• Journal of the Korean Operations Research and Management Science Society
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• v.33 no.2
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• pp.27-44
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• 2008

Owl-based ontology is useful to realize the context-aware services which are composed of the distributed and self-configuring modules. Many ontology-based inference engines are developed to infer useful information from ontology. Since these engines show the uniqueness in terms of speed and information richness, it's difficult to ensure stable operation in providing dynamic context-aware services, especially when they should deal with the complex and big-size ontology. To provide a best inference service, the purpose of this paper is to propose a novel methodology of context-aware engine selection in a contextually prompt manner Case-based reasoning is applied to identify the causality between context and inference engined to be selected. Finally, a series of experiments is performed with a novel evaluation methodology to what extent the methodology works better than competitive methods on an actual context-aware service.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.1
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• pp.248-268
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• 2018

The performance of smartphone applications are usually constrained in user interactions due to resource limitation and it promises great opportunities to improve the performance by exploring the smartphone built-in and embedded sensing techniques. However, heterogeneity in techniques, semantic gap between sensor data and usable context, and complexity of contextual situations keep the techniques from seamless integration. Relevant studies mainly focus on feasibility demonstration of emerging sensing techniques, which rarely address both general architectures and comprehensive technical solutions. Based on a proposed functional model, this investigation provides a general architecture to deal with the dynamic context for context-aware automation and decision support. In order to take advantage of the built-in sensors to improve the performance of mobile applications, an ontology-based method is employed for context modelling, linguistic variables are used for heterogeneous context presentation, and semantic distance-based rule matching is employed to customise functions to the contextual situations. A case study on mobile application authentication is conducted with smartphone built-in hardware modules. The results demonstrate the feasibility of the proposed solutions and their effectiveness in improving operational efficiency.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.105-114
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• 2006

Context-Awareness is a important technology to support optimized services automatically by recognizing various context informations in ubiquitous environments. Previous middlewares which supports ubiquitous environments used a centralized storage and DBMS to store and manage context informations and service contents. Centralized management of context informations and service contents sometimes hinders the autonomy of moving node and interoperability between difference middlewares. In this paper, we design the systems which stores context informations in moving node by distributed form and shares service contents between middlewares in distributed ubiquitous environments. And it provides Context-Aware scripts to supports the definition of context informations reasoning and execution of services. It verifies the usefulness of the designed systems by applying the scenario of music playing service based on context awareness

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2007.11a
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• pp.451-456
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• 2007

유비쿼터스 컴퓨팅 환경을 구축하기 위해서는 사용자 및 주변 상황에 관한 인지기술이 필수적이다. 이에 따라 이기종 분산형 시스템에서 언어와 기종에 영향을 받지 않고 사용자 Context를 인지하고 표현하는 문제는 해결해야할 중요한 과제로 대두되었다. 이에 따라, 본 논문에서는 이 과제를 해결하기 위하여 시맨틱 웹 기술 및 퍼지 개념을 이용하여 사용자 Context를 기술하는 것을 제안한다. 온톨로지는 컴퓨터가 정보자원의 의미를 파악하고 자동적으로 처리할 수 있도록 고안된 지식표현 언어이므로 이기종 시스템 하에서의 사용자 Context를 표현하는데 적합하다. 한편, 사용자가 접할 실세계의 환경은 일반집합(Crisp Set)으로 표현하기 힘들기 때문에 본 논문에서는 퍼지개념과 표준 웹 온톨로지 언어 OWL이 융합된 Fuzzy OWL언어를 사용했다. 본 논문에서 제안하는 방법은 Context를 Fuzzy OWL로 표현하기 위하여 먼저 사용자가 접한 환경정보들을 수치로 표현한다. 그리고 이를 OWL로 기술하며 OWL로 표현된 사용자 Context를 Fuzzy OWL로 변환한다. 마지막으로 퍼지 개념이 포함된 사용자 Context를 이용하여 자동적인 상황인지가 가능한지 여부를 퍼지 추론 엔진인 FiRE를 사용하여 실험한다. 본 논문에서 제시한 방법을 사용하면 이기종 분산시스템에서도 사용할 수 있는 형태로 Context를 기술할 수 있다. 그리고 기술된 Context를 기반으로 현재 사용자가 접한 환경의 상태를 추론할 수 있다. 또한 퍼지 기술 로직 언어(Fuzzy Description Logic)기반 추론기인 FiRE를 이용하여 이를 검증한다.

• Journal of Electrical Engineering and information Science
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• v.1 no.2
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• pp.1-8
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• 1996

This paper presents a text-driven discourse analysis system, called DPAS. DPAS constructs a discourse structure by weaving together clauses in the text by finding discourse relations between a clause and the clauses in a context. The basic processing model of DPAS is based on the stack based model of discourse analysis suggested by Grosz and Sidner. We extend the model with dynamic programming method to handle various discourse ambiguities effectively and efficiently. We develop the idea of a context space to keep all information of a context. DPAS parses a text by considering all possible discourse relations between a clause and a context. Since different discourse relations may result in different states of a context, DPAS maintains multiple context spaces for an ambiguous text. Since maintaining all interpretations until the whole text is processed requires too much computing resources, DPAS uses the idea of depth-limited search to limit the search space. If there is more than one discourse relation between an input clause and a context, DPAS constructs context spaces one context space for each discourse relation. Then, DPAS applies heuristics to choose the most desirable context space after it processes some more input clauses. Since the basic idea of DPAS is domain independent, although we used descriptive texts to demonstrate DPAS, we believe the idea of DPAS can be extended to understand other styles of texts.

• Journal of the Korea Society of Computer and Information
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• v.11 no.1 s.39
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• pp.185-194
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• 2006

The ubiquitous computing environment focuses on recognizing the context and Physical entities, whereas, previous computing environments mainly focused on the conversational interactions between the computer and the user. For this reason, there has been an increase in the research of context aware computing environments. In previous researches , context services are designed using context ontology used in context aware middleware. So, context service cannot change the context ontology in execution time. We propose a hierarchical context ontology management for context aware service to change their ontology in execution time. And we also a resolution model for context conflict which is occurred in inference of context. We have designed a middleware based on this model and implemented the middleware. As the middleware is implemented on the OSGi framework, it can cause interoperability among devices such as computers, PDAs, home appliances and sensors. It can also support the development and operation of context aware services, which are required in the ubiquitous computing environment.

• The KIPS Transactions:PartD
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• v.15D no.3
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• pp.411-420
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• 2008

This paper implemented the u-Healthcare Context Information System (HCIS) supporting ubiquitous healthcare by using location, health and titrating environment information collected from sensors/devices equipped in home for healthcare home service. The HCIS is based on the Distributed Object Group Framework (DOGF), a management model which can customize distributed resources, and manages various context information, applications and devices as a group in healthcare home environment, as one more logical units. Also, this system provides continuous healthcare multimedia service considering a resident's location using Mobile Proxy, and the healthcare context information through Context Provider to a resident in home. For verifying execution of our system, we implemented the seamless multimedia service based on resident's location and the prescription/advice and schedule notification/alarm service as healthcare applications in home. And we showed the executing results of healthcare home service by using service device existed in the residential space on which the resident is located according to the healthcare scenario.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.6
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• pp.488-501
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• 2009

In ubiquitous environments, invisible devices and software are connected to one another to provide convenient services to users. In order to provide such services, we must have mobile devices that connect users and services. But such services are usually limited to those served on a single mobile device. To resolve the resource limitation problem of mobile devices, a nearby resource sharing research has been studied. Also, not only the nearby resource share but also a resource recommendation through context-based resource reasoning has been studied such as an UMO Project. The UMO Project share and manage the various context information for the personalization resource recommendation and reason based on current context information. Also, should verify resource inference rules for reliable the resource recommendation. But, to create various context information requires huge cost and time in actuality. Thus, we propose a inference verification tool called USim to resolve problem. The proposed inference verification tool provides convenient graphic user interfaces and it easily creates context information. The USim exactly verifies new inference rules through dynamic changes of context information.

• Journal of Korea Entertainment Industry Association
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• v.13 no.4
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• pp.63-70
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• 2019

We extract the symptom of panic disorder from the context awareness environment. It extracts body context information through natural movement that exists in everyday life and uses a component of panic disorder. The ontology theory can be used to provide information on the degree of symptoms of panic disorder through inference process. For the components of panic disorder to the information processing based on ontology are defined as Classes. Panic disorder index is expressed through ontology modeling so that the condition of panic disorder can be known. The derivation of panic disorder component and panic disorder index will enable context awareness based information service for panic disorder. The context information is periodically synchronized with the context awareness on based device. Panic disorder can be used to improve the lifestyle of panic disorder.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4B
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• pp.226-234
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• 2005

Context-Aware is the most important facts to reason a personalized and optimized service and to provide it to user. In the previous researches, user and surrounding environment were main facts of Context-Aware and middleware or center server has been proposed to support Context-Aware. In the daily space(for example, home, office, Car, etc), interactions between user and service can be a important facts of Context-Aware. In this paper, Context Autogenesis service model is introduced, simplified the Context-Aware process and designed the middleware which performs decentralize management for Context-Aware information of user's portable devices, so that problems occurred during the management and operation of existing Context-Aware system can be minimized and supporting user anonymity