• 방송공학회논문지
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• 제9권1호
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• pp.54-63
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• 2004

서로 다른 프레임 율을 가진 영상매체 사이의 프레임 호환을 위해, 움직임 추정 (motion estimation, ME)과 움직임 보상을 이용한 중간 영상 삽입 (합성) 기법 (motion compensated interpolation, MCI)이 활용되는데, 본 논문에서는 MCI에 적합한 움직임 추정기법을 제안하고, 제안한 움직임 추정 기법을 종래의 MCI에 적용한다. 종래의 방법에선 움직임 추정 블록과 MCI 블록의 크기가 동일하나, 본 논문에서 사용된 움직임 추정 블록은 MCI 블록과 같은 중심 축을 가지고, MCI 블록보다 더 크기 때문에 인접 블록과 중첩된 특성을 가진다. 제안한 움직임 추정 블록에 의한 계산량 증가를 줄이기 위해, 제안한 움직임 추정 블록내의 화소를 샘플링 하여 움직임 추정을 실행하였다. 제안한 방식을 검증하기 위해, 움직임 추정 블록을 다양한 샘플 계수로 샘플링 한 후 움직임 추정을 실행하였다. 제안한 방식으로 추정된 움직임 벡터 (motion vector, MV)를 활용하여 MCI를 수행하였으며, 수행된 결과를 종래의 방식에 의한 결과와 비교하였다.

• 한국소음진동공학회논문집
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• 제25권3호
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• pp.169-175
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• 2015

This study aims to improve the dynamic stiffness of an inspection robot frame to prevent derailment from transmission lines. Finite element models for the transmission lines and robot frame are developed for the multi-body dynamic simulation. Natural frequency analysis was conducted using the FE models. Three types of spacer damper clamps installed on 4-conductor transmission lines are used to evaluate the derailment of the robot. Multi-body dynamic simulations with FE models are demonstrated for sub-span oscillation. When the robot operates, derailment of inspection robot from the transmission lines is determined because of resonance. To prevent the resonance, body position was changed and thickness optimization was conducted. The results show that derailment was not occurred because of the natural frequency improvement.

• 한국자기공명학회논문지
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• 제19권1호
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• pp.18-22
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• 2015

The structural geometry of $[N(CH_3)_4]_2CdCl_4$ in a hexagonal phase is studied by $^1H$ MAS NMR, $^{13}C$ CP/MAS NMR, and $^{14}N$ NMR. The changes in the chemical shifts for $^{13}C$ and $^{14}N$ in the hexagonal phase are explained by the structural geometry. In addition, the temperature dependencies of the spin-lattice relaxation time in the rotating frame $T_{1{\rho}}$ for $^1H$ MAS NMR and $^{13}C$ CP/MAS NMR are measured.

• 반도체디스플레이기술학회지
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• 제20권4호
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• pp.141-145
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• 2021

The brightness of the Organic Light Emitting Diode (OLED) display is controlled by thin-film transistors (TFTs). Regardless of the materials and the structures of TFTs, an OLED suffers from the instable threshold voltage (V_th) of a TFT during operation. When designing an OLED pixel with circuit simulation tool such as SPICE, a designer needs to take V_th shift into account to improve the reliability of the circuit and various compensation methods have been proposed. In this paper, the effect of the compensation circuits from two typical OLED pixel circuits proposed in the literature are studied by the transient simulation with a SPICE tool in which the stretched-exponential time dependent V_th shift function is implemented. The simulation results show that the compensation circuits improve the reliability at the beginning of each frame, but V_th shifts from all TFTs in a pixel need to be considered to improve long-time reliability.

• Steel and Composite Structures
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• 제45권4호
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• pp.563-577
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• 2022

This paper presents experimental and numerical investigations of a new seismic enhancement method for existing reinforced concrete (RC) frames by using an external sub-structure, the hybrid seismic retrofit method (HSRM) system. This retrofit system is an H-shaped frame bolt-connected to an existing RC frame with an infilled-concrete layer between their gaps. Two RC frames were built, one with and one without HSRM, and tested under cyclic loading. The experimental findings showed that the retrofitted RC frame was superior to the non-retrofitted specimen in terms of initial stiffness, peak load, and energy dissipation capacity. A numerical simulation using a commercial program was employed for verification with the experiments. The results obtained from the simulations were consistent with those from the experiments, indicating the finite element (FE) models can simulate the seismic behaviors of bare RC frame and retrofitted RC frame using HSRM.

• 한국소음진동공학회논문집
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• 제19권8호
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• pp.781-787
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• 2009

This research is concerned with the application of the active linear actuator to the active vibration control of structure. The active linear actuator will be mounted on the sub-frame so that it can cancel the excitation transferred from the engine. Accelerometer mounted on the sub-frame detects the vibration and its signal is fed into the DSP controller where the control algorithm is installed. The output of the DSP controller is connected to the driver which amplifies the DSP output. In general, the pulse width modulation power amplifier is used to drive the voice-coil type actuator. This study shows the dynamic characteristics of the active linear actuator and active vibration control experimental results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.403-408
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• 2005

In recent years, vehicle accessories substitute steel for aluminum. But, subframe play a important role of vehicle safety. Therefore, dynamic characteristic of steel subframe is understood at real vehicle. And this is able to apply dynamic characteristic of Aluminum. At this paper, we confirm dynamic load that is operated Steel subframe with experiment And result of finite element analysis which is operated dynamic load is compared with result of experiment.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 춘계학술대회 논문집
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• pp.639-644
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• 2009

This research is concerned with the application of the active linear actuator to the active vibration control of structure. The active linear actuator will be mounted on the sub-frame so that it can cancel the excitation transferred from the engine. Accelerometer mounted on the sub-frame detects the vibration and its signal is fed into the DSP controller where the control algorithm is installed. The output of the DSP controller is connected to the driver which amplifies the DSP output. In general, the pulse width modulation power amplifier is used to drive the voice-coil type actuator. This study shows the dynamic characteristics of the active linear actuator and active vibration control experimental results.

• 한국소음진동공학회논문집
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• 제15권12호
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• pp.1332-1339
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• 2005

The vibration of Powertrain are one of the import design characteristics of a vehicle. Powertrain is mostly mounted to the front subframe and powertrain mounting has an important role in determining the vehicle vibration characteristics. In this paper, the accuracy of the vibration analysis for the front subframe is discussed. The dynamic characteristic of subframe are measured from vehicle test and the finite element model updating are performed that natural frequency, mass and MAC of the experimental and theoretical modal analysis are compared. The subframe mounting stiffness are obtained the iteration method based on the vibration of subframe from vehicle test. Finally, the result of dynamic analysis which is operated dynamic load is compared with experimental one of vehicle test.

• 호남수학학술지
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• 제41권1호
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• pp.185-195
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• 2019

In this work, we study the conditions between null geodesic curves and timelike ruled surfaces in dual Lorentzian space. For this study, we establish a system of differential equations characterizing timelike ruled surfaces in dual Lorentzian space by using the invariant quantities of null geodesic curves on the given ruled surfaces. We obtain the solutions of these systems for special cases. Regarding to these special solutions, we give some results of the relations between null geodesic curves and timelike ruled surfaces in dual Lorentzian space.