in this paper, construction rules of the root locus of a positive feedback system whose loop transfer function is not strictly proper have been investigated. the root locus method is being used since 1950. it is demonstrated that some of the steps in this technique are not general and for a positive feedback system whose loop transfer function is not strictly proper are not valid. to overcome t...

due to the changes which may occur in their parameters, systems are usually demonstrated by some subsystems for different conditions. this paper employs modified petri nets (mpn) to model theses subsystems and makes it simple to analyze them. in this method, first, the continuous transfer function is converted to a discrete transfer function and then, by mpn, system is modeled and analyzed. all...

The design of optical transfer function (OTF) is of significant importance for optical information processing in various imaging and vision systems. Typically, OTF design relies on sophisticated bulk optical arrangement in the light path of the optical systems. In this letter, we demonstrate a surface-wave-interferometry aperture (SWIA) that can be directly incorporated onto optical sensors to ...

We present a study of radiative transfer in dusty, clumpy star-forming regions. A series of self-consistent, three-dimensional, continuum radiative transfer models are constructed for a grid of models parameterized by central luminosity, filling factor, clump radius, and face-averaged optical depth. The temperature distribution within the clouds is studied as a function of this parameterization...

PURPOSE Optical penalization is emerging as an alternative to patching for the treatment of amblyopia. Bangerter foils offer a form of optical penalization that is distinctly different from standard techniques making use of atropine or spectacle lens manipulation, or both, to produce defocus. The authors examined the optical properties of Bangerter foils and compared them with the effect of def...

A porphyrin-silicon nanowire (Si-NW) hybrid field-effect transistor is introduced. The hybrid device has separate electrical and optical gates surrounding the Si-NW channel. Porphyrin, a component of chlorophyll, is employed as an optical gate to modulate the potential of the Si-NW channel. Due to the independently formed hybrid gates, both optical and electrical excitation can effectively modu...

Optical measurements were carried out by infrared spectroscopy on AA'3B4O12 A-site ordered quadruple perovskite EuCu3Fe4O12 (microscopic sample) as function of temperature. At 240 K (=TMI), EuCu3Fe4O12 undergoes a very abrupt metal to insulator transition, a paramagnetic to antiferromagnetic transition and an isostructural transformation with an abrupt large volume expansion. Above TMI, optical...

Over the last years two-photon excitation 4Pi-microscopy with an axial resolution of ~100 nm has been demonstrated in multiple biological applications [1-3]. The artefact-free presentation of the recorded structures has been possible because of the contiguous optical transfer function (OTF), which allows reliable image deconvolution. The use of two-photon excitation (2PE) has been critical to s...

In this study, we propose a method of evaluating the spectral resolution crossed-asymmetric Czerny-Turner spectrometers by comparing impact different slit functions on optical transfer function, and widths, through simulation experiments. The results show that, Gaussian function is suitable for narrower such as 25 ?m, rectangle or convolution slit-scattering with wider 50 150 200 ?m. proposed c...