An estimate for the numerical radius of the Hilbert space operators and a numerical radius inequality

We provide a number of sharp inequalities involving the usual operator norms of Hilbert space operators and powers of the numerical radii. Based on the traditional convexity inequalities for nonnegative real numbers and some generalize earlier numerical radius inequalities, operator. Precisely, we prove that if \A_i,\B_i,\X_i\in\bh ($i=1,2,\cdots,n$), $m\in\N$, $p,q>1$ with $\frac{1}{p}+\frac{1}{q}=1$ and $\phi$ and $\psi$ are non-negative functions on $[0,\infty)$ which are continuous such that $\phi(t)\psi(t)=t$ for all $t \in [0,\infty)$, then \begin{equation*} w^{2r}\bra{\sum_{i=1}^{n}\X_i\A_i^m\B_i}\leq \frac{n^{2r-1}}{m}\sum_{j=1}^{m}\norm{\sum_{i=1}^{n}\frac{1}{p}S_{i,j}^{pr}+\frac{1}{q}T_{i,j}^{qr}}-r_0\inf_{\norm{x}=1}\rho(\xi), \end{equation*} where $r_0=\min\{\frac{1}{p},\frac{1}{q}\}$, S_{i,j}=\X_i\phi^2\bra{\abs{\A_i^{j*}}}\X_i^*, T_{i,j}=\bra{\A_i^{m-j}\B_i}^*\psi^2\bra{\abs{\A_i^j}}\A_i^{m-j}\B_i and \rho(x)=\frac{n^{2r-1}}{m}\sum_{j=1}^{m}\sum_{i=1}^{n}\bra{\seq{S_{i,j}^r\xi,\xi}^{\frac{p}{2}}-\seq{T_{i,j}^r\xi,\xi}^{\frac{q}{2}}}^2.Comment: No comment

Unsupervised Content Based Image Retrieval by Combining Visual Features of an Image With A Threshold

Content-based image retrieval (CBIR) uses the visual features of an image such as color, shape and texture to represent and index the image. In a typical content based image retrieval system, a set of images that exhibit visual features similar to that of the query image are returned in response to a query. CLUE (CLUster based image rEtrieval) is a popular CBIR technique that retrieves images by clustering. In this paper, we propose a CBIR system that also retrieves images by clustering just like CLUE. But, the proposed system combines all the features (shape, color, and texture) with a threshold for the purpose. The combination of all the features provides a robust feature set for image retrieval. We evaluated the performance of the proposed system using images of varying size and resolution from image database and compared its performance with that of the other two existing CBIR systems namely UFM and CLUE. We have used four different resolutions of image. Experimentally, we find that the proposed system outperforms the other two existing systems in ecery resolution of imag

Maximal service area problem for optimal siting of emergency facilities

Geographic information systems (GIS) have been integrated to many applications in facility location problems today. However, there are still some GIS capabilities yet to be explored thoroughly. This study utilizes the capability of GIS to generate service areas as the travel time zones in a facility location model called the maximal service area problem (MSAP). The model is addressed to emergency facilities for which accessibility is an important requirement. The objective of the MSAP is to maximize the total service area of a specified number of facilities. In the MSAP, continuous space is deemed as the demand area, thus the optimality was measured by how large the area could be served by a set of facilities. Fire stations in South Jakarta, Indonesia, were chosen as a case study. Three heuristics, genetic algorithm (GA), tabu search (TS) and simulated annealing (SA), were applied to solve the optimization problem of the MSAP. The final output of the study shows that the three heuristics managed to provide better coverage than the existing coverage with the same number of fire stations within the same travel time. GA reached 82.95% coverage in 50.60 min, TS did 83.20% in 3.73 min, and SA did 80.17% in 52.42 min, while the existing coverage only reaches 73.82%

Fabrication and Evaluation of 2-Hydroxyethyl Methacrylate-co-Acrylic Acid Hydrogels for Sustained Nicorandil Delivery

Purpose: To fabricate and evaluate oral 2-hydroxyethyl methacrylate co-acrylic acid hydrogels as a drug delivery system for sustained release of nicorandil.Methods: HEMA-co-AA hydrogels using different monomer concentrations were prepared by free radical polymerization. N, N-methylene bis acrylamide (MBA) was used as crosslinker and potassium persulphate (KPS) as initiator. Nicorandil (20 mg) loaded hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis and differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) . Swelling ratio, equilibrium swelling (ES), gel content (gc), porosity measurement (P) and in vitro drug release of the delivery system were evaluated.Results: Swelling ratio and ES decreased as AA concentration (%) was reduced from 3.173 to 2.93 (pH 1.2) and 16.42 to 15.01 (pH 7.4) and 68.49 to 65.90 (pH 1.2) and 93.91 to 93.34 (pH 7.4), respectively, while HEMA and MBA showed opposite effects. Gel content (%) and porosity (%) ranged from 83.76 to 88.0, respectively from F1 to F9. With increase monomer content (AA), drug release increased from 85.99 to 89.38 %. However, when the concentrations of HEMA and MBA were raised, drug release decreased.Conclusion: HEMA-co-AA hydrogels are potential pH-sensitive and sustained-release system for nicorandil.Keywords: Hydrogel, 2-Hydroxyethyl Methacrylate-co-acrylic Acid, Sustained Drug Release, Monomer, Nicorandil, Swelling Ratio, Porosit

Hydrophobicity properties of graphite and reduced graphene oxide of the polysulfone (PSf) mixed matrix membrane

Hydrophobicity properties of graphite and reduced graphene oxide (rGO) (from exfoliated graphite/rGO) towards PSf polymer membrane characteristic and properties at different additives weight concentrations (1, 2, 3, 4 and 5 wt. %) were investigated. Both PSF/graphite and PSf/rGO membranes were characterized in term of hydrophobicity, surface bonding, surface roughness and porosity. FTIR peaks revealed that membrane with graphite and reduced graphene oxide nearly diminished their O-H bonding which was opposite to the graphene oxide peak that shows a strong O-H bonding as increased exfoliated times. These results were in line with the contact angle results that showed strong hydrophobicity of graphite and reduced graphene oxide membranes as increased these additives concentration. The effect of strong hydrophobicity in these membranes also has resulted in smoother surface roughness compared to pristine PSf membrane. Further investigation of the performance of water flux also proved that both above membranes have strong hydrophobic effect, with the lowest pure water flux rate (L/m2h) was given by PSf/rGO 3% membrane at 19.2437 L/m2h

Formal Analysis of Linear Control Systems using Theorem Proving

Control systems are an integral part of almost every engineering and physical system and thus their accurate analysis is of utmost importance. Traditionally, control systems are analyzed using paper-and-pencil proof and computer simulation methods, however, both of these methods cannot provide accurate analysis due to their inherent limitations. Model checking has been widely used to analyze control systems but the continuous nature of their environment and physical components cannot be truly captured by a state-transition system in this technique. To overcome these limitations, we propose to use higher-order-logic theorem proving for analyzing linear control systems based on a formalized theory of the Laplace transform method. For this purpose, we have formalized the foundations of linear control system analysis in higher-order logic so that a linear control system can be readily modeled and analyzed. The paper presents a new formalization of the Laplace transform and the formal verification of its properties that are frequently used in the transfer function based analysis to judge the frequency response, gain margin and phase margin, and stability of a linear control system. We also formalize the active realizations of various controllers, like Proportional-Integral-Derivative (PID), Proportional-Integral (PI), Proportional-Derivative (PD), and various active and passive compensators, like lead, lag and lag-lead. For illustration, we present a formal analysis of an unmanned free-swimming submersible vehicle using the HOL Light theorem prover.Comment: International Conference on Formal Engineering Method

Numerical optimization of (FTO/ZnO/CdS/CH₃NH₃SnI₃/GaAs/Au) perovskite solar cell using solar capacitance simulator with efficiency above 23% predicted

The presented study deals with the investigations of the methyl ammonium tin halide (CH3NH3SnI3) based perovskite solar cells for optimized device performance using solar capacitance simulations software. Several necessary parameters such as metal work functions, thickness of structural layers, charge carrier’s mobility and defect density have been explored to evaluate the device performance. Calculations reveal that for the best efficiency of device the maximum thickness of the perovskite (CH3NH3SnI3) absorber layer must be 4.2 μm. The thickness values of 0.01 μm for ZnO electron transport layer (ETL), 0.871 μm for GaAs hole transport layer and 0.001 μm for CdS buffer layer have been found which proved to be optimum for maximum power conversion efficiency (PCE) of 23.80% for the device. The variation of open circuit voltage (Voc), Short circuit current (Jsc), Fill Factor (FF %), quantum efficiency (QE) against thickness of all layers and interface defect densities in FTO/ZnO/CdS/CH3NH3SnI3/GaAs/Au composition have been critically explored and their crucial role for the device performance has been reported. Heterojunctions between ZnO-ETL and CdS buffer layers have shown improved device performance and PCE. Current investigations may prove to be useful for designing and fabrication of climate friendly, non-toxic and highly efficient solar cells

Characteristics of butt welding imperfections joint using co-occurrence matrix

1164-1169The goal of this paper is to study the characteristics of the butt joint imperfections with different types of joint shapes (curve, straight and tooth saw work piece) according to their class categories (good welds, excess welds, insufficient welds and no welds). The work piece is placed in a center position on the workbench. The distance between camera and workpiece is set as 300 mm during welding imperfections process and the entire work piece image is taken from the same distance to maintain the accuracy. The input feature vector is determined by feature co-occurrence matrix consisting of energy, correlation, homogeneity and contrast both no scaled and scaled by 0.5. Results show that no welds class categories exhibit higher homogeneity compared to the other class categories. This is because the homogeneity value depends on bright and dark parts of a certain size and also include some changes from dark to bright. Meanwhile, insufficient welds class categories produced larger contrast value, but good weld class categories recorded higher contrast value

Arsenic an emerging issue: experiences from Pakistan

Arsenic contamination has emerged as a serious public health concern in Pakistan. In Punjab over 20% of the population are exposed to arsenic contamination of over 10 ppb in drinking water while nearly 3% of the population are exposed to over 50 ppb. In Sindh, the situation is even worse with 36% and 16% of population exposed to arsenic contaminated water over 10 ppb and 50 ppb respectively. Both shallow and deep sources have arsenic contamination. A recent study on prevalence of arsenicosis confirmed presence of 40 cases in the study population giving a prevalence 140/100,00 for established and borderline cases. The purpose of this paper is to share experiences gained in implementing an arsenic mitigation programme in the country