Graph measures and network robustness

Network robustness research aims at finding a measure to quantify network robustness. Once such a measure has been established, we will be able to compare networks, to improve existing networks and to design new networks that are able to continue to perform well when it is subject to failures or attacks. In this paper we survey a large amount of robustness measures on simple, undirected and unweighted graphs, in order to offer a tool for network administrators to evaluate and improve the robustness of their network. The measures discussed in this paper are based on the concepts of connectivity (including reliability polynomials), distance, betweenness and clustering. Some other measures are notions from spectral graph theory, more precisely, they are functions of the Laplacian eigenvalues. In addition to surveying these graph measures, the paper also contains a discussion of their functionality as a measure for topological network robustness

Surface bubble nucleation phase space

Recent research has revealed several different techniques for nanoscopic gas nucleation on submerged surfaces, with findings seemingly in contradiction with each other. In response to this, we have systematically investigated the occurrence of surface nanobubbles on a hydrophobised silicon substrate for various different liquid temperatures and gas concentrations, which we controlled independently. We found that nanobubbles occupy a distinct region of this phase space, occurring for gas concentrations of approximately 100-110%. Below the nanobubble phase we did not detect any gaseous formations on the substrate, whereas micropancakes (micron wide, nanometer high gaseous domains) were found at higher temperatures and gas concentrations. We moreover find that supersaturation of dissolved gases is not a requirement for nucleation of bubbles.Comment: 4 pages, 4 figure

Droplet size from Venturi air induction spray nozzles

Sprays are of great importance for many applications, with drop size being a crucial parameter. Especially in agriculture applications, simple flat fan spray nozzles are often supplemented by a Venturi component to achieve larger drop sizes and hence, prevent unwanted spray drift of the smallest droplets. The general believe is that these larger drops are usually attributed to the fact that the liquid sheet produced by the nozzle breaks up more easily due to the pre-existing ’holes’ formed by the induced air bubbles. Here, we extend descriptions of how nozzle and fluid parameters determine droplet size distributions from Venturi nozzles. We show that the mean droplet size is determined by the nozzle’s orifice area as is the case for ordinary flat fan nozzles, but that the additional pressure drop over the Venturi chamber needs to be taken into account. Using this parameter, relations that were derived for flat fan nozzles can be re-used. This allows to show that the increase in droplet size compared to conventional nozzles is due to the additional pressure drop in the Venturi chamber, and not to a change in breakup mechanism due to the presence of air bubbles in the liquid sheet.</p

Future time perspective:A systematic review and meta-analysis

The ability to foresee, anticipate, and plan for future desired outcomes is crucial for wellbeing, motivation, and behavior. However, theories in organizational psychology do not incorporate time-related constructs such as Future Time Perspective (FTP), and research on FTP remains disjointed and scattered, with different domains focusing on different aspects of the construct, using different measures, and assessing different antecedents and consequences. In this review and meta-analysis, we aim to clarify the FTP construct, advance its theoretical development, and demonstrate its importance by: (a) integrating theory and empirical findings across different domains of research in order to identify major outcomes and antecedents of FTP, and (b) empirically examining whether and how these variables are moderated by FTP measures and dimensions. Results of a meta-analysis of k = 212 studies reveal significant relationships between FTP and major classes of consequences (i.e., those related to achievement, well-being, health behavior, risk behavior, and retirement planning), and between antecedents and FTP, as well as moderating effects of different FTP measures and dimensions. Highlighting the importance of FTP for organizational psychology theories, our findings demonstrate that FTP predicts these outcomes over-and-above the big five personality traits and mediates the associations between these personality traits and outcomes

Cascading Failures in Interconnected Power-to-Water Networks

The manageability and resilience of critical infrastructures, such as power and water networks, is challenged by their increasing interdependence and interconnectivity. Power networks often experience cascading failures, i.e. blackouts, that have unprecedented economic and social impact. Al- though knowledge exists about how to control such complex non-linear phenomena within a single power network, little is known about how such failures can spread and coevolve in the water network when failing power components energize the water distribution infrastructure, i.e. pumps and valves. This paper studies such a scenario and specifically the impact of power cascading failures on shortages of water supply. A realistic exemplary of an interconnected power-to-water network is experimentally evaluated using a modular simulation approach. Power and waterflow dynamics are simulated separately by taking into account different maximum powerlines capacities and water demand requirements. Results showcase the strong dependency of urban water sup- ply systems on the reliability of power networks, with severe shortages of water supply being caused by failures originating indistant power lines, especially for heavily loaded power networks

Development of statistical process control (SPC) matlab-based software for automotive industries application

This project is motivated by an interest in promoting the use computer-based statistical process control (SPC) in manufacturing sector specifically for automotive industries in Malaysia. The use of computer-based SPC is essential in quality function. They are capable to perform various operations or tasks very accurately at fast speeds. SPC techniques are simple statistical techniques to help identify process problems and it can be implemented as simple as analyzing data and plotting charts. However, the development of SPC in Malaysian small and medium-sized enterprises (SMEs) is found lacking because they remain to use traditional SPC techniques which the data are calculated and analyzed manually. Consequently, manual work on traditional SPC has focused on particular limitations; with only little quality faults are detectable, time-consuming and burdensome. This paper highlights the results of an effort to design the SPC computer-based system for conducting simple statistical analysis. The system named as MagNa version 1.0 MATLAB-based software, which is able to offer more benefits to the Malaysian SMEs specifically for automotive industries application

De week van ... Romy van der Kooij

In iedere editie nemen we een kijkje in het leven van een B.I.L. lid. Dit keer vertelt Romy van der Kooij (19) over een typische week in november. Romy is eerstejaars bestuurskundestudent en is actief in de Commissie Activiteiten