• Journal of KIISE:Computing Practices and Letters
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• v.15 no.3
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• pp.167-177
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• 2009

This paper is about our experience of developing a context-aware exhibit guide system called MyGuide by applying Simtext development methodology. In particular, we introduce some issues to be considered in development process, the way that we solved them, and other things related to context. In requirements elicitation phase, we reduced the complexity of requirements by separating business logic requirements and context-awareness related requirements. After that, we modeled context, and designed software architecture, classes, and database in sequence during design phase. We considered system requirements and context modeling issues for context modeling because it influences class and database design.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.9
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• pp.621-628
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• 2013

This paper presents a framework for context-aware smart phone applications based on Android. The mobile context-aware system is composed of a low level context collection module, a high level context generation module and a service provision module. Existing android system cannot provide an appropriate application framework to integrate these independent modules. In this paper, we provide an application framework which make each module a component, and provide appropriate services to each component. This framework hides the Android platform, so that the complexity for organical combination can be minimized and the application developers can make the mobile context-aware applications easily.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.16 no.2
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• pp.119-124
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• 2016

According to the expansion of smartphone penetration and development of wearable device, personal context information can be easily collected. To use this information, the context aware recommender system has been actively studied. The key issue in this field is how to deal with the context information, as users are influenced by different contexts while rating items. But measuring the similarity among contexts is not a trivial task. To solve this problem, we propose context aware post-filtering to apply the context compensation. To be specific, we calculate the compensation for different context information by measuring their average. After reflecting the compensation of the rating data, the mechanism recommends the items to the user. Based on the item recommendation list, we recover the rating score considering the context information. To verify the effectiveness of the proposed method, we use the real movie rating dataset. Experimental evaluation shows that our proposed method outperforms several state-of-the-art approaches.

• 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.

• Journal of Advanced Navigation Technology
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• v.14 no.3
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• pp.432-438
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• 2010

In this paper, we propose a system which can perceive status of semiconductor equipment and evaluate its performance. The proposed system acquires the information such acceleration, pressure, temperature and gas sensors in the surrounding semiconductor equipment. After acquiring information, it is sent to server through multi hop transmission. The transmitted data generates 3 steps alarm using context-aware algorithm of unit or multiple event. From the experiment's result of the proposed system, we confirm that the reliability and efficiency of information is more improved about 80% than a system that doesn't use context-aware algorithm. Moreover, this system can be effective status monitoring of semiconductor equipment because lots of client nodes acquire surrounding information.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.2005-2014
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• 2008

In this paper, it is presented to utilize UPnP as RFID service discovery and control mechanism for context-aware services. Using UPnP, it is possible to achieve easy deployment of context-aware services and to provide zero-configuration for RFID services. In addition, SQL based cleaning module which raises detection rates is developed since context-aware applications heavily rely on streams of data gathered from RFID tags. Using the cleaning technique, detection rates are improved from 60-80% to 98% or more In order to verify RFID context aware service based on the UPnP, sample context-aware scenario for physical distribution services is implemented on UPnP over RFID system. The impacts of UPnP messages (or service advertisements on network congestion and SQL cleaning module are experimented and analyzed, and the result show the good correctness and validity of the proposed system.

• Journal of Internet Computing and Services
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• v.10 no.2
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• pp.125-132
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• 2009

The goal of our research is to develop a smart context-aware guide system that provides a smart and personalized guide services based on implicit awareness of context. As a context-aware guide application, we have developed a location-aware smart bus guide system for Seoul based on PDA and GPS. It guides users to the nearby bus stops and provides users with information about the bus lines at the bus stops.

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

• Convergence Security Journal
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• v.9 no.1
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• pp.11-17
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• 2009

The object of this paper is to design a school-zone safety management system based on context-aware, integrated with computing technology. When it occurs to kidnap of elementary school students, the monitoring device creates context information through a combination object extraction and context-aware technology and alarm administrator about an emergency situation. In addition, the proposed system that requires a human perspective, a railroad crossing, statistics research of traffic, and a variety of applications such as factory automation systems can be used to be the best choice.

• Korea Information Processing Society Review
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• v.11 no.6
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• pp.56-75
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• 2004

In this article we address some system characteristics and challenging issues in developing Context-aware Middleware for Ubiquitous Computing. The functionalities of a Context-aware Middleware includes gathering context data from hardware/software sensors, reasoning and inferring high-level context data, and disseminating/delivering appropriate context data to interested applications/services. The Middleware should facilitate the query, aggregation, and discovery for the contexts, as well as facilities to specify their privacy policy. Following a formal context model using ontology would enable syntactic and semantic interoperability, and knowledge sharing between different domains. Moddleware should also provide different kinds of context classification mechanical as pluggable modules, including rules written in different types of logic (first order logic, description logic, temporal/spatial logic, fuzzy logic, etc.) as well as machine-learning mechanical (supervised and unsupervised classifiers). Different mechanisms have different power, expressiveness and decidability properties, and system developers can choose the appropriate mechanism that best meets the reasoning requirements of each context. And finally, to promote the context-trigger actions in application level, it is important to provide a uniform and platform-independent interface for applications to express their need for different context data without knowing how that data is acquired. The action could involve adapting to the new environment, notifying the user, communicating with another device to exchange information, or performing any other task.