Digital holography (DH) has been extensively applied in particle field measurements due to its promising ability to simultaneously provide the three-dimensional location and in-plane size of particles. Particle detect...
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Digital holography (DH) has been extensively applied in particle field measurements due to its promising ability to simultaneously provide the three-dimensional location and in-plane size of particles. Particle detection methods are crucial in hologram data processing to determine particle size and particle in-focus depth, which directly affect the measurement accuracy and robustness of DH. In this work, inspired by clustering algorithms, a new clustering-based particle detection (CBPD) method was proposed for DH. To the best of our knowledge this is the first time that clustering algorithms have been applied in processing holograms for particle detection. The results of both simulations and experiments confirmed the feasibility of our proposed method. This data-driven method features automatic recognition of particles, particle edges and background, and accurate separation of overlapping particles. Compared with seven conventional particle detection methods, the CBPD method has improved accuracy in measuring particle positions and displacements.
Affected by many factors such as irregular cluster distribution, complex terrain and wake effect, the operation conditions of each unit in large-scale doubly fed wind farm are different. In order to improve the accura...
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ISBN:
(纸本)9781728143231;9781728143224
Affected by many factors such as irregular cluster distribution, complex terrain and wake effect, the operation conditions of each unit in large-scale doubly fed wind farm are different. In order to improve the accuracy of equivalent output model of wind farm, an improved equivalent modeling method of doubly fed wind farm is proposed. Firstly, the characteristic state variable matrix which can represent the operation state of each unit is selected as the clustering index, and the improved fuzzy c-means clustering algorithm is used to divide the cluster, then the parameters of the peer check-in model are identified based on the global optimal position variation particle swarm optimization algorithm, and finally the same group of units is equivalent to a fan. DIgSILENT simulation software is used for modeling, two dynamic conditions of wind speed step and three-phase short circuit fault. The simulation results show that the dynamic characteristics of the equivalent model are basically the same as that of the detailed model. Compared with the traditional single machine equivalent model, the accuracy of this method is higher.
A new algorithm is presented to find clusters in a dataset of points in R-n with no prior knowledge of possible clustering. The algorithm detects clusters in a top down fashion by testing modality of density functions...
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ISBN:
(纸本)9781450371056
A new algorithm is presented to find clusters in a dataset of points in R-n with no prior knowledge of possible clustering. The algorithm detects clusters in a top down fashion by testing modality of density functions generated from the dataset and splitting the set accordingly. Results on synthetic and text datasets demonstrate that the method is comparable to other established unsupervised learning algorithms, which do in fact require the number of clusters ab initio. The method proves to be particularly suitable for certain distributions and offers a valid alternative in situations where most of the well-known algorithms do not produce consistent results.
Sensors and mobile phones are becoming very useful to gather a huge amount of data rapidly and to understand the behaviour of the human. Today, the real challenge is how to benefit from the use of Big Data performant ...
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Sensors and mobile phones are becoming very useful to gather a huge amount of data rapidly and to understand the behaviour of the human. Today, the real challenge is how to benefit from the use of Big Data performant tools and machine learning algorithms to get the desired value. The present paper presents a comparative study of clustering algorithms (Kmeans, Bisecting Kmeans and Gaussian mixture) for a real time miscarriage prediction. Wearable healthcare sensors ((heart rate sensor, temperature sensor and activity sensor) and mobile phone are used for gathering real time data about the pregnant women. Sensors are managed using IoT technologies such as Raspberry Pi to collect and process data in real time. Prediction’s results are sent to the doctor through a mobile phone created and the pregnant woman receives recommendations based on her behaviour. Our study compares the performance and the efficiency of the predictive models created by the three algorithms, including time to build the model, clusters distribution and centres definition. We evaluate models using the Internal clustering validation silhouette method. The dataset generated and analyzed during the current study is available on GitHub platform via the following link: https://***/hibaasri/Miscarriage-Prediction . Databricks platform and Spark are used to analyze data and build models.
The purpose of this study is to research and explore the clustering algorithm, and provide methods for clustering characteristics evaluation and clustering dimension selection, in order to help the user to understand ...
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ISBN:
(纸本)9781450377324
The purpose of this study is to research and explore the clustering algorithm, and provide methods for clustering characteristics evaluation and clustering dimension selection, in order to help the user to understand the impact and meaning of clustering parameters and data dimensions on clustering, thereby strengthening the use of clustering algorithm. In previous studies, many scholars have proposed various types of clustering algorithms. Most of these algorithms need to set the clustering parameters, and the selection of clustering parameters will affect the results after clustering. Therefore, the user must fully understand the meaning of clustering parameters for clustering and select appropriate clustering parameters for clustering, then the clustering algorithm can be effectively used to help solve decision-making problems. Based on the above factors, this study focus on doing further analysis and description on the meaning of the clustering data distribution & the meaning of parameters to the clusters, and the relationship among the clusters, find out the important clustering feature and propose a new clustering evaluation formula, and expect to assist the decision-maker to find appropriate clustering parameters effectively.
clustering is an unsupervised data mining technique where exploration is done with little knowledge of data classes. Its aim is to recognize the hidden information from the data for effective decision-making. Though m...
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Query reformulation techniques are essential for information retrieval systems. These techniques eliminate the bad queries (short and ambiguous queries) and minimize users search time. There are two kinds of technique...
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Query reformulation techniques are essential for information retrieval systems. These techniques eliminate the bad queries (short and ambiguous queries) and minimize users search time. There are two kinds of techniques in literature; the first uses the query logs with the click-through data to identify relevant queries and propose them to the user. The second group uses relevant terms extracted from different sources such as Wikipedia, Wordnet, and pseudo-relevant documents to expand the initial query and increase the likelihood with relevant documents. Both groups generate false queries because they do not consider the user interests and due to the assumption that the user clicks only on relevant results (first group) and that the top-k retrieved documents (top 5 to 15) are relevant (second group).In this paper, we propose a novel approach to reformulate the user queries using his profile (which contains the user interests). The approach retrieves documents related to the query from four different data sources (≈ 1000 doc). Then, it extracts the topics of these documents using the Lingo clustering algorithm (cluster the document with the same topic) and Text razor API (extract the potential topics of each cluster). Finally, it generates queries based on these topics and the user profile. The results show that the proposed approach outperforms the existing solution in [email protected] , [email protected] , and MAP.
In the context of the Vehicle Routing Problem with Backhauls, which involves delivering to linehaul and picking up from backhaul customers, we propose a novel mathematical model that can decompose the main problem int...
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Academic procrastination is a common phenomenon in China's higher vocational education. Due to the weakening of the role of teacher supervisors and the lack of students' self-control, the academic procrastinat...
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ISBN:
(纸本)9781450398091
Academic procrastination is a common phenomenon in China's higher vocational education. Due to the weakening of the role of teacher supervisors and the lack of students' self-control, the academic procrastination of students in online learning is more likely to occur. At present, it has become a trend to use educational data mining and artificial intelligence technology to evaluate, predict and intervene in online learning, so as to solve the problem of practical teaching lag and improve the teaching effect of vocational education. In this paper, the data of "Computer Application Foundation" course of higher vocational students on Chaoxing platform is used to process the data by using K-means and DBSCAN clustering algorithms, and the performance of the two algorithms is evaluated by using the contour coefficient. The results show that the K-means algorithm has better performance. The students were divided into active learners, mild procrastinators and severe procrastinators by K-means clustering algorithm. Then, combined with decision tree (DT), neural network (NN) and Naive Bayes (NB) algorithm to verify the accuracy of K-means clustering algorithm in identifying the classification of students' procrastination tendency, this paper hopes to provide some advises for online learning procrastinators and encourage students to keep learning initiative and enthusiasm.
Wireless sensor networks have been employed widely in various fields, including military, health care, and manufacturing applications. However, the sensor nodes are limited in terms of their energy supply, storage cap...
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Wireless sensor networks have been employed widely in various fields, including military, health care, and manufacturing applications. However, the sensor nodes are limited in terms of their energy supply, storage capability, and computational power. Thus, in order to improve the energy efficiency and prolong the network life cycle, we present a genetic algorithm-based energy-efficient clustering and routing approach GECR. We add the optimal solution obtained in the previous network round to the initial population for the current round, thereby improving the search efficiency. In addition, the clustering and routing scheme are combined into a single chromosome to calculate the total energy consumption. We construct the fitness function directly based on the total energy consumption thereby improving the energy efficiency. Moreover, load balancing is considered when constructing the fitness function. Thus, the energy consumption among the nodes can be balanced. The experimental results demonstrated that the GECR performed better than other five methods. The GECR achieved the best load balancing with the lowest variances in the loads on the cluster heads under different scenarios. In addition, the GECR was the most energy-efficient with the lowest average energy consumed by the cluster heads and the lowest energy consumed by all the nodes. (C) 2018 Elsevier Inc. All rights reserved.
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