3171453
Teaching real time OSs with DORITOS
We are developing a teaching package that can be used in a college course that would fill a gap among current science majors and teach senior-level undergraduate students theory and practice of real-time operating systems, including their requirements, characteristics, internals, and specification. This course has two components: (1) a theoretical part, and (2) a practical hands-on implementation component achieved with DORITOS (Distributed Object-Based Real-time InsTructional Operating System) as the implementation environment. DORITOS' design is based on UC-Berkeley's NACHOS. The DORITOS package will be distributed with DKaffe (a modified version of Kaffe JVM) and a basic system which allows students to run simple threads.In this paper, we focus on the practical, hands-on system that allows students to learn the internals of a Real-time Operating Systems (RTOS). Throughout the term, assignments require students to use and modify DORITOS to implement real-time elements as well as to analyze the performance of implemented algorithms.
41382506
Promoting cooperation using 'kin' biased conditional strategy in the iterated prisoner's dilemma game
Abstract This paper introduces a new mechanism using tit-for-tat (TFT)-like strategy that successfully promotes cooperation in the iterated prisoner's dilemma (IPD) game. The mechanism is based on a corollary of our previously presented kinship hypothesis : cooperation can emerge when players tend to cooperate with players that are similar but tend to defect to players that are dissimilar. A theoretical motivation for the new mechanism is presented as well as experimental results supporting the theory. The experimental results show that kinship biased conditional cooperation (KBCC) greatly improves the survival of cooperative individuals, eventually driving the population to cooperating equilibrium.
14162832
Text-independent open-set speaker identification for military missions using genetic rule-based system
We present a genetic classifier system approach to the text-independent open-set speaker identification problem. Classifier systems are widely used in symbolic problem for dynamically changing open-ended learning. Signal processing problems require processing of real-valued parameters that classifier systems are not designed for. On the other hand, the approaches based on common cepstral encoding with clustering algorithms handle the closed-set speaker identification quite well. This research solves the open-set problem by hybridizing these two approaches.
739
Cooperative game theory within multi-agent systems for systems scheduling
Research concerning organization and coordination within multi-agent systems continues to draw from a variety of architectures and methodologies. The work presented in this paper combines techniques from game theory and multi-agent systems to produce self-organizing, polymorphic, lightweight, embedded agents for systems scheduling within a large-scale real-time systems environment. Results show how this approach is used to experimentally produce optimum real-time scheduling through the emergent behavior of thousands of agents. These results are obtained using a SWARM simulation of systems scheduling within a high energy physics experiment consisting of 2500 digital signal processors.
34275264
SWARMs of Self-Organizing Polymorphic Agents
The field of swarm intelligence is increasingly being seen as providing a framework for solving a wide range of large-scale, distributed, complex problems. Of particular interest are architectures and methodologies that address organization and coordination of a large number of relatively simple agents distributed across the system in a way that encourages some desirable global emergent behavior. This paper describes a SWARM simulation of a distributed approach to fault mitigation within a large-scale data acquisition system for BTeV, a particle accelerator-based high energy physics experiment currently under development at Fermi National Accelerator Laboratory. Incoming data is expected to arrive at a rate of over 1 terabyte every second, distributed across 2500 digital signal processors. Simulation results show how lightweight polymorphic agents embedded within the individual processors use game theory to adapt roles based on the changing needs of the environment. SWARM architecture and implementation methodologies are detailed.
37165855
Prototype of Fault Adaptive Embedded Software for Large-Scale Real-Time Systems
This paper describes a comprehensive prototype of large-scale fault adaptive embedded software developed for the proposed Fermilab BTeV high energy physics experiment. Lightweight self-optimizing agents embedded within Level 1 of the prototype are responsible for proactive and reactive monitoring and mitigation based on specified layers of competence. The agents are self-protecting, detecting cascading failures using a distributed approach. Adaptive, reconfigurable, and mobile objects for reliablility are designed to be self-configuring to adapt automatically to dynamically changing environments. These objects provide a self-healing layer with the ability to discover, diagnose, and react to discontinuities in real-time processing. A generic modeling environment was developed to facilitate design and implementation of hardware resource specifications, application data flow, and failure mitigation strategies. Level 1 of the planned BTeV trigger system alone will consist of 2500 DSPs, so the number of components and intractable fault scenarios involved make it impossible to design an 'expert system' that applies traditional centralized mitigative strategies based on rules capturing every possible system state. Instead, a distributed reactive approach is implemented using the tools and methodologies developed by the Real-Time Embedded Systems group.
8407543
A system for desktop conceptual 3D design
In the traditional design process for a 3D environment, people usually depict a rough prototype to verify their ideas, and iteratively modify its configuration until they are satisfied with the general layout. In this activity, one of the main operations is the rearrangement of single and composite parts of a scene. With current desktop virtual reality (VR) systems, the selection and manipulation of arbitrary objects in 3D is still difficult. In this work, we present new and efficient techniques that allow even novice users to perform meaningful rearrangement tasks with traditional input devices. The results of our work show that the presented techniques can be mastered quickly and enable users to perform complex tasks on composite objects. Moreover, the system is easy to learn, supports creativity, and is fun to use.
16147050
Moving objects with 2D input devices in CAD systems and Desktop Virtual Environments
Part assembly and scene layout are basic tasks in 3D design in Desktop Virtual Environment (DVE) systems as well as Computer Aided Design (CAD) systems. 2D input devices such as a mouse or a stylus are still the most common input devices for such systems. With such devices, a notably difficult problem is to provide an efficient and predictable object motion in 3D based on their 2D motion. This paper presents a new technique to move objects in CAD/DVE using 2D input devices.The technique presented in this paper utilizes the fact that people easily recognize the depth-order of shapes based on occlusions. In the presented technique, the object position follows the mouse cursor position, while the object slides on various surfaces in the scene. In contrast to existing techniques, the movement surface and the relative object position is determined using the whole area of overlap of the moving object with the static scene. The resulting object movement is visually smooth and predictable, while avoiding undesirable collisions. The proposed technique makes use of the framebuffer for efficiency and runs in real-time. Finally, the evaluation of the new technique with a user study shows that it compares very favorably to conventional techniques.
12397912
Laser Pointers as Collaborative Pointing Devices
Single Display Groupware (SDG) is a research area that focuses on providing collaborative computing environments. Traditionally, most hardware platforms for SDG support only one person interacting at any given time, which limits collaboration. In this paper, we present laser pointers as input devices that can provide concurrent input streams ideally required to the SDG environment. First, we discuss several issues related to utilization of laser pointers and present the new concept of computer controlled laser pointers. Then we briefly present a performance evaluation of laser pointers as input devices and a baseline comparison with the mouse according to the ISO 9241-9 standard. Finally, we describe a new system that uses multiple computer controlled laser pointers as interaction devices for one or more displays. Several alternatives for distinguishing between different laser pointers are presented, and an implementation of one of them is demonstrated with SDG applications.
9965855
SESAME: towards better 3D conceptual design systems
Conceptual design dominates the early stages of most creative design processes. During these stages, the designer makes important decisions about the parameters of a model that are aimed at satisfying a set of design criteria. To do this, the designer produces many sketches of various possible solutions. Meanwhile, computer-aided design (CAD) systems are becoming the dominant visual medium used in design practice. However, these tools evolved as documentation production tools and do not support conceptual thinking. This paper presents a list of guidelines for computer support for conceptual design activities on 3D scenes and presents SESAME (Sketch, Extrude, Sculpt, and Manipulate Easily), a system based on these guidelines. Finally, we present a user study comparing SESAME with a conventional CAD package to demonstrate the effectiveness of SESAME.
18176797
User evaluations on form factors of tangible magic lenses
Magic Lens is a small inset window embedded in a large context display, which provides an alternative view to the region of interest selected from the context view. This metaphor is used for 3D visualization in our Augmented Virtual Environment infrastructure, SCAPE (Stereoscopic Collaboration in Augmented and Projective Environments), which is composed of an immersive room display for a high level of detail, life-size virtual world and a workbench display for simplified god-like view to the world. A tangible Magic Lens is used on the workbench display to allow direct and intuitive selection of continuous levels of detail, bridging the gap between the two extreme levels of detail in SCAPE. This paper presents our first step to the user evaluations of tangible Magic Lens. We conducted two sets of user evaluations, one mainly testing the lens aspect ratio, and another for the lens size. For both of the tests, two types of tasks are conducted: information gathering and relating the detailed information with the context. We found that the aspect ratio of a lens plays more important role in user preference for smaller lenses than for larger ones. Meanwhile, the size of a lens is the most important factor that affects the user performance in the two types of tasks.