scholarly journals Broadcasting in weighted trees under the postal model

2016 ◽  
Vol 621 ◽  
pp. 73-81
Author(s):  
Yu-Hsuan Su ◽  
Ching-Chi Lin ◽  
D.T. Lee
Keyword(s):  
Weighted Trees ◽  
Postal Model

The w-centroids and least w-central subtrees in weighted trees

2017 ◽  
Vol 36 (4) ◽  
pp. 1118-1127
Author(s):  
Erfang Shan ◽  
Liying Kang
Keyword(s):  
Weighted Trees

Scheduling the construction of value and discount weighted trees for maximum net present value

2020 ◽  
Vol 115 ◽  
pp. 104578
Author(s):  
P.A. Grossman ◽  
M. Brazil ◽  
J.H. Rubinstein ◽  
D.A. Thomas
Keyword(s):  
Net Present Value ◽  
Present Value ◽  
Weighted Trees

APPROXIMATING THE NEAREST NEIGHBOR INTERCHARGE DISTANCE FOR NON-UNIFORM-DEGREE EVOLUTIONARY TREES

2001 ◽  
Vol 12 (04) ◽  
pp. 533-550 ◽  
Author(s):  
WING-KAI HON ◽  
TAK-WAH LAM
Keyword(s):  
Approximation Algorithms ◽  
Maximum Degree ◽  
Nearest Neighbor ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Approximation Ratio ◽  
Evolutionary Trees ◽  
Weighted Trees ◽  
Np Complete ◽  
Necessary And Sufficient

The nearest neighbor interchange (nni) distance is a classical metric for measuring the distance (dissimilarity) between evolutionary trees. It has been known that computing the nni distance is NP-complete. Existing approximation algorithms can attain an approximation ratio log n for unweighted trees and 4 log n for weighted trees; yet these algorithms are limited to degree-3 trees. This paper extends the study of nni distance to trees with non-uniform degrees. We formulate the necessary and sufficient conditions for nni transformation and devise more topology-sensitive approximation algorithms to handle trees with non-uniform degrees. The approximation ratios are respectively [Formula: see text] and [Formula: see text] for unweighted and weighted trees, where d ≥ 4 is the maximum degree of the input trees.

Combinatorial Algorithms for the Uniform-Cost Inverse 1-Center Problem on Weighted Trees

2018 ◽  
Vol 44 (4) ◽  
pp. 813-831 ◽  
Author(s):  
Kien Trung Nguyen ◽  
Huong Nguyen-Thu ◽  
Nguyen Thanh Hung
Keyword(s):  
Combinatorial Algorithms ◽  
Center Problem ◽  
Weighted Trees

Tree-dependent extreme values: the exponential case

1990 ◽  
Vol 27 (01) ◽  
pp. 124-133 ◽  
Author(s):  
Vijay K. Gupta ◽  
Oscar J. Mesa ◽  
E. Waymire
Keyword(s):  
Branching Process ◽  
Extreme Values ◽  
Rooted Tree ◽  
Domain Of Attraction ◽  
Extreme Value Distribution ◽  
Value Theory ◽  
Extreme Value ◽  
Extinction Time ◽  
Brownian Excursion ◽  
Weighted Trees

The length of the main channel in a river network is viewed as an extreme value statistic L on a randomly weighted binary rooted tree having M sources. Questions of concern for hydrologic applications are formulated as the construction of an extreme value theory for a dependence which poses an interesting contrast to the classical independent theory. Equivalently, the distribution of the extinction time for a binary branching process given a large number of progeny is sought. Our main result is that in the case of exponentially weighted trees, the conditional distribution of n–1/2 L given M = n is asymptotically distributed as the maximum of a Brownian excursion. When taken with an earlier result of Kolchin (1978), this makes the maximum of the Brownian excursion a tree-dependent extreme value distribution whose domain of attraction includes both the exponentially distributed and almost surely constant weights. Moment computations are given for the Brownian excursion which are of independent interest.

On Cesáro Averages for Weighted Trees in the Random Forest

2019 ◽  
Vol 37 (1) ◽  
pp. 223-236 ◽  
Author(s):  
Hieu Pham ◽  
Sigurður Olafsson
Keyword(s):  
Random Forest ◽  
Weighted Trees ◽  
Cesaro Averages

A LOWER BOUND FOR ORDER-PRESERVING BROADCAST IN THE POSTAL MODEL

1993 ◽  
Vol 03 (04) ◽  
pp. 313-320 ◽  
Author(s):  
PHILIP D. MACKENZIE
Keyword(s):  
Communication Network ◽  
Lower Bound ◽  
Lower Bounds ◽  
Message Passing ◽  
Upper Bounds ◽  
Communication Latency ◽  
Multiple Messages ◽  
Postal Model ◽  
Parameter Ranges

In the postal model of message passing systems, the actual communication network between processors is abstracted by a single communication latency factor, which measures the inverse ratio of the time it takes for a processor to send a message and the time that passes until the recipient receives the message. In this paper we examine the problem of broadcasting multiple messages in an order-preserving fashion in the postal model. We prove lower bounds for all parameter ranges and show that these lower bounds are within a factor of seven of the best upper bounds. In some cases, our lower bounds show significant asymptotic improvements over the previous best lower bounds.

scholarly journals Enumeration of One Class of Plane Weighted Trees

2015 ◽  
Vol 209 (2) ◽  
pp. 282-291
Author(s):  
Yu. Yu. Kochetkov
Keyword(s):  
Weighted Trees
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