Numerical Study of Longitudinal Inter-Distance and Operational Characteristics for High-Speed Capsular Train Systems

High-speed capsular vehicles are firstly suggested as an idea by Elon Musk of Tesla Company. Unlike conventional high-speed trains, capsular vehicles are individual vessels carrying passengers and freight with the expected maximum speed of near 1200 [km/h] in a near-vacuum tunnel. More individual vehicle speed, dispatch, and position control in the operational aspect are expected over connected trains. This numerical study and investigation evaluate and analyze inter-distance control and their characteristics for high-speed capsular vehicles and their operational aspects. Among many aspects of operation, the inter-distance of multiple vehicles is critical toward passenger/freight flow rate and infrastructural investment. In this paper, the system’s equation, equation of the motion, and various characteristics of the system are introduced, and in particular control design parameters for inter-distance control and actuation are numerically shown. As a conclusion, (1) Inter-distance between vehicles is a function of error rate and second car start time, the magnitude range is determined by second car start time, (2) Inter-distance fluctuation rate is a function of error rate and second car start time, however; it can be minimized by choosing the correct second car start time, and (3) If the second car start time is chosen an integer number of push-down cycle time at specific velocity error rate, the inter-distance fluctuation can be zero.

Numerical simulation of optical coupling between a microring resonator and a directly connected straight waveguide

We studied numerically optical coupling of whispering gallery modes of a microring resonator with modes of a radially directed straight waveguide connected to the microring. Optical outcoupling from the resonator through the waveguide was calculated for different widths of the latter. The output was maximized under conditions when the width fits an odd integer number of half-wavelengths of light inside the microring.

Finding out square root of an integer number using Single Electron Transistor

The single-electron transistor (SET) attracts the researchers, scientists or technologists to design and construct large scale circuits for the sake of the consumption of ultra-low power and its small size. All the incidences in a SET-based circuit happen when only a single electron tunnels through the transistors under the proper applied bias voltage and a small gate voltage or multiple gate voltages. The oscillatory conduction as the function of the variable-multiple /single gate voltage is exhibited by SET. This uncommon characteristic provides the ability of executing the functions of AND, OR, XOR, Inverter and some combinational circuits like multiplexer, subtractor etc. For implementing a square root circuit, SET would be a best candidate to fulfil the requirements. The processing speed of SET based devices will be nearly close to electronic speed. Noise during processing gets ultra-low when the circuits is built with SETs. The square root circuit is presented here for sixteen bit input numbers. The input bit numbers can be increased with the increasing of the depth of the pattern very easily. And this will provide us the greater accuracy about the squared root value. Power consumption in the single electron circuit is low irrespective of bipolar junction transistor (BJT) or Complementary Metal Oxide Semiconductor (CMOS) circuits. Reducing the numbers of nodes, the power consumption is reduced.

Lorentz-invariant system with quantum mechanical properties

In this work we study potential fluids, within which eddies exist which have quantum mechanical properties because according to Helmholtz they are made up of an integer number of lines and their displacement in a potential medium is a function of a frequency. However, this system is Lorentz-invariant since Maxwell’s equations can be obtained from it, and this is what we demonstrate here. The considered hypothesis is that the electric charge arises naturally as the intensity of the eddy in the potential fluid, that is, the circulation of the velocity vector of the elements that constitute it, along that potential (it is not another parameter, whose experimental value must be added, as proposed by the standard model of elementary particles). Hence, the electric field appears as the rotational of the velocity field, at each point of the potential medium, and the magnetic field appears as the variation with respect to the velocity field of the potential medium, which is equivalent to the Biot and Savart law. From these considerations, Maxwell’s equations are reached, in particular his second equation which is the non-existence of magnetic monopoles, and the fourth equation which is Ampere’s law, both of which to date are obtained empirically demonstrated theoretically. The electromagnetic field propagation equation is also arrived at, thus this can be considered a demonstration that a potential medium in which eddies exist constitutes a Lorentz-invariant with quantum mechanical properties.

Post-processing deflectometry grid images using particle image velocimetry analysis

Deflectometry is a full-field optical technique for surface slope measurement based on recording the deformation of a grid image. A hybrid method is explored in which the grid images from a deflectometry measurement are processed using a particle image velocimetry analysis tool. The hybrid approach is compared to a common phase shifting algorithm for grid images based on a windowed discrete Fourier transform. The resulting slope maps compare well with those identified using the spatial phase shifting procedure. While the traditional phase shifting method has a tuning requirement that limits the optical setup to configurations that produce an integer number of pixels per grid period in the image, the use of particle image velocimetry analysis omits this calibration step. The applicability of an existing turnkey tool to perform full-field vibration imaging using deflectometry can benefit to research concerning mechanical vibration and related experimental methods.

Optimal Versus Equal Dimensions of Round Bales of Agricultural Materials Wrapped with Plastic Film—Conflict or Compliance?

For the assumed bale volume, its dimensions (diameter, height), minimizing the consumption of the plastic film used for bale wrapping with the combined 3D method, depend on film and wrapping parameters. Incorrect selection of these parameters may result in an optimal bale diameter, which differs significantly from its height, while in agricultural practice bales with diameters equal or almost equal to the height dominate. The aim of the study is to formulate and solve the problem of selecting such dimensions of the bale with a given volume that the film consumption is minimal and, simultaneously, the bale diameter is equal or almost equal to its height. Necessary and sufficient conditions for such equilibria of the optimal bale dimensions are derived in the form of algebraic equations and inequalities. Four problems of the optimal bale dimension design guaranteeing assumed equilibrium of diameter and height are formulated and solved; both free and fixed bale volume are considered. Solutions of these problems are reduced to solving the sets of simple algebraic equations and inequalities with respect to two variables: integer number of film layers and continuous overlap ratio in bottom layers. Algorithms were formulated and examples regarding large bales demonstrate that they can handle the optimal dimensions' equilibria problems.

Simultaneous All-optical 1's Complement Cum Division-by-two Schemes

Odd and even number detection is an important mathematical operation. Generally when any number divisible by 2 then it is called even number, otherwise it is odd number. Division by 2 can be easily obtained by putting a point before least significant bit (LSB) of any binary number. As an example a number (27)10 = (11011)2 when divided by 2 its result will be (1101.1)2 = (13.5)10. Hence when we find the fractional bit as logic-1 we can say that the number is odd, otherwise it is even. This operation can be obtained by using a demultiplexer. Here we have developed an optical circuit which can divide any binary integer number by 2, apart from that its 1’s complement can also be obtained from the circuit. Both of the result can be obtained simultaneously. Terahertz optical asymmetric demultiplexer (TOAD) based generally switch assumes a vital part to plan this n-bit circuit. Numerical simulations are done to urge the exhibition of the circuit.

Information-Measuring Complex to Detect High Frequency Gravitational Waves

The gravitational waves predicted by the general theory of relativity and detected by the Laser Interferometer Gravitational-wave Observatory (LIGO) have typical frequencies in the range of 30 ... 300 Hz. Current theories of gravity predict the existence of high-frequency gravitational waves with frequencies of 10 ... 100 MHz, including those of cosmological origin, induced by quantum fluctuations of the scalar field at the stage of cosmological inflation in the early Universe.Multi-beam optical resonators, in particular the Fabry-Perot interferometers, can be used to detect high-frequency gravitational waves. When using multi-beam optical resonators, it is possible to use the phenomenon of low-frequency optical resonance, which allows us to have a selective response to the gravitational wave effect. The gravitational-optical resonance in a multi-beam interferometer occurs if the condition is fulfilled that an integer number of half-waves of gravitational radiation is along the length of the resonator.The use of a multi-beam interferometer to detect high-frequency gravitational waves does not require the creation of a complex system for decoupling mirrors used for gravitational antennas operating in the low-frequency part of the spectrum. This is due to the fact that the frequency of mechanical vibrations of the interferometer mirrors is significantly less than the frequency of the gravitational wave.The paper considers possible optical schemes of a high-frequency gravitational antenna: based on the traditional Michelson interferometer, in the arms of which two Fabry-Perot interferometers are available, and on the basis of the Mach-Zehnder optical scheme, where Fabry-Perot interferometers can be made in the form of two perpendicular arms, with reflecting mirrors at the bend of the beam. The advantage of the second scheme is that three photo-detectors, one being main and two others being auxiliary, can be used, and there is a possibility to detect radiation transmitted by Fabry-Perot interferometers.To prove that detection of high-frequency gravitational waves is possible, a potential sensitivity of the high-frequency gravitational antenna has been estimated in the paper.

Deformation Estimation Using Beidou GEO-Satellite-Based Reflectometry

Deformation monitoring has been brought to the fore and extensively studied in recent years. Global Navigation Satellite System Reflectometry (GNSS-R) techniques have so far been developed in deformation estimation applications, which however, are subject to the influence of mobile satellites. Rather than compensating for the path delay variations caused by mobile satellites, adopting Beidou geostationary Earth orbit (GEO) satellites as transmitters directly eliminates the satellite-motion-induced phase error and thus provides access to stable phase information. This paper presents a novel deformation monitoring concept based on GNSS-R utilizing Beidou GEO satellites. The geometrical properties of the GEO-based bistatic GNSS radar system are explored to build a theoretical connection between deformation quantity and the echo carrier phases. A deformation retrieval algorithm is proposed based on the supporting software receiver, thus allowing echo carrier phases to be extracted and utilized in deformation retrieval. Two field validation experiments are conducted by constructing passive bistatic radars with reflecting plates and ground receiver. Utilizing the proposed algorithm, the experimental results suggested that the GEO-based GNSS reflectometry can achieve deformation estimations with an accuracy of around 1 cm when the extracted phases does not exceed one complete cycle, while better than 3 cm when considering the correct integer number of phase cycles. Consequently, based on the passive bistatic radar system, the potential of achieving continuous, low-cost deformation monitoring makes this novel technique noteworthy.

Numerical semigroups bounded by the translation of a plane monoid

Let $$\mathbb {N}$$ N be the set of nonnegative integer numbers. A plane monoid is a submonoid of $$(\mathbb {N}^2,+)$$ ( N 2 , + ) . Let M be a plane monoid and $$p,q\in \mathbb {N}$$ p , q ∈ N . We will say that an integer number n is M(p, q)-bounded if there is $$(a,b)\in M$$ ( a , b ) ∈ M such that $$a+p\le n \le b-q$$ a + p ≤ n ≤ b - q . We will denote by $${\mathrm A}(M(p,q))=\{n\in \mathbb {N}\mid n \text { is } M(p,q)\text {-bounded}\}.$$ A ( M ( p , q ) ) = { n ∈ N ∣ n is M ( p , q ) -bounded } . An $$\mathcal {A}(p,q)$$ A ( p , q ) -semigroup is a numerical semigroup S such that $$S= {\mathrm A}(M(p,q))\cup \{0\}$$ S = A ( M ( p , q ) ) ∪ { 0 } for some plane monoid M. In this work we will study these kinds of numerical semigroups.