Jürgen Symanzik

In this presentation, we will introduce our new R package, SWEVIS. Its main purpose is to visualize and explore spatial and spatio-temporal SWE data. SWEVIS includes our recently developed Bayesian statistical model to forecast SWE. It also implements multivariate exploratory data analysis (EDA) and exploratory spatial data analysis (ESDA) techniques, with a focus on SWE data. Three main features are provided for SWE data: (i) data manipulation methods, (ii) forecasting, and (iii) linkage between map views and interactive statistical graphics.

Purpose: A key emerging problem in radiology and radiation oncology for treatment planning is to review data intensive multimodality image sets. This process becomes more challenging as the number of image sets increases beyond one or two. We investigated the potential of the Image Tour (‘Image Grand Tour’ in the statistics community) for quantitatively combining multiple image sets into a single more useful image set. Methods: The Image Tour is a method for combining and visualizing multi‐spectral images or multiple registered images. The idea underlying the Image Tour is to project a linear combination of the pixel vectors into one‐dimensional space (for each pixel) and render these projected values as a gray‐scale image. The Image Tour continuously moves through the set of all possible projections of the input images for a single plane of interest in the registered image sets. Features that are hidden in a set of images due to background noise or almost identical nearby pixel values may eventually be revealed by some linear re‐combination of the input images. The user stops or flags tour projections which are judged particularly useful. We demonstrate the Image Tour applied to carotid MRIimages where no single MRI modality is capable of simultaneously revealing the four main features of the diseased carotid (the area with plaque, the remaining blood flow, fatty mass, and a calcification). Results: In this set of multiple pulse sequence MRIimages, the Image Tour ‘discovers’ multiple projections that clearly allow the user to distinguish among the interesting carotid artery features. Finding these projections is facilitated by the ‘video tour’ process of the Image Tour. Conclusions: The Image Tour has good potential both as a practical method of managing multi‐modality image sets for radiology/radiation oncology applications as well as potentially improving the accuracy of identifying relevant radiographic features.

The purpose of this study was to examine what patterns were revealed using heatmaps with hierarchical clustering to examine preschooler’s performance, speed, and developmental progressions in counting and seriation. The chapter describes a study conducted with 35 preschoolers who used six touchscreen virtual manipulative mathematics apps in two different learning sequences: counting and seriation. The analysis employed heatmaps coupled with hierarchical clustering to highlight changes in children’s performance, speed, and developmental progressions, between a pre- and post- assessment app after using two learning apps. This method allowed for analysis of individual and whole group data examining several tasks within each app and also several apps within each learning sequence. The analysis revealed different clusters of children grouped according to their developmental progressions which were related to incremental changes in performance and speed from the Pre to Post App use.

This project focused on building theory and knowledge about the nature of young children’s ways of thinking and interacting with virtual manipulatives using touch-screen mathematics apps. To conduct cutting edge research on novel topics such as this requires researchers to develop new and different tools to be used to answer unique questions, collect new kinds of data, and analyze the data in different ways. During the project, researchers interviewed 90 children ages 3 to 8 while the children interacted with mathematics apps on iPads. A variety of research tools needed to be developed to conduct the research. These tools included: interview protocols, procedures for app selection, observation protocols, parent surveys and interaction protocols, and data analysis protocols. This paper reports on the processes researchers used to develop the research tools for the project.

Leaf shape traits have long been a focus of many disciplines, but the complex genetic and environmental interactive mechanisms regulating leaf shape variation have not yet been investigated in detail. The question of the respective roles of genes and environment and how they interact to modulate leaf shape is a thorny evolutionary problem, and sophisticated methodology is needed to address it. In this study, we investigated a framework-level approach that inputs shape image photographs and genetic and environmental data, and then outputs the relative importance ranks of all variables after integrating shape feature extraction, dimension reduction, and tree-based statistical models. The power of the proposed framework was confirmed by simulation and a Populus szechuanica var. tibetica data set. This new methodology resulted in the detection of novel shape characteristics, and also confirmed some previous findings. The quantitative modeling of a combination of polygenetic, plastic, epistatic, and gene-environment interactive effects, as investigated in this study, will improve the discernment of quantitative leaf shape characteristics, and the methods are ready to be applied to other leaf morphology data sets. Unlike the majority of approaches in the quantitative leaf shape literature, this framework-level approach is data-driven, without assuming any pre-known shape attributes, landmarks, or model structures.

Computational Statistics is an international journal that fosters the publication of applications and methodological research in the field of computational statistics. In this article, we will discuss the motivation, history, some specialties, and the future scope of this journal.

Statistical Computing, as we in this section all know, is the center of Statistics. The program for the upcoming JSM 2011 in Miami Beach indicates that centrality. The Section on Statistical Computing is the main sponsor of 27 technical sessions and activities, and cosponsor of 50 more for a total of 77. The session and paper titles cover the entire gamut of statistical activity and many scientific and social issues. The cosponsors include most of the sections of ASA and many of the asso-

Morphological shape trait has long been a focus of many disciplines, but searching for structure in shape curves is opening unprecedented possibilities for investigating the complex features of morphological shape and help recognizing the genetics and landscape mechanisms that affect shape. Visualization studies of the interplay among landscape measurement, biological markers, and shape image can characterize important genetic and environmental effects on shape and discover their relative importance. In this article, we adapt five visual data mining methods to visualize the shape patterns under three different genotypes (aa, Aa, and AA), three location factors (longitude, latitude, and elevation), and two principal components (PC1 and PC3). Our study is motivated by a Quantitative Trait Loci (QTL) shape mapping research on the real leaf shape data of a natural population of poplar, Populus szechuanica var tibetica. Based on the estimated genotype information by the Linkage Disequili...

Background:The trends and patterns of the mortality rates for causes of death are meaningful information. They can provide a basis for national demographic and health care policies by identifying the number, causes, and geographical distribution of deaths.Objective:To explore and analyze the characteristics of the mortality rates for major causes of death in Korea.Methods:Some common data analysis methods were used to describe the data. We also used some visualization techniques such as heat maps and line plots to present mortality rates by gender, age, and year.Results:Our analysis shows the crude mortality rates have continually decreased over the last 25 years from 1983, though they have increased slightly since 2006. In addition, the top eight causes of death accounted for 80% of all Korean deaths in 2015. During the period 2005-2015, the leading cause of death was cancer in male and circulatory diseases in female. The trend for respiratory diseases shows a steep upward trend in...

Storing data and the results of your programming efforts is important for working over multiple sessions and sharing your results with collaborators. Since when MATLAB closes, all the variables in the workspace are lost, data must be stored in some other way than workspace variables. Sometimes data must also be readable by or written in a form that can be read by other programs.

This study examined second-grade children’s interactions with six virtual manipulative mathematics apps on the iPad. Following 30-40 minute interviews where children interacted individually with the apps under the guidance of an interviewer, pre and post assessments revealed statistically significant differences in second graders performance and efficiency using one series of apps to learn skip counting concepts, but no significant differences when using a series of apps to learn place value concepts. Results are discussed in terms of differences among the virtual manipulative apps that produced differing outcomes for children. Introduction “Apps” are technology applications for mobile devices with a touch screen (Groger, Silcher, Westkamper, & Mitschang, 2013). Many mathematics apps contain virtual manipulatives that students can manipulate to support the visualization of mathematics concepts. Virtual manipulatives (VMs) are defined by Moyer, Bolyard, and Spikell (2002) as “an interactive, Webbased visual representation of a dynamic object that presents opportunities for constructing mathematical knowledge” (p. 373). In a recent analysis of the Education Category of Apple’s App Store (Shuler, 2012), findings revealed that, of the over 500,000 apps available on iTunes and over 300,000 on Android, 72% of the top selling apps target preschool or elementary aged children, and the second most popular subject for apps is mathematics (13%). Yet there is very little research on how mathematics apps benefit children’s learning. The purpose of this study was to examine young children’s learning performance and efficiency during clinical interviews in which each child interacted with a variety of virtual manipulative mathematics iPad apps. Theoretical Perspective and Review of the Literature VM iPad apps have become popular because they use representations to display abstract mathematical concepts in a pictorial way and children can interact with these representations. Theorists like Bruner (1964) proposed that during cognitive development children make sense of their world through enactive means (i.e., the manipulation of physical objects) that then connect with iconic (visual images, pictures) and symbolic (words, numbers, symbols) representations. Therefore, interactions with representations are important for children’s cognitive development. Proponents of embodied cognition theories argue that children’s physical manipulations of representations and their abstractions of mathematical ideas do not follow one from the other, but rather they go hand in hand (Lakoff & Nunez, 2000). Our position on the use of virtual manipulatives for touch-screen devices is that tool fluency and mathematical understanding are not simply a process of internalizing concrete artifacts into mental representations (Nemirovsky, Kelton, & Rhodehamel, 2013). We concur with Nemirovsky et al. that when children are interacting with representations on touch-screen devices, there is no separation between mind and body because action and thought are intertwined. Manipulating objects on a touch-screen device is not a precursor to mathematical thought – it is, itself, mathematical thought. Most studies examining the use of touch-screen devices for mathematics learning are fairly new. For example, Paek, Hoffman and Black (2013) conducted a series of quantitative studies of a VM mathematics app and reported results on connecting feedback (i.e., audio and visual) and interaction types (i.e., touch versus mouse) in firstand second-grade students’ learning. Generally, their studies suggested that audio feedback may be important initially, but interaction type (i.e., touch-screen vs. mouse) has more influence long-term. Other studies about the use of touch-screen devices are much more general in nature, and rather than examining features of the touch-screen environment, they focus simply on the use of the iPad for mathematics instruction in general. Methods This paper is part of a larger study that used an initiation mixed methods research design (Greene, Caracelli, & Graham, 1989). Other papers from the larger research project detail children’s learning progressions, explore app affordances and their influence on learning, and describe specific strategies children used (see e.g., Moyer-Packenham, forthcoming). This paper asked: How do interactions with VM iPad apps immediately impact young children’s learning performance and efficiency? Learning performance was defined as accuracy on pre and post assessment tasks using VM iPad apps. Learning efficiency was defined as changes in the speed with which children completed a variety of learning tasks using the VM iPad apps. Participants Thirty-two children, ages 7 and 8, enrolled in Grade 2, participated in this study. Children were recruited from elementary schools using informational brochures/letters. Most children were Caucasian (85%) and one-third of children reported low Socio-Economic status (33%)…

The e ect of the ordering of questions in sample surveys has been well investigated. However, there has been no study so far that examined the e ect of the ordering of exam questions on the exam behavior of students. In this paper, we will discuss the e ect of the ordering of questions on the student behavior for an introductory long{distance statistics course. Because we were working with the electronic textbook CyberStats that records exact submission times of student answers to exam questions, the following research question could be answered: Do students usually answer exam questions in sequential order (independent from the exam questions) or do they tend to jump from one exam question to another while leaving some types of (apparentely more di cult) exam questions until the very end? As it turned out, many students answer exam questions in almost perfect sequential order. This may easily lead to the result that those students will miss simple exam questions towards the end of ...

During the year 2004, Utah State University offered three sessions of an introductory long–distance statistics course (Stat 2000) for students in its International Program in Hong Kong. These sessions were based on the electronic textbook CyberStats. The exams were given electronically and all student answers were stored in the CyberStats data base. All means that if a student changed the answer to question multiple times, all previous answers were still accessible and not only the final answer. In this paper, we investigate how those changes in answers affected students’ scores. 98.6% of the multiple–choice questions and 84.4% of text–based questions got answered at least once. Conditional on the fact that a question got answered at least once, text– based answers got changed at a rate of 10.8% that almost doubles the rate at which multiple–choice answers got changed (5.7%). Text–based answers got changed for the second time at a higher rate (1.3%) than multiple–choice answers (0.8...

Interactive and dynamic statistical graphics enable data analysts in all fields to carry out visual investigations leading to insights into relationships in complex data. Interactive and dynamic statistical graphics involve methods for viewing data in the form of point clouds or modeled surfaces. Higher-dimensional data can be projected into one-, two- or three-dimensional planes in a set of multiple views or as a continuous sequence of views which constitutes motion through the higher-dimensional space containing the data.

Throughout the year 2004, Utah State Univer-sity offered three long–distance introductory statis-tics courses (Stat 2000) for students in its Interna-tional Program in Hong Kong. These courses had the main instructor in the USA, a local instructor in Hong Kong, and were ...

This paper discusses the use of a geographic information systems (GIS), Arcview 2.1, linked with a dynamic graphics program, XGobi, in the statistical analysis of spatial data. The link allows multivariate data, collected at geographic locations and stored in Arcview, to be passed into XGobi and analyzed dynamically. The connection between the points in XGobi and the spatial locations from which they were collected is maintained so that points in either Arcview or XGobi can be brushed and the corresponding points in the other application identified immediately. Spatial cumulative distribution functions (SCDFs), spatially lagged scatter plots, and variogram cloud plots can be displayed in XGobi using the link. In each type of plot, the connection to the spatial sampling location is maintained and user interaction can take place in either application. The link is used to predict and analyze SCDFs of forest crown health in the northeastern United States. The SCDFs are predicted from fi...