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1
Csizmadia, Sz. "The Transit and Light Curve Modeller." Monthly Notices of the Royal Astronomical Society 496, no. 4 (February 10, 2020): 4442–67. http://dx.doi.org/10.1093/mnras/staa349.
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ABSTRACT Transit and Light Curve Modeller (TLCM), a computer code with the purpose of analysing photometric time series of transits simultaneously with the out-of-transit light variations and radial velocity curves of transiting/eclipsing binary systems, is presented here. Joint light-curve and radial velocity fits are possible with it. The code is based on the combination of a genetic algorithm and simulated annealing. Binning, beaming, reflection, and ellipsoidal effects are included. Both objects may have their own luminosities and therefore one can use TLCM to analyse the eclipses of both exoplanet and well-detached binary systems. A simplified Rossiter–McLaughlin effect is included in the radial velocity fit, and drifts and offsets of different instruments can also be fitted. The impact of poorly known limb darkening on the Rossiter–McLaughlin effect is shortly studied. TLCM is able to manage red-noise effects via wavelet analysis. It is also possible to add parabolic or user-defined baselines and features to the code. I also predict that light variations due to beaming in some systems exhibiting radial velocity drift should be observed by, e.g. PLATO. The fit of the beaming effect is improved by invoking a physical description of the ellipsoidal effects, which has an impact on the modelling of the relativistic beaming; I also point out the difficulties that are stemming from the fact that beaming and first-order reflection effects have the same form of time dependence. Recipe is given, which describes how to analyse grazing transit events. The code is freely available.
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Kovacs, Geza. "More planetary candidates from K2 Campaign 5 using TRAN_K2." Astronomy & Astrophysics 643 (November 2020): A169. http://dx.doi.org/10.1051/0004-6361/202038726.
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Context. The exquisite precision of space-based photometric surveys and the unavoidable presence of instrumental systematics and intrinsic stellar variability call for the development of sophisticated methods that distinguish these signal components from those caused by planetary transits. Aims. Here, we introduce the standalone Fortran code TRAN_K2 to search for planetary transits under the colored noise of stellar variability and instrumental effects. We use this code to perform a survey to uncover new candidates. Methods. Stellar variability is represented by a Fourier series and, when necessary, by an autoregressive model aimed at avoiding excessive Gibbs overshoots at the edges. For the treatment of systematics, a cotrending and an external parameter decorrelation were employed by using cotrending stars with low stellar variability as well as the chip position and the background flux level at the target. The filtering was done within the framework of the standard weighted least squares, where the weights are determined iteratively, to allow a robust fit and to separate the transit signal from stellar variability and systematics. Once the periods of the transit components are determined from the filtered data by the box-fitting least squares method, we reconstruct the full signal and determine the transit parameters with a higher accuracy. This step greatly reduces the excessive attenuation of the transit depths and minimizes shape deformation. Results. We tested the code on the field of Campaign 5 of the K2 mission. We detected 98% of the systems with all their candidate planets as previously reported by other authors. We then surveyed the whole field and discovered 15 new systems. An additional three planets were found in three multiplanetary systems, and two more planets were found in a previously known single-planet system.
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Püsküllü, Çağlar, and Faruk Soydugan. "Analysis of ground-based observations of some exoplanets." Canadian Journal of Physics 96, no. 7 (July 2018): 681–84. http://dx.doi.org/10.1139/cjp-2017-0780.
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We present analyses of the transit light curves and transit time measurements of the exoplanets HAT-P-3b, HD 189733b, and WASP-43b. Transit light curves were collected at Çanakkale Onsekiz Mart University Observatory and TÜBİTAK National Observatory. The models were produced by WINFITTER code and stellar, planetary, and orbital properties were obtained and discussed. We searched for significant signals at the O-C diagrams generated with our transit times and additional data based on Exoplanet Transit Database.
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Han, Xiao. "Analysis on E-Ticket Image Recognition Technology Based on Mobile QR Code." Electronics Science Technology and Application 2 (December 2, 2015): 19. http://dx.doi.org/10.18686/esta.v5i3.4.
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<p>Currently, most urban rail transits have adopted IC card technology, yet a huge amount of passengers has to wait and buy tickets in the railway stations or stations located in large-scale shopping malls. As a result, there exists potential safety hazard to the operation department. This paper proposes the electronic ticket system based on mobile 2D barcode; the ticket inspection system is able to swiftly recognize 2D barcode ticket, which is a key technology; it mainly analyzes and researches the recognition of QR Code. QR Code image is recognized and analyzed to effectively reduce recognition time and upgrade recognition rate. With the development of the technology, it is able to realize swift ticket procurement and inspection in the rail transit field. </p>
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Püsküllü, Çağlar, and Faruk Soydugan. "Transit analysis of the exoplanet host Kepler-485." Canadian Journal of Physics 96, no. 7 (July 2018): 685–87. http://dx.doi.org/10.1139/cjp-2017-0781.
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In this study, we present solutions of the transit light curves of the recently discovered exoplanet Kepler-485b observed by the Kepler space telescope. To obtain stellar, planetary, and orbital properties, WINFITTER code was applied to transit light curve data, which are available at the NASA Exoplanet Archive (NEA).
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Liakos, Alexios, Dimitris Mislis, and Panagiotis Niarchos. "The Third Body in the Eclipsing Binary AV CMi: Hot Jupiter or Brown Dwarf?" Proceedings of the International Astronomical Union 7, S282 (July 2011): 57–58. http://dx.doi.org/10.1017/s1743921311026871.
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AbstractNew transit light curves of the third body in the system AV CMi have been obtained. The eclipsing pair's light curves were re-analysed with the W-D code and new absolute elements were derived for the two components. Moreover the new light curves (together with those given by Liakos & Niarchos 2010) of the third body transiting one of the components were analysed with the Photometric Software for Transits (PhoS-T). The results from both analyses are combined with the aim to study the nature of the third component.
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Salamun, Sukri, Luluk Elvitaria, and Liza Trisnawati. "Quick Response Code untuk Monitoring Kehadiran Kuliah Dosen." SATIN - Sains dan Teknologi Informasi 6, no. 1 (June 26, 2020): 53–61. http://dx.doi.org/10.33372/stn.v6i1.585.
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Kelas Bersama dosen merupkan salah satu fasilitas yang ada di Universitas Abdurrab Pekanbaru, kelas ini digunakan oleh dosen-dosen yang mengajar mata kuliah teori. Dalam aktifitas yang sedang berjalan sebelum adanya system absensi ini para dosen masih menggunakan absensi tertulis yang mana aktifitas ini tidak efisiean dikarenakan terjadinya antrian jika dalam jam yang sama terdapat jumlah dosen yang mengajar sangat banyak. Oleh karena itu dibuatlah sebuah system absensi dengan Quick Response code atau yang lebih dikenal dengan QR code. System yang di buat akan di integrasikan melalui peraangkat android dosen sehingga dosen tidak perlu mencetak QR code lagi, mereka cukup login pada aplikasi yang sudah terpasang pada perangkat android masing-masing dan aktifitas absensi ini dilakukan pada sebuah ruangan yang dinamakan ruang transit dosen, ruangan ini berfungsi sebagai ruang tunggu dosen, sebelum dose memasuki ruang kelas kuliah. Pada ruang transit dosen disediakan perangkat komputer yang sudah memiliki kamera yang berfungsi untuk membaca QR code pada saat absensi. Pada penelitian ini metode yang digunakan adalah analisis situasi dan analisis kebtuhan yang mana sebelum membuat aplikasi ini dibutuhkan data berupa aktifitas mengajar dosen dan laporan kehadiran pada setiap perkuliahan.
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Nair, Sujay, and Jonathan Varghese. "Transit Analysis of Exoplanets TrES-5 b and WASP-43 b with the EXOplanet Transit Interpretation Code." Research Notes of the AAS 4, no. 6 (June 4, 2020): 82. http://dx.doi.org/10.3847/2515-5172/ab98f5.
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Deck, Katherine M., Eric Agol, Matthew J. Holman, and David Nesvorný. "TTVFast: AN EFFICIENT AND ACCURATE CODE FOR TRANSIT TIMING INVERSION PROBLEMS." Astrophysical Journal 787, no. 2 (May 12, 2014): 132. http://dx.doi.org/10.1088/0004-637x/787/2/132.
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Rugescu, Radu D., Alina Bogoi, and Radu Cirligeanu. "Intricacy of the Transit Manifold Concept Paid-off by Computational Accuracy." Applied Mechanics and Materials 325-326 (June 2013): 142–47. http://dx.doi.org/10.4028/www.scientific.net/amm.325-326.142.
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Despite its intricacy the numerical method applied within the TRANSIT code proved successful in describing discontinuous, non-isentropic flows in rocket engines and solar-gravitational towers for green energy. A number of 0-D approaches are known to render some results in demonstrating the feasibility of the solar tower concept, or in unsteady simulation of transient phases in rocket engines. Computational efficiency is demonstrated by CFD simulation of the starting transients in ADDA solid rocket engines and in the SEATTLER solar mirror tower. The code is exclusively directed to unsteady flow simulations in slender channels. The wave front model scheme covers the dual behavior of fully non-isentropic flow with mass addition and mixing in the thrust chamber or blunt heat addition in a heater and fully isentropic through the exhaust nozzle or gravity draught in a tall tower. Along the tower of the solar-gravity draught power plants small perturbation discontinuous flows are covered. Code robustness is demonstrated during runs on the PC.
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Aase, Johnny Grøneng, Henrik Hyndøy, Agnar Tveten, Ingrid Hjulstad Johansen, Hege Imsen, Eirik Veum Wilhelmsen, Trude Duelien Skorge, Alfred Ingvar Halstensen, Arne Johan Ulven, and Jon Magnus Haga. "The Polar Code and Telemedicine." Yearbook of Polar Law Online 12, no. 1 (December 13, 2021): 349–65. http://dx.doi.org/10.1163/22116427_012010021.
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One result of a warmer global climate is increased maritime activity in the Arctic. Areas that used to be covered by ice and snow are now accessible for the scientific community and commercial users. The Norwegian government has chosen tourism as a pillar of the economy of Svalbard and facilitates the development of the tourism industry. Aase and Jabour have shown that tourist vessels sail as far north as 82° N, beyond the range of geostationary satellites. The Polar Code states that appropriate communication equipment to enable telemedical assistance in polar areas shall be provided. This paper describes a series of functional telemedicine tests carried out on board the Norwegian Coast Guard vessel NoCGV Svalbard during her transit between Svalbard and the Norwegian mainland in September 2019. Communication was established between the vessel and Haukeland University Hospital in Bergen, Norway, using the new Iridium NEXT constellation of communication satellites. Our tests show that medical services that require low bandwidths work.
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Juvan, Ines G., M. Lendl, P. E. Cubillos, L. Fossati, J. Tregloan-Reed, H. Lammer, E. W. Guenther, and A. Hanslmeier. "PyTranSpot: A tool for multiband light curve modeling of planetary transits and stellar spots." Astronomy & Astrophysics 610 (February 2018): A15. http://dx.doi.org/10.1051/0004-6361/201731345.
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Several studies have shown that stellar activity features, such as occulted and non-occulted starspots, can affect the measurement of transit parameters biasing studies of transit timing variations and transmission spectra. We present PyTranSpot, which we designed to model multiband transit light curves showing starspot anomalies, inferring both transit and spot parameters. The code follows a pixellation approach to model the star with its corresponding limb darkening, spots, and transiting planet on a two dimensional Cartesian coordinate grid. We combine PyTranSpot with a Markov chain Monte Carlo framework to study and derive exoplanet transmission spectra, which provides statistically robust values for the physical properties and uncertainties of a transiting star-planet system. We validate PyTranSpot’s performance by analyzing eleven synthetic light curves of four different star-planet systems and 20 transit light curves of the well-studied WASP-41b system. We also investigate the impact of starspots on transit parameters and derive wavelength dependent transit depth values for WASP-41b covering a range of 6200−9200 Å, indicating a flat transmission spectrum.
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Kjurkchieva, Diana P., and Dinko P. Dimitrov. "New Approach for Solution of the Planet Transit Problem." Proceedings of the International Astronomical Union 7, S282 (July 2011): 474–75. http://dx.doi.org/10.1017/s1743921311028158.
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AbstractWe propose a new approach for a solution of the planet transit problem that is based on numerical calculation of integrals. The paper presents our method for the case of linear limb-darkening law and orbital inclination i = 90°, and illustrates the work of the code PTS written on the basis of our approach.
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Nie, Guang Yuan, Zhen Zhou Yuan, and Hao Ling Wu. "Analysis and Calculation on the Capacity of Stairway in Urban Rail Transit Hubs." Applied Mechanics and Materials 587-589 (July 2014): 1733–36. http://dx.doi.org/10.4028/www.scientific.net/amm.587-589.1733.
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In order to study the capacity of stairway in urban rail transit hubs, pedestrian flow and density were collected by the survey of upward stairway and downward stairway in Beijing Xizhimen rail transit hub. With the survey data, this paper fits flow-density curves and establishes corresponding function models. Based on the traffic flow theory, it calculates the actual capacity of upward stairway and downward stairway, and makes a contrast with the Code for Metro Design. Furthermore, the suggested design capacity of stairway is given based on the level of service. The results will provide references for the design of stairway in urban rail transit hubs.
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Vitor de Araújo Biagi, José, Marcia Lucchino Ferreira, Luciana Claudia Silva Lima, and Fabio Ferreira Morong. "BREVES COMENTARIOS A RESPEITO DOS IMPACTOS NORMATIVOS DA LEI 13.546/2017 - HOMICÍDIO CULPOSO." Colloquium Socialis 2, Especial 2 (December 1, 2018): 187–92. http://dx.doi.org/10.5747/cs.2018.v02.nesp2.s0276.
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This study aims to understand the legal modifications included on the brazilian legal order by the Federal Law nº 13.546 of december 2017, specifically to the Brazilian Transit Code, regulated by the Federal Law nº 9.053/1997. The study was originated by the yearning to analyze the possible impacts arising from the inclusion of the qualified form of the manslaughter crime during the driving of a motor vehicle, due alcohol or analogous substances intake, in the terms of the §3º article 302 of the Brazilian Transit Code. The legal deduction method was applied along with the doctrinal analysis, national legislation and the jurisprudence relevant to the case. It is concluded that, even with a severe penalty applied to those defaulter, it is possible to exist a feel of impunity in the community, particularities aside, hardly the offender driver will face a closed penalty
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Gomes, G. O., E. Bolmont, and S. Blanco-Cuaresma. "Influence of equilibrium tides on transit-timing variations of close-in super-Earths." Astronomy & Astrophysics 651 (July 2021): A23. http://dx.doi.org/10.1051/0004-6361/202040202.
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With the current growth in the discovery of close-in low-mass exoplanets, recent works have been published with the aim to discuss the influences of planetary interior structure parameters on both the shape of transit light curves as well as variations in the timing of transit events of these planets. One of the main aspects explored in these works is the possibility that the precession of the argument of periapsis caused by planetary tidal interactions may lead to unique effects on the transit light curves of the exoplanets, such as the so-called transit-timing variations (TTVs). In this work, we investigate the influence of planetary tidal interactions on the transit-timing variations of short-period low-mass rocky exoplanets. For this purpose, we employed the recently developed creep tide theory to compute tidally induced TTVs. We implemented the creep tide in the recently-developed Posidonius N-body code, thus allowing for a high-precision evolution of the coupled spin-orbit dynamics of planetary systems. As a working example for the analyses of tidally induced TTVs, we applied our version of the code to the K2-265 b planet. We analyzed the dependence of tidally induced TTVs with the planetary rotation rate, uniform viscosity coefficient, and eccentricity. Our results show that the tidally induced TTVs are more significant in the case where the planet is trapped in nonsynchronous spin-orbit resonances, in particular the 3/2 and 2/1 spin-orbit resonant states. An analysis of the TTVs induced separately by apsidal precession and tidally induced orbital decay has allowed for the conclusion that the latter effect is much more efficient at causing high-amplitude TTVs than the former effect by 2–3 orders of magnitude. We compare our findings for the tidally induced TTVs obtained with Posidonius with analytical formulations for the transit timings used in previous works, and we verified that the results for the TTVs coming from Posidonius are in excellent agreement with the analytical formulations. These results show that the new version of Posidonius containing the creep tide theory implementation can be used to study more complex cases in the future. For instance, the code can be used to study multiplanetary systems, in which case planet-planet gravitational perturbations must be taken into account in addition to tidal interactions to obtain the TTVs.
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Covington, Kenya L. "Overcoming Spatial Mismatch: The Opportunities and Limits of Transit Mode in Addressing the Black–White Unemployment Gap." City & Community 17, no. 1 (March 2018): 211–35. http://dx.doi.org/10.1111/cico.12278.
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Spatial inequality is a central characteristic of U.S. metropolitan areas. Overcoming related employment disadvantages requires a broad set of responses: relocation, economic development, or an increase in mobility. Given the difficulty of widespread relocation or urban rebuilding programs, increasing mobility through transportation options may be a core solution in the short term. This article explains the racial gap in unemployment under spatial mismatch in the largest metropolitan areas by examining racial gaps in automobile access and public transit use. Research questions focus on which transit options are important to negotiate spatial mismatch and whether there are racial differences in the transit effect. Presented are descriptive and multivariate analyses using 2000 data from the U.S. Census, the Economic Census, and the Zip Code Business Pattern files. Findings show that comparatively, automobile access dominates the public transit effect on Black and White male unemployment in the 100 largest MSAs. First–difference analyses show that Black/White gaps in automobile access correlate with greater racial unemployment disparities, while racial gaps in public transit access seem to be associated with lower racial disparities in unemployment.
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Lutin, Jerome M. "Proposal for Incorporating Public Transit Provisions into a State Highway Access Management Code." Transportation Research Record: Journal of the Transportation Research Board 2171, no. 1 (January 2010): 52–56. http://dx.doi.org/10.3141/2171-06.
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Tingley, Brandon, Gilles Sadowski, and Christos Siopis. "Towards a fully automated eclipsing binary solver for Gaia." Proceedings of the International Astronomical Union 4, S253 (May 2008): 402–3. http://dx.doi.org/10.1017/s1743921308026768.
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AbstractGaia, an ESA cornerstone mission, will obtain of the order of 100 high-precision photometric observations and lower precision radial velocity measurements over five years for around a billion stars – several hundred thousand of which will be eclipsing binaries. In order to extract the characteristics of these systems, a fully automated code must be available. During the process of this development, two tools that may be of use to the transit community have emerged: a very fast, simple, detached eclipsing binary simulator/solver based on a new approach and an interacting eclipsing binary simulator with most of the features of the Wilson-Devinney and Nightfall codes, but fully documented and written in easy-to-follow and highly portable Java. Currently undergoing development and testing, this code includes an intuitive graphical interface and an optimizer for the estimation of the physical parameters of the system.
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Heller, René, Michael Hippke, Jantje Freudenthal, Kai Rodenbeck, Natalie M. Batalha, and Steve Bryson. "Transit least-squares survey." Astronomy & Astrophysics 638 (June 2020): A10. http://dx.doi.org/10.1051/0004-6361/201936929.
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The Sun-like star Kepler-160 (KOI-456) has been known to host two transiting planets, Kepler-160 b and c, of which planet c shows substantial transit-timing variations (TTVs). We studied the transit photometry and the TTVs of this system in our search for a suspected third planet. We used the archival Kepler photometry of Kepler-160 to search for additional transiting planets using a combination of our Wōtan detrending algorithm and our transit least-squares detection algorithm. We also used the Mercury N-body gravity code to study the orbital dynamics of the system in trying to explain the observed TTVs of planet c. First, we recovered the known transit series of planets Kepler-160 b and c. Then we found a new transiting candidate with a radius of 1.91−0.14+0.17 Earth radii (R⊕), an orbital period of 378.417−0.025+0.028 d, and Earth-like insolation. The vespa software predicts that this signal has an astrophysical false-positive probability of FPP3 = 1.8 × 10−3 when the multiplicity of the system is taken into account. Kepler vetting diagnostics yield a multiple event statistic of MES = 10.7, which corresponds to an ~85% reliability against false alarms due to instrumental artifacts such as rolling bands. We are also able to explain the observed TTVs of planet c with the presence of a previously unknown planet. The period and mass of this new planet, however, do not match the period and mass of the new transit candidate. Our Markov chain Monte Carlo simulations of the TTVs of Kepler-160 c can be conclusively explained by a new nontransiting planet with a mass between about 1 and 100 Earth masses and an orbital period between about 7 and 50 d. We conclude that Kepler-160 has at least three planets, one of which is the nontransiting planet Kepler-160 d. The expected stellar radial velocity amplitude caused by this new planet ranges between about 1 and 20 m s−1. We also find the super-Earth-sized transiting planet candidate KOI-456.04 in the habitable zone of this system, which could be the fourth planet.
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Guilluy, G., V. Andretta, F. Borsa, P. Giacobbe, A. Sozzetti, E. Covino, V. Bourrier, et al. "The GAPS programme at TNG." Astronomy & Astrophysics 639 (July 2020): A49. http://dx.doi.org/10.1051/0004-6361/202037644.
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Context. Exoplanets orbiting very close to their parent star are strongly irradiated. This can lead the upper atmospheric layers to expand and evaporate into space. The metastable helium (He I) triplet at 1083.3 nm has recently been shown to be a powerful diagnostic to probe extended and escaping exoplanetary atmospheres. Aims. We perform high-resolution transmission spectroscopy of the transiting hot Jupiter HD 189733 b with the GIARPS (GIANO-B + HARPS-N) observing mode of the Telescopio Nazionale Galileo, taking advantage of the simultaneous optical+near infrared spectral coverage to detect He I in the planet’s extended atmosphere and to gauge the impact of stellar magnetic activity on the planetary absorption signal. Methods. Observations were performed during five transit events of HD 189733 b. By comparison of the in-transit and out-of-transit GIANO-B observations, we computed high-resolution transmission spectra. We then used them to perform equivalent width measurements and carry out light-curves analyses in order to consistently gauge the excess in-transit absorption in correspondence with the He I triplet. Results. We spectrally resolve the He I triplet and detect an absorption signal during all five transits. The mean in-transit absorption depth amounts to 0.75 ± 0.03% (25σ) in the core of the strongest helium triplet component. We detect night-to-night variations in the He I absorption signal likely due to the transit events occurring in the presence of stellar surface inhomogeneities. We evaluate the impact of stellar-activity pseudo-signals on the true planetary absorption using a comparative analysis of the He I 1083.3 nm (in the near-infrared) and the Hα (in the visible) lines. Using a 3D atmospheric code, we interpret the time series of the He I absorption lines in the three nights not affected by stellar contamination, which exhibit a mean in-transit absorption depth of 0.77 ± 0.04% (19σ) in full agreement with the one derived from the full dataset. In agreement with previous results, our simulations suggest that the helium layers only fill part of the Roche lobe. Observations can be explained with a thermosphere heated to ~12 000 K, expanding up to ~1.2 planetary radii, and losing ~1 g s−1 of metastable helium. Conclusions. Our results reinforce the importance of simultaneous optical plus near infrared monitoring when performing high-resolution transmission spectroscopy of the extended and escaping atmospheres of hot planets in the presence of stellar activity.
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Kislyakova, K. G., M. Holmström, P. Odert, H. Lammer, N. V. Erkaev, M. L. Khodachenko, I. F. Shaikhislamov, E. Dorfi, and M. Güdel. "Transit Lyman-α signatures of terrestrial planets in the habitable zones of M dwarfs." Astronomy & Astrophysics 623 (March 2019): A131. http://dx.doi.org/10.1051/0004-6361/201833941.
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Aims. We modeled the transit signatures in the Lyman-alpha (Ly-α) line of a putative Earth-sized planet orbiting in the habitable zone (HZ) of the M dwarf GJ 436. We estimated the transit depth in the Ly-α line for an exo-Earth with three types of atmospheres: a hydrogen-dominated atmosphere, a nitrogen-dominated atmosphere, and a nitrogen-dominated atmosphere with an amount of hydrogen equal to that of the Earth. For all types of atmospheres, we calculated in-transit absorption they would produce in the stellar Ly-α line. We applied it to the out-of-transit Ly-α observations of GJ 436 obtained by the Hubble Space Telescope (HST) and compared the calculated in-transit absorption with observational uncertainties to determine if it would be detectable. To validate the model, we also used our method to simulate the deep absorption signature observed during the transit of GJ 436b and showed that our model is capable of reproducing the observations. Methods. We used a direct simulation Monte Carlo (DSMC) code to model the planetary exospheres. The code includes several species and traces neutral particles and ions. It includes several ionization mechanisms, such as charge exchange with the stellar wind, photo- and electron impact ionization, and allows to trace particles collisions. At the lower boundary of the DSMC model we assumed an atmosphere density, temperature, and velocity obtained with a hydrodynamic model for the lower atmosphere. Results. We showed that for a small rocky Earth-like planet orbiting in the HZ of GJ 436 only the hydrogen-dominated atmosphere is marginally detectable with the Space Telescope Imaging Spectrograph (STIS) on board the HST. Neither a pure nitrogen atmosphere nor a nitrogen-dominated atmosphere with an Earth-like hydrogen concentration in the upper atmosphere are detectable. We also showed that the Ly-α observations of GJ 436b can be reproduced reasonably well assuming a hydrogen-dominated atmosphere, both in the blue and red wings of the Ly-α line, which indicates that warm Neptune-like planets are a suitable target for Ly-α observations. Terrestrial planets, on the other hand, can be observed in the Ly-α line if they orbit very nearby stars, or if several observational visits are available.
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Kozáková, Jana, Mária Urbánová, and Radovan Savov. "Factors Influencing the Extent of the Ethical Codes: Evidence from Slovakia." Journal of Risk and Financial Management 14, no. 1 (January 17, 2021): 40. http://dx.doi.org/10.3390/jrfm14010040.
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Even though formalization of ethical principles is a must in today’s business, research and evidence in the Slovak conditions remain scarce. Yet, creating an ethical business climate and especially the formalization of ethics through codes of ethics incorporated in corporate standards is a particularly interesting phenomenon in the conditions of transit economies due to the significant role of multinationals in this process. Therefore, the purpose of this study was to examine main factors influencing the extent of ethical codes in 225 subsidiaries of multinational companies operating in Slovakia. The conducted questionnaire study containing items focused on area and extent of ethical code, number of employees, economic performance, regional and industrial scope, ownership structure, and nationality of executive director was used as a tool for data collection. Factor analysis was processed to identify the interdependencies between observed variables and to find the latent variables. Further, the Kruskal–Wallis test was applied to identify the differences among the variables along with the Bonferroni correction test, which specified the items between which the significant difference occurred. The following findings emerged. First, companies with lower extent of ethical code use general phrases. When they want to specialize on any ethics problems, extent must be wider. Second, companies with a lower number of employees do not need extensive ethical code due to clear rules with which they are familiar in a direct way by owners. In multinational companies, the communication of ethical rules is realized via ethical codes with specific purposes because the direct way is impossible. Third, companies with foreign ownership used different managerial approaches, and therefore ethical codes differ in extent and content.
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Mol Lous, M., E. Weenk, M. A. Kenworthy, K. Zwintz, and R. Kuschnig. "A search for transiting planets in the β Pictoris system." Astronomy & Astrophysics 615 (July 2018): A145. http://dx.doi.org/10.1051/0004-6361/201731941.
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Context. Transiting exoplanets provide an opportunity for the characterization of their atmospheres, and finding the brightest star in the sky with a transiting planet enables high signal-to-noise ratio observations. The Kepler satellite has detected over 365 multiple transiting exoplanet systems, a large fraction of which have nearly coplanar orbits. If one planet is seen to transit the star, then it is likely that other planets in the system will transit the star too. The bright (V = 3.86) star β Pictoris is a nearby young star with a debris disk and gas giant exoplanet, β Pictoris b, in a multi-decade orbit around it. Both the planet’s orbit and disk are almost edge-on to our line of sight. Aims. We carry out a search for any transiting planets in the β Pictoris system with orbits of less than 30 days that are coplanar with the planet β Pictoris b. Methods. We search for a planetary transit using data from the BRITE-Constellation nanosatellite BRITE-Heweliusz, analyzing the photometry using the Box-Fitting Least Squares Algorithm (BLS). The sensitivity of the method is verified by injection of artificial planetary transit signals using the Bad-Ass Transit Model cAlculatioN (BATMAN) code. Results. No planet was found in the BRITE-Constellation data set. We rule out planets larger than 0.6 RJ for periods of less than 5 days, larger than 0.75 RJ for periods of less than 10 days, and larger than 1.05 RJ for periods of less than 20 days.
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He, Matthias Y., Eric B. Ford, and Darin Ragozzine. "Architectures of exoplanetary systems – I. A clustered forward model for exoplanetary systems around Kepler’s FGK stars." Monthly Notices of the Royal Astronomical Society 490, no. 4 (November 5, 2019): 4575–605. http://dx.doi.org/10.1093/mnras/stz2869.
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ABSTRACT Observations of exoplanetary systems provide clues about the intrinsic distribution of planetary systems, their architectures, and how they formed. We develop a forward modelling framework for generating populations of planetary systems and ‘observed’ catalogues by simulating the Kepler detection pipeline (SysSim). We compare our simulated catalogues to the Kepler DR25 catalogue of planet candidates, updated to include revised stellar radii from Gaia DR2. We constrain our models based on the observed 1D marginal distributions of orbital periods, period ratios, transit depths, transit depth ratios, transit durations, transit duration ratios, and transit multiplicities. Models assuming planets with independent periods and sizes do not adequately account for the properties of the multiplanet systems. Instead, a clustered point process model for exoplanet periods and sizes provides a significantly better description of the Kepler population, particularly the observed multiplicity and period ratio distributions. We find that $0.56^{+0.18}_{-0.15}$ of FGK stars have at least one planet larger than 0.5R⊕ between 3 and 300 d. Most of these planetary systems ($\sim 98{{\ \rm per\ cent}}$) consist of one or two clusters with a median of three planets per cluster. We find that the Kepler dichotomy is evidence for a population of highly inclined planetary systems and is unlikely to be solely due to a population of intrinsically single planet systems. We provide a large ensemble of simulated physical and observed catalogues of planetary systems from our models, as well as publicly available code for generating similar catalogues given user-defined parameters.
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Younes Bayane, Fatima Amounas, Lahcen El Bermi. "A Novel Digital Signature based on Error Correcting Codes." International Journal on Recent and Innovation Trends in Computing and Communication 7, no. 3 (March 20, 2019): 25–28. http://dx.doi.org/10.17762/ijritcc.v7i3.5253.
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A digital signature is a cryptographic primitive for ensuring the authenticity of digital documents. A valid digital signature allows checking that a message was created by a known sender (authentication), that the sender cannot deny having sent the message (nonrepudiation), and that the message was not altered in transit (integrity).The idea of constructing practical signatures based on error correcting codes was introduced by Courtois et al in [1]. The main goal is to make digital signature for which the security is based on decoding syndrome problem. In this paper, a new construction of digital signature is considered which is an extension of the error correcting code construction. The proposed method consists of reordering the message bits to get a decodable word. Then apply an efficient decoding algorithm to get signature.
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Rein, Edan, and Aviv Ofir. "Fast and precise light-curve model for transiting exoplanets with rings." Monthly Notices of the Royal Astronomical Society 490, no. 1 (September 12, 2019): 1111–19. http://dx.doi.org/10.1093/mnras/stz2556.
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ABSTRACT The presence of silicate material in known rings in the Solar system raises the possibility of ring systems existing even within the snow line – where most transiting exoplanets are found. Previous studies have shown that the detection of exoplanetary rings in transit light curves is possible, albeit challenging. To aid such future detection of exoplanetary rings, we present the Polygon + Segments model for modelling the light curve of an exoplanet with rings. This high-precision model includes full ring geometry as well as possible ring transparency and the host star’s limb darkening. It is also computationally efficient, requiring just a 1D integration over a small range, making it faster than existing techniques. The algorithm at its core is further generalized to compute the light curve of any set of convex primitive shapes in transit (e.g. multiple planets, oblate planets, moons, rings, combination thereof, etc.) while accounting for their overlaps. The python source code is made available.
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Ligi, Roxanne, Denis Mourard, Karine Perraut, Philippe Bério, Lionel Bigot, Andrea Chiavassa, Anne-Marie Lagrange, and Nicolas Nardetto. "Modeling transiting exoplanet and spots For interferometric study." Proceedings of the International Astronomical Union 9, S302 (August 2013): 202–5. http://dx.doi.org/10.1017/s1743921314002087.
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AbstractUp to now, many techniques have been developed to detect and observe exoplanets, the radial velocity (RV) method being the most prolific one. However, stellar magnetic spots can mimic an exoplanet transit signal and lead to a false detection. A few models have already been developed to constrain the different signature of exoplanets and spots, but they only concern RV measurements or photometry. An interferometric approach, with high angular resolution capabilities, could resolve this problem.Optical interferometry is a powerful method to measure accurate stellar diameters, and derive fundamental parameters of stars and exoplanets minimum masses. We have built an analytical code able to calculate visibility moduli and closure phases of stars with a transiting exoplanet, to be compared with a star with no exoplanet. From the difference of interferometric signal, we can derive the presence of the exoplanet, but this requires that the star is resolved enough. We have tested this code with current available facilities like VEGA/CHARA and determined which already discovered exoplanets systems can be resolved enough to test this method.To make a more general study, we also tested different parameters (exoplanet and stellar diameters, exoplanet position) that can lead to a variation of the minimum baseline length required to see the exoplanet signal on the visibility modulus and the phase. Stellar spots act in the same way, but the difference of local intensity between an exoplanet transit and a spot can easily be studied thanks to the interferometric measurements.
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Bonfanti, A., and M. Gillon. "MCMCI: A code to fully characterise an exoplanetary system." Astronomy & Astrophysics 635 (February 28, 2020): A6. http://dx.doi.org/10.1051/0004-6361/201936326.
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Context. Useful information can be retrieved by analysing the transit light curve of a planet-hosting star or induced radial velocity oscillations. However, inferring the physical parameters of the planet, such as mass, size, and semi-major axis, requires preliminary knowledge of some parameters of the host star, especially its mass or radius, which are generally inferred through theoretical evolutionary models. Aims. We seek to present and test a whole algorithm devoted to the complete characterisation of an exoplanetary system thanks to the global analysis of photometric or radial velocity time series combined with observational stellar parameters derived either from spectroscopy or photometry. Methods. We developed an integrated tool called MCMCI. This tool combines the Markov chain Monte Carlo (MCMC) approach of analysing photometric or radial velocity time series with a proper interpolation within stellar evolutionary isochrones and tracks, known as isochrone placement, to be performed at each chain step, to retrieve stellar theoretical parameters such as age, mass, and radius. Results. We tested the MCMCI on the HD 219134 multi-planetary system hosting two transiting rocky super Earths and on WASP-4, which hosts a bloated hot Jupiter. Even considering different input approaches, a final convergence was reached within the code, we found good agreement with the results already stated in the literature and we obtained more precise output parameters, especially concerning planetary masses. Conclusions. The MCMCI tool offers the opportunity to perform an integrated analysis of an exoplanetary system without splitting it into the preliminary stellar characterisation through theoretical models. Rather this approach favours a close interaction between light curve analysis and isochrones, so that the parameters recovered at each step of the MCMC enter as inputs for purposes of isochrone placement.
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Lavanya, N., and M. Balakrishna. "A New Technique for File Sharing Mechanism Ad hoc Networks." International Journal of Advanced Research in Computer Science and Software Engineering 8, no. 3 (March 30, 2018): 1. http://dx.doi.org/10.23956/ijarcsse.v8i3.585.
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Network coding is a data transmission technique which allows intermediate nodes in a network to re-code data in transit. In contrast to traditional network communication where a node repeats incoming data to its outgoing channel without modifying the payload, a node implementing network coding not only repeats but also alters data. Network coding has been demonstrated to increase network throughput compared to the traditional forwarding transmission. It has potentially broad applications in many areas, including traditional computer networks, wireless ad-hoc networks, and peer to peer systems. This paper process a new technique for file sharing in P2P.
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Bielska, Tetiana Valentynіvna, and Mariia Hryhorivna Lashkina. "THE COUNTRIES OF TRANSITION DEMOCRACY IN THE PROCESS OF DEMOCRATIC TRANSIT: AN ARCHETYPAL ASPECT." UKRAINIAN ASSEMBLY OF DOCTORS OF SCIENCES IN PUBLIC ADMINISTRATION 1, no. 14 (June 16, 2018): 34–50. http://dx.doi.org/10.31618/vadnd.v1i14.97.
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The authors offer non-standard views on the processes of establishing democracy in developing countries. In the article the processes of democratic transit by using archetypal methodology are analyzed; the processes of the influence of archetypes on democratic institutions in the conditions of information society and technological revolution are considered. The laws and conditions of the formation or destruction of state institutions in transition democracies, their hybridity, partially authoritarian hierarchy or chaos, and uncertainty of progress towards the goal are determined. The authors, by using of the methodology of E. Dyurgeym — imposition of biological methods of research on social processes, metaphorically compare the stages of personality development and the processes of state formation and conclude that the Ukrainian state is now in the stage of individualization and understanding itself. The structure of personality according to K. Jung is considered, its main components are distinguished. The authors suggest that in countries that have recently embarked on a path of democracy, the connection between rational and irrational is stronger than in countries that are entrenched in established democracies. These processes are metaphorically compared by the authors with the connection of the conscious and unconscious in the formation of the individual. They come to the conclusion that the lack of archetypal subconscious nature and code of culture and national codes of democratic values creates obstacles to their formation in the public consciousness. This is reflected in the socio-political activity of the state and in the functionality of its institutions. In the information society, the vector of the influence of archetypes on democratic social institutions, which leads to a hybrid distortion of the concept of the state as a device of violence and pressure, has changed. Postcommunist transformations represent a new wave, but the trajectories and outcomes of postcommunist transformations are different for states, so democratic transit is uneven.
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Palle, E., L. Nortmann, N. Casasayas-Barris, M. Lampón, M. López-Puertas, J. A. Caballero, J. Sanz-Forcada, et al. "A He I upper atmosphere around the warm Neptune GJ 3470 b." Astronomy & Astrophysics 638 (June 2020): A61. http://dx.doi.org/10.1051/0004-6361/202037719.
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High resolution transit spectroscopy has proven to be a reliable technique for the characterization of the chemical composition of exoplanet atmospheres. Taking advantage of the broad spectral coverage of the CARMENES spectrograph, we initiated a survey aimed at characterizing a broad range of planetary systems. Here, we report our observations of three transits of GJ 3470 b with CARMENES in search of He (23S) absorption. On one of the nights, the He I region was heavily contaminated by OH− telluric emission and, thus, it was not useful for our purposes. The remaining two nights had a very different signal-to-noise ratio (S/N) due to weather. They both indicate the presence of He (23S) absorption in the transmission spectrum of GJ 3470 b, although a statistically valid detection can only be claimed for the night with higher S/N. For that night, we retrieved a 1.5 ± 0.3% absorption depth, translating into a Rp(λ)∕Rp = 1.15 ± 0.14 at this wavelength. Spectro-photometric light curves for this same night also indicate the presence of extra absorption during the planetary transit with a consistent absorption depth. The He (23S) absorption is modeled in detail using a radiative transfer code, and the results of our modeling efforts are compared to the observations. We find that the mass-loss rate, Ṁ, is confined to a range of 3 × 1010 g s−1 for T = 6000 K to 10 × 1010 g s−1 for T = 9000 K. We discuss the physical mechanisms and implications of the He I detection in GJ 3470 b and put it in context as compared to similar detections and non-detections in other Neptune-size planets. We also present improved stellar and planetary parameter determinations based on our visible and near-infrared observations.
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Daskalaki, Ivi, and Nadina Leivaditi. "Education and Hospitality in Liminal Locations for Unaccompanied Refugee Youths in Lesvos." Migration and Society 1, no. 1 (December 1, 2018): 51–65. http://dx.doi.org/10.3167/arms.2017.010106.
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The closure of borders along the “Balkan route” and the EU-Turkey agreement in 2016 resulted in the involuntary immobility of thousands of refugees in Greece. Since then, the large-scale emergency relief aid on the Greek shores has been replaced by the development of provisions for the gradual integration of refugees within wider European society. In such a context, education comes to the fore in the management of Europe’s so-called “refugee crisis.” This article explores refugee youths’ educational engagements in the framework of their “temporary” accommodation in a Transit Shelter for Unaccompanied (Male) Minors on the island of Lesvos. The article discusses how the youths themselves act upon educational arrangements made by their caretakers within a context of limited agency inscribed in a “code” of filoxenia (hospitality to foreigners). This code positions refugee youths both as temporary “guests” and simultaneously as “subjects” of discipline in the residency and in wider society.
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Daskalaki, Ivi, and Nadina Leivaditi. "Education and Hospitality in Liminal Locations for Unaccompanied Refugee Youths in Lesvos." Migration and Society 1, no. 1 (December 1, 2018): 51–65. http://dx.doi.org/10.3167/arms.2018.010106.
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The closure of borders along the “Balkan route” and the EU-Turkey agreement in 2016 resulted in the involuntary immobility of thousands of refugees in Greece. Since then, the large-scale emergency relief aid on the Greek shores has been replaced by the development of provisions for the gradual integration of refugees within wider European society. In such a context, education comes to the fore in the management of Europe’s so-called “refugee crisis.” This article explores refugee youths’ educational engagements in the framework of their “temporary” accommodation in a Transit Shelter for Unaccompanied (Male) Minors on the island of Lesvos. The article discusses how the youths themselves act upon educational arrangements made by their caretakers within a context of limited agency inscribed in a “code” of filoxenia (hospitality to foreigners). This code positions refugee youths both as temporary “guests” and simultaneously as “subjects” of discipline in the residency and in wider society.
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Ackerer, Julien, Benjamin Jeannot, Frederick Delay, Sylvain Weill, Yann Lucas, Bertrand Fritz, Daniel Viville, and François Chabaux. "Crossing hydrological and geochemical modeling to understand the spatiotemporal variability of water chemistry in a headwater catchment (Strengbach, France)." Hydrology and Earth System Sciences 24, no. 6 (June 17, 2020): 3111–33. http://dx.doi.org/10.5194/hess-24-3111-2020.
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Abstract. Understanding the variability of the chemical composition of surface waters is a major issue for the scientific community. To date, the study of concentration–discharge relations has been intensively used to assess the spatiotemporal variability of the water chemistry at watershed scales. However, the lack of independent estimations of the water transit times within catchments limits the ability to model and predict the water chemistry with only geochemical approaches. In this study, a dimensionally reduced hydrological model coupling surface flow with subsurface flow (i.e., the Normally Integrated Hydrological Model, NIHM) has been used to constrain the distribution of the flow lines in a headwater catchment (Strengbach watershed, France). Then, hydrogeochemical simulations with the code KIRMAT (i.e., KInectic Reaction and MAss Transport) are performed to calculate the evolution of the water chemistry along the flow lines. Concentrations of dissolved silica (H4SiO4) and in basic cations (Na+, K+, Mg2+, and Ca2+) in the spring and piezometer waters are correctly reproduced with a simple integration along the flow lines. The seasonal variability of hydraulic conductivities along the slopes is a key process to understand the dynamics of flow lines and the changes of water transit times in the watershed. The covariation between flow velocities and active lengths of flow lines under changing hydrological conditions reduces the variability of water transit times and explains why transit times span much narrower variation ranges than the water discharges in the Strengbach catchment. These findings demonstrate that the general chemostatic behavior of the water chemistry is a direct consequence of the strong hydrological control of the water transit times within the catchment. Our results also show that a better knowledge of the relations between concentration and mean transit time (C–MTT relations) is an interesting new step to understand the diversity of C–Q shapes for chemical elements. The good match between the measured and modeled concentrations while respecting the water–rock interaction times provided by the hydrological simulations also shows that it is possible to capture the chemical composition of waters using simply determined reactive surfaces and experimental kinetic constants. The results of our simulations also strengthen the idea that the low surfaces calculated from the geometrical shapes of primary minerals are a good estimate of the reactive surfaces within the environment.
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Jia, Peng-Fei, Hong-Yu Ni, Xing-Hui Zhang, Su Huang, Li-Hua Li, and Yang Yang. "Research on GIS Monitoring System in Operation Based on Rail Robot." E3S Web of Conferences 243 (2021): 02001. http://dx.doi.org/10.1051/e3sconf/202124302001.
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GIS is prone to various defects and faults after putting into operation, and the failure rate is high. At present, the inspection methods of GIS in operation include traditional inspection mode, two-dimensional code inspection mode, radio frequency identification technology mode and robot inspection mode. However, the current inspection robot has the disadvantages of weak adaptability to complex environment, insufficient inspection scope, low efficiency and low intelligence. Therefore, this paper designs a GIS monitoring system based on the rail robot. By installing all kinds of sensors on the rail robot, with the help of binocular vision and mechanical arm, the omni-directional live detection of GIS in transit can be realized.
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Prianto, Cahyo, Harun Ar-Rasyid, and Nico Ekklesia Sembiring. "Pengembangan Sistem Transportasi Pada Gudang In-Transit Merge Dengan Integrasi Sistem Android." Komputika : Jurnal Sistem Komputer 9, no. 2 (October 20, 2020): 147–53. http://dx.doi.org/10.34010/komputika.v9i2.3005.
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The problem that arises in the business activities of companies that are based on the sale of goods is the lack of a system that can help companies carry out the activities of shipping goods from warehouses to stores. Therefore, in this project, a web-based and Android-integrated transportation and routing selection system will be developed. So that it can facilitate officers in choosing the type of transportation and also the driver in seeing the route.The function of selecting the type of transportation is very important to assist officers in selecting the type of transportation suitable for delivering goods. As well as with the routing function that can help the driver to find out the intended route. By developing this system, companies can easily access and monitor goods sent to the store and guarantee the safety of the goods sent will get to the store through the token feature. This application is designed using the PHP programming language and Code Igniter (CI) and MySQL framework as the database and UML as the analysis process and also integrates the Android system. This application can be accessed by super administrators, warehouse officers, staff, drivers, and shop owners who have registered in this application, which makes this application convenient for users to use.
Keywords - Development; System; Warehouse; In-Transit Merge; Transportation.
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Rao, Sriram, Ashish Mahabal, Niyanth Rao, and Cauligi Raghavendra. "Nigraha: Machine-learning-based pipeline to identify and evaluate planet candidates from TESS." Monthly Notices of the Royal Astronomical Society 502, no. 2 (January 27, 2021): 2845–58. http://dx.doi.org/10.1093/mnras/stab203.
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ABSTRACT The Transiting Exoplanet Survey Satellite (TESS) has now been operational for a little over two years, covering the Northern and the Southern hemispheres once. The TESS team processes the downlinked data using the Science Processing Operations Center (SPOC) pipeline and Quick Look pipeline (QLP) to generate alerts for follow-up. Combined with other efforts from the community, over 2000 planet candidates have been found of which tens have been confirmed as planets. We present our pipeline, Nigraha, that is complementary to these approaches. Nigraha uses a combination of transit finding, supervised machine learning, and detailed vetting to identify with high confidence a few planet candidates that were missed by prior searches. In particular, we identify high signal-to-noise ratio shallow transits that may represent more Earth-like planets. In the spirit of open data exploration, we provide details of our pipeline, release our supervised machine learning model and code as open source, and make public the 38 candidates we have found in seven sectors. The model can easily be run on other sectors as is. As part of future work, we outline ways to increase the yield by strengthening some of the steps where we have been conservative and discarded objects for lack of a datum or two.
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Maxted, P. F. L., and S. Gill. "qpower2: A fast and accurate algorithm for the computation of exoplanet transit light curves with the power-2 limb-darkening law." Astronomy & Astrophysics 622 (January 24, 2019): A33. http://dx.doi.org/10.1051/0004-6361/201834563.
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Context. The power-2 law, Iλ( μ) = 1 − c(1−μα), accurately represents the limb-darkening profile for cool stars. It has been implemented in a few transit models to-date using numerical integration but there is as-yet no implementation of the power-2 law in analytic form that is generally available. Aims. Our aim is to derive an analytic approximation that can be used to quickly and accurately calculate light curves of transiting exoplanets using the power-2 limb-darkening law. Methods. An algorithm to implement the power-2 law is derived using a combination of an approximation to the required integral and a Taylor expansion of the power-2 law. The accuracy of stellar and planetary radii derived by fitting transit light curves with this approximation is tested using light curves computed by numerical integration of limb-darkening profiles from 3D stellar model atmospheres. Results. Our algorithm (qpower2) is accurate to about 100 ppm for broad-band optical light curves of systems with a star-planet radius ratio p = 0.1. The implementation requires less than 40 lines of python code so can run extremely fast on graphical processing units (GPUs; ∼1 million models per second for the analysis of 1000 data points). Least-squares fits to simulated light curves show that the star and planet radius are recovered to better than 1% for p < 0.2. Conclusions. The qpower2 algorithm can be used to efficiently and accurately analyse large numbers of high-precision transit light curves using Monte Carlo methods.
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Harrington, J. Patrick. "Polarized Continuum Radiation from Stellar Atmospheres." Proceedings of the International Astronomical Union 10, S305 (December 2014): 395–400. http://dx.doi.org/10.1017/s1743921315005116.
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AbstractContinuum scattering by free electrons can be significant in early type stars, while in late type stars Rayleigh scattering by hydrogen atoms or molecules may be important. Computer programs used to construct models of stellar atmospheres generally treat the scattering of the continuum radiation as isotropic and unpolarized, but this scattering has a dipole angular dependence and will produce polarization. We review an accurate method for evaluating the polarization and limb darkening of the radiation from model stellar atmospheres. We use this method to obtain results for: (i) Late type stars, based on the MARCS code models (Gustafsson et al. 2008), and (ii) Early type stars, based on the NLTE code TLUSTY (Lanz and Hubeny 2003). These results are tabulated at http://www.astro.umd.edu/~jph/Stellar_Polarization.html While the net polarization vanishes for an unresolved spherical star, this symmetry is broken by rapid rotation or by the masking of part of the star by a binary companion or during the transit of an exoplanet. We give some numerical results for these last cases.
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Sklyarov, German N. "Horizontal Inter-Budget Transfers Provided as an Alternative to “Transit” Transfers (On the Example of Municipal Districts)." Juridical Science and Practice 16, no. 1 (2020): 55–62. http://dx.doi.org/10.25205/2542-0410-2020-16-1-55-62.
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The article is devoted to the problem of using «transit» inter-budget transfers when providing subsidies to municipalities from the budget of a constituent entity of the Russian Federation. An analysis of regulatory legal acts establishing the procedure and conditions for the provision of subsidies from the budget of the Novosibirsk Region allows us to conclude that there is insufficient legal regulation of the conditions for using subsidy funds by recipients of the subsidy, which leads to a distortion of the nature of inter-budget transfers. As a way out of this situation, the author considers the possibility of using subsidies to the budgets of municipalities from local budgets, the provision of which is provided for in Article 142.3 of the Budget Code of the Russian Federation.
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D’Angelo, C. Villarreal, M. Schneiter, and A. Esquivel. "On the influence of magnetic fields in neutral planetary wakes." Proceedings of the International Astronomical Union 12, S328 (October 2016): 192–97. http://dx.doi.org/10.1017/s174392131700388x.
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AbstractWe present a 3D magnetohydrodynamic study of the effect that stellar and planetary magnetic fields have on the calculated Lyα absorption during the planetary transit, employing parameters that resemble the exoplanet HD209458b. We assume a dipolar magnetic field for both the star and the planet, and use the Parker solution to initialize the stellar wind. We also consider the radiative processes and the radiation pressure.We use the numerical MHD code Guacho to run several models varying the values of the planetary and stellar magnetic moments within the range reported in the literature.We found that the presence of magnetic fields influences the escaping neutral planetary material spreading the absorption Lyα line for large stellar magnetic fields.
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Pino, Lorenzo, David Ehrenreich, Aurélien Wyttenbach, Vincent Bourrier, Valerio Nascimbeni, Kevin Heng, Simon Grimm, et al. "Combining low- to high-resolution transit spectroscopy of HD 189733b." Astronomy & Astrophysics 612 (April 2018): A53. http://dx.doi.org/10.1051/0004-6361/201731244.
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Space-borne low- to medium-resolution (ℛ ~ 102–103) and ground-based high-resolution spectrographs (ℛ ~ 105) are commonly used to obtain optical and near infrared transmission spectra of exoplanetary atmospheres. In this wavelength range, space-borne observations detect the broadest spectral features (alkali doublets, molecular bands, scattering, etc.), while high-resolution, ground-based observations probe the sharpest features (cores of the alkali lines, molecular lines). The two techniques differ by several aspects. (1) The line spread function of ground-based observations is ~103 times narrower than for space-borne observations; (2) Space-borne transmission spectra probe up to the base of thermosphere (P ≳ 10−6 bar), while ground-based observations can reach lower pressures (down to ~10−11 bar) thanks to their high resolution; (3) Space-borne observations directly yield the transit depth of the planet, while ground-based observations can only measure differences in the apparent size of the planet at different wavelengths. These differences make it challenging to combine both techniques. Here, we develop a robust method to compare theoretical models with observations at different resolutions. We introduce πη, a line-by-line 1D radiative transfer code to compute theoretical transmission spectra over a broad wavelength range at very high resolution (ℛ ~ 106, or Δλ ~ 0.01 Å). An hybrid forward modeling/retrieval optimization scheme is devised to deal with the large computational resources required by modeling a broad wavelength range ~0.3–2 μm at high resolution. We apply our technique to HD 189733b. In this planet, HST observations reveal a flattened spectrum due to scattering by aerosols, while high-resolution ground-based HARPS observations reveal sharp features corresponding to the cores of sodium lines. We reconcile these apparent contrasting results by building models that reproduce simultaneously both data sets, from the troposphere to the thermosphere. We confirm: (1) the presence of scattering by tropospheric aerosols; (2) that the sodium core feature is of thermospheric origin. When we take into account the presence of aerosols, the large contrast of the core of the sodium lines measured by HARPS indicates a temperature of up to ~10 000K in the thermosphere, higher than what reported in the literature. We also show that the precise value of the thermospheric temperature is degenerate with the relative optical depth of sodium, controlled by its abundance, and of the aerosol deck.
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Allard, F., D. Homeier, and B. Freytag. "Models of very-low-mass stars, brown dwarfs and exoplanets." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370, no. 1968 (June 13, 2012): 2765–77. http://dx.doi.org/10.1098/rsta.2011.0269.
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Within the next few years, GAIA and several instruments aiming to image extrasolar planets will be ready. In parallel, low-mass planets are being sought around red dwarfs, which offer more favourable conditions, for both radial velocity detection and transit studies, than solar-type stars. In this paper, the authors of a model atmosphere code that has allowed the detection of water vapour in the atmosphere of hot Jupiters review recent advances in modelling the stellar to substellar transition. The revised solar oxygen abundances and cloud model allow the photometric and spectroscopic properties of this transition to be reproduced for the first time. Also presented are highlight results of a model atmosphere grid for stars, brown dwarfs and extrasolar planets.
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Ramadhan, Hilali Hussein, and Juyoul Kim. "Radiological Risk Assessment of Vehicle Transport Accidents Associated with Consumer Products Containing Naturally Occurring Radioactive Materials." Applied Sciences 11, no. 18 (September 18, 2021): 8719. http://dx.doi.org/10.3390/app11188719.
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Natural and artificial ionizing radiation can be harmful to human health when they come into contact with people and the environment. Transport of naturally occurring radioactive materials (NORMs) and consumer products containing NORM in the public domain is inevitable owing to their potential applications. This study evaluates the dose and risk to the public from transport accidents of NORM and consumer products. Radiological and physical data were obtained from previous literature. The median and maximum values of radioactivity concentration were applied to consumer products and NORM data, which serve as an input. An external dose rate at 1 m from a transported shipment was calculated using Microshield® Pro version 12.11 code, which serves as input to RADTRAN 6 code. Based on developed transport accident scenarios, a RADTRAN 6 code was used to estimate collective dose and risk. The sensitivity analysis was conducted by considering the variation of release, aerosol, and respirable fractions of radionuclides at 0.1%, 1%, 10%, and 100% from the transported shipment during an accident, respectively. The results of dose and risk to the general public because of the damage of the shipment container following a fire accident are below the annual regulatory limits of 1 man-Sv recommended by IAEA transport regulation of 2018. The sensitivity results of all NORMs and associated consumer products are also below the regulatory limits. Therefore, radiological safety can be ensured in the event of a transport accident involving the transit of NORM and consumer products containing NORM.
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Guo, Jingnan, Saša Banjac, Lennart Röstel, Jan C. Terasa, Konstantin Herbst, Bernd Heber, and Robert F. Wimmer-Schweingruber. "Implementation and validation of the GEANT4/AtRIS code to model the radiation environment at Mars." Journal of Space Weather and Space Climate 9 (2019): A2. http://dx.doi.org/10.1051/swsc/2018051.
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A new GEANT4 particle transport model – the Atmospheric Radiation Interaction Simulator (AtRIS, Banjac et al. 2018. J Geophys Res Space Phys 123. https://doi.org/10.1029/2018JA026042) – has been recently developed in order to model the interaction of radiation with planets. The upcoming instrumentational advancements in the exoplanetary science, in particular transit spectroscopy capabilities of missions like JWST and E-ELT, have motivated the development of a particle transport code with a focus on providing the necessary flexibility in planet specification (atmosphere and soil geometry and composition, tidal locking, oceans, clouds, etc.) for the modeling of radiation environment for exoplanets. Since there are no factors limiting the applicability of AtRIS to Mars and Venus, AtRIS’ unique flexibility opens possibilities for new studies. Following the successful validation against Earth measurements (Banjac et al. 2018. J Geophys Res Space Phys 123. https://doi.org/10.1029/2018JA026042), this work applies AtRIS with a specific implementation of the Martian atmospheric and regolith structure to model the radiation environment at Mars. We benchmark these first modeling results based on different GEANT4 physics lists with the energetic particle spectra recently measured by the Radiation Assessment Detector (RAD) on the surface of Mars. The good agreement between AtRIS and the actual measurement provides one of the first and sound validations of AtRIS and the preferred physics list which could be recommended for predicting the radiation field of other conceivable (exo)planets with an atmospheric environment similar to Mars.
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Li, Nan. "A Conceptual Framework for Site Design of Urban Design in China." Advanced Materials Research 878 (January 2014): 866–72. http://dx.doi.org/10.4028/www.scientific.net/amr.878.866.
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This paper indicates that there are no more sustainable concerns and instructions about urban design in current China relative planning Code when using the principles of eco-design principles as a lens to critical thinking about site choice, land use, transportation, road system, architecture massing, and spatial urban form. Furthermore, it is very hard for urban designer to design a sustainable project. This can be mitigated by taking mixed land use, TOD (Transit-Oriented Development), and 3D (Three Dimension) design methods. However, to design a sustainable site, to build a high performance building, other eco-design issues such as water saving, energy efficiency, air quality improvement, 3R materials use, eco-landscape etc. must be considered carefully in future design. Sustainable thinking should be the guideline through the whole urban design process.
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Deeg, Hans. "UTM, a universal simulator for lightcurves of transiting systems." Proceedings of the International Astronomical Union 4, S253 (May 2008): 388–91. http://dx.doi.org/10.1017/s1743921308026720.
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AbstractThe Universal Transit Modeller (UTM) is a light-curve simulator for all kinds of transiting or eclipsing configurations between arbitrary numbers of several types of objects, which may be stars, planets, planetary moons, and planetary rings. Applications of UTM to date have been mainly in the generation of light-curves for the testing of detection algorithms. For the preparation of such test for the Corot Mission, a special version has been used to generate multicolour light-curves in Corot's passbands. A separate fitting program, UFIT (Universal Fitter) is part of the UTM distribution and may be used to derive best fits to light-curves for any set of continuously variable parameters. UTM/UFIT is written in IDL code and its source is released in the public domain under the GNU General Public License.
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Rosich, A., E. Herrero, M. Mallonn, I. Ribas, J. C. Morales, M. Perger, G. Anglada-Escudé, and T. Granzer. "Correcting for chromatic stellar activity effects in transits with multiband photometric monitoring: application to WASP-52." Astronomy & Astrophysics 641 (September 2020): A82. http://dx.doi.org/10.1051/0004-6361/202037586.
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Context. The properties, distribution, and evolution of inhomogeneities on the surface of active stars, such as dark spots and bright faculae, significantly influence the determination of the parameters of an orbiting exoplanet. The chromatic effect they have on transmission spectroscopy, for example, could affect the analysis of data from future space missions such as James Webb Space Telescope and Ariel. Aims. To quantify and mitigate the effects of those surface phenomena, we developed a modelling approach to derive the surface distribution and properties of active regions by modelling simultaneous multi-wavelength time-series observables. Methods. We present an upgraded version of the StarSim code, now featuring the capability to solve the inverse problem and derive the properties of the stars and their active regions by modelling time-series data. As a test case, we analyse ~600 days of BV RI multiband photometry from the 0.8-m Joan Oró (TJO) and 1.2-m STELLA telescopes of the K2 V exoplanet host star WASP-52. From the results, we further simulated the chromatic contribution of surface phenomena on the observables of its transiting planet. Results. Using StarSim we are able to determine the relevant activity parameters of WASP-52 and reconstruct the time-evolving longitudinal map of active regions. The star shows a heterogeneous surface composed of dark spots with a mean temperature of 575 ± 150 K lower than the photospheric value, with filling factors ranging from 3 to 14%. We used the results to study the chromatic effects on the depths of exoplanet transits obtained at different epochs and corresponding to different stellar spot distributions. In the case of WASP-52, which has peak-to-peak photometric variations of ~7% in the visible, the residual effects of dark spots on the measured transit depth of its giant planet, after applying the calculated corrections, are about 10−4 at 550 nm and 3 × 10−5 at 6 μm. Conclusions. We demonstrate that by using contemporaneous ground-based multiband photometry of an active star, it is possible to reconstruct the parameters and distribution of active regions over time, thus making it feasible to quantify the chromatic effects on the planetary radii measured with transit spectroscopy and mitigate them by about an order of magnitude.
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Bolmont, E., B. O. Demory, S. Blanco-Cuaresma, E. Agol, S. L. Grimm, P. Auclair-Desrotour, F. Selsis, and A. Leleu. "Impact of tides on the transit-timing fits to the TRAPPIST-1 system." Astronomy & Astrophysics 635 (March 2020): A117. http://dx.doi.org/10.1051/0004-6361/202037546.
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Transit timing variations (TTVs) can be a very efficient way of constraining masses and eccentricities of multi-planet systems. Recent measurements of the TTVs of TRAPPIST-1 have led to an estimate of the masses of the planets, enabling an estimate of their densities and their water content. A recent TTV analysis using data obtained in the past two years yields a 34 and 13% increase in mass for TRAPPIST-1b and c, respectively. In most studies to date, a Newtonian N-body model is used to fit the masses of the planets, while sometimes general relativity is accounted for. Using the Posidonius N-body code, in this paper we show that in the case of the TRAPPIST-1 system, non-Newtonian effects might also be relevant to correctly model the dynamics of the system and the resulting TTVs. In particular, using standard values of the tidal Love number k2 (accounting for the tidal deformation) and the fluid Love number k2f (accounting for the rotational flattening) leads to differences in the TTVs of TRAPPIST-1b and c that are similar to the differences caused by general relativity. We also show that relaxing the values of tidal Love number k2 and the fluid Love number k2f can lead to TTVs which differ by as much as a few 10 s on a 3−4-yr timescale, which is a potentially observable level. The high values of the Love numbers needed to reach observable levels for the TTVs could be achieved for planets with a liquid ocean, which if detected might then be interpreted as a sign that TRAPPIST-1b and TRAPPIST-1c could have a liquid magma ocean. For TRAPPIST-1 and similar systems the models to fit the TTVs should potentially account for general relativity, for the tidal deformation of the planets, for the rotational deformation of the planets, and to a lesser extent for the rotational deformation of the star, which would add up to 7 × 2 + 1 = 15 additional free parameters in the case of TRAPPIST-1.