We present a fast algorithm to compute an optimal rec-tilinear Steiner tree for extremal point sets. A point set is extremal if each point lies on the boundary of a rectilinear convex hull of the point set. Our algorithm can be used in homotopic routing in VLSI layout design and it runs in O(k 2 n) time, where n is the size of the point set and k is the size of its rectilinear convex hull.

This study presents a design method to fabricate a novel hybrid-structure flat plate heat pipe (NHSP heat pipe) for a concentrator photovoltaic. The NHSP heat pipe is composed of a flattened copper pipe and a sintered wick structure, and a coronary-stent-like rhombic copper mesh supports the structure. The coronary-stent-like supporting structure enhances the mechanical strength and shortens th...

Rehabilitation of a watermain by grouted sliplining is usually carried out when the existing pipe is only partially deteriorated. Although designs that neglect the structural contributions from the existing pipe and the grout are generally conservative, the performance of the rehabilitated pipe needs to be better understood for effective design and management of buried water pipes. Presented in...

The problem of drawing a graph in the plane with a minimum number of edge crossings—called the crossing number of a graph—is a well-studied problem which dates back to the first half of the twentieth century, as mentioned in [11], and was formulated in full generality in [3]. It was shown that this problem is NP-Complete [4], and that it remains so even when restricted to cubic graphs [5]. Many...

Pipe vibration is often excited in the deep ocean by ship motions, wave forces and vortex shedding. Elastic joints along the pipe are modeled in an attempt to move the resonance frequencies away from the pipe system. The numerical examples focus on the investigation of single and multiple elastic joints along a long pipe and their effect on three-dimensional (3-D) nonlinear coupled pipe respons...

Diameter pipe.robot, called the Multifunctional Robot for IN-pipe inSPECTion. In-pipe robots, which have a long history of development in robotics, can be.This paper describes a mobile feeder pipe inspection robot that can minimize the irradiation dose to human workers by automating the measurement process.Recently, many pipe inspection robot systems have been developed. Initially, development ...

Recently, Aichholzer, Garćıa, Orden, and Ramos derived a remarkably improved lower bound for the number of (≤ k)-edges in an n-point set, and as an immediate corollary an improved lower bound on the rectilinear crossing number of Kn. We use simple allowable sequences to extend all their results to the more general setting of simple generalized configurations of points and slightly improve the l...

This paper proposes a comparison between rectilinear and radio-concentric networks. Indeed, those networks are often observed in urban areas, in several cities all over the world. One of the interesting properties of such networks is described by the straightness measure from graph theory, which assesses how much moving from one node to another along the network links departs from the network-i...

One form of hybrid evolutionary algorithm encodes solutions to its target problem as permutations of the problem's elements. A greedy heuristic assembles the solution a permutation represents by appending the problem's elements to the solution in the order the permutation speci es. The algorithm searches the problem's solution space by searching the space of permutations. A hybrid genetic algor...

Motivated by practical VLSI routing applications, we study the maximum vertex degree of a minimum spanning tree (MST). We prove that under the Lp norm, the maximum vertex degree over all MSTs is equal to the Hadwiger number of the corresponding unit ball; we show an even tighter bound for MSTs where the maximum degree is minimized. We give the best-known bounds for the maximum MST degree for ar...