Digital Commons Network^™

A Statically-Typed Language With Classes, Mike Beaven, Ryan Stanisfer, Dan Wetklow

Department of Computer Science Technical Reports

No abstract provided.

The Cops Security Checker System, Daniel Farmer, Eugene H. Spafford

Department of Computer Science Technical Reports

No abstract provided.

Convex Decomposition Of Polyhedra And Robustness, Chanderjit Bajaj, Tamal K. Dey

Department of Computer Science Technical Reports

No abstract provided.

Digital Search Trees Again Revisited: The Internal Path Length Perspective, Peter Kirschenhofer, Helmut Prodinger, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.

Typed Token Approach For Database Processing During Network Partitioning, Bharat Bhargava, Shy-Renn Lian

Department of Computer Science Technical Reports

No abstract provided.

A Data Structure For Analyzing Collisions Of Moving Objects, George Vanecek

Department of Computer Science Technical Reports

No abstract provided.

Loop Coalescing And Scheduling For Barrier Mimd Architectures, Matthew T. O'Keefe, Henry G. Dietz

Department of Electrical and Computer Engineering Technical Reports

Barrier MIMDs are asynchronous Multiple Instruction stream Multiple Data stream architectures capable of parallel execution of variable execution time instructions and arbitrary control flow (e.g., while loops and calls); however, they differ from conventional MlMDs in that the need for run-time synchronization is significantly reduced. This work considers the problem of scheduling nested loop structures on a barrier MIMD. The basic approach employs loop coalescing, a technique for transforming a multiply-nested loop into a single loop. Loop coalescing is extended to nested triangular loops, in which inner loop bounds are functions of outer loop indices. Also, a more efficient scheme …

Adaptive Control Of Flexible Joint Robots Derived From Arm Energy Considerations, Shaheen Ahmad, Fouad Mrad

Department of Electrical and Computer Engineering Technical Reports

Almost all industrial robots exhibit joint flexibility due to mechanical compliance of their gear boxes. In this paper we outline the design of three controllers for flexible joint robots. Two of the three controllers are suitable for parameter adaptation, the candidate Lyapunov functions for these two controllers are derived from arm energy considerations. The desired actuator trajectory in a flexible joint robot is dependent not only on the desired kinematic trajectory of the link but also on the link dynamics. Unfortunately, link dynamic parameters are unknown in most cases, as a result the desired actuator trajectory is also unknown: To …

A Lower Bound On Embedding Large Hypercubes Into Small Hypercubes, Ajay K. Gupta, Alfred J. Boals, Naveed A. Sherwani, Susanne E. Hambrusch

Department of Computer Science Technical Reports

No abstract provided.

The Damping Of Panels By Thick Layers Of Elastic Porous Media, Nae-Ming Stuart Shiau, T J. Wahl, J Stuart Bolton

Publications of the Ray W. Herrick Laboratories

In this paper a technique is presented for calculating the response of a panel to a line force input when loaded by both a finite‐depth layer of elastic porous material and a heavy fluid. Damping theories normally require that an attached damping layer be thin compared to the flexural wavelength in the base panel. Here this requirement is avoided by allowing explicitly for wave propagation within the damping layer. Specifically, the porous damping layer is modeled using a theory derived by Biot that allows for the existence of two dilatational waves and a transverse wave. Conditions required to couple the …

Adaptability Experiments In The Raid Distributed Database System, Bharat Bhargava, Karl Friesen, Abdelsalam Helal, John Riedl

Department of Computer Science Technical Reports

No abstract provided.

Data Layout Optimization And Code Transformation For Paged Memory Systems, Lung-Yu Chang, Henry G. Dietz

Department of Electrical and Computer Engineering Technical Reports

Supercomputers need not only to have fast functional units, but also to have rapid access to massive quantities of data. Virtual memory paging and physically distributed memory systems both attempt to provide this large data space, but performance of a computer system using either memory organization is highly dependent on the page reference pattern and the number of pages available locally. Despite this, surprisingly little work has been done toward using the compiler to optimize memory system performance. In this paper, we introduce compiler techniques which use a combination of data layout and code transformation to improve paging performance for …

Programming Of Path Specific Robot Operations With Optimal Part Placement, Rick Guptill, Shaheen Ahmad

Department of Electrical and Computer Engineering Technical Reports

In this paper we describe a task level programming system for path specific robot operations. We define path specific tasks as those robot tasks in which the path the manipulator end effector has to follow is fixed and is given, such operations may include welding or sealant application. The initial path selection is made through a graphical interface using a pointing device (such as a mouse) to outline the desired path on a CAD model of the workpiece. The final result of the system is the part location, which enables the chosen manipulator to optimally perform the desired task. Optimality …

The Second International Conference On Expert Systems For Numerical Computing, John R. Rice, Robert Vichnevetsky, Elias N. Houstis

Department of Computer Science Technical Reports

No abstract provided.

Recruitment And Retention Of Engineers And Managers In Transportation Agencies, Donald L. Hiatte

Purdue Road School

No abstract provided.

The Tennessee Geodetic Reference Network (Tgrn): An Update*, James H. Zeigler

Purdue Road School

No abstract provided.

If You're Not Managing Your Department, Then Who Is?, Kent O. Lande

Purdue Road School

No abstract provided.

Shape Recovery From Robot Contour Tracking With Force Feedback, Shaheen Ahmad, Chuan N. Lee

Department of Electrical and Computer Engineering Technical Reports

In this paper we describe a process for shape recovery from robot contour-tracking operations with force feedback. Shape recovery is an important task for self-teaching robots and for exploratory operations in unknown environments. An algorithm which directs a position controlled robot around an unknown planar contour using the steady state contact force information is described in this paper. The shape recovery from the planar contouring is not a trivial problem. It is experimentally found that there is significant distortion of the original contour if direct kinematics is used to recover the object’s shape, as we are unable to recover the …

Supporting Queries In The O-Raid Object-Oriented Database System, James G. Mullen, Jagannathan Srinivasan, Prasun Dewan, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.

A Limiting Distribution For The Depth In Patricia Tries, Bonita Rais, Philippe Jacquet, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.

P-Complete Geometric Problems, Mikhail J. Atallah, Paul Callahan, Michael T. Goodrich

Department of Computer Science Technical Reports

No abstract provided.

Adaptive Control Of Flexible Joint Robots Derived From Arm Energy Considerations, Shaheen Ahmad, Fouad Mrad

Department of Electrical and Computer Engineering Technical Reports

Almost all industrial robots exhibit joint flexibility due to mechanical compliance of their gear boxes. In this paper we outline a design of an adaptive controller for flexible joint robots based on the arms energy. The desired actuator trajectory in a flexible joint robot is dependent not only on the desired kinematic trajectory of the link but also on the link dynamics. Unfortunately, link dynamic parameters are unknown in most cases, as a result the desired actuator trajectory is also unknown. To overcome this difficulty, a number of control schemes have suggested the use of acceleration and link jerk feedback. …

Pulse Width Modulated Control Of Robotic Manipulators, Hebertt Sira-Ramirez, Mohammed Zribi, Shaheen Ahmad

Department of Electrical and Computer Engineering Technical Reports

In this paper we propose a practical discontinuous feedback control scheme for the regulation of joint positions of robotic manipulators. A robust on-off switching control strategy based on a pulse-width-modulation (PWM) feedback scheme is proposed for the joint torques. The discontinuous PWM controller design is carried out on the basis of a suitable controller designed for an average model which is of continuous nature. Simulations of the closed loop performance of the proposed control scheme are presented for a two-link robotic manipulator

Towards Automatic Grid Generation Using Binary Space Partition Trees, George Vanecek

Department of Computer Science Technical Reports

No abstract provided.

G1 Interpolation Using Piecewise Quadric And Cubic Surfaces, Chanderjit L. Bajaj

Department of Computer Science Technical Reports

No abstract provided.

Geometric Computations With Algebraic Varieties Of Bounded Degree, Chanderjit L. Bajaj

Department of Computer Science Technical Reports

No abstract provided.

The Use Of Bottom Ash In Highway Embankments, Subgrades, And Subbases : Executive Summary, Wei-Hsing Huang

JTRP Technical Reports

This research assessed those properties of power plant bottom ash likely to affect its use as highway fill or pavement material, based on laboratory investigation conducted on eleven Indiana bottom ashes. Laboratory tests included: chemical analysis, mineralogical study, microscopic examination of ash particles, specific gravity, grain size distribution, sulfate soundness, Los Angeles abrasion, permeability, shear strength, moisture-density relations, degradation under compaction, compressibility, and California bearing ratio.

The various test values and properties were compared to- those of representative granular soils or appropriate specifications. These comparisons provide information necessary for judging the suitability of bottom ash in Indiana highway construction.

The …

Fiber Reinforced Aluminum Alloy For The Moving Parts Of Rotary Compressor, T. Komatsubara, M. Okajima, H. Hoshino, Y. Obokata

International Compressor Engineering Conference

No abstract provided.

The Use Of An Ejector As A Refrigerant Expander, A. A. Kornhauser

International Refrigeration and Air Conditioning Conference

No abstract provided.

Status Report On Polyalkylene Glycol Lubricants For Use With Hfc-134a In Refrigeration Compressors, S. G. Sundaresan

International Refrigeration and Air Conditioning Conference

No abstract provided.