Spaces of paths and the path topology

2016 ◽  
Vol 57 (9) ◽  
pp. 092503 ◽  
Author(s):  
Robert J. Low
Keyword(s):  
Path Topology

scholarly journals The Traffic Grooming Problem in Optical Networks with Respect to ADMs and OADMs: Complexity and Approximation

Algorithms ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 151
Author(s):  
Michele Flammini ◽  
Gianpiero Monaco ◽  
Luca Moscardelli ◽  
Mordechai Shalom ◽  
Shmuel Zaks
Keyword(s):  
Cost Function ◽  
Optical Networks ◽  
Cost Minimization ◽  
Convex Combination ◽  
Optical Network ◽  
Switching Cost ◽  
Wavelength Assignment ◽  
Intermediate Node ◽  
Polynomial Time Approximation Algorithm ◽  
Path Topology

All-optical networks transmit messages along lightpaths in which the signal is transmitted using the same wavelength in all the relevant links. We consider the problem of switching cost minimization in these networks. Specifically, the input to the problem under consideration is an optical network modeled by a graph G, a set of lightpaths modeled by paths on G, and an integer g termed the grooming factor. One has to assign a wavelength (modeled by a color) to every lightpath, so that every edge of the graph is used by at most g paths of the same color. A lightpath operating at some wavelength λ uses one Add/Drop multiplexer (ADM) at both endpoints and one Optical Add/Drop multiplexer (OADM) at every intermediate node, all operating at a wavelength of λ. Two lightpaths, both operating at the same wavelength λ, share the ADMs and OADMs in their common nodes. Therefore, the total switching cost due to the usage of ADMs and OADMs depends on the wavelength assignment. We consider networks of ring and path topology and a cost function that is a convex combination α·|OADMs|+(1−α)|ADMs| of the number of ADMs and the number of OADMs deployed in the network. We showed that the problem of minimizing this cost function is NP-complete for every convex combination, even in a path topology network with g=2. On the positive side, we present a polynomial-time approximation algorithm for the problem.

Adaptive Tool Path Planning Strategy for 5-Axis CNC Machining of Free Form Surfaces

2019 ◽  
Author(s):  
Hrishikesh Mane ◽  
S. S. Pande
Keyword(s):  
Tool Path ◽  
Cnc Machining ◽  
Memory Storage ◽  
Free Form ◽  
Cnc Machine ◽  
Planning Strategy ◽  
Part Quality ◽  
Tool Paths ◽  
Path Topology ◽  
Free Form Surfaces

Abstract This paper presents a curvature based adaptive iso-parametric strategy for the efficient machining of free form surfaces on 5-axis CNC machine using the flat end mill tool. One iso-parametric boundary of the surface is selected as the initial tool path. Set of cutter contact (CC) points are chosen adaptively on the initial tool path considering desired profile tolerance. Adjacent iso-parametric tool paths are computed adaptively based on the scallop height constraint unlike the traditional iso-parametric approach. The path topology is post-processed to generate the part program for 5-axis CNC machine in ISO format. The system was rigorously tested for various case studies by comparing the results with the traditional 5-axis iso-parametric tool path strategy, iso-scallop strategy and iso-planar strategy of a commercial software. Our system was found to generate efficient tool paths in terms of part quality, productivity and memory storage compared to the conventional strategies.

scholarly journals Invariance of domain in Minkowski space with path topology

2015 ◽  
Vol 191 ◽  
pp. 131-136 ◽  
Author(s):  
Gunjan Agrawal ◽  
Nisha Godani
Keyword(s):  
Minkowski Space ◽  
Path Topology

The path topology and the causal completion

2006 ◽  
Vol 47 (7) ◽  
pp. 072503 ◽  
Author(s):  
Do-Hyung Kim
Keyword(s):  
Path Topology

scholarly journals Selecting the Best Routing Traffic for Packets in LAN via Machine Learning to Achieve the Best Strategy

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Bo Zhang ◽  
Rongji Liao
Keyword(s):  
Neural Network ◽  
Machine Learning ◽  
Time Delay ◽  
Real Time ◽  
Shortest Path ◽  
Computer Network ◽  
Routing Algorithm ◽  
The Neural Network ◽  
Path Topology ◽  
Path Computations

The application of machine learning touches all activities of human behavior such as computer network and routing packets in LAN. In the field of our research here, emphasis was placed on extracting weights that would affect the speed of the network's response and finding the best path, such as the number of nodes in the path and the congestion on each path, in addition to the cache used for each node. Therefore, the use of these elements in building the neural network is worthy, as is the exploitation of the feed forwarding and the backpropagation in the neural network in order to reach the best prediction for the best path. The goal of the proposed neural network is to minimize the network time delay within the optimization of the packet paths being addressed in this study. The shortest path is considered as the key issue in routing algorithm that can be carried out with real time of path computations. Exploiting the gaps in previous studies, which are represented in the lack of training of the system and the inaccurate prediction as a result of not taking into consideration the hidden layers' feedback, leads to great performance. This study aims to suggest an efficient algorithm that could help in selecting the shortest path to improve the existing methods using weights derived from packet ID and to change neural network iteration simultaneously. In this study, the design of the efficient neural network of appropriate output is discussed in detail including the principles of the network. The findings of the study revealed that exploiting the power of computational system to demonstrate computer simulation is really effective. It is also shown that the system achieved good results when training the neural network system to get 2.4% time delay with 5 nodes in local LAN. Besides, the results showed that the major features of the proposed model will be able to run in real time and are also adaptive to change with path topology.

Sign in / Sign up

Export Citation Format

Share Document