• International Journal of Internet, Broadcasting and Communication
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• 제8권2호
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• pp.31-37
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• 2016

History documentaries in Korea have developed various forms of production techniques to overcome the limits of insufficient historical records and videos, and dramatic elements that make the viewers immersed. Through diverse production techniques, history documentaries can maximize the factuality, vividness, and informativeness, allowing the viewers to understand and share the historical events. This paper analyzed the "immersion and experience" techniques of the programs that have been the main turning points of the history documentary so far and produced and realized the virtual reality through utilizing "Uigwe", a 3D history documentary broadcasted on KBS which showed the possibility of applying the virtual reality technique as a new broadcasting contents format.

• Transactions on Electrical and Electronic Materials
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• 제8권3호
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• pp.125-130
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• 2007

DLC coating on ceramics is very useful for manufacturing the materials with hardness and low friction. Adhesion of DLC thin film on ceramics, on the other hand, is usually very weak. Adhesion of DLC film depends on many parameters such as contamination and chemical bonding between thin film and substrate. In this study, adhesion of DLC film on ceramics was improved by the intermediate layer when the plasma immersion ion deposition (PIID) technique was applied. It is found that the chemical composition and the thickness of intermediate layer have significantly an effect on the adhesion of DLC thin film on $Al_2O_3$.

• 대한기계학회논문집
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• 제18권6호
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• pp.1535-1541
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• 1994

The void content of carbon fiber reinforced composite laminates was determined by the ultrasonic nondestructive technique. The ultrasonic immersion, through-transmission method developed stresses the utilization of spectral analysis and frequency dependence of the attenuation due to porosity. The measured attenuation shows approximately linear behavior over the frequency range investigated. The linear relationship between the void content and the attenuation slop (d $\alpha$/df) is found to hold, but the constant of proportionality is quite different for samples with different pore morphology. The void volume fraction determined by the attenuation slope agreed very well with that obtained by the acid digestion analysis.

• Membrane and Water Treatment
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• 제4권2호
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• pp.83-93
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• 2013

In the present investigation, were synthesized composite membranes prepared by simultaneous casting of two polymer solutions using the technique of phase inversion by immersion / precipitation. The support layer was prepared using polyethersulfone and polysulfone as base polymer and for the top layer was used sulfonated polysulfone (SPSU) with 50% sulfonation degree. The morphology of the resulting membranes were characterized by scanning electron microscopy (SEM). The final results showed that it is possible to prepare composite membranes by simultaneous casting of two polymer solutions with adherence between the two layers. Regarding the permeation tests, the developed membranes presented values of hydraulic permeability within the range of commercial nanofiltration (NF) membranes. Values rejection of 80% ammonium ions can be increased by using a SPSU with a greater degree of sulfonation.

• Journal of Welding and Joining
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• 제20권5호
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• pp.106-112
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• 2002

In the present study, the wettability and interfacial tension between (bare Cu, electroless Ni/cu, immersion Au/Ni/Cu) substrates and indium solder were investigated as a function of soldering temperature, types of flux. The wettability of In solder increased with soldering temperature and solid content of flux. The wettability of In solder was affected by the substrate metal finish used, i.e., nickel, gold and copper. On the bare Cu substrate, In solder wet better than any of the substrate metal finishes tested. Intermetallic compound formation between liquid solder and substrate reduced the interfacial energy and improved wettability. For the identification of intermetallic compounds, X-Ray Diffraction(LRD) were employed. Experimental results showed that the intermetallic compounds, such as Cu11In9 and In27Ni10 are observed f3r different substrates respectively. The wetting kinetics is investigated by measuring wetting time with the wetting balance technique. The activation energy of wetting calculated for the In solder/cu substrate and In solder/electroless Au/Ni/Cu substrate are 36.13 and 27.36 kJ/mol, respectively.

• 한국생산제조학회지
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• 제20권3호
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• pp.225-231
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• 2011

In this paper, a new end-milling force modelling technique was suggested by considering runout, and its result was compared with real measured force. The specific cutting force is the multiplication of cutting force coefficient and uncut chip thickness. This parameter was used for experimental modelling and prediction of theoretical force. These coefficients, which can be obtained by fitting measured average forces in several conditions, were used for the formulation of theoretical force. The mechanism of end-milling force with runout was developed in this research and its result was verified by comparing the fluctuating theoretical force and its measured one. The fluctuation of force was incurred by a geometric shape of workpiece and its runout in holding. The result of suggested force considering runout shows a good consistency with measured one. So this modelling method can be used effectively for a prediction of end-milling force with runout effect.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.28-29
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• 2006

High-Speed Centrifugal Compaction Process (HCP) is a wet compacting method, in which powders are compacted under a huge centrifugal force. The HCP was well applied to small alumina specimens, but the compact easily cracked when we applied the HCP to other materials. We clarified how the cracks introduced and found that the formation of such a flow pattern was related to the Colioli's force in the centrifugal field.

• Bulletin of the Korean Chemical Society
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• 제16권12호
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• pp.1167-1172
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• 1995

A coverage of about 1 μm-sized pores of a membrane filter by four monolayers of maleic acids copolymers and poly(allylamine) (PAA) was attained by Langmuir-Blodgett (LB) technique through a covalent cross-linking followed a polyion complexation at the air-water interface. The copolymers were prepared to have side chains of hydrocarbon tail, carboxyl, and/or oligoether in the repeat unit. The surface pressure-area isotherms showed that the monolayers on an aqueous PAA have more expanded area than on pure water. The monolayers were transferable on a calcium fluoride substrate and a fluorocarbon membrane filter as Y deposition type, and the resulting LB films were characterized by FT-IR spectroscopy and scanning electron microscopy. A polymer network produced through interchain amide formation was confirmed in as-deposited films. The films were heat-treated in order to complete the cross-linking. SEM observation of the heat-treated film on a porous membrane filter showed that the four layer film was sufficiently stable to cover the filter pore of about 1 μm. Immersion of the film in water or in chloroform did not cause any change in its appearance on SEM and in FT-IR spectra.

• Journal of information and communication convergence engineering
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• 제17권3호
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• pp.205-212
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• 2019

Motion tracking and localization devices are an important building block of motion tracking systems in a virtual reality (VR) environment. This study is about improving the accuracy of motion and location for enhancing user immersion in experience type VR environment to position tracking technique. In this study, we propose and test a design of such a device. The module data test of the attitude and heading reference system shows that the implementation with the MPU-9250 sensor is successful and adequate to be used with short operation time. We consider various sensor hardware dependencies of VR, and compare various correction methods and filtering methods to lower the motion to photon (MTP) time that user movement is fully reflected on the display using sensor devices. The Kalman filter is used to combine the accelerometer with the gyroscope in the sensing unit.

• 실천공학교육논문지
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• 제14권2호
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• pp.367-376
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• 2022

본 연구에서는 학습자 관점에서 메타버스 플랫폼인 '스페이셜'을 중심으로 수업 도구로서의 사용자 경험을 분석하였다. 대학 수업에서의 메타버스 플랫폼 스페이셜의 사용성 평가를 위하여 SUS를 활용하였고, 스페이셜을 활용한 수업에 대한 몰입감과 만족도를 평가하기 위하여 Magnitude Estimation 방법을 활용하였다. 그리고 수업 도구로서의 스페이셜 사용에 관한 사용자 경험 의견을 수집하기 위하여 설문기법을 활용하였다. 스페이셜 시스템에 대한 사용성 평가 결과를 보면 수강생들은 스페이셜의 사용성, 몰입감, 만족도에 대해 꽤 긍정적으로 평가하였다. 그리고 메타버스 플랫폼 스페이셜의 사용자 경험 내용을 보면, 수강생들은 메타버스가 비대면 공간 속에서도 많은 사람들의 모여 소통할 수 있는 장을 제공할 수 있는 교육 도구로서 그 효용가치를 높게 평가하는 것을 알 수 있었다. 메타버스는 다른 온라인 플랫폼에 비하여 사용편의성, 상호작용, 몰입감, 흥미유발을 장점으로 들 수 있다. 특히 키보드와 터치방식, 그리고 디스플레이 외에 음성, 동작, 시선 등 오감을 활용한 상호작용이 가능하다는 것이 큰 장점으로 인식되었다. 반면 메타버스의 높은 개방성과 자유도, 그리고 흥미요소는 학습을 촉진하는 동시에 저해 요인이 될 수 있음을 알 수 있었다. 그럼에도 불구하고 결론적으로 메타버스 플랫폼 '스페이셜'은 온라인 강의실 생성과 다양한 학습 기능들을 제공하고 있고, 교수자와 학습자 또는 학습자와 학습자 간의 다양한 상호작용이 가능하기 때문에 대학 수업에서 효과적으로 적용할 수 있을 것으로 판단된다.