• International Journal of Highway Engineering
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• v.12 no.4
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• pp.187-196
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• 2010

The purpose of this study is to develop the calibration method for temperature effects to improve the accuracy of the Weigh-In-Motion(WIM) system for collecting long-term truck weight data. WIM system was installed at a location where the truck traffic volume is high and weight data has been collected from January 2010. In this study, as a calibration measure, the first axle weight of Truck Type 10, the semi tractor-trailer is used based on the fact that the first axle weight is relatively constant, independent of the cargo weight. From this fact, calibration equations are developed from the relationship between the axle weight and the temperature(daily mean, maximum and minimum). Analysis on calibrated weight data shows adequacy of the proposed calibration method. Results of this study can be used to improve the accuracy of the WIM system and to carry out more rational design of pavement and bridge structures.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.213-216
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• 2006

In this paper a development of shaft power measuring system for a small vessel is discussed. It is important that the exact power measurement of marine engine which is used for ship's propulsion since the engine power is related to ship's usage and its shaft design. Two gearwheel and magnetic sensors are adopted to measure torsional angle on the shaft. High resolution encoder is also applied to compensate the output signal from gearwheel. The calculation of shaft power is executed using measured signal and angular velocity of rotating machine and the result is plotted on the monitoring screen.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.1
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• pp.75-82
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• 2011

Marine current energy is one of the most interesting renewable and clean energy resources that have been less exploited. Especially, Korea has worldwide outstanding tidal current energy resources and it is highly required to develop tidal in-stream energy conversion system in coastal area. The objective of study is to investigate harnessing techniques of tidal current energy and to design the a 100 kW horizontal axis tidal turbine using blade element momentum theory with Prandtl's tip loss factor for optimal design procedures. In addition, Influence of Prandtl's tip loss factor at local blade positions as a function of tip speed ratio was studied, and the analysed results showed that power coefficient of designed rotor blade using NACA 63812 was 0.49 at rated tip speed ratio.

• The KIPS Transactions:PartD
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• v.18D no.2
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• pp.143-148
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• 2011

In this paper developed a wearable activity device and algorithm which can be converted into the real-time activity and monitoring by acquiring sensor row data to be occurred when a person is walking by using a tri-axial accelerometer. Test was proceeded at various step speeds such as slow walking, walking, fast walking, slow running, running and fast running, etc. for 36 minutes in accordance with the test protocol after wearing a metabolic test system(K4B2), Actical and the device developed in this study at the treadmill with 59 participants of subjects as its target. To measure the activity of human body, a regression equation estimating the Energy Expenditure(EE) was drawn by using data output from the accelerometer and information on subjects. As a result of experiment, the recognition rate of algorithm being proposed was shown the activity conversion algorithm was enhanced by 1.61% better than the performance of Actical.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.7
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• pp.594-599
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• 2017

In this thesis, the development and the verification of the test-aid are described, providing various attitude errors through the electric stimulus to the Sun sensor. This test-aid for 2-axis analogue Sun sensor is used for polarity test in the assembly stage for GK2 satellite. The test-aid used for GK2 satellite is for COMS satellite and, due to the failure risk, manufactured by domestic company. The characteristics of the COMS test-aid used for GK2 satellite and the manufactured test-aid are showed with similar through the several tests. In this thesis, there are conformed the capability for replacing of test-aid because the characteristics of the manufactured test-aid is acquired same as that of the COMS test-aid using the controller tuning functions.

• Journal of Korean Society of Steel Construction
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• v.28 no.4
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• pp.263-270
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• 2016

Corrosion resistance steel has been widely used for port and offshore structures exposed to harsh coastal and oceanic environments, due to lower corrosion rate. New higher strength corrosion resistance steel tubes named STKM500 in KS D 3300 were recently developed by domestic technology and expected to replace foreign ASTM A690 steel. In this study, tensile test results are included to show higher yield and tensile strength of STKM500. Then, buckling test results obtained from 2m, 6m, and 12m steel tubes are demonstrated, based on which an allowable axial compressive stress curve for STKM500 steel tubes is suggested.

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.1-7
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• 2012

In this research, a single-axis attitude control test bed is developed, and simulation and tests experiments are performed, as a preliminary research of a quad-rotor aerial vehicle development. A single-axis test bed with seesaw configuration is manufactured using two motors and propellers, and the aerodynamic parameters are derived by thrust tests. The response of the system is estimated with Matlab/Simulink, and experiments are performed with attitude control computer and an attitude sensor onboard the test bed. Comparing the results of simulated and tested data, factors of steady-state errors during experiments are found, and performances of used attitude control algorithm and the control computer were verified. In these process, essential preliminary data for attitude control of a quad-rotor unmanned aerial vehicle were acquired.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.12
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• pp.1238-1244
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• 2009

This work proposes a GUI-type on-line diagnostic program using SIMULINK and Fuzzy-Neuro algorithms for a helicopter turboshaft engine. During development of the diagnostic program, a look-up table type base performance module for reducing computer calculating time and a signal generation module for simulating real time performance data are used. This program is composed of the on-line condition monitoring program to monitor on-line measuring performance condition, the fuzzy inference system to isolate the faults from measuring data and the neural network to quantify the isolated faults. The reliability and capability of the proposed on-line diagnostic program were confirmed through application to the helicopter engine health monitoring.

• Journal of Korean Society of Steel Construction
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• v.9 no.4 s.33
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• pp.557-578
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• 1997

The objective of the study in this paper was to develop a beam-column element to model members with purely flexural yielding, as well as members with yielding under combined flexure and axial force during severe earthquake ground motins. The developed element can be considered as an one-component series hinge type model. It has the capability to model plastic axial deformation and changes in axial stiffness, and employs hardening rules to handle monotonic, cyclic or arbitrary loading. In general, when compared to experimental results and fiber model predictions, the element showed significantly better performance than the bilinear hinger model and could properly model the beam-column behavior of bare steel members in moment resisting frames. The developed element can more accurately predict local deformation demands and overall responses of structural systems under earthquake loadings than the bilinear hinge element.

• Convergence Security Journal
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• v.14 no.1
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• pp.11-21
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• 2014

South Korea should not be in subordinate position in international relationships like the past. As the status of middle power. South Korea achieves peaceful unification through overcoming North Korea's nuclear and conventional threats, and builds military power in Northeast Asia as a 'balancer'. This can firstly be achieved by constructing "attack systems triad". 'attack systems triad' can be established through integrating the C41SR as a common strategy for the purposes of preemptive deterrence and retaliatory deterrence against the dangers of the present and the future. Second, denial deterrence can be achieved by establishing "defense system triad" by combining common military power and defensive weapon system. Finally, development of independent advanced technological strategies can be achieved by building defense industry and combination of research and development through constructing "Infra triad". As for constructing and reinforcing the future of the ROK military, a unilateral principle and policy efforts to achieve the aforementioned force construction models are needed. This can only be achieved through the government's national vision to take on the role of mediator and a basis founded upon the consensus of the public.