208,237 research outputs found
A machine learning practice of predicting CO2 levels with the measurement data from university departmental offices
No full textIntroduction: In office spaces, users spend around 1/3 of their daily time, thus maintaining good air quality is an important aspect of keeping a healthy and efficient working environment. As office occupants usually have a regular daily and weekly schedule, machine learning can be a useful method to find the air quality pattern. Its result can benefit the indoor activities to improve the indoor activities and even further development on the smart buildings when the building infrastructure is ready.
In a department area of Politecnico di Milano, multiple low-cost air quality sensors have been installed since September 2023 which measure parameters mainly including temperature, humidity, radon, CO2, VOCs, air pressure and light. In this research, the CO2 data measured in the selected offices are used in this analysis practice.
This research aims to explore how machine learning can benefit long-term monitoring in improving air quality in the offices, taking CO2 as a practice, and how the existing monitoring system in the building can be improved to response to the changing indoor air quality (IAQ) level according to the model training process and the prediction performance.
Methodology: This research tried to apply the regression learner from MATLAB to train the models based on the data collected from the selected offices respectively in the past 1 year (from 2023 Sep 05 to 2024 Sep 05). The training used the basic information as a predictor including the date of the year, time of day, room code, and day of week. Meanwhile, the level of CO2 is selected as the response in training. After the comparison of the results in RMSE (Root-mean-square Error) with different models, the training eventually selected the bagged tree model in terms of its performance and the total training time.
The trained model then was optimized by the Experiment Manager tools from MATLAB with 50 trials by tuning the 4 hyperparameters of the bagged tree model, including method, number of learning cycles, learn rate and min leaf size. The one with the best performance in RMSE was selected in the validation session.
The validation was the comparison between the measured data from Sep 06 to Oct 30 2024 and the prediction from the trained and optimized model. The performance of validation and the model were interpreted in terms of its RMSE, residuals and Coefficient of determination (R2).
Result: The model of rooms has RMSE results between 14.95 to 16.09 after the training and optimization varying from different rooms. Then, in comparisons between the original and model predicted CO2 values, the predicted CO2 levels basically follow the schedule of the rooms, with similar variation rates at the beginning and end of the working hours. This means that the model is able to catch the features of CO2 level variations in the selected offices based on the historical data.
However, the predictions show differences from the measurements with the dates as predictors in 2024, with RMSE from 100.52 to 107.74. These differences lay in the daily variations, especially the peaks of several days are much higher than the prediction results. These are due to several realistic reasons such as the number of occupants in 2024 being more than in 2023 and the schedule of occupants changing each week, etc. which are not included in monitoring and training.
Conclusion: In general, the performance of this model currently is limited by the predictor parameters from the historical data monitored in the past 1 year, but it can already be useful in reflecting the CO2 variations in these offices. The training process also shows the 3 types of information that could be added to the monitoring system to help benefit and respond to the IAQ level changes more smoothly and accurately, including the daily number of people, the occupancy schedule, and the ventilations by window operations.
During this training, it can be found that, in the model training for CO2 level in these offices, the number of occupants and their ventilation behaviours are the 2 influential factors that are important but not measured in the existing monitoring system, especially the number of occupants which dynamic during the year and highly related to the CO2 increasing rate and the peak level. The number of occupants and the schedule can be added as one monitoring parameter in the future to make the prediction more accurate.
On the other hand, other factors such as the dimensions of the room are less influential and can be simulated based on the calculation with the CO2 historical records and the number of occupants.
In addition, this method can be used in spaces with more occupants, such as classrooms, open offices or shopping centres with large numbers of occupants by minimizing the influence of the changes on the average number of occupants on the CO2 prediction
Yu. N. Chumakov: Memories of Meeting Yu. M. Lotman
No full textThe article features an excerpt from Chumakov’s memoirs, describing how, in the late 1960s, he got acquainted with Lotman’s book Lectures on Structural Poetics and then met the author of the lectures at the Pushkin Conference in Pskov. According to the memoirist, Lotman’s Lectures on Structural Poetics gave literary studies in the 1970s a new language, which may then have been modified within some other schools of literary studies, but it laid the foundation for the scientific description of the fiction text. Investigation of the fiction text has been characterized since the late 1960s by the structuralist approach. The memoirs also mention Chumakov’s defending his candidate dissertation, in which Lotman acted as an opponent (the dissertation was entitled “Problems of Pushkin’s Poetics: (Lyrics, The Stone Guest, Eugene Onegin)” and was defended in Saratov, in 1970.
One part of Chumakov’s candidate dissertation, as well as his report at the Pushkin conference in Pskov, was devoted to the role of the notes and “Passages from Onegin’s Journey” in Pushkin’s novel “Eugene Onegin”. Independently of each other, Chumakov and Lotman came to the conclusion that the notes are not a supplement, but real independent parts within the novel in verse, along with its eight chapters
Mesozoic to Cenozoic intracontinental deformation and dynamics of the North China Craton
No full textAbstract not availableS.Z. Li, Y.H. Suo, M. Santosh, L.M. Dai, X. Liu, S. Yu, S.J. Zhao and C. Ji
Yu. M. Smirnov's General Equivariant Shape Theory
Get PDFA general equivariant shape theory for arbitrary -spaces in the case of a
compact group is constructed by using the method of pseudometrics suggested
by Yu. M. Smirnov as early as in 1985 at the fifth Tiraspol symposium on
general topology and its applications.Comment: 6 page
p-adic logarithmic forms and a problem of Erdo{double acute}s
No full textFor any m∈ℤ let P(m) denote the greatest prime divisor of m with the convention that P(m)=1 when m∈{1,0,-1}. By the problem of Erdo{double acute}s in the title of the present paper we mean the general version of his problem, that is, his conjecture from 1965 that (Formula Presented) (see Erdo{double acute}s [10]) and its far-reaching generalization to Lucas and Lehmer numbers. In the present paper the author delivers three refinements upon Yu [40] required by C. L. Stewart for solving completely the problem of Erdo{double acute}s (see Stewart [25]). The author gives also some remarks on the solution of this problem, aiming to be more streamlined with respect to the p-adic theory of logarithmic forms.</p
M. Yu. Lermontov’s Wills: on the Writer's Artistic Evolution
No full textСтатья поступила в редакцию 14.09.2014 г.Рассматриваются стихотворения М. Ю. Лермонтова «Дереву», «Завещание» («Есть место: близ тропы глухой...»), «Завещание» («Наедине с тобою, брат…»), а также заметка «Мое завещание», имеющие отношение к жанровой традиции завещания. Устанавливается воздействие на Лермонтова народнопоэтической традиции «отдавания наказов» (ямщицкие и солдатские песни), что позволяет углубить представление об особенностях фольклоризма поэта и направлении его творческой эволюции.The author studies M. Yu. Lermontov’s poems To a Tree, The Testament (There is a place), The Testament (Brother, I'd like to be alone with you) along with his My Will that are all rooted in the genre of the will. The article studies the influence folk poetic tradition of giving orders (coachmen’s and soldiers’ songs) had on Lermontov which allows the author to acquire a deeper understanding of the peculiarities of the poet’s folklore background and the directions of his artistic evolution
Lepidozonates adusta Yu & Wang 2021, comb. nov.
No full textLepidozonates adusta (Park, 2000) comb. nov. (Figs 1, 5, 7, 8, 12) Philharmonia adusta Park, 2000: 242. TL: China (Taiwan, Pingtung). TD: MGCL. Lepidozonates viciniolus Park, 2013: 223, syn. nov. TL: China (Taiwan, Taichung). TD: MGCL. Material examined. CHINA, Zhejiang: 4♂ 3♀, Jiufu Village, Mt. Longtang, 520 m, 28–30.VIII.2014, leg. AH Yin, QY Wang & SR Li, slide Nos. YS20081 ♂, YS20192 ♀; Hainan: 3♂ 3♀, Tianchi, Jianfengling, 787 m, 15, 17.VII. 2015, leg. QY Wang, SR Li & MT Chen, slide Nos. YS20191 ♀, YS20196 ♂; 10♂ 2♀, Tianchi, Jianfengling, 787 m, 5–8.III.2016, leg. QY Wang, SR Li & SN Zhao, slide Nos. YS 20095♂, YS20195♂; 1♂ 1♀, Mt. Wuzhi, 733 m, 21.XII.2017, leg. MJ Qi & S Yu; 1♂, Mingfenggu, Jianfengling, 965 m, 13.I.2018, leg. MJ Qi & S Yu. Adult (Figs 1, 5). Wingspan 13.5–18.5 mm. Diagnosis. This species can be distinguished from its congeners in the male genitalia by the sub-triangular juxta with neither posterior lobes nor a flap, the aedeagus with two needle-like cornuti (Fig. 8), in the female genitalia by the weakly sclerotized antrum longer than wide, and the ductus bursae shorter than the corpus bursae (Fig. 12). Distribution. China (Hainan, Taiwan, Zhejiang). Remarks. Lepidozonates viciniolus is synonymized with Philharmonia adusta Park, 2000. Lepidozonates viciniolus is identical to P. adusta in appearance, venation, as well as in the male and female genitalia, and closely distributed geographically. The presence of the plumose scales on the pleural membrane are not mentioned in the original description, but other characters are well in consistent with those of P. adusta.Published as part of Yu, Shuai & Wang, Shuxia, 2021, Genus Lepidozonates Park (Lepidoptera, Lecithoceridae) from China, with description of a new species, pp. 591-597 in Zootaxa 4903 (4) on pages 592-593, DOI: 10.11646/zootaxa.4903.4.7, http://zenodo.org/record/443149
“He Was the Only Professor for Us...”: Yu. M. Lotman – Teacher and Scholar
No full textThe article presents an interview of I. Z. Belobrovtseva, characterizing the personality of Yu. M. Lotman as well as the significance of his works for structural semiotics in literary criticism of the 20th century. Irina Zakharovna Belobrovtseva is an Estonian specialist in literary studies, Doctor of Philology, Professor of Russian Literature at the Institute for the Humanities of Tallinn University, Laureate of the Estonian State Prize in Science. Her research interests are Russian literature and culture of the 20th – 21st centuries, Estonian literature and culture, Russian literature of Estonia. She is author of the following books: “Over the Blank Page Alone and with Hope: Articles on Contemporary Estonian Literature” (1987), “Reading Poetry Together: A Guide for Teachers” (1994), “Mikhail Bulgakov’s Novel “Master and Margarita”: Constructive Principles of Text Organization” (1997), “Mikhail Bulgakov’s Novel “The Master and Margarita”. Commentary.” (co-authored with S. Kulyus, 2004, 2006, 2007), “The Image of a "Small Enemy": the Baltic States and Poland in the Mirror of Soviet Caricature (1918–1940)” (co-authored with D. Vseviov, A. Danilevsky, 2014), “Leonid Zurov. In the Shadow of Bunin” (2020) and others
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
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