• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.6
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• pp.1600-1619
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• 2023

Organizations and other institutions have recently started using cloud service providers to store and share information in light of the Internet of Things (IoT). The major issues with this storage are preventing unauthorized access and data theft from outside parties. The Block chain based Security Sharing scheme with Data Access Control (BSSDAC) was implemented to improve access control and secure data transaction operations. The goal of this research is to strengthen Data Access Control (DAC) and security in IoT applications. To improve the security of personal data, cypher text-Policy Attribute-Based Encryption (CP-ABE) can be developed. The Aquila Optimization Algorithm (AOA) generates keys in the CP-ABE. DAC based on a block chain can be created to maintain the owner's security. The block chain based CP-ABE was developed to maintain secures data storage to sharing. With block chain technology, the data owner is enhancing data security and access management. Finally, a block chain-based solution can be used to secure data and restrict who has access to it. Performance of the suggested method is evaluated after it has been implemented in MATLAB. To compare the proposed method with current practices, Rivest-Shamir-Adleman (RSA) and Elliptic Curve Cryptography (ECC) are both used.

• Journal of KIBIM
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• v.12 no.1
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• pp.72-80
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• 2022

It has become mandatory to designs by BIM in construction. It is urgent to make accurate decisions through the linkage between complex and various types of data in projects. In particular, block-chain based data sharing process (using BIM files, general construction submitted files) is essential to support reliable decision making in complex data flood systems. Prior to developing data sharing system based on block-chain, in this paper, a data linkage method is proposed so that practitioners can simultaneously utilize existing construction information and BIM data. Examples are shown based on the construction classification system and file expression, and incentive strategies are explored through a survey so that heterogeneous information can be used at the same time in overall projects.

• Journal of the Korea Society of Computer and Information
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• v.23 no.10
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• pp.73-80
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• 2018

The shared economy began with the concept of sharing the physical and intellectual assets of individuals with others. Nowadays, the concept of shared economy is becoming one of the industries as an enterprise type. Especially, with the development of the Internet and smart devices, various forms of shared economy have been developed in accordance with the need of sharing of individual income. Digital content is also a shareable commodity and it is seeking to utilize it as an item of shared economy. Accordingly, when digital contents are used as a shared economy, there are various possible threats -security threats that may arise in the course of transactions, potential for theft, alteration and hacking of contents. In this paper, we propose transaction method and content protection method using block chain-ethereum technology to reduce security threats and transparent transactions that can occur in digital contents transactions. Through the proposed method, the trust of the consumer and the supplier can be measured and the encryption can be performed considering the characteristics of the data to be traded. Through this paper, it is possible to increase the transparency of smart transaction of digital contents and to reduce the risk of content distortion, hacking, etc.

• 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'.

• The KIPS Transactions:PartA
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• v.16A no.2
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• pp.89-100
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• 2009

With the advance in digital technologies and the increasing prevalence of high quality multimedia contents, there is a growing user demand for multimedia devices, such as mobile phones, digital TV, PMP, digital camcoders, digital cameras. Such devices provide various services associated with multimedia file manipulation, including multimedia contents playback, multimedia file editing, etc. Conventional file systems exhibit a performance-related drawback that requires considerable amount of time and disk I/Os in order to store large-sized edited multimedia files. This paper proposes a fast, efficient writing technique for large-sized edited multimedia files by using data block sharing with adjustment of inode block pointers. Our experiments show that the proposed scheme not only improves write performance of the Ext3 file system on average by 16 times with various types of edited multimedia files, but also reduces consumed disk space dramatically through the data block sharing.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.6
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• pp.82-91
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• 1996

In this paper, an image coding technique using fractal interpolation is proposed. Similar to the conventional methods, an image is partitioned into blocks and each block is coded independently. However, an interpolation point is ahsared by its neighboring blocks. This means that each block can use all its interpolation points with minimal increase of new data. For a simple implementation, triangular blocks are used instead of square blocks and new coefficients are difined. Data obtained in the encoding process hav estatistical characteristics suitable sfor entropy coding, an dthus arithmetic coding is perfomred for improving the compression efficiency. The results of the proposed coder in comparison with those of a conventional coder show that the interpolation method reduces block effect caused by a memoryless block coder, especially at low bit rates. This improvement is due to sharing of information between adjacent blocks. Moreover, th enumber of iteration required in ecoding process is reduced since more information is used to decode each block.

• ETRI Journal
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• v.29 no.6
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• pp.820-822
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• 2007

ARIA and the Advanced Encryption Standard (AES) are next generation standard block cipher algorithms of Korea and the US, respectively. This letter presents an area-efficient unified hardware architecture of ARIA and AES. Both algorithms have 128-bit substitution permutation network (SPN) structures, and their substitution and permutation layers could be efficiently merged. Therefore, we propose a 128-bit processor architecture with resource sharing, which is capable of processing ARIA and AES. This is the first architecture which supports both algorithms. Furthermore, it requires only 19,056 logic gates and encrypts data at 720 Mbps and 1,047 Mbps for ARIA and AES, respectively.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.5
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• pp.121-128
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• 2002

Although multiprocessor systems are widely used in recent years to run commercial workloads, data sharing patterns are rarely explored due to several difficulties. In this paper, we made in-depth sharing pattern analysis for a representative OLTP application, the TPC-B benchmark, running on a cache-coherent shared-memory multiprocessor system. In addition, to illustrate their effects on the performance, the number of cache misses were measured for various numbers of processors, cache sizes and cache block sizes. From these measurements, we found out the shared data in TPC-B largely bear quite different sharing characteristics from those in scientific applications.

• The Transactions of the Korea Information Processing Society
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• v.7 no.4
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• pp.1082-1091
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• 2000

In Distributed Shared Memory systems, false sharing occurs when two different data items, not shared but accessed by two different processors, are allocated to a single block and is an important factor in degrading system performance. The paper first analyzes shared memory allocation and reference patterns in parallel applications that allocate memory for shared data objects using a dynamic memory allocator. The shared objects are sequentially allocated and generally show different reference patterns. If the objects with the same size are requested successively as many times as the number of processors, each object is referenced by only a particular processor. If the objects with the same size are requested successively much more than the number of processors, two or more successive objects are referenced by only particular processors. On the basis of these analyses, we propose a memory allocation scheme which allocates each object requested by different processors to different pages and evaluate the existing memory allocation techniques for reducing false sharing faults. Our allocation scheme reduces a considerable amount of false sharing faults for some applications with a little additional memory space.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.5B
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• pp.477-483
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• 2011

In this paper, we propose the design and implementation of the storage-based data sharing system in the separate network environment to improve efficiency of data transmission. The previous system generates files per received packet and transmit files to another network through storage. This system causes inefficiency by reading unnecessary blocks, when it transmits a number of files through storage. Our proposed system deals with this inefficiency by adopting concept of snapshot. Consequently, we create one file with snapshot so that the number of files can be reduced and the file size can be optimized according to the block size. The proposed system improves the response time significantly with the minimized reading of unnecessary blocks, compared to the previous system.