• The Transactions of the Korea Information Processing Society
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• v.5 no.1
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• pp.24-32
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• 1998

The bus contention among bus-based shared-memory multiprocessors limits their performance. In addition, under split bus transaction environment, multiprocessors may make some memory requests unnecessary stand by in the memory access buffer, which makes system performance worse. This unnecessary stand-by can be eliminated by maintaining the bitmap table which contains the status bit for each memory block. However, this mechanism requires a great size of SRAM for the status information, which is fully mapped from the whole memory blocks. To solve this problem, we propose a bitmap cache which exploits partial mapping and locality of references. The simulation results show that the proposed system can greatly reduce the capacity of SRAM for the status information with little deteriorating its performance.

• The Transactions of the Korea Information Processing Society
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• v.4 no.2
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• pp.325-337
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• 1997

This paper introduces the basic concepts and requirements of database system based on the object-oriented paradigm,and presents the overview of the design of an object-oriented data base system which refects those conceprs and requirements . The system imolemented on C++,consists of three structure layers.The inner layer, which is in fact a storage system,performs file I/O,while the inermediate layer is responisible for most of the functions except the ones rerated to the user interface, such as the transaction management,the schema manage-ment,and the management of buffers in main memory etc.The outer layer,designed mainly for the uwerunteface,mot only privides the functions for graphical user interface,preprocessor,and interpreter etc,but also supports extended SQL for object-oriented features.

• The Transactions of the Korea Information Processing Society
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• v.6 no.5
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• pp.1143-1152
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• 1999

A Mobile computing environment is a new paradigm which provides users with the access to information irrespective of users' location. A transaction scheduling method for the mobile computing environment must be designed so that database consistency is maintained with considering the limited performance of mobile hosts and the narrow bandwidth of a wireless network. The scheduling method using a lock has some problems: the high message overhead between a server and a mobile host for maintaining a lock and the high abort ratio of the mobile transactions owing to violating the serializability when a mobile host uses a cache. So, in this paper, we propose an efficient transaction management method using timestamp to resolve these problems. The proposed method is used in the environment under which a mobile host uses a cache having two versions for each cached data item and a server maintains several versions for each data item. So, even though a mobile transaction is executed during several broadcasting interval, can be committed. As a result, the proposed method can improve the commit ratio of the mobile transactions by maintaining multiversion for each data item and does not require the additional message exchange to schedule transactions by using timestamp.

• Journal of KIISE:Databases
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• v.34 no.3
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• pp.261-269
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• 2007

As a basic research to integrate and to retrieve XML documents efficiently, this paper proposes a clustering method by structures of XML documents. We apply an algorithm processing the many transaction data to the clustering of XML documents, which is a quite different method from the previous algorithms measuring structure similarity. Our method performs the clustering of XML documents not only using the cluster histograms that represent the distribution of items in clusters but also considering the global cluster cohesion. We compare the proposed method with the existing techniques by performing experiments. Experiments show that our method not only creates good quality clusters but also improves the processing time.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.275-278
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• 2008

Recently, there are many research of datamining. On the transaction dataset, association rules is made by finding of interesting patterns. A part of mining, sub-structure mining is increased in interest of and applied to many high technology. But graph mining has more computing time then itemset mining. Therefore, that need efficient way for avoid duplication. GASTON is best algorithm of duplication free. This paper analyze GASTON and expect the future work.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.252-256
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• 2023

쇼어 알고리즘을 실행할 수 있는 양자 컴퓨터의 발전으로 인해 기존 ECC(Elliptic Curve Cryptography)를 사용하던 블록체인이 PQC(Post Quantum Cryptography)로의 전환을 고려하고 있다. 하지만 PQC 는 기존 암호에 비해 큰 사이즈, 느린 서명/검증 속도 등과 같은 문제점이 존재한다. 본 논문에서는 우리가 WISA'23 에서 새롭게 제안한 PQ-DPoL 합의 알고리즘에 NIST(National Institute of Standards and Technology)가 선정한 Crystal-Dilithium, Falcon 그리고 Sphincs+를 적용하여 비교 분석하였다. 실험 결과에 따르면, 매우 큰 서명 크기를 가지고 있기 때문에 블록에 담기는 트랜잭션의 수가 감소하므로 Sphincs+의 성능이 가장 떨어짐을 확인하였다. 또한 Dilithium 은 Falcon 과 비슷한 성능을 보여주었다. 그 중에서도 Falcon 이 가장 우수한 성능을 보여주었다. 이는 Falcon 의 공개키와 서명의 크기가 다른 알고리즘에 비해 작기 때문이다. 따라서 양자내성을 갖는 블록체인에는 Falcon 512 알고리즘이 가장 적합할 것으로 생각된다. 그러나 블록체인의 속도와 보안 강도는 Trade-off 관계이므로 보안성을 중요시하는 블록체인 네트워크에서는 Sphincs+가 적합할 수 있을 것으로 보인다. 따라서 블록체인 네트워크의 상황과 목적에 따라 적절한 알고리즘을 사용해야 될 것으로 생각된다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.5
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• pp.125-133
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• 2016

Data processing capacity and speed are rapidly increasing due to the development of hardware and software in recent time. As a result, data usage is geometrically increasing and the amount of data which computers have to process has already exceeded five-thousand transaction per second. That is, the importance of Big Data is due to its 'real-time' and this makes it possible to analyze all the data in order to obtain accurate data at right time under any circumstances. Moreover, there are many researches about this as construction of smart factory with the application of Big Data is expected to have reduction in development, production, and quality management cost. In this paper, system using In-Memory Data Grid for high speed processing is implemented in semiconductor process which numerous data occur and improved performance is proven with experiments. Implemented system is expected to be possible to apply on not only the semiconductor but also any fields using Big Data and further researches will be made for possible application on other fields.

• The KIPS Transactions:PartD
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• v.13D no.7 s.110
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• pp.947-958
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• 2006

In order to increase extensibility and reusability of business components, the variable things need to be analyzed from the analysis phase and identified as components. In this paper, we propose a rule-based analysis pattern, which can effectively extract object-based main concepts from a variable business process in the analysis phase and identify a variable business component by applying the pattern to the UML Components development process. It can make analysis artifacts consistent and readable for analysts with different level of knowledge and experience to apply the pattern to analysis of rule-based variable business processes. And also, variable business components can be easily identified by applying the pattern to the UML Components development process. In order to prove the feasibility of the pattern, we have applied the pattern the deposit and import/export subsystem of the banking domain. According to our experience, we can make the same business conceptual models between the deposit and import/export subsystem due to the main concepts suggested by the pattern and effectively identify a variable business components in the UML Components development process.

• Journal of KIISE:Databases
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• v.36 no.3
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• pp.226-234
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• 2009

A data stream is a massive unbounded sequence of data elements continuously generated at a rapid rate. Due to the characteristics of a data stream, it is impossible to save all the data elements of a data stream. Therefore it is necessary to define a new synopsis structure to store the summary information of a data stream. For this purpose, this paper proposes a cuboid prefix tree that can be effectively employed in evaluating an iceberg query over data streams. A cuboid prefix tree only stores those itemsets that consist of grouping attributes used in GROUP BY query. In addition, a cuboid prefix tree can compute multiple iceberg queries simultaneously by sharing their common sub-expressions. A cuboid prefix tree evaluates an iceberg query over an infinitely generated data stream while efficiently reducing memory usage and processing time, which is verified by a series of experiments.

• The KIPS Transactions:PartD
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• v.13D no.5 s.108
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• pp.661-670
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• 2006

With the development of e-Commerce and the proliferation of easily accessible information, information filtering systems such as recommender and SDI systems have become popular to prune large information spaces so that users are directed toward those items that best meet their needs and preferences. Until now, many information filtering methods have been proposed to support filtering systems. XML is emerging as a new standard for information. Recently, filtering systems need new approaches in dealing with XML documents. So, in this paper our system suggests a method to create multiform user profiles with XML's ability to represent structure. This system consists of two parts; one is an administrator profile definition part that an administrator defines to analyze users purchase pattern before a transaction such as purchase happens directly. an other is a user profile creation part module which is applied by the defined profile. Administrator profiles are made from DTD information and it is supposed to point the specific part of a document conforming to the DTD. Proposed system builds user's profile more accurately to get adaptability for user's behavior of buying and provide useful product information without inefficient searching based on such user's profile.