• Journal of Korea Multimedia Society
• /
• v.13 no.1
• /
• pp.133-142
• /
• 2010

As the ubiquitous technology has penetrated into almost every aspect of modern life, the research of the security technology to solve the weakness of security in the ubiquitous environment is received much attention. Because, however, today's security systems are usually based on the fixed rules, many security systems can not handle diverse situations in the ubiquitous environment appropriately. Although many existing researches on context aware security service are based on ACL (Access Control List) or RBAC (Role Based Access Control), they have an overhead in the management of security policy and can not manipulate unexpected situations. Therefore, in this paper, we propose a context-aware security service providing multiple authentications and authorization from a security level which is decided dynamically in a context-aware environment using FCM (Fuzzy C-Means) clustering algorithm and Fuzzy Decision Tree. We show proposed model can solve typical conflict problems of RBAC system due to the fixed rules and improve overhead problem in the security policy management. We expect to apply the proposed model to the various applications using contextual information of the user such as healthcare system, rescue systems, and so on.

• Journal of Korea Multimedia Society
• /
• v.9 no.4
• /
• pp.460-469
• /
• 2006

Recently, a demand of adaptive multimedia service, which supports multimedia service migration according to user's location and characteristics of user device, is increased. In this paper, we propose a service migration system, which becomes aware of user device using intelligent agent. And we design and implement the ontology-based intelligent agent, which is aware of the context in its environment. Moreover, we implement a context reasoning system using location information.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.05a
• /
• pp.509-512
• /
• 2008

Ubiquitous Computing System란, 언제 어디서나 통신 및 컴퓨팅이 가능하고 컴퓨팅 시스템이 상호간에 정보를 공유하고 협력하는 컴퓨팅 시스템이다. 이로써 기존의 컴퓨팅 환경과 같이 사용자와 컴퓨터간의 대화형 상호작용이 아닌 물리적인 환경 상황(Context)등을 시스템이 스스로 인식하고 이를 기반으로 사용자와의 상호 작용을 지원하는 상황인식 기술이 필수적인 요소로 부각되고 있다. 또한, Ubiquitous Computing System을 위해 사용자 및 주변 환경 정보를 감지하는 센서(Sensor) 기술이 필요하다. 하지만 사용자 및 주변 환경으로부터 입력되는 불확실하거나 모호한 상황정보에 대한 표현과 추론에 대한 연구는 부족한 실정이다. 본 논문은 이런 이유에서 Rule-based System을 기반으로 CRS와 DOS의 개념을 도입한 새로운 상황인식 기반의 Architecture를 제안하고, 이를 VHDL을 통해 SoC로 구현하였다. CRS를 통해 실시간으로 다양한 센서에서 들어오는 많은 데이터에 가중치를 부여하여 각 센서마다 중요도를 달리 부여한다. 이로써, System은 Sensor 입력 값의 중요도에 따라 처리 순서를 우선적으로 부여하여 처리 속도를 높인다. 또, DOS를 통해 각양각색의 사용자에게 획일적인 서비스를 제공하는 것이 아니라 상황 변화의 패턴에 따라 개별화되고 특화된 서비스를 제공한다. 마지막으로, Ubiquitous Computing System의 향후 발전 가능성을 예상하고, 본 논문에서 제시한 Context-aware Architecture에 의해 구현된 UoC의 유용성을 짐작해 본다.

• The Journal of the Korea Contents Association
• /
• v.16 no.11
• /
• pp.434-443
• /
• 2016

Users can set manually Android phone to do particular tasks on some situations. This type of setting is inconvenient, and also provide with unnecessary services, which don't consider users' situation. In this research, we design and implement a context-aware automatic task setting application. Users can get context-aware service by setting desired tasks based on contexts using this system. We design a language for describing context-action rules, and statically check validity of context-action rules by performing syntax and semantic check.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.10a
• /
• pp.481-484
• /
• 2010

In this paper, we implements the USN based context-aware vessel system for a group of ships which receives the specific sensor data that is the result of context-aware after collecting from each of the among a group of ships. The received date is shared and managed by monitoring system. If this monitoring system have trouble the sensor from any ship, the it's control was transferred from the main monitoring ship to the any ship and the second main ship collect the data then recognize the context-aware. Also, this system have the advantage of that reduce the load due to the sensor node communication because just collect the optional sensor data.

• Knowledge Management Research
• /
• v.9 no.4
• /
• pp.65-75
• /
• 2008

Knowledge workers' workload to register knowledge can cause quality defects in the quality as well as the quantity of knowledge that must be accumulated in a knowledge management system(KMS). To enhance the availability of a KMS by acquiring more quality-guaranteed knowledge, autonomous knowledge acquisition which outdoes the automated acquisition must be initiated. Adopting the capabilities of context-awareness and inference in the field of context-aware computing, this paper intends to autonomously identify and acquire knowledge from knowledge workers' daily lives. Based on knowledge workers' context information, such as location, identification, schedule, etc, a methodology to monitor, sense, and gather knowledge that resides in their ordinary discussions is proposed. Also, a prototype systems of the context-based knowledge acquisition system(CKAS), which autonomously dictates, analyzes, and stores dialogue-based knowledge is introduced to prove the validity of the proposed concepts. This paper's methodology and prototype system can support relieving knowledge workers' burden to manually register knowledge, and hence provide a way to accomplish the goal of knowledge management, efficient and effective management of qualified knowledge.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.4
• /
• pp.90-97
• /
• 2014

Context-aware systems provide proper services for the user according to current contexts. However, it is not actively deployed in our daily lives as expected, due to many concerns including occurrences of exceptions. C++/C#/JAVA provide exception handling facilities for desktop computing programs, but context-aware system developers might feel far more difficult to make use of such general facilities, because it is hard to decide the timing and position of exception handling with various devices engaged. In this paper, we propose an exception detection and handling mechanism using device semantics and AspectJ so that it can constantly detect a large number of devices to allow the programmers to detect and handle exceptions with less burden.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.2
• /
• pp.383-403
• /
• 2021

With the development of mobile edge computing (MEC), some late-model application technologies, such as self-driving, augmented reality (AR) and traffic perception, emerge as the times require. Nevertheless, the high-latency and low-reliability of the traditional cloud computing solutions are difficult to meet the requirement of growing smart cars (SCs) with computing-intensive applications. Hence, this paper studies an efficient offloading decision and resource allocation scheme in collaborative vehicular edge computing networks with multiple SCs and multiple MEC servers to reduce latency. To solve this problem with effect, we propose a context-aware offloading strategy based on differential evolution algorithm (DE) by considering vehicle mobility, roadside units (RSUs) coverage, vehicle priority. On this basis, an autoregressive integrated moving average (ARIMA) model is employed to predict idle computing resources according to the base station traffic in different periods. Simulation results demonstrate that the practical performance of the context-aware vehicular task offloading (CAVTO) optimization scheme could reduce the system delay significantly.

• KIPS Transactions on Software and Data Engineering
• /
• v.8 no.4
• /
• pp.145-152
• /
• 2019

Unlike a single value from a sensor device, a massive data set has characteristics for various processing aspects; input data may be formed in a different format, the size of input data varies, and the processing time of analyzing input data is not predictable. Therefore, context aware systems may contain complex modules, and these modules can be implemented and used in different ways. In order to solve these problems, we propose a method to handle context information from the result of analyzing massive data. The proposed method considers analysis work as a different type of abstracting context and suggests the way of representing context information. In experiment, we demonstrate how the context processing engine works properly in a couple of steps with healthcare services.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.47 no.6
• /
• pp.19-27
• /
• 2010

Many security issues occur in cloud computing service environment such as authentication, access control, and so on. In this paper, we propose an effective authentication and access control model which provide integrated management and control when we access various resources in cloud computing environment. To address these problems, we suggest a context-aware single sign-on and access control system using context-awareness, integrated authentication, access control, and OSGi service platform in cloud computing environment. And we show design and implementation of context-aware single sign-on and access control system. Also we verified the flexibility and convenience of the proposed system through multi fact based integrated authentication in cloud computing environment. We could provide flexible and secure seamless security service by user context in cloud computing environment.