206612774
Design of Very Lightweight Agents for reactive embedded systems
Large-scale real-time high-performance data acquisition computing systems often require to be fault-tolerant and adaptive to changes. We consider a multi-agent system based approach to achieve these goals. This research is a part of ongoing research efforts to build a triggering and data acquisition system (known as BTeV) for particle-accelerator-based high energy physics experiments at Fermi National Laboratory. The envisioned hardware consists of pixel detectors and readout sensors embedded in the accelerator, which are connected to specialized FPGAs (field-programmable gate arrays). The FPGAs are connected to approximately 2,500 digital signal processors (DSPs). After initial filtering and processing of data by the DSPs, a farm of approximately 2,500 Linux computers are responsible for post-processing a large amount of high speed data input. To support the adaptive fault-tolerance feature, we introduce the notion of very lightweight agents (VLAs), which are designed to be adaptive but small in footprint and extremely efficient. Each digital signal processor will run a very lightweight agent along with a physics application program that collects and processes input data from the corresponding FPGA. Since VLAs can be proactive or reactive, Brooks' subsumption architecture is a good basis for the design. In this paper we present several necessary changes in the original subsumption architecture to better serve the BTeV architecture.
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.
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.
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.
21082870
Environment Organization of Roles Using Polymorphism
In the field of multi-agent systems, there has lately been a growing interest on ways in which the environment can better be exploited to coordinate agent behavior and manage complex problems. This paper describes an environment that is able to organize and adapt agent roles as conditions warrant. Roles are adapted using polymorphism as directed by the environment. The design combines strategies from game theory and other biologically inspired models to address fault mitigation in large-scale, real-time, distributed systems. It is implemented on a prototype of the data acquisition system for BTeV, a High Energy Physics experiment consisting of 2500 digital signal processors. Results show environment organization of roles for the lightweight agents embedded within each of the individual processors.
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.
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.
16396247
Intelligent Manipulation Techniques for Conceptual 3D Design
One of the main operations in conceptual 3D design is the rearrangement of single and composite objects. This paper presents a new conceptual 3D design system that affords easy manipulation of composite objects. We discuss several alternative manipulation techniques to separate complex parts off an existing model. Then, we present a new way to move such parts in a 3D scene, as well as an algorithm to place parts at arbitrary locations. Finally, we present and discuss the results of a user study of these manipulation techniques.