Multimedia application for educational purposes: Development of algorithmic thinking

AbstractThis paper is based on many years’ experience with multimedia applications supporting the area of computer science education and it could serve as an inspirational material directed to all educators developing students’ algorithmic thinking. Education of subjects related with computer science is from the perspective of other for centuries taught subjects, still in its infancy. Even nowadays a teaching method aimed at developing algorithmic thinking of students is still the subject of extensive discussions and teachers are looking for different ways on how to access it to students. Next to the educational approach to this base of computer science it is also important to find a suitable support for students’ self-learning. Multimedia applications give teachers an excellent chance to demonstrate and visualize the subject matter more clearly and comprehensibly, as well as also enabling them to prepare study material for students which optimizes their study habits. Along with large software products developed by a team of professionals there are also various smaller programs dealing with objects appropriate to course subject matter created on a script given by the teacher with regard to students’ needs. In the paper such application prepared to intensify self-preparation of students in subjects developing algorithmic thinking is introduced and its benefit discussed. Animations useful to be used as an introductory complement to lectures are introduced as well. At the end advantages of the professional virtual learning environment containing such study material are mentioned

Code Park: A New 3D Code Visualization Tool

We introduce Code Park, a novel tool for visualizing codebases in a 3D game-like environment. Code Park aims to improve a programmer's understanding of an existing codebase in a manner that is both engaging and intuitive, appealing to novice users such as students. It achieves these goals by laying out the codebase in a 3D park-like environment. Each class in the codebase is represented as a 3D room-like structure. Constituent parts of the class (variable, member functions, etc.) are laid out on the walls, resembling a syntax-aware "wallpaper". The users can interact with the codebase using an overview, and a first-person viewer mode. We conducted two user studies to evaluate Code Park's usability and suitability for organizing an existing project. Our results indicate that Code Park is easy to get familiar with and significantly helps in code understanding compared to a traditional IDE. Further, the users unanimously believed that Code Park was a fun tool to work with.Comment: Accepted for publication in 2017 IEEE Working Conference on Software Visualization (VISSOFT 2017); Supplementary video: https://www.youtube.com/watch?v=LUiy1M9hUK

A parent-centered radial layout algorithm for interactive graph visualization and animation

We have developed (1) a graph visualization system that allows users to explore graphs by viewing them as a succession of spanning trees selected interactively, (2) a radial graph layout algorithm, and (3) an animation algorithm that generates meaningful visualizations and smooth transitions between graphs while minimizing edge crossings during transitions and in static layouts. Our system is similar to the radial layout system of Yee et al. (2001), but differs primarily in that each node is positioned on a coordinate system centered on its own parent rather than on a single coordinate system for all nodes. Our system is thus easy to define recursively and lends itself to parallelization. It also guarantees that layouts have many nice properties, such as: it guarantees certain edges never cross during an animation. We compared the layouts and transitions produced by our algorithms to those produced by Yee et al. Results from several experiments indicate that our system produces fewer edge crossings during transitions between graph drawings, and that the transitions more often involve changes in local scaling rather than structure. These findings suggest the system has promise as an interactive graph exploration tool in a variety of settings

Dynamic Animations of Journal Maps: Indicators of Structural Changes and Interdisciplinary Developments

The dynamic analysis of structural change in the organization of the sciences requires methodologically the integration of multivariate and time-series analysis. Structural change--e.g., interdisciplinary development--is often an objective of government interventions. Recent developments in multi-dimensional scaling (MDS) enable us to distinguish the stress originating in each time-slice from the stress originating from the sequencing of time-slices, and thus to locally optimize the trade-offs between these two sources of variance in the animation. Furthermore, visualization programs like Pajek and Visone allow us to show not only the positions of the nodes, but also their relational attributes like betweenness centrality. Betweenness centrality in the vector space can be considered as an indicator of interdisciplinarity. Using this indicator, the dynamics of the citation impact environments of the journals Cognitive Science, Social Networks, and Nanotechnology are animated and assessed in terms of interdisciplinarity among the disciplines involved

Interactive Visualization of the Market Graph

Financial markets are a fruitful area for data exploration, but the overwhelming size and dimension of the datasets usually prohibit meaningful analysis, especially on a large scale. Thus, there is a need for effective visualization tools to assist in efficiently exploring the data space. In this paper, we present a novel visualization tool that empowers a user with an interactive tool for finding meaningful relationships in historical or real-time financial market data. To reduce the size of data to be visualized, we summarize the areas of interest within the market graph by displaying only the pre-computed clusters, and aggregated inter- and intra-cluster edges. Target graph structures and their associated attributes are encoded using several visually intuitive schemes, and a modified force-directed model is used to layout the graph with minimal visual clutter while retaining important spatial properties. We also provide a brief overview of an underlying parallel data-mining pipeline which enables us to apply this visualization tool to real-time stock market data

Animating the development of Social Networks over time using a dynamic extension of multidimensional scaling

The animation of network visualizations poses technical and theoretical challenges. Rather stable patterns are required before the mental map enables a user to make inferences over time. In order to enhance stability, we developed an extension of stress-minimization with developments over time. This dynamic layouter is no longer based on linear interpolation between independent static visualizations, but change over time is used as a parameter in the optimization. Because of our focus on structural change versus stability the attention is shifted from the relational graph to the latent eigenvectors of matrices. The approach is illustrated with animations for the journal citation environments of Social Networks, the (co-)author networks in the carrying community of this journal, and the topical development using relations among its title words. Our results are also compared with animations based on PajekToSVGAnim and SoNIA

Visualizing Astrophysical N-body Systems

I begin with a brief history of N-body simulation and visualization and then go on to describe various methods for creating images and animations of modern simulations in cosmology and galactic dynamics. These techniques are incorporated into a specialized particle visualization software library called MYRIAD that is designed to render images within large parallel N-body simulations as they run. I present several case studies that explore the application of these methods to animations of star clusters, interacting galaxies and cosmological structure formation.Comment: 25 pages, accepted in the New Journal of Physics for upcoming Focus issue on Visualization in Physics. Accompanying animations including a free bittorrent download of the DVD GRAVITAS are available at http://www.galaxydynamics.org/gravitas.htm

Teaching Parallel Computing to Freshmen

Parallelism is the future of computing and computer science and should therefore be at the heart of the CS curriculum. Instead of continuing along the evolutionary path by introducing parallel computation “top down” (first in special junior-senior level courses), we are taking a radical approach and introducing parallelism at the earliest possible stages of instruction. Specifically, we are developing a completely new freshman-level course on data structures that integrates parallel computation naturally, and retains the emphasis on laboratory instruction. This will help to steer our curriculum as expeditiously as possible toward parallel computing. Our approach is novel in three distinct and essential ways. First, we will teach parallel computing to freshmen in a course designed from beginning to end to do so. Second, we will motivate the course with examples from scientific computation. Third, we use multimedia and visualization as instructional aids. We have two primary objectives: to begin a reform of our undergraduate curriculum with an laboratory-based freshman course on parallel computation, and to produce tools and methodologies that improve student understanding of the basic principles of parallel computing. Parallelism is the future of computing and computer science and should therefore be at the heart of the CS curriculum. Instead of continuing along the evolutionary path by introducing parallel computation “top down” (first in special junior-senior level courses), we are taking a radical approach and introducing parallelism at the earliest possible stages of instruction. Specifically, we are developing a completely new freshman-level course on data structures that integrates parallel computation naturally, and retains the emphasis on laboratory instruction. This will help to steer our curriculum as expeditiously as possible toward parallel computing. Our approach is novel in three distinct and essential ways. First, we will teach parallel computing to freshmen in a course designed from beginning to end to do so. Second, we will motivate the course with examples from scientific computation. Third, we use multimedia and visualization as instructional aids. We have two primary objectives: to begin a reform of our undergraduate curriculum with an laboratory-based freshman course on parallel computation, and to produce tools and methodologies that improve student understanding of the basic principles of parallel computing

Semiotic Analysis of Computer Visualization

The purpose of this chapter is to discuss the semiotic approach to form theory of computer visualization. Such theory should be the foundation of design, development, and evaluations of visualization systems. The “direct” semiotic analysis of visualization is defined and the scheme of the analysis is considered. This analysis reveals “who is who” in the process of the visualization semiosis and helps in design and development of the real visualization systems. The analysis allows to describe the problems arising at developments of specialized systems in terms of the semiotics and showing how this analysis can serve as a tool for the visualization systems design. It is important to analyze the sign nature of the human‐computer interface and the visualization. Such conceptions as computer metaphor, metaphor action, and metaphor formula are defined. The properties of metaphors are analyzed with a view to possible usage of metaphors for specific applications. The properties are considered by the example of the hierarchical sequence of the natural Room‐Building‐City (Landscape) metaphors. Also the properties of the molecule metaphor are considered in the context of software visualization systems. In conclusion, some approaches to the theory of computer visualization are outlined

Visualization/animation of programs based on abstract representations and formal mappings

In the context of Alma (a system for program visualization and algorithm animation), we use an internal representation-based on the concept of an attributed abstract syntax tree decorated with attribute values, a DAST-to associate (static) figures to grammar rules (productions) and to step over program dynamics executing state changes in order to perform its animation. We do not rely upon any source program annotations (visual/animation statements, or parameters), neither on any special visual data types. On account of such principle, the approach becomes source language independent. It means that we can apply the same visualizer and animator, that is the Alma's back-end, to different programming languages; all that we need is different front-ends to parse each program into the DAST we use. In this paper we discuss Alma design goals and architecture, and we present the two mappings that associate to productions figures and rewriting rules to systematically draw a visual representation (exhibiting data and control flow) of a given source program and to animate its execution.FC