56 research outputs found
LM radar reflectivity simulation Final report
Ultrasonic simulation of lunar module radar reflectivit
Photoelectric Properties of MOS-like Structures with Twofold SRO Films
AbstractThe optical properties of silicon rich oxide (SRO) have been deeply studied because, between other reasons, they emit an intense photoluminescence (PL) from visible to the near infrared range when excited with UV light. MOS-like structures with SRO film as the active layer have shown an enhanced conductivity under different illumination conditions. In this paper, MOS-like structures with double SRO layer were fabricated in order to have a barrier to isolate the silicon substrate from the active SRO layer. Results show that all structures have a higher current when light shines on them than that obtained under dark conditions. A possible application of this photo-effect can be used to increase the response of photodetectors and silicon solar cells
Metal-THINGS: The association and optical characterization of SNRs with HI holes in NGC 6946
NGC~6946, also known as the `Fireworks' galaxy, is an unusual galaxy that
hosts a total of 225 supernova remnant (SNR) candidates, including 147
optically identified with high [SII]/Ha line ratios. In addition, this galaxy
shows prominent HI holes, which were analyzed in previous studies. Indeed, the
connection between SNRs and HI holes together with their physical implications
in the surrounding gas is worth of attention. This paper explores the
connection between the SNRs and the HI holes, including an analysis of their
physical link to observational optical properties inside and around the rims of
the holes, using new integral field unit (IFU) data from the Metal-THINGS
survey. We present an analysis combining previously identified HI holes, SNRs
candidates, and new integral field unit (IFU) data from Metal-THINGS of the
spiral galaxy NGC 6946. We analyze the distributions of the oxygen abundance,
star formation rate surface density, extinction, ionization, diffuse ionized
gas, and the Baldwin-Phillips-Terlevich classification throughout the galaxy.
By analyzing in detail the optical properties of the 121 previously identify HI
holes in NGC 6946, we find that the SNRs are concentrated at the rims of the HI
holes. Furthermore, our IFU data shows that the star formation rate and
extinction are enhanced at the rims of the holes. To a lesser degree, the
oxygen abundance and ionization parameter show hints of enhancement on the rims
of the holes.
Altogether, this provides evidence of induced star formation taking place at
the rims of the holes, whose origin can be explained by the expansion of
superbubbles created by multiple supernova explosions in large stellar clusters
dozens of Myr ago.Comment: Accepted by A&
Enterprise transformation: Why are we interested, what is it, and what are the challenges?
© IIE, INCOSE. The concept of enterprise transformation has become increasingly popular as companies recognize the need to achieve an integrated perspective within and across organizational boundaries to address complex challenges. Yet, there is little clarity concerning what constitutes an “enterprise” or indeed “enterprise transformation.” This article is conceived as an initial step along the journey towards this clarity. There is considerable work to be done in delineating this area of interest and this article is offered as a stimulus for debate on what constitutes enterprise transformation. Drawing on themes from the management and systems engineering disciplines, the article will propose four characteristics of “enterprise” as a unit for transformation and look at why this holistic unit of analysis has become critical to businesses. The article will also ask what constitutes transformation, and offer characterizing criteria to distinguish this magnitude of change from more incremental changes. A recent empirical case study will be examined to further elucidate challenges faced in defining, leading, and transforming multi-organizational enterprises. Finally, a near-term research agenda is outlined for the evolving discipline of enterprise transformation
Subject - specific - frequency - band for motor imagery EEG signal recognition based on common spatial spectral pattern
Over the last decade, processing of biomedical signals using machine learning algorithms has gained widespread attention. Amongst these, one of the most important signals is electroencephalography (EEG) signal that is used to monitor the brain activities. Brain-computer-interface (BCI) has also become a hot topic of research where EEG signals are usually acquired using non-invasive sensors. In this work, we propose a scheme based on common spatial spectral pattern (CSSP) and optimization of temporal filters for improved motor imagery (MI) EEG signal recognition. CSSP is proposed as it improves the spatial resolution while the temporal filter is optimized for each subject as the frequency band which contains most significant information varies amongst different subjects. The proposed scheme is evaluated using two publicly available datasets: BCI competition III dataset IVa and BCI competition IV dataset 1. The proposed scheme obtained promising results and outperformed other state-of-the-art methods. The findings of this work will be beneficial for developing improved BCI systems
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