Markdown To Question & Test Interoperability,
2021
San Jose State University
Markdown To Question & Test Interoperability, Su Kim
Master's Projects
As the classroom setting shifted to a virtual one as a result of Covid-19, numerous software are readily available to accommodate for the change, including Canvas, the online course management system. Canvas has a core feature that allows teachers to generate and administer quizzes for students through their interface, but it does not fully utilize the potential with online exams. The first step to exploring this potential is this project, known as Markdown to Question & Test Interoperability (M2QTI). Based on the QTI specifications, this tool lets users to plan and write quizzes in Markdown format. Combined with Canvas’s ability …
Applying Simulated Annealing As An Intelligent Genetic Mutation Operator For Finding Most Probable Explanations On Bayesian Belief Networks,
2021
The American University in Cairo AUC
Applying Simulated Annealing As An Intelligent Genetic Mutation Operator For Finding Most Probable Explanations On Bayesian Belief Networks, Sahr Attia Afara
Archived Theses and Dissertations
No abstract provided.
Changes In R,
2021
Czech Technical University
Changes In R, Tomas Kalibera, Sebastian Meyer, Kurt Hornik, Gennadiy Starostin, Luke Tierney
The R Journal
We present important changes in the development version of R (referred to as R-devel, to become R 4.2) and give a summary of the new search engine interfaced by RSiteSearch(). Some statistics on bug tracking activities in 2021 are also provided.
The Vote Package: Single Transferable Vote And Other Electoral Systems In R,
2021
University of Washington
The Vote Package: Single Transferable Vote And Other Electoral Systems In R, Adrian E. Raftery, Hana ŠevčÍková, Bernard W. Silverman
The R Journal
We describe the vote package in R, which implements the plurality (or first-past-the-post), two-round runoff, score, approval, and Single Transferable Vote (STV) electoral systems, as well as methods for selecting the Condorcet winner and loser. We emphasize the STV system, which we have found to work well in practice for multi-winner elections with small electorates, such as committee and council elections, and the selection of multiple job candidates. For single-winner elections, STV is also called Instant Runoff Voting (IRV), Ranked Choice Voting (RCV), or the alternative vote (AV) system. The package also implements the STV system with equal preferences, for …
Volume Approximation And Sampling For Convex Polytopes In R,
2021
National & Kapodistrian University of Athens
Volume Approximation And Sampling For Convex Polytopes In R, Apostolos Chalkis, Vissarion Fisikopoulos
The R Journal
Sampling from high-dimensional distributions and volume approximation of convex bodies are fundamental operations that appear in optimization, finance, engineering, artificial intelligence, and machine learning. In this paper, we present volesti, an R package that provides efficient, scalable algorithms for volume estimation, uniform, and Gaussian sampling from convex polytopes. volesti scales to hundreds of dimensions, handles efficiently three different types of polyhedra and provides non existing sampling routines to R. We demonstrate the power of volesti by solving several challenging problems using the R language
Openskies - Integration Of Aviation Data Into The R Ecosystem,
2021
Okinawa Institute of Science and Technology Graduate University
Openskies - Integration Of Aviation Data Into The R Ecosystem, Rafael Ayala, Daniel Ayala, Lara Sellés Vidal, David Ruiz
The R Journal
Aviation data has become increasingly more accessible to the public thanks to the adoption of technologies such as Automatic Dependent Surveillance-Broadcast (ADS-B) and Mode S, which provide aircraft information over publicly accessible radio channels. Furthermore, the OpenSky Network provides multiple public resources to access such air traffic data from a large network of ADS-B receivers. Here, we present openSkies, the first R package for processing public air traffic data. The package provides an interface to the OpenSky Network resources, standardized data structures to represent the different entities involved in air traffic data, and functionalities to analyze and visualize such …
A New Versatile Discrete Distribution,
2021
The University of Auckland
A New Versatile Discrete Distribution, Rolf Turner
The R Journal
This paper introduces a new flexible distribution for discrete data. Approximate moment estimators of the parameters of the distribution, to be used as starting values for numerical optimization procedures, are discussed. “Exact” moment estimation, effected via a numerical procedure, and maximum likelihood estimation, are considered. The quality of the results produced by these estimators is assessed via simulation experiments. Several examples are given of fitting instances of the new distribution to real and simulated data. It is noted that the new distribution is a member of the exponential family. Expressions for the gradient and Hessian of the log-likelihood of the …
Passed: Calculate Power And Sample Size For Two Sample Tests,
2021
University of Missouri
Passed: Calculate Power And Sample Size For Two Sample Tests, University Of Missouri Li, Ryan P. Knigge, Kaiyi Chen, Emily V. Leary
The R Journal
Power and sample size estimation are critical aspects of study design to demonstrate minimized risk for subjects and justify the allocation of time, money, and other resources. Researchers often work with response variables that take the form of various distributions. Here, we present an R package, PASSED, that allows flexibility with seven common distributions and multiple options to accommodate sample size or power analysis. The relevant statistical theory, calculations, and examples for each distribution using PASSED are discussed in this paper.
Robust And Efficient Optimization Using A Marquardt-Levenberg Algorithm With R Package Marqlevalg,
2021
Bordeaux Population Health Research Center
Robust And Efficient Optimization Using A Marquardt-Levenberg Algorithm With R Package Marqlevalg, Viviane Philipps, Boris P. Hejblum, Mélanie Prague, Daniel Commenges, Cécile Proust-Lima
The R Journal
Implementations in R of classical general-purpose algorithms for local optimization generally have two major limitations which cause difficulties in applications to complex problems: too loose convergence criteria and too long calculation time. By relying on a Marquardt-Levenberg algorithm (MLA), a Newton-like method particularly robust for solving local optimization problems, we provide with marqLevAlg package an efficient and general-purpose local optimizer which (i) prevents convergence to saddle points by using a stringent convergence criterion based on the relative distance to minimum/maximum in addition to the stability of the parameters and of the objective function; and (ii) reduces the computation time in …
Emss: New Em-Type Algorithms For The Heckman Selection Model In R,
2021
Konkuk University
Emss: New Em-Type Algorithms For The Heckman Selection Model In R, Kexuan Yang, Sang Kyu Lee, Jun Zhao, Hyoung-Moon Kim
The R Journal
When investigators observe non-random samples from populations, sample selectivity problems may occur. The Heckman selection model is widely used to deal with selectivity problems. Based on the EM algorithm, Zhao et al. (2020) developed three algorithms, namely, ECM, ECM(NR), and ECME(NR), which also have the EM algorithm’s main advantages: stability and ease of implementation. This paper provides the implementation of these three new EM-type algorithms in the package EMSS and illustrates the usage of the package on several simulated and real data examples. The comparison between the maximum likelihood estimation method (MLE) and three new EM-type algorithms in robustness issues …
Stratigrapher: Concepts For Litholog Generation In R,
2021
University of Liege
Stratigrapher: Concepts For Litholog Generation In R, Sébastien Wouters, Anne-Christine Da Silva, Frédéric Boulvain, Xavier Devleeschouwer
The R Journal
The StratigrapheR package proposes new concepts for the generation of lithological logs, or lithologs, in R. The generation of lithologs in a scripting environment opens new opportunities for the processing and analysis of stratified geological data. Among the new concepts presented: new plotting and data processing methodologies, new general R functions, and computer-oriented data conventions are provided. The package structure allows for these new concepts to be further improved, which can be done independently by any R user. The current limitations of the package are highlighted, along with the limitations in R for geological data processing, to help identify the …
Msae: An R Package Of Multivariate Fay-Herriot Models For Small Area Estimation,
2021
Politeknik Statistika STIS
Msae: An R Package Of Multivariate Fay-Herriot Models For Small Area Estimation, Novia Permatasari, Azka Ubaidillah
The R Journal
The paper introduces an R Package of multivariate Fay-Herriot models for small area estimation named msae. This package implements four types of Fay-Herriot models, including univariate Fay-Herriot model (model 0), multivariate Fay-Herriot model (model 1), autoregressive multivariate Fay-Herriot model (model 2), and heteroskedastic autoregressive multivariate Fay-Herriot model (model 3). It also contains some datasets generated based on multivariate Fay-Herriot models. We describe and implement functions through various practical examples. Multivariate Fay-Herriot models produce a more efficient parameter estimation than direct estimation and univariate model.
Software Engineering And R Programming: A Call For Research,
2021
Australian National University
Software Engineering And R Programming: A Call For Research, Melina Vidoni
The R Journal
Although R programming has been a part of research since its origins in the 1990s, few studies address scientific software development from a Software Engineering (SE) perspective. The past few years have seen unparalleled growth in the R community, and it is time to push the boundaries of SE research and R programming forwards. This paper discusses relevant studies that close this gap Additionally, it proposes a set of good practices derived from those findings aiming to act as a call-to-arms for both the R and RSE (Research SE) community to explore specific, interdisciplinary paths of research
Editorial,
2021
Monash University
Editorial, Dianne Cook
The R Journal
On behalf of the R Foundation and the Editorial board, I am pleased to present Volume 13 Issue 2 of the R Journal. This is the biggest issue ever!
First, some news from the Editorial board. A big thank you to Mike Kane, who has finished his term. As Editor-in-Chief in 2020, Mike expanded operations to include Associate Editors in the reviewing process. The R Journal now has a team of 20 Associate Editors. This has helped to manage the increasing number of submissions. We welcome new Associate Editors, Przemek Biecek, Chris Brunsdon, Mine Çetinkaya-Rundel, Kieran Healy, Adam Loy, Priyanga …
Elliptical Symmetry Tests In R,
2021
Ghent University
Elliptical Symmetry Tests In R, Slad̄Ana Babić, Christophe Ley, Marko Palangetić
The R Journal
The assumption of elliptical symmetry has an important role in many theoretical developments and applications. Hence, it is of primary importance to be able to test whether that assumption actually holds true or not. Various tests have been proposed in the literature for this problem. To the best of our knowledge, none of them has been implemented in R. This article describes the R package ellipticalsymmetry which implements several well-known tests for elliptical symmetry together with some recent tests. We demonstrate the testing procedures with a real data example.
An R Package For Robust Solution To The Behrens-Fisher Problem,
2021
Eskisehir Osmangazi University
An R Package For Robust Solution To The Behrens-Fisher Problem, Gamze Güven, ŞÜkrü Acıtaş, Hatice ŞAmkar, Birdal ŞEnoğLu
The R Journal
Welch’s two-sample t-test based on least squares (LS) estimators is generally used to test the equality of two normal means when the variances are not equal. However, this test loses its power when the underlying distribution is not normal. In this paper, two different tests are proposed to test the equality of two long-tailed symmetric (LTS) means under heterogeneous variances. Adaptive modified maximum likelihood (AMML) estimators are used in developing the proposed tests since they are highly efficient under LTS distribution. An R package called RobustBF is given to show the implementation of these tests. Simulated Type I error rates …
Tramme: Mixed-Effects Transformation Models Using Template Model Builder,
2021
Universität Zürich
Tramme: Mixed-Effects Transformation Models Using Template Model Builder, Bálint Tamási, Torsten Hothorn
The R Journal
Linear transformation models constitute a general family of parametric regression models for discrete and continuous responses. To accommodate correlated responses, the model is extended by incorporating mixed effects. This article presents the R package tramME, which builds on existing implementations of transformation models (mlt and tram packages) as well as Laplace approximation and automatic differentiation (using the TMB package), to calculate estimates and perform likelihood inference in mixed-effects transformation models. The resulting framework can be readily applied to a wide range of regression problems with grouped data structures.
Changes On Cran,
2021
WU Wirtschaftsuniversität Wien
Changes On Cran, Kurt Hornik, Uwe Ligges, Achim Zeileis
The R Journal
In the past 6 months, 1077 new packages were added to the CRAN package repository. 113 packages were unarchived and 331 were archived. The following shows the growth of the number of active packages in the CRAN package repository:
Cat.Dt: An R Package For Fast Construction Of Accurate Computerized Adaptive Tests Using Decision Trees,
2021
Universidad Carlos III de Madrid
Cat.Dt: An R Package For Fast Construction Of Accurate Computerized Adaptive Tests Using Decision Trees, Javier Rodríguez-Cuadrado, Juan C. Laria, David Delgado-Gómez
The R Journal
This article introduces the cat.dt package for the creation of Computerized Adaptive Tests (CATs). Unlike existing packages, the cat.dt package represents the CAT in a Decision Tree (DT) structure. This allows building the test before its administration, ensuring that the creation time of the test is independent of the number of participants. Moreover, to accelerate the construction of the tree, the package controls its growth by joining nodes with similar estimations or distributions of the ability level and uses techniques such as message passing and pre-calculations. The constructed tree, as well as the estimation procedure, can be visualized using the …
Spnetwork: A Package For Network Kernel Density Estimation,
2021
Urbanisation Culture et Société
Spnetwork: A Package For Network Kernel Density Estimation, Jeremy Gelb
The R Journal
This paper introduces the new package spNetwork that provides functions to perform Network Kernel Density Estimate analysis (NKDE). This method is an extension of the classical Kernel Density Estimate (KDE), a non parametric approach to estimate the intensity of a spatial process. More specifically, it adapts the KDE for cases when the study area is a network, constraining the location of events (such as accidents on roads, leaks in pipes, fish in rivers, etc.). We present and discuss in this paper the three main versions of NKDE: simple, discontinuous, and continuous that are implemented in spNetwork. We illustrate how to …
