• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.301-303
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• 2003

The extraction of 3D road network from high-resolution aerial images is still one of the current challenges in digital photogrammetry and computer vision. For many years, there are many researcher groups working for this task, but unt il now, there are no papers for doing this with TLS (Three linear scanner), which has been developed for the past several years, and has very high-resolution (about 3 cm in ground resolution). In this paper, we present a methodology of road extraction from high-resolution digital imagery taken over urban areas using this modern photogrammetry’s scanner (TLS). The key features of the approach are: (1) Because of high resolution of TLS image, our extraction method is especially designed for constructing 3D road map for next -generation digital navigation map; (2) for extracting road, we use the global context of the intensity variations associated with different features of road (i.e. zebra line and center line), prior to any local edge. So extraction can become comparatively easy, because we can use different special edge detector according different features. The results achieved with our approach show that it is possible and economic to extract 3D road data from Three Linear Scanner to construct next -generation digital navigation road map.

• Asian-Australasian Journal of Animal Sciences
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• 제5권2호
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• pp.229-235
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• 1992

The usefulness of a portable linear electronic scanner. B-mode ultrasonic machine, was evaluated for estimating the longissimus muscle area from ultrasonic measurement of the muscle depth in 22 live pigs. The electronic scanner was easy to operate for muscle measurements in live pigs, which did not have to be held but were caged. The cross-sectional images of longissimus muscle and covering muscles and fat appeared on the monitor with grey scale in real time. It was easy to identify the ultrasonograms of fat and muscular tissues because the images differed in the degree of the grey scale. The longissimus muscle had less echogenic image than the other muscles. The boundary lines between first, second or third layers of backfat and the longissimus muscle were distinct on the ultrasonogram. The ultrasonic measurement at the shoulder was not acceptable because of the unstable measurements and the complex tissue structure. The repeatabilities for the measurements of longissimus muscle depth at one-half body length and last rib were acceptable. The simple correlation coefficients between ultrasonic estimates of the muscle depth in live pigs and the actual areas in the carcass, were 0.50 and 0.55 at the last rib and the one-half body length, respectively. Therefore, those positions were similarly suitable to measure. The method of electronic scanner for determining longissimus muscle area from the muscle depth was suitable for practical use in the field because of the simple and inexpensive technique.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2006년도 춘계학술발표회 논문집
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• pp.177-180
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• 2006

In this paper we proposed a method of automatic point segmentation acquired by 2D laser scanner to recognize moving objects. Recently, Laser scanner is noticed as a new method in the field of close range 3D modeling. But the majority of the researches are pointed on precise 3D modeling of static objects using expensive 3D laser scanner. 2D laser scanner is relatively cheap and can obtain 2D coordinate information of moving object's surface or can be utilized as 3D laser scanner by rotating the system body. In these reasons, some researches are in progress, which are adopting 2D laser scanner to robot control systems or detection of objects moving along linear trajectory. In our study, we automatically segmented point data of 2D laser scanner thus we could recognize each of the object passing through a section.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.653-656
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• 2005

This paper introduces design, fabrication and experiment process of a novel scanner for the high speed AFM(Atomic Force Microscope). A proper design modification is proposed through analyses on the dynamic characteristics of the existing linear motion stages using a dynamic analysis program, Recurdyn. Since the scanning speed of each direction is allowed to be different, the linear motion stage for the high-speed scanner of AFM can be so designed to have different resonance frequencies for the modes with one dominant displacement in the desired directions. One way to achieve this objective is to use one-direction flexure mechanism for each direction and to mount one stage for fast motion on the other stage for slow motion. This unsymmetrical configuration separates the frequencies of the two vibration modes with one dominant displacement in each desired direction, hence, the coupling between the motions in the two directions. In addition, a pair of actuators is used for each axis to decrease the cross talks in the two motions and gives a force large enough to actuate the slow motion stage, which carries the fast motion stage. After these design modifications, a novel scanner with scanning speed higher than 10 Hz can be achieved to realize undistorted images in the high speed AFM.

• 전기학회논문지
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• 제65권1호
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• pp.65-72
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• 2016

This paper presents the analysis of the analysis of thrust characteristics of linear induction motors(LIMs) according to secondary reaction plate. LIMs are well known as high speed transport systems, which can obtain thrust directly without gears and links, or auxiliary mechanisms. A simple structure, easy maintenance, and less environmental pollution are advantages of LIMs. In transport systems using LIMs, the secondary reaction plate is an important design factor, because it has considerable impact on the cost of the railway as well as the performance of the LIMs. This paper deals analyzed the characteristics of linear induction motor used for moving the vehicle of container scanner. Thrust, efficiency and load characteristic were interpreted with FEM regarding two models whose material of secondary reaction plate was copper and aluminum. It suggested the interpretation of thrust, efficiency and power factor characteristic along slip and compared the operation ability of linear induction motor through characteristics analysis along the load.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.652-655
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• 2004

The geometry of satellite image captured by linear pushbroom scanner is different from that of frame camera image. Since the exterior orientation parameters for satellite image will vary scan line by scan line, the epipolar geometry of satellite image differs from that of frame camera image. As we know, 2D affine orientation for the epipolar image of linear pushbroom scanners system are well-established by using the collinearity equation (Testsu Ono, 1999). Also, another epipolar geometry of linear pushbroom scanner system is recently established by Habib(2002). He reported that the epipolar geometry of linear push broom satellite image is realized by parallel projection based on 2D affine models. Here, in this paper, we compared the Ono's method with Habib's method. In addition, we proposed a method that generates epipolar resampled images. For the experiment, IKONOS stereo images were used in generating epipolar images.

• Journal of Korean Dental Science
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• 제15권1호
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• pp.1-8
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• 2022

Purpose: Intraoral scanners, desktop scanners, and cone-beam computed tomography (CBCT) are being used in a complementary way for diagnosis and treatment planning. Limited patient-based results are available about dimensional reproducibility among different three-dimensional imaging systems. This study aimed to evaluate dimensional reproducibility among patient-derived digital models created from an intraoral scanner, desktop scanner, and two CBCT systems. Materials and Methods: Twenty-nine arches from sixteen patients who were candidates for implant treatments were enrolled. Different types of CBCT systems (KCT and VCT) were used before and after the surgery. Polyvinylsiloxane impressions were taken on the enrolled arches after the healing period. Gypsum casts were fabricated and scanned with an intraoral scanner (CIOS) and desktop scanner (MDS). Four test groups of digital models, each from CIOS, MDS, KCT, and VCT, respectively, were compared to the reference gypsum cast group. For comparison of linear measurements, intercanine and intermolar widths and left and right canine to molar lengths were measured on individual gypsum cast and digital models. All measurements were triplicated, and the averages were used for statistics. Bland-Altman plots were drawn to assess the degree of agreement between each test group with the reference gypsum cast group. A linear mixed model was used to analyze the fixed effect of the test groups compared to the reference group (α=0.05). Result: The Bland-Altman plots showed that the bias of each test group was -0.07 mm for CIOS, -0.07 mm for MDS, -0.21 mm for VCT, and -0.25 mm for KCT. The linear mixed model did not show significant differences between the test and reference groups (P>0.05). Conclusion: The linear distances measured on the digital models created from CIOS, MDS, and two CBCT systems showed slightly larger than the references but clinically acceptable reproducibility for diagnosis and treatment planning.

• 대한치과교정학회지
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• 제51권2호
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• pp.95-104
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• 2021

Objective: To evaluate the trueness and precision of full-arch scans acquired using five intraoral scanners and investigate the factors associated with the dimensional accuracy of the intraoral scan data. Methods: Nine adult participants (mean age, 34.3 ± 8.3 years) were recruited. Four zirconium spheres (Ø 6 mm) were bonded to the canines and the molars. Following acquisition of reference scans using an industrial-grade scanner, five intraoral scanners, namely i500, CS3600, Trios 3, iTero, and CEREC Omnicam, were used to scan the arches. Linear distances between the four reference spheres were automatically calculated, and linear mixed model analysis was performed to compare the trueness and precision of the intraoral scan data among the different scanners. Results: The absolute mean trueness and precision values for all intraoral scanners were 76.6 ± 79.3 and 56.6 ± 52.4 ㎛, respectively. The type of scanner and the measured linear distances had significant effects on the accuracy of the intraoral scan data. With regard to trueness, errors in the intermolar dimension and the distance from the canine to the contralateral molar were greater with Omnicam than with the other scanners. With regard to precision, the error in the linear distance from the canine to the molar in the same quadrant was greater with Omnicam and CS3600 than with the other scanners. Conclusions: The dimensional accuracy of intraoral scan data may differ significantly according to the type of scanner, with the amount of error in terms of trueness being clinically significant.

• Korean Journal of Geomatics
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• 제4권1호
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• pp.23-30
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• 2004

This study aims to establish interior orientation for various types of sensors including frame cameras, panoramic cameras, line cameras, and whisk-broom scanners. To do so, this study suggests the classification of components of interior orientation of which elements are different according to the sensors. This is entailed by incorporation of sensor characteristics into mathematical models of interior orientation parameters are suggested for being used as guidelines in recovering systematic distortions. Finally, the potential errors resulted from the assumption of regarding sensor model of whisk-broom scanner model as that of push-broom scanner are discussed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.845-846
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• 2006

In this paper, we describe a capacitive position sensing and motion control scheme of a MEMS scanner used for laser display application. The laser displays can be made by scanning laser beams much the same way a CRT scans electron beams. So the accuracy of the scanner motion determines the quality of the displayed image. The MEMS scanner under consideration is composed of electrostatic comb electrodes with initial gap and requires large driving voltage. Due to the under-damping and nonlinear driving characteristics, the scanner motion is subject to be an unwanted oscillation. For the linear scanner motion, we devise a differential charge amplifier and phase compensator. The experimental results show that the implemented feedback control system provides sufficient electrical damping and improves the dynamic performance of the scanner.