92 results on '"hyper-parameters"'
Search Results
52. Motion trajectory prediction based on a CNN-LSTM sequential model.
- Author
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Xie, Guo, Shangguan, Anqi, Fei, Rong, Ji, Wenjiang, Ma, Weigang, and Hei, Xinhong
- Abstract
Accurate monitoring the surrounding environment is an important research direction in the field of unmanned systems such as bio-robotics, and has attracted much research attention in recent years. The trajectories of surrounding vehicles should be predicted accurately in space and time to realize active defense and running safety of an unmanned system. However, there is uncertainty and uncontrollability in the process of trajectory prediction of surrounding obstacles. In this study, we propose a trajectory prediction method based on a sequential model, that fuses two neural networks of a convolutional neural network (CNN) and a long short-term memory network (LSTM). First, a box plot is used to detect and eliminate abnormal values of vehicle trajectories, and valid trajectory data are obtained. Second, the trajectories of surrounding vehicles are predicted by merging the characteristics of CNN space expansion and LSTM time expansion; the hyper-parameters of the model are optimized according to a grid search algorithm, which satisfies the double-precision prediction requirement in space and time. Finally, data from next generation simulation (NGSIM) and Creteil roundabout in France are taken as test cases; the correctness and rationality of the method are verified by prediction error indicators. Experimental results demonstrate that the proposed CNN-LSTM method is more accurate and features a shorter time cost, which meets the prediction requirements and provides an effective method for the safe operation of unmanned systems. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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53. Land-cover classification of multispectral LiDAR data using CNN with optimized hyper-parameters.
- Author
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Pan, Suoyan, Guan, Haiyan, Chen, Yating, Yu, Yongtao, Nunes Gonçalves, Wesley, Marcato Junior, José, and Li, Jonathan
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- *
CONVOLUTIONAL neural networks , *LIDAR , *IMAGE segmentation , *CLASSIFICATION - Abstract
Multispectral LiDAR (Light Detection And Ranging) is characterized of the completeness and consistency of its spectrum and spatial geometric data, which provides a new data source for land-cover classification. In recent years, the convolutional neural network (CNN), compared with traditional machine learning methods, has made a series of breakthroughs in image classification, object detection, and image semantic segmentation due to its stronger feature learning and feature expression abilities. However, traditional CNN models suffer from some issues, such as a large number of layers, leading to higher computational cost. To address this problem, we propose a CNN-based multi-spectral LiDAR land-cover classification framework and analyze its optimal parameters to improve classification accuracy. This framework starts with the preprocessing of multi-spectral 3D LiDAR data into 2D images. Next, a CNN model is constructed with seven fundamental functional layers, and its hyper-parameters are comprehensively discussed and optimized. The constructed CNN model with the optimized hyper-parameters was tested on the Titan multi-spectral LiDAR data, which include three wavelengths of 532 nm, 1064 nm, and 1550 nm. Extensive experiments demonstrated that the constructed CNN with the optimized hyper-parameters is feasible for multi-spectral LiDAR land-cover classification tasks. Compared with the classical CNN models (i.e., AlexNet, VGG16 and ResNet50) and our previous studies, our constructed CNN model with the optimized hyper-parameters is superior in computational performance and classification accuracies. [ABSTRACT FROM AUTHOR]
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- 2020
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54. Hyper-parameter Optimization of Sticky HDP-HMM Through an Enhanced Particle Swarm Optimization
- Author
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Li, Jiaxi, Yin, Junfu, Chung, Yuk Ying, Sha, Feng, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Weikum, Gerhard, Series editor, Hirose, Akira, editor, Ozawa, Seiichi, editor, Doya, Kenji, editor, Ikeda, Kazushi, editor, Lee, Minho, editor, and Liu, Derong, editor
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- 2016
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55. A New Hyper-Parameter Optimization Method for Power Load Forecast Based on Recurrent Neural Networks
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Yaru Li, Yulai Zhang, and Yongping Cai
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BO ,hyper-parameters ,black box function ,PSO ,RNN ,LSTM ,Industrial engineering. Management engineering ,T55.4-60.8 ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
The selection of the hyper-parameters plays a critical role in the task of prediction based on the recurrent neural networks (RNN). Traditionally, the hyper-parameters of the machine learning models are selected by simulations as well as human experiences. In recent years, multiple algorithms based on Bayesian optimization (BO) are developed to determine the optimal values of the hyper-parameters. In most of these methods, gradients are required to be calculated. In this work, the particle swarm optimization (PSO) is used under the BO framework to develop a new method for hyper-parameter optimization. The proposed algorithm (BO-PSO) is free of gradient calculation and the particles can be optimized in parallel naturally. So the computational complexity can be effectively reduced which means better hyper-parameters can be obtained under the same amount of calculation. Experiments are done on real world power load data, where the proposed method outperforms the existing state-of-the-art algorithms, BO with limit-BFGS-bound (BO-L-BFGS-B) and BO with truncated-newton (BO-TNC), in terms of the prediction accuracy. The errors of the prediction result in different models show that BO-PSO is an effective hyper-parameter optimization method.
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- 2021
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56. Employing categorical boosting (CatBoost) and meta-heuristic algorithms for predicting the urban gas consumption.
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Qian, Leren, Chen, Zhongsheng, Huang, Yiqian, and Stanford, Russell J.
- Abstract
This study was conducted on the presentation of a method to improve the forecast of urban gas consumption based on the weather variables including temperature, pressure, humidity, wind speed and also the gas price. The diversity of input variables as well as investigating a short-term (daily) scale, led to creation complex and nonlinear relationships between the variables, which makes its solving difficult. To this end, the categorical boosting (CatBoost) method is combined with some meta-heuristic algorithms to create hybrid models. These meta-heuristic algorithms include Phasor Particle Swarm Optimization, Artificial Bee Colony, Battle Royale Optimizer, Grey Wolf Optimizer, Satin Bowerbird algorithm, and Fruit Fly Optimization Algorithm. During the network training, the K-Fold cross-validation has also been used to prevent overfitting. Finally, using an actual dataset, the performance of the proposed method is investigated. The results showed that the proposed method can predict the value of short-term urban gas consumption. The results showed that the hybrid Catboost-PPSO model had the best performance among all presented hybrid models. Therefore, using the PPSO algorithm to optimize the hyper-parameters of the CatBoost network is recommended for predicting gas consumption. • The study was performed on the forecast of urban gas consumption. • Meta-heuristic algorithms help CatBoost network to perform more efficiently. • The results showed that the hybrid Catboost-PPSO model has the best performance. • The results showed that the hybrid Catboost-FOA model performs weaker than others. • In training and testing, the TIC values of the hybrid Catboost-PPSO model are 0.0013 and 0.0540. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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57. Qualitative Transfer for Reinforcement Learning with Continuous State and Action Spaces
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Garcia, Esteban O., de Cote, Enrique Munoz, Morales, Eduardo F., Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Ruiz-Shulcloper, José, editor, and Sanniti di Baja, Gabriella, editor
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- 2013
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58. Determination of Software Reliability Demonstration Testing Effort Based on Importance Sampling and Prior Information
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Li, Qiuying, Wang, Jian, and Thaung, Khine Soe, editor
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- 2012
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59. Multi-spectral Remote Sensing Images Classification Method Based on SVC with Optimal Hyper-parameters
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Guo, Yi-nan, Xiao, Dawei, Cheng, Jian, Yang, Mei, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Goebel, Randy, editor, Siekmann, Jörg, editor, Wahlster, Wolfgang, editor, Deng, Hepu, editor, Miao, Duoqian, editor, Lei, Jingsheng, editor, and Wang, Fu Lee, editor
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- 2011
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60. Fully Automatic Brain Tumor Segmentation using End-To-End Incremental Deep Neural Networks in MRI images.
- Author
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naceur, Mostefa Ben, Saouli, Rachida, Akil, Mohamed, and Kachouri, Rostom
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IMAGE segmentation , *DEEP learning , *BIOLOGICAL neural networks , *MAGNETIC resonance imaging ,BRAIN tumor diagnosis - Abstract
Highlights • A new fully automatic end-to-end deep learning model for brain tumor segmentation. • EnsembleNet uses Ensemble Learning to aggregate the results of two models which are based on an incremental deep neural network. • We present a new training strategy which unifies the training methods of deep learning models. • The new method of designing deep learning models with the advantage of GPU implementation, our models are one order of magnitude faster compared to the state-of-the-art. Graphical abstract Abstract Background and Objective : Nowadays, getting an efficient Brain Tumor Segmentation in Multi-Sequence MR images as soon as possible, gives an early clinical diagnosis, treatment and follow-up. The aim of this study is to develop a new deep learning model for the segmentation of brain tumors. The proposed models are used to segment the brain tumors of Glioblastomas (with both high and low grade). Glioblastomas have four properties: different sizes, shapes, contrasts, in addition, Glioblastomas appear anywhere in the brain. Methods : In this paper, we propose three end-to-end Incremental Deep Convolutional Neural Networks models for fully automatic Brain Tumor Segmentation. Our proposed models are different from the other CNNs-based models that follow the technique of trial and error process which does not use any guided approach to get the suitable hyper-parameters. Moreover, we adopt the technique of Ensemble Learning to design a more efficient model. For solving the problem of training CNNs model, we propose a new training strategy which takes into account the most influencing hyper-parameters by bounding and setting a roof to these hyper-parameters to accelerate the training. Results : Our experiment results reported on BRATS-2017 dataset. The proposed deep learning models achieve the state-of-the-art performance without any post-processing operations. Indeed, our models achieve in average 0.88 Dice score over the complete region. Moreover, the efficient design with the advantage of GPU implementation, allows our three deep learning models to achieve brain segmentation results in average 20.87 s. Conclusions : The proposed deep learning models are effective for the segmentation of brain tumors and allow to obtain high accurate results. Moreover, the proposed models could help the physician experts to reduce the time of diagnostic. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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61. Genetic algorithm hyper-parameter optimization using Taguchi design for groundwater pollution source identification.
- Author
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Xuemin Xia, Simin Jiang, Nianqing Zhou, Xianwen Li, and Lichun Wang
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GENETIC algorithms ,GROUNDWATER pollution ,POLLUTION monitoring ,SIMULATED annealing ,TAGUCHI methods - Abstract
Groundwater pollution has been a major concern for human beings, since it is inherently related to people's health and fitness and the ecological environment. To improve the identification of groundwater pollution, many optimization approaches have been developed. Among them, the genetic algorithm (GA) is widely used with its performance depending on the hyper-parameters. In this study, a simulation-optimization approach, i.e., a transport simulation model with a genetic optimization algorithm, was utilized to determine the pollutant source fluxes. We proposed a robust method for tuning the hyper-parameters based on Taguchi experimental design to optimize the performance of the GA. The effectiveness of the method was tested on an irregular geometry and heterogeneous porous media considering steady-state flow and transient transport conditions. Compared with traditional GA with default hyper-parameters, our proposed hyper-parameter tuning method is able to provide appropriate parameters for running the GA, and can more efficiently identify groundwater pollution. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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62. Optimized Generative Pre-training EEG to Sentiment Classification (OGPTSC)
- Author
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Hassan, Amira
- Subjects
- BART, BERT, EEG, GPT, Hyper-parameters, Sentiment classifications
- Abstract
This research aims to revolutionize electroencephalogram (EEG) analysis by proposing and developing an innovative method for sentiment classification, introducing the groundbreaking "Optimized Chat Generative Pre-training EEG to Sentiment Classification (OGPTSC)." This novel approach harnesses the power of Generative Pre-training (GPT2) as the vocabulary language model while utilizing an intelligent hyper-parameter selection method to fine-tune and optimize the model's performance. Extensive testing is conducted on a widely recognized dataset to evaluate the OGPTSC's prowess, demonstrating its exceptional capabilities in sentiment classification. Notably, this research extends its scrutiny beyond the OGPTSC by applying the same hyper-parameter selection technique to well-established models such as BERT, BART, and Multi-Layer Perceptions, thus enhancing these models' overall reliability and generalizability. A key innovation of this research lies in improving model structure through a comprehensive tuning process. This process dynamically adapts the models' configurations by strategically leveraging classification loss and error during training. As a result, the refined models exhibit unprecedented levels of accuracy and robustness. The outcomes of the experiments vividly portray the superiority of the OGPTSC model over existing approaches that utilized the same dataset and techniques (BERT Model, BART Model, and Multi-Layer Perceptions). The OGPTSC's exceptional performance in sentiment classification firmly establishes it as a groundbreaking solution, surpassing previous benchmarks and setting a new standard in EEG analysis and sentiment classification. Furthermore, the optimized versions of the renowned BERT Model, BART Model, and Multi-Layer Perceptions also showcase remarkable improvements over their predecessors. These enhancements solidify their positions as formidable contenders in the sentiment classification domain, providing researchers and practitioners with an invaluable toolkit to tackle complex EEG-based sentiment analysis tasks. In summary, this research presents an impressive and influential contribution to EEG analysis and sentiment classification. The development and evaluation of the OGPTSC model and the enhancement of existing state-of- the-art models inspire a new wave of research and application possibilities in the field. These optimized models demonstrated superiority and versatility and laid the foundation for future advancements in natural language processing, sentiment analysis, and beyond.
- Published
- 2023
63. A novel adaptive optimization framework for SVM hyper-parameters tuning in non-stationary environment: A case study on intrusion detection system.
- Author
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Kalita, Dhruba Jyoti, Singh, Vibhav Prakash, and Kumar, Vinay
- Subjects
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INTRUSION detection systems (Computer security) , *METAHEURISTIC algorithms , *SUPPORT vector machines , *MATHEMATICAL optimization - Abstract
• Building IDS in non-stationary environment. • Proposed a module to track the changing optima for hyper-parameters. • Proposed knowledge transfer mechanism that can be used with metaheuristic optimization algorithms. • Minimize the average optimization time. • Proposed framework helps is retaining the performance of IDS in non-stationary environment. Building an Intrusion Detection System (IDS) in non-stationary environment is challenging because, in such an environment, intrusion-related data grow every day. A machine learning model trained in a stationary environment where training data does not change, often fails to retain its performance in real world environment. This is because dynamism in data makes the hyper-parametric values of the underlying classifier shift in the search space. For making such a model work for intrusion detection in non-stationary environment, one must have to run hyper-parametric optimization algorithm again and again at various time instances. But the expansion of the existing data in non-stationary environment, makes such a way of tunning the hyper-parameters computationally expensive. So, there is a requirement of more adaptive and computationally efficient optimization frameworks for hyper-parameters to build IDS in non-stationary environment. This paperwork proposes a novel framework to train a Support Vector Machine (SVM) for intrusion detection by optimizing its hyper-parameters C and γ dynamically. For designing this framework, we have used Moth-Flame Optimization (MFO) as the base optimization algorithm which can be run with random initialization. Further, for utilizing the knowledge generated by running the base optimization algorithm, we have introduced two algorithms- a Lightweight MFO and a simple Knowledge-Based Search. The Lightweight MFO uses the knowledge for initializing the starting solutions and the Knowledge-Based Search uses the knowledge as search space. Based on the result of a drift detection module, the proposed framework identifies the most appropriate algorithm to be used at a particular time instance when re-training of the model is required due to the change in the data. Results have shown a significant reduction in the average time complexity of the hyper-parametric optimization process. We have evaluated our proposed framework on benchmark NSL-KDD dataset and got significantly encouraging convergence rate and detection performance. The obtained average accuracy for IDS built using our proposed framework is 97.5%. Further , we have also compared our framework by considering other metaheuristic algorithms as base optimization algorithms and found that our proposed framework, which uses MFO as a base optimization algorithm outperforms the others. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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64. An integrated fuzzy support vector regression and the particle swarm optimization algorithm to predict indoor thermal comfort.
- Author
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Megri, Fayçal, Megri, Ahmed Cherif, and Djabri, Riadh
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FUZZY systems ,SUPPORT vector machines ,PARTICLE swarm optimization ,REGRESSION analysis ,INDOOR air quality - Abstract
The thermal comfort indices are usually identified using empirical thermal models based on the human balanced equations and experimentations. In our paper, we propose a statistical regression method to predict these indices. To achieve this goal, first, the fuzzy support vector regression (FSVR) identification approach was integrated with the particle swarm optimization (PSO) algorithm. Then PSO was used as a global optimizer to optimize and select the hyper-parameters needed for the FSVR model. The radial basis function (RBF) kernel was used within the FSVR model. Afterward, these optimal hyper-parameters were used to forecast the thermal comfort indices: predicted mean vote (PMV), predicted percentage dissatisfied (PPD), new standard effective temperature (SET*), thermal discomfort (DISC), thermal sensation (TSENS) and predicted percent dissatisfied due to draft (PD). The application of the proposed approach on different data sets gave successful prediction and promising results. Moreover, the comparisons between the traditional Fanger model and the new model further demonstrate that the proposed model achieves even better identification performance than the original FSVR technique. [ABSTRACT FROM AUTHOR]
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- 2016
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65. Performance analysis of the convolutional recurrent neural network on acoustic event detection
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Yong-Joo Chung and Suk-Hwan Jung
- Subjects
Normalization (statistics) ,0209 industrial biotechnology ,Control and Optimization ,Computer Networks and Communications ,Computer science ,Recurrent neural network ,Convolutional neural network ,02 engineering and technology ,020901 industrial engineering & automation ,Hyper parameters ,Acoustic event detection ,0202 electrical engineering, electronic engineering, information engineering ,Computer Science (miscellaneous) ,Optimal combination ,Electrical and Electronic Engineering ,Instrumentation ,Hyper-parameters ,Segment length ,Convolutional recurrent neural network ,Hardware and Architecture ,Control and Systems Engineering ,020201 artificial intelligence & image processing ,Performance improvement ,Algorithm ,Information Systems - Abstract
In this study, we attempted to find the optimal hyper-parameters of the convolutional recurrent neural network (CRNN) by investigating its performance on acoustic event detection. Important hyper-parameters such as the input segment length, learning rate, and criterion for the convergence test, were determined experimentally. Additionally, the effects of batch normalization and dropout on the performance were measured experimentally to obtain their optimal combination. Further, we studied the effects of varying the batch data on every iteration during the training. From the experimental results using the TUT sound events synthetic 2016 database, we obtained optimal performance with a learning rate of 1/10000. We found that a longer input segment length aided performance improvement, and batch normalization was far more effective than dropout. Finally, performance improvement was clearly observed by varying the starting points of the batch data for each iteration during the training.
- Published
- 2020
66. Evaluating the effects of hyperparameters in convolutional neural networks
- Subjects
глÑбокое обÑÑение ,гипеÑпаÑамеÑÑÑ ,convolutional neural networks ,deep learning ,нейÑоннÑе ÑеÑи ,ÑвеÑÑоÑнÑе нейÑоннÑе ÑеÑи ,hyper-parameters ,neural networks - Abstract
Тема вÑпÑÑкной квалиÑикаÑионной ÑабоÑÑ: «ÐÑенка ÑÑÑекÑов гипеÑпаÑамеÑÑов в ÑвеÑÑоÑнÑÑ Ð½ÐµÐ¹ÑоннÑÑ ÑеÑÑÑ Â».ÐÐ°Ð½Ð½Ð°Ñ ÑабоÑа поÑвÑÑена иÑÑÐ»ÐµÐ´Ð¾Ð²Ð°Ð½Ð¸Ñ ÑÑÑекÑов гипеÑпаÑамеÑÑов нейÑоннÑÑ ÑеÑей в ÑвеÑÑоÑнÑÑ Ð½ÐµÐ¹ÑоннÑÑ ÑеÑÑÑ Ñ Ð¸ÑполÑзованием набоÑа даннÑÑ CIFAR-10. ÐадаÑи, коÑоÑÑе ÑеÑалиÑÑ Ð² Ñ Ð¾Ð´Ðµ иÑÑледованиÑ:ÐÐ±Ð·Ð¾Ñ Ð³Ð¸Ð¿ÐµÑпаÑамеÑÑов и ÑÑÑеÑÑвÑÑÑÐ¸Ñ Ð¼ÐµÑодов Ð´Ð»Ñ Ð¿Ð¾Ð½Ð¸Ð¼Ð°Ð½Ð¸Ñ ÑÑÑекÑов гипеÑпаÑамеÑÑов ÑвеÑÑоÑнÑÑ Ð½ÐµÐ¹ÑоннÑÑ ÑеÑей.РазÑабоÑка базовой модели (ÑвеÑÑоÑной нейÑонной ÑеÑи) Ñ Ð¸ÑполÑзованием набоÑа даннÑÑ CIFAR-10.ÐзаимодейÑÑвие гипеÑпаÑамеÑÑов в ÑазÑабоÑанной ÑвеÑÑоÑной нейÑонной ÑеÑи.ÐизÑализаÑÐ¸Ñ Ð¿ÑоизводиÑелÑноÑÑи модели Ñ Ð¸ÑполÑзованием ÑазлиÑнÑÑ Ð³Ð¸Ð¿ÐµÑпаÑамеÑÑов.Ðнализ взаимодейÑÑÐ²Ð¸Ñ Ð³Ð¸Ð¿ÐµÑпаÑамеÑÑов в ÑвеÑÑоÑнÑÑ Ð½ÐµÐ¹ÑоннÑÑ ÑеÑÑÑ .Ðонимание влиÑÐ½Ð¸Ñ ÐºÐ¾Ð¼Ð±Ð¸Ð½Ð°Ñий гипеÑпаÑамеÑÑов ÑвеÑÑоÑнÑÑ Ð½ÐµÐ¹ÑоннÑÑ ÑеÑей.РабоÑа вÑполнена на оÑнове оÑкÑÑÑого набоÑа даннÑÑ CIFAR-10. Ðа ÑзÑке пÑогÑаммиÑÐ¾Ð²Ð°Ð½Ð¸Ñ Python 3 Ñ Ð±Ð¸Ð±Ð»Ð¸Ð¾Ñеками pytorch и matplotlib.ÐейÑоннÑе ÑеÑи имеÑÑ Ð¼Ð½Ð¾Ð¶ÐµÑÑво гипеÑпаÑамеÑÑов, вклÑÑÐ°Ñ Ð²ÑÐ±Ð¾Ñ Ð¼ÐµÑода гÑадиенÑного ÑпÑÑка, ÑÑнкÑии акÑиваÑии, ÑегÑлÑÑизаÑиÑ, ноÑмализаÑиÑ, ÑÐ°Ð·Ð¼ÐµÑ Ð¿Ð°ÑÑии и Ñак далее. ХоÑÑ ÑÑÑеÑÑвÑÑÑ Ð¿ÐµÑедовÑе меÑодÑ, взаимодейÑÑвие Ð¼ÐµÐ¶Ð´Ñ ÑазлиÑнÑми ваÑианÑами гипеÑпаÑамеÑÑов Ð¼Ð¾Ð¶ÐµÑ Ð±ÑÑÑ ÑÑÑдно пÑедÑказаÑÑ.ÐÐ»Ñ Ð¸Ð·ÑÑÐµÐ½Ð¸Ñ ÑÑого бÑла ÑазÑабоÑана Ð±Ð°Ð·Ð¾Ð²Ð°Ñ Ð¼Ð¾Ð´ÐµÐ»Ñ (ÑвеÑÑоÑÐ½Ð°Ñ Ð½ÐµÐ¹ÑÐ¾Ð½Ð½Ð°Ñ ÑеÑÑ) Ñ ÑоÑноÑÑÑÑ Ð±Ð¾Ð»ÐµÐµ 90% на набоÑе даннÑÑ CIFAR-10 Ñ Ð¸ÑполÑзованием ÑледÑÑÑÐ¸Ñ Ð¼ÐµÑодов: Ñкала ÑкоÑоÑÑи обÑÑениÑ, ÑменÑÑение веÑа, гÑадиенÑное вÑÑезание, ноÑмализаÑÐ¸Ñ Ð´Ð°Ð½Ð½ÑÑ , ноÑмализаÑÐ¸Ñ Ð¿Ð°ÑÑии, ÑвелиÑение даннÑÑ , ÐÑÑаÑоÑнÑе ÑвÑзи.С помоÑÑÑ ÑÑой модели бÑло пÑоведено наÑÑное иÑÑледование, поÑвÑÑенное изÑÑÐµÐ½Ð¸Ñ ÑÑÑекÑов гипеÑпаÑамеÑÑов в ÑвеÑÑоÑнÑÑ Ð½ÐµÐ¹ÑоннÑÑ ÑеÑÑÑ . ÐÑ ÑкÑпеÑименÑиÑовали Ñ ÑазлиÑнÑми гипеÑпаÑамеÑÑами базовой модели, а заÑем ÑаÑÑмоÑÑели пÑоизводиÑелÑноÑÑÑ Ð¼Ð¾Ð´ÐµÐ»Ð¸ в оÑноÑении пеÑеобÑÑениÑ, недообÑÑÐµÐ½Ð¸Ñ Ð¸ ÑоÑноÑÑи, а Ñакже ÑÑÐ¾Ð±Ñ Ð¿Ð¾Ð½ÑÑÑ ÑложнÑÑ Ð²Ð·Ð°Ð¸Ð¼Ð¾ÑвÑÐ·Ñ Ð¼ÐµÐ¶Ð´Ñ Ð³Ð¸Ð¿ÐµÑпаÑамеÑÑами и пÑоизводиÑелÑноÑÑÑÑ Ð¼Ð¾Ð´ÐµÐ»Ð¸.РезÑлÑÑаÑÑ Ð¿Ð¾ÐºÐ°Ð·ÑваÑÑ Ð¿Ð¾Ð²ÐµÐ´ÐµÐ½Ð¸Ðµ базовой модели пÑи иÑполÑзовании ÑазлиÑнÑÑ Ð³Ð¸Ð¿ÐµÑпаÑамеÑÑов, а Ñакже показÑваÑÑ, как ÑложнÑе завиÑимоÑÑи Ð¼ÐµÐ¶Ð´Ñ Ð³Ð¸Ð¿ÐµÑпаÑамеÑÑами влиÑÑÑ Ð½Ð° конеÑнÑÑ Ð¿ÑоизводиÑелÑноÑÑÑ Ð¼Ð¾Ð´ÐµÐ»Ð¸, демонÑÑÑиÑÑÑ Ð²Ð°Ð¶Ð½Ð¾ÑÑÑ Ð¿Ð¾Ð½Ð¸Ð¼Ð°Ð½Ð¸Ñ Ð²Ð»Ð¸ÑÐ½Ð¸Ñ ÐºÐ¾Ð¼Ð±Ð¸Ð½Ð°Ñий гипеÑпаÑамеÑÑов. Ðа оÑновании иÑÑÐ»ÐµÐ´Ð¾Ð²Ð°Ð½Ð¸Ñ Ð¼Ð¾Ð¶Ð½Ð¾ ÑделаÑÑ Ð²Ñвод, ÑÑо Ð´Ð»Ñ Ð´Ð¾ÑÑÐ¸Ð¶ÐµÐ½Ð¸Ñ Ð½Ð°Ð¸Ð²ÑÑÑей ÑоÑноÑÑи ÑÑебÑеÑÑÑ Ð¾Ð¿ÑималÑное ÑоÑеÑание опÑимизаÑоÑа, ÑÑнкÑии акÑиваÑии, ÑазмеÑа паÑÑии и иниÑиализаÑии., The theme of the final graduation research: «Evaluating the effects of hyper-parameters in convolutional neural networks».This research is devoted to research the effects of neural networks hyper-parameters in Convolutional Neural networks using the CIFAR-10 dataset. The Tasks that were solved during the research:Review of hyperparameters and existing methods for understanding the effects of hyperparameters in convolutional neural networks.Development of a base model (convolutional neural network) using CIFAR-10 dataset.Interaction of hyperparameters in the developed convolutional neural network.Visualization of model performance using different hyperparameters .Analysis of the interaction of hyperparameters in convolutional neural networks.Understanding the impact of Convolutional Neural Networks hyperparameter combinations.The work was carried out based on an open dataset CIFAR-10 . In the Python 3 programming language, with the pytorch and matplotlib libraries.Neural networks have many hyper-parameters, including choice of gradient descent method, activation functions, regularization, normalization, batch size, and so on. While best practices exist, interactions between different hyperparameter options can be difficult to predict.To study this, a base model (convolutional neural network) with more than 90% accuracy was developed on the CIFAR-10 dataset using the following techniques: Learning Rate Scale, Weight Decay, Gradient Cutting, Data Normalization , Batch Normalization, Data Augmentation, Residual Connections.Through this model, a scientific research was carried out dedicated to studying the effects of hyper-parameters in convolutional neural networks. We experimented with different hyper-parameters on the base model and then looked at the performance of the model with regard to overfitting, underfitting and accuracy and also to be able to understand the complicated relationship between hyper-parameters and model performance.The results show the behavior of the model when using different hyperparameters and also reveal how complicated dependencies between hyperparameters influence the final performance of the model, demonstrating that it is important to understand the impact of hyperparameter combinations. Based on the research, it can be concluded that an optimal combination of optimizer, activation function,batch size and initialization is required to reach the highest accuracy.
- Published
- 2022
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67. An Enhanced Hyper-Parameter Optimization of a Convolutional Neural Network Model for Leukemia Cancer Diagnosis in a Smart Healthcare System
- Author
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Joseph Bamidele Awotunde, Agbotiname Lucky Imoize, Oluwafisayo Babatope Ayoade, Moses Kazeem Abiodun, Dinh-Thuan Do, Adão Silva, and Samarendra Nath Sur
- Subjects
Internet of Medical of Things ,convolutional neural network ,deep learning ,machine learning ,diagnosis ,leukemia dataset ,prostate cancer dataset ,hyper-parameters ,Electrical and Electronic Engineering ,Biochemistry ,Instrumentation ,Atomic and Molecular Physics, and Optics ,Analytical Chemistry - Abstract
Healthcare systems in recent times have witnessed timely diagnoses with a high level of accuracy. Internet of Medical Things (IoMT)-enabled deep learning (DL) models have been used to support medical diagnostics in real time, thus resolving the issue of late-stage diagnosis of various diseases and increasing performance accuracy. The current approach for the diagnosis of leukemia uses traditional procedures, and in most cases, fails in the initial period. Hence, several patients suffering from cancer have died prematurely due to the late discovery of cancerous cells in blood tissue. Therefore, this study proposes an IoMT-enabled convolutional neural network (CNN) model to detect malignant and benign cancer cells in the patient’s blood tissue. In particular, the hyper-parameter optimization through radial basis function and dynamic coordinate search (HORD) optimization algorithm was used to search for optimal values of CNN hyper-parameters. Utilizing the HORD algorithm significantly increased the effectiveness of finding the best solution for the CNN model by searching multidimensional hyper-parameters. This implies that the HORD method successfully found the values of hyper-parameters for precise leukemia features. Additionally, the HORD method increased the performance of the model by optimizing and searching for the best set of hyper-parameters for the CNN model. Leukemia datasets were used to evaluate the performance of the proposed model using standard performance indicators. The proposed model revealed significant classification accuracy compared to other state-of-the-art models.
- Published
- 2022
68. Photovoltaic Power Prediction Based on Improved Sparse Bayesian Regression.
- Author
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Li, Yuancheng, Li, Zhaorong, Yang, Liqun, and Wang, Bei
- Subjects
- *
PHOTOVOLTAIC power generation , *ELECTRIC power distribution grids , *PRODUCTION scheduling , *BAYESIAN analysis , *REGRESSION analysis - Abstract
The photovoltaic grid connection can impact the power grid and affect its stability; therefore, making predictions about photovoltaic power is critically important for the grid scheduling department to properly plan power generation. The characteristics of photovoltaic power are analyzed, and the principle of sparse Bayesian regression is studied; thus, a photovoltaic power prediction model based on the sparse Bayesian regression algorithm is established. Traditional sparse Bayesian regression uses the maximum likelihood method to optimize hyper-parameters, which has some disadvantages, for example, the optimization effect excessively depends on initial values and iterations are difficult to determine. In this article, the artificial bee colony is used instead of the maximum likelihood method to optimize the hyper-parameters. An improved sparse Bayesian regression model based on artificial bee colony optimization is proposed that considers meteorological factors and historical power data. Finally, the state grid Scenery Storage Demonstration Project data are used to test the proposed prediction model. The simulation result shows that the improved sparse Bayesian regression model achieves good prediction effects. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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69. Source code analysis with LDA.
- Author
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Binkley, David, Heinz, Daniel, Lawrie, Dawn, and Overfelt, Justin
- Subjects
- *
DIRICHLET forms , *SOURCE code , *PROBABILITY theory , *COMPUTER software development , *BIG data - Abstract
Latent Dirichlet allocation (LDA) has seen increasing use in the understanding of source code and its related artifacts in part because of its impressive modeling power. However, this expressive power comes at a cost: The technique includes several tuning parameters whose impact on the resulting LDA model must be carefully considered. The aim of this work is to provide insights into the tuning parameters' impact. Doing so improves the comprehension of both researchers who look to exploit the power of LDA in their research and those who interpret the output of LDA-using tools. It is important to recognize that the goal of this work is not to establish values for the tuning parameters because there is no universal best setting. Rather, appropriate settings depend on the problem being solved, the input corpus (in this case, typically words from the source code and its supporting artifacts), and the needs of the engineer performing the analysis. This work's primary goal is to aid software engineers in their understanding of the LDA tuning parameters by demonstrating numerically and graphically the relationship between the tuning parameters and the LDA output. A secondary goal is to enable more informed setting of the parameters. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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70. A Data-Driven Gaussian Process Regression Model for Two-Chamber Microbial Fuel Cells.
- Author
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He, Y.-J. and Ma, Z.-F.
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PERFORMANCE of microbial fuel cells ,GAUSSIAN processes ,REGRESSION analysis ,ENERGY conversion ,NONPARAMETRIC estimation ,CHARGE exchange ,GLUTAMIC acid ,ELECTROCHEMICAL analysis - Abstract
Rapidly and accurately modeling of microbial fuel cells (MFCs) plays an important role not only in thorough understanding of the effects of operating conditions on system performance, but also in the successful implementation of real-time maximization of power output. Although the first principle electrochemical model has better generalization performance, it is often time-consuming for model construction and is hard to real-time application. In this study, a nonparametric Gaussian process regression (GPR) model is used to capture the nonlinear relationship between operating conditions and output voltage in the MFCs. A simple online learning strategy is proposed to recursively update the hyper-parameters of the GPR model. The applicability and effectiveness of the proposed method is validated by both the simulation and experimental datasets from the acetate and the glucose and glutamic acid two-chamber MFCs. The results illustrate that the online GPR model provides a promising method for capturing the complex nonlinearity phenomenon in MFCs, which can be greatly helpful for further real-time optimization of MFCs. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
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71. Particle Swarm Optimization Based Deep Learning Model for Scene Classification of Remote Sensing Images
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Singh, Jagroop, Singh, Gurjeet, Singh, Jagroop, and Singh, Gurjeet
- Abstract
Classification of remote sensing images is an open area of research. Recently deep learning models are extensively utilized to classify the images. To overcome the overfitting issue, an ensemble deep learning model is proposed. The hyper-parameter of the proposed model is tuned using particle swarm optimization. Initially, the features of remote sensing images are extracted. Theater, feature selection approach is used. The extracted features are then used to build the model by using the particle swarm optimization-based ensemble deep learning model. Extensive experiments are performed using the proposed model. The comparative analysis show that the proposed model outperforms the existing model.
- Published
- 2021
72. Phase II monitoring of linear profiles with random explanatory variable under Bayesian framework
- Author
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Saddam Akber Abbasi, Muhammad Riaz, Zhengming Qian, and Tahir Abbas
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Prior distributions ,021103 operations research ,General Computer Science ,Computer science ,Hyper-parameters ,Bayesian probability ,0211 other engineering and technologies ,General Engineering ,Exponentially weighted moving average ,Phase (waves) ,02 engineering and technology ,Variable (computer science) ,Posterior distributions ,Prior probability ,0202 electrical engineering, electronic engineering, information engineering ,Statistical process control ,020201 artificial intelligence & image processing ,Control chart ,Run length properties ,Sensitivity (control systems) ,Algorithm ,Selection (genetic algorithm) - Abstract
Linear profiles monitoring have been successfully implemented in many industrial applications. The design structures of control charts for profiles monitoring are mostly based on two major classifications namely Classical and Bayesian. This study investigates the novel Bayesian exponentially weighted moving average and multivariate exponentially weighted moving average control charts for the monitoring of linear profiles, when explanatory variable(s) are random. The informative priors of normal and inverse gamma; and Bramwell, Holdsworth, Pinton (BHP) and Levy distributions are considered as conjugate and non-conjugate priors respectively. The proposed Bayesian schemes are evaluated using different run length characteristics. The schemes are also validated with simulation study and real-world data sets. The outcomes demonstrate that the Bayesian methods perform effectively better than the competing methods. The specified values of hyper-parameters are selected carefully after elicitation and sensitivity analysis of hyper-parameters. It has been observed that careful consideration is required while selecting the priors and possible values of hyper-parameters. The selection of appropriate priors and corresponding hyper-parameters comes up with efficient control structures which provide tangible benefits. 2018 Elsevier Ltd The authors would like to acknowledge the Editor and Referees for their constructive comments that lead to significant improvements in the manuscript. The authors would like to acknowledge their parent Universities for providing excellent research facilities. Moreover, Dr. Muhammad Riaz would like to acknowledge Deanship of Scientific Research for supporting the study under Project Number IN171016. Scopus
- Published
- 2019
73. Selecting Hyper-Parameters of Gaussian Process Regression Based on Non-Inertial Particle Swarm Optimization in Internet of Things
- Author
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Yu-Xi Hu, Ruey-Shun Chen, Naixue Xiong, Chien-Ming Chen, Yeh-Cheng Chen, and Lanlan Kang
- Subjects
020203 distributed computing ,General Computer Science ,Series (mathematics) ,Computer science ,Generalization ,non-inertial particle swarm optimization ,General Engineering ,Process (computing) ,Swarm behaviour ,Particle swarm optimization ,02 engineering and technology ,Regression ,Physics::Geophysics ,Nonlinear system ,Mutation Gaussian process regression ,Kriging ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,General Materials Science ,hyper-parameters ,lcsh:Electrical engineering. Electronics. Nuclear engineering ,Algorithm ,time series regression ,lcsh:TK1-9971 - Abstract
Gaussian process regression (GPR) is frequently used for uncertain measurement and prediction of nonstationary time series in the Internet of Things data, nevertheless, the generalization and regression efficacy of GPR are directly impacted by its selection of hyper-parameters. In the study, a non-inertial particle swarm optimization with elite mutation-Gaussian process regression (NIPSO-GPR) is proposed to optimize the hyper-parameters of GRP. NIPSO-GPR can adaptively obtain hyper-parameters of GPR via uniform non-inertial velocity update formula and adaptive elite mutation strategy. When compared with several frequently used algorithms of hyper-parameters optimization on linear and nonlinear time series sample data, experimental results indicate that GPR after hyper-parameters optimized by NIPSO-GPR has better fitting precision and generalization ability.
- Published
- 2019
74. Optimized neural networks in industrial data analysis
- Author
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Caballero, Liesle, Jojoa, Mario, and Percybrooks, Winston S.
- Published
- 2020
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75. Nonlinear multivariable modeling of locomotive proton exchange membrane fuel cell system.
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Li, Qi, Chen, Weirong, Liu, Zhixiang, Guo, Ai, and Huang, Jin
- Subjects
- *
PROTON exchange membrane fuel cells , *PARTICLE swarm optimization , *FUEL cells , *COMPUTER algorithms , *ALGORITHMS - Abstract
A nonlinear multivariable model of a locomotive proton exchange membrane fuel cell (PEMFC) system based on a support vector regression (SVR) is proposed to study the effect of different operating conditions on dynamic behavior of a locomotive PEMFC power unit. Furthermore, an effective informed adaptive particle swarm optimization (EIA-PSO) algorithm which is an adaptive swarm intelligence optimization with preferable search ability and search rate is utilized to tune the hyper-parameters of the SVR model for the improvement of model performance. The comparisons with the experimental data demonstrate that the SVR model based on EIA-PSO can efficiently approximate the dynamic behaviors of locomotive PEMFC power unit and is capable of predicting dynamic performance in terms of the output voltage and power with a high accuracy. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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- View/download PDF
76. A nonlinear least squares quasi-Newton strategy for LP-SVR hyper-parameters selection.
- Author
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Rivas-Perea, Pablo, Cota-Ruiz, Juan, and Rosiles, Jose-Gerardo
- Abstract
This paper studies the problem of hyper-parameters selection for a linear programming-based support vector machine for regression (LP-SVR). The proposed model is a generalized method that minimizes a linear-least squares problem using a globalization strategy, inexact computation of first order information, and an existing analytical method for estimating the initial point in the hyper-parameters space. The minimization problem consists of finding the set of hyper-parameters that minimizes any generalization error function for different problems. Particularly, this research explores the case of two-class, multi-class, and regression problems. Simulation results among standard data sets suggest that the algorithm achieves statistically insignificant variability when measuring the residual error; and when compared to other methods for hyper-parameters search, the proposed method produces the lowest root mean squared error in most cases. Experimental analysis suggests that the proposed approach is better suited for large-scale applications for the particular case of an LP-SVR. Moreover, due to its mathematical formulation, the proposed method can be extended in order to estimate any number of hyper-parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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77. A Generalized Polynomial Chaos-Based Method for Efficient Bayesian Calibration of Uncertain Computational Models.
- Author
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Tagade, Piyush M. and Choi, Han-Lim
- Subjects
- *
POLYNOMIAL chaos , *GAUSSIAN processes , *DISTRIBUTION (Probability theory) , *STATIONARY processes , *MARKOV processes , *CALIBRATION - Abstract
This paper addresses the Bayesian calibration of dynamic models with parametric and structural uncertainties, in particular where the uncertain parameters are unknown/poorly known spatio-temporally varying subsystem models. Independent stationary Gaussian processes with uncertain hyper-parameters describe uncertainties of the model structure and parameters, while Karhunen-Loeve expansion is adopted to spectrally represent these Gaussian processes. The Karhunen-Loeve expansion of a prior Gaussian process is projected on a generalized Polynomial Chaos basis, whereas intrusive Galerkin projection is utilized to calculate the associated coefficients of the simulator output. Bayesian inference is used to update the prior probability distribution of the generalized Polynomial Chaos basis, which along with the chaos expansion coefficients represent the posterior probability distribution. The proposed method is demonstrated for calibration of a simulator of quasi-one-dimensional flow through a divergent nozzle with uncertain nozzle area profile. The posterior distribution of the nozzle area profile and the hyper-parameters obtained using the proposed method are found to match closely with the direct Markov Chain Monte Carlo-based implementation of the Bayesian framework. Efficacy of the proposed method is demonstrated for various choices of prior. Posterior hyper-parameters of the model structural uncertainty are shown to quantify acceptability of the simulator model. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
78. hyOPTXg: OPTUNA hyper-parameter optimization framework for predicting cardiovascular disease using XGBoost.
- Author
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Srinivas, Polipireddy and Katarya, Rahul
- Subjects
CARDIOVASCULAR diseases ,RECEIVER operating characteristic curves ,HEART diseases ,HEART failure ,MATHEMATICAL optimization - Abstract
• We proposed a novel model hyOPTXg to identify cardiovascular disease. • The proposed model hyOPTXg utilized the XGBoost and OPTUNA techniques. • Data pre-processing and hyper-parameter tuning techniques were applied. Cardiovascular disease is a dangerous disorder that causes the most significant number of deaths across the world. In the past years, researchers proposed several automated systems to identify heart disease early so that there is a chance to enhance the diagnosis process. This research paper proposes an expert model called hyOPTXg, which predicts heart disease using an optimized XGBoost classifier. To produce a better system using a classifier, we need decent hyper-parameter tuning. So, we tuned the hyper-parameters of XGBoost and trained the model using tuned parameters. The framework used for hyper-parameter tuning is OPTUNA (hyper-parameter optimization technique). This system was tested on three datasets: The Cleveland dataset and the Heart Failure prediction dataset from Kaggle and heart disease UCI from Kaggle. We used various metrics to assess the system's efficiency, including recall, precision, f1-score, accuracy, and the ROC chart's area under the curve (AUC). And we got better results compared to other systems which other authors propose in recent times. We got 94.7% in the Cleveland dataset,89.3% in the Kaggle heart failure dataset, and 88.5% in the heart disease UCI Kaggle dataset. Our prediction result says that we got better results than other systems proposed by the other authors. And we did a comparison study of our model with other authors' models. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
79. Spatio-temporal interpolation of precipitation during monsoon periods in Pakistan
- Author
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Hussain, Ijaz, Spöck, Gunter, Pilz, Jürgen, and Yu, Hwa-Lung
- Subjects
- *
SPATIO-temporal variation , *METEOROLOGICAL precipitation , *MONSOONS , *INTERPOLATION , *WATER supply management , *HYDROLOGIC models , *RAINFALL frequencies - Abstract
Abstract: Spatio-temporal estimation of precipitation over a region is essential to the modeling of hydrologic processes for water resources management. The changes of magnitude and space–time heterogeneity of rainfall observations make space–time estimation of precipitation a challenging task. In this paper we propose a Box–Cox transformed hierarchical Bayesian multivariate spatio-temporal interpolation method for the skewed response variable. The proposed method is applied to estimate space–time monthly precipitation in the monsoon periods during 1974–2000, and 27-year monthly average precipitation data are obtained from 51 stations in Pakistan. The results of transformed hierarchical Bayesian multivariate spatio-temporal interpolation are compared to those of non-transformed hierarchical Bayesian interpolation by using cross-validation. The software developed by [11] is used for Bayesian non-stationary multivariate space–time interpolation. It is observed that the transformed hierarchical Bayesian method provides more accuracy than the non-transformed hierarchical Bayesian method. [Copyright &y& Elsevier]
- Published
- 2010
- Full Text
- View/download PDF
80. In vivo quantitation of metabolites with an incomplete model function.
- Author
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Popa, E., Capobianco, E., De Beer, R., van Ormondt, D, and Graveron-Demilly, D
- Subjects
METABOLITES ,MATHEMATICAL models ,BIOMARKERS ,NUCLEAR magnetic resonance spectroscopy ,SIGNAL processing ,PARAMETER estimation ,MONTE Carlo method ,ESTIMATION theory - Abstract
Metabolites can serve as biomarkers. Estimation of metabolite concentrations from an in vivo magnetic resonance spectroscopy (MRS) signal often uses a reference signal to estimate a model function of the spectral lineshape. When no reference signal is available, the a priori unknown in vivo lineshape must be inferred from the data at hand. This makes quantitation of metabolites from in vivo MRS signals a semi-parametric estimation problem which, in turn, implies setting of hyper-parameters by users of the software involved. Estimation of metabolite concentrations is usually done by nonlinear least-squares (NLLS) fitting of a physical model function based on minimizing the residue. In this work, the semi-parametric task is handled by complementing the usual criterion of minimal residue with a second criterion acting in tandem with it. This second criterion is derived from the general physical knowledge that the width of the line is limited. The limit on the width is a hyper-parameter; its setting appeared not critical so far. The only other hyper-parameter is the relative weight of the two criteria. But its setting too is not critical. Attendant estimation errors, obtained from a Monte Carlo calculation, show that the two-criterion NLLS approach successfully handles the semi-parametric aspect of metabolite quantitation. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
81. Bootstrap Approximation to Prediction MSE for State–Space Models with Estimated Parameters.
- Author
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Pfeffermann, Danny and Tiller, Richard
- Subjects
- *
PARAMETER estimation , *ESTIMATES , *STATISTICAL bootstrapping , *ESTIMATION theory , *STOCHASTIC processes , *MATHEMATICAL statistics - Abstract
We propose simple parametric and nonparametric bootstrap methods for estimating the prediction mean square error (PMSE) of state vector predictors that use estimated model parameters. As is well known, substituting the model parameters by their estimates in the theoretical PMSE expression that assumes known parameter values results in underestimation of the true PMSE. The parametric method consists of generating parametrically a large number of bootstrap series from the model fitted to the original series, re-estimating the model parameters for each series using the same method as used for the original series and then estimating the separate components of the PMSE. The nonparametric method generates the series by bootstrapping the standardized innovations estimated for the original series. The bootstrap methods are compared with other methods considered in the literature in a simulation study that also examines the robustness of the various methods to non-normality of the model error terms. Application of the bootstrap method to a model fitted to employment ratios in the USA that contains 18 unknown parameters, estimated by a three-step procedure yields unbiased PMSE estimators. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
82. Sensitivity of Bayes Estimators to Hyper-Parameters with an Application to Maximum Yield from Fisheries.
- Author
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Millar, Russell B.
- Subjects
- *
FISH populations , *BAYES' estimation , *POPULATION dynamics , *PARAMETER estimation , *TUNA - Abstract
Priors are seldom unequivocal and an important component of Bayesian modeling is assessment of the sensitivity of the posterior to the specified prior distribution. This is especially true in fisheries science where the Bayesian approach has been promoted as a rigorous method for including existing information from previous surveys and from related stocks or species. These informative priors may be highly contested by various interest groups. Here, formulae for the first and second derivatives of Bayes estimators with respect to hyper-parameters of the joint prior density are given. The formula for the second derivative provides a correction to a previously published result. The formulae are shown to reduce to very convenient and easily implemented forms when the hyper-parameters are for exponential family marginal priors. For model parameters with such priors it is shown that the ratio of posterior variance to prior variance can be interpreted as the sensitivity of the posterior mean to the prior mean. This methodology is applied to a nonlinear state-space model for the biomass of South Atlantic albacore tuna and sensitivity of the maximum sustainable yield to the prior specification is examined. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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83. Joint Bayesian Analysis of Factor Scores and Structural Parameters in the Factor Analysis Model.
- Author
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Lee, Sik-Yum and Shi, Jian-Qing
- Abstract
A Bayesian approach is developed to assess the factor analysis model. Joint Bayesian estimates of the factor scores and the structural parameters in the covariance structure are obtained simultaneously. The basic idea is to treat the latent factor scores as missing data and augment them with the observed data in generating a sequence of random observations from the posterior distributions by the Gibbs sampler. Then, the Bayesian estimates are taken as the sample means of these random observations. Expressions for implementing the algorithm are derived and some statistical properties of the estimates are presented. Some aspects of the algorithm are illustrated by a real example and the performance of the Bayesian procedure is studied using simulation. [ABSTRACT FROM AUTHOR]
- Published
- 2000
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- View/download PDF
84. Genetically optimized prediction of remaining useful life.
- Author
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Agrawal, Shaashwat, Sarkar, Sagnik, Srivastava, Gautam, Reddy Maddikunta, Praveen Kumar, and Gadekallu, Thippa Reddy
- Subjects
JET engines ,TURBOFAN engines ,DEEP learning ,FORECASTING ,MATHEMATICAL optimization ,GENETIC algorithms - Abstract
• The NASA dataset is trained with a tuned 2-layer LSTM and GRU models. • The results are compared to existing outputs and inference shown. • Introduce a semi-novel optimization algorithm using genetic algorithms. • Hyper-parameters of the model – learning rate and batch size are self-tuned by a genetic algorithm. The application of remaining useful life (RUL) prediction is very important in terms of energy optimization, cost-effectiveness, and risk mitigation. The existing RUL prediction algorithms mostly constitute deep learning frameworks. In this paper, we implement LSTM and GRU models and compare the obtained results with a proposed genetically trained neural network. The current models solely depend on ADAM and SGD for optimization and learning. Although the models have worked well with these optimizers, even little uncertainties in prognostics prediction can result in huge losses. We hope to improve the consistency of the predictions by adding another layer of optimization using Genetic Algorithms. The hyper-parameters – learning rate and batch size are optimized beyond manual capacity. These models and the proposed architecture are tested on the NASA Turbofan Jet Engine dataset. The optimized architecture can predict the given hyper-parameters autonomously and provide superior results. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
85. A New Hyper-Parameter Optimization Method for Power Load Forecast Based on Recurrent Neural Networks.
- Author
-
Li, Yaru, Zhang, Yulai, and Cai, Yongping
- Subjects
- *
RECURRENT neural networks , *PARTICLE swarm optimization , *ALGORITHMS , *MACHINE learning , *FORECASTING , *COMPUTATIONAL complexity , *LOAD forecasting (Electric power systems) - Abstract
The selection of the hyper-parameters plays a critical role in the task of prediction based on the recurrent neural networks (RNN). Traditionally, the hyper-parameters of the machine learning models are selected by simulations as well as human experiences. In recent years, multiple algorithms based on Bayesian optimization (BO) are developed to determine the optimal values of the hyper-parameters. In most of these methods, gradients are required to be calculated. In this work, the particle swarm optimization (PSO) is used under the BO framework to develop a new method for hyper-parameter optimization. The proposed algorithm (BO-PSO) is free of gradient calculation and the particles can be optimized in parallel naturally. So the computational complexity can be effectively reduced which means better hyper-parameters can be obtained under the same amount of calculation. Experiments are done on real world power load data, where the proposed method outperforms the existing state-of-the-art algorithms, BO with limit-BFGS-bound (BO-L-BFGS-B) and BO with truncated-newton (BO-TNC), in terms of the prediction accuracy. The errors of the prediction result in different models show that BO-PSO is an effective hyper-parameter optimization method. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
86. Fully Automatic Brain Tumor Segmentation using End-to-End Incremental Deep Neural Networks in MRI images
- Author
-
Rachida Saouli, Rostom Kachouri, Mostefa Ben Naceur, Mohamed Akil, Laboratoire d'Informatique Intelligente (LINFI), Université Mohamed Khider de Biskra (BISKRA), Laboratoire d'Informatique Gaspard-Monge (LIGM), Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM), and Université Paris-Est Marne-la-Vallée (UPEM)-École des Ponts ParisTech (ENPC)-ESIEE Paris-Fédération de Recherche Bézout-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Fully automatic ,Computer science ,Health Informatics ,02 engineering and technology ,[INFO.INFO-NE]Computer Science [cs]/Neural and Evolutionary Computing [cs.NE] ,Convolutional neural network ,Pattern Recognition, Automated ,030218 nuclear medicine & medical imaging ,Machine Learning ,03 medical and health sciences ,0302 clinical medicine ,[INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing ,[INFO.INFO-LG]Computer Science [cs]/Machine Learning [cs.LG] ,Image Processing, Computer-Assisted ,0202 electrical engineering, electronic engineering, information engineering ,[INFO.INFO-IM]Computer Science [cs]/Medical Imaging ,Humans ,Brain segmentation ,Training ,Segmentation ,Diagnosis, Computer-Assisted ,Brain tumor segmentation ,Brain Neoplasms ,business.industry ,Deep learning ,Hyper-parameters ,Process (computing) ,Brain ,[INFO.INFO-CV]Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV] ,020207 software engineering ,Pattern recognition ,Magnetic Resonance Imaging ,Ensemble learning ,Computer Science Applications ,Convolutional neural networks ,Neural Networks, Computer ,Artificial intelligence ,Glioblastoma ,business ,Algorithms ,Software - Abstract
International audience; Background and Objective: Nowadays, getting an efficient Brain Tumor Segmentation in Multi-Sequence MR images as soon as possible, gives an early clinical diagnosis, treatment and follow-up. The aim of this study is to develop a new deep learning model for the segmentation of brain tumors. The proposed models are used to segment the brain tumors of Glioblastomas (with both high and low grade). Glioblastomas have four properties: different sizes, shapes, contrasts, in addition, Glioblastomas appear anywhere in the brain. Methods: In this paper, we propose three end-to-end Incremental Deep Convolutional Neural Networks models for fully automatic Brain Tumor Segmentation. Our proposed models are different from the other CNNs-based models that follow the technique of trial and error process which does not use any guided approach to get the suitable hyper-parameters. Moreover, we adopt the technique of Ensemble Learning to design a more efficient model. For solving the problem of training CNNs model, we propose a new training strategy which takes into account the most influencing hyper-parameters by bounding and setting a roof to these hyper-parameters to accelerate the training. Results: Our experiment results reported on BRATS-2017 dataset. The proposed deep learning models achieve the state-of-the-art performance without any post-processing operations. Indeed, our models achieve in average 0.88 Dice score over the complete region. Moreover, the efficient design with the advantage of GPU implementation, allows our three deep learning models to achieve brain segmentation results in average 20.87 seconds. Conclusions: The proposed deep learning models are effective for the segmentation of brain tumors and allow to obtain high accurate results. Moreover, the proposed models could help the physician experts to reduce the time of diagnostic.
- Published
- 2018
87. Deep Neural Network Hyper-Parameter Setting for Classification of Obstructive Sleep Apnea Episodes
- Author
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Giovanna Sannino, Ivanoe De Falco, Giuseppe A. Trunfio, Giuseppe De Pietro, Ernesto Tarantino, Antonio Della Cioppa, and Umberto Scafuri
- Subjects
Obstructive Sleep Apnea ,Computer science ,classification ,data reduction ,Deep Neural Network ,Differential Evolution ,hyper-parameters ,Software ,Signal Processing ,Mathematics (all) ,Computer Science Applications1707 Computer Vision and Pattern Recognition ,Computer Networks and Communications ,0206 medical engineering ,Evolutionary algorithm ,02 engineering and technology ,Machine learning ,computer.software_genre ,Evolutionary computation ,Task (project management) ,0202 electrical engineering, electronic engineering, information engineering ,Training set ,Artificial neural network ,business.industry ,020601 biomedical engineering ,Data set ,Differential evolution ,Test set ,Task analysis ,020201 artificial intelligence & image processing ,Artificial intelligence ,business ,computer - Abstract
The wide availability of sensing devices in the medical domain causes the creation of large and very large data sets. Hence, tasks as the classification in such data sets becomes more and more difficult. Deep Neural Networks (DNNs) are very effective in classification, yet finding the best values for their hyper-parameters is a difficult and time-consuming task. This paper introduces an approach to decrease execution times to automatically find good hyper-parameter values for DNN through Evolutionary Algorithms when classification task is faced. This decrease is obtained through the combination of two mechanisms. The former is constituted by a distributed version for a Differential Evolution algorithm. The latter is based on a procedure aimed at reducing the size of the training set and relying on a decomposition into cubes of the space of the data set attributes. Experiments are carried out on a medical data set about Obstructive Sleep Anpnea. They show that sub-optimal DNN hyper-parameter values are obtained in a much lower time with respect to the case where this reduction is not effected, and that this does not come to the detriment of the accuracy in the classification over the test set items.
- Published
- 2018
88. A dynamic framework for tuning SVM hyper parameters based on Moth-Flame Optimization and knowledge-based-search.
- Author
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Kalita, Dhruba Jyoti, Singh, Vibhav Prakash, and Kumar, Vinay
- Subjects
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PARTICLE swarm optimization , *MATHEMATICAL optimization , *GENETIC algorithms , *MACHINE learning , *SUPPORT vector machines , *SOCIAL problems - Abstract
• Considered dynamic nature of data for real world problems. • Proposed shift detection for shifting optimum. • Proposed knowledge based search with MFO. • Fast convergence rate to minimize execution time. • Proposed framework is highly inclined towards accuracy of SVM. In the real world, most of the collections of data are dynamic in nature, i.e. their size may grow with time. This dynamic nature of the data not only reduces the performance of the classifiers but also demands more optimized models for retaining the performance. Due to this, machine learning models developed in a static environment cannot be deployed efficiently to solve the real-world problems. Nowadays, maximum existing works consider only the static behaviour of the data for the training of machine learning models where the size of the collection of training data does not change over time. This paperwork imposes Support Vector Machine (SVM) in a dynamic environment. It has been identified that shifting of the optimum values of two hyper-parameters C (Penalty Parameter) and γ (Kernel Parameter) in the search space is one of the primary reasons for the performance degradation of SVM in dynamic environment. This paper proposes a novel framework that uses a new optimization module Knowledge-Based-Search (KBS) along with Moth –Flame Optimization (MFO) to optimize C and γ in a dynamic environment to train SVM efficiently. KBS uses knowledge gathered at various instances of time, which are the bi-products of MFO. MFO in our framework is the base optimization algorithm which works underneath KBS. The experiments have shown that KBS helps in controlling the exponential growth of the time complexity of the optimization process where only MFO is used to optimize C and γ. Integration of KBS with MFO brings down the time complexity to a large extent. To validate the proposed framework we have used a simulated dynamic environment for profit/loss classification problem for organizations. The experiments have also shown that KBS's integration with MFO outperforms integration of KBS with other modern optimization techniques such as Particle Swarm Optimization (PSO), Multi-Verse Optimization (MVO), Grey-Wolf Optimization (GWO), Cuckoo Search (CS), Whale Optimization Algorithm (WOA), Genetic Algorithm (GA), Fire-Fly Algorithm (FFA) and Salp Swarm Algorithm (SSA). [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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89. An evolutionary hyper-heuristic to optimise deep belief networks for image reconstruction.
- Author
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Sabar, Nasser R., Turky, Ayad, Song, Andy, and Sattar, Abdul
- Subjects
IMAGE reconstruction ,HEURISTIC - Abstract
Deep Belief Networks (DBN) have become a powerful tools to deal with a wide range of applications. On complex tasks like image reconstruction, DBN's performance is highly sensitive to parameter settings. Manually trying out different parameters is tedious and time consuming however often required in practice as there are not many better options. This work proposes an evolutionary hyper-heuristic framework for automatic parameter optimisation of DBN. The hyper-heuristic framework introduced here is the first of its kind in this domain. It involves a high level strategy and a pool of evolutionary operators such as crossover and mutation to generates DBN parameter settings by perturbing or modifying the current setting of a DBN. Providing a large set of operators could be beneficial to form a more effective high level strategy, but in the same time would increase the search space hence make it more difficulty to form a good strategy. To address this issue, a non-parametric statistical test is introduced to identify a subset of effective operators for different phases of the hyper-heuristic search. Three well-known image reconstruction datasets were used to evaluate the performance of the proposed framework. The results reveal that the proposed hyper-heuristic framework is very competitive when compared to the state of art methods. • We propose a hyper-heuristic to optimise Deep Belief Networks. • We use a large set of heuristic with in the hyper-heuristic. • We propose a non-parametric statistical test to identify the best heuristics. • We tested the proposed hyper-heuristics on three different datasets. • The results demonstrated the effectiveness of the hyper-heuristic. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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90. Inversion pour image texturée : déconvolution myope non supervisée, choix de modèles, déconvolution-segmentation
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VĂCAR, Cornelia Paula, STAR, ABES, Giovannelli, Jean-François, Berthoumieu, Yannick, Tupin, Florence, Colin, Thierry, Dobigeon, Nicolas, and Fablet, Ronan
- Subjects
Inverse problems ,BAYES ,Problème inverse ,Segmentation ,[INFO.INFO-TI] Computer Science [cs]/Image Processing [eess.IV] ,Hyper-parameters ,Déconvolution ,Deconvolution ,Hyper-paramètre - Abstract
This thesis is addressing a series of inverse problems of major importance in the fieldof image processing (image segmentation, model choice, parameter estimation, deconvolution)in the context of textured images. In all of the aforementioned problems theobservations are indirect, i.e., the textured images are affected by a blur and by noise. Thecontributions of this work belong to three main classes: modeling, methodological andalgorithmic. From the modeling standpoint, the contribution consists in the development of a newnon-Gaussian model for textures. The Fourier coefficients of the textured images are modeledby a Scale Mixture of Gaussians Random Field. The Power Spectral Density of thetexture has a parametric form, driven by a set of parameters that encode the texture characteristics.The methodological contribution is threefold and consists in solving three image processingproblems that have not been tackled so far in the context of indirect observationsof textured images. All the proposed methods are Bayesian and are based on the exploitingthe information encoded in the a posteriori law. The first method that is proposed is devotedto the myopic deconvolution of a textured image and the estimation of its parameters.The second method achieves joint model selection and model parameters estimation froman indirect observation of a textured image. Finally, the third method addresses the problemof joint deconvolution and segmentation of an image composed of several texturedregions, while estimating at the same time the parameters of each constituent texture.Last, but not least, the algorithmic contribution is represented by the development ofa new efficient version of the Metropolis Hastings algorithm, with a directional componentof the proposal function based on the”Newton direction” and the Fisher informationmatrix. This particular directional component allows for an efficient exploration of theparameter space and, consequently, increases the convergence speed of the algorithm.To summarize, this work presents a series of methods to solve three image processingproblems in the context of blurry and noisy textured images. Moreover, we present twoconnected contributions, one regarding the texture models andone meant to enhance theperformances of the samplers employed for all of the three methods., Ce travail est dédié à la résolution de plusieurs problèmes de grand intérêt en traitement d’images : segmentation, choix de modèle et estimation de paramètres, pour le cas spécifique d’images texturées indirectement observées (convoluées et bruitées). Dans ce contexte, les contributions de cette thèse portent sur trois plans différents : modéle, méthode et algorithmique.Du point de vue modélisation de la texture, un nouveaumodèle non-gaussien est proposé. Ce modèle est défini dans le domaine de Fourier et consiste en un mélange de Gaussiennes avec une Densité Spectrale de Puissance paramétrique.Du point de vueméthodologique, la contribution est triple –troisméthodes Bayésiennes pour résoudre de manière :–optimale–non-supervisée–des problèmes inverses en imagerie dans le contexte d’images texturées ndirectement observées, problèmes pas abordés dans la littérature jusqu’à présent.Plus spécifiquement,1. la première méthode réalise la déconvolution myope non-supervisée et l’estimation des paramètres de la texture,2. la deuxième méthode est dédiée à la déconvolution non-supervisée, le choix de modèle et l’estimation des paramètres de la texture et, finalement,3. la troisième méthode déconvolue et segmente une image composée de plusieurs régions texturées, en estimant au même temps les hyperparamètres (niveau du signal et niveau du bruit) et les paramètres de chaque texture.La contribution sur le plan algorithmique est représentée par une nouvelle version rapide de l’algorithme Metropolis-Hastings. Cet algorithme est basé sur une loi de proposition directionnelle contenant le terme de la ”direction de Newton”. Ce terme permet une exploration rapide et efficace de l’espace des paramètres et, de ce fait, accélère la convergence.
- Published
- 2014
91. A Monte Carlo method for an objective Bayesian procedure
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Ogata, Yosihiko
- Published
- 1990
- Full Text
- View/download PDF
92. Maximum likelihood-based online adaptation of hyper-parameters in CMA-ES
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Loshchilov, I., Schoenauer, M., Sebag, M., Nikolaus Hansen, Laboratory of Intelligent Systems (LIS), Laboratory of Intelligent Systems / EFPL-Laboratory of Intelligent Systems / EFPL, Laboratoire de Recherche en Informatique (LRI), Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Machine Learning and Optimisation (TAO), Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Laboratoire de Recherche en Informatique, Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Th. Bartz-Beielstein and J. Branke and B. Filipič and J. Smith, ANR-10-COSI-0002,SIMINOLE,Méthodes de simulations pour des applications de grande échelle en physique expérimentale : inférence statistique, optimisation et apprentissage discriminant(2010), Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université Paris-Sud - Paris 11 (UP11)-Laboratoire de Recherche en Informatique (LRI), and Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec
- Subjects
FOS: Computer and information sciences ,derivative-free optimization ,Computer Science - Artificial Intelligence ,Computer Science::Neural and Evolutionary Computation ,MathematicsofComputing_NUMERICALANALYSIS ,Computer Science - Neural and Evolutionary Computing ,CMA-ES ,stochastic optimization ,Computer Science::Numerical Analysis ,[INFO.INFO-AI]Computer Science [cs]/Artificial Intelligence [cs.AI] ,Artificial Intelligence (cs.AI) ,adaptation of hyper-parameters ,Astrophysics::Solar and Stellar Astrophysics ,Neural and Evolutionary Computing (cs.NE) ,hyper-parameters ,evolutionary algorithms - Abstract
The Covariance Matrix Adaptation Evolution Strategy (CMA-ES) is widely accepted as a robust derivative-free continuous optimization algorithm for non-linear and non-convex optimization problems. CMA-ES is well known to be almost parameterless, meaning that only one hyper-parameter, the population size, is proposed to be tuned by the user. In this paper, we propose a principled approach called self-CMA-ES to achieve the online adaptation of CMA-ES hyper-parameters in order to improve its overall performance. Experimental results show that for larger-than-default population size, the default settings of hyper-parameters of CMA-ES are far from being optimal, and that self-CMA-ES allows for dynamically approaching optimal settings., Comment: 13th International Conference on Parallel Problem Solving from Nature (PPSN 2014) (2014)
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