• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.3
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• pp.127-135
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• 2015

Context-aware mobile cloud computing is a new promising paradigm that allows to improve user experience by analyzing contextual information such as user location, time of the day, neighboring devices and current activity. In this paper we provide performance study of context-aware mobile cloud computing system with Volare middleware. Volare monitors the resources and context of the device. and dynamically adapts cloud service requests accordingly, at discovery time or at runtime. This approach allows for more resource-efficient and reliable cloud service discovery, as well as significant cost savings at runtime. We also have studied the performance of context-aware mobile cloud computing for different quality of service (QoS) adaptation policies. Our simulations results show that when battery level is low and CPU usage is high and user cannot maintain the initial QoS, service cost is decreased according to current adaptation policy. In conclusion, the current adaptation policy suggested in this paper may improve user experience by providing a dynamically adapted service cost according to a situation.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.05a
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• pp.131-138
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• 2005

Recommender systems have been widely advocated as a way of coping with the problem of information overload in e-business environment. Most of the existing recommender systems focused on what kind of items to recommend, although when to recommend to the target customer considering their context is an important issue. Even right item might be a spam advertisement or wrong recommendation for the customer if it can not be recommended at the right context. It is particularly important for recommendations where the user's context is changing rapidly, such as in both handheld and ubiquitous computing environment. Therefore, we propose CARS (Context-Aware Recommender System) based on CBR and context-awareness for ubiquitous computing environment. CBR is used to generate a target customer class and proper context. Context-awareness is used to gather suer context information from sensors, networks, device status, user profiles, and other sources. An illustrative case example is suggested to explain the procedure of CARS.

• Journal of Korea Society of Digital Industry and Information Management
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• v.4 no.3
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• pp.19-31
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• 2008

Currently, RFID is receiving attention from the industry and the academy because it is considered as an enabling technology for ubiquitous computing, in particular context perception. In this paper, we survey the existing context-aware RFID systems and introduce three main issues in the systems - the context information, the context-aware services, and the context-aware RFID system architectures. We classify context information into six groups, the services into five context-aware service types, and the systems into four architecture styles. This study will help stakeholders such as customers and developers to understand their RFID systems and to develop new services.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.3
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• pp.300-305
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• 2005

Context-aware intelligent services are essential in ubiquitous computing and intelligent robots environments, which make decisions on which services to start with the consideration of surrounding contexts. In the ubiquitous and intelligent environments, context-aware service engines should be light-weighted due to the resource restrictions on the devices. This paper presents a context-aware service engine which is designed for light-weighted devices. The context-aware service engine has been designed with special attention to improve the execution speed and to minimize the memory requirement.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.613-615
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• 2004

유비쿼터스 컴퓨팅 환경에서 가장 중요한 이슈중의 하나는 상황인지(Context-Aware)가 가능한 환경을 구축하는 것이다. Context-Aware 환경이 구축되면 주변의 상황을 감지하여 특정 어플리케이션을 실행한다거나, 시스템을 재구성하는 등의 일을 수행할 수 있다. 그동안 이런 상황인지가 가능한 환경을 Context-Aware 미들웨어를 통해 구현하려는 연구가 많이 수행되었다. Context-Aware 미들웨어를 구현하기 위해 무엇보다도 중요한 것은 실제 세계의 다양한 종류의 상황을 컴퓨팅 환경에 적용시키는 것이다. 그러나 현실 세계에서 Context의 종류는 거의 무한하다고 할 수 있다. 기술이 발전하게 되면서 인지 가능한 Context의 종류도 무한정 늘어나게 될 것이다 또한 실제 세계에서의 Context들은 추상적인 경우가 많이 있다. 그러나 Context가 추상적이라 해도 다른 Context 정보를 이용해서 구체화 할 수 있다. 이런 과정을 위해 Conte지들을 계층적으로 관리해야 할 필요가 있다. 본 논문에서는 Context-Aware 미들웨어를 구현할 때 Context들의 이런 여러 가지 특성들을 고려해서 Context Type을 관리랄 수 있는 하나의 객체를 제안하고, 다른 방법들과 비교, 분석해 보았다.

• International Journal of Contents
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• v.2 no.1
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• pp.9-16
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• 2006

Recently many researches are investigating for ubiquitous computing and network. In the real world many sensor devices must be equipped to provide many services for users. To make computing environment easy and more user friendly, middleware system not only hides all complexities (network, system, services, etc), but also needs to have efficient context inference scheme and system reconfiguration capability. In this paper we suggest context-aware middleware design for sensor network which provides efficient computing environment for end-users. We also present XML based implementation of our system.

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

• The KIPS Transactions:PartC
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• v.12C no.3 s.99
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• pp.457-464
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• 2005

This paper describes an Adaptive Context-aware Service (ACS) using Model Driven Architecture (MDA)-based Service Creation Environment (SCE) on PARLAY X based service delivery platform in ubiquitous computing environments. It can be expected that both the context-awareness and adaptation in ubiquitous computing environments will be deployed. But the existing context-aware middleware lacks in considering adaptation. Therefore, the object of this paper is to support the architecture and the Application Programming Interface (API) of the network service for both the context-awareness and adaptation in ubiquitous computing environment. ACS is to provide users with the adaptive network service to the changing context constraints as well as detecting the changing context. For instance, ACS can provide users with QoS in network according to the detected context, after detecting the context such as location and speed. The architecture of ACS is comprised of a Service Creation Environment (SCE), Adaptive Context Broker and PARLAY gateway. SCE is to use Context-based Constraint Language (CCL) for an expression of context-awareness and adaptation. Adaptive Context Broker is to make a role of the broker between SCE and PARLAY G/W. PARLAY G/W is to support API for PARLAY X-based service delivery platform.

• Journal of Service Research and Studies
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• v.2 no.2
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• pp.91-98
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• 2012

The emergence of new types of embedded computing devices and developments in wireless networking are broadening the domain of computing from the work place and home office to other facets of everyday life. This trend is expected to lead to a proliferation of Internet of Things (IoT) environments, in which inexpensive and interconnected computing devices are capable of supporting users in a range of tasks. Context-aware computing is a key source to develop such smart services. However, there are many challenges to enable services to be smart; Heterogeneous Computing Environments, Resource Limitations, Large Amount of Data Produced, and Different Requirements for Context Interpretation. Because of these challenges, there are difficulties in providing smart service by utilizing IoT devices. Currently, many researchers are conducting researches on mobile-computing based smart service development and provisioning and network infrastructure for interconnected IoT devices. Still, there are some limitations on developing core technologies for IoT computing based smart service development. In order to remedy this situation, this thesis presents a reusable framework that provides unique and noble features which are required in developing advanced context-aware IoT applications.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.5
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• pp.587-592
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• 2004

Context-aware computing systems require real-time context reasoning process for context awareness. Context reasoning can be done by comparing input information from sensors with knowledge-base within system. This method is identical with it of rule-based systems. In this paper, we propose hardware rule-based system architecture which can process context reasoning in real-time. Compared to previous architecture, hardware rule-based system architecture can reduce the number of constraints on rule representations and combinations of condition terms in rules. The modified content addressable memory, crossbar switch network and pre-processing module are used for reducing constraints. Using SystemC for description can provide easy modification of system configuration later.