• Journal of Internet Computing and Services
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• v.4 no.5
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• pp.51-60
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• 2003

Asynchronous iteration is a way to reduce performance degradation of some parallel algorithms due to load imbalance or transmission delay between computing nodes, which requires asymmetric communication between the nodes of different speeds. To implement such asynchronous communication on distributed memory systems, we suggest an MPMD method that creates an additional separate server process on each computing node, and compare it with an SPMD method that creates a single process per node.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.216-219
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• 2012

최근 정보의 다양화와 대량화로 인해 대두된 빅데이터 환경은 여러 분야로의 연구 방향을 제시하고 있다. 이미 데이터 양이 페타바이트 규모를 넘어서고 있으며, 이를 처리하기 위한 방안이 연구중이다. 본 논문에서는 무선 통신기기 및 센서 기술의 발달로 대규모 네트워크 구축이 가능해진 센서 데이터 중 차량에 사용되는 센서 데이터를 연구하는 방안을 제시하고자 한다. 빅데이터 개념이 대두되면서 이슈화되고 있는 Hadoop 시스템을 이용하여 자동차 센서 데이터 (CAN Message)를 분석하고자 한다.

• ETRI Journal
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• v.41 no.4
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• pp.465-472
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• 2019

The major challenge in wireless body area networks (WBAN) is setting up a protected communication between data consumers and a body area network controller while meeting the security and privacy requirements. This paper proposes efficient and secure data communication in WBANs using a Twofish symmetric algorithm and ciphertext-policy attribute-based encryption with constant size ciphertext; in addition, the proposed scheme incorporates policy updating to update access policies. To the best of the author's knowledge, policy updating in WBAN has not been studied in earlier works. The proposed scheme is evaluated in terms of message size, energy consumption, and computation cost, and the results are compared with those of existing schemes. The result shows that the proposed method can achieve higher efficiency than conventional methods.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.01a
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• pp.143-144
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• 2021

본 연구는 위치정보를 기반으로 앱과 웹에 위치정보 및 경로 정보를 관리하는 코로나 대응 및 관리 시스템이다. 현재 코로나19 바이러스 때문에 많은 사람들이 언제 어디서 감염이 되었는지 모르고 어떠한 위치에 있었는지 정확히 동선 파악이 어렵다. 이 문제를 해결하기 위해 본 연구는 앱과 웹을 활용해 사용자 위치정보 저장, 문자 전송, 지도에 경로를 안내하는 시스템을 연구하였다. 매장에는 방문자 정보를 수집하는 단말기를 설치하고 수집된 정보는 웹 데이터베이스에 저장되어 웹과 앱에 코로나 관련 서비스를 제공한다. 주요기능으로는 게시판, 코로나19 정보, 환자현황, 경로 추적 정보, 메시지전송, 통계 정보를 제공한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.999-1002
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• 2007

널리 보급된 컴퓨터와 인터넷 그리고 모바일기기의 발달은 우리사회에 큰 변화를 주었다. 이는 이동성을 제공하면서 휴대 인터넷을 사용할 수 있는 서비스를 절실히 필요로 하게 되었고 그러한 요구에 부응하여 WiBro가 탄생하였다. 본 논문에서는 WiBro의 Downlink(DL)와 Uplink(UL)의 속도를 다양한 환경에서 현재 시판중인 WiBro 모뎀으로 성능을 평가해 보았고, 그 결과 WiBro에서 추구하는 DL:UL의 비율과 비슷하게 나옴을 확인하였다. 하지만 서비스 지역의 건물 내에서 WiBro의 서비스를 원활하게 받지 못하는 문제점을 발견하였고, 그 해결책으로 Fixed RS, Nomadic RS, 그리고 Mobile RS 3가지 방식을 제안하였다. 특히 건물의 경우는 Fixed RS(Relay Station)에서 Broadcast message 방식과 Wake-up 방식을 사용하도록 제안하였다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.6
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• pp.478-488
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• 2023

This paper investigates the naval application of laser communication as a potential replacement for traditional acoustic wave communication in underwater environments. We developed a laser transceiver using Arduino and MATLAB, conducting a water tank experiment to validate communication feasibility across diverse underwater conditions. In the first experiment, when transmitting data through a laser, the desired message was converted into data and transmitted, received, and confirmed to be converted into the correct message. In the second experiment, the operation of communication in underwater situations was confirmed, and in the third experiment, the intensity of light was measured using the CDS illuminance sensor module and the limits of laser communication were measured and confirmed in various underwater situations. Additionally, MATLAB code was employed to gather data on salinity, water temperature, and water depth for calculating turbidity. Optimal wavelength values (532nm, 633nm, 785nm, 1064nm) corresponding to calculated turbidity levels (5, 20, 55, 180) were determined and presented. The study then focuses on analyzing potential applications in naval tactical communication, remote sensing, and underwater drone control. Finally, we propose measures for overcoming current technological limitations and enhancing performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.1
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• pp.50-58
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• 2003

In this paper, a new cm (Caller ID) transceiver is introduced for SMS(Short Message Service) and e-mail services by the wire and digital cordless phones in 900MHz like as mobile phones. For this wireless digital cm phone, improved radio transceiver modules is proposed and implementedusing the analysis of data processing errors. As a result, many wireless cm services can be popular without the kind of switching systems.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.3
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• pp.501-506
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• 2008

Medical environments incorporate complex and integrated data networks to transfer vast amounts of patient information, such as images, waveforms, and other digital data. To assure interoperability of images, waveforms and patient data, health level seven(HL7) was developed as an international standard to facilitate the communication and storage of medical data. We also adopted medical waveform description format encoding rule(MFER) standard for encoding waveform biosignal such as ECG, EEG and so on. And, the study converted a broad domain of clinical data on patients, including MFER, into a HL7 message, and saved them in a clinical database in hospital. According to results obtained in the test environment, it was possible to acquire the same HL7 message and biosignal data as ones acquired during transmission. Through this study, we might conclude that the proposed system can be a promising model for electronic medical record system in u-healthcare environment.

• Journal of Broadcast Engineering
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• v.7 no.2
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• pp.192-201
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• 2002

This paper develops a novel robust information hiding technique that uses channel codes derived from the error-correcting coder. The message encoded by the cover encoder is hidden in DCT transform domain of the cover image. The method exploits the sensitivity of human eyes to adaptively embed a visually recognizable message in an image without affecting the perceptual quality of the underlying cover image. Experimental results show that the proposed data hiding technique is robust to cropping operations, lossy JPEG compression, noise interference and secure against known stego attacks. The performance of the proposed scheme with turbo coder is superior to that without turbo coder.

• International Commerce and Information Review
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• v.5 no.2
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• pp.207-225
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• 2003

The purpose of this study is to examine the legal aspects on the formation of international contract in electronic commerce. The findings could be summarized as follows. rug, the contract doctrine of the contract formation by electronic data message, time of dispatch and receipt of data message, error in electronic communication, contract form and electronic signature could be supported or protected by the existing contract doctrine. Second, In relation to the contract formation arranged by electronic agents, the established contract doctrine provides no clear answer to the question whether changes provided by the interaction of electronic agents are enforceable. The enforceability question is left to future legislation. Finally, It is necessary that a significant level of formality together with the disclosure on the contract formality by certain act be conveyed 10 a potential buyer so that the buyer is impressed that the contact by the certain act could be valid.