• 터널과지하공간
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• 제13권3호
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• pp.180-186
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• 2003

동적 인장강도를 평가하기 위해 수치해석기법을 이용하여 홉킨슨효과를 가정한 동적 인장시험의 암석 파쇄 과정을 해석하였다. 동적 인장 파쇄 과정과 정적 인장 파쇄 과정에 명확한 차이가 있음을 밝혔으며, 동적 인장강도와 정적 인장강도의 상위는 응력집중현상과 응력재분배에 의해 발생된다는 것을 지적하였다. 그러나 정적파쇄와 동적파쇄 과정에 큰 차이가 있음에도 불구하고 정적 인장강도와 동적 인장강도는 미시적 인장강도의 균질성 계수가 증가함에 따라 미시적 인장강도의 평균치에 근접하였다. 본 연구로부터 암석의 불균질성은 동적 인장강도에 영향을 미치는 요인이며, 동적 인장강도와 정적 인장강도의 상위를 발생시키는 중요한 요인임을 지적하였다.

• 한국실내디자인학회논문집
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• 제20권1호
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• pp.14-23
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• 2011

The purpose of this study is to analyse the inclinations and expressions in contemporary architecture. Specially, we call this tendency and architectural movements as architectural metamorphosis. Metamorphosis in architecture present the core of the change of Forms and spirits in a change of outward shape and terrestrial identity. As in Ovid's extended dramatic poem of change and transformation, Metamorphoses, all Souls are deathless, and migrates from one form to another. Like these stories in Metamorphoses, Ovid tells the soul never dies, but leaps one form to anther, and can take any shape. So the architectural form, transformation and deformation in contemporary architecture means architectural sensations and cognitions can even approach the soul of form and shape under the transformation. The expressions and design strategies of metamorphosis in comtemporary architecture reveal continuous and sequential formations of space, linear structure with force and vector, rhythmical wavement and folding surface, lively wiggly flows of volumns and objects, and so on. Such qualities came from the periodical needs; separation of structure and surface, poly-surfacial movement, poly-sensual expression and experience, dematerialization and the dematerialized space, formless of non-formal architecture, digital architecture. Architecture of Metamorphosis is the ways and the needs of our period to overcome the static limits prohibits the liberal thoughts, to find the ways toward the opportunities and diversities and to unlock the imaginaire of the contemporary architecture.

• 융합신호처리학회논문지
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• 제7권3호
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• pp.136-142
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• 2006

공유 메모리 관리를 위한 기존의 방법들은 가상 큐 길이의 정적 제한을 통해 일정 크기의 버퍼 할당을 보장하려는 방식과 전체 버퍼 공간의 할당 측면에서 공유 버퍼의 이용률을 높이고자 하는 방식 등으로 나눌 수 있다. 완전공유 방식의 경우 낮은 트래픽 부하에서 높은 메모리 공유 효과를 보이나 트래픽 부하가 높아지면 특정 가상큐가 공유 메모리를 과다하게 점유하는 것을 방지하는 의미에서의 보호 효과를 거의 기대하기 힘들다. 반대로 정적 임계치 방식의 경우 트래픽 조건 변화에 따른 적절한 임계치 설정이 불가능하다. 본 논문에서는 공유 메모리의 공정 할당이라는 단순한 기능을 가지는 동적 임계치 방식을 확장하여 구현이 용이하고 높은 메모리 이용률과 서비스 품질기능 측면에서 우선 순위에 따른 차등 적인 패킷처리 기능을 갖는 가중형 동적 임계치 방식을 제안하고 컴퓨터 시뮬레이션을 통하여 그 성능을 확인하였다.

• 센서학회지
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• 제16권4호
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• pp.277-285
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• 2007

In this paper, we outline the research issues that we are pursuing towards building of location aware environments for mainly ubiquitous healthcare applications. Such location aware application can provide what is happening in this space. To locate an object, such as patient or elderly person, the active ceiling-mounted reference beacons were placed throughout the building. Reference beacons periodically publish location information on RF and ultrasonic signals to allow application running on mobile or static nodes to study and determine their physical location. Once object-carried passive listener receives the information, it subsequently determines it's location from reference beacons. The cost of the system was reduced while the accuracy in our experiments was fairly good and fine grained between 7 and 12 cm for location awareness in indoor environments by using only the sensor nodes and wireless sensor network technology. Passive architecture used here provides the security of the user privacy while at the server the privacy was secured by providing the authentication using Geopriv approach. This information from sensor nodes is further forwarded to base station where further computation is performed to determine the current position of object.

• 한국항공우주학회지
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• 제35권2호
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• pp.130-135
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• 2007

스마트무인기 파워효과 풍동시험은 2005~2006에 3달여간 항공우주연구원 중형아음속풍동에서 수행되었다. 풍동시험 모델은 정적시험 모델을 활용하였고, 틸트로터 형태의 추진장치를 시험부에 고정하여 파워효과를 모사하였다. 파워효과는 기본적으로 로터가 장착된 시험과 로터가 장착되지 않은 시험의 차로 구해지나, 이 때 두 시험간의 흐름각 차이 및 지지부 간섭량 변화 등을 적절히 보정하여야 한다.

• International Journal of Aeronautical and Space Sciences
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• 제15권3호
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• pp.219-231
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• 2014

We develop a preliminary design optimization procedure in this paper regarding the wing planform in a solar-powered high-altitude long-endurance unmanned aerial vehicle. A high-aspect-ratio wing has been widely adopted in this type of a vehicle, due to both the high lift-to-drag ratio and lightweight design. In the preliminary design, its characteristics need to be addressed correctly, and analyzed in an appropriate manner. In this paper, we use the three-dimensional Euler equation to analyze the wing aerodynamics. We also use an advanced structural modeling approach based on a geometrically exact one-dimensional beam analysis. Regarding the structural integrity of the wing, we determine detailed configuration parameters, specifically the taper ratio and the span length. Next, we conduct a multi-objective optimization scheme based on the response surface method, using the present baseline configuration. We consider the structural integrity as one of the constraints. We reduce the wing weight by approximately 25.3 % from that in the baseline configuration, and also decrease the power required approximately 3.4 %. We confirm that the optimized wing has sufficient flutter margin and improved static longitudinal/directional stability characteristics, as compared to those of the baseline configuration.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.514-517
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• 1996

In solving multi-level knapsack problems, conventional heuristic approaches often assume a short-sighted plan within a static decision enviornment to find a near optimal solution. These conventional approaches are inflexible, and lack the ability to adapt to different problem structures. This research approaches the problem from a totally different viewpoint, and a new method is designed and implemented. This method performs intelligent actions based on memories of historic data and learning. These actions are developed not only by observing the attributes of the optimal solution, the solution space, and its corresponding path to the optimal solution, but also by applying human intelligence, experience, and intuition with respect to the search strategies. The method intensifies, or diversifies the search process appropriately in time and space. In order to create a good neighborhood structure, this method uses two powerful choice rules that emphasize the impact of candidate variables on the current solution with respect to their profit contribution. A side effect of so-called "pseudo moves", similar to "aspirations", supports these choice rules during the evaluation process. For the purpose of visiting as many relevant points as possible, strategic oscillation between feasible and infeasible solutions around the boundary is applied for intensification. To avoid redundant moves, short-term (tabu-lists), intermediate-term (cycle detection), and long-term (recording frequency and significant solutions for diversification) memories are used. Test results show that among the 45 generated problems (these problems pose significant or insurmountable challenges to exact methods) the approach produces the optimal solutions in 39 cases.lutions in 39 cases.

• 한국콘텐츠학회논문지
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• 제19권11호
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• pp.278-287
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• 2019

공간 정보 추출은 자연어 텍스트에 있는 정적 및 동적인 공간 정보를 공간 개체와 그들 사이의 관계로 명확히 표시하여 추출하는 것을 말한다. 이 논문은 2단계 양방향 LSTM-CRF 앙상블 모델을 사용하여 한국어 공간 정보를 추출할 수 있는 심층 학습 방법을 제안한다. 또한 공간 개체 추출과 공간 관계 속성 추출을 통합한 모델을 소개한다. 한국어 공간정보 말뭉치(Korean SpaceBank)를 사용하여 실험한 결과 제안한 심층학습 방법이 기존의 CRF 모델보다 우수함을 보였으며, 특히 제안한 앙상블 모델이 단일 모델보다 더 우수한 성능을 보였다.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권3호
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• pp.272-276
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• 2005

This paper deals with the method to calculate the rotor eddy current losses of permanent magnet high-speed machines considering the effects of time/space flux harmonics. The flux harmonics caused by the slot geometry in the stator is calculated from the time variation of the magnetic field distribution obtained by the magneto-static finite element analysis and double Fast Fourier Transform. And, using the analytical approach considering the multiple flux harmonics and the Poynting vector, the rotor losses is evaluated in each rotor composite. Using this method is simple and workable for any kind of stator slot shape for rotor loss analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.1081-1087
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• 1992

A novel digital control algorithms are developed for an active power filter (APF) using a pulse-width modulated (PWM) rectifier with current link. A main control algorithm compensating both the reactive power and harmonic currents with fast dynamic response is derived through a vector approach. A space vector modulation technique is developed for the PWM rectifier in order to generate the desired current vector of the APF. The system generates no acoustic noise and it is implemented with a minimal control hardware structure using the Intel 80196 single-chip microcomputer. Experimental results show that the proposed scheme gives good dynamic and static performance for the APF system.