• Journal of KIISE:Databases
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• v.34 no.4
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• pp.357-368
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• 2007

This paper proposes the SAMD(Synchronization Algorithms based on Message Digest) algorithm based on message digest in order to data synchronization between a database server and a mobile database. The SAMD algorithm makes the images at the database server and the mobile database using message digest tables and compares two images in order to select the rows needed to synchronization. If two images are different, the synchronization is progressed according to synchronization policy. The SAMD algorithm does not use techniques which are dependent the some database vendor and also triggers, stored procedures and timestamps. The SAMD only uses the standard SQL functions for the synchronization. Therefore the SAMD algorithm is used in any combinations of the database server and the mobile database because the SAMD algorithm is not depended on some database venders. Also the SAMD algorithm shows better performance compared with existing synchronization products.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.712-714
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• 2018

The system of this paper designs and implements a used trading system that is commonly used on the Internet. In order to pursue local transactions based on location, we designed the system by dividing the region in consideration of the general characteristics of used transactions that are restricted by transactions through distance and location. To do this, I used MySQL as the database engine and I used PHP, an Internet server-based scripting language, for database interworking. Due to the characteristics of secondary transactions, information security and design of each product are considered.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.353-355
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• 2018

The system of this paper designs and implements a used trading system that is commonly used on the Internet. In order to pursue local transactions based on location, we designed the system by dividing the region in consideration of the general characteristics of used transactions that are restricted by transactions through distance and location. To do this, I used MySQL as the database engine and I used PHP, an Internet server-based scripting language, for database interworking. Due to the characteristics of secondary transactions, information security and design of each product are considered.

• Smart Structures and Systems
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• v.17 no.4
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• pp.669-690
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• 2016

Advances in sensor technologies have led to the instrumentation of sensor networks for bridge monitoring and management. For a dense sensor network, enormous amount of sensor data are collected. The data need to be managed, processed, and interpreted. Data management issues are of prime importance for a bridge management system. This paper describes a data management infrastructure for bridge monitoring applications. Specifically, NoSQL database systems such as MongoDB and Apache Cassandra are employed to handle time-series data as well the unstructured bridge information model data. Standard XML-based modeling languages such as OpenBrIM and SensorML are adopted to manage semantically meaningful data and to support interoperability. Data interoperability and integration among different components of a bridge monitoring system that includes on-site computers, a central server, local computing platforms, and mobile devices are illustrated. The data management framework is demonstrated using the data collected from the wireless sensor network installed on the Telegraph Road Bridge, Monroe, MI.

• Journal of Platform Technology
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• v.9 no.2
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• pp.3-9
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• 2021

The management of sensor information requires the functions for registering, modifying and deleting rapidly sensor information about various many sensors. In this research, Celery and MongoDB are used for developing a sensory data management system. Celery supplies a queue structure based on asynchronous communication in Python. Celery is a distributed simple job-queue but reliable distributed system suitable for processing large message. MongoDB is a NoSQL database that is capable of managing various informal information. In this experiment, we have checked that variety of sensor information can be processed with this system in a IoT environment. To improve the performance for handling a message with sensory data, this system will be deployed in the edge of a cloud infrastructure.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.9
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• pp.371-376
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• 2015

The Internet of Things (IoT) significantly increases the amount of data. Database compression is important for big data because it can reduce costs for storage systems and save I/O bandwidth. However, it could show low performance for write-intensive workloads such as OLTP due to the updates of compressed pages. In this paper, we present practical guidelines for the performance improvement of database compression. Especially, we propose the SELECTIVE strategy, which compresses only tables whose space savings are close to the expected space savings calculated by the compressed page size. Experimental results using the TPC-C benchmark and MySQL show that the strategy can achieve 1.1 times better performance than the uncompressed counterpart with 17.3% space savings.

• Journal of Korea Society of Industrial Information Systems
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• v.8 no.2
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• pp.98-107
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• 2003

The purpose of this study is to propose the schema for process repository that overcomes the limitations of existing process repositories in which it is not easy to compare and analyze such the unstructured data as a process model. To achieve this goal, the previous studies on process repository are reviewed, the schema for process repository is designed, and the tables for relational database are created. For the validation of the schema presented in this paper, the process model stored in relational database is examed using SQL. The contributions of this study are as follows. First, the schema for process repository storing process models is designed and validated. Second, the process model created by the new schema and stored in relational database leads to improve the performance of process analysis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.804-807
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• 2012

Cloud service provider has to protect client's information securely since all the resources are offered by the service provider, and a large number of users share the resources. In this paper, a NoSQL-based anomaly detection system is proposed in order to enhance the security of mobile cloud services. The existing integrated security management system that uses a relational database can not be used for real-time processing of data since security log from a variety of security equipment and data from cloud node have different data format with unstructured features. The proposed system can resolve the emerging security problem because it provides real time processing and scalability in distributed processing environment.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.3
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• pp.430-433
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• 2007

There have been several researches to manipulate XML Queries efficiently since XML has been accepted in many areas. Among the many of the researches majority of them adopt relational databases as underlying systems because relational model which is used the most widely for managing large data efficiently. In this paper we develop XQuery to SQL Translation Algorithms called XSTAR that can efficiently handle XPath, XQuery FLWORs with nested iteration expressions, element constructors and keywords retrieval on relational database as well as constructing XML fragments from the transformed SQL results. The entire algorithms mentioned in XSTAR have been implemented as the XQuery processor engine in XML management system, XPERT, and we can test and confirm it's prototype from "http ://dblab.kmu.ac.kr/project.jsp".

• Digital Contents
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• no.5 s.108
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• pp.90-95
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• 2002

지난 호에서는 정적 SQL(Static SQL)의 장점과 Oracle8i에서 도입된 analytic function이라는 새로운 기능을 이용해서 부분범위처리가 가능한 효율적인 게시판 구현에 대해서 살펴보았다. 이번 호에서는 analytic function, FBI(Function Based Index), 순환관계(connect by ㆍㆍㆍstart with)를 이용한 응답글(속칭 리플)이 있는 게시판의 부분범위처리에 대해서 살펴보고, 게시판의 총글수나 사용자별 마일리지합 정보 등 집계성이나 항상 사용자가 온라인상에 보고자하는 정보들을 효율적으로 관리하기 위해 materialized view를 적용하는 방법에 대해서 알아보겠다.