Journal articles on the topic 'Defects'
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1
Mostovoy, Sergey, and Oleg Pavlovsky. "Simulation of lattice statistical models with defects: Critical Casimir Effect." EPJ Web of Conferences 175 (2018): 03005. http://dx.doi.org/10.1051/epjconf/201817503005.
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The influence of lattice structure defects on phase transition phenomena was studied in framework of 2D spin model. Effective mass of defect was proposed for investigation of conformal properties of the model at critical point. The volume dependence of defect’s mass at critical point and the Critical Casimir interaction of two defects were studied. It was shown that this Casimir interaction is attraction for any value of hopping parameter. The confinement of the defect on the defects line and the process of defects line collapse were studied. Applications in nanophysics and biophysics were discussed.
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Garabano, Germán, César Pesciallo, Alfredo Montero Vinces, Diego José Gómez, Fernando Bidolegui, and Alberto Cid Casteulani. "Defectos óseos segmentarios infectados en huesos largos: tratamiento con técnica de Masquelet.[Masquelet technique for the treatment of infected segmental long-bone defects]." Revista de la Asociación Argentina de Ortopedia y Traumatología 84, no. 1 (February 20, 2019): 15–26. http://dx.doi.org/10.15417/issn.1852-7434.2019.84.1.853.
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Introducción: Los defectos óseos segmentarios infectados son entidades de complejo tratamiento. La técnica de Masquelet representa una alternativa para estos casos. El objetivo de este estudio retrospectivo, multicéntrico fue mostrar los resultados clínicos y radiológicos obtenidos con esta técnica de reconstrucción en defectos óseos segmentarios infectados de fémur y tibia, caracterizar los defectos tratados y describir los diferentes aspectos de la técnica quirúrgica.Materiales y Métodos: Analizamos a 24 pacientes (14 hombres y 10 mujeres; edad promedio 36.16 años [rango 18-67]) tratados con la técnica de Masquelet, operados entre 2011 y 2016. El seguimiento promedio fue de 16.5 meses (rango 12-27) desde el segundo tiempo quirúrgico. Se analizaron el hueso afectado, la longitud del defecto (en cm), el tiempo de consolidación y el control del proceso infeccioso.Resultados: La longitud del defecto óseo tratado fue, en promedio, de 5,7 cm (rango 3-12), fue superior a 4 cm en el 50% de los casos, el defecto óseo segmentario de mayor tamaño en la tibia fue de 12 cm y de 10 cm en el fémur. Se logró la consolidación ósea en todos los casos, en 4.5 meses. Un paciente presentó una recidiva del proceso infeccioso a los 12 meses de la consolidación.Conclusiones: La técnica de Masquelet o de la membrana inducida ofrece una alternativa razonable y sencilla para un problema altamente desafiante como son los defectos óseos segmentario infectados. La tasa de consolidación es superior al 90% aun en casos complejos. ABSTRACTIntroduction: Infected segmental bone defects are challenging conditions which require a complex treatment. The Masquelet technique is an alternative for these cases. The aim of this retrospective, multicenter study was to show the clinical and radiological outcomes achieved with the use of this reconstruction technique in infected femoral and tibial segmental defects in order to characterize the defects treated and describe different aspects of this surgical approach.Methods: We analyzed 24 patients (14 men and 10 women; average age 36.16 years [range 18-67]) treated with the Masquelet technique between 2011 and 2016. The average follow-up was 16.5 months (range 12-27) from the second surgical stage. We analyzed the affected bone, defect length (cm), consolidation time and infection control.Results: Average length of treated bone defect was 5.7 cm (range 3-12), exceeding 4 cm in 50% of the cases. The largest segmental bone defect was 12 cm at the tibia and 10 cm at the femur. Bone consolidation was achieved in all cases, on an average of 4.5 months. One patient presented a recurrent infection 12 months after successful consolidation.Conclusions: The Masquelet technique, or induced membrane technique, offers a reasonable and simple alternative to a highly challenging problem, such as infected segmental bone defects, achieving a consolidation rate greater than 90% even in complex cases.
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Pond, R. C. "TEM studies of line defects in interfaces." Proceedings, annual meeting, Electron Microscopy Society of America 46 (1988): 586–87. http://dx.doi.org/10.1017/s0424820100104996.
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Line defects are ubiquitious features in interfaces, and have important structural and mechanistic role. Recently, a crystallographic theory of such defects has been presented which appears to offer a comprehensive framework for their classification. The object of the present paper is firstly to outline the characterisation and classification of defects according to this treatment. Secondly, we illustrate examples of defects in the distinctive classes observed using tern, and discuss the various imaging techniques which have been employed.In the absence of a rigorous treatment of line defects in single crystals and interfaces, which would require the development of a discrete field theory, approximate methods of defect characterisation are used. The most popular method involves mapping a contour, initially constructed around a defect of interest, into a reference space. For defeats in single crystals this Burgers circuit method, introduced by Frank, is very helpful, but suffers from certain procedural inconveniences in the case of interfacial defects.
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Zhan, Hai Fei, and Yuan Tong Gu. "Exploration of the Defect’s Effect on the Mechanical Properties of Different Orientated Nanowires." Advanced Materials Research 328-330 (September 2011): 1239–44. http://dx.doi.org/10.4028/www.scientific.net/amr.328-330.1239.
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Molecular dynamics (MD) simulations have been carried out to investigate the defect’s effect on the mechanical properties of copper nanowire with different crystallographic orientations, under tensile deformation. Three different crystallographic orientations have been considered. The deformation mechanism has been carefully discussed. It is found that the Young’s modulus is insensitive to the defect, even when the nanowire’s crystallographic orientation is different. However, due to the defect’s effect, the yield strength and yield strain appear a large decrease. The defects have played a role of dislocation sources, the slips or stacking faults are first generated around the locations of the defects. The necking locations have also been affected by different defects. Due to the surface defect, the plastic deformation has received a large influence for the and orientated nanowires, and a relative small influence is seen for the nanowire.
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Zhan, Hai Fei, Yuan Tong Gu, Cheng Yan, and Prasad K. D. V. Yarlagadda. "Numerical Exploration of the Defect’s Effect on Mechanical Properties of Nanowires under Torsion." Advanced Materials Research 335-336 (September 2011): 498–501. http://dx.doi.org/10.4028/www.scientific.net/amr.335-336.498.
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Molecular dynamics (MD) simulations have been carried out to investigate the defect’s effect on the mechanical properties of single-crystal copper nanowire with different surface defects, under torsion deformation. The torsional rigidity is found insensitive to the surface defects and the critical angle appears an obvious decrease due to the surface defects, the largest decrease is found for the nanowire with surface horizon defect. The deformation mechanism appears different degrees of influence due to surface defects. The surface defects play a role of dislocation sources. Comparing with single intrinsic stacking faults formation for the perfect nanowire, much affluent deformation processes have been activated because of surface defects, for instance, we find the twins formation for the nanowire with a surface 45odefect.
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Almazova, L. A., and O. S. Sedova. "SIMULATION OF THE SURFACE DEFECTS INFLUENCE ON THE ALUMINUM ALLOY BEHAVIOUR UNDER THE CYCLIC LOAD CONDITIONS." Frontier materials & technologies, no. 1 (2022): 7–14. http://dx.doi.org/10.18323/2782-4039-2022-1-7-14.
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Aluminum and its alloys, such as the Al–Si–Mg alloy, are widely used in various industrial and engineering fields due to their mechanical properties. In this case, the defects occurring during the casting process adversely affect the behavior of this alloy under cyclic load conditions. Therefore, the study aimed to investigate the surface defect influence on the material's fatigue strength is currently of great importance. The paper presents a numerical investigation based on the finite element method intended to evaluate the effect of the interaction of the complex-shaped defects on the stress of the Al–Si–Mg aluminum alloy. The developed complex-defect model consists of a hemispherical main (base) defect and a secondary defect at the bottom of the main one. The authors use the Chaboche model to describe the material’s behavior under the cyclic load conditions. The paper contains the computational solution constructed with the ANSYS Workbench platform. The authors supposed that it is possible to approximate the considered complex defect form by an equivalent simplified defect. The study shows that the maximum von Mises stress values for the complex-shaped defects are achieved at the joint of the secondary defect with the main one. In the case of an equivalent defect, the maximum values are observed at the defect's bottom and on the periphery. The authors comparatively estimated the uncertainty obtained using an equivalent defect and the cases of three complex-shaped defects and three hemispherical defects without additional (secondary) damage. This estimation shows that in the case of a complex-shaped defect, the equivalent defect model has an error of 14.5 %, which is 6.5 % greater than in the case of the hemispherical defects without secondary damages at the bottom.
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Mostovoy, S. D., and O. V. Pavlovsky. "Particle-like behavior of defects near a defect line in 2D Ising model: Defect–antidefect pair production and interaction." International Journal of Modern Physics B 33, no. 12 (May 10, 2019): 1950117. http://dx.doi.org/10.1142/s0217979219501170.
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The aim of this work is to investigate Casimir effect in a system comprising of a defect line along with isolated defects (vacancies) in 2D Ising model. We have found out that the interaction energy has a decaying exponent with distance between defects. We are interested in an analogy between Casimir behavior of this defect structure and quantum field theory. The simplest deformation of a defect line (a defect’s position change) can be treated as defect–“antidefect” pair creation. Single defect is attracted to a defect line. By means of Monte Carlo simulation, the energy of pair creation and Casimir interaction potential are calculated. The interaction turned out that a Yukawa potential turns to the Coulomb’s one at phase transition point.
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Chen, Yue, Xuehao Pan, and Lingfang Deng. "Study on the Localization of Defects in Typical Steel Butt Welds Considering the Effect of Residual Stress." Applied Sciences 13, no. 4 (February 18, 2023): 2648. http://dx.doi.org/10.3390/app13042648.
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When using magnetic memory detection technology to locate weld cracks and porous defects, the traditional zero-point polarity theory leads to misjudgments in defect location and difficulty in distinguishing between the residual stress and the magnetic signals generated by defects due to the influence of external noise and residual stress. Therefore, this paper considers the different mechanisms of magnetic signal generation in areas where crack- and porosity-type defects and residual stresses are located and discusses research focused on the detection of weld defect localization considering the influence of residual stresses. Using the mechanism of magnetic signal generation as a starting point, the three-dimensional magnetic modulus gradient polarity determination method is proposed to distinguish residual stress and defects’ magnetic signals. Through the COMSOL simulation of a welding defect’s finite element magnetic signal, the resulting magnetic signal is converted into a characteristic determination formula for characterization. To verify the accuracy of the simulated characterization, the 3D magnetic signal is extracted and verified manually. Finally, a double orthogonal wavelet transform is introduced to eliminate the random noise in the gradient of the three-dimensional magnetic modulus. The results show that the theoretical analysis, numerical simulation, and experimental results agree with each other. The three-dimensional magnetic modulus gradient values of cracks and pores are much higher than that of the defect-free residual stress area. The three-dimensional magnetic gradient modulus can locate defects and characterize the lengths of defects. The dual orthogonal wavelet eliminates noise interference while improving the accuracy of locating three-dimensional magnetic modulus gradient defects.
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Melikhova, Oksana, Jakub Čížek, Ivan Procházka, Tetyana E. Konstantinova, and Igor A. Yashchishyn. "Inhibition of Positronium Formation in Yttria Stabilized Zirconia Nanopowders Modified by Addition of Chromia." Materials Science Forum 733 (November 2012): 249–53. http://dx.doi.org/10.4028/www.scientific.net/msf.733.249.
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The effect of chromia additive on defects in yttria stabilized zirconia (YSZ) nanopowders was investigated in this work. It was found that positrons are trapped at vacancy-like misfit defect at grain boundaries and at larger defects situated at triple points. Moreover, a long-lived ortho-positronium contribution was found in YSZ nanopowder without chromia. Addition of chromia prolongs the lifetime of positrons trapped at vacancy-like misfit defects which indicates segregation of Cr ions at grain interfaces and interaction of Cr with vacancy-like misfit defets. Moreover addition of chromia completely suppresses formation of positronium.
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Khoury, Muin J., José F. Cordero, Joseph Mulinare, and John M. Opitz. "Selected Midline Defect Associations: A Population Study." Pediatrics 84, no. 2 (August 1, 1989): 266–72. http://dx.doi.org/10.1542/peds.84.2.266.
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Using data from the population-based Metropolitan Atlanta Congenital Defects Program, the association of seven relatively common and easily ascertainable groups of midline defects was studied. These defects were neural tube defects (575 patients), oral clefts (633 patients), omphalocele (141 patients), esophageal atresia/tracheoesophageal fistula (88 patients), imperforate anus (151 patients), conotruncal heart defects (289 patients), and diaphragmatic hernia (75 patients). Known syndromes were excluded from the analysis. Of 1743 infants with at least one midline defect, 86 (4.9%) had at least a second midline defect, and 9 (0.5%) had two additional midline defects. Pairwise analysis of the seven defects shows that, although most midline defects tend to be statistically associated with other midline defects, specific combinations of midline defects are seen. For example, neural tube defects are more strongly associated with cleft lip with or without cleft palate than with cleft palate alone; imperforate anus is more strongly associated with spina bifida than with anencephaly or encephalocele. Moreover, some combinations of defects are not observed (eg, neural tube defect and conotruncal heart defect, clefts and diaphragmatic hernia, omphalocele and esophageal atresia/tracheoesophageal fistula). These data point to the need for further refinement in the study of the association of midline defects in terms of embryologic and pathogenetic mechanisms because most midline defects tend to occur as an isolated defect, some midline defects occur with nonmidline defects (such as limb defects), and specific associations among midline defects are observed.
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Zhang, Kai, Zhurong Dong, Zhan Yu, and Yunze He. "Shape Mapping Detection of Electric Vehicle Alloy Defects Based on Pulsed Eddy Current Rectangular Sensors." Applied Sciences 8, no. 11 (October 26, 2018): 2066. http://dx.doi.org/10.3390/app8112066.
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In this paper, we investigate pulsed eddy current (PEC) testing based on a rectangular sensor for the purpose of defect shape mapping in electric vehicle lightweight alloy material. Different dimensional defects were machined on the 3003 aluminum alloy and detected using the A-scan technique and C-scan imaging in two scanning directions. The experiment results indicated that defect plane shape could be preliminarily obtained and length and width could be estimated based upon C-scan contour images. Consequently, the comparison of results between the two directions showed that the C-scan identification in the direction of magnetic flux was better than in the direction of the exciting current. Finally, subsurface defects and irregular defects were detected to verify the performance of shape mapping as a recommended approach. The conclusion drawn indicates that the proposed method, based on PEC rectangular sensors, is an effective approach in reconstructing a defect’s shape.
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Touil, D. R., A. Daas, B. Helifa, A. C. Lahrech, and L. Ibn Khaldoun. "Simple Giant Magnetoresistance Probe Based Eddy Current System of Defect Characterization for Non-Destructive Testing." Advanced Electromagnetics 11, no. 2 (May 11, 2022): 43–48. http://dx.doi.org/10.7716/aem.v11i2.1910.
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The purpose of this paper is to present a new giant magnetoresistance (GMR) sensor, in eddy current testing technique for surface defect detection, in conducting materials, we show that the GMR based eddy currents probe is more sensitive than the inductive probe. A flat coil mounted on ferrite pot used to produce an alternate magnetic field, which gives rise to eddy currents in the material under test. Aluminum plates use with defects have nominal depths, widths, and lengths. The defects scanned with the sensing axis perpendicular to the defect length. Two parameters extracted from the GMR output voltage signal obtained, and a simple correlation between the defect’s dimensions and the GMR output voltage proposed.
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Lewis, David A., Christopher A. Loffredo, Adolfo Correa-Villaseñor, P. David Wilson, and Gerard R. Martin. "Descriptive epidemiology of membranous and muscular ventricular septal defects in the Baltimore-Washington Infant Study." Cardiology in the Young 6, no. 4 (October 1996): 281–90. http://dx.doi.org/10.1017/s1047951100003905.
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AbstractAlthough ventricular septal defect is the most common form of congenital heart disease, its epidemiology is not completely understood. The Baltimore-Washington Infant Study, a case-control study of congenital cardiovascular malformations, enrolled 4,390 case infants during the study period 1981–1989. Ventricular septal defect, the most common malformation, was present in 1,465 (33%) of affected infants. The purpose of this report was to describe the epidemiological characteristics of membranous and muscular ventricular septal defects, the most common types of ventricular septal defects. Membranous ventricular septal defects (n=895) and muscular ventricular septal defects (n=429) accounted for 90% of all ventricular defects. During the study, prevalence increased from 0.9 to 2.1 /1000 live births. Associated non-cardiac defects, such as chromosomal defects, genetic syndromes, and defects of other organs were more common among infants with ventricular septal defect than among control infants, and more common among infants with membranous ventricular defect (20.8%) than among those with muscular defects (7.5%). Infants with ventricular septal defects and non-cardiac defects had increased mortality in comparison to infants with isolated ventricular septal defects or controls. Epidemiological information derived from population-based studies provide valuable data for counseling families and may allow for examination of etiologic factors.
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Nurlaelah, Azis, and Usman Sudjadi. "The Classification of Residential Defects (Case Study: Citra Garden Residence in Indonesia)." Applied Mechanics and Materials 507 (January 2014): 97–106. http://dx.doi.org/10.4028/www.scientific.net/amm.507.97.
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The classification of residential defects (case study: Citra Garden Residence in Indonesia) was studied. This study aims to more satisfied customers. The study begins with the literature review to formulate the classification of house defects. Then classify the defect of house into two, namely the classification of house defects based on period of post hand over, and the classification of house defects based on category of the defects. Further studies followed by dividing the classification of house defects based on period of post-hand over into three parts, namely before hand over period (inviting time), hand over period, and post-hand over period. The next step is to check the complaint report from the customer service in Citra Garden Residence in Indonesia to quantificate the defects of the house. The classification of house defects based on category of the defects divided into two, namely structural defect (minor, moderate, serious), and nonstructural defect (minor, moderate, serious). The next step is also to check the complaint report from the customer service in Citra Garden Residence in Indonesia to quantificate the defects of the house.The results show that complaint hand over in the level minor defect is the highest complaint. Complaint in the serious defect is the lowest complaint.
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Mohammadi, Farnoush, Abbas Azari, Nariman Nikparto, and Heliya Ziaei. "Reconstruction of the Occipital and Parietal Congenital Defect with 3D Custom-Made Titanium Prosthesis: A Case Report with Four and a Half Years of Follow-Up and a Brief Review of Literature." Case Reports in Dentistry 2021 (October 20, 2021): 1–6. http://dx.doi.org/10.1155/2021/7027701.
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Management of patients with congenital skull defects requires a multidisciplinary approach. Considering the defect’s location and size, brain protection, and the cosmetic outcome makes such reconstructions challenging. Due to limited resemblance to skull contour and donor site morbidity of autogenous bone grafts, alloplastic materials are widely used for skull reconstructions. Titanium alloys have proper strength values, low infection rates, favorable osseointegration property, and excellent marginal adaptability when manufactured by computer-aided design (CAD) and computer-aided manufacturing (CAM). A 13-year-old female patient presented with congenital defects at the superior third of occipital bone and posterior thirds of the bilateral parietal bones. On CT scan, the exact size and shape of the defect were determined. Using CAD/CAM, a 3D virtual model of the prosthesis was designed and then printed with titanium alloy (TiAl6V4) via additive manufacturing method. The prosthesis was placed on the defect in a total surgery time of only 90 minutes. On 4.5 years of follow-up, the contour of the skull was ideal and the skin over the defect and neurologic status was intact. Due to their biocompatibility and rigidity, custom-made titanium prostheses are promising options for reconstructing complex skull defects.
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Park, Junmo, and Deokseok Seo. "Defect Index of Timberwork in House, Korea." Forests 12, no. 7 (July 8, 2021): 896. http://dx.doi.org/10.3390/f12070896.
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Wood is a material that is familiar to humans and environment-friendly, and it is used widely as a building material. However, as the dispute over housing defects have increased in Korea, various defects have occurred in timberwork and have become disputes. Notwithstanding, efforts to analyze defects in timberwork systematically to reasonably solve the problem are lacking. In this study, defects in timberwork from housing complexes in Korea were standardized, and critical defects were selected to suggest a method as a management standard. The standard for defects includes time, types of facility work, location and subject, and defect phenomenon. The defect time is categorized into before handover and after handover, whereas facility work is divided into woodwork, door and window work, finishing work, and miscellaneous work. Location and subject are categorized into 13 areas, such as ceiling, floor, and door, and phenomena concerned are of 14 types, including faults and no installation. Therefore, the standardized defect items according to such criteria are classified into a total of 63 types. Ten defect items, whose numbers of defect occurrences per defect and defect repair cost ratio above the average, were selected, including discoloration and breakage of the wooden floor. The repair cost ratio of these defect items accounted for 85.62% of the total repair costs. On the contrary, the repair cost for the defects from the timber work outlined in the Construction Appraisal Practice, a representative defect standard in Korea, was 54.54% of the total. Meanwhile, according to the Defect Judgment Standard, the defect repair cost attributed 45.54% of the total. Therefore, since the 10 defect items proposed in this study can explain the defects in the timberwork compared with other standards, it would be reasonable to designate these 10 defect items as essential defects.
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Kawakita, Shirou, Mitsuru Imaizumi, Shogo Ishizuka, Hajime Shibata, Shigeru Niki, Shuichi Okuda, and Hiroaki Kusawake. "Characterization of Electron-Induced Defects in Cu (In, Ga) Se2 Thin Films by Photoluminescence." MRS Proceedings 1771 (2015): 157–61. http://dx.doi.org/10.1557/opl.2015.405.
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ABSTRACTCIGS thin films were irradiated with 100 or 250 keV electrons to reveal the radiation defect by analyzing PL measurement. The PL intensity decreased due to non-radiative recombination defects induced by electron irradiation. Furthermore, the intensity 0.8 eV peak of the PL spectrum was observed from CIGS films irradiated with 250 eV electrons and is said to correspond to In-antisite defects in CIGS materials. The defects can usually change into InCu-VCu complex defects combined with VCu, since the formation energy of the complex defect is lower than that of each defect. Cu interstitial defects induced by 250 keV electron irradiation would diffuse to VCu of the complex defect, whereupon the complex defect might become an In-antisite defect due to 250 keV electron irradiation.
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Zhang, Zhongli, Can Wang, Xiaowen Hu, and Yushan Ni. "Shape Effect of Surface Defects on Nanohardness by Quasicontinuum Method." Micromachines 11, no. 10 (September 30, 2020): 909. http://dx.doi.org/10.3390/mi11100909.
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Nanoindentation on a platinum thin film with surface defects in a rectangular shape and triangular shape was simulated using the quasicontinuum method to study the shape effect of surface defects on nanohardness. The results show that the nanohardness of thin film with triangular defects is basically larger than those with rectangular defects, which is closely related to the height of the surface defects at the boundary near to the indenter. Moreover, the triangular defect might have an enhancement effect on nanohardness by a certain size of the defects and the boundary orientation of the defect, where such an enhancement effect increases as the defect grows. Furthermore, the nanohardness decreases when the defect is folded from wide to narrow in the same atom cavity, and particularly expresses a more obvious drop when the height of the defects increases. In addition, larger sizes of the rectangular defect induce more reduction in nanohardness, while the nanohardness of the triangular surface defect is sensitive to the periodic arrangement of atoms changed by the boundary orientation of the defect, which is well explained and demonstrated by the calculation formula theory of necessary load for dislocation emission.
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Prasmana, Muhammad Farid, Deny Andesta, and Hidayat Hidayat. "Analysis of the Causes of Defects in the Timber Production Process Using the FMEA (Failure Mode Effect Analysis) Method Approach at PT. KQW." Jurnal Sains dan Teknologi Industri 20, no. 2 (February 16, 2023): 639. http://dx.doi.org/10.24014/sitekin.v20i2.21837.
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PT. KQW is related to quality. Some problems occur during the production process and product results, which are associated with the level of defects in the production process. From historical production data for April 2022 – June 2022, glulam wood products contribute the most defects, both congenital physical defects of the material itself and during the production process. This study aims to identify the level of defects in wood products, determine the factors that cause defects in wood products, and determine the efforts made to reduce the level of damage to wood products. The formulation of the problem in this study is how to control the damage/defects of wood products faced by PT. KQW. This research method uses FMEA. This research resulted in defects in the production process of glulam wood cracks, holes and breaks. The highest types of defect are hollow wood. Identification of the causes of every kind of defect, the order of the highest RPN value for each NG defect. There are 3 solution recommendations based on the highest RPN value for each defect. For cracked wood defects, the highest RPN is because the workers are less thorough (100). Then for hollow wood defects, the highest RPN is due to poor raw materials (147). The highest RPN for broken wood defects is due to less engine pressure (224). Keywords:FMEA, Timber Production Process, RPN, Defect, Failure
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Park, Jungeun, Yongwoon Cha, Hamad Al Jassmi, Sangwon Han, and Chang-taek Hyun. "Identification of Defect Generation Rules among Defects in Construction Projects Using Association Rule Mining." Sustainability 12, no. 9 (May 9, 2020): 3875. http://dx.doi.org/10.3390/su12093875.
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This study aims to identify the defect generation rules between defects, to support effective defect prevention at construction sites. Numerous studies have been performed to identify the relations between defect causes, to prevent defects in construction projects. However, identifying the inter-causal pattern does not yet guarantee an ultimate grasp of what constitutes proper defect mitigation strategies, unless the underlying defect-to-defect generation rules are thoroughly understood too. Specifically, if a defect generated in a work process is ignored without taking necessary corrective action, then additional defects could be generated in its following works as well. Thus, to minimize defect generation, this study analyzes the defects in the sequence of a construction work. To achieve this, the authors collected 9054 defect data, and association rule mining is used to analyze the rules between the defects. Consequently, 216 rules are identified, and 152 rules are classified into 3 categories along with 4 experts (71 expected rules, 22 unexpected but explainable rules, and 59 unexpected and unexplainable rules). The generation rules between the defects identified in this study are expected to be used to regularize various defect types to determine those that require priority management.
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Widyawati, Fauzi, and Lino Marano. "IDENTIFIKASI CACAT LASAN FCAW PADA FONDASI MESIN KAPAL MENGGUNAKAN METODE ULTRASONIC TESTING." Jurnal TAMBORA 5, no. 2 (July 21, 2021): 53–58. http://dx.doi.org/10.36761/jt.v5i2.1124.
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Ultrasonic testing is one of the non-destructive inspection methods for welding results. The ultrasonic testing method has several advantages, namely it can be used to analyze the position of the defect in the object, both the depth of the defect and the dimensions of the defect, and it is an environmentally friendly method. Physical defects that are in solid objects of course cannot be known from direct vision so it is necessary to carry out an inspection of an object to see whether or not there are defects that occur in solid objects. Ultrasonic testing of the results of FCAW welding on the foundation of the ship's engine. FCAW welding is applied to the foundation with two types of welding positions, namely the overhead position coded P1 and the horizontal position coded P2. The test was carried out using a wave frequency of 4 MHz and using a 0° probe for analysis of defects in the area around the weld metal and a 70° probe for analysis of the weld metal. The tests were carried out using the ASME section V and ASTM E164 standards as the standard for determining defects. The test results at the P1 welding position found two types of defects, namely incomplete fusion defects with five welding points with the longest defect length of 40mm and porosity defects with two points with the longest defect length of 30mm. While the results of ultrasonic testing at the P2 welding position found two types of defects, namely slag inclusion defects with a defect length of 35mm and incomplete penetration defects with a defect length of 20 mm. The conclusion of ultrasonic testing is that the difference in welding positions is that the welding position greatly affects the quality of the welding results. The defects resulting from the welding position also vary.
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Ria Nova, Sukman Tulus Putra, Siti Nurmaini, and Radiyati Umi Partan. "Cardiac Septal Defects in Children: Hemodynamics, Clinical Manifestations and Detection." Bioscientia Medicina : Journal of Biomedicine and Translational Research 5, no. 6 (August 9, 2021): 608–13. http://dx.doi.org/10.32539/bsm.v5i6.393.
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Cardiac septal defect in children is one of the congenital heart defects characterized by atrial septal defects (ASD), ventricular septal defects (VSD) and defects in both atrial and ventricular septum (AVSD). The hemodynamic changes that occur are caused by a left to the right shunt. Differences in location, size of the defect and pulmonary vascular resistance make hemodynamic differences and clinical manifestations between the three types of cardiac septal defects. Detection of cardiac septal defects can be done by clinical examination by listening to the characteristic heart sounds and murmurs for each defect. However, clinical examination alone is often still difficult to determine the type of cardiac septal defect so that several supporting examinations such as photothorax, ECG, echocardiogram and cardiac catheterization need to be done to help establish the diagnosis.
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BAJNOK, Z., and A. GEORGE. "FROM DEFECTS TO BOUNDARIES." International Journal of Modern Physics A 21, no. 05 (February 20, 2006): 1063–77. http://dx.doi.org/10.1142/s0217751x06025262.
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In this paper we describe how relativistic field theories containing defects are equivalent to a class of boundary field theories. As a consequence previously derived results for boundaries can be directly applied to defects, these results include reduction formulas, the Coleman–Thun mechanism and Cutcosky rules. For integrable theories the defect crossing unitarity equation can be derived and defect operator found. For a generic purely transmitting impurity we use the boundary bootstrap method to obtain solutions of the defect Yang–Baxter equation. The groundstate energy on the strip with defects is also calculated.
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BERRY, B. W., and E. C. GREEN. "Inspection Systems and Mechanical Removal Systems for Bone and Cartilage Particles in Ground Beef Patties." Journal of Food Protection 51, no. 5 (May 1, 1988): 369–72. http://dx.doi.org/10.4315/0362-028x-51.5.369.
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Ground beef patties were processed from boneless beef which was subjected to two different inspection systems for bone and cartilage defects. One system permitted a higher (“high”) level of defects (USDA Food Safety and Inspection Service, Meat and Poultry Inspection Requirements), while the other system (USDA PP-B-2120 Federal Purchasing Specification) permitted only a lower (“low”) level of defects. Before formation into patties, the ground beef was subjected to three processing systems for defect removal (none, Weiler Bone Collector System, Speco Spiral Groove Plate System). A sensory approach (teeth and tongue) for detecting defects with cooked patty samples revealed more bone and cartilage defects in the “high” than the “low” formulation regardless of defect removal system. While the defect removal systems reduced the levels of detected defects in the “high” formulation, neither system produced patties with defect levels achieved through inspection procedures required to produce “low” levels of these defects. However, it appears that much of the bone remaining as a defect in boneless beef is reduced in size during grinding so as to be undetectable by sensory approaches.
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Alabi, Olumuyiwa Michael, Farrah Azwanee Aminuddin, Mohd Saidin Misnan, and Nur Emma Mustaffa. "Construction Defects and their Classifications in the Construction Phase of Building Projects – A Review." International Journal of Research and Innovation in Social Science VIII, no. II (2024): 2407–19. http://dx.doi.org/10.47772/ijriss.2024.802172.
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Construction defects are a common issue faced by buildings, and they can occur at any point during the building’s lifespan. The construction industry often considers construction defects as the top issue. However, accurately identifying the type of construction defects can be challenging, which makes it difficult to determine their causes and potential mitigation strategies. Several studies have been conducted to identify the various types of construction defects, and this review aims to consolidate and examine the categories of construction defects that occur mostly at the construction stage of building projects to improve the accuracy of detecting their causes and ensuring effective mitigating techniques. Based on the examination and descriptive analysis of previously published research, this review identifies several defect classifications based on; defect nature, defect occurrence time, defect functionality, and defect based on the building process. Classifying construction defects will help construction stakeholders identify potential causes of construction defects at the construction stage and offer preventive strategies during the design and construction stages, which may eventually lead to a reduction in the time and cost of major repairs during the occupancy stage.
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An, Ning, Xunwen Su, Dongmei Zhu, and Mileta M. Tomovic. "Influence of Defects on In-Plane Dynamic Properties of Hexagonal Ligament Chiral Structures." Sustainability 14, no. 18 (September 12, 2022): 11432. http://dx.doi.org/10.3390/su141811432.
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Although the six-ligament chiral structure has many unique properties, due to its special structure, the stress concentration is prone to defects. In addition, additive manufacturing is also prone to defects. This paper studies the effect of defects, which is helpful for the better application of the six-ligament chiral structure. Several new six-ligament chiral structures with random and concentrated defects were designed to explore the effects of the defects on the in-plane dynamic properties. The structures were studied with the finite element ANSYS/LSDYNA numerical simulation and experimental methods. According to the defect-free six-ligament chiral structures exhibiting different deformation modes at different impact velocities, the effects of the defect rate and type (concentrated and random defects) on the six-ligament chiral structure, the in-plane impact deformation mode and energy absorption characteristics are discussed. The research results show that the defect rate and type reduce the energy absorption characteristics of the chiral structure to varying degrees, and the impact deformation mode also changes under medium- and low-speed impact. With the increase in speed, the influence of the defects on the deformation mode weakens. Moreover, the effects of the concentrated and random defects on the platform stress are different. When the defect rate is low, the effect of the random defects is more significant, and as the defect rate increases, the effect of the concentrated defects is more obvious. The study can provide guidance for structural design, predict the failure form of structures containing defects when they are impacted, and realize material recycling.
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Yahya Aji Setiawan and Ari Zaqi Alfaritsy. "Analisa Pengendalian Kualitas Produk Tauge Dengan Metode Six Sigma Di CV. Berkah Kecambah Tauge Aling." Jurnal Teknik Mesin, Industri, Elektro dan Informatika 2, no. 2 (June 14, 2023): 222–35. http://dx.doi.org/10.55606/jtmei.v2i2.1893.
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CV Berkah Kecambah Tauge Aling is a company engaged in the field of food or vegetable bean sprouts made from green beans. In the production of CV Berkah Kecambah Tauge Aling there was a product defect in January 2023 which occurred, namely the result of the defect rate which was known to have the highest number of defects in the yellow color defect of 1818 packages, with a defect percentage of 58.3%. Then the Bad Smell defects with a total of 879 defects, a percentage of defects obtained by 28.2%, the type of defective packaging torn with a total of 423 defects, a percentage of defects of 13.6%. it is known that the diagram (p-chart) with the type of product defect still has 13 points exceeding the upper control limit or UCL and there are 12 points exceeding the lower control limit or LCL with a proportion of 0.148. Judging from the results of DPMO calculations and Sigma Levels, an average DPMO of 49619 is obtained, so that if there is a product defect of 49619 out of 1,000,000 opportunities in the Sprouts production process at CV. The Blessing of Aling Bean Sprouts. In the FMEA diagram to find out the factors and RPN values that result in product defects including human factors, machines, materials, methods, and the environment, the results of the FMEA analysis cause the biggest defects, namely yellowing defects with an RPN value of 810.
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Huh, Sang Moo, and Woo-Je Kim. "The Derivation of Defect Priorities and Core Defects through Impact Relationship Analysis between Embedded Software Defects." Applied Sciences 10, no. 19 (October 4, 2020): 6946. http://dx.doi.org/10.3390/app10196946.
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As embedded software is closely related to hardware equipment, any defect in embedded software can lead to major accidents. Thus, all defects must be collected, classified, and tested based on their severity. In the pure software field, a method of deriving core defects already exists, enabling the collection and classification of all possible defects. However, in the embedded software field, studies that have collected and categorized relevant defects into an integrated perspective are scarce, and none of them have identified core defects. Therefore, the present study collected embedded software defects worldwide and identified 12 types of embedded software defect classifications through iterative consensus processes with embedded software experts. The impact relation map of the defects was drawn using the decision-making trial and evaluation laboratory (DEMATEL) method, which analyzes the influence relationship between elements. As a result of analyzing the impact relation map, the following core embedded software defects were derived: hardware interrupt, external interface, timing error, device error, and task management. All defects can be tested using this defect classification. Moreover, knowing the correct test order of all defects can eliminate critical defects and improve the reliability of embedded systems.
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Yoshino, M., Y. Shinzato, and Masahiko Morinaga. "Energetics of Native Defects in Al2O3 and SiO2." Materials Science Forum 449-452 (March 2004): 713–16. http://dx.doi.org/10.4028/www.scientific.net/msf.449-452.713.
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Formation energies of various defects in Al2O3and SiO2are calculated by using the plane-wave pseudopotential method. Also, the formation energies of Schottky defects and Frenkel defects are evaluated on the basis of these calculations. It is shown that formation energies of these defects are higher in SiO2than in Al2O3. In other words, less defects are formed in SiO2than in Al2O3. It is also found that the principal defect is the cation Frenkel defect in Al2O3but the anion Frenkel defect in SiO2. These results agree with the experimental results that Al ions diffuse preferably in Al2O3but oxygen ions diffuse in SiO2at high temperatures.
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Lupo, Philip J., Natalie P. Archer, Rachel D. Harris, Lisa K. Marengo, Jeremy M. Schraw, Adrienne T. Hoyt, Susan Tanksley, et al. "Newborn screening analytes and structural birth defects among 27,000 newborns." PLOS ONE 19, no. 7 (July 5, 2024): e0304238. http://dx.doi.org/10.1371/journal.pone.0304238.
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Background Emerging evidence suggests newborn screening analytes may yield insights into the etiologies of birth defects, yet no effort has evaluated associations between a range of newborn screening analytes and birth defects. Methods This population-based study pooled statewide data on birth defects, birth certificates, and newborn screening analytes from Texas occurring between January 1, 2007 and December 31, 2009. Associations between a panel of thirty-six newborn screening analytes, collected by the statewide Texas Newborn Screening Program, and the presence of a birth defect, defined as at least one of 39 birth defects diagnoses recorded by the Texas Birth Defects Registry, were assessed using regression analysis. Findings Of the 27,643 births identified, 20,205 had at least one of the 39 birth defects of interest (cases) as identified by the Texas Birth Defects Registry, while 7,438 did not have a birth defect (controls). Among 1,404 analyte-birth defect associations evaluated, 377 were significant in replication analysis. Analytes most consistently associated with birth defects included the phenylalanine/tyrosine ratio (N = 29 birth defects), tyrosine (N = 28 birth defects), and thyroxine (N = 25 birth defects). Birth defects most frequently associated with a range of analytes included gastroschisis (N = 29 analytes), several cardiovascular defects (N = 26 analytes), and spina bifida (N = 23 analytes). Conclusions Several significant and novel associations were observed between newborn screening analytes and birth defects. While some findings could be consequences of the defects themselves or to the care provided to infants with these defects, these findings could help to elucidate mechanisms underlying the etiology of some birth defects.
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Guo, Ling, Koji Kamei, Kenji Momose, and Hiroshi Osawa. "Evaluation and Reduction of Epitaxial Wafer Defects Resulting from Carbon-Inclusion Defects in 4H-SiC Substrate." Materials Science Forum 897 (May 2017): 39–42. http://dx.doi.org/10.4028/www.scientific.net/msf.897.39.
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In this study, we investigated the epitaxial surface defects resulting from the carbon-inclusion defects in 4H-SiC substrate. Most carbon-inclusion defects developed into one of three types of epitaxial surface defects under normal epitaxial growth conditions. Among them, we found a regular hexagonal pit by high-resolution microscopy, which we regarded as a large-pit defect, and which had an adverse impact on the reverse electrical characteristics of Schottky barrier diodes. Conversion of a carbon-inclusion defect to a large-pit defect or a triangular defect could be reduced by reducing the C/Si ratio.
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Naumenko, E. A., O. V. Rozhkova, and I. A. Kovaleva. "Comprehensive study of characteristic signs of defects detected during magnetic powder control at the final stage of production of seamless hot‑rolled pipes." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 1 (March 13, 2023): 69–72. http://dx.doi.org/10.21122/1683-6065-2023-1-69-72.
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Defects on the outer surface of seamless hot‑rolled steel pipes are formed both as a result of the defects’ transformation in the surface and macrostructure of the initial workpiece, and due to non‑compliance with the rolling technology. Timely detection of defects and elimination of the causes of their formation, allows you to get high‑quality products with high operational reliability. Detection of violations of technology, control of the technological process, carrying out metallographic studies allow classifying defects and establishing the nature and causes of their formation.The article presents the results of a metallographic study of a defect on the outer surface of a hot‑rolled seamless pipe. The genetic and morphological signs of the defect were determined. Descriptions of the appearance of the defect, the microstructure in the defect zone are given. A comparative analysis of the defect detected during magnetic powder control with defects on experimental pipe blanks with artificial defects was carried out. Based on the data obtained, the causes of the defect formation are determined, its classification is given.
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Milion, Raphael N., Thaís da C. L. Alves, José Carlos Paliari, and Luisa H. B. Liboni. "CBA-Based Evaluation Method of the Impact of Defects in Residential Buildings: Assessing Risks towards Making Sustainable Decisions on Continuous Improvement Activities." Sustainability 13, no. 12 (June 9, 2021): 6597. http://dx.doi.org/10.3390/su13126597.
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Evaluating the impact of defects in buildings and ranking the most impactful ones enables construction companies to better choose which paths to take in light of continuous improvement activities to support more sustainable decisions regarding the design and operation of buildings. As a result, the risks of the different choices are more clearly identified while assessing all tangible and intangible aspects of residential building defects in a structured way. Although recent studies on managing construction defects in residential buildings have focused on monetary losses associated with maintenance activities based on the defect’s frequency and severity, these studies do not take into account the levels of customer satisfaction. To address this gap, this paper proposes a novel evaluation method of the impact of defects to support decision-making in managing defect occurrences in residential buildings. The goal is to rank the defects’ impact based on a combination of some critical aspects: frequency of occurrence, financial considerations on repairing such defects, the impact that these defects have on customer satisfaction, and the cost and complexity of preventing and minimizing these defect occurrences through continuous improvement activities. The method consists of a structured set of steps that use data from technical assistance departments and customer satisfaction surveys, where information about the users’ level of satisfaction and the occurrence of defects is available. In this paper, data obtained from a construction company were used to test and validate the proposed method. The method also examines the challenges and barriers associated with the technique and points out that difficulties in acquiring reliable data are a bottleneck for making conscious and sustainable decisions to address construciton defects. Moreover, the case study results highlight essential capabilities needed by companies to correctly assess the impact of defects, such as correctly logging data in a structured database and having skilled personnel to verify defects users might have complained about. The paper ends by proposing a set of guidelines to use the method and stressing that structured methods for decision-making are crucial to analyze construction defects in a structured way while also incorporating the user’s perspective. The proposed method is expected to improve sustainable managerial decisions where economic, environmental, social, and technical risks can be accounted for to enhance the quality of projects from the customer’s perspective. Such analysis can help optimize and prioritize the use of resources and minimize the economic impact of activities on the construction company.
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Liu, Jie, Cangming Liang, Jintao Feng, Anhong Xiao, Hui Zeng, Qujin Wu, and Tonglan Yu. "A Multi-Feature Fusion-Based Automatic Detection Method for High-Severity Defects." Electronics 12, no. 14 (July 14, 2023): 3075. http://dx.doi.org/10.3390/electronics12143075.
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It is crucial to detect high-severity defects, such as memory leaks that can result in system crashes or severe resource depletion, in order to reduce software development costs and ensure software quality and reliability. The primary cause of high-severity defects is usually resource scheduling errors, and in the program source code, these defects have contextual features that require defect context to confirm their existence. In the context of utilizing machine learning methods for defect automatic confirmation, the single-feature label method cannot achieve high-precision defect confirmation results for high-severity defects. Therefore, a multi-feature fusion defect automatic confirmation method is proposed. The label generation method solves the dimensionality disaster problem caused by multi-feature fusion by fusing features with strong correlations, improving the classifier’s performance. This method extracts node features and basic path features from the program dependency graph and designs high-severity contextual defect confirmation labels combined with contextual features. Finally, an optimized Support Vector Machine is used to train the automatic detection model for high-severity defects. This study uses open-source programs to manually implant defects for high-severity defect confirmation verification. The experimental results show that compared with existing methods, this model significantly improves the efficiency of confirming high-severity defects.
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Salemi, Jason L., Jean Paul Tanner, Sara Kennedy, Suzanne Block, Marie Bailey, Jane A. Correia, Sharon M. Watkins, and Russell S. Kirby. "A Comparison of Two Surveillance Strategies for Selected Birth Defects in Florida." Public Health Reports 127, no. 4 (July 2012): 391–400. http://dx.doi.org/10.1177/003335491212700407.
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Objective. We linked data from two independent birth defects surveillance systems with different case-finding methods in an overlapping geographic area to assess Florida's suveillance of birth defects (e.g., neural tube defects, orofacial clefts, gastroschisis/omphalocele, and chromosomal defects), focusing on sensitivity and completeness of ascertainment measures. Methods. Live-born infants identified from each system born during 2003–2006 in a nine-county catchment area with specific birth defects were linked to birth certificates. Using the enhanced surveillance system as a gold standard, we calculated the sensitivity of the Florida Birth Defects Registry (FBDR) for identifying infants. Next, we used capture-recapture models to estimate the completeness of case ascertainment and the prevalence of each birth defect in the catchment area. We used multivariable logistic regression models with backward elimination to estimate adjusted odds ratios and 95% confidence intervals for factors significantly associated with the FBDR's failure to capture infants ultimately identified by enhanced surveillance. Results. The FBDR's sensitivity was 89.3%, and the overall completeness of ascertainment was estimated as 86.6%. Defect-specific sensitivity and completeness of ascertainment varied significantly by defect. The combined defect-specific sensitivity for all malformations under study was 86.6%; completeness of ascertainment ranged from 45.6% for anencephaly to 88.6% for Down syndrome, 87.9% for spina bifida without anencephaly, and 87.0% for orofacial clefts. Conclusions. For the defects under study, the FBDR captured nearly nine of every 10 infants born with selected birth defects. However, the FBDR's ability to identify specific defects was both more limited and defect dependent with widely varying defect-specific sensitivities.
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Zhang, Wei, Zhen Yu Ma, Wen Ge Zhang, Qing Ling Lu, and Xiao Bing Nie. "Correlation Analysis of Software Defects Density and Metrics." Applied Mechanics and Materials 713-715 (January 2015): 2225–28. http://dx.doi.org/10.4028/www.scientific.net/amm.713-715.2225.
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It is very useful for improving software quality if we can find which software metrics are more correlative with software defects or defects density. Based on 33 actual software projects, we analyzed 44 software metrics from application level, file level, class level and function level, and do correlation analysis with the number of software defects and defect density, the results show that software metrics have little correlation with the number of software defects, but are correlative with defect density. Through correlation analysis, we selected five metrics that have larger correlation with defect density, these metrics can be used for improving software quality and predicting software defects density.
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Tri Basuki, Rahmat, and Uly Amrina. "Rahmat Tri Basuki, Uly Amrina." Go-Integratif : Jurnal Teknik Sistem dan Industri 3, no. 02 (November 30, 2022): 87–97. http://dx.doi.org/10.35261/gijtsi.v3i02.6942.
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PT Bumimulia Indah Lestari found defects in the oil bottle packaging products it produces, which include perforated bottles, black spots on bottles, and defects on labels. The type of defect on the bottle label is the highest defect in the period from July to December 2021 compared to other defects. This research is focused on the problem of defects in the inverted label as the dominant defect of the entire defect label. Researchers use the DMAIC method to solve these problems. The improvement resulting from the DMAIC method is the manufacture of a jig tool called Jig Go No Go which aims to reduce the number of defects and increase productivity in bottle products. The implementation of the jig can reduce the defect label as a whole from 5.8% to 3.3% and the sigma value increases from 2.488 to 2.493.
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Putri, Nandita Melati, Narottama Tunjung, and Patricia Marcellina Sadikin. "Closure of meningomyelocele defects using various types of keystone-design perforator island flaps." Archives of Plastic Surgery 48, no. 3 (May 15, 2021): 261–68. http://dx.doi.org/10.5999/aps.2020.01326.
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Background Various methods have been described to close large meningomyelocele defects, but no technique has been proven superior to others. This study presents cases of meningomyelocele defect closure with a keystone-design perforator island flap.Methods A retrospective study was performed on 14 patients with meningomyelocele defects closed using various types of keystone flaps.Results The median age of the patients at surgery was 10.5 days (range, 1–369 days) and the average defect size was 22.5 cm2 (range, 7.1–55.0 cm2). The average operative time for defect closure was 89.6 minutes (range, 45–120 minutes). Type IV bilateral keystone flaps were used for four defects, type IV unilateral flaps for six defects, type IIA flaps for two defects, and type III flaps for two defects.Conclusions All the defects healed completely with no major complications. The keystone-design perforator island flap is a reliable, easy, and fast technique to close large meningomyelocele defects.
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Cao, Zhen, Da-Peng Hao, Gang Tang, Zhi-Peng Xun, and Hui Xia. "Influence of cluster shaped defects on fracture process of fiber bundle." Acta Physica Sinica 70, no. 20 (2021): 204602. http://dx.doi.org/10.7498/aps.70.20210310.
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Defects that exist inside composites have an important effect on the tensile fracture properties of composites. The fiber bundle model is a theoretical model commonly used to study the tensile fracture properties of disorder materials. Existing work on fiber bundle models with single fiber defects shows that after single fiber defects are introduced into the fiber bundle model, the defects have a significant effect on the tensile fracture properties of the model. Since there are more complex microscopic defect structures in actual materials, such as voids, gaps, impurities, dislocations, micro-cracks, etc, it is necessary to build a multi-size defect model. In order to study the defects of different sizes and damage degrees existing in actual materials, the spatial size of the defect, the degree of defect and the distribution of fiber damage levels within the defect and other influencing factors are introduced to construct an extended fiber bundle model with cluster shaped defects. For the model, it is first assumed that the degree of defect of the fiber inside each cluster decays linearly from the center to the outside in two spatial attenuation forms: exponential decay and constant degree of defect. In the fiber bundle model of this cluster-shaped defect, the two most important factors are the number of defects <i>α</i> and the upper limit of defect size <i>β</i>. The numerical simulation method is used to analyze the influence of the number of defects, the upper limit of defect size, and spatial distribution of degree of defective fibers inside defect on the macroscopic mechanical properties and statistical properties of fracture when the model is subjected to quasi-static load borne under the nearest neighbor stress redistribution. Through the simulation analysis, it is found that owing to the overlapping competition mechanism of the defect spatial distribution, when the upper limit <i>β</i> of the defect size is large, the influence of the number of defects on the system load capacity trends to saturation. Since the defect degree of the defect center fiber is proportional to the defect size, with the upper limit <i>β</i> of the defect size increasing, its influence on the load capacity of the model becomes more and more significant. When large size defects exist, even if the number of defects is small, the load bearing performance of the material will be significantly reduced. The spatial distribution function of the damage degree of fiber inside the defect has no substantial influence on the above rules, and only changes the specific value of each fracture property. The simulation analysis results in this paper have certain theoretical significance in improving the mechanical properties of composite materials.
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Li, Zhan, Yun Liu, Tao Wei, Minghao Li, Ziwen Wang, Zhongying Xue, and Xing Wei. "Investigation on the Transformation of B-Defect in As-Grown Czochralski Silicon Crystal during Annealing Process." ECS Journal of Solid State Science and Technology 11, no. 2 (February 1, 2022): 024007. http://dx.doi.org/10.1149/2162-8777/ac53f6.
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When a silicon ingot is grown by the Czochralski method, different defects, such as A-defect (a dislocation loop or dislocation loops cluster), B-defect (widely accepted as an interstitial atoms cluster), COP (crystal originated particle, a void), and grown-in oxygen precipitates will emerge. Nowadays most crystal defects can be characterized directly. However, due to the extremely small size and stress, B-defects can only be indirectly characterized by the formation of oxygen precipitates. What’s more, it is unclear whether B-defects transform into oxygen precipitates directly or B-defects grow and transform into A-defects firstly and further facilitate oxygen precipitation via the dislocation pinning effect. In this work, after implementing an optimized anneal at 900 °C for 3 h and HCl vapor-phase etch at 900 °C for 2 min, nano-scale defects transformed from B-defects are efficiently detected by a surface particle counter. Scanning electron microscope and energy-dispersive X-ray spectroscopy results prove that these nano-scale defects are all oxygen precipitates. This explicit result indicates that B-defects can induce the formation of oxygen precipitates directly rather than relying on the formation of A-defects, which would help to better understand the characteristic of B-defect in relatively low temperature and the transformation process between different defects in silicon ingot.
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Jiang, Yin Fang, Zhen Ning Guo, Yong Qi Yan, and Qin Huang. "Study on Inside and Outside Circumferential Defects of Pipes and Ultrasonic Guided Wave." Advanced Materials Research 460 (February 2012): 411–14. http://dx.doi.org/10.4028/www.scientific.net/amr.460.411.
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The difference between inside circumferential defects and outside circumferential defects was proved using the theory of reflection waves, the course of propagation and reflection from inside circumferential defects and outside circumferential defects in steel pipes was simulated with L(0,2) mode by the numerical simulation program ANSYS, and the curves of the reflection waves were obtained. The investigation indicated that the relationship between reflection coefficient of each kind of circumferential defects and the circumference of the defects was linear; in additional, it was found that the reflection coefficient of outside circumferential defects was a little higher than the reflection coefficient of inside circumferential defects; the difference between inside and outside circumferential defect became more obvious as the thickness of the defect increases. So the results provide a basis for detecting and distinguishing circumferential defects of pipes.
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Amin, Tahsinul, Mehdi Pervez, and Ayesha Najma Nur. "Frequency of Birth Defects in a Tertiary Care Hospital in Bangladesh." Bangladesh Journal of Child Health 44, no. 1 (October 12, 2020): 8–12. http://dx.doi.org/10.3329/bjch.v44i1.49679.
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Background: Birth defects usually present at birth and may cause morbidity and mortality in the newborn. These defects may involve any organ system of the body. Gradually the incidence is rising due to various etiologies. The objective of the study was to find out the frequency, types and etiology of birth defects.
Materials & Methods: This cross-sectional study was done in a tertiary care hospital in Bangladesh. In this study, 100 neonates with birth defects were enrolled, thoroughly examined, investigated and evaluated. Then collected data were analyzed.
Results: The frequency of birth defects in this study was 1.54%. The most frequent birth defect was club foot deformity i.e. 11% and the most frequently involved organ system was cardiovascular system i.e. 28%. Among the birth defects 78% were major and only 22% were minor. Among those children with birth defect mortality was 17%; 41% were referred to advanced center and 42% were improved and discharged. In some of the cases with birth defect chromosomal anomaly, congenital infection (TORCH), maternal diabetes was found as causing factor.
Conclusion: The frequency of birth defects was found 1.54% and most of the birth defects were major defect. Club foot deformity was found as the most common birth defect.
Bangladesh J Child Health 2020; VOL 44 (1) :8-12
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Liu, Jinxin, and Kexin Li. "Intelligent Metal Welding Defect Detection Model on Improved FAST-PNN." Coatings 12, no. 10 (October 11, 2022): 1523. http://dx.doi.org/10.3390/coatings12101523.
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In order to solve the problem of accurate and efficient detection of welding defects in the process of batch welding of metal parts, an improved Probabilistic Neural Network (PNN) algorithm was proposed to build an automatic identification model of welding defects. Combined with the characteristics of the PNN model, the structure and algorithm flow of the FAST-PNN algorithm model are proposed. Extraction of welding defect image texture features of metal welded parts by a Gray Level Co-occurrence Matrix (GLCM) screens out the characteristic indicators that can effectively characterize welding defects. Weld defect texture features are used as input to build a defect classification model with FAST-PNN, for accurate and efficient classification of welding defects. The results show that the improved FAST-PNN model can effectively identify the types of welding defects such as burn-through, pores and cracks, etc. The classification recognition accuracy and recognition efficiency have been significantly improved. The proposed defect welding identification method can accurately and effectively identify the damage types of welding defects based on a small number of defect sample images. Welding defects can be quickly identified and classified by simply collecting weld images, which helps to solve the problem of intelligent, high-precision, fast real-time online detection of welding defects in modern metal structures; it provides corresponding evidence for formulating response strategies, with a certain theoretical basis and numerical reference.
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Zhao, Jun, Lulu Yin, Jing Chen, Yizhou Yang, Yinhong Zhu, and Bai Yang. "Analysis of the Mechanical Performance of Sleeve Considering the Different Distributions of Grouting Defects." Buildings 13, no. 11 (November 16, 2023): 2873. http://dx.doi.org/10.3390/buildings13112873.
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To study the influence of grouting defects on the mechanical properties of grouting sleeves, 49 groups of specimens with different specifications were made considering the length and location of defects, monotonic axial tension tests were carried out to study the influence of grouting defects on its failure process, failure mode, load-displacement curve, bearing capacity and other mechanical properties, and the influence law of different distribution defects on the grouting sleeve was analyzed. This research shows that there are two forms of sleeve failure: steel bar fracture failure and steel bar pullout failure. The bearing capacity of specimens with a defect length of 2D and 3D varies with the defect type. The ultimate displacement of specimens with a defect length of 2D varies with the defect type. The ultimate displacement of specimens with a defect length of 3D increases with the increase in bearing capacity. By moving defects, it is found that if there is a vertical overlap of defects in the upper or middle part of the specimen, the bearing capacity of the specimen will be greatly affected.
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Zhao, Xiaoji, Yanlu Li, and Xian Zhao. "Density Functional Theory Study of the Point Defects on KDP (100) and (101) Surfaces." Molecules 27, no. 24 (December 17, 2022): 9014. http://dx.doi.org/10.3390/molecules27249014.
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Surface defects are usually associated with the formation of other forms of expansion defects in crystals, which have an impact on the crystals’ growth quality and optical properties. Thereby, the structure, stability, and electronic structure of the hydrogen and oxygen vacancy defects (VH and VO) on the (100) and (101) growth surfaces of KDP crystals were studied by using density functional theory. The effects of acidic and alkaline environments on the structure and properties of surface defects were also discussed. It has been found that the considered vacancy defects have different properties on the (100) and (101) surfaces, especially those that have been reported in the bulk KDP crystals. The (100) surface has a strong tolerance for surface VH and VO defects, while the VO defect causes a large lattice relaxation on the (101) surface and introduces a deep defect level in the band gap, which damages the optical properties of KDP crystals. In addition, the results show that the acidic environment is conducive to the repair of the VH defects on the surface and can eliminate the defect states introduced by the surface VO defects, which is conducive to improving the quality of the crystal surface and reducing the defect density. Our study opens up a new way to understand the structure and properties of surface defects in KDP crystals, which are different from the bulk phase, and also provides a theoretical basis for experimentally regulating the surface defects in KDP crystals through an acidic environment.
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Jin, Youpeng, Aiyun Wang, Yulin Wang, Yuemei Wang, Wei Wang, and Xiaoming Hou. "Natural history of prenatal ventricular septal defects and their association with foetal echocardiographic features." Cardiology in the Young 22, no. 3 (November 4, 2011): 323–26. http://dx.doi.org/10.1017/s1047951111001521.
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AbstractObjectiveTo describe the evolution of ventricular septal defects in infants from intra-uterine diagnosis to the age of 3 years or until documented echocardiographic closure of the defect, as well as any relationship between closure rate, time and foetal echocardiographic features.MethodsBetween January, 2004 and December, 2006, 268 cases of congenital cardiac defect were detected in 14,993 pregnancies referred to our hospital for routine foetal echocardiography; of these cases, 125 had isolated ventricular septal defect. The mothers were scheduled for regular ultrasonography every 2 weeks from diagnosis until the ventricular septal defect closed or 3 years postnatally.ResultsOf the 125 cases of ventricular septal defects, the pregnancy was terminated in 25, four resulted in death, two defects closed spontaneously in utero, 55 closed at a mean age of 13.7 months postnatally, 17 were treated with surgery, nine remained unclosed, and 13 cases were lost to follow-up. Only 7.7% of muscular ventricular septal defects remained patent as compared with 35.7% of perimembranous ventricular septal defects (p is less than 0.01). Muscular ventricular septal defects closed earlier than perimembranous ventricular septal defects. All the ventricular septal defects less than or equal to 3 millimetres closed, whereas only 79.5% of the defects greater than 3 millimetres closed before the age of 3 years; 60.9% of the defects less than or equal to 3 millimetres closed before the age of 1 year as compared with 41.7% of the defects greater than 3 millimetres. The velocity of right-to-left flow was negatively correlated with closure rate but not related to closure period.ConclusionVentricular septal defects can close in utero or during the postnatal period, and both the size and site play a role in the natural history, with small and muscular ventricular septal defects having a high closure rate and early closure.
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Mezhoud, Cherifa, Ali Berreksi, Abdelhamid Bedjou, and Bert Bosseler. "Prioritization of maintenance work in wastewater networks using decision support methods." Journal of Water, Sanitation and Hygiene for Development 12, no. 2 (January 17, 2022): 186–99. http://dx.doi.org/10.2166/washdev.2022.165.
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Abstract Sanitation networks are extremely important infrastructures because of their function and capital-intensive nature. Indeed, network knowledge is essential for a reliable prioritization of maintenance work. In this context, this research work is interested in the evaluation and the prioritization of the defects of an Urban Sanitation Network (USN), taking into account the criteria of the FMECA method (failure mode and effects and criticality analysis), namely the probability of defect occurrence (P), the defect's detectability (D) and the defect impact (I). The methodology adopted is based on the combination of three methods: the analytic hierarchy process (AHP) used to assign weights to FMECA criteria, the weighted product model (WPM) method to determine the defect impact and the technique for order of preference by similarity to ideal solution method (TOPSIS) to classify sanitation defects in descending order in order to prioritize maintenance interventions. A case study of a real sewerage project in the city of Bejaia (Algeria) essentially composed of eight non-visitable sections evaluated from television inspections was used to illustrate and validate the proposed model. The results show that the following defects: collapse, chemical attack, pipe surface degradation, and abrasion are considered as critical defects requiring immediate intervention due to their significant influence on the section performance rate, which is between 0%≤P<50%, contrary to the other studied parameters which present a performance rate of P>50%. These results prove that the combination of AHP–WPM–TOPSIS methods can be used to design an effective management and maintenance system.
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Nourian-Avval, Ahmad, and Ali Fatemi. "Characterization and Analysis of Porosities in High Pressure Die Cast Aluminum by Using Metallography, X-Ray Radiography, and Micro-Computed Tomography." Materials 13, no. 14 (July 9, 2020): 3068. http://dx.doi.org/10.3390/ma13143068.
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Mechanical performance of cast aluminum alloys is strongly affected by the defects formed during solidification. For example, fractography studies of the fatigue specimens have shown that fatigue failure in aluminum castings containing defects is almost always initiated from defects, among which pores are most detrimental. However, elimination of these pores is neither always economically nor technically possible. This work characterizes defects in high pressure die cast aluminum alloy as an illustrative material, but the methods used can be applicable to other types of castings and defects. The defects were evaluated using metallography as well as micro-computed tomography techniques. The variability of defects between the specimens of two sizes as well as different porosity levels are studied statistically. The distributions of defects based on location within the specimens are also analyzed. Moreover, the maximum defect size within the specimens are estimated using extreme value statistics, which can be used as an input to fatigue life prediction models. Extreme value statistics is applied on both 2D and 3D defect data. The accuracy of each approach is verified by comparing the estimated maximum defect size within the specimens with the maximum observed defects on fracture surfaces of fatigue specimens.
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Lee, Y. K., Young Pyo Kim, M. W. Moon, Woong Ho Bang, Kyu Hwan Oh, and Woo Sik Kim. "The Prediction of Failure Pressure of Gas Pipeline with Multi Corroded Region." Materials Science Forum 475-479 (January 2005): 3323–26. http://dx.doi.org/10.4028/www.scientific.net/msf.475-479.3323.
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The failure assessment for the defects in multiple corroded region has been considered with the real-size pipeline burst tests and the associated Finite Element Method. The corroded gas pipeline made of X65 steel with various types of artificially machined pits has been used for a number of series of burst tests on gas pipeline. The failure pressures for the designed multiple corroded defect on gas pipelines have been measured by using in-situ burst testing and classified with respect to each designed defect sizes - length, width and depth - and distance between defects. The result from the experiments has been modeled and compared with Finite Element Method. As the result of FEM simulation, the failure pressure in multiple defects is lower than that in single defect, and closer to failure pressure in single defect of total length of defects in multiple defects as the distance between each defect is closer.
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Peng, Peiran, Ying Wang, Can Hao, Zhizhong Zhu, Tong Liu, and Weihu Zhou. "Automatic Fabric Defect Detection Method Using PRAN-Net." Applied Sciences 10, no. 23 (November 26, 2020): 8434. http://dx.doi.org/10.3390/app10238434.
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Fabric defect detection is very important in the textile quality process. Current deep learning algorithms are not effective in detecting tiny and extreme aspect ratio fabric defects. In this paper, we proposed a strong detection method, Priori Anchor Convolutional Neural Network (PRAN-Net), for fabric defect detection to improve the detection and location accuracy of fabric defects and decrease the inspection time. First, we used Feature Pyramid Network (FPN) by selected multi-scale feature maps to reserve more detailed information of tiny defects. Secondly, we proposed a trick to generate sparse priori anchors based on fabric defects ground truth boxes instead of fixed anchors to locate extreme defects more accurately and efficiently. Finally, a classification network is used to classify and refine the position of the fabric defects. The method was validated on two self-made fabric datasets. Experimental results indicate that our method significantly improved the accuracy and efficiency of detecting fabric defects and is more suitable to the automatic fabric defect detection.