14121852
Programming by demonstration - constructing task level plans in hybrid dynamic framework
This paper presents a novel approach to constructing a task level plan for an assembly task from demonstration. A hybrid dynamic system is chosen as an attractive way to model assembly tasks. We propose a framework where the mappings required within the hybrid dynamic system model are extracted from a demonstration. We extract the event path planner mapping, which determines a task level plan. Demonstrated paths are broken down into their base elements, called transitions. A path plan is then constructed from transitions that were well demonstrated. We test the approach by having a robot execute an assembly task using constructed task plans. The framework produces excellent results because: 1) the robot can perform selected paths better than when it simply copies the demonstrator, and 2) it allows flexible path selection so the robot can be given a disposition in how it executes the task.
13891792
Constructing Task-Level Assembly Strategies in Robot Programming by Demonstration
Programming by demonstration (PbD) is a technique for programming robots that holds much promise in making robots more accessible to ordinary, non-technical users. However, a well-known difficulty with the method is that a human will often demonstrate the task to be programmed inconsistently or even erroneously, leading to the inclusion of what is essentially noise in the demonstration. A number of techniques exist in the literature for filtering out this type of noise; however, most focus on very low level control command details. In this paper, we propose a new, complementary direction of research. We take a “task-level” view of the demonstration, and note that noise can exist at this level also. We propose a framework, based on a hybrid dynamic system modeling approach, to select the most optimal, task-level execution strategies that were demonstrated. We apply our framework to a real household task of inserting the compressible spindle of a paper towel holder into its supports. We conduct experiments to show that significant improvements in robot performance of the task can be achieved by a PbD regime that includes our method.
12151643
Discretization Approach and Nonparametric Modeling for Long-Term HIV Dynamic Model
Modeling viral load response in long-term HIV dynamics is important for AIDS clinical study. It allows one to examine how a patient recuperates for an antiviral treatment. This paper investigates a discretization approach to the viral load based on a long-term HIV dynamic model. We propose a two-stage nonparametric procedure for estimating the viral load and the time-varying new productive virus. Simulation study shows that the proposed estimated methods are efficient and powerful for fitting long-term viral load measurements.
2466823
Two methods for creating chinese painting
We present two methods to create realistic Chinese painting. The first method is to create 3D Chinese painting animation using existing software packages. The second method is an expressive paint tool which allows an artist to interactively create 2D Chinese painting.
43039500
A Linear Time Algorithm for Isomorphism of Graphs of Bounded Average Genus
Recent progress in topological graph theory has shown potential applicability of average genus to graph isomorphism testing. The present paper describes an initial effort at combining topological invariants with combinatorial analysis to design efficient graph isomorphism algorithms. In particular, a linear time algorithm for isomorphism of graphs of bounded average genus is presented.
2698140
On fixed-parameter tractability and approximability of NP-hard optimization problems
Fixed-parameter tractability and approximability of NP-hard optimization problems are studied based on a model GC(s(n), Pi /sub k//sup L/). The main results are (1) a class of NP-hard optimization problems, including dominating-set and zero-one integer-programing, are fixed-parameter tractable if and only if GC(s(n), Pi /sub 2//sup L/) contained in P for some s(n) in omega (log n); (2) most approximable NP-hard optimization problems are fixed-parameter tractable. In particular, the class MAX NP is fixed-parameter tractable; (3) a class of optimization problems do not have fully polynomial time approximation scheme unless GC(s(n), Pi /sub k//sup L/) contained in P for some s(n) in omega (log n) and for some k>l; and (4) every fixed-parameter tractable optimization problem can be approximated in polynomial time to a non-trivial ratio.<<ETX>>
691108
Utilization-based admission control for real-time applications
In this paper, we present a methodology to use utilization-based admission control in guaranteed real-time communication in a scalable fashion. We make admission control scalable by using a configuration-time test to determine a safe utilization level of servers. Admission control at run-time then is reduced to simple utilization tests on the servers along the path of the new flow. Furthermore, we discuss how appropriate route selection improve utilization levels, design a safe route selection heuristic algorithm to achieve high utilization of resources, and derive two bounds on the maximum utilization level for given traffic in a network. We compare the results of our route selection heuristics with that of a shortest-path based algorithm, and find that our heuristics can achieve a much higher maximum utilization level than that of the shortest-path based algorithm.