3206497
Polymorphic self-* agents for stigmergic fault mitigation in large-scale real-time embedded systems
Organization and coordination of agents within large-scale, complex, distributed environments is one of the primary challenges in the field of multi-agent systems. A lot of interest has surfaced recently around self-* (self-organizing, self-managing, self-optimizing, self-protecting) agents. This paper presents polymorphic self-* agents that evolve a core set of roles and behavior based on environmental cues. The agents adapt these roles based on the changing demands of the environment, and are directly implementable in computer systems applications. The design combines strategies from game theory, stigmergy, and other biologically inspired models to address fault mitigation in large-scale, real-time, distributed systems. The agents are embedded within the individual digital signal processors of BTeV, a High Energy Physics experiment consisting of 2500 such processors. Results obtained using a SWARM simulation of the BTeV environment demonstrate the polymorphic character of the agents, and show how this design exceeds performance and reliability metrics obtained from comparable centralized, and even traditional decentralized approaches.
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.
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.
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.
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.
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.
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.
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.