• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.556-558
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• 2005

본 연구에서 제안하는 3차원 인터렉티브 스케칭 시스템은 쉽고 간략한 인터페이스 환경으로 유연하고 정교한 물체 생성 및 변형이 가능한 3차원 개념설계 시스템이다. 제품의 설계 과정에서 무선 완드를 이용하여 3차원 공간에 일련의 프리핸드 스트로크로 곡면을 정의하고 생성된 곡면은 캘리그래픽 스트로크를 이용하여 실시간으로 변형할 수 있는 공간 곡면의 정의와 실시간 자유 변형 알고리즘을 포함한다. 공간 곡면 정의 알고리즘은 무선완드의 입력 방위에 따라 상이한 물체를 생성하고 변형하는 기술로서 물체 생성시 필요한 인터페이스의 양을 최소화 할 수 있다. 또한 절러 차례 캘리그라픽 스트로크 입력으로 수정과 변형이 실시간 통합적으로 이루어지는 자유변형 알고리즘은 기존의 공학적. 수치적 접근방식에서 탈피한 직관적이며 유연한 모델링 방식을 제안하여 전문가가 아니더라도 쉽게 공학적 모델을 생성. 변형 할 수 있다. 누구나 쉽게 본 시스템의 도움으로 직관적이며 공학적으로 건전한 제품을 설계할 수 있는 디자인 설계의 획기적인 변화를 마련할 것이다.

• Journal of the Korea Concrete Institute
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• v.17 no.6 s.90
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• pp.1019-1024
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• 2005

To research effects of various chemical superplasticizers(Lignosulfonic acid, Naphthalene sulfonated formaldehyde condensate, melamine sulfonated formaldehyde condensate, and Polycarboxylate) on the hydration of cement, experiments involving XRD, SEM, and DSC have been analysed with cement paste specimens. Regardless of types and dosages of superplasticizers, hydration reaction of specimen applied superplasticizer was delayed to 3 day, but then it showed similarity to plain which don't add superplasticizer. Moreover, the hydrating rate of cement paste was retarded as dosage of superplasticizer was increased. Also, kinetics related with hydrate of cement paste was slow in order of lignosulfonic acid, polycarboxylate, melamine and naphthalene sulfonated formaldehyde condensate. Nevertheless, when all kinds of chemical admixtures were used, morphologies of these hydrates were denser and more uniform than those of plain.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.919-921
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• 2013

영상시장의 개척과 디지털 기술의 발전과 더불어 차세대 3D 입체영상기술에 대한 관심과 수요가 증가하고 있다. 입체 정보는 크게 '단안 입체 정보(monoscopic depth cue)'와 '양안 입체 정보(stereoscopic depth cue)'로 분류 할 수 있다. 단안 입체 정보는 은폐, 상대적 크기, 상대적 밀도, 시야 안의 높이, 공기투시, 운동투시, 초점조절인 7가지로 경험에 의한 입체감을 지각하는 것을 말하며 양안 입체 정보는 두 눈으로 볼 때 처음으로 깊이를 지각 할 수 있는 것으로 크게 '동시시(simultaneous perception)', '융합(sensory fusion)', '입체시(stereoscopic vision)'의 세종류의 기능으로 분류한다. 3D 촬영은 이 양안시의 원리를 이용하여 두 대의 카메라의 좌우 영상을 합성하여 깊이감 있는 영상을 만들어 내게 된다. 본 논문에서는 3D 촬영방법은 촬영방식에 따라 크게 평행방식, 직교방식, 교차방식이 있는데 이중 중 원거리 촬영에 유리한 교차방식을 활용하여 사이드 바이 사이드 리그(Rig; 카메라를 수평으로 설치할 수 있도록 만들어진 장치)를 원거리 촬영에 맞게 축간거리를 기존의 리그 사이즈보다 2배 이상 긴 리그를 제작하여 보다 먼 거리에서의 상이한 좌우 영상획득이 가능하도록 설계하였다. 또한, 일정한 간격에 따라 피사체를 촬영하면서 거리에 따른 양 카메라의 가장 이상적인 IOD(Interocular Distance)와 CONV(Convergence)를 찾고, 교차방식촬영에 따른 특징적인 아티팩트인 키스톤 왜곡(Keystone distance)의 보정을 통한 원거리 입체영상을 효과적으로 획득하는데 본 연구방법을 제안하고자 한다.

• Journal of the Korea Computer Graphics Society
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• v.23 no.5
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• pp.9-17
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• 2017

Filming using multiple cameras is required for the production of the multi-screen content. It can fill the viewer's field of view (FOV) entirely to provide an increased sense of immersion. In such a filming scenario, it is very important to monitor how images captured by multiple cameras are displayed as a single content or how the content will be displayed in an actual theatre. Most recent studies on creating the content of special format have been focused on their own purposes, such as stereoscopic and panoramic images. There is no research on content creation optimized for theatres that use three screens that are spreading recently. In this paper, we propose a novel content production system with a rig that can control three cameras and monitoring software specialized for multi-screen content. The proposed rig can precisely control the angles between the cameras and capture wide angle of view with three cameras. It works with monitoring software via remote communication. The monitoring software automatically aligned the content in real time, and the alignment of the content is updated according to the angle of camera rig. Futher, the producion efficiency is greatly improved by making the alignment information available for post-production.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.4
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• pp.327-333
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• 2015

Wind turbines, in the case of less than rated wind speed, is controlled to achieve maximum power. MPC(Maximun Power Control) method, by controlling the rotational speed of the generator, is a method to achieve maximum power but should know the wind speed. However, for several reasons, there have been proposed methods of estimating the wind speed rather than measuring wind speed. TSR(Tip Speed Ratio) is needed to know to estimate the wind speed. However, a complex interaction formula has to be solved to find a TSR. Therefore, many methods have been suggested to solve a complex interaction formula. In this paper, the new method has been proposed to simplify the complicated interaction formula by using the regression method. Matlab/Simulink is used to simulate and to verify the proposed method.

• Korean Journal of Pharmacognosy
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• v.7 no.3
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• pp.171-178
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• 1976

The Lignan glycosides and related compounds of Araliaceous family herbal drugs and its synthetic route are discussed by quoting 61 references.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.4
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• pp.337-342
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• 2016

A spudcan is mounted on the lower leg of the jack-up rig, a device for preventing a rollover of a structure and to support the structure in a stable sea floor. At the time of inserting the surface of the spud can to penetrate when the sand layer is stable and smoothly pulled to the clay layer, and at that time of recovery when uploading the spud can is equipped with a water injection device. In this study, it is significant to optimize the shape of pipelines holes for water injection device and it was set in two kinds of shape, the oval and round. Interpretation of the subject into the site of Gulf of Mexico offshore Wind Turbine Installation Vessels (WTIV) was chosen as a target platform. Using the ANSYS Workbench commercial programs, optimal design was conducted. The results of this study can be applied to the hole-shaped design of various marine structures.

• Journal of the Korean Wood Science and Technology
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• v.45 no.3
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• pp.268-277
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• 2017

In this study, lignocellulose nanofibrils (LCNFs) were prepared from Pussy willow wood powder by disk-milling after pretreatment using the cosolvent of 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac) and N,N-dimethylformamide (DMF) with different mixing ratios for different time. All pretreated samples showed native cellulose I polymorph and cellulose crystallinity was lowest when cosolvent of DMF with 30% [EMIM]Ac was used. Average crystallite size of raw material and the pretreated product by MDF and its cosolvent with 10% [EMIM]Ac was found to be about 3.2 nm and decreased with increasing pretreatment time at the DMF cosolvent with 30% [EMIM]Ac. Defibrillation efficiency was improved by loosening wood cell wall structure by the pretreatment using co-solvent system of [EMIM]Ac and DMF.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3839-3847
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• 2009

This study presents a revitalization of the professional leagues through the identification of the problem based on analyzing the domestic professional sports business environment. The development plan for emerging problem is present along with guidelines that are appropriate for local environment and situation for league revitalization. First, the creation of a variety of marketing opportunity and integrated marketing strategy must be accompanied by the development for generating of the professional sports league's revenue. Second, Marketing of a player's potential should be developed. and utilized. Third, the domestic players and foreign players salary cap celery cap placed on the proportion of salary should be lower. Finally, Youth Club, based on the activation of a growing base should be made.

• Journal of the Korean Wood Science and Technology
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• v.43 no.1
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• pp.9-16
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• 2015

This study was carried out to investigate the effect of delignification on properties of lignocellulose nanofibers (LCNFs) prepared by wet disk-milling (WDM) after steam and ozone oxidation pre-treatments and their nanopaper sheets. Delignification treatment was effective to obtain fine morphology with uniform fiber diameter less than 35 nm without aggregation, and increased the specific surface area (SSA) and filtration time of LCNFs. In particular, SSA and filtration time of the LCNFs prepared by WDM after ozone pretreatment increased 1.5 and 5.4 times after further delignification. Delignification also increased whiteness and decreased the redness of nanopaper sheets. The highest color difference (41.9) before and after the delignification was obtained in LCNFs prepared by WDM after the steam pretreatment. Tensile properties of nanopaper sheets were also increased by further delignification. The highest tensile strength was found to be 142 MPa.