Information Parameters of Electrical Quantities of the Transient for Determining the Single-Phase Earth Fault Location in Сable Medium-Voltage Systems

Rapid fault determination of single-phase earth fault (SPEF) and SPEF location on the line are extremely important for the speedy elimination of damage and restoring normal operation of the power supply. Effective methods of SPEF determination on the cable lines under voltage do not still exist in medium voltage networks. The electrical values of the transition process that occurs during the breakdown of the insulation can be used for solving the problem of determining the place of single-phase including self-eliminating faults. The best method to study the electromagnetic transients at SPEF in medium-voltage networks and to identify the information parameters, which can be used for distant SPEF determination, is a combination of analytical methods on the basis of simplified models of the electrical networks and the method of computer simulation

Bilinear Spherical Maximal Functions of Product Type

In this paper we introduce and study a bilinear spherical maximal function of product type in the spirit of bilinear Calderón–Zygmund theory. This operator is different from the bilinear spherical maximal function considered by Geba et al. in (Math Res Lett20(4):675–694, 2013). We deal with lacunary and full versions of this operator, and prove weighted estimates with respect to genuine bilinear weights beyond the Banach range. Our results are implied by sharp sparse domination for both the operators,following ideas by Lacey (J Anal Math 139(2):613–635, 2019). In the case of the lacunary maximal operator we also use interpolation of analytic families of operators to address the weighted boundedness for the whole range of tuplesRYC2018-025477-I Ikerbasqu

Bilinear Bochner-Riesz square function and applications

In this paper we introduce Stein's square function associated with bilinear Bochner-Riesz means and develop a systematic study of its $L^p$ boundedness properties. We also discuss applications of bilinear Bochner-Riesz square function in the context of bilinear fractional Schr\"{o}dinger multipliers, generalized bilinear spherical maximal function and more general bilinear multipliers defined on $\mathbb{R}^{2n}$ of the form $(\xi,\eta)\rightarrow m\left(|(\xi,\eta)|^2\right)$.Comment: Comments are welcom

Sharp endpoint Lp−L^p-estimates for Bilinear spherical maximal functions

In this article, we address endpoint issues for the bilinear spherical maximal functions. We obtain borderline restricted weak type estimates for the well studied bilinear spherical maximal function $$\mathfrak{M}(f,g)(x):=\sup_{t>0}\left|\int_{\mathbb S^{2d-1}}f(x-ty_1)g(x-ty_2)\;d\sigma(y_1,y_2)\right|,$$ in dimensions $d=1,2$ and as an application, we deduce sharp endpoint estimates for the multilinear spherical maximal function. We also prove sharp $L^p-$estimates for the local spherical maximal function in all dimensions $d\geq 2$, thus resolving a question left open in the work of Jeong and Lee (https://doi.org/10.1016/j.jfa.2020.108629). We further study necessary conditions for the bilinear maximal function, $$\mathcal M (f,g)(x)=\sup_{t>0}\left|\int_{\mathbb S^{1}}f(x-ty)g(x+ty)\;d\sigma(y)\right|$$ to be bounded from $L^{p_1}(\mathbb R^2)\times L^{p_2}(\mathbb R^2)$ to $L^p(\mathbb R^2)$ and prove sharp results for a linearized version of $\mathcal M$.Comment: 24 pages, 3 figures and 2 tables. Added new results for full and local bilinear spherical maximal functions. Improved the presentation and changed the title of the pape

Retinoblastoma gene mutations in primary human bladder cancer.

Inactivation of the retinoblastoma (RB) gene is known to be implicated in the pathogenesis of several types of human cancers. Since structural alterations of the RB gene have not been well examined in human bladder cancer, we looked for mutations in the entire coding region of this gene using polymerase chain reaction (PCR) and single-strand conformational polymorphism analysis of RNA. We also examined allelic loss of the RB gene using PCR-based restriction fragment length polymorphism analysis. Of 30 samples obtained from patients with bladder cancer, eight (27%) were found to have RB gene mutations. DNA sequencing of the PCR products revealed five cases with single point mutations and three cases with small deletions. These mutations included one (10%) of ten low-grade (grade 1) tumours, four (50%) of eight intermediate-grade (grade 2) tumours and three (25%) of 12 high-grade (grade 3) tumours. Likewise, mutations were found in four (21%) of 19 superficial (pTa and pT1) tumours and four (36%) of 11 invasive (pT2 or greater) tumours. In 15 informative cases, loss of heterozygosity at the RB locus was shown in five cases (33%), three cases with RB mutations and two without them. These results suggest that RB gene mutations are involved in low-grade and superficial bladder cancers as well as in high-grade and invasive cancers

Selective complex single-phase earth fault protection for distribution medium-voltage networks

This article deals with selective protection against single-phase earth faults at 6 – 10 kV electrical networks. Different kinds of earth faults, factors influencing the implementation of protection, various principles of protection implementation, are described. Requirements and structure of complex protection applicable to networks with any neutral grounding mode and providing separation of various kinds of earth faults are given in this text

Application of higher harmonics in protection against single-phase earth faults in resonant grounded cable networks of medium voltage

Protections based by higher harmonics absolute measurements the zero sequence currents of the protected object connections against single-phase earth faults in resonant grounded cable networks of medium voltage industrial and urban energy supply systems have been widely applied in Russia since the late 60s of the 20th century. However, some operational problems connected with sufficient selectivity and sensitivity of these protection devices appeared with time. Sensitivity and selectivity of this protection are considerably determined by the instability degree of the higher harmonics total level in single-phase earth fault current of the protected network. Well-known Russian expert Kiskachi V.M. gave approximate estimate of the higher harmonics instability degree at the end of the 60s. Nowadays due to load changes in the main substations load in resonant grounded cable networks of medium voltage higher harmonics fluctuations in single-phase to earth fault current. The simulation models of this networks application and the accumulated experimental data about real networks allow to specify the existing estimates of higher harmonics instability in single-phase to earth fault current and their applicability conditions

Study of Automatic Forest Road Design Model Considering Shallow Landslides with LiDAR Data of Funyu Experimental Forest

In this study, a model to automatically design a forest road considering shallow landslides using LiDAR data was examined. First, in order to develop a shallow landslide risk map of the Funyu Experimental Forest, a slope stability analysis was carried out using the infinite slope stability analysis formula. The soil depth was surveyed at 167 points using simple penetration tests, and the frequency distributions of the soil depth were estimated as logarithmic normal distributions. A soil depth map of the experimental forest was made using the mode values of the lognormal distributions. Then, shallow landslide risk maps were also made for the experimental forest by a slope stability analysis using these soil depth distributions. Finally, an automatic forest road design model was developed with a LiDAR based highly accurate Digital Terrain Model (DTM) and shallow landslide risk map using cubic spline interpolation and dynamic programming. The program has capability of minimizing the earthwork costs while avoiding shallow landslide risk areas. The program can be effectively used to design an environmentally sound low volume road automatically