• Title/Summary/Keyword: Measuring Interval

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Damage Classification by Time Density Function of Ultrasonic Pulse Signal occurred at Tire (타이어에서 발생하는 초음파펄스신호의 시간밀도함수에 의한 손상 분별)

  • Kang, Dae-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.6
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    • pp.291-296
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    • 2015
  • The tire damage classification method is researched on the periodicity detection of ramdomness ultrasonic signals to occur at the driving vehicle tire. Setting method of adaptive threshold is proposed in order to valid pulse detection by tire damage in ultrasonic noise on the road and used low pass filter for decrease signal ramdomness as preprocessing. Time interval of detected pulse is setted the density function depend on the vehicle's speed and the method of tire damage detection is proposed that measuring the first peak's time of time density function.The result of time density function in case of one damage material, the first peak's time is measured within the error limit of tire's rotation period, 169.8ms and 97.9ms and 81.8ms, about the speed of 50km/h and 80km/h and 100km/h. In case of more than one damage material, the sum of each peak's time is measured within the error limit of tire's rotation period about the speed.

Estimation of Tree Heights from Seasonal Airborne LiDAR Data (계절별 항공라이다 자료에 의한 수고 추정)

  • Jeon, Min-Cheol;Jung, Tae-Woong;Eo, Yang-Dam;Kim, Jin-Kwang
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.4
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    • pp.441-448
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    • 2010
  • This paper estimates the tree height using Airborne LiDAR that is obtained for each season to analyze its influence based on a canopyclosure and data fusion. The tree height was estimated by extracting the First Return (RF) from the tree and the Last Return (LR) from the surface of earth to assume each tree via image segmentation and to obtain the height of each tree. Each data on tree height that is collected from seasonal data and the result of tree height acquired from the data fusion were compared. A tree height measuring device was used to measure on site and its accuracy was compared. Also, its applicability on the result of fused data that is obtained through the Airborne LiDAR is examined. As a result of the experiment, the result of image segmentation for an individual tree was closer to the result of site study for 1 meter interval when compared to the 0.5 meter interval of point cloud. In case of the tree height, the application of fused data enables a closer site measurement result than the application of data for each season.

A Study on the Association between Sasang Constitutions(QSCC II) and Huh's Morphological Diagramming (사상체질분류검사지(QSCCII)에 의한 체질진단과 허식(許式) 체간측정치의 상관성 연구)

  • Choi, Sun-Mi;Hong, Jeong-Mi;Chi, Sang-En;Jung, Bong-Yeon;Ahn, Kyoo-Seok
    • Korean Journal of Oriental Medicine
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    • v.8 no.1
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    • pp.75-92
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    • 2002
  • The purpose of this study was to investigate the difference of the morphological diagram by Sasang Constitutions and compare with Huh's morphological diagram, a theory based on the Four Cho Theory(四焦設) by Lee Je-Ma. We classified the Sasang Constitutions of 104 Korean College Students(average age 23.81) using QSCC II. Before measuring of morphologic diagrams, we exert the subjects to take supine position on the bed, and make it a rule that our staffs mesure each people directly. The 50% of the total subjects was Soeumin, 26.9% was Soyangin and 23.1% was Taeumin, our study shows the higher percentage than the other studies in Soeumin. The results as follows ; In the cases of man, Taeumin have more developed Low-Middle Cho(the interval between stomach line and Navel line) than other constitutions, whereas Soeumin has more developed Low cho(the interval between Navel line and Ilium line). In the cases of woman, there is no significant difference of Huh's morphology diagram among three Sasang constitutions. We analyzed the difference of obesity among sasang constitutions, and we found that the BMI(Body Mass Index$(Kg/m^2)$) of Taeumin was significantly higher than other constitutions in male. But there was no significant difference among Sasang constitutions in female. We have not found the exact accordance between the real measurement and Huh's Theory. But for man, there are several statistically significant results, indicating the usefulness of the Huh's Morphological Diagramming theory on the discriminating ability of Sasang Constitutions Classificaton. So this results suggest that the use of the Huh's theory should be improved in the classification of the Sasang Constitutions, considering the difference of morphology by sex.

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Water Saving Irrigation Manual of Spring Chinese Cabbage (봄배추의 물 절약형 관개기준 설정)

  • Eom, Ki-Cheol;Jung, Pil-Kyun;Koh, Mun-Hwan;Kim, Sang-Hee;Yoo, Sung-Yung;Park, So-Hyun;Hur, Seung-Oh;Ha, Sang-Keun
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.6
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    • pp.812-822
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    • 2010
  • Water management is the most important and difficult problems in crop cultivation. The farmers are doing irrigation, those when to irrigate and how much to irrigate, depending on their experiences. The irrigation manual as water saving is possible, those irrigation interval and amount of irrigation, are developed based on the lysimeter experiments carried out by the RDA for 11 years about potential evapotranspiration, crop coefficient. The manual can be used with easy to the farmer without soil sampling and any kinds of sensors measuring soil water status.

Improvement of The Desalination Performance through The Split Electrodes in The Capacitive Deionization Process (축전식 탈염 공정에서의 분할 전극을 통한 탈염 성능 향상)

  • Kim, Yong Bin;Rhim, Ji Won
    • Membrane Journal
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    • v.29 no.5
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    • pp.292-298
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    • 2019
  • The purpose of this study was to improve the desalination performance by using split electrodes in the capacitive desalination process. The experiment was carried out by measuring the desalination efficiency of the NaCl aqueous solution according to the partitioning of the electrode at 20 mL/min flow rate, 1.2 V, 3 min adsorption conditions, and -1 V, 1 min desorption conditions. The desalination efficiency for the non-divided electrodes with a surface area of $146cm^2$ reached 40% while the divided electrode with a surface area of $133cm^2$ showed a desalination efficiency of 57%. The desalination efficiency of the same split electrode was 49% at 2 cm divided interval and 57% at 1cm divided interval. The desalination efficiency of the split electrode was higher than that of the normal CDI and narrower divided intervals increased the performance.

Statistical Analysis for Assessment of Fingerprint Sensors (지문 인식 센서 평가를 위한 통계학적 분석)

  • Nam Jung-Woo;Kim Hak-Il
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.16 no.4
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    • pp.105-118
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    • 2006
  • The purpose of this research is twofold. The first is to develop the measures for evaluating performance of fingerprint sensor modules quantitatively and objectively. The second is to present the methodology for evaluating compatibilities among disparate fingerprint sensors. This paper focuses on the performance evaluation not of fingerprint authentication algorithm but of fingerprint sensors. Presented in this paper are several indicators and their measuring schemes such as the actual resolution of fingerprint images, the level of distortion by horizontal and vertical resolutions of fingerprint image, the intensity distribution for various illuminating conditions. Nine commercial sensor modules have been tested and the test results are expressed by using 95% confidence interval based on 50 acquired fingerprint images. The experimental results are compared with the manufacturer's sensor specification.

Knee Joint Isokinetic Rehabilitation Exercise Equipment Usability Evaluation

  • Byoung-Kwon Lee;Seung-Hwa Jung;Hye-Ri Shin;Dong-Wook Han;Chang-Young Kim;Jong-Min Woo;Dae-Sung Park
    • Physical Therapy Rehabilitation Science
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    • v.11 no.4
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    • pp.414-420
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    • 2022
  • Objective: In this study, the test-retest reliability and validity were presented to evaluate the usability of isokinetic rehabilitation equipment for the knee joint. Design: Cross-sectional design, reliability & validity study. Methods: Thirty healthy adults participated in the study. A CSMI dynamometer was used as a standardized measuring device to present the validity of the equipment. It was measured based on the dominant leg. The average peak torque value was selected as the measurement variable. After the measurement, a questionnaire was conducted on safety, satisfaction, and performance through the usability evaluation questionnaire. Results: The knee joint isokinetic rehabilitation equipment showed high reliability with Intraclass Correlations Coefficients (ICC) =0.883~0.956. In order to check the validity of the equipment, the 95% confidence interval of the mean difference limit was confirmed by the Bland & Altman plot. As a result, all three angular velocities showed a smaller confidence interval in the flexion than in extension. There were less than 10 plots that were not included in 2 Standard Deviation (SD) between all measurements. As a result of the usability evaluation questionnaire, the average of the safety domain(4.9±0.4), satisfaction domain(4.1±0.8), performance domain(4.3±0.8). Conclusions: If the product is improved by supplementing the items identified in the usability evaluation process, it is judged that it can be used as a useful device in various knee joint rehabilitation fields.

Deep Learning-Based Lumen and Vessel Segmentation of Intravascular Ultrasound Images in Coronary Artery Disease

  • Gyu-Jun Jeong;Gaeun Lee;June-Goo Lee;Soo-Jin Kang
    • Korean Circulation Journal
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    • v.54 no.1
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    • pp.30-39
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    • 2024
  • Background and Objectives: Intravascular ultrasound (IVUS) evaluation of coronary artery morphology is based on the lumen and vessel segmentation. This study aimed to develop an automatic segmentation algorithm and validate the performances for measuring quantitative IVUS parameters. Methods: A total of 1,063 patients were randomly assigned, with a ratio of 4:1 to the training and test sets. The independent data set of 111 IVUS pullbacks was obtained to assess the vessel-level performance. The lumen and external elastic membrane (EEM) boundaries were labeled manually in every IVUS frame with a 0.2-mm interval. The Efficient-UNet was utilized for the automatic segmentation of IVUS images. Results: At the frame-level, Efficient-UNet showed a high dice similarity coefficient (DSC, 0.93±0.05) and Jaccard index (JI, 0.87±0.08) for lumen segmentation, and demonstrated a high DSC (0.97±0.03) and JI (0.94±0.04) for EEM segmentation. At the vessel-level, there were close correlations between model-derived vs. experts-measured IVUS parameters; minimal lumen image area (r=0.92), EEM area (r=0.88), lumen volume (r=0.99) and plaque volume (r=0.95). The agreement between model-derived vs. expert-measured minimal lumen area was similarly excellent compared to the experts' agreement. The model-based lumen and EEM segmentation for a 20-mm lesion segment required 13.2 seconds, whereas manual segmentation with a 0.2-mm interval by an expert took 187.5 minutes on average. Conclusions: The deep learning models can accurately and quickly delineate vascular geometry. The artificial intelligence-based methodology may support clinicians' decision-making by real-time application in the catheterization laboratory.

The reliability of dual rehabilitative ultrasound imaging measurements for muscle co-activation

  • Hahn, Joohee;Ha, Hyun-Geun;Lee, Hwang-Jae;Lim, Seungyeop;Lee, Wan-hee
    • Physical Therapy Rehabilitation Science
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    • v.6 no.3
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    • pp.152-157
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    • 2017
  • Objective: The aim of this study was to determine the intra-rater and inter-rater reliability of the dual rehabilitative ultrasound imaging (D-RUSI) when simultaneously measuring muscle thickness changes at rest and during co-contraction of the biceps brachii (BB) and triceps brachii (TB). Design: Cross-sectional study. Methods: This study included 36 healthy participants (23 men, 13 women). The participants sat on a chair in a comfortable position with a cushion placed under their elbow to maintain a 90-degree elbow flexion angle. The muscle thickness of the biceps brachii and triceps brachii was measured twice using the D-RUSI by two examiners during resting and co-contraction states. One week later, the same procedure was performed once again. Results: The intra-class correlation coefficients (ICCs) for intra-rater reliability ranged from 0.887 to 0.989 and the confidence interval was within an acceptable range of 0.778 to 0.994. The standard error of measurement (SEM) values ranged from 0.303 to 0.866 and the minimal detectable change (MDC) values ranged from 0.84 to 2.40. The ICCs for inter-rater reliability ranged from 0.758 to 0.925. The SEM values ranged from 0.702 to 1.486 and the MDC values ranged from 1.95 to 4.12. Conclusions: The use of the D-RUSI of the BB muscle had a very good intra-rater reliability and very good inter-rater reliability at the resting state, and a, good inter-rater reliability at the co-activation state. ICC values showed very good intra-reliability and inter-reliability for the TB muscle. the D-RUSI is a useful tool for simultaneously measuring the thickness of two muscles when the BB is an agonist and the TB is an antagonist during co-activation of the upper arm.

An experimental study on the characteristic times of viscoelastic fluids by falling ball viscometer (낙구식 점도계를 이용한 점탄성 유체의 특성시간에 관한 실험적 연구)

  • 전찬열;유상신
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.1
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    • pp.241-250
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    • 1990
  • Characteristic relaxation time and characteristic diffusion time of viscoelastic fluids are determined experimentally by measuring the zero-shear-rate viscosity by falling ball viscometer and the infinite-shear-rate viscosity by capillary tube viscometer. Fluids used in experiments are aqueous solutions of polyacrylamide Separan AP-273 and the polymer concentrations range from 300 to 2000 wppm. A newly designed laser beam and timer system is employed to overcome the difficulty in measuring terminal velocities of the low concentration solutions. Ball removal device is prepared to remove the dropped ball from the bottom of cylinder without disturbing the testing fluid. In order to measure the zero-shear-rate viscosity, densities of hollow aluminium balls are adjusted very close to the densities of testing fluids. Characteristic diffusion time, which is ball viscometer. However, terminal velocity of a needle by falling ball viscometer is not affected by the time interval of dropping needles and characteristic diffusion time is not measured with a dropping needle. Powell-Eyring model predicts the highest values of the characteristic relaxation times among models used for heat transfer experimental works for a given polymer solution. As degradation of a polymer solution continues, the zero-shear-rate viscosity decreases more seriously than the infinite-shear-rate viscosity. Characteristic relaxation times of polymer solutions decreases as degradation continues.