Characterizing User-to-User Connectivity with RIPE Atlas

Characterizing the interconnectivity of networks at a country level is an interesting but non-trivial task. The IXP Country Jedi is an existing prototype that uses RIPE Atlas probes in order to explore interconnectivity at a country level, taking into account all Autonomous Systems (AS) where RIPE Atlas probes are deployed. In this work, we build upon this basis and specifically focus on "eyeball" networks, i.e. the user-facing networks with the largest user populations in any given country, and explore to what extent we can provide insights on their interconnectivity. In particular, with a focused user-to-user (and/or user-to-content) version of the IXP Country Jedi we work towards meaningful statistics and comparisons between countries/economies. This is something that a general-purpose probe-to-probe version is not able to capture. We present our preliminary work on the estimation of RIPE Atlas coverage in eyeball networks, as well as an approach to measure and visualize user interconnectivity with our Eyeball Jedi tool.Comment: In Proceedings of the Applied Networking Research Workshop (ANRW '17

Analysis of Thermal Interconnectivity of Utilities in Rural Alaska

Presented to the Faculty of the University of Alaska Anchorage in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCEThroughout the arctic there are two primary community utilities with dramatically contrary thermodynamic concerns. These are the intensely exothermic diesel electric power generation, and the strongly endothermic water and sewer utility. In this context exothermic processes must expel excess heat while endothermic process requires heat input. Failure of engineers, community planners, funding agencies, and interest groups to recognize the full social, economic, and environmental impact to the sustainability of utilities has come at tremendous cost. This is exemplified in many remote Alaskan communities such as Toksook Bay, Minto, Deering, and Kotlik

Elastic biodegradable starch/ethylene-co-vinyl alcohol fibre-mesh scaffolds for tissue engineering applications

The fabrication of a biomaterial scaffold, with adequate physical and structural properties for tissue engineering applications, is reported. A blend of starch with ethylene-vinyl alcohol (50/50 w/w, SEVA-C) is used to produce 3D fibre-mesh scaffolds by wet-spinning. The scaffolds are characterized in terms of morphology, porosity, interconnectivity, and pore size, using scanning electron microscopy (SEM) and microcomputed tomography (μCT). The degradation behavior, as well as the mechanical properties of the scaffolds, is investigated in presence of alpha-amylase enzyme at physiological concentration. Scaffolds with porosities ranging from 43 to 52%, interconnectivity of ∼70.5% and pore size between 118 and 159 μm, can be fabricated using the proposed methodology. The scaffolds exhibit an elastic behavior in the wet state with a compressive modulus of 7.96±0.32 MPa. Degradation studies show that SEVA-C scaffolds are susceptible to enzymatic degradation by alpha-amylase, confirmed by the increase of weight loss (40% of weight loss after 12 weeks) and presence of degradation products (reducing sugars) in solution. The diameter of SEVA-C scaffolds decreases with degradation time, increasing the overall porosity, interconnectivity and pore size. In vitro cell studies with human osteosarcoma cell line (SaOs-2) showed a nontoxic and cytocompatible behavior of the developed fibre mesh scaffolds. The positive cellular response, together with structural and degradable properties, suggests that 3D SEVA-C fibre-meshes may be good candidates as tissue engineering scaffolds. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40504. Copyright © 2014 Wiley Periodicals, Inc.This work was supported by national funds through the Portuguese Foundation for Science and Technology under the scope of the project PTDC/CTM/67560/2006 and by the European Regional Development Fund (ERDF) through the Operational Competitiveness Programme “COMPETE” (FCOMP-01-0124-FEDER-007148)

The Interconnectivity of Weather System and Ozone Concentration Over West Africa

The relationship between some meteorological parameters and ozone distributions as revealed by satellite EPTOM over four West African stations namely, Lagos (Nigeria), Dakar (Senegal) Lamto (Ivory Coast) and Ekona (Cameroon) was studied for the period 1997 to 2002. The mean ozone concentration over these stations for the period were 270.8±0.3DU at Lagos, 264.9±0.3DU at Dakar, 269.8±0.3DU and 269.0±03DU at Lamto and Ekona respectively. The average monthly maximum ozone concentration of 288.6DU and 285.1DU respectively were observed for Lagos and Dakar, between July and August, which coincided with the period of tropical summer rain-fall over the West African region. This coincidence could be attributed to reduction in the effect of the extra-tropical suction pump (ETSP) action responsible for the transportation of ozone concentration from the tropical stratosphere into the mid and high latitudinal region. This re-duction may be due to decrease in the atmospheric heat engine expected to drive the ETSP, as the tropical surface temperature and evaporation are at their minimum during the raining sea-son. The surface temperature and evaporation at Lagos-Nigeria both had significant negative correlation values of -0.73 and -0.68 with the ozone concentration respectively

Reaction-Diffusion Processes on Interconnected Scale-Free Networks

We study the two particle annihilation reaction $A+B\rightarrow \emptyset$ on interconnected scale free networks, using different interconnecting strategies. We explore how the mixing of particles and the process evolution are influenced by the number of interconnecting links, by their functional properties, and by the interconnectivity strategies in use. We show that the reaction rates on this system are faster than what was observed in other topologies, due to the better particle mixing which suppresses the segregation effect, inline with previous studies performed on single scale free networks.Comment: 11 pages, 5 figure

The Five Indicia of Virtual Property

[Excerpt] “Many Americans use “it” every day. Although it is intangible, it may be worth thousands of dollars. Because we can both control it and prevent other people from controlling it, we assume, without much thought, that we own it. Sometimes we pay someone a monthly fee to hold it for us. Sometimes, simply by using it, we increase its value. When we finish using it, we often sell it. “It” is virtual property, and it may take the form of an email address, a website, a bidding agent, a video game character, or any number of other intangible, digital commodities. If it were to be damaged or stolen, the immediate questions would be: (1) how should a court identify it; and (2) what degree of legal protection should it receive? Because no court or legislature in the United States yet has recognized virtual property interests, a combination of contract and custom currently controls the relationship between Internet users and service providers. […] The question therefore becomes, how should courts identify protectable virtual property interests? Partially due to the dramatic success of Massively Multiplayer Online Games (MMOGs)9 and the rise of secondary markets for virtual characters and treasures from those games, a recent frenzy of legal scholarship has struggled to resolve this question. This note supports the legal recognition of virtual property interests, as already convincingly justified by the legal analogy to traditional property interests set forth by Professor Joshua Fairfield, buttressed by the practical reality that virtual property has significant economic value. Building on these rationales, this note proposes five indicia, common to most forms of virtual property, which a court should use to identify legally protectable virtual property interests on the Internet. These indicia are: (1) rivalry; (2) persistence; (3) interconnectivity; (4) secondary markets; and (5) value-added-by-users. This note cautions, however, against applying this newfound definition indiscriminately against the interests of the very entities without whom the property would not exist: the businesses hosting the remotely accessed computer resources (i.e., the service providers). […] Part III of this note applies the five indicia to the well-established framework of traditional property to illustrate this balancing process. Throughout the development of the law in this area, courts must retain the freedom and flexibility to craft appropriate equitable remedies on a case-by-case basis, and special attention should be directed to the practical issues commonly faced by Internet service providers. The ultimate purpose of virtual property jurisprudence should be to strike a balance that provides legal redress to users whose legitimate virtual property interests have been violated while simultaneously reducing liability and disincentives to service providers who promote and sustain the growth of the Internet.

Data Center Interconnects at 400G and Beyond

Current trends in Data Center Interconnectivity are considered in the light of increasing traffic and under the constraint of limited cost and power consumption.Comment: This project has received funding from the European Union Horizon 2020 research and innovation programme under grant agreement No 762055 (BlueSpace project) and from the German ministry of education and research (BMBF) under contract 16KIS0477K (SENDATE Secure-DCI project