• Journal of Korean Society for Geospatial Information Science
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• v.15 no.3
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• pp.27-32
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• 2007

3D based information is demanded increasingly as cities grow three dimensionally and buildings become large and complex. The use of 3D GIS is also getting attention as fundamental data for ubiquitous computing applications such as location-based guidance, path finding and emergency escaping. However, most 3D modeling techniques are focused on the visualization of buildings or terrains and do not have topological structures required in spatial analyses. In this paper, we introduce a method to incorporate topological relationship into 3D models by combining 2D GIS layers and 3D model. We divide indoor spaces of a 3D model into discrete objects and then define the relationship with corresponding features in 2D GIS layers through database records. We also show how to construct hallways network in the 2D-3D integrated building model. Finally, we test different cases of route finding situations inside a building such as normal origin-destination path finding and emergency evacuation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10B
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• pp.988-993
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• 2009

In recent years, the development of ubiquitous computing technology as vital information anytime, anywhere to monitor and manage the demand for U-healthcare services is increasing. Accordingly, remote blood sugar management, remote blood pressure management, and research on U-healthcare service have been very active. But, the existing U-healthcare service monitoring devices and services has been implemented in different operating platforms and programing languages which are provided by diverse application service providers. For this reason, the users have difficulty in receiving diverse U-healthcare services. In this paper, SOA-based U-healthcare monitoring system has been designed and implemented. Through implementation, it is confirmed that the proposed SOA based U-healthcare monitoring system can increase the reuse of each service component to make it easier to reconstruct the structure of the new services.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10B
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• pp.845-854
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• 2008

In this paper, we propose a clustering algorithm for efficient energy management of sensor network consisted of sensor nodes that have restricted energy to solve these problem. Proposed algorithm improves energy efficiency by controlling sensing power. And it has distinctive feature that is applied in various network environment. The performance evaluation result shows that the energy efficiency is improved by 5% in the case of all sensor node fixed and by $10{\sim}15%$ in the case of all sensor node moving. It is confirmed through experiment process that the proposed algorithm brings energy efficiency ratio improvement of $5{\sim}15%$ more than the existing algorithm. Proposed algorithm derived an upper bound on the energy efficiency for Ubiquitous Computing environment that have various network environment that is with ZigBee technology of IEEE 802.15.4 bases. Also, we can blow bring elevation for lifetime of sensor network greatly for lifetime of sensor node as is small. And we think that may expand practical use extent of a sensor network technology more in fast changed network environment.

• Journal of the Korea Society of Computer and Information
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• v.12 no.3
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• pp.295-302
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• 2007

The environment of education has been undergoing dramatic developments in recent years with the development of information technology such as digital information transfer, storage and communication methods. Education and training technology is constantly evolving and growing. Because we continually meet the new and interesting advances in our world. The evolution in education and training at a distance can be characterized as a move from traditional learning to u-learning. This paper concerns with the application of u-based education methodology for people with disabilities targeting to empower them. Instead of the classic educational support such as extended time to take exams, a reader and/or scribe to assist with exams and note taking services. In this paper, we introduce the definition of inclusion and disabilities which does not been fully understood what they mean and then possible implementing materials which can empower the students with disabilities with accomplishments. We would like to point out that we concentrate on the aspects of instructional science particularly related with inclusive classes.

• Journal of the Korea Society of Computer and Information
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• v.13 no.4
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• pp.51-58
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• 2008

In this paper, we propose a place modeling based on the distribution of scale-invariant features, and a place recognition method that recognizes places by comparing the place model in a database with the extracted features from input data. The proposed method is based on the assumption that every place can be represented by unique feature distributions that are distinguishable from others. The proposed method uses global information of each place where one place is represented by one distribution model. Therefore, the main contribution of the proposed method is that the time cost corresponding to the increase of the number of places grows linearly without increasing exponentially. For the performance evaluation of the proposed method, the different number of frames and the different number of features are used, respectively. Empirical results illustrate that our approach achieves better performance in space and time cost comparing to other approaches. We expect that the Proposed method is applicable to many ubiquitous systems such as robot navigation, vision system for blind people, wearable computing, and so on.

• Journal of Digital Convergence
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• v.14 no.8
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• pp.269-276
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• 2016

Public Safty-LTE(Long Term Evolution) is being deployed in the direction of reducing cost by using both of municipal network and commercial network. However, LTE Network is difficult to ensure the survivability during the information communication infrastructure failures. In addition, it is vulnerable in communication coverage of inside buildings and underground. In this study, we propose to implement effectively the network survivability technique through the convergence to the proven technology. As the advent of the IoT Age, smart sensors which are embedded in the environment and the things will be able to provide a useful infrastructure for ensuring the network survivability. Based on the feature of the smart sensor, we designed the sink node architecture to guarantee the network survivability in disaster situation through the convergence of the small cell technology and extension of wireless network coverage technology. The computing power inherent in the environment is a valuable resource that can be utilized in the disaster situation.

• Journal of the Korea Society of Computer and Information
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• v.11 no.2 s.40
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• pp.43-52
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• 2006

LRecently, with increasing interest in ubiquitous computing, knowledge discovery method is needed with consideration of the efficiency and the effectiveness of wide range and various forms of data. Spatial Characterization which extends former characterization method with consideration of spatial and non-spatial property enables to find various form of knowledge in spatial region. The previous spatial characterization methods have the problems as follows. Firstly, former study shows the problem that the result of searched knowledge is unable to perform the multiple spatial analysis. Secondly, it is unable to secure the useful knowledge search since it searches the limited spatial region which is allocated by the user. Thus, this study suggests spatial characterization which applies to density based clustering.

• The Journal of the Korea Contents Association
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• v.8 no.9
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• pp.19-26
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• 2008

With the development of ubiquitous computing and the construction of infrastructure for one-to-one personalized services, the importance of context-aware services based on user's situation and environment is being spotlighted. The smart home technology connects real space and virtual space, and converts situations in reality into information in a virtual space, and provides user-oriented intelligent services using this information. In this paper, we proposed the discovery of the behavior sequence pattern using the mining in the smart home. We discovered the behavior sequence pattern by using mining to add time variation to the association rule between locations that occur in location transactions. We can predict the path or behavior of user according to the recognized time sequence and provide services accordingly. To evaluate the performance of behavior consequence pattern using mining, we conducted sample t-tests so as to verify usefulness. This evaluation found that the difference of satisfaction by service was statistically meaningful, and showed high satisfaction.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.7
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• pp.907-912
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• 2007

The present level of ubiquitous computing technology have developed to the point where Home-server provides services that user require directly for user in the intelligent space. But it will need intelligent system to provides more active services for user in the near future. In this paper, we define the environment information about situation that user is in as Context, and collect the Context that stereotype as 4W1H form for construct the system that can decision service will be provide from information about a situation that user is in, without user's involvement. Additionally we collect information about user's emotional state, use these informations as nodes of Bayesian network for probabilistic reasoning. From that, we materialize Context Awareness system about it that what kind of situation user is in. And, we propose the Context-based Service reasoning model using Bayesian Network from the result of Context Awareness.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.3
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• pp.284-294
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• 2008

In this paper, we describe an implementation of small mobile robot that can be used at research and application of mobile sensor networking. This robot that will constitute the sensor network, as a platform of multi-robot system for each to be used as sensor node, has to satisfy restrictions in many aspects in order to perform sensing, communication protocol, and application algorithms. First, the platform must be designed with a robust structure and low power consumption since its maintenance after deployment is difficult. Second, it must have flexibility and modularity to be used effectively in any structure so that it can be used in various applications. Third, it must support the technique of wireless network for ubiquitous computing environment. At last, to let many nodes be scattered, it must be cost-effective and small. Considering the above restrictions of the mobile platform for sensor network, we designed and implemented robots control the current of actuator by using additional circuit for power efficiency. And we chose MSP430 as MCU, CC2420 as RF transceiver, and etc, that have the strength in the aspect of power. For flexibility and modularity, the platform has expansion ports. The results of experiments are described to show that this robot can act as sensor node by RF communication process with Zigbee standard protocol, execute the navigation process with simple obstacle avoidance and the moving action with RSSI(Received Signal Strength Indicator), operate at low-power, and be made with approx. $100.