Showing papers on "Chorus published in 2019"

Origin of two-band chorus in the radiation belt of Earth

Abstract: Naturally occurring chorus emissions are a class of electromagnetic waves found in the space environments of the Earth and other magnetized planets. They play an essential role in accelerating high-energy electrons forming the hazardous radiation belt environment. Chorus typically occurs in two distinct frequency bands separated by a gap. The origin of this two-band structure remains a 50-year old question. Here we report, using NASA's Van Allen Probe measurements, that banded chorus waves are commonly accompanied by two separate anisotropic electron components. Using numerical simulations, we show that the initially excited single-band chorus waves alter the electron distribution immediately via Landau resonance, and suppress the electron anisotropy at medium energies. This naturally divides the electron anisotropy into a low and a high energy components which excite the upper-band and lower-band chorus waves, respectively. This mechanism may also apply to the generation of chorus waves in other magnetized planetary magnetospheres.

Statistical Results of the Power Gap Between Lower-Band and Upper-Band Chorus Waves

Abstract: The primary power gap of chorus waves is statistically investigated using 7‐year waveform data from THEMIS probes for the first time. Overall, ~2/3 of chorus events have a power gap between the lower and upper bands. Both the gap frequency and the frequency bandwidth of the gap have a broad distribution, which peaks at frequencies of ~0.49fce and ~0.07fce, respectively. The gap frequency tends to increase with increasing |MLAT| (magnetic latitude), while the frequency width gradually increases with L‐shell. In most of banded events, the peak frequency of upper band is roughly twice that of lower band. Two types of events are studied. For Type I events, one population is located around Pup/Plow = 10 , and the other is around Pup/Plow = 10 . However, Type II events are roughly concentrated around Pup/Plow = 10 . The gap frequency positively correlates with the frequency of upper band. Our study provides detailed observational constraints on potential mechanisms of the power gap formation.

Theatricalizing Protest: The chorus of the commons

Abstract: This essay considers five instances of costumed political protest between 2008--19, by way of the Red Rebel Brigade, the Guy Fawkes mask, the Handmaid’s Tale costume, the pussyhat and the yellow ja...

Excitation of extremely low‐frequency chorus emissions: The role of background plasma density

Abstract: Low-frequency chorus emissions have recently attracted much attention due to the suggestion that they may play important roles in the dynamics of the Van Allen Belts. However, the mechanism (s) generating these low-frequency chorus emissions have not been well understood. . In this letter, we report an interesting case in which background plasma density lowered the lower cutoff frequency of chorus emissions from above 0.1 fce (typical ordinary chorus) to 0.02 fce (extremely low-frequency chorus). Those extremely low-frequency chorus waves were observed in a rather dense plasma, where the number density Ne was found to be several times larger than has been associated with observations of ordinary chorus waves. For suprathermal electrons whose free energy is supplied by anisotropic temperatures, linear growth rates (calculated using in-situ plasma parameters measured by the Van Allen Probes) show that whistler mode instability can occur at frequencies below 0.1 fce when the background plasma density Ne increases. Especially when Ne reaches 90 cm–3 or more, the lowest unstable frequency can extend to 0.02 fce or even less, which is consistent with satellite observations. Therefore, our results demonstrate that a dense background plasma could play an essential role in the excitation of extremely low-frequency chorus waves by controlling the wave growth rates.

The Chorus of Drama in the Fourth Century BCE: Presence and Representation

Abstract: The Chorus of Drama in the Fourth Century BCE seeks to upend conventional thinking about the development of drama from the fifth to the fourth centuries. Set in the context of a theatre industry extending far beyond the confines of the City Dionysia and the city of Athens, the identity of choral performers and the significance of their contribution to the shape and meaning of drama in the later Classical period (c.400–323) as a whole is an intriguing and under-explored area of enquiry. Drawing together the fourth-century historical, material, dramatic, literary, and philosophical sources that attest to the activity and quality of dramatic choruses, the book provides a new way of talking and thinking about the choruses of drama after the deaths of Euripides and Sophocles. Having considered the positive evidence for dramatic choral activity, the book provides a radical rethinking of two oft-cited yet ill-understood phenomena that have traditionally supported the idea that the chorus of drama ‘declined’ in the fourth century: the inscription of χοροῦ μέλος‎ in papyri and manuscripts in place of fully written-out choral odes, and Aristotle’s invocation of embolima (Poetics 1456a25–32). The book goes on to explore how influential fourth-century authors such as Plato, Demosthenes, and Xenophon, as well as artistic representations of choruses on fourth-century monuments, have had an important role in shaping later scholars’ understanding of the dramatic chorus throughout the Classical period. The book’s conclusions, too, have implications for the broader story we wish to tell about Attic drama, and its most enigmatic and fundamental element, the chorus.

The Application of the Reference Book of Choral Pedagogy in the “Chorus Foundation” Course in a Non-state-owned Normal College in China

Abstract: There are a series of problems in contemporary normal school chorus courses in China, including the lack of national top-level guidance documents, insufficient professional teachers, insufficient class hours, and misalignment between design of teaching materials and reality. In response to the above problems, the author flexibly applies an English-written book Choral Pedagogy as a teaching aid in the “Chorus Foundation” course in a non-state-owned normal college in Shanghai to make up for the chorus teaching content of the existing textbooks. In the course, students have been shown choral pedagogy, scientific singing mechanism, and vocal health etc..

Wayward Lives, Beautiful Experiments: Intimate Histories of Social Upheaval, by Saidiya Hartman

Abstract: The title of the final chapter of Saidiya Hartman’s newest book declares “The chorus opens the way” (Wayward 345). The chorus is Hartman’s name for the collective voice of the black, female, queer ...

On Automating Conversations.

Abstract: From 2016 to 2018, we developed and deployed Chorus, a system that blends real-time human computation with artificial intelligence (AI) and has real-world, open conversations with users. We took a top-down approach that started with a working crowd-powered system, Chorus, and then created a framework, Evorus, that enables Chorus to automate itself over time. Over our two-year deployment, more than 420 users talked with Chorus, having over 2,200 conversation sessions. This line of work demonstrated how a crowd-powered conversational assistant can be automated over time, and more importantly, how such a system can be deployed to talk with real users to help them with their everyday tasks. This position paper discusses two sets of challenges that we explored during the development and deployment of Chorus and Evorus: the challenges that come from being an "agent" and those that arise from the subset of conversations that are more difficult to automate.

Song chorus method and device

Abstract: The invention relates to a song chorus method and device. The method comprises steps: a re-chorus request from a first terminal is acquired; according to the re-chorus request, the accompaniment partof a first chorus song under the re-chorus request by the first terminal and the singing part of a target chorus object in the first chorus song are acquired; the accompaniment part of the first chorus song and the singing part of the target chorus object in the first chorus song are sent to the first terminal; and a second chorus song is acquired, wherein the second chorus song is obtained by combining the accompaniment part, the singing part of the target chorus object and the singing part recorded by the first terminal. The technical scheme provided in the invention enables a user to selecta song which completes chorus already for chorus, and the song chorus flexibility is further improved.

Research on Vocal Chorus Experimental Course of Music Education in Normal Colleges from the Perspective of Music Creation

Abstract: Vocal music course is a compulsory course in music education specialty of normal university, and it is also the main course of music specialty of normal university. As far as the current vocal music teaching is concerned, the setting of vocal music teaching content is relatively single, and the training of practical performance ability is relatively weak. Therefore, the author analyzes the rigor of the vocal music course of music education in higher education and proposes solutions to make the vocal music course better in music teaching activities. Studies have shown that there are still many problems in the music education profession, which affects and restricts the development of the discipline of music education in higher education.

Asociacionismo coral en el Cádiz del S. XIX: El orfeón gaditano

Abstract: The documentation that has come up to us from Cadiz Chorus is very scarce. Nevertheless, it must have been a very popular society in the second half of 19th century. The musicological tradition reduces the incipient activity of the choral movement to the north of Spain. At present, it is necessary to claim the role of the periphery. The working grouping, the sense of nation, the musical pedagogy of base, are the elements that set in the choruses. Definitely, tradition has constructed different speeches on the Chorus on which it is worth to go in depth, refutate or put into context.

Multifunctional lecture platform for vocal music teaching and working method thereof

Abstract: The invention relates to the technical field of vocal music teaching, in particular to a multifunctional lecture platform for vocal music teaching. The multifunctional lecture platform comprises a mounting base; the mounting base is provided with a lecture platform shell, the lecture platform shell is internally provided with a lifting lecture table and a first chorus platform, the first chorus platform is internally provided with a second chorus platform, and the second chorus platform is internally provided with a third chorus platform; damping grooves are formed in the tops of the lecture platform shell, the first chorus platform, the second chorus platform and the third chorus platform respectively, each damping groove is internally provided with a damping device, and the tops of the damping devices are fixedly connected with a standing top plate. According to the multifunctional lecture platform, through the formation of the stepped multi-stage chorus platforms, a teacher can conveniently and directly carry out chorus practice teaching in a class during vocal music teaching.

Networked chorus method and computer readable storage medium

Abstract: The invention discloses a networked chorus method and a computer readable storage medium. The method comprises the steps that first on-demand equipment acquires and displays a user list and/or a chorus song list; the first on-demand device selects a user from the user list and establishes connection with a second on-demand device associated with the user, or selects a chorus song from the chorus song list and establishes connection with the second on-demand device associated with the chorus song; and the first video-on-demand equipment and the second video-on-demand equipment carry out chorus.The chorus object can be autonomously selected, and the chorus experience of the user is improved.