• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.4B
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• pp.323-338
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• 2003

The main memory database systems (MMDBMS) efficiently supports various database applications that require high performance since it employs main memory rather than disk as a primary storage. Recently, it has been increased needs that have the fast data processing as well as the efficient modeling of application requiring for a complicated structure, and conformity to applications that need the strict dta consistency. In MMDBMS, because all the data is located in the main memory, it can support the usable expression methods of data satisfying their needs without performance overhead. The method has the operation to manipulate the data and the constraint such as referential integrity in more detail. The data model consists of this methods is an essential component to decide the expression power of DBMS. In this paper, we discuss about various requests to provide the communication services and propose the data model that support it. The mainly discussed issues are 1) definition of the relationship between tables using the pointer, 2) navigation of the data using the relationship, 3) support of the referential integrity for pointer, 4) support of the uniform processing time for the join, 5) support of the object-oriented concepts, and 6) sharing of an index on multi-tables. We discuss the pointer-based data model that designed to include these issues to efficiently support complication environments.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.71-76
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• 2005

XML is rapidly becoming one of the most widely adopted technologies for information exchange and representation on the World Wide Web. However, the large part of data is still stored in a relational database. Hence, we need to convert relational data into XML documents. The most important point of the conversion is to reflect referential integrities In relational schema model to XML schema model exactly. Until now, FT, NeT and CoT are suggested as existing approaches for conversion from the relational schema model to the XML schema model but these approaches only reflect referential integrities which are defined explicitly for conversion. In this paper, we suggest an algorithm for automatic extraction of implicit referential integrities such as foreign key constraints which is not defined explicitly in the initial relational schema model. We present translated XML documents by existing algorithms and suggested algorithms as comparison evaluation. We also compare suggested algorithm and conventional algorithms by simluation in accuracy part.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.6
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• pp.589-601
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• 2003

XLink is XML Linking Language that defines links between XML documents or XML elements. It uses XML syntax to create structures that can describe links similar to the simple unidirectional hyperlinks of HTML, as well as more sophisticated links. There exist several relationships between resources that linked by XLink. Without supports from XML Repository for these relationship management, there is a huge overhead related to the management of relationships during both application development and maintenance, since the relationships need to be hard-coded directly into the application program itself. In this paper, we propose an XLink supporting system in object repository. We describe the design and implementation of this system on top of XDOM(persistent DOMlink XML repository). To support XLink, our system offers referential relationship semantics, extended link and the expansion of DOM tree for XLink.

• Journal of Internet Computing and Services
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• v.10 no.2
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• pp.99-116
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• 2009

For the mapping of two dimensional table structures of relational databases to the hierarchical XML documents, we apply the foreign key relationships of relational databases. In other words, the primary key of another table referenced by a foreign key of one tuple is mapped to the parent of the foreign key. Then XML hierarchies with order are expressed. In addition, the XML view file generated by the foreign key mappings shows side effects in the case of the relational database update for the satisfaction of referential integrity constraint in the foreign key. Thus, by inferring the foreign key roles at the generation of XML hierarchies, we can anticipate where the side effects occur in the hierarchies. We keep the XML view files up-to-date by reflecting the side effects to the XML files at the update of the underlying relational databases.

• Journal of Internet Computing and Services
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• v.9 no.2
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• pp.107-118
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• 2008

The XP, the representative methodology of Agile software development, maximizes the effectiveness of the development by focusing on development itself and using primitive and basic process definition that can be easily implemented in the fields. However, the most of XP's practices came from those of engineering and the manogement practices of work product tend to be overlooked. The research on the implementation of those manogement practices has not been performed enough. Because of deficiency of processes that guide the change control over major baselines of work product and that describe proper continuous integration and refactoring in XP, the integrity of those work products is difficult to be guaranteed. To fulfill this work product integrity, CM(configuration manogement) should be hired and CMMI(Capability Maturity Model Integration) is considered to be the best references for that purpose, CMMI defines the required practices of CM and leave implementation details to the organization so that it could customize those practices based on the characteristics of its development methods. The CM process implementation guidelines based on CMMI could provides work product integrity with a way of keeping XP's agility that includes continuous integration, refactoring and small release. In this research, we selected CM process factors applicable to XP among CMMI's CM practices and based on them we developed the CM implementation guidelines.

• The Korean Journal of Archival Studies
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• no.14
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• pp.191-240
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• 2006

For long-term preservation of electronic records, the information on the whole processes of management from the time of creation of the electronic information should be captured and managed together. Such information is supported by preservation metadata thus the implementation of preservation metadata is important for preservation of electronic records maintaining the record-ness. Preservation metadata is the information that supports the process of digital preservation and functions th maintain long-term viability, renderability, understandability, authenticity and identity of digital resources. Preservation metadata should be developed applying the international standard Reference Model for an Open Archival Information System(OAIS) to have international interoperability for exchange and reuse. Initial international preservation metadata schemas were developed standardizing the OAIS Reference Model. But the preservation metadata schema of Victorian Electronic Records Strategy(VERS) and recently published Data Dictionary of PREMIS Working Group were developed in advanced types that are different from the existing framework. Those were advanced th practical ones from conceptual one. Comparing these two cases, proposed the elements of integral preservation metadata for long-term preservation of electronic records. This thesis has the significance that it has suggested the direction for future development of the elements of preservation metadata by setting the past discussions related to preservation metadata in order and proposing integral preservation metadata elements for long-term preservation of electronic records.

• Journal of Korean Society of Archives and Records Management
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• v.18 no.4
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• pp.125-148
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• 2018

This study was intended to investigate the long-term preservation policy of electronic records published abroad to derive and compare the policy elements necessary for policy establishment. The U.S., Canada, United Kingdom, Australia, and Switzerland archives were selected, which officially announced the e-Record Preservation Policy. Research and analysis of the long-term preservation policies of the five selected countries resulted in six main policy elements. These six policy elements are preservation scope, long-term preservation strategy, risk management, integrity assurance methods, preservation infrastructure, and reference models. We compared and analyzed five long-term preservation policies through policy elements and found six implications as a result. The implications were focused on establishing a long-term preservation strategy in line with the actual state of the institution and using long-term preservation policies outside of the country as advanced cases for various types of electronic records.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.4
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• pp.779-787
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• 2018

As security problems of the paper ballot have been emerged on and on, electronic voting with enhanced security and convenience has been introduced in several countries. However, it has not been adopted most of countries because of the problems that come from interdependence and security flaws. Meanwhile, the blockchain technology has high reliability due to the mechanism of mining that miners verify and preserve blocks independently by using P2P formation which does not have a central authority. Furthermore, because each block refers to the hash of the previous block. if any one block is changed, it is very difficult to forge and modify the blockchain because all blocks must be changed. If this technology is applied to the E-voting, integrity, and transparency about the result of the ballot is guaranteed. In this paper, we propose and implement an electronic voting system based on blockchain that improves interdependence, the reliability of excessive TTP and single point of failure come from original electronic voting. Also, we analyze the security and advantage of the proposal system compared with the existing bitcoin-based electronic voting system.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.3
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• pp.161-172
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• 2013

Metadata registry (MDR) is the international standard, developed by ISO/IEC for exchange and sharing data between databases. Many MDR systems are used in diverse domains such as medical service, bibliography, environment for sharing and integrating data. However, those systems have different physical structures individually because the MDR standard defines only the metamodel for registering and storing metadata. It causes heterogeneity between the system structures and requires additional cost to maintain interoperability. ISO/IEC 13249-8 Metadata Registry Access (MRA) is developing as an international standard to provide a consistent access facility to data stored in different metadata registries. However, MRA does not consider the relationships between the concepts (classes) defined in the MDR specification. It causes that incorrect query results returned from MDR systems. It also requires additional cost of modeling and rewriting queries to reflect each physical model. Therefore, this paper suggests eMRA which considers the relationships between the concepts in MDR. The comparative evaluations are described to show the advantages of eMRA. eMRA has superior performance in query modeling and referential integrity than MRA defined by the relationship between the concept of MDR.