844 resultados para Data mining and knowledge discovery
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This research presents several components encompassing the scope of the objective of Data Partitioning and Replication Management in Distributed GIS Database. Modern Geographic Information Systems (GIS) databases are often large and complicated. Therefore data partitioning and replication management problems need to be addresses in development of an efficient and scalable solution. ^ Part of the research is to study the patterns of geographical raster data processing and to propose the algorithms to improve availability of such data. These algorithms and approaches are targeting granularity of geographic data objects as well as data partitioning in geographic databases to achieve high data availability and Quality of Service(QoS) considering distributed data delivery and processing. To achieve this goal a dynamic, real-time approach for mosaicking digital images of different temporal and spatial characteristics into tiles is proposed. This dynamic approach reuses digital images upon demand and generates mosaicked tiles only for the required region according to user's requirements such as resolution, temporal range, and target bands to reduce redundancy in storage and to utilize available computing and storage resources more efficiently. ^ Another part of the research pursued methods for efficient acquiring of GIS data from external heterogeneous databases and Web services as well as end-user GIS data delivery enhancements, automation and 3D virtual reality presentation. ^ There are vast numbers of computing, network, and storage resources idling or not fully utilized available on the Internet. Proposed "Crawling Distributed Operating System "(CDOS) approach employs such resources and creates benefits for the hosts that lend their CPU, network, and storage resources to be used in GIS database context. ^ The results of this dissertation demonstrate effective ways to develop a highly scalable GIS database. The approach developed in this dissertation has resulted in creation of TerraFly GIS database that is used by US government, researchers, and general public to facilitate Web access to remotely-sensed imagery and GIS vector information. ^
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The study examines the thought of Yanagita Kunio (1875–1962), an influential Japanese nationalist thinker and a founder of an academic discipline named minzokugaku. The purpose of the study is to bring into light an unredeemed potential of his intellectual and political project as a critique of the way in which modern politics and knowledge systematically suppresses global diversity. The study reads his texts against the backdrop of the modern understanding of space and time and its political and moral implications and traces the historical evolution of his thought that culminates in the establishment of minzokugaku. My reading of Yanagita’s texts draws on three interpretive hypotheses. First, his thought can be interpreted as a critical engagement with John Stuart Mill’s philosophy of history, as he turns Mill’s defense of diversity against Mill’s justification of enlightened despotism in non-Western societies. Second, to counter Mill’s individualistic notion of progressive agency, he turns to a Marxian notion of anthropological space, in which a laboring class makes history by continuously transforming nature, and rehabilitates the common people (jomin) as progressive agents. Third, in addition to the common people, Yanagita integrates wandering people as a countervailing force to the innate parochialism and conservatism of agrarian civilization. To excavate the unrecorded history of ordinary farmers and wandering people and promote the formation of national consciousness, his minzokugaku adopts travel as an alternative method for knowledge production and political education. In light of this interpretation, the aim of Yanagita’s intellectual and political project can be understood as defense and critique of the Enlightenment tradition. Intellectually, he attempts to navigate between spurious universalism and reactionary particularism by revaluing diversity as a necessary condition for universal knowledge and human progress. Politically, his minzokugaku aims at nation-building/globalization from below by tracing back the history of a migratory process cutting across the existing boundaries. His project is opposed to nation-building from above that aims to integrate the world population into international society at the expense of global diversity.
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long-term research on freshwater ecosystems provides insights that can be difficult to obtain from other approaches. Widespread monitoring of ecologically relevant water-quality parameters spanning decades can facilitate important tests of ecological principles. Unique long-term data sets and analytical tools are increasingly available, allowing for powerful and synthetic analyses across sites. long-term measurements or experiments in aquatic systems can catch rare events, changes in highly variable systems, time-lagged responses, cumulative effects of stressors, and biotic responses that encompass multiple generations. Data are available from formal networks, local to international agencies, private organizations, various institutions, and paleontological and historic records; brief literature surveys suggest much existing data are not synthesized. Ecological sciences will benefit from careful maintenance and analyses of existing long-term programs, and subsequent insights can aid in the design of effective future long-term experimental and observational efforts. long-term research on freshwaters is particularly important because of their value to humanity.
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The purpose of the study was to investigate the physiological and psychological benefits provided by a self-selected health and wellness course on a racially and ethnically diverse student population. It was designed to determine if students from a 2-year Hispanic serving institution (HIS) from a large metropolitan area would enhance their capacity to perform physical activities, increase their knowledge of health topics and raise their exercise self-efficacy after completing a course that included educational and activity components for a period of 16 weeks. A total of 185 students voluntarily agreed to participate in the study. An experimental group was selected from six sections of a health and wellness course, and a comparison group from students in a student life skills course. All participants were given anthropometric tests of physical fitness, a knowledge test, and an exercise self-efficacy scale was given at the beginning and at the conclusion of the semester. An ANCOVA analyses with the pretest scores being the covariate and the dependent variable being the difference score, indicated a significant improvement of the experimental group in five of the seven anthropometric tests over the comparison group. In addition, the experimental group increased in two of the three sections of the exercise self-efficacy scale indicating greater confidence to participate in physical activities in spite of barriers over the comparison group. The experimental group also increased in knowledge of health related topics over the comparison group at the .05 significance level. Results indicated beneficial outcomes gained by students enrolled in a 16-week health and wellness course. The study has several implications for practitioners, faculty members, educational policy makers and researchers in terms of implementation of strategies to promote healthy behaviors in college students and, to encourage them to engage in regular physical activities throughout their college years.
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This paper details the research methods an introductory qualitative research class used to both study an issue related to race and identity, and to familiarize themselves with data collection strategies. Throughout the paper the authors attempt to capture the challenges, disagreements, and consensus building that marked this unusual research endeavor.
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The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.
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The program PanTool was developed as a tool box like a Swiss Army Knife for data conversion and recalculation, written to harmonize individual data collections to standard import format used by PANGAEA. The format of input files the program PanTool needs is a tabular saved in plain ASCII. The user can create this files with a spread sheet program like MS-Excel or with the system text editor. PanTool is distributed as freeware for the operating systems Microsoft Windows, Apple OS X and Linux.
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Research on temporal-order perception uses temporal-order judgment (TOJ) tasks or synchrony judgment (SJ) tasks in their binary SJ2 or ternary SJ3 variants. In all cases, two stimuli are presented with some temporal delay, and observers judge the order of presentation. Arbitrary psychometric functions are typically fitted to obtain performance measures such as sensitivity or the point of subjective simultaneity, but the parameters of these functions are uninterpretable. We describe routines in MATLAB and R that fit model-based functions whose parameters are interpretable in terms of the processes underlying temporal-order and simultaneity judgments and responses. These functions arise from an independent-channels model assuming arrival latencies with exponential distributions and a trichotomous decision space. Different routines fit data separately for SJ2, SJ3, and TOJ tasks, jointly for any two tasks, or also jointly for the three tasks (for common cases in which two or even the three tasks were used with the same stimuli and participants). Additional routines provide bootstrap p-values and confidence intervals for estimated parameters. A further routine is included that obtains performance measures from the fitted functions. An R package for Windows and source code of the MATLAB and R routines are available as Supplementary Files.
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Postprint
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Peer reviewed
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Funding and trial registration: Scottish Government Chief Scientist Office grant CZH/3/17. ClinicalTrials.gov registration NCT01602705.
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In this work, we present an adaptive unequal loss protection (ULP) scheme for H264/AVC video transmission over lossy networks. This scheme combines erasure coding, H.264/AVC error resilience techniques and importance measures in video coding. The unequal importance of the video packets is identified in the group of pictures (GOP) and the H.264/AVC data partitioning levels. The presented method can adaptively assign unequal amount of forward error correction (FEC) parity across the video packets according to the network conditions, such as the available network bandwidth, packet loss rate and average packet burst loss length. A near optimal algorithm is developed to deal with the FEC assignment for optimization. The simulation results show that our scheme can effectively utilize network resources such as bandwidth, while improving the quality of the video transmission. In addition, the proposed ULP strategy ensures graceful degradation of the received video quality as the packet loss rate increases. © 2010 IEEE.