• Title/Summary/Keyword: Position reliability

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A Numerical Simulation of Flows in an Engine Cooling Passage (엔진 냉각유로 내의 유동에 관한 수치해석)

  • 허남건;윤성영;조원국;김광호
    • Transactions of the Korean Society of Automotive Engineers
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    • v.1 no.1
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    • pp.32-40
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    • 1993
  • Flow fields in model engine cooling passages are studied numerically by using TURBO-3D program, a finite volume based 3-D turbulent flow program adopting a general body fitted coordinate system. The effects of exit position on mass flow rate at each gasket hole are examined for a model cooling passage in order to understand the flow distribution inside the water jacket. The results of the present study can be applied to the design of high performance, high reliability engine.

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Development of a Motorized Seatbelt Retractor (모터 구동형 시트벨트 Retractor 개발)

  • Shin, Yun-Su;Kim, Myung-Dong;Park, Joon-Hyung;Kim, Il-Hwan
    • Proceedings of the KIEE Conference
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    • 2006.10c
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    • pp.336-338
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    • 2006
  • Motorized retractors enhance the safety of passengers by removing the slack of webbing and by holding upright driving position. Reliability of a driving mechanism that includes one-way clutch between the driving motor and webbing is directly linked to the safety of passenger. In this research, conditions for locking one-way clutch and also conditions for sustaining locking are theoretically investigated. the operation of a motorized retractor under realistic conditions is simulated in order to validate the proposed retractor design.

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Development of automatic yield-test equipment for the Micromirror Array (Micromirror Array의 Yield 측정을 위한 방법 개발)

  • Cho, Kwang-Woo;Kim, Ho-Seong;Shin, Hyung-Jae
    • Proceedings of the KIEE Conference
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    • 1998.07g
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    • pp.2547-2549
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    • 1998
  • Automatic yield-test equipment for micro mirror array using image processing was developed. This computerized test equipment can classify the error states of the micromirrors. The test results are displayed on the monitor as a map which shows the error states and position. It is possible to measure yield and reliability with this test equipment for micromirror array using image processing.

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Application of Acoustic Holography to Automobile Aeroacoustic Noise of Low Coherence (낮은 상관 관계를 갖는 자동차 공력 소음에 대한 음향 홀로그래피)

  • Nam, Kyoung-Uk;Kim, Yang-Hann
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.561-564
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    • 2004
  • Acoustic holography is applied to automobile aeroacoustic noise. Automobile aeroacoustic noise has low coherence due to multiple independent sources and measurement noise. This paper discusses the reliability of acoustic holography on this low coherence condition. Main subjects are the number and position of reference microphones, which is used for a step-by-step scanning method, and measurement noise. A real automobile experiment verifies the results.

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DIAGNOSTIC RELIABILITY OF THE DYNAMIC MRI FOR THE INTERNAL DERANGEMENT OF TEMPORO-MANDIBULAR JOINTS (악관절내장증의 진단에 있어 Dynamic MRI의 효용)

  • Park, Chang-Hwan;Kim, Myung-Rae;Kim, Sun-Jong;Cheong, Eun-Chul
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.16 no.3
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    • pp.273-280
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    • 1994
  • The Magnetic Resonance Imaging has been used widely to evaluate the disk position without any interruption of the TMJ structures, and the Dynamic MRI presenting computed serial imaging or the video-recorded simulation images is thought to be very effective to evaluate the disk position under function. This is to study the correlation between the clinical diagnosis and the findings of Dynamic MRI for the diagnosis of internal derangement of the temporomandibular joints. 30 joints(15 patients) were examined clinically, and the movement of TMJ meniscus was reviewed in the dynamic MRI. The comparative results are as follows : 1. All internal derangements of TMJ disk displacement without reduction were consistent with MRI findings. 2. 5 joints (50%) of disk displacements with reduction could not be confirmed by MRI findings. 3. The disk displacements in MRI were found in 55% of painful joints, 50% of clicking joints, and 70% of the joints with restricted movement. 4. The reliability of MRI for the diagnosis of TMD was evaluated as 77% ; 24 of 30 joints who presented with clinical diagnosis of TMD. 5. MRI is very reliable to diagnose the disk displacement without reduction, but it is rather not so effective to diagnose the early derangement or muscle disorders.

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Accuracy Estimation of Electro-optical Camera (EOC) on KOMPSAT-1

  • Park, Woon-Yong;Hong, Sun-Houn;Song, Youn-Kyung
    • Korean Journal of Geomatics
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    • v.2 no.1
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    • pp.47-55
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    • 2002
  • Remote sensing is the science and art of obtaining information about an object, area or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation./sup 1)/ EOC (Electro -Optical Camera) sensor loaded on the KOMPSAT-1 (Korea Multi- Purpose Satellite-1) performs the earth remote sensing operation. EOC can get high-resolution images of ground distance 6.6m during photographing; it is possible to get a tilt image by tilting satellite body up to 45 degrees at maximum. Accordingly, the device developed in this study enables to obtain images by photographing one pair of tilt image for the same point from two different planes. KOMPSAT-1 aims to obtain a Korean map with a scale of 1:25,000 with high resolution. The KOMPSAT-1 developed automated feature extraction system based on stereo satellite image. It overcomes the limitations of sensor and difficulties associated with preprocessing quite effectively. In case of using 6, 7 and 9 ground control points, which are evenly spread in image, with 95% of reliability for horizontal and vertical position, 3-dimensional positioning was available with accuracy of 6.0752m and 9.8274m. Therefore, less than l0m of design accuracy in KOMPSAT-1 was achieved. Also the ground position error of ortho-image, with reliability of 95%, is 17.568m. And elevation error showing 36.82m was enhanced. The reason why elevation accuracy was not good compared with the positioning accuracy used stereo image was analyzed as a problem of image matching system. Ortho-image system is advantageous if accurate altitude and production of digital elevation model are desired. The Korean map drawn on a scale of 1: 25,000 by using the new technique of KOMPSAT-1 EOC image adopted in the present study produces accurate result compared to existing mapping techniques involving high costs with less efficiency.

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Development of a Pain Assessment Tool for Critically Ill Patients (중환자 통증사정 도구 개발)

  • Choi, Eun Hee;Kim, Jin Hee;Choi, Kyung Ok;Yoo, Jung Sook;Kim, Mi Soon;Kim, Pil Ja;Jang, In Sun
    • Journal of Korean Clinical Nursing Research
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    • v.18 no.1
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    • pp.136-148
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    • 2012
  • Purpose: The purpose of this study was to develop a reliable and valid pain assessment tool suitable for critically ill patients with communication problem in Korean intensive care unit. Methods: This pain assessment tool, Critical Care Non-verbal Pain Scale (CNPS), was developed based on review of national and international researches. Data were collected from ten intensive care units at five major general hospitals in Seoul. Reliability and validity were tested during performance of position change and endotracheal suctioning. Pain was measured before, during, and 20 minutes after the two procedures. Results: Interrater reliability of the CNPS was analyzed by ICC (Intraclass correlation coefficients). ICC values were significant from .833 to .883. Significant correlation between the FPS (Face Pain Scale) scores and the CNPS scores verified concurrent validity of the CNPS. For position change, CNPS scores increased significantly between before and during (t=-23.399, p<.001) and decreased significantly between during and 20 minutes after (t=22.760, p<.001). For endotracheal suctioning, CNPS scores increased significantly between before and during (t=-29.064, p<.001) and significantly decreased between during and 20 minutes after (t=28.194, p<.001), verifying construct validity of the CNPS. Conclusion: Results indicate that the CNPS can be used to assess pain of critically ill patients who have communication problem.

Correlation Between Knee Muscle Strength and Maximal Cycling Speed Measured Using 3D Depth Camera in Virtual Reality Environment

  • Kim, Ye Jin;Jeon, Hye-seon;Park, Joo-hee;Moon, Gyeong-Ah;Wang, Yixin
    • Physical Therapy Korea
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    • v.29 no.4
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    • pp.262-268
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    • 2022
  • Background: Virtual reality (VR) programs based on motion capture camera are the most convenient and cost-effective approaches for remote rehabilitation. Assessment of physical function is critical for providing optimal VR rehabilitation training; however, direct muscle strength measurement using camera-based kinematic data is impracticable. Therefore, it is necessary to develop a method to indirectly estimate the muscle strength of users from the value obtained using a motion capture camera. Objects: The purpose of this study was to determine whether the pedaling speed converted using the VR engine from the captured foot position data in the VR environment can be used as an indirect way to evaluate knee muscle strength, and to investigate the validity and reliability of a camera-based VR program. Methods: Thirty healthy adults were included in this study. Each subject performed a 15-second maximum pedaling test in the VR and built-in speedometer modes. In the VR speedometer mode, a motion capture camera was used to detect the position of the ankle joints and automatically calculate the pedaling speed. An isokinetic dynamometer was used to assess the isometric and isokinetic peak torques of knee flexion and extension. Results: The pedaling speeds in VR and built-in speedometer modes revealed a significantly high positive correlation (r = 0.922). In addition, the intra-rater reliability of the pedaling speed in the VR speedometer mode was good (ICC [intraclass correlation coefficient] = 0.685). The results of the Pearson correlation analysis revealed a significant moderate positive correlation between the pedaling speed of the VR speedometer and the peak torque of knee isokinetic flexion (r = 0.639) and extension (r = 0.598). Conclusion: This study suggests the potential benefits of measuring the maximum pedaling speed using 3D depth camera in a VR environment as an indirect assessment of muscle strength. However, technological improvements must be followed to obtain more accurate estimation of muscle strength from the VR cycling test.

Reliability Prediction of a Pin Puller (핀풀러 신뢰도 예측)

  • Lee, Hyo-Nam;Jang, Seung-Gyo;Oh, Jong-Yun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.8
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    • pp.625-631
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    • 2013
  • Reliability of a pin puller was predicted by Monte Carlo simulation. The prediction method is based on the stress-strength interference model that failure occurs if the stress exceeds the strength. In this study, the strength is considered as the energy delivered by combustion of pyrotechnics to retreat the pin to a predetermined position, whereas the stress is regarded as the energy required to resist the pin movement. The former mainly depends on the amount of pyrotechnic charge and the latter is governed by several friction forces and the energy dissipation within locking mechanism. Both the variables of stress and strength were computed using an analytical performance model. The method presented here, not depending upon a large number of test item, can be applicable to predict the reliability of other kinds of pyrotechnic devices.

Test-retest Reliability of Sit-to-Stand and Gait Assessment Using the Wii Balance Board (Wii Balance Board를 이용한 Sit-to-Stand와 보행기능 측정의 검사-재검사 신뢰도)

  • Yang, Seong-rye;Oh, Yu-ri;Jeon, Ye-rim;Park, Dae-sung
    • Physical Therapy Korea
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    • v.23 no.3
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    • pp.40-47
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    • 2016
  • Background: Assessments of Sit-to-Stand (STS) and gait functions are essential procedures in evaluating level of independence for the patients after stroke. In a previous study, we developed the software to analyze center of pressure (COP) in standing position on Wii Balance Board (WBB). Objects: This purpose of this study is to measure test-retest reliability of ground reaction forces, COP and time using WBB on STS and gait in healthy adults. Methods: Fifteen healthy participants performed three trials of STS and gait on WBB. The time (s), vertical peak (%) and COP path-length (cm) were measured on both tasks. Additionally, counter (%), different peak (%), symmetry ratio, COP x-range and COP y-range were analyzed on STS, 1st peak (%), 2nd peak (%) of weight were analyzed on gait. Intra-class correlation coefficient (ICC), standard error measurement (SEM) and smallest real difference (SRD) were analyzed for test-retest reliability. Results: ICC of all variables except COP path-length appeared to .676~.946 on STS, and to .723~.901 on gait. SEM and SRD of all variables excepting COP path-length appeared .227~8.886, .033~24.575 on STS. SEM and SRD excepting COP path-length appeared about .019~3.933, .054~11.879 on gait. Conclusion: WBB is not only cheaper than force plate, but also easier to use clinically. WBB is considered as an adequate equipment for measuring changes of weight bearing during balance, STS and gait test which are normally used for functional assessment in patients with neurological problems and elderly. The further study is needed concurrent validity on neurological patients, elderly patients using force plate and WBB.