3,800 research outputs found

    An exploratory study on the impact of electoral participation upon a terrorist group’s use of violence in a given year

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    Recent studies seeking to understand the determinants of terrorism tend to focus upon situational, rather than structural measures. Typically these studies examine the interaction of terrorist attacks and repressive state actions. However, we know very little about other situational measures that may impact upon a group’s scale of violent activity within a particular year. This preliminary study analyses terrorist attacks committed by both the Provisional IRA (PIRA) and ETA and the electoral performances of the groups’ political wings, Sinn Fein and Batasuna, from 1970 to 1998 and from 1978 to 2005 respectively. More specifically, this paper examines whether the nature and content of terrorist attacks differ in the build-up to that group’s political-wing participating in elections. In other words, this article is a preliminary study of the influence of electoral participation on attack frequency and target selection. Results suggest that PIRA significantly decreased their attacks in an election year and this had a positive impact upon Sinn Fein’s electoral performance. On the other hand, ETA significantly increased its attacks in an election year and this had no significant impact upon Batasuna’s electoral performance

    Wind turbine condition assessment through power curve copula modeling

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    Power curves constructed from wind speed and active power output measurements provide an established method of analyzing wind turbine performance. In this paper it is proposed that operational data from wind turbines are used to estimate bivariate probability distribution functions representing the power curve of existing turbines so that deviations from expected behavior can be detected. Owing to the complex form of dependency between active power and wind speed, which no classical parameterized distribution can approximate, the application of empirical copulas is proposed; the statistical theory of copulas allows the distribution form of marginal distributions of wind speed and power to be expressed separately from information about the dependency between them. Copula analysis is discussed in terms of its likely usefulness in wind turbine condition monitoring, particularly in early recognition of incipient faults such as blade degradation, yaw and pitch errors

    Charter and Party Boat Operators in the U.S. Gulf of Mexico: A Social Structure Perspective

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    To better address the charter and party boat fishery needs in the U.S. Gulf of Mexico, fishery managers must understand the linkages between the industry and other groups and organizations that affect its success. Gulf state charter and party boat operators were interviewed to ascertain the extent of their social network linkages, membership in community organizations, business community relationships, and linkages to information sources. Approximately one-third to one-half of the charter and party boat operators did not belong to local community organizations that could assist their business through tourism promotion or natural resource protection. Despite their limited integration in the community, the vast majority of operators gave and received referrals from other businesses. Of four major information sources, the National Weather Service and the County Marine Extension agents were rated highest and lowest, respectively, in mean importance to charter and party boat operators. Results suggest that business success can be enhanced by strengthening network ties between operators and local businesses, chambers of commerce, and tourism organizations. For this to occur, individual operators and charter/party boat organizations need to become more effective in representing industry interests. Informational linkages between industry and govemment agencies also need improvement

    Novel hybrid organic/inorganic single-sited catalysts and supports for fine chemical and pharmaceutical intermediate synthesis

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    The study of catalysis is a fundamental aspect of chemical engineering, as its implications affect all chemical transformations. Traditionally, catalysis has been subdivided into two areas: homogeneous and heterogeneous catalysis. Homogeneous catalysis refers to single-sited catalysts that exist in the same phase as the reaction media. These catalysts tend to be highly active and selective but often difficult to recover and reuse. In contrast, heterogeneous catalysts are typically multi-sited catalysts that exist in a different phase from the reaction media. These catalysts tend to be less active and selective than their homogeneous counterparts. However, the vast majority of industrial scale catalysts are heterogeneous because they can be easily separated, making them easily implemented in continuous processes, allowing for efficient, large scale operations. Due to the limitations of traditional homogeneous and heterogeneous catalysts, researchers have increasingly investigated hybrid catalysts that incorporate aspects of homogeneous and heterogeneous catalysis. This is accomplished via immobilization of homogeneous catalyst analogues onto solid-phase supports, thereby preserving the activity and selectivity of homogeneous catalysts while allowing for facile recovery and reuse from the insoluble, heterogeneous support. A variety of systems is presented here including organic and organometallic catalysts immobilized on organic and inorganic supports. Five cases are included. The first discusses utilization of supported acid and base catalysts for use in one-pot cascade reactions. The second example illustrates use of silica-coated magnetic nanoparticle supported acid catalysts for organic transformations. The third case presents novel polymer brush supported Cobalt-salen catalysts for the enantioselective, hydrolytic kinetic resolution of epoxides. A fourth case presents novel, magnetic polymer brush supported organic and organometallic catalysts for organic transformations. The fifth example illustrates polymer and silica supported ruthenium-salen catalysts for the asymmetric cyclopropanation of olefins. The overall goal of this thesis work is to develop novel supports and immobilization techniques to advance the field of hybrid organic/inorganic catalysts for the production of fine chemical and pharmaceutical intermediates.Ph.D.Committee Chair: Jones, Christopher; Committee Member: Agrawal, Pradeep; Committee Member: Teja, Amyn; Committee Member: Weck, Marcus; Committee Member: Zhang, Joh

    Group‐Focused Counseling: Classifying the Essential Skills

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/89577/1/j.2164-4918.1982.tb00669.x.pd

    Cuff-less continuous blood pressure monitoring system using pulse transit time techniques

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    This paper describes the development of a continuous cuff-less blood pressure system based on the pulse transit time (PTT) technique. In this study, PTT is defined by two different approaches denoted as PTT1 and PTT2. PTT1 is the time difference between the R-wave peak of the Electrocardiogram (ECG) and the peak of the Photoplethysmogram (PPG). PTT2 is the time difference between two peak PPG signals on same cardiac cycle at different positions on the body. The ECG is acquired on the chest using 3 lead electrodes and a reflection mode optical sensor is deployed on brachial artery and fingertip to monitor the PPGs. These data were synchronized using a National Instruments data acquisition card along with Matlab software for subsequent analysis. A wrist-type cuff-based blood pressure device was used to measure blood pressure on the right hand. Brachial blood pressure was measured on the upper left arm using oscillometric blood pressure monitor. Experiments were conducted by elevating the right hand at different position to investigate variability of PTT under the effects of hydrostatic pressure. Next the variability of PTT due to blood pressure changes during a Valsalva maneuver was investigated. The result shows that the PTT1 is inversely proportional to blood pressure in both experiments. Meanwhile, there is weak correlation between PTT2 and blood pressure measurement which suggests that by excluding the pre-ejection period (PEP) time in PTT calculation may reduce the accuracy of PTT for blood pressure measurement. In conclusion, PTT measurement between ECG and PPG signals has potential to be a reliable technique for cuff-less blood pressure measurement

    Upset Dynamics of an Airliner Model: A Nonlinear Bifurcation Analysis

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    Development of tubular cardiovascular phantom system for pulse transit time simulation

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    This paper presents on the development of a tubular cardiovascular phantom system to simulate pulse transit time (PTT). The PTT defined as the delay time between two pulses in one cardiac cycle has been shown to be promising method for cuffless continuous blood pressure (BP) measurement. However most of the PTT measurement was performed on human subjects, thus giving a difficulty in validating sensor performance due to variability of BP. Therefore, a cardiovascular phantom system was proposed for simulate the PTT measurement. An electronic controlled module was developed to control pump operation for pulse generation. Plastic optical fibre (POF) sensors were used to measure the pulse signal on the flexible tube and the results were compared with an in-line pressure sensor. In this experiment, the delay time between two pulses were calculated offline using Matlab software and correlated with pulse pressure. The result demonstrate that the pulse delay time recorded by both sensors decreased with increase of pulse rate and pulse pressure. These results on the phantom study showed similar pattern to the human model, thus indicating that the system is able to simulate PTT for sensor validation purposes
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