• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.607-612
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• 1992

This paper presents a tip position control of a single-link flexible arm with a payload by using closed loop control. The shifting problem of the arm from the initial position to desired position is considered by the variation of the displacement gain $G_{p}$ and velocity gain $G_{v}$. The system is composed of a flexible arm with payload, DC servomotor, and a ballscrew mechanism. The flexible arm is mounted on a mobile stage driven by a servomotor and ballscrew. As a result, the increase of the displacement and velocity gain respectively comes to the reduction of tip vibration. Theoretical results are approximately in good agreement with those obtained experimentally.y.y.

• Journal of Power Electronics
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• 제8권4호
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• pp.317-324
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• 2008

This paper proposes a Multiband Shunt Hybrid Active Filter (SHAF) with sensorless control. A plant is modeled in the discrete- time domain and a controller is designed using the Pole shifting law in the polynomial domain. This control approach is very useful for filtering the load harmonics with reduced sensor counts where a low cost solution like SHAF is required. Multiple Synchronous Reference Frames (MSRF) and low pass filters are used to measure the $5^{th}$ and $7^{th}$ harmonic components separately from the load and filter currents. Individual current controllers are designed for the $5^{th}$ and $7^{th}$ harmonic currents. Control is realized in the stationary, three-phase (abc) reference frame. Performance of the controller is validated through simulation, using realistic plant and controller models, as well as experimentally on a full-scale distribution system.

• 말소리와 음성과학
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• 제9권3호
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• pp.57-65
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• 2017

The current study explored how Korean-speaking children processed the multiple acoustic cues (VOT and f0) for the stop laryngeal contrast (/t'/, /t/, and /$t^h$/) and examined whether individual perceptual strategies could be related to a general cognitive ability performing executive functions (EF). 15 children (aged from 7 to 8) participated in the speech perception task identifying the three Korean laryngeal stops (3AFC) on listening to the auditory stimuli of C-/a/ with synthetically varying VOT and f0. They completed a series of EF tasks to measure working memory, inhibition, and cognitive shifting ability. The findings showed that children used the two cues in a highly correlated manner. While children utilized VOT consistently for the three laryngeal categories, their use of f0 was either reduced or enhanced depending on the phonetic categories. Importantly, the children's processing strategies of a f0 suppression for a tense-aspirated contrast were meaningfully associated with children's better cognitive abilities such as working memory, inhibition, and attentional shifting. As a preliminary experimental investigation, the current research demonstrated that listeners with inefficient processing strategies were poor at the EF skills, suggesting that cognitive skills might be responsible for developmental variations of processing sub-phonemic information for the linguistic contrast.

• 한국운동역학회지
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• 제16권1호
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• pp.159-166
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• 2006

The purpose of this study were analysed fatigue character of lumbar extension Muscle during repeated trunk flexion-extension motion we used EMG multi-telemeter (WEB 5000, Nihon Koden, Japan), Medex lumbar extension machine(Ocala, USA). We evaluated 20 persons on chronic low back pain group and 20 persons on control group. We analysed the quantitative variables IMF, MF, decreased ratios of MF to investigate fatigue. As a result, the following conclusion was drawn : 1. Each lumbar IMF of CLBP was L5> L3> L1 in the order of their size. CON group was similar quantitative and same order. But the relationship of two groups were not significantly. 2 The IMF within lumbar position(L1-L3, L1-L5, L3-L5) of two groups was significantly all positions(p<.05). 3. The MF shifting at lumbar position of two groups during repeated trunk flexion-extension motion was decrease shifting pattern with increase repeating motion, especially CLBP group was suddenly dropping than CON at all lumbar positions(L1, L3, L5) on early stage motion(34 set). 4. The lumbar fatigue of CLBP was higher than CON during repeated trunk flexion-extention motion, so CLBP supposed more tired than CON. And it was significantly within two groups at lumbar positions(L1, L3 : p<.05, L5 : P<.01).

• Nuclear Engineering and Technology
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• 제55권3호
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• pp.1009-1014
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• 2023

Muon tomography is a useful method for monitoring special nuclear materials (SNMs) such as spent nuclear fuel inside dry cask storage. Multiple Coulomb scattering of muons can be used to provide information about the 3-dimensional structure and atomic number(Z) of the inner materials. Tomography using muons is less affected by the shielding material and less harmful to health than other measurement methods. We developed a muon detector for muon tomography, which consists of a plastic scintillator, 64 long wavelength-shifting (WLS) fibers attached to the top of the plastic scintillator, and silicon photomultipliers (SiPMs) connected to both ends of each WLS fiber. The muon detector can acquire X and Y positions simultaneously using a position determination algorithm. The design parameters of the muon detector were optimized using DETECT2000 and Geant4 simulations, and a muon detector prototype was built based on the results. Spatial resolution measurement was performed using simulations and experiments to evaluate the feasibility of the muon detector. The experimental results were in good agreement with the simulation results. The muon detector has been confirmed for use in a muon tomography system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.262-263
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• 2006

This paper presents a scheme to solve the congestion problem with phase-shifting transformer(PST) and power generation using linear programming method. A good design of PST and power generation control can improve total transfer capability(TTC) in interconnected systems. This paper deals with an application of optimization technique for TTC calculation. linear programming method is used to maximize power flow of tie line subject to security constraints such as voltage magnitude and real power flow. The proposed method is applied to 10 machines 39 buses model systems to show its effectiveness.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.108-108
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• 2006

The role of conformational entropy of polymer chains in polymer crystallization is investigated by molecular modeling and theory. The entropy of folded loops dominates at experimentally relevant temperatures to dictate short equilibrium lamellar thicknesses, which are much smaller than the extended chain thickness. Also the entropic barriers control the kinetics of polymer crystallization. These results based on chain entropy are different from the classical views of how polymer chains crystallize.

• 한국정밀공학회지
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• 제21권1호
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• pp.101-108
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• 2004

An electro-hydraulic manipulator using hydraulic actuators has many nonlinear elements, and its parameter fluctuations are greater than those of an electrically driven manipulator. So it is relatively difficult to obtain stable control performance. In this report, we applied disturbance estimation and compensation type robust control to all axes in a 3-link electro-hydraulic manipulator. From the results of experiment, it was confirmed that the performance of trajectory tracking and attitude regulating is greatly improved by the disturbance observer, which model is the same for each axis. On the other hand, for the autonomous assembly tasks, it is said that compliance control is one of the most available methods. Therefore we proposed compliance control which is based on the position control by disturbance observer for our manipulator system. To realize more stable contact work, the states in the compliance loop are feedback, where not only displacement but also velocity and acceleration are considered. And we applied this compliance control to Peg-in-Hole insertion task and analyzed mechanical relation between peg and hole. Also we proposed new method of shifting the position of end-effector periodically for the purpose of smooth insertion. As a result of using this method, it is experimentally confirmed that Peg-in-Hole insertion task with a clearance of 0.05［mm］can be achieved.

• Journal of electromagnetic engineering and science
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• 제3권1호
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• pp.50-56
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• 2003

This paper proposes a coding scheme of control channel for mobile packet communication to maximize the minimum Hamming distance, which is based on shifting of basis vectors of Reed Muller code with optimized dynamic puncturing and/or(partial) sequence repetition. Since the maximum likelihood decoding can be performed using the extremely simple FHT(Fast Hadamard Transformation), it is suitable for real time optimum decoding of control channel information with very little complexity. We show applications of the proposed coding method to TFCI(Transport Format Combination Indicator) code in split and normal modes of 3GPP W-CDMA system. We also discuss how this method can reduce rate indication error over AWGN(Additive White Gaussian Noise) as well as fading channels when the proposed coding scheme is applied to 1xEV-DV system of $3^{rd}$TEX> generation partnership project 2(3GPP2) to indicate the data rate transmitted on the reverse traffic channel by a Mobile Station(MS).

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전력기술부문
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• pp.223-225
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• 2005

This paper presents a scheme to solve the congestion problem using hybrid control with phase-shifting transformer(PST) and power generation in power systems. A good design of PST and power generation control can improve total transfer capability(TTC) in interconnected systems. This paper deals with an application of optimization technique for TTC calculation. The optimization method is used to maximize power flow of tic line subject to security constraints such as voltage magnitude and real power flow. The proposed method is applied to 10 machines 39 buses model systems to show its effectiveness.