• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.7
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• pp.2703-2718
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• 2015

Nowadays, public cloud storage is gaining popularity and a growing number of users are beginning to use the public cloud storage for online data storing and sharing. However, how the encrypted data stored in public clouds can be effectively shared becomes a new challenge. Proxy re-encryption is a public-key primitive that can delegate the decryption right from one user to another. In a proxy re-encryption system, a semi-trusted proxy authorized by a data owner is allowed to transform an encrypted data under the data owner's public key into a re-encrypted data under an authorized recipient's public key without seeing the underlying plaintext. Hence, the paradigm of proxy re-encryption provides a promising solution to effectively share encrypted data. In this paper, we propose a new certificate-based proxy re-encryption scheme for encrypted data sharing in public clouds. In the random oracle model, we formally prove that the proposed scheme achieves chosen-ciphertext security. The simulation results show that it is more efficient than the previous certificate-based proxy re-encryption schemes.

• Journal of Information Processing Systems
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• v.9 no.2
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• pp.287-300
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• 2013

Cloud storage is provided as a service in order to keep pace with the increasing use of digital information. It can be used to store data via networks and various devices and is easy to access. Unlike existing removable storage, many users can use cloud storage because it has no storage capacity limit and does not require a storage medium. Cloud storage reliability has become a topic of importance, as many users employ it for saving great volumes of data. For protection against unethical administrators and attackers, a variety of cryptography systems, such as searchable encryption and proxy re-encryption, are being applied to cloud storage systems. However, the existing searchable encryption technology is inconvenient to use in a cloud storage environment where users upload their data. This is because this data is shared with others, as necessary, and the users with whom the data is shared change frequently. In this paper, we propose a searchable re-encryption scheme in which a user can safely share data with others by generating a searchable encryption index and then re-encrypt it.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.2
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• pp.29-30
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• 2011

The purpose of this study is to closely examine relationship of the system re-use intention depending on CRS technology acceptance. Accordingly, questionnaire was widely distributed to 160 CRS users by convenient sampling targeting people in charge of task among employees for airlines and travel agencies, who are working-level staffs for CRS. Among these things, totally 142 valid materials were used in analysis. The analytical data processing was utilized SPSSWIN VER 18.0 and AMOS 18.0. The findings can be summarized as follows. Influential variables in CRS technology acceptance had significant influence upon the perceived ease use, the perceived usability, and the re-use intention. Also, the significant positive(+) influence was revealed to be had upon the perceived usability by the perceived ease use and upon the re-use intention by the perceived usability and ease use.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.26-31
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• 2005

In national prospective, the needs to develop water resources has been increased due to water shortage from diverse use of water resources in agricultural areas. Existing agricultural water demand, which has mainly been limited to the use of farming, are now expanding to diverse water uses such as supporting daily lives, diluting environmental pollution as well as industrial use for agricultural complex currently under construction in agricultural region. In this situation, for the sake of effective procurement of water resources and supply method, it is definitely required to enhance the effectiveness of budget investment and project proceedings through integrated re-development which links projects to strengthen existing dams, reservoirs and hydraulic facilities. The major scopes of this research includes developing different types of system such as selecting potential sites to re-construct reservoirs including generating base maps and thematic maps, data collection regarding water demands and reservoir status; analyzing reservoir data; estimating developable capacity and index calculation; and forecasting inundated areas. In addition, this study provides other products such as developing output generation system which can support wide use of data built and analyzed; database generation for better data management; data analysis including selection, extraction, indexation, and calculation of base items through standardization; data security system prohibiting exterior proliferation and malicious manufacturing of data.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.1
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• pp.147-158
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• 2017

Internet is changing the way consumers shop and buy goods and services, and has rapidly evolved into a global phenomenon. The primary purpose of this study is to investigate the influence of consumer's on-line shopping values on satisfaction and intention to re-use. Economic value, emotional value, convenience value, social value, product variety were identified as affecting factors of satisfaction and intention to re-use of on-line shopping purchasing based on prior studies of on-line shopping behavior. This study tested the hypothesized model using the data from 132 consumers who have purchased products in on-line shopping mall. According to the result, economic value, emotional value, product variety are significantly related to the consumer satisfaction but convenience value, social value are not. Consumer satisfaction of online purchasing was also shown to be related to the intention to re-use. It can provide practical guidelines on effective operation strategies for consumer loyalty.

• Journal of Intelligence and Information Systems
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• v.10 no.3
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• pp.105-114
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• 2004

In the past year, the increasing concern about the biometric recognition makes the great activities on the security fields, such as the entrance control or user authentication. In particular, although the features of face recognition, such as user friendly and non-contact made it to be used widely, unhappily it has some disadvantages of low accuracy or low Re-attempts Rates. For this reason, I suggest the new approach to re-classify the classified data of recognition result data to solve the problems. For this study, I will use the typical appearance-based, PCA(Principal Component Analysis) algorithm and verify the performance improvement by adopting the re-classification approach using 200 peoples (10 pictures per one person).

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.4
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• pp.2254-2275
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• 2017

In this paper, we present an IND-CCA2 secure certificateless proxy re-encryption scheme in the random oracle model. A certificateless public key cryptography simplifies the certificate management in a traditional public key infrastructure and the built-in key escrow feature in an identity-based public key cryptography. Our scheme shares the merits of certificateless public key encryption cryptosystems and proxy re-encryption cryptosystems. Our certificateless proxy re-encryption scheme has several practical and useful properties - namely, multi-use, unidirectionality, non-interactivity, non-transitivity and so on. The security of our scheme bases on the standard bilinear Diffie-Hellman and the decisional Bilinear Diffie-Hellman assumptions.

• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.31-37
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• 2019

This study examined the sub - dimensions of mobile food platform service characteristics and verified how they affect the usability, usability and re - use intention. The data collection is from February 11, 2019 to February 28, 2019. The researcher visited the food service company and presented the questionnaire by direct interview. The results of the analysis are summarized as follows. First, the ubiquitous connectivity and interactivity of the mobile eater platform service have a significant effect on ease of use, but the situational awareness has no significant effect. Second, ubiquitous connectivity, situational awareness, and interactivity have a significant effect on usability, and ease of use has a significant effect on usability. Third, ubiquitous connectivity has a significant effect on re - use intention, and situational awareness and interactivity have a significant effect on re - use intention. Fourth, ease of use has no significant effect on re-use intention, but usefulness has a significant effect on re-use intention.

• The Journal of the Korea Contents Association
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• v.17 no.12
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• pp.117-126
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• 2017

As the recent research environment and research paradigm have become data-driven, Open Science, based on openness and sharing of public research results, has emerged as a global agenda for scientific research. National policies for sharing and re-use of research data from publicly-funded research are in effect globally. Therefore, in Korea, it is urgent to build policies and infrastructure for sharing and re-use of research data. In this paper, we investigate the current status of research data management of science and technology research institutes in Korea. We conducted in-depth interviews with researchers from 22 research institutes belonging to the National Research Council of Science & Technology, and 20 universities in Korea, asking about terms of creation management utilization of research data, willingness to share data, and needs for sharing and re-use of research data. From these interviews, we drew implications for open research data and future directions.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.2
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• pp.147-155
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• 2013

Proxy re-encryption scheme has advantage where plaintext does not get exposed during re-encryption process. This scheme is popular for sharing server-saved data in case of cloud computing or mobile office that uses server to save data. Since previous proxy re-encryption schemes can use re-encryption key over and over again, it may abuse re-encryption. To solve this problem, conditional proxy re-encryption scheme was proposed. But, it is computationally expensive generate the same number of re-encryption key with the number of condition values. In this paper, we propose an efficient conditional proxy re-encryption scheme in terms of re-encryption key generation. The proposed scheme uses only encryption and decryption process. Therefore it has advantage to generate one re-encryption key for one person. The proposed scheme is secure against chosen-ciphertext attack.