7,203 research outputs found
Interval type‑2 fuzzy aggregation operator in decision making and its application
Type-2 fuzzy sets (T2FSs) can deal with higher modeling and uncertainties which exist in the real-world application, specifically
in the control systems. Particularly the climate changes are always uncertain and thus, the type-2 fuzzy controller is an
effective system to handle those situations. Polyhouse is a methodology used to cultivate the plants. It breaks the seasonal
hurdle of the formulation and it is also suitable for the conflictive climate conditions. Controlling and directing internal
parameters of the polyhouse play an essential role in the growth of the plant. Among those, humidity is an important element
when one deals with the growth of the plant in polyhouse. It affects the weather, as well as the global change of the climate
and hence, the inner climate of the polyhouse will be disturbed. In this paper, operational laws for triangular interval type-2
fuzzy numbers and derived triangular interval type-2 weighted geometric (TIT2WG) operator with their desired mathematical
properties using Dombi triangular norms. Also, humidity control is analyzed using interval type-2 fuzzy controller (IT2FC)
with the use of derived aggregation operator which is the aim of the paper. Further stability of the system has been analyzed
by applying four different defuzzification methods and the method is recommended which gives a better response
Multifunctional star-shaped polylactic acid implants for use in angioplasty
Star-shaped polylactic acids with different tacticity were synthesized and both polymers are capable of bestowing properties of anticoagulation and angiogenesis to their living host.</p
Excitation of the GDR and the Compressional Isoscalar Dipole State by alpha scattering
The excitation of the isovector giant dipole resonance (GDR) by alpha
scattering is investigated as a method of probing the neutron excess in exotic
nuclei. DWBA calculations are presented for 28O and 70Ca and the interplay of
Coulomb and nuclear excitation is discussed. Since the magnitude of the Coulomb
excitation amplitude is strongly influenced by the Q-value, the neutron excess
plays an important role, as it tends to lower the energy of the GDR. The
excitation of the compressional isoscalar dipole state in 70Ca by alpha
scattering is also investigated. It is shown that the population of this latter
state may be an even more sensitive probe of the neutron skin than the
isovector GDR.Comment: 7 pages, 5 figures, Latex2
Learning and adaptation in speech production without a vocal tract
How is the complex audiomotor skill of speaking learned? To what extent does it depend on the specific characteristics of the vocal tract? Here, we developed a touchscreen-based speech synthesizer to examine learning of speech production independent of the vocal tract. Participants were trained to reproduce heard vowel targets by reaching to locations on the screen without visual feedback and receiving endpoint vowel sound auditory feedback that depended continuously on touch location. Participants demonstrated learning as evidenced by rapid increases in accuracy and consistency in the production of trained targets. This learning generalized to productions of novel vowel targets. Subsequent to learning, sensorimotor adaptation was observed in response to changes in the location-sound mapping. These findings suggest that participants learned adaptable sensorimotor maps allowing them to produce desired vowel sounds. These results have broad implications for understanding the acquisition of speech motor control.Published versio
Reflection confocal nanoscopy using a super-oscillatory lens
A Superoscillatory lens (SOL) is known to produce a sub-diffraction hotspot
which is useful for high-resolution imaging. However, high-energy rings called
sidelobes coexist with the central hotspot. Additionally, SOLs have not yet
been directly used to image reflective objects due to low efficiency and poor
imaging properties. We propose a novel reflection confocal nanoscope which
mitigates these issues by relaying the SOL intensity pattern onto the object
and use conventional optics for detection. We experimentally demonstrate
super-resolution by imaging double bars with 330 nm separation using a 632.8 nm
excitation and a 0.95 NA objective. We also discuss the enhanced contrast
properties of the SOL nanoscope against a laser confocal microscope, and the
degradation of performance while imaging large objects.Comment: 17 pages, 15 figures, supplementary include
MR Spectroscopic Imaging of Peripheral Zone in Prostate Cancer Using a 3T MRI Scanner: Endorectal versus External Phased Array Coils.
Magnetic resonance spectroscopic imaging (MRSI) detects alterations in major prostate metabolites, such as citrate (Cit), creatine (Cr), and choline (Ch). We evaluated the sensitivity and accuracy of three-dimensional MRSI of prostate using an endorectal compared to an external phased array "receive" coil on a 3T MRI scanner. Eighteen patients with prostate cancer (PCa) who underwent endorectal MR imaging and proton (1H) MRSI were included in this study. Immediately after the endorectal MRSI scan, the PCa patients were scanned with the external phased array coil. The endorectal coil-detected metabolite ratio [(Ch+Cr)/Cit] was significantly higher in cancer locations (1.667 ± 0.663) compared to non-cancer locations (0.978 ± 0.420) (P < 0.001). Similarly, for the external phased array, the ratio was significantly higher in cancer locations (1.070 ± 0.525) compared to non-cancer locations (0.521 ± 0.310) (P < 0.001). The sensitivity and accuracy of cancer detection were 81% and 78% using the endorectal 'receive' coil, and 69% and 75%, respectively using the external phased array 'receive' coil
Changing Bases: Multistage Optimization for Matroids and Matchings
This paper is motivated by the fact that many systems need to be maintained
continually while the underlying costs change over time. The challenge is to
continually maintain near-optimal solutions to the underlying optimization
problems, without creating too much churn in the solution itself. We model this
as a multistage combinatorial optimization problem where the input is a
sequence of cost functions (one for each time step); while we can change the
solution from step to step, we incur an additional cost for every such change.
We study the multistage matroid maintenance problem, where we need to maintain
a base of a matroid in each time step under the changing cost functions and
acquisition costs for adding new elements. The online version of this problem
generalizes online paging. E.g., given a graph, we need to maintain a spanning
tree at each step: we pay for the cost of the tree at time
, and also for the number of edges changed at
this step. Our main result is an -approximation, where is
the number of elements/edges and is the rank of the matroid. We also give
an approximation for the offline version of the problem. These
bounds hold when the acquisition costs are non-uniform, in which caseboth these
results are the best possible unless P=NP.
We also study the perfect matching version of the problem, where we must
maintain a perfect matching at each step under changing cost functions and
costs for adding new elements. Surprisingly, the hardness drastically
increases: for any constant , there is no
-approximation to the multistage matching maintenance
problem, even in the offline case
Erbium-doped fiber amplifier elements for structural analysis sensors
The use of erbium-doped fiber amplifiers (EDFA's) in optical fiber sensor systems for structural analysis is described. EDFA's were developed for primary applications as periodic regenerator amplifiers in long-distance fiber-based communication systems. Their in-line amplification performance also makes them attractive for optical fiber sensor systems which require long effective lengths or the synthesis of special length-dependent signal processing functions. Sensor geometries incorporating EDFA's in recirculating and multiple loop sensors are discussed. Noise and polarization birefringence are also considered, and the experimental development of system components is discussed
- …
