scholarly journals Minimal Data Fidelity for Stellar Feature and Companion Detection

2021 ◽  
Vol 163 (1) ◽  
pp. 6
Author(s):  
Sahil Agarwal ◽  
J. S. Wettlaufer

Abstract Technological advances in instrumentation have led to an exponential increase in exoplanet detection and scrutiny of stellar features such as spots and faculae. While the spots and faculae enable us to understand the stellar dynamics, exoplanets provide us with a glimpse into stellar evolution. While the ubiquity of noise (e.g., telluric, instrumental, or photonic) is unavoidable, combining this with increased spectrographic resolution compounds technological challenges. To account for these noise sources and resolution issues, we use a temporal multifractal framework to study data from the Spot Oscillation And Planet 2.0 tool, which simulates a stellar spectrum in the presence of a spot, a facula or a planet. Given these controlled simulations, we vary the resolution as well as the signal-to-noise ratio (S/N) to obtain a lower limit on the resolution and S/N required to robustly detect features. We show that a spot and a facula with a 1% coverage of the stellar disk can be robustly detected for a S/N (per pixel) of 35 and 60, respectively, for any spectral resolution above 20,000, while a planet with a radial velocity of 10 m s−1 can be detected for a S/N (per pixel) of 600. Rather than viewing noise as an impediment, our approach uses noise as a source of information.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sara Sá ◽  
Laura Hendriks ◽  
Isabel Pombo Cardoso ◽  
Irka Hajdas

AbstractRecently, radiocarbon dating underwent considerable technological advances allowing unprecedented sample size downscaling. These achievements introduced novel opportunities in dating cultural heritage objects. Within this pioneering research, the possibility of a direct 14C dating of lead white pigment and organic binder in paint samples was investigated on polychrome sculptures, a foremost artistic expression in human history. The polychromy, an indivisible part of polychrome sculpture, holds a key role in the interpretation and understanding of these artworks. Unlike in other painted artworks, the study of polychromies is repeatedly hampered by repaints and degradation. The omnipresence of lead white within the original polychromy was thus pursued as dating proxy. Thermal decomposition allowed bypassing geologic carbonate interferences caused by the object's support material, while an added solvent extraction successfully removed conservation products. This radiocarbon dating survey of the polychromy from 16 Portuguese medieval limestone sculptures confirmed that some were produced within the proposed chronologies while others were revised. Within this multidisciplinary study, the potential of radiocarbon dating as a complementary source of information about these complex paint systems guiding their interpretation is demonstrated. The challenges of this innovative approach are highlighted and improvements on sampling and sample preparation are discussed.


Galaxies ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 14
Author(s):  
Tomohiro Ishikawa ◽  
Shoki Iwaguchi ◽  
Yuta Michimura ◽  
Masaki Ando ◽  
Rika Yamada ◽  
...  

The DECi-hertz Interferometer Gravitational-wave Observatory (DECIGO) is the future Japanese, outer space gravitational wave detector. We previously set the default design parameters to provide a good target sensitivity to detect the primordial gravitational waves (GWs). However, the updated upper limit of the primordial GWs by the Planck observations motivated us toward further optimization of the target sensitivity. Previously, we had not considered optical diffraction loss due to the very long cavity length. In this paper, we optimize various DECIGO parameters by maximizing the signal-to-noise ratio (SNR) of the primordial GWs to quantum noise, including the effects of diffraction loss. We evaluated the power spectrum density for one cluster in DECIGO utilizing the quantum noise of one differential Fabry–Perot interferometer. Then we calculated the SNR by correlating two clusters in the same position. We performed the optimization for two cases: the constant mirror-thickness case and the constant mirror-mass case. As a result, we obtained the SNR dependence on the mirror radius, which also determines various DECIGO parameters. This result is the first step toward optimizing the DECIGO design by considering the practical constraints on the mirror dimensions and implementing other noise sources.


2012 ◽  
Vol 241-244 ◽  
pp. 2491-2495 ◽  
Author(s):  
Antonio Boscolo ◽  
Francesca Vatta ◽  
Francesco Armani ◽  
Emanuele Viviani ◽  
Daniele Salvalaggio

This paper presents a physical channel emulator solution for applications such as Bit Error Rate Testing of Error Correcting Codes. The solution relies on an analog White Gaussian Noise Generator coupled additively with an analog data signal to emulate the communication channel. This is interfaced to a computer through a USB connection, allowing the use of programs in different environments, such as Matlab and Labview. This solution can allow different types of channels to be emulated and with different noise sources. A software-based method to measure Signal to Noise Ratio and to characterize the channel is also presented. The system has been validated using a Matlab interface implementing multiple error correcting codes and showed good agreement with the theoretical model.


Yuridika ◽  
2019 ◽  
Vol 34 (2) ◽  
pp. 194
Author(s):  
Abdul Atsar

Law is very influenced on the development of Technology. The current legal tool has no readiness so that it can not keep up with the rapid technological advances. The purpose of this study is to analyze the application of regulation on protection system and law enforcement of ICT design based on creative economy to improve people's competitiveness. Research is a normative juridical study. The approach of this research is the approach of legislation, concepts and cases. This research is analytical descriptive. This study, using secondary data sources. Technique of collecting data with literature study. Data analysis technique by qualitative normative descriptive method.The regulation of the legal protection system of industrial design of ICT, in Law no. 31 Year 2000, has not been regulated explicitly about the element of novelty, the application of constitutive stelsel cause obstacles. The law enforcement of ICT design is not yet effective, because of three aspects: 1) The legal substance aspect is not yet explicitly regulated about the novelty element in Industrial Design terms and the qualification and classification of the object of Right, the substantive requirement of Right of Industrial Design, the provisions of sanctions that distinguish between rights violations caused by the substance of the "same" and "similar" Industrial Design Designs registered for commercial purposes; 2) the aspect of its law enforcers, there is no appeal commission of industrial design, law enforcers have not understood the substance of the provisions of industrial design law; 2) Legal culture aspect. Indonesian society is still communal.


2020 ◽  
pp. 51-60
Author(s):  
Muhammad Rahmatullah ◽  
Agung Pramudya

With the large availability of bamboo in Indonesia which has several advantages in terms of material characteristics in its application to products, this research activity aims to explore the potential of bamboo with lamination techniques, so as to find the potential of laminated bamboo which is suitable for application to traveling bag products. will be appointed as a concept in the product of the means of carrying that will be designed. The purpose of this study is to present a novel design on a travel bag by combining natural and artificial materials by analyzing concrete data regarding the characteristics and techniques of processing bamboo materials that are suitable for the design of a travel bag. The study was conducted as a reference / source of information / theoretical study / data analysis in working on project design 5 and Professional Work. In this study, the method used is qualitative and quantitative methods by conducting observations, surveys and research on traveling activities and research carried out related to activities, characteristics, and means of carrying used when traveling. If the application and processing techniques of bamboo material are used in the right type of travel bag, there will be a novelty in the design of the travel bag


2018 ◽  
Vol 5 (1) ◽  
pp. 19
Author(s):  
Krisna Sujaya

Tradisi angklung badud merupakan salah satu bentuk kesenian berjenis angklung buhun yang berasal dari Dusun Margajaya Kecamatan Cijulang Kabupaten Pangandaran. Tradisi angklung badud tumbuh dan berkembang dalam masyarakat Dusun Margajaya, Kecamatan Cijulang. Hal ini diindikasikan dari penggunaan tradisi angklung badud sebagai media dalam ritual pertanian padi, yang merupakan mayoritas profesi masyarakat Dusun Margajaya, Kecamatan Cijulang. Penelitian ini termasuk dalam penelitian deskriptif kualitatif, yaitu penelitian yang memberikan gambaran mengenai keadaan atau gejala yang terjadi tanpa melepaskan objek yang diteliti. Teknik pengumpulan data dalam penelitian ini menggunakan teknik observasi, wawancara dan dokumentasi. Hasil penelitian ini bahwa seiring dengan berkembangnya zaman dan kemajuan teknologi yang semakin maju, perkembangan dan pelestarian tradisi angklung badud semakin memprihatinkan. Banyak faktor yang yang menjadikan eksistensi tradisi angklung badud berada di posisi yang mengkhawatirkan. Beberapa faktor yang mempengaruhi terhambatnya perkembangan angklung badud diantaranya: 1). Perubahan sistem pertanian masyarakat sebagai akar tradisi angklung badud, 2). Sistem pewarisan yang kurang optimal, 3). Akulturasi budaya yang menggerus pelestarian angklung badud. 4). Mind set masyarakat yang lebih menyukai hal-hal yang bersifat modern, 5). Kurangnya kesadaran masyarakat dalam melestarikan tradisi lokal, 6). Kepedulian pemerintah daerah yang kurang optimal terhadap pelestarian angklung badud.AbstractThe tradition of Badud angklung is one of the art forms of angklung buhun originating from Margajaya Hamlet, Cijulang District, Pangandaran Regency. The Badud angklung tradition grows and develops in the people of Margajaya Hamlet, Cijulang District. This is indicated by the use of the angklung badud tradition as a medium in rice farming rituals, which constitutes the majority of the profession of the people of the Margajaya Hamlet, Cijulang District. This research is included in descriptive qualitative research, namely research that provides an overview of the situation or symptoms that occur without releasing the object under study. Data collection techniques in this study used observation, interview and documentation techniques. The results of this study that along with the development of the times and increasingly advanced technological advances, the development and preservation of the Badud angklung tradition is increasingly alarming. Many factors that make the existence of the Angud Angklung tradition in a worrying position. Several factors that influence the development of badud angklung include: 1). Changes in the community farming system as the root of the Badud angklung tradition, 2). Less optimal inheritance system, 3). Cultural acculturation which undermines the preservation of badud angklung. 4). The mind set of people who prefer things that are modern, 5). Lack of public awareness in preserving local traditions, 6). The sub-optimal government's concern for the preservation of badud angklung.


2017 ◽  
Vol 2 (4) ◽  
pp. 15
Author(s):  
Mamun Ahmed ◽  
Nasimul Hyder Maruf Bhuyan

In this paper, we have presented the design, implementation and comparison result of Least Mean Square (LMS) algorithm and Normalized LMS (NLMS) algorithm using a 4 channel microphone array for noise reduction as well as speech enhancement. Adaptive sub band Generalized Side lobe Canceller (GSC) beam former has been used for experiment and analysis. Tested results were done by using one speech signal and a small number of noise sources. The side lobe canceller was evaluated with the adaptation of LMS and NLMS. The overall development of Signal to Noise Ratio (SNR) has been determined from the input and output powers of signal and noise, with signal only as input and noise, as input to the GSC. The NLMS algorithm considerably improves speech quality with noise suppression levels of up to 13 dB, while the LMS algorithm is giving up to 10 dB. In different ways of SNR measure was under various types of blocking matrix, step sizes and various noise locations. The whole process will be used for hands-free telephony, video conferencing etc. in a noisy environment.


Vidya Karya ◽  
2021 ◽  
Vol 35 (2) ◽  
pp. 78
Author(s):  
Muhdi Harto ◽  
Misbah Misbah

The world of education is again disturbed by the massive spread of the COVID-19 virus or coronavirus disease. The use of technology is considered to facilitate and be a solution and innovation in the learning process that can be a way out so that the teaching and learning process during the COVID-19 period becomes more effective. One of the innovations that teachers can do as educators in delivering learning materials is using models in collaboration with technological advances in the learning process, especially in science learning. This research is descriptive in the form of a literature study. Data sources come from 15 scientific articles from national journals and accredited national journals. Based on the literature review that has been carried out, it can be concluded that the use of online learning models in collaboration with technology such as the Zoom platform, google classroom, WhatsApp, and others can be used in the science learning process at all levels of education during the COVID-19 pandemic. This is because this learning model is centred on students so that they are not dependent on the teacher, which is in line with the basis of online learning, which requires students to think critically, be active in exploring or understanding the subject matter presented. Students are required to establish communication between fellow students and the teacher who acts as a moderator.Keywords: Covid-19; Inovations; Online Learning; Science Dunia pendidikan kembali terusik dengan adanya penyebaran virus COVID-19 atau coronavirus disease secara masif. Penggunaan teknologi dianggap bisa mempermudah dan menjadi solusi serta inovasi dalam proses pembelajaran yang bisa menjadi jalan keluar sehingga proses belajar mengajar di masa COVID-19 menjadi lebih efektif. Salah satu inovasi yang bisa dilakukan guru sebagai tenaga pendidik dalam menyampaikan materi pembelajaran yaitu penggunaan model yang dikolaborasikan dengan kemajuan teknologi dalam proses pembelajaran khususnya pada pembelajaran sains. Penelitian ini merupakan penelitian deskriptif berupa studi kepustakaan. Sumber data berasal dari 15 artikel ilmiah dari jurnal nasional maupun jurnal nasional terakreditasi. Berdasarkan kajian literatur yang telah dilakukan, dapat disimpulkan bahwa penggunaan model pembelajaran online leaning yang dikolaborasikan dengan teknologi seperti platform Zoom, google classroom, whatsapp, dan lainnya dapat digunakan dalam proses pembelajaran sains pada semua jenjang pendidikan di masa pandemi COVID-19. Hal ini karena model pembelajaran ini berpusat kepada peserta didik sehingga mereka tidak ketergatungan kepada guru, yang sejalan dengan dasar dari pembelajaran secara daring yaitu menuntut peserta didik untuk berpikir kritis, aktif dalam menjelajahi atau memahami materi pelajaran yang disampaikan serta peserta didik dituntut agar dapat menjalin komunikasi yang baik antara sesama peserta didik dan juga guru yang berperan sebagai moderator.Kata kunci: Covid-19; Inovasi; Online Learning; Sains


1985 ◽  
Vol 107 ◽  
pp. 245-262
Author(s):  
D. J. Mullan

Flare stars derive their name from intermittent increases in luminosity which have certain characteristics reminiscent of solar flares (e.g. enhanced strengths of emission lines in the stellar spectrum during the outbursts). When a flare star is observed in a filter which transmits, say, the violet part of the visible spectrum, the increase in luminosity during a flare may range from noise level up to perhaps 100 times the quiescent brightness. During a flare, certain spectral features of the quiescent star (e.g. molecular bands) remain visible, indicating that the flare occupies only a fraction of the visible disk. Thus, analagous to a solar flare, a stellar flare is confined to a single active region. However the total power is large enough to affect the integrated light from the stellar disk. In contrast, the largest solar flare (Etot ≈ 1032 ergs) has a rate of energy release (L ≈ 1029 erg/sec) which is so small that a distant observer would record such a flare as a luminosity increase of less than 10−4Lsun. However, even apart from the flares themselves, it has become apparent in recent years that flare stars in their “quiescent state” provide some extreme contrasts with the sun.


1984 ◽  
Vol 108 ◽  
pp. 407-408
Author(s):  
Edward L. Fitzpatrick

Multiple high-dispersion IUE spectra of SK159 in the Small Magellanic Cloud (SMC) have been obtained and averaged in order to study interstellar gas associated with the SMC and, in particular, to search for evidence of SMC halo gas. A single high-dispersion IUE spectrum of SK159 was analyzed by Prévot et al. (1980). They reported the absence of C IV and only the marginal detection of Si IV at SMC velocities. The higher signal-to-noise ratio in our data allow a more definitive investigation of the absorption characteristics of these ions. SK159 is relatively cool, spectral type BO.5 Iaw (Walborn 1983) and is located in a region free of strong nebulosity. Thus the interstellar line spectrum will be less contaminated by H II region absorption than in previous studies of SMC stars. This favorable circumstance is somewhat offset by the great complexity of the underlying stellar spectrum and the resultant blending of stellar and interstellar lines.


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