• Journal of Korea Multimedia Society
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• v.13 no.9
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• pp.1272-1284
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• 2010

As the mobile computers are becoming powerful and are used like general-purpose computers, operating systems for mobile computers also require swap system functionality that utilizes main memory efficiently. Flash memory is widely used as storage device for mobile computers but current linux swap system does not consider flash memory. Swap system is tightly related with process execution since it stores the contents of process in execution. By taking advantage of this characteristics, in this paper, we study a new linux swap system called PASS(Process-Aware Swap System), which allocates the different flash memory blocks to each process. Trace-driven experimental results show that PASS outperforms existing linux swap system with existing garbage collection schemes in terms of garbage collection cost.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.9
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• pp.2080-2089
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• 1997

Recent evolution in compute technology makesthe multimedia processing widely availiable. Conventional storage systems do not meet the requirements of multimedia data. Several approaches were suggested to improve disk storing methods for them. Bocheck proposed a disk partitioning technique for multiple steams assuming that all steams have same retrieval intervals with the same amount data for each access. While Bocheck's one provides a good method for same period, it does not consider the case of different periods of continous media streams. This paper proposes a new partitioning technique in which a fixed number of blocks are assigned for stresms with different retrieval periodicity. The analysis shows this problem is the same as the one scheduling the steams into a given sequence. The simulation was done to compare the proposed m-sequence merge method with the conventional Scan-EDF and Partitioning methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.4
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• pp.923-948
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• 2013

The main concern in mobile peer-to-peer (P2P) networks is security because jamming or eavesdropping on a wireless link is much easier than on a wired one and such damage can be incurred without physical access or contact. In particular, authentication has increasingly become a requirement in mobile P2P environments. This paper presents a new mutual authentication mechanism which requires less storage space and maintains a high level of security in mobile P2P networks. The proposed mechanism improves efficiency by avoiding the use of centralized entities and is designed to be agile in terms of both reliability and low-cost implementation. The mechanism suggested in the simulation evaluates the function costs occurring in authentication between the devices under mobile P2P network environment comparing to existing method in terms of basic operation costs, traffic costs, communications costs, storage costs and scalability. The simulation results show that the proposed mechanism provides high authentication with low cryptography processing overhead.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.298-300
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• 2003

A management information system of the Nanji Islands National Marine Reserve is designed and constructed based on method of integration of remote sensing and geographic information system (GIS). The system consists of two sub-systems, dynamic monitoring information system and general database system. The former is used for storage and manage fundamental geographical data (topographical and bathymetric map), satellite remote sensing data (IKONOS, SPOT, IRS, NOAA and SeaWiFS etc.) and multimedia data. The latter is used for storage and manage resource data (shellfish and alga etc.), environmental data (meteorological and hydrologic) and in situ data. As part of electronic government, this system will be submitted to local government for monitoring, management and decision.

• Journal of Information Processing Systems
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• v.13 no.1
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• pp.68-82
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• 2017

Nowadays, geographic information system (GIS) is developed and implemented in many areas. A huge volume of vector map data has been accessed unlawfully by hackers, pirates, or unauthorized users. For this reason, we need the methods that help to protect GIS data for storage, multimedia applications, and transmission. In our paper, a selective encryption method is presented based on vertex randomization and hybrid transform in the GIS vector map. In the proposed algorithm, polylines and polygons are focused as the targets for encryption. Objects are classified in each layer, and all coordinates of the significant objects are encrypted by the key sets generated by using chaotic map before changing them in DWT, DFT domain. Experimental results verify the high efficiency visualization by low complexity, high security performance by random processes.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.7
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• pp.675-683
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• 2000

For real time services of multimedia applications, storage systems should provide data without degrading their performance. Since it is very important to recover data immediately at a disk failure, the disk recovery system is required. This paper presents a hybrid recovery scheme which prevents degraded the performance on a single disk failure at RAID level 5 architecture until the failed disk is replaced with a new disk. The proposed scheme is very economical compared to previous spare disk schemes because it does not use extra disks. The performance of the proposed scheme is evaluated and analyzed with that of the RAID level 5 for various requested sizes through the simulation. The results show that the performance of the proposed scheme is improved up to 20 percents at the failure mode and 80 percents at the reconfigured mode. After a multimedia server system has been built with a RAID controller and hard disks, the data recovery performance of the propose scheme are compared with the results of simulation.

• Journal of the Korea Society of Computer and Information
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• v.14 no.6
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• pp.1-10
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• 2009

Flash memory has the advantages of nonvolatile, low power consumption, light weight, and high endurance. This enables the flash memory to be utilized as a storage of mobile computing device such as PMP(Portable Multimedia Player). Potable device with a mass flash memory can store various multimedia data such as video, audio, or image. Typical index systems for mobile computer are inefficient to search a form of text like lyric or title. In this paper, we propose a new text index system, named EMTEX(Embedded Text Index). EMTEX has the following salient features. First, it uses a compression algorithm for embedded system. Second, if a new insert or delete operation is executed on the base table. EMTEX updates the text index immediately. Third, EMTEX considers the characteristics of flash memory to design insert, delete, and rebuild operations on the text index. Finally, EMTEX is executed as an upper layer of DBMS. Therefore, it is independent of the underlying DBMS. We evaluate the performance of EMTEX. The Experiment results show that EMTEX can outperform th conventional index systems such as Oracle Text and FT3.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.5 no.5
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• pp.59-68
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• 2015

Since interdisciplinary convergence could beyond the borders of each disciplines, it is able to create new and meaningful knowledge through collaborative research between different study areas. Especially, in recent years, the Digital Humanities has attracted the attention as the convergence form of the Humanities and ICT. From a research methodology perspective, the Digital Humanities is a tool that can be used as a convergence system for various information utilization such as storage, retrieve, share, and spread. In view of Information system, Digital Humanities has been constructed and used in a variety of systems. Among them, studies related to information visualization for the Digital Humanities have been actively conducted. To visualize data or information, various types such as images, multimedia, interface, and etc could be applied. In this paper, we analyze the cases of various information visualization in digital humanities systems, and propose a method to utilize them in the Humanities and Area Studies.

• Journal of Korea Multimedia Society
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• v.1 no.1
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• pp.1-17
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• 1998

Video information is an important component of multimedia systems such as Digital Library, World-Wide Web (WWW), and Video-On-Demand (VOD) service system. Video information has hierarchical document structure inherently, so it is named "structure video document" in this paper. This paper proposes a data model, a query language, and an indexing scheme for structured video documents in order to store, retrieve, and share video documents efficiently. In representing structured video documents, the object-oriented data modeling technique is used since the hierarchical structure information can be modeled as complex objects. We also define object types for the structure information. Our query language supports not only content-based retrieval, which means the queries based on the structure of video documents, and spatial/temporal relation for video documents. In order to perform structure queries efficiently, as well as to reduce the storage overhead of indices, an optimized inverted index structure is proposed.

• Journal of Korea Multimedia Society
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• v.10 no.3
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• pp.391-400
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• 2007

According to the recent advances in multimedia computing, storage and searching technology have made large volume of music contents become prevalent. Also there has been increasing needs for the study on efficient categorization and searching technique for music contents management. In this paper, a new classifying method using the local information of music content and music tone feature is proposed. While the conventional classifying algorithms are based on entire information of music content, the algorithm proposed in this paper focuses on only the specific local information, which can drastically reduce the computing time without losing classifying accuracy. In order to improve the classifying accuracy, it uses a new classification feature based on music tone. The proposed method has been implemented as a part of MuSE (Music Search/Classification Engine) which was installed on various systems including commercial PDAs and PCs.