• Journal of Institute of Control, Robotics and Systems
• /
• v.13 no.6
• /
• pp.542-546
• /
• 2007

In the vision of ubiquitous computing environment, smart objects would communicate each other and provide many kinds of information about user and their surroundings in the home. This information enables smart objects to recognize context and to provide active and convenient services to the customers. However in most cases, context-aware services are available only with expert systems. In this paper, we present generalized activity recognition application in the smart home based on a naive Bayesian network(BN) and fuzzy clustering. We quantize continuous sensor data with fuzzy c-means clustering to simplify and reduce BN's conditional probability table size. And we apply mutual information to learn the BN structure efficiently. We show that this system can recognize user activities about 80% accuracy in the web based virtual smart home.

• Journal of Korea Spatial Information System Society
• /
• v.9 no.1
• /
• pp.91-104
• /
• 2007

In ubiquitous computing environment, people expect services to change actively in response to the change of themselves and surrounding environment. In order to meet such expectations, the streaming service needs technologies for migrating through various devices, following the user's movement, and the technology of individualized streaming push service. In this paper, we designed and implemented U-Stream, a ubiquitous streaming service system, based on user-defined context and stream view. The system classifies contexts according to streaming service migration and allows users to define some contexts and, by doing so, provides user-oriented individualized services rather than uniform services based solely on the developers' anticipations.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.5
• /
• pp.486-494
• /
• 2014

Intelligent homes consist of ubiquitous sensors, home networks, and a context-aware computing system. These homes are expected to offer many services such as intelligent air-conditioning, lighting control, health monitoring, and home security. In order to realize these services, many researchers have worked on various research topics including smart sensors with low power consumption, home network protocols, resident and location detection, context-awareness, and scenario and service control. This paper presents the real-time metabolic rate estimation method that is based on measured heart rate for human adaptive appliance (air-conditioner, lighting etc.). This estimation results can provide valuable information to control smart appliances so that they can adjust themselves according to the status of residents. The heart rate based method has been experimentally compared with the location-based method on a test bed.

• KIPS Transactions on Computer and Communication Systems
• /
• v.4 no.9
• /
• pp.289-296
• /
• 2015

The explosive growth of information has been difficult for users to get an appropriate information in time. The various ways of new services to solve problems has been provided. As customized service is being magnified, the personalized recommendation system has been important issue. Collaborative filtering system in the recommendation system is widely used, and it is the most successful process in the recommendation system. As the recommendation is based on customers' profile, there can be sparsity and cold-start problems. In this paper, we propose personalized movie recommendation system using collaborative filtering techniques and context-based techniques. The context-based technique is the recommendation method that considers user's environment in term of time, emotion and location, and it can reflect user's preferences depending on the various environments. In order to utilize the context-based technique, this paper uses the human emotion, and uses movie reviews which are effective way to identify subjective individual information. In this paper, this proposed method shows outperforming existing collaborative filtering methods.

• Convergence Security Journal
• /
• v.11 no.4
• /
• pp.77-83
• /
• 2011

In addition to the rapid development of health information technology services for the development of new medical information, a lot of research is underway. Improve health care services for patients are many ways to help them. However, no information about the security, if only the technology advances in health care systems will create an element of risk and threat. Today's issues and access issues are stable over a public network. Ad hocsensor network using secure, non-integrated health information system's security vulnerabilities does not solve the security vulnerabilities. In the development and utilization of health information systems to be subject to greater restrictions. Different security policies in an environment with a medical information system security policy mechanism that can be resolved if people get here are needed. Context-aware and flexible policy of integration and confidential medical information through the resistance should be guaranteed. Other cross-domain access control policy for telecommunications should be protected. In this paper, that the caller's medical information system, diversification, diversification Security agent in the environment, architecture, design, plan, role-based security system are proposed. The proposed system architecture, design work in the field and in the utilization of one model are expected to be.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.46 no.4
• /
• pp.111-120
• /
• 2009

In this paper, we propose ubiWarehouse system which can efficiently manages mass and many kinds of parts such as automotive parts. First, user's work situation is defined systematically as context type of 5W1H, context-aware system is separated on function, and each module operates independently. An efficient route is selected and relevant parts frequently treated at the same time are gathered by calculating the suitability of parts and racks. If other users currently are on a visit or are supposed to visit soon, the hun of visit is changed making a concession for preventing collision. As a result, the proposed system with avoiding competition can provide users with routes for inbound or outbound parts, and can effectively use spaces of a warehouse by arranging racks to gather relevant parts to near location. Also, individual service can be offered by evaluating user propensity using history of the warehouse job, and the accuracy of stock information can be improved by processing of unexpected context and real-time renewing of warehousing and delivering.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.6
• /
• pp.115-121
• /
• 2007

Recently, Location Based Service including tracking and way-finding services has been activated rapidly in the ubiquitous computing environment. According as the ubiquitous computing environment is developed, various types of sensor to acquire various data including location of the moving object are used widely, and acquired sensor data becomes abundant. However, the existing location management system based on a single location sensor is difficult to support LBS efficiently in the ubiquitous computing environment. In this paper, therefore, we propose the location management system in the ubiquitous computing environment that can manage the location data and the various sensor data efficiently. In addition, the location management system adopts the core technology for efficiently storing and transferring a large-volume of various data such as location data and for efficiently processing the various requests from a variety of servers and sensors. Especially, our architecture that is presented in this paper can support context-aware services and autonomous services efficiently in the ubiquitous computing environment.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.3 s.35
• /
• pp.119-132
• /
• 2005

The health care system revolutionized by the use of information and communication technologies. Computer information processing and electronic communication technologies play an increasingly important role in the area of health care. We propose a new role based access control model for pervasive health care systems, which changed location, time, environment information. Also our model can be solved the occurrence of an reduction authority problem to pervasive health care system at emergency environment. We propose a new role based access control model for pervasive health care systems, which combines role-to-role delegations, negative permission, context concept and dynamic context aware access control. With out approach we aim to preserver the advantages of RBAC and offer groat flexibility and fine-grained access control in pervasive healthcare information systems.

• Knowledge Management Research
• /
• v.10 no.1
• /
• pp.1-15
• /
• 2009

As pervasive computing technology, which aims to get linked to useful knowledge, information or services anytime, anywhere, using any devices and/or artifacts, is proliferating, desirable impacts on knowledge management systems are now available. The pervasive computing technology will potentially enable the knowledge management systems to realize individualization and socialization and ultimately increase the knowledge processing productivity. However, researchers who apply the pervasive computing methodologies to novel way of knowledge management have been very few. These result in unsatisfactory consideration of establishing pervasive knowledge management systems. Hence, the purpose of this paper is to cast the vision of pervasive knowledge management and search for a couple of possible research issues and possibilities. This paper suggests a framework of ubiDSS, an amended knowledge management system for the next generation deploying pervasive and autonomous knowledge acquisition capabilities of ubiquitous computing technologies. Also the CKAM, context-based knowledge acquisition module, is illustrated as a prototype of future knowledge management systems.

• Journal of KIISE:Software and Applications
• /
• v.35 no.3
• /
• pp.137-148
• /
• 2008

Services system which has been emerging as a new way of application development utilizes services as fundamental units for developing a system. Services system can offer services within web environment as well as the ubiquitous environment where mobile devices are connected to wired or wireless network. In order to provide the functionality that meets users' requirements, the most appropriate service should be selected among candidate services by taking requests and context information into account. Therefore, it is important that the service system should provide services to users by dynamically adapting to users' requirements and context information. Since different users request same functionality with different context information, one service can be differently offered to users so that variability can happen to the service systems. Most researches on context-aware systems have a tendency to solve dynamic adaptation by using more or less ad hoc manner In this paper, we consider various types of services which are performed according to context information as variability and propose adaptable architecture by applying concepts of product line architecture in order to deal with variabilities systematically.