2,506 research outputs found

    The determination of measures of software reliability

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    Measurement of software reliability was carried out during the development of data base software for a multi-sensor tracking system. The failure ratio and failure rate were found to be consistent measures. Trend lines could be established from these measurements that provide good visualization of the progress on the job as a whole as well as on individual modules. Over one-half of the observed failures were due to factors associated with the individual run submission rather than with the code proper. Possible application of these findings for line management, project managers, functional management, and regulatory agencies is discussed. Steps for simplifying the measurement process and for use of these data in predicting operational software reliability are outlined

    Vol. 16, No. 2 (Full Issue)

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    Assessing creativity with self-report scales: A review and empirical evaluation.

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    This article reviews recent developments in the assessment of creativity using self-report scales. We focus on four new and promising scales: the Creative Achievement Questionnaire, the Biographical Inventory of Creative Behaviors, the revised Creative Behavior Inventory, and the Creative Domain Questionnaire. For each scale, we review evidence for reliability, validity, and structure, and we discuss important methodological features for users to consider. We then present new analyses of each scale based on a large, diverse sample. We evaluate each scale's item-level and scale-level psychometric features, using both classical test theory and item response theory, and we examine how the scales converge. All four scales performed well and covaried highly with each other. Based on the latest generation of tools, self-report creativity assessment is probably much better than creativity researchers think it is

    Spatial Genetic and Distribution Modeling for the Conservation of Hellbender Salamanders

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    Ecological data is inherently spatial; however, it is still the norm to model ecological data as spatially invariant. Failure to account for spatial structure in response variables and modeled relationships can result in inflated coefficient values, shifts in the relative importance and sign of predictors, cross-scale contradictions in relationships, and reduced predictive power due to the averaging of modeled relationships. When ecological models are used to support conservation decision-making, model error can be costly leading to both misallocation of limited resources and distrust of science-based management. My dissertation focuses on developing methods to account for spatial structure in two models commonly used to inform conservation decisions. Both chapters focus on the imperiled hellbender salamander (Cryptobranchus alleganiensis) and were designed to provide guidance on the conservation and management of a species that is facing precipitous declines throughout much of its range. In chapter one, I modeled the relationship between the hellbender genome and climate and stream variables across the range of the species. I extended multiple matrix regression into a mixed modeling framework to account for strong spatial population structuring. The approach improved model fits, shrunk coefficient estimates, and increased the concordance of model results with an independent analysis of locus-specific environmental associations. The results of the model were used to forecast genomic vulnerability across the range of the species and the resulting map suggested a potential genetic mismatch between current and future conditions in portions of the range that accommodate stable populations. In chapter two, I developed a species distribution model to help target sampling and translocation locations for eastern hellbenders (Cryptobranchus alleganiensis alleganiensis). It extended presence-only modeling into a mixed modeling framework to help account for autocorrelation and nonstationarity in the intensity of hellbender occurrences and unexplained environmental heterogeneity across physiographic provinces. The spatially explicit approach improves overall model discrimination and dramatically improves model performance in regions most in need of conservation guidance. Taken together, the chapters provide flexible methods to improve the performance of common ecological models and tangible products to support hellbender conservation

    Assessing Creativity With Self-Report Scales : A Review and Empirical Evaluation

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    This article reviews recent developments in the assessment of creativity using self-report scales. We focus on four new and promising scales: the Creative Achievement Questionnaire, the Biographical Inventory of Creative Behaviors, the revised Creative Behavior Inventory, and the Creative Domain Questionnaire. For each scale, we review evidence for reliability, validity, and structure, and we discuss important methodological features for users to consider. We then present new analyses of each scale based on a large, diverse sample. We evaluate each scale\u27s item-level and scale-level psychometric features, using both classical test theory and item response theory, and we examine how the scales converge. All four scales performed well and covaried highly with each other. Based on the latest generation of tools, self-report creativity assessment is probably much better than creativity researchers think it is

    VI Workshop on Computational Data Analysis and Numerical Methods: Book of Abstracts

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    The VI Workshop on Computational Data Analysis and Numerical Methods (WCDANM) is going to be held on June 27-29, 2019, in the Department of Mathematics of the University of Beira Interior (UBI), Covilhã, Portugal and it is a unique opportunity to disseminate scientific research related to the areas of Mathematics in general, with particular relevance to the areas of Computational Data Analysis and Numerical Methods in theoretical and/or practical field, using new techniques, giving especial emphasis to applications in Medicine, Biology, Biotechnology, Engineering, Industry, Environmental Sciences, Finance, Insurance, Management and Administration. The meeting will provide a forum for discussion and debate of ideas with interest to the scientific community in general. With this meeting new scientific collaborations among colleagues, namely new collaborations in Masters and PhD projects are expected. The event is open to the entire scientific community (with or without communication/poster)

    Employing Natural History Collections in the Aid of Conservation: Streamlining an Approach to Model Species Distributions En Masse for the Preservation of Biodiversity

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    Using species distribution models (SDMs) in Natural History Collections (NHCs) can influence how humans implement conservation changes in flora and fauna communities and ecosystems. Through the use of legacy data (old NHCs and their associated locality/collection information), data correction (background data or pseudo absences added to presence-only data), and the SDM software, Maxent (and its associated geographic information systems or GIS projected models), it has been shown that it is feasible to create a low budget protocol/setup to project the past, present and future of species population changes. This has been done in the past few decades as more collections and their locality data have become digitized, potentially allowing more natural history collecting institutions and scientists to participate in more conservation projects. We can learn from how past and present population ranges have changed due to climate change, urbanization, and deforestation (among other changes) to be able to project where species ranges could exist in the future. The ultimate goal of this project is to provide both a streamlined protocol to input NHC data into Maxent in order to share the results of the Maxent models and associated statistics of NHC data, even if not publication worthy, to larger stakeholders, environmental policy makers and non-profits. Additionally, this project can allow scientists to follow up on the methods and results of the models to see if there really are possible conservation concerns. Interns, citizen sciences, collections workers (non-PhD scientists) can do this in smaller NHCs, and report their findings from their collections. This project has the potential to have a broader impact on rare species housed in smaller collections. Further, it has the capacity to be able allow for specific species and biota to be conserved with the help of precise small grants for specified flora and fauna to be modeled. While this type of project is not the end all be all cure for the biodiversity crisis, it can be a way to use available resources and technology for the advancement of our planet and its inhabitants

    ELECTROPHYSIOLOGY OF BASAL GANGLIA (BG) CIRCUITRY AND DYSTONIA AS A MODEL OF MOTOR CONTROL DYSFUNCTION

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    The basal ganglia (BG) is a complex set of heavily interconnected nuclei located in the central part of the brain that receives inputs from the several areas of the cortex and projects via the thalamus back to the prefrontal and motor cortical areas. Despite playing a significant part in multiple brain functions, the physiology of the BG and associated disorders like dystonia remain poorly understood. Dystonia is a devastating condition characterized by ineffective, twisting movements, prolonged co-contractions and contorted postures. Evidences suggest that it occurs due to abnormal discharge patterning in BG-thalamocortocal (BGTC) circuitry. The central purpose of this study was to understand the electrophysiology of BGTC circuitry and its role in motor control and dystonia. Toward this goal, an advanced multi-target multi-unit recording and analysis system was utilized, which allows simultaneous collection and analysis of multiple neuronal units from multiple brain nuclei. Over the cause of this work, neuronal data from the globus pallidus (GP), subthalamic nucleus (STN), entopenduncular nucleus (EP), pallidal receiving thalamus (VL) and motor cortex (MC) was collected from normal, lesioned and dystonic rats under awake, head restrained conditions. The results have shown that the neuronal population in BG nuclei (GP, STN and EP) were characterized by a dichotomy of firing patterns in normal rats which remains preserved in dystonic rats. Unlike normals, neurons in dystonic rat exhibit reduced mean firing rate, increased irregularity and burstiness at resting state. The chaotic changes that occurs in BG leads to inadequate hyperpolarization levels within the VL thalamic neurons resulting in a shift from the normal bursting mode to an abnormal tonic firing pattern. During movement, the dystonic EP generates abnormally synchronized and elongated burst duration which further corrupts the VL motor signals. It was finally concluded that the loss of specificity and temporal misalignment between motor neurons leads to corrupted signaling to the muscles resulting in dystonic behavior. Furthermore, this study reveals the importance of EP output in controlling firing modes occurring in the VL thalamus
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