Noise-based Enhancement for Foveated Rendering

Human visual sensitivity to spatial details declines towards the periphery. Novel image synthesis techniques, so-called foveated rendering, exploit this observation and reduce the spatial resolution of synthesized images for the periphery, avoiding the synthesis of high-spatial-frequency details that are costly to generate but not perceived by a viewer. However, contemporary techniques do not make a clear distinction between the range of spatial frequencies that must be reproduced and those that can be omitted. For a given eccentricity, there is a range of frequencies that are detectable but not resolvable. While the accurate reproduction of these frequencies is not required, an observer can detect their absence if completely omitted. We use this observation to improve the performance of existing foveated rendering techniques. We demonstrate that this specific range of frequencies can be efficiently replaced with procedural noise whose parameters are carefully tuned to image content and human perception. Consequently, these fre- quencies do not have to be synthesized during rendering, allowing more aggressive foveation, and they can be replaced by noise generated in a less expensive post-processing step, leading to improved performance of the ren- dering system. Our main contribution is a perceptually-inspired technique for deriving the parameters of the noise required for the enhancement and its calibration. The method operates on rendering output and runs at rates exceeding 200 FPS at 4K resolution, making it suitable for integration with real-time foveated rendering systems for VR and AR devices. We validate our results and compare them to the existing contrast enhancement technique in user experiments

Comparative Analysis of Flexural Capacity of Bamboo Reinforced and Conventional Steel Reinforced Concrete Beams Through Numerical Evaluation

Steel reinforcement bars are commonly used in the building industry, but their production contributes to toxic waste and emissions. Bamboo is being marketed as a sustainable alternative due to its low cost and tensile strength. It is a readily available natural material that can potentially replace steel as a conventional reinforcement. The idea of hybrid beams (50% bamboo and 50% steel) was developed to get equal outcomes in terms of the structural reaction, and ABAQUS was used to develop a set of beams. By using conventional dimensions and material qualities, a total of five beams were modeled. According to the analysis, the maximum displacements for each beam would be different. The load-displacement curve of five beams was obtained and it was determined that when combined with steel, bamboo may partially replace it

Comparison of Frequency of Recurrence after Burr Hole Evacuation of Chronic Subdural Hematoma with or without Subdural Drain.

Chronic subdural hematoma (CSDH) is known to have a significant recurrence rate. The rate of recurrence of chronic subdural hematoma after surgery ranges from roughly 5% to 30%.  Burr hole evacuation without drainage is performed as a first line of treatment for CSDH. As there is controversy in literature regarding the use of drainage after burr hole evacuation, the results of my study may be helpful for selecting a proper treatment modality as a first line of treatment for CSDH in terms of recurrence. The objective of this study was to compare the frequency of recurrence after burr hole evacuation of CSDH with and without subdural drain. It was a randomized controlled trial conducted in Department of Neurosurgery, Allied hospital, Faisalabad form Aug 2016 to Aug 2018 RESULTS:In our study, out of 130 cases(65 in each group). 84.62%(n=55) in Group-A and 76.92%(n=50) in Group-B were between above 40 years of age whereas 15.38%(n=10) in Group-A and 23.08%(n=15) were between 18-40 years of age, mean+sd was calculated as  64.03+7.61 years in Group-A and 62.28+7.83 years in Group-B, 78.46%(n=51) in Group-A and 72.31%(n=47) in Group-B were male while 21.54%(n=14) in Group-A and 27.69%(n=18) in Group-B were females, comparison of frequency of recurrence after burr hole evacuation of CSDH with and without subdural drain shows 10.77%(n=7) in Group-A and 27.69%(n=18) in Group-B, p value was 0.01 showing a significant difference. CONCLUSION: We concluded that the frequency of recurrence after burrhole evacuation of CSDH is significantly lower with drain when compared without subdural drain

Comparing Mean Post-Operative Back Pain Score between Hemilaminectomy and Conventional Laminectomy in Patients of Lumbar Stenosis

Objective:  To observe the comparative mean post-operative back-pain score between hemilaminectomy and conventional laminectomy in patients of lumbar stenosis. Material and Methods:  The randomized controlled study was carried out in Neurosurgery Unit, Allied Hospital, Faisalabad, Pakistan. A total of 60 patients were distributed equally in two groups. Group A underwent hemilaminectomy while group B underwent conventional laminectomy. A linear median fascial incision was made on the side with more pain or symptoms. Only in the hemilaminectomy group, ipsilateral decompression was performed. It involves partial resection of adjacent parts of the hemi laminae of the superior and inferior vertebrae using operative loupes or neurosurgical microscope. Mean ±SD was calculated for quantitative data including back pain score. Results:  Mean age was 46.2 ± 6.94 years in hemi group and 46.3 ± 6.74 years in the conventional group. We observed that in hemi group, the back pain score was 2.23 ± 0.73 and it was 2.7 ± 0.65 in the conventional group (p-value was 0.011). Significant differences (p value<0.050) existed in these age ranges with respect to the back pain score in both surgery groups. A significant difference (p value < 0.0001) observed only in male patients between two surgery groups for the back pain scores. Conclusion:  Mean post-operative back pain score is significantly reduced in hemilaminectomy cases when compared with conventional laminectomy in patients of lumbar stenosis