882 research outputs found
Common fixed-point theorems and c-distance in ordered cone metric spaces
We present a generalization of several fixed and common fixed point theorems on c -distance in ordered cone metric spaces. In this way, we improve and generalize various results existing in the literature.Наведено узагальнення деяких теорем про нерухому точку та спільну нерухому точку для с-відстані в упорядкованих конічних метричних просторах. Таким чином, покращено та узагальнено різноманітні результати, що наведені в літературі
Bridging the Gap Between Artificial Neural Networks and Kernel Regressions for Vector-Valued Problems in Microwave Applications
Thanks to their convex formulation, kernel regressions have shown an improved accuracy with respect to artificial neural network (ANN) structures in regression problems where a reduced set of training samples are available. However, despite the above interesting features, kernel regressions are inherently less flexible than ANN structures since their implementations are usually limited to scalar-output regression problems. This article presents a vector-valued (multioutput) formulation of the kernel ridge regression (KRR) aimed at bridging the gap between multioutput ANN structures and scalar kernel-based approaches. The proposed vector-valued KRR relies on a generalized definition of the reproducing kernel Hilbert space (RKHS) and on a new multioutput kernel structure. The mathematical background of the proposed vector-valued formulation is extensively discussed together with different matrix kernel functions and training schemes. Moreover, a compression strategy based on the Nystrom approximation is presented to reduce the computational complexity of the model training. The effectiveness and the performance of the proposed vector-valued KRR are discussed on an illustrative example consisting of a high-speed link and on the optimization of a Doherty amplifier
Evaluating the development of life and progress of heavy vehicles based on Analytical Hierarchy Process (AHP) in main subsystems
The development of automotive products considering product lifecycle is considered as one of the automotive strategic key issues. In this article, Analytical Hierarchy Process (AHP) is used to evaluate the lifetime of heavy vehicles. To do this research, subsystems of weighted Titan heavy vehicle and the position of desired vehicle compared to other vehicles in the various subsystems and in general by the technical standards, new technologies and aesthetic appearance is evaluated. Finally, the curve of progress and technology life of Titan vehicle is provided. The results show that technical standards in automotive technology growth curve has the greatest impact in comparison with other properties. About Titan vehicle according to the technology lifecycle should be considered this issue that the technology of this vehicle because spending their maturity era is in decline. Regarding the investigation of new technologies, we have to think to make changes in vehicle technology or finding alternative technology. According to the first priority, criteria and the weight of analytic hierarchy process, the technical criteria, first the action should be done in technical improvements of the vehicle, and also considering that the sub-criteria of engine performance assigned the highest weight to itself, most of the studies should be placed in order to improve Titan automotive technology in terms of vehicle performance.Keywords: lifecycle, lifecycle of technology, heavy vehicles, subsystems, Analytical Hierarchy Process (AHP
Crosstalk analysis of multi‐microstrip coupled lines using transmission line modeling
This article presents a new analytical method to predict crosstalk of a homogeneous terminated two microstrip coupled lines over a ground plane using transmission line theory. The derived formula is frequency and location dependent, which can be used to quickly estimate the crosstalk of a coupled line. Also, the effect of the geometrical parameters of the lines and load are included in the derived formula. Presented method can be used for the other types of coupled lines including lossy or lossless lines. To verify the accuracy of the introduced method, a few microstrip coupled line structures with different geometrical parameters are considered numerically and experimentally. The results of crosstalk based on the proposed analytical methods, simulation study using high frequency structure simulator and those obtained by measurements are reported and compared with each other. It is shown that our proposed method accurately estimates the amount of crosstalk for a two microstrip coupled lines
Crosstalk analysis at near-end and far-end of the coupled transmission lines based on eigenvector decomposition
In this paper, a new analytical method is proposed to accurately estimate the near-end and far-end crosstalk of a coupled Transmission Lines (TLs) based on eigenvector decomposition. For a non-homogenous two coupled lines, the related linear differential equations system (LDES) is derived for distributed voltage and current and then using matrix analysis, its four distinct eigenvalues and their associated eigenvectors are determined. It is shown that the two eigenvalues represent the self-propagation constant, while the other ones are linked to the mutual propagation constant of the coupled lines. In addition to, for these lines a closed form expression for near-end and far-end crosstalk is presented. In special case of homogenous coupled lines, the LDES is also determined and it is shown that they provide two couples of eigenvalues. Using the concept of generalized eigenvalues, the solution of these systems is derived and a closed form formula is derived for crosstalk. In order to verify the accuracy of the proposed method a few types of coupled lines, including homogeneous or non-homogeneous are investigated and the amount of crosstalk is estimated. The calculated crosstalk is presented and compared with those obtained by numerical investigation. It is shown that a good agreement is obtained between the calculated and measured results
Crosstalk analysis of uniform and nonuniform lossy microstrip-coupled transmission lines
In this article, an analytical method is presented to precisely estimate the crosstalk of uniform and nonuniform microstrip-coupled transmission lines (TLs) in frequency domain using modified transmission matrix. The obtained expression is quantitatively related in terms of the geometrical parameters of the coupled lines. A straightforward procedure is presented to obtain a closed form formula to accurately determine the crosstalk of a microstrip-coupled line. For a nonuniform structure, the TL is divided into a few series of uniform sections with a specific modified transmission matrix. The total modified transmission matrix is determined by multiplying the modified transmission matrix of different sections and then the crosstalk can be calculated using the total modified transmission matrix. Several structures are considered to confirm the validity of the presented method. It is shown that the obtained results are in a good agreement with those obtained by simulation and measurement
Antioxidants Classification and Applications in Lubricants
Oxidation is a chemical reaction that occurs in lubricants upon exposure to an oxidizing agent such as oxygen and can be catalyzed by copper and iron. Antioxidants are a group of chemicals that can be used in the formulation of lubricants to stop or reduce the rate of oxidation. Based on the mechanism of action, antioxidants are categorized as primary antioxidants (radical scavengers), secondary antioxidants (Peroxide decomposers), and metal deactivators (complex-forming or chelating agents). Selection of the antioxidants in a formulation is a critical decision that depends on the base oil, application and other ingredients in the formulations. Presence of some other ingredients in the product with antagonistic behavior may suppress the role of antioxidants; however, optimal application of antioxidants with synergistic behavior would increase the stabilization impact of the ingredients on the base oil
Clinical trial of the effects of coenzyme Q10 supplementation on glycemic control and markers of lipid profiles in diabetic hemodialysis patients
Abstract
Purpose:
The current study was conducted to determine the effects of coenzyme Q10 (CoQ10) supplementation on glycemic control and markers of lipid profiles risk in diabetic hemodialysis (HD) patients.
Methods:
This randomized, double blind, placebo-controlled clinical trial was performed among 60 diabetic HD patients.
Subjects were randomly allocated into two groups to take either 120 mg/day of CoQ10 supplements or placebo (n= 30each group) for 12 weeks.
Results:
After 12 weeks of intervention, CoQ10 supplementation, compared with the placebo, resulted in a significant
decrease in serum insulin concentrations (− 2.5 ± 4.0 vs.+ 2.8 ± 5.3 μIU/mL, P < 0.001), homeostasis model of assessment estimated insulin resistance (− 0.9 ± 2.1 vs. + 1.2 3.0, P = 0.002), and significant increase in the quantitative insulin sensitivity check index (+ 0.009 ± 0.01 vs. − 0.02 ± 0.05, P = 0.003). In addition, a trend toward a greater decrease in serum triglycerides (− 5 ± 53 vs. + 17 ± 44, P = 0.078) and VLDL-cholesterol levels (− 0.9 ± 10 vs. + 3 ± 9, P = 0.078) was observed in the CoQ10 group compared to the placebo group. We did not observe any significant effect of CoQ10 supplementation
on fasting glucose, HbA1c and other lipid profiles compared with the placebo.
Conclusions:
Overall, our study supported that CoQ10 supplementation to diabetic HD patients for 12 weeks had beneficial
effects on markers of insulin metabolism, but did not affect fasting glucose, HbA1c, and lipid profiles.
Keywords:
Coenzyme Q10 supplementation · Hemodialysis · Glycemic control · Lipid profile
SUSY dark matter and lepton flavor violation
We study lepton flavor-violating (LFV) processes within a supersymmetric
type-I seesaw framework with flavor-blind universal boundary conditions,
properly accounting for the effect of the neutrino sector on the dark matter
relic abundance. We consider several possibilities for the neutrino Yukawa
coupling matrix and show that in regions of SUSY parameter space that yield the
correct neutralino relic density, LFV rates can differ from naive estimates by
up to two orders of magnitude. Contrary to common belief, we find that current
LFV limits do not exclude neutrino Yukawa couplings larger than top Yukawa
couplings. We introduce the ISAJET-M program that was used for the
computations.Comment: 37 pages, 9 figures, 6 tables. Version to appear in PR
- …