Computational Geometry Education for Computer Graphics Students

The paper surveys main features of computational geometry and presents the argument that a course oriented to applied computational geometry should be a part of the computer graphics curriculum, as it teaches effective algorithmic methods and helps to develop abstract thinking. Possible contents of the course and forms suitable and interesting for computer graphics students are discussed. The students' feedback on such a course has been mostly positive.     

Visual Supercomputing: Technologies, Applications and Challenges

If we were to have a Grid infrastructure for visualization, what technologies would be needed to build such an infrastructure, what kind of applications would benefit from it, and what challenges are we facing in order to accomplish this goal? In this survey paper, we make use of the term ‘visual supercomputing’ to encapsulate a subject domain concerning the infrastructural technology for visualization. We consider a broad range of scientific and technological advances in computer graphics and visualization, which are relevant to visual supercomputing. We identify the state‐of‐the‐art technologies that have prepared us for building such an infrastructure. We examine a collection of applications that would benefit enormously from such an infrastructure, and discuss their technical requirements. We propose a set of challenges that may guide our strategic efforts in the coming years.     

eNVyMyCar: A Multiplayer Car Racing Game for Teaching Computer Graphics

The development of a computer game is widely used as a way of conveying concepts regarding Computer Science. There are several reasons for this: it stimulates creativity, it provides an immediate sense of achievement (when the code works), it typically covers all the aspects of an introductory course, and it is easy to find ideas just by looking around and finding stimulation from one's environment and from fellow students. In this paper we present eNVyMyCar, a framework for the collaborative/competitive development of a computer game, and report the experience of its use in two Computer Graphics courses held in 2007. We developed a multiplayer car racing game where the student's task is just to implement the rendering of the scene, while all the other aspects, communication and synchronization are implemented in the framework and are transparent to the developer. The innovative feature of our framework is that all on‐line users can see the views produced by their fellow students. This motivates students to improve their work by comparing it with other students and picking up ideas from them. It also gives students an opportunity to show off to their classmates.     

Computer-based reading and writing across the curriculum: Two case studies of L2 writers

Since the early 1980s, second language (L2) writing specialists have been examining possible roles for computers in L2 writing instruction. How, and to what extent, L2 students use computer for academic literacy purposes beyond the writing classroom, that is, across the curriculum, has not received much attention. Because a common goal of L2 college level writing courses is to prepare students to write in these other domains, an awareness of computer-based literacy activities in non-L2 writing courses is essential to the cause of helping L2 writing instructors connect what students learn in their courses to how they write (and read) in other courses. This paper describes research aimed at contributing to such awareness: a qualitative study of the computer-based reading and writing activity of two undergraduate English as a Second Language (ESL) students beyond ESL writing courses.     

Teaching Quaternions is not Complex

Quaternions are used in many fields of science and computing, but teaching them remains challenging. Students can have a great deal of trouble understanding essentially what quaternions are and how they can represent rotation matrices. In particular, the similarity transform which actually achieves rotation, can often be baffling even after students have seen a full derivation. This paper outlines a constructive method for teaching quaternions, which allows students to build intuition about what quaternions are, and why simple multiplication is not adequate to represent a rotation. Through a set of examples, it demonstrates exactly how quaternions relate to rotation matrices, what goes wrong when q v is naively used to rotate vectors, and how the similarity transform fixes the problem.     

《离散数学》教学方法探讨

离散数学是计算机科学与技术专业的一门重要的专业基础课,它不仅是许多计算机专业课的必备基础,而且对于培养学生的抽象思维能力和逻辑推理能力也有着重要的作用。结合该课程具有概念多、方法性强、高难度、高度抽象等学科特点,作者提出了一系列教学方法,在实践中取得了良好的效果。这对于提高离散数学课程的教学水平和教育质量,改进学生的学习方法乃至对今后的教学实践均有着一定指导意义。     

Teaching, Exploring, Learning—Developing Tutorials for In-Class Teaching and Self-Learning

This paper presents an experience report on a novel approach for a course on intermediate and advanced computer graphics topics. The approach uses Teachlet Tutorials, a combination of traditional seminar–type teaching with interactive exploration of the content by the audience, plus development of self-contained tutorials on the topic. In addition to a presentation, an interactive software tool is developed by the students to assist the audience in learning and exploring the topic's details. This process is guided through set tasks. The resulting course material is developed for two different contexts: (a) for classroom presentation and (b) as an interactive, self-contained, self-learning tutorial. The overall approach results in a more thorough understanding of the topic both for the student teachers as well as for the class participants. In addition to detailing the Teachlet Tutorial approach, this paper presents our experiences implementing the approach in our Advanced Computer Graphics course and presents the resultant projects. Most of the final Teachlet Tutorials were surprisingly good and we had excellent feedback from the students on the approach and course.     

《离散数学》教学方法探讨

离散数学是计算机科学与技术专业的一门重要的专业基础课,它不仅是许多计算机专业课的必备基础,而且对于培养学生的抽象思维能力和逻辑推理能力也有着重要的作用。结合该课程具有概念多、方法性强、高难度、高度抽象等学科特点,作者提出了一系列教学方法,在实践中取得了良好的效果。这对于提高离散数学课程的教学水平和教育质量,改进学生的学习方法乃至对今后的教学实践均有着一定指导意义。     

The State of the Art in Topology‐Based Visualization of Unsteady Flow

Vector fields are a common concept for the representation of many different kinds of flow phenomena in science and engineering. Methods based on vector field topology are known for their convenience for visualizing and analysing steady flows, but a counterpart for unsteady flows is still missing. However, a lot of good and relevant work aiming at such a solution is available. We give an overview of previous research leading towards topology‐based and topology‐inspired visualization of unsteady flow, pointing out the different approaches and methodologies involved as well as their relation to each other, taking classical (i.e. steady) vector field topology as our starting point. Particularly, we focus on Lagrangian methods, space–time domain approaches, local methods and stochastic and multifield approaches. Furthermore, we illustrate our review with practical examples for the different approaches.     

Visualization for the Physical Sciences

Close collaboration with other scientific fields is an important goal for the visualization community. Yet engaging in a scientific collaboration can be challenging. The physical sciences, namely astronomy, chemistry, earth sciences and physics, exhibit an extensive range of research directions, providing exciting challenges for visualization scientists and creating ample possibilities for collaboration. We present the first survey of its kind that provides a comprehensive view of existing work on visualization for the physical sciences. We introduce novel classification schemes based on application area, data dimensionality and main challenge addressed, and apply these classifications to each contribution from the literature. Our survey helps in understanding the status of current research and serves as a useful starting point for those interested in visualization for the physical sciences.     

Automatic Animation for Time‐Varying Data Visualization

This paper presents a digital storytelling approach that generates automatic animations for time‐varying data visualization. Our approach simulates the composition and transition of storytelling techniques and synthesizes animations to describe various event features. Specifically, we analyze information related to a given event and abstract it as an event graph, which represents data features as nodes and event relationships as links. This graph embeds a tree‐like hierarchical structure which encodes data features at different scales. Next, narrative structures are built by exploring starting nodes and suitable search strategies in this graph. Different stages of narrative structures are considered in our automatic rendering parameter decision process to generate animations as digital stories. We integrate this animation generation approach into an interactive exploration process of time‐varying data, so that more comprehensive information can be provided in a timely fashion. We demonstrate with a storm surge application that our approach allows semantic visualization of time‐varying data and easy animation generation for users without special knowledge about the underlying visualization techniques.     

The communicative power of knowledge visualizations in mobilizing information and communication technology research

ABSTRACT

This editorial explores knowledge visualization, a field of study that investigates the power of visual formats to represent knowledge, as a strategy to enhance knowledge mobilization of results from ICT4D research. We highlight the fact that there are evidence-based guidelines for creating and crafting visualizations in academic writing. We also provide some visualization examples that highlight general knowledge visualization criteria such as anchor and extend, familiarity, clarity and consistency, include text, prudent simplicity and aesthetics. Although visualization is not the central theme of any of the papers in this issue, the papers offer a variety of visualization techniques as appropriate to the knowledge domain.     

Dual actuator logging disk architecture and modeling

In this paper, we present a dual actuator logging disk architecture to minimize write access latencies. We reduce small synchronous write latency using the notion of logging writes, i.e. writing to free sectors near the current disk head location. However, we show through analytic models and simulations that logging writes by itself is not sufficient to reduce write access latencies, particularly in environments with writes to new data and intermixed reads and writes. Therefore, we augment the logging write method with the addition of a second disk actuator. Our models and simulations show that the addition of the second actuator offers significant performance benefits over a normal disk over a wide range of disk access patterns, and comparisons to strictly logging disk architectures show advantages over a range of disk access patterns.     

Contrast Restoration by Adaptive Countershading

The ABSTRACT is to be in fully-justified italicized text, between two horizontal lines, in one-column format, below the author and affiliation information. Use the word “Abstract” as the title, in 9-point Times, boldface type, left-aligned to the text, initially capitalized. The abstract is to be in 9-point, single-spaced type. The abstract may be up to 3 inches (7.62 cm) long. Leave one blank line after the abstract, then add the subject categories according to the ACM Classification Index (see http://www.acm.org/class/1998/ ).     

Collaborative Writing of Text and Hypertext

A good writer understands his audience. Collaborative writing allows authors to act as readers and thus to create text which an audience is more likely to appreciate. This paper describes four sets of experiences in collaborative writing. In one of the experiences secondary school students who were unable to produce a sophisticated document independently were able to produce a quality document through a group process. Given the correct combination of authors and goals, a simple computer editor can be very helpful. Hypertext differs from text in that links among chunks of text are made explicit. It could be argued that collaborative writing would work particularly well with hypertext because the links among the writers' ideas could be more easily explored. In experiences with graduate students at two universities, this hypothesis has not been supported. The students did not understand how these links should be created and thus could not collaboratively write hypertext.     

Construction of C-space roadmaps from local sensory data. What should the sensors look for?

This paper presents an incremental navigation strategy for general articulated robots:the robot may start with no a priori information about its environment, and is guaranteed either to find the goal if it is reachable or halt. The strategy, termed theincremental roadmap algorithm, constructs a roadmap based on on-line distance data which is encoded as a repulsive potential field. The incremental behavior is achieved with two novel abstract sensors: thecritical-point detector and thepassage-point detector. The detectors provide a complete characterization of what the robot should look for in its configuration space to achieve globally convergent navigation. The approach thus provides a new framework, which will hopefully yield the first navigation algorithm that is both completely general and practical.     

Using VisTrails and Provenance for Teaching Scientific Visualization

Over the last 20 years, visualization courses have been developed and offered at universities around the world. Many of these courses use established visualization libraries and tools (e.g. VTK, ParaView, AVS, VisIt) as a way to provide students a hands‐on experience, allowing them to prototype and explore different visualization techniques. In this paper, we describe our experiences using VisTrails as a platform to teach scientific visualization. VisTrails is an open‐source system that was designed to support exploratory computational tasks such as visualization and data analysis. Unlike previous scientific workflow and visualization systems, VisTrails provides a comprehensive provenance management infrastructure. We discuss how different features of the system, and in particular, the provenance information have changed the dynamics of the Scientific Visualization course we offer at the University of Utah. We also describe our initial attempts at using the provenance information to better assess our teaching techniques and student performance.     

The State of the Art in Flow Visualization: Dense and Texture-Based Techniques

Flow visualization has been a very attractive component of scientific visualization research for a long time. Usually very large multivariate datasets require processing. These datasets often consist of a large number of sample locations and several time steps. The steadily increasing performance of computers has recently become a driving factor for a reemergence in flow visualization research, especially in texture‐based techniques. In this paper, dense, texture‐based flow visualization techniques are discussed. This class of techniques attempts to provide a complete, dense representation of the flow field with high spatio‐temporal coherency. An attempt of categorizing closely related solutions is incorporated and presented. Fundamentals are shortly addressed as well as advantages and disadvantages of the methods.     

Model-driven visualizations of constraint-based local search

Visualization is often invaluable to understand the behavior of optimization algorithms, identify their bottlenecks or pathological behaviors, and suggest remedial techniques. Yet developing visualizations is often a tedious activity requiring significant time and expertise. This paper presents a framework for the visualization of constraint-based local search (CBLS) algorithms. Given a high-level model and a declarative visualization specification, the CBLS visualizer systematically produces animations to visualize constraints and objectives, violations, and conflicts, as well as the temporal behavior of these measures. The visualization specification is declarative and typically composed of a triple (what,where,how) indicating what to display, where, and with which graphical objects. The visualizer architecture is compositional and extensible. It provides building blocks which can be assembled freely by the user and focuses almost exclusively on static aspects, the dynamic aspects being automated by the use of invariants. The paper highlights various functionalities of the visualizer and describes a blueprint for its implementation.