Model and method development for determining the completeness of information for remote detection of landmarks for autonomous mobile robots

The object of research is the completeness of information for making a navigation decision by an autonomous mobile robot when it performs a task in an unfamiliar area without GPS. It is difficult to identify a landmark in the absence and abundance of information. One of the most problematic places is the mathematical description of the criterion according to which an autonomous robot makes a decision about the completeness of information. The paper substantiates a model and method for determining the completeness of information by a robot equipped with several landmarks detection tools operating on different physical principles. It is shown that the implementation of the method requires a priori information on the probability of detecting various landmarks by passive and active means against a continuous and discontinuous background at different illumination of objects, in day and night conditions under different weather conditions. The values of the probability of detecting a specific type of landmark obtained in such studies serve as the basis for constructing an information cadastre for a job performing tasks on the ground. Three formulas are proposed for determining the coefficient of completeness of information, taking into account a priori and a posteriori inventories, and recommended areas of application. The value of this coefficient depends on the threshold level of the probability of detecting a landmark. The reliability of a decision made by a robot is greatest when it is made under conditions of a certain level of completeness of information. The proposed method can be used for other technical objects from which the measurement information is received. Compared with the known methods, it expands the boundaries of application and reveals the possibility of assessing the completeness of information in constantly changing conditions. Along with a change in these conditions, the characteristics of the completeness of information also change. The coefficient of completeness of information can approach unity even in the absence of separate means of detecting landmarks, and then the method makes it possible to assess the need for their use in the given conditions.

Insights into the Crystal Chemistry of the Serandite–Schizolite–Pectolite Series

ABSTRACT The compositional series {Na} [[M1+M2](Ca2XMn2–2X)Si3O8(OH)] includes the minerals serandite (X = 0), schizolite (X = 0.5), and pectolite (X = 1). Six crystals are structurally and chemically characterized in detail (four from Ilímaussaq, Greenland; two from Mont Saint-Hilaire, Québec, Canada): one serandite, one pectolite, and four schizolite crystals. Those originating from Greenland show up to 0.05 apfu LREE3+ (La + Ce + Pr + Nd + Eu + Gd). For each, all H atoms were located, and final R1 factors were below 4.4% (<R1> = 2.35%). The results are compared with previously published crystal structure data from an additional 16 samples, originating from worldwide (mostly) igneous environments. Across the series, for all investigated samples, Ca and Mn order preferentially at the octahedral M1 and M2 sites, respectively, following the exchange M2Ca + M1Mn ↔ M1Ca + M2Mn. Site-occupancies closely adhere to a two-site distribution coefficient, calculated here to be K = 20.0(5), for ideal mixing where activity coefficients approach unity. For the above order-disorder exchange, ΔHex is calculated to be –1.77 kcal. With knowledge of K, site assignment and species determination may be accurately made solely with compositional data, where 0 ≤ ΣCa < 0.55 apfu, serandite; 0.55 ≤ ΣCa < 1.45 apfu, schizolite; and 1.45 ≤ ΣCa ≤ 2 apfu, pectolite, with the dominant-constituent rule mandating M1Ca < M1Mn (M2Ca < M2Mn), serandite; M1Ca > M1Mn (M2Ca < M2Mn), schizolite; and M1Ca > M1Mn (M2Ca > M2Mn), pectolite. Polyhedral distortion and structural strain at the M1 and M2 sites, calculated using the equations of Robinson et al. (1971) and solutions to Kirchhoff network equations, respectively, show a predictable, cooperative variation across the entire compositional series; however, prominent discontinuities in distortion and strain behavior are observed for the schizolite composition.

Empirical Relationships Among Five Types of Well-Being

Philosophers, psychologists, economists, and other social scientists continue to debate the nature of human well-being. The authors argue that this debate centers around five main conceptualizations of well-being: hedonic well-being, life satisfaction, desire fulfillment, eudaimonia, and non-eudaimonic objective list well-being. Although each type of well-being is conceptually different, this chapter addresses the question of whether they are empirically distinguishable. The authors first developed and validated a measure of desire fulfillment and then examined associations between this new measure and several other well-being measures. In addition, they explored associations among all five types of well-being and found high correlations among all measures of well-being. However, correlations generally did not approach unity even when correcting for unreliability. Furthermore, correlations between well-being and related constructs (e.g., demographics, personality) depended on the type of well-being measured. The authors conclude that empirical findings based on one type of well-being measure may not generalize to all types of well-being.

Simplified models of the symmetric single-pass parallel-plate counterflow heat exchanger: a tutorial

The heat exchanger is important in practical thermal processes, especially those of (i) the molten-salt storage schemes, (ii) compressed air energy storage schemes and (iii) other load-shifting thermal storage presumed to undergird a Smart Grid. Such devices, although central to the utilization of energy from sustainable (but intermittent) renewable sources, will be unfamiliar to many scientists, who nevertheless need a working knowledge of them. This tutorial paper provides a largely self-contained conceptual introduction for such persons. It begins by modelling a novel quantized exchanger, 1 impractical as a device, but useful for comprehending the underlying thermophysics. It then reviews the one-dimensional steady-state idealization which demonstrates that effectiveness of heat transfer increases monotonically with (device length)/(device throughput). Next, it presents a two-dimensional steady-state idealization for plug flow and from it derives a novel formula for effectiveness of transfer; this formula is then shown to agree well with a finite-difference time-domain solution of the two-dimensional idealization under Hagen–Poiseuille flow. These results are consistent with a conclusion that effectiveness of heat exchange can approach unity, but may involve unwelcome trade-offs among device cost, size and throughput.

Catalysis of heat-to-work conversion in quantum machines

We propose a hitherto-unexplored concept in quantum thermodynamics: catalysis of heat-to-work conversion by quantum nonlinear pumping of the piston mode which extracts work from the machine. This concept is analogous to chemical reaction catalysis: Small energy investment by the catalyst (pump) may yield a large increase in heat-to-work conversion. Since it is powered by thermal baths, the catalyzed machine adheres to the Carnot bound, but may strongly enhance its efficiency and power compared with its noncatalyzed counterparts. This enhancement stems from the increased ability of the squeezed piston to store work. Remarkably, the fraction of piston energy that is convertible into work may then approach unity. The present machine and its counterparts powered by squeezed baths share a common feature: Neither is a genuine heat engine. However, a squeezed pump that catalyzes heat-to-work conversion by small investment of work is much more advantageous than a squeezed bath that simply transduces part of the work invested in its squeezing into work performed by the machine.

IMPLEMENTING THE ECONOMICAL 1 → M PHASE-COVARIANT QUANTUM CLONING VIA THE DETECTION OF CAVITY DECAY

We propose a scheme to realize the economical 1 → M phase-covariant quantum cloning in 2-dimension with M Λ-type three-level atoms in an optical cavity. In our scheme, we do not require addressing and exactly manipulating on every atoms, never so much as controlling the time of interaction between atoms and photon. The success or failure of cloning can be determined simply by detecting the polarization of the photon leaking out of the cavity. With the use of an automatic feedback, the success probability of the scheme can be made to approach unity. And the desired output state is a superposition of different combination of two grounds states and thus is free from decoherence caused by spontaneous emission.

Exact solutions for Sturm–Liouville problems on trees via novel substitute systems and the Wittrick–Williams algorithm

Since 1970, the Wittrick–Williams algorithm has been applied with increasing sophistication in structural mechanics to guarantee that eigenvalues cannot be missed and are calculated accurately. The underlying theorem enables its application to any discipline requiring eigenvalues of self-adjoint systems of differential equations. Its value in mathematics was recently illustrated by studying Sturm–Liouville equations on large homogeneous trees with Dirichlet boundary conditions and n (≤43) levels. Recursive subsysteming was applied n −1 times to assemble the tree progressively from sub-trees. Hence, numerical results confirmed the recent theoretical bounds of Sobolev & Solomyak for n →∞. In addition, a structural mechanics analogy yielded a proof that many eigenvalues had high multiplicities determined by n and the branching number b . Inspired by the structural mechanics analogy, we now prove that all eigenvalues of the tree are obtainable from n substitute chains r (=1, 2, …, n ) which involve only r consecutively linked differential equations and which have only singlefold eigenvalues. Equations are also derived for the multiplicities these eigenvalues have for the tree. Hence, double precision calculations on a PC readily gave eigenvalues for n =10 6 and b =10, i.e. ≃10 999 999 linked Sturm–Liouville equations. Moreover, a simple equation is derived which gives all the eigenvalues of uniform trees with Dirichlet conditions at both ends, and band-gap spectra are numerically demonstrated and theoretically justified for trees with the Dirichlet conditions at either end replaced by Neumann ones. Additionally, even if each multiple eigenvalue would be counted as if it were singlefold, the proportion of eigenvalues that are multiple is proved to approach unity as n →∞.

Acoustic Radiation Models of Brake Systems From Stationary LDV Measurements

This paper presents a study of the acoustic radiation from a stationary brake system that was conducted in order to better understand the acoustic radiation from squealing brake systems. A large class of squeal mechanisms are associated with the resonant behavior of an operating brake system. In this work, an analysis is presented that equates the natural frequencies and modes of a mechanically-excited stationary brake system to those of an operating brake system. The equivalence allows one to conduct experiments on stationary brake systems in order to gain insight into the acoustic radiation mechanisms of squealing systems, which is a substantial convenience given the difficulty of artificially inducing squeal. The methodology is applied to scanning LDV measurements of the normal velocity of a shaker-excited stationary brake system. Acoustic radiation efficiencies and intensities of the modes were computed by importing the experimentally measured velocities into a BEM software package. These efficiencies approach unity at a coincidence frequency defined by comparing acoustic wavelengths to the wavelengths of flexural waves that propagate circumferentially around the rotor. For the particular system tested, this remarkably high radiation efficiency occurred at frequencies above 2–3 kHz.

Comparison of the Thermal Stabilities of Amorphous Hydrides Formed by Zr-Based Metallic Glasses

Differential scanning calorimetry (DSC) and x-ray diffraction (XRD) measurements were performed on a-Zr2 PdHx, a-Zr3 RhHx, a-Zr76 Fe24 Hx, and a- Zr2NiHx to assess the effects of hydrogen on their thermal stabilities. Only exothermic DSC peaks were observed for the hydrogen-free glasses and are shown to correspond to the formation of crystalline intermetallic phases. On the other hand, heating of the amorphous hydrides gives decomposition reactions with the generation of ZrHx (1.5 <x < 2.0) and either free metal (e.g., Rh) or a Zr-depleted intermetallic (e.g., ZrPd). With the exception of the Zr2 PdHx samples, hydrogenation significantly decreases the thermal stabilities (i.e., the exothermic transitions occur at lower temperatures in the amorphous hydrides). Endothermic peaks, which are associated with hydrogen evolution from the glass, are observed when the hydrogen-to-metal ratios approach unity.