• Journal of Korean Library and Information Science Society
• /
• v.40 no.3
• /
• pp.25-47
• /
• 2009

The purpose of this study is to analyze ISO/DIS 28560 and to cope with the current developments in library RFID technologies. The user data elements in part 1 and encoding rules in part 2 and part 3 of ISO/DIS 28560 are explored. In addition, a few corresponding cases regarding user data elements on ISO/DIS 28560 are investigated. Based on the corresponding cases, four user data elements are selected. They are , , , and . This study expects to allow fertile ground for discussion on the selection of user data elements in Korea.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.10 no.1
• /
• pp.99-104
• /
• 2014

Nowadays, various researches fulfill in many communication engineering area for B4G (Beyond Forth Generation). Next LTE-A (Long Term Evolution Advanced), MU-MIMO (Multi-User Multi Input Multi Output) method raises to upgrade throughput performance. However, the method of user selection is not decided because of many types and discussions in MU-MIMO system. Many existing methods are powerful for enhancing performance but have various restrictions in practical implementation. Fairness problem is primary restriction in this area. Existing papers emphasis algorithm to increase sum-rate but we introduce an algorithm about dealing with fairness problem for real commercialization implementation. Therefore, this paper introduces new user selection method in MU-MIMO system. This method overcomes a fairness problem in SUS (Semiorthogonal User Selection) algorithm. We can use the method to get a similar sum-rate with SUS and a high fairness performance. And this paper uses a hybrid method with SC-SUS (Superposition Coding SUS) algorithm and SUS algorithm. We find a threshold value of optimal performance by experimental method. We show this performance by computer simulation with MATLAB and analysis that results. And we compare the results with another paper's that different way to solve fairness problem.

• Journal of Korean Institute of Industrial Engineers
• /
• v.42 no.4
• /
• pp.280-289
• /
• 2016

User authentication is an important issue on computer network systems. Most of the current computer network systems use the ID-password string match as the primary user authentication method. However, in password-based authentication, whoever acquires the password of a valid user can access the system without any restrictions. In this paper, we present a keystroke dynamics-based user authentication to resolve limitations of the password-based authentication. Since most previous studies employed a fixed-length text as an input data, we aims at enhancing the authentication performance by combining four different variable creation methods from a variable-length free text as an input data. As authentication algorithms, four one-class classifiers are employed. We verify the proposed approach through an experiment based on actual keystroke data collected from 100 participants who provided more than 17,000 keystrokes for both Korean and English. The experimental results show that our proposed method significantly improve the authentication performance compared to the existing approaches.

• Journal of Satellite, Information and Communications
• /
• v.12 no.4
• /
• pp.141-145
• /
• 2017

Spectrum sensing is a critical functionality of Cognitive Radio(CR) systems and the CR systems can be applied to RF energy harvesting systems to improve an energy harvesting rate. There are number of spectrum sensing techniques. One of techniques is energy detection. Energy detection is the simplest detection method and is the most commonly used. But, energy detection has a hidden terminal problem in real wireless communication, because of secondary user (SU) can be affected by frequency fading and shadowing. Cooperative spectrum sensing can solve this problem using spatial diversity of SUs. But it has a problem of increasing data by processing multiple secondary. So, we propose the system model using adaptive spectrum sensing algorithm and system model is simulated. This algorithm chooses sensing method between single energy sensing and cooperative energy according to the received signal's Signal to Noise Ratio (SNR) from Primary User (PU). The simulation result shows that adaptive spectrum sensing has an efficiency and improvement in CR systems.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.40 no.1
• /
• pp.150-164
• /
• 2017

The development of an appropriate public service quality model has become increasingly recognised as an important subject of interest in the public sector as well as academia. In particular, the public systems enacted by governments are widely used and have a significant impact on national competitiveness. But few researches have been conducted to explore the quality dimensions of a public system service and empirically examine the relationship among related variables. Therefore, in this study, we strive to develop a quality measurement model of public system service that can be effectively used in practice. Using 601 samples gathered through a structured survey from project engineers, a conceptual quality model of public system is presented and discussed. Given the exploratory nature of this study, an exploratory factor analysis is used to investigate quality dimensions and partial least square (PLS) is employed in determining the structural relationships. From empirical results, we found that the quality dimensions of the public system had four distinct quality dimensions (design quality, environment quality, primary outcome quality, additive outcome quality). All four quality dimensions showed good representative factors in explaining user satisfaction. Perceived trust was proved to significantly mediate the relationship between quality dimensions and user satisfaction. Our research is expected to contribute to the literature by providing a good conceptual framework for assessing public system quality by linking four quality dimensions with user satisfaction. In particular, the developed model can elaborately measure process quality and multi-functional outcome quality of the system by the supplementation of design quality and additive outcome quality respectively. Practical implications are also suggested on the basis of our analysis.

• Proceedings of the Korea Contents Association Conference
• /
• 2004.05a
• /
• pp.241-260
• /
• 2004

Trade portal site is one of the tools which makes it possible for small and medium-sized enterprises(SMEs) to manage international trade activities more efficiently by using the newest information and telecommunication technology. So Korean SMEs should utilize trade portal sites more actively to promote global competitive power. Based on the theory of service quality and an existing research related to using information technology. this research analyzed the primary factors which affect user's utilization satisfaction in using trade portal sites. According to the results of the empirical study on actual users of the representative trade portal sites by using multiple regression analysis, The primary factors, such as service quality, government policy and cost have affected user's utilization satisfaction in using trade portal site. and user's utilization satisfaction have positive effect on continuous using intention. These research results will provide many useful insights to the managers of trade portal sites, e-trade system developers and government policy makers.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.2B
• /
• pp.108-117
• /
• 2007

Recursive DNS is configured as primary or secondary DNS on user PC and performs domain name resolution corresponding user's DNS query. At present, the amount of DNS traffic is occupied high rate in the total internet traffic and the internet traffic would be increased by failure of IPv6 DNS queries and responses as IPv6 transition environment. Also, existing Recursive DNS service mechanisms is unstable on malicious user's attack same as DoS/DDoS Attack and isn't provide to user trust DNS service fail-over. In this paper, we propose IPv6 Recursive DNS service mechanisms for based on anycast for improving stability. It is that fail-over Recursive DNS is configured IPv6 Anycast address for primary Recursive DNS's foil-over. this mechanisms increases reliability and resiliency to DoS/DDoS attacks and reduces query latency and helps minimize DNS traffic as inducing IPv6 address.

• 한국HCI학회:학술대회논문집
• /
• 2008.02b
• /
• pp.651-655
• /
• 2008

It provides a three-dimensional virtual experience consisting of information presented to and perceived by the senses of the user. Recently, the advent of a virtual avatar, which mimics the appearance and behavior of humans, enable that the virtual reality (VR) can provide not only a virtual space but also a virtual society to be interact with a virtual avatar which represents humans. But, it is impossible that the user directly interacts with the VE in previous studies, though direct interactions occur in real social relationship. Therefore, In this study, we know that the cognition about a avatar when the user directly interacts with the virtual avatar in the VE. In order to investigate this purpose, we performed a fMRI study using VE that a avatar accept or reject the user's offer when the user offer his (or her) hand to a avatar. In result of questionnaire about the user's feeling by avatar's action, the user feels about avatar's acceptance action that the avatar acts positively and suitably. In contrast the user feels about avatar's rejective action that the avatar acts negatively and disapprovingly. In result of fMRI analysis, the primary visual area, the visual association area, the SMA, the premotor area, the cerebellum and etc, activate in common with the other avatar's acceptance action and rejective action. The results show that the subject recognizes not only avatars as social objects but also avatar's action as socially meaningful action. In other words, it is possible to transfer social context and emotion through avatar's action.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.4
• /
• pp.1192-1207
• /
• 2014

Dynamic spectrum sharing is a key technology to improve spectrum utilization in wireless networks. The elastic spectrum management provides a new opportunity for licensed primary users and unlicensed secondary users to efficiently utilize the scarce wireless resource. In this paper, we present a game-theoretic framework for dynamic spectrum allocation where the primary users rent the unutilized spectrum to the secondary users for a monetary profit. In reality, due to the ON-OFF behavior of the primary user, the quantity of spectrum that can be opportunistically shared by the secondary users is limited. We model this situation with the renewal theory and formulate the spectrum pricing scheme with the Bertrand game, taking into account the scarcity of the spectrum. By the Nash-equilibrium pricing scheme, each player in the game continually converges to a strategy that maximizes its own profit. We also investigate the impact of several properties, including channel quality and spectrum substitutability. Based on the equilibrium analysis, we finally propose a decentralized algorithm that leads the primary users to the Nash-equilibrium, called DST. The stability of the proposed algorithm in terms of convergence to the Nash equilibrium is also studied.

• Journal of information and communication convergence engineering
• /
• v.12 no.2
• /
• pp.97-103
• /
• 2014

In spectrum sensing, there is a tradeoff between the probability of missed detection and the probability of a false alarm according to the value of the sensing threshold. Therefore, it is important to determine the sensing threshold suitable to the environment of cognitive radio networks. In this study, we consider a cognitive radio-based ad hoc network where secondary users directly communicate by using the same frequency band as the primary system and control their transmit power on the basis of the distance between them. First, we investigate a condition in which the primary and the secondary users can share the same frequency band without harmful interference from each other, and then, propose an algorithm that controls the sensing threshold dynamically on the basis of the transmit power of the secondary user. The analysis and simulation results show that the proposed sensing threshold control algorithm has low probabilities of both missed detection and a false alarm and thus, enables optimized spectrum sharing between the primary and the secondary systems.