• 한국HCI학회:학술대회논문집
• /
• 2006.02a
• /
• pp.970-975
• /
• 2006

There is a tradeoff between user's privacy and utility of context-aware services in ubiquitous computing environments. Many privacy models have been proposed to support the disclosure of personal information at different levels of detail, in ubiquitous computing environments. However, most of these models do not allow for explicit criteria to assess the benefit users are likely to reap by disclosing their personal information. In this paper, we propose an automated decision making mechanism that evaluates the "benefit of disclosure" for the users based on trust relationships between users and information requesters and manages the disclosure of user's personal information accordingly. Unlike other trust models, we do not regard the reputation of an information requester as sufficient to determine his/her trustworthiness. Instead, we represent trustworthiness as a function of information requester's reputation in the eyes of the user and his/her competence in a given context. To validate our mechanism, we apply it to context-aware healthcare application that monitors physiological condition of a user.

• Korean Journal of Computational Design and Engineering
• /
• v.12 no.3
• /
• pp.171-181
• /
• 2007

Ubiquitous computing is a vision of our future computing lifestyle in which computer systems seamlessly integrate into our everyday lives, providing services and information in anywhere and anytime fashion. Augmented reality (AR) can naturally complement ubiquitous computing by providing an intuitive and collaborative visualization and simulation interface to a three-dimensional information space embedded within physical reality. This paper presents a service framework and its applications for providing context-aware u-car maintenance services using augmented reality, which can support a rich set of ubiquitous services and collaboration. It realizes bi-augmentation between physical and virtual spaces using augmented reality. It also offers a context processing module to acquire, interpret and disseminate context information. In particular, the context processing module considers user's preferences and security profile for providing private and customer-oriented services. The prototype system has been implemented to support 3D animation, TTS (Text-to-Speech), augmented manual, annotation, and pre- and post-augmentation services in ubiquitous car service environments.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2004.05a
• /
• pp.845-848
• /
• 2004

Ubiquitous Computing 환경은 컴퓨터 중심의 환경이 아닌 사용자가 편리성과 효율성이 극대화된 서비스들을 제공 받을 수 있는 사용자 중심의 환경이다. 이러한 환경에서 사용자들은 자신의 정보가 언제 어디서 사용되고 있고 어떠한 목적으로 유출되고 있는지 알기 어렵다. 따라서 사용자를 식별하고 개인의 특성에 따라 관련된 서비스를 제공하는데 있어 사용자의 필요정보를 적절하게 보호할 수 있는 메커니즘이 필요하다. 본 논문에서는 Ubiquitous환경에서 특정목적에 국한된 서비스 제공이 아닌 다양한 목적에 따라 서비스가 제공될 수 있도록 사용자의 목적과 상황에 맞는 User Model을 제안하고자 한다. 또한 사용자의 상황에 맞는 Context Content를 구별하여 Privacy등급을 결정하고 사용자마다 독립적이고 안전한 Context-Aware Service를 제공하는 User Model은 사용자마다 정해진 정적 Context와 상황에 따라 변화하는 동적 Context를 모두 고려하여 높은 신뢰성과 안전성을 지닌 방법을 제공한다. 그리고 제안된 User Model의 정의와 시나리오를 설명한다.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.15 no.2
• /
• pp.37-52
• /
• 2005

Traditional access control models like role-based access control model are insufficient in security needs in ubiquitous computing environment because they take no thought of access control based on user's context or environment condition. In these days, although researches on context-aware access control using user's context or environment conditions based on role-based access control are emerged, they are on the primary stage. We present context definitions md an access control model to provide more flexible and dynamic context-aware access control based on role-based access control. Specially, we describe the conflict problems occurred in the middle of making an access decision. After classifying the conflict problems, we show some resolutions to solve them. In conclusion, we will lay the foundations of the development of security policy and model assuring right user of right object(or resource) and application service through pre-defined context and context classification in ubiquitous computing environments. Beyond the simplicity of access to objects by authorized users, we assure that user can access to the object, resource, or service anywhere and anytime according to right context.

• The KIPS Transactions:PartD
• /
• v.18D no.5
• /
• pp.393-402
• /
• 2011

This paper describes a design and application of middleware that is essential to the context-aware system. We define a transducer interface protocol in order to deal with a variety of context data. For the purpose of systematic process of data between middleware modules, a message oriented middleware is designed and implemented. Memory improves the performance of high-performance computing system compared to previous strategies. Context aware middleware adopts service oriented architecture so that functions in modules may be independent and scalability can be remarkable. Using messages across modules decreases the complexity of the application development. In order to justify the usefulness of the proposed context aware middleware, we carried out our experiments in bridge health monitoring system and verified the efficacy.

• Journal of information and communication convergence engineering
• /
• v.18 no.3
• /
• pp.183-187
• /
• 2020

The general Wi-Fi network connection structure is that a number of IoT (Internet of Things) sensor nodes are directly connected to one AP (Access Point) node. In this structure, the range of the network that can be established within the specified specifications such as the range of signal strength (RSSI) to which the AP node can connect and the maximum connection capacity is limited. To overcome these limitations, multiple middleware bridge technologies for dynamic scalability and load balancing were studied. However, these network expansion technologies have difficulties in terms of the rules and conditions of AP nodes installed during the initial network deployment phase In this paper, an intelligent edge computing IoT device is developed for constructing an intelligent autonomous cluster edge computing network and applying it to real-time road danger context aware and notification system through an intelligent risk situation recognition algorithm.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.42 no.5
• /
• pp.49-58
• /
• 2005

There has been an increase in the interest of applications that use a combination of both pervasive computing technology and context-aware technology. This application based on the development environment along with the support of developing context-aware applications is now being researched thoroughly and by many. The service management system provides services that are needed for context-aware applications. This system is an integral part of the developmental environment of context-aware applications. But there is a restrictive matching based on ontology that uses simple syntactic matching or a plain type of service used in previous researches. And there is also no consideration for context-aware information. Also, if the user is unable to find a service that is satisfactory, or is a service which a user does not desire, they may use a service which is composed of other existing services. This paper proposes a service management system based on context-aware information. The proposed system enables the accurate finding of services by considering semantic matching methods based on ontology and context-aware information. If the user does not find a service that is helpful in the service registry, it can provide the service list to enable other existing service compositions, by providing the functionality of these service compositions. As a result, the experiment of the system proposed has shown that the system properly supported the service discovery based on context-aware information and service composition.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.6
• /
• pp.99-109
• /
• 2011

Ubiquitous computing technology makes an impact on the appearance of u-learning and presents an advanced direction of futuristic school education. In ubiquitous learning environments, various embedded computational devices will be pervasive and interoperable across the network for supporting the learning, so users may utilize these devices anytime anywhere. An important next step for ubiquitous learning is the introduction of context-aware learning service that employing knowledge and reasoning to understand the local context and share this information in support of intelligent learning services. However, the existing studies on design and application of ontology context model to support context-aware service in actual school environments are incomplete state. This paper, therefore, suggests a scheme of constructing ubiquitous learning space for existing school network by introducing USN to support context-aware ubiquitous learning services. This paper, also, designs an ontology based context model for ubiquitous school environments which describes context information through OWL. To determine the suitability of proposed ubiquitous learning space and ontology context model, we implement some of context-aware learning services in the ubiquitous learning environments.

• Journal of KIISE:Computer Systems and Theory
• /
• v.32 no.11_12
• /
• pp.617-628
• /
• 2005

The services for ubiquitous computing environments have to provide automatically user-specific adaptive services in dynamically changed environments with many informations provided by both a user and his/her environment. Workflows used in business and distributed computing environments support service automation by connecting many tasks with rules or orderings of tasks. Therefore we must specify context information on transition condition to support context-aware services by adapting a workflow to ubiquitous computing environments. In this paper, we present a structural context model to specify context information on transition constraints of the workflow. And we propose an uWDL Ubiquitous Workflow Description Language) based on web services, which provides web service interfaces which are standardized and independent on heterogeneous and various platforms, protocols, and languages. The uWDL tan be interpreted and executed by a workflow engine, and provide users autonomic services based on context-awareness.

• Journal of KIISE:Software and Applications
• /
• v.31 no.2
• /
• pp.111-125
• /
• 2004

In this paper, we applied user-centered context to Smart Home Applications. Current research activities on smart home have just focused on the infrastructure without considering user's contexts and implementation cost. We first realized the user-centered personalized services using ubi-UCAM (a Unified Context-aware Application Model), which exploited contexts from various kinds of smart sensors. We, then, verified its usefulness in the ubiquitous computing-enabled home environment. It can be extended to various application areas since it guarantees independence between sensors and services. Accordingly, it will play a key role in future smart home environment.