• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2005년도 추계학술대회
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• pp.299-311
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• 2005

This article introduces developing trends of an "Ubiquitous Interface" as an access method for use of various network resources, such as public wireless networks and un-licensed wireless networks in ubiquitous sensor network environments, without troublesome settings or operations by users. "Ubiquitous Interface" is include a relatively wide sense meaning not only physical interface of specified device or between processors, but anything method for access USN. These "Ubiquitous Interface" able to provide seamless services that adapt autonomously to the user's movements and changes in the state of wireless resources. Recently, strongly recommended candidates are RFID, NFC, Multi-mode mobile terminal, Wearable computer and OSGi for integrated digital home networking system as a future ubiquitous interface. These candidates are have to have flexibility and multiple physical communication channel for seamless service hand over and serve easy connection at huge USN to user. And, must have flexible software structure and multi-functional middleware. Consequently, for more enhance performance of an ubiquitous interface and developing, need more structured and integrated future plan.

• 디지털산업정보학회논문지
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• 제10권2호
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• pp.47-59
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• 2014

In this paper, I propose a new energy efficient clustering scheme to prolong the network lifetime by reducing energy consumption at the sensor node. It is possible that a node determines whether to participate in clustering with certain probability based on local density. This scheme is useful under the environment that sensor nodes are deployed unevenly within the sensing area. By adjusting the probability of participating in clustering dynamically with local density of nodes, the energy consumption of the network is reduced. So, the lifetime of the network is extended. In the region where nodes are densely deployed, it is possible to reduce the energy consumption of the network by limiting the number of node which is participated in clustering with probability which can be adjusted dynamically based on local density of the node. Through computer simulation, it is verified that the proposed scheme is more energy efficient than LEACH protocol under the environment where node are densely located in a specific area.

• 디지털산업정보학회논문지
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• 제11권1호
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• pp.69-78
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• 2015

Internet of Things(IoT) is electronic devices and household appliances use wireless sensor network in environment of high speed wireless network and LTE mobile service. The combination of the development of Internet and wireless network led to development of new forms of service such as electronic devices and household appliances can connect to the Internet through various sensors and online servers such as a Home Network. Even though Internet of Things is useful, there are problems in Internet of Things. In environment of Internet of Things, information leakage could happens by illegal eavesdropping and spoofing. Also illegal devices of wireless communication interference can cause interfere in Internet of things service, physical damage and denial of service by modulation of data and sensor. In this thesis, it will analyze security threats and security vulnerability in environment of mobile services and smart household appliances, then it will suggest plan. To solve security issues, it is important that IT and RFID sensor related companies realize importance of security environment rather than focus on making profit. It is important to develop the standardized security model that applies to the Internet of Things by security-related packages, standard certification system and strong encrypted authentication.

• 디지털콘텐츠학회 논문지
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• 제8권4호
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• pp.425-430
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• 2007

본 논문에서는 주파수 자원의 고갈로 인하여 차세대 무선 정보통신으로 사용의 가능성이 예상되는 가시광 소자를 조명, 신호기, 전광표시, 표시 등에 이용하여, 발광효율의 가시 광 반도체가 조명이나 표시에 이용되어지는 경향이 있고 거기다 고속으로 점멸 가능한 능력을 갖는 것이나 이을 이용한 가시광 통신의 무선 통신에의 응용과 표준화 기술에 대하여 알아보고자한다.

• 디지털산업정보학회논문지
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• 제11권4호
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• pp.25-31
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• 2015

Smart healthcare environments which merge medical and IT technology are getting ready for the third generation centering EHR from current second generation. As a basic technology for the introduction and activation of EHR systems it requires heterogeneous network interworking techniques between various wired and wireless medical devices. Interworking technology for heterogeneous network among various medical devices is needed to introduce EHR system. The heterogeneous network interworking technology is needed for construction of a reliable data system to convert each of unstructured data into structured data. Therefore, in this paper, we identify the domestic and international trends of smart medical field and analyze the characteristics of wired and wireless communication technology that is used in a heterogeneous network. and also suggest requirements needed for interworking technology and provide interworking technology based on them. we expect that proposed method which is designed for smart healthcare environments would provide a basic architecture needed for third smart medical technology generation.

• 디지털융복합연구
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• 제13권12호
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• pp.13-21
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• 2015

무선 브로드밴드 기술의 발전은 산업계 전반에 다양한 변화를 안겨주고 있다. 새로운 무선 브로드밴드 기술의 등장으로 인해 기존 산업의 경쟁력은 강화되었고 새로운 융합형 서비스와 신생산업들이 등장하게 되었다. 본 연구에서는 차세대 무선 브로드밴드 산업의 동향을 분석하고 이를 활성화시킬 수 있는 방안을 제시하는 것을 목적으로 한다. 이를 위해, 먼저 최근 무선 브로드밴드 산업의 동향을 분석하였고, 무선 브로드밴드 산업 성장에 영향을 주는 요소로 무선 네트워크 기술, 콘텐츠, 서비스를 파악하였다. 파악된 요소별로 차세대 무선 브로드밴드 산업의 동향을 조사하였고, 네트워크 기술 발전을 성장 동력으로 하는 무선 브로드밴드 산업의 선순환 성장 모형을 제시하였다. 끝으로 무선 네트워크 기술 개발 관점에서 무선 브로드밴드 산업을 활성화시킬 수 있는 방안들을 기술하였다. 본 연구의 결과는 차세대 무선 브로드밴드 산업에 대한 통찰력 있는 시각을 제공하며 향후 무선 브로드밴드 산업을 발전시키는 제도방안 수립에 도움을 줄 것으로 기대된다.

• 디지털콘텐츠학회 논문지
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• 제7권2호
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• pp.103-108
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• 2006

모바일 응용을 실현하는데 있어서 근거리 무선 통신과 네트워킹 기술의 중요성은 증가하고 있다. 예를 들어 지그비 기술은 베터리의 수명이 수개월에서 수년에 이르는 기기 사이의 저 가격과 저 전력 연결을 제공한다. 또한, 지그비는 블루투스에서 제공하는 네트워크 구성보다 큰 메쉬 네트워크를 구축할 수 있다. 지그비 규격의 주된 특징은 네트워크의 유연성, 저가격, 저전력 소모이며 고정, 휴대 및 모바일 기기사이의 Ad-hoc 네트워크에서 저속 데이터 전송이다. 홈 네트워크와 홈 자동화 분야는 간단한 네트워크의 예로써 지그비의 큰 시장중의 하나이다. 본 논문은 잡음과 간섭 그리고 라이시안 페이딩 환경에서 지그비 시스템과 DSSS-BPSK 신호의 성능을 분석하였고 근거리 무선 채널에서 간섭과 페이딩의 영향에 따른 성능 감쇠에 대하여 연구하였다. 특히, 라이시안 페이딩과 간섭 레벨에 따른 오율 특성을 BER 성능 그림을 통하여 나타내었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제3권6호
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• pp.597-611
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• 2009

With the advent of ubiquitous computing society, many advanced technologies have enabled wireless sensor networks which consist of small sensor nodes. However, the sensor nodes have limited computing resources such as small size memory, low battery life, short transmission range, and low computational capabilities. Thus, decreasing energy consumption is one of the most significant issues in wireless sensor networks. In addition, numerous applications for wireless sensor networks are recently spreading to various fields (health-care, surveillance, location tracking, unmanned monitoring, nuclear reactor control, crop harvesting control, u-city, building automation etc.). For many of them, supporting security functionalities is an indispensable feature. Especially in case wireless sensor networks should provide a sufficient variety of security functions, sensor nodes are required to have more powerful performance and more energy demanding features. In other words, simultaneously providing security features and saving energy faces a trade-off problem. This paper presents a novel energy-efficient security architecture in an IEEE 802.15.4-based wireless sensor network called the Hybrid Adaptive Security (HAS) framework in order to resolve the trade off issue between security and energy. Moreover, we present a performance analysis based on the experimental results and a real implementation model in order to verify the proposed approach.

• 디지털산업정보학회논문지
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• 제10권4호
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• pp.109-116
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• 2014

In recent, ISM (Industrial Scientific Medical) band that is 2.4GHz band authorized free of charge is being widely used for smart phone, notebook computer, printer and portable multimedia devices. Accordingly, studies have been continuously conducted on the possibility of coexistence among nodes using ISM band. In particular, the interference of IEEE 802.11b based Wi-Fi device using overlapping channel during communication among IEEE 802.15.4 based wireless sensor nodes suitable for low-power, low-speed communication using ISM band causes serious network performance deterioration of wireless sensor networks. This paper examined a method of identifying channel status to avoid interference among wireless communication devices using IEEE 802.11b (Wi-Fi) and other ISM bands during communication among IEEE 802.15.4 based wireless sensor network nodes in ISM band. To identify channels occupied by Wi-Fi traffic, various studies are being conducted that use the RSSI (Received Signal Strength Indicator) value of interference signal obtained through ED (Energy Detection) feature that is one of IEEE 802.15.4 transmitter characteristics. This paper examines an algorithm that identifies the possibility of using more accurate channel by mixing utilization of interference signal and RSSI mean value of interference signal by wireless sensor network nodes. In addition, it verifies such algorithm by using OPNET Network verification simulator.

• Asia Marketing Journal
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• 제15권3호
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• pp.1-14
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• 2013

Our research brings managerial insights for developing new digital convergence of devices and services. To explain the phenomenon of device and service convergence, we combine two different approaches from separate research fields: a perceptual mapping technique generally used for segmentation in marketing and associative network analysis mobilized to understanding network structure of core and peripheral as well as the information mediating role of nodes in network science. By combining these two approaches, we provide an in-depth analysis of the associations among devices and services by assessing the centrality of device and service nodes in an associative network. This is done by examining the connections between these services and devices as well as investigating the role of mediation in the combined device-service associative network. Our results based on bi-partite network analysis of survey responses from 250 Internet Protocol (IP) television viewers show which device and which service will play the major role in future device and service convergence as well as which characteristics and functionalities have to be incorporated into future convergence. Among the devices, the mobile handset with the betweenness centrality of 0.26 appears to be the device that would lead future device convergence. Among the services, wireless broadband with the betweenness centrality of 0.276 appears to be the service on which future service convergence needs to be developed. This result is quite unexpected, since wireless broadband has a lower penetration rate than other services, such as fixed broadband and cable TV. In addition, we indicate the possibility of converging devices, such as personal digital assistant (PDA) and mobile handset, and services, such as IPTV and mobile Internet, into wireless broadband services in the future.