• Title/Summary/Keyword: Chorus

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Radiation belt electron losses induced by wave-particle interactions

  • Summers, Danny
    • Bulletin of the Korean Space Science Society
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    • 2009.10a
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    • pp.32.2-32.2
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    • 2009
  • We examine cyclotron resonant interactions of radiation belt electrons with VLF chorus, plasmaspheric ELF hiss and electromagnetic ion cyclotron (EMIC) waves. Bounce-averaged diffusion rates depend on wave mode, equatorial pitch-angle, electron energy and L-shell. As well, diffusion rates can be sensitive to the latitudinal distributions of particle density and wave power. For different configurations of the plasmasphere, we calculate electron precipitation loss timescales due to combined scattering by VLF chorus, ELF hiss and EMIC waves.

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Rule-Based Generation of Four-Part Chorus Applied With Chord Progression Learning Model (화성 진행 학습 모델을 적용한 규칙 기반의 4성부 합창 음악 생성)

  • Cho, Won Ik;Kim, Jeung Hun;Cheon, Sung Jun;Kim, Nam Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.11
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    • pp.1456-1462
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    • 2016
  • In this paper, we apply a chord progression learning model to a rule-based generation of a four-part chorus. The proposed system is given a 32-note melody line and completes the four-part chorus based on the rule of harmonics, predicting the chord progression with the CRBM model. The data for the training model was collected from various harmony textbooks, and chord progressions were extracted with key-independent features so as to utilize the given data effectively. It was shown that the output piece obtained with the proposed learning model had a more natural progression than the piece that used only the rule-based approach.

Effectiveness of Mating Call Playbacks in Anuran Call Monitoring: a Case Study of Three-striped Pond Frogs (Rana nigromaculata)

  • Sung, Ha-Cheol;Kim, Su-Kyung;Park, Shi-Ryong;Park, Dae-Sik
    • Animal cells and systems
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    • v.9 no.4
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    • pp.199-203
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    • 2005
  • We studied the effectiveness of mating call playbacks on call monitoring of three-striped pond frogs (Rana nigromaculata). Playback experiments were conducted between 2100 to 0030 at 15 sites located at Chungwon, Chungbuk, and Yeongi, Chungnam, in May 2005. We recorded call responses of 25 males to two different call playbacks, (i) single mating calls from a single male and (ii) chorus mating calls from five males, by randomly presenting the calls with a 15 min-gap between the two playbacks. We compared the number of response calls of the focal males for three min before, during, and after the playbacks. Five of 25 males were silent before stimulus presentation, but all the males emitted calls after the playbacks. The number of calls in response to single playback calls significantly differed among the three playback periods, where males gave more calls during the playback than before or after the playbacks. In addition, subject males presented significantly more calls to single call playbacks than to chorus call playbacks. The results of this study suggest that playback using repeated single mating calls is effective in call monitoring of R. nigromaculata males.

Automatic Music Summarization Method by using the Bit Error Rate of the Audio Fingerprint and a System thereof (오디오 핑거프린트의 비트에러율을 이용한 자동 음악 요약 기법 및 시스템)

  • Kim, Minseong;Park, Mansoo;Kim, Hoirin
    • Journal of Korea Multimedia Society
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    • v.16 no.4
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    • pp.453-463
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    • 2013
  • In this paper, we present an effective method and a system for the music summarization which automatically extract the chorus portion of a piece of music. A music summary technology is very useful for browsing a song or generating a sample music for an online music service. To develop the solution, conventional automatic music summarization methods use a 2-dimensional similarity matrix, statistical models, or clustering techniques. But our proposed method extracts the music summary by calculating BER(Bit Error Rate) between audio fingerprint blocks which are extracted from a song. But we could directly use an enormous audio fingerprint database which was already saved for a music retrieval solution. This shows the possibility of developing a various of new algorithms and solutions using the audio fingerprint database. In addition, experiments show that the proposed method captures the chorus of a song more effectively than a conventional method.

Environmental Factors Affecting the Start of the Dawn Chorus of Wild Birds and the Differences between Each Species (야생조류 새벽 지저귐 개시에 영향을 주는 환경요인과 종간 차이)

  • Ki, Kyong-Seok;Hong, Suk-Hwan;Gim, Ji-Youn
    • Korean Journal of Environment and Ecology
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    • v.29 no.3
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    • pp.344-352
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    • 2015
  • This study aims to identify the difference in the starting time of the dawn chorus of different species of birds and related environmental conditions. For this study, the bird songs were recorded every 2 hours a day starting from 2 hours before sunrise for a whole spring season (from April to June, 2014) in Korea. The recorded sounds were analyzed to find the starting time of each species' song by sonogram pattern using a sound analyzing program (Adobe Audition CC). To analyze the relationship between the environmental conditions and the time of the birdsong of each species, we collected the data of environmental conditions: daily precipitation, Julian date, time of sunrise and moonrise, temperature data and twilight time from the Korea Meteorological Office. As a result of this study, it was found that there are several statistical correlation between the starting time of the birdsong and environmental conditions (every environmental condition except daily precipitation and time of moonrise). Also, the difference of the starting time among each species were identified. The species were divided into 3 groups (early, mid and late) by their wake-up time. Ring-necked pheasant and yellow-throated bunting were categorized as 'Early' group and all woodpeckers were categorized as'Late' group. This study is significant as it first presented a classification of wild birds in Korea by the starting time of their dawn chorus. However, further studies are required to identify why each species to do their dawn singing at different times.

Short-duration Electron Precipitation Studied by Test Particle Simulation

  • Lee, Jaejin;Kim, Kyung-Chan;Lee, Jong-Gil
    • Journal of Astronomy and Space Sciences
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    • v.32 no.4
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    • pp.317-325
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    • 2015
  • Energy spectra of electron microbursts from 170 keV to 340 keV have been measured by the solid-state detectors aboard the low-altitude (680 km) polar-orbiting Korean STSAT-1 (Science and Technology SATellite). These measurements have revealed two important characteristics unique to the microbursts: (1) They are produced by a fast-loss cone-filling process in which the interaction time for pitch-angle scattering is less than 50 ms and (2) The e-folding energy of the perpendicular component is larger than that of the parallel component, and the loss cone is not completely filled by electrons. To understand how wave-particle interactions could generate microbursts, we performed a test particle simulation and investigated how the waves scattered electron pitch angles within the timescale required for microburst precipitation. The application of rising-frequency whistler-mode waves to electrons of different energies moving in a dipole magnetic field showed that chorus magnetic wave fields, rather than electric fields, were the main cause of microburst events, which implied that microbursts could be produced by a quasi-adiabatic process. In addition, the simulation results showed that high-energy electrons could resonate with chorus waves at high magnetic latitudes where the loss cone was larger, which might explain the decreased e-folding energy of precipitated microbursts compared to that of trapped electrons.