Optimal state encoding for quantum walks and quantum communication over spin systems

Recent work has shown that a simple chain of interacting spins can be used as a medium for high-fidelity quantum communication. We describe a scheme for quantum communication using a spin system that conserves z-spin, but otherwise is arbitrary. The sender and receiver are assumed to directly control several spins each, with the sender encoding the message state onto the larger state-space of her control spins. We show how to find the encoding that maximises the fidelity of communication, using a simple method based on the singular-value decomposition. Also, we show that this solution can be used to increase communication fidelity in a rather different circumstance: where no encoding of initial states is used, but where the sender and receiver control exactly two spins each and vary the interactions on those spins over time. The methods presented are computationally efficient, and numerical examples are given for systems having up to 300 spins.Comment: 10 pages, LaTeX, 7 EPS figures. Corrected an error in the definition and interpretation of C_B(T

Teaching Virtual Characters to use Body Language

Non-verbal communication, or “body language”, is a critical component in constructing believable virtual characters. Most often, body language is implemented by a set of ad-hoc rules.We propose a new method for authors to specify and refine their character’s body-language responses. Using our method, the author watches the character acting in a situation, and provides simple feedback on-line. The character then learns to use its body language to maximize the rewards, based on a reinforcement learning algorithm

THREE DIMENSIONAL MODELING AND ANIMATION OF FACIAL EXPRESSIONS

Facial expression and animation are important aspects of the 3D environment featuring human characters. These animations are frequently used in many kinds of applications and there have been many efforts to increase the realism. Three aspects are still stimulating active research: the detailed subtle facial expressions, the process of rigging a face, and the transfer of an expression from one person to another. This dissertation focuses on the above three aspects. A system for freely designing and creating detailed, dynamic, and animated facial expressions is developed. The presented pattern functions produce detailed and animated facial expressions. The system produces realistic results with fast performance, and allows users to directly manipulate it and see immediate results. Two unique methods for generating real-time, vivid, and animated tears have been developed and implemented. One method is for generating a teardrop that continually changes its shape as the tear drips down the face. The other is for generating a shedding tear, which is a kind of tear that seamlessly connects with the skin as it flows along the surface of the face, but remains an individual object. The methods both broaden CG and increase the realism of facial expressions. A new method to automatically set the bones on facial/head models to speed up the rigging process of a human face is also developed. To accomplish this, vertices that describe the face/head as well as relationships between each part of the face/head are grouped. The average distance between pairs of vertices is used to place the head bones. To set the bones in the face with multi-density, the mean value of the vertices in a group is measured. The time saved with this method is significant. A novel method to produce realistic expressions and animations by transferring an existing expression to a new facial model is developed. The approach is to transform the source model into the target model, which then has the same topology as the source model. The displacement vectors are calculated. Each vertex in the source model is mapped to the target model. The spatial relationships of each mapped vertex are constrained

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

Interactive 3D Simulation of Escher-like Impossible Worlds

figures and impossible worlds. Many of his works illustrate mathematical and geometrical concepts such as perspective and limits. Works by Escher have motivated scientists over the years to discover the mathematical foundations of his work, ultimately leading to applications that are able to model and render scenes similar to the ones created by Escher. Presented is an application that is capable of displaying a special class of impossible worlds that have been created by the artist. The software displays worlds that appear physically correct, but are connected in an impossible manner, similar to Escher’s Another World II or Relativity. Portal rendering is employed to create real-time interactive visualizations of such scenes, which can be freely explored by the user

A meta-authoring tool for specifying behaviour in virtual reality environments

Includes bibliographical references (leaves 94-99).In this dissertation, we explore methods for empowering non-programmers with the ability to develop their own virtual environment applications. We explored some of the existing systems to determine what methodologies have already been successfully (or unsuccessfully) applied in the fields of virtual environment systems, authoring tools, and graphical user interfaces. From these methodologies we describe an ideal virtual environment authoring system with which comparisons may be drawn to evaluate existing systems. This ideal system represents a tool ideal in its ability to allow users of differing levels of skill to rapidly create virtual environment applications of any sophistication. Creating such a single, generic authoring tool for every different kind of application is, practically, an impossible task - more so if the authors are non-programmers. A more realistic solution to the problem would be to think of every environment as having a particular context such as a virtual museum or gallery. Creating authoring tools specific to these types of environment contexts greatly reduces the problem. We have therefore produced a progressive meta-authoring system that allows both novice and advanced users to create useful virtual reality applications, allowing the smooth migration of novice users to becoming more experienced. We believe that our system overcomes problems in architecture and support for novice users that can be found in many other authoring systems for virtual environments

An Evaluation of Open Digital Gaming Platforms for Developing Computational Thinking Skills

Due to business needs and the growing importance of technology in society, in recent years, the concept of computational thinking has emerged, especially focused on its inclusion in compulsory education as a relevant complement, transversal to traditional subjects. In parallel, various initiatives have developed interactive digital tools for learners to meet this type of thinking through a series of activities commonly framed as games. In this chapter, we evaluate many of the existing free access platforms to propose pedagogical, design, and content approaches with which they can be compared

Vector garden

Vector Garden demonstrates the vital role of vector graphics in web designing. Its purpose is to create a complex, dynamic, multidimensional and interactive virtual fairyland where viewers can escape into a creative world of imagination, hope and fantasy. Put together with Macromedia Flash and Adobe Illustrator, Vector Garden is a non- commercial online experimental design in the vector graphic style website design. By combining a variety of elements of both visual and audio designing, including typographies, colors, layouts, graphics, sounds and ActionScripts, it presents an underlying concept of Vector graphics, their applications in and relationships to the world of designing

ROOT - A C++ Framework for Petabyte Data Storage, Statistical Analysis and Visualization

ROOT is an object-oriented C++ framework conceived in the high-energy physics (HEP) community, designed for storing and analyzing petabytes of data in an efficient way. Any instance of a C++ class can be stored into a ROOT file in a machine-independent compressed binary format. In ROOT the TTree object container is optimized for statistical data analysis over very large data sets by using vertical data storage techniques. These containers can span a large number of files on local disks, the web, or a number of different shared file systems. In order to analyze this data, the user can chose out of a wide set of mathematical and statistical functions, including linear algebra classes, numerical algorithms such as integration and minimization, and various methods for performing regression analysis (fitting). In particular, ROOT offers packages for complex data modeling and fitting, as well as multivariate classification based on machine learning techniques. A central piece in these analysis tools are the histogram classes which provide binning of one- and multi-dimensional data. Results can be saved in high-quality graphical formats like Postscript and PDF or in bitmap formats like JPG or GIF. The result can also be stored into ROOT macros that allow a full recreation and rework of the graphics. Users typically create their analysis macros step by step, making use of the interactive C++ interpreter CINT, while running over small data samples. Once the development is finished, they can run these macros at full compiled speed over large data sets, using on-the-fly compilation, or by creating a stand-alone batch program. Finally, if processing farms are available, the user can reduce the execution time of intrinsically parallel tasks - e.g. data mining in HEP - by using PROOF, which will take care of optimally distributing the work over the available resources in a transparent way