each state. Approximately 400 winter ride interviews were conducted in Wisconsin and Minnesota. A summary of the method for each survey is included. In Phase I, focus groups were conducted with drivers to get an initial indication of what the driving public believes in regards to pavements and to frame issues for inclusion in the more representative statewide surveys of drivers conducted in Phase II. Phase II interviews gathered information about improvement policy tradeoff issues and about preliminary thresholds of improvement in terms of physical pavement indices. In Phase III, a two step recruitment and post-drive interview procedure yielded thresholds of ride and condition index summarized for each state. Results show that, in general, the driving public wants longer lasting pavements and are willing to pay for them. They want to minimize construction delay, improve entire sections of highway at one time but they dislike detours, and prefer construction under traffic even if it stretches out construction time. Satisfaction with pavements does not correlate directly to a high degree with physical pavement indices, but was found instead to be a complex, multi-faceted phenomenon. A psychological model was applied to explain satisfaction to a respectable degree for the social sciences. Results also indicate a high degree of trust in the 3 DOTs which is enhanced when the public is asked for input on specific highway segments. Conclusions and recommendations include a 3-step methodology for other state studies.
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Français L'observation ethnographique des politisations différentielles pendant une campagne électorale en contexte autoritaire changeant est un analyseur privilégié de plusieurs processus. Sur un plan empirique, elle donne à voir les modalités diversifiées d'appropriation du moment électoral par les acteurs, les tentatives d'ajustement d'une partie de la gauche marocaine à la perte de son électorat de granit et aux transformations du marché électoral, mais également un mouvement de fond : celui de l'inversion ponctuelle du principe censitaire, en lien avec la désertion des urnes par les plus dotés culturellement et matériellement et avec la mutation du vote urbain populaire. Sur un plan théorique, l'examen des tâtonnements en oeuvre - avant leur naturalisation - permet de poursuivre le dialogue entre les travaux sur le clientélisme politique et sur la politisation, au croisement des approches socio-historiques et de sociologie politique, en contextes autoritaires et démocratiques. Il montre l'intérêt de dépasser les oppositions entre conceptions restrictives et extensives de la politisation, pour se saisir processuellement et in situ des politisations différentielles des acteurs, des registres et des pratiques. English Differential Forms of Politicization and Mutual Acculturation in an Authoritarian ContextThe ethnographic observation of differential forms of politicization during an electoral campaign in a changing authoritarian context is an ideal means of analyzing a number of processes. Empirically, it enables us to observe the actors' diverse ways of appropriating the electoral moment, a Moroccan leftist party's attempts to adjust to the loss of its electoral base and the transformations of the electoral market. It also enables us to observe a one-time reversal of the symbolic voting restrictions, in correlation with the desertion of the polls by the those best equipped to participate, both culturally and materially, and with the transformation of the urban popular vote. In theoretical terms, examination of such ongoing processes - before their stabilization - allows us to follow the interplay between the work on political clientelism and on politicization, at the intersection of sociohistorical and political sociological approaches, in authoritarian and democratic contexts. It demonstrates the value of moving beyond the opposition between restrictive and extensive conceptions of politicization, to grasp the process in situ of differential forms of the politicization of actors, registers and practices.
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The last two decades have seen many exciting examples of tiny robots from a few cm3 to less than one cm3. Although individually limited, a large group of these robots has the potential to work cooperatively and accomplish complex tasks. Two examples from nature that exhibit this type of cooperation are ant and bee colonies. They have the potential to assist in applications like search and rescue, military scouting, infrastructure and equipment monitoring, nano-manufacture, and possibly medicine. Most of these applications require the high level of autonomy that has been demonstrated by large robotic platforms, such as the iRobot and Honda ASIMO. However, when robot size shrinks down, current approaches to achieve the necessary functions are no longer valid. This work focused on challenges associated with the electronics and fabrication. We addressed three major technical hurdles inherent to current approaches: 1) difficulty of compact integration; 2) need for real-time and power-efficient computations; 3) unavailability of commercial tiny actuators and motion mechanisms. The aim of this work was to provide enabling hardware technologies to achieve autonomy in tiny robots. We proposed a decentralized application-specific integrated circuit (ASIC) where each component is responsible for its own operation and autonomy to the greatest extent possible. The ASIC consists of electronics modules for the fundamental functions required to fulfill the desired autonomy: actuation, control, power supply, and sensing. The actuators and mechanisms could potentially be post-fabricated on the ASIC directly. This design makes for a modular architecture. The following components were shown to work in physical implementations or simulations: 1) a tunable motion controller for ultralow frequency actuation; 2) a nonvolatile memory and programming circuit to achieve automatic and one-time programming; 3) a high-voltage circuit with the highest reported breakdown voltage in standard 0.5 μm CMOS; 4) thermal actuators fabricated using CMOS compatible process; 5) a low-power mixed-signal computational architecture for robotic dynamics simulator; 6) a frequency-boost technique to achieve low jitter in ring oscillators. These contributions will be generally enabling for other systems with strict size and power constraints such as wireless sensor nodes.
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Natural language processing has achieved great success in a wide range of ap- plications, producing both commercial language services and open-source language tools. However, most methods take a static or batch approach, assuming that the model has all information it needs and makes a one-time prediction. In this disser- tation, we study dynamic problems where the input comes in a sequence instead of all at once, and the output must be produced while the input is arriving. In these problems, predictions are often made based only on partial information. We see this dynamic setting in many real-time, interactive applications. These problems usually involve a trade-off between the amount of input received (cost) and the quality of the output prediction (accuracy). Therefore, the evaluation considers both objectives (e.g., plotting a Pareto curve). Our goal is to develop a formal understanding of sequential prediction and decision-making problems in natural language processing and to propose efficient solutions. Toward this end, we present meta-algorithms that take an existent batch model and produce a dynamic model to handle sequential inputs and outputs. Webuild our framework upon theories of Markov Decision Process (MDP), which allows learning to trade off competing objectives in a principled way. The main machine learning techniques we use are from imitation learning and reinforcement learning, and we advance current techniques to tackle problems arising in our settings. We evaluate our algorithm on a variety of applications, including dependency parsing, machine translation, and question answering. We show that our approach achieves a better cost-accuracy trade-off than the batch approach and heuristic-based decision- making approaches. We first propose a general framework for cost-sensitive prediction, where dif- ferent parts of the input come at different costs. We formulate a decision-making process that selects pieces of the input sequentially, and the selection is adaptive to each instance. Our approach is evaluated on both standard classification tasks and a structured prediction task (dependency parsing). We show that it achieves similar prediction quality to methods that use all input, while inducing a much smaller cost. Next, we extend the framework to problems where the input is revealed incremen- tally in a fixed order. We study two applications: simultaneous machine translation and quiz bowl (incremental text classification). We discuss challenges in this set- ting and show that adding domain knowledge eases the decision-making problem. A central theme throughout the chapters is an MDP formulation of a challenging problem with sequential input/output and trade-off decisions, accompanied by a learning algorithm that solves the MDP.
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Comunidad es un conjunto de personas que conviven en determinado lugar geográfico y con una serie de características comunes entre sí.En ella juega un papel muy decisivo la Biblioteca Escolar ya que esta depende las posibles y futuras influencias que se den relacionados con los aspectos económicos, sociales, políticos, culturales y psicológicos proyectados al bienestar comunal.En el caso del país de Nicaragua todos y cada uno de los que habrán de ejercer funciones bibliotecarias, son conscientes del rol que desempeñaran. Si en un tiempo, su verdadera misión, no fue posible realizarla o llevarla a cabo ya que no convenía a los intereses de la clase explotadora y que más bien le era mejor mantenerla sumergida en un letargo, ahora, con el cambio realizado, con las puertas que antes se mantenían cerradas y que ahora que abren de par en par; mostrándonos los verdaderos objetivos que ella persigue, sus finalidades, así como para brindar los reconocimientos antes prohibidos, viene a ser para todos aquellos consecuentes con el proceso revolucionario en que se vive, como un punto estratégico en la nueva educación.
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In this dissertation, we apply mathematical programming techniques (i.e., integer programming and polyhedral combinatorics) to develop exact approaches for influence maximization on social networks. We study four combinatorial optimization problems that deal with maximizing influence at minimum cost over a social network. To our knowl- edge, all previous work to date involving influence maximization problems has focused on heuristics and approximation. We start with the following viral marketing problem that has attracted a significant amount of interest from the computer science literature. Given a social network, find a target set of customers to seed with a product. Then, a cascade will be caused by these initial adopters and other people start to adopt this product due to the influence they re- ceive from earlier adopters. The idea is to find the minimum cost that results in the entire network adopting the product. We first study a problem called the Weighted Target Set Selection (WTSS) Prob- lem. In the WTSS problem, the diffusion can take place over as many time periods as needed and a free product is given out to the individuals in the target set. Restricting the number of time periods that the diffusion takes place over to be one, we obtain a problem called the Positive Influence Dominating Set (PIDS) problem. Next, incorporating partial incentives, we consider a problem called the Least Cost Influence Problem (LCIP). The fourth problem studied is the One Time Period Least Cost Influence Problem (1TPLCIP) which is identical to the LCIP except that we restrict the number of time periods that the diffusion takes place over to be one. We apply a common research paradigm to each of these four problems. First, we work on special graphs: trees and cycles. Based on the insights we obtain from special graphs, we develop efficient methods for general graphs. On trees, first, we propose a polynomial time algorithm. More importantly, we present a tight and compact extended formulation. We also project the extended formulation onto the space of the natural vari- ables that gives the polytope on trees. Next, building upon the result for trees---we derive the polytope on cycles for the WTSS problem; as well as a polynomial time algorithm on cycles. This leads to our contribution on general graphs. For the WTSS problem and the LCIP, using the observation that the influence propagation network must be a directed acyclic graph (DAG), the strong formulation for trees can be embedded into a formulation on general graphs. We use this to design and implement a branch-and-cut approach for the WTSS problem and the LCIP. In our computational study, we are able to obtain high quality solutions for random graph instances with up to 10,000 nodes and 20,000 edges (40,000 arcs) within a reasonable amount of time.
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Dissertação de Mestrado para obtenção do grau de Mestre em Arquitectura, apresentada na Universidade de Lisboa - Faculdade de Arquitectura.
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Tese (doutorado)—Universidade de Brasília, Instituto de Psicologia, Psicologia Clínica e Cultura, 2015.
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Concurrent software executes multiple threads or processes to achieve high performance. However, concurrency results in a huge number of different system behaviors that are difficult to test and verify. The aim of this dissertation is to develop new methods and tools for modeling and analyzing concurrent software systems at design and code levels. This dissertation consists of several related results. First, a formal model of Mondex, an electronic purse system, is built using Petri nets from user requirements, which is formally verified using model checking. Second, Petri nets models are automatically mined from the event traces generated from scientific workflows. Third, partial order models are automatically extracted from some instrumented concurrent program execution, and potential atomicity violation bugs are automatically verified based on the partial order models using model checking. Our formal specification and verification of Mondex have contributed to the world wide effort in developing a verified software repository. Our method to mine Petri net models automatically from provenance offers a new approach to build scientific workflows. Our dynamic prediction tool, named McPatom, can predict several known bugs in real world systems including one that evades several other existing tools. McPatom is efficient and scalable as it takes advantage of the nature of atomicity violations and considers only a pair of threads and accesses to a single shared variable at one time. However, predictive tools need to consider the tradeoffs between precision and coverage. Based on McPatom, this dissertation presents two methods for improving the coverage and precision of atomicity violation predictions: 1) a post-prediction analysis method to increase coverage while ensuring precision; 2) a follow-up replaying method to further increase coverage. Both methods are implemented in a completely automatic tool.
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Senate File 2355, 85th General Assembly, states the Iowa Department of Transportation shall submit annual reports regarding the implementation of efficiency measures identified in the "Road Use Tax Fund Efficiency Report," January 2012. This report shall provide details of activities undertaken in the previous quarter relating to one-time and long-term program efficiencies and partnership efficiencies. Issues covered include savings realized from the implementation of particular efficiency measures; updates concerning measures that have not been implemented; efforts involving cities, counties, other jurisdictions, or stakeholder interest groups; any new efficiency measures identified or undertaken; and identification of any legislative action that may be required to achieve efficiencies.
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We use a probing strategy to estimate the time dependent traffic intensity in an Mt/Gt/1 queue, where the arrival rate and the general service-time distribution change from one time interval to another, and derive statistical properties of the proposed estimator. We present a method to detect a switch from a stationary interval to another using a sequence of probes to improve the estimation. At the end, we compare our results with two estimators proposed in the literature for the M/G/1 queue.
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We have designed a mobile application that takes advantage of the built-in features of smart phones such as camera and GPS that allow users to take geo-tagged photos while on the move. Urban residents can take pictures of broken street furniture and public property requiring repair, attach a brief description, and submit the information as a maintenance request to the local government organisation of their city. This paper discusses the design approach that led to the application, highlights a built-in mechanism to elicit user feedback, and evaluates the progress to date with user feedback and log statistics. It concludes with an outlook highlighting user requested features and our own design aspirations for moving from a reporting tool to a civic engagement tool.
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Background: Malaria is a major public health burden in the tropics with the potential to significantly increase in response to climate change. Analyses of data from the recent past can elucidate how short-term variations in weather factors affect malaria transmission. This study explored the impact of climate variability on the transmission of malaria in the tropical rain forest area of Mengla County, south-west China. Methods: Ecological time-series analysis was performed on data collected between 1971 and 1999. Auto-regressive integrated moving average (ARIMA) models were used to evaluate the relationship between weather factors and malaria incidence. Results: At the time scale of months, the predictors for malaria incidence included: minimum temperature, maximum temperature, and fog day frequency. The effect of minimum temperature on malaria incidence was greater in the cool months than in the hot months. The fog day frequency in October had a positive effect on malaria incidence in May of the following year. At the time scale of years, the annual fog day frequency was the only weather predictor of the annual incidence of malaria. Conclusion: Fog day frequency was for the first time found to be a predictor of malaria incidence in a rain forest area. The one-year delayed effect of fog on malaria transmission may involve providing water input and maintaining aquatic breeding sites for mosquitoes in vulnerable times when there is little rainfall in the 6-month dry seasons. These findings should be considered in the prediction of future patterns of malaria for similar tropical rain forest areas worldwide.
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This paper describes a program called Patches that was implemented to assist a group of Australian and Malaysian pre-service teachers to enhance their intercultural competence through their involvement in a series of reciprocal learning activities. Each learning experience was considered a “patch” that eventually created a “quilt of intercultural learning.” The purpose of this study was to enhance the intercultural competence of domestic and international students through organized intercultural activities, through a series of reflective writing sessions, and mutual engagement on a common project. The effectiveness of the Patches program was analysed in accordance with Deardorff’s elements of intercultural competence. The qualitative findings indicate that both cohorts of preservice teachers showed elements of intercultural competence through participation in the program, with both groups reporting a deeper appreciation and understanding of how to communicate more effectively in intercultural contexts.
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In this paper, we generalize the existing rate-one space frequency (SF) and space-time frequency (STF) code constructions. The objective of this exercise is to provide a systematic design of full-diversity STF codes with high coding gain. Under this generalization, STF codes are formulated as linear transformations of data. Conditions on these linear transforms are then derived so that the resulting STF codes achieve full diversity and high coding gain with a moderate decoding complexity. Many of these conditions involve channel parameters like delay profile (DP) and temporal correlation. When these quantities are not available at the transmitter, design of codes that exploit full diversity on channels with arbitrary DIP and temporal correlation is considered. Complete characterization of a class of such robust codes is provided and their bit error rate (BER) performance is evaluated. On the other hand, when channel DIP and temporal correlation are available at the transmitter, linear transforms are optimized to maximize the coding gain of full-diversity STF codes. BER performance of such optimized codes is shown to be better than those of existing codes.