• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.6
• /
• pp.1101-1105
• /
• 2006

Ubiquitous computing network comprises a variety of distributed service devices. Today Web services technology enables the heterogeneous devices to provide their own services and interact with each other via well-defined Internet protocol. Nevertheless, service devices in ubiquitous environments require more event-driven, autonomous interaction beyond rather passive service-oriented architecture of the present time. This paper presents an ECA (Event-Condition-Action) rule description language in an attempt to support capability for autonomous interactions among service-oriented devices in ubiquitous computing network. Specifically, the proposed WS-ECA is an XML-based ECA rule description language for web service-enabled devices. The rules are embedded in distributed devices which invoke appropriate services in the network if the rules are triggered by some internal or external events. The presented ECA-based device coordination approach is expected to facilitate seamless inter-operation among the web service-enabled devices in the emerging ubiquitous computing environment.

• Journal of Korean Society of Transportation
• /
• v.26 no.3
• /
• pp.179-186
• /
• 2008

It is crucial in traffic flow management to maintain productivity and the traffic stability at the same time especially under congested traffic conditions. This issue has not been explicitly addressed under the intelligent transportation system environments. However, the ubiquitous transportation system environments make it possible to collect the data for each vehicle's position and velocity and to perform more sophisticated traffic flow management at individual vehicle or platoon level through V2V and V2I communications. In this paper, a preventive traffic flow management scheme is proposed, in which the objective is to maintain traffic flow stability while the productivity of the system is not decreased. The management scheme is proposed based on Greenshield's model because it is simple and easy to handle. It is considered that further research should be performed to evaluate the various traffic flow models.

• Journal of Korean Society of Transportation
• /
• v.28 no.4
• /
• pp.167-175
• /
• 2010

The ubiquitous transportation system environments make it possible to collect each vehicle's position and velocity data and to perform more sophisticated traffic flow management at the individual vehicle or platoon level through vehicle to vehicle (V2V) and vehicle to infrastructure (V2I) communication. It is necessary to develop a traffic flow management scheme to take advantage of the ubiquitous transportation system environments. This paper proposes an algorithm to advise the optimal speed for each vehicle according to the traffic flow condition. The algorithm aims to stabilize the traffic flow by advising the equilibrium speed to the vehicles speeding or crawling under freely flowing condition. And it aims to prevent or at least alleviate the shockwave propagation by advising the optimal speed that should dampen the speed drop under critical flow conditions. This paper builds a simulation testbed and performs some simulation experiments for the proposed algorithm. The proposed algorithm shows the expected results in terms of travel time reduction and congestion alleviation.

• The Journal of the Korea Contents Association
• /
• v.13 no.11
• /
• pp.523-532
• /
• 2013

Since conventional methods for the reconstruction of 3D objects used a number of cameras or pictures, they required specific hardwares or they were sensitive to the photography environment with a lot of processing time. In this paper, we propose a 3D object reconstruction method using one photograph based on structured light in ubiquitous environments. We use color pattern of the conventional method for structured light. In this paper, we propose a novel pipeline consisting of various image processing techniques for line pattern extraction and matching, which are very important for the performance of the object reconstruction. And we propose the optimal cost function for the pattern matching. Using our method, it is possible to reconstruct a 3D object with efficient computation and easy setting in ubiquitous or mobile environments, for example, a smartphone with a subminiature projector like Galaxy Beam.

• KIPS Transactions on Computer and Communication Systems
• /
• v.4 no.4
• /
• pp.117-124
• /
• 2015

As recent developing computing environments, service is provided without time or place's limitation, and it is constituted dynamically. Above all, in terms of education supporting system, there is need to conceive user's information and provide optimal service as to right with applying context awareness under Ubiquitous computing environment. It should have groundwork based on user location and time. It is requires service providing based on user location under the condition of class to offer appropriate service with the context. In addition, context information providing technology is needed to offer right education support service in the class, where are different context information. Hence, in this research it is suggested education supporting system to provide context-based for instructor. The framework of this system has a foundation within previous work about Multi-agent based Distributed Framework. To examine implementation of context-based education supporting system in Ubiquitous computing environments suggested by this report, arranging system can fit information relates to instructor's location for service applying in the class.

• Journal of Intelligence and Information Systems
• /
• v.16 no.1
• /
• pp.57-69
• /
• 2010

The ubiquitous transportation system environments make it possible to collect each vehicle's position and velocity data and to perform more sophisticated traffic flow management at individual vehicle or platoon level through V2V and V2I communication. It is necessary to develop a new data processing methodology to take advantage of the ubiquitous transportation system environments. This paper proposed to build 3-dimension data profiles to maintain the detailed traffic flow information contained in the individual vehicles' data and at the same time to keep the profiles from the meaningless fluctuations. Also methods to build the platoon profile and the shock wave speed profile are proposed, which have not been possible under ITS(Intelligent Transportation System) environments.

• Proceedings of the IEEK Conference
• /
• summer
• /
• pp.52-56
• /
• 2004

Computing today is becoming ubiquitous. In such ubiquitous computing environments, entities expect to access resources and services at any time from anywhere. Therefore, the question rises of how to establish trust relationship in previously unknown devices or resources with such environment. After reviewing a model to delegate trust to communicating entities in ubiquitous environment and its security problems, we present a new model for secure delegation over communication entities. We adopt two-party signature scheme as cryptographic primitives. Additionally, we apply threshold cryptosystems to our model for more secure enhancement.

• International Journal of Internet, Broadcasting and Communication
• /
• v.5 no.1
• /
• pp.9-13
• /
• 2013

This paper presents the concepts of ubiquitous computing technology to construct a ubiquitous learning environment that enables learning to take place anywhere at any time. This ubiquitous learning environment is described as an environment that supports students' learning using digital media in geographically distributed environments. The u-learning model is a web-based e-learning system that could enable learners to acquire knowledge and skills through interaction between them and the ubiquitous learning environment. Students are allowed to be in an environment of their interest. The communication between devices and the embedded computers in the environment allows learner to learn while they are moving, hence, attaching them to their learning environment.

• Transportation Technology and Policy
• /
• v.8 no.3
• /
• pp.51-60
• /
• 2011

• The Journal of the Korea Contents Association
• /
• v.9 no.1
• /
• pp.475-483
• /
• 2009

With the development of information communication and network technologies, ubiquitous era that supports various services regardless of places and time has been advancing. The development of such technologies have a great influence on educational environments. As a result, e-learning concepts that learners use learning contents in anywhere and anytime have been proposed. The various learning contents authoring systems that consider the e-learning environments have also been developed. However, since most of the existing authoring systems support only PC environments, they is not suitable for various ubiquitous mobile devices. In this paper, we design and implement a contents authoring system based on learning activities for u-learning environments. Our authoring system significantly improves the efficiency for authoring contents and supports various ubiquitous devices as well as PCs.