• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4A
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• pp.434-439
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• 2008

This paper proposes an efficient coarse frequency synchronizer for digital video broadcasting - second generation (DVB-S2). The input signal requirement of acquisition range for coarse frequency estimator in the DVB-S2 is around ${\pm}1.5625Mhz$, which corresponds to 6.25% of the symbol rate at 25Mbaud. At the process of analyzing the robust algorithm among data-aided approaches, we find that the Luise & Reggiannini (L&R) algorithm is the most promising one for coarse frequency estimation with respect to estimation performance and complexity. However, it requires many multipliers and adders to compute output values of correlators. We propose an efficient architecture identifying the serial correlator with the buffer and multiplexers. The proposed coarse frequency synchronizer can reduce the hardware complexity about 92% of the direct implementation. The proposed architecture has been implemented and verified on the Xilinx Virtex II FPGA.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.545-549
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• 2002

For the efficient method for acquisition of informations suitable to user's preferences and objectives in distributed environment, various researches on push agent which automatically processes its roles and sends the results to users are continued. The existing push agent models have induced increasing network overheads and traffics by continuous transmission of informations in the network environment of limitative bandwidth. In this paper, for the solution of the problems on these existing push agent systems and their interoperability, we design a push agent model based on CORBA event service. The proposed model solves the above problems and provides the retrieved results which are more suitable for user's requirement more fast and stably through the optimal path searching and controling method. And, it also supports the filtering technique for processing the duplicated or useless data that comes from the various distributed information systems.

• Journal of Advanced Navigation Technology
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• v.12 no.4
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• pp.324-331
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• 2008

In this paper, we developed the crops monitoring system using wireless sensor networks. It can acquire the information about the cultivation environments from a temperature, humidity, illumination and soil sensor then use the detailed information for very useful. The acquisition about the cultivation environment information with wireless sensor networks can be made up an environment that an administrator is able to confirm the information and wherever in a remote place instead of conventional way visiting the cultivate place by investing a lot of money and time. Therefore, it could be saving money, time and effort, and reduced the damages from the natural disasters such as a cold-weather damage and drought. In addition, we could be possible preventing from the damages of blight and harmful insects according to the temperature by an analysis. In agriculture field, this system could be supported for making a foundation of the advanced technology developing endless, and, in IT field, it is look forward to preparing the opportunity which creates a new requirement on the new technology.

• Journal of the Korea Society for Simulation
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• v.16 no.3
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• pp.11-18
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• 2007

Recently, as weapon systems have been more diverse and complicated, the factors of risk increase in development. Consequently, demanding reduction of acquired costs and period increase. Under the acquisition environment, more efficiently to develop weapon system, the necessity of application of defense M&S from requirement phase is on the rise. As the importance of M&S is stressed under distributed environment, so the standard of M&S(HLA, SEDRIS, etc.) and the system engineering process, namely FEDEP(Federation Development & Execution Process) have been developed. In this paper using the 5 phase expression, we constructed underwater engagement simulation(UNES) that prototype to develop naval weapon system test bed which take up integrated architecture in HLA. we developed simulators according to FEDEP for expandability and described process applying FEDEP fur UNES development.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.5
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• pp.105-113
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• 2019

Korean military uses 'Tactical information communication network' to exchange information between units. In this study, we developed a media processing board for multi-party voice and video telephony based on open source software. On the other hand, in order to apply open source software for weapon systems and parts that are mounted on weapon systems, appropriate review is required according to the weapon system software development and management manual of the Defense Acquisition Program Administration (DAPA). In this study, the analysis of the requirement items was performed and the appropriate countermeasures were proposed for the open software applied to the media processing board with respect to 'the guidelines for the application of weapon systems to open source software', an appendix to the DAPA's manual.

• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.568-573
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• 2023

Range resolution is the ability to distinguish different targets placed in same angular direction but at different distances from the radar. Normally, Range resolution requirement is defined as the width of transmitting pulse. The width of transmitting pulse does not mean the ability to distinguish two different targets. Range resolution performance to detect and track targets separately depends on the signal processing and tracking algorithm not only the width of transmitting pulse. This paper analyzes the processing steps in algorithms to affect the range resolution performance and verifies the results by roof-lab ground test using beacon signal. As a result, to track targets with the same angular position separately, it is desirable to have larger range difference than plot-track association test gate.

• Journal of Korea Water Resources Association
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• v.41 no.3
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• pp.293-303
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• 2008

Reservoir turbidity flows degrade the efficiency and sustainability of water supply system in many countries located in monsoon climate region. A decision support system called RTMMS aimed to assist reservoir operations was developed for the real time monitoring, modeling, and management of turbidity flows induced by flood runoffs in Daecheong reservoir. RTMMS consists of a real time data acquisition module that collects and stores field monitoring data, a data assimilation module that assists pre-processing of model input data, a two dimensional numerical model for the simulation of reservoir hydrodynamics and turbidity, and a post-processor that aids the analysis of simulation results and alternative management scenarios. RTMMS was calibrated using field data obtained during the flood season of 2004, and applied to real-time simulations of flood events occurred on July of 2006 for assessing its predictive capability. The system showed fairly satisfactory performance in reproducing the density flow regimes and fate of turbidity plumes in the reservoir with efficient computation time that is a vital requirement for a real time application. The configurations of RTMMS suggested in this study can be adopted in many reservoirs that have similar turbidity issues for better management of water supply utilities and downstream aquatic ecosystem.

• Journal of the Korea Institute of Building Construction
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• v.13 no.6
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• pp.579-584
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• 2013

The stable fueling and water supply should be prerequisites to guarantee the operational sustainment of military command post. Meanwhile, in terms of the operational sustainment, it is verified that the current wave-guided below cutoff (WBC) system cannot satisfy the requirement of control associated with water supply and fueling within the command post. In this study, as the dielectric substance can block electromagnetic pulse (EMP), it was tried to identify the shielding effectiveness of the multi WBCs filled with water and diesel for attenuating the EMP effect using experiment based on the MIL STD 188-125-1. According to the experimental results, used water in the experiment show the shielding effectiveness from around 640 MHz frequency because of minerals contained in the water. Furthermore, it was noted that EMP attenuating strength of the WBC filled with diesel was enlarged from around 1,680 MHz frequency. Resultingly, it could be concluded that it is enough to supply stable water and diesel through the multi WBC to block EMP within the military command post for guaranteeing the military operations sustainment.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1413-1420
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• 2018

This study was conducted to provide the information for the promotion of oral health in nursing students. The subjects were 207 in female students for self-administered questionnaires. The percentage of subject to visit dental clinic was 64.3%, to Regular checkup was 25.9%, cure of caries was 23.5% for last one year. The percentage of reasons not treated 'less importance' were 12.6%, 'fear of the dental clinic' was 10.6%. The average number of brushing teeth were 3.1. 56.0% students brush their teeth for two ~ three minutes. But intention of visit to the dentist were 'only when treated' was 51.7%, 'only when there is pain' was 10.1%. The intention of oral education was 54.6%, the content of the desired education 'whitening' were 34.5%, 'prevention of bad breath' was 19.2%. Dental health information acquisition path 'internet' were 42.0%, 'family or friends' was 25.6%. Susceptibility was 2.47 points, severity was 2.00 points, benefit was 4.03 points in oral health belief. Compared to students who needed dental treatment but did not receive treatment, oral health beliefs were higher among those who were treated(p<.001), students with cavities showed a higher level of oral health belief than those without cavities(p<.001). There was significant corelation between 'number of caries' and susceptibility(r=.330, p=.002), severity(r=.25, p=.019). The result should be reflected in the development of effective program for nursing students' oral health care.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.470-478
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• 2019

As the growth of the domestic defense industry is remarkable regarding technology level and export size, technology protection is necessary. Particularly, there is a need to apply anti-tamper measures to prevent critical technologies from illegally being taken out of weapon systems. However, there is no security protection strategy and system built yet in ROK. Precedent studies discussed the trend analysis and technical research for specific protective techniques, and the application of anti-tamper using limited procedures was provided. Recently, methods of how to select the technology for protection were studied based on risk management. Nonetheless, these studies cannot be associated with the acquisition process for the whole life-cycle, having difficulty with actual development and evaluation of the weapon systems. The objective of our study is to derive the system requirements of the weapon system for which anti-tamper measures have been determined to apply. Specifically, requirements items suitable for the development of anti-tamper weapon systems were derived based on ISO/IEC 19790, the CMVP standard for the development and verification of cryptographic modules. Also, its utilization in technical reviews and test & evaluations was presented. The usefulness of the research results was confirmed through inductive inference and comparative evaluation. The result can be expected to play a role in initiating extensive activities needed for technology protection of the weapon systems.