This paper presents stability robustness results for linear multivariable discrete-time systems with uncertainties. Robust stability of the full-state feedback linear quadratic regulator in the ...presence of perturbations of the system parameters is investigated. These results are based on recently developed bounds on structured perturbations of a stable linear discrete-time system. The paper applies these results to a paper-machine head box system example.
A reduced-order dynamic compensator design is presented with stability robustness for linear discrete systems, by including a stability robustness component in addition to the standard quadratic ...state and control terms in the performance criterion. The robustness component is based on an unstructured perturbation stability bound for time varying perturbations. The controller design is developed by the parameter optimization technique and involves the solution of five algebraic matrix equations, four of which are discrete-time Lyapunov matrix equations.< >
Single-phase phosphors that emit broadband white-light are needed for white-light-emitting diodes (wLEDs) to reach their full potential. However, it is challenging to achieve broad white-light ...emission from single-phase materials. Consequently, polycrystalline inorganic bulk compounds that emit white-light sans doping are rare. We report on broadband white-light emission from a well-known garnet compound, i.e., yttrium iron garnet (YIG), without activator-ion doping. Upon near-UV excitation at 370 nm, polycrystalline bulk YIG emits broadband white-light with (1931) Commission Internationale de L’Eclairage (CIE) coordinates as (0.28, 0.35) and correlated color temperature (CCT) as 8029 K. Variable excitation wavelengths ranging from 280 to 600 nm enable color-tunable emission as cyan-white-blue-green-yellow-orange-red, including near-white-light emission for a broad range of excitation from 325 to 390 nm. Moreover, a short lifetime (sub-nanosecond) is obtained, which is desirable for LED and other applications. We demonstrated the propriety of YIG as a single-phase converting phosphor for illumination by fabricating prototype wLEDs using commercial InGaN UV-LED chips (λ = 380 nm) for excitation. The CIE coordinates and CCT of prototype wLEDs were obtained as (0.34, 0.37) and 5284 K, respectively. We believe that the reported findings signify the great potential of YIG as a single-phase white-light-emitting phosphor for broadband emission, which offers a new perspective and a viable approach for the development of wLEDs.
We report on multiple excitonic resonances in bilayer tungsten diselenide (BL-WSe
) stacked at different angles and demonstrate the use of the stacking angle to control the occurrence of these ...excitations. BL-WSe
with different stacking angles were fabricated by stacking chemical vapour deposited monolayers and analysed using photoluminescence measurements in the temperature range 300–100 K. At reduced temperatures, several excitonic features were observed and the occurrences of these exitonic resonances were found to be stacking angle dependent. Our results indicate that by controlling the stacking angle, it is possible to excite or quench higher order excitations to tune the excitonic flux in optoelectronic devices. We attribute the presence/absence of multiple higher order excitons to the strength of interlayer coupling and doping effect from SiO
/Si substrate. Understanding interlayer excitations will help in engineering excitonic devices and give an insight into the physics of many-body dynamics.
Integration of yttrium iron garnet (YIG) with Si can bring new avenues for garnet-based complementary metal-oxide semiconductor compatible devices. Herein, investigations on the morphological, ...electrical, and magnetic properties of postgrowth annealed YIG thin films grown on Si substrate were systematically performed at nanoscale lateral resolution, employing the variants of atomic force microscopy (AFM) viz., conductive AFM (C-AFM), kelvin probe force microscopy, and magnetic force microscopy (MFM). Scanning electron microscopy analysis has revealed the formation of three different regions with varied crystallinity defined as center, dark, and surrounding matrix. Interestingly, AFM topography has not shown any surface variation of the obtained three different regions. Despite no variation in their surface topography, notable changes occur in their local conductivity, surface potential, and microstructure of their magnetic domains. C-AFM studies have shown the formation of conducting channels with three different resistivity regions. The tunneling current was enhanced nearly 50 times from the dark region (~1 pA) to the center region (~50 pA). MFM image analysis reveals the formation of two different magnetically active domains in the form of circles (-0.3°) distributed in a surrounding matrix (+0.3°) with a steep change in their magnetic phase degree. The formation of circular magnetic domains with highly distinguishable regions has suggested the potential of YIG/Si films for magnetic memory application. This work has shed light on the prospective of YIG/Si films for resistive and magnetic memory applications and fundamental aspects of growth of YIG on nongarnet substrates.
Breast cancer is the most frequent cancer among women after lung cancer. It is second popular cause of death in the world. Breast cancer cells usually form a tumor (abnormal tissue).There are two ...types of breast cancer tumors: those that are non-cancerous, or ‘benign’, and those that are cancerous, which are ‘malignant’. Early detection of cancer tumors can prevent its mortality and can take respective precautions according to the type of cancer tumor (either it is benign or malignant). The main objective of this paper is to early diagnosis of the malignancy of cancer tumors which helps to decrease the death rate and helps to give more lives. The selection of suitable deep learning technique is a challenge for the diagnosis of breast cancer. So we created model for prediction of malignancy of cancer tumors using neural network to analyze risk levels that helps in prognosis. It is useful for a doctor to predict the stage of cancer and take respective precautions
A suprascapular nerve entrapment can occur at the suprascapular notch or at the spinoglenoid notch. So, the size and shape of the suprascapular notch are associated with suprascapular entrapment ...neuropathy as well as with an injury to the suprascapular nerve in arthroscopic procedures. The knowledge on the variations along the course of the nerve is important in understanding the source of the entrapment syndrome.
The present study was carried out on 104 scapulae which were obtained from the Department of Anatomy, NRI Medical College and from other nearby medical colleges. The suprascapular notches in the scapulae were classified, based on the descriptions of Rengachary et al and Ticker et al. The distance between the suprascapular notch and the supraglenoid tubercle, and the distance between the posterior rim of the glenoid cavity and the medial wall of the spinoglenoid notch at the base of the scapular spine, were determined. The data were analyzed statistically.
Based on the Rengachary classification, the type III notch was more common. The suprascapular foramen was observed in 2 scapulae. In 56.73% scapulae, the superior transverse diameter was greater than the maximum depth. The U shaped notch (69.23%) was more common. 2.88% and 8.65% scapulae fell short of the mentioned respective safe zone distances from the margin of the glenoid cavity.
Such studies may be useful in understanding the role of the notch in causing nerve entrapment and to prevent iatrogenic nerve injuries while posterior approaches are made to the shoulder joint.
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