Predictive Model for the Bottomhole Pressure based on Machine Learning
The objective of this work is to develop a predictive model for multiphase wellbore flows using the machine learning approach. The artificial neural network is developed and then trained on the dataset generated using the numerical simulator of the full-scale transient wellbore flows. After the training is completed, the neural network is used to predict one of the key parameters of the wellbore flow, namely, the bottomhole pressure. The novelty of this work is related to the application of the neural network to analyze highly transient processes taking place in wellbores. In such processes, most of the parameters of interest can be represented by interdependent time series of variables linked through complex physical phenomena pertinent to the nature of multiphase flows. The proposed neural network with two hidden layers demonstrated the capability to predict the bottomhole pressure within 5% of the normalized root mean squared error for many complex wellbore configurations and flows. It is also shown that relatively higher prediction errors are mainly observed in the case of slug flows where the transient nature of flows is pronounced the most. Finally, the developed model is tested on data affected by noise. It is demonstrated that although the error of prediction slightly increases in contrast to the data without noise, the model captures essential features of the studied transient process. Description of the developed models, analysis of various test use cases, and possible future research directions are outlined.
The paper makes a brief introduction into multiple classifier systems and describes a particular algorithm which improves classification accuracy by making a recommendation of an algorithm to an object. This recommendation is done under a hypothesis that a classifier is likely to predict the label of the object correctly if it has correctly classified its neighbors. The process of assigning a classifier to each object involves here the apparatus of Formal Concept Analysis. We explain the principle of the algorithm on a toy example and describe experiments with real-world datasets.
The paper deals with the problems of creating and tuning a system of automated anaphora resolution for Russian. Such a system is introduced, combining rule-based and machine learning approaches. It shows F-measure from 0.51 to 0.59. Freeling serves as an underlying morphological layer and an account of its quality is given, with its influence on anaphora resolution workflow. The anaphora resolution system itself is available to download and use, coming with online demo.
In an effort to make reading more accessible, an automated readability formula can help students to retrieve appropriate material for their language level. This study attempts to discover and analyze a set of possible features that can be used for single-sentence readability prediction in Russian. We test the influence of syntactic features on predictability of structural complexity. The readability of sentences from SynTagRus corpus was marked up manually and used for evaluation.
In Experimental Economics, laboratory and eld experiments are conducted on subjects in order to improve theoretical knowledge about human behavior in interactions. Although paying dierent amounts of money restricts the preferences of the subjects in experiments, the exclusive application of analytical game theory does not suce to explain the recorded data. It exacts the development and evaluation of more sophisticated models. In some experiments, human subjects are involved into an interaction with automated agents and these agents are used for simulating human interactions. The more data is used for the evaluation, the more of statistical signicance can be achieved. Since huge amounts of behavioral data are required to be scanned for regularities and automated agents are required to simulate and to intervene human interactions, Machine Learning is the tool of choice for the research in Experimental Economics. Moreover modern economics extensively involves network structures, which can be modeled as graphs or more complicated relational structures. This volume contains the papers presented at the inaugural International Workshop on Experimental Economics and Machine Learning (EEML 2012) held on May 9, 2012 at the Katholieke Universiteit Leuven, Belgium. This year the committee decided to accept 8 full papers for publication in the proceedings and two abstracts for presentation at the conference. Each submission was reviewed by on average 3 program committee members. R. Tagiew proposes a new method for mining determinism in human strategic behavior. N. Buzun et al. present a comparison of methods and measures for overlapping community detection. A. Fishkov et al. discuss a new click model for relevance prediction inWeb search. A. Drutsa et al. applied novel data visualisation techniques to socio-semantic network data. Gilabert et al. made an experimental study on the relationship between trust and budgetary slack. O. Barinova et al. proposed using online random forest for interactive image segmentation. A. Bezzubtseva et al. built a new typology of collaboration platform users. V. Zaharchuk et al. proposed a new recommender system for interactive radio network services. D. Ignatov et al. designed a prototype system for collaborative platform data analysis.
This paper is an overview of the current issues and tendencies in Computational linguistics. The overview is based on the materials of the conference on computational linguistics COLING’2012. The modern approaches to the traditional NLP domains such as pos-tagging, syntactic parsing, machine translation are discussed. The highlights of automated information extraction, such as fact extraction, opinion mining are also in focus. The main tendency of modern technologies in Computational linguistics is to accumulate the higher level of linguistic analysis (discourse analysis, cognitive modeling) in the models and to combine machine learning technologies with the algorithmic methods on the basis of deep expert linguistic knowledge.
The Programme for International Student Assessment (PISA) is an influential worldwide study that tests the skills and knowledge in mathematics, reading, and science of 15-yearold students. In this paper, we show that PISA scores of individual students can be predicted from their digital traces. We use data from the nationwide Russian panel study that tracks 4,400 participants of PISA and includes information about their activity on a popular social networking site. We build a simple model that predicts PISA scores based on students’ subscriptions to various public pages on the social network. The resulting model can successfully discriminate between low- and high-performing students (AUC = 0.9). We find that top-performing students are interested in pages related to science and art, while pages preferred by low-performing students typically concern humor and horoscopes. The difference in academic performance between subscribers to such public pages could be equivalent to several years of formal schooling, indicating the presence of a strong digital divide. The ability to predict academic outcomes of students from their digital traces might unlock the potential of social media data for large-scale education research.
Event logs collected by modern information and technical systems usually contain enough data for automated process models discovery. A variety of algorithms was developed for process models discovery, conformance checking, log to model alignment, comparison of process models, etc., nevertheless a quick analysis of ad-hoc selected parts of a journal still have not get a full-fledged implementation. This paper describes an ROLAP-based method of multidimensional event logs storage for process mining. The result of the analysis of the journal is visualized as directed graph representing the union of all possible event sequences, ranked by their occurrence probability. Our implementation allows the analyst to discover process models for sublogs defined by ad-hoc selection of criteria and value of occurrence probability
The Handbook of CO₂ in Power Systems' objective is to include the state-of-the-art developments that occurred in power systems taking CO₂ emission into account. The book includes power systems operation modeling with CO₂ emissions considerations, CO₂ market mechanism modeling, CO₂ regulation policy modeling, carbon price forecasting, and carbon capture modeling. For each of the subjects, at least one article authored by a world specialist on the specific domain is included.
Many electronic devices operate in a cyclic mode. This should be considered when forecastingreliability indicators at the design stage.The accuracy of the prediction and the planning for the event to ensure reliability depends on correctness of valuation and accounting greatest possiblenumber of factors. That in turn will affect the overall progress of the design and, in the end,result in the quality and competitiveness of products
Let G be a semisimple algebraic group whose decomposition into the product of simple components does not contain simple groups of type A, and P⊆G be a parabolic subgroup. Extending the results of Popov , we enumerate all triples (G, P, n) such that (a) there exists an open G-orbit on the multiple flag variety G/P × G/P × . . . × G/P (n factors), (b) the number of G-orbits on the multiple flag variety is finite.
I give the explicit formula for the (set-theoretical) system of Resultants of m+1 homogeneous polynomials in n+1 variables