• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.517-522
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• 2014

In this paper we propose an axially distributed image-sensing method with a wide-angle lens to capture the wide-area scene of 3D objects. A lot of parallax information can be collected by translating the wide-angle camera along the optical axis. The recorded wide-area elemental images are calibrated using compensation of radial distortion. With these images we generate volumetric slice images using a computational reconstruction algorithm based on ray back-projection. To show the feasibility of the proposed method, we performed optical experiments for visualization of a partially occluded 3D object.

• Information Systems Review
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• v.8 no.1
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• pp.141-158
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• 2006

Recently, developing U-City as an integrated set of ubiquitous space services has been regarded as a promising field in realizing ubiquitous computing technology. However, well organized requirement analyses of U-City to declare what kinds of ubiquitous space services are needed and which ubiquitous computing technology should be incorporated to come up with the needs are still insufficient. Hence, the aims of this paper are to propose a set of unique U-City construction philosophies and to analyze which services should be offered in the ubiquitous space services in U-Cities. A field survey to the citizens who are potential end users of the ubiquitous space services was conducted to analyze the success factors of U-City using CSF methodology. Focused group interview with professionals in the field of ubiquitous computing technology in Korea was then performed to identify the relationship of the ubiquitous space services and the critical success factors.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.329-333
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• 2006

New computing paradigm in ubiquitous computing environments is revolutionizing the way people interact with computers, services and the surrounding physical spaces. In order to provide stronger authentication, MIST proposed an authentication framework for ubiquitous computing environments and assigned confidence values to some authentication methods to facility the combining. However, the assigned confidence values lack sufficient evidence. In this paper reliable confidence values for each authentication method used in MIST is proposed. These confidence values can combine multiple confidence values in some manner, producing a more accurate net confidence value. Authentication entities with confidence values allows the authentication framework to blond nicely into ubiquitous computing environments.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.15-16
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• 2012

본 논문에서는 우선순위 기반의 RTS/CTS 통신 기법을 적용하여 생체모방형 ROV 를 제어하기 위한 수중 MAC 프로토콜을 제안하였다. MANET 기반의 하천 수질 환경 감시 시스템이 효율적으로 운용되기 위한 수중 MAC 프로토콜이 지원됨으로써 이동성이 강조되는 생체모방형 ROV 제어를 위한 실시간성을 보장할 수 있다.

• Information Systems Review
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• v.8 no.1
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• pp.43-61
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• 2006

Evaluating ubiquitous computing services is important for the commercialization of the ubiquitous services which will be running on electronic markets. However, despite its importance and usefulness, assessing ubiquitous computing services is still in its early stage. Moreover, sufficient study of making a distinction what are 'ubiquitous computing services' or not has not been provided yet. Hence, this paper aims to propose an integrated methodology to assess the ubiquitous computing services. A multilayered approach is considered to assess not only technical but also behavioral perspectives. To show the feasibility of the assessment model, three use cases are studied and evaluated.

• Journal of the Korean Institute of Educational Facilities
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• v.14 no.4
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• pp.4-13
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• 2007

In 21st century, mankind greets an era of ubiquitous computing where physical and virtual space are merged through the innovation of digital and IT(Information Technology), meanwhile ubiquitous computing and network paradigm suggest a new direction which our future educational system should head for. A society where people, computers, and objects can be connected with each other anytime and anywhere, that is, a society of ubiquitous computing where everything in our living space are interconnected by a immense network system may bring a variety of changes into our educational environment in schools. In this study I analysed the forecast of school educational orientation and ubiquitous educational environment and facilities in developed countries, and on the basis of the result, I performed a fundamental work for formation of a ubiquitous classroom environment which is feasible in Korea. In the section of conclusion, I present a model of ubiquitous classroom as a scenario based on ubiquitous computing technology applicable to future classroom environment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.9
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• pp.4398-4417
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• 2017

Multi-user Multiple-Input and Multiple-Output (MU-MIMO) has potential for prominently enhancing the capacity of wireless network by simultaneously transmitting to multiple users. User selection is an unavoidable problem which bottlenecks the gain of MU-MIMO to a great extent. Major state-of-the-art works are focusing on improving network throughput by using Channel State Information (CSI), however, the overhead of CSI feedback becomes unacceptable when the number of users is large. Some work does well in balancing tradeoff between complexity and achievable throughput but is lack of consideration of fairness. Current works universally ignore the rational utilizing of time resources, which may lead the improvements of network throughput to a standstill. In this paper, we propose TOUSE, a scalable and fair user selection scheme for MU-MIMO. The core design is dynamic-time-warping-based user selection mechanism for downlink MU-MIMO, which could make full use of concurrent transmitting time. TOUSE also presents a novel data-rate estimation method without any CSI feedback, providing supports for user selections. Simulation result shows that TOUSE significantly outperforms traditional contention-based user selection schemes in both throughput and fairness in an indoor condition.

• The Journal of the Korea Contents Association
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• v.7 no.12
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• pp.283-291
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• 2007

In the age of ubiquitous computing, computer systems will be seamlessly integrated into our everyday life, providing services and information to us in an anywhere, anytime fashion. This ubiquitous computing can be used for developing a ubiquitous learning (U-learning). In this paper, we present a framework for U-school in which ubiquitous computing technologies are applied to advance the existing ERSS (Korea's Educational Resources Sharing System). Our framework applies mobile, sensor, and context-aware technologies to the existing ERSS. This framework presents a user-centric learning environment, using user-centric scenario. The U-school with context-aware services therefore can lead to the just-in-time learning or learner-led learning based on dynamic contexts acquired from learners, teachers and computing entities.

• Journal of the Korean Professional Engineers Association
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• v.39 no.1
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• pp.50-53
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• 2006

I forecasted how much IT and ubiquitous technology will grow after 20 years. First of all, 1 think the goal of ubiquitous technology and relative main technology is our life. 1 will give examples of ubiquitous technology that affects travel, school and family life and how much it has changed. Lastly I will check the problems and securities in ubiquitous technology. By that time, we will have meaningful time to inspect the change of future technology.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.11a
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• pp.147-156
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• 2005

In developing the ubiquitous computing technology based services (ubiquitous services), evaluating how much value of those services is created or added is very crucial. The efforts to evaluate the ubiquitous services have been progressed in two perspectives - technical perspective and behavioral perspective. Despite its importance, however, the methodologies which integrate both perspectives have been still very rare. Hence, this paper aims perspectives have been still very rare. Hence, this paper aims to propose an integrated ubiquitous service valuation methodology based on the multi-layered approach including technical and behavioral perspectives. To do so, we conducted a case study with currently existing location based service (LBS) such as navigation systems by conducting focus group interview (FGI) and field survey.