• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4786-4793
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• 2012

In a recent mobile computing environment, the research for a transaction model have been actively carried out to deal with real-time transaction. However, the research for recovery model is relatively insufficient. Therefore, it would be very important for mobile recovery methods for database stability, just in case of data loss due to hand-off in mobile computing system. So, further efficient research should be keenly done to reduce I/O hand-off in mobile computing systems. SLL method increases I/O time due to sequential file. This paper have been suggested to efficient mobile recovery method in mobile computing system. Finally, it has been clearly demonstrated for system efficiency, conducting the performance assessment that currently proposed recovery system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.4
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• pp.805-811
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• 2003

System test is an important factor in the development process of good quality complex software in time, ensuring user requirements. Transaction processing module of database management systems schedules multiple transactions effectively and ensures that each transaction preserves data consistency. In this paper, we propose automatic functional testing techniques which ensure systematically that the implemented concurrency control function confirms to its requirements. The proposed testing technique tests functions of concurrency control module based on scenario without user intervention, and displays the result of functional testing. Finally, we utilize the proposed functional testing technique in the testing process of a database management system.

• The KIPS Transactions:PartA
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• v.10A no.4
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• pp.313-320
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• 2003

This paper design and implements a synchronized agent mechanism that be able to synchronize SFT (Slow Frequency Transaction) data among e-business processes in distributed environment. This synchronized agent system is adopted to use mobile agent to guarantee the interoperability of the distributed processes and to solve some problems at the client/server architecture and proposes a policy to synchronize data of e-business processes on the any platforms of distributed heterogeneous systems. The proposed synchronization policy is based on the time-stamp transaction with the system priority on the unicasting transportation.

• The KIPS Transactions:PartD
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• v.9D no.1
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• pp.11-20
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• 2002

We propose a new concurrency control algorithm for enhancing the degree of parallelism of the transactions in fully replicated databases designed to improve the availability and the reliability. The update transactions can be logically decomposed of a read-only transaction and a write-only transaction. In our algorithm, a set of read operations of an update transaction is treated as a read-only transaction and the read-only transaction reads data items in the site to which it is submitted. And a set of write operations of the update transaction is treated as a write-only transaction and it is submitted to all corresponding sites after the update transaction has been completed. By using the proposed update protocol, all write-only transactions can execute at all sites atomically. The proposed algorithm can have transactions execute concurrently at the site to which they are submitted and, after the completion of each transaction, the update protocol is performed for updating their data items and checking their serializability. Therefore, the degree of parallelism of the transactions can be improved. Especially, if the probability of conflict among transactions is low, we can expect the higher degree of their parallelism.

• The Journal of Information Technology
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• v.3 no.3
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• pp.117-134
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• 2000

Client-server DBMS based on a data-skipping model can exploit client resources effectively by allowing inter-transaction caching. However, inter-transaction caching raises the need of transactional cache consistency maintenance(TCCM) protocol, since each client is able to cache a portion of the database dynamically. Detection-based TCCM schemes can reduce the message overhead required for cache consistency if they validate clients replica asynchronously, and thus they cm show high throughput rates. However, they tend to show high ratios of transaction abort since transactions can access invalid replica. For coping with this drawback, this paper develops a new notion of shadow transaction, which is a backup-purpose one that is kept ready to replace an aborted transaction. This paper proposes a new detection-based TCCM scheme named DL-ST on the basis of the notion of shadow transaction. Using a simulation model, this paper evaluates the effect of shadow transaction in terms of transaction through rate and abort ratio.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.10 no.1
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• pp.107-119
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• 2006

Recently with developments of an internet and web techniques, the amount of data that are stored in database is increasing rapidly. So the range of adaption in database has been expanded and a research of Data Mining techniques finding useful skills from the huge database has been progressed. Many original algorithms have been developed by cutting down the item set and the size of database isn't required in the entire course of creating frequent item sets. Although those skills could save time in some course, it requires too much time for adapting those techniques in other courses. In this paper, an algorithm is proposed. In an Transaction Database that the length of it's transactions are short or the number of items are relatively small, this algorithm scans a database once by using a Hashing Technique and at the same time, stores all parts of the set, can be appeared at each transaction, in an Hash-table. So without an influence of n minimum percentage of support, it can discover a set of frequent items in more shorter time than the time what is used by an original algorithm.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.144-149
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• 2020

A database called Home Location Register(HLR) plays a major role in location management in mobile cellular networks. The objectives of this paper are to identify the problems of the current HLR system through rigorous analysis, to suggest solutions to them. The current HLR backup method is a process of simply writing the changed memory SLD block to disk, which has a problem in maintaining database consistency. Since information change and backup are performed separately by separate processes, there is a risk of information inconsistency when an error restart occurs. To solve this problem, a transaction concept was introduced for subscriber-related operation functions and a recovery method through logging and checkpointing was introduced. The subscriber related functions of tasks terminated normally by the suggested process are recovered with consistency even after system restarts. Performance is also not affected seriously because disk tasks for log occur with only subscriber related functions.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.265-276
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• 1997

There have been many studies on efficient discovery of association rules in large databases. However, it is nontrivial to maintain such discovered rules in large databases because a database may allow frequent or occasional updates and such updates may not only invalidate some existing strong association rules but also turn some weak rules into strong ones. The major idea of updating algorithm is to resuse the information of the old large itemsets and to integrate the support information of the new large itemsets in order to substantially reduce the pool of candidate sets to be re-exmained. In this paper, an updating algorithm is proposed for efficient maintenance of discovered assocation rules when new transaction data are added to a transaction database. And superiority of the proposed updating algorithm will be shown by comparing with FUP algorithm that was already proposed.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.406-408
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• 2004

To develop enterprise architecture based distributed application needs consideration of various factors such as division of role between web-designer and software developer, defining entity and its usage, database connection and transaction processing. This paper presents DONSL(Data Server of Non SQL-Query) architecture that provides solution to above aspects through web-tier object modeling guaranteeing efficient transaction processing and performance between web-tier and 08MS through simplified usage of query logic property.

• Journal of the Korea Society of Computer and Information
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• v.6 no.2
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• pp.34-40
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• 2001

This thesis shows that 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-fer path. A modified algorithm that solves this problem is proposed.