• KIISE Transactions on Computing Practices
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• v.22 no.10
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• pp.504-512
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• 2016

In this paper, we propose a personalized event recommendation scheme using user's activity analysis and collaborative filtering in social network environments. The proposed scheme predicts un-evaluated attribute values through analysis of user activities, relationships, and collaborative filtering. The proposed scheme also incorporates a user's recent preferences by considering the recent history for the user or context-aware information to precisely grasp the user's preferences. As a result, the proposed scheme can recommend events to users with a high possibility to participate in new events, preventing indiscriminate recommendations. In order to show the superiority of the proposed scheme, we compare it with the existing scheme through performance evaluation.

• 한국전산유체공학회:학술대회논문집
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• 2008.03a
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• pp.166-170
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• 2008

The changing process from hovering mode to transition one is of importance to determine a stability of tilt-rotor aircraft, which is utilized in UAV(Unmaned Aerial Vehicle). The analysis on fluid flows and aerodynamic characteristics according to variation of tilting angle of rotor is essential step in development of tilt-rotor. In the present study, the computation domain is divided into the rotating and stationary regions in order to consider the rotating blades. For the convenient realization of various tilting angle as well as application of boundary condition, the whole computation region is constructed into sphere domain. The near farfield boundary condition is adopted. The airfoil used in computation is NACA 0012. The computation results for the hovering mode are validated by comparing with previously conducted experimental results. From the results, the flow fields around rotor blade and the aerodynamic characteristics in transition mode are observed. The computational result will provide the basis for development and performance evaluation of tilt-type aircraft.

• Journal of the Society of Disaster Information
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• v.16 no.1
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• pp.203-209
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• 2020

Purpose: This study aims to support the dispatcher to analysis the architecture type of fire. Method: Analysis the dispatch protocol guideline (released by gyunggi fire brigade) and make the dispatch scenario by site, combustibles, evacuation, fire extinguish systems. Result: After making scenario, develop the system (for dispatcher), is based on the tablet PC. Conclusion: Dispatch systems apply not only fire but rescue and disaster. This study focus on the fire, but It is need to expend the rescue and disaster. in korea, Fire Safety Evaluation and Multishop DB are possible to link to this system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1A
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• pp.64-73
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• 2000

Since so many potentials of services, applications, marketing and regulation, it is difficult to decide the fair pricing scheme of network services. However, these considerations are not particular to the operation of a communications network, which is closely related to technological constraints for QoS guarantee. In this paper, the power spectral analysis of MPEG video based on the P-MMBBP model is discussed in the manner of the QoS degradation to the packet delay. As a consequence of the QoS-degradation, a new fair-pricing scheme with the discount factor is proposed. As a result, the proposed scheme shows good characteristics to guarantee the fairness of the charging in the Internet wide-area network.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.1
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• pp.33-43
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• 2016

This study investigates the performance of hollow precast segmental bridge columns with reinforcement details for material quantity reduction. The proposed triangular reinforcement details are economically feasible and rational, and facilitate shorter construction periods. The precast segmental bridge columns provides an alternative to current cast-in-place systems. We tested a model of hollow precast segmental bridge columns under a constant axial load and a quasi-static, cyclically reversed horizontal load. We used a computer program, Reinforced Concrete Analysis in Higher Evaluation System Technology (RCAHEST), for analysis of reinforced concrete structures. The used numerical method gives a realistic prediction of performance throughout the loading cycles for hollow precast segmental bridge column specimens investigated. As a result, proposed reinforcement details for material quantity reduction was equal to existing reinforcement details in terms of required performance.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.1
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• pp.21-31
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• 2016

This study investigates the seismic performance of new hollow reinforced concrete (RC) bridge piers with triangular reinforcement details. The developed triangular reinforcement details are economically feasible and rational, and facilitate shorter construction periods. We tested a model of new hollow RC bridge piers with triangular reinforcement details under a constant axial load and a quasi-static, cyclically reversed horizontal load. We used a computer program, Reinforced Concrete Analysis in Higher Evaluation System Technology (RCAHEST), for analysis of RC structures. The used numerical method gives a realistic prediction of seismic performance throughout the loading cycles for several hollow pier specimens investigated. As a result, developed triangular reinforcement details for material quantity reduction was equal to existing reinforcement details in terms of required performance.

• Education of Primary School Mathematics
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• v.16 no.2
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• pp.163-182
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• 2013

The purpose of this study is an analysis on the 3rd graders' achievement in the elementary school. For this purpose, this study, first, analysed on the 3rd graders' achievement like the ratios of the achievement levels for whole students, sexual students, and regional students. Second, this study analysed the 3rd graders' assessment results like the total averages, averages for the contents area, sexual students, and regional students. Third, this study analysed students' special responses on the items.

• Journal of Surface Science and Engineering
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• v.50 no.6
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• pp.498-503
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• 2017

The aim of the present study is to evaluate electrochemical corrosion characteristics of base metal and weldment of Al-Mg alloy in seawater solution. The specimen was 5mm thick 5083-H321 Al alloy plate which was butt-welded using gas metal arc welding (GMAW). To identify the types of inclusions in the weldment, the microstructural observation was performed along with Energy dispersive spectrometer (EDS) analysis. The anodic polarization experiments were performed to evaluate the corrosion characteristics. After the anodic polarization test, the corroded surface was observed by SEM(scanning electron microscope) and EDS. The result of the analysis revealed a large number of voids in the weldment, especially coarse grains and inclusions in the heat affected zone. The corrosion current density of the weldment was found to be approximately 13 times higher than that of the base metal, indicating lower corrosion resistance of the weldment due to the defects in the weldment and the heat affected zone.

• Journal of Advanced Navigation Technology
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• v.7 no.1
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• pp.30-37
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• 2003

In this paper, we have analyzed the BER (Bit Error Rate) performance of MC-CDMA systems under indoor wireless environment with class A impulsive noise suggested by Middleton. For the performance evaluation, we considered from strong to weak impulsive noise characteristics. And we have evaluated the degree of performance improvement by using turbo code as a compensation technique to impulsive noise. From the result of analysis, it is found powerful performance improvement scheme must be adopted in the system under impulsive noise environment, and when turbo code scheme is adopted, system BER performance is improved by the $10^{-2}$. As the impulsive noise characteristics approaches AWGN characteristics, the degree of performance improvement by adopting turbo code become larger.

• Journal of KIBIM
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• v.11 no.3
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• pp.34-44
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• 2021

This study quantitatively analyzes the work performance of the structural safety diagnosis team that diagnoses pipe racks. To this end, a method for evaluating the performance of the structural safety diagnosis team using the queuing model was proposed. For verification, the case of applying the existing method and the method of introducing a 3D laser scanner for one site was used. The period, number of people, and initial investment cost of each project were collected through interviews with case project experts. As a result of analyzing the performance of the structural safety diagnosis team using the queuing model, it was possible to confirm the probability of delay in the work of each project and the amount of delayed work. Through this, the cost (standby cost) when the project was delayed was analyzed. Finally, economic analysis was conducted in consideration of the waiting cost, labor cost, and initial investment cost. The results of this study can be used to decide whether to introduce 3D laser scanners.