• Title/Summary/Keyword: Frequency Dependent Control

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Investigation on Vibration Control of Squeeze Mode ER Mount Subjected to 200 kg of Static Load (200 kg급 압착모드형 ER 마운트의 진동제어성능 고찰)

  • 정우진;정의봉;홍성룡;최승복
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.11
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    • pp.882-889
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    • 2002
  • This paper presents vibration control performance of a squeeze mode ER mount for high static load. After experimentally investigating the field-dependent damping force under the squeeze mode motion, a squeeze mode ER mount which can support 200 kg of static load is designed and manufactured. Displacement transmissibility of the proposed ER mount is experimentally evaluated in frequency domain with respect to the intensity of the electric field, and a sky-hook control algorithm is designed to attenuate unwanted vibration. Vibration isolation capabilities of the flow mode ER mount and rubber mount are compared to those of the proposed squeeze mode ER mount.

Effect of MLN8237, a Novel Aurora A Kinase Inhibitor, on the Spontaneous Fragmentation of Ovulated Mouse Oocytes

  • Park, Ji-Hun;Choi, Tae-Saeng
    • Reproductive and Developmental Biology
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    • v.35 no.4
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    • pp.499-502
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    • 2011
  • Aurora A kinase is a mitotic serine/threonine kinase whose proposed functions include the maturation of centrosomes, G2/M transition, alignment of chromosomes at metaphase, and cytokinesis. In this study, we investigated the effect of MLN8237, an aurora A kinase inhibitor, on the postovulatory aging of oocytes based on the frequency of oocyte fragmentation, cdk1 kinase activity, and cyclin B degradation. The fragmentation of ovulated oocytes during prolonged culture was inhibited by treatment with MLN8237 in a concentration-dependent manner. The frequency of fragmented oocytes was significantly lower in oocytes treated with 2 ${\mu}M$ MLN8237 (13%) than in control oocytes (64%) after two days of culture. Most of the control (non-fragmented) oocytes (91%) were activated after two days of culture. In comparison, only 22% of the MLN8237-treated oocytes were activated; the rest of the oocytes (78%) were still in metaphase with an abnormal spindle and dispersed chromosomes. Next, cdk1 activity and the level of cyclin B were examined. The level of cyclin B and cdk1 activity in MLN8237-treated oocytes were nearly equal to those in control oocytes. Our results indicate that MLN8237 inhibited the fragmentation of ovulated oocytes during prolonged culture, although it blocked the spontaneous decrease in activity of cdk1 and degradation of cyclin B. This mechanism of inhibition is different from that in oocytes treated with nocodazole, which have high levels of cdk1 activity and cyclin B.

The Effectiveness of Bladder Training on Self Voiding after Removal of Catheter in Female Patients with Craniotomy (개두술 여성환자에게 시행한 방광훈련이 유치도뇨관제거후 자가배뇨에 미치는 효과)

  • Lee, Jung-Lim;Kim, Keum-Soon
    • The Korean Journal of Rehabilitation Nursing
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    • v.2 no.1
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    • pp.72-84
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    • 1999
  • The purpose of this study was to identify the effectiveness of bladder training on self voiding after removal of catheter in female patients with craniotomy, finally to develop a bladder rehabilitation program for cognitive impaired patients. Nonequivalent control group posttest design was used. The population of this study consisted of 34 hospitalized neurosurgical patients, all patients have been received craniotomy. 17 patients were assigned to the experimental group and another 17 patients to the control group. The homogeneity of general characteristics of the subjects was no significant difference. Bladder training program consisted of pre-training education, the bladder training, positive verbal reinforcement. The experimental group has been received bladder training and the control group has been received gravity drainage. The dependent variable, the frequency of voiding trial untill self voiding achieves, the frequency of urinary retention, the amount of residual urine, the occurrence, of urinary incontinence, were measured during 3 days after catheter removed. The data analyzed with SPSSWIN ; frequency, percentage, t-test and $X^2$-test were used to analyze homogeneity of general characteristics of subjects between the experimental and the control group. T-test, Mann-Whitney U test, and $X^2$-test were used to determine the effect of bladder training. The result of the study were as follows : There was significant difference in the frequency of voiding trial untill self voiding achieves between the experimental group and the control group. There was no significant difference in the frequency of urinary retention between the experimental group and the control group. There was no significant difference in the amount of residual urine between the experimental group and the control group. However, there was significant difference in the amount of residual urine in urinary retention patients. There was significant difference in the occurrence of urinary incontinence between the experimental group and the control group. In conclusion, bladder training program as a nursing intervention was effective in conclusion, bladder self voiding ability after removal of catheter for craniotomy patients. Therefore, it is recommended to use the bladder training program clinically for the bladder management of cognitive impaired patients.

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OPTIMAL PREVIEW CONTROL OF TRACKED VEHICLE SUSPENSION SYSTEMS

  • Youn, I.;Lee, S.;Tomizuka, M.
    • International Journal of Automotive Technology
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    • v.7 no.4
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    • pp.469-475
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    • 2006
  • In this paper, an optimal suspension system with preview of the road input is synthesized for a half tracked vehicle. The main goal of this research is to improve the ride comfort characteristics of a fast moving tracked vehicle in order to maintain the driver's driving capability. Several different kinds of preview control algorithms are evaluated with active or semi-active suspension systems. The road information estimated from the motion of the 1st road-wheel is adequate to make the best use of the preview control algorithm for tracked vehicles. The ride-comfort characteristics of the tracked vehicle are more dependent on pitching angular acceleration than heaving acceleration. The pitching motion is reduced by the suspension system with hard outer suspensions and soft inner suspensions. Simulation results show that the performance of sky-hook algorithms for ride comfort nearly follow that of full state feedback algorithms.

A Voice Controlled Service Robot Using Support Vector Machine

  • Kim, Seong-Rock;Park, Jae-Suk;Park, Ju-Hyun;Lee, Suk-Gyu
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1413-1415
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    • 2004
  • This paper proposes a SVM(Support Vector Machine) training algorithm to control a service robot with voice command. The service robot with a stereo vision system and dual manipulators of four degrees of freedom implements a User-Dependent Voice Control System. The training of SVM algorithm that is one of the statistical learning theories leads to a QP(quadratic programming) problem. In this paper, we present an efficient SVM speech recognition scheme especially based on less learning data comparing with conventional approaches. SVM discriminator decides rejection or acceptance of user's extracted voice features by the MFCC(Mel Frequency Cepstrum Coefficient). Among several SVM kernels, the exponential RBF function gives the best classification and the accurate user recognition. The numerical simulation and the experiment verified the usefulness of the proposed algorithm.

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Control Strategy of MMC-HVDC under Unbalanced Grid Voltage Conditions

  • Zhang, Jianpo;Zhao, Chengyong
    • Journal of Power Electronics
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    • v.15 no.6
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    • pp.1499-1507
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    • 2015
  • High voltage direct current transmission based on modular multilevel converter (MMC-HVDC) is one of the most promising power transmission technologies. In this study, the mathematical characteristics of MMC-HVDC are analyzed in a synchronous rotational reference frame. A hybrid current vector controller based on proportional integer plus resonant is used to uniformly control the DC and double-base frequency AC currents under unbalanced grid voltage conditions. A corresponding voltage dependent current order limiter is then designed to solve the overcurrent problems that may occur. Moreover, the circulating current sequence components are thoroughly examined and controlled using a developed circulating current suppressor. Simulation results verify the correctness and effectiveness of the proposed control schemes.

Development of the semi-active controlled variable damper system for passenger vehicles (승용차용 반능동형 가변댐퍼시스템의 개발)

  • 허승진;심정수;이광기;김홍석;황성호
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1995.04a
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    • pp.45-50
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    • 1995
  • 본 연구에서는 기존에 널리 사용되고 있는 스카이훅 제어 알고리즘(skyhook control algorithm)[3]을 바탕으로 확장 개발된 모드 스카이훅 제어(mode skyhook control) 개념 및 주파수 감응식 제어(frequency dependent control)개념[4][5]을 실용화하기 위하여 응답속도가 20msec이하의 비교적 빠른 응답 속도를 갖는 전자기식 작동기 (electro-magnetic actuator)에 의해 가변되는 4단 반능동형 가변 댐퍼 시스템을 개발한 후, 다음과 같은 성능의 향상을 시험결과를 통하여 보이고자 한다. -저속에서의 승차감 향상과 고속에서의 주행 안정성 향상 -커브 주행 또는 급격한 핸들 작동시의 롤안정성 (rolling stability) 향상 -제동 및 급발진시의 차체 피칭 운동 방지 (anti-dive, anti-squat)

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Electrical Characterization of Para-Sexiphenyl Organic Electroluminescenct Devices (Para-sexiphenyl 유기 EL 소자의 전기적 특성)

  • Lee, Yonq-Soo;Park, Jae-Hoon;Choi, Jong-Sun
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.1739-1741
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    • 2000
  • DC current density-voltage and impedance spectroscopy studies have been performed on indium-tin-oxide(ITO)/para-sexiphenyl(6p)/aluminium organic electroluminescent device. The device exhibited a blue color emission, The turn-on voltage of the device is observed at 5V from the current density-voltage measurements. The impedance spectroscopy measurements show that a resonance frequency shift with applied DC bias is observed and a single semi-circle Cole-Cole plot is confirmed. The bias-dependent bulk resistance and bias-independent bulk capacitance is observed.

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Seismic Response Control Performance of Linear and Nonlinear TLD Models (선형 및 비선형 TLD의 지진응답 제어성능 평가)

  • Lee, Sang-Hyun;Woo, Sung-Sik;Chung, Lan
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.519-526
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    • 2006
  • This paper compares the seismic response control performance of linear and non-linear models fer tuned liquid damper (TLD). The existing linear and nonlinear TLD models were used for the numerical analysis of single degree of freedom (SDOF) and multi degree of freedom (MDOF) systems with TLD. The nonlinear model considers the variation of the frequency and damping of the TLD with varying excitation amplitude while the linear one has the invariant parameters. Numerical analysis results from SDOF systems indicate that the nonlinear model shows about 5% better control performance than linear one when the mass ratio is 2% and the optimal parameters for reducing peak responses are dependent on the characteristics of the excitation earthquake loads.

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A Study on Perceived Self-efficacy in Non-insulin Dependent Diabetes Mellitus (제 2형 당뇨병환자의 자기효능에 관한 연구)

  • Choi, Yeon-Hee
    • Research in Community and Public Health Nursing
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    • v.8 no.2
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    • pp.304-313
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    • 1997
  • This study was designed to identify the degree of perceived self-efficacy and self-esteem in non - insulin dependent diabetes mellitus. The 278 Diabetic patients participating in this study were selected from a diabetic clinic. The period of data collection was September 2 to September 10, 1996. Collected data were analyzed by means of Frequency, Mean, SD, t - test, Pearson correlation, ANOVA using SPSS/PC+. The result are summarized as follows: 1. The mean score of perceived self-efficacy were 3.52 in total, 3.91 for medication, 3.40 for exercise, 3.60 for diet control, 3.18 for glucose test, 3.53 for general management. And the mean score of self-esteem were 3.51 2. Perceived self-efficacy and self-esteem had statistically significant positive correlations (r=.3125, p=.001). 3. The results of testing for the degree of perceived self -efficacy, according to the subject's demographic variables, showed that there were significant differences in sex (t=4.14, p<0.001), the level of education(t=6.24, p<0.01) and diabetic education(t=3.25, p<0.05). These results suggest that perceived self-efficacy and self-esteem is an important variable in the compliance of diabetic patients.

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