• Journal of Advanced Navigation Technology
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• v.11 no.2
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• pp.163-169
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• 2007

In this paper, we propose a method of trigger pulse generation to capture the image on time by making a synchronization between the x-ray generator and digital x-ray image acquisition system. we designed a wireless trigger pulse generation circuit to make a synchronization between x-ray generator and digital image acquisition system and analysis its performance. When it starts to detect a certain level of x-ray radiation or above from the air, this method starts to generate a ACQ_START signal to indicate the timing for image acquisition starting from digital image acquisition system. Hence, when it starts to detect under certain level of x-ray signal from the air, this method starts to generate a ACC_END signal to indicate the timing for image acquisition stop from digital image acquisition system. Image acquisition is activated only this time between ACQ_START and ACQ_END signal. By doing this wireless detecting of x-ray signal from remote, we can get more accurate timing for capturing the x-ray image and any type of x-ray generator can be connected to digital image acquisition system, regards of wired protocol. This makes easy installation. We could get 3.5 line pair / mm resolution at 20 mAs of x-ray level with resolution chart. This is same or better image comparing to conventional wired result.

• Restorative Dentistry and Endodontics
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• v.27 no.2
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• pp.113-121
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• 2002

Conventional intraoral radiography continues to be the most widely used image modality for the diagnosis of dental caries. But, conventional intraoral radiography has several shortcomings, including the difficulty of exposing and processing intraoral film of consistently acceptable quality. In addition, radiographic retaking that was the result of processing errors, may result in increased discomfort and radiation dose to the patient. Recently, various digital radiographies substitute for conventional intraoral radiography to overcome these disadvantages. The advantages of digital radiography are numerous. One of advantages Is the elimination of processing errors. In addition, the radiation dose for digital system is approximately 20% to 25% of that required for conventional intraoral radiography Another potential advantage of digital imaging is the ability to perform image quality enhancements such as contrast and density modulation, which may increase diagnostic accuracy. The purpose of this study was to compare the diagnostic ability of artificial proximal defects to conventional intraoral radiography, direct digital image(CDX2000HQ$^{\circledR}$) and indirect digital image(Digora$^{\circledR}$). Artificial defects were made in proximal surfaces of 60 extracted human molars using #1/2, #1, #2 round bur. Five dentists assessed proximal defects on conventional intraoral radiography, direct digital image(CDX2000HQ$^{\circledR}$) and indirect digital image(Digora$^{\circledR}$). ROC(Receiver Operating Characteristic) analysis and Two-way ANOVA test were used for the evaluation of detectability, and following results were acquired. 1. The mean ROC area of conventional intraoral radiography, direct digital image(CDX2000HQ$^{\circledR}$) and indirect digital Image(Digora$^{\circledR}$) were 0.6766, 0.7538, 0.6791(Grade I), 0.7176, 0.7594, 0.7361(Grade II), and 0.7449, 0.7608, 0.7414(Grade III), respectively. 2. Diagnostic ability of direct digital image was higher than other image modalities. But, there was no statistically significant difference among other imaging modalities for Grade I, II, III lesion(p>0.05). In conclusion, when direct and indirect digital system are comparable with conventional intraoral radiography. these systems may be considered an alternative of conventional intraoral radiography for the diagnosis of proximal surface caries.

• Transactions of Materials Processing
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• v.11 no.7
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• pp.620-627
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• 2002

The purpose of this paper is the development of an automated measurement system for micro spring based on the digital image processing technique. This micro spring can be used in various engineering applications such as filament, load bearing springs, hard disk suspension and many others. Main functionality of the micro spring inspection system is to measure the representative pitch of the micro spring. The derivative operators are used for edge detection in gray level image. Measurement system developed in this paper consisted of new auto feeding mechanism to take advantage of air pressure. In the process of development of the micro spring inspection system based on the image processing and analysis, strong background technology and know-how have been accumulated to measure micro mechanical parts.

• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.2
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• pp.33-38
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• 2012

The purpose of luminance measurement in lighting design of urban scale is to prevent light trespass and light pollution, caused by over-bright. Specially, the illumination of road, tunnel and sports complex as urban infrastructure is measured by international standard for illuminance and luminance. It has been used the spot luminance meter and the image photometer to define the characteristics of qualitative and quantitative in exterior lighting. This study introduced the concept of HDR Image, procedure of HDR Image creation and analysis. Applications of HDR Image, particularly within the apartment building exterior lighting design analysis, have been demonstrated. The procedure proposed in this study is a affordable method that is useful for the assessment of luminance distribution in the scene with electric light. It also provides a measurement capability with the high resolution luminance data within a large field of view efficiently and quickly, which is not possible to achieve with a luminance meter.

• Journal of Digital Contents Society
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• v.19 no.9
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• pp.1787-1793
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• 2018

Shadow is a common phenomenon observed in natural scenes, but it has a negative influence on image analysis such as object recognition, feature detection and scene analysis. Therefore, the process of detecting and removing shadows included in digital images must be considered as a pre-processing process of image analysis. In this paper, the existing methods for acquiring 1D invariant images, one of the feature elements for detecting and removing shadows contained in a single natural image, are described, and a method for obtaining 1D invariant images based on linear regression has been proposed. The proposed method calculates the log of the band-ratio between each channel of the RGB color image, and obtains the grayscale image line by linear regression. The final 1D invariant images were obtained by projecting the log image of the band-ratio onto the estimated grayscale image line. Experimental results show that the proposed method has lower computational complexity than the existing projection method using entropy minimization, and shadow detection and removal based on 1D invariant images are performed effectively.

• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.523-530
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• 2014

Machine material and structural strain are critical factors for appraising mechanical properties and safety. Particularly in three and four-point bending tests, which appraise the deflection and flexural strain of an object due to external force, measurements are made by the crosshead movement or deflection meter of a universal testing machine. The Digital Image Correlation (DIC) method is one of the non-contact measurement methods. It uses the image analyzing method that compares the reference image with the deformed image for measuring the displacement and strain of the objects caused by external force. Accordingly, the advantage of this method is that the object's surface roughness, shape, and temperature have little influence. However, its disadvantage is that it requires extensive time to compare the reference image with the deformed image for measuring the displacement and strain. In this study, an algorithm is developed for DIC that can improve the speed of image analysis for measuring the deflection and strain of an object caused by a three-point bending load. To implement this algorithm for improving the speed of image analysis, LabVIEW 2010 was used. Furthermore, to evaluate the accuracy of the developed fast correlation algorithm, the deflection of an aluminum specimen under a three-point bending load was measured by using the universal test machine and DIC measurement system.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.157-162
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• 2003

The 3D Image which embodies real object to 3D space of computer enables various geometrical analysis as well as visualization of complex 3D shape by giving sense for the real and cubic effect that can not be offered in 2D image. Human gives real object to same physical properties in 3D space imagination world of computer, and it is expected that this enables offering of various information by user strengthening interface between human-computer to observe object in real condition. In this study, formal style routine of 3D image creation applying digital photogrammetry was designed for more practical, highly trusty 3D image creation, and the system was emboded using object-oriented technique which strengthen user interface. Also, the discontinuity information about rock slope using 3D image is acquired that is orientation, persistence, spacing and aperture etc.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.1
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• pp.30-35
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• 2017

In this study, we measured the natural frequencies of aluminum honeycomb sandwich beams using digital image correlation technique. The vibration images were captured using two high speed digital cameras and the images were converted to displacements by the digital image correlation technique. Displacement data in time domain were tranformed to frequency domain data by fast Fourier transform software. To reduce noise invoked by random exitation, a spectrum averaging technique and Savitsky-Golay digital filter were adopted. A conventional vibration measurement using an accelerometer and a finite element analysis were performed to compare the results by high speed digital camera measurement method. In conclusion, new method using high speed digital cameras and digital image correlation technique can measure the vibration of beam structures and can be applied to bio-structures where sensors cannot be attached.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.80-85
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• 2024

The concept of single-modal digital art originated in the 20th century and has evolved through three key stages. Over time, digital art has transformed into multi-modal interaction, representing a new era in art forms. Based on multi-modal theory, this paper aims to explore the characteristics of interactive digital art in innovative art forms and its impact on user experience. Through an analysis of practical application of multi-modal interactive digital art, this study summarises the impact of creative models of digital art on the physical and mental aspects of user experience. In creating audio-visual-based art, multi-modal digital art should seamlessly incorporate sensory elements and leverage computer image processing technology. Focusing on user perception, emotional expression, and cultural communication, it strives to establish an immersive environment with user experience at its core. Future research, particularly with emerging technologies like Artificial Intelligence(AR) and Virtual Reality(VR), should not merely prioritize technology but aim for meaningful interaction. Through multi-modal interaction, digital art is poised to continually innovate, offering new possibilities and expanding the realm of interactive digital art.

• International Journal of Highway Engineering
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• v.18 no.6
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• pp.145-152
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• 2016

OBJECTIVES : Visibility at night can be improved by using retroreflection for short distances and phosphorescent line markings for long distances. In this study, we analyzed the characteristics of the phosphorescent line marking through a laboratory luminance test. Field performance analysis was performed through tests conducted on the road. We also examined the luminance measurement methods using the digital image obtained during the phosphorescent visibility evaluation. METHODS : In this study, the laboratory luminance test of the phosphorescent line marking was conducted using seven specimens to characterize the luminance changes according to the type of the glass beads, the thickness of the phosphorescent line marking, and the brightness and irradiation time of the light source. Phosphorescent and general line markings were made at 150 m to investigate the field luminance performance. A preliminary review of the luminance measurement methods was made using a digital image from a digital single-lens reflex (DSLR) camera. The measured luminance ratio of the general and the phosphorescent line markings was compared with the calculated luminance ratio using luminance analysis. RESULTS : Through the laboratory luminance test, it was seen that the change in luminance, which corresponds to the brightness of the light source, appears large but the influence of the thickness and irradiation time is low. The field performance test of the phosphorescent line marking conducted on the road involved measuring the luminance on the day the marking was made and 7 days after the marking was made. The luminance was found to be $190mcd/m^2$ at 30 min after sunset and approximately $10-12mcd/m^2$ 4h after sunset. The results of the luminance test were captured using a digital image for each time group. The luminance ratio of the phosphorescent line marking, when compared to that of the general line marking, showed a similar trend within a 13% maximum error. Additionally, when this luminance ratio is compared to the direct field measurement, it could be confirmed that the luminance ratio, as captured in the digital image, showed a similar tendency. CONCLUSIONS : 1) The change in luminance corresponding to the brightness of the light source is significant in comparison with that corresponding to the thickness and the irradiation time. In addition, the results of the field test for the phosphorescent line marking satisfied the phosphorescent fire protection standard. 2) We examined the validity of the luminance measurement method using a digital image and we concluded that the change in the luminance ratio shows a similar tendency in both the cases. The results can form the basis for luminance measurement methodology for the construction and maintenance of phosphorescent line markings.