Stress is Enhancing Mindset and Potential Links to Cardiovascular and Neuroendocrine Responses

Undergraduate Basi

TCP with Network Coding Performance Under Packet Reordering

The adverse impact of packet reordering besides packet loss is significant on the goodput performance of TCP (Transmission Control Protocol), a dominant protocol for reliable and connection-oriented transmission. With the primary purpose of improving the TCP goodput in lossy networks, the Network Coding technique was introduced. TCP/NC (TCP with Network Coding) is a promising approach which can recover lost packets without retransmission. However, the packet reordering has not been considered, and no study on that issue is found for TCP/NC. Therefore, in this paper, we investigate the goodput performance degradation due to the out-of-order reception of data or acknowledgment packets and propose a new scheme for TCP/NC to estimate and adapt to the packet reordering. The results of our simulation on ns-3 (Network Simulation 3) suggest that the proposed scheme can maintain the TCP goodput well in a wide range of packet reordering environments compared to TCP NewReno as well as TCP/NC.International Conference on Emerging Internetworking, Data & Web Technologies (EIDWT 2019), 26-28 February, 2019, Fujairah Campus, United Arab Emirate

An Exploratory Examination of Police Shooting Data

Graduate Applie

Problèmes de graphes motivés par des modèles basse et haute résolution de grands assemblages de protéines

To explain the biological function of a molecular assembly (MA), one has to know its structural description. It may be ascribed to two levels of resolution: low resolution (i.e. molecular interactions) and high resolution (i.e. relative position and orientation of each molecular subunit, called conformation). Our thesis aims to address the two problems from graph aspects.The first part focuses on low resolution problem. Assume that the composition (complexes) of a MA is known, we want to determine all interactions ofsubunits in the MA which satisfies some property. It can be modeled as a graph problem by representing a subunit as a vertex, then a subunit interaction is an edge, and a complex is an induced subgraph. In our work, we use the fact that a subunit has a bounded number of interactions. It leads to overlaying graph with bounded maximum degree. For a graph family F and a fixed integer k, given a hypergraph H = (V (H), E(H)) (whose edges are subsets of vertices) and an integer s, M AX (∆ ≤ k)-F -O VERLAY consists in deciding whether there exists a graph with degree at most k such that there are at least s hyperedges in which the subgraph induced by each hyperedge (complex) contains an element of F. When s = |E(H)|, it is called (∆ ≤ k)-F -O VERLAY . We present complexity dichotomy results (P vs. NP-complete) for MAX (∆ ≤ k)-F-OVERLAY and (∆ ≤ k)-F-OVERLAY depending on pairs (F, k).The second part presents our works motivated by high resolution problem. Assume that we are given a graph representing the interactions of subunits, a finite set of conformations for each subunit and a weight function assessing the quality of the contact between two subunits positioned in the assembly. Discrete Optimization of Multiple INteracting Objects (D OMINO ) aims to find conformations for the subunits maximizing a global utility function. We propose a new approach based on this problem in which the weight function is relaxed, CONFLICT COLORING . We present studies from both theoretical and experimental points of view. Regarding the theory, we provide a complexity dichotomy result and also algorithmic methods (approximation and fixed paramater tracktability). Regarding the experiments, we build instances of CONFLICT COLORING associated with Voronoi diagrams in the plane. The obtained statistics provide information on the dependencies of the existences of a solution, to parameters used in ourexperimental setup.Pour comprendre les fonctions biologiques d’un assemblage moléculaire (AM), il est utile d’en avoir une représentation structurale. Celle-ci peut avoir deux niveaux de résolution : basse résolution (i.e. interactions moléculaires) et haute résolution (i.e. position relative et orientation de chaque sous-unité, appelée conformation). Cette thèse s’intéresse à trouver de telles représentations à l’aide de graphes.Dans la première partie, nous cherchons des représentations basse résolution. Etant donné la composition des complexes d’un AM, notre but est de déterminer les interactions entre ses différentes sous-unités. Nous modélisons l’AM à l’aide d’un graphe : les sous-unités sont les sommets, les interactions entre elles sont les arêtes et un complexe est un sous-graphe induit. Utilisant le fait qu’une sous-unité n’a qu’un nombre limité d’interactions, nous arrivons au problème suivant. Pour un graphe F et un entier k fixés, étant donné un hypergraphe H et un entier s, MAX (∆ ≤ k)-F-OVERLAY consiste à décider s’il existe un graphe de degré au plus k tel qu’au moins s hyperarêtes de H induisent un sous-graphe contenant F (en tant que sous-graphe). La restriction au cas s = |E(H)| est appelée (∆ ≤ k)-F-OVERLAY . Nous donnons une dichotomie de complexité (P vs. NP-complet) pour MAX (∆ ≤ k)-F-OVERLAY et (∆ ≤ k)-F-OVERLAY en fonction du couple (F, k).Dans la seconde partie, nous nous attaquons à la haute résolution. Nous sont donnés un graphe représentant les interactions entre sous-unités, un ensemble de conformations possibles pour chaque sous-unité et une fonction de poids représentant la qualité de contact entre les conformations de deux sous-unités interagissant dans l’assemblage. Le problème Discrete Optimization of Multiple INteracting Objects (D OMINO ) consiste alors à trouver les conformations pour les sous-unités qui maximise une fonction d’utilité globale. Nous proposons une nouvelle approche à ce problème en relâchant la fonction de poids, ce qui mène au problème de graphe CONFLICT COLORING . Nous donnons tout d’abord des résultats de complexité et des algorithmes (d’approximation et à paramètre fixé). Nous menons ensuite des expérimentations sur des instances de CONFLICT COLORING associées à des diagrammes de Voronoi dans le plan. Les statistiques obtenues nous informent sur comment les parmètres de notre montage expérimental influe sur l’existence d’une solution

高パケットロス環境でのネットワーク符号化TCPの改良とその応用に関する研究

九州工業大学博士学位論文（要旨）学位記番号：情工博甲第324号 学位授与年月日：平成29年3月24

TCP network coding with adapting parameters for bursty and time-varying loss

The Transmission Control Protocol (TCP) with Network Coding (TCP/NC) was proposed to introduce packet loss recovery ability at the sink without TCP retransmission, which is realized by proactively sending redundant combination packets encoded at the source. Although TCP/NC is expected to mitigate the goodput degradation of TCP over lossy networks, the original TCP/NC does not work well in burst loss and time-varying channels. No apparent scheme was provided to decide and change the network coding-related parameters (NC parameters) to suit the diverse and changeable loss conditions. In this paper, a solution to support TCP/NC in adapting to mentioned conditions is proposed, called TCP/NC with Loss Rate and Loss Burstiness Estimation (TCP/NCwLRLBE). Both the packet loss rate and burstiness are estimated by observing transmitted packets to adapt to burst loss channels. Appropriate NC parameters are calculated from the estimated probability of successful recoverable transmission based on a mathematical model of packet losses. Moreover, a new mechanism for coding window handling is developed to update NC parameters in the coding system promptly. The proposed scheme is implemented and validated in Network Simulator 3 with two different types of burst loss model. The results suggest the potential of TCP/NCwLRLBE to mitigate the TCP goodput degradation in both the random loss and burst loss channels with the time-varying conditions

NP-completeness of the game Kingdomino

Kingdomino is a board game designed by Bruno Cathala and edited by Blue Orange since 2016. The goal is to place $2 \times 1$ dominoes on a grid layout, and get a better score than other players. Each $1 \times 1$ domino cell has a color that must match at least one adjacent cell, and an integer number of crowns (possibly none) used to compute the score. We prove that even with full knowledge of the future of the game, in order to maximize their score at Kingdomino, players are faced with an NP-complete optimization problem

Detection of nonlinearity in a dynamic system using deformation modes obtained from the Wavelet Transfrom of measured responses

An efficient approach to Structural Health Monitoring of dynamical systems based on the Wavelet Transform (WT) and the concept of subspace angle is presented. The objective is to propose a detection method that is sensitive to the onset of nonlinear behaviour in a dynamic system. For this purpose, instantaneous frequencies are identified first from output-only vibration signals using the Wavelet Transform. Time varying deformation shapes are then extracted by analyzing the whole measurement data set on the structure. From this information, different dynamic states of the structure may be detected by inspecting time variations of ‘modal’ features. The experimental structure considered here as application example is a clamped beam with a geometric nonlinearity. Detection of nonlinearity is carried out by means of the concept of subspace angles between instantaneous deformation modes extracted from measurement data using the continuous Wavelet Transform. The method consists in controlling the angular coherence between active subspaces of the current and reference states respectively. The proposed technique, which shows a good sensitivity to small changes in the dynamic behaviour of the structure, may also be used for damage detection