• Title/Summary/Keyword: Invertor

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Different Biomechanical Characteristics in Proprioception, Muscle Strength, and Time to Peak Torque at Velocity of 300°/sec of the Ankle Joint in People With or Without Functional Ankle Instability (각속도 300°/sec에서 기능적 발목불안 유무에 따른 고유수용성감각, 발목 근력, 그리고 최고 회전력까지 걸리는 시간의 생체역학적 특성 차이)

  • Park, Eun-Young;Kim, Won-Ho
    • Physical Therapy Korea
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    • v.20 no.3
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    • pp.45-53
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    • 2013
  • The purpose of this study was to examine the differentiation of proprioception, invertor and evertor muscle strength, and time to peak torque at a velocity of $300^{\circ}/sec$ of the ankle joint in people with or without functional ankle instability (FAI). Nineteen subjects with a history of ankle sprain participated. All subjects were divided into FAI group ($n_1=9$, Cumberland ankle instability tool (CAIT)${\leq}24$) and a control group ($n_2=10$) based on their CAIT scores. Isokinetic dynamometer was used to measure the sense of active joint position of the ankle at mid-range and end-range of an inversion motion and invertor as well as the evertor muscle strength and time to peak torque at $300^{\circ}/s$. The FAI group showed a statistically reduction in invertor and evertor muscle strength and time to peak torque when compared to the control group (p<.05). Muscle strength and time to peak torque of the invertor and evertor, as well as the sense of active joint position at end-range were also lower in the FAI group than in the control (p<.05). Correlations between CAIT score and position sense at end-range (r=-.577) and invertor muscle strength (r=.554) were statistically significant (p<.05). Individuals with FAI showed reduction in invertor and evertor muscle strength and recruitment time as well as in proprioception of the ankle joint. Thus, proprioception and invertor and evertor muscle strength of the ankle joint at fast angular velocity may be investigated when examining and planning care for individuals with FAI.

Effects of Ankle Invertor and Plantar Flexor Stretching on Balance and Walking Ability of Stroke Patients

  • Song, Ji Yoon;Kim, Joong Hwi
    • The Journal of Korean Physical Therapy
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    • v.34 no.4
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    • pp.181-186
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    • 2022
  • Purpose: This study was to applied to stretching plantar flexor and invertor at the same time to observe the effect of balance and walking ability. Methods: Subjects were instructed patients with ankle limited of motion, 6 months after stroke. We classified 20 subjects into two groups (experimental group: stretching plantar flexor and invertor at the same time, control group: only stretching plantar flexor). each group included 10 subjects and applied ankle stretcher for 20 minutes, 5 times/week during 4 weeks (total 20 times). Results: Both experimental group and control group showed significant increases in static balance, however, the significantly increases in step length and gait speed was observed only in the experimental group. There was no significant increases in step length and gait speed in the control group. Conclusion: Simultaneous stretching of ankle invertor and plantar flexion is effective in improving balance and walking ability in chronic stroke patients.

A study to improve the Performance of induction motor using Min Max algorithm and dead time compensation method (Min Max 알고리즘과 Dead Time 보상기법에 의한 유도전동기의 성능 향상에 관한 연구)

  • Kim, Hyung-Gu;Yang, Oh
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.976-978
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    • 1999
  • Recently PWM invertor is broadly used for control of induction motor. The invertor is able to generate sin wave current from high speed switching power device such as IGBT. However the invertor is disturbed by dead time inevitably needed to prevent a short of the DC link voltage, and the dead time mainly causes distortions of the output current. In this Paper the dead time compensation method which corrects the voltage error from dead time, and Min Max algorithm enlarging the operating voltage of PWM were Proposed. This method can be implemented by software programming without any additional hardware circuit. The proposed algorithms were implemented by DSP(TMS320C31, 40MHz) and FPGA(QL2007, Quick Logic) described in VHDL. and applied to 3 phase induction motor(2.2 KW) to show the superior performance

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A study of Ankle flexibility and Isokinetic Muscular strength between Chronic ankle sprain and Normal dancers (만성 발목관절 염좌인 무용수와 정상인 무용수의 유연성과 등속성 근력 비교연구)

  • Lee, In-hak;;Lee, Hyeon-Wook;Han, Sang-Wan
    • The Journal of Korean Physical Therapy
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    • v.13 no.3
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    • pp.735-749
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    • 2001
  • The purpose of this study was to compare the flexibility and isokinetic differences between normal dancers and dancers with chronically sprained ankle. For the experiment Eversion/Inversion testing was performed by a Cybex 770 isokinetic dynamometer at the a speeds of 30$^{\circ}$ /sec and 120$^{\circ}$ /sec on each 7 subject group. The results were; 1) No differences were found between the two groups in ROM of ankle, but ROM of eversion has 2.8$^{\circ}$ higher in the injury group than the normal group. 2) Differences were found between the two groups in peak torque. average power, total work at the evertor and invertor in injury side.(30$^{\circ}$ /sec) 3) Differences were found between the two groups in peak torque at the evertor and invertor in normal side.(30$^{\circ}$ /sec) 4) Differences were found between the two groups in total work at the evertor in normal side. (30$^{\circ}$ /sec) 5) Differences were found between the two groups in peak torque, total work at the evertor and invertor in injury side. (120$^{\circ}$ /sec)

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Dielectric Breakdown Voltage and Dielectric Properties of High Voltage Mutilayer Ceramic Capacitor with C0G Temperature Coefficient Characteristics (C0G 온도계수 특성을 가지는 고압용 적층 칩 캐패시티의 유전 및 내전압 특성)

  • Yoon, Jung-Rag;Woo, Byong-Chul;Chung, Tae-Serk
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.2
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    • pp.137-143
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    • 2008
  • High voltage MLCCs with C0G temperature coefficient characteristics could apply DC-DC invertor were investigated for its dielectric properties. Also we manufactured MLCC through various process and studied the characteristics of dielectric break down voltage [BDV] and dielectric property as the variation of thickness in the green sheet and how to pattern the internal electrode. As the thickness of green sheet is increase, the dielectric BDV per unit thickness is decreased. But as the pattern of internal electrodes were floated we could manufacture the high voltage MLCC maintained its dielectric BDV a unit.

Adaptive DC to AC Invertor Design based on Fuzzy Inference for Power Consumption monitoring (퍼지 추론을 이용한 적응적 DC/AC 인버터 설계)

  • 김윤호
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.7
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    • pp.1520-1526
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    • 2003
  • Design and implementation method or the 100[W] DD/AC invertor using PICl6C711 processor is described in this paper. Especially, fuzzy inference algorithm is involved in this system which can be adaptive to the environment variation. Input/output control and power consumption monitoring is controlled based on PIC16C711 processor, which compute the optimal values acquired from inference engine. Such experimental as function, efficiency, motoring are performed and experimental results showed that monitoring error is less than 2% and widely used in the area of industrial fields.

Diagnosis System of Obsolete Sunlight Generation Equipment (태양광 발전 노후 설비 진단 시스템)

  • Lee, Seong-Real
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.05a
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    • pp.535-537
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    • 2021
  • Sensor node and remote terminal unit (RTU) for diagnosis of obsolete sunlight generation equipments is proposed in this research. Sensor node can surveil monitor ambient temperature, current and voltage of invertor, and can communicate with RTU through RS485 channel. RTU can gather sensing data from sensor nodes and can transmit these data to management server through LTE CAT. M1 channel.

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The Evaluation of Factors Which Influence Binding Efficiency of Modified in Vivo Erythrocyte Labeling Technique (변형 체내 표지법에 의한 적혈구 표지시 결합효율에 영향을 미치는 인자 평가)

  • Seo, Han-Kyung;Kim, Min-Woo;Lim, Seok-Tae;Sohn, Myung-Hee
    • The Korean Journal of Nuclear Medicine
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    • v.38 no.4
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    • pp.300-305
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    • 2004
  • Purpose: We underwent this study to evaluate the factors which influence labeling efficiency when modified in vivo erythrocyte labeling technique was used. Materials and methods: Thirty healthy volunteers (M:F=19:11, age:$25{\pm}2$ yrs) were enrolled in this study. Totally, two hundred ten samples were obtained from them. The 1 mg of stannous pyrophosphate was injected intravenously at the beginning of labeling. After suitable tinning time (5 min, 20 min, 35 min) passed by, blood (5 mL, 3 mL or 1 mL) was withdrawn into 10 mL syringe previously containing Tc-99m (740 MBq) and anticoagulant (heparin, ACD or CPDA) through 19-gauged scalp needle. The generator ingrowth time of Tc-99m was within 24 hrs in each case. The blood samples were placed on rotating invertor during incubation (10 min, 25 min, 40 min) but some of them were not. Immediately after the conclusion of incubation, the labeled blood specimens to analyze were centrifuged. and then %Unbound Tc-99m was calculated. Statical analysis was used paired T-test and one way ANOVA with SPSS 10.0. Results: The binding efficiency at 1 mL of blood volume was $73{\pm}32%,\;91{\pm}10%$ at 3 mL and $96{\pm}7%$ at 5 mL (p<0.01). The binding efficiency at 5 min of tinning time was $45{\pm}23%,\;98{\pm}6%$, at 20 min and $97{\pm}8%$ at 35 min (p<0.001). The binding efficiency at 10 min of incubation time was $96{\pm}7%,\;95{\pm}12%$ at 25 min and $98{\pm}3%$ at 40 min (p>0.05). The binding efficiency in case of using rotating invertor was $96{\pm}7%$ and the binding efficiency in case of not using it was $87{\pm}18%$ (p>0.05). There was no significant difference between them. In binding efficiency according to kinds of anticoagulants, ACD was $98{\pm}4%$, CPDA was $97{\pm}6%$ and heparin was $89{\pm}20%$ (p<0.001). Conclusion: When modified in vivo erythrocyte labeling technique is used with Tc-99m, the methods to obtain the highest labeling efficiency are as follow. The withdrawing blood volume should be over 3 mL, tinning time should be kept between 20 min and 35 min, and incubation time should be kept between 10 min and 40 min. ACD or CPDA have to be used as a anticoagulant except heparin and the blood samples should be placed on rotating invertor during incubation.

The analysis of the conversive limitation of electric energy for the gate turn on thyristor inverter (Gate turn on thyristor 역변환장치의 변환전력한계치에 대하여)

  • Hee Yung Chun
    • 전기의세계
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    • v.17 no.2
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    • pp.6-10
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    • 1968
  • The conversive limitation of electric energy for the thyristor inverter is analysed under the boundary conditions which the term of a negative inverse voltage is longer than that of the turn off time of the thyristor under commutation. It is clear that the maximum electric energy conversion is affected by the turn off time of the thyristor, the reactance of a commutation reactor, the capacity of a commutation condenser and the voltage of Direct current source. It is useful for design the thyrister invertor and the motor speed control to apply the above conclusion.

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A New Resonant Type Inverter with Low Voltage Stress (낮은 전압 Stress를 갖는 새로운 공진형 인버터)

  • Jung, Yong-Chae;Cho, Gyu-Hyeong
    • Proceedings of the KIEE Conference
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    • 1992.07b
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    • pp.1150-1153
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    • 1992
  • A new soft-switching resonant type inverter is proposed to obtain the low voltage stress. In this proposed inverter, only one additional switch is used for the soft commutation. Therefore, a simple structure and a easy control can be available. Moreover, the PWM capability can be highly improved due to tile convenient choice of switching condition. Based on the operational principle, analysis and design procedures are described. Through the simulation, the operation of the proposed invertor is verified.

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