• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1596-1601
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• 2003

As the internet communication is prevalent in recent years, it becomes quite possible to monitor and control some mechanical plants from the remote place through the TCP/IP communication. Such a concept is expected to be applied to many industrial systems for easy maintenance and trouble shooting as well as various kinds of expensive test equipments for sharing. In this research, remote data monitoring and speed control for a DC-motor is implemented and tested through TCP/IP communication with embedded micro-controllers. It showed the possibility of reliable remote control system design utilizing the internet communication.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 B
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• pp.816-818
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• 1998

In this paper, a highly reliable communication network for DCS (Distributed Control System) in nuclear power plant is designed. The structure and characteristics of DCS in nuclear power plant is briefly explained. The features needed for a communication network for DCS in nuclear power plant is described. According to the above features, a layer structure for the communication network is determined and each layer is designed in detail. Accuracy of the model was evaluated by computer simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.833-836
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• 1987

The error probability for coherent frequency-hopped spread-spectrum multiple-access communications is computed. We employ PSK as a modulation scheme. The channel capacity is performance measure and the minimum bit signal-to-noise ratio for reliable communications is obtained.

• International Journal of Railway
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• 제3권2호
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• pp.39-45
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• 2010

The RF-CBTC (Radio Frequency-Communication Based Train Control) System is a communication system in railroad systems. The communication method of RF-CBTC system is the wireless between the wayside device and on-board device. The wayside device collects its location and speed from each train and transmits the distance from the forwarding train to the speed-limit position to it. The on-board device controlling device controls the speed optimum for the train. In the case of the RF-CBTC system used in Korea, transmission frequency is 2.4 [GHz]. It is the range of ISM(Industrial Scientific and Medical equipment) band and transmission of voice and data is performed by CDMA (Code Division Multiple Access) method. So noises are made in the AWGN (Additive White Gaussian Noise) and fading environment. Currently, the SNR (Signal to Noise Ratio) is about 20 [dB], so due to bit errors made by noises, transmission of reliable information to the train is not easy. Also, in the case that two tracks are put to a single direction, it is needed that two trains transmit reliable voice and data to a wayside device. But, by noises, it is not easy that just a train transmits reliable information. In this paper, we estimated the BER (Bit Error Rate) related to the SNR of voice and data transmission in the environment such as AWGN and fading from the RF-CBTC system using the CDMA method. Also, we supposed the SNR which is required to meet the BER standard for voice and data transmission. By increasing the processing gain that is a ratio of chip transmission to voice and data transmission, we made possible voice and data transmission from maximally two trains to a wayside device, and demonstrated it by using Matlab program.

• International journal of advanced smart convergence
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• 제12권1호
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• pp.140-148
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• 2023

With the OTT media market growing rapidly, the significance of trustworthy data verification and certification cannot be emphasized enough. This study delves into the crucial need for such measures in South Korea, exploring the steps involved, the technological and policy-related considerations, and the challenges that may arise once these measures are put into place. Drawing on in-depth interviews and the analytical hierarchy process (AHP), this study surveyed various stakeholder groups, both directly and indirectly related to OTT data authentication and certification. By assessing the severity of OTT data-related issues and identifying the requirements for reliability-improvement policies, participants shared their valuable insights and opinions on this pressing matter. The survey results clearly indicate a divided opinion among stakeholders and industry experts on the reliability of OTT data, with some expressing trust while others remain skeptical. However, there was a consensus that advertising-based AVOD is more reliable than SVOD. By analyzing the priorities of authentication and verification, this study paves the way for the establishment and operation of a Korean MRC (KMRC), centered on the OTT media industry. The KMRC will serve as a vital platform for ensuring the authenticity and accuracy of OTT data in South Korea, providing businesses and industry players with a reliable source of information for informed decision-making. This study highlights the pressing need for reliable data authentication and certification in the rapidly growing OTT media market, and provides a persuasive case for the establishment of a KMRC in South Korea to meet this critical need.

• 한국통신학회논문지
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• 제39B권3호
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• pp.180-187
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• 2014

본 논문은 도로에 설치된 인프라 시스템 및 타 자율 주행 차량과 협력하여 주행하는 협력형 무인 자율 주행 차량 기술을 위한 멀티케스트 통신 기법을 소개한다. 협력형 자율 주행 차량은 주행 안전성 향상을 위해 인프라 시스템 및 주변 차량과 통신한다. 교환되는 정보는 차량 안전과 관련 된 정보이며 다수의 자율 주행 차량에게 정의된 시간 내에 반드시 전송되어야 한다. 그러나 차량 통신 국제 표준인 WAVE는 협력형 자율 주행을 위해 요구되는 멀티케스팅 통신의 높은 전송 성공을 보장하지 않는다. 본 논문에서는 WiVCL이라는 MAC 계층의 고신뢰 멀티케스트 기법을 제안한다. IEEE 802.11p 및 BMW와 비교한 결과 WiVCL은 높은 전송 성공률과 예측 가능한 전송 지연 시간을 보여줌을 확인할 수 있었다.

• 기술혁신연구
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• 제5권1호
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• pp.223-248
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• 1997

In this study the comparative analysis of four nations' Delphi technological forecasts in information and communication industry was carried out. The nations were Korea, Japan, Germany and France. The reliability test of realization time forecast was also conducted. There were some technologies of which four nations forecast almost same realization time whereas other technologies which four nations showed large variance in forecasting realization time. This means that experts from different nations had different views and prospects on the same technology. It is expected that prospecting international technological trend from this study will contribute to formulating long-range plan for technological development in information and communication in Korea. The result of the comparative analysis of four nations' forecasts in information and communication technology can be summarized as follows. a)As for the realization time, most of the technologies were forecast by four nations to be similar, the differences ranging from one to three years. It was found that on the whole, the longer the time of the forecast, the bigger the variance. The German forecast showed the biggest variance. b)In reliability test Korean was found to be the most reliable and Japan, France and Germany were in descending order. The response of all panel members was found to be more reliable than that of the panel members with high expertise, which means that there were substantially different views among panel members with high expertise on the realization time of the same technology.

• Smart Structures and Systems
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• 제5권2호
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• pp.119-137
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• 2009

Smart sensors densely distributed over structures can use their computational and wireless communication capabilities to provide rich information for structural health monitoring (SHM). Though smart sensor technology has seen substantial advances during recent years, implementation of smart sensors on full-scale structures has been limited. Hardware resources available on smart sensors restrict data acquisition capabilities; intrinsic to these wireless systems are packet loss, data synchronization errors, and relatively slow communication speeds. This paper addresses these issues under the hardware limitation by developing corresponding middleware services. The reliable communication service requires only a few acknowledgement packets to compensate for packet loss. The synchronized sensing service employs a resampling approach leaving the need for strict control of sensing timing. The data aggregation service makes use of application specific knowledge and distributed computing to suppress data transfer requirements. These middleware services are implemented on the Imote2 smart sensor platform, and their efficacy demonstrated experimentally.

• 한국정보통신학회논문지
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• 제7권8호
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• pp.1714-1725
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• 2003

본 논문에서는 사용자가 이동 단말기를 이용하여 유료 컨텐츠에 대해 부가 서비스를 제공받을 경우 사용자와 컨텐츠 제공자간에 상호 신뢰할 수 있는 과금 방법들을 제안하고자 한다. 제안하는 방법은 이동 통신 환경에서 단문 메시지, 벨소리, 이미지와 음악 데이터 전송, 그리고 게임과 같은 다양한 종류의 서비스에 대해서 과금 방법을 지원한다. 또한 암호 학적인 해쉬 체인 방법을 이용하여 이동 단말기의 계산 부하를 줄이고 사용자와 컨텐츠 제공자간에 전송되는 데이터 량을 줄였으며, 각 사용자들의 컨텐츠 이용에 대한 증거를 저장하지 않고도 신뢰성 있는 과금이 가능하기 때문에 컨텐츠 제공자 측에서 메모리 공간을 절약할 수 있다.

• 전자공학회논문지CI
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• 제39권2호
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• pp.1-9
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• 2002

DSOM, DCOM, CORBA, Java RMI 같은 객체 지향 분산 프로그래밍 환경을 이용한 분산 응용 프로그램 개발이 일반화되고 있다. 그러나, 이러한 분산 미들웨어들은 응용프로그램의 품질과 재사용성을 향상시켜 주지만, 결함 허용 기능을 지원하지 않음으로서 신뢰성이 보장된 객체 기반 분산 응용프로그램의 설계 및 구현을 복잡하게 한다. 본 논문에서는 RMI 메커니즘을 기반으로 한 결함 허용 분산 시스템 개발 환경인 에버그린(Evergreen)을 제안하고자 한다. 에버그린은 신뢰성 있는 분산 컴퓨팅을 지원하기 위해서 체크포인트와 롤백 복구(rollback recovery) 메커니즘을 이용하여 설계되었다 일련의 실험을 통해 에버그린의 성능을 평가하였고 최적의 디자인 목표를 지원하기 위한 확장 가능성을 확인하였다.