• 한국컴퓨터그래픽스학회논문지
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• 제14권1호
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• pp.1-10
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• 2008

본 논문에서는 동영상을 입력하여 손으로 그린 듯 한 회화적 애니메이션을 생성하기 위한 방법을 제안한다. 회화적 애니메이션에서 가장 중요한 요소 중 하나는 프레임 간 브러시 스트로크의 시간적 일관성을 유지하는 것이다. 이것은 프레임 간 브러시 스트로크들의 부드러운 움직임을 보장해주는 중요한 역할을 한다. 본 논문에서는 브러시 스트로크의 부드러운 움직임을 위해서 모션 영역들을 이용한다. 모션 영역은 프레임 간 객체들이 움직이는 영역을 의미하며 두 가지 타입으로 구성되어져 있다. 강한 모션 영역은 연속되는 두 장의 프레임 간 평가된 모션 벡터에 의해서 리얼 에지 및 히든 에지가 움직이는 영역을 말한다. 리얼 에지는 객체들의 윤곽선을 의미하며 히든 에지는 그라데이션 현상이 나타나는 영역에서 명암의 결의 방향을 표현하기 위한 경계를 의미한다. 약한 모션 영역은 모션이 발생한 전체 영역 중 강한 모션 영역을 뺀 영역을 말한다. 회화적 애니메이션에서 시간적 일관성은 이러한 모션 영역들을 이용하여 캔버스 위에 브러시들을 덧칠함으로써 유지될 수 있다.

• 한국환경과학회지
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• 제29권4호
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• pp.339-349
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• 2020

This study aims to identify participating resident awareness of the improvements to forest carbon cycle villages created by the Korea Forest Service by introducing a system for district heating basedon forest biomass in mountainous areas. Hwacheon Forest Carbon Circulation village was established in Paroho-neureup village in Yuchon-ri, Hwacheon-gun between 2011 and 2013. However, its operation has not been smooth due to the increasing number of households rapidly leaving the district heating system. This study surveyed 76 households that participated in the district heating system using forest biomass in the early stages of the project. This includes households participating in the district heating system(participating households) and households not currently participating in the district heating system(withdrawal households) from September 2019. Surveys focused on the process of participating in forest carbon cycle village projects, and satisfaction in local heating and policy requirements. Of the 67 households, excepting those not allowed to participate in the survey due to death or having moved elsewhere, 36 households participated and 31 households the were in the process of leaving the village were also included. As a result, there was a significant difference between participating and exiting households in the motivation and satisfaction level of district heating. The results of this study are expects to reflect the importance of awareness of residents in the operation of the forest carbon cycle village. This will be utilized as an important dataset for improvement as a means to promote the re-entry if outgoing households. It will also help set the direction of the forest town revitalization project, utilizing forest biomass in the future.

• Strategy21
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• 통권39호
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• pp.163-197
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• 2016

The completion of Jeju Naval Base on February 2016 made the Republic of Korea Navy(ROKN) review the size and role of the Maritime Task Flotilla(MTF). The new strategic environment for the 12st century and the new challenges require the Navy to counter North Korea's provocations and prevent potential enemy's threat. The Navy is also required to take part in the variety of international roles and missions commensurated with Korea's global status to maximize the national interest. Despite these changes, Korea's military construction concept is still unable to break away from the old paradigm of the North Korean threat largely centered. In order to develop the current MTF into the Task Group with the construction of Jeju Naval Base, the Navy must newly not only establish new force development plan and fleet management concepts but also go to persuade and convince policy decision makers. To this end, the following efforts should be promoted. First, the ROK Navy steps up efforts in order to share with the Task Group's vision and strategy. The Navy should also provide the size and structure as well as the missions and roles of the Task Group to react to new maritime security environment. Second, the Navy analyse the MTF's ability and what is required and necessary to perform its duty. After that, it must set out the direction of the Task Group's force development. Third, the current missions and roles of the MTF should be re-established to respond various threats. Finally, accommodating of new technology to the MTF should intensify its strengths. The ROK Navy has a mixed force structure consisting of three fixed- base fleets and a MTF. The fixed base fleet has a passive force to defend and protect its own sea areas, but the MTF should actively not only counter North Korea's threats, including ballistic missiles, but also fight potential threats and takes international missions as a primary task force. However, the MTF has a limited capability to accomplish given missions and long-range operations, and thus, the ROK Navy is strongly required to construct the Task Group.

• 한국항공우주학회지
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• 제46권2호
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• pp.114-123
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• 2018

풍력타워는 수직형 풍력터빈의 성능을 향상하기 위하여 사용되어진다. 하지만 풍력타워의 성능은 내부반경, 외부반경, 안내벽의 개수 등의 설계변수에 의하여 좌우된다. 따라서 본 연구에서는 풍력타워의 효율적인 설계변수를 찾기 위하여 실험적인 연구를 수행하였다. 실험에 사용된 풍동의 시험부는 높이 2 m, 폭 2.2 m이며, 7개의 안내벽을 가진 풍력타워의 한 층을 모델로 제작하고, 그 내부에 풍력터빈을 설치하였다. 다양한 설계변수에 대하여 실험을 하기 위하여 세 가지 종류의 안내벽을 사용하였다. 상대적인 성능평가를 위하여 동일한 입구속도에서 풍력타워를 원주방향으로 회전이동하여 출력계수를 측정하였다. 실험의 결과에서 풍력타워의 내부반경과 풍력터빈의 회전반경과의 간격이 풍력터빈의 성능을 향상하는데 가장 큰 영향을 미치는 변수임을 보였다.

• 공학교육연구
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• 제9권2호
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• pp.52-70
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• 2006

다학제 및 학제간의 다양한 지식과 실질적인 경험을 바탕으로 진화해온 특수 전공분야로서 시스템 엔지니어링은 오늘 날 대형 복합시스템의 개발에 필수적인 분야이다. 컴퓨터의 발달과 분석적 해석기법의 발달로 인해 사회적 요구는 더욱 다양하고 복잡해 졌다. 이러한 변화의 대안으로 대두하고 있는 분야가 시스템 엔지니어링이다. 시스템 엔지니어링은 '고객의 필요를 만족하는 통합된 시스템 생명주기의 균형 잡힌 시스템의 해결책을 개발하고 검증하는 학제간 프로세스이며, 문제정의, 대안조사, 아키텍팅, 시스템 모델, 통합, 시스템 개발 및 성능평가를 하향식, 포괄적이며 반복적으로 문제를 풀어나가는 프로세스이다. 본 논문의 목적은 시스템 엔지니어링에 대하여 소개하고 외국과 한국의 교육현황을 조사하여 해외 시스템 엔지니어링 교육의 사례연구를 통해서 우리나라의 공학교육 발전을 위한 시스템 엔지니어링 교육발전 방안을 제안하려고 한다.

• Wind and Structures
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• 제30권5호
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• pp.465-474
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• 2020

Vortex-induced vibrations of a yawed flexible cylinder near a plane boundary are numerically investigated at a Reynolds number Re_n= 500 based on normal component of freestream velocity. Free to oscillate in the in-line and cross-flow directions, the cylinder with an aspect ratio of 25 is pinned-pinned at both ends at a fixed wall-cylinder gap ratio G/D = 0.8, where D is the cylinder diameter. The cylinder yaw angle (α) is varied from 0° to 60° with an increment of 15°. The main focus is given on the influence of α on structural vibrations, flow patterns, hydrodynamic forces, and IP (Independence Principle) validity. The vortex shedding pattern, contingent on α, is parallel at α=0°, negatively-yawed at α ≤ 15° and positively-yawed at α ≥ 30°. In the negatively- and positively-yawed vortex shedding patterns, the inclination direction of the spanwise vortex rows is in the opposite and same directions of α, respectively. Both in-line and cross-flow vibration amplitudes are symmetric to the midspan, regardless of α. The RMS lift coefficient C_L,rms exhibits asymmetry along the span when α ≠ 0°, maximum C_L,rms occurring on the lower and upper halves of the cylinder for negatively- and positively-yawed vortex shedding patterns, respectively. The IP is well followed in predicting the vibration amplitudes and drag forces for α ≤ 45° while invalid in predicting lift forces for α ≥ 30°. The vortex-shedding frequency and the vibration frequency are well predicted for α = 0° - 60° examined.

• International Journal of Aeronautical and Space Sciences
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• 제18권1호
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• pp.8-16
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• 2017

Most of small air vehicles with moving wing fly at low Reynolds number condition and the reduced frequency of the moving wing ranges from 0.0 to 1.0. The physical phenomena over the wing dramatically vary with the reduced frequency. This study examines experimentally the effect of the reduced frequency at low Reynolds number. The NACA0012 airfoil performs sinusoidal pitching motion with respect to the quarter chord with the four reduced frequencies of 0.1, 0.2, 0.4 and 0.76 at the Reynolds number $2.3{\times}10^4$. Smoke-wire flow visualization, unsteady surface pressure measurement, and unsteady force calculation are conducted. At the reduced frequency of 0.1 and 0.2, various boundary layer events such as reverse flow, discrete vortices, separation and reattachment change the amplitude and the rotation direction of the unsteady force hysteresis. However, the boundary layer events abruptly disappear at the reduced frequency of 0.4 and 0.76. Especially at the reduced frequency of 0.76, the local variation of the unsteady force with respect to the angle of attack completely vanishes. These results lead us to the conclusion that the unsteady aerodynamic characteristics of the reduced frequency of 0.2 and 0.4 are clearly distinguishable and the unsteady aerodynamic characteristics below the reduced frequency of 0.2 are governed by the boundary layer events.

• Current Research on Agriculture and Life Sciences
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• 제25권
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• pp.19-23
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• 2007

This research to streets at Daegu, and view adjective how people react when draw a bird into interior in city utilize and examine becoming direction of street trees system. Findings on survey, citizens appear by average 2.87 in management degree of street trees and average 2.76 in various of species of trees, discontent thing more or less by average 2.91 in satisfaction of the beauty, and demonstrate high shame from satisfaction for season stuff to comparative high 3.24, generally, citizens appear by there are parts to improve by do dissatisfaction about street trees system at Daegu. Also, street trees 2 lines plantings for a bird is average 3.05, shows affirmative feedback about that shrub utilization for a bird see high numerical value by average 3.4 and people draw a bird to space of city. Therefore, construct street trees friendly to the nature and be considered to need to re-establish set street trees environment in citizens preference to recover city ecosystem. As result that examine reaction which treat in street trees planting programs to draw birds into city through view adjective, Likert scales about 2 lines plantings of street trees and additional planting of shrub show affirmative feedback by average 3.4 both ordinary people and specialist group, if people want to draw birds into city by various of method, various research should be accomplished.

• 유통과학연구
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• 제15권1호
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• pp.83-93
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• 2017

Purpose - After the transition, the development of defense industry in Eastern Europe has been regressed. Recently, they have internationally recognized that new products have been exported and contributed to the Innovation-Based Manufacturing of national economy such as unmanned reconnaissance aircraft, water purification technology, and mobile chemical laboratory, etc. The military forces in Eastern Europe are re-armed by the localization of self-produced munitions in their own defense industry, and then emphasize fostering their own defense industry. Thus, if they make a collaboration with other nations as a industrial cluster, it will gain a competitive edge on the defense industry. Research design, data, and methodology - The study was designed with the data of each national defense department. The research of the subject was reviewed before and after the transition. Thousands of workers have worked in defense industries before the transition, however, the defense industry and experts left after the transition. The Hungarian defense spending on GDP also dropped sharply from 1.72% in 2000 to 0.85% in 2013. But, due to the crisis in Ukraine and the crisis of Syrian refugees, the Viségrad Group (V4) member countries have also increased their interest in a defense and industries as well as the confidence in the EU and NATO. Results - On the whole, the joint of military training and purchase of defense materials were found in order to form the EU cooperative combat troops in CEE. There are the implementation of a joint manual plan for strengthening V4 security policy and the joint military exercises for V4 every year, and the others are electronic warfare and innovation of V4 national forces. Through such a performance analysis methodology, we found that the defense industry is developed through the national cluster cooperation among CEEs and spreading global distribution. Conclusions - Eastern Europe and Balkan countries have been looking forward to cooperating with the non-EU countries such as Korea and other defense industries. There are a lot of potential development into a new civilian cooperation defense industry for global-distribution. Thus, Korea should develop electronic commercial applications, not just as a weapon exporting region.

• 한국항공우주학회지
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• 제39권7호
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• pp.585-595
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• 2011

사각형 및 원형 출구 형상 synthetic jet의 수치적 연구를 통하여 유입류가 존재할 경우 평판에서의 유동 구조 및 유동 제어 효과를 분석하였다. 사각형 출구 형상의 경우, jet 직후에 강한 vortex가 생성되지만 주변에 적은 momentum을 공급하기 때문에 유입류 방향으로 갈수록 유동제어 효과가 감소하게 된다. 원형 출구 형상의 경우, 규칙적인 vortex의 형태가 slot 중앙부터 끝까지 나타나고 보다 멀리까지 jet vorticity의 영향이 미치게 된다. 유동제어 효과를 예상하기 위하여 위치 별 wall shear stress를 비교하였다. 이에 원형 출구 형상이 사각형 출구 형상보다 유동제어 효과가 더 클 것으로 판단된다. 또한 최적의 원형 출구 형상을 도출하기 위하여, hole gap과 diameter의 변화에 따른 유동 구조 및 유동 제어 효과를 비교 분석하였다. 그 결과, hole diameter와 gap를 고려하여 원형 출구 형상을 설계할 경우 유동제어 효과를 극대화 할 수 있음을 밝혔다.