In this paper we propose using experiments with Balanced-Sample Binary Trees (BSBTrees) as assignments and lecture material in intermediate data structures courses (CS2/3). BSBTrees are composite data structures that have a temporarily constructed form that precedes their normal construction. We present them in the context of binary search trees. To do this we first investigate the retrieval properties of randomly generated binary search trees and show how temporary construction can improve both worst case and average case behavior. We provide a brief analysis of BSBTree performance and description of the classes that can be used for BSBTree implementation. Last we discuss the use of BSBTrees in CS2 and CS3 courses and a survey of student opinions about BSBTrees.

Peshkin and Sanderson (1988) showed that parts can be aligned as they move on a conveyor belt against a passive sequence of fences. In this paper the authors describe the first complete algorithm to design such sequences for a given convex polygonal part. The algorithm is complete in the sense that it is guaranteed to find a design if one exists and to terminate with a negative report otherwise. Based on an exact breadth-first search of the design space, the algorithm is also guaranteed to find the design requiring the fewest fences. The authors describe the algorithm and compare results with those previously reported. The authors conjecture that a fence design exists to orient any convex polygonal part defined by a sequence of rational vertices.

We built a system that allows a robot manipulator to be teleoperated via the WWW. Although the field of teleoperation dates back over 50 years, the WWW provides a low-cost and widely-available interface that can make teleoperated resources accessible to anyone with a desktop or laptop computer and modem. The "Mercury Project" consists of an industrial robot arm fitted with a CCD camera and a pneumatic system. We placed a sandbox filled with buried artifacts in the robot workspace. Using the ISMAP feature of HTTP, users can remotely move the camera to view desired locations or direct a short burst of compressed air into the sand to view the newly cleared region. To our knowledge, the Mercury Project is the first system to permit WWW users to remotely view and alter the real world. This paper focuses on interface design, robot hardware, and system architecture.

To be cost effective and highly precise, many industrial assembly robots have only four degrees of freedom (DOF) plus a binary pneumatic gripper. Such robots commonly permit parts to be rotated only about a vertical axis. However it is often necessary to reorient parts about other axes prior to assembly. In this paper the authors describe a way to orient parts about an arbitrary axis by introducing a rotating bearing between the jaws of a simple gripper. Based on this mechanism, the authors are developing a rapidly configurable vision-based system for feeding parts. In this system, a camera determines initial part pose; the robot then reorients the part to achieve a desired final pose. The authors have implemented a prototype version in their laboratory using a commercially-available robot system.>