• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.685-689
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• 2023

The proposed system in the study aims to detect forest fires in real-time stream data received from the drone-camera. Recently, the number of wildfires has been increasing, and also the large scaled wildfires are frequent more and more. In order to prevent forest fire damage, many experiments using the drone camera and vision analysis are actively conducted, however there were many challenges, such as network speed, pre-processing, and model performance, to detect forest fires from real-time streaming data of the flying drone. Therefore, this study applied image data processing works to capture five good image frames for vision analysis from whole streaming data and then developed the object detection model based on YOLO_v2. As the result, the classification model performance of forest fire images reached upto 93% of accuracy, and the field test for the model verification detected the forest fire with about 70% accuracy.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.4
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• pp.331-344
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• 2023

The performance of the existing tunnel scanning system was analyzed through the post-evaluation of NETIS (New Technology Information System) and Inspection Support Technology Performance Catalog. Suggestions for improvement and development direction of the tunnel scanning system were deduced. As new technology of Japan gave priority to providing user-centered information, it was possible to objectively compare and analyze the characteristics of various tunnel scan systems through post-evaluation of NETIS and standard test methods in the Inspection Support Technology Performance Catalog. Construction New Technology of Korea was centered on suppliers of technology certification, making it impossible to objectively compare the performance of tunnel scanning systems. The performance was compared and evaluated indirectly by comparing the specifications of the camera, which is a core device of Japan's tunnel scanning system. For the future development of tunnel scanning systems, high-resolution and fast exposure performance of cameras and corresponding high-intensity lighting devices are required. For this purpose, it is necessary to make an experimental environment in which the performance of the camera and lighting can be analyzed indoors.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.957-965
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• 2011

Recently, railway industry has been developed not only functional parts such as acceleration and high performance of the railway but also emotional parts such as improved ride comfort and blocking noise. However, some important components of railway such as wheel and rail always had exposed too much operation time, cyclic load and rolling contact directly. The variations of load, vibration and chemical compositions were caused of wheel and rail having a lot of different types of contact fatigue damages. Therefore, It is necessary to improve inspection and maintenance technology in order to ensure safety and reliability of railway. Many researchers have already been reported the technology. Magnetic camera, one of the non-destructive testing technique can be used to inspect and evaluate the changes of magnetic field in ferromagnetic and paramagnetic materials with cracks. When an electromagnetic is applied to a specimen, a magnetic field will be distorted around a crack on the specimen. In present paper, the distribution of magnetic property in wheel with cracks using magnetic camera had investigated. The crack can be detected and evaluated by distribution analysis of magnetic field. The magnetic camera technique can be detected and evaluated the crack by rolling contact fatigue.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.113-121
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• 2002

Nowadays, developed camera, camcorder, CCTV and copier system accept a wide angle and a telephoto lens, and have an excellent capacity. Also, it is small as using aspheric surface. In this paper, after we evaluate and analyze two-group zoom lens system and three-group zoom lens system for camera, we refer to it, and design three-group zoom lens system for camera. Therefore, when we design a zoom lens system for camera, we use a symmetrical system. As using an aspheric surface, we can try to a miniaturization and an efficient improvement. We use optical valuable measure methods, a ray intercept plot, MTF and Seidel coefficient. So, we can confirm to have a similar level to compare with reference model.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.5
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• pp.127-135
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• 2015

In this paper, we propose the semi-auto camera calibration method including user input. The proposed method estimates the vanishing points using user defined reference lines and defines the constraint for reducing outlier in vanishing points estimation process. The proposed camera calibration method based on both algebraic and geometric method improves a calibration performance for difficult condition, which represents that existing method can't calibrate a image. Experimental results show that the proposed method calibration accuracy higher than existing method.

• Journal of Fashion Business
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• v.19 no.6
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• pp.28-41
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• 2015

Properties of textile fabrics influence the appearance, aesthetics, and performance of garment. Drape and related properties of fabrics affect profoundly the static and dynamic appearance during wearer's movement. The three dimensional shape of the folded structure often deforms with time or with subtle vibration around the fabric specimen during the drape measurement. Due to the uneven and complex nature of fabrics, the overall shape of the fabric specimen on the drape tester often becomes unstable. There is a need to understand the fundamental mechanisms of how draping may generate pleasing forms. Two drape test methods, conventional Cusick drape test, and in-built drape tester, based on a depth camera, are compared. Fabric specimens including cotton, linen, silk, wool, polyester, and rayon are investigated for the fabric drape and other physical/mechanical parameters. Drape coefficient values of fabric specimens are compared based on the final drape images, together with the intermediate 3D drape images of the specimens during elevation process of the drape tester equipped with a stepper motor system. The correlation coefficient between the data based on the two methods is reasonably high. Another advantage from the depth camera system is that it allows further analysis of three-dimensional information regarding the fabric drape shape, including the shape of nodes or crest and trough.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.7
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• pp.1450-1455
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• 2009

Assumed that an IPTV camera system is to be used as an ad-hoc sensor for the surveillance and diagnostics of safety-critical equipments installed in the in-containment building of the nuclear power plant, an major problem is the presence of high dose-rate gamma irradiation fields inside the one. In order to uses an IPTV camera in such intense gamma radiation environment of the in-containment building, the radiation-weakened devices including a CCD imaging sensor, FPGA, ASIC and microprocessors are to be properly shielded from high dose-rate gamma radiation using the high-density material, lead or tungsten. But the passive elements such as mirror, lens and window, which are placed in the optical path of the CCD imaging sensor, are exposed to a high dose-rate gamma ray source directly. So, the gamma-ray irradiation characteristics of the passive elements, is needed to test. A CCD camera lens, made of glass material, have been gamma irradiated at the dose rate of 4.2 kGy/h during an hour up to a total dose of 4 kGy. The radiation induced color-center in the glass lens is observed. The degradation performance of the gamma irradiated lens is explained using an color component analysis.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.31-35
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• 2008

Purpose: This study is to design a triplet optical system for CCTV camera lens. Methods: It was a telescopic lens with $5^{\circ}$ field angle, 56 mm focal length, 20 mm diameter, and 2/3 inches sized CCD array detector. Results: The performance of the subject optical system was evaluated by applying ray fan, spot diagram, and diffraction optical MTF. The wavelength was achromatized at Fraunhofer C, d and F-line, and both MTF and tangential & sagittal MTF shows more than 70% at spatial frequency of 50 linepairs/mm. Conclusions: The marketable triplet optical system for CCTV camera was designed and its utility was considered.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.4
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• pp.454-460
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• 2016

Unlike conventional visible light communications (VLC) adopting photo detectors (PD), optical camera communications (OCC) employs cameras in detecting the transmitted data. Especially, the data rate of OCC can be enhanced by using the principle of rolling-shutter, which is the operating scheme of a CMOS image sensor. In this study, we consider a novel OCC system for high-speed real time video processing to transmit high speed data from LED and to acquire image utilizing rolling-shutter effect of CMOS image sensor. Also, we demonstrate the improved performance of proposed system using a test-bed.

• Korean Journal of Optics and Photonics
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• v.26 no.4
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• pp.187-194
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• 2015

A system of infrared camera optics with wide field of view and anamorphic lenses is proposed, and its validity verified through manufacture. The infrared camera produced provides a wide field of view of over 100 degrees in the horizontal direction, and an even greater magnification in the vertical direction. As a result, the system can have a wider surveillance range and improved detection ability at the same time. In addition, a new optomechanical automatic athermalization mechanism is proposed and applied to the infrared camera. Its performance and utility is proved through testing.