Template-Based Volume Viewing

We present an efficient three-phase algorithm for volume viewing that is based on exploiting coherency between rays in parallel projection. The algorithm starts by building a ray-template and determining a special plane for projection - the base-plane. Parallel rays are cast into the volume from within the projected region of the volume on the base-plane, by repeating the sequence of steps specified in the ray-template. We carefully choose the type of line to be employed and the way the template is being placed on the base-plane in order to assure uniform sampling of the volume by the discrete rays. We conclude by describing an optimized software implementation of our algorithm and reporting its performance.     

Control of constrained linear systems using fast sampling rates

This paper addresses the problem of optimal control of constrained linear systems when fast sampling rates are utilised. We show that there exists a well-defined limit as the sampling rate increases. An immediate consequence of this result is the existence of a finite sampling period such that the achieved performance is arbitrarily close to the limiting performance.     

Lattice-based volumetric global illumination

We describe a novel volumetric global illumination framework based on the Face-Centered Cubic (FCC) lattice. An FCC lattice has important advantages over a Cartesian lattice. It has higher packing density in the frequency domain, which translates to better sampling efficiency. Furthermore, it has the maximal possible kissing number (equivalent to the number of nearest neighbors of each site), which provides optimal 3D angular discretization among all lattices. We employ a new two-pass (illumination and rendering) global illumination scheme on an FCC lattice. This scheme exploits the angular discretization to greatly simplify the computation in multiple scattering and to minimize illumination information storage. The GPU has been utilized to further accelerate the rendering stage. We demonstrate our new framework with participating media and volume rendering with multiple scattering, where both are significantly faster than traditional techniques with comparable quality.     

Optimal Design of Internet-Based Auctions

Online auctions are a profitable, exciting, and dynamic part of electronic commerce, and behave in ways, which do not match classical auction theory. This paper models an online auction in terms of a Markov chain on a state space defined by the current price of the item and the number of bidders who have been previously bumped. It provides a mathematical model, some approximations, which were necessary to convert it into a tractable problem and solutions to a small and a medium-sized theoretical auction. The model results were validated through a comparison with real-world online auction data, showing promise as a predictor of final auction prices. The results of the auction model are also useful in solving an optimization problem that incorporates inventory management considerations in determining optimal auction size.     

Representation of highly-complex knowledge in a database

This paper presents a unified framework for representing highly-complex knowledge in a database as a new paradigm for handling large and complex information in an easy and efficient manner. The framework provides a database with the capabilities to support next generation databases for decision support systems through the use of derivation rules, temporal information, knowledge from multiple sources with different measures of quality and epistemic knowledge. The model integrates concepts from both thedatabase and theartificial intelligence disciplines.     

Time-averaged aerodynamic forces acting on a hemisphere immersed in a turbulent boundary

The time-averaged pressure distribution over the surface of a hemisphere immersed in a fully developed turbulent boundary layer developing along a smooth, plane wall has been measured for a number of hemispheres of differing diameter d in order to establish the relationship between the aerodynamic force acting on such a hemisphere and the characteristics of the boundary layer. It is found that the drag coefficients defined by $\text{C}{}_{\mathrm{<mtext>D</mtext><mtext>\tau </mtext>}}\text{= D/(}\text{1}\text{2}\text{πu}{}_{\mathrm{\tau }}{}^2\text{A}$ may be expressed as a function of u_τd/ν alone in the range $\text{d/δ ? 1.0}$, where D is the pressure drag, u_τ the shear velocity, ν the kinematic viscosity, A denotes the area of the hemisphere projected onto a plane normal to the main flow direction, and δ is the boundary-layer thickness.     

Wearable,Human‐Interactive,Health‐Monitoring,Wireless Devices Fabricated by Macroscale Printing Techniques

Wearable human‐interactive devices are advanced technologies that will improve the comfort, convenience, and security of humans, and have a wide range of applications from robotics to clinical health monitoring. In this study, a fully printed wearable human‐interactive device called a “smart bandage” is proposed as the first proof of concept. The device incorporates touch and temperature sensors to monitor health, a drug‐delivery system to improve health, and a wireless coil to detect touch. The sensors, microelectromechanical systems (MEMS) structure, and wireless coil are monolithically integrated onto flexible substrates. A smart bandage is demonstrated on a human arm. These types of wearable human‐interactive devices represent a promising platform not only for interactive devices, but also for flexible MEMS technology.     

Towards a Perfect CMOS CCII

DC offset and inaccurate voltage follower action betweenterminals Y and X, the relatively highimpedance seen at terminal X and inaccurate currentfollower action between terminals X and Zplague simple circuit realizations of the CCII. This paper summarizesthe methods employed and compares the improvement of the CCIIcharacteristics achieved by a variety of published circuits,with emphasis laid on CMOS realizations. In these comparisons,the conventionally employed but inaccurate current mirror outputstages were replaced by a circuit employing current isolationand thereby providing accurate current follower action betweenterminals X and Z. Furthermore, twonovel realizations of a differential CCII – basedtransconductance amplifier are described, which can also be employedas input stage of an instrumentation voltage amplifier exhibitingan exceptionally high CMRR and excellent frequency response.Finally, a current fan out circuit for cascode CCII –swill be introduced, whose transfer function value is electronicallyadjustable.     

Application of complementary techniques to a bipolar translinear gain cell and a translinear CCII+

A multistage translinear amplifier is described, employing complementary techniques. The input cell includes a common mode rejection circuit, which maintains the push-pull output if a single ended input is applied without affecting the performance. Another example describes a translinear CCII+ employing an input Buffer, whose current transfer function is practically one due to the Darlington configuration employed. Finally, this CCII+ is employed as output stage for an inverting current amplifier.Abbreviations LT Loop Transmission - THD Total Harmonic Distortion A shortened version has been publixhed in ECCTD'93, European Converence on Circuit Theory and Design, Elsevier Science Publishers B.V., pp. 1561–1564.     

Quantum rod-sensitized solar cell: nanocrystal shape effect on the photovoltaic properties

The effect of the shape of nanocrystal sensitizers in photoelectrochemical cells is reported. CdSe quantum rods of different dimensions were effectively deposited rapidly by electrophoresis onto mesoporous TiO(2) electrodes and compared with quantum dots. Photovoltaic efficiency values of up to 2.7% were measured for the QRSSC, notably high values for TiO(2) solar cells with ex situ synthesized nanoparticle sensitizers. The quantum rod-based solar cells exhibit a red shift of the electron injection onset and charge recombination is significantly suppressed compared to dot sensitizers. The improved photoelectrochemical characteristics of the quantum rods over the dots as sensitizers is assigned to the elongated shape, allowing the build-up of a dipole moment along the rod that leads to a downward shift of the TiO(2) energy bands relative to the quantum rods, leading to improved charge injection.