• 정보와 통신
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• 제19권9호
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• pp.31-42
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• 2002

CRL (Communications Research Laboratory, Independent Administrative Institution, Japan) is developing ITS wireless communication technologies in millimeter-wave frequency region. Technologies are categorized for inter-vehicle communications (IVC) and road-vehicle communications (RVC). In this paper, system concepts and the experimental facilities are introduced. The experimental facility for inter-vehicle communications is gotten ready in 60 GHz frequency region and the experimental system for road-vehicle communications is based on RoF (Radio on Fiber) technology in 36-37GHz frequency region.

• Journal of Communications and Networks
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• 제16권5호
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• pp.479-484
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• 2014

In this paper, we consider the construction of cyclic and quasi-cyclic structured q-ary low-density parity-check (LDPC) codes over a designated small field. The construction is performed with a pre-defined sliding-window, which actually executes the regular mapping from original field to the targeted field under certain parameters. Compared to the original codes, the new constructed codes can provide better flexibility in choice of code rate, code length and size of field. The constructed codes over small fields with code length from tenths to hundreds perform well with q-ary sum-product decoding algorithm (QSPA) over the additive white Gaussian noise channel and are comparable to the improved spherepacking bound. These codes may found applications in wireless sensor networks (WSN), where the delay and energy are extremely constrained.

• Journal of Communications and Networks
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• 제7권4호
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• pp.401-407
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• 2005

Simulations are currently an essential tool to develop and test wireless sensor networks (WSNs) protocols and to analyze future WSNs applications performance. Researchers often simulate their proposals rather than deploying high-cost test-beds or develop complex mathematical analysis. However, simulation results rely on physical layer assumptions, which are not usually accurate enough to capture the real behavior of a WSN. Such an issue can lead to mistaken or questionable results. Besides, most of the envisioned applications for WSNs consider the nodes to be at the ground level. However, there is a lack of radio propagation characterization and validation by measurements with nodes at ground level for actual sensor hardware. In this paper, we propose to use a low-computational cost, two slope, log-normal path­loss near ground outdoor channel model at 868 MHz in WSN simulations. The model is validated by extensive real hardware measurements obtained in different scenarios. In addition, accurate model parameters are provided. This model is compared with the well-known one slope path-loss model. We demonstrate that the two slope log-normal model provides more accurate WSN simulations at almost the same computational cost as the single slope one. It is also shown that the radio propagation characterization heavily depends on the adjusted model parameters for a target deployment scenario: The model parameters have a considerable impact on the average number of neighbors and on the network connectivity.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.941-943
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• 2013

스마트미터가 전력공급자와의 양방향 통신을 통하여 요금정보와 전기사용 상황을 서로 주고받기 위해서는 표준화된 통신 프로토콜이 필요하게 된다. 이 통신 프로토콜은 사용자의 인증과 보안을 해결하고 사용자측에서 소비되는 전기 사용량을 전기 공급자에게 전달하게 된다. 본 논문에서는 스마트미터의 국제통신 프로토콜이 적용된 양방향 통신 및 제어 기술, 전기 기기의 등록 및 해제를 위한 통신방식을 설계하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.1320-1323
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• 2002

This paper reviews the Korean government’s selection process of core wireless communications technologies, and presents technology trends, perspectives and strategies of 5 core technologies to develop in wireless communications areas based on the mid term IT technology development plan(2002∼2004). Delphi Panel Method and Analytic Hierarchy Process(AHP) Analysis were adapted to select 30 core technologies in 9 strategic areas. Especially, 5 core wireless communications technologies out of 24 required technologies are selected: 4 G Core Technology, Broadband Wireless Access Network Technology, IMT-2000 Plus STP Technology, OBP Based Multimedia Satellite Communications Technology, Stratosphere Communications System Technology. Strategic national IT R&D program has been essential to continue success story of CDMA technology, and acquiring technology independency from advanced nations. In long term perspectives, a strategy of intensive investment with prudent selection onto core technologies should be deployed in the IT R&D programs. Also, the national IT R&D programs should be limited in the high risk & high returen areas where only government can afford the failures as well as better spill over effects are expected for the technology development and national economy. Korean industry has some strength in wireless communications technology area. Therefore, more policy concerns should be given into this area not only to secure present strength but also to explore better technology competitiveness.

• 정보와 통신
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• 제19권11호
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• pp.70-84
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• 2002

In this paper we discuss a multi-threaded baseband Processor capable of executing all physical layer processing of high data rate communications systems completely in software. We discuss the enabling technology for a software defined radio approach and present results for GPRS. 802.11b, and 2Mbps WCDMA. All of these protocols can be executed in real-time on the SB9600 chip using the Sandblaster core.

• 한국IT서비스학회지
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• 제16권4호
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• pp.1-13
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• 2017

This study examines how specific technology from Information and Communications Technology (ICT)-which plays a critical role in increasing productivity by promoting a spread of technology across the society though the use of big data, mobile or wearable devices-impacts of the productivity of society and productivity of added values, respectively. The impact of technology was studied from the perspective of efficiency levels of input. In order to provide an analysis, we have categorized ICT into 16 specific technologies and have set the number of companies and number of employees each as an input factor while setting the respective output and the output of added values as an output factor. Afterwards, we have applied data envelopment analysis (DEA) which is a form of nonparametric frontier analysis and measured the productivity and efficiency of added values for each technology. According to the analysis results, there were 2 technologies by the CRS standards, and 3 technologies by the VRS standards that showed relative efficiency levels. We have also presented some efficiency improvement strategies for specific technologies that revealed relative inefficiency and offered a reference set and projection point. In addition, we provide an analysis on scale efficiencies (SE), diminishing returns to scale (DRS), and increasing returns to scale (IRS) of each ICT.

• 한국정보시스템학회:학술대회논문집
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• 한국정보시스템학회 2004년도 춘계학술대회
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• pp.202-213
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• 2004

An effective use of information and communications technology is thought of as critical for achieving corporate competitiveness. This study identifies patterns of corporate use of communications technology, and examines how the use of those technologies is associated with business strategies and the level of information intensity. A survey study on a sample of Korean corporations shows that the use of communications technology is closely related both to business strategy and information intensity, and that communications technologies can be divided into two types in terms of their usage pattern. The structured communication technology is found to be related to the tools and services that support structured tasks, and the The unstructured technology to the tools the use of which is less structured and more flexible. Cost-based strategy is found to be closely related to the use of structured communication technology, while differentiation strategy is closely related to the use of unstructured communication technology.

• 정보과학회지
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• 제28권5호
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• pp.48-56
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• 2010

• 정보와 통신
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• 제13권5호
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• pp.52-69
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• 1996