• Title/Summary/Keyword: Position measurement

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Effect of Ankle Position on Hallux Flexion Force and Muscles Activity of Abductor Hallucis (발목자세가 엄지발가락 굽힘 힘과 엄지벌림근의 근활성도에 미치는 효과)

  • Jung, Doyoung
    • Journal of The Korean Society of Integrative Medicine
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    • v.5 no.2
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    • pp.43-50
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    • 2017
  • Purpose : There is no validated method for measuring the toe flexor strength that can isolate the intrinsic muscles of the foot from the extrinsic muscles. This study compared the hallux flexion force (HFF) and muscle activity in the foot and ankle according to ankle position [plantarflexion (PF), neutral, and dorsiflexion (DF)]. Method : The study enrolled 17 subjects. In the sitting position, the HFF and activities of the abductor hallucis (AbdH), tibialis anterior (TA), and gastrocnemius (GCM) muscles were measured using a digital dynamometer and a wireless electromyography system, respectively. Subjects were instructed to flex the great toe maximally in three different ankle positions. Three 5-second trials were performed to measure the HFF and muscle activities in each condition. Repeated-measures ANOVA was used to compare the variables and paired t-tests with the Bonferroni correction were used for post-hoc pair-wise comparisons. The significance level was set at .016. Result : The HFF in DF was significantly greater than in any other ankle position (p<.01). The TA activity was greatest in ankle DF and that of the GCM was greatest in PF (both p<.01). However, there was no significant difference in AbdH activity according to ankle position. Conclusion : These results suggest that selective strength measurement of the foot intrinsic muscles in HFF should be performed with the ankle in the neutral position.

Performance Improvement of a Floating Solution Using a Recursive Filter

  • Cho, Sung Lyong;Lee, Sang Jeong;Park, Chansik
    • Journal of Positioning, Navigation, and Timing
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    • v.3 no.3
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    • pp.117-122
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    • 2014
  • In CDGPS, ambiguity resolution is determined by the performance of a floating solution, and thus, the performance needs to be improved. In the case of precise positioning at a stationary position, the batch method using multiple measurements is used for the accuracy improvement of a position. The position accuracy performance of a floating solution is outstanding, but it has a problem of high computation cost because all measurements are used. In this study, to improve the floating solution performance of the initial static user in CDGPS, a floating solution method using a recursive filter was implemented. A recursive filter estimates the position solution of the current epoch using the position solution of up to the previous epoch and the pseudorange measurement of the current epoch. The computation cost of the floating solution method using a recursive filter was found to be similar to that of the epoch-by-epoch method. Also, based on actual GPS signals, the floating solution performance was found to be similar to that of the batch method. The floating solution using a recursive filter could significantly improve the performance of the prompt initial position and ambiguity resolution of the initial static user.

Analyzing Position-Domain Hatch Filter for Real-Time Kinematic Differential GNSS (실시간 동적 차분 위성항법을 위한 위치영역 Hatch 필터의 성능 해석)

  • Lee, Hyeong-Geun;Ji, Gyu-In;Rizos, C.
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.2
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    • pp.48-55
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    • 2006
  • Performance characteristics of the position-domain Hatch filter is analyzed for differential global navigation satellite systems. It is shown that the position-domain Hatch filter generates white measurement residual sequences, which is beneficial property for fault detection. It is also shown that the position-domain Hatch filter yields more accurate a priori state estimate than the position-domain Kalman-type filter. Thus, it can be concluded that the position-domain Hatch filter is beneficial in wide application areas where fault-tolerance and accuracy are required at the same time.

Modified Kalman Filter Method for the Position Estimation of an Autonomous Mobile Robot (자율이동 로봇의 위치추정을 위한 변형된 칼만필터 방식)

  • Eom, Ki-Hwan;Kang, Seong-Ho;Kim, Joo-Woong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.4
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    • pp.781-790
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    • 2008
  • In order to improve on the divergence by noise convariance in the Kalman filter position estimation, we propose a method of position estimating through compensating the autonomous mobile robot's noise. Proposed method is the modified Kalman filter using neural network. It is prevented the divergence by the estimation of measurement noise covariance and system noise covariance. In order to verify the effectiveness of the proposed method, we performed simulations and experiments for position estimation. The results show that convergence and position error is reduced than the Kalman filter method.

The Effect of Arm Movements in the during Standing Position on Lower Limb Global Synkinesis and Balance in Stroke Patients

  • Moon, YoungJun;Jeong, DaeKeun;Kang, Jeongil
    • Journal of International Academy of Physical Therapy Research
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    • v.10 no.3
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    • pp.1849-1855
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    • 2019
  • Background: Stroke patients require arm movement exercising for various stimulations in standing position for various stimulations rather than in a sitting position because they require integrated skillful movements, such as stretching, holding, and controlling. Objective: This study was conducted to provide foundational clinical data about lower limb global synkinesis in stroke patients using arm movements in a standing position. Design: Randomized controlled trial. Methods: The subjects were divided into a control group (n = 10) and an experimental group (n = 10), and a pre-test was conducted to evaluate leg global synkinesis (GS) and balance. Intervention method is stretching an arm to hold a ball, repeating supination and pronation of the hand only while maintaining the arm extended as much as possible, repeating shoulder abduction and adduction while holding the pegboard. This was followed by a three-week intervention during which re-measurement was conducted in the same way as was done for the pre-test. Results: The control group showed a significant difference in GS and balance during plantar flexion (p<.05), and the experimental group showed a significant difference in GS and balance during all movements (p<.05, p<.01, respectively). There was a significant difference in GS and balance between the two groups during dorsiflexion (p<.05, p<.01, respectively). Conclusion: The findings demonstrate that human arm movements in a standing position can reduce GS in the affected limb, and balance can be improved by stimulating the surrounding tissues of the affected limb and changing them positively.

Lateral Position Measurement System for Precision Alignment of Roll-to-Roll Printing Using Alignment Patterns and Quantity of Light (정렬패턴과 광량을 이용한 롤투롤 인쇄전자공정의 횡 방향 웹 위치 측정 시스템)

  • Jung, Minkyu;Kim, Hyungi;Oh, Dongho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.9
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    • pp.879-884
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    • 2015
  • Printed electronics is a technology that produces electronic devices and circuits by printing functional ink on a web, which is a film-like flexible material. This technology is suitable for large-scale and high-speed mass production, and is a next-generation process technology that can fabricate electronic devices from flexible materials. As precise measurement of the positions of the web is required in order to commercialize such a printed electronics process, a measurement system with an optical encoder with a precision of micrometers had been proposed in the preceding research of this study. However, the lateral positions of the web could not be measured in the preceding research as the phenomenon of the entire web being moved in the lateral direction could not be detected. In this study, a measurement system that utilizes the differences in the amount of light reflected from the alignment patterns depending on the web positions in the lateral direction was proposed for measuring the lateral positions of the web. In addition, its reliability was verified and then the effect when measuring printed alignment patterns was analyzed by experiments.

TEST AND PERFORMANCE ANALYSIS METHODS OF LOW EARTH ORBIT GPS RECEIVER (지구저궤도 GPS 수신기의 시험 및 성능 분석 방법)

  • Chung Dae-Won;Lee Sang-Jeong
    • Journal of Astronomy and Space Sciences
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    • v.23 no.3
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    • pp.259-268
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    • 2006
  • The use of GPS receiver at outer space becomes common in low earth orbit. Recently most of satellites use GPS receiver as navigation solution for finding satellite position. However, the accuracy of navigation solution acquiring directly from GPS receiver is not enough in satellite application such as map generation. Post-processing concepts such as Precise Orbit Determination (POD) are recently applied to satellite data processing to improve satellite position accuracy. The POD uses raw measurement data instead of navigation solution of GPS receiver. The performance of raw measurement data depends on raw measurement data accuracy and tracking loop algorithm of GPS receiver. In this paper, a method for evaluating performance of raw measurement data is suggested. Test environment and procedure of the low earth orbit satellite acquiring for navigation solution of GPS receiver and navigation solution of POD are described. In addition, accuracy on navigation solution of GPS receiver, raw measurement data, and navigation solution of POD are analyzed. The proposed method can be applicable to general low earth orbit satellite.

Measurement of Orbit using Standardized Processing of CT Scan

  • Kim, Yong Oock
    • Journal of International Society for Simulation Surgery
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    • v.1 no.1
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    • pp.7-12
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    • 2014
  • Purpose Surgical correction of various occular problems which do not have visual problem in plastic surgical area is to normalize the appearance of the face by restoring the normal position of orbit and eyeball. With development of surgical technique, the orbit can be restored exactly in trauma patient and can be moved totally in hypertelorism, as an example of congenital disease. All these surgeries are based on the hypothesis that the position of oclular glove moves in the plane in a quantitatively predictable reationship to osseous orbit movement. However, no studies have critically evaluated between the change of periorbital soft tissue and the outcome of the surgical correction, because there is no method of objective, quantitave evaluation of the periorbital soft tissue. Method Author suggest the methodology for quantitative assessment of ocular and periocular fat changes using the manipulation of digital images of computed tomographic scan. Results The method was allowed to evaluate inter-dacryon distance, inter-centroid distance, movement of the medial orbital wall, movement of the lateral orbital wall, alteration of thickness of the lateral periorbital fat as indicator of movement of the orbital wall and orbit in the patient with congenital periorbital anomaly and postoperative periorbital surgery. The goal of surgical correction of various occular problems which do not have visual problem in plastic surgical area is to normalize the appearance of the face by restoring the normal position of orbit and eyeball. With development of surgical technique, the orbit can be restored exactly in trauma patient and can be moved totally in hypertelorism, as an example of congenital disease. All these sugeries are based on the hypothesis that the position of oclular glove moves in the plane in a quantitatively predictable relationship to osseous orbit movement. However, no studies have critically evaluated between the change of periorbital soft tissue and the outcome of the surgical correction, because there is no method of objective, quantitave evaluation of the periorbital soft tissue. In this report, author suggest the methodology for quantitative assessment of ocular and periocular fat changes using the manipulation of digital images of computed tomographic scan. Conclusion The method suggested is objective and accurate method in measurement of the orbital contents. It takes time and is not easy to do, however, this kind of measurement for fine structures will be more easily available in near future.

Redundant Sensor Systems for the Measurement under Uncertain Conditions (불확실한 조건에서의 계측을 위한 잉여센서시스템)

  • 도용태
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2000.11a
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    • pp.436-439
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    • 2000
  • To interact with surroundings robots and other automated machines employ sensors. However, the sensors measurements are uncertain in some amount and this may limit the potential applications of machines. Varying surrounding conditions and noises of sensor signals are major sources of the uncertainty. In this paper the uncertainty is tried to be reduced by using redundant sensor systems, where the redundancy is accomplished by varying the parameters of logically defined sensors. The target value redundantly measured is estimated adaptively. An experiment was done for measuring the stereoscopic 3D position measurement in an inconsistent light condition.

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레이저를 이용한 볼나사 리드오차 측정에 관한 연구

  • 윤영식;박철우;이상조
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.254-259
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    • 1994
  • Recently, the precision ball screw becomes the essence of the high-precision industries and is playing a key role in the positioning devices. The standard and definition of pitch error in a precision ball screw is specified by KS, JIS or ISO. However, the method of measuring the pitch error is not concrete. In this study. laser measurement system(LMS) with a laser position transducer and a machine-tools is developed. In order to verify the stability of the LMS, several experiments with the standard ball screw is performed.

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