• Journal of Korea Multimedia Society
• /
• v.7 no.6
• /
• pp.832-840
• /
• 2004

In ubiquitous environments, context is any information that can be used to characterize the situation of an entity such as a person or an object. Many sensors and small computers collect contexts and provide applications with them. Thus, ubiquitous applications need to represent contexts and exploit them effectively. In this paper, we design and implement a context-aware messaging system, called UMS (Ubiquitous Messaging System), based on Java and Jini. UMS can represent various contexts using XML scripts, and communicate text messages regardless of user's location using the proxy mechanism of Jini.

• International Journal of Internet, Broadcasting and Communication
• /
• v.9 no.4
• /
• pp.44-50
• /
• 2017

To understand whether Falling, which is one of the causes of injuries, occurs, various behavior recognition research is proceeding. However, in most research recognize only the fact that Falling has occurred and provide the service. As well as the occurrence of the Falling, the risk varies greatly based on the type of Falling and the situation before and after the Falling. Therefore, when Falling occurs, it is necessary to infer the user's current situation and provide appropriate services. In this paper, we propose to base on Fog Computing and Cloud Computing to design Context-aware System using analysis of behavior data and process sensor data in real-time. This system solved the problem of increase latency and server overload due to large capacity sensor data.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.5
• /
• pp.3153-3158
• /
• 2014

Children in schoolzone accidents occur frequently in order to actively respond to the situation on the module for automated recognition research. By the vehicle penetration such like schoolzone, child object recognition, and GPS coordination information, the monitoring scenario can be constructed, and if an event occurs corresponding to strategic scenario so that suitable reaction can be provided to increase safety level to the schoolzone. In this paper, a GPS sensor and the image sensor and the monitoring server on the network based on the integration of context-aware methods have been studied. The image sensor section and the GPS section through analysis of the situation analysis and recognition of the object based on the scenario can actively cope with the situation according to the methods proposed.

• Proceedings of the Korea Society of Information Technology Applications Conference
• /
• 2005.11a
• /
• pp.225-228
• /
• 2005

A context-aware services platform supporting mobile agents consists of sensor nodes and a sensor coordinator. Sensor nodes collect environmental information and transmit the collected information to the sensor coordinator through wireless sensor networks. The sensor coordinator passes the information to the context-aware service module, and the mobile agent. The context-aware service module or the mobile agent performs services suitable for a user's situation based on the environmental information and a service actuation message is delivered to an actuation node through the sensor coordinator. In this paper, we present a context-aware services platform structure employed in our project, and describe context-aware services platform interfaces with a context-aware service module and mobile agents.

• Journal of KIISE:Computer Systems and Theory
• /
• v.34 no.5_6
• /
• pp.214-227
• /
• 2007

A context-aware service in ubiquitous computing environments aims to supply services according to users' situation information that is dynamically occurring. The existing context-aware workflow systems, such as FollowMe and uFlow, provide context-aware services based on a workflow, which uses users' situation information as transition conditions of a service. But they can't apply users' new service demands, which may dynamically occur even when a workflow is on going, to a workflow scenario. In this paper we propose a context-aware workflow system, which can reapply users' new service demands into an initial workflow without interrupting or deleting the workflow. The proposed system can provide context-aware services without interrupting of service by recognizing exactly a place holder that has to be changed in a workflow scenario and by reconstructing only the changed parts through an incremental parsing method. Therefore, a user can immediately apply his new service demands to an on-going workflow scenario, and he can be guaranteed continuous executions of context-aware services according to a workflow scenario, which includes new service demands.

• Journal of the Korea Society of Computer and Information
• /
• v.24 no.3
• /
• pp.65-75
• /
• 2019

Non-Functional Requirements (NFR) play a crucial role during the software development process. Currently, NFRs are considered more important than Functional Requirements and can determine the success of a software system. NFRs can be very complicated to understand due to their subjective manner and especially their conflicting nature. Self-adaptive systems (SAS) are operating in dynamically changing environment. Furthermore, the configuration of the SAS systems is dynamically changing according to the current systems context. This means that the configuration that manages the trade-off between NFRs in this context may not be suitable in another. This is because the NFRs satisfaction is based on a per-context basis. Therefore, one context configuration to satisfy one NFR may produce a conflict with another NFR. Furthermore, current approaches managing Non-Functional Requirements trade-off stops managing them during the system runtime which of concern. To solve this, we propose fragmentizing the NFRs and their alternative solutions in form of Multi-entity Bayesian network fragments. Consequently, when changes occur, our system creates a situation specific Bayesian network to measure the impact of the system's conditions and environmental changes on the NFRs satisfaction. Moreover, it dynamically decides which alternative solution is suitable for the current situation.

• KIPS Transactions on Software and Data Engineering
• /
• v.4 no.9
• /
• pp.409-418
• /
• 2015

In order to delivery of the correct information in IoT environment, it is important to deduce collected information according to a user's situation and to create a new information. In this paper, we propose a control access scheme of information through context-aware to protect sensitive information in IoT environment. It focuses on the access rights management to grant access in consideration of the user's situation, and constrains(access control policy) the access of the data stored in network of unauthorized users. To this end, after analysis of the existing research 'CP-ABE-based on context information access control scheme', then include dynamic conditions in the range of status information, finally we propose a access control policy reflecting the extended multi-dimensional context attribute. Proposed in this paper, access control policy considering the dynamic conditions is designed to suit for IoT sensor fusion environment. Therefore, comparing the existing studies, there are advantages it make a possible to ensure the variety and accuracy of data, and to extend the existing context properties.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.5B
• /
• pp.542-551
• /
• 2009

We proposed the context based user profile which is aware of its user's situation and based on user's situation it recommends personalized services. The user profile which consists of (context, service) pair can be acquired by the context and the service usage of a user; it then can be used to recommend personalized services for the user. In this paper, we show how they can be evolved without previously known user information so that not to violate privacy during the learning phase; in the result our user profile can be applied to any new environment without any modification to model only except context profiles. Using context-awareness based user profile, the service usage pattern of a user can be learned by the union of contexts and the preferred services can be recommended by the current environments. Finally, we evaluate the precision of proposed approach using simulation with data sets of UCI depository and Weka tool-kit.

• Proceedings of the KSPS conference
• /
• 2006.05a
• /
• pp.123-125
• /
• 2006

One of the biggest problems unsolved in emotional speech acquisition is how to make or find a situation which is close to natual or desired state from humans. We proposed a method to collect emotional speech data by scriptual context. Several contexts from the scripts of drama were chosen by the experts in the area. Context were divided into 6 classes according to the contents. Two actors, one male and one female, read the text after recognizing the emotional situations in the script.

• Proceedings of the Korea Society of Design Studies Conference
• /
• 2004.05a
• /
• pp.132-133
• /
• 2004