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A lost-in-space star identification algorithm based on a one-dimensional Convolutional Neural Network (1D CNN) is proposed. The lost-in-space star identification aims to identify stars observed with corresponding catalog stars when there is no prior attitude information. With the help of neural networks, the robustness and the speed of the star identification are improved greatly. In this paper, a modified log-Polar mapping is used to constructed rotation-invariant star patterns. Then a 1D CNN is utilized to classify the star patterns associated with guide stars. In the 1D CNN model, a global average pooling layer is used to replace fully-connected layers to reduce the number of parameters and the risk of overfitting. Experiments show that the proposed algorithm is highly robust to position noise, magnitude noise, and false stars. The identification accuracy is 98.1% with 5 pixels position noise, 97.4% with 5 false stars, and 97.7% with 0.5 Mv magnitude noise, respectively, which is significantly higher than the identification rate of the pyramid, optimized grid and modified log-polar algorithms. Moreover, the proposed algorithm guarantees a reliable star identification under dynamic conditions. The identification accuracy is 82.1% with angular velocity of 10 degrees per second. Furthermore, its identification time is as short as 32.7 miliseconds and the memory required is about 1920 kilobytes. The algorithm proposed is suitable for current embedded systems.

The recent advent in the multimedia tools and their wide availability lead to a critical issue of protecting the privacy of multimedia content in cyber-physical security of industrial set-ups predominantly in surveillance. This paper emphasizes on preserving the authenticity of multimedia content in industrial surveillance by presenting an efficient hashing technique based on normalization, log-polar mapping and singular value decomposition. The core idea is to produce a hash sequence from the key-frames extracted from industrial surveillance video providing better robustness and security. For this purpose, the input key-frame is first normalized to make it resilient against the affine distortions. Log-polar mapping is then applied on the normalized key-frame, and an initial hash sequence is generated using the properties of singular value decomposition. At last, a randomization process is applied to construct the final hash sequence. Extensive experiments on various key-frames are conducted to demonstrate the robustness of the proposed framework against various intentional/unintentional distortions.

The recognition, decoding and tracking of vortex patterns is of increasing importance in many fields, ranging from the astronomical observations of distant galaxies to turbulence phenomena in liquids or gases. Currently, coherent light beams with orbital angular momentum (OAM) are of particular interest for optical communication, metrology, micro-machining or particle manipulation. One common task is to identify characteristic spiral patterns in pixelated intensity maps at real-world signal-to-noise ratios. A recently introduced combination of polar mapping and Fast Fourier Transform (FFT) was extended to novel sampling configurations and applied to the quantitative analysis of the spiral interference patterns of OAM beams. It is demonstrated that specific information on topological parameters in non-uniform arrays of OAM beams can be obtained from significantly distorted and noisy intensity maps by extracting one- or two-dimensional angular frequency spectra from single or concatenated circular cuts in either spatially fixed or scanning mode. The method also enables the evaluation of the quality of beam shaping and optical transmission. Results of proof-of-principle experiments are presented, resolution limits are discussed, and the potential for applications is addressed.

This paper investigates the high stress concentration zone for fatigue crack estimation on the damaged tower crane pulley by measuring magnetic flux leakage. Fatigue crack analysis is important to prevent any component failure that could harm workers. Precautions must be taken to locate the possibilities of failure region on a tower crane pulley. For this study, magnetic flux leakage signals were measured using metal magnetic memory method to predict the high stress concentration area. The respective signals were collected for 30 scanning lines on the tower crane pulley surface and merged to provide a better graphical view to estimate the irregularities or defect location more accurately. The metal magnetic memory polar mapping was compared with the finite element analysis results for validation. The highest von Mises stress value obtained through the finite element analysis is 167.84 MPa using three-dimensional tetrahedral mesh for the size of 3 mm. Thus, the comparison revealed the similarities of stress concentration zone between the results and will produce more accurate prediction for the actual irregularity or defect location on the failed component.

The purpose of this paper is to define bipolar soft generalized compact sets and bipolar soft generalized compact spaces. The structures ofg~~-centralized bipolar soft generalized closed sets collection in a bipolar soft generalized compact space are given. Moreover, some main properties of bipolar soft generalized compactness are discussed and their relationships are studied. The concept of a bipolar soft generalized compactness is introduced and it investigates under what condition a bipolar soft generalized topological space forms a bipolar soft generalized compact space. The relation between bipolar soft generalized compact space and soft generalized compact space is proposed. Furthermore, some further properties of bipolar soft mappings, such as bipolar soft composite mappings, are presented and some of their characteristics are explained. Additionally, novel classes of bipolar soft mapping such as bipolar soft generalized continuous, bipolar soft generalized open, and bipolar soft generalized closed mappings are defined. Finally, some results and counterexamples are obtained.

Multiple personality disorder (MPD) or dissociative identity disorder is the mental disease in which one can observe the existence of two or more than two personalities in a single person. We define the controversies nearby the diagnosis of MPD with its associated mental disorders. We discuss the various symptoms of MPD, dissociative amnesia, depersonalization or derealization disorder, and major depression disorder. After this exploration, we perceive that these disorders enclose parallel symptoms and it is difficult to identify the accurate type of disorder with its severeness. Since in experimental diagnosis the indeterminacy and falsity parts are often neglected. Due to this problem, we cannot see the accuracy in the patient’s improvement record and cannot predict the duration of treatment. To eradicate these boundaries, we present the m-polar neutrosophic soft set (MPNSS) and m-polar neutrosophic soft mapping (MPNS-mapping) with its inverse mapping. These notions are proficient and valuable to diagnose the disorder appropriately by connecting it with the mathematical modeling. The connection of m-polar neutrosophic set (MPNS) with the soft set characterizes a relation among patients, symptoms, and treatments which decreases the complexity of the case study. We build a chart based on a fuzzy interval [0, 1] to range the types of disorders. We establish an algorithm based on MPNS-mapping to identify the disease appropriately and to select the finest treatment for the corresponding disease of every patient. At last, we introduce the generalized MPNS-mapping which will helps a doctor to save the patient’s improvement record and to predict the period of treatment until the disease is cured.

Traditionally, in machine vision images are represented using cartesian coordinates with uniform sampling along the axes. On the contrary, biological vision systems represent images using polar coordinates with non-uniform sampling. For various advantages provided by space-variant representations many researchers are interested in space-variant computer vision. In this direction the current work proposes a novel and simple space variant representation of images. The proposed representation is compared with the classical log-polar mapping. The log-polar representation is motivated by biological vision having the characteristic of higher resolution at the fovea and reduced resolution at the periphery. On the contrary to the log-polar, the proposed new representation has higher resolution at the periphery and lower resolution at the fovea. Our proposal is proved to be a better representation in navigational scenarios such as driver assistance systems and robotics. The experimental results involve analysis of optical flow fields computed on both proposed and log-polar representations. Additionally, an egomotion estimation application is also shown as an illustrative example. The experimental analysis comprises results from synthetic as well as real sequences.

Log-polar imaging is a kind of foveal, biologically inspired visual representation with advantageous properties in practical applications in computer vision, robotics, and other fields. While the cheapest, most flexible, and most common approach to get log-polar images is to use software-based mappers, this solution entails a cost which prevents certain experiments or applications from being feasible. This may be the case in some real-time (robotic) applications and, in general, when the conversion cost is not affordable for the task at hand. To overcome this drawback and make log-polar imaging more generally available, parallel solutions with affordable modern multi-core architectures have been devised, implemented, and tested in this work. Experimental results reveal that speed-up factors as high as or higher than 10 or 20, depending on the configuration, are possible to get log-polar images from large gray-level or color cartesian images using commodity graphics processors. Remarkable speedups are also reported for current multi-core processors. This noteworthy performance allows visual tasks that would otherwise be unthinkable with sequential implementations to become feasible. Additionally, since three different approaches have been explored and compared in terms of several criteria, different cost-effective choices are advisable depending on different visual task requirements or hardware availability.

Introduction: The term “myocardial bridging” is used to describe an anatomic variant where a band of cardiac muscle overlies a segment of an epicardial coronary artery. It is a highly debated topic, because it can cause conditions such as acute coronary syndrome. Myocardial bridging (MB) can be diagnosed using invasive procedures, but also non-invasive ones, such as Multislice Computed Tomography Angiography (MSCTA).Objectives: A comparative analysis was performed on the patients who were admitted to the clinic with typical angina, ischemic ECG changes and muscular bridging shown on MSCTA, and patients with the same symptoms, but without MB. A sub-study was also undertaken in which the MB site and ischemia revealed by thickening of the myocardial muscle, using 3D Polar Mapping, were compared.Materials and methods: A retrospective study assessed 59 patients with typical angina pectoris, shortness of breath and clinical appearance of an acute coronary syndrome, and for whom MSCTA was carried out. Patients were divided into two groups: Group 1 — patients with MB, and Group 2 — patients without MB. Thirty patients in Group 1 had 3D polar mapping to evaluate the thickness of the myocardial muscle.Results: The mean age of our patients with muscular bridging was 55.51 ± 11.4 years, CI 51.57–59.45 years. Patients without MB had a mean age of 59.17 ± 9.6 years, CI 54.98–63.6 years, p = 0.211. 24.32% of the patients with MB were females and 60.86% from the patients without MB were males, p = 0.040. 40.54% of patients presented with MB in the first segment of the LAD and 15.62% had an MB in the second segment of LAD. In patients with an ischemic site smaller than 2 cm of the MB, the ischemic myocardial area was more pronounced compared to the patients with higher length MB (21.85 ± 6.123% vs. 17.62 ± 5.856%).Conclusions: MSCTA is an important procedure that contributes to the clinical investigations of patients with typical angina and suspected acute coronary syndrome. There is a good positive correlation between the location of the MB and the ischemic segments as shown on 3D CT-based polar maps.

The concept of digital rights management architecture for multimedia will be presented in this paper, with focus on robust digital image watermarking, which is able to undergo geometrical attacks performed against the embedded watermarks. Geometrical attacks are still an open problem for many digital watermarking algorithms used in present time. Most of geometrical attacks can be described by using affine transforms. A new approach to improve robustness against geometrical attacks is presented. The discrete Fourier transform and log-polar mapping are used for watermark embedding and for watermark detection. Some attacks against the embedded watermarks are performed and the results are given. Also two modifications, usage of the proposed method as a synchronization template and implementation for the color images, are presented and experimental results are given too.