Depth of field guided visualisation on light field displays

Light field displays are capable of realistic visualization of arbitrary 3D content. However, due to the finite number of light rays reproduced by the display, its bandwidth is limited in terms of angular and spatial resolution. Consequently, 3D content that falls outside of that bandwidth will cause aliasing during visualization. Therefore, a light field to be visualized must be properly preprocessed. In this thesis, we propose three methods that properly filter the parts in the input light field that would cause aliasing. First method is based on a 2D FIR circular filter that is applied over the 4D light field. Second method utilizes the structured nature of the epipolar plane images representing the light field. Third method adopts real-time multi-layer depth-of-field rendering using tiled splatting. We also establish a connection between lens parameters in the proposed depth-of-field rendering and the display’s bandwidth in order to determine the optimal blurring amount. As we prepare light field for light field displays, a stage is added to the proposed real-time rendering pipeline that simultaneously renders adjacent views. The rendering performance of the proposed methods is demonstrated on Holografika’s Holovizio 722RC projection-based light field display

Antialiasing Filtering for Projection-Based Light Field Displays

Projection-based light field displays can achieve realistic visualization of a 3D scene. However, these displays can reproduce only a finite number of light rays, thus their bandwidth is limited in terms of angular and spatial resolution. Consequently, a display cannot show parts of the 3D scene that falls outside of its bandwidth region without aliasing distortion. Therefore, light fields should be properly pre-processed before visualizing them on a light field display. In this paper, we develop two methods for designing antialiasing filters that will either remove or blur parts of the scene in the input light field that causes aliasing. We illustrate the effectiveness of the proposed methods by comparing the visualized light fields on a projection-based light field display before and after applying the designed antialiasing filters.Peer reviewe

A Path Analysis of Factors Affecting Social Control of Cybercultural Transgressions

Social control of cyberspace is a necessity to restrict online transgressions (non-normative behaviors), and reduce their disruptive effects. The current study aimed at examining the factors affecting social control of cybercultural transgressions. A questionnaire was administered to Iranian social media users, and 989 participants have filled it out. A path analysis model was constructed testing the effects of Low Self-Control, Depression, Negative Interpersonal Relationships, Computer/ Internet Self-Efficacy, Netiquette, and Normative Beliefs on Transgressive Behaviors, and Transgressive Content Consumption. The results showed that Low Self-Control increased both criterion variables, and fully or partially mediated the effects of other variables on them, except for Negative Interpersonal Relationships. The important contribution of the current study was the recognition of the role of self-control as a mediator among examined variables. The findings of this study can be employed to devise new policies and initiatives to socially control the cybercultural transgressions, without applying coercion

Talent Management and Recruitment Strategies

Since the organization of the future will face the challenges of an increasingly competitive, and to manage these challenges require more competent managers and executives today would be more effective, so the talent management becomes more important every day in organizations be enjoyed. The talent management as a system for identifying, hiring, training, promotion and maintenance of talented people, with the aim of optimizing the ability to achieve business results, by definition. Talent management refers to the process in which human talent for key jobs and positions it in the next, identified through a variety of programs of education, be prepared for these occupations. The research presented in this paper, the method was descriptive - analytical, that is, a library, and through review. Theses, journals, Latin, Persian, and took advantage of the book, this review recruitment strategies, and identify critical Talents as the initial step in the process is talent management, as well as to assess the benefits and disadvantages Energy issue inside and outside the organization, and approach to the issue of human resources, and tools to identify Talents the organization pays model. DOI: 10.5901/mjss.2014.v5n20p308

High prevalence of Helicobacter pylori infection in Behcet’s disease

Background: Behcet’s disease (BD) is a multisystem disease of unknown etiology. There are several clues which may indicate an ethiopathogenesis role for Helicobacter pylori infection in this disease. Methods: In a case control study in an out patient department, 48 patients with BD were compared to age, sex matched controls regarding presence of H. pylori infection by serology and urea breath test (UBT). Results: Ongoing H. pylori infection was more prevalent among patients with BD using result of UBT with odds ratio of 3.1 (95% CI: 1.34 – 7.26, PV < 0.001). Conclusion: H. pylori infection may have a role in the pathogenesis of BD

AlGaInAs/InP Based Five & Three Quantum Wells Mode Locked Laser Diodes: A Comparative Study

Comparison of performance of semiconductor mode-locked laser diodes fabricated using AlGaInAs/InP material containing 5 and 3 quantum wells (QWs) inside the active region is reported. The simulations and experimental results show that lasers containing five QWs materials produce larger beam divergence and temporally broader optical pulses. For improvement in the mode-locking of lasers and reducing the far-field pattern, the number of QWs inside the active region was decreased from five to three and a far-field decreasing layer along with a thick spacer layer were introduced in the n-cladding region of epitaxial material. Before growing the material, simulations were carried out to optimise the design. The lower optical confinement factor and higher gain saturation energy of three QWs based mode-locked lasers provide higher average and peak output power, reduced and symmetric far-field pattern, better radio frequency (RF) spectra, shorter optical pulses, and stable optimal mode-locking for a wide range of gain current and saturable absorber reverse voltage

Effective similarity variables for the computations of MHD flow of Williamson nanofluid over a non-linear stretching surface

The present study concerns investigating the two-dimensional Magnetohydrodynamics (MHD) boundary layer flow of Williamson nanofluid over a non-linear stretching sheet. The focus of this study is based on the global influence of the non-Newtonian Williamson fluid parameter (λ) rather than the local one that exists in the literature for linear and non-linear stretching cases. The mathematical model of the problem is based on the law of conservation of mass, momentum, and energy. The derived partial differential equations are transformed into ordinary differential equations by applying an appropriate similarity transformation. The subsequent equations are solved numerically by using the Shooting method. The physical quantities Skin friction coefficient, as well as the Sherwood and Nusselt numbers are computed locally. To validate the implemented shooting method, a comparison is made with the results obtained by Matlab function bvp4c, and good agreement is found. The Prandtl number, Pr, has an increasing impact of 25.14% on the wall temperature gradient. The impact of various physical parameters are presented through graphs and tables

Examining the Effect of Salt Dust Storms of Lake Urmia on Vegetation

Urmia Lake is one of the largest saline lakes in the world, which has greatly decreased in recent years. It has created many dangers and concerns especially concerning salt dust in its arid areas. Therefore, this research aimed to investigate the relationship between vegetation and dust in the cities around Lake Urmia. For this purpose, first, using MODIS images and NDVI index, changes in the vegetation of the region in 2010 to 2020 were determined, and then, using the MERRA-2 database, the dust concentration was extracted for the mentioned years. The results showed that the mean NDVI in the study area follows a steady trend with a total mean of 0.2957 and sometimes increases or decreases due to the influence of external factors such as dust. Accordingly, the highest rate (0.3495) of the average NDVI is related to 2018 and the lowest rate (0.2579) is related to 2013. Furthermore, to investigate the relationship between vegetation and dust, two methods of linear and logarithmic regression were used. Based on linear regression (0.7703) and logarithmic (0.7153), the findings showed that the highest determination coefficient between the two indicators was in May

Experimental and theoretical insights to demonstrate the hydrogen evolution activity of layered platinum dichalcogenides electrocatalysts

Abstract Hydrogen is a highly efficient and clean renewable energy source and water splitting through electrocatalytic hydrogen evolution is a most promising approach for hydrogen generation. Layered transition metal dichalcogenides-based nano-structures have recently attracted significant interest as robust and durable catalysts for hydrogen evolution. We systematically investigated the platinum (Pt) based dichalcogenides (PtS2, PtSe2 and PtTe2) as highly energetic and robust hydrogen evolution electrocatalysts. PtTe2 catalyst unveiled the rapid hydrogen evolution process with the low overpotentials of 75 and 92 mV (vs. RHE) at a current density of 10 mA cm−2, and the small Tafel slopes of 64 and 59 mV/dec in acidic and alkaline medium, respectively. The fabricated PtTe2 electrocatalyst explored a better catalytic activity than PtS2 and PtSe2. The density functional theory estimations explored that the observed small Gibbs free energy for H-adsorption of PtTe2 was given the prominent role to achieve the superior electrocatalytic and excellent stability activity towards hydrogen evolution due to a smaller bandgap and the metallic nature. We believe that this work will offer a key path to use Pt based dichalcogenides for hydrogen evolution electrocatalysts

Avoiding Drug Resistance by Substrate Envelope-Guided Design: Toward Potent and Robust HCV NS3/4A Protease Inhibitors

Hepatitis C virus (HCV) infects millions of people worldwide, causing chronic liver disease that can lead to cirrhosis, hepatocellular carcinoma, and liver transplant. In the last several years, the advent of direct-acting antivirals, including NS3/4A protease inhibitors (PIs), has remarkably improved treatment outcomes of HCV-infected patients. However, selection of resistance-associated substitutions and polymorphisms among genotypes can lead to drug resistance and in some cases treatment failure. A proactive strategy to combat resistance is to constrain PIs within evolutionarily conserved regions in the protease active site. Designing PIs using the substrate envelope is a rational strategy to decrease the susceptibility to resistance by using the constraints of substrate recognition. We successfully designed two series of HCV NS3/4A PIs to leverage unexploited areas in the substrate envelope to improve potency, specifically against resistance-associated substitutions at D168. Our design strategy achieved better resistance profiles over both the FDA-approved NS3/4A PI grazoprevir and the parent compound against the clinically relevant D168A substitution. Crystallographic structural analysis and inhibition assays confirmed that optimally filling the substrate envelope is critical to improve inhibitor potency while avoiding resistance. Specifically, inhibitors that enhanced hydrophobic packing in the S4 pocket and avoided an energetically frustrated pocket performed the best. Thus, the HCV substrate envelope proved to be a powerful tool to design robust PIs, offering a strategy that can be translated to other targets for rational design of inhibitors with improved potency and resistance profiles.IMPORTANCE Despite significant progress, hepatitis C virus (HCV) continues to be a major health problem with millions of people infected worldwide and thousands dying annually due to resulting complications. Recent antiviral combinations can achieve \u3e 95% cure, but late diagnosis, low access to treatment, and treatment failure due to drug resistance continue to be roadblocks against eradication of the virus. We report the rational design of two series of HCV NS3/4A protease inhibitors with improved resistance profiles by exploiting evolutionarily constrained regions of the active site using the substrate envelope model. Optimally filling the S4 pocket is critical to avoid resistance and improve potency. Our results provide drug design strategies to avoid resistance that are applicable to other quickly evolving viral drug targets