Search results for "Graph theory"

Fast Available Bandwidth sampling for ADSL links: rethinking the estimation for larger-scale measurements

2009

Most existing tools for measuring the end-to-end available bandwidth require access to both end-hosts of the measured path, which severely restricts their usability. Few tools have been developed to overcome this limitation, but all of them focus on achieving high precision and are not suitable for large campaigns. In this paper we develop FAB-Probe , a tool aimed at characterizing the available bandwidth of a large number of paths, adapting it particularly for ADSL settings. FAB-Probe is an evolution of ABwProbe , a tool that estimates the available bandwidth in non-cooperative ADSL environments. Analyzing carefully the needs of such a characterization tool, we optimize and rethink ABwProb…

Constrained consistency enforcement in AHP

2020

Abstract Decision-making in the presence of intangible elements must be based on a robust, but subtle, balance between expert know-how and judgment consistency when eliciting that know-how. This balance is frequently achieved as a trade-off reached after a feedback process softens the tension frequently found between one force steadily pulling towards (full) consistency, and another force driven by expert feeling and opinion. The linearization method, developed by the authors in the framework of the analytic hierarchy process, is a pull-towards-consistency mechanism that shows the path from an inconsistent body of judgment elicited from an expert towards consistency, by suggesting optimal c…

Fast Algorithms for Pseudoarboricity

2015

The densest subgraph problem, which asks for a subgraph with the maximum edges-to-vertices ratio d∗, is solvable in polynomial time. We discuss algorithms for this problem and the computation of a graph orientation with the lowest maximum indegree, which is equal to ⌈d∗⌉. This value also equals the pseudoarboricity of the graph. We show that it can be computed in O(|E| √ log log d∗) time, and that better estimates can be given for graph classes where d∗ satisfies certain asymptotic bounds. These runtimes are achieved by accelerating a binary search with an approximation scheme, and a runtime analysis of Dinitz’s algorithm on flow networks where all arcs, except the source and sink arcs, hav…

On the Non-uniform Redundancy in Grammatical Evolution

2016

This paper investigates the redundancy of representation in grammatical evolution (GE) for binary trees. We analyze the entire GE solution space by creating all binary genotypes of predefined length and map them to phenotype trees, which are then characterized by their size, depth and shape. We find that the GE representation is strongly non-uniformly redundant. There are huge differences in the number of genotypes that encode one particular phenotype. Thus, it is difficult for GE to solve problems where the optimal tree solutions are underrepresented. In general, the GE mapping process is biased towards short tree structures, which implies high GE performance if the optimal solution requir…

Perovskite Solar Cells: Heteroatom Effect on Star-Shaped Hole-Transporting Materials for Perovskite Solar Cells (Adv. Funct. Mater. 31/2018)

2018

Cover Feature: Self-Assembly of Clicked Star-Shaped Triazines into Functional Nanostructures (ChemNanoMat 1/2019)

2018

Self-assembly of Clicked Star-Shaped Triazines into Functional Nanostructures

2019

Two non‐amphiphilic star‐shaped 2,4,6‐tris(1,2,3‐triazol‐4‐yl)‐1,3,5‐triazines showing different behavior in terms of self‐assembly and luminescent properties are described. They aggregate in the liquid phase to form low‐dimensional nanostructures with a variety of morphologies, such as spherical particles, one‐hole hollow spheres, toroids, twisted fibers or helical nanotubes, just by varying the conditions of a straightforward reprecipitation method. Aggregation has an opposite effect concerning the fluorescent properties of the proposed compounds, either causing the enhancement or the quenching of the emission after the self‐assembly. Quantum chemical calculations have been also performed…

Uniqueness of diffusion on domains with rough boundaries

2016

Let $\Omega$ be a domain in $\mathbf R^d$ and $h(\varphi)=\sum^d_{k,l=1}(\partial_k\varphi, c_{kl}\partial_l\varphi)$ a quadratic form on $L_2(\Omega)$ with domain $C_c^\infty(\Omega)$ where the $c_{kl}$ are real symmetric $L_\infty(\Omega)$-functions with $C(x)=(c_{kl}(x))>0$ for almost all $x\in \Omega$. Further assume there are $a, \delta>0$ such that $a^{-1}d_\Gamma^{\delta}\,I\le C\le a\,d_\Gamma^{\delta}\,I$ for $d_\Gamma\le 1$ where $d_\Gamma$ is the Euclidean distance to the boundary $\Gamma$ of $\Omega$. We assume that $\Gamma$ is Ahlfors $s$-regular and if $s$, the Hausdorff dimension of $\Gamma$, is larger or equal to $d-1$ we also assume a mild uniformity property for $\Omega$ i…

Государственная граница как пограничный объект в сети трансграничного сотрудничества: случай границы Латвии, Эстонии и России

2019

Цель публикации – раскрыть функции государственной границы в качестве пограничного объекта в сети трансграничного сотрудничества в случае внутренней и внешней границы ЕС.Теоретическое обрамление публикации составляет теория пограничных объектов – производное теории сети агентов, которую в своей работе «Институциональная экология, «интерпретация» и пограничные объекты: любители и профессионалы в зоологическом музее позвоночных в Беркли» (1989) развивали Сьюзaн Ли Стар и Джеймс Гриземер.Пограничные объекты как теоретическое понятие были созданы на основании взаимодействия различных социальных миров друг с другом и на точке, когда им необходима взаимная интерпретация (Worrall, 2010). Пограничн…

A Definitive Pharmacophore Modelling Study on CDK2 ATP Pocket Binders: Tracing the Path of New Virtual High-Throughput Screenings

2020

Cyclin Dependent Kinases-2 (CDK2) are members of serine/threonine protein kinases family. They play an important role in the regulation events of the eukaryotic cell division cycle, especially during the G1 to S phase transition. Experimental evidence indicate that excessive expression of CDK2s should cause abnormal cell cycle regulation. Therefore, since a long time, CDK2s have been considered potential therapeutic targets for cancer therapy. In this work, onehundred and forty-nine complexes of inhibitors bound in the CDK2-ATP pocket were submitted to short MD simulations (10ns) and free energy calculation. Comparison with experimental data (K<sub>i</sub>, K<sub>d</su…