• Journal of Korea Multimedia Society
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• v.8 no.2
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• pp.279-286
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• 2005

As the mobile environment has been generalized, data synchronization with mobile devices or mobile device and PC/server is required. To deal with the problem, the consortium was established by the companies, such as Motorola, Ericsson, and Nokia, and released SyncML(Synchronization Markup Language) as a standard of industrial area for interoperating with data synchronization and various transmission protocol. But, in synchronization process, when more than two clients requested data synchronization, data conflict can be happened. This paper studies the various conflict reasons that can happen in data synchronization processes and groups them systematically Through the analyzed information, we compose the Change Log Information(CLI) that can keep track of the chased information about synchronization. And we suggest an operation policy using CLI. Finally, we design an algorithm and adapt the policy as a method for the safety and consistency of data.

• Information Systems Review
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• v.6 no.1
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• pp.155-166
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• 2004

As the necessity of such mobile wireless terminals as PDAs or Cellular phones drastically increases, the terminals play important role in various business areas. In this paper, a bidding system in mobile wireless environments is constructed. However, with many mobile wireless terminals modifying at the same time their (duplicated) bidding values for a given data item, data coherency for the data item becomes essential. Therefore, in this paper, a bidding system using SyncML data synchronization mechanism is proposed and constructed. SyncML is one of data synchronization mechanisms proposed by the SyncML Initiative, a consortium of mobile wireless mobile technology leaders for universal data synchronization. The bidding system is implemented and tested in LINUX, C++, and PocketPC 2000 emulator programming environments.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.535-538
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• 2004

모바일 환경이 일반화 되면서 모바일 디바이스간 또는 모바일 디바이스와 PC 또는 서버와의 동기화가 요구되었다. 모토로라, 에릭슨, 노키아 등의 업체들은 컨소시엄을 구성하여 데이터의 동기화와 다양한 전송 프로토콜과의 연동을 목표로 산업계의 표준인 SyncML(Synchronization Markup Language)을 제정하였다. 그러나, 동기화 과정에서 둘 이상의 클라이언트가 동일한 데이터 동기화를 요청했을 때 데이터 충돌이 일어나게 된다. 본 논문에서는 데이터 동기화 과정에서 발생할 수 있는 다양한 충돌에 대해서 분석하고, 체계적으로 분류하였다. 이를 바탕으로 동기화에 대한 정보를 추적할 수 있는 Change Log Information을 구성하고 운영 원칙을 제정하여, 데이터의 안정성과 일치성을 보장하기 위한 Conflict Resolution을 제안한다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.460-462
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• 2003

PDA(Personal Data Assistant)나 Handheld PC와 같은 모바일 디바이스(Mobile Device)를 이용하여 주소록이나 일정관리와 같은 개인 정보를 관리하는 것이 일반적인 추세이다. 모바일 디바이스는 그 특성상 중요한 정보를 신뢰성 있는 서버와 같은 컴퓨터에 중복 저장하는 것이 필요한데, 동일한 데이터를 중복 저장하면 데이터 동기화(Data Synchronization)를 통하여 일치성을 유지하도록 해야 한다. 그러나 동기화 과정에서 데이터 충돌이 발생할 수 있다. 본 논문에서는 이러한 데이터 충돌에 대한 해결 정책을 제시하였고, 그 중 서버 우선 정책과 클라이언트 우선 정책에 필요한 해결 규칙을 설명하였다. 서버 우선 정책은 서버에 이미 존재하고 있는 값을 유지하는 것을 기본으로 하는 정책이며, 클라이언트 우선 정책은 클라이언트가 요청한 값이 우선하는 정책이다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2373-2379
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• 2015

COMS(Communication, Ocean and Meteorological Satellite), the first Korean geostationary meteorological satellite, provides free meteorological information through HRIT/LRIT(High/Low Rate Information Transmission) service. This work presents the development of data receiver circuit that is essential to the implementation of a low-cost meteorological information receiver system. The data receiver circuit processes the data units according to the specification of physical layer and data link layer of HRIT/LRIT service. For this purpose, the circuit consists of a Viterbi decoder, a sync. word detector, a derandomizer, a Reed-Solomon decoder and so on. The circuit also supports PCI express interface to pass the information data on to the host PC. The circuit was implemented on an FPGA(field programmable gate array) and its function was verified through simulations and hardware implementation.

• IE interfaces
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• v.19 no.4
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• pp.306-315
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• 2006

In this paper we analyze whether we can use the mobile phone having been highly distributed into young generation as a device for the u-learning in Korean public education. For this purpose we deal with the technical maturity in three axes. Firstly, we examine the authoring nature of mobile internet-based contents such as both text and motion picture for the contents developers in the public education. As a research result the authoring of text has almost no difficulty, but that of the motion picture shows some problems. Secondly, we deal with whether u-learners can easily get and use u-contents on both mobile phone and PC respectively. After analysing this factor, we found that the downloading of motion picture contents into mobile phone is very limited. Therfore we talk about the usability and problem of various PC Sync tools and propose their standardization. Finally, the needs of the introduction of the ubiquitous SCORM which could enable to reuse u-contents among different Korean telco’s mobile phones are discussed. Here we describe some functionality of both ubiquitous SCORM and u-LMS. Our study looks like almost the first work examining the technological maturity for the introduction of u-learning with mobile phone in Korean public education and it could be used as a reference for the study of any other wireless telecommunication-based u-learning other than mobile telecommunication.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.221-228
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• 2002

The NAVER is based on a cluster of low-cost personal computers. The goal of NAVER is to provide flexible, extensible, scalable and re-configurable framework for the diverse virtual environments especially for Gamsung research experiments. Personal computers are divided into three servers are according to their specific functions: Render Server, Device Server and Control Server. While Device Server contains external modules requiring event-based communication for the integration, Control Server contains external modules requiring synchronous communication every frame. And, the Render Server consists of 5 managers: Scenario Manager, Event Manger, Command Manager, Interaction Manager and Sync Manager. In this paper, we discuss NAVER as effective distributed system and its application to Gamsung experiment.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2003.11a
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• pp.209-212
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• 2003

본 논문에서는 PC 환경에서 지상파 디지털 멀티미디어 방송(Digital Multimedia Broadcasting, DMB)을 수신할 수 있는 PC 기반 지상파 DMB 수신기용 백엔드 시스템 개발에 대해 서술한다. 지상파 DMB는 기존의 지상파 아날로그 또는 디지털 TV에 비해 탁월한 이동 수신 성능을 보인다. 본 논문에서는 국내 지상파 DMB 표준안에 부합하는 수신기의 백엔드 (back-end)를 PC 환경에서 소프트웨어로 구현하였다. 지상파 DMB는 유럽의 디지털 오디오 방송(Digital Audio Broadcasting, DAB) 표준인 EUREKA-147을 기반으로 MPEG-4 표준에 의한 멀티미디어 서비스를 제공한다. 지상파 DMB의 멀티미디어 서비스는 MPEG-4 AVC(Advance Video Coding) 압축 비디오와 BSAC(Bit Slice Arithmetic Coding) 압축 오디오를 MPEG-4 시스템의 SL(Sync Layer) 표준으로 패킷화 후 MPEG-2 TS(Transport Stream)에 실어 DAB의 스티림 모드를 통해 전송하는 방식을 사용한다. 본 논문에서는, 지상파 DMB 수신을 위한 프론트엔드(front-end)는 외장형 기기를 이용하고, 이로부터 USB 인터페이스를 통해 기저대역 다중화 스트림을 PC 상으로 업로드한 뒤, 소프트웨어에 의해 역다중화하고 압축을 푼 후, 오디오와 비디오를 재생하는 지상파 DMB 백엔드 시스템을 구현하고 이를 검증하였다.

• Journal of information and communication convergence engineering
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• v.6 no.2
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• pp.233-237
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• 2008

This paper presents proposal for an application (only for Windows-based Mobile) that can synchronize the Third Generation Windows-based mobile with the prescribed server. This application can be used by mobile users to send information directly to the WAS server wirelessly. In this paper a comparison between Third Generation technology and WLAN ( both are parallel technologies first one embodied by IMT-2000 standards and the second one by ITU Standards) has been made and also a comparison between Wi-Fi and Bluetooth has been made.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1137-1138
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• 2008

The purpose of this study is to implement a landscape lighting system that displays full color video by precisely controlling the R, G, B (Red, Green, Blue) LEDs which have a resolution of 256 each. The system implemented in this study consists of a PC, MASTER, SLAVEs and MODULEs. The PC sets the various landscape lighting displays, and the image files can be sent to the MASTER through a virtual serial port connected to the USB (Universal Serial Bus). The MASTER sends a sync signal to the SLAVE. The SLAVE uses the signal received from the MASTER and the landscape lighting display pattern.