2,590 research outputs found

    Input significance analysis: feature selection through synaptic weights manipulation for EFuNNs classifier

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    This work is interested in ISA methods that can manipulate synaptic weights namelyConnection Weights (CW) and Garson’s Algorithm (GA) and the classifier selected isEvolving Fuzzy Neural Networks (EFuNNs). Firstly, it test FS method on a dataset selectedfrom the UCI Machine Learning Repository and executed in an online environment, recordthe results and compared with the results that used original and ranked data from the previouswork. This is to identify whether FS can contribute to improved results and which of the ISAmethods mentioned above that work well with FS, i.e. give the best results. Secondly, to attestthe FS results by using a differently selected dataset taken from the same source and in thesame environment. The results are promising when FS is applied, some efficiency andaccuracy are noticeable compared to the original and ranked data.Keywords: feature selection; feature ranking; input significance analysis; evolvingconnectionist systems; evolving fuzzy neural network; connection weights; Garson’salgorithm

    Non-parametric Methods for Correlation Analysis in Multivariate Data with Applications in Data Mining

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    In this thesis, we develop novel methods for correlation analysis in multivariate data, with a special focus on mining correlated subspaces. Our methods handle major open challenges arisen when combining correlation analysis with subspace mining. Besides traditional correlation analysis, we explore interaction-preserving discretization of multivariate data and causality analysis. We conduct experiments on a variety of real-world data sets. The results validate the benefits of our methods

    Kognition arviointi : Hajautetun tiedon sovelluksia

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    The amount of information collected by personal health records, smartphone ecosystems, and other cloud services has increased enormously in recent years. This has, for instance, led to new ways of automated physical exercise assessment, but this also introduces the potential for novel methods and applications in the automated evaluation of various mental factors such as cognitive state and stress. Extracting such latent variables holds considerable promise, in particular in group-level analysis. Furthermore, the current initiatives and research programs collecting masses of health data from large cohorts create opportunities for developing the methodology. The lack of targeted research is partially hindering the development of the analysis of obscure factors, progress of machine learning and other algorithmic solutions, and the evolution of novel applications and technologies. As described in this introduction, various features inherent in biosignals increase the complexity in the research. In this thesis I provide an introduction to the emerging ubiquitous recording of physiological signals, its effects on the industry, opportunities for organizations and management, and data analytics and measurement techniques. The aim is to seek the future prospects of systemic scenarios and large-scale initiatives. The original publications reviewed in this thesis seek biosignals for features responsive for cognitive states such as stress and, more interestingly, second-order factors derived from inter-individual responses and activations. By introducing more complex features to psychophysiological research, group analytics can be further developed. Second-order analyses provide robust signal features and may lead to advanced applications in assessing well-being and performance. The original publications consist of three research articles and a primer review. The experiments include recordings of magnetoencephalography (MEG), heart rate variability (HRV), and electrodermal activity (EDA), and they exemplify systemic use cases of biosignals. The included primer review discusses general methods in psychophysiological research in human–computer interaction (HCI). Together with this introduction, my experimental results provide evidence that taking psychophysiological measurements from the laboratory to ecologically valid environments is plausible and effective. The literature suggests that consumer-grade devices and personal internet of things will revolutionize myriad sectors, e.g., organizational management. Together with an exponentially increasing data collection and novel applications, the industry will have large economical impacts.Henkilökohtaisen terveystiedon kerääminen ja tallennus on lisääntynyt valtavasti viime vuosina. Monet käyttävät tietoa esimerkiksi fyysisen harjoittelun tukena. Tämän lisäksi mitattua tietoa on alettu hyödyntää esimerkiksi stressitilojen tunnistamisessa. Tällaista fysiologisten signaalien arviointia kutsutaan psykofysiologiaksi. Jatkokehityksen avulla tällaiset piirteet sopivat varsinkin ryhmäanalyyseihin ja suurempien joukkojen arvioimiseen. Menetelmien kehitystä tukevat useat suuret väestötason tutkimusavaukset. Toisaalta juuri kohdennetun tutkimuksen puute osaltaan hidastaa tallennetusta tiedosta eristettävien piilevien piirteiden hyödyntämisen yleistymistä uusissa algoritmeissa ja sovel- luksissa. Tässä yhteenvedossa esittelen, mitkä asiat vaikuttavat osaltaan tähän kehitykseen. Esittelen fysiologisten signaalien mittaamisen taustoja, sekä mittausmenetelmien kehitystä. Lisäksi pohdin kaupallisten sovellusten mahdollisuuksia ja muita tulevaisuuden näkymiä. Johdanto-osuus toimii siten taustamateriaalina soveltavalle osiolle ja liitetyille osajulkaisuille. Osajulkaisut tutkivat kohdennetummin biosignaalien soveltuvuutta kognitiivisen toim- intakyvyn arvioimisessa. Jäljemmät julkaisut keskittyvät useiden yksilöiden biosignaalien kovarianssia hyödyntäviin menetelmiin. Tällaiset menetelmät luovat pohjaa kehittyneem- mille analyysitavoille ja signaalien yhä tehokkaammalle hyödyntämiselle hyvinvoinnin ja toimintakyvyn arvioinnissa. Kolme ensimmäistä osajulkaisua ovat kokeellisia tutkimusar- tikkeleita ja viimeinen on katsaus olemassa olevaan tutkimukseen. Tutkimusasetelmissa hyödynnetyt fysiologiset menetelmät ovat magnetoenkefalografia (MEG), sykevälivaihtelu (HRV) ja ihosähköinen vaste (EDA). Katsaus toisaalta tarkastelee psykofysiologian hyödyn- tämistä tietokoneen käyttöliittymätutkimuksessa (HCI). Yhdessä tämän yhteenvedon kanssa tutkimustulokset edistävät mittausmenetelmien hyödynnettävyyttä luonnollisissa ympäristöissä, sekä psykofysiologisten signaalien käyttöä vaihtelevissa ja kontrolloimattomissa olosuhteissa. Kirjallisuudesta löytyy viitteitä kulutta- jalaitteiden ja esineiden internetin kasvusta ja potentiaalista mullistaa useita sektoreita, kuten organisaatioiden ohjaus. Lähteet ennustavat myös markkinoiden kasvua. Yhdessä kaikkialle levittyvä tiedon kerääminen ja uudet sovellukset sekä datalähtöiset analyysimenetelmät voivat johtaa suuriin muutoksiin

    Path to eurobonds. Bruegel Working Paper 2012/10, July 2012

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    This paper discusses proposals for common euro area sovereign securities. Such instruments can potentially serve two functions: in the short-term, stabilize financialmarkets and banks and, in the medium-term, help improve the euro area economic governance framework through enhanced fiscal discipline and risk-sharing. Many questions remain onwhether financial instruments can ever accomplish such goals without bold institutional and political decisions, and,whether, in the absence of such decisions, they can create new distortions. The proposals discussed are also not necessarily competing substitutes; rather, they can be complements to be sequenced along alternative paths that possibly culminate in a fully-fledged Eurobond. The specific path chosen by policymakers should allow for learning and secure the necessary evolution of institutional infrastructures and political safeguards

    Cooperative Coevolution for Non-Separable Large-Scale Black-Box Optimization: Convergence Analyses and Distributed Accelerations

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    Given the ubiquity of non-separable optimization problems in real worlds, in this paper we analyze and extend the large-scale version of the well-known cooperative coevolution (CC), a divide-and-conquer optimization framework, on non-separable functions. First, we reveal empirical reasons of why decomposition-based methods are preferred or not in practice on some non-separable large-scale problems, which have not been clearly pointed out in many previous CC papers. Then, we formalize CC to a continuous game model via simplification, but without losing its essential property. Different from previous evolutionary game theory for CC, our new model provides a much simpler but useful viewpoint to analyze its convergence, since only the pure Nash equilibrium concept is needed and more general fitness landscapes can be explicitly considered. Based on convergence analyses, we propose a hierarchical decomposition strategy for better generalization, as for any decomposition there is a risk of getting trapped into a suboptimal Nash equilibrium. Finally, we use powerful distributed computing to accelerate it under the multi-level learning framework, which combines the fine-tuning ability from decomposition with the invariance property of CMA-ES. Experiments on a set of high-dimensional functions validate both its search performance and scalability (w.r.t. CPU cores) on a clustering computing platform with 400 CPU cores

    A Predictive Model for Scaffolding Manhours in Heavy Industrial Construction Projects: An application of machine learning

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    In cold countries like Canada, modular construction is widely adopted in heavy industrial construction projects due to weather uncertainties. To facilitate the construction processes, the temporary structures, especially scaffolding, are essential since it provides easy access for workers to carry out construction activities at different levels of the height and also ensures the safety of laborers. As indirect costs of projects, the scaffolding is estimated by 15-40% of project costs. Furthermore, according to the increase in the size of the projects, the scaffolding uses a larger amount of resources than estimated ones, which may cause budget overrun and schedule delay. However, due to the lack of systematic and scientific models to estimate scaffolding productivity, the heavy industrial company has difficulty to plan and allocate the resources for scaffold activities before construction. To overcome these challenges, this paper proposes a predictive model to estimate scaffolding productivity based on the historical scaffolding data of a heavy industrial project. The proposed model is developed based on the following steps: (i) identifying the key parameters (e.g. specific trades, work type, different scaffold methods, task times spent using scaffolds, and weights of the scaffolds) that influence the scaffolding manhours and project productivity; and (ii) developing the predictive models for scaffold manhours using machine learning algorithms including multiple linear regression, decision tree regression, random forest regression and artificial neural networks(ANN) . The accuracy of models have been measured with evaluation metrics which are mean absolute error (MAE) and root mean squared error (RMSE) and the R squared value. The findings reveal up to 90% accuracy for ANN models
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