• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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• pp.215-219
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• 2016

본 논문에서는 인간의 시각적 특성을 반영한 Just Noticeable Difference (JND) 모델을 사용한 움직임 예측을 통한 프레임율 향상 기법을 제안한다. 기존의 다중 프레임 기반 움직임 예측을 통한 프레임율 향상 기법은 움직임 벡터의 정확성을 높이기 위해 다중 프레임을 사용하며, 전체 영역에 대해 같은 블록 크기와 탐색 영역으로 움직임 예측을 수행함으로써 불필요한 계산량이 많아지고 움직임 벡터의 부정확한 예측이 수행된다는 단점이 있다. 제안하는 알고리듬은 인간의 시각적 특성을 고려한 Free Energy-based Just Noticeable Difference (FEJND) 모델을 사용하여 이전 프레임과 현재 프레임만을 사용하여 영역 특성에 따른 적응적 움직임 예측을 수행하여 정확성을 높인다. 실험 결과에 따라 제안하는 알고리듬의 성능이 향상되었음을 알 수 있다.

• Korean Institute of Interior Design Journal
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• no.25
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• pp.205-212
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• 2000

The purpose of this study was to analyze the form of composition and principle of reduction in architectural composition. Theorical category is to find reduction system with the connection between idea of society and tradition in compositional frame. The results were as follows : First, it is appeared the mimesis of style. The mimesis of style is differentiated characteristics between Greek Style or Roman Style and Gothic Revival or Renaissance Revival. Second, it is the reduction of primitive of form. It si divided with mimesis of nature and reduction of primitive hut. Like Laugier the former find the architectural prototype, the latter is convinced of simplicity, purity of nature with us.

• Structural Engineering and Mechanics
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• v.11 no.3
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• pp.273-286
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• 2001

Viscoelastic (VE) dampers have shown to be capable of providing structures with considerable additional damping to reduce the dynamic response of structures. However, the VE material appears to be sensitive to the variations in ambient temperature and vibration frequency. To minimize these effects, a new VE material has been developed. This new material shows less sensitivity to variations in vibration frequency and temperature. However, it is highly dependent on the shear strain. Experimental studies on the seismic behavior of a 2/5 scale five-story steel frame with these new VE dampers have been carried out. Test results show that the structural response can be effectively reduced due to the added stiffness and damping provided by the new type of VE dampers under both mild and strong earthquake ground motions. In addition, analytical studies have been carried out to describe the strain-dependent behavior of the VE damper. The dynamic properties and hysteresis behavior of the dampers can be simulated by a simple bilinear model based on the equivalent dissipated energy principle proposed in this study.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.4
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• pp.432-446
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• 1996

A stochastic Hamilton variational principle(SHVP) is formulated for dynamic problems of linear continuum. The SHVP allows incorporation of probabilistic distributions into the finite element analysis. The formulation is simplified by transformation of correlated random variables to a set of uncorrelated random variables through a standard eigenproblem. A procedure based on the Fourier analysis and synthesis is presented for eliminating secularities from the perturbation approach. In addition to, a method to analyse stochastic design sensitivity for structural dynamics is present. A combination of the adjoint variable approach and the second order perturbation method is used in the finite element codes. An alternative form of the constraint functional that holds for all times is introduced to consider the time response of dynamic sensitivity. The algorithms developed can readily be adapted to existing deterministic finite element codes. The numerical results for stochastic analysis by proceeding approach of cantilever, 2D-frame and 3D-frame illustrates in this paper.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1641-1644
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• 2005

Magnetic actuation utilizes the mechanic torque that is the result of interaction of the current in a coil with an external magnetic field. A main obstacle is, however, that torques can only be produced perpendicular to the magnetic field. In addition, there is uncertainty in the Earth magnetic field models due to the complicated dynamic nature of the field. Also, the magnetic hardware and the spacecraft can interact, causing both to behave in undesirable ways. This actuation principle has been a topic of research since earliest satellites were launched. Earlier magnetic control has been applied for nutation damping for gravity gradient stabilized satellites, and for velocity decrease for satellites without appendages. The three axes of a micro-satellite can be stabilized by using an electromagnetic actuator which is rigidly mounted on the structure of the satellite. The actuator consists of three mutually-orthogonal air-cored coils on the skin of the satellite. The coils are excited so that the orbital frame magnetic field and body frame magnetic field coincides i.e. to make the Euler angles to zero. This can be done using a Neural Network controller trained by PD controller data and driven by the difference between the orbital and body frame magnetic fields.

• Earthquakes and Structures
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• v.24 no.4
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• pp.247-258
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• 2023

Multiple pounding tuned rolling mass damper (MPTRMD) distributed in the cavity of voided slabs is proposed to passively control multi-story frame structures, which disperses the mass of the oscillator to multiple dampers so that the control device can be miniaturized without affecting the vibration control performance. The mechanism and the differential motion equations of the MPTRMD-controlled multi-degree-of-freedom system are derived based on the Lagrange principle. Afterward, this advanced RMD is applied to a simplified 20-floor steel frame to evaluate the seismic control performance in the numerical analysis. A four-storey frame structure equipped with MPTRMD is then taken for a shaking table test to verify its effectiveness of control performance. The pounding mechanism has been detailed studied numerically and experimentally as well. The numerical and experimental results show that the proposed damper is practically promising not only for its prominent control performance but also for its lightweight and space-saving. Additionally, the pounding mechanism influenced by the variable impact parameters exhibits a balance between the two effects of motional limitations and energy dissipation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.1
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• pp.13-24
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• 1993

The tangent stiffness matrices of the plane frame and the thin-walled space frame are derived by using the principle of virtual displacement. In case of the plane frame, the shape function and stiffness matrices are presented for the rigid-hinged condition. For the unsymmetric thin-walled space frame, the elastic and geometric stiffness matrices in three cases of the unrestrained torsion, the restrained torsion, and the restrained anti unrestrained torsion are evaluated by using the various Hermitian polynomials as the shape function. Numerical examples for the lateral buckling analysis of the space frames and the circular arch illustrate the accuracy and convergence characteristics of the derived formulations.

• Journal of Digital Convergence
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• v.14 no.8
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• pp.461-468
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• 2016

Illustration, which is shown in the textbook for educational purpose is used to explain basic educational theory, rather than carrying meaning itself. It has proper educational value when presented appropriately according to the process of knowledge acquirement. This research organized new analyzing criterion for the frame and content analysis subjected on 4 sanitation textbooks of middle school, moreover looked into actual situation by convergent analysis. This is for political suggestion that is helpful to further textbook development; by understanding improvement point required in reaching educational purpose presented in health education course manual. Results are as following. First, in the aspect of frame, diagrams with proper function to explain principle of health and sanitary activities should be more frequently suggested. Second in the aspect of content, illustrations for simple data providing or for decoration should be reduced while illustrations suggesting experimental results should be added, to reorganize health textbook according to the purpose of health education course.

• Structural Engineering and Mechanics
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• v.54 no.4
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• pp.793-807
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• 2015

Constructing the influence lines of forces of statically indeterminate structures is a traditional issue in structural engineering and mechanics. However, the existing kinematic method for establishing these force influence lines is an indirect or mixed approach by combining the force method with the theorem of reciprocal displacements, which is yet inconsistent with the kinematic method for statically determinate structure. This paper proposes the direct kinematic method in conjunction with the load-displacement differential relation for exactly constructing influence lines of reaction and internal forces of indeterminate structures. Firstly, through applying the principle of virtual displacement, the formula for influence lines of reaction and internal forces of indeterminate structure via direct kinematic method is derived based on the released structure. Then, a computational approach with a clear concept and unified procedure as well as wide applicability based on the load-displacement differential relation of beam is suggested to achieve conveniently the closed-form expression of force influence lines, and exactly draw them. Finally, three representative examples for constructing force influence lines of statically indeterminate beams and frame illustrate the superiority of the proposed method.

• Structural Engineering and Mechanics
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• v.63 no.1
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• pp.23-35
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• 2017

A nonlinear static procedure considering work-energy principle and global failure mechanism to estimate base shears of reinforced concrete (RC) frame-type structures is presented. The relative energy equation comprising of elastic vibrational energy, plastic strain energy and seismic input energy is obtained. The input energy is modified with a factor depending on damping ratio and ductility, and the energy that contributes to damage is obtained. The plastic energy is decreased with a factor to consider the reduced hysteretic behavior of RC members. Given the pre-selected failure mechanism, the modified energy balance equality is written using various approximations for modification factors of input energy and plastic energy in scientific literature. External work done by the design lateral forces distributed to story levels in accordance with Turkish Seismic Design Code is calculated considering the target plastic drift. Equating the plastic energy obtained from energy balance to external work done by the equivalent inertia forces considering, a total of 16 energy-based base shears for each frame are derived considering different combinations of modification factors. Ductility related parameters of modification factors are determined from pushover analysis. Relative input energy of multi degree of freedom (MDOF) system is approximated by using the modal-energy-decomposition approach. Energy-based design base shears are compared with those obtained from nonlinear time history (NLTH) analysis using recorded accelerograms. It is found that some of the energy-based base shears are in reasonable agreement with the mean base shear obtained from NLTH analysis.