scholarly journals Ensemble Analysis of the Students Length of Study at University of Klabat Manado Indonesia

2021 ◽  
Vol 1811 (1) ◽  
pp. 012079
Author(s):  
Niel Ananto ◽  
Ani Budi Astuti ◽  
Achmad Efendi
2021 ◽  
Vol 149 ◽  
Author(s):  
Junwen Tao ◽  
Yue Ma ◽  
Xuefei Zhuang ◽  
Qiang Lv ◽  
Yaqiong Liu ◽  
...  

Abstract This study proposed a novel ensemble analysis strategy to improve hand, foot and mouth disease (HFMD) prediction by integrating environmental data. The approach began by establishing a vector autoregressive model (VAR). Then, a dynamic Bayesian networks (DBN) model was used for variable selection of environmental factors. Finally, a VAR model with constraints (CVAR) was established for predicting the incidence of HFMD in Chengdu city from 2011 to 2017. DBN showed that temperature was related to HFMD at lags 1 and 2. Humidity, wind speed, sunshine, PM10, SO2 and NO2 were related to HFMD at lag 2. Compared with the autoregressive integrated moving average model with external variables (ARIMAX), the CVAR model had a higher coefficient of determination (R2, average difference: + 2.11%; t = 6.2051, P = 0.0003 < 0.05), a lower root mean-squared error (−24.88%; t = −5.2898, P = 0.0007 < 0.05) and a lower mean absolute percentage error (−16.69%; t = −4.3647, P = 0.0024 < 0.05). The accuracy of predicting the time-series shape was 88.16% for the CVAR model and 86.41% for ARIMAX. The CVAR model performed better in terms of variable selection, model interpretation and prediction. Therefore, it could be used by health authorities to identify potential HFMD outbreaks and develop disease control measures.


2019 ◽  
Vol 16 (16) ◽  
pp. 126-142
Author(s):  
Lidiya Sokolova

Introduction. The article analyzes R. Schumann’s “Fantastic Pieces” op. 88 as a creative debut in the subsequent development of the piano trio genre. The “Fantastic Pieces” op. 88 are the first composer’s creative experience in combining such musical instruments. Theoretical Background. The analysis of musicological literature did not reveal any special research dedicated to this score, but only its references in E. Karelina’s (1996) thesis research and D. Zhitomirsky’s (1964) monograph. Thus, this article is the first special research of the compositional and ensemble analysis of R. Schumann’s “Fantastic Pieces”, op. 88. The objectives of the research: to analyze compositional-dramatic and ensemble features of R. Schumann’s “Fantastic Pieces”, op. 88, to identify their specific features. The object of the research: R. Schumann’s chamber-instrumental creative activity. The subject of the research: to identify the value of R. Schumann’s “Fantastic Pieces”, op. 88 in the further development of the piano trio genre. Methods: musical-theoretical, aimed at analyzing the musical text of the chosen work; genre-stylistic, allowing to identify the compositional-dramatic and ensemble features of R. Schumann’s “Fantastic Pieces”, op. 88. Research material: R. Schumann’s “Fantastic Pieces” op. 88 for piano, violin and cello. Results and Discussion. The first experience in mastering the piano trio genre of R. Schumann occurred in the “Fantastic Pieces” op. 88, composed in 1842. This was the first composer’s experience in combining such musical instruments. This work is a cycle of four pieces: “Romance”, “Humoresque”, “Duetto” and “Final”. It is noteworthy that R. Schumann used these names in other works. It is useful enough to recall his 3 piano romances op. 28, Humoresque op. 20a, 4 marches op. 76. Despite the four-part character of the work, this composition does not coincide with the sonata-symphonic structure, but is organized according to the suite principle. R. Schumann’s different vision of the trio-ensemble genre is represented by a clear differentiation of works with an individual composition. Therefore, the cycles op. 88 and op. 132 receive program names: “Fantastic Pieces” and “Fairytale Narratives”, respectively, and the trio with the classical (sonata) organization of the cycle acquire sequence numbers and are referred to as “piano trios”. The very names of the parts in the cycle reveal the opposition of two metaphoric spheres, characteristic of the romantic era: lyrical and genre-scherzo ones. The paired relationship of these metaphoric spheres stands out particularly. Such a metaphoric doubling gives the matching modes the rondality features within the whole cycle. This metaphoric paired relationship between the parts allows you to single out two macro parts in a cycle. The first macro part is represented by the lyric “Romance” and the scherzo “Humoresque”, the second one – by the tender song “Duetto” and the marching “Final”. At the same time, the macro parts demonstrate individual features of one or another semantic type. The metaphoric opposition of romantic pieces is also enhanced by tempo and ear-catching contrast. Such an alternation of various metaphoric types gives the entire cycle the features of a kaleidoscopic suite. The proportion of genre parts stands out particularly, which is manifested in both their scale and complexity of the compositional organization. Thus, the lyrical parts are represented by tripartite forms. Quick genre pieces are composed in various forms (“Humoresque” is created in a complex tripartite form with a developed polythematic middle part, and the “Final” is in a rondo form, with the links acting as refrains). Despite the romantic nature of the cycle organization, the “Fantastic Pieces” tone plan is a classical one: a-moll –F-dur– d-moll – a-moll (A-dur). Conclusions. It was revealed that the suite-based principle of composition organization and genre-stylistic features of the cycle (opposition of lyrical and genre-scherzo metaphoric spheres) connect the romantic “Fantastic Pieces” op. 88 with its piano miniatures of the 1830s. Ensemble analysis of R. Schumann “Fantastic Pieces”, op. 88 showed that in his first work for the piano trio, the composer “transplanted” solo piano works into a poly-timbre ensemble, taking it in the context of piano music. At the same time, the composer did not reduce the role of strings to the “service” function, but actively used all their melodic and proper ensemble possibilities in the chosen trio. For example, if “Romance” ensemble demonstrated the piano domination, “Humoresque” – the parity of the instruments, then in “Duetto” primacy was given to stringed instruments. In “Final”, each section of the musical form is highlighted by an appeal to one of the main ensemble techniques. A series of altering various semantic spheres, defining the suite properties of the “Fantastic Pieces”, subordinates the ensemble properties used by the composer. For each number and even its individual sections, their special complex was chosen, which in different semantic contexts had a metaphoric-semantic meaning. It was revealed that the organizing means of creating the ensemble in the R. Schumann’s trio was the polyphonic technique presented in his work in a wide variety, which would later be widely developed in his piano trios.


2019 ◽  
Vol 147 (12) ◽  
pp. 4389-4409 ◽  
Author(s):  
Yunji Zhang ◽  
David J. Stensrud ◽  
Fuqing Zhang

Abstract This study explores the benefits of assimilating infrared (IR) brightness temperature (BT) observations from geostationary satellites jointly with radial velocity (Vr) and reflectivity (Z) observations from Doppler weather radars within an ensemble Kalman filter (EnKF) data assimilation system to the convection-allowing ensemble analysis and prediction of a tornadic supercell thunderstorm event on 12 June 2017 across Wyoming and Nebraska. While radar observations sample the three-dimensional storm structures with high fidelity, BT observations provide information about clouds prior to the formation of precipitation particles when in-storm radar observations are not yet available and also provide information on the environment outside the thunderstorms. To better understand the strengths and limitations of each observation type, the satellite and Doppler radar observations are assimilated separately and jointly, and the ensemble analyses and forecasts are compared with available observations. Results show that assimilating BT observations has the potential to increase the forecast and warning lead times of severe weather events compared with radar observations and may also potentially complement the sparse surface observations in some regions as revealed by the probabilistic prediction of mesocyclone tracks initialized from EnKF analyses as various times. Additionally, the assimilation of both BT and Vr observations yields the best ensemble forecasts, providing higher confidence, improved accuracy, and longer lead times on the probabilistic prediction of midlevel mesocyclones.


2019 ◽  
Vol 25 (64) ◽  
pp. 14572-14582 ◽  
Author(s):  
Rachael Dickman ◽  
Emma Danelius ◽  
Serena A. Mitchell ◽  
D. Flemming Hansen ◽  
Máté Erdélyi ◽  
...  

2020 ◽  
Vol 33 (11) ◽  
pp. 4853-4869 ◽  
Author(s):  
Boyin Huang ◽  
Michelle L’Heureux ◽  
Zeng-Zhen Hu ◽  
Xungang Yin ◽  
Huai-Min Zhang

AbstractPrevious research has shown that the 1877/78 El Niño resulted in great famine events around the world. However, the strength and statistical significance of this El Niño event have not been fully addressed, largely due to the lack of data. We take a closer look at the data using an ensemble analysis of the Extended Reconstructed Sea Surface Temperature version 5 (ERSSTv5). The ERSSTv5 standard run indicates a strong El Niño event with a peak monthly value of the Niño-3 index of 3.5°C during 1877/78, stronger than those during 1982/83, 1997/98, and 2015/16. However, an analysis of the ERSSTv5 ensemble runs indicates that the strength and significance (uncertainty estimates) depend on the construction of the ensembles. A 1000-member ensemble analysis shows that the ensemble mean Niño-3 index has a much weaker peak of 1.8°C, and its uncertainty is much larger during 1877/78 (2.8°C) than during 1982/83 (0.3°C), 1997/98 (0.2°C), and 2015/16 (0.1°C). Further, the large uncertainty during 1877/78 is associated with selections of a short (1 month) period of raw-data filter and a large (20%) acceptance criterion of empirical orthogonal teleconnection modes in the ERSSTv5 reconstruction. By adjusting these two parameters, the uncertainty during 1877/78 decreases to 0.5°C, while the peak monthly value of the Niño-3 index in the ensemble mean increases to 2.8°C, suggesting a strong and statistically significant 1877/78 El Niño event. The adjustment of those two parameters is validated by masking the modern observations of 1981–2017 to 1861–97. Based on the estimated uncertainties, the differences among the strength of these four major El Niño events are not statistically significant.


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