• Title/Summary/Keyword: BiLSTM Model

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CAB: Classifying Arrhythmias based on Imbalanced Sensor Data

  • Wang, Yilin;Sun, Le;Subramani, Sudha
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.7
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    • pp.2304-2320
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    • 2021
  • Intelligently detecting anomalies in health sensor data streams (e.g., Electrocardiogram, ECG) can improve the development of E-health industry. The physiological signals of patients are collected through sensors. Timely diagnosis and treatment save medical resources, promote physical health, and reduce complications. However, it is difficult to automatically classify the ECG data, as the features of ECGs are difficult to extract. And the volume of labeled ECG data is limited, which affects the classification performance. In this paper, we propose a Generative Adversarial Network (GAN)-based deep learning framework (called CAB) for heart arrhythmia classification. CAB focuses on improving the detection accuracy based on a small number of labeled samples. It is trained based on the class-imbalance ECG data. Augmenting ECG data by a GAN model eliminates the impact of data scarcity. After data augmentation, CAB classifies the ECG data by using a Bidirectional Long Short Term Memory Recurrent Neural Network (Bi-LSTM). Experiment results show a better performance of CAB compared with state-of-the-art methods. The overall classification accuracy of CAB is 99.71%. The F1-scores of classifying Normal beats (N), Supraventricular ectopic beats (S), Ventricular ectopic beats (V), Fusion beats (F) and Unclassifiable beats (Q) heartbeats are 99.86%, 97.66%, 99.05%, 98.57% and 99.88%, respectively. Unclassifiable beats (Q) heartbeats are 99.86%, 97.66%, 99.05%, 98.57% and 99.88%, respectively.

Sensitivity of abacus and Chasdaq in the Chinese stock market through analysis of Weibo sentiment related to Corona-19 (코로나-19관련 웨이보 정서 분석을 통한 중국 주식시장의 주판 및 차스닥의 민감도 예측 기법)

  • Li, Jiaqi;Oh, Hayoung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.1
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    • pp.1-7
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    • 2021
  • Investor mood from social media is gaining increasing attention for leading a price movement in stock market. Based on the behavioral finance theory, this study argues that sentiment extracted from social media using big data technique can predict a real-time (short-run) price momentum in Chinese stock market. Collecting Sina Weibo posts that related to COVID-19 using keyword method, a daily influential weighted sentiment factors is extracted from the sizable raw data of over 2 millions of posts. We examine one supervised and 4 unsupervised sentiment analysis model, and use the best performed word-frequency and BiLSTM mdoel. The test result shows a similar movement between stock price change and sentiment factor. It indicates that public mood extracted from social media can in some extent represent the investors' sentiment and make a difference in stock market fluctuation when people are concentrating on a special events that can cause effect on the stock market.

Assessment of maximum liquefaction distance using soft computing approaches

  • Kishan Kumar;Pijush Samui;Shiva S. Choudhary
    • Geomechanics and Engineering
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    • v.37 no.4
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    • pp.395-418
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    • 2024
  • The epicentral region of earthquakes is typically where liquefaction-related damage takes place. To determine the maximum distance, such as maximum epicentral distance (Re), maximum fault distance (Rf), or maximum hypocentral distance (Rh), at which an earthquake can inflict damage, given its magnitude, this study, using a recently updated global liquefaction database, multiple ML models are built to predict the limiting distances (Re, Rf, or Rh) required for an earthquake of a given magnitude to cause damage. Four machine learning models LSTM (Long Short-Term Memory), BiLSTM (Bidirectional Long Short-Term Memory), CNN (Convolutional Neural Network), and XGB (Extreme Gradient Boosting) are developed using the Python programming language. All four proposed ML models performed better than empirical models for limiting distance assessment. Among these models, the XGB model outperformed all the models. In order to determine how well the suggested models can predict limiting distances, a number of statistical parameters have been studied. To compare the accuracy of the proposed models, rank analysis, error matrix, and Taylor diagram have been developed. The ML models proposed in this paper are more robust than other current models and may be used to assess the minimal energy of a liquefaction disaster caused by an earthquake or to estimate the maximum distance of a liquefied site provided an earthquake in rapid disaster mapping.

KNU Korean Sentiment Lexicon: Bi-LSTM-based Method for Building a Korean Sentiment Lexicon (Bi-LSTM 기반의 한국어 감성사전 구축 방안)

  • Park, Sang-Min;Na, Chul-Won;Choi, Min-Seong;Lee, Da-Hee;On, Byung-Won
    • Journal of Intelligence and Information Systems
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    • v.24 no.4
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    • pp.219-240
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    • 2018
  • Sentiment analysis, which is one of the text mining techniques, is a method for extracting subjective content embedded in text documents. Recently, the sentiment analysis methods have been widely used in many fields. As good examples, data-driven surveys are based on analyzing the subjectivity of text data posted by users and market researches are conducted by analyzing users' review posts to quantify users' reputation on a target product. The basic method of sentiment analysis is to use sentiment dictionary (or lexicon), a list of sentiment vocabularies with positive, neutral, or negative semantics. In general, the meaning of many sentiment words is likely to be different across domains. For example, a sentiment word, 'sad' indicates negative meaning in many fields but a movie. In order to perform accurate sentiment analysis, we need to build the sentiment dictionary for a given domain. However, such a method of building the sentiment lexicon is time-consuming and various sentiment vocabularies are not included without the use of general-purpose sentiment lexicon. In order to address this problem, several studies have been carried out to construct the sentiment lexicon suitable for a specific domain based on 'OPEN HANGUL' and 'SentiWordNet', which are general-purpose sentiment lexicons. However, OPEN HANGUL is no longer being serviced and SentiWordNet does not work well because of language difference in the process of converting Korean word into English word. There are restrictions on the use of such general-purpose sentiment lexicons as seed data for building the sentiment lexicon for a specific domain. In this article, we construct 'KNU Korean Sentiment Lexicon (KNU-KSL)', a new general-purpose Korean sentiment dictionary that is more advanced than existing general-purpose lexicons. The proposed dictionary, which is a list of domain-independent sentiment words such as 'thank you', 'worthy', and 'impressed', is built to quickly construct the sentiment dictionary for a target domain. Especially, it constructs sentiment vocabularies by analyzing the glosses contained in Standard Korean Language Dictionary (SKLD) by the following procedures: First, we propose a sentiment classification model based on Bidirectional Long Short-Term Memory (Bi-LSTM). Second, the proposed deep learning model automatically classifies each of glosses to either positive or negative meaning. Third, positive words and phrases are extracted from the glosses classified as positive meaning, while negative words and phrases are extracted from the glosses classified as negative meaning. Our experimental results show that the average accuracy of the proposed sentiment classification model is up to 89.45%. In addition, the sentiment dictionary is more extended using various external sources including SentiWordNet, SenticNet, Emotional Verbs, and Sentiment Lexicon 0603. Furthermore, we add sentiment information about frequently used coined words and emoticons that are used mainly on the Web. The KNU-KSL contains a total of 14,843 sentiment vocabularies, each of which is one of 1-grams, 2-grams, phrases, and sentence patterns. Unlike existing sentiment dictionaries, it is composed of words that are not affected by particular domains. The recent trend on sentiment analysis is to use deep learning technique without sentiment dictionaries. The importance of developing sentiment dictionaries is declined gradually. However, one of recent studies shows that the words in the sentiment dictionary can be used as features of deep learning models, resulting in the sentiment analysis performed with higher accuracy (Teng, Z., 2016). This result indicates that the sentiment dictionary is used not only for sentiment analysis but also as features of deep learning models for improving accuracy. The proposed dictionary can be used as a basic data for constructing the sentiment lexicon of a particular domain and as features of deep learning models. It is also useful to automatically and quickly build large training sets for deep learning models.

Subdivision Ensemble Model for Highlight Detection (하이라이트 검출을 위한 구간 분할 앙상블 모델)

  • Lee, Hansol;Lee, Gyemin
    • Journal of Broadcast Engineering
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    • v.25 no.4
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    • pp.620-628
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    • 2020
  • Automatically predicting video highlight is an important task for media industry and streaming platform providers to save time and cost of manual video editing process. We propose a new ensemble model that combines multiple highlight detectors with each focusing on different parts of highlight events. Therefore, our model can capture more information-rich sections of events. Furthermore, the proposed model can extract improved features for highlight detection particularly when the train video set is small. We evaluate our model on e-sports and baseball videos.

Korean Named Entity Recognition using Joint Learning with Language Model (언어 모델 다중 학습을 이용한 한국어 개체명 인식)

  • Kim, Byeong-Jae;Park, Chan-min;Choi, Yoon-Young;Kwon, Myeong-Joon;Seo, Jeong-Yeon
    • 한국어정보학회:학술대회논문집
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    • 2017.10a
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    • pp.333-337
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    • 2017
  • 본 논문에서는 개체명 인식과 언어 모델의 다중 학습을 이용한 한국어 개체명 인식 방법을 제안한다. 다중 학습은 1 개의 모델에서 2 개 이상의 작업을 동시에 분석하여 성능 향상을 기대할 수 있는 방법이지만, 이를 적용하기 위해서 말뭉치에 각 작업에 해당하는 태그가 부착되어야 하는 문제가 있다. 본 논문에서는 추가적인 태그 부착 없이 정보를 획득할 수 있는 언어 모델을 개체명 인식 작업과 결합하여 성능 향상을 이루고자 한다. 또한 단순한 형태소 입력의 한계를 극복하기 위해 입력 표상을 자소 및 형태소 품사의 임베딩으로 확장하였다. 기계 학습 방법은 순차적 레이블링에서 높은 성능을 제공하는 Bi-directional LSTM CRF 모델을 사용하였고, 실험 결과 언어 모델이 개체명 인식의 오류를 효과적으로 개선함을 확인하였다.

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Target extraction in Korean aspect-based sentiment analysis using stepwise feature of multi-task learning model (다중 작업 학습의 단계적 특징을 활용한 한국어 속성 기반 감성 분석에서의 대상 추출)

  • Ho-Min Park;Jae-Hoon Kim
    • Annual Conference on Human and Language Technology
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    • 2022.10a
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    • pp.630-633
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    • 2022
  • 속성기반 감성 분석은 텍스트 내에 존재하는 속성에 대해 세분화된 감성 분석을 수행하는 과제를 말한다. 세분화된 감성분석을 정확하게 수행하기 위해서는 텍스트에 존재하는 감성 표현과 그것이 수식하는 대상에 대한 정보가 반드시 필요하다. 그리고 순서대로 두 가지 정보는 이후 정보를 텍스트에서 추출하기 위해 중요한 단서가 된다. 따라서 본 논문에서는 KorBERT와 Bi-LSTM을 이용한 단계적 특징을 활용한 다중 작업 학습 모델을 사용하여 한국어 감성 분석 말뭉치의 감성 표현과 대상을 추출하는 작업을 수행하였다. 제안한 모델을 한국어 감성 분석 말뭉치로 학습 및 평가한 결과, 감성 표현 추출 작업의 출력을 추가적인 특성으로 전달하여 대상 추출 작업의 성능을 향상시킬 수 있음을 보였다.

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Sentiment Analysis System by Using BERT Language Model (BERT 언어 모델을 이용한 감정 분석 시스템)

  • Kim, Taek-Hyun;Cho, Dan-Bi;Lee, Hyun-Young;Won, Hye-Jin;Kang, Seung-Shik
    • Proceedings of the Korea Information Processing Society Conference
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    • 2020.11a
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    • pp.975-977
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    • 2020
  • 감정 분석은 문서의 주관적인 감정, 의견, 기분을 파악하기 위한 방법으로 소셜 미디어, 온라인 리뷰 등 다양한 분야에서 활용된다. 문서 내 텍스트가 나타내는 단어와 문맥을 기반으로 감정 수치를 계산하여 긍정 또는 부정 감정을 결정한다. 2015년에 구축된 네이버 영화평 데이터 20 만개에 12 만개를 추가 구축하여 감정 분석 연구를 진행하였으며 언어 모델로는 최근 자연어처리 분야에서 높은 성능을 보여주는 BERT 모델을 이용하였다. 감정 분석 기법으로는 LSTM(Long Short-Term Memory) 등 기존의 기계학습 기법과 구글의 다국어 BERT 모델, 그리고 KoBERT 모델을 이용하여 감정 분석의 성능을 비교하였으며, KoBERT 모델이 89.90%로 가장 높은 성능을 보여주었다.

A Symptom Recognition Method of Diseases for Senior User Based on Language Model (시니어 사용자를 위한 언어 모델 기반 질환 증상 인식 방법)

  • Park, Min-Kyung;Choi, Jin-Woo;Whangbo, Taeg-Keun
    • Proceedings of the Korea Information Processing Society Conference
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    • 2020.05a
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    • pp.461-463
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    • 2020
  • 2025년 초고령 사회로 진입할 것으로 예상됨에 따라 고령화 시대에 발생하는 문제점들을 IT기술을 응용하여 지능적으로 해결할 수 있는 인공지능 헬스케어 솔루션이 주목받고 있다. BIS리서치의 보고서에 따르면 헬스케어 산업의 챗봇 시장 규모가 2029년 약 4억 9,800만 달러로 성장할 것으로 예상된다. 따라서 시니어 사용자를 위한 기술 연구가 적극적으로 필요한 시점이다. 본 논문에서는 사전학습한 언어모델과 BiLSTM기반 신경망 모델을 이용하여 시니어 사용자에게 특화된 질환 증상 인식 모델 구현에 관한 범위 및 방법에 관해 기술한다. 이는 시니어 대상 건강관리 챗봇 솔루션에 도입하여 시니어 사용자에게 자주 발생하는 질환들을 조기에 발견할 수 있도록 지원하여 위험의 발생 예방에 도움을 주는 서비스가 될 것으로 전망한다.

Optimizing ELECTRA-based model for Zero Anaphora Resolution (생략복원을 위한 ELECTRA 기반 모델 최적화 연구)

  • Park, Jinsol;Choi, Maengsik;Matteson, Andrew;Lee, Chunghee
    • Annual Conference on Human and Language Technology
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    • 2021.10a
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    • pp.329-334
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    • 2021
  • 한국어에서는 문장 내의 주어나 목적어가 자주 생략된다. 자연어 처리에서 이러한 문장을 그대로 사용하는 것은 정보 부족으로 인한 문제 난이도 상승으로 귀결된다. 생략복원은 텍스트에서 생략된 부분을 이전 문구에서 찾아서 복원해 주는 기술이며, 본 논문은 생략된 주어를 복원하는 방법에 대한 연구이다. 본 논문에서는 기존에 생략복원에 사용되지 않았던 다양한 입력 형태를 시도한다. 또한, 출력 레이어로는 finetuning layer(Linear, Bi-LSTM, MultiHeadAttention)와 생략복원 태스크 형태(BIO tagging, span prediction)의 다양한 조합을 실험한다. 국립국어원 무형 대용어 복원 말뭉치를 기반으로 생략복원이 불필요한 네거티브 샘플을 추가하여 ELECTRA 기반의 딥러닝 생략복원 모델을 학습시키고, 생략복원에 최적화된 조합을 검토한다.

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