• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.4
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• pp.59-68
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• 1997

In analysis of underground structures, the effects of artificial boundary conditions are considered as one of the major reasons for differences from experimental results. These phenomena can be overcome by using the boundary elements which satisfy the multi-layered half space conditions. The fundamental solutions of multi-layered half-space for boundary element method is formulated satisfying the transmission and reflection of waves at each layer interface and radiation conditions at bottom layer. The governing equations can be obtained from the displacements at each layer which are expressed in terms of harmonic functions. All types of waves can be included using the complete response from semi-infinite integrals with respect to horizontal wavenumbers using expansion of Fourier series and Hankel transformation. Two dimensional Green's functions are derived from cylindrical Navier equations and potentials performing infinite integration in y-direction. In this case, it is effective to transform into two dimensional problem using semi-analytical integration and sinusoidal Bessel function. Some verifications are given to show the accuracy and efficiency of the developed method, and numerical examples to demonstrate the dynamic behavior of underground with various properties.

• Journal of the Korea Concrete Institute
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• v.23 no.6
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• pp.781-790
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• 2011

This paper contains the experimental results on strengthening effect of RC beams strengthened with NSM CFRP reinforcement and various strengthening details. A total of 14 beams have been tested to analyze strengthening effects of NSMR with various reinforcement details. Variables were cross-sectional shape of CFRP reinforcements, strengthening areas, grooves the number and location etc. Test results revealed that failure modes of NSMR showed two types. One was bond failure at interface between concrete and filler and the other was CFRP rupture. Also, failure mode of specimens with two grooves occurred premature bond failure because of superposition of failure surfaces at concrete around grooves. failure mode of MI specimens considered the equivalent section have changed bond failure to CFRP rupture and CFRP efficiency has improved 83% to 100%.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.482-484
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• 2017

Over the past 70 years, movies and television have revolutionized the way people communicate. However, even with this development, TV has been used only as a means of communication targeting an unspecified number of people due to the restriction of media such as radio waves and movies. However, the development of the Internet and online video has come to a time when 100 million people watch YouTube videos uploaded from the other side of the world by eliminating these restrictions. The message that you want to deliver now can be delivered to anyone, but making the image with these messages remains the last obstacle to communication. To solve these problems, we implemented a web application and a video production program through AWS. This system basically provides the administrator with the video production through the easy interface, the information management and the program on the server on the internet through AWS, the assigned lecture including the computer and the smart phone, the learning materials, And implemented to increase the efficiency of educational video production service.

• The KIPS Transactions:PartD
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• v.14D no.2
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• pp.181-190
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• 2007

In component based development, component modeling for understanding and analyzing is the important part and is used to improve reusability. Generally, components are need to be divided into two types according to their usages, where the developer and assembler are usually different. To make a good component model, a complete component and interface specification for those components are needed. And the component model needs to adept two different views of developer and assembler. In this paper, we suggest two different views of component model that is related to views from developer and assembler, and we expand UML. Also we validate the efficiency of the suggested model by developing and applying a tool for building, managing and automatic transformation.

• Journal of the Korea Institute of Building Construction
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• v.14 no.3
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• pp.244-251
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• 2014

Project Management Information System (PMIS) has not yet fully met needs of the construction industry. Based on the deficiency of the current system, the present study performed a survey to identify a need for mobile PMIS in the industry. The survey revealed that most respondents expect the development of mobile PMIS would contribute to improving the productivity and efficiency of field operations. Based on the survey findings, this study proposes a suite of modules for mobile PMIS, which are focused on construction management, document management, schedule management, and field information management. Mobile PMIS would allow to access from the field through mobile devices by using tablet computers and smart-phones. The study also suggests that the effectiveness of the system can be enhanced by user interfaces that are customized for each module.

• Journal of Digital Convergence
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• v.15 no.3
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• pp.195-200
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• 2017

The purpose of this study is to provide a virtual CG - based image production system for a simulator camera. The video production system proposed in this study is designed to synchronize the virtual camera of the graphic tool with the simulator camera at the shooting site and the CG application image editing, And can be easily and easily performed through a graphic tool by being controlled virtually through a control interface. Blaze Knights, an animation created by Dongseo University, was used to illustrate the superiority of the research results by comparing the progress and the amount of work before and after the application of the system. According to the results of the research, the CG artist's work efficiency is increased, while the physical constraint is minimized when the scene of the CG application image is minimized. It is possible to produce various scenes and minimize the re- We expect the contribution to the industry to be high.

• Journal of the Ergonomics Society of Korea
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• v.31 no.4
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• pp.601-607
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• 2012

Objective: The aim of this study is to classify between intentional and natural blinks in vision based eye tracking system. Through implementing the classification method, we expect that the great eye tracking method will be designed which will perform well both navigation and selection interactions. Background: Currently, eye tracking is widely used in order to increase immersion and interest of user by supporting natural user interface. Even though conventional eye tracking system is well focused on navigation interaction by tracking pupil movement, there is no breakthrough selection interaction method. Method: To determine classification threshold between intentional and natural blinks, we performed experiment by capturing eye images including intentional and natural blinks from 12 subjects. By analyzing successive eye images, two features such as eye closed duration and pupil size variation after eye open were collected. Then, the classification threshold was determined by performing SVM(Support Vector Machine) training. Results: Experimental results showed that the average detection accuracy of intentional blinks was 97.4% in wearable eye tracking system environments. Also, the detecting accuracy in non-wearable camera environment was 92.9% on the basis of the above used SVM classifier. Conclusion: By combining two features using SVM, we could implement the accurate selection interaction method in vision based eye tracking system. Application: The results of this research might help to improve efficiency and usability of vision based eye tracking method by supporting reliable selection interaction scheme.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.531-537
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• 2015

In order to maximize power output from the solar panels, one needs to keep the panels aligned with the sun. So solar tracker having high reliability must be designed. This paper cares about the design and evaluation of a two-axis solar tracker system based on fuzzy logic control with LabVIEW. The research focus on planning mechanical parts, making an intelligent controller which controls and monitors all parameters via user interface implemented of a fuzzy decision support system for control of photovoltaic panel movement. We also develop a real solar tracker system and analyze the influence indexes such as environment, weather, season, and light condition. The solar tracker is tested in real condition and all parameters related to the system operation are recorded and analyzed. The developed solar tracking system got a much higher efficiency about 38 % compare to fixed solar panel although the weather condition is affected a lot to the solar panel. So we confirmed the our auto tracking system is more effective and can allow more energy to be produced.

• Elastomers and Composites
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• v.55 no.1
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• pp.59-66
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• 2020

Herein, we investigated the thermal conductivity and thermal stability of natural rubber composite systems containing hybrid fillers of boron nitride (BN) and aluminum nitride (AlN). In the hybrid system, the bimodal distribution of polygonal AlN and planar BN particles provided excellent filler-packing efficiency and desired energy path for phonon transfer, resulting in high thermal conductivity of 1.29 W/mK, which could not be achieved by single filler composites. Further, polyethylene glycol (PEG) was compounded with a commonly used naphthenic oil, which substantially increased thermal conductivity to 3.51 W/mK with an excellent thermal stability due to facilitated energy transfer across the filler-filler interface. The resulting PEG-incorporated hybrid composite showed a high thermal degradation temperature (T₂) of 290℃, a low coefficient of thermal expansion of 26.4 ppm/℃, and a low thermal distortion parameter of 7.53 m/K, which is well over the naphthenic oil compound. Finally, using the Fourier's law of conduction, we suggested a modeling methodology to evaluate the cooling performance in thermal management system.

• Journal of IKEEE
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• v.19 no.4
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• pp.625-631
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• 2015

In this paper, an 8051 microcontroller with application-specific instructions and I/O ports for data transmission is designed. The designed microcontoller includes two UART ports and one SMBus port to control external devices and to transmit data with them. Application-specific instruction is developed and added to the instruction set to exploit these I/O ports. So the designed microcontroller can perform multi-device control and multi-byte transmission. Also, it can reduce the code size of the application program. Especially, the designed microcontroller does not stall and can execute other programs during data transmission, which significantly increases its efficiency. Synthesized in 0.18 um technology, the area overhead due to application-specific instructions was negligible. Operations of all instructions and I/O ports were verified to run correctly on a FPGA board.