Heroes of Berlin Wall Struggle

When the Berlin Wall fell 25 years ago, on Nov. 9, 1989, symbolically signaling the end of the Cold War, it was no surprise that many credited President Ronald Reagan and Soviet leader Mikhail Gorbachev for bringing it down. But the true heroes behind the fall of the Berlin Wall are those Eastern Europeans whose protests and political pressure started chipping away at the wall years before. East German citizens from a variety of political backgrounds and occupations risked their freedom in protests against communist policies and one-party rule in what they called the peaceful revolution. [excerpt

HI and Cosmology: What We Need To Know

There are three distinct regimes in which radio observations of the redshifted 21 cm line of HI can contribute directly to cosmology in unique ways. The regimes are naturally divided by redshift, from high to low, into: inflationary physics, the Dark Ages and reionization, and galaxy evolution and Dark Energy. Each measurement presents its own set of technical, theoretical, and observational challenges, making "what we need to know" not so much an astrophysical question at this early stage as a comprehensive experimental question. A wave of new pathfinder projects are exploring the fundamental aspects of what we need to know (and what we should expect to learn in the coming years) in order to achieve the goals of the Square Kilometer Array (SKA) and beyond.Comment: From AIP Conference Proceedings, Volume 1035, 2008, "The Evolution of Galaxies through the Neutral Hydrogen Window". 7 page

Design and Evaluation of Menu Systems for Immersive Virtual Environments

Interfaces for system control tasks in virtual environments (VEs) have not been extensively studied. This paper focuses on various types of menu systems to be used in such environments. We describe the design of the TULIP menu, a menu system using Pinch Gloves™, and compare it to two common alternatives: floating menus and pen and tablet menus. These three menus were compared in an empirical evaluation. The pen and tablet menu was found to be significantly faster, while users had a preference for TULIP. Subjective discomfort levels were also higher with the floating menus and pen and tablet

Learning 3D Navigation Protocols on Touch Interfaces with Cooperative Multi-Agent Reinforcement Learning

Using touch devices to navigate in virtual 3D environments such as computer assisted design (CAD) models or geographical information systems (GIS) is inherently difficult for humans, as the 3D operations have to be performed by the user on a 2D touch surface. This ill-posed problem is classically solved with a fixed and handcrafted interaction protocol, which must be learned by the user. We propose to automatically learn a new interaction protocol allowing to map a 2D user input to 3D actions in virtual environments using reinforcement learning (RL). A fundamental problem of RL methods is the vast amount of interactions often required, which are difficult to come by when humans are involved. To overcome this limitation, we make use of two collaborative agents. The first agent models the human by learning to perform the 2D finger trajectories. The second agent acts as the interaction protocol, interpreting and translating to 3D operations the 2D finger trajectories from the first agent. We restrict the learned 2D trajectories to be similar to a training set of collected human gestures by first performing state representation learning, prior to reinforcement learning. This state representation learning is addressed by projecting the gestures into a latent space learned by a variational auto encoder (VAE).Comment: 17 pages, 8 figures. Accepted at The European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases 2019 (ECMLPKDD 2019

Combining WASP and Kepler data: the case of the Sct star KIC 7106205

Ground-based photometric observations from Wide Angle Search for Planets (WASP) have been calibrated, scaled and combined with Kepler observations of the δ Sct star KIC 7106205, allowing us to extend the time base of the study of the unexplained amplitude and frequency variation of a single pressure mode at ν = 13.3942 d−1 by 2 yr. Analysis of the combined data sets, spanning 6 yr, show that the amplitude modulation in KIC 7106205 has a much larger range than a previous study of the Kepler data alone indicated. The single pressure mode decreased from 11.70 ± 0.05 mmag in 2007, to 5.87 ± 0.03 mmag in 2009, and to 0.58 ± 0.06 mmag in 2013. Observations of the decrease in mode amplitude have now been extended back 2 yr before the launch of Kepler. With observations over a longer time span, we have been able to further investigate the decrease in mode amplitude in KIC 7106205 to address the question of mode amplitude stability in δ Sct stars. This study highlights the usefulness of the WASP data set for extending studies of some Kepler variable stars

A First Step Towards Nuance-Oriented Interfaces for Virtual Environments

Designing usable interfaces for virtual environments (VEs) is not a trivial task. Much of the difficulty stems from the complexity and volume of the input data. Many VEs, in the creation of their interfaces, ignore much of the input data as a result of this. Using machine learning (ML), we introduce the notion of a nuance that can be used to increase the precision and power of a VE interface. An experiment verifying the existence of nuances using a neural network (NN) is discussed and a listing of guidelines to follow is given. We also review reasons why traditional ML techniques are difficult to apply to this problem

Consistency of parity-violating pion-nucleon couplings extracted from measurements in 18F and 133Cs

The recent measurement of the nuclear anapole moment of 133Cs has been interpreted to yield a value of the weak pion-nucleon coupling H_pi^1 which contradicts the upper limit from the 18F experiments. We argue that because of the sensitivity of the anapole moment to H_rho^0 in the odd proton nucleus 133Cs, there is a combination of weak meson-nucleon couplings which satisfies both experiments and which is (barely) in agreement with theory. In addition, the anapole moment measurement in 205Tl gives a constraint which is inconsistent with the value from 133Cs, calling into question the theory of nuclear anapole moments. We argue that measurements of directional asymmetry in n+p-->d+gamma and in the photo-disintegration of the deuteron by circularly polarized photons, combined with results from pp scattering, would determine H_pi^1 and several other weak meson-nucleon couplings in a model-independent way.Comment: 9 pages, RevTeX, 1 figure, eps, submitted to Phys. Rev.

Affordances and Feedback in Nuance-Oriented Interfaces

Virtual Environments (VEs) and perceptive user interfaces must deal with complex users and their modes of interaction. One way to approach this problem is to recognize users’ nuances (subtle conscious or unconscious actions). In exploring nuance-oriented interfaces, we attempted to let users work as they preferred without being biased by feedback or affordances in the system. The hope was that we would discover the users’ innate models of interaction. The results of two user studies were that users are guided not by any innate model but by affordances and feedback in the interface. So, without this guidance, even the most obvious and useful components of an interface will be ignored