• Journal of Periodontal and Implant Science
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• v.48 no.4
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• pp.202-212
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• 2018

Purpose: Bone-to-implant contact (BIC) is difficult to measure on micro-computed tomography (CT) because of artifacts that hinder accurate differentiation of the bone and implant. This study presents an advanced algorithm for measuring BIC in micro-CT acquisitions using a spiral scanning technique, with improved differentiation of bone and implant materials. Methods: Five sandblasted, large-grit, acid-etched implants were used. Three implants were subjected to surface analysis, and 2 were inserted into a New Zealand white rabbit, with each tibia receiving 1 implant. The rabbit was sacrificed after 28 days. The en bloc specimens were subjected to spiral (SkyScan 1275, Bruker) and round (SkyScan 1172, SkyScan 1275) micro-CT scanning to evaluate differences in the images resulting from the different scanning techniques. The partial volume effect (PVE) was optimized as much as possible. BIC was measured with both round and spiral scanning on the SkyScan 1275, and the results were compared. Results: Compared with the round micro-CT scanning, the spiral scanning showed much clearer images. In addition, the PVE was optimized, which allowed accurate BIC measurements to be made. Round scanning on the SkyScan 1275 resulted in higher BIC measurements than spiral scanning on the same machine; however, the higher measurements on round scanning were confirmed to be false, and were found to be the result of artifacts in the void, rather than bone. Conclusions: The results of this study indicate that spiral scanning can reduce metal artifacts, thereby allowing clear differentiation of bone and implant. Moreover, the PVE, which is a factor that inevitably hinders accurate BIC measurements, was optimized through an advanced algorithm.

• Journal of the Korean Society of Clothing and Textiles
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• v.48 no.2
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• pp.233-253
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• 2024

This study analyzed differences between three-dimensional (3D) body scanning and manual measurements, aiming to assess whether 3D scanning can replace traditional anthropometric tools, such as tape measures and calipers. Data from 4,478 participants in the 8th Size Korea Project were analyzed, covering 43 measurement items. Since Given that the 3D and manual measurements were performed on the same subjects in the 8th Size Korea Project, it was possible to determine the correlation more accurately between the two measurement methods more accurately. Using Applying ISO 20685-1(2018) standards, 15 out of the 43 items fell within allowable error limits. When classified into six types, "small circumferences" and "segment lengths" showed averages of 3.35 mm and 3.10 mm, respectively, within acceptable range. "Body heights" and "body depths" slightly exceeded the limit, with averages of 5.28 mm and 6.58 mm. "Body widths" and "large circumferences" surpassed the limit, with means of 16.77 mm and 16.18 mm. The study offers an objective basis to for validate validating 3D measurements' measurements' reliability and accuracy, addressing various industries' needs for information on the human body's dimensions information.

• Applied Microscopy
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• v.47 no.3
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• pp.95-100
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• 2017

High resolution measurements of the carrier profile in semiconductor devices is required as the semiconductor industry progresses from the 10-nm lithography node to 7-nm and beyond. We examine the factors which determine the resolution of the present method of scanning spreading resistance microscopy as well as such factors for the newer method of scanning frequency comb microscopy that is now under development. Also, for the first time, we consider the sensitivity of both methods to the location of heterogeneities in the semiconductor. In addition, mesoscopic effects on these measurements are considered for the first time. Two simple analytical models are extended to study the sensitivity to heterogeneities as well as mesoscopic effects.

• Imaging Science in Dentistry
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• v.48 no.2
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• pp.111-119
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• 2018

Purpose: This study was conducted to evaluate the accuracy of linear measurements of 3-dimensional (3D) images generated by cone-beam computed tomography (CBCT) and facial scanning systems, and to assess the effect of scanning parameters, such as CBCT exposure settings, on image quality. Materials and Methods: CBCT and facial scanning images of an anthropomorphic phantom showing 13 soft-tissue anatomical landmarks were used in the study. The distances between the anatomical landmarks on the phantom were measured to obtain a reference for evaluating the accuracy of the 3D facial soft-tissue images. The distances between the 3D image landmarks were measured using a 3D distance measurement tool. The effect of scanning parameters on CBCT image quality was evaluated by visually comparing images acquired under different exposure conditions, but at a constant threshold. Results: Comparison of the repeated direct phantom and image-based measurements revealed good reproducibility. There were no significant differences between the direct phantom and image-based measurements of the CBCT surface volume-rendered images. Five of the 15 measurements of the 3D facial scans were found to be significantly different from their corresponding direct phantom measurements(P<.05). The quality of the CBCT surface volume-rendered images acquired at a constant threshold varied across different exposure conditions. Conclusion: These results proved that existing 3D imaging techniques were satisfactorily accurate for clinical applications, and that optimizing the variables that affected image quality, such as the exposure parameters, was critical for image acquisition.

• Fashion & Textile Research Journal
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• v.18 no.4
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• pp.468-476
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• 2016

Recent advancements in optics technology enable us to realize fast scans of hands using two-dimensional (2D) image scanners. In this paper, we propose an automatic hand measurement system using 2D image scanners for customized glove production. To develop the automatic hand measurement system, firstly hand scanning devices has been constructed. The devices are designed to block external lights and have user interface to guide hand posture during scanning. After hands are scanned, hand contour is extracted using binary image processing, noise elimination and outline tracing. And then, 19 hand landmarks are automatically detected using an automatic hand landmark detection algorithm based on geometric feature analysis. Then, automatic hand measurement program is executed based on the automatically extracted landmarks and measurement algorithms. The automatic hand measurement algorithms have been developed for 18 hand measurements required for custom-made glove pattern making. The program has been coded using the C++ programming language. We have implemented experiments to demonstrate the validity of the system using 11 subjects (8 males, 3 females) by comparing automatic 2D scan measurements with manual measurements. The result shows that the automatic 2D scan measurements are acceptable in the customized glove making industry. Our evaluation results confirm its effectiveness and robustness.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.275-278
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• 1996

Accuracy and reproducibility of coordinates, angles/areas and volume measurements are the mai goal of imaging-guided stereotactic systems. Errors in measurements are due to pitfalls in a present systems. Factors responsible for inaccuracy and variability on measurements are inappropriate display window settings, unequal spatial resolution, display/film distortion, inappropriate slice width, lack of isocentricity between gantry and frame, and nonparallelism between frame and scanning plan. The most important factor responsible for errors when using stereotactic frames is the nonparallel relationship to the plane of scanning. For the solution of above problem, author developed a computer program for the measurement of the coordinates of intracerebral target, which is operated using the personal computer. This program can calculate the actual spatial coordinates regardless of the inappropriate parallelism between frame and scanning plane and decrease the range of errors of measurements.

• Journal of Mechanical Science and Technology
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• v.16 no.12
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• pp.1719-1724
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• 2002

A previously designed capillary viscometer with measuring differential pressure was modified to measure the viscosity of non-Newtonian fluids including unadulterated blood continuously over numerous shear rates in a single measurement. Because of unavoidable experimental noise and a limited number of data, the previous capillary viscometer experienced an inaccuracy and could not directly determine a viscosity without an iterative calculation. However, in the present measurement there are numerous data available near the point of interest so that the numeric value of the derivative, d(In Q)/d(In Q$\sub$w/), is no longer sensitive to the method of differentiation. In addition, relatively low and wide shear rate viscosity measurements were possible because of the present precision pressure-scanning method with respect to time. For aqueous polymer solutions, excellent agreement was found between the results from the pressure-scanning capillary viscometer and those from a commercially available rotating viscometer. In addition, the pressure-scanning capillary viscometer measured the viscosity of unadulterated whole blood without adding any anticoagulants.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.863-864
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• 2011

• Electrical & Electronic Materials
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• v.11 no.11
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• pp.17-21
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• 1998

The surface potential distribution on insulating polymers was measured by scanning of the probe of an electrostatic voltmeter. The measurements were done for two measured by scanning of the probe of an electrostatis voltmeter. The measurements were done for two cases. In the first case, it was measured on the free surface of insulating films which had been inserted between plane electodes after the removal of the upper brass disk electrode. In the second case, we measured the charging region between a circular and its opposing concentric ring electrodes after the removal of dc ramp voltage in air and nitrogen gas.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.3
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• pp.27-32
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• 2008

This paper describes a contact atomic force microscope (AFM) that can be used for high-speed precision measurements of microstructured surfaces. The AFM is composed of an air-bearing X stage, an air-bearing spindle with the axis of rotation in the Z direction, and an AFM probe unit. The traversing distance and maximum speed of the X stage are 300 mm and 400 mm/s, respectively. The spindle has the ability to hold a sample in a vacuum chuck with a maximum diameter of 130 mm and has a maximum rotation speed of 300 rpm. The bandwidth of the AFM probe unit in an open loop control circuit is more than 40 kHz. To achieve precision measurements of microstructured surfaces with slopes, a scanning strategy combining constant height measurements with a slope compensation technique is proposed. In this scanning strategy, the Z direction PZT actuator of the AFM probe unit is employed to compensate for the slope of the sample surface while the microstructures are scanned by the AFM probe at a constant height. The precision of such a scanning strategy is demonstrated by obtaining profile measurements of a microstructure surface at a series of scanning speeds ranging from 0.1 to 20.0 mm/s.