This study proposes a crack identification algorithm to analyze the surface condition of porcelain insulators and to efficiently visualize cracks. The proposed image processing algorithm for crack identification consists of two primary steps. In the first step, the brightness is eliminated by converting the image to the lab color space. Then, the background is removed by the K-means clustering method. After that, the optimum image treatment is applied using morphological image processing and median filtering to remove unnecessary noise, such as blobs. In the second step, the preprocessed image is converted to grayscale, and any cracks present in the image are identified. Next, the region properties, such as the number of pixels and the ratio of the major to the minor axis, are used to separate the cracks from the noise. Using this image processing algorithm, the precision of crack identification for all the sample images was approximately 80%, and the F1 score was approximately 70. Thus, this method can be helpful for efficient crack monitoring.

In order to acquire clear images capable of diagnosing cracked tooth by light transmission, the optical properties of LED light source were examined. Based on the results, the prototype which basically consisted of LED light source, bandpass filter and commercial compact camera module was designed and manufactured. The wavelength and optical power of the LED in the prototype were 850 nm and 7 mW/Sr, respectively. In evaluation of the prototype using microscope, the observation of the crack with width of above 17 μm was possible. In addition, image analysis to obtain shape information on the observed tooth cracks was carried out.

In this study, Cu(In, 5,Ga)Se2 (CIGS) thin films were prepared on the Mo coated soda-lime glass by the DC magnetron sputtering and a subsequent selenization process. For the selenization process. selenization rapid thermai process(WIP) with cracker cell, which was helpful to smaller an atomic of Se, was adopted. To make GIGS layer, they were then annealed with the cracked Se. Based on this selenization method, we made several GIGS thin film and investigated the effects of In deposition time, and selenization time. Through x-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and atomic force microscopy (AFM), it is found that the Mo/In/CuGa structure and the high sputtering power shows the dominant chalcopyrite structure and have a uniform distribution of the grain size. The CIGS films with the In deposition time of 5 ruin has the best structure due to the smooth surface. And CIGS films with the selenization time of 50 mm show good crystalline growth without any voids.