Remembering Edith and Gabrielle: picture postcards of monuments as portable lieux de mémoire

Picture postcards quickly gained popularity in Western Europe around 1900. The photographs on these postcards represent a wide variety of topics. From the start, the monument was one of the most popular themes. In this article we would like to focus on picture postcards of three Brussels monuments erected in the late 1910s and early 1920s to commemorate two Great War heroines, namely the British-born nurse Edith Cavell (1865-1915) and the Belgian spy Gabrielle Petit (1893-1916). After briefly discussing the monuments and picture postcards in their specific commemorative context, we will argue that these picture postcards, thanks to the use of specific photographic strategies, can be read as what the French cultural historian Pierre Nora coined ‘portable realms of memory’

A ’Millipede’ scanner model - Energy consumption and performance

This short report (1) describes an energy model for the seek and read/write operations in a mass-balanced Y-scanner for parallel-probe storage by IBM [1] and (2) updates the settings of the MEMS model in DiskSim with recent published figures from this XY-scanner. To speedup system simulations, a straight forward second-order model is used without control loop. Read/write operation is modeled by quasi-static calculations. To approximate seek behavior, ’bang-bang’ control is assumed; the result is close to the actual behavior with control loop [2]. Unfortunately, no energy measurements were available to validate the model. Using the proposed energy model, we are able to study the energy consumption of a MEMS-based storage device for different application areas and file systems

OLFAR a radio telescope based on nano satellites in moon orbit

It seems very likely that missions with nano-satellites in professional scientific or commercial applications will not be single-satellite missions. Well structured formations or less structured swarms of nano-satellites will be able to perform tasks that cannot be done in the “traditional” way. The Dutch space-born radio telescope project OLFAR, the Orbiting Low Frequency Array, is a good example of a typical “swarm task”. The OLFAR radio telescope will be composed of an antenna array based on nano-satellites orbiting the moon to shield the receiving nodes from terrestrial interference. The array will receive frequencies in a band from around 30 kHz to 30 MHz. This frequency band is scientifically very interesting, since it will be able to detect signals originating from the yet unseen “Dark Ages” ranging from the Big Bang until around 400 million year after. Another science driver is the LF activity from (exo) planets. In this paper the design parameters for the satellites and the swarm will be given and status of the OLFAR project will be reported. Details will be given about the antenna system, the LF-receiver and the signals that are expecte

Fairness in sovereign debt restructuring

Experience from events of sovereign debt restructuring over the last decade exemplifies that the prevailing process is mainly shaped by exchange-offer launched by the debtor. This suggests that negotiations for changing the repayment terms of the debt take place in an Ultimatum Game which centres virtually the whole bargaining power on the debtor side. Creditors vote according to reservations values that might be influenced by fairness consideration both vis-à-vis the debtor and their fellow creditors. And as fairness is usually a highly subjective influence this can result heterogeneity of reservation values which might impede effective intra-creditor coordination for the benefit of the debtor. --

Legal and Institutional Barriers to Optimal Financial Architecture for New Economy Firms in Developing Countries

developing countries, new economy, ICT, law and finance, legal constraints

Design, Modeling, and Geometric Control on SE(3) of a Fully-Actuated Hexarotor for Aerial Interaction

In this work we present the optimization-based design and control of a fully-actuated omnidirectional hexarotor. The tilt angles of the propellers are designed by maximizing the control wrench applied by the propellers. This maximizes (a) the agility of the UAV, (b) the maximum payload the UAV can hover with at any orientation, and (c) the interaction wrench that the UAV can apply to the environment in physical contact. It is shown that only axial tilting of the propellers with respect to the UAV's body yields optimal results. Unlike the conventional hexarotor, the proposed hexarotor can generate at least 1.9 times the maximum thrust of one rotor in any direction, in addition to the higher control torque around the vehicle's upward axis. A geometric controller on SE(3) is proposed for the trajectory tracking problem for the class of fully actuated UAVs. The proposed controller avoids singularities and complexities that arise when using local parametrizations, in addition to being invariant to a change of inertial coordinate frame. The performance of the controller is validated in simulation.Comment: 9 pages, 9 figures, ICRA201

An overview of Mirjam and WeaveC

In this chapter, we elaborate on the design of an industrial-strength aspectoriented programming language and weaver for large-scale software development. First, we present an analysis on the requirements of a general purpose aspect-oriented language that can handle crosscutting concerns in ASML software. We also outline a strategy on working with aspects in large-scale software development processes. In our design, we both re-use existing aspect-oriented language abstractions and propose new ones to address the issues that we identified in our analysis. The quality of the code ensured by the realized language and weaver has a positive impact both on maintenance effort and lead-time in the first line software development process. As evidence, we present a short evaluation of the language and weaver as applied today in the software development process of ASML

Analytical Model of an Isolated Single-atom Electron Source

An analytical model of a single-atom electron source is presented, where electrons are created by near-threshold photoionization of an isolated atom. The model considers the classical dynamics of the electron just after the photon absorption, i.e. its motion in the potential of a singly charged ion and a uniform electric field used for acceleration. From closed expressions for the asymptotic transverse electron velocities and trajectories, the effective source temperature and the effective source size can be calculated. The influence of the acceleration field strength and the ionization laser energy on these properties has been studied. With this model, a single-atom electron source with the optimum electron beam properties can be designed. Furthermore, we show that the model is also applicable to ionization of rubidium atoms, thus also describes the ultracold electron source, which is based on photoionization of laser-cooled alkali atoms

Lensing reconstruction from line intensity maps: the impact of gravitational nonlinearity

We investigate the detection prospects for gravitational lensing of three-dimensional maps from upcoming line intensity surveys, focusing in particular on the impact of gravitational nonlinearities on standard quadratic lensing estimators. Using perturbation theory, we show that these nonlinearities can provide a significant contaminant to lensing reconstruction, even for observations at reionization-era redshifts. However, we show how this contamination can be mitigated with the use of a "bias-hardened" estimator. Along the way, we present an estimator for reconstructing long-wavelength density modes, in the spirit of the "tidal reconstruction" technique that has been proposed elsewhere, and discuss the dominant biases on this estimator. After applying bias-hardening, we find that a detection of the lensing potential power spectrum will still be challenging for the first phase of SKA-Low, CHIME, and HIRAX, with gravitational nonlinearities decreasing the signal to noise by a factor of a few compared to forecasts that ignore these effects. On the other hand, cross-correlations between lensing and galaxy clustering or cosmic shear from a large photometric survey look promising, provided that systematics can be sufficiently controlled. We reach similar conclusions for a single-dish survey inspired by CII measurements planned for CCAT-prime, suggesting that lensing is an interesting science target not just for 21cm surveys, but also for intensity maps of other lines.Comment: 40+18 pages, 13 figures, 5 tables. v2: JCAP published version, with typos fixed and clarifications adde