8366022
A rationality-based modeling for coalition support
We present a game theoretic model for multi-agent resource distribution and allocation where agents in the environment must help each other to survive. Each agent maintains a set of two-tuples T=(A, P) called friendship values representing actual friendship and perceived friendship. The model directly addresses problems in reputation management schemes in multi-agent systems and peer-to-peer distributed systems. We present algorithms for maintaining the friendship values as well as a utility equation used in each agent's decision making. For an application problem, we adapted our formal model to the military coalition support problem in peace-keeping missions. Simulation results show that efficient resource allocation and sharing with minimum communication cost is achieved without centralized control.
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.
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.
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.
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.
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.