COMPARISON OF ANATOMICAL INFORMATION OF COLUMNA VERTEBRAE CERVICAL IN 15 TO 20-DEGREE RIGHT POSTERIOR OBLIQUE PROJECTION

Columna cervical vertebrae are a type of long bone that occurs on the back of the head. One of the radiological examinations most frequently performed in the hospital is the examination of the right posterior oblique projection cervical vertebrae (RPO). However, to see the cervical vertebrae column radiograph that is more optimal for cases of HNP, fractures, fissures, root symdrome. with a variation of the angle of 15 ° and 20 ° cranially. To find out which method is the most informative to display the right posterior oblique (RPO) projection with an angle of 15 ° and 20 ° cranially. This research is a type of quantitative research with statistical expansion. This research uses phantom. The research was conducted at the STIKes Awal Bros Pekanbaru in August 2020. The vertebral column results were used well, namely at an angle of 15 ° with clearly visible vertebral foramen, clearly visible intervertebral disc, visible C4 - C7, spinous process, clearly visible intervertebral disc.

Greedy Randomized and Maximal Weighted Residual Kaczmarz Methods with Oblique Projection

For solving large-scale consistent linear system, a greedy randomized Kaczmarz method with oblique projection and a maximal weighted residual Kaczmarz method with oblique projection are proposed. By using oblique projection, these two methods greatly reduce the number of iteration steps and running time to find the minimum norm solution, especially when the rows of matrix A are close to linear correlation. Theoretical proof and numerical results show that the greedy randomized Kaczmarz method with oblique projection and the maximal weighted residual Kaczmarz method with oblique projection are more effective than the greedy randomized Kaczmarz method and the maximal weighted residual Kaczmarz method respectively.

A Spatial-Temporal Approach Based on Antenna Array for GNSS Anti-Spoofing

The presence of spoofing signals poses a significant threat to global navigation satellite system (GNSS)-based positioning applications, as it could cause a malfunction of the positioning service. Therefore, the main objective of this paper is to present a spatial-temporal technique that enables GNSS receivers to reliably detect and suppress spoofing. The technique, which is based on antenna array, can be divided into two consecutive stages. In the first stage, an improved eigen space spectrum is constructed for direction of arrival (DOA) estimation. To this end, a signal preprocessing scheme is provided to solve the signal model mismatch in the DOA estimation for navigation signals. In the second stage, we design an optimization problem for power estimation with the estimated DOA as support information. After that, the spoofing detection is achieved by combining power comparison and cross-correlation monitoring. Finally, we enhance the genuine signals by beamforming while the subspace oblique projection is used to suppress spoofing. The proposed technique does not depend on external hardware and can be readily implemented on raw digital baseband signal before the despreading of GNSS receivers. Crucially, the low-power spoofing attack and multipath can be distinguished and mitigated by this technique. The estimated DOA and power are both beneficial for subsequent spoofing localization. The simulation results demonstrate the effectiveness of our method.