• 제목/요약/키워드: long short-time memory neural network

검색결과 122건 처리시간 0.026초

CNN-LSTM 합성모델에 의한 하수관거 균열 예측모델 (Short-Term Crack in Sewer Forecasting Method Based on CNN-LSTM Hybrid Neural Network Model)

  • 장승주;장승엽
    • 한국지반신소재학회논문집
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    • 제21권2호
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    • pp.11-19
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    • 2022
  • 본 연구에서는 하수관거 내부에서 촬영된 균열 데이터를 활용하여 균열검출에 대한 시계열 예측 성능을 개선하기 위해 GoogleNet의 전이학습과 CNN- LSTM(Long Short-Term Memory) 결합 방법을 제안하였다. LSTM은 합성곱방법(CNN)의 장기의존성 문제를 해결할 수 있으며 공간 및 시간적 특징을 동시에 모델링 할 수 있다. 제안 방법의 성능을 검증하기 위해 하수관거 내부 균열 데이터를 활용하여 학습데이터, 초기학습률 및 최대 Epochs를 변화하면서 RMSE를 비교한 결과 모든 시험 구간에서 제안 방법의 예측 성능이 우수함을 알 수 있다. 또한 데이터가 발생하는 시점에 대한 예측 성능을 살펴본 결과 역시 제안방법이 우수하게 나타나 균열검출의 예측에서 제안 방법이 효율적인 것을 검증하였다. 기존 합성곱방법(CNN) 단독 모델과 비교함으로써 본 연구를 통해 확보된 제안 방법과 실험 결과를 활용할 경우 콘크리트 구조물의 균열데이터뿐만 아니라 시계열 데이터가 많이 발생하는 환경, 인문과학 등 다양한 영역에서 응용이 가능하다.

기계학습의 LSTM을 적용한 지상 기상변수 예측모델 개발 (Development of Surface Weather Forecast Model by using LSTM Machine Learning Method)

  • 홍성재;김재환;최대성;백강현
    • 대기
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    • 제31권1호
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    • pp.73-83
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    • 2021
  • Numerical weather prediction (NWP) models play an essential role in predicting weather factors, but using them is challenging due to various factors. To overcome the difficulties of NWP models, deep learning models have been deployed in weather forecasting by several recent studies. This study adapts long short-term memory (LSTM), which demonstrates remarkable performance in time-series prediction. The combination of LSTM model input of meteorological features and activation functions have a significant impact on the performance therefore, the results from 5 combinations of input features and 4 activation functions are analyzed in 9 Automated Surface Observing System (ASOS) stations corresponding to cities/islands/mountains. The optimized LSTM model produces better performance within eight forecast hours than Local Data Assimilation and Prediction System (LDAPS) operated by Korean meteorological administration. Therefore, this study illustrates that this LSTM model can be usefully applied to very short-term weather forecasting, and further studies about CNN-LSTM model with 2-D spatial convolution neural network (CNN) coupled in LSTM are required for improvement.

Activity recognition of stroke-affected people using wearable sensor

  • Anusha David;Rajavel Ramadoss;Amutha Ramachandran;Shoba Sivapatham
    • ETRI Journal
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    • 제45권6호
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    • pp.1079-1089
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    • 2023
  • Stroke is one of the leading causes of long-term disability worldwide, placing huge burdens on individuals and society. Further, automatic human activity recognition is a challenging task that is vital to the future of healthcare and physical therapy. Using a baseline long short-term memory recurrent neural network, this study provides a novel dataset of stretching, upward stretching, flinging motions, hand-to-mouth movements, swiping gestures, and pouring motions for improved model training and testing of stroke-affected patients. A MATLAB application is used to output textual and audible prediction results. A wearable sensor with a triaxial accelerometer is used to collect preprocessed real-time data. The model is trained with features extracted from the actual patient to recognize new actions, and the recognition accuracy provided by multiple datasets is compared based on the same baseline model. When training and testing using the new dataset, the baseline model shows recognition accuracy that is 11% higher than the Activity Daily Living dataset, 22% higher than the Activity Recognition Single Chest-Mounted Accelerometer dataset, and 10% higher than another real-world dataset.

Application of Deep Learning: A Review for Firefighting

  • Shaikh, Muhammad Khalid
    • International Journal of Computer Science & Network Security
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    • 제22권5호
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    • pp.73-78
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    • 2022
  • The aim of this paper is to investigate the prevalence of Deep Learning in the literature on Fire & Rescue Service. It is found that deep learning techniques are only beginning to benefit the firefighters. The popular areas where deep learning techniques are making an impact are situational awareness, decision making, mental stress, injuries, well-being of the firefighter such as his sudden fall, inability to move and breathlessness, path planning by the firefighters while getting to an fire scene, wayfinding, tracking firefighters, firefighter physical fitness, employment, prediction of firefighter intervention, firefighter operations such as object recognition in smoky areas, firefighter efficacy, smart firefighting using edge computing, firefighting in teams, and firefighter clothing and safety. The techniques that were found applied in firefighting were Deep learning, Traditional K-Means clustering with engineered time and frequency domain features, Convolutional autoencoders, Long Short-Term Memory (LSTM), Deep Neural Networks, Simulation, VR, ANN, Deep Q Learning, Deep learning based on conditional generative adversarial networks, Decision Trees, Kalman Filters, Computational models, Partial Least Squares, Logistic Regression, Random Forest, Edge computing, C5 Decision Tree, Restricted Boltzmann Machine, Reinforcement Learning, and Recurrent LSTM. The literature review is centered on Firefighters/firemen not involved in wildland fires. The focus was also not on the fire itself. It must also be noted that several deep learning techniques such as CNN were mostly used in fire behavior, fire imaging and identification as well. Those papers that deal with fire behavior were also not part of this literature review.

Blind Drift Calibration using Deep Learning Approach to Conventional Sensors on Structural Model

  • Kutchi, Jacob;Robbins, Kendall;De Leon, David;Seek, Michael;Jung, Younghan;Qian, Lei;Mu, Richard;Hong, Liang;Li, Yaohang
    • 국제학술발표논문집
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    • The 9th International Conference on Construction Engineering and Project Management
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    • pp.814-822
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    • 2022
  • The deployment of sensors for Structural Health Monitoring requires a complicated network arrangement, ground truthing, and calibration for validating sensor performance periodically. Any conventional sensor on a structural element is also subjected to static and dynamic vertical loadings in conjunction with other environmental factors, such as brightness, noise, temperature, and humidity. A structural model with strain gauges was built and tested to get realistic sensory information. This paper investigates different deep learning architectures and algorithms, including unsupervised, autoencoder, and supervised methods, to benchmark blind drift calibration methods using deep learning. It involves a fully connected neural network (FCNN), a long short-term memory (LSTM), and a gated recurrent unit (GRU) to address the blind drift calibration problem (i.e., performing calibrations of installed sensors when ground truth is not available). The results show that the supervised methods perform much better than unsupervised methods, such as an autoencoder, when ground truths are available. Furthermore, taking advantage of time-series information, the GRU model generates the most precise predictions to remove the drift overall.

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A Systems Engineering Approach for Predicting NPP Response under Steam Generator Tube Rupture Conditions using Machine Learning

  • Tran Canh Hai, Nguyen;Aya, Diab
    • 시스템엔지니어링학술지
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    • 제18권2호
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    • pp.94-107
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    • 2022
  • Accidents prevention and mitigation is the highest priority of nuclear power plant (NPP) operation, particularly in the aftermath of the Fukushima Daiichi accident, which has reignited public anxieties and skepticism regarding nuclear energy usage. To deal with accident scenarios more effectively, operators must have ample and precise information about key safety parameters as well as their future trajectories. This work investigates the potential of machine learning in forecasting NPP response in real-time to provide an additional validation method and help reduce human error, especially in accident situations where operators are under a lot of stress. First, a base-case SGTR simulation is carried out by the best-estimate code RELAP5/MOD3.4 to confirm the validity of the model against results reported in the APR1400 Design Control Document (DCD). Then, uncertainty quantification is performed by coupling RELAP5/MOD3.4 and the statistical tool DAKOTA to generate a large enough dataset for the construction and training of neural-based machine learning (ML) models, namely LSTM, GRU, and hybrid CNN-LSTM. Finally, the accuracy and reliability of these models in forecasting system response are tested by their performance on fresh data. To facilitate and oversee the process of developing the ML models, a Systems Engineering (SE) methodology is used to ensure that the work is consistently in line with the originating mission statement and that the findings obtained at each subsequent phase are valid.

Contextual Modeling in Context-Aware Conversation Systems

  • Quoc-Dai Luong Tran;Dinh-Hong Vu;Anh-Cuong Le;Ashwin Ittoo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제17권5호
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    • pp.1396-1412
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    • 2023
  • Conversation modeling is an important and challenging task in the field of natural language processing because it is a key component promoting the development of automated humanmachine conversation. Most recent research concerning conversation modeling focuses only on the current utterance (considered as the current question) to generate a response, and thus fails to capture the conversation's logic from its beginning. Some studies concatenate the current question with previous conversation sentences and use it as input for response generation. Another approach is to use an encoder to store all previous utterances. Each time a new question is encountered, the encoder is updated and used to generate the response. Our approach in this paper differs from previous studies in that we explicitly separate the encoding of the question from the encoding of its context. This results in different encoding models for the question and the context, capturing the specificity of each. In this way, we have access to the entire context when generating the response. To this end, we propose a deep neural network-based model, called the Context Model, to encode previous utterances' information and combine it with the current question. This approach satisfies the need for context information while keeping the different roles of the current question and its context separate while generating a response. We investigate two approaches for representing the context: Long short-term memory and Convolutional neural network. Experiments show that our Context Model outperforms a baseline model on both ConvAI2 Dataset and a collected dataset of conversational English.

데이터 예측을 위한 텐서플로우 기반 기계학습 알고리즘 비교 연구 (A Comparative Study of Machine Learning Algorithms Based on Tensorflow for Data Prediction)

  • ;장성봉
    • 정보처리학회논문지:컴퓨터 및 통신 시스템
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    • 제10권3호
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    • pp.71-80
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    • 2021
  • 기계학습에서 정확한 데이터 예측을 위해서는 적절한 인공신경망 알고리즘을 선택해야 한다. 이러한 알고리즘에는 심층 신경망 (DNN), 반복 신경망 (RNN), 장단기 기억 (LSTM) 네트워크 및 게이트 반복 단위 (GRU) 신경망등을 들 수 있다. 개발자가 실험을 위해, 하나를 선택해야 하는 경우, 각 알고리즘의 성능에 대한 충분한 정보가 없었기 때문에, 직관에 의존할 수 밖에 없었다. 본 연구에서는 이러한 어려움을 완화하기 위해 실험을 통해 예측 오류(RMSE)와 처리 시간을 비교 평가 하였다. 각 알고리즘은 텐서플로우를 이용하여 구현하였으며, 세금 데이터를 사용하여 학습을 수행 하였다. 학습 된 모델을 사용하여, 세금 예측을 수행 하였으며, 실제값과의 비교를 통해 정확도를 측정 하였다. 또한, 활성화 함수와 다양한 최적화 함수들이 알고리즘에 미치는 영향을 비교 분석 하였다. 실험 결과, GRU 및 LSTM 알고리즘의 경우, RMSE(Root Mean Sqaure Error)는 0.12이고 R2값은 각각 0.78 및 0.75로 다른 알고리즘에 비해 더 낳은 성능을 보여 주었다. 기본 심층 신경망(DNN)의 경우, 처리 시간은 가장 낮지만 예측 오류는 0.163로 성능은 가장 낮게 측정 되었다. 최적화 알고리즘의 경우, 아담(Adam)이 오류 측면에서 최고의 성능을, 처리 시간 측면에서 최악의 성능을 보여 주었다. 본 연구의 연구결과는 데이터 예측을 위한 알고리즘 선택시, 개발자들에게 유용한 정보로 사용될 것으로 예상된다.

시계열 분해 및 데이터 증강 기법 활용 건화물운임지수 예측 (Forecasting Baltic Dry Index by Implementing Time-Series Decomposition and Data Augmentation Techniques)

  • 한민수;유성진
    • 품질경영학회지
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    • 제50권4호
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    • pp.701-716
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    • 2022
  • Purpose: This study aims to predict the dry cargo transportation market economy. The subject of this study is the BDI (Baltic Dry Index) time-series, an index representing the dry cargo transport market. Methods: In order to increase the accuracy of the BDI time-series, we have pre-processed the original time-series via time-series decomposition and data augmentation techniques and have used them for ANN learning. The ANN algorithms used are Multi-Layer Perceptron (MLP), Recurrent Neural Network (RNN), and Long Short-Term Memory (LSTM) to compare and analyze the case of learning and predicting by applying time-series decomposition and data augmentation techniques. The forecast period aims to make short-term predictions at the time of t+1. The period to be studied is from '22. 01. 07 to '22. 08. 26. Results: Only for the case of the MAPE (Mean Absolute Percentage Error) indicator, all ANN models used in the research has resulted in higher accuracy (1.422% on average) in multivariate prediction. Although it is not a remarkable improvement in prediction accuracy compared to uni-variate prediction results, it can be said that the improvement in ANN prediction performance has been achieved by utilizing time-series decomposition and data augmentation techniques that were significant and targeted throughout this study. Conclusion: Nevertheless, due to the nature of ANN, additional performance improvements can be expected according to the adjustment of the hyper-parameter. Therefore, it is necessary to try various applications of multiple learning algorithms and ANN optimization techniques. Such an approach would help solve problems with a small number of available data, such as the rapidly changing business environment or the current shipping market.

LSTM 인공신경망을 이용한 자동차 A/S센터 수리 부품 수요 예측 모델 연구 (A Study on the Demand Prediction Model for Repair Parts of Automotive After-sales Service Center Using LSTM Artificial Neural Network)

  • 정동균;박영식
    • 한국정보시스템학회지:정보시스템연구
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    • 제31권3호
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    • pp.197-220
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    • 2022
  • Purpose The purpose of this study is to identifies the demand pattern categorization of repair parts of Automotive After-sales Service(A/S) and proposes a demand prediction model for Auto repair parts using Long Short-Term Memory (LSTM) of artificial neural networks (ANN). The optimal parts inventory quantity prediction model is implemented by applying daily, weekly, and monthly the parts demand data to the LSTM model for the Lumpy demand which is irregularly in a specific period among repair parts of the Automotive A/S service. Design/methodology/approach This study classified the four demand pattern categorization with 2 years demand time-series data of repair parts according to the Average demand interval(ADI) and coefficient of variation (CV2) of demand size. Of the 16,295 parts in the A/S service shop studied, 96.5% had a Lumpy demand pattern that large quantities occurred at a specific period. lumpy demand pattern's repair parts in the last three years is predicted by applying them to the LSTM for daily, weekly, and monthly time-series data. as the model prediction performance evaluation index, MAPE, RMSE, and RMSLE that can measure the error between the predicted value and the actual value were used. Findings As a result of this study, Daily time-series data were excellently predicted as indicators with the lowest MAPE, RMSE, and RMSLE values, followed by Weekly and Monthly time-series data. This is due to the decrease in training data for Weekly and Monthly. even if the demand period is extended to get the training data, the prediction performance is still low due to the discontinuation of current vehicle models and the use of alternative parts that they are contributed to no more demand. Therefore, sufficient training data is important, but the selection of the prediction demand period is also a critical factor.