Specific Transformation Research Articles

Optimization of distribution network reconfiguration based on Markov chain Monte Carlo method

Peak load shaving and load balancing are of great significance to reduce distribution network loss and improve resource utilization. Given this background, an optimization strategy for distribution network reconfiguration based on Markov chain Monte Carlo method is proposed. In this strategy, a load characteristic curve clustering method considering DBI index is proposed to obtain the typical load curves of each public transformer and special transformer user under low voltage distribution line based on the historical load curves. Then, an optimization model for distribution network reconfiguration based on Markov chain Monte Carlo method is proposed to minimize the average peak–valley difference of the distribution line, and the line connection modification scheme is obtained. Finally, case studies on two 10 kV distribution lines in Zhejiang province are performed for verifying the effectiveness of the proposed model. The results show that the proposed method can improve the line load rate and realize the peak load shaving and valley load filling of line load, which provides a reference for distribution network reconfiguration.

Derivation of Special Relativity Transformation Formulas Without Time Slowing and Length Shrinking——Modification of Relativistic Aberration Formula

Derivation of Special Relativity Transformation Formulas Without Time Slowing and Length Shrinking——Modification of Relativistic Aberration Formula

Derivation of Special Relativity Transformation Formulas without Time Delay Effect and Length Contraction Effect

Derivation of Special Relativity Transformation Formulas without Time Delay Effect and Length Contraction Effect

Derivation of Special Relativity Transformation Formulas Without Time Slowing and Length Shrinking——Modification of Relativistic Aberration Formula

Derivation of Special Relativity Transformation Formulas Without Time Slowing and Length Shrinking——Modification of Relativistic Aberration Formula

Derivation of Special Relativity Transformation Formulas Without Time Slowing and Length Shrinking——Modification of Relativistic Aberration Formula

Derivation of Special Relativity Transformation Formulas Without Time Slowing and Length Shrinking——Modification of Relativistic Aberration Formula

Derivation of Special Relativity Transformation Formulas Without Time Slowing and Length Shrinking

Derivation of Special Relativity Transformation Formulas Without Time Slowing and Length Shrinking

Derivation of Special Relativity Transformation Formulas Without Time Slowing and Length Shrinking——Modification of Relativistic Aberration Formula

Derivation of Special Relativity Transformation Formulas Without Time Slowing and Length Shrinking——Modification of Relativistic Aberration Formula

Derivation of Special Relativity Transformation Formulas Without Time Slowing and Length Shrinking——Modification of Relativistic Aberration Formula

Derivation of Special Relativity Transformation Formulas Without Time Slowing and Length Shrinking——Modification of Relativistic Aberration Formula

Hybrid Nanofluid Flow Induced by an Oscillating Disk Considering Surface Catalyzed Reaction and Nanoparticles Shape Factor.

Lately, a new class of nanofluids, namely hybrid nanofluids, has been introduced that performs much better compared with the nanofluids when a healthier heat transfer rate is the objective of the study. Heading in the same direction, the present investigation accentuates the unsteady hybrid nanofluid flow involving CuO, Al2O3/C2H6O2 achieved by an oscillating disk immersed in the porous media. In a study of the homogeneous and heterogeneous reactions, the surface catalyzed reaction was also considered to minimize the reaction time. The shape factors of the nanoparticles were also taken into account, as these play a vital role in assessing the thermal conductivity and heat transfer rate of the system. The assumed model is presented mathematically in the form of partial differential equations. The system is transformed by invoking special similarity transformations. The Keller Box scheme was used to obtain numerical and graphical results. It is inferred that the blade-shaped nanoparticles have the best thermal conductivity that boosts the heat transfer efficiency. The oscillation and surface-catalyzed chemical reactions have opposite impacts on the concentration profile. This analysis also includes a comparison of the proposed model with a published result in a limiting case to check the authenticity of the presented model.

Новая методика расчета силового трансформатора для системы бесконтактного заряда аккумуляторных батарей подводного робота

Object and purpose of research. The research object is a special power transformer, which is a necessary functional element of the contactless battery charging system for autonomous undersea robots. There are separate primary and secondary parts of the transformer with a non-magnetic gap between windings and center-tocenter shift. It is to be taken into account during its design and requires a special purpose method, which is the focus of this study. The suggested method makes it possible to achieve the design parameters for the transformer using a ferrite cup-shaped magnetic conductor optimized for specific power, taking into account onboard undersea robot specifics. Materials and methods. The method suggests a system of relative units with a basic value of the outside core diameter. The method is based on the coefficient of magnetic coupling between windings and relative turn inductance completely defining the transformer electromagnetic properties as a function of relative gap and center-to-center shift between windings [1]. Calculations are done using mathematical modeling in Ansys Maxwell and Solidworks software packages. Design parameters of the transformer to provide maximum charge power are determined by maximum ampere turns related to admissible overheating of magnetic conductor with a full use of magnetic conductor aperture. Main results. The number of ampere turns and cross-section of windings are calculated, as well as the invertor frequency is determined at a given supply voltage and range of ferrite cup-shaped magnetic conductors. The calculated transformer parameters have to ensure the maximum wattage at admissible overheating of windings and given nonmagnetic gaps and center-to-center shifts. A case study and full-scale experiment has confirmed the choice of solutions and drawn conclusions. Conclusion. The use of the transformer designed by this method in the system raises the total efficiency of autonomous undersea robots.

Formula omitted]-dressing method for the nonlocal mKdV equation

We apply the ∂¯-dressing method to study nonlocal modified Korteweg-de Vries (nonlocal mKdV) equation. A spatial and a time singular spectral problems associated with nonlocal mKdV equation are derived from a local 2×2 matrix ∂¯-equation via two linear constraint equations. A nonlocal mKdV hierarchy is proposed by using recursive operator. And the conservation laws of the nonlocal mKdV are derived by the temporal linear spectral problem. The N-solitions of the nonlocal mKdV equation are constructed still based the ∂¯-equation by choosing a special spectral transformation matrix. Further the explicit one- and two-soliton solutions are obtained. The results on the mKdV equation can be recovered from the conclusion given above as special reductions.

Study of Animated Manifestations in Some of the Characters in the Paintings of Sultan Mohammad

In the Persian traditional painting, we confront a special view. It changes the coordinates of our visual comprehension in order to abshact from matter and representation of realities which are cryptographic behind that, and it changes the known rules of seeing and accepting. In a fantastic atmosphere such as Persian painting, there is a special system which the whole of qualities are affected by it. The “Movement“ as an important element is one of those elements. Persian painter who is affected by rich Persian philosophy and literature, notes the “Movement” as an important matter and although he hasn’t any tools for actual ideogram of “Movement“, he tries to express his sightly moves in 2D paper, that’s his equipment in best conditions. All of the exaggerates and stylizations which applied on the human figures are special movement creators. One of the leading Iranian painters who has embodied spaces full of fantasy and pure imagination in his paintings, Sultan Mohammad Naghash, is one of the painters of Tabriz II school. This study tries to examine these images of motion fantasy; The author’s question is: “In what form and style are the animated effects in the human characters of Sultan Muhammad’s works manifested?” The purpose of this study is to achieve a meaningful structure and purposeful method in drawing human figures and also to achieve a coherent and generalizable method in the body of contemporary Iranian visual arts. The research method is based on the descriptive-analytical study of Sultan Mohammad’s iconography and adopts a two-way structuralist-semantic approach. The result of this study is to understand and receive the method of exaggeration and special transformation of Sultan Mohammad in drawing the figures based on the intended meaning of the drawing and predicting the way of movement for the mentioned figures.

Special transformer sharing mode: Utilizing special transformers of buildings to supply power for charging stations

AbstractIn view of the limited capacity for public transformers to accept electric vehicles (EVs) and the large cost of putting in new transformers to supply power in the parking lot of urban buildings, a special transformer sharing mode (STSM) is proposed, where charging station operators utilize the special transformers of buildings to supply power for charging stations. To enhance the applicability of STSM, single regulation and joint regulation methods for the charging price strategy of charging stations are put up, and the mathematical model of joint regulation is focused on. First of all, a joint regulation mechanism is established, in which EVs are guided to charge off‐peak and off‐station through the joint regulation. Secondly, integrating charging fees, queuing costs, and transfer costs, the equivalent charging prices for EV users are put forward. Based on the difference of the equivalent charging prices, transfer probability model for EVs’ charging periods and charging stations is proposed. Furthermore, the overall objective of joint regulation is built based on the net income of all parties. And an optimization method for the joint regulation of charging prices is proposed. Then, regulation lifting ratio is put forward to reflect the superiority of joint regulation over single regulation. Based on this, an evaluation model for joint station diameter threshold is established. The practical result proves that through single regulation and joint regulation, approximately 200–500 additional EVs can be powered, which will result in significant savings in infrastructure construction and investment costs.

Brane world creation from flat or almost flat space in dynamical tension string theories

There is great interest in the construction of brane worlds, where matter and gravity are forced to be effective only in a lower dimensional surface, the brane . How these could appear as a consequence of string theory is a crucial question and this has been widely discussed. Here we will examine a distinct scenario that appears in dynamical tension theories and where string tension is positive between two surfaces separated by a short distance and at the two surfaces themselves the string tensions become infinite, therefore producing an effective confinement of the strings and therefore of all matter and gravity to the space between these to surfaces, which is in fact a new type of stringy brane world scenario. The basic formulation for obtaining this scenario consist of assuming two types of strings characterized by a different constant of integration related to the spontaneous string tension generation. These string tension multiplied by the embedding metric define conformally related metrics that both satisfy Einsteins equation. The braneworlds appear very naturally when these two metrics are both flat spaces related by a special conformal transformation. The two types of string tensions are determined and they blow up at two close expanding surfaces. A puzzling aspect appears then: the construction is based on flat spaces, but then there are also strings with very large tension near the boundaries of the braneworld,so can the back reaction from the infinite tension strings destroy the flat space background? Fortunatelly that can be resolved using the mechanism Universe creation from almost flat (or empty) spaces, which incorporates a gas of very large string tensions in a membrane, studied before in 1+1 membranes in a 2+1 embedding space and now is generalized for a 1+(D-2) membrane moving in a 1+(D-1) space.

Research on influencing factors of line loss rate of regional distribution network based on apriori-interpretative structural model

The power industry involves people’s livelihood. While ensuring the normal operation of the power system, power companies also need to consider strengthening line loss management to promote grid efficiency. Through grounded theory, 19 factors affecting regional distribution network line loss are extracted from the management and technical perspectives. The Apriori algorithm is used to analyze the data of Chuzhou distribution network line loss rate, and the connection between different influencing factors and line loss rate is analyzed. Association rules are used to filter out the key influencing factors. Finally, the calculation results of the Apriori algorithm and the interpretation structure model (ISM) are combined to make up for the shortcomings of ISM’s strong subjectivity and draw the influence path diagram of the regional distribution network line loss rate based on Apriori-ISM. The results show that measurement errors, the number of strain-resistant sections, the total number of special transformers, the cross-sectional area of conductors, the number of aging transformers, load switching, power theft, and operating time are the direct factors affecting the line loss rate of the regional distribution network, whose confidence levels are 100%, 81.06%, 91.76%, 89.36%, 89.38%, 83.23%, 84.39% and 90.53% respectively, and the correlation is strong.

Numerical methods for Cauchy principal value integrals of oscillatory Bessel functions

In this paper, we first propose different combination methods to compute the Cauchy principal value integrals of oscillatory Bessel functions. By special transformations, the considered integrals are converted to finite integrals and infinite integrals. Then, the finite integrals can be calculated through the Filon-type method, the Clenshaw–Curtis–Filon method and the Clenshaw–Curtis–Filon-type method, respectively. We compute the infinite integral through the numerical steepest descent method. Moreover, the error analysis with respect to frequency ω is given through theoretical analysis. Eventually, we present several numerical experiments which are in accord with our analysis. Particularly, the accuracy can be improved by either using more nodes or adding more derivatives interpolation at endpoints. The accuracy will increase drastically with the growth of frequency ω if both the number of nodes and interpolated multiplicity are fixed.

Demand response ability evaluation based on seasonal and trend decomposition using LOESS and S–G filtering algorithms

With the more and more frequent short-term peak loads appear in power systems in recent years, it is challenging to keep load and frequency steady for power systems. Demand response is launched to shave the load peak and fill the load valley. Daily load and regularity of electricity consumption behavior for special transformer users are studied in this paper. Demand response ability evaluation method based on seasonal and trend decomposition using locally weighted regression (LOESS) and Savitzky–Golay (S–G) filtering algorithms is proposed, which can optimize the effectiveness of demand response, and make the total power of demand response as close to expectations as possible. First, according to the arrangements of startup and shutdown for various devices of special transformer users in the actual production and business, seasonal load curve platforms that can reflect the habit of devices put into production for special transformer users in a day are obtained by seasonal and trend decomposition using LOESS (STL). Second, the S–G filtering algorithm is used to determine the load power for each load curve platform and evaluate the demand response ability of special transformer users. To show the effectiveness of the proposed evaluation method, a peak-shaving demand response for special transformer users in Zhejiang province is utilized for case studies. The simulation results of users with different demand response abilities show that the evaluation method proposed can accurately evaluate the demand response ability of special transformer users and provide scientific guidance for power companies to implement demand-side management.

Spinors and conformal correlators

In conformal field theory, momentum eigenstates can be parameterized by a pair of real spinors, in terms of which special conformal transformations take a simpler form. This well-known fact allows to express 2-point functions of primary operators in the helicity basis, exposing the consequences of unitarity. What is less known is that the same pair of spinors can be used, together with a pair of scalar quantities, to parameterize 3-point functions. We develop this formalism in 3 dimensions and show that it provides a simple realization of the operator product expansion (OPE) for scalar primary operators acting on the vacuum.

High pressure-induced phase transition in nanocrystalline iron confined by single-walled carbon nanohorns

This study examines the high-pressure structural properties of nanocrystalline Fe confined by single-walled carbon nanohorns (SWCNHs) and SWCNHs (filled with Fe nanoparticles) named Fe-filled SWCNHs up to a pressure of 21.8 GPa. In detail, the Fe-filled SWCNHs did not undergo a special structural transformation at up to 21.8 GPa, except the partial irreversible amorphization of graphene sheets forming the core part above ∼18 GPa. Cubic Fe (bcc Fe) and Fe3O4 coexisted simultaneously in the Fe-filled SWCNHs. The Fe encapsulated by the SWCNH underwent a reversible transformation from bcc Fe to a hexagonal Fe (hcp Fe) at 11.7 GPa and reversed to bcc Fe at 6.2 GPa with a width of the domain of coexistence of bcc hcp of the order of 5 GPa. Due to the effect of the special tubular confinement of the SWCNHs, the high-pressure behavior of Fe confined by them exhibited a sharp contrast to that of Fe confined by carbon nanotubes. In comparison to the bulk bcc Fe, hcp Fe, and Fe3O4, these nanocrystallines confined by SWCNHs had higher compressibility than their bulk phases. Fe3O4 did not exhibit any phase transformation until 21.8 GPa, where this was similar to the results of bulk Fe3O4.

A new algorithm for the identification of sinusoidal signal frequency with constant parameters

The paper presents a solution for identifying the frequency of a sinusoidal signal with constant parameters. The issue can be relevant for compensation of disturbances, control of dynamic objects, and other tasks. The authors propose a method to improve the quality of the estimation of the sinusoidal signal frequency and to ensure exponential convergence to zero of the estimation errors. At the first stage, the sinusoidal signal is presented as an output signal of a linear generator of finite dimension. The signal parameters (amplitude, phase, and frequency) are unknown. At the second stage, the Jordan form of the matrix and the delay operator are applied to parameterize the sinusoidal signal. After a series of special transformations, the simplest equation is obtained containing product of one frequency-dependent unknown parameter and a known function of time. To find the unknown parameter, the authors used the methods of gradient descent and least squares. A new algorithm for the parametrization of a sinusoidal signal is presented. The solution is based on transforming the signal model to a linear regression equation. The problem is solved using gradient descent and least squares tuning methods based on a linear regression equation obtained by parametrizing a sinusoidal signal. The results involve the analysis of the capabilities of the proposed estimation method using computer modeling in the Matlab environment (Simulink). The results confirmed the convergence of the frequency estimation errors to the true values. The developed method can be effectively applied to a wide class of tasks related to compensating or suppressing disturbances described by sinusoidal or multisinusoidal signals, for example, to control a surface vessel with compensation of sinusoidal disturbances.