On The Modeling of Twin Rotor MIMO System Using Chirp Inputs as Test Signals

This paper addresses the modeling problem for the twin rotor multi input multi output system. To develop experimental data, this popular commercial laboratory model of a helicopter from Feedback Instruments Ltd is excited with band limited chirp inputs. The conclusions drawn in this paper lead to four significant achievements: 1) derivation of a linear nominal model for Twin Rotor MIMO System, TRMS in short, from its equivalent nonlinear mathematical representation; 2) dynamic modeling of TRMS; 3) determination of non‐minimum phase dynamics; and 4) determination of linear operating region. The work considers systematic study of the system dynamics of TRMS and analytical treatment of its identified data leading to derivation of the RHP zero dynamics followed by pictorial illustrations indicating resonant modes associated with the plant. The method used in the present paper can be essentially used in modeling of 2 × 2 plants exhibiting non‐minimum phase dynamics and model uncertainties.     

SEBS elastomers for fabrication of microfluidic devices with reduced drug absorption by injection molding and extrusion

The majority of microfluidic devices used for cell culture, including Organ-on-a-Chips (Organ Chips), are fabricated using polydimethylsiloxane (PDMS) polymer because it is flexible, optically clear, and easy to mold. However, PDMS possesses significant challenges for high volume manufacturing and its tendency to absorb small hydrophobic compounds limits its usefulness as a material in devices used for drug evaluation studies. Here, we demonstrate that a subset of optically clear, elastomeric, styrenic block copolymers based on styrene-ethylene-butylene-styrene exhibit reduced absorption of small hydrophobic molecules and drug compounds compared to PDMS and that they can be fabricated into microfluidic devices with fine features and the flexibility required for Organ Chips using mass production techniques of injection molding and extrusion.     

Light scattering from anisotropic, randomly rough, perfectly conducting surfaces

An approach is introduced for performing rigorous numerical simulations of electromagnetic wave scattering from randomly rough, perfectly conducting surfaces. It is based on a surface integral technique, and consists of determining the unknown electric surface current densities from which the electromagnetic field everywhere can be determined. The method is used to study the scattering of a p-polarized beam from an anisotropic Gaussian, randomly rough, perfectly conducting surface. It is demonstrated that the surface anisotropy gives rise to interesting and pronounced signatures in the angular intensity distribution of the scattered light. The origins of these features are discussed.     

Fovea center detection based on the retina anatomy and mathematical morphology

In this work, we present a new fovea center detection method for color eye fundus images. This method is based on known anatomical constraints on the relative locations of retina structures, and mathematical morphology. The detection of this anatomical feature is a prerequisite for the computer aided diagnosis of several retinal diseases, such as Diabetic Macular Edema. The proposed method is adaptive to local illumination changes, and it is robust to local disturbances introduced by pathologies in digital color eye fundus images (e.g. exudates). Our experimental results using the DRIVE image database indicate that our method is able to detect the fovea center in 37 out of 37 images (i.e. with a success rate of 100%). Using the DIARETDB1 database, our method was able to detect the fovea center in 92.13% of all tested cases (i.e. in 82 out of 89 images). These results indicate that our approach potentially can achieve a better performance than comparable methods proposed in the literature.     

Behavioral detection of malware: from a survey towards an established taxonomy

Behavioral detection differs from appearance detection in that it identifies the actions performed by the malware rather than syntactic markers. Identifying these malicious actions and interpreting their final purpose is a complex reasoning process. This paper draws up a survey of the different reasoning techniques deployed among the behavioral detectors. These detectors have been classified according to a new taxonomy introduced inside the paper. Strongly inspired from the domain of program testing, this taxonomy divides the behavioral detectors into two main families: simulation-based and formal detectors. Inside these families, ramifications are then derived according to the data collection mechanisms the data interpretation, the adopted model and its generation, and the decision support.     

Scarecrow: If I only had AI

At the 1992 AAAI robot contest one of the top finishers was Scarecrow—a robot that had no computer in the traditional sense, was built out of less than $200 of parts, and was explained and operated by a five year old. The designers sought to demonstrate the capabilities and competence that can be accomplished by using a strictly reactive architecture for well defined tasks such as that contest. This paper reexamines the Scarecrow robot and puts it into historical context. With fifteen years of perspective, we can also see what Scarecrow has to say about the perception of intelligence.

Mixture model for face-color modeling and segmentation

In this paper, we propose a general methodology for face-color modeling and segmentation. One of the major difficulties in face detection and retrieval is partial face extraction due to highlights, shadows and lighting variations. We show that a mixture-of-Gaussians modeling of the color space, provides a robust representation that can accommodate large color variations, as well as highlights and shadows. Our method enables to segment within-face regions, and associate semantic meaning to them, and provides statistical analysis and evaluation of the dominant variability within a given archive.     

Trench-Hall devices

A trench-Hall device sensitive to magnetic inductions parallel to the chip surface is reported in this paper. The vertically oriented active region is defined by two parallel trenches with a distance of only 2.4 μm. Deep contacts connect the active region of the device at its bottom at a depth of 20 μm. These deep contacts allow a symmetrical operating condition of the active region analogous to a lateral symmetrical Hall plate, which is favorable for dynamic offset reduction. With the presented technology, trench-Hall devices with a sensitivity of 320 V/A with a nonlinearity below 0.1% are realized. Additionally, the presented fabrication technique enables the electrically insulated cointegration of sensor and circuitry on a single CMOS chip     

Phase relationships in the system Cr-W-O and thermodynamic properties of CrWO4 and Cr2WO6

The phase diagram of the Cr-W-O system at 1000° C was established by metallographic and X-ray identification of the phases present after equilibration in evacuated silica capsules. Two ternary oxide phases, CrWO₄ and Cr₂WO₆ were detected. The oxygen potential over the three-phase mixtures, W+Cr₂O₃ s+CrWO₄, WO_2.90+CrWO₄+Cr₂WO₆ and Cr₂O₃+CrWO₄+Cr₂WO₆, were measured by solid state cells incorporating Y₂O₃ stabilized ZrO₂ electrolyte and Ni+NiO reference electrode. The Gibbs' energies of formation of the two ternary phases can be represented by the following equations $$\begin{gathered} W(s) + \tfrac{1}{2} Cr_2 O_3 (s) + \tfrac{5}{4} O_2 (g) \to CrWO_4 (s) \hfill \\ \Delta G^0 = - 172 047 + 48.725T ( \pm 230) cal mol^{ - 1} \hfill \\ Cr_2 O_3 (s) + WO_3 (s) \to Cr_2 WO_6 (s) \hfill \\ \Delta G^0 = - 3 835 + 0.235{\rm T} ( \pm 500) cal mol^{ - 1} \hfill \\ \end{gathered}$$