35 research outputs found
Synchronized Audio-Visual Transients Drive Efficient Visual Search for Motion-in-Depth
In natural audio-visual environments, a change in depth is usually correlated with a change in loudness. In the present study, we investigated whether correlating changes in disparity and loudness would provide a functional advantage in binding disparity and sound amplitude in a visual search paradigm. To test this hypothesis, we used a method similar to that used by van der Burg et al. to show that non-spatial transient (square-wave) modulations of loudness can drastically improve spatial visual search for a correlated luminance modulation. We used dynamic random-dot stereogram displays to produce pure disparity modulations. Target and distractors were small disparity-defined squares (either 6 or 10 in total). Each square moved back and forth in depth in front of the background plane at different phases. The target’s depth modulation was synchronized with an amplitude-modulated auditory tone. Visual and auditory modulations were always congruent (both sine-wave or square-wave). In a speeded search task, five observers were asked to identify the target as quickly as possible. Results show a significant improvement in visual search times in the square-wave condition compared to the sine condition, suggesting that transient auditory information can efficiently drive visual search in the disparity domain. In a second experiment, participants performed the same task in the absence of sound and showed a clear set-size effect in both modulation conditions. In a third experiment, we correlated the sound with a distractor instead of the target. This produced longer search times, indicating that the correlation is not easily ignored
Irreversible work of separation and heat-driven separation
Estimates of the minimal necessary work of separation for mechanical separation processes and of the minimal necessary heat consumption for heat-driven separation processes with given productivity are derived in this paper. It is shown that for heat-driven processes the productivity is limited, and this limiting productivity is estimated
Estimation of the Maximum Output of the Process of Rectification of a Continuous Mixture with Regard for the Irreversibility of the Heat and Mass Transfer in It
Finite-time thermodynamics: Realizability domains of thermodynamic systems and P. Salamon’s problem of efficiency corresponding to maximum power output of the system
The paper analyses performance boundaries of systems converting the heat energy into the mechanical or separation work. Authors approach this problem from the view-point of the finite-time thermodynamics. Using thermodynamic balance equations, authors provide the algorithm for calculation of realizability domain for such systems. The paper shows that the performance of these systems is the upper bounded function of the heat flux, assuming that heat and mass transfer coefficients are given. Authors present sufficient conditions under which the efficiency (specific heat flux per unit of the useful flux) of the system does not depend on kinetic coefficients when operating in the maximum performance mode. The paper shows how to use these conditions to optimally choose the separation order for multicomponent distillation
On the Possibility of Improving the Thermodynamic Characteristics of Multiflow Heat Transfer Systems
Finite time thermodynamics: Limiting performance of diffusion engines and membrane systems
In this paper, the limiting performance of membrane systems with inhomogeneous composition is studied within the class of fixed rate processes. The problem of maintaining a nonequilibrium state in such a system using minimal power (separation problem) and the problem of extracting maximal power from such a system (diffusion engine problem) are formulated and solved. Results are obtained for diffusion engines with constant and periodic contact between the working body and the reservoirs. © 2005 American Chemical Society
Finite-time thermodynamics: Limiting possibilities of irreversible separation processes
In this paper, new thermodynamic limits on the performance of irreversible separation processes are derived, including work of separation in finite time (a generalization of Van'T Hoff reversible work of separation for finite rate processes), maximal productivity of heat-driven separation process (an analogue of Novikov-Curzon-Ahlborn maximal power of a heat engine), and the minimal possible dissipation in an irreversible distillation column, the ideal operating line, for which this dissipation level is achieved, the profile of heat supply/removal that realizes the ideal operating line, and the distillation column'S maximal productivity
Controllable open macrosystems in thermodynamics and microeconomics
In this paper stationary regimes of open macro-systems that include active subsystems (with controlled parameters) near equilibrium are considered. A generalized Prigogine extremal principle for such systems is formulated and proved. The conditions on optimal behavior of active subsystems in such systems are derived. It is shown that the obtained general results can be specified for thermodynamic and microeconomic systems to obtain the heat engine maximal power, the minimal irreversible work of separation, the limiting productivity of heat driven separation and the maximal capital extraction. © Springer 2005
About control of electricity market
We consider auction problem for network of inter-connected energy markets. The conditions of optimality for this problem are derived. The numerical method based on these conditions for running auction is constructed. It is shown how running auction can be achieved by using automated control system. © 2009 Pleiades Publishing, Ltd