1,721,790 research outputs found
Soft measurement method for f-CaO content of cement clinker
No full text本发明涉及水泥生产技术领域，尤其是涉及一种水泥熟料f-CaO含量软测量方法。本发明包括：选取生料的三率值、生料细度、煤粉热值、煤粉灰分、生料加料量、分解炉出口温度、窑电流和篦冷机的一篦床压力为辅助变量；对采集到的辅助变量的数据集合进行离群值去除、滤波和标准化，形成输入数据集合；对所述输入数据集合进行分类，对每个类分别建立部分最小二乘子模型和权重模型，再将每个子模型的输出进行加权平均得到最终的软测量结果；软测量模型校正：采用长期校正的方式对软测量模型进行校正。本发明能够测量出难以在线检测而又十分重要的熟料f-CaO含量，使水泥熟料烧成过程先进控制的实施成为可能
Simulated Experiment Study of Factors Influencing the Hydration Activity of f-CaO in Basic Oxygen Furnace Slag
Get PDFThe compositions and formation process of f-CaO in BOF slag were revealed and simulated to understand its expansion rules and why its hydration activity is low. BSE showed the compositions of f-CaO, which included calcium iron phase and calcium iron manganese phase, were diverse. The hydration activity sequence was Ca2Fe2O5 and Ca3Fe1.5Mn1.5O8 in tricomponent f-CaO < CaO in tricomponent f-CaO < monocomponent f-CaO; only Ca2Fe2O5 and Ca3Fe1.5Mn1.5O8 were hard to hydrate, and the volume expansion rates of the tricomponent f-CaO varied with different compositions. Inductively, in BOF slag, the hydration activity sequence was solid solutions CaO-FeOx and CaO-FeOx-MnOy in tricomponent f-CaO < CaO in tricomponent f-CaO < monocomponent f-CaO; the volume expansion rates of tricomponent f-CaO changed with different compositions, and CaO-FeOx and CaO-FeOx-MnOy were difficult to hydrate. The reason why solid solutions CaO-FeOx and CaO-FeOx-MnOy were hard to hydrate was that their hydration reaction driving force, which is the absolute value of standard molar reaction Gibbs functions, decreased
Prediksi Kualitas Klinker Semen Melalui Kandungan F-Cao Dengan Teknik Machine Learning Berdasarkan Parameter Operasi Pembakaran Kiln
No full textPT. Semen XYZ memerlukan pembakaran kiln yang tepat untuk menghasilkan klinker semen yang baik. Kandungan F-CaO dalam klinker merupakan sisa batu kapur tidak terbakar sempurna dalam indeks persen. Indeks F-CaO dianggap penting karena mempengaruhi kualitas klinker dan menurunkan kualitas semen. Kandungan f-CaO dalam klinker semen tidak dapat diukur secara langsung dan diprediksi komposisinya secara cepat serta akurat. Prediksi f-CaO sulit dilakukan karena hubungan antar variabel dan ketidakpastian proses kalsinasi klinker. Diperlukan model prediksi hasil klinker berdasarkan parameter operasi sehingga mudah dikendalikan oleh operator CCR maupun manager operasi. Prediksi kandungan f-CaO dapat mempengaruhi kualitas semen dan dapat digunakan dalam optimasi konsumsi energi dalam proses produksi klinker.
F-CaO klinker semen diprediksi berdasarkan data operasi yang bersifat real-time tiap jam yang dikumpulkan selama satu tahun. Data yang diperlukan meliputi parameter bahan baku umpan dan parameter operasi yang diatur pada Central Control Room (CCR). Data yang terkumpul perlu diproses dahulu menggunakan pembersihan outlier, pembersihan baris dengan nilai kosong dan normalisasi. Setelah data yang terkumpul siap, data diolah dengan menggunakan beberapa teknik, diantaranya Support Vector Regression (SVR), Neural Network (NN) dan Gradient Boosting (GB). Diperlukan pengaturan yang tepat pada ketiga teknik tersebut agar menghasilkan prediksi yang paling dekat dengan data aktualnya.
Faktor utama yang mempengaruhi hasil prediksi meliputi: temperatur material pada stage 4 SLC (0.536), total batu bara burner (0.536), temperatur exit preheater SLC (0.531), total kilnfeed yang masuk pada preheater (0.526), kecepatan ID fan EP (0.518), speed kiln (-0.517), temperatur material ILC (0.513), draft udara pada inlet kiln (0.490), LSF pada klinker (0.481), vakum pada kiln hood draft (0.412). Algoritma Gradient Boosting (GB) terpilih sebagai algoritma yang terbaik dengan nilai evaluasi MSE 0.107, RMSE 0.328, MAE 0.216 dan R-squared 0.887.
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PT. XYZ cement requires proper kiln combustion to produce good cement clinker. The F-CaO content in clinker is the rest of limestone not completely burned in the percent index. The F-CaO index is considered important because it affects clinker quality and decreases cement quality. The f-CaO content in cement clinker cannot be measured directly and its composition is predicted quickly and accurately. F-CaO prediction is difficult because of the relationship between variables and the uncertainty of the clinker calcination process. A clinker result prediction model is needed based on operating parameters so that it is easily controlled by CCR operators and operations managers. Prediction of f-CaO content can affect cement quality and can be used in optimizing energy consumption in clinker production processes.
F-CaO cement clinker is predicted based on real-time hourly operating data collected over the course of a year. The required data includes feed raw material parameters and operating parameters set in the Central Control Room (CCR). The collected data needs to be processed first using outlier cleanup, row cleaning with blank values and normalization. After the collected data is ready, the data is processed using several techniques, including Support Vector Regression (SVR), Neural Network (NN) and Gradient Boosting (GB). It is necessary to find the right settings in order to produce predictions that are closest to the actual data.
The main factors influencing the prediction results include: material temperature at stage 4 SLC (0.536), total coal burner (0.536), exit preheater SLC temperature (0.531), total kilnfeed entering the preheater (0.526), ID fan EP speed (0.518), kiln speed (-0.517), ILC material temperature (0.513), air draft at the kiln inlet (0.490), LSF at clinker (0.481), vacuum at the kiln hood draft (0.412). The Gradient Boosting (GB) algorithm was chosen as the best algorithm with an evaluation value of MSE 0.107, RMSE 0.328, MAE 0.216 and R-squared 0.887.
Keywords: Free lime, Gradient Boosting, Machine Learning, Neural Network, Support Vector Regression
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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