Surface orientation from texture: isotropy or homogeneity (or both)?

We examine two models for human perception of shape from texture, based on two assumptions about the surface texture: isotropy and homogeneity. Observers made orientation judgments on planar textured surfaces. Surface textures were either isotropic or anisotropically stretched or compressed. If subjects used an isotropy assumption, they would make biased orientation estimates for the anisotropic textures. In some conditions some observers showed no bias for the anisotropic textures relative to the isotropic textures. In general, even when the observers showed bias, the biases were significantly less than those predicted if the observer used only deviation from isotropy as a cue. Observers appear to use both the deviation from isotropy and a texture gradient or affine texture distortion cue for shape from texture.     

Developing architectural platforms: a disciplined approach

The Mescal project brings a formalized, disciplined methodology to the design of programmable platform-based systems, enabling the exploration of a wide array of architectures and a correct-by-construction path to implementation.     

Water-Energy Nexus in Resource-poor Economies: The Indian Experience

The paper examines the nature of water-energy interactions at the level of end users in an economy where the demand for both water and energy exceeds the available supplies of these resources. The paper attempts an assessment of the nature of coping strategies adopted by individuals to deal with shortages/uncertainties/unreliability in the availability of water and energy per se and in inter-linked activities, and to provide indicative estimates of the cost of the prevailing supply scenario. The paper also examines the nature of policy interventions that could help in moving towards bridging the gap between the demand and supply of water and energy, especially in inter-linked activities. The scope of the paper is confined to the agricultural/irrigation and urban water supply sectors. Attempts at bridging the gap between demand and supply of both the resources call for both short-run and long-run solutions. A favourable policy environment, improved management of utilities, better organization and methods of existing infrastructure, metering of consumption, charging of rational tariffs for these services, larger investments in the creation of new capacities and a more active role of the private sector could to a large extent help in narrowing the gap and making the water and energy sectors more sustainable in the long run.     

Cross-entropy optimisation of multiple-input multiple-output capacity by transmit antenna selection

Radio channel capacity can be increased dramatically using a multiple-input multiple-output (MIMO) scheme, but at the expense of hardware complexity. An efficient approach for complexity reduction is antenna subset selection at the transmitter and/or receiver. A novel transmit antenna selection algorithm is presented using the cross-entropy optimisation method to maximise channel capacity. In contrast with the existing work, the proposed algorithm guarantees a result to within 99% of the true optimum (i.e. the maximal capacity with selected transmit antennas) with substantially low complexity. The simulation results indicate that the proposed algorithm is independent of the relationship between the selected transmit array size and receive array size. The proposed scheme has the potential to make practical MIMO systems with high performance simpler to implement.     

Nanostructured titanium/diamond-like carbon multilayer films: deposition, characterization, and applications

Titanium/diamond-like carbon multilayer (TDML) films were deposited using a hybrid system combining radio frequency (RF)-sputtering and RF-plasma enhanced chemical vapor deposition (PECVD) techniques under a varied number of Ti/diamond-like carbon (DLC) bilayers from 1 to 4, at high base pressure of 1 × 10(-3) Torr. The multilayer approach was used to create unique structures such as nanospheres and nanorods in TDML films, which is confirmed by scanning electron microscopy (SEM) analysis and explained by a hypothetical model. Surface composition was evaluated by X-ray photoelectron spectroscopy (XPS), whereas energy dispersive X-ray analysis (EDAX) and time-of-flight secondary ion mass spectrometer (ToF-SIMS) measurements were performed to investigate the bulk composition. X-ray diffraction (XRD) was used to evaluate the phase and crystallinity of the deposited TDML films. Residual stress in these films was found to be significantly low. These TDML films were found to have excellent nanomechanical properties with maximum hardness of 41.2 GPa. In addition, various nanomechanical parameters were calculated and correlated with each other. Owing to metallic interfacial layer of Ti in multilayer films, the optical properties, electrical properties, and photoluminescence were improved significantly. Due to versatile nanomechanical properties and biocompatibility of DLC and DLC based films, these TDML films may also find applications in biomedical science.     

Thoughts on a methodology to analyse viability of private-sector participation in new infrastructure projects in developing countries

A model has been developed for investment analysis of all types of infrastructure projects: it addresses some of the key issues for developing countries regarding private-sector participation in infrastructure projects. As an illustration, financial analyses of a bulk water supply project and a water distribution project in Sri Lanka are carried out to estimate subsidy percentages required to make the projects viable. To reap maximum benefits from private-sector participation in water supply, the Government should review its policy on water pricing and institute a reasonable increase in tariffs.     

Raman Spectral Mapping of III–V Nitride and Graphene Nanostructures

Among several spectroscopic imaging techniques to visualise the nanostructures, Raman spectral imaging is one of the most indispensible non-destructive tools. We discuss the limitations and the importance of each step involved in the Raman imaging in the visualization of different nanostructures and illustrated with examples. Raman spectroscopic imaging of nanostructures is demonstrated for differentiation of morphology in InN nanorods, crystallographic orientation for single square faceted GaN nanotube and layer thickness of graphene layers. The limitations of the spatial and spectral resolutions of the Raman maps are evaluated in the illustration.