• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.327-334
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• 2024

In this paper, we developed a system with a near-infrared LED light source with a wavelength of 950nm to acquire palm vein images and a white LED light source to acquire palm creases based on Raspberry Pi. In addition, we implemented a unique pattern-extractable image processing technology that can prevent counterfeiting and enhance security of mixed creases and palmprints through image pre-processing (Gray scaling, Histogram Equalization, Blurring, Thresholding, Thinning) for the acquired vein and palm images, and secured a source technology that can be used in a security-enhanced system.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.8
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• pp.167-171
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• 2014

While the development of a portable plate panel display, thinning, high color reproduction, high brightness studies have been actively performed. LED, OLED is used as a light source. The research on quantum dot is much accomplished by the material of light source. Such quantum dot is the next generation semiconductor nano fluorescent substance because quantum dot has the high color reproduction and flexible display characteristic. In this study, we presented to method of using the quantum dot for implementation of the plate panel display. Quantum Dot (CdSe/ZnS), having a 100um thickness, is spread in PET barrier film. A Blue LED having a wavelength of 455nm as a light source irradiating light to the optical characteristic of the devices produced and evaluated. Also we presented the possibility for application with the color change film of the LCD.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.697-705
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• 2014

This paper presents a vision based object width measurement method and its application where the light sectioning method is employed. The target object for measurement is a tread, which is the most outside component of an automobile tire. The entire system applying the measurement method consists of two processes, i.e. a calibration process and a detection process. The calibration process is to identify the relationships between a camera plane and a laser plane, and to estimate a camera lens distortion parameters. As the process requires a test pattern, namely a jig, which is elaborately manufactured. In the detection process, first of all, the region that a laser light illuminates is extracted by applying an adaptive thresholding technique where the distribution of the pixel brightness is considered to decide the optimal threshold. Then, a thinning algorithm is applied to the region so that the ends and the shoulders of a tread are detected. Finally, the tread width and the shoulder width are computed using the homography and the distortion coefficients obtained by the calibration process.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1315-1318
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• 2004

Based on fuzzy 2-mean classification and template matching method, we propose a new algorithm to detect the edges of an image. In the algorithm, fuzzy 2-mean classification can classify all pixels in the mask into two clusters whatever the mask in the dark or light region; and template matching not only determines the edge's direction, but also thins the detected edge by a set of inference rules and, by the way, reduces the impulse noises.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.4
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• pp.111-123
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• 1996

In this paper, a new edge-based segmentation algorithm for range image using pseudo reflectance images (PRIs) is proposed. A model of pseudo reflectance which is useful in analyzing three dimensional scene and objects is introduced and then three PRIs are generated by the model. For generating three PRIs, bels and jain's differential window operator is selected and three different light source directions are determined. Three edge images are extracted from each PRI and a fused (logical ORing) edge image is constructed for the benefit of enhanced edge formation. The final segmentation results of the proposed algoritm are obtained after the processing of thinning, labeling and correcting erroeneous regions with the fused edge image. The good performance of edge detection and segmentation is confirmed via computer simulation with synthetic and real range images.

• Transactions of Materials Processing
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• v.16 no.2 s.92
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• pp.144-149
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• 2007

The superplastic forming/diffusion bonding(SPF/DB) is widely used in the automotive and aerospace industry because it has great advantage to produce complex, light and strong parts. But the superplastic forming process requires much forming time and generates excessive thinning in the thickness distribution of formed part. It is necessary to minimize trial and error for SPF/DB Process. Finite element analysis using $L_{18}$ orthogonal may table of Taguchi method for 3-Sheet D/B process is carried out. Through the study, effect of process parameters, such as DH region size, thickness and friction coefficient, is evaluated and the optimum condition is derived.

• Journal of Korea Multimedia Society
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• v.22 no.12
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• pp.1356-1367
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• 2019

This paper proposes a novel active stereo matching technique using white auxiliary stripe pattern. The conventional active stereo matching techniques that uses two cameras and an active source such as projector can accurately estimate disparity information even in the areas with low texture compared to the passive ones. However, it is difficult that the conventional active stereo matching techniques using color code patterns acquire these patterns robustly if the object is composed of various colors or is exposed to complex lighting condition. To overcome this problem, the proposed method uses an additional white auxiliary stripe pattern to get and localize the color code patterns robustly. This paper proposes a process based on adaptive thresholding and thinning to obtain the auxiliary pattern accurately. Experimental results show that the proposed method more precisely measures the stepped sample whose depth is known in advance than the conventional method.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.655-658
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• 2003

The crack of concrete structure plays an important role in the durability and safety of structure. Therefore, the features such as width, length, and direction of that must be measured periodically. The conventional method of measurement of cracks is manually sketched, however. it takes a fairly long time and lacks quantitative objectivity. This study proposes the algorithm to extract and analyze cracks automatically. The proposed algorithm is composed of two sub-algorithms. The extraction algorithm includes elimination of effect due to light, binarization. and noise reduction. The analysis algorithm includes thinning process, labeling, and calculation of crack width, length, and direction. The test to demonstrate the algorithm is fulfilled using the images of cracks on real concrete surface.

• The Korean Journal of Community Living Science
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• v.15 no.1
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• pp.27-33
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• 2004

Natural dyeing means coloring with dyes extracted from plants, minerals or animals found in nature. Natural dyeing provides calm and natural colors; it has antibacterial and deodorizing qualities; and the dyeing process is environmentally friendly. This study extracted natural dyes from young fruit by thinning out the superfluous fruits of Naju pear trees, and then examined its dyeing properties, the optimal dyeing conditions, and its color fastness for practical use. The results indicated that dyeing is ideal when it had Cu mordant treatment (5% concentration at 9$0^{\circ}C$, pH 4) for 50 min. The color fastness of natural dyes with Cu mordant treatment was very excellent after rubbing and dry cleaning, and also good after exposure to perspiration, light and washing.

• Journal of Veterinary Clinics
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• v.30 no.4
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• pp.324-328
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• 2013

A 5-year-old intact male Yorkshire terrier dog was referred with a 1-week history of blindness. In both eyes, menace responses and pupillary light reflexes were absent. The indirect ophthalmoloscopy revealed multiple small gray-white and discoloration lesion in mid-nontapetum area in both eyes. Electroretinograms showed diminished amplitude of a- and b-waves. Multifocal serous retinal detachments were detected with optical coherence tomography (OCT) over the small gray-white and discoloration lesion in the fundus. After one week of treatments, the indirect ophthalmoloscopy showed that irregular patches and hyperpigmentation in the center of hyperreflectivity area. Reattachment and retinal thinning were observed by the OCT. The results indicate that OCT scanning is considered to be a useful method for retinal evaluation in dogs with chorioretinitis.