Muitos dos sistemas de computação existentes atualmente são concorrentes, ou seja, neles constam diversas entidades que, ao mesmo tempo, operam sobre um conjunto de recursos compartilhados. Nesse contexto, devemos controlar a concorrência das diversas operações realizadas, ou então a interferência entre elas poderia causar inconsistências nos recursos compartilhados ou nas próprias operações realizadas. Nesse texto, vamos tratar especificamente de estruturas de dados concorrentes, ou seja, estruturas de dados cujas operações associadas -- consideramos inserção, remoção e busca -- sejam passíveis de execução simultânea por diversas entidades. Tendo em vista o controle da concorrência, vamos adotar uma abordagem baseada no emprego de locks, uma primitiva de sincronização muito usual na literatura. Nossa discussão será apresentada em termos de certas estruturas de dados chamadas skip graphs, que têm propriedades interessantes para outros contextos, como o contexto de sistemas distribuídos. / Many existing computer systems are concurrent, or, in other words, they are composed of many entities that, at the same time, operate over some set of shared resources. In this context, we must control the concurrency of the operations, otherwise the interference between them could cause inconsistencies in the shared resources or in the operations themselves. In this text, we specifically discuss concurrent data structures, or, in other words, data structures over which the associated operations -- we consider insertion, removal and search -- could be executed simultaneously by various entities. In order to control the concurrency, we will employ an aproach based on the use of locks, a widely known synchronization primitive in the literature. Our discussion will be presented in terms of data structures called skip graphs, which have interesting properties in other contexts, as the context of distributed systems.

Muitos dos sistemas de computação existentes atualmente são concorrentes, ou seja, neles constam diversas entidades que, ao mesmo tempo, operam sobre um conjunto de recursos compartilhados. Nesse contexto, devemos controlar a concorrência das diversas operações realizadas, ou então a interferência entre elas poderia causar inconsistências nos recursos compartilhados ou nas próprias operações realizadas. Nesse texto, vamos tratar especificamente de estruturas de dados concorrentes, ou seja, estruturas de dados cujas operações associadas -- consideramos inserção, remoção e busca -- sejam passíveis de execução simultânea por diversas entidades. Tendo em vista o controle da concorrência, vamos adotar uma abordagem baseada no emprego de locks, uma primitiva de sincronização muito usual na literatura. Nossa discussão será apresentada em termos de certas estruturas de dados chamadas skip graphs, que têm propriedades interessantes para outros contextos, como o contexto de sistemas distribuídos. / Many existing computer systems are concurrent, or, in other words, they are composed of many entities that, at the same time, operate over some set of shared resources. In this context, we must control the concurrency of the operations, otherwise the interference between them could cause inconsistencies in the shared resources or in the operations themselves. In this text, we specifically discuss concurrent data structures, or, in other words, data structures over which the associated operations -- we consider insertion, removal and search -- could be executed simultaneously by various entities. In order to control the concurrency, we will employ an aproach based on the use of locks, a widely known synchronization primitive in the literature. Our discussion will be presented in terms of data structures called skip graphs, which have interesting properties in other contexts, as the context of distributed systems.

This study investigated the significance of semantics in computer-generated word frequency counts in response to a call for new word lists (Read, 2000; Gardner, 2007). Read claims that no corpus projects to date have produced any "definitive, stand-alone word-frequency lists" (p. 226). Many researchers are wary of the fact that the concept of a word is never clearly defined in most studies that have dealt with word frequency counts. It is clear from the research that one universally acceptable construct for the concept of word does not exist. In fact, many past word frequency counts only examine word forms without considering the word meanings and the possible effects of homography on lists. Ming-Tzu and Nation (2004) did some research on the Academic Word List (AWL) that addresses some criticisms of word-frequency lists. They evaluate the extent of homography throughout the AWL. However, words found in the AWL are often not a part of the highest frequency word-forms in English. The present study focuses on high frequency words. It evaluates a randomized sample of 46 lemmas that occur at least 1500 times in the British National Corpus (BNC). A further random sampling of 200 examples for each lemma, in context, was semantically analyzed and tallied. One hundred of these examples were from the written portion and the other 100 from the spoken portion. The list of meanings for each word was compiled using conflated WordNet senses and some additional senses. Each context was double and sometimes triple rated. The results indicate that the impact of semantic frequency versus form-based frequency is considerable. The study suggests that the presence of homography tends to be extensive in many high-frequency word forms, across major registers of the language, and within each of the four major parts of speech. It further suggests that basing frequency on semantics will considerably alter the content of a high-frequency word list.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / A typical telemetry system for aircraft flight-testing transmits one or several data streams to the ground for real-time display and analysis, and also records the same stream onboard for later playback. During test operations, only a fraction of the available data is used at any given time for real-time display or analysis. More efficient use of the RF channel could be realized if only the data needed for the current test point is transmitted, rather than the entirety of the data. Intelligent selection of a subset of the data stream can provide large reductions in the required telemetry downlink bandwidth. As one of the Advanced Range Telemetry (ARTM) On-Board Data Management (OBDM) initiatives, a prototype on-board data selection subsystem is being developed and demonstrated. The demonstration utilizes COTS telemetry workstations to the maximum extent possible and includes “plug-in” data requestor, selection, and server components to implement the added DML functionality. A significant objective of the OBDM/DML project will be to validate RF channel models to help minimize the amount of flight-testing necessary to validate the DML concept. This paper will discuss the OBDM/DML architecture, integration of several custom components with the COTS portions of the ARTM “test bench”, and the current status of the OBDM/DML development and test program.

No description available.

No description available.

This project sought to find a rigorous and manageable method for measuring the difficulty of texts in te reo Māori written for children, beyond junior reading material in Māori-medium educational settings. The project examined a range of readability measures based on semantic and/or syntactic features of text, following the work of Warwick Elley (1969) and Richard Benton et al. (1995). Features such as the difficulty of content words, average sentence length, standardised type:token ratios and the use of function words were used in different combinations to create seven methods to measure text difficulty. Teachers’ and students’ ratings of text difficulty, and students’ scores on reading comprehension tasks related to the texts were used as criteria to examine the validity of the readability methods. The findings revealed that indices of either vocabulary load or lexical density when used in combination with the number of function types in the text, produce statistical significance with the criterion measures. Further research is needed to confirm their validity for use in Māori –medium classroom settings. The Māori word lists developed for this project as the basis of the readability approaches have the potential for more widespread analyses of language proficiency measures for students in Māori-medium settings.

In the study of the violin, teacher and student are involved in an on-going process of identifying, analyzing and overcoming technical and musical obstacles on the way to complete mastery of the instrument. Etudes often bridge the gap between exercises and "real music," and, as such, are extremely valuable as a step to mastering various playing skills in a musical setting. Nevertheless, without an encyclopedic memory, a teacher may find it difficult to locate appropriate etudes for an individual student with a specific technical problem.The charts from this study are designed to be used as an aid in locating and assigning etudes to students based upon their grade level and the technical difficulty they are having. The etudes selected were determined by their availability in three or more published editions to be those most commonly used.First, each etude was assigned a grade level. Next, each etude was catalogued by performance difficulty. Each performance category was carefully defined and limited. Finally, the writer determined whether the performance problem being studied was a "primary" difficulty of that etude, or whether the problem existed as a "secondary" component.After determining the technical difficulty to be studied, a violinist may consult the list of etudes addressing that particular difficulty. The list of etudes is organized from the simplest to the most difficult, and for each etude it is noted whether the problem is of primary (P) or secondary (S) importance. Finally, each etude is cross-referenced with other technical problems, and a teacher or student may make the decision whether to study the problem in isolation or in conjunction with other technical difficulties. / School of Music

This dissertation concentrates on transformation of the Czech armaments industry after 1989. As the topic is elaborated in wide context, the first chapters describe the history of Czechoslovak armaments production from the end of the World War I up to 1989. Then there is a main part, content of which is outlined in the title of this work. Among other things there are complete lists of firms participating in armaments production in 1989 and in 2007, comparison of them, and dividing into the suggested branch structure. Appropriateness and criteria of the origin of both the lists are mentioned in the methodology of the work. The specific development of the armaments industry in the second half of the 1990s and at the beginning of the 21st century is not forgotten as well. The last part of this work describes the most important Czech armaments firms of present and their characteristics across the production spectrum.

In a "publish-or-perish culture", the ranking of scientific journals plays a central role in assessing the performance in the current research environment. With a wide range of existing methods for deriving journal rankings, meta-rankings have gained popularity as a means of aggregating different information sources. In this paper, we propose a method to create a meta-ranking using heterogeneous journal rankings. Employing a parametric model for paired comparison data we estimate quality scores for 58 journals in the OR/MS/POM community, which together with a shrinkage procedure allows for the identification of clusters of journals with similar quality. The use of paired comparisons provides a flexible framework for deriving an aggregated score while eliminating the problem of missing data.