• Journal of Digital Contents Society
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• v.8 no.4
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• pp.607-613
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• 2007

Current changes in the written language curriculum have lead to emphasis being placed on the process involved in writing rather than the product. Writing is being viewed as a means of exploration, with text being manipulated in revision until a clear message is conveyed. This study focuses on the use of the computer in written language, as a tool to facilitate learning, increase interaction and alter children's attitudes. Some children from a local primary school participated in a project which gave them access to a computer and guidance during the process of revision. Evaluation of this study showed a two-fold effect. Firstly the writing behaviors of the children developed with their increased involvement in the process. For example, the children began to read what they had written thereby independently evaluating the content. Secondly, arising from this, as a sense of control over their writing was gained the children's attitudes towards writing became more positive.

• Journal of Information Processing Systems
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• v.13 no.4
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• pp.653-667
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• 2017

The significant advances in information and communication technologies are changing the process of how information is accessed. The internet is a very important source of information and it influences the development of other media. Furthermore, the growth of digital content is a big problem for academic digital libraries, so that similar tools can be applied in this scope to provide users with access to the information. Given the importance of this, we have reviewed and analyzed several proposals that improve the processes of disseminating information in these university digital libraries and that promote access to information of interest. These proposals manage to adapt a user's access to information according to his or her needs and preferences. As seen in the literature one of the techniques with the best results, is the application of recommender systems. These are tools whose objective is to evaluate and filter the vast amount of digital information that is accessible online in order to help users in their processes of accessing information. In particular, we are focused on the analysis of the fuzzy linguistic recommender systems (i.e., recommender systems that use fuzzy linguistic modeling tools to manage the user's preferences and the uncertainty of the system in a qualitative way). Thus, in this work, we analyzed some proposals based on fuzzy linguistic recommender systems to help researchers, students, and teachers access resources of interest and thus, improve and complement the services provided by academic digital libraries.

• Journal of information and communication convergence engineering
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• v.2 no.2
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• pp.128-131
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• 2004

We suggest resource authorization system based on RBAC admitting someone to access resources. In existing grid environment, The authorization mechanism on user's resource is to give users an authority on the basis of DN(Distinguished Name) of proxy certificate and map file mapped in local system ID by one-to-one. In this case, it is difficulty in resource management such as each accounting management, memory resource, and disk resource, if the number of users, who want to use them is increased. To solve this problem, we specify the role of user's task in extension fields of his proxy certificate instead of the authorization mechanism of user's ID and propose resource authorization system being able to access his resource.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1394-1401
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• 2007

Secure access control is a hot issue of large-scale organizations or information systems, because they have numerous users and information objects. In many cases, system developers should implement an access control module as a part of application. This way induces difficult modification of the module and repeated implementation for new applications. In this paper we implement a Java API library for access control to support system developers who use Java. They can easily build up access control module using our library. Our library supports typical access control models, and it can offer new types of access control. Furthermore, it is able to run multiple access control models at the same time.

• Journal of the Korean Society for information Management
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• v.7 no.1
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• pp.96-120
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• 1990

Academic and research computer networks are the essential communications component that can provide scientists and engineers with convenient access to local and remote computing and information resources. Nowadays, academic and research computer networks, providing access to a variety of resources and information services, can significantly increase the productivity of scientists and engineers. In Korea there have been some activities of academic and research networks since early of 1980. This study presents background of development of computer network, summaries the types of services offered by academic and research computer networks and analyses the potential benefits resulting from their availability. Use and need of Korean researchers about academic and research computer networks are also reviewed as well as it prospects Korean Computer Network for Education and Research & Development, a new national-base network being implemented by government.

• Journal of Communications and Networks
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• v.5 no.3
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• pp.187-196
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• 2003

We consider the use of error control coding in direct sequence-code-division multiple access (OS-COMA) systems that employ multiuser detection (MUO) and space diversity. The relative performance gain between Reed-Solomon (RS) code and convolutional code (CC) is well known in [1] for the single user, additive white Gaussian noise (AWGN) channel. In this case, RS codes outperform CC's at high signal-to-noise ratios. We find that this is not the case for the multiuser interference channel mentioned above. For useful error rates, we find that soft-decision CC's to be uniformly better than RS codes when used with DS-COMA modulation in multiuser space-time channels. In our development, we use the Gaussian approximation on the interference to determine performance error bounds for systems with low number of users. Then, we check their accuracy in error rate estimation via system's simulation. These performance bounds will in turn allow us to consider a large number of users where we can estimate the gain in user-capacity due to channel coding. Lastly, the use of turbo codes is considered where it is shown that they offer a coding gain of 2.5 dB relative to soft-decision CC.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.10
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• pp.4136-4156
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• 2020

Recently, data can be safely shared or stored using the infrastructure of cloud computing in various fields. However, issues such as data security and privacy affect cloud environments. Thus, a variety of security technologies are required, one of them is security technology using CP-ABE. Research into the CP-ABE scheme is currently ongoing, but the existing CP-ABE schemes can pose security threats and are inefficient. In terms of security, the CP-ABE approach should be secure against user collusion attacks and masquerade attacks. In addition, in a dynamic cloud environment where users are frequently added or removed, they must eliminate user access when they leave, and so users will not be able to access the cloud after removal. A user who has left should not be able to access the cloud with the existing attributes, secret key that had been granted. In addition, the existing CP-ABE scheme increases the size of the ciphertext according to the number of attributes specified by the data owner. This leads to inefficient use of cloud storage space and increases the amount of operations carried out by the user, which becomes excessive when the number of attributes is large. In this paper, CP-ABE access control is proposed to block access of withdrawn users in dynamic cloud environments. This proposed scheme focuses on the revocation of the attributes of the withdrawn users and the output of a ciphertext of a constant-size, and improves the efficiency of the user decryption operation through outsourcing.

• International Journal of Advanced Culture Technology
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• v.4 no.4
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• pp.70-74
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• 2016

Electronic commerce (E-commerce) using virtual reality (VR) has the advantage of being able to purchase products without restrictions of time and location by overcoming the limitations of existing offline transactions. It is still a rudimentary but fast growing technology, and the use of E-commerce in VR is expanding. The barriers that consumers might face in utilizing E-commerce in VR is the relevance to Information and Communications Technologies (ICT) technology. Fundamentally, it requires Internet access and use through PCs or mobile devices such as smart phones. Because unlike off-line markets, it is difficult to determine the purchase patterns of customers, customer purchasing behavior analysis must be done using computer access records. In order to expand and develop E-commerce in VR in the future, learning ability should be improved through combining with artificial neural network by deep learning that is recently in the spotlight, and the ability to overcome errors need to be improved to enable use in various fields.

• Journal of Broadcast Engineering
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• v.21 no.1
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• pp.113-116
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• 2016

Cognitive radio network technology is that secondary (unlicensed) users use the spectrum of primary (licensed) users without interfering primary communication. In this paper, we propose multiple access scheme for a cognitive radio network, where multiple secondary users access spectrum of one primary user. We consider two types of multiple access scheme, one is p-persistent and one is non-persistent, and apply these two schemes in the secondary network. For each multiple access scheme, total throughput of secondary network is derived and verified by Monte Carlo simulation. Simulation results show that maximum total throughput of the secondary network is achieved when channel access probability or the number of maximum waiting frames is chosen appropriately.

• Journal of the Korea Society of Computer and Information
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• v.7 no.2
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• pp.46-52
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• 2002

Trend of wire internet has been transferred to wireless internet gradually due to the spread of mobile phone which made Possible Mobility and portability which wire internet could not afford. Not only front line of business part can access business information but also people can use government information for their daily life without limit of place. The frequent report of larceny and misuse of information has been issued to social sector that the need for IDS considering wire wireless internet. In this paper to design IDS to protect information first, searched wire internet intrusion type, intrusion detection method, and wireless intrusion type. In this paper, first, separate abnormal access at the point of system landing and detect intrusion attack with disguise through mobile wireless internet. Due to the intruder can access system normally with disguise, Circuit Patrol model has been suggested to monitor from intrusion attack.