• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.172-176
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• 2006

A game starting, the process of running has some loading steps. In general, textures use corresponding images saved externally and the file format of images affects the loading time of game. We propose some ideas for the texture using method by comparison with loading time according to some file formats.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1705-1708
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• 2005

Recently, flash memory is becoming popular as storage system to store and retrieve multimedia files. However, there are few researches about multimedia file system for flash memory based storage devices. We have been designing and developing a novel multimedia file systems for flash memory. In this paper, we describe the semantics of real-time retrieval of multimedia data and present scheduling scheme to guarantee the real-time requirements in our multimedia file system.

• The Journal of the Korea Contents Association
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• v.14 no.12
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• pp.565-573
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• 2014

We have various e-commerce like on-line banking, stock trading, shopping using a PC or SmartPhone. In e-commerce, two parties use the certificate for identification and non-repudiation but, the attack on the certificate user steadily has been increasing since 2005. The most of hacking is stealing the public certificate and private key files. After hacking, the stolen public certificate and private key file is used on e-commerce to fraud. Generally, the private key file is encrypted and saved only with the user's password, and an encrypted private key file can be used after decrypted with user password. If a password is exposed to hackers, hacker decrypt the encrypted private key file, and uses it. For this reason, the hacker attacks user equipment in a various way like installing Trojan's horse to take over the user's certificate and private key file. In this paper, I propose the management method to secure private key of PKI using One Time Password certification technique. As a result, even if the encrypted private key file is exposed outside, the user's private key is kept safely.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.8
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• pp.525-533
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• 2009

Staging technique is used to provide files for a job in the Grid. If a staged file has large volume, the start time of the job is delayed and the throughput of job in the Grid may decrease. Therefore, removal of staging overhead helps the Grid operate more efficiently. In this paper, we present two methods for efficient file provisioning to clear the overhead. First, we propose RA-RFT, which extends RFT of Globus Toolkit and enables it to utilize RLS with replica information. RA-RFT can reduce file transfer time by doing partial transfer for each replica in parallel. Second, we suggest Remote Link that uses remote I/O instead of file transfer. Remote link is able to save storage of computational nodes and enables fast file provisioning via prefetching. Through various experiments, we argue that our two methods have an advantage over existing staging techniques.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.14-19
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• 2007

As XML is used by standard format for information expression and information exchange in various field, Many Company began to use SVG by user interface or information expression tool of embedded system such as mobile phone based wireless internet. Because SVG has many additional information to keep structure of SVG document exception real data, there is a problem that transfer time of SVG file is so cost for quantity of transmitted data actually. To solve this problem, many researches using compression conception have been conducted for applying to an embedded system. This paper proposes SMETA that can use existing researches using compression concept at once. SMETA divides SVG file to each part that can allocate meaning, and gives semantic metadata to each part without alteration of SVG structure. SMETA can reduce site of transmitted SVG file actually by transmitting specification part of SVG file that metadata does not agree or has unlisted part in an embedded system between an embedded system and server, before transmit whole SVG file. By size of transmitting SVG file is decreasing, transfer time can be shortened accordingly.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1289-1300
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• 2011

In recent computer systems with high-performance, users execute programs needing large memory and programs intensively accessing files simultaneously. Such a large memory requirement makes virtual memory systems access swap spaces in disk, and intensive file accesses require file systems to access file system partitions in disk. Executing the two kinds of programs at once incurs large disk seeks between swap spaces and file system partitions frequently. To solve the problem, this paper proposes a new scheme called SAF to create several swap spaces in a file system partition, where pages to be paged out are stored. When a page is paged out, the scheme stores the page to one of the swap spaces close to a disk location where the most recently accessed file is located. The chosen swap space in the file system partition is closer to the disk location than the traditional swap space, so that our scheme can reduce the large disk seek time spent to move to the traditional swap space in paging out a page. The experiment of our scheme implemented in FreeBSD 6.2 shows that SAF reduces the execution time of several benchmarks over FreeBSD ranging from 14% to 42%.

• The KIPS Transactions:PartA
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• v.17A no.2
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• pp.63-72
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• 2010

Recently, the need for multimedia devices, such as digital TV, and camcorder has increased. These devices provide many services on multimedia files such as playing, recording, and editing. Throughout these services, in case of storing edited large-scaled multimedia files, existing file system have several capability problems that are taking too much time and requiring disk I/O. In this paper, we propose the use of Linux Ext2 file system based 'Block-Link file (BL-file) system' in order to solve these problems. For the BL-file system, when editing and storing large-scaled files, there is no data input or output but only modification of the metadata. Additionally, by sharing data blocks between multimedia files, we can save disk spaces. Moreover, because the managing of data block sharing information is more convenient than the existing FWAE technique, we can lessen system overhead. The BL-file system is based on Ext2 file system and implemented in a Linux environment, and the usefulness of the proposed technique is validated by applying the Linux multimedia file-editing tool 'Avidemux'.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.3
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• pp.139-150
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• 2015

The major components of IoT(Internet of Things) environment are IoT devices rather than the conventional desktop computers. One of the intrinsic characteristics of IoT devices is diversity in view of data type and data access method. In addition, IoT devices usually deal with real-time data. In order to use such IoT data for internal business or cloud services, an IoT platform capable of easy domain management and consistent data access interface is required. This paper proposes a Linux FUSE-based virtual file system connecting IoT devices on POSIX file system view. It is possible to manage IoT domain with the native Linux utilities such as mkdir, mknod, ls and find in the file system. Also, the file system makes it possible to access or control IoT devices through POSIX interface such as open(), read(), write() or close() without any separate APIs or utilities. A test result shows that the management performance of the file system is lower than that of linux file system negligibly.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.6
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• pp.1266-1272
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• 1997

Due to the price and performanceof uniprocessor workstations and off-the shelf networking, network of workstations(NOW) ae now a cost-effective parallel processing platform tht is competitive with supercomputers. Meanwhile, current network fiile system protocols rely heavily on a central server to coordinate file activity among client workstations. This central server can become a bottleneck that limits scalibility for environments with large numbers of clients. In this paper, we propsoe a highly reliable and effective software RAID file system on the network of workstation environment. We present results form a trace-driven simulation study that shows that the designed software RAID file system is more effective in the aspect of elapsed time when compared with client/server file systems.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.3
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• pp.171-178
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• 2015

Recently NAND flash memory has been found to be the primary cause of low performance in the smart device. NAND flash memory is different from each other the execution time of I/O operations that flash file system is required. Therefore, it is necessary to compare and analyze the flash file system I/O performance for the efficient I/O on smart device. In this paper, it was tested and analyzing the I/O performance of the YAFFS2, JFFS2, UBIFS. Experimental results most read I/O performance is good, but the writing I/O performance is not good. For UBIFS, showed a more good I/O performance compared to other flash file system.