• Title/Summary/Keyword: Position reliability

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Reliability of Lateral Deviation Measurement in the Hyoid Bone With Center Point and Lateral Motion Tests

  • Min, Hye-jin;Yoon, Tae-lim
    • Physical Therapy Korea
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    • v.26 no.3
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    • pp.76-83
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    • 2019
  • Background: The hyoid bone is the only non-jointed structure among the skeletal tissues of the head and neck region, and its movement and posture depend on the attached muscle, ligament, and fascia. The location of the hyoid bone is important for airway maintenance, vocalization, chewing, swallowing, breathing, and head and scapular position. In general, the location of the hyoid bone is measured using radiographs and 3D computed tomography, and no studies have reported on clinical measurement methods. Objects: This study was performed to suggest clinical measurement methods for lateral deviation of the hyoid bone and to evaluate their reliability. Methods: In this study, 24 healthy volunteers (12 males, 12 females) in Cheongju-si participated. Two examiners performed the center point test and lateral motion test twice each to measure the lateral displacement of the hyoid bone. The reliability of the center point test was analyzed using intra-class correlation coefficients (ICC), and the reliability of the lateral motion test was analyzed using Cohen's kappa coefficient. Results: The intra-rater reliability of the center point test was good, and the inter-rater reliability was moderate. The intra- and inter-rater reliability of the lateral motion test showed substantial reliability. Conclusion: Based on these results, the center point test and the lateral motion test can be used as an alternative methods of the measurement of lateral deviation of the hyoid bone for people who have musculoskeletal disorders of the head, neck, and scapula.

A reliability analysis of syndrome differentiation questionnaire for obesity (비만변증 설문지에 대한 신뢰도 분석)

  • Kang, Byeong-Kab;Moon, Jin-Seok;Choi, Sun-Mi
    • Korean Journal of Oriental Medicine
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    • v.13 no.1 s.19
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    • pp.109-114
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    • 2007
  • The high position condition 10 escape which the obesity person appeals. Obesity Pattern-Identification question it will yell and 243 subjects which to the obesity in the patient of 517 subjects which draw up correspond. (longitude obesity 153 person, altitude obesity 90 person) against it analyzes. In order to analyze the reliability of the items which diagnose each Pattern-Identification it used Cronbach alpha coefficient and escape it did the alpha of each item. Alpha value of each Pattern-Identification than appears more highly the item which it will be able to consider an elimination in the item which decreases a reliability. In that phlegm-retention syndrome is bigger alpha coefficient 0.784 than 'meal quantity is few'(0.787) a possibility of seeing in the item which decreases a reliability to the place where it diagnoses it puts in phlegm-retention syndrome.

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A Hybrid ARQ Scheme with Changing the Modulation Order (변조 차수 변경을 통한 하이브리드 자동 재전송 기법)

  • Park, Bum-Soo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.3
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    • pp.336-341
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    • 2014
  • When using a higher-order modulation scheme, there are variations in bit-reliability depending on the bit position in a modulation symbol. Variations of bit-reliability in the codeword block lower the decoding performance. Also, the decoding performance increases as the sum of the bit-reliabilities in the codeword block increases. This paper presents a novel hybrid automatic repeat request scheme that increases the sum of the reliabilities of the transmitted bits by lowering the modulation order, and decreases the variations of bit-reliability in the codeword block by preferentially retransmitting bits with low reliability. The proposed scheme outperforms the constellation rearrangement scheme. Furthermore, the proposed scheme also provides a good solution in cases where the size of the retransmission block is smaller than the size of the initial transmission block.

Reliability Evaluation for Hinge of Folder Devices Using ESPI

  • Kyungyoung Jhang;Minkwan Hyun;Lee, Taehun;Seokwon Chang
    • International Journal of Reliability and Applications
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    • v.5 no.1
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    • pp.15-24
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    • 2004
  • Folder type electronic devices have hinge to support the rotational motion of folder. This hinge is stressed by the rotational inertia moment of folder at the maximum open limit position of folder. This stress is repeated whenever the folder is open, and it is a cause of hinge fracture. In this paper, the reliability evaluation for the hinge fracture in the folder type cellular phone is discussed. For this, the durability testing machine using crank-rocker mechanism is developed to evaluate the life cycle of the hinge, and the degradation after repetitions of opening and shutting is evaluated from the deformation around the hinge, where the deformation is measured by ESPI (electronic speckle pattern interferometer). Experimental results showed that ESPI was able to measure the deformation of hinge precisely, so we could monitor the change of deformation around the hinge as the repetition number of folder open is increased.

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Estimate of Flashover Position from E-field Calculation along Electrode Gap Distance (진공인터럽터 극간 랩거리 조정에 따른 각 부위의 전계값 계산을 통한 진공인터럽터 내부 절연파괴부위 예측)

  • Yoon, Jae-Hun;Lim, Kee-Jo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.03b
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    • pp.23-23
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    • 2010
  • Because of power consumption increase, global warming, and limitation of installation, not only high reliability and interruption capability but also compact and light power apparatuses are needed. In this paper, various models that short and long gap distance were used to analyze E field of each model. Calculation value was estimated of flashover position. As a result, short and long gap distance that vacuum interrupter inner between move electrode and fix electrode not coincided flashover position of each model. short gap distance estimated flashover position at electrode edge. but long gap distance model confirmed $E_{max}$ value at center shield. in this paper was compared electric field value. and estimated of flashover position from electric field calculation.

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A Position Control System of D.C. Motor Using Microprocessor (마이크로프로세서를 이용한 직류전동기의 위치제어 시스템)

  • An, Mi-Rang;Kim, Jong-Soo;Kim, Young-Seok;Joe, Kee-Yeon
    • Proceedings of the KIEE Conference
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    • 1987.11a
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    • pp.355-358
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    • 1987
  • A design of digital position control system with DC Motor is presented. The digital position control system is constructed by power circuits, interface circuits and control circuits using single chip microprocessor (8096). All control functions are implemented on the 16 bit micro-processor requiring only on incremental encoder for speed and position sensing. The control schemes are used by the proportional control for some modifications and braking algorithms. This digital position system offered to the fast response, good steady-state accuracy, flexibility and reliability, Hardware, software features and experimental results of this system are described.

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Sensorless Speed Control of Switched Reluctance Motor Using Rotor Angle Compensation Method (회전각 보상방식을 이용한 스위치드 리럭턴스 전동기의 센서리스 속도제어)

  • Shin, K.J.;Yoon, K.Y.;Kwon, Y.A.
    • Proceedings of the KIEE Conference
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    • 1999.07a
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    • pp.64-66
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    • 1999
  • Switched reluctance motor(SRM) has the advantages of simple structure, low rotor inertia and high efficiency. However, position sensor is essential in SRM in order to synchronize the phase excitation to the rotor position. The position sensors increase the cost of drive system and tend to reduce system reliability. This paper investigates the speed control of sensorless SRM in which the phase current and change rate are utilized in position decision, and the period of dwell angle is variable by compensating the rotor angle. The proposed system consists of position decision, phase locked loop controller, switching angle controller and inverter. The performances in the proposed system are verified through experiments.

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Sensorless Speed Control of Switched Reluctance Motor Using PIC16 series Micom (PIC 16계열 마이컴을 이용한 센서리스 SRM의 속도제어)

  • Shin, K.J.;Kwon, Y.A.
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.684-686
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    • 2000
  • Switched reluctance motor(SRM) has the advantages of simple structure, low rotor inertia. and high efficiency. However position sensor is essential in SRM in order to synchronize the phase excitation to the rotor position. The position sensors increase the cost of drive system and tend to reduce system reliability. This paper investigates the speed control of sensorless SRM in which the phase current and change rate are utilized in position decision, and the period of dwell angle is variable by compensating the rotor angle for speed control. The proposed system consists of position decision. phase locked loop controller, switching angle controller and inverter. The performances in the proposed system are verified through the experiment.

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Sensorless Drive for Brushless DC Motor Using Simple Voltage Detecting Circuit (간단한 전압 검출 회로를 이용한 BLDC 전동기의 센서리스제어)

  • Go, Sung-Chul;Ahn, Joon-Seon;Lee, Ju
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.1294-1296
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    • 2005
  • Because of its cost effectiveness, the Brushless DC Motor(BLDCM) is focused by the industry these days. Considering the constant back-EMF region of the BLDCM, only a simple position information should be provided for constant torque control. From this point of view, using expensive position sensors, such as encoder, resolver, etc, decreases the cost effectiveness of the BLDCM. The Proposed detecting circuit detects position of zero crossing point(ZCP) then relative position could be calculated from ZCP. This circuit is robust to noise because of working in the current level. BLDCM is driven from the position information by the ZCP The reliability on BLDCM sensorless control using the voltage detecting circuit is shown through simulation using Matlab.

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A Novel Position Sensorless Speed Control Scheme for Permanent Magnet Synchronous Motor Drives

  • Won, Tae-Hyun;Lee, Man-Hyung
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.2B no.3
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    • pp.125-132
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    • 2002
  • PMSMS (permanent magnet synchronous motors) are widely used in industrial applications and home appliances because of their high torque to inertia ratio, superior power density, and high efficiency. For high performance control, accurate informations about the rotor position is essential. Sensorless algorithms have lately been studied extensively due to the high cost of position sensors and their low reliability in harsh environments. A novel position sensorless speed control for PMSMs uses indirect flux estimation and is presented in this paper. Rotor position and angular velocity are estimated by the proposed indirect flux estimation. Linkage flux and magnetic field flux are calculated by the voltage equations and the measured phase current without any integration. Instead of linkage flux calculation with integral operation, indirect flux and differential magnetic field are used for the estimation of rotor position. A proper rejection technique fur current noise effect in the calculation of differential linkage flux is introduced. The proposed indirect flux detecting method is free from the integral rounding error and linkage flux drift problem, because differential linkage flux can be calculated without any integral operation. Furthermore, electrical parameters of the PMSM can be measured by the proposed TCM (time compression method) for soft starting and precise estimation of rotor position. The position estimator uses accurate electrical parameters that are obtained from the proposed TCM at starting strategy. In the operating region, a proper compensation method fur temperature effect can compensate fir the estimation error from the variation of electrical parameters. The proposed novel position sensorless speed control scheme is verified by the experimental results.