A combinatorial method for the evaluation of yield of fault-tolerant systems-on-chip

In this paper we develop a combinatorial method for the evaluation of yield of fault-tolerant systems-on-chip. The method assumes that defects are produced according to a model in which defects are lethal and affect given components of the system following a distribution common to all defects. The distribution of the number of defects is arbitrary. The method is based on the formulation of the yield as 1 minus the probability that a given boolean function with multiple-valued variables has value 1. That probability is computed by analyzing a ROMDD (reduced ordered multiple-valuedecision diagram) representation of the function. For efficiency reasons, we first build a coded ROBDD (reduced ordered binary decision diagram) representation of the function and then transform that coded ROBDD into the ROMDD required by the method. We present numerical experiments showing that the method is able to cope with quite large systems in moderate CPU times.Postprint (published version

Identifying the rotation rate and the presence of dynamic weather on extrasolar Earth-like planets from photometric observations

With the recent discoveries of hundreds of extrasolar planets, the search for planets like Earth and life in the universe, is quickly gaining momentum. In the future, large space observatories could directly detect the light scattered from rocky planets, but they would not be able to spatially resolve a planet's surface. Using reflectance models and real cloud data from satellite observations, here we show that, despite Earth's dynamic weather patterns, the light scattered by the Earth to a hypothetical distant observer as a function of time contains sufficient information to accurately measure Earth's rotation period. This is because ocean currents and continents result in relatively stable averaged global cloud patterns. The accuracy of these measurements will vary with the viewing geometry and other observational constraints. If the rotation period can be measured with accuracy, data spanning several months could be coherently combined to obtain spectroscopic information about individual regions of the planetary surface. Moreover, deviations from a periodic signal can be used to infer the presence of relatively short-live structures in its atmosphere (i.e., clouds). This could provide a useful technique for recognizing exoplanets that have active weather systems, changing on a timescale comparable to their rotation. Such variability is likely to be related to the atmospheric temperature and pressure being near a phase transition and could support the possibility of liquid water on the planet's surface

Linear polarization of rapidly rotating ultracool dwarfs

Abstract. We present imaging linear polarimetry data of a sample of 18 late-M, L-, and early-T type dwarfs taken with the Z-and J-band filters and the LIRIS instrument of the 4.2-m William Herschel Telescope. All of our targets have projected rotational velocities ≥ 30 km s −1 and oblate ultracool atmospheres (T eff < 2700 K), which may harbor clouds of condensate particles. Our polarimetric measurements have typical error bars of ±0.13%, i.e., linear polarization degrees larger than 0.4% can be detected with a confidence of ≥ 3σ. Seven dwarfs appear to be polarized in the J-band with indices of P = 0.4-0.7%, suggesting the presence of atmospheric dusty structures. There is a hint that the dwarfs with the largest rotations (v sin i ≥ 60 km s −1 ) show higher incidence of detected J-band linear polarization than the dwarfs with smaller projected rotational velocities. We also detect linear polarization variability indicative of "weather"

The EBLM project. II. A very hot, low-mass M dwarf in an eccentric and long period eclipsing binary system from SuperWASP

In this paper, we derive the fundamental properties of 1SWASPJ011351.29+314909.7 (J0113+31), a metal-poor (-0.40 +/- 0.04 dex), eclipsing binary in an eccentric orbit (~0.3) with an orbital period of ~14.277 d. Eclipsing M dwarfs orbiting solar-type stars (EBLMs), like J0113+31, have been identified from WASP light curves and follow-up spectroscopy in the course of the transiting planet search. We present the first binary of the EBLM sample to be fully analysed, and thus, define here the methodology. The primary component with a mass of 0.945 +/- 0.045 Msun has a large radius (1.378 +/- 0.058 Rsun) indicating that the system is quite old, ~9.5 Gyr. The M-dwarf secondary mass of 0.186 +/- 0.010 Msun and radius of 0.209 +/- 0.011 Rsun are fully consistent with stellar evolutionary models. However, from the near-infrared secondary eclipse light curve, the M dwarf is found to have an effective temperature of 3922 +/- 42 K, which is ~600 K hotter than predicted by theoretical models. We discuss different scenarios to explain this temperature discrepancy. The case of J0113+31 for which we can measure mass, radius, temperature and metallicity, highlights the importance of deriving mass, radius and temperature as a function of metallicity for M dwarfs to better understand the lowest mass stars. The EBLM Project will define the relationship between mass, radius, temperature and metallicity for M dwarfs providing important empirical constraints at the bottom of the main sequence.Comment: 13 pages, 7 figures. Accepted for publication in A&

The K2-ESPRINT Project. I. Discovery of the Disintegrating Rocky Planet K2-22b with a Cometary Head and Leading Tail

We present the discovery of a transiting exoplanet candidate in the K2 Field-1 with an orbital period of 9.1457 hr: K2-22b. The highly variable transit depths, ranging from $\sim$0\% to 1.3\%, are suggestive of a planet that is disintegrating via the emission of dusty effluents. We characterize the host star as an M-dwarf with $T_{\rm eff} \simeq 3800$ K. We have obtained ground-based transit measurements with several 1-m class telescopes and with the GTC. These observations (1) improve the transit ephemeris; (2) confirm the variable nature of the transit depths; (3) indicate variations in the transit shapes; and (4) demonstrate clearly that at least on one occasion the transit depths were significantly wavelength dependent. The latter three effects tend to indicate extinction of starlight by dust rather than by any combination of solid bodies. The K2 observations yield a folded light curve with lower time resolution but with substantially better statistical precision compared with the ground-based observations. We detect a significant "bump" just after the transit egress, and a less significant bump just prior to transit ingress. We interpret these bumps in the context of a planet that is not only likely streaming a dust tail behind it, but also has a more prominent leading dust trail that precedes it. This effect is modeled in terms of dust grains that can escape to beyond the planet's Hill sphere and effectively undergo `Roche lobe overflow,' even though the planet's surface is likely underfilling its Roche lobe by a factor of 2.Comment: 22 pages, 16 figures. Final version accepted to Ap

Obliquity measurement and atmospheric characterization of the WASP-74 planetary system

We present new transit observations of the hot Jupiter WASP-74 b ($T_\mathrm{eq} \sim$ 1860 K) using the high-resolution spectrograph HARPS-N and the multi-colour simultaneous imager MuSCAT2. We refine the orbital properties of the planet and its host star, and measure its obliquity for the first time. The measured sky-projected angle between the stellar spin-axis and the planet's orbital axis is compatible with an orbit well-aligned with the equator of the host star ($\lambda = 0.77\pm0.99 \mathrm{deg}$). We are not able to detect any absorption feature of H$\alpha$, or any other atomic spectral features, in its high-resolution transmission spectra due to low S/N at the line cores. Despite previous claims regarding the presence of strong optical absorbers such TiO and VO gases in the atmosphere of WASP-74 b, the new ground-based photometry combined with a reanalysis of previously reported observations from the literature shows a slope in the low-resolution transmission spectrum steeper than expected from Rayleigh scattering alone.Comment: Accepted for publication in Astronomy & Astrophysics. 12 pages, 8 figures, 5 table

Language Ferments in Dubrovnik Renaissance Literature

U radu se analiziraju gramatičke i leksičke značajke jezika dubrovačkih renesansnih književnika. Taj se jezik uspoređuje s hrvatskim arhaičnim štokavskim sustavima i novoštokavskim sustavima. Dubrovački je govor u renesansno doba još u znatnoj mjeri sadržavao značajke arhaične štokavštine na svim jezičnim razinama, a mnoge od tih značajki sukladne su čakavskima. Istodobno je to vrijeme kada novoštokavske inovacije počinju postupno narušavati taj sustav, neke brže, a neke sporije. To se stanje odrazilo i u jeziku renesansnih autora, jer su promjene organskoga idioma utjecale na jezik pisaca, osobito u onim elementima u kojima pojedine jezične realizacije nisu uvjetovane versifikacijskim potrebama. Analiza se temelji na velikom broju primjera iz različitih djela različitih autora: Marina Držića, Dinka Ranjine, Dominka Zlatarića, Mavra Vetranovića, Frana Lukarevića, Nikole Dimitrovića, Nikole Nalješkovića, Antuna Sasina, Saba Mišetića Bobaljevića »Glušca«, Marina Kaboge i Maroja Mažibradića.Dubrovnik 16th century authors still to a considerable extent preserve numerous features of archaic Shtokavian usage that are compatible with Chakavian and Kaikavian. Notwithstanding their knowledge of the written word from previous centuries and the vigorous and constant communication with their Chakavian speaking fellow nationals, many non-Neo-Shtokavian features of these writers did not originate under this influence but were simply the result of the fact that Dubrovnik speech at that time was still to a considerable extent not Neo-Shtoka-vian. The results of a neglect of the phenomenon of archaic Croatian Shtokavian in Croatian philology have been manifested in the attitude of researchers to the language of the Dubrovnik Renaissance writers. Thus it has happened that the various dualities that we meet in their language, the result of the gradual transition of the Dubrovnik idiom with its archaic Shtokavian to Neo-Shtokavian, have been interpreted in terms of Shtokavian-Chakavian contacts. What is usually called Chakavian in Dubrovnik Renaissance writing mostly has Western Shtokavian Dubrovnik features, that is, the features of archaic Croatian Shtokavian. Thinking about the Chakavian influence has largely been determined by the fact that the literary language of the earlier periods in Croatian philology has often been sharply demarcated from historical dialectology. And so it happened that some linguistic approaches were considered the influence of literary works from older period or even the influence of other speech idioms, while the fact that Dubrovnik writers could simply have adopted a given linguistic usage from their own local speech was ignored. There has been particular discussion of the considerable mingling of Shtokavian and Chakavian in analyses of the language of the Ranjina Miscellany. Since the poetic language of the authors of the first half of the collection, Šiško Menčetić and Džore Držić, is more archaic than the literary language of later authors of the th century, this literary language has regularly aroused the particular attention of philologists and many of the linguistic features of these authors have been considered signs of Chakavian usage. It can be said in general that in the language of the Ranjina Miscellany there are some Chakavian influences (for example, verbs of the vaze type), but many other older manifestations belong equally to Chakavian and archaic Croatian Western Shtokavian. In Dubrovnik Renaissance literary works the compatibility of the two Shtokavian – old and new – systems is particularly marked. Dubrovnik speech still at that time contained significant features of archaic Shtokavian at all linguistic levels, but at the same time this was the period when Neo-Shtokavian innovations began gradually to break this system down, some more rapidly and some more slowly. So it was in Dubrovnik speech, and so in literary writing, for changes of organic idiom had an influence of the language of writers. Naturally, in works in verse one also has to take into consideration the various needs of the form, such as rhyme, metre, rhythm and refined nuances of style. In prose works, however, much of this is missing, and in such texts it is much easier to follow the merging and fusion of the old and the new Shtokavian system. In brief, when it is borne in mind that the grammatical system and lexical inventory of archaic Shtokavian and Chakavian at the time of the Croatian Renaissance, and at a later time as well, contained many common features, then it becomes superfluous to discuss the Chakavianisms in the Dubrovnik idiom of that period. Since it is often also gladly claimed that Marin Držić, unlike his literary predecessors in the city, endorsed the language of the Dubrovnik commoners, it has to be concluded that the speech of these ordinary people was in many features not yet Neo-Shtokavian, but preserved some features of archaic Shtokavian. This is shown incontrovertibly by language analysis of the prose parts of the texts of Marin Držić and the exchanges of Dubrovnik figures. Nor are the differences among the languages of the individual Dubrovnik authors as big as is usually pointed out, for the many overlaps at all language levels have been overlooked. Many concrete examples from diverse works of diverse Dubrovnik authors from the 16th century clearly show that the most important linguistic features in these works are comparable. It is usually said, for example, that Nikola Dimitrović, through his many innovations and introduction of elements of the vernacular and Italianisms, paved the way for Marin Držić. But it has to be pointed out that, notwithstanding this, there are very recognisable features of archaic Shtokavian at various language levels, in the lexis as well, in spite of the many new lexemes he included in his work. Also visible in this writer is the parallel existence of the old system and the new system that gradually began to replace it. The parallelism in the two systems can be seen in the works of Nikola Nalješković. Examples incontrovertibly show that the biggest turn towards Neo-Shtokavian was made by Dinko Ranjina, although naturally in his language there are influences of archaic Western Shtokavian and some others as well. The prose texts of Dinko Zlatarić are usually taken as an example of advanced Neo-Shtokavian, but in Zlatarić too there is still a far from negligible proportion of old declensions. The prose idiom of Frano Lukarević also has partially older forms of declensions, and also usages that do not have the new iotation. The differences in the literary languages of Šiško Menčetić and Džore Držić on the one hand, Marin Držić, for example, on the other, Dinko Ranjina as a third way and Dinko Zlatarić as a fourth, actually to a considerable extent reflect changes in the Dubrovnik vernacular, which was gradually shifting from the archaic Western Shtokavian dialect into the Neo-Shtokavian. However, this process was not in any way concluded in the period of the Renaissance. The language of some of the Dubrovnik Baroque authors, of the 17th and first half of the 18th, is still in many elements non-Neo-Shtokavian-ised, while under the influence of the literary tradition of previous centuries, archaic Croatian Shtokavian case forms were still being used by some authors even in the 19th century; for example, in the second half of the century, by Antun Kaznačić in his versified works

The CARMENES search for exoplanets around M dwarfs. Two temperate Earth-mass planet candidates around Teegarden’s Star

Context.Teegarden’s Star is the brightest and one of the nearest ultra-cool dwarfs in the solar neighbourhood. For its late spectral type (M7.0 V),the star shows relatively little activity and is a prime target for near-infrared radial velocity surveys such as CARMENES.Aims.As part of the CARMENES search for exoplanets around M dwarfs, we obtained more than 200 radial-velocity measurements of Teegarden’sStar and analysed them for planetary signals.Methods.We find periodic variability in the radial velocities of Teegarden’s Star. We also studied photometric measurements to rule out stellarbrightness variations mimicking planetary signals.Results.We find evidence for two planet candidates, each with 1.1M⊕minimum mass, orbiting at periods of 4.91 and 11.4 d, respectively. Noevidence for planetary transits could be found in archival and follow-up photometry. Small photometric variability is suggestive of slow rotationand old age.Conclusions.The two planets are among the lowest-mass planets discovered so far, and they are the first Earth-mass planets around an ultra-cooldwarf for which the masses have been determined using radial velocities.We thank the referee Rodrigo Díaz for a careful review andhelpful comments. M.Z. acknowledges support from the Deutsche Forschungs-gemeinschaft under DFG RE 1664/12-1 and Research Unit FOR2544 “BluePlanets around Red Stars”, project no. RE 1664/14-1. CARMENES isan instrument for the Centro Astronómico Hispano-Alemán de Calar Alto(CAHA, Almería, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de InvestigacionesCientíficas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut für Astronomie, Instituto de Astrofísica de Andalucía, LandessternwarteKönigstuhl, Institut de Ciències de l’Espai, Institut für Astrophysik Göttingen,Universidad Complutense de Madrid, Thüringer Landessternwarte Tautenburg,Instituto de Astrofísica de Canarias, Hamburger Sternwarte, Centro de Astro-biología and Centro Astronómico Hispano-Alemán), with additional contribu-tions by the Spanish Ministry of Economy, the German Science Foundationthrough the Major Research Instrumentation Programme and DFG ResearchUnit FOR2544 “Blue Planets around Red Stars”, the Klaus Tschira Stiftung, thestates of Baden-Württemberg and Niedersachsen, and by the Junta de Andalucía.Based on data from the CARMENES data archive at CAB (INTA-CSIC). Thisarticle is based on observations made with the MuSCAT2 instrument, devel-oped by ABC, at Telescopio Carlos Sánchez operated on the island of Tener-ife by the IAC in the Spanish Observatorio del Teide. Data were partly col-lected with the 150-cm and 90-cm telescopes at the Sierra Nevada Observa-tory (SNO) operated by the Instituto de Astrofísica de Andalucía (IAA-CSIC).Data were partly obtained with the MONET/South telescope of the MOnitoringNEtwork of Telescopes, funded by the Alfried Krupp von Bohlen und HalbachFoundation, Essen, and operated by the Georg-August-Universität Göttingen,the McDonald Observatory of the University of Texas at Austin, and the SouthAfrican Astronomical Observatory. We acknowledge financial support from theSpanish Agencia Estatal de Investigación of the Ministerio de Ciencia, Inno-vación y Universidades and the European FEDER/ERF funds through projectsAYA2015-69350-C3-2-P, AYA2016-79425-C3-1/2/3-P, AYA2018-84089, BES-2017-080769, BES-2017-082610, ESP2015-65712-C5-5-R, ESP2016-80435-C2-1/2-R, ESP2017-87143-R, ESP2017-87676-2-2, ESP2017-87676-C5-1/2/5-R, FPU15/01476, RYC-2012-09913, the Centre of Excellence ”Severo Ochoa”and ”María de Maeztu” awards to the Instituto de Astrofísica de Canarias (SEV-2015-0548), Instituto de Astrofísica de Andalucía (SEV-2017-0709), and Cen-tro de Astrobiología (MDM-2017-0737), the Generalitat de Catalunya throughCERCA programme”, the Deutsches Zentrum für Luft- und Raumfahrt throughgrants 50OW0204 and 50OO1501, the European Research Council through grant694513, the Italian Ministero dell’instruzione, dell’università de della ricerca andUniversità degli Studi di Roma Tor Vergata through FFABR 2017 and “Mis-sion: Sustainability 2016”, the UK Science and Technology Facilities Council through grant ST/P000592/1, the Israel Science Foundation through grant848/16, the Chilean CONICYT-FONDECYT through grant 3180405, the Mexi-can CONACYT through grant CVU 448248, the JSPS KAKENHI through grantsJP18H01265 and 18H05439, and the JST PRESTO through grant JPMJPR1775

The Detectability of Earth's Biosignatures Across Time

Over the past two decades, enormous advances in the detection of exoplanets have taken place. Currently, we have discovered hundreds of earth-sized planets, several of them within the habitable zone of their star. In the coming years, the efforts will concentrate in the characterization of these planets and their atmospheres to try to detect the presence of biosignatures. However, even if we discovered a second Earth, it is very unlikely that it would present a stage of evolution similar to the present-day Earth. Our planet has been far from static since its formation about 4.5 Ga ago; on the contrary, during this time, it has undergone multiple changes in it's atmospheric composition, it's temperature structure, it's continental distribution, and even changes in the forms of life that inhabit it. All these changes have affected the global properties of Earth as seen from an astronomical distance. Thus, it is of interest not only to characterize the observables of the Earth as it is today, but also at different epochs. Here we review the detectability of the Earth's globally-averaged properties over time. This includes atmospheric composition and biosignatures, and surface properties that can be interpreted as sings of habitability (bioclues). The resulting picture is that truly unambiguous biosignatures are only detectable for about 1/4 of the Earth's history. The rest of the time we rely on detectable bioclues that can only establish an statistical likelihood for the presence of life on a given planet.Comment: To appear in "Handbook of Exoplanets", eds. Deeg, H.J. & Belmonte, J.A, Springer (2018). arXiv admin note: text overlap with arXiv:astro-ph/0609398 by other author