• KIPS Transactions on Computer and Communication Systems
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• v.6 no.5
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• pp.211-218
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• 2017

Recent robot software platform research focuses on providing intelligent service via abstraction of robot devices. Context-aware techniques are necessary for intelligent robot services, which are based on the perception of environmental information obtained from heterogeneous sensors in IoT environment. Robot Operating System (ROS) provides protocols to operate robot devices. ROS includes functions for abstracting heterogeneous sensors themselves in order to control the robot, however, it lacks the ability to provide context information that the robot can perceive based on environmental information through consistent collection methods. In this paper, we propose a relay system for ROS to provide context-aware robot service. The proposed system makes it possible for ROS to control and provide context-aware robot services with relay of an external context-aware system and ROS. In experiments, we demonstrate procedures that robot services abstracted from ROS and an external context-aware system works together based on the proposed system.

• The Journal of the Korea Contents Association
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• v.14 no.7
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• pp.29-44
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• 2014

To provide context aware service, certain phenomena and situation information of the user should be detecting and monitoring using sensors. But, the sensor data has heterogeneity about system, syntax, structure, and semantics. So, it is difficult to apply to various services. To solve this issue, we should remove these heterogeneities and convert to context information that is easy to provide context aware services. Also, the existing context aware service mash-up environment require relevant sensor type, criteria of context, programing ability to define the service situation. So, it is difficult to create service for a non-technical user. Therefore, we propose ontology based user-centric service environment to provide context aware IoT services. It provide context awareness and user-desired services using data that acquired via IoT paradigm. The proposed environment consist of the ontology based semantic sensor data processing and the user-centric service environment. It provide convert the object data to the context information and service mash-up process to create user service in easy way.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.5_6
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• pp.214-227
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• 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 Korea Multimedia Society
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• v.10 no.6
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• pp.786-798
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• 2007

As we go about our daily lives, people often collect surrounding information and adapt to the situation. Computer development trends show that one wants computers to work like human beings, i.e. computers can sense its context and adapt corresponding to context changes. To implement this expectation, a context aware service layer is needed. In this layer, sensors capture its environment and send this information to the service center. Considering received information as its context, the service center seeks the suitable operation according to the context. Tills paper presents a context aware service which is applied in controlling air-conditioner. The air-conditioner includes sensors which are installed at some special positions in a room. Each of these sensors gathers comfort-influenced information like temperature, humidity and sends them to air-conditioner. The air-conditioner adapts its operation to the environment according to the sensed information. To control the air-conditioner effectively, we use a genetic algorithm which is suitable in adaptation issues. The simulation shows that the room condition can be maintained at a comfortable level by using context-aware services in the operation of the air-conditioning system.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.2
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• pp.59-68
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• 2016

Context-aware services recognize the context of situation environments of users and provide useful services according to the context for users. Usual rule-based systems can be used for context-aware services with the specified rules that express context information and operations. This paper proposes a light-weight rule engine that minimizes memory consumption for resource-constrained smart things. The rule engine manages rules at the minimum condition level, removes memories for intermediate rule matching results, and uses hash tables to store rules and context information efficiently. The implemented engine is verified using a rule set of a mouse training system and experiment results shows the engines consumes very little memory compared to the existing Rete algorithm with some sacrifice of execution time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7B
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• pp.619-631
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• 2006

With the advent of ubiquitous computing environments, it has become increasingly important for applications to take full advantage of context information, such as the user's location, to offer greater services to the user without any explicit request. In this paper, we propose context-aware active services on the basis of CAMUS (Context-Aware Middleware for URC Systems). CAMUS is a middleware for providing context-aware applications with development and execution methodology. Accordingly, the applications developed by CAMUS respond in a timely fashion to contexts. To evaluate, we apply proposed active services to TV application domain. Therefore, we implement and experiment the TV contents recommendation service agent, control service agent and TV task based on CAMUS. The context-aware TV task is to recommend programs and control of TV according to user preference, location and voice commands.

• Journal of Information Technology Services
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• v.13 no.1
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• pp.197-207
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• 2014

With the recent advance in smartphones, users are allowed to use mobile applications anytime anywhere, and change their way to interact with smart environment and people. As a result, the need for developing context-aware applications on smartphones has a great attention from users and developers. This paper proposes a context-aware framework for supporting UI/UX of smartphones. The proposed framework collects a wide range of sensory data from smartphones and allows developers to analyze and model context models for their desired apps. In addition, it also supports real-time inference within the apps to make them to adapt to context. In order to show effectiveness of the proposed framework, we introduce two smartphone apps: context-aware home screen and automatic detection of smartphone problem use. Therefore, we expect that the proposed framework will help developers easily implement their apps with respect to context-awareness.

• Journal of Internet Computing and Services
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• v.10 no.6
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• pp.145-157
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• 2009

In recent years, there have been several researches applying workflow technologies for service automation on ubiquitous computing environments. However, most context-aware workflow languages have difficulties in supporting composite workflows composed of single workflows, because these languages are still in its early stage and they only provide single workflow services to their users. This paper introduces CAWL, which is a context-aware workflow language. CAWL is for describing individual service workflows to make integrated service workflows. By using CAWL, service developers are able to reuse existing workflows to develop new context-aware workflow services. Therefore, development efforts and time can be saved and workflow resusability also increased. CAWL is expected to make it easy to develop applications related to context-aware workflow services on ubiquitous computing environments.

• Journal of Intelligence and Information Systems
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• v.13 no.1
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• pp.29-47
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• 2007

Acquiring context data in a timely and correct way is now regarded as one of the crucial characteristics of the proactive service which runs on ubiquitous computing environment. Moreover, context model should be well designed to provide a solid context-aware system. Since the ubiquitous computing systems aim to provide context-aware services everywhere with any available devices, legacy services which uses context models assuming single or limited domain should be extended enough to be useful even for multi-domain muli-services. This leads us to a motivation to build a generic context model with an appropriate type of model. Hence, the purpose of this paper is to propose a generic context model by assessing a variety of model types with a sort of evaluation measures.

• Journal of Korean Institute of Industrial Engineers
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• v.35 no.1
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• pp.51-57
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• 2009

There are a variety of users and devices in a context-aware computing environment. In this environment, the service provided to a user may be the composition of diverse services rather than one independent service. Before user's devices provide the composite service to the user, they should perceive user's needs by gathering related information segments from other surrounding devices and/or sensors. We consider a context-aware computing environment providing composite and adapted service to users and propose an information processing model that characterizes the device where the collected data should be processed through services and/or applications. Based on this model, we provide an analytical tool to obtain some performance measures of the context-aware computing environment.