The visibility graph of a set of nonintersecting polygonal obstacles in the plane is an undirected graph whose vertices are the vertices of the obstacles and whose edges are pairs of vertices (u, v) such that the open...
详细信息
The visibility graph of a set of nonintersecting polygonal obstacles in the plane is an undirected graph whose vertices are the vertices of the obstacles and whose edges are pairs of vertices (u, v) such that the open line segment between u and v does not intersect any of the obstacles. The visibility graph is an important combinatorial structure in computational geometry and is used in applications such as solving visibility problems and computing shortest paths. An algorithm is presented that computes the visibility graph of s set of obstacles in time O(E + n log n), where E is the number of edges in the visibility graph and n is the total number of vertices in all the obstacles.
Let A be a set and k ∈ N be such that we wish to know the answers to x 1 ∈ A?, χ 2 ∈ A?, …, X k ∈ A? for various k-tuples (x 1 ,x 2 , …,X k )· If this problem requires k queries to A in order to be solv...
Let A be a set and k ∈ N be such that we wish to know the answers to x 1 ∈ A?, χ 2 ∈ A?, …, X k ∈ A? for various k-tuples (x 1 ,x 2 , …,X k )· If this problem requires k queries to A in order to be solved in polynomial time then A is called polynomial terse or pterse. We show the existence of both arbitrarily complex pterse and non-pterse sets; and that P=NP iff every NP-complete set is pterse. We also show connections with p-immunity, polynomial separability, p-generic sets, and the boolean hierarchy. Our techniques allow us to prove that Unique Satisfiability (USAT) is, in some sense, "close" to Satisfiability. In particular, we show that USAT is coNP-hard.
A common structure arising in computational geometry is the subdivision of a plane defined by the faces of a straight line planar graph. We consider a natural generalization of this structure on a polyhedral surface. ...
详细信息
We present a verified sliding window protocol which uses modulo-N sequence numbers to achieve reliable flow-controlled data transfer between a source and a destination. Communication channels are assumed to lose, dupl...
详细信息
As a step in our efforts toward the study of real-time monitoring of the inferential process in reasoning systems, we have devised a method of representing knowledge for the purpose of default reasoning. A meta-level ...
详细信息
作者：
JOLLIFF, JVCALLAHAN, CMUSNCapt. James V. Jolliff
USNgraduated from the U. S. Naval Academy in 1954. Following graduation he served in the USS S. N. Moore (DD—747) and USS Cimarron (AO—22). He received his MS degrees in Naval Architecture from Webb Institute of Naval Architecture and in Financial Management from The George Washington University. He culminated his education at The Catholic University of America where he was awarded his Doctorate in Ocean Engineering in 1972. Capt. Jolliff has served in Naval Shipyards as Ship Superintendent Assistant Repair Officer and Assistant Planning & Estimating Superintendent and as such was primarily concerned with the repair and conversion of U. S. Navy skips. In addition he has served as Maintenance Officer Staff of Commander Mine Force U. S. Pacific Fleet as Co—Chairman of the Naval Engineering Division
Engineering Department U. S. Naval Academy and as CV Design Manager in the Advanced Concepts Division and as Head
Ship Survivability Office Naval Ship Engineering Center. An active member of ASNE since 1966 he has served as a member of the National Council and is currently the Chairman of the Journal Committee. He has had several papers presented at ASNE Day and published in the Journal and in 1976 was one of the recipients of the ASNE President's Award. At the present time he is assigned as the Commanding Officer Naval Coastal Systems Laboratory (NCSL) Panama City Fla. Mr. Casville M. Callahanis a native of Southwest Virginia where he attended Elementary and Secondary School prior to his three year's service in the U. S. Navy during World War II. He graduated from Lincoln Memorial University
Harrogate Tenn. in 1950 receiving his BS degree in Mathematics. In 1952 he received his MS degree in Mathematics from Auburn University Auburn Ala. and taught mathematics at Lincoln Memorial University and at Florida State University Tallahassee Fla. prior to joining the staff of the Mine Defense Laboratory in 1955. He has progressed through a variety of assignments as the Labo
Test and Evaluation have become paramount in today's department of Defense acquisition process. Therefore, the U. S. Navy requires both private and public facilities to accomplish the final goals of the “Fly befo...
Test and Evaluation have become paramount in today's department of Defense acquisition process. Therefore, the U. S. Navy requires both private and public facilities to accomplish the final goals of the “Fly before Buy” concept. Such a facility exists at the Naval Coastal Systems Laboratory (NCSL); an integral part of the Chief of Naval Material's, Director of Navy Laboratories organization. This paper briefly addresses the Laboratory, its mission, and its history. This is followed by an in—depth facilities overview in order to create an understanding of the slow but steady evolution of NCSL's unique fixed facilities. These facilities, when coupled to the local natural environment, provide a unique in situ test and evaluation capability which is unequalled in the United States for assessing seagoing coastal systems. Of prime consideration is the Range Date Acquisition Center (RADAC) and Its ancillary subsystems for tracking, environmental monitoring, communications, and post run analysis. The paper is concluded with a discussion of both past and present use of the aforementioned facilities with an emphasis on user acceptance and future potential growth.
Considering velocity perturbations as white noise and assuming exponential decay of velocities to the mean velocity μ, we obtain a two‐parameter Langevin equation. The conditional and steady‐state probability densi...
Let f(x) ε Lipα, 0 n (x) is some n–th trigonometric polynomial. We define a generating sequence {pn>} such that it is non-negative, non-increasing and [formula omitted] Approximation of functions belonging to th...
暂无评论