• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.2
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• pp.405-424
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• 2013

In publishing applications, it is advantageous to embed data in halftone images. The CPT scheme (Chen-Pan-Tseng, 2000) is a steganographic data hiding scheme that was proposed for binary images, e.g., facsimiles. The CPT scheme uses a secret key and weight matrix to protect the hidden data and can hide as many as $r={\lfloor}{\log}_2(m{\times}n+1){\rfloor}$ bits of data in the image by changing at most 2 bits in the image. Our proposed scheme also uses a secret key to protect it from being compromised and a weight matrix to increase the data hiding rate. Our scheme improves the performance of the CPT scheme by using the simple principle of splitting each block into two parts. Our proposed scheme is called improved CPT (ICPT) and has a very high embedding capacity compared to previous schemes. Experimental results demonstrate that our proposed scheme generally has higher performance than previous schemes.

• International Journal of Contents
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• v.7 no.1
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• pp.8-13
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• 2011

For energy-efficiency in Wireless Sensor Networks (WSNs), when a sensor node detects events, the sensing period for collecting the detailed information is likely to be short. The lifetime of WSNs decreases because communication modules are used excessively on a specific sensor node. To solve this problem, the TARP decentralized network packets to neighbor nodes. It considered the average data transmission rate as well as the data distribution. However, since the existing scheme did not consider the energy consumption of a node in WSNs, its network lifetime is reduced. In this paper, we propose an energy awareness congestion control scheme based on genetic algorithms in WSNs. The proposed scheme considers the remaining amount of energy and the transmission rate on a single node in fitness evaluation. Since the proposed scheme performs an efficient congestion control, it extends the network lifetime. In order to show the superiority of the proposed scheme, we compare it with the existing scheme through performance evaluation. It is shown that the proposed scheme enhances the data fairness and improves the network lifetime by about 27% on average over the existing scheme.

• Korean Institute of Interior Design Journal
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• v.19 no.5
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• pp.105-112
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• 2010

The purpose of this study is to suggest the color scheme based on the color image types through the color analysis of workstation furniture which is on the market. This color scheme of the workstation furniture is expected to be give the comfort to office environment when planning office. For this study, It is selected the three furniture firms that have a brand of office furniture and their web site that is showed color sample of furniture. The following researches are drawn based upon the purpose. First, the color image types of interior space is classified and the color image words that are suitable for each types is extracted based on the results of existing literature. Second, the distribution of its hue and tone is analysed after collecting the each firm's color sample of desk top, panel and chair. Third, the color image appearing in each furniture color is analysed by color image scale positioning. Forth, the color scheme of desk top, panel and chair is suggested by its color scheme palette. The result of this study is expected to help comfortable environment by providing the color scheme for selection of furniture color in work space. Not all color of each furniture is sufficient to be combined color scheme, the result is indicated that the color scheme of workstation by color image types is possible for color planning in office environment.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.5
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• pp.284-290
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• 2002

We propose a new authenticated encryption scheme that does not require any block encryption algorithm. Our scheme is based on the Horster-Michels-Petersen authenticated encryption scheme, and it uses a technique in the Bae~Deng signcryption scheme so that the sender's signature can be verified by an arbitrary third party. Since our scheme does not use any block encryption algorithm, we can reduce the code size in its implementation. The computation and communication costs of the proposed scheme are almost the same as those of the Bao-Deng scheme that uses a block encryption algorithm. Our scheme also satisfies all the security properties such as confidentiality, authenticity and nonrepudiation.

• Journal of the Korean Society for Library and Information Science
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• v.49 no.1
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• pp.319-340
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• 2015

The purpose of this study is to provide a plan of classification scheme to efficiently manage the collected cultural resource in Asian Culture Information Agency (ACIA) of Asian Culture Complex. The characteristic and category of the cultural resources are identified after studying objectives and acquisition policies of ACIA. This paper in here compares classification schemes such as HRAF scheme, UNESCO cultural framework, Folklore Archive scheme, and classification scheme of Academy of Korean Studies. On the basis of it, this study proposes the principle and criterion of the new classification scheme in ACIA. The new classification scheme is classified as the cultural, social, and natural area in sequence. The number of main classes is set up 16 items.

• The Journal of Sustainable Design and Educational Environment Research
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• v.2 no.1
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• pp.29-48
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• 2002

This study is for achievement of the expected aim on establish principle colour scheme of exterior and interior school facilities. Also this study aims to utilization of the data which is need for educational colour scheme of school facilities basically. The result of this study is as follows; 1) Domestic case study in primary school colour value distributed middle and high level between 5R and 6Y, the case study of foreign colour scheme distributed low and middle level. 2) Domestic case study in middle school facilities colour scheme distributed same colour of R, YR and the chroma distributed between 1 to 4. 3) The case study of domestic and foreign high school colour scheme distributed that in cases of domestic the colour scheme distributed very loose style and foreign cases distributed same colour of RP to YR with middle and high level of value and low chroma. 4) Exterior school facilities colour scheme distributed in Busan is that N~5GY(value 8~9 and chroma 0~8) in main school building skin material colour, 0~4 value and 7.5~9 chroma in assistant skin material colour. 5) Interior school facilities colour scheme distributed same colour of B, BF, PB, RP, N, YR in class room and open classroom in school mainly.

• Journal of Digital Convergence
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• v.10 no.4
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• pp.207-215
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• 2012

This paper proposes a proxy-based caching optimization scheme for improving the streaming media services in wireless mobile ad hoc networks. The proposed scheme utilizes the proxy for data packet transmission between media server and nodes in WLANs, and the proxy locates near the wireless access pointer. For caching optimization, this paper proposes NFCO (non-full cache optimization) and CFO (cache full optimization) scheme. When performs the streaming in the proxy, the NFCO and CFO is to optimize the caching performance. This paper compared the performance for optimization between the proposed scheme and the server-based scheme and rate-distortion scheme. Simulation results show that the proposed scheme has better performance than the existing server-only scheme and rate distortion scheme.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.1
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• pp.81-87
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• 2014

Password-based authentication using smart card provides two factor authentications, namely a successful login requires the client to have a valid smart card and a correct password. While it provides stronger security guarantees than only password authentication, it could also fail if both authentication factors are compromised ((1) the user's smart card was stolen and (2) the user's password was exposed). In this case, there is no way to prevent the adversary from impersonating the user. Now, the new technology of biometrics is becoming a popular method for designing a more secure authentication scheme. In terms of physiological and behavior human characteristics, biometric information is used as a form of authentication factor. Biometric information, such as fingerprints, faces, voice, irises, hand geometry, and palmprints can be used to verify their identities. In this article, we review the biometric-based authentication scheme by Cheng et al. and provide a security analysis on the scheme. Our analysis shows that Cheng et al.'s scheme does not guarantee any kind of authentication, either server-to-user authentication or user-to-server authentication. The contribution of the current work is to demonstrate these by mounting two attacks, a server impersonation attack and a user impersonation attack, on Cheng et al.'s scheme. In addition, we propose the enhanced authentication scheme that eliminates the security vulnerabilities of Cheng et al.'s scheme.

• ETRI Journal
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• v.33 no.4
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• pp.621-628
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• 2011

The redactable signature scheme was introduced by Johnson and others in 2002 as a mechanism to support disclosing verifiable subdocuments of a signed document. In their paper, a redactable signature based on RSA was presented. In 2009, Nojima and others presented a redactable signature scheme based on RSA. Both schemes are very efficient in terms of storage. However, the schemes need mechanisms to share random prime numbers, which causes huge time consuming computation. Moreover, the public key in the scheme of Johnson and others is designed to be used only once. In this paper, we improve the computational efficiency of these schemes by eliminating the use of a random prime sharing mechanism while sustaining the storage efficiency of them. The size of our signature scheme is the same as that of the standard RSA signature scheme plus the size of the security parameter. In our scheme, the public key can be used multiple times, and more efficient key management than the scheme of Johnson and others is possible. We also prove that the security of our scheme is reduced to the security of the full domain RSA signature scheme.

• Nuclear Engineering and Technology
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• v.53 no.10
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• pp.3171-3181
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• 2021

This research serves to advance the development of engineering computational fluid dynamics (CFD) computing efficiency for the analysis of pressurized water reactor (PWR) core using rod-type fuel assemblies with mixing vanes (one kind of typical PWR core). In this research, a CFD scheme based on the reconstruction of the initial fine flow field (RIF CFD scheme) is proposed and analyzed. The RIF scheme is based on the quantitative regulation of flow velocities in the rod-type PWR core and the principle that the CFD computing efficiency can be improved greatly by a perfect initialization. In this paper, it is discovered that the RIF scheme can significantly improve the computing efficiency of the CFD computation for the rod-type PWR core. Furthermore, the RIF scheme also can reduce the computing resources needed for effective data storage of the large fluid domain in a rod-type PWR core. Moreover, a flow-ranking RIF CFD scheme is also designed based on the ranking of the flow rate, which enhances the utilization of the flow field with a closed flow rate to reconstruct the fine flow field. The flow-ranking RIF CFD scheme also proved to be very effective in improving the CFD efficiency for the rod-type PWR core.