• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.705-708
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• 2003

본 논문에서는 무선 센서 네트워크의 특성을 고려한 미디어제어 프로토콜의 설계에 있어서의 고려사항 및 설계기법에 대해서 제안하고 있다. 무선 센서 네트워크는 제한된 에너지를 가지는 배터리를 에너지원으로 사용하는 센싱 디바이스들로 구성되어 있으며, 이러한 디바이스들로 구성된 네트워크는 하나 혹은 그 이상의 공통의 작업을 수행하는데 그 목적이 있다. 일반적으로 무선 센서네트워크는 ad hoc 헝태의 구조를 가지며, 각각의 노드들은 장시간동안 비활성화 상태에 머무르게 되며, 센싱을 하기 위한 특정 이벤트가 발생하였을 때만 활성 상태로 전이하게 된다. 이와 같은 센서 네트워크의 특성은 IEEE802.11 과 같은 기존의 무선 미디어 제어 프로토콜과는 차별성을 띄게 된다. 센서 네트워크는 노드별 미디어 접근 공정성이나 시간지연보다는 에너지절약과 위상자동설정에 더 중점을 두고 있기 때문에 이에 적합한 미디어 제어 기술이 필요한 것이다. 본 고에서는 에너지 소모를 최소화하고 위상 자동 설정을 지원하기 위한 3 가지의 기법들에 대해서 제안하고자 한다. 첫째로 이벤트 발생 여부에 따른 노드의 신호감지 및 Sleep 상태 전이 및 이웃 노드들과의 가상동기화기법을 이용한 에너지 절약 기법에 대해서 제안하고, 충돌회피 기법에 대해서 살펴보도록 하겠다.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.131-135
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• 2008

Nowadays various information devices using electronic technology has been released. And these digital devices will be continuously developed to make a satisfaction of customer's needs. So digital device will support network service using communication technology, so users will use the internet service anywhere, anytime. Also the networked device which is used in ubiquitous computing environment should be evaluated by new evaluation framework. Therefore previous usability evaluation framework need to reflect the characteristics of ubiquitous computing. However most of pervious research about ubiquitous computing was about conceptual issues like rules and characteristics of ubiquitous computing, so the research of usability testing and evaluation method for ubiquitous computing is rarely conducted. This research's purpose is developing the evaluation framework for ubiquitous computing device and usability model for ubiquitous computing. To develop the evaluation framework, we collect the evaluation indexes which have need used in GUI evaluation And we extract evaluation indexes for ubiquitous computing based on literature review.

• Journal of the Korea Convergence Society
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• v.12 no.11
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• pp.221-228
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• 2021

This study was conducted to improve the convenience of design of mobile VR devices use in a way binds smart phones. Research on traditional mobile VR devices is insufficient. So the first survey was conducted on users 100 to understand the current status and status of mobile VR devices. As a result, it was found that the satisfaction with the convenience of use was significantly lowered, and countermeasures were needed. Then, a second survey of 30 Heavy Users was conducted to find out specific usability and problems of mobile VR devices. Through this, problems, ease of use, and other opinions of mobile VR devices were found. The survey results were analyzed through the Descriptive Statistics Act, and it was found that improvement was urgent due to low satisfaction with wearing and network. In-depth interviews were conducted with the same respondents. As with the problems derived first, problems such as wearing satisfaction, excessive head weight for long-term use, and lack of content could be found. Based on the previous studies, the focus group interview consisting of 6 experts derived the ease of use evaluation element. It consists of elements that can satisfy the convenience of use of mobile VR devices for creation, wearing satisfaction, network, morphology, learning, and spatiality, and has a total of 26. Using this evaluation elements, it is intended to provide better ease of use to users who will use the mobile VR device.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.6
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• pp.617-623
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• 2016

Recently, IoT technology has been applied to the control of appliances in the home, and information about temperature, humidity, etc. is collected and the application of the system to control the indoor environment automatically is increasing. Currently, the network configuration of IoT devices is mainly used to connect IoT devices to the Internet through wireless gateways. Since such a method is dependent on a gateway, there are limitations in providing various services. Therefore, this paper proposes an independent method of gateway by using IoT network without using gateway by applying long distance wireless communication technology. IoT devices using the proposed long distance wireless internet technology can connect to a remote server and provide mobility that can not be supported by existing methods, thereby providing more various services. The performance evaluation of the proposed network configuration method is compared with the delay time and the amount of data generated in the existing network method constituted by the gateway and the proposed network configuration method respectively. Experimental results show that the proposed method decreases the delay time and the amount of data generated by the gateway.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1167-1176
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• 2014

In this paper, a relay communication scheme for enhancing the WiMedia network performance by device's mobility is proposed. WiMedia protocol is suitable for the application that supports the real-time multimedia service in Ship Area Network since it supports high speed data transfer. However, the device's mobility is caused the dramatic change of link state and network topology, and is occurred the degradation of network performance. Therefore, a relay communication scheme for WiMedia network is proposed in this paper. The proposed technique can intelligently treat the change of link state, and solve the degradation of network performance.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.1
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• pp.98-103
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• 2021

In this study, we propose a group communication technique that guarantees security and expandability by configuring a network consisting of IoT terminals equipped with security functions. As the number of devices participating in the network increases, network resources are proportionally reduced, and adding a security function to the IoT device increases the delay time due to encryption in the IoT device. If the error rate that occurs in the network increases, network resources are quickly consumed due to retransmission. Therefore, IoT terminals are grouped to ensure scalability while supporting security, reducing the consumption of network resources even when the number of participating nodes increases, thus ensuring scalability. For the future implementation, the encryption method used in IoT terminals considered the standard of IEEE802.5.4, and the standardization trend was investigated and classified. The proposed method applies IoT devices that provide security functions of the IEEE802.5.4 standard to the group communication base to ensure reliability and scalability. In the performance evaluation, the effectiveness of the proposed method was confirmed by comparing the delay times when grouping IoT devices with security functions through simulation.

• Journal of KIISE:Software and Applications
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• v.34 no.3
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• pp.219-225
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• 2007

UPnP AV Framework automatically integrates and manages various AV devices that are connected to network as an important component in home network. Therefore, user can access and control AV contents at any time. But, other existing home entertainment systems target multimedia service support that is based on multimedia home server system. In this paper, we propose an integrated home entertainment system (u-MUSE system) that supports remote control service. It can manage application in remote AV device or control AV contents directly in home network environment. The proposed system sufficiently performs role of control center for electronic devices in home via integrated system control and AV contents playback service.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.7
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• pp.1727-1733
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• 2014

In this paper, an intelligent home network middleware interconnection adapter between devices was designed. Home network middleware interconnection adaptor is present in UPnP, LonWorks, LnCP, HAVi, etc. Various types of middleware and for use of a number of middleware is required to modify an existing system. But this study designed by middleware interconnection adaptor a number of existing middleware systems without modification was designed to allow interlocking. The Performance evaluation of designed interconnection middleware adaptor produced by various companies was used devices, experimental device was implemented. And mobile application was developed by using developed interconnection middleware adaptor. Also the performance was evaluated in a mobile application.

• Korea Information Processing Society Review
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• v.11 no.3
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• pp.55-66
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• 2004

홈 네트워크는 다양한 종류의 가전기기들과 다양한 네트워크가 혼재해 있는 유비쿼터스 네트워크 환경이다. 홈 네트워크를 구성하는 가전기기들은 기능과 특징에 따라 크게 멀티미디어 가전기기, 단순 제어 가전기기로 구분할 수 있다. 멀티미디어 가전기기의 경우 영상 및 음성 정보를 전송하기 위해 큰 대역폭을 가지는 하부 네트워크를 이용하고 있으며 영상 및 음성 정보의 전송과 제어를 위해 많은 제어 모듈을 가지고 있다. 반면 단순 제어 가전기기들은 제어 및 상태 정보의 신뢰성 있는 전송을 위한 하부 네트워크를 사용하고 있으며 단순한 제어 모들을 가지고 있다. (중략)

• Journal of the Korea Society of Computer and Information
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• v.13 no.6
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• pp.225-232
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• 2008

When a single source of multimedia contents is distributed to multiple reproduction devices, the audio and video contents require synchronous play for multi-channel stereo sound and lip-synchronization. The multimedia system in vehicle, especially, has researched to move to wireless environments from legacy wired environments. This paper proposes the advanced algorithm for providing synchronized services of real-time multimedia traffic in IEEE 802.11 WLANs [1]. For these, we implement the advanced IEEE 1588 Precision Time Protocol [2] and the environments for simulation. Also, we estimate and analysis performance of the algorithm, then we experiment and analysis after the porting of algorithm in wireless LAN devices (Linksys wrt-350n AP network device) to characterize timing synchronization accuracy.