Cracking the Cocoa Nut: User Interface Programming at Runtime

International audienceThis article introduces runtime toolkit overloading, a novel approach to help third-party developers modify the interaction and behavior of existing software applications without access to their underlying source code. We describe the abstractions provided by this approach as well as the mechanisms for implementing them in existing environments. We describe Scotty, a prototype implementation for Mac OS X Cocoa that enables developers to modify existing applications at runtime, and we demonstrate a collection of interaction and functional transformations on existing off-the-shelf applications. We show how Scotty helps a developer make sense of unfamiliar software, even without access to its source code. We further discuss what features of future environments would facilitate this kind of runtime software development

Dosage Microbiologique des Acides Aminés des Moûts de Raisin et des Vins

Nous avons déterminé au moyen des méthodes microbiologiques classiques dix-sept acides aminés se trouvant à l'état libre dans une série de moûts et de vins. Ces méthodes s'appliquent parfaitement à ces milieux sans autre traitement préalable qu'une neutralisation et une dilution convenable. L'arginine, la praline, la thréonine, l'acide glutamique sont les quatre acides aminés les plus abondants. Ils représentent plus de 85 0/o de l'azote aminé des moûts; dans les vins cependant, ils ne constituent plus qu'une fraction de 60 %. La fermentation alcoolique fait apparaître en effet de petites quantités d'acides aminés qui n'existaient pas à l'état libre dans les moûts; la composition azotée des vins est moins abondante mais plus variée que celle des moûts. Ces dosages montrent encore que les taux des acides aminés assimilables par les levures selon la réaction d'EHRLICH sont absents dans le moût de raisin, ou seulement présents à doses extrèmement faibles. Entre autres conséquences qui découlent de ces observations et contrairement aux notions admises jusqu'à maintenant, l'alcool isobutylique et l'alcool isoamylique des vins ne tirent leur origine que pour une part très minime de la valine et des leucines des moûts.Enfin s'il existe une certaine concordance entre les chiffres d'azote aminé obtenus par dosage microbiologique et par formoltitration dans le cas des vins rouges, les écarts obtenus pour les moûts et surtout les vins blancs suggèrent que les techniques microbiologiques dosent encore certains petits polypeptides pouvant être dégradés par les bactéries

Keck Observatory Laser Guide Star Adaptive Optics Discovery and Characterization of a Satellite to the Large Kuiper Belt Object 2003 EL_(61)

The newly commissioned laser guide star adaptive optics system at Keck Observatory has been used to discover and characterize the orbit of a satellite to the bright Kuiper Belt object 2003 EL_(61). Observations over a 6 month period show that the satellite has a semimajor axis of 49,500 ± 400 km, an orbital period of 49.12 ± 0.03 days, and an eccentricity of 0.050 ± 0.003. The inferred mass of the system is (4.2 ± 0.1) × 10^(21) kg, or ~32% of the mass of Pluto and 28.6% ± 0.7% of the mass of the Pluto-Charon system. Mutual occultations occurred in 1999 and will not occur again until 2138. The orbit is fully consistent neither with one tidally evolved from an earlier closer configuration nor with one evolved inward by dynamical friction from an earlier more distant configuration

What influences the speed of prototyping? An empirical investigation of twenty software startups

It is essential for startups to quickly experiment business ideas by building tangible prototypes and collecting user feedback on them. As prototyping is an inevitable part of learning for early stage software startups, how fast startups can learn depends on how fast they can prototype. Despite of the importance, there is a lack of research about prototyping in software startups. In this study, we aimed at understanding what are factors influencing different types of prototyping activities. We conducted a multiple case study on twenty European software startups. The results are two folds, firstly we propose a prototype-centric learning model in early stage software startups. Secondly, we identify factors occur as barriers but also facilitators for prototyping in early stage software startups. The factors are grouped into (1) artifacts, (2) team competence, (3) collaboration, (4) customer and (5) process dimensions. To speed up a startups progress at the early stage, it is important to incorporate the learning objective into a well-defined collaborative approach of prototypingComment: This is the author's version of the work. Copyright owner's version can be accessed at doi.org/10.1007/978-3-319-57633-6_2, XP2017, Cologne, German

Satellites of the largest Kuiper Belt objects

We have searched the four brightest objects in the Kuiper Belt for the presence of satellites using the newly commissioned Keck Observatory Laser Guide Star Adaptive Optics system. Satellites are seen around three of the four objects: Pluto (whose satellite Charon is well-known and whose recently discovered smaller satellites are too faint to be detected), 2003 EL61 (where a second satellite is seen in addition to the previously known satellite), and 2003 UB313 (where a satellite is seen for the first time). The object 2005 FY9, the brightest Kuiper Belt object (KBO) after Pluto, does not have a satellite detectable within 0".4 with a brightness of more than 1% of the primary. The presence of satellites around three of the four brightest KBOs is inconsistent with the fraction of satellites in the Kuiper Belt at large at the 99.2% confidence level, suggesting a different formation mechanism for these largest KBO satellites. The two satellites of 2003 EL61, and the one satellite of 2003 UB313, with fractional brightnesses of 5% and 1.5%, and 2%, of their primaries, respectively, are significantly fainter relative to their primaries than other known KBO satellites, again pointing to possible differences in their origin

Forces on Dust Grains Exposed to Anisotropic Interstellar Radiation Fields

Grains exposed to anisotropic radiation fields are subjected to forces due to the asymmetric photon-stimulated ejection of particles. These forces act in addition to the ``radiation pressure'' due to absorption and scattering. Here we model the forces due to photoelectron emission and the photodesorption of adatoms. The ``photoelectric'' force depends on the ambient conditions relevant to grain charging. We find that it is comparable to the radiation pressure when the grain potential is relatively low and the radiation spectrum is relatively hard. The calculation of the ``photodesorption'' force is highly uncertain, since the surface physics and chemsitry of grain materials are poorly understood at present. For our simple yet plausible model, the photodesorption force dominates the radiation pressure for grains with size >~0.1 micron exposed to starlight from OB stars. We find that the anisotropy of the interstellar radiation field is ~10% in the visible and ultraviolet. We estimate size-dependent drift speeds for grains in the cold and warm neutral media and find that micron-sized grains could potentially be moved across a diffuse cloud during its lifetime.Comment: LaTeX(41 pages, 19 figures), submitted to Ap

Hydrascope: Creating Multi-Surface Meta-Applications Through View Synchronization and Input Multiplexing

International audienceAs computing environments that combine multiple displays and input devices become more common, the need for applications that take advantage of these capabilities becomes more pressing. However, few applications are designed to support such multi-surface environments. We investigate how to adapt existing applications without access to their source code. We introduce HydraScope, a framework for transforming existing web applications into meta-applications that execute and synchronize multiple copies of applications in parallel, with a multi-user input layer for interacting with it. We describe the Hydra-Scope architecture, validated with five meta-applications

Semi-supervised Learning for Photometric Supernova Classification

We present a semi-supervised method for photometric supernova typing. Our approach is to first use the nonlinear dimension reduction technique diffusion map to detect structure in a database of supernova light curves and subsequently employ random forest classification on a spectroscopically confirmed training set to learn a model that can predict the type of each newly observed supernova. We demonstrate that this is an effective method for supernova typing. As supernova numbers increase, our semi-supervised method efficiently utilizes this information to improve classification, a property not enjoyed by template based methods. Applied to supernova data simulated by Kessler et al. (2010b) to mimic those of the Dark Energy Survey, our methods achieve (cross-validated) 95% Type Ia purity and 87% Type Ia efficiency on the spectroscopic sample, but only 50% Type Ia purity and 50% efficiency on the photometric sample due to their spectroscopic follow-up strategy. To improve the performance on the photometric sample, we search for better spectroscopic follow-up procedures by studying the sensitivity of our machine learned supernova classification on the specific strategy used to obtain training sets. With a fixed amount of spectroscopic follow-up time, we find that deeper magnitude-limited spectroscopic surveys are better for producing training sets. For supernova Ia (II-P) typing, we obtain a 44% (1%) increase in purity to 72% (87%) and 30% (162%) increase in efficiency to 65% (84%) of the sample using a 25th (24.5th) magnitude-limited survey instead of the shallower spectroscopic sample used in the original simulations. When redshift information is available, we incorporate it into our analysis using a novel method of altering the diffusion map representation of the supernovae. Incorporating host redshifts leads to a 5% improvement in Type Ia purity and 13% improvement in Type Ia efficiency.Comment: 16 pages, 11 figures, accepted for publication in MNRA