Home > Non – Linear Defect Sizing Via Grayscale Thresholding Technique Applied to Digital Radiographic Images of Industrial Materials ── With Special Focus on Nuclear Fuels
Non – Linear Defect Sizing Via Grayscale Thresholding Technique Applied to Digital Radiographic Images of Industrial Materials ── With Special Focus on Nuclear Fuels
Determination of the size of a defect in a given material is important from industrial usage point of view. In this work, a computational technique has been developed that takes a humble step forward from just qualitative description of defect, such as “big” or “small” to its area-wise quantification. Our program (by the name “DEFAREA”) accepts a 2D grayscale image of an investigated specimen as input and sizes the irregular shaped defects contained therein in terms of the area occupied by them. In case where a defect feature is of regular shape being a projected image of a cylinder or a sphere the program is also able to produce volumetric results. The program exploits the fact that defects offer color contrasts that are different from the rest of the image (such as bone fracture in X- ray radiograph). It is based on grayscale thresholding (GT) whereby it first iterates down to compute a minimum value of graylevel that separates the first peak from the rest of the distribution in the grayscale spectrum of the given input image. This threshold, which is representative of a particular shade of gray color, is then used to identify, select and count the number of pixels which have graylevel values below the computed threshold. The number of segmented pixels within the whole image size then easily produces not only a numeric fraction of the defective portion of inspected specimen but also the area occupied by the defect if the physical sizes and dimensional measurements of the specimen are known. The main part of the algorithm, however, revolves around devising a reliable computational method to obtain a certainty range in the reported defect size. Certainty range is needed as there physically exists a transition region (TR) between the defective and the immaculate parts of the investigated object that can not be put in either category. TR offers lesser contrast with the flawless part of the image than the pure defect areas. So a given defect is doubly quantified with and without appending the transition region around it with the aid of user-defined adjustability in the computed grayscale threshold. Then finally an average value of defect size is calculated along with an associated certainty. The presented algorithm is validated against physical measurements of some locally fabricated metallic plates having drilled holes of known sizes simulated as defects in them in which the results indicate that it correctly selects and quantifies at least 94.7% of the actual required regions of interest in a given image and it gives less than 8% false alarm rate. The algorithm is then applied to sizing of a wide range of defects commonly encountered in nuclear industry regarding reactor fuels. The images of nuclear fuels used as input in the program are collected from a reference standard source of neutron radiographs. The present work confirms the ability to quantify various kinds of defects such as chipping in nuclear fuel, cracks, voids, melting, deformation, inclusion of foreign materials, heavy isotope accumulation and non-uniformity etc. The classes of fuel range from those of research and power reactors to fast breeders, from fresh nuclear fuel to post-irradiate, and from pellets to annular and vibro-compacted fuel. It is also demonstrated that the program can handle a variety of image sizes, displays several output modes of image segmentation and works well without the need of any smoothening or eroding morphological operations.
Peace initiatives during the regime of the Prophet attain to how understand to studied be to needs (صلى الله عليه وسلم) Muhammad and maintain peace in a diverse society. The measures for peace, taken by the Prophet (ﷺ) can be divided into two types: The Internal Steps and The External Steps. One of the fundamental objectives of his prophetic annunciation was ‘purification and refinement’, which was the core of his internal measures for peace. These measures produced moral values such as love and harmony, reconciliation and sacrifice among them. These personality traits were then translated into the establishment of equitable justice system and reciprocally, a just system leads to shape behaviors contributing to peace and harmony. For steps external the on focused also (صلى الله عليه وسلم) Prophet The peace. These external measures include the treaty of al-Madīnah, the agreement with the Christian delegation of Najrān, the treat of Ḥudaybiyah and the announcement of the amnesty at the conquest of Mekkah. Thus, the study of the Prophet’s (ﷺ) life unfolds that if we want global peace, we have to follow the principles, practiced. (صلى الله عليه وسلم) Prophet the by down laid and
In this study generalized exponential ratio type estimators have been proposed for estimating the finite population mean, using the information from single and two auxiliary variables, under sampling design such as single and two phase sampling. For each proposed estimator bias of order two and mean square error of order one are derived using single and two phase equal probability sampling with single and two auxiliary variables. A class of these estimators have been developed and their bias of order one and mean square errors of order one have been derived. Mathematical comparison has been furnished of the generalized proposed estimators with the existing estimators. Shrinkage estimators of the proposed estimators have been defined along with their mean square errors for single and two phase sampling. To put side by side the proposed estimators with existing estimators, numerical study has been carried out with single and two phase equal probability sampling. It is experiential that the proposed estimators are more efficient than simple random sampling, Ratio, Bhal and Tuteja (1991), Samiuddin and Hanif (2006), Sisodia and Dwivedi (1981), Upadhyaya (1999), Singh and Tailor (2003) and Noor-ul-Amin and Hanif (2012) and others. In case of unequal probability sampling the proposed estimator is also more efficient than the simple random sampling, Ratio, Bhal and Tuteja (1991), Sisodia and Dwivedi (1981) and Singh and Tailor (2003). To study the properties of the estimators, simulation has been carried out and it is evident that the proposed estimators are consistent estimators of population mean. It also shows that normal distribution is the most significant fitted distribution on the proposed estimators.