• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.37
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• pp.251-261
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• 1996

Databases are critical to business information systems and RDBMS is most widely used for the database system. Normalization was designed to control various anomalies(insert, update, and delete anomalies). However normalized database design does not account for the tradeoffs necessary for the performance reason. In this research, we model a database design problem without storage constraint. Given a normalized database design, in this model, we do the denormalization of duplicating columns in order in reduce frequent join processes. In this paper, we consider insert, update, delete, and storage cost, and the anomalies are treated by additional disk I/O cost necessary for each insert, update transaction. We propose a branch and bound method, and show considerable cost reduction.

• The Journal of Information Technology and Database
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• v.3 no.1
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• pp.3-24
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• 1996

Databases are critical to business information systems, and RDBMS is most widely used for the database system. Normalization has been designed to control various anomalies(insert, update, and delete anomalies). However, normalized database design does not account for the tradeoffs necessary for the performance. In this research, we develop a model for database design by denormalization of duplicating attributes in order to reduce frequent join processes. In this mood, we consider insert, update, delete, and query costs. The anomaly and data inconsistency are removed by additional disk I/O which is necessary for each update and insert transaction. We propose a branch and bound method for this model, and show considerable cost reduction.

• 한국컴퓨터산업교육학회:학술대회논문집
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• 2003.11a
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• pp.33-38
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• 2003

Reports have a significant meaning in time-constrained large transaction environments, such as airplane control systems or wargame simulations. This is due to the necessity of generating reports within a limited scope of time without restraining the operation performance of large transaction environments. In order to generate reports in large transaction environments while satisfying time - constrained requirements, this paper propose a model which combines the incremental operation mechanism and materialized view mechanism using triggers and stored procedures. Further, the implementation and evaluation of the preposed model provides analysis for model characteristics.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12A
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• pp.1891-1898
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• 1999

Traditional syntax-oriented serializability notions are considered to be not enough to handle in particular various types of transaction in terms of duration of execution. To deal with this situation, altruistic locking has attempted to reduce delay effect associated with lock release moment by use of the idea of donation. An improved form of altruism has also been deployed in extended altruistic locking in a way that scope of data to be early released is enlarged to include even data initially not intended to be donated. In this paper, we first of all investigated limitations inherent in both altruistic schemes from the perspective of alleviating starvation occasions for transactions in particular of short-lived nature. The idea of two-way donation locking(2DL) has then been experimented to see the effect of more than single donation in distributed database systems. Simulation experiments shows that 2DL outperforms the conventional two-phase locking in terms of the degree of oncurrency and average transaction waiting time.

• Journal of the Korea Society of Computer and Information
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• v.8 no.3
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• pp.26-33
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• 2003

The edge-chasing deadlock detection algorithm of Choudhary fails to remove the existing deadlocks after committing the transaction whose priority is lowest on the transaction wait-for path. We proposed a modified algorithm that solves this problem. In this thesis, the performance of the modified algorithm is compared with that of the Tsai's deadlock detection algorithm that uses transaction-resource graph(TR graph) using simulation approach.

• The KIPS Transactions:PartD
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• v.18D no.3
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• pp.169-178
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• 2011

Recently, data sharing between enterprises or organizations is required matter for task cooperation. In this process, when the enterprise opens its database to the affiliates, it can be occurred to problem leaked sensitive information. To resolve this problem it is needed to hide sensitive information from the database. Previous research hiding sensitive information applied different heuristic algorithms to maintain quality of the database. But there have been few studies analyzing the effects on the items modified during the hiding process and trying to minimize the hided items. This paper suggests eFP-Tree(Extended Frequent Pattern Tree) based FP-Tree(Frequent Pattern Tree) to hide sensitive frequent itemsets. Node formation of eFP-Tree uses border to minimize impacts of non sensitive frequent itemsets in hiding process, by organizing all transaction, sensitive and border information differently to before. As a result to apply eFP-Tree to the example transaction database, the lost items were less than 10%, proving it is more effective than the existing algorithm and maintain the quality of database to the optimal.

• Journal of KIISE:Databases
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• v.30 no.6
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• pp.629-640
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• 2003

A shared disk (SD) cluster couples multiple nodes for high performance transaction processing, and all the coupled nodes share a common database at the disk level. In the SD cluster, a transaction routing corresponds to select a node for an incoming transaction to be executed. An affinity-based routing can increase local buffer hit ratio of each node by clustering transactions referencing similar data to be executed on the same node. However, the affinity-based routing is very much non-adaptive to the changes in the system load, and thus a specific node will be overloaded if transactions in some class are congested. In this paper, we propose a dynamic transaction routing scheme that can achieve an optimal balance between affinity-based routing and dynamic load balancing of all the nodes in the SD cluster. The proposed scheme is novel in the sense that it can improve the system performance by increasing the local buffer hit ratio and reducing the buffer invalidation overhead.

• Journal of KIISE:Databases
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• v.31 no.3
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• pp.297-306
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• 2004

Push-based broadcasting in wireless information services is a very effective technique to disseminate information to a massive number of clients when the number of data items is small. When the database is large, however, it nay be beneficial to integrate a pull-based (client-to-server) backchannel with the push-based broadcast approach, resulting in a hybrid data delivery. In this paper, we analyze the performance behavior of a predeclaration-based transaction processing, which was originally devised for a push-based data broadcast, in the hybrid data delivery through an extensive simulation. Our results show that the use of predeclaration-based transaction processing can provide significant performance improvement not only in a pure push data delivery, but also in a hybrid data delivery.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4B
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• pp.285-290
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• 2006

Various aspects should be taken into account while developing a distributed architecture based on a multi-tier model or an enterprise architecture. Among those, the separation of role between page designer and page developer, defining entity which is used for database connection and transaction processing are very much important. In this paper, we presented DONSL(Data Server of Non SQL query) architecture to solve these problems applying web tier object modelling. This architecture solves the above problems by simplifying tiers coupling and removing DAO(Data Access Object) and entity from programming logic. We concentrate upon these three parts. One is about how to develop the DAO not concerning the entity modification, another is automatic transaction processing technique including SQL generation and the other is how to use the AET/MET(Automated/Manual Execute d Transaction) effectively.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.433-437
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• 2005

Most research organizations, universities and enterprises manage the transaction informations (customer informations, account informations, transaction results and so on), which is a fundamental item in the part of buying and research capital expenditure for the execution of R&D project or relative works. But because they don't only manage transaction information systematically but also don't put to practical use as sharing knowledge, many researchers duplicate their operations and it is shown a drop in efficiency. Also there are many problems because useful informations are unapproachable in the side of research management. In this paper, we propose the database design, application plan and service method for joint utilize of transaction information. And we prove the proposed method by service which is operated within intranet system. The transaction information shared by the proposed method will be useful knowledge and a major factor of efficiency improvement in research management field.