• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.7
• /
• pp.2719-2735
• /
• 2015

In the cloud environment, users pay more attentions to their data security since all of them are stored in the cloud server. Researchers have proposed many mutual authentication schemes for the access control of the cloud server by using the smart card to protect the sensitive data. However, few of them can resist from the smart card lost problem and provide both of the forward security and the backward security. In this paper, we propose a novel authentication scheme for cloud computing which can address these problems and also provide the anonymity for the user. The trick we use is using the password, the smart card and the public key technique to protect the processes of the user's authentication and key exchange. Under the Elliptic Curve Diffie-Hellman (ECDH) assumption, it is provably secure in the random oracle model. Compared with the existing smart card based authentication schemes in the cloud computing, the proposed scheme can provide better security degree.

• Proceedings of the Korean Information Science Society Conference
• /
• 2011.06a
• /
• pp.89-92
• /
• 2011

국제 표준 ISO/IEC 11179는 메타데이터를 등록하고 관리하기 위한 메타데이터 레지스트리 표준으로서 메타데이터의 공유 및 재사용으로 인하여 시스템 간 상호운용성을 보장한다. 이러한 특성 때문에 현재 많은 나라에서 메타데이터 레지스트리들이 구축되어 있다. 그러나 이러한 메타데이터 레지스트리들은 국제 표준을 기반하고 있음에도 불구하고 메타데이터 레지스트리에 접근하기 위한 표준 인터페이스의 부재로 인해 사용자가 상이한 메타데이터 레지스트리에 접근할 때 각각 다른 접근 방법을 사용해야 한다는 불편함이 야기된다. 이러한 문제의 해결을 위하여 국제 표준 ISO/IEC 13249-8 MRA(Metadata Registry Access)가 제안되었다. 이 논문에서는 국제 표준으로 제정중인 MRA에 기반하여 메타데이터 레지스트리에 접근하기 위한 인터페이스를 개발한다. SQL 표준에 있는 사용자 정의 타입을 오라클 환경에서 사용하여 메타데이터 레지스트리를 물리적으로 구축하고 메타데이터 레지스트리에 접근하는 멤버함수를 정의한다. 마지막으로, 메타데이터 레지스트리에 접근하기 위한 MRA 인터페이스를 검증하고 평가한다. 사용자는 이러한 인터페이스를 사용하여 서로 상이한 메타데이터 레지스트리들에 효과적으로 접근할 수 있다.

• Journal of information and communication convergence engineering
• /
• v.9 no.2
• /
• pp.244-250
• /
• 2011

Gossip is a well-known protocol which was proposed to implement broadcast service with a high reliability in an arbitrarily connected network of sensor nodes. The probabilistic techniques employed in gossip have been used to address many challenges which are caused by flooding in wireless sensor networks (WSNs). However, very little work has yet been done on real-time wireless sensor networks which require not only highly reliable packets reception but also strict time constraint of each packet. Moreover, the unique energy constraining feature of sensor makes existing solutions unsuitable. Combined with unreliable links, redundant messages overhead in real-time wireless sensor networks is a new challenging issue. In this paper, we introduce a Reliable Gossip Zone, a novel fine-tailored mechanism for real-time wireless sensor networks with unreliable wireless links and low packet redundancy. The key idea is the proposed forwarding probability algorithm, which makes forwarding decisions after the realtime flooding zone is set. Evaluation shows that as an oracle broadcast service design, our mechanism achieves significantly less message overhead than traditional flooding and gossip protocols.

• The KIPS Transactions:PartD
• /
• v.12D no.2 s.98
• /
• pp.189-198
• /
• 2005

XML is rapidly becoming the standard for data representation and exchange, and XML documents are being adopted in various applications. Since the late 1990s, some native XML database management systems(DBMSs) have been developed. More recently, commercial relational DBMS vendors try to incorporate full functionalities of XML into their products, such as Oracle, MS SQL and IBM DB2. In this paper, we implement a well-known RDBMS-based XML data storage and indexing technique, called XPath Accelerator, and tune it in an industry-leading RDBMS. Our contributions are two-folds: 1) an in-depth implementation of the XPath Accelerator technique and 2) its tuning to exploit the advanced query processing techniques of an RDBMS.

• Journal of Digital Convergence
• /
• v.11 no.4
• /
• pp.209-213
• /
• 2013

This paper aims to design and realize mobile webapp ticket reservation system based smartphone with N-tier mobile webapp framework. In mobile framework, presentation-tier utilizes HTML5/CSS3 and Sencha Touch, middle-tier consists of spring framework and MyBatis, database-tier using oracle possible to apply enterprise services mobile webbapp offices. In this study, mobile framework deploy and configuration management without the support of the app in N-tier that does not need to be considered in the smartphone-based mobile webapp ticket reservation system analysis and design, and then implementation.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.3
• /
• pp.1742-1760
• /
• 2017

Recent evolution in the open access internet technology demands that the identifying information of a user must be protected. Authentication is a prerequisite to ensure the protection of user identification. To improve Qu et al.'s scheme for remote user authentication, a recent proposal has been published by Huang et al., which presents a key agreement protocol in combination with ECC. It has been claimed that Huang et al. proposal is more robust and provides improved security. However, in the light of our experiment, it has been observed that Huang et al.'s proposal is breakable in case of user impersonation. Moreover, this paper presents an improved scheme to overcome the limitations of Huang et al.'s scheme. Security of the proposed scheme is evaluated using the well-known random oracle model. In comparison with Huang et al.'s protocol, the proposed scheme is lightweight with improved security.

• Proceedings of the Korea Association of Information Systems Conference
• /
• 2001.12a
• /
• pp.181-193
• /
• 2001

최근 대학도서관들은 정보화 환경에 대한 능동적 대처를 위하여 많은 노력을 기울이고 있다. 교수나 학생의 연구, 교육, 학습에 필요한 각종 전자 정보원을 한 장소에서 검색, 열람이 가능하고 대학의 구성원들에게 새로운 정보기술과 정보의 활용 능력을 교육시키기 위한 다양한 기능을 가진 하나의 복합 공간으로서 전자 정보실 또는 멀티미디어실(이하 멀 티미디어실) 등을 설치, 운영하고 있다 그러나 아직도 대학도서관 내의 멀티미디어실의 역할과 개념이 모호하다는 지적이 나오고 있다. 이러한 가운데 운영면에서도 표준 솔루션의 부재로 관리 전산화가 이루어져 있는 곳이 부족하여 인력 및 시간의 낭비가 초래되고 이용자 관리에 있어서 어려움을 겪고 있는 실정이다. 체계적인 운영이 이루어지지 않고서는 양질의 서비스 제공은 기대하기 어려울 것이다. 따라서 전국 대학 도서관에 적용할 수 있는 표준적인 멀티미디어실 관리 시스템의 개발이 필요하다. 본 연구에서는 UML(Unified Modeling Language) 기반의 정보시스템 구축 방법론을 제시하고, 제시된 방법론의 유효성(effectiveness)을 검증하기 위하여, 본 방법론에 입각하여 동국대학교 경주캠퍼스의 멀티미디어실 업무 프로세스를 분석 설계하였다. 시스템 구현을 위해서, 데이터 베이스로는 Oracle RDBMS를, 개발도구로는 Visual Basic 6.0을 사용하였다 본 논문에서 구현된 시스템을 통하여 멀티미디어실의 효과적인 운영관리에 대한 기반정립에 기여하고, 향후 장기적인 발전계획 수립에 하나의 도구로서 사용될 수 있다고 판단된다.

• The Journal of Information Technology and Database
• /
• v.8 no.1
• /
• pp.105-116
• /
• 2001

XML is a standard markup language for exchange and storage of formed or well-formed information in World Wide Web. Because the source data of XML message for exchange of information in World Wide Web is stored in legacy database, it is necessary for the easy connection between XML application and database system. In Oracle8i, 9i, Informix and SQL2000, DBMS vendors make upgrade to DBMS for using XML. This method of upgrade between XML application and database system is Platform-dependent and DBMS-dependent. Also It is necessary for the method of the platform- and DBMS-independent connection between XML application and database system. The methods for the connection between XML DTD and RDB schema are studied for the easy connection between XML application and database system. But the study for the easy connection between XML DTD and ORDB schema is a little. For multimedia application, we use the extended DBMS from RDBMS. It is necessary for the study to the transformation from XML DTD to ORDB schema. In this paper, for easier connection between XML application and database system, we propose the method of the transformation from XML DTD to ORDB schema using Object Model.

• Asia pacific journal of information systems
• /
• v.12 no.2
• /
• pp.137-162
• /
• 2002

As the ERP system become recognized as a strategic weapon of a firm, the way how to implement the system successfully has been an important issue for both practitioners and the academic community. The objective of this research is to identify the critical success factors influencing the implementation of the ERP system and to suggest the tasks to be considered first for the effective implementation of the system. The results from the analysis of data collected from the 169 firms among those which have implemented either the Oracle package or the SAP package in Korea are as follows. The important factors for the successful implementation of the ERP system include the strength of rivalry among competing firms; the degree to which information systems are matured; the information systems strategy of a firm; the support and concern from the top; and the technical openness between the ERP system and the legacy system such as network, hardware, and software. The tasks to be considered first for the effective implementation of the ERP system cover the same degree of feeling between labor and management on the threat to survive; the formulation of information systems strategy at the strategic level; CEO's strong will and resolution; the process automation and informatization of a firm; and the infrastructure including intranet and databases.

• International Journal of Ocean System Engineering
• /
• v.1 no.4
• /
• pp.205-210
• /
• 2011

High data-rate underwater communications is demanded. This demand imposes stringent requirements on underwater communication equipment of phase-locked-loop (PLL). Phase noise in PLL is unwanted and unavoidable. In this paper, we investigate the PLL phase noise effect on high order QAM for underwater communication systems. The phase noise model using power spectral density is adopted for performance evaluation. The phase noise components considered in PLL are reference oscillator, voltage controlled oscillator (VCO), filter and divider. The filters in PLL noise are assumed to be second order active and passive low pass filters. Through simulation, we analyze the phase noise characteristics of the four components and then investigate the performance improvement factor of each component. Consequently, we derive specifications of VCO, phase detector, divider to meet performance requirement of high data-rate communication using QAM under phase noise influence.