• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1518-1521
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• 2010

현재 모바일 환경에서 다양한 자료 동기화 프로토콜 및 솔루션이 개발되었지만 이들 간의 상호호환성은 보장되고 있지 않은 실정이어서 관리의 어려움이 따르고 있다. 이에 본 연구팀은 통합된 자료 동기화 서버를 운용하기 위한 방안으로 서로 다른 자료 동기화 프로토콜 기반의 동기화 메시지 또는 자료를 통일된 형식으로 변환하기 위한 스탠드 얼론 (Stand alone) 자료 동기화 게이트웨이와 임베디드 자료 동기화 게이트웨이를 개발하였다. 하지만 두 게이트웨이는 규모의 확장성 (Scalability)과 자료 변환 성능 측면에서 상반된 장단점을 가지므로 두 게이트웨이의 성능을 비교/분석하여 전체 자료 동기화 시스템의 특성에 따라 상대적으로 효율적인 게이트웨이를 선택 운용하여야 할 필요성이 발생하였다. 게이트웨이 시스템의 특성상 성능 평가를 위해서는 다수의 모바일 단말기를 운용하여야 한다는 어려움이 있으므로 본 논문에서는 성능 분석을 위한 시뮬레이션 모델을 설계하였다. 시뮬레이션 모델을 통해 전체 단말기의 수와 동기화 요청 빈도에 따른 두 게이트웨이의 성능의 팔꿈치 지점을 파악할 수 있을 것이며, 이를 통해 각 자료 동기화 시스템 별 적합한 게이트웨이를 선택 운용하는데 도움이 될 것이다. 또한 병목현상이 발생하는 팔꿈치 지점을 개선함으로써, 전체 자료 동기화 시스템의 성능 향상에도 기여할 수 있을 것이다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.335-342
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• 2010

Nowadays, the major manufacturer of the mobile devices has offered its own solution for the data synchronization. But each manufacturer uses its proprietary data synchronization method so that the compatibility of data can not be guaranteed. To solve such problems, a gateway is needed to convert different forms of data into a unified form of data and vice versa. Some problems have been found in the experiments with the previously implemented gateway. First, a bottleneck state might arise if a number of mobile devices request data synchronization simultaneously. Second, the gateway itself would become a serious vulnerable point to an attack during the process of converting received data. The proposed gateway can solve this bottleneck state and security issue since it converts data and processes synchronization request in a mobile device. In this paper, the proposed gateway is constructed and the results of some experiments with the gateway are presented. According to the results, the proposed gateway operates properly and it is relatively insensitive to the bottleneck state.

• Journal of the Korea Society of Computer and Information
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• v.16 no.5
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• pp.79-91
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• 2011

In this paper, a DS (Data Synchronization) server for mobile communication environments is constructed and the suitability and the performance of its operations are validated. The DS server provides a way to update the newest data and keep data consistency for clients (mobile devices). In addition, the DS server constructed in this paper supports various synchronization types, and detects all changes and conflicts. In case of data conflicts, the DS server resolves the conflicts according to the several policies implemented in this work. The DS server conforms to the OMA(Open Mobile Alliance) DS standard protocol for interoperability with other mobile devices and servers. In addition to the transmission-by record scheme proposed by the OMA DS standard protocol, the DS server constructed in this paper also provides the transmission-by field scheme for the enhancement transmission performance between the server and clients. In order to validate its operations, data synchronization between the DS server and the SCTS (SyncML Conformance Test Suit), the suitability validation tool provided by the OMA, is performed. The validation results show that the DS server constructed in this paper satisfies all of the test cases except the Large Object function. The Large Object function will be implemented later because the function is not needed for the personal information synchronization process which this paper aims for. Also, synchronization times of the DS server are measured while increasing the number of data and clients. The results of the performance evaluations demonstrate that the DS server is scalable, in the sense that it has not suffered from any serious bottlenecks with respect to the number of data and clients. We expect that this work will provide a framework for various studies in the future for improving mobile DS operations.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.5
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• pp.137-148
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• 2010

In this paper, a mobile office support. system which consists of mobile devices and servers is proposed. An efficient mobile office support system is required to study since the existing mobile office support systems may face the serious problems such as an absence of interoperability, difficulties of data synchronization and device management in the near future, especially when a company has a large number of outdoor service employees. In this paper, a mobile office support system requirements for a company with a large number of outdoor service employees is proposed. And then, the methods to satisfy the requirements using a remote data synchronization and a remote device management technologies are proposed. The mobile office support system proposed in this paper synchronizes remotely a large number of various mobile devices of employees with centralized servers located in the company. In addition, it manages the mobile devices remotely for the employees. This paper proposes a mobile office support system based on OMA(Open Mobile Alliance) DS(Data Synchronization) and DM(Device Management) protocols. As OMA DS and DM protocols are de facto international standards, the interoperability between the mobile office support systems can be guaranteed.

• Spatial Information Research
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• v.17 no.1
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• pp.67-77
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• 2009

Mobile mapping systems with CCD cameras, GPS and IMU etc. can acquire massive photos and geographic informations along by roads. But it is easy to involve many errors or omissions of images and informations about roads and facilities with various files. And there were contained any conflicts or non-consistencies in massive mobile mapping data which were acquired by multiple survey teams in various survey regions. As an image tag standard, Exif helps us to encapsulate the precise GPS times and essential informations in the header of JPEG files and uses with the identification code for consistent managements of massive mobile mapping data in this paper. And Systematic management systems with data synchronization technology manage more consistently massive photos and their information.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.123-124
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• 2009

현대 사회에서의 정보의 보관과 사용은 그 위치에 상관없이 언제나 어디서든 행해져야 한다. 특히나 많은 스케줄 시간의 싸움 속에서 살아가는 현대인들에게 자신의 시간 관리는 필수적이다. 본 논문에서는 현재 사용되는 모바일 아이팟 플랫폼과 개인 스케줄을 사용할 수 있게 제공하는 여러 웹 포탈시스템을 이용하여 두 개체간 스케줄과 주소록을 손쉽게 동기화 하고 이용할 수 있는 시스템을 제안하고 있다. 이 시스템을 통하여 아이팟 내의 스케줄, 주소록 데이터를 하나의 웹 서버에 공유하지 않고 여러 사이트에 손쉽게 동기화 할 수 있도록 함으로서 자료의 손실 줄이고 보다 안정적으로 보관 할 수 있을 것이다.

• Spatial Information Research
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• v.19 no.4
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• pp.73-79
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• 2011

With the recent increase in demand for geo-registered imagery, Mobile Mapping Systems(MMS), which can quickly construct geographic information, has become important. The main part of MMS is the high-precision observation system, which collects geographic information at a certain speed. MMS has a complex data generation process and requires a standard-specific vehicle for its use, limiting its application range. In this paper, lightweight MMS is proposed to overcome its complexity by replacing the time synchronizer with a high-speed camera and by stabilizing motion with MEMS IMU/GPS. The proposed low-cost, portable method is expected to produce of geo-registered imagery efficiently.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04a
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• pp.842-844
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• 2003

멀티미디어 기능과 더불어 인터넷과 컴퓨터를 이용한 학습은 교육의 큰 영역으로 자리 잡고 있다. 하지만 기존의 PC 환경에서는 학교와 가정 등 고정된 장소에서의 이용이라는 제약이 따른다. 이러한 제한점은 모바일 기기들의 보급 확대와 모바일 기기의 성능 향상으로 극복될 수 있다. 특히 PDA(Personal Digital Assistant)는 데이터를 축적하거나 멀티미디어 교육 자료를 이용하는 등 온라인 교육용 컨텐츠를 학습자에게 전달하고 효과적으로 커뮤니케이션 하는데 적합하다고 할 수 있겠다. 하지만 기존의 PC 기반 컨텐츠들은 PDA기반으로 재구축 되어야 사용이 가능한 실정이다. 이에 PDA의 장점인 휴대성, 저장성, 멀티미디어 이용, 인터넷 이용, PC와 동기화를 통한 데이터 공유 등을 이용할 수 있는 고등학교 영어 듣기 평가를 PDA에서 학습할 수 있도록 eMbedded Visual Tools을 이용해 Windows CE 3.0 기반 PDA에서 구현하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.479-482
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• 2014

최근 모바일 컴퓨팅 환경이 발전함에 따라 모바일 디바이스 이용자들에게 다양한 서비스를 제공하기 위한 방법으로 클라우드 스토리지 서비스가 주목받고 있으며, 여러 장치의 데이터 동기화를 지원해준다. 이러한 편리성을 제공하고 있지만, 개인과 기업의 핵심 자료 유출에 따른 보안 이슈가 중요한 문제로 대두되고 있기 때문에, 클라우드 스토리지 보안 검증의 중요성도 증대되었다. 이처럼 클라우드 스토리지 서비스는 보안 검증 과정을 거친다. 본 논문에서는 기존의 클라우드 스토리지 보안 평가 가이드라인의 문제점을 분석하여 다형성, 종속성, 병렬성, 중복성 등을 고려해 효율적인 클라우드 스토리지 보안 평가를 위한 새로운 방법론을 제시 하였다. 제시한 방법론을 이용해 클라우드 스토리지 보안검증 프로세스를 설계하였다.

• IEMEK Journal of Embedded Systems and Applications
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• v.5 no.4
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• pp.217-224
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• 2010

Nowadays, people perform their tasks anywhere anytime using their mobile devices. For this reason, data synchronization (DS) between mobile devices and a central server has become one of the most essential technologies in mobile environments. Currently, several mobile DS protocols are proposed and used. However, the existing DS protocols cannot guarantee interoperability between them. To solve the problem, an embedded DS gateway has been developed in our previous study. The gateway runs on a Windows Mobile-based emulator. It converts data on a mobile device into common data specified by OMA DS standard protocol and vice versa. The embedded gateway has been built to support the OMA DS standard protocol. In order to verify that the embedded gateway conforms to the OMA DS standard protocol, two kinds of OMA conformance tests have to be conducted - interoperability test with an OMA DS-based server and conformance test with SCTS (SyncML Conformance Test Suit). In this paper, some parts of the gateway previously built are modified and the modified gateway is installed on a Windows Mobile-based smart phone. And the interoperability test and the conformance test with the SCTS are conducted. The results of the tests show that the embedded DS gateway operates properly on the Windows Mobile-based smart phone and that the gateway passes the tests, verifying its conformity to the OMA DS standard protocol. In addition, DS performance tests show that DS delay times between a real smart phone and a DS server increase gently as the number of DS data increases. In other words, the embedded DS gateway built in this paper can be used for a real smart phone at a reasonable performance cost.