209 research outputs found

    Neural Network-based Power Flow Model

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    Power flow analysis is used to evaluate the flow of electricity in the power system network. Power flow calculation is used to determine the steady-state variables of the system, such as the voltage magnitude/phase angle of each bus and the active/reactive power flow on each branch. The DC power flow model is a popular linear power flow model that is widely used in the power industry. Although it is fast and robust, it may lead to inaccurate line flow results for some transmission lines. Since renewable energy sources such as solar farms or offshore wind farms are usually located far away from the main grid, accurate line flow results on these critical lines are essential for power flow analysis due to the unpredictable nature of renewable energy. Data-driven methods can be used to partially address these inaccuracies by taking advantage of historical grid profiles. In this paper, a neural network (NN) model is trained to predict power flow results using historical power system data. Although the training process may take time, once trained, it is very fast to estimate line flows. A comprehensive performance analysis between the proposed NN-based power flow model and the traditional DC power flow model is conducted. It can be concluded that the proposed NN-based power flow model can find solutions quickly and more accurately than DC power flow model

    Mining heterogeneous information graph for health status classification

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    In the medical domain, there exists a large volume of data from multiple sources such as electronic health records, general health examination results, and surveys. The data contain useful information reflecting people’s health and provides great opportunities for studies to improve the quality of healthcare. However, how to mine these data effectively and efficiently still remains a critical challenge. In this paper, we propose an innovative classification model for knowledge discovery from patients’ personal health repositories. By based on analytics of massive data in the National Health and Nutrition Examination Survey, the study builds a classification model to classify patients’health status and reveal the specific disease potentially suffered by the patient. This paper makes significant contributions to the advancement of knowledge in data mining with an innovative classification model specifically crafted for domain-based data. Moreover, this research contributes to the healthcare community by providing a deep understanding of people’s health with accessibility to the patterns in various observations

    Exploring benefits of applying Google Workspace for Education in English as a foreign language classroom

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    The application of technology in language classrooms is widely believed to benefit learners. In the context of teaching and learning English as a foreign language (EFL) for high school students in Vietnam, there are few studies on the benefits of applying Google Workspace for Education (GWE). This small-scale qualitative study seeks to explore the benefits of applying GWE as a technological solution in the EFL classroom with high school students. The participants were eight eleventh graders in the north of Vietnam learning English in evening classes at an English center. To collect data, the students were interviewed. The qualitative data was analyzed based on themes. The results indicated that the benefits of applying GWE were evident in enhanced attitude and motivation for learning and improved learning skills. Based on the results of this study, it is recommended that Google tools be utilized for English language learning and instruction

    Stability analysis for switched discrete-time linear singular systems

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    The stability of arbitrarily switched discrete-time linear singular (SDLS) systems is studied. Our analysis builds on the recently introduced one-step-map for SDLS systems of index-1. We first provide a sufficient stability condition in terms of Lyapunov functions. Furthermore, we generalize the notion of joint spectral radius of a finite set of matrix pairs, which allows us to fully characterize exponential stability

    The one-step-map for switched singular systems in discrete-time

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