• 제목/요약/키워드: Context-based

검색결과 5,116건 처리시간 0.031초

상황 인식 기반의 유비쿼터스 컴퓨팅을 위한 접근 제어 시스템 (An Access Control System for Ubiquitous Computing based on Context Awareness)

  • 이지연;안준선;도경구;창병모
    • 정보처리학회논문지A
    • /
    • 제15A권1호
    • /
    • pp.35-44
    • /
    • 2008
  • 다양한 모바일 기기들이나 무선 네트워크들에 의한 무분별한 자원 접근은 시스템에 문제를 일으킬 수 있으므로 접근 권한 관리는 매우 중요하다. 본 논문에서는 프로그래머가 각 응용 프로그램에 맞는 접근 권한 규칙을 정책 파일로 작성하고 이를 실행시키는 접근 제어 시스템을 구현하였다. 본 논문에서 구현된 접근 제어 시스템인 CACM(Context-awareness Access Control Manager)은 상황 인식 기반의 유비쿼터스 컴퓨팅을 위한 프레임워크인 JCAF을 바탕으로 구현하였다. CACM은 프로그래머가 작성한 정책 파일을 바탕으로 접근을 제어한다. 또한 본 논문에서는 정책 파일을 정적 분석하여 잘못된 정책 파일 규칙 알려주는 지원 시스템을 제공하며 본 시스템을 사용하여 개발된 유비쿼터스 응용 프로그램의 실행을 시뮬레이션 할 수 있는 시뮬레이터와 시뮬레이션 결과를 제공한다.

Credibility Assessment of Online Information in Context

  • Rieh, Soo Young
    • Journal of Information Science Theory and Practice
    • /
    • 제2권3호
    • /
    • pp.6-17
    • /
    • 2014
  • The purpose of this study is to examine to what extent the context in which people interact with online information affects people's credibility perceptions. In this study, credibility assessment is defined as perceptions of credibility relying on individuals' expertise and knowledge. Context has been characterized with respect to three aspects: Context as user goals and intentions, context as topicality of information, and context as information activities. The data were collected from two empirical studies. Study 1 was a diary study in which 333 residents in Michigan, U.S.A. submitted 2,471 diary entries to report their trust perceptions associated with ten different user goals and nine different intentions. Study 2 was a lab-based study in which 64 subjects participated in performing four search tasks in two different information activity conditions - information search or content creation. There are three major findings of this study: (1) Score-based trust perceptions provided limited views of people's credibility perceptions because respondents tended to score trust ratings consistently high across various user goals and intentions; (2) The topicality of information mattered more when study subjects assessed the credibility of user generated content (UGC) than with traditional media content (TMC); (3) Subjects of this study exerted more effort into making credibility judgments when they engaged in searching activities than in content creation. These findings indicate that credibility assessment can or should be seen as a process-oriented notion incorporating various information use contexts beyond simple rating-based evaluation. The theoretical contributions for information scientists and practical implications for web designers are also discussed.

Analysis of Research status based on Citation Context

  • Kim, Byungkyu;Choi, Seon-heui;Kang, Muyeong;Kang, Ji-Hoon
    • International Journal of Contents
    • /
    • 제11권2호
    • /
    • pp.63-68
    • /
    • 2015
  • A citation analysis utilizes the relations among citations and is the most popular bibliometric method. This analysis is based on 1) the evaluation by paper, journal and researcher of the research output, 2) the identification of emerging research topics, 3) the production of a map of the intellectual structure of the research domain and 4) various services for academic information. However, this approach has a limitation in that a citation is treated in a very simple manner, even though the purpose of citation can vary greatly. To address this problem, new approaches have been studied that take into account the citation context. This research separates the citations according to the citation functions and tries to conduct an analysis according to the newly classified citations. Furthermore, research on the citation summarization and visualization based on both the citation context and the citation function of the citations was also attempted. However, since there are very few studies related to citation context in South Korea, more research and development is needed in this area. This study analyzes the status of the research in terms of the citation context. For this, we utilized social network analysis methods.

CoAID+ : 소셜 컨텍스트 기반 가짜뉴스 탐지를 위한 COVID-19 뉴스 파급 데이터 (CoAID+ : COVID-19 News Cascade Dataset for Social Context Based Fake News Detection)

  • 한소은;강윤석;고윤용;안지원;김유심;오성수;박희진;김상욱
    • 정보처리학회논문지:소프트웨어 및 데이터공학
    • /
    • 제11권4호
    • /
    • pp.149-156
    • /
    • 2022
  • 최근 전 세계적으로 COVID-19이 유행하는 상황 속에서 이와 관련된 가짜뉴스가 심각한 사회적 혼란을 야기하고 있다. 이러한 배경에서 가짜뉴스를 정확하게 탐지하기 위해, 뉴스가 소셜 미디어를 통해 파급되는 과정과 같은 소셜 컨텍스트 정보를 활용하는 소셜 컨텍스트 기반 탐지 기법들이 널리 사용되고 있다. 그러나 대부분의 기 구축된 가짜뉴스 탐지를 위한 데이터들은 뉴스 자체의 내용 정보 위주로 구성되어, 소셜 컨텍스트 정보를 거의 포함하지 않는다. 즉, 이 데이터들에는 소셜 컨텍스트 기반 탐지 기법을 적용할 수 없으며, 이러한 데이터의 한계는 가짜뉴스 탐지 연구 분야의 발전을 저해하는 방해 요소이다. 본 논문은 이러한 한계를 극복하기 위해, 기존의 저명한 가짜뉴스 데이터인 CoAID 데이터를 기반으로, 소셜 컨텍스트 정보를 추가적으로 수집하여, CoAID 데이터의 뉴스 내용 정보와 해당 뉴스들의 소셜 컨텍스트 정보를 모두 포함하는 CoAID+ 데이터를 구축한다. 본 논문에서 구축한 CoAID+ 데이터는 기존의 대부분의 소셜 컨텍스트 기반 탐지 기법들에 적용될 수 있으며, 향후 새로운 소셜 컨텍스트 기반 탐지 기법들에 대한 연구도 더욱 활성화시킬 수 있을 것으로 기대된다. 마지막으로, 본 논문은 다양한 관점에서 CoAID+ 데이터를 분석하여 진짜뉴스와 가짜뉴스의 파급 패턴 및 키워드에 따른 파급 패턴도 파악하여 소개한다.

jini 기반의 context-aware chatting program (A Jini-based context-aware chatting program)

  • 박한솔;최태욱;정기동
    • 한국정보처리학회:학술대회논문집
    • /
    • 한국정보처리학회 2003년도 추계학술발표논문집 (중)
    • /
    • pp.1177-1180
    • /
    • 2003
  • 차세대 비젼 컴퓨팅 환경인 유비쿼터스 컴퓨팅(Ubiquitous Computing)환경에서는 사용자에 대한 상황(context)변화에 적응적(adaptive)으로 서비스 해줄 수 있는 응용이 필수적인 요소라고 할 수 있다. Service기반의 분산 네트워크인 JINI를 기반으로, 사용자에 대한 상황을 인식(context-aware)하기 위한 시스템 연구 역시 관심의 대상이라고 한 수 있겠다. 본 논문에서는 이러한 환경을 기반으로 사용자에 대한 행동, 감정상태, 위치와 같은 정보를 인식할 수 있으며, 검색을 통해 사용자의 위치정보, 활동형태 등의 context들을 질의 할 수 있는 Context-aware 챗팅 프로그램을 기술하고 있다. 또한 인터페이스를 사용하는 사용자들에 대한 context 데이터의 표현과 질의를 위해 메타언어인 eXtensible Makup Language (XML)을 사용하였다. 이러한 context-aware system은 편재형 컴퓨팅환경 하에서 사용자에게 유효한 context를 생성 및 관리, 응용 서비스에서 유용하게 이용할 수 있을 것이다.

  • PDF

유비쿼터스 컴퓨팅 환경에서의 상황 인식을 위한 확률 확장 온톨로지 모델 (Probability-annotated Ontology Model for Context Awareness in Ubiquitous Computing Environment)

  • 정헌만;이정현
    • 한국컴퓨터정보학회논문지
    • /
    • 제11권3호
    • /
    • pp.239-248
    • /
    • 2006
  • 유비쿼터스 컴퓨팅 환경에서 현재의 상황 인식 어플리케이션은 다루고 있는 상황 정보가 정확하다고 가정하지만, 실제로 센서로 입력되고 해석된 상황 정보들은 종종 모호하거나 불확실하다. 본 논문에서는 상황 정보의 모호성을 해결하기 위하여 베이지안 네트워크를 사용하고 상황 정보를 표현하기 위해 온톨로지 기반 모델을 확장한 확률 모델을 제안한다. 이 논문에서 제시한 확률 확장 온톨로지 기반 상황 인식 미들웨어는 유비쿼터스 환경에서 요구되는 다양한 상황 인식 서비스의 개발 및 운용을 효과적으로 지원 할 수 있다.

  • PDF

상황인식 기반 지능형 최적 경로계획 (Intelligent Optimal Route Planning Based on Context Awareness)

  • 이현정;장용식
    • Asia pacific journal of information systems
    • /
    • 제19권2호
    • /
    • pp.117-137
    • /
    • 2009
  • Recently, intelligent traffic information systems have enabled people to forecast traffic conditions before hitting the road. These convenient systems operate on the basis of data reflecting current road and traffic conditions as well as distance-based data between locations. Thanks to the rapid development of ubiquitous computing, tremendous context data have become readily available making vehicle route planning easier than ever. Previous research in relation to optimization of vehicle route planning merely focused on finding the optimal distance between locations. Contexts reflecting the road and traffic conditions were then not seriously treated as a way to resolve the optimal routing problems based on distance-based route planning, because this kind of information does not have much significant impact on traffic routing until a a complex traffic situation arises. Further, it was also not easy to take into full account the traffic contexts for resolving optimal routing problems because predicting the dynamic traffic situations was regarded a daunting task. However, with rapid increase in traffic complexity the importance of developing contexts reflecting data related to moving costs has emerged. Hence, this research proposes a framework designed to resolve an optimal route planning problem by taking full account of additional moving cost such as road traffic cost and weather cost, among others. Recent technological development particularly in the ubiquitous computing environment has facilitated the collection of such data. This framework is based on the contexts of time, traffic, and environment, which addresses the following issues. First, we clarify and classify the diverse contexts that affect a vehicle's velocity and estimates the optimization of moving cost based on dynamic programming that accounts for the context cost according to the variance of contexts. Second, the velocity reduction rate is applied to find the optimal route (shortest path) using the context data on the current traffic condition. The velocity reduction rate infers to the degree of possible velocity including moving vehicles' considerable road and traffic contexts, indicating the statistical or experimental data. Knowledge generated in this papercan be referenced by several organizations which deal with road and traffic data. Third, in experimentation, we evaluate the effectiveness of the proposed context-based optimal route (shortest path) between locations by comparing it to the previously used distance-based shortest path. A vehicles' optimal route might change due to its diverse velocity caused by unexpected but potential dynamic situations depending on the road condition. This study includes such context variables as 'road congestion', 'work', 'accident', and 'weather' which can alter the traffic condition. The contexts can affect moving vehicle's velocity on the road. Since these context variables except for 'weather' are related to road conditions, relevant data were provided by the Korea Expressway Corporation. The 'weather'-related data were attained from the Korea Meteorological Administration. The aware contexts are classified contexts causing reduction of vehicles' velocity which determines the velocity reduction rate. To find the optimal route (shortest path), we introduced the velocity reduction rate in the context for calculating a vehicle's velocity reflecting composite contexts when one event synchronizes with another. We then proposed a context-based optimal route (shortest path) algorithm based on the dynamic programming. The algorithm is composed of three steps. In the first initialization step, departure and destination locations are given, and the path step is initialized as 0. In the second step, moving costs including composite contexts into account between locations on path are estimated using the velocity reduction rate by context as increasing path steps. In the third step, the optimal route (shortest path) is retrieved through back-tracking. In the provided research model, we designed a framework to account for context awareness, moving cost estimation (taking both composite and single contexts into account), and optimal route (shortest path) algorithm (based on dynamic programming). Through illustrative experimentation using the Wilcoxon signed rank test, we proved that context-based route planning is much more effective than distance-based route planning., In addition, we found that the optimal solution (shortest paths) through the distance-based route planning might not be optimized in real situation because road condition is very dynamic and unpredictable while affecting most vehicles' moving costs. For further study, while more information is needed for a more accurate estimation of moving vehicles' costs, this study still stands viable in the applications to reduce moving costs by effective route planning. For instance, it could be applied to deliverers' decision making to enhance their decision satisfaction when they meet unpredictable dynamic situations in moving vehicles on the road. Overall, we conclude that taking into account the contexts as a part of costs is a meaningful and sensible approach to in resolving the optimal route problem.

Scale Invariant Auto-context for Object Segmentation and Labeling

  • Ji, Hongwei;He, Jiangping;Yang, Xin
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제8권8호
    • /
    • pp.2881-2894
    • /
    • 2014
  • In complicated environment, context information plays an important role in image segmentation/labeling. The recently proposed auto-context algorithm is one of the effective context-based methods. However, the standard auto-context approach samples the context locations utilizing a fixed radius sequence, which is sensitive to large scale-change of objects. In this paper, we present a scale invariant auto-context (SIAC) algorithm which is an improved version of the auto-context algorithm. In order to achieve scale-invariance, we try to approximate the optimal scale for the image in an iterative way and adopt the corresponding optimal radius sequence for context location sampling, both in training and testing. In each iteration of the proposed SIAC algorithm, we use the current classification map to estimate the image scale, and the corresponding radius sequence is then used for choosing context locations. The algorithm iteratively updates the classification maps, as well as the image scales, until convergence. We demonstrate the SIAC algorithm on several image segmentation/labeling tasks. The results demonstrate improvement over the standard auto-context algorithm when large scale-change of objects exists.

Aspect-Based Sentiment Analysis with Position Embedding Interactive Attention Network

  • Xiang, Yan;Zhang, Jiqun;Zhang, Zhoubin;Yu, Zhengtao;Xian, Yantuan
    • Journal of Information Processing Systems
    • /
    • 제18권5호
    • /
    • pp.614-627
    • /
    • 2022
  • Aspect-based sentiment analysis is to discover the sentiment polarity towards an aspect from user-generated natural language. So far, most of the methods only use the implicit position information of the aspect in the context, instead of directly utilizing the position relationship between the aspect and the sentiment terms. In fact, neighboring words of the aspect terms should be given more attention than other words in the context. This paper studies the influence of different position embedding methods on the sentimental polarities of given aspects, and proposes a position embedding interactive attention network based on a long short-term memory network. Firstly, it uses the position information of the context simultaneously in the input layer and the attention layer. Secondly, it mines the importance of different context words for the aspect with the interactive attention mechanism. Finally, it generates a valid representation of the aspect and the context for sentiment classification. The model which has been posed was evaluated on the datasets of the Semantic Evaluation 2014. Compared with other baseline models, the accuracy of our model increases by about 2% on the restaurant dataset and 1% on the laptop dataset.

위치기반 푸쉬서비스 플랫폼 설계 및 구현 (Design and Implementation of a Location-Based Push-Service Platform)

  • 심재민;이응재;주용완;남광우;류근호
    • 한국공간정보시스템학회 논문지
    • /
    • 제11권4호
    • /
    • pp.47-55
    • /
    • 2009
  • 최근 이동전화, 와이브로, HSDPA 등 무선인터넷 기술이 발전하면서 이용자의 위치, 상황을 고려한 교통, 관광, 쇼핑 및 긴급구조 등의 맞춤형서비스들이 주목받고 있다. 이용자의 상황에 맞는 맞춤형서비스 제공을 위해서는 무선 단말기를 장착하고 이동하는 이동객체의 연속적으로 변화하는 위치 정보, 시간 정보, 그리고 속도 변화와 같은 동적인 특성 등을 종합적으로 고려해야 한다. 이 논문은 이동객체가 발생시키는 컨텍스트 처리를 위한 트리거의 유형을 정의하고 이러한 트리거를 처리하기 위한 방법들을 설계하고 이용자의 위치에 따라 정보를 제공하기 위한 이동객체의 컨텍스트 트리거를 포함하는 위치기반 푸쉬서비스 플랫폼을 제안한다. 제안된 시스템은 휴대폰 및 텔레매틱스 단말 내장형 GPS의 Ms-assisted 측위 모드 또는 Stand-alone 측위 모드를 기반으로 단말에서 이동객체 스트립 정보를 수집하고, 이용자 단말 에이전트를 통해 이용자의 컨텍스트를 추출하여 이를 서버에 전송하도록 분산 처리 기능을 갖는다.

  • PDF