180,684 research outputs found
An Empirical analysis of Open Source Software Defects data through Software Reliability Growth Models
No full textThe purpose of this study is to analyze the reliability growth of Open Source Software (OSS) using Software Reliability Growth Models (SRGM). This study uses defects data of twenty five different releases of five OSS projects. For each release of the selected projects two types of datasets have been created; datasets developed with respect to defect creation date (created date DS) and datasets developed with respect to defect updated date (updated date DS). These defects datasets are modelled by eight SRGMs; Musa Okumoto, Inflection S-Shaped, Goel Okumoto, Delayed S-Shaped, Logistic, Gompertz, Yamada Exponential, and Generalized Goel Model. These models are chosen due to their widespread use in the literature. The SRGMs are fitted to both types of defects datasets of each project and the their fitting and prediction capabilities are analysed in order to study the OSS reliability growth with respect to defects creation and defects updating time because defect analysis can be used as a constructive reliability predictor. Results show that SRGMs fitting capabilities and prediction qualities directly increase when defects creation date is used for developing OSS defect datasets to characterize the reliability growth of OSS. Hence OSS reliability growth can be characterized with SRGM in a better way if the defect creation date is taken instead of defects updating (fixing) date while developing OSS defects datasets in their reliability modellin
Maximum Entropy Bootstrap for Time Series: The meboot R Package
No full textThe maximum entropy bootstrap is an algorithm that creates an ensemble for time series inference. Stationarity is not required and the ensemble satisfies the ergodic theorem and the central limit theorem. The meboot R package implements such algorithm. This document introduces the procedure and illustrates its scope by means of several guided applications.
Nur-i-Afshan V.02 no.34 August 1898 Supplement
No full textContents: News and notes - Current thought : a call for prayer for India by Ward, R. J. - Golden keys [Poetry] by Atiq Ullah - Telegrams [Letter]
This volume of Nur-i-Afshan published weekly on Fridays from Ludhiana
Sample Selection Models in R: Package sampleSelection
No full textThis paper describes the implementation of Heckman-type sample selection models in R. We discuss the sample selection problem as well as the Heckman solution to it, and argue that although modern econometrics has non- and semiparametric estimation methods in its toolbox, Heckman models are an integral part of the modern applied analysis and econometrics syllabus. We describe the implementation of these models in the package sampleSelection and illustrate the usage of the package on several simulation and real data examples. Our examples demonstrate the effect of exclusion restrictions, identification at infinity and misspecification. We argue that the package can be used both in applied research and teaching.
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Microwave Sensing Dataset for Noninvasive Monitoring of Ventricle Enlargement due to Alzheimer's Disease
No full textThe research hypothesis for this study was to investigate the potential of microwave imaging using unidirectional antennas for monitoring neurodegenerative diseases, specifically Alzheimer's disease. The data was collected using a wearable device and measurement setup that included five lamb brain phantoms that were designed to mimic the lateral ventricle enlargement due to Alzheimer's disease .The data include both the magnitude and the phase for each of the five phantoms at each discrete frequency.The most interesting thing about this study is that the data from the microwave imaging with unidirectional antennas was able to accurately show the enlargement of the lateral ventricles and the presence of cerebral spinal fluid in the lamb brain phantoms. This suggests that this method could be used to track neurodegenerative diseases like Alzheimer's.This data can be interpreted and used by researchers and scientists working on developing novel signal processing and imaging techniques, as well as those interested in validating simulation results. It can also be used to further investigate the potential of microwave imaging for monitoring neurodegenerative diseases
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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