Papers by Charles Cavanaugh
Journal of Systems and Software, 2007
Design and integration of the sensing and control subsystems of CajunBot
Proceedings. The 7th International IEEE Conference on Intelligent Transportation Systems (IEEE Cat. No.04TH8749)
ABSTRACT This paper covers the design and integration of the sensing and control subsystems of th... more ABSTRACT This paper covers the design and integration of the sensing and control subsystems of the CajunBot autonomous ground vehicle, which competed and qualified in the 2004 DARPA Grand Challenge. The event took place 8-13 March 2004 near Los Angeles, CA, USA, and closed near Las Vegas, NV, USA. The challenge was to create a vehicle that would travel without intervention approximately 150 mi through desert terrain using a set of waypoints while avoiding obstacles, both natural and man-made, in under ten hours for a prize of US ε. In order to make the route more challenging, the exact route was only provided the morning of the race, two hours from start time. The starting line, in Barstow, CA, USA, consisted of six chutes separated by concrete barriers from which a total of fifteen autonomous ground vehicles, or bots, were launched.
Encoding scheme for efficient ultra-fast flash ADC
Digest of Papers. 2004 Topical Meeting onSilicon Monolithic Integrated Circuits in RF Systems, 2004.
We propose an efficient encoding scheme to be designed using the robust principle of programmable... more We propose an efficient encoding scheme to be designed using the robust principle of programmable logic arrays (PLA) for an ultra-fast flash analog to digital converter (ADC). High-speed operation in the MHz-GHz range is the major goal of flash ADC design. A high-speed ADC needs a fast comparator, a high-speed encoder, and a fast sample and hold (S-H) circuit. These three areas of high-speed ADC design require equally careful attention. Technological advancement has produced superior high-speed comparators. The speed of encoders has been dealt with mostly on the algorithmic part. We propose a CMOS based encoder design to be integrated with a CMOS based high-speed comparator for system-on-chip (SoC). Depending on the availability of high-speed comparators, our design exploits the design of the comparator for the benefit of speeding up the encoder.
Diagnosing Quality of Service Problems in Distributed, Real-time Systems
This paper describes a novel approach and model for the management of quality of service in dynam... more This paper describes a novel approach and model for the management of quality of service in dynamic, distributed, real-time systems through intelligent diagnosis of quality of service violations. By integrating computational and communication diagnosis with profiles of resource usage and timing under a wide range of workloads and hardware, a diagnosis algorithm isolates the bottleneck in the path and provides the resource management middleware with the information it needs to make an allocation. The improvement obtained through the capabilities of the algorithm is validated through experimentation using repeatable scenarios and a dynamic, distributed benchmark.
In this paper we present the architecture and framework for a benchmark suite that has been devel... more In this paper we present the architecture and framework for a benchmark suite that has been developed as part of the DeSiDeRaTa project. The proposed benchmark suite is representative of the emerging generation of distributed, mission-critical, real-time control systems that operate in dynamic environments. Systems that operate in such environments may have unknown worst-case scenarios, may have large variances in the sizes of the data and event sets that they process (and thus, have large variances in execution latencies and resource requirements), and may be very difficult to characterize statically, even by time-invariant statistical distributions. The proposed benchmark suite (called DynBench) is useful for evaluation of the Quality of Service (QoS) management and/or Resource Management (RM) services in distributed real-time systems. As such, DynBench includes a set of performance metrics for the evaluation of the QoS and RM technologies in dynamic distributed real-time systems. The paper demonstrates the successful application of DynBench in evaluation of the DeSiDeRaTa QoS management middle-ware.
Abstract. Monitoring the performance of a network by which a real-time distributed system is conn... more Abstract. Monitoring the performance of a network by which a real-time distributed system is connected is very important. If the system is adaptive or dynamic, the resource manager can use this information to create or use new processes. We may be interested to determine how much load a host is placing on the network, or what the network load index is. In this paper, a simple technique for evaluating the current load of network is proposed. If a computer is connected to several networks, then we can get the load index of that host for each network. We can also measure the load index of the network applied by all the hosts. The dynamic resource manager of DeSiDeRaTa should use this technique to achieve its requirements. We have verified the technique with two benchmarks – LoadSim and DynBench. 1
In this paper we present the architecture and framework for a benchmark suite that has been devel... more In this paper we present the architecture and framework for a benchmark suite that has been developed as part of the DeSiDeRaTa project. The benchmark suite is representative of the emerging generation of distributed, mission-critical, real-time control systems that operate in dynamic environments. Systems that operate in such environments may have unknown worst-case scenarios, may have large variances in the sizes of the data and event sets that they process (and thus, have large variances in execution latencies and resource requirements), and may be very difficult to characterize statically, even by time-invariant statistical distributions. The benchmark suite (called DynBench) is useful for evaluation of the Quality of Service (QoS) management and/or Resource Management (RM) services in distributed real-time systems. As such, DynBench includes a set of performance metrics for the evaluation of the QoS and RM technologies in dynamic, distributed real-time systems. The paper demonstrates the successful application of DynBench in evaluation of the DeSiDeRaTa QoS management middleware
Toward a simulation benchmark for distributed mission-critical real-time systems
Proceedings. 2005 IEEE Networking, Sensing and Control, 2005.
Given the overall increasing trend of airspace demand by commercial, military, and general aviati... more Given the overall increasing trend of airspace demand by commercial, military, and general aviation, researchers are developing new software tools to enhance the level of automation in air traffic control systems to alleviate the already-crowded airspace by allowing controllers and pilots more freedom in planning and conducting flights. These tools utilize high-performance commercial workstations that use high-speed networks and function together to form a distributed real-time computing system. This paper describes a three-dimensional air traffic control simulation benchmark developed by the author for the purpose of running simulations of air traffic scenarios, adding new capabilities, and gauging performance, security, and reliability quality of service management techniques on a variety of platforms.
Towards a characterization of quality of service management approaches in distributed, real-time systems
Proceedings 15th International Parallel and Distributed Processing Symposium. IPDPS 2001
... 38. B. Shirazi, L. Welch, B. Ravindran, C. Cavanaugh, and E.- N. Huh. Dynbench: a benchmark s... more ... 38. B. Shirazi, L. Welch, B. Ravindran, C. Cavanaugh, and E.- N. Huh. Dynbench: a benchmark suite for dynamic realtime systems. Journal of Parallel and Distributed Computing Practices (Accepted), 2000. 39. P. Steenkiste, A. Fisher, and H. Zhang. ...
Quality of service management for dynamic distributed, real-time systems
Dynamic, distributed, real-time systems control an environment that varies widely without any tim... more Dynamic, distributed, real-time systems control an environment that varies widely without any time-invariant statistical or deterministic characteristic, are spread across multiple loosely-coupled computers, and must control the environment in a timely manner. In order to ensure that such a system meets its timeliness guarantees, there must be a means to monitor and maintain the quality of service in the system. The QoS manager is a monitoring and diagnosis system for real-time paths, collections of time-constrained and precedence-constrained applications. This dissertation addresses the issues of monitoring communication subpaths of continuous paths and resource usage of computational subpaths, forecasting of latency for continuous paths, and diagnosis of communication subpaths of continuous paths.
Guest Editor's introduction
J. Syst. Softw., 2007
The Laboratory's Engineering and Fabrication Branch (TEO) has a long tradition of supplying q... more The Laboratory's Engineering and Fabrication Branch (TEO) has a long tradition of supplying quality electronic, electromechanical, and mechanical hardware to a broad range of APL programs. From the early days of proximity fuzes and shipboard missiles to today's combat systems, radars, and spacecraft, the skilled engineers, craftsmen, and clerical personnel of TEO have made significant contributions to the design and manufacture of Laboratory systems. The creativity and extensive expertise of our staff (currently more than 250 strong) have been applied to such activities as submarine detection, ocean physics, biomedical instrumentation, shuttle astronomy, photon and particle detection, space physics, satellite navigation, and reconnaissance. The involvement of TEO in Laboratory programs ranges from small fabrication and assembly tasks (a few hours) in support of prototype development programs to major engineering, design, and fabrication efforts (thousands of hours) for fully...
Lecture Notes in Computer Science, 2000
Dynamic, distributed, real-time systems control an environment that varies widely without any tim... more Dynamic, distributed, real-time systems control an environment that varies widely without any time-invariant statistical or deterministic characteristic, are spread across multiple loosely-coupled computers, and must control the environment in a timely manner. In order to ensure that such a system meets its timeliness guarantees, there must be a means to monitor and maintain the quality of service in the system. The QoS manager is a monitoring and diagnosis system for real-time paths, collections of time-constrained and precedence-constrained applications. These applications may be distributed across multiple, heterogeneous computers and networks. This paper addresses the QoS negotiation features of the QoS manager and its interaction with the middleware resource manager. The major contributions of the paper are the negotiation algorithms and protocol that minimize the impact on the other paths' QoS while maximizing the unhealthy path's QoS. The approach and algorithms for QoS negotiation are presented.
Summary form only given. Dynamic, distributed, real-time control systems control a widely varying... more Summary form only given. Dynamic, distributed, real-time control systems control a widely varying environment, are made up of application programs that are dispersed among loosely-coupled computers, and must control the environment in a timely manner. The environment determines the number of threats; thus, it is difficult to determine the range of the workload at design time using static worst-case execution time analysis. While a system is lightly loaded, it is wasteful to reserve resources for the heaviest load. Likewise, it is also possible that the load will increase higher than the assumed worst case. A system that has a preset number of resources reserved to it is no longer guaranteed to meet its deadlines under such conditions. In order to ensure that such applications meet their real-time requirements, a mechanism is required to monitor and maintain the real-time quality of service (QoS): a QoS manager, which monitors the processing timing (latency) and resource usage of a d...
Dynamic Resource Management Algorithm for a Distributed Real-time System
In this paper we propose a framework and algorithm for dynamic resource management in a distribut... more In this paper we propose a framework and algorithm for dynamic resource management in a distributed real-time system. Our assumptions are as follows: first, multiple real-time & non real-time processes are active throughout the system. Those processes in the critical path for a given task, i.e., autopilot, fire control (as in firing weapons), surveillance, collaborative planning, are RT for the duration of the task and may or may not be party to multiple tasks in either critical or ancillary capacities. For instance, the radar may be part of the critical path during surveillance, but have uses other thaan that, say to take a snampshot during a collaborative planning sessiong that may serve an ancillary use (as a supplementary illusatration for discussion, e.g., "this is the depot we will go after tomorrow during a flyover") But then, if you can fly over it, why not go after it then? Another example: during a coordinated maneuver, plane-to-plane communications are in the cr...
We demonstrate a 30-element vibrotactile array that fits the palm of a large-handed user. The arr... more We demonstrate a 30-element vibrotactile array that fits the palm of a large-handed user. The array is driven by input to a touchpad, thereby allowing one user to haptically "draw" on a remote user's hand. Pulse-width modulation is used to control tactor intensity, and the multiple intensity levels are used by an anti-aliasing procedure that allows the array to represent
Book Review: Revolt! The Next Great Transformation from Kleptocracy Capitalism to Libertarian Socialism through Counter Ideology, Societal Education, & Direct Action by John Asimakopoulos
Theory In Action, 2012
Important considerations for execution time analysis of dynamic, periodic processes
Proceedings 15th International Parallel and Distributed Processing Symposium. IPDPS 2001, 2001
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Heterogeneous resource management for dynamic real-time systems
Proceedings 9th Heterogeneous Computing Workshop (HCW 2000) (Cat. No.PR00556), 2000
Page 1. Heterogeneous Resource Management for Dynamic Real-Time Systems Eui-Nam Huh, Lonnie R. We... more Page 1. Heterogeneous Resource Management for Dynamic Real-Time Systems Eui-Nam Huh, Lonnie R. Welch Department of Electrical Engineering and Computer Science, Ohio University {ehuh|[email protected]} ...
Lecture Notes in Computer Science, 1999
In this paper we present the architecture and framework for a benchmark suite that has been devel... more In this paper we present the architecture and framework for a benchmark suite that has been developed as part of the DeSiDeRaTa project. The proposed benchmark suite is representative of the emerging generation of distributed, mission-critical, real-time control systems that operate in dynamic environments. Systems that operate in such environments may have unknown worst-case scenarios, may have large variances in the sizes of the data and event sets that they process (and thus, have large variances in execution latencies and resource requirements), and may be very difficult to characterize statically, even by time-invariant statistical distributions. The proposed benchmark suite (called DynBench) is useful for evaluation of the Quality of Service (QoS) management and/or Resource Management (RM) services in distributed real-time systems. As such, DynBench includes a set of performance metrics for the evaluation of the QoS and RM technologies in dynamic distributed real-time systems. The paper demonstrates the successful application of DynBench in evaluation of the DeSiDeRaTa QoS management middle-ware.
Lecture Notes in Computer Science, 1998
Dynamic real-time systems function in unpredictable environments and have requirements that span ... more Dynamic real-time systems function in unpredictable environments and have requirements that span many domains such as time, survivability, and scalability. The system requirements are typically determined as a function of the environment, further exacerbating the unpredictability of the problem. Existing solutions, for the most part, have focussed on problems for which the attributes are static, and there exists a rich set of solutions for such problems. Our problem domain has attributes that are inherently dynamic rather than static, requiring a new approach. We present a model for resource management for dynamic real-time systems. The model includes a language for specifying both static and dynamic attributes. Dynamic attributes include those that are measured as well as requirements that are evaluated on-line. In addition, we describe a resource management architecture for such systems.
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Papers by Charles Cavanaugh