• 제목/요약/키워드: dynamic topic model

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Background Subtraction in Dynamic Environment based on Modified Adaptive GMM with TTD for Moving Object Detection

  • Niranjil, Kumar A.;Sureshkumar, C.
    • Journal of Electrical Engineering and Technology
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    • 제10권1호
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    • pp.372-378
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    • 2015
  • Background subtraction is the first processing stage in video surveillance. It is a general term for a process which aims to separate foreground objects from a background. The goal is to construct and maintain a statistical representation of the scene that the camera sees. The output of background subtraction will be an input to a higher-level process. Background subtraction under dynamic environment in the video sequences is one such complex task. It is an important research topic in image analysis and computer vision domains. This work deals background modeling based on modified adaptive Gaussian mixture model (GMM) with three temporal differencing (TTD) method in dynamic environment. The results of background subtraction on several sequences in various testing environments show that the proposed method is efficient and robust for the dynamic environment and achieves good accuracy.

동적 토픽 모델링과 감성 분석을 이용한 COVID-19 구간별 비대면 근무 부정요인 검출에 관한 연구 (Detection of Complaints of Non-Face-to-Face Work before and during COVID-19 by Using Topic Modeling and Sentiment Analysis)

  • 이선민;천세진;박상언;이태욱;김우주
    • 한국정보시스템학회지:정보시스템연구
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    • 제30권4호
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    • pp.277-301
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    • 2021
  • Purpose The purpose of this study is to analyze the sentiment responses of the general public to non-face-to-face work using text mining methodology. As the number of non-face-to-face complaints is increasing over time, it is difficult to review and analyze in traditional methods such as surveys, and there is a limit to reflect real-time issues. Approach This study has proposed a method of the research model, first by collecting and cleansing the data related to non-face-to-face work among tweets posted on Twitter. Second, topics and keywords are extracted from tweets using LDA(Latent Dirichlet Allocation), a topic modeling technique, and changes for each section are analyzed through DTM(Dynamic Topic Modeling). Third, the complaints of non-face-to-face work are analyzed through the classification of positive and negative polarity in the COVID-19 section. Findings As a result of analyzing 1.54 million tweets related to non-face-to-face work, the number of IDs using non-face-to-face work-related words increased 7.2 times and the number of tweets increased 4.8 times after COVID-19. The top frequently used words related to non-face-to-face work appeared in the order of remote jobs, cybersecurity, technical jobs, productivity, and software. The words that have increased after the COVID-19 were concerned about lockdown and dismissal, and business transformation and also mentioned as to secure business continuity and virtual workplace. New Normal was newly mentioned as a new standard. Negative opinions found to be increased in the early stages of COVID-19 from 34% to 43%, and then stabilized again to 36% through non-face-to-face work sentiment analysis. The complaints were, policies such as strengthening cybersecurity, activating communication to improve work productivity, and diversifying work spaces.

곡선 교량과 AGT 차량의 상호작용에 의한 동적 응답 해석 (Dynamic Response Analysis of Curved Bridge-AGT Vehicle Interaction System)

  • 이안호;송재필;김기봉
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2002년도 추계학술대회 논문집(I)
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    • pp.721-726
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    • 2002
  • The topic on today is dynamic response analysis of curved bridge-AGT(Automated Guide-way Transit) vehicle interaction system. Rubber wheel type AGT vehicle is adopted in this study, and the vehicle is idealized as three dimensional eleven DOF model. Three types of composited steel box girder bridges are modelized with F.E. method. And three types of artificially generated surface roughnesses are adopted for analysis. The dynamic equations of curved bridge, AGT vehicle and surface roughness are derived by using Lagrange's equation of motion. And the equations are solved by Newmark-${\beta}$ method. As a result, The dynamic increasement factor is inverse proportional to radius curvature.

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성과측정의 전략적 활용을 위한 동적균형모형 구축 방법 (On Building A Dynamic BSC Model for Strategic Performance Measurement)

  • 박상현;이준철;이정화;김동호;김상욱
    • 한국시스템다이내믹스연구
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    • 제2권1호
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    • pp.69-92
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    • 2001
  • The Managing and measuring performance have long been a popular topic in business. Traditions of financially-oriented managing and measuring performance have provided managers with relatively objective and scientific results of measuring performance until now. But today the value of organization is influenced more by intangible assets than tangible assets. Nobody thus believes that the performance and the value of organization can be measured by financial indicators only. In this background, numerous researches have been conducted to find alternatives to measuring the value of organization's intangible assets. One of the remarkable achievements would be "Balanced Score Card (BSC), "which covers three sectors of indicators, each from customer relations, internal process innovations, and learning and human resource development, in addition to traditional financial indicators. Unfortunately, even BSC, let alone others, fails to accomodate all performance indicators as a holistic system. Namely, performance measuring techniques including BCS, at present, fail to reflect the dynamic features in their model - i.e., the casual relations and the interactions between the indicators, and there is no way of taking into account the impact of delayed feedback which flows from introduction of new policy and legislative changes, etc. Therefore, this paper attempts to devise a means for adding dynamic features to BSC, by introducing the system dynamics concept, with a focus on the effect of casual relations and feedback structure.

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How Content Affects Clicks: A Dynamic Model of Online Content Consumption

  • Inyoung Chae;Da Young Kim
    • Asia pacific journal of information systems
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    • 제31권4호
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    • pp.606-632
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    • 2021
  • With many consumers being exposed to news via social media platforms, news organizations are challenged to attract visitors and generate revenue during visits to their websites. They therefore need detailed information on how to write articles and headlines to increase visitors' engagement with the content to drive advertising revenues. For those news organizations whose business model depends mainly on advertisements, rather than subscriptions, it is particularly crucial to understand what makes the website attractive to their visitors, what drives users to stay on the website, and what factors affect a user's exit decision. The current research examines individual news consumers' choices to find patterns of increase or decrease in user engagement relative to a variety of topics, as well as to the mood or tone of the content. Using clickstream data from a major news organization, the authors develop a user-level dynamic model of clickstream behavior that takes into account the content of both headlines and stories that visitors read. The authors find that readers appear to exhibit state dependence in the tone of the articles that they read. They also show how the topics expressed in headlines can affect the amount of content readers consume when visiting the news organization to a much larger degree than the topics expressed in the content of the article. Online publishers can make use of such findings to present visitors with content that is likely to maintain and/or increase their engagement and consequently drive advertising revenue.

해양사고의 인적요인 분석에 관한 연구 - 선박충돌사고를 중심으로 - (An Analysis of Human Factor in Marine Accidents - Collision Accidents -)

  • 양원재;권석재;금종수
    • 해양환경안전학회:학술대회논문집
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    • 해양환경안전학회 2004년도 춘계학술발표회
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    • pp.7-11
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    • 2004
  • Maritime safety and marine environmental protection are the most important topic in marine society. But, so many marine accidents rave been occurred with the development of marine transportation industry. On the other side, ship is being operated under a highly dynamic environment and many factors are related with ship's collision Nowadays, the increasing tendency to the human errors of ship's collision is remarkable, and the investigation of the human errors has been heavily concentrated. This study analysed on the human errors of ship's collision related to the negligence of lookout and classified basic error type using GEMS(Generic Error Modeling System) dynamic model.

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부동산 정책 관련 트위터 게시물 분석을 통한 대중 여론 이해 (Understanding Public Opinion by Analyzing Twitter Posts Related to Real Estate Policy)

  • 김규리;오찬희;주영준
    • 한국문헌정보학회지
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    • 제56권3호
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    • pp.47-72
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    • 2022
  • 본 연구는 시간의 흐름에 따른 부동산 정책의 주제 동향과 부동산 정책에 대한 대중의 감성 여론을 파악하고자 하였다. 부동산 정책 관련 키워드('부동산정책', '부동산대책')를 이용하여 2008년 2월 25일부터 2021년 8월 31일까지 13년 6개월 동안 작성된 총 91,740개의 트위터 게시물을 수집하였다. 데이터를 전처리하고 공급, 부동산세, 금리, 인구 분산으로 범주화 하여 총 18,925개의 게시물에 대하여 감성 분석과 다이나믹 토픽 모델 분석을 진행하였다. 범주별 키워드는 공급 범주(임대주택, 그린벨트, 신혼부부, 무주택자, 공급, 재건축, 분양), 부동산세 범주(종부세, 취득세, 보유세, 다주택자, 투기), 금리 범주(금리), 인구 분산 범주(세종, 신도시)와 같다. 감성 분석 결과, 한 명이 평균 하나 또는 두 개의 긍정 의견을 게시한 걸로 확인되었고, 부정, 중립 의견의 경우, 한 명이 두 개 또는 세 개의 게시물을 게시한 걸로 확인되었다. 또한 일부 대중들은 부동산 정책에 일관된 감정을 가지고 있지 않고 긍정, 부정, 중립의 의견을 모두 표현하는 것을 유추할 수 있었다. 다이나믹 토픽 모델링 결과, 부동산 투기 세력, 불로소득 주제에 대한 부정적인 반응이 꾸준히 파악되었으며, 긍정적인 주제로는 주택 공급 확대와 무주택자들의 부동산 구입 혜택에 대한 기대감을 확인할 수 있었다. 본 연구는 기존 선행연구들이 특정 부동산 정책의 변화와 평가에 초점을 맞춰 분석한 것과는 달리, 소셜미디어 플랫폼 중 하나인 트위터에서 게시물을 수집하고 감성 분석, 다이나믹 토픽 모델링 분석을 활용하여 부동산 정책 평가자인 대중의 감성과 여론을 알아보고 시간의 흐름에 따른 부동산 정책에 관한 잠재적 주제와 동향을 파악했다는 것에 학술적 의의가 있다. 또한, 본 연구를 통해 부동산 정책에 대한 대중의 여론에 기반한 새로운 정책 제정에 도움을 주려고 한다.

MMORPG의 Version Up 전략을 통한 이용자 유지 - System Dynamics 기법을 활용한 업데이트(Update)와 CRM전략 분석 -

  • 노태우;백옥희;이상근
    • 한국경영정보학회:학술대회논문집
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    • 한국경영정보학회 2008년도 춘계학술대회
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    • pp.383-393
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    • 2008
  • Online games are the popular topic due to the increased total online game market volume nowadays. And many studies on online games are released. But most studies used the questionnaire method that reveals only section of the situation like a snapshot. For this reason, previous studies have a little limitation that does not show dynamical changing issues like a product life cycle and changes in customer's mind Because of this, we studied on online games with the system dynamic model which can show dynamic simulations to analysis time series data. We chose MMORPG (Massively Multi-play Online) RPG (Role Playing Game) in sort of online games because it has many absorbing factors and enthusiastic users. We designed the simulation model which analyzes the influences of update and CRM strategy on users. We put the game developer who is ready for updated version game and released that periodically and focused on dormant users who used to be enthusiastic about MMORPG. The simulation results showed that the update has positive influences on new users gathering and hold established users. And CRM strategies help to prevent dormant users from transferring to rivals by offering them re-absorbing factors. Through this study, we confirmed the importance of update on online games and the necessity of introducing CRM strategy in the online game market.

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MMORPG의 버전업 전략을 통한 이용자 유지: 시뮬레이션 기법을 활용한 업데이트와 CRM전략 분석 (Simulation Analysis of Version Up Strategy for Holding Online Game Customers through Update and CRM)

  • 노태우;백수정;이상근
    • 한국정보시스템학회지:정보시스템연구
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    • 제17권4호
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    • pp.281-299
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    • 2008
  • An online game is popular topic due to the increased total online game market volume nowadays. Even though many studies on an online game are released, most studies have used survey method that reveal only section of the situation like a snapshot. For this reason, previous studies have a little limitation that does not show dynamically changing issues like a product life cycle and change in customer's satisfaction. Because of this, we researched on an online game with the system dynamic model which can show dynamic simulation to analysis time series data. We chose MMORPG (Massively Multi-play Online Role Playing Game) in sort of an online game because it has many absorbing factors and enthusiastic users. We assumed that the game developer is ready for updated version game and release that periodically and focused on dormant users who used to be enthusiastic about MMORPG and designed simulation model which analyze how to influence of update and CRM strategy on users. The simulation results showed that the update has positive influences to gather new users and hold established users and CRM strategies help to prevent dormant users from transferring to rivals to offer them re-absorbing factors. Through this study, we confirmed importance of update on a online game and suggested the necessity to introduce CRM strategy in an online game market.

Fragility evaluation of integral abutment bridge including soil structure interaction effects

  • Sunil, J.C.;Atop, Lego;Anjan, Dutta
    • Earthquakes and Structures
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    • 제20권2호
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    • pp.201-213
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    • 2021
  • Contrast to the conventional jointed bridge design, integral abutment bridges (IABs) offer some marked advantages like reduced maintenance and enhanced service life of the structure due to elimination of joints in the deck and monolithic construction practices. However, the force transfer mechanism during seismic and thermal movements is a topic of interest owing to rigid connection between superstructure and substructure (piers and abutments). This study attempts to model an existing IAB by including the abutment backfill interaction and soil-foundation interaction effects using Winkler foundation assumption to determine its seismic response. Keeping in view the significance of abutment behavior in an IAB, the probability of damage to the abutment is evaluated using fragility function. Incremental Dynamic Analysis (IDA) approach is used in this regard, wherein, nonlinear time history analyses are conducted on the numerical model using a selected suite of ground motions with increasing intensities until damage to abutment. It is concluded from the fragility analysis results that for a MCE level earthquake in the location of integral bridge, the probability of complete damage to the abutment is minimal.