Most research on ad-hoc wireless networks makes simplifying assumptions about radio propagation. The “Flat Earth” model of the world is surprisingly popular: all radios have circular range, have perfect coverage in that range, and travel on a two-dimensional plane. CMU’s ns-2 radio models are better but still fail to represent many aspects of realistic radio networks, including hills, obstacles...

Split-liver transplantation (SLT), a procedure where one cadaver liver is divided to provide for two recipients, offers immediate expansion of the existing cadaver donor pool. To date, the principal beneficiaries of SLT have been adult/pediatric recipient pairs with excellent outcomes reported; however, the current scarcity of cadaver organs has renewed interest in expanding these techniques to...

The paper describes an application of the A* algorithm for flight path planning for airplanes with defined motion dynamics operating in a continuous three-dimensional space constrained by existing physical obstacles. The presented A* algorithm modification provides significant acceleration (reduction of the state space) of the path planning process. The described algorithm is able to find a pat...

When a robot moves about a 2D world such as a planar surface, it is important that obstacles to the robot's motions be detected. This classical problem of \obstacle detection" has proven to be di cult. Many researchers have formulated this problem as being the process of determining where a robot cannot move due to the presence of obstacles. An alternative approach presented here is to determin...

Thh paper presents a new method for computing the configuration-space map of obstacles that is used in motion-planning algorithms. The method derives from the observation that, when the robot is a rigid object that can only translate, the configuration space is a convolution of the workspace and the robot. This convolution is computed with the use of the Fast Fourier Transform (FFT) algorithm. ...

In this paper, we consider planning motions of objects of regular shape rolling on a plane among obstacles. Theoretical foundations and applications of this type of operations in robotic manipulation and locomotion have been discussed elsewhere. In this paper, we propose a novel algorithm that improves upon existing techniques in that: i) it is finitely computable and predictable (an upper boun...

despite several authors having studied the strategic approach to environmental orientation and,considering that environmental proactivity is emerging in business strategy, it still remains unclear which realactions influence a firm’s environmental orientation. an empirical analysis of a sample of 126 spanish companies shows that firms’ actions are explained as training, information and divulgat...

This paper presents a collision avoidance method for multiple UAV sharing the same aerial space with noncooperative aircraft based on velocity planning. The proposed method finds a safe trajectory, modifying the velocity profile of the different vehicles involved in the collision and considering mobile obstacles. The proposed method applies two steps: Search Tree and Tabu Search. The objective ...