scholarly journals Topology Uniformity Pinning Control for Multi-agent Flocking

2021 ◽  
Author(s):  
Jintao Liu ◽  
Ming He ◽  
Qiang Liu ◽  
Jie Wang ◽  
Mingguang Zou ◽  
...  
Keyword(s):  
Mathematical Proof ◽  
Laplacian Matrix ◽  
Pinning Control ◽  
Selection Strategy ◽  
Node Selection ◽  
Synchronization Index ◽  
Selection Strategies ◽  
Np Hard Problem ◽  
Multi Agent ◽  
Better Than

The optimal pinning node selection for multi-agent flocking is a NP-hard problem. The current pinning node selection strategies mainly depend on complex network node characteristics which are lack of rigorous mathematical proof for flocking control. This paper studies the effect and selection strategy of pinning node based on matrix eigenvalue theory. Firstly, the effect on the eigenvalue of Laplacian matrix by pinning node is analyzed. Secondly, the synchronization index which reflects topology uniformity of multi-agent system is proposed to exert maximum influence on the system synchronizability. A practicable optimal pinning node selection method based on synchronization index is proposed and analyzed by the eigenvalue perturbation method. Finally, the simulations show the rate of system convergence by using optimal synchronizability pinning node is better than the maximum degree centrality.

A novel atlas-selection approach for multi-atlas based segmentation using the correlation of inter-atlas similarities

2014 ◽  
Author(s):  
Patrik Raudaschl ◽  
Karl Fritscher ◽  
Paolo Zaffino ◽  
Greg Sharp ◽  
Marta Spadea ◽  
...  
Keyword(s):  
State Of The Art ◽  
Selection Strategy ◽  
Automated Segmentation ◽  
Image Guided Radiotherapy ◽  
Image Guided ◽  
Selection Strategies ◽  
Segmentation Quality ◽  
Selection Approach ◽  
Left And Right ◽  
Better Than

Automated segmentation is a frequently applied task in the course of medical imaging. Furthermore, it is a substantial component of image-guided radiotherapy. Atlas based segmentation is one of the most frequently used approach for automated segmentation. Especially for multi-atlas based segmentation, segmentation quality and speed largely depends on the underlying registration and atlas selection strategy. In this work an atlas selection strategy that is based on the correlation of inter-atlas similarities within a set of atlas images is presented. Segmentation quality is analyzed by calculating dice coefficients and 95% Hausdorff distances for the left and right parotid with respect to different numbers of atlases. Results are compared to other state of the art atlas selection strategies. It can be shown that the developed atlas selection technique performs slightly better than NMI-based selection if a low number of atlases is used.

scholarly journals Push and Rotate: a Complete Multi-agent Pathfinding Algorithm

2014 ◽  
Vol 51 ◽  
pp. 443-492 ◽  
Author(s):  
B. de Wilde ◽  
A. W. Ter Mors ◽  
C. Witteveen
Keyword(s):  
State Of The Art ◽  
Hard Problem ◽  
Post Processing ◽  
Wide Range ◽  
Np Hard Problem ◽  
Multi Agent ◽  
Strong Performance ◽  
Minimal Sequence ◽  
Better Than ◽  
Start Location

Multi-agent Pathfinding is a relevant problem in a wide range of domains, for example in robotics and video games research. Formally, the problem considers a graph consisting of vertices and edges, and a set of agents occupying vertices. An agent can only move to an unoccupied, neighbouring vertex, and the problem of finding the minimal sequence of moves to transfer each agent from its start location to its destination is an NP-hard problem. We present Push and Rotate, a new algorithm that is complete for Multi-agent Pathfinding problems in which there are at least two empty vertices. Push and Rotate first divides the graph into subgraphs within which it is possible for agents to reach any position of the subgraph, and then uses the simple push, swap, and rotate operations to find a solution; a post-processing algorithm is also presented that eliminates redundant moves. Push and Rotate can be seen as extending Luna and Bekris's Push and Swap algorithm, which we showed to be incomplete in a previous publication. In our experiments we compare our approach with the Push and Swap, MAPP, and Bibox algorithms. The latter algorithm is restricted to a smaller class of instances as it requires biconnected graphs, but can nevertheless be considered state of the art due to its strong performance. Our experiments show that Push and Swap suffers from incompleteness, MAPP is generally not competitive with Push and Rotate, and Bibox is better than Push and Rotate on randomly generated biconnected instances, while Push and Rotate performs better on grids.

Static group synchronization of second-order multi-agent systems via pinning control

2019 ◽  
Vol 356 (9) ◽  
pp. 4842-4858 ◽  
Author(s):  
Xiang-Gui Guo ◽  
Hong-Jian Li ◽  
Jun-Jie Zhao ◽  
Wei-Wei Che
Keyword(s):  
Pinning Control ◽  
Second Order ◽  
Multi Agent Systems ◽  
Agent Systems ◽  
Multi Agent ◽  
Group Synchronization ◽  
Static Group

scholarly journals Drooms Store Strategy To Win Business Competition On E-Commerce Lazada

2021 ◽  
Vol 19 (1) ◽  
pp. 13
Author(s):  
Asep Sugara ◽  
MD Sukamto ◽  
Rida Ramdani
Keyword(s):  
Selection Strategy ◽  
Target Market ◽  
Promotion Strategy ◽  
Product Selection ◽  
Advertising Strategy ◽  
Selection Strategies ◽  
Research Activities ◽  
Business Analysis ◽  
Analysis Strategy ◽  
Product Sales

This study aims to determine the Droom Store strategy in winning business competition in Lazada E-Commerce and increasing customer satisfaction. The analytical approach used is to use a qualitative approach. Where the owner of Drooms Store used as key informants with data collection using triangulation techniques. The results of research at Drooms Store using the techniques above, strategies that can win business competition in Lazada E-Commerce are product selection strategies which are the basis of product sales in which there are product research activities, namely where the seller determines the scale of the benefits of a product. product, then the price of the product, and also the target market. Product advertising strategy which is the second stage after the product selection strategy where this product advertising strategy can reach consumers and attract consumers to buy products. Then there is a product promotion strategy that aims to boost sellers to increase. A business analysis strategy that aims to control the business at Drooms Store . In other words, Lazada's E-commerce for the strategy that we will use has been very well supported by Lazada

scholarly journals On a Class of Optimal Stopping Problems with Mixed Constraints

2010 ◽  
Vol Vol. 12 no. 2 ◽  
Author(s):  
F. Thomas Bruss
Keyword(s):  
Selection Strategy ◽  
Optimal Selection ◽  
Recursive Structure ◽  
Limiting Behavior ◽  
Mixed Constraints ◽  
Selection Strategies ◽  
International Audience ◽  
Optimal Stopping Problems ◽  
The Cost ◽  
Independent Identically Distributed

International audience Let X(1),X(2),...,X(n) be independent, identically distributed uniform random variables on [0, 1]. We can observe the outcomes sequentially and must select online at least r of them, and, moreover, in expectation at least mu >= r. Here mu need not be integer. We see X(k) as the cost of selecting item k and want to minimize the expected total cost under the described combined (r, mu)-constraint. We will see that an optimal selection strategy exists on the set S(n) of all selection strategies for which the decision at instant k may depend on the value X(k), on the number N(k) of selections up to time k and of the number n - k of forthcoming observations. Let sigma(r,mu)(n) be the corresponding S(n)-optimal selection strategy and v(r,mu)(n) its value. The main goal of this paper is to determine these and to understand the limiting behavior of v(r,mu)(n). After discussion of the specific character of this combination of two types of constraints we conclude that the S(n)-problem has a recursive structure and solve it in terms of a double recursion. Our interest will then focus on the limiting behavior of nv(r,mu)(n) as n -> infinity. This sequence converges and its limit allows for the interpretation of a normalized limiting cost L (r, mu) of the (r, mu)-constraint. Our main result is that L(r, mu) = g(r) ((mu - r)(2)/(2)) where g(r) is the r(th) iterate of the function g(x) = 1 + x + root 1 + 2x. Our motivation to study mixed-constraints problems is indicated by several examples of possible applications. We also shortly discuss the intricacy of the expectational part of the constraint if we try to extend the class of strategies S n to the set of full-history-dependent and/or randomized strategies.

scholarly journals Optimizing Pinned Nodes to Maximize the Convergence Rate of Multiagent Systems with Digraph Topologies

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yujuan Han ◽  
Wenlian Lu ◽  
Tianping Chen ◽  
Changkai Sun
Keyword(s):  
Convergence Rate ◽  
Multiagent Systems ◽  
Spanning Trees ◽  
Laplacian Matrix ◽  
Pinning Control ◽  
Left Eigenvector ◽  
Underlying Network ◽  
Eigenvalues Of The Laplacian ◽  
Eigenvalue Zero ◽  
Theoretical Results

This paper investigates how to choose pinned node set to maximize the convergence rate of multiagent systems under digraph topologies in cases of sufficiently small and large pinning strength. In the case of sufficiently small pinning strength, perturbation methods are employed to derive formulas in terms of asymptotics that indicate that the left eigenvector corresponding to eigenvalue zero of the Laplacian measures the importance of node in pinning control multiagent systems if the underlying network has a spanning tree, whereas for the network with no spanning trees, the left eigenvectors of the Laplacian matrix corresponding to eigenvalue zero can be used to select the optimal pinned node set. In the case of sufficiently large pinning strength, by the similar method, a metric based on the smallest real part of eigenvalues of the Laplacian submatrix corresponding to the unpinned nodes is used to measure the stabilizability of the pinned node set. Different algorithms that are applicable for different scenarios are develped. Several numerical simulations are given to verify theoretical results.

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