• Journal of the Korea Computer Industry Society
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• v.9 no.3
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• pp.121-128
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• 2008

This paper suggested a location-based traffic information service system using TPEG and GIS. Measurement technique, location server, applied service technique, and linkage technique with database were used to provide the location-based traffic information service. In particular, TPEG-RTM includes location information and load traffic message. The location information to be included in each message displayed a specific point, section or region limit of the load. Actually, because it was impossible to receive data using TPEG receiver, a proposed program included in this paper was used to produce an arbitrary database and read it, Also, TPEG event happened time was indicated on the map for matching test of a TPEG message and WGS84 coordinate, and finally it was verified with art example of a vehicle approaching to an event happened place.

• Korean Journal of Computational Design and Engineering
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• v.2 no.2
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• pp.103-110
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• 1997

In the development of large complex assembly, most design changes are from the following reasons.: 1) insufficient consideration of assembling sequence of downstream process. 2) interference and fit-up of related parts. 3) initial design changes which are not completely resolved. In order to reduce the first reason of above, the assembly-centric modeling methodology was proposed in the part (1) of the thesis. In this part (2), a Digital Mock-Up system, which is a tool to build a virtual mock-up in design stage, has been developed in order to prevent the other two reasons. The system can build a virtual assembly in various ways as followings.: 1) assembling parts which are located in user defined envelope. 2) assembling parts with the specified disciplines. 3) assembling parts that are selected in the part list. It can also make an assembly by the combination of above methods. In addition to that, it has the functions to read/write the virtual assembly and to explode parts of the assembly in desired direction. With the virtual assembly, engineers can design interference free parts without making physical mock-up. The system has been implemented with Oracle database management system in CATIA environment.

• IEMEK Journal of Embedded Systems and Applications
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• v.6 no.3
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• pp.190-200
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• 2011

Android platform provides a content provider and a cursor mechanism to access the internal SQLite engine. Content providers not only store and retrieve data but also make it accessible to applications. Applications can only share data through content provider, since there's no common storage area that Android packages can access. Cursor is an interface that provides random read-write access to the result set returned by a database query. However, this cursor possesses two major limitations. First, a cursor does not support a join clause among cursors, since the cursor can only access a single table in the content provider. Second, the cursor is not capable of creating user-customized field in the predefined content providers. In this paper, we propose the unified cursor architecture that merges several cursors into a single virtual cursor. Cursor translation look-aside buffer (TLB), column windowing mechanism and virtual data management are the three major techniques we have adopted to implement our structure. And we also propose a delayed synchronization method between an application and a proposed unified cursor. An application can create a user-customized field and sort multiple tables using a unified cursor on Android platform.

• Journal of KIISE:Software and Applications
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• v.29 no.7
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• pp.436-449
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• 2002

This paper describes on our experience of developing the Database Connector as an interconnection method between multimedia database, and the streaming framework. It is possible to support diverse and mature multimedia database services such as retrieval and join operation during the streaming if an interconnection method is provided in between streaming system and multimedia databases. The currently available interconnection schemes, however have mainly used the file systems or the relational databases that are Implemented with separated form of meta data, which deafs with information of multimedia contents, and streaming data which deals with multimedia data itself. Consequently, existing interconnection mechanisms could not come up with many virtues of multimedia database services during the streaming operation. In order to resolve these drawbacks, we propose a novel scheme for an interconnection between streaming framework and multimedia database, called the Inter-Process Communication (IPC) based Database connector, under the assumption that two systems are located in a same host. We define four transaction primitives; Read, Write, Find, Play, as well as define the interface for transactions that are implemented based on the plug-in, which in consequence can extend to other multimedia databases that will come for some later years. Our simulation study show that performance of the proposed IPC based interconnection scheme is not much far behind compared with that of file systems.

• The Transactions of the Korea Information Processing Society
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• v.5 no.11
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• pp.2797-2808
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• 1998

Multimedia scenario database system is a read-only multimedia-on-demand system which transfers scenarios representing the display ordering of multimedia objects. A scenario is a graph of multimedia objects and it contains spatial, temporal and contextual information of multimedia data. By structuring multimedia objects as a scenario, it is possible to enforce their display order based on their context. Furthermore, it can provide multiple display paths as well as the sharing of objects between different scenarios. As a result, the multimedia scenario database system can perform the pre-scheduling of multimedia objects, which makes it possible to reorder the transmission order of objects in a scenario. Consequently, the overall system resource such as data buffer and network bandwidth can be highly utilized. In this paper, we discuss the requirements of structuring a scenario to design a scenario database that stores and manages multimedia scenario. Furthermore, we devise and analyze several scheduling policies based on the reordering mechanism for the objects in a scenario.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.9
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• pp.445-458
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• 2007

This article presents a novel infrastructure for large-memory database processing using commodity hardware with operating system support. We exploit inexpensive PCs and a high-speed network capable of Remote Direct Memory Access (RDMA) operations to build a new memory hierarchy between fast volatile memory and slow disk storage. The new memory hierarchy guarantees a reasonable response time, and its storage size enables us to run large-memory database systems with little performance degradation. The proposed architecture has two main components: (1) a remote memory system inside the Linux kernel to manage other computers' memory pages efficiently and (2) a remote memory pager responsible for manipulating remote read/write operations on remote memory pages. We insist that the proposed architecture is practical enough to support the rigorous demands of commercial in-memory database systems by demonstrating the performance of publicly available main-memory databases (e.g., MySQL) on our prototyped system. The experimental results show very interesting results from the TPC-C benchmark.

• Journal of Internet of Things and Convergence
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• v.2 no.4
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• pp.15-20
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• 2016

This paper describes the construction of knowledge data retrieval management system based on medical image CT. The developed system is aimed to improve the efficiency of the hospital by reading the medical images using the intelligent retrieval technology and diagnosing the patient 's disease name. In this study, the medical image DICOM file of PACS is read, the image is processed, and feature values are extracted and stored in the database. We have implemented a system that retrieves similarity by comparing new CT images required for medical treatment with the feature values of other CTs stored in the database. After converting 100 CT dicom provided for academic research into JPEG files, Code Book Library was constructed using SIFT, CS-LBP and K-Mean Clustering algorithms. Through the database optimization, the similarity of the new CT image to the existing data is searched and the result is confirmed, so that it can be utilized for the diagnosis and diagnosis of the patient.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.6
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• pp.1364-1370
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• 2005

There are many security models for database systems using policy-based access control. RBAC (Role-based Access Control) is used for complementing MAC (Mandatory Access Control) and DAC (Discretionary Access Control) and is for performing flexibly security policies meet applied environment. We implemented the database security system that applies DAC, MAC, and RBAC to meet security requirements of users. However, security policies are constructed redundantly whenever security policies are needed to each user in this system. Even though the proposed security system can flexibly control more complicated 'read' access to various data sizes for individual users, it is obvious that there is a possibility that a new policy can be a duplication of existing policies. In this paper, we introduce the problem of policy duplication and propose the policy management module. With this proposed module, constructed policies are checked for duplication and deleted or merged with existing policies.

• Journal of KIISE:Databases
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• v.31 no.2
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• pp.140-149
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• 2004

Data broadcast has received much attention as a very efficient method for disseminating data items in mobile environment with large number of mobile clients. In this approach, a database server periodically and continuously broadcasts data items through wireless channels and clients perform read-only transactions by accessing necessary data items from the air. While broadcasting, the server must also process update transactions on the database, which raises an obstacle for client's accessing consistent data. In this research, we propose a new algorithm SCDSC(Serialization Checking with DirtySet on Commit) which is an alternative for solving the concurrency control problem efficiently. The SCDSC is a kind of optimistic concurrency control in that a client checks the consistency of data using a DirtySet as a part of data broadcast when it commits its transaction. In each broadcast cycle, the server updates and disseminates the DirtySet with newly changed data items for last few cycles in the sliding window approach. We perform an analysis and a simulation study to evaluate the performance of our SCDSC algorithm in terms of data consistency and data currency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.393-401
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• 2013

Most traditional databases exploit record-oriented storage model where the attributes of a record are placed contiguously in hard disk to achieve high performance writes. However, for search-mostly datawarehouse systems, column-oriented storage has become a proper model because of its superior read performance. Today, flash memory is largely recognized as the preferred storage media for high-speed database systems. In this paper, we introduce fast column-oriented database model and then propose a new column-aware index management scheme for the high-speed column-oriented datawarehouse system. Our index management scheme which is based on enhanced $B^+$-Tree achieves high search performance by embedded flash index and unused space compression in internal and leaf nodes. Based on the results of the performance evaluation, we conclude that our index management scheme outperforms the traditional scheme in the respect of the search throughput and response time.