Narrow Results

In this work, we study the influence of the temperature on the mechanism of current transfer in the reverse branch of the current–voltage (I–V) characteristics of n-CdS/p-CdTe heterostructures. The study of the heterostructure, using the technique of on energy-dispersive X-ray analysis, showed that a layer of CdS_xTe${}_{1-x}$ is formed at the boundary of the heterojunction with a varying composition, being equal $x\approx 0.48$ from the side of CdS and $x\approx 0.02$ from the CdTe side. In the studied range of the temperatures and bias voltage, the current-voltage characteristics are described well by a power law $J=A{V}^{\alpha }$, where the exponent $\alpha$ changes with the temperature and voltage. Under the influence of the temperature and charge carrier concentration, the mechanism of current transfer in the structure changes from exclusion ($\alpha \approx 0.5$) to ohmic ($\alpha \approx 1$), and then goes to injection ($\alpha \approx 2$). The inhomogeneous intermediate CdS_xTe${}_{1-x}$i-layer at the boundary of the n-CdS/p-CdTe heterostructure is characterized by the presence of metastable states that rearrange at high temperatures and certain charge carrier concentrations. As a result of this, the exclusion slows down and electrons are injected from the rear molybdenum contact.

In volume rendering, an important issue in acceleration is to reduce the calculations for occluded voxels. Although this issue has been addressed in the ray casting approach, it is difficult to apply the idea to the projection approach due to uncertain termination conditions. In this paper, we propose a new method to effectively address the exclusion problem in the projection approach, so the rendering process can be accelerated without impairing the rendered image quality. In the rendering process, this new method employs the dynamic screen technique to manage the pixels whose accumulated opacity has not reached 1.0. A ray-cast link at each pixel is set up to record the rendered voxels for the corresponding ray cast from the pixel to intersect. According to the rendered voxels covering the pixels whose accumulated opacity value is below 1.0, visible voxels are selected to render from front to back by the neighboring relationship between the rendered voxels and the voxels to be rendered. Thus, the occluded voxels are dynamically excluded from the loading and rendering processes accurately. Our proposed method can be in general applied to both parallel and perspective projections, using regular and irregular volume datasets. Our experimental results showed that the proposed method can significantly accelerate volume rendering if the data volume has a high percentage of occluded voxels. This method can also perform fairly efficiently for the expensive shading calculations if requested in volume rendering.

Labor market discrimination is very difficult to pinpoint, even more difficult to measure and almost impossible to “prove”. This paper reviews the literature and makes two main contributions: first, it builds a four-fold typology to think about discrimination — overt or covert; conscious or unconscious; legal or illegal and real or perceived. Second, it identifies screens and filters — devices through which discrimination plays out in the labor market. Unless more empirical studies identify the play of discrimination and exclusion, subordinate groups may well be told that discrimination is actually in their heads — that they are imagining it.

We have studied the effect of diffusion controlled opinion dynamics on a ring lattice where agents are placed on a fraction of sites. We have chosen the diffusion on a circular ring as a simple model to study emphasizing on the fact that agents approach their nearest neighbor for exchanging opinion. The agents execute simple exclusion process (SEP) on the ring and exchange opinion with neighboring agents according to a fixed rule. Our study shows that as agent density decreases, higher conviction power is necessary to create consensus. We have also investigated the nature of active-to-absorbing state phase transition for various densities and found that there are two universality classes for density $\rho =1$ and $\rho <1$.