• Korean Journal of Radiology
• /
• v.22 no.2
• /
• pp.168-178
• /
• 2021

Objective: To provide an automatic method for segmentation and diameter measurement of type B aortic dissection (TBAD). Materials and Methods: Aortic computed tomography angiographic images from 139 patients with TBAD were consecutively collected. We implemented a deep learning method based on a three-dimensional (3D) deep convolutional neural (CNN) network, which realizes automatic segmentation and measurement of the entire aorta (EA), true lumen (TL), and false lumen (FL). The accuracy, stability, and measurement time were compared between deep learning and manual methods. The intra- and inter-observer reproducibility of the manual method was also evaluated. Results: The mean dice coefficient scores were 0.958, 0.961, and 0.932 for EA, TL, and FL, respectively. There was a linear relationship between the reference standard and measurement by the manual and deep learning method (r = 0.964 and 0.991, respectively). The average measurement error of the deep learning method was less than that of the manual method (EA, 1.64% vs. 4.13%; TL, 2.46% vs. 11.67%; FL, 2.50% vs. 8.02%). Bland-Altman plots revealed that the deviations of the diameters between the deep learning method and the reference standard were -0.042 mm (-3.412 to 3.330 mm), -0.376 mm (-3.328 to 2.577 mm), and 0.026 mm (-3.040 to 3.092 mm) for EA, TL, and FL, respectively. For the manual method, the corresponding deviations were -0.166 mm (-1.419 to 1.086 mm), -0.050 mm (-0.970 to 1.070 mm), and -0.085 mm (-1.010 to 0.084 mm). Intra- and inter-observer differences were found in measurements with the manual method, but not with the deep learning method. The measurement time with the deep learning method was markedly shorter than with the manual method (21.7 ± 1.1 vs. 82.5 ± 16.1 minutes, p < 0.001). Conclusion: The performance of efficient segmentation and diameter measurement of TBADs based on the 3D deep CNN was both accurate and stable. This method is promising for evaluating aortic morphology automatically and alleviating the workload of radiologists in the near future.

• Journal of the Semiconductor & Display Technology
• /
• v.20 no.4
• /
• pp.114-118
• /
• 2021

In this research, the dimensional error of the measured specimen according to the measurement method was analyzed for the length, angle, radius of curvature and diameter using a projector which is used in industry. One-way analysis was performed on each data tested 30 times using a statistical technique. Through the experiment, it was found that an error occurred in each data when measuring the length and radius of curvature according to the measurement method, and the null hypothesis that no error occurred when measuring the angle and length was established. Based on this experimental data, the automatic measurement when measuring the projector causes less measurement error, so automatic measurement is recommended when measuring a small product. Also, an optimal measuring method is suggested for securing reliability on formulations of measurement automation.

• Particle and aerosol research
• /
• v.8 no.1
• /
• pp.29-35
• /
• 2012

The Faraday cup electrode of different size has been developed and evaluated to investigate the diffusion effect of particles by Brownian motion in a particle beam mass spectrometer(PBMS). Particles which focused and accelerated by aerodynamic lens are charged to saturation in an electron beam, and then deflected electrostatically into a Faraday cup detector for measurement of the particle current. The concentration of particles is converted from currents detected by Faraday cup. Measurements of particle current as a function of deflection voltage are combined with measured relationships between particle velocity and diameter, charge and diameter, and mass and diameter, to determine the particle size distribution. The particle currents were measured using 5, 10, 20, 40 mm sized Faraday cup that can be move to one direction by motion shaft. The current difference for each sizes as a function of position was compared to figure out diffusion effect during transport. Polystyrene latex(PSL) 100, 200 nm sized standard particles were used for evaluation. The measurement using 5 mm sized Faraday cup has the highest resolution in a diffusion distance and the smaller particles had widely diffused.

• Journal of Welding and Joining
• /
• v.12 no.3
• /
• pp.109-117
• /
• 1994

Spot welding has wide used with a high work efficiency in the automotive and aerospace industries. Up to the present, the technique mainly used to test spot welds on production lines has been entirely depended upon destructive chisel or peel testing. Therefore, it's being very important assignment to secure the NDE technique which can be evaluate spot weld quality with more efficiency and high reliability. This paper discusses the feasibility of UNDE techniques to evaluate spot weld quality. For the sake of the approach to the quantitative measurement of nugget diameter and the discrimination of a the corona bond from nugget, ultrasonic c-scan image and distribution of reflective echo amplitude was measured by immersion method with the mechanical and the electronic scanning of point-focussed ultrasonic beam(25 MHz). As the results of this study, corona bond which is the most dangerous types of interface defects can be successfully detected, as well as expulsion and voids. Ultrasonic testing results were confirmed and compared by optical microscope and SAM(Scanning Acoustic Microscope) observation of the spot-weld cross section. The results show that the nugget diameter can be successfully measured with the accuracy of 0.8 mm.

• Journal of Sensor Science and Technology
• /
• v.14 no.4
• /
• pp.250-257
• /
• 2005

Respiratory tubes with the length of 35 mm and the diameter of 10, 15, and 20 mm were made and both the static($P_{S}$) and dynamic($P_{D}$) pressures were measured for steady flow rates ranging 1-12 l/sec. Regression analysis resulted successful fitting of $P_{S}$ and $P_{D}$ data with quadratic equations with correlation coefficients higher than 0.99. The measurement standards of the American Thoracic Society (ATS) were applied to $P_{S}$ data, which demonstrated the smallest tube diameter of 15 mm to satisfy the ATS standards. The maximum $P_{D}$ value of the velocity type transducer with the diameter of 15 mm was estimated to be 75 cm$H_{2}O$, implying approximately 7 times larger sensitivity than the widely used pneumotachometer. These results showed that the velocity type respiratory air flow transducer is a unique device accomplishing miniaturization with the sensitivity increased, thus would be of great advantage to develop portable devices.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.8 no.3
• /
• pp.145-151
• /
• 2006

The purpose of this study was to analyze the relationship between the annual variation in diameter growth of Quercus spp. and climatic factors such as monthly temperature, precipitation and solar radiation in central and northern Korea. Annual diameter growth was measured by using stem cores of 262 Quercus trees, and the correlation between the diameter growth and the climatic factors was analyzed. Mean diameter growth of Quercus spp. in Jungwangsan was larger than that in Woraksan, and mean diameter growth by the species was large in order of Q. serrata>Q. variablis>Q. mongolica>Q. dentata. The diameter growth pattern of Quercus spp. in Woraksan was different from that in Jungwangsan. Positive correlations between diameter growth of Quercus trees and temperature or the solar radiation during July were found in Jungwangsan. Significant correlations between diameter growth and solar radiation during March and precipitation during June were found in Woraksan. It is suggested that climatic factors similarly affect the diameter growth of Quercus spp. in a mountainous terrain, but influences of the climatic factors depend on other environmental conditions such as altitude, topography and soil depth.

• Korean Journal of Veterinary Research
• /
• v.40 no.2
• /
• pp.373-381
• /
• 2000

Serial ultrasonographic examinations were performed on pregnant Korean Jindo bitches. Measurements of inner chorionic cavity diameter and fetal head diameter were made from pregnancy day 15 to parturition. These measurements were converted retrospectively based on the day of parturition (day 0). The data of inner chorionic cavity diameter obtained from day -42 to day -25 and fetal head diameter obtained from day -24 to day -1 were used to prediction of parturition day. Formulas for the prediction of parturition day using the method of least squares were derived. These formulas were then used to predict parturition dates based on single measurements of inner chorionic cavity diameter or fetal head diameter in 17 additional pregnant Korean Jindo bitches. Predicted date of parturition was then compared to actual whelping date. In the prediction of parturition based on inner chorionic cavity diameter, 7 of 10 bitches were coincided prediction date and actual whelping date, and the prediction was accurate to within 1 day in 3 of 10 bitches. The prediction of parturition based on fetal head diameter was accurate to within 1 day in 6 of 7 bitches and within 2 days in 1 of 7 bitches. In conclusion, the ultrasound measurement of inner chorionic cavity diameter and fetal head diameter are practical and accurate tool in the prediction of parturition.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.54 no.12
• /
• pp.585-587
• /
• 2005

In this paper, We studied two methods to measure optical characteristics of an electrodeless light source using the integrating sphere(diameter 1.5m). One is to use a center measurement method and the other is to use a side measurement method. As a result of analysis, a side measurement methode without auxiliary lamp is almost similar against a center measurement with auxiliary lamp to reduce a measurement of an error for luminous flux, luminous efficacy and spectral distribution etc. Therefore, Sample which cannot measured by reason of big size and heavy weight can be measured by a side measurement method.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.4
• /
• pp.85-96
• /
• 2000

An Eggcrate assembly is an important part to hold and support 16,000 tubes containing hot and contaminated water in the steam generator of nuclear power plant. As a great number of tubes should be inserted into the eggcrate assembly, the dimensions of each eggcrate grid are one of the critical factors to determine the availability of tube insertion. in this paper. we propose a machine vision algorithm for measuring the inner-circle diameter of each eggcrate grid whose shape is not exact quadrangular. The overall procedure of the algorithm is composed of camera calibration, eggcrate image preprocessing, grid height adjustment, and inner-circle diameter estimation. The algorithm is tested on real specimens and the results show that the algorithm works fairly well.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2002.10a
• /
• pp.53-56
• /
• 2002

This study presents an evaluation of the mechanical pipe flowmeter at low hydraulic heads. Three flowmeters each of 75mm and 25mm diameter were used. The Flowmeter was tested with experimental open channel apparatus. Relationship between flowmeter values and bucket values was good. The 75mm diameter flow meter showed small relative errors with hydraulic heads above 9cm. The 25mm diameter flow meter showed small relative errors with hydraulic heads above 2cm. The Irrigation flow measurement using the mechanical pipe flowmeter of 75mm diameter in paddy fields needs hydraulic head above 9cm, which is easy to get in tertiary canals.