• Title/Summary/Keyword: topic model

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LSTM based Language Model for Topic-focused Sentence Generation (문서 주제에 따른 문장 생성을 위한 LSTM 기반 언어 학습 모델)

  • Kim, Dahae;Lee, Jee-Hyong
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2016.07a
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    • pp.17-20
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    • 2016
  • 딥러닝 기법이 발달함에 따라 텍스트에 내재된 의미 및 구문을 어떠한 벡터 공간 상에 표현하기 위한 언어 모델이 활발히 연구되어 왔다. 이를 통해 자연어 처리를 기반으로 하는 감성 분석 및 문서 분류, 기계 번역 등의 분야가 진보되었다. 그러나 대부분의 언어 모델들은 텍스트에 나타나는 단어들의 일반적인 패턴을 학습하는 것을 기반으로 하기 때문에, 문서 요약이나 스토리텔링, 의역된 문장 판별 등과 같이 보다 고도화된 자연어의 이해를 필요로 하는 연구들의 경우 주어진 텍스트의 주제 및 의미를 고려하기에 한계점이 있다. 이와 같은 한계점을 고려하기 위하여, 본 연구에서는 기존의 LSTM 모델을 변형하여 문서 주제와 해당 주제에서 단어가 가지는 문맥적인 의미를 단어 벡터 표현에 반영할 수 있는 새로운 언어 학습 모델을 제안하고, 본 제안 모델이 문서의 주제를 고려하여 문장을 자동으로 생성할 수 있음을 보이고자 한다.

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Representing the views of product data using extended Topic Maps (확장된 토픽맵을 이용한 제품 데이터에서의 관점의 표현)

  • 채희권;최영환;김광수
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2003.05a
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    • pp.1157-1164
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    • 2003
  • 제품개발과정에서 생성된 제품정보모델은 시간에 따라 계속 변하고 미확정적인 정보가 포함된 UDM(Under Defined Model)이다. 정보모델에서 관점(viewpoint)은 UDM을 표현하고 관리하는 중요한 요소이다. 토픽맵(Topic Map) 이용한 정보모델은 관점의 표현이 용이하며, 관점에 따라 인간이 정보를 이해하고 조작하는 것을 돕는다. 그러나 토픽맵은 제품개발과정의 정보모델과 같은 UDM의 표현은 가능하나, 적합하지는 않다. 따라서 본 논문에서는 토픽맵이 UDM에 적합하도록 토픽맵의 문법을 확장하였다. 그리고 UDM으로부터 전자상거래에 적용 가능만 FDM(Fully Defined Model)으로 변화하는 과정에 대하여 논하였다. 관점이 적용된 UDM으로는 제품을 개발하는 과정 중에 생성되는 제품 모델을 적용하였으며, 대량생산이 된 이후의 제품 모델이나 제품개발단계에서 결정이 이루어진 후의 제품모델을 FDM 또는 UDM보다 모델의 의미가 보다 확정적인 확정적UDM을 사용하였다. 그리고 세탁기의 제품정보모델을 구현 예로 사용하여, UDM이 FDM 또는 확정적UDM으로 변화하는 과정을 설명하였다.

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Decentralized Sliding Mode Feedback Control Design Method for a Large Scale System with a Poly topic Models (폴리토픽 모델을 갖는 대규모 시스템을 위한 비집중화 슬라이딩 모드 제어기 설계)

  • Choi, Han-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.1
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    • pp.1-4
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    • 2010
  • Based on the sliding mode control theory, a decentralized controller design method is developed for a large scale system with a poly topic model. In terms of LMIs, we derive sufficient conditions for the existence of the decentralized controller guaranteeing a stable sliding motion. We also give an LMI-based control design algorithm. Finally, the proposed method is applied to decentralized stabilization of double-inverted pendulums. Simulation results show that our method gives not only the robust stability but perfect rejection of norm-bounded uncertainties.

Vocabulary Analysis of Safety Warnings in Construction Site (건설현장 안전 지적 사항 분석)

  • Kang, Kyung-Su;Ryu, Han-Guk
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.11a
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    • pp.40-41
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    • 2019
  • The purpose of this study is to analyze the vocabulary related to safety accidents based on the reports recorded on the violation of safety rules at the construction sites. We used Word2Vec and Topic Model as natural language processing techniques to analyze the safety accidents presented in the reports of the large enterprise. The words that appeared based on the occupational accident types such as the fall, falling objects, and others were derived and visualized. We derive the frequency and similarity of the words and topics of the accident that occur at the construction site. In future studies, we will be able to proceed with the generation of texts from pictures based on images and this reports.

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Multiple Cause Model-based Topic Extraction and Semantic Kernel Construction from Text Documents (다중요인모델에 기반한 텍스트 문서에서의 토픽 추출 및 의미 커널 구축)

  • 장정호;장병탁
    • Journal of KIISE:Software and Applications
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    • v.31 no.5
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    • pp.595-604
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    • 2004
  • Automatic analysis of concepts or semantic relations from text documents enables not only an efficient acquisition of relevant information, but also a comparison of documents in the concept level. We present a multiple cause model-based approach to text analysis, where latent topics are automatically extracted from document sets and similarity between documents is measured by semantic kernels constructed from the extracted topics. In our approach, a document is assumed to be generated by various combinations of underlying topics. A topic is defined by a set of words that are related to the same topic or cooccur frequently within a document. In a network representing a multiple-cause model, each topic is identified by a group of words having high connection weights from a latent node. In order to facilitate teaming and inferences in multiple-cause models, some approximation methods are required and we utilize an approximation by Helmholtz machines. In an experiment on TDT-2 data set, we extract sets of meaningful words where each set contains some theme-specific terms. Using semantic kernels constructed from latent topics extracted by multiple cause models, we also achieve significant improvements over the basic vector space model in terms of retrieval effectiveness.

A Topic Modeling-based Recommender System Considering Changes in User Preferences (고객 선호 변화를 고려한 토픽 모델링 기반 추천 시스템)

  • Kang, So Young;Kim, Jae Kyeong;Choi, Il Young;Kang, Chang Dong
    • Journal of Intelligence and Information Systems
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    • v.26 no.2
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    • pp.43-56
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    • 2020
  • Recommender systems help users make the best choice among various options. Especially, recommender systems play important roles in internet sites as digital information is generated innumerable every second. Many studies on recommender systems have focused on an accurate recommendation. However, there are some problems to overcome in order for the recommendation system to be commercially successful. First, there is a lack of transparency in the recommender system. That is, users cannot know why products are recommended. Second, the recommender system cannot immediately reflect changes in user preferences. That is, although the preference of the user's product changes over time, the recommender system must rebuild the model to reflect the user's preference. Therefore, in this study, we proposed a recommendation methodology using topic modeling and sequential association rule mining to solve these problems from review data. Product reviews provide useful information for recommendations because product reviews include not only rating of the product but also various contents such as user experiences and emotional state. So, reviews imply user preference for the product. So, topic modeling is useful for explaining why items are recommended to users. In addition, sequential association rule mining is useful for identifying changes in user preferences. The proposed methodology is largely divided into two phases. The first phase is to create user profile based on topic modeling. After extracting topics from user reviews on products, user profile on topics is created. The second phase is to recommend products using sequential rules that appear in buying behaviors of users as time passes. The buying behaviors are derived from a change in the topic of each user. A collaborative filtering-based recommendation system was developed as a benchmark system, and we compared the performance of the proposed methodology with that of the collaborative filtering-based recommendation system using Amazon's review dataset. As evaluation metrics, accuracy, recall, precision, and F1 were used. For topic modeling, collapsed Gibbs sampling was conducted. And we extracted 15 topics. Looking at the main topics, topic 1, top 3, topic 4, topic 7, topic 9, topic 13, topic 14 are related to "comedy shows", "high-teen drama series", "crime investigation drama", "horror theme", "British drama", "medical drama", "science fiction drama", respectively. As a result of comparative analysis, the proposed methodology outperformed the collaborative filtering-based recommendation system. From the results, we found that the time just prior to the recommendation was very important for inferring changes in user preference. Therefore, the proposed methodology not only can secure the transparency of the recommender system but also can reflect the user's preferences that change over time. However, the proposed methodology has some limitations. The proposed methodology cannot recommend product elaborately if the number of products included in the topic is large. In addition, the number of sequential patterns is small because the number of topics is too small. Therefore, future research needs to consider these limitations.

Spatio-temporal Semantic Features for Human Action Recognition

  • Liu, Jia;Wang, Xiaonian;Li, Tianyu;Yang, Jie
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.10
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    • pp.2632-2649
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    • 2012
  • Most approaches to human action recognition is limited due to the use of simple action datasets under controlled environments or focus on excessively localized features without sufficiently exploring the spatio-temporal information. This paper proposed a framework for recognizing realistic human actions. Specifically, a new action representation is proposed based on computing a rich set of descriptors from keypoint trajectories. To obtain efficient and compact representations for actions, we develop a feature fusion method to combine spatial-temporal local motion descriptors by the movement of the camera which is detected by the distribution of spatio-temporal interest points in the clips. A new topic model called Markov Semantic Model is proposed for semantic feature selection which relies on the different kinds of dependencies between words produced by "syntactic " and "semantic" constraints. The informative features are selected collaboratively based on the different types of dependencies between words produced by short range and long range constraints. Building on the nonlinear SVMs, we validate this proposed hierarchical framework on several realistic action datasets.

A Comparative Study on Nonparametric Reliability Estimation for Koziol-Green Model with Random Censorship

  • Cha, Young-Joon;Lee, Jae-Man
    • Journal of the Korean Data and Information Science Society
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    • v.8 no.2
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    • pp.231-237
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    • 1997
  • The Koziol-Green(KG) model has become an important topic in industrial life testing. In this paper we suggest MLE of the reliability function for the Weibull distribution under the KG model. Futhermore, we compare Kaplan-Meier estimator, Nelson estimator, Cheng & Chang estimator, and Ebrahimi estimator with proposed estimator for the reliability function under the KG model.

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A comparative study of domestic and international research trends of mathematics education through topic modeling (토픽모델링을 활용한 국내외 수학교육 연구 동향 비교 연구)

  • Shin, Dongjo
    • The Mathematical Education
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    • v.59 no.1
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    • pp.63-80
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    • 2020
  • This study analyzed 3,114 articles published in KCI journals and 1,636 articles published in SSCI journals from 2000 to 2019 in order to compare domestic and international research trends of mathematics education using a topic modeling method. Results indicated that there were 16 similar research topics in domestic and international mathematics education journals: algebra/algebraic thinking, fraction, function/representation, statistics, geometry, problem-solving, model/modeling, proof, achievement effect/difference, affective factor, preservice teacher, teaching practice, textbook/curriculum, task analysis, assessment, and theory. Also, there were 7 distinct research topics in domestic and international mathematics education journals. Topics such as affective/cognitive domain and research trends, mathematics concept, class activity, number/operation, creativity/STEAM, proportional reasoning, and college/technology were identified from the domestic journals, whereas discourse/interaction, professional development, identity/equity, child thinking, semiotics/embodied cognition, intervention effect, and design/technology were the topics identified from the international journals. The topic related to preservice teacher was the most frequently addressed topic in both domestic and international research. The topic related to in-service teachers' professional development was the second most popular topic in international research, whereas it was not identified in domestic research. Domestic research in mathematics education tended to pay attention to the topics concerned with the mathematical competency, but it focused more on problem-solving and creativity/STEAM than other mathematical competencies. Rather, international research highlighted the topic related to equity and social justice.