Let S be a collection of n non-intersecting line segments in the plane in general position. Two segments u and v are deened as visible if a line segment could be drawn from some point of u to some point of v that intersects no other segment in S. The full visibility graph associated with S is denoted as G(S), and deened to be the graph whose n vertices correspond to the line segments of S and w...

This paper introduces a robotic system that uses a PTZ camera to find the human in the room and locate its position. Then the robot is guided to go near to the human. This includes human detection and localization, robot localization and robot navigation. Human's head and face is detected by using a combination of motion detection, shape analysis and color information. The 3-D position of human...

Given a 3-SAT formula, a graph can be constructed in polynomial time such that the graph is a point visibility graph if and only if the 3-SAT formula is satisfiable. This reduction establishes that the problem of recognition of point visibility graphs is NP-hard.

matroids are important combinatorial structures and connect close-lywith graphs. matroids and graphs were all generalized to fuzzysetting respectively. this paper tries to study  connections betweenfuzzy matroids and fuzzy graphs. for a given fuzzy graph, we firstinduce a sequence of matroids  from a sequence of crisp graph, i.e.,cuts of the fuzzy graph. a fuzzy matroid, named graph fuzzy matro...

This paper introduces a methodology for avoiding obstacles by controlling the robot’s velocity. Contemporary approaches to obstacle avoidance usually dictate a detour from the originally planned trajectory to its goal position. In our previous work, we presented a method for predicting the motion of obstacles, and how to make use of this prediction when planning the robot trajectory to its goal...

An industrial robot today uses measurements of its joint positions and models of its kinematics and dynamics to estimate and control its end-effector position. Substantially better end-effector position estimation and control performance would be obtainable if direct measurements of its end-effector position were also used. The subject of this paper is extended Kalman filtering for precise esti...