• Journal of the Korea Convergence Society
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• v.9 no.8
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• pp.33-39
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• 2018

In the Internet of Things (IoT) era, objects are connected to each other by wired and wireless networks, and information is exchanged whenever necessary. Channel and network environments change over time; thus, a carrier sensing function that identifies whether signals containing information are present in the channel is essential. The carrier sensing circuit of a wireless communication system determines the receiver sensitivity, and the receiver sensitivity is closely related to the service coverage and service quality of the system. As the receiver sensitivity decreases, the service coverage increases but it becomes sensitive to noise. However, as the receiver sensitivity increases, the service coverage decreases but it becomes insensitive to the noise. Therefore, carrier sensing design and optimization are very important from the viewpoint of the receiver sensitivity and noise sensitivity. This paper proposes an effective carrier sensing technique from the viewpoint of the receiver sensitivity for the long range IoT.

• The KIPS Transactions:PartC
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• v.15C no.5
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• pp.375-382
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• 2008

As the use of Internet and information communication technology is being generalized, the SSL protocol is essential in Internet because the important data should be transferred securely. While the SSL protocol is designed to defend from active attack such as message forgery and message alteration, the cipher suite setting can be easily modified. If the attacker draw on a malfunction of the client system and modify the cipher suite setting to the symmetric key algorithm which has short key length, he should eavesdrop and cryptanalysis the encrypt data. In this paper, we examine the domestic web site whether they generate the security session in the symmetric key algorithm which has short key length and propose the solution of the cipher suite setting problem.

• Journal of the Korea Computer Industry Society
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• v.2 no.10
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• pp.1355-1364
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• 2001

Internal control comprises the plan of Organization and all of the coordinate methods and measure adopted within a business to safeguard its assets. check the accuracy and reliability of its accounting data, promote operation efficiency, and encourage adherence to prescribed managerial policies. Internal accounting control is classified into General Control and Application Control. Essential elements of internal accounting control as follows : 1. General Control $\circled1$ Organization and operation controls. $\circled2$ System development and Documentation controls. $\circled3$ Hardware controls. $\circled4$ Software and hardware Accessibility controls. $\circled5$ General systems security and protection 2. Application control $\circled1$Input control. $\circled2$ Processing control. $\circled3$ Output control. Internal accounting control can establish a total management information system by connecting with mana-gement control of a company, and enable decision makers to establish decision support system(DSS), is so vital today.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5C
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• pp.737-749
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• 2004

Kerberos authenticates clients using symmetric-key cryptography, and supposed to Oust other systems of the realm in distributed network environment. But, authentication and authorization are essential elements for the security. In this paper, we design an efficient and secure authentication/authorization mechanism by introducing the public/private-key and installing the proxy privilege server to Kerberos. In the proposed mechanism, to make a system more secure, the value of the session key is changed everytime using MAC(message authentication code) algorithm with the long-term key for user-authentication and a random number exchanged through the public key. Also, we reduce the number of keys by simplifying authentication steps. Proxy privilege server certifies privilege request of client and issues a privilege attribute certificate. Application server executes privilege request of client which is included a privilege attribute certificate. Also, a privilege attribute certificate is used in delegation. We design an efficient and secure authentication/authorization algorithm with Kerberos.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.11
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• pp.27-34
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• 2005

Mobile Ad Hoc Networks (MANETs) are self-organized networks that do not rely in their operation on wired infrastructure. As in any networking technology, security is an essential element in MANET as well, for proliferation of this type of networks. But supporting secure communication in MANETs proved to be a significant challenge, mainly due to the fact that the set of nodes in the network can change frequently and rapidly and due to the lack of access to the wired infrastructure. In particular, the trust model and the authentication protocols, which were developed for wired and infrastructure-based networks, cannot be used in MANETs. In this paper, we address the problem of efficient authentication of distributed mobile users in geographically large networks. In particular, we propose a new authentication scheme for this case of MANETs. The proposed scheme exploits Randomized Groups to efficiently share authentication information among nodes that together implement the function of a distributive Certification Authority (CA). We then evaluate the performance of authentication using Randomized Groups.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.6
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• pp.379-386
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• 2014

Recently, middleboxes play a key role in many network settings such as firewalls, VPN gateways, proxies, intrusion detection and prevention systems, and WAN optimizers. However, achieving the performance and security benefits that middleboxes offer is highly complex, and therefore it is essential to manage middleboxes efficiently and dynamically. In this respect, Software-Defined Networking (SDN) offers a promising solution for middlebox policy enforcement by using logically centralized management, decoupling the data and control planes, and providing the ability to programmatically configure forwarding rules. Also, cloud computing and distributed Network Function Virtualization (NFV) can enable to manage middleboxes more easily. We introduce SDN-based middlebox management framework in integrated wired and wireless networks and discuss the further issues.

• Journal of Korean Society of Archives and Records Management
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• v.3 no.1
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• pp.111-127
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• 2003

Web-based information resources should be managed and used methodically in the same manner as the paper-based resources are managed and used. It is necessitated by the prevalence of web-based delivery of a variety of information. To develop a web-based digital collection, it is critical to establish a set of standardized evaluation criteria for web-resources. The evaluation criteria needs to include authority, trustworthy, reliability, functionality, relatedness, accessibility, structure, design, user support, and security related matters. However, it is also necessary to have certain flexibility to either emphasize or include particular evaluation criteria to reflect varying characteristics of the web resources especially for the purpose of developing an effective digital collection. In addition, it is essential to review the evaluation criteria with respect to value, demand, duplication prevention, and intellectual property, which are relevant to the web-based digital collection development. Finally, various strategies were suggested as means to develop more effective web-based digital resource collection. These strategies include organizing a selection committee to ensure the objectivity and consistency in web-resource evaluation; developing a model for web-based digital resource collection; sharing new standards, protocols, markups, and metadata with other digital libraries; and developing user-centered digital resource collection.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.5
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• pp.1181-1186
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• 2013

Mobile network has become an essential tool for mutual communications, so a survey research published that most of the smartphone users use Mobile Instant Messenger every day. In this paper, we developed a wire-wireless integrated web messenger that can be used in various platform of mobile devices and desktop computer for communicating between users of some companies. We defined a multi-organization as several independent companies. Our web messenger was developed for communicating of users of a multi-organization. So one of functions of our web messenger is to restrict access to some particular departments in each company for the security of their company. Developed web messenger worked reliably from variety of web browsers on most of platforms such as android, iOs and desktop computers.

• The Journal of Information Technology
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• v.6 no.1
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• pp.85-105
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• 2003

The study revealed that the companies are still reluctant to stop using document-based payment methods although they are aware the use of electronic payment system would reduce express and save time. Considering problems that are suggested in the conventional payment method, more companies will introduce and utilize the electronic payment system. Moreover, as the refined electronic payment system is essential in electronic trade, active studies on this field would greatly contribute to the development of electronic payment system. The prevailing settlement of international trade still relies on trading documents while the legal issues are not finalized for electronic bill of lading (B/L) and electronic bill. This research purpose on comparing some e-trading models in character and presenting the obstacles of e-trading activation and the solutions. e-trading models this research has studied are BOLERO, TradeCard, electronic L/C etc. Comparing characteristic points of the e-trading model in this article are as follows; 1)Access ways as a global e-trading model, 2)Structural and Functional characteristic, 3)Role as a global e-trading model, 5)Legal and Application issues in practice, 6)Security issues for Technology. But Further studies on this subject would be needed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.1976-1979
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• 2008

Studies on binary adder have been variously developed. According to those studies of critical worst delay and mean delay time of asynchronous binary adders, carry select adders (CSA) based on hybrid structure showed 17% better performance than ripple carry adders (RCA) in 32 bit asynchronous processors, and 23% better than in 64 bit microprocessor implemented. In the complicated signal processing systems such as RSA, it is essential to optimize the performance of binary adders which play fundamental roles. The researches which have been studied so far were subject mostly to addition algorithms or adder structures. In this study, we analyzed and designed adders in an asp;ect of synthesis method. We divided the ways of implementing adders into groups, each of which was synthesized with different synthesis options. Also, we analyzed the variously implemented adders to evaluate the performance and area so that we can propose a different approach of designing optimal binary adders.