• Journal of the Korea Society of Computer and Information
• /
• v.13 no.4
• /
• pp.205-211
• /
• 2008

Conventional context-aware service models permit the access of resources only by user authentication, but the ubiquitous environments where the context information around users is changing frequently require the resource access control according to the rapid changes. This paper proposes a scheme to control access permission of resource dynamically as context information of user changes. Our access control model is based on traditional CASA (Context-Aware Security Architecture), but can restrict the access of the user already has been authorized. With the real-time checking of context information, our scheme gives different access controls according to changes in environmental information, and provides more secure services than conventional context-aware models.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2007.11a
• /
• pp.63-66
• /
• 2007

기존의 홈네트워크 시스템에서 사용자의 단순한 명령을 통해 서비스를 제공하는 기술은 이미 구현되어 있다. 그렇지만 가정이라는 환경은 이렇게 단순한 환경이기보다, 다수의 가족 구성원으로 이루어져 있으며 그에 따른 다양한 명령과 상황이 존재하고 있다. 이러한 다변화된 특성에 맞추어 사용자의 단순 명령보다 한 단계 높은 수준으로 사용자의 욕구를 능동적으로 추론해 낼 수 있는 모델의 제안이 필요하다. 본 논문에서 베이지안 네트워크를 활용하여 사용자의 주변 환경 정보로 규정된 Context를 인식하고 인식된 결과를 통해 사용자가 요구하는 적합한 서비스(Context-based Service)를 추론해 낼 수 있는 모델을 제시하고자 한다.

• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 2006.06a
• /
• pp.122-129
• /
• 2006

The context-awareness has become the one of core technologies and the indispensable function. for application services in ubiquitous computing environment. In this research, we incorporated the capability of context-awareness in a music recommendation system. Our proposed system consists of such components as Intention Module, Mood Module and Recommendation Module. Among these modules, the Intention Module infers whether a user wants to listen to the music or not from the environmental context information. We built the Intention Module using data mining techniques such as decision tree, support vector machine and case-based reasoning. The results showed that the case-based reasoning model outperformed the other models and its accuracy was 84.1%.

• Proceedings of the Korean Information Science Society Conference
• /
• 2006.06a
• /
• pp.322-324
• /
• 2006

유비쿼터스 컴퓨팅은 사물에 컴퓨터 기능이 내장되어 언제, 어디에서나, 어느 장치로도 편리하게 주변 환경으로부터 서비스를 사용할 수 있게 하는 정보기술의 패러다임이다. 이를 위해선 상황인지가 전제되어야 하는데 여기서 상황인지라 함은 시스템의 다양한 센서 정보를 바탕으로 스스로 상황(Context)을 인지하는 것으로서, 그 정의에 있어서, 아직 논란이 많으나 지능형 서비스를 위한 중요한 개념이다. 본 논문에서는 센서로부터 바로 생성된 Raw Context 정보를 Low-Level Context라고 하고 이를 복합(Fusion)하여 이미 알려진 High-Level Context로 분류하는 논리적 연산을 추론에 기반한 상황인지로서 정의한다. 이때 센서 정보를 통해 특정한 상황정보를 추론하기 위한 모델을 설계하여 상황인지 미들웨어에 적용시켜 보고 그에 따른 효율적인 구조를 기술한다.

• International Journal of Human Ecology
• /
• v.11 no.1
• /
• pp.35-47
• /
• 2010

Based on concepts of human ecology, this study explored how diverse systems- cultural setting, work context and maternal perception- shape paternal involvement in child care. For this purpose, I compared Korean fathers (n=93) and Korean sojourner fathers in the United States (n=129). Hypothesized structural equation model explaining direct and indirect relationships among variables was developed. The results showed that cultural context had no direct relationship with paternal involvement. Cultural context showed indirect influence on paternal involvement through fathers' work context. Maternal perception, which had significant relationship with paternal involvement, was not explained by cultural context. However, it was significantly influenced by work context.

• The Journal of Society for e-Business Studies
• /
• v.12 no.3
• /
• pp.1-17
• /
• 2007

A virtual enterprise (VE) can be mapped into a multi-agent system (MAS) that consists of various agents with specific role(s), communicating with each other to accomplish common goal(s). However, a MAS for enacting VE requires more advanced mechanism such as context that can guarantee autonomy and dynamism of VE members considering heterogeneity and complex structure of them. This paper is to suggest a context-based MAS as a platform for constructing and managing virtual enterprises. In the Context-based MAS a VE is a collection of Actor, Interaction (among Actors), Actor Context, and Interaction Context. It can raise the speed and correctness of decision-making and operation of VE enactment using context, i.e., information about the situation (e.g., goal, role, task, time, location, media) of Actors and Interactions, as well as simple data of their properties. The Context-based MAS for VE we proposed('VECoM') may consists of Context Ontology, Context Model, Context Analyzer, and Context Reasoner. The suggested approach and system is validated through an example where a VE tries to find a partner that could join co-development of new technology.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.11
• /
• pp.5459-5473
• /
• 2017

Recently, a tracking algorithm called the spatial-temporal context model has been proposed to locate a target by using the contextual information around the target. This model has achieved excellent results when the target undergoes slight occlusion and appearance changes. However, the target location in the current frame is based on the location in the previous frame, which will lead to failure in the presence of fast motion because of the lack of a prediction mechanism. In addition, the spatial context model is updated frame by frame, which will undoubtedly result in drift once the target is occluded continuously. This paper proposes two improvements to solve the above two problems: First, four possible positions of the target in the current frame are predicted based on the displacement between the previous two frames, and then, we calculate four confidence maps at these four positions; the target position is located at the position that corresponds to the maximum value. Second, we propose a target reliability criterion and design an adaptive threshold to regulate the updating speed of the model. Specifically, we stop updating the model when the reliability is lower than the threshold. Experimental results show that the proposed algorithm achieves better tracking results than traditional STC and other algorithms.

• MALSORI
• /
• no.50
• /
• pp.139-150
• /
• 2004

A Phonetic Tied-Mixture (PTM) model has been proposed as a way of efficient decoding in large vocabulary continuous speech recognition systems (LVCSR). It has been reported that PTM model shows better performance in decoding than triphones by sharing a set of mixture components among states of the same topological location[5]. In this paper we propose a Phonetic Tied-Mixture Syllable (PTMS) model which extends PTM technique up to syllables. The proposed PTMS model shows 13% enhancement in decoding speed than PTM. In spite of difference in context dependent modeling (PTM : cross-word context dependent modeling, PTMS : word-internal left-phone dependent modeling), the proposed model shows just less than 1% degradation in word accuracy than PTM with the same beam width. With a different beam width, it shows better word accuracy than in PTM at the same or higher speed.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.44 no.3
• /
• pp.8-13
• /
• 2007

The context-aware environment focuses on recognizing the context and physical entities. For this reason, there has been an increasement in research of context-aware computing environment. Ontology-based context models are widely used in ubiquitous environment because of context sharing and reusing. In this paper, we propose a proactive retrieval method using ontology in context-aware environment. The method use a concept level of hierarchical concept tree in ontology for more efficient retrieval. This paper describes the proactive retrieval method and ontology model. Several experiments are performed and the results verify that the proposed method's efficiency is better than other existing methods.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.1
• /
• pp.265-273
• /
• 2014

In this paper, context-aware technologies using a Kinect sensor for a digital signage which is increasingly growing as the 4th screen media is presented. Generalized context-aware functions for a digital signage were studied and a context-aware digital signage platform was developed. It can support a natural user interface for controlling a digital signage and actively provide contents adapted to its context. As a basic context, user's gesture and voice, the number of users, sound direction were considered. In the future, the advanced functions such as age, gender will be studied. The implemented platform could be a good reference model when developing a general context-aware digital signage.