• Journal of Internet Computing and Services
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• v.7 no.3
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• pp.31-39
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• 2006

Ubiquitous and pervasive environment presents opportunities for a rich set of location aware applications such as car navigation and intelligent robots, interactive virtual games, logistics service, asset tracking etc. Typical indoor location systems require better accuracy than what current outdoor location systems provide, Outdoor location technologies such as GPS have poor indoor performance because of the harsh nature of indoor environments, In this paper we present a novel reducing interference location system that is particularly well suited to support context aware computing. The system, called EEM (Enhance Envelop Method) alms to combine the advantages of real time tracking systems that implement distributed environment with the suitability of infrastructure sensor network.

• Journal of Information Technology Services
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• v.7 no.2
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• pp.149-164
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• 2008

As the computing landscape is shifting to ubiquitous computing environments, there is increasingly growing the demand for a variety of device controls that react to user's implicit activities without excessively drawing user attentions. We developed an EMG-based car interface that enables the physically handicapped to drive a car using their functioning peripheral nerves. Our method extracts electromyogram signals caused by wrist movements from four places in the user's forearm and then infers the user's intent from the signals using multi-layered neural nets. By doing so, it makes it possible for the user to control the operation of car equipments and thus to drive the car. It also allows the user to enter inputs into the embedded computer through a user interface like an instrument LCD panel. We validated the effectiveness of our method through experimental use in a car built with the EMG-based interface.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.2
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• pp.143-157
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• 2008

Ubiquitous Web Services is able to be specified future Web Services technology for connecting with various application services in any device and network environments. The devices, in ubiquitous environment, have dynamic characteristic such as location and statuse. So, we must support methods of dynamic service discovery in ad-hoc network. There are many related works at transaction, security, QoS, semantic and Web Services composition with various fields. Recently, the studies are interested in the Ubiquitous by development of computing and network technology. However, they are an early stage. For this reason, in this paper, we propose a WSUN(Web Services on Universal Networks) for Ubiquitous Web Services. It is a SOA based framework. And this paper extracts necessity of WSUN environment from scenario. The framework is composed of US Broker(Universal Service Broker). It is designed for satisfying the conditions and supports dynamic service discovery using a US Registry (Universal Service Registry). Consequently. clients are able to discover and use Universal Service by protocol stack of the US Broker for Web Services. And it is a strong point which supports interoperability between heterogeneous networks.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.861-864
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• 2008

In ubiquitous computing environments that can be connected to the networks any time any where, wearable computer should be able to offer a variety service. The necessity of a variety service using wearable computer becomes more important. In this paper, we can not only provide services over interaction of wearable computer devices, but also propose the method of the better service over interaction of the cell phone.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.406-408
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• 2005

본 연구는 유비쿼터스 컴퓨팅 환경에 존재하는 다양한 서비스들 간의 상호 작용을 지원하는 서비스 상호작용 브로커의 설계와 구현에 대해 소개한다. 유비쿼터스 컴퓨팅 환경을 위한 서비스 상호 작용 브로커는 (1) 소형 기기에서도 동작이 가능해야 하며, (2) 환경에서 제공되는 다양한 서비스들과 상호 작용이 가능해야 하여, (3) 확장이 용이해야 한다. 본 연구에서 개발한 서비스 상호 작용 브로커는 불필요한 기능을 제거함으로써 사이즈를 크게 줄였다. 또한 다른 웹 서비스 미들웨어들과의 상호 운용성을 갖추고 있다. 마지막으로 계층화된(layered) 구조를 채택하여 확장이 용이하도록 하였다.

• Journal of Information Technology Applications and Management
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• v.12 no.4
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• pp.13-24
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• 2005

The sensor network is a key component of the ubiquitous computing system which is expected to be widely utilized in logistics control, environment/disaster control, medical/health-care services, digital home and other applications. Nodes in the sensor network are small-sized and exposed to adverse environments. They are demanded to perform their missions with very limited power supply only. Also the sensor network is composed of much more nodes than the wireless ad hoc networks are. In case that some nodes consume up their power capacity, the network topology should change, and rerouting/retransmission is necessitated. Communication protocols studied for conventional wireless networks or ad hoc networks are not suited for the sensor network resultantly. Schemes should be devised to control the efficient usage of node power in the sensor network. This paper proposes a medium access protocol to enhance the efficiency of energy consumption in the sensor network node. Its performance is analyzed by simulation.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.1-4
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• 2004

가까운 미래에는 보이지 않는 수많은 장치들과 소프트웨어들이 서로 연결되어 각각의 사용자들에게 편리한 서비스를 제공할 것이다. 유비쿼터스 컴퓨팅 환경의 목표는 상이하며 유동적인 사용자들의 요구를 달성하기 위해 많은 서비스들 중 적절한 것들을 선택하고, 그것을 알맞게 구성하여 제공하는 것이다. 동적 서비스 구성을 위하여 본 연구에서는 다음을 제시하고 있다. 첫째, 서비스 구성에 필요한 요소를 파악한 후, 각 요소의 역할, 관계, 계층구조 그리고 속성을 표현하는 온톨로지를 기술한다. 둘째, 서비스 구성을 위한 필요한 규칙들을 기술한다. 셋째, 위의 두 가지를 이용하여 사용자의 목적에 따르는 서비스를 구성하기 위한 체계적인 알고리즘을 제시한다. 마지막으로, 본 연구의 결과를 예제 시나리오에 적용하여 동적 서비스 구성 가능성을 제시한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9B
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• pp.767-774
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• 2008

With the development of ubiquitous sensor networks, the need for communication among mobile nodes has been increased. When the existing TCP is applied to MANET, link failure, route change and network partition make TCP recognize congestion. As a result, TCP shows a poor performance. In this paper, using cross-layer design a new TCP congestion control algorithm that is suitable for MANET is designed and analyzed with ns2.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.494-499
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• 2007

애드 혹 유비쿼터스 컴퓨팅 환경의 가장 큰 특징은 연결의 역동성이다. 노드의 이동으로 인하여 두 노드를 연결하기 위한 경로를 지속적으로 재발견하여야 한다. 한편, 응용 계층에서도 사용자에게 현재의 상황에서 가장 적절한 서비스를 제공하기 위하여 연결된 서비스를 동적으로 재발견/재구성하게 된다. 이러한 환경에서는 이러한 재발견의 부담을 줄이는 것이 중요하다. 발견을 위한 비용이 응용 계층과 네트워크 계층에서 이중으로 발생하는 것을 회피하기 위하여 본 연구에서는 응용 계층의 레이블을 네트워크 계층에서 라우팅의 대상으로 사용하도록 제안한다. 물론 IP 주소에 기반한 라우팅도 동시에 지원한다. 본 연구에서는 IP 주소는 물론이고 응용 계층 레이블을 수용할 수 있는 공유된 라우팅 기법으로서 SGR(shared generic routing)을 제안한다. 시뮬레이션을 통하여 SGR이 발견의 비용을 효과적으로 줄 수 있음을 보였고 리눅스 운영 체제 환경에서 구현하여 실제 적용 가능성을 제시하였다.

• IEMEK Journal of Embedded Systems and Applications
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• v.1 no.2
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• pp.43-55
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• 2006

A home network is a typical ubiquitous computing network that consists of various consumer devices and service environments. Home networks are requiring increasingly more complicated services, such as multimedia home theater and the monitoring and controlling of heterogeneous devices. Accordingly, a mutually connecting mechanism is needed among heterogeneous devices and services redundant. The current paper presents a Multimedia Room Bridge Adapter (MRBA) system that is designed to manage heterogeneous devices and support various services. In addition, a hardware and software prototype is implemented based on the proposed architecture.