• ETRI Journal
• /
• v.28 no.4
• /
• pp.425-434
• /
• 2006

We propose a fast macroblock mode prediction and decision algorithm based on contextual information for Pslices in the H.264/AVC video standard, in which the mode prediction part is composed of intra and inter modes. There are nine $4{\times}4$ and four $16{\times}16$ modes in the intra mode prediction, and seven block types exist for the best coding gain based on rate-distortion optimization. This scheme gives rise to exhaustive computations (search) in the coding procedure. To overcome this problem, a fast inter mode prediction scheme is applied that uses contextual mode information for P-slices. We verify the performance of the proposed scheme through a comparative analysis of experimental results. The suggested mode search procedure increased more than 57% in speed compared to a full mode search and more than 20% compared to the other methods.

• Journal of Communications and Networks
• /
• v.14 no.4
• /
• pp.364-373
• /
• 2012

In this paper, we propose combined relay selection and cooperative beamforming schemes for physical layer security. Generally, high operational complexity is required for cooperative beamforming withmultiple relays because of the required information exchange and synchronization among the relays. On the other hand, while it is desirable to reduce the number of relays participating in cooperative beamforming because of the associated complexity problem, doing so may degrade the coding gain of cooperative beamforming. Hence, we propose combined relay selection and cooperative beamforming schemes, where only two of the available relays are selected for beamforming and data transmission. The proposed schemes introduce a selection gain which partially compensates for the decrease in coding gain due to limiting the number of participating relays to two. Both the cases where full and only partial channel state information are available for relay selection and cooperative beamforming are considered. Analytical and simulation results for the proposed schemes show improved secrecy capacities compared to existing physical layer security schemes employing cooperative relays.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.7A
• /
• pp.639-645
• /
• 2010

In the paper, a selection relaying scheme is proposed and analyzed in which relays retransmit the erroneous packet without checking the correctness of their received packets. The proposal not only achieves the full diversity gain in a limited number of retransmissions but it also gets better performance than other schemes. Additionally, a threshold in the number of retransmissions and the closed form expression for packet error rate (PER) are derived. Simulation results are given to confirm the accuracy of analysis and to significantly prove advantages of the proposal.

• Journal of electromagnetic engineering and science
• /
• v.13 no.3
• /
• pp.173-177
• /
• 2013

This paper presents a new method for analyzing the maximum efficiency of a wireless power transfer (WPT) system with multiple n resonators. The method is based on ABCD matrices and allows transformation of the WPT system with multiple n resonators into a single two-port network system. The general maximum efficiency equation of a WPT system with multiple n resonators is derived using the ABCD matrix. Use of this equation allows placement of the relay resonators for maximum efficiency even though they are asymmetrical. The general maximum efficiency equation and the method of the optimum placement are verified by a full wave simulation. The results show that the method is useful for the analysis of a WPT system with relay resonators.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.9
• /
• pp.1727-1735
• /
• 2002

The usage of beam scanning type laser marker is rapidly increasing in the field of semiconductor equipment. A device called ″beam adjuster″ is employed to adjust the visible diode laser, which points the marking position for various setting. The device is very sensitive to manufacturing tolerance and assembly condition. Axiomatic approach has been applied to the design of the device. An existing design is analyzed based on the Independence Axiom. The existing design is found to violate the axiom. Two new designs are proposed to satisfy the Independence Axiom. The Information Axiom is utilized to evaluate the designs. A design is selected to have the minimum information content. The significance of this research is that a full cycle of axiomatic design is applied to a real engineering product.

• Asia pacific journal of information systems
• /
• v.9 no.3
• /
• pp.75-92
• /
• 1999

Executive information systems (EIS) developers are faced with an increasingly difficult choice problem in the evaluation and selection of software packages. For many reasons, they frequently must depend on identification and evaluation of features of packages. When EIS software evaluation is regarded as an unstructured or semi-structured group decision making problem, the most appropriate decision-aiding methods are needed to help effective group interaction. This paper examines evaluation criteria of full-featured EIS packages and considers the priority of these criteria using the Analytic Hierarchy Process (AHP). Two exploratory phases are presented. In the first phase, an approach combining the AHP with the linear weighted attribute method is presented to computer qualities of some packages. In the second phase, the decision making group includes EIS developers, users, and vendors to prioritize evaluation criteria.

• Proceedings of the KSPS conference
• /
• 2007.05a
• /
• pp.135-137
• /
• 2007

This study has experimented and materialized a computational lexical processing model which hybridizes full model and decomposition model as applying lexical acquisition, one of early stages of human lexical processes, to Korean. As the result of the study, we could simulate the lexical acquisition process of linguistic input through experiments and studying, and suggest a theoretical foundation for the order of acquitting certain grammatical categories. Also, the model of this study has shown proofs with which we can infer the type of the mental lexicon of the human cerebrum through fu1l-list dictionary and decomposition dictionary which were automatically produced in the study.

• Journal of the Korean Society for Library and Information Science
• /
• v.30 no.4
• /
• pp.105-127
• /
• 1996

This paper considers the nature of a digital library in terms of definitions and its technical environment It also explores some of the problems and issues involved in demanding and supplying information So current publishing systems and the library resources were investigated. The relative advantages of both electronic and paper journals are also briefly considered and it is suggested that research relating to build the full text database is required. Finally it considers the innovative management technology such as TQM, Business Process Reengineering to innovative library itself.

• Asia pacific journal of information systems
• /
• v.21 no.1
• /
• pp.29-47
• /
• 2011

Despite the growing attention to the effective utilization of ICT system in workplace, there is an accumulation of evidence from the literature indicating that organizations do not utilize newly introduced ICT systems to their full functional potential and an amount of new implementations continue to fail. We explore the reasons for the underutilization of new ICT by focusing on the individuals' social networks. This paper investigates how the social networks influence individual adaptation to the new ICT and its related performance. Based on the coping theory, we establish a research model that explains the coping mechanism. Collected data are analyzed to test the proposed model and its hypotheses using PLS and UCINET. The results show that the coping effort mechanism of individuals can be explained in terms of their positions within social networks. We conclude the paper by discussing theoretical and practical implications for the research findings and by proposing future studies.

• Journal of information and communication convergence engineering
• /
• v.18 no.1
• /
• pp.22-27
• /
• 2020

Content centric networking (CCN) is regarded as promising internet architecture because it can provide network efficiency in terms of bandwidth consumption by separating contents from a specific network location and decrease network congestion events. However, the application of a CCN does not widely consider the side effects of mobile devices, particularly mobile content sources. For content source mobility, a full routing update is required. Therefore, in this study, a route optimization scheme is proposed for mobile content sources in a CCN environment to provide low communication overhead, short download time, and low resource consumption. The proposed scheme establishes a direct path between content requesters and a mobile content source for the exchange of interest and data packets using interest-piggybacked data packets. Based on the inherent CCN naming characteristics, the content source does not know the name prefix of the content consumer, and thus the proposed optimized CCN scheme utilizes the content router in the home domain of the content source.