• International Journal of Computer Science & Network Security
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• 제21권5호
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• pp.256-266
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• 2021

The Convolutional Neural Network (CNN) has recently made potential improvements in face verification applications. In fact, different models based on the CNN have attained commendable progress in the classification rate using a massive amount of data in an uncontrolled environment. However, the enormous computation costs and the considerable use of storage causes a noticeable problem during training. To address these challenges, we focus on relevant data trained within the CNN model by integrating a lifting method for a better tradeoff between the data size and the computational efficiency. Our approach is characterized by the advantage that it does not need any additional space to store the features. Indeed, it makes the model much faster during the training and classification steps. The experimental results on Labeled Faces in the Wild and YouTube Faces datasets confirm that the proposed CNN framework improves performance in terms of precision. Obviously, our model deliberately designs to achieve significant speedup and reduce computational complexity in deep CNNs without any accuracy loss. Compared to the existing architectures, the proposed model achieves competitive results in face recognition tasks

• 한국항공운항학회지
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• 제30권2호
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• pp.1-6
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• 2022

Recently, the development of UAM, which was named by NASA as an alternative to solve the traffic and environmental problems caused by the rapidly progressing urbanization. When designing UAM, the location of lift fans greatly affects the core technology of the eVTOL type, distributed electric propulsion technology and aerodynamic performance of the vehicle. In this paper, a hybrid UAM model was designed using OpenVSP, an open source aircraft configuration modeling program, and aerodynamic analysis was performed according to the lift fans position change by the vortex lattice method. As a result, it is confirmed that the flight parameters and trailing wakes are stable by fixing the lift fan with the state rotated 0° to the flow direction of the aircraft during cruise flight. Also, OpenVSP is a suitable tool to be used in aircraft configuration modeling and design.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1999년도 하계 학술대회 논문집
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• pp.83-88
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• 1999

인발식 마늘 수확기의 기본개념은 마늘줄기가 인발 가이드를 따라 마늘줄기 인발부로 안내되어 지면 상방향으로 인발, 이송되는 방식으로서 인력에 의한 마늘수확 메카니즘과 유사하다. 그러나 수확기가 전진함에 따라 마늘이 연속적으로 인발되어 인력작업에 비해 매우 높은 수확능률을 갖는다. 또한 굴취식 수확기와 비교하여 연료가 절감되고 통마늘의 손상이 적은 장점이 있다. (중략)

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.471-476
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• 1993

In this paper we proposed the digital implementation of an $H^{\infty}$-optimal controller using lifting technique and $H^{\infty}$-control theory. The discrete controller is obtained through iterative adjustment of sampling time and weighting function, which can ber performed by computing the L$_{2}$-induced input to output norm of the sampled-data system with bandlimited exogenous input. The resulting sampled-data bandlimited exogenous input. The resulting sampled-data system is stable and the performance including inter-sampling behaviour of the hybrid system can be also optimized.d.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.455-458
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• 2003

An optimal control approach to robust control design is proposed in this study for rigid robotic systems under the unknown load and the other uncertainties. The uncertainties are quadratically bounded for some positive definite matrix. Iterative method to find the matrix is shown. Simulations arc made for a weight-lifting operation of a two-link manipulator and the robust control performance of robotic systems by the proposed algorithm is remarkable.

• 한국정밀공학회지
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• 제20권12호
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• pp.176-182
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• 2003

An optimal control approach to robust control design is proposed in this study for rigid robotic systems under the unknown load and the other uncertainties. The uncertainties are quadratically bounded for some positive definite matrix. Iterative method to find the matrix is shown. Simulations are made for a weight-lifting operation of a two-link manipulator and the robust control performance of robotic systems by the proposed algorithm is remarkable.

• 연구논문집
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• 통권24호
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• pp.13-26
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• 1994

The choice of design parameters for a robot arm depends on the desired workspace, load lifting capacity, application requirements, and the performance of the robot. The inverse process, which is the determination of a single robot's workspace for a given specification is also a common practice and is as important to the designers as it is to the users. Based on the geometric influence coefficients, the workspace areas on the vertical Y-Z plane are investigated and calculated. Using these areas, the effects of link parameters, link length ratios and joint rotation angles, are investigated.

• 한국건설관리학회논문집
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• 제13권4호
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• pp.48-59
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• 2012

갱폼(Gangform)은 기준층 설치 후 반복사용이 가능하여 기존 합판 거푸집에 비해 공기단축이 가능하고 높은 경제성을 확보할 수 있는 시스템 거푸집이다. 또한 거푸집의 처짐량이 작고 외력에 대한 안정성이 높은 장점을 지니고 있다. 그러나 갱폼의 운반 및 인양작업은 타워크레인의 동력에 전적으로 의존하고 있으며, 갱폼 인양작업을 위해 공동주택 골조공사 6~7일 사이클 중 1일의 공기를 차지하는 등 전체 골조 공기에 있어 큰 비중을 차지하고 있다. 이러한 문제점을 해결하기 위해 국내외 관련 업계를 중심으로 갱폼 인양과 관련된 다양한 연구 및 기술개발 노력이 수행되어 왔다. 특히, '공동주택 전용 갱폼 인양 자동화 기술 개발에 관한 연구'는 타워크레인의 동력원에 의존하지 않고 별도의 인양장치에 의해 갱폼의 인양작업을 가능할 수 있도록 하는 개념 디자인을 제안하였다. 이에 대한 후속 연구로써 본 연구에서는 구조해석 프로그램을 활용하여 선행 연구를 통해 제안된 갱폼 인양 자동화 기술의 구조적 안정성을 해석하고, 실제 공동주택 건설현장의 공정데이터를 적용하여 갱폼 인양 자동화 기술 적용 시 기존 타워크레인의 양중부하 감소 효과를 분석함으로써 제안된 공동주택 전용 갱폼 인양 자동화 기술의 기술적 타당성을 제시하고자 한다.

• 대한조선학회논문집
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• 제49권6호
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• pp.528-533
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• 2012

Flexible composite propellers are subject to large deformation under heavy loading, and hence the hydrodynamic performance of deformed propeller might deviate from that of the metallic propeller under negligible deformation. To design the flexible propeller, it is therefore necessary to be able to evaluate the structural response of the blades to the hydrodynamic loadings, and then the influence of the blade deformation upon the hydrodynamic loadings. We use the lifting-surface-theory-based propeller analysis and design codes in solving the hydrodynamic problem, and the finite-element-method program formulated with 20-node iso-parametric solid elements for the analysis of the structural response. The two different hydrodynamic and structural programs are arranged to communicate through the carefully-designed interface scheme which leads to the derivation of the geometric parameters such as the pitch, the rake and the skew distributions common to both programs. The design of flexible propellers, suitable for manufacturing, is shown to perform the required thrust performance when deformed in operation. Sample design shows the fast iteration scheme and the robustness of the design procedure of the flexible propellers.

• 한국통신학회논문지
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• 제29권10C호
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• pp.1414-1424
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• 2004

본 논문에서는 동영상의 장면전환점 중 급진적인 장면전환점인 컷(cut)과 점진적인 장면전환점인 페이드(fade)와 디졸브(dissolve) 구간을 웨이블릿 변환영역에서 검출하는 알고리즘을 제안한다. 웨이블렷 변환을 이용한 기존의 연구들은 공간영역과 변환영역 각각의 특징을 이용하여 장면전환점을 검출한다. 그러나 본 논문은 입력된 컬러영상을 먼저 YW 공간으로 변환하고, Y 성분에 대해 리프팅기법을 적용하여 2 레벨 웨이블릿 변환 후, 변환영역에서 공간영역의 특징이 유지되는 저주파 부대역을 히스토그램 비교하고, 나머지 고주파 부대역에서 추출된 에지 정보를 전체(global), 부분(semi-global), 국부(local) 영역으로 정의하여 웨이블릿 에지 히스토그램 비교를 한다. 모의실험 결과 기존의 방법보다 recall에서는 약 17%, precision에서는 약 18%의 성능향상을 보였으며 점진적인 장면 전환점인 페이드와 디졸브 구간 검출에도 좋은 성능을 나타내었다.