• The Journal of the Korea Contents Association
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• v.11 no.8
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• pp.475-487
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• 2011

In this paper, we present a systematic method to derive spectrum of high-order pulse and a novel design of e-Learning system that deals with deriving the spectrum using concept-based branching method. Spectrum of high-order pulse can be derived using conventional methods including 'Consecutive Differentiations' or 'Convolutions', however, their complexity of calculation should be too high to be used as the order of the pulse increase. We develop a recursive algorithm according to the order of pulse, and then derive the formula of spectrum connected to the order with a newly designed look-up table. Moving along, we design an e-Learning content for studying the procedure of deriving high-order pulse spectrum described above. In this authoring, we use the concept-based object branching method including conventional page or title-type branching in sequential playing. We design all four Content-pages divided into 'Modeling', 'Impulse Response and Transfer Function', 'Parameters' and 'Look-up Table' by these conceptual objects. And modules and sub-modules are constructed hierarchically as conceptual elements from the Content-pages. Students can easily approach to the core concepts of the analysis because of the effects of our new teaching method. We offer step-by-step processes of the e-Learning content through unit-based branching scheme for difficult modules and sub-modules in our system. In addition we can offer repetitive learning processes for necessary block of given learning objects. Moreover, this method of constructing content will be considered as an advanced effectiveness of content itself.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.1
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• pp.102-108
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• 2016

A flying drone generates vibrations in a great variety of frequencies, and it requires a gimbal system stabilization loop design in order to obtain clean and accurate image from the camera attached to the drone under this environment. The gimbal system for drone comprises the structure that supports the camera module and the stabilization loop which follows the precise angle while blocking the vibration from outside. This study developed a dynamic model for one axis for the stabilization loop design of a gimbal system for drones and applied classical PID controller and intelligent PID controller. The Stabilization loop design was developed by using MATLAB/Simulink and compared the performance of each controller through simulation. Especially, the intelligent PID controller can be designed almost without the dynamic model and it demonstrates that the angle can be followed without readjusting the parameters of the controller even when the characteristics of the model changes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.718-724
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• 2017

Considerable efforts have been made to expand the boundaries of domestic offshore plant industries, which have focused on the construction of the structures, to the engineering field. On the other hand, time domain analysis, which is one of the most important areas in designing floating offshore plants, relies mainly on the information given by foreign companies. As an early design of the Dynamic Positioning System (DPS) is mostly conducted by several specialized companies, domestic ship builders need to spend time and money to reflect the analysis into the hull shape design. This paper presents the framework required to analyze time domain performance of floating type offshore structures, which are equipped with DPS. To easily perform time domain analysis, framework generates the required input data for the solver, and is modularized to test the control algorithm and performance of a certain DPS. The effectiveness of the developed framework was verified by a simulation with a model ship and the total time for the entire analysis work was reduced by 50% or more.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2241-2248
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• 2011

This paper describes the design of a palette-type 60watt high power amplifier module using gallium nitride(GaN) devices with high power and efficiency performances for WiMAX and LTE systems. The line-up for the high gain amplifier module consists of the pre-amplifier stage with low power and high gain, 8watt GaN driving amplifier stage, and 60watt GaN high power amplifier stage of Doherty structure with two 30watt GaN devices. The obtained gain is 61.4dB with an excellent gain flatness of ${\pm}$0.075dB over 2.5~2.68GHz. GaN devices and the Doherty structure are adopted for the improvement of high efficiency and output power. The measurement for the fabricated high power amplifier module of palette type is performed using the widely known WiMAX signal all over the world. In the example of RRH(remote radio head) application of the fabricated amplifier module, the measured efficiency is 37~38% with the 10watts of modulated output power. It is shown that when the fabricated amplifier module is activated with a digital predistorter(DPD), the measured ACLR is better than 46dBc under the 10watts of modulated output power.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.8
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• pp.911-918
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• 2010

With limitation of frequency bandwidth, the range accuracy of typical radars is limited. In this paper, for short distance measurements, the use of an AM(Amplitude Modulated) radar which provides improved range accuracy is proposed. The AM radar signal consists of a carrier frequency signal and double-sideband components. The fabricated AM radar operates with +10 dBm output power and 35 dB receiver gain at 24.128 GHz center frequency with 20 MHz bandwidth, and the range accuracy is measured as ${\pm}15\;cm$.

• Journal of Korea Multimedia Society
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• v.4 no.1
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• pp.1-12
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• 2001

EDI is being considered as a new way for exchange business data in the form of electronic document, aiming the paperless transaction in business-to-business commerce. However, only a few enterprises select and practically use EDI accepts the closed and complicated method based on exclusive protocol for electronic document exchange. There, second, is insufficient regulation and system that support it. Last, the cost for operating is too high. In this paper, Open EDI Document Information Management System (OEIMS) was designed for solving the problem that mentioned above. We represented exchange document in code from as XML DTD. OEIMS that makers feasible to transfer their document through the web with low cost and, manage and search the information more efficiently and effectively using object-oriented database. We suggest OEIMS that provide efficiency to reposit and manage a system by modulized design of structural feature from EDI unlike other systems.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.3
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• pp.237-247
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• 2005

It is necessary to forecast the various dismantling activities prior to dismantling nuclear facilities by using various software instead of a physical mock-up system because the dismantling in a contaminated with radioactivity cause the results of an unexpected situation. The component that needs to develop a dismantling mock-up system was examined. There are many component systems such as a decommissioning database system,3D dosimetric mapping that represents a distribution of a radionuclide contamination, a component of modeling for nuclear facility and devices include the decontamination and decommissioning. The research of software architecture about these components was carried out because these component systems that have been independently doesn't describe not only to visual an activities of Decontamination and Decommissioning(D&D) but also to evaluate it. The result was established an architecture that consist of an visualization module which could be visualized an D&D activities and a simulation module which can be evaluated a dismantling schedule and decommissioning cost.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.2
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• pp.36-40
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• 2009

In this paper we discuss about the practical implementation of a combined CO and CO2 dual sensor module that is adapted by NDIR (Non-Dispersive Infrared) method that measures the absorbance of gas like CO and CO2 by using gas particles' characteristics that absorb specific wave lengths of infrared ray. NDIR has a long life time, excellent measurement and precision compared to the existing contact types or chemical types of CO2 sensors. Since optical cavity technology that had been developed until now can measure CO2 only we research and develop an optimal optical cavity design and density-temperature calibration technologies that can measure CO and CO2 at the same time and is important to decide the performance of the sensor module according to well-designed wave guides of the different length.

• Korean Journal of Construction Engineering and Management
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• v.14 no.5
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• pp.144-152
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• 2013

Recently construction projects become more bigger. So construction companies have being performed cost and schedule management task by using PMIS. In engineering and construction phase, progress management which occur the most frequent information I/O(input and output) should be managed effectively by PMIS. Although most information by PMIS manage efficiently, cost-schedule information for progress management is difficult to be managed due to recurrent information input. thus when changed by price fluctuation and change order, progress management could not connnect cost information with schedule information. So it caused inaccuracy of progress measurement and data increase in PMIS. To solve this problem, This study suggests improved module for progress management through integration of cost-schedule using quantity take-offs as progress measurement method.

• Membrane Journal
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• v.6 no.1
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• pp.44-52
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• 1996

For the purpose of the optimal design of a frame and plate type of pervaporation module, model equations which can predict the effects of feed flow condition on the temperature distribution of the feed developed in the module were established and the temperature distribution with feed flow condition was investigated through the model si$$\mu$ation. With increasing the Reynolds number of feed flow in the module, the flow velocity gradient in the channel height-direction as well as the volume rate of feed which acts as energy source for the evaporation of perrneants on the permeate-side surface of a membrane increased to such an extent that both mass and heat flux in the channel height direction could increase and the temperature drop of feed due to the evaporation of the permeant could be reduced correspondingly. A decrease in channel height caused the temperature drop of feed because of decreasing feed flow in the module. It was observed that the si$$\mu$ation result on the effect of Re on the temperature distribution of feed in the module has an agreement with experiment.