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  • Presentation 
    Analyzing Word Frequencies in Large Text Corpora using Inter-arrival Times and Bootstrapping

    Analyzing Word Frequencies in Large Text Corpora using Inter-arrival Times and Bootstrapping

    This video was recorded at European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML PKDD), Athens 2011. Comparing frequency counts over texts or corpora is an important task in many applications and scientific disciplines. Given a text corpus, we want to test a hypothesis, such as "word X is frequent", "word X has become more frequent over time", or "word X is more frequent in male than in female speech". For this purpose we need a null model of word frequencies. The commonly used bag-of-words model, which corresponds to a Bernoulli process with fixed parameter, does not account for any structure present in natural languages. Using this model for word frequencies results in large numbers of words being reported as unexpectedly frequent. We address how to take into account the inherent occurrence patterns of words in significance testing of word frequencies. Based on studies of words in two large corpora, we propose two methods for modeling word frequencies that both take into account the occurrence patterns of words and go beyond the bag-of-words assumption. The first method models word frequencies based on the spatial distribution of individual words in the language. The second method is based on bootstrapping and takes into account only word frequency at the text level. The proposed methods are compared to the current gold standard in a series of experiments on both corpora. We find that words obey different spatial patterns in the language, ranging from bursty to non-bursty/uniform, independent of their frequency, showing that the traditional approach leads to many false positives.

    Subjects:
    Management and Computing
    Keywords:
    Computational linguistics Text processing (Computer science) Discourse analysis -- Data processing
    Resource Type:
    Presentation
     
    OER
  • Others 
    Agent Based Modeling using AnyLogic Professional

    Agent Based Modeling using AnyLogic Professional

    Agent based modeling focuses on the individual active components of a system. This is in contrast to both the more abstract system dynamics approach, and the process-focused discrete event method. With agent based modeling, active entities, known as agents, must be identified and their behavior defined. They may be people, households, vehicles, equipment, products, or companies, whatever is relevant to the system. Connections between them are established, environmental variables set, and simulations run. The global dynamics of the system then emerge from the interactions of the many individual behaviors. AnyLogic combines professional discrete event, system dynamics, and agent based modeling in one platform for efficient, no compromise results. In our white paper, Multimethod Simulation Modeling for Business Applications, we investigate these three main simulation modeling approaches and construct a multimethod model example to illustrate the advantages of multimethod simulation modeling. Read the white paper and see why hybrid models are always a better choice!

    Course related:
    CE631 Simulation and IT Applications in Construction
    Subjects:
    Business Information Technology and Computing
    Keywords:
    Computer simulation Multiagent systems System analysis -- Data processing
    Resource Type:
    Others
     
  • Others 
    Abaqus e-learning

    Abaqus e-learning

    4RealSim serves its customers by providing Dassault Systemes’ SIMULIA products (Abaqus, Isight, Tosca, fe-safe, Simpack, XFLOW), VCollab and HyperSizer.
    4RealSim offers high-quality Finite Element engineering services to assess, validate and optimize the response of products, assemblies and processes.
    4RealSim offers training and mentoring to learn the analysis tools and improve FEA methodologies. Trainings are available online or organized in class rooms.
    4RealSim offers customer-tailored and regulatory compliant Computer Modelling & Simulation services for the life-science and medical-device industry.

    Subjects:
    Business Information Technology and Computing
    Keywords:
    Abaqus (Electronic resource) Finite element method
    Resource Type:
    Others