Approaches to mathematical design of ballistic experiment: Part II

Mathematical expedients used in designing ground tests of aerodynamic object models with the aim of finding experimental conditions optimal in terms of the body and accuracy of extracted information are described. In the first part of this paper, the method used in designing the ballistic experiment is demonstrated with processing of single-experiment data. In the second part, the validity of the design approach is illustrated by simultaneously processing trajectory data obtained in several experiments.     

Corrected Seya-Namioka design: Part I

The purpose of this communication is to design the optimum optical parameters of a corrected Seya-Namioka mounting, by using the Strehl criterion.     

Algorithm for determining the aerodynamic characteristics of a freely flying object from discrete data of ballistic experiment. Part I

In part 1 of this paper, an algorithm for numerically solving the inverse problem of motion of a solid through the atmosphere is described that constitutes the basis for identifying the aerodynamic characteristics of an object from trajectory data and the respective identification procedure is presented. In part 2, methods evaluating the significance of desired parameters and adequacy of a mathematical model of motion, approaches to metrological certification of experimental equipment, and results of testing the algorithm are discussed.     

冲击电流计测高阻实验中放电与计时同步装置的设计

用电子秒表和双刀双掷闸刀结合设计出冲击电流计测高阻实验中的计时与放电同步装置，大大减小了测量误差，且操作更加方便。     

Thin-disk piezoceramic ultrasonic motor. Part I: design and performance evaluation

The purpose of this study is to gain the knowledge and experience in the design of thin-disk piezoceramic-driving ultrasonic actuator dedicated. In this paper, the design and construction of an innovative ultrasonic actuator is developed as a stator, which is a composite structure consisting of piezoceramic (PZT) membrane bonded on a metal sheet. Such a concentric PZT structure possesses the electrical and mechanical coupling characteristics in flexural wave. The driving ability of the actuator comes from the mechanical vibration of extension and shrinkage of a metal sheet due to the converse piezoelectric effect, corresponding to the frequency of a single-phase AC power. By applying the constraints on the specific geometry positions on the metal sheet, the various behaviors of flexural waves have been at the different directions. The rotor is impelled by the actuator with rotational speeds of 600 rpm in maximum using a friction-contact mechanism. Very high actuating and braking abilities are obtained. This simple and inexpensive structure of actuator demonstrates that the mechanical design of actuator and rotor could be done separately and flexibly according to the requirements for various applications. And, its running accuracy and positioning precision are described in Part II.A closed loop servo positioning control i.e. sliding mode control (SMC) is used to compensate automatically for nonlinearly mechanical behaviors such as dry friction, ultrasonic vibrating, slip-stick phenomena. Additionally, SMC scheme has been successfully applied to position tracking to prove the excellent robust performance in noise rejection.     

Algorithm for determining the aerodynamic characteristics of a freely flying object from discrete data of ballistic experiment. Part 2

In part 1 of this paper, an algorithm for numerically solving the inverse problem of motion of a solid through the atmosphere is described that constitutes the basis for identifying the aerodynamic characteristics of an object from trajectory data and the respective identification procedure is presented. In part 2, methods evaluating the significance of desired parameters and adequacy of a mathematical model of motion, approaches to metrological certification of experimental equipment, and results of testing the algorithm are discussed.     

Verification of mathematical formulae applied to overhead stage canopy design

This paper presents a comparison of the experimental research concerning overhead stage canopies with a numerical approach based on selected mathematical models. The numerical predictions are made using the simplified asymptotic curves suggested by Rindel and modified by Skålevik. For singular cases a prediction with detailed calculations based on the Fresnel–Kirchhoff approximation is also given. The aim of the work is to verify proposed algorithms for designing reflective panels as well as to determine the conditions of conducting such procedures. It is shown that based on Rindel’s approximation one may determine some substantial information about sound reflection from the panels i.e. the value of upper limit frequency as well as the relative sound reflection level. On the other hand, the lower cut-off frequency should be calculated using Skålevik’s model as the value obtained from Rindel’s formula is undervalued. Such an approach could be applied to design reflective structures. However, it has some limitations for example for arrays of perturbed symmetry or sparse arrays as well as in the case of non-perpendicular angles of sound wave incidence. Then it may be necessary to apply more accurate numerical models.     

A mathematical interpretation of Dirac's formalism: Part c: free field operators

In the present paper we give a mathematical regorization and interpretation of the canonical (anti-) commutation relations which occur in the theory of the quantized free field. In our set-up, with respect to the physics, we felt inspired by the paper [Ro] of B. Robertson. His paper covers all essential elements of the subject under consideration. The main part of [Ro] will be mathematically justified and even generalized. In this connection we mention also the monograph [Sh] of A.S. Shvarz. With respect to the involved mathematics the papers [Co] of J. M. Cook and [KMP] of P. Kristensen et al. have been a source of inspiration.Our set-up is closely related to two of our earlier papers [EG 1–2] in which we presented a mathematical interpretation of Dírac's formalism. This interpretation is based on two new mathematical concepts: the concept of Dirac basis ans the concept of bracket. The bracket is no longer regarded as a “number” but as an analytic function on the open right half of the complex plane. As in [EG 1–2], we use the theory of generalized functions which has been constructed by one of us (cf. [G]).Quantum theory and distribution theory seem to be dissolubly connected. One might wonder whether the choice of the distribution theory plays an essential role in a mathematical interpretation of Dirac's formalism and related physical concepts. The answer is threefold: There are strong indications that similar interpretations can be derived in a very wide class of distribution theories (which include Schwarz's theory of tempered distributions). This class has been described in our papers [EK] and [EGK]. On the other hand, the distribution theory employed here, introduces generalized functions in a way very close to the physical intuitive view on improper functions. Moreover, it seems natural to adapt the used distribution theory to the concrete quantum mechanical system under consideration.     

Thermodynamic design data for absorption heat pump systems operating on monomethylamine-water. Part I: Cooling

The Gibbs phase rule and thermodynamic properties of the working pair limit the choice of operating temperatures. For any combination of temperatures, the concentrations in the absorber and the generator and hence the flow ratios are fixed. For any particular working pair, the coefficient of performance is related to the flow ratio.Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy-based coefficients of performance have been presented for monomethylamine-water absorption systems for cooling. The interactions of operating temperatures have been illustrated graphically.     

Monolithic white LEDs: Approaches, technology, design

The results of investigations of monolithic white InGaAlN LEDs with an active region containing several thin InGaN layers, emitting in the range from blue to yellow-green, and separated by short-period InGaN/GaN superlattices, are presented. The influence of the growth conditions and layer sequence in the active region on the optical properties of monolithic white LEDs was studied with the aim of controlling their color parameters.     

Thermodynamic design data for absorption heat pump systems operating on water-carrol. Part I: Cooling

The Gibbs phase rule and thermodynamic properties of the working pair limit the choice of operating temperatures. For any combination of temperatures, the concentrations in the absorber and the generator and hence the flow ratios are fixed. For any particular working pair, the coefficient of performance is related to the flow ratio.Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for water-carrol (lithium bromide-ethylene glycol, ratio 4.5) absorption systems for cooling. The interaction of operating temperatures have been illustrated graphically.     

太阳能电池基本特性测定实验 --一个与能源利用有关的综合设计性实验

“太阳能电池基本特性测定”是与能源利用有关的新的综合性设计实验．本文简述了该实验的原理、实验方法及测量结果,得出了太阳能电池基本参数短路电流Iac,开路电压Uoc与太阳能电池接收到的相对光强度J／Jn的近似函数关系。     

Algebraic approach to the theory of chronological products of currents: Part I

An algebra $\text{F}$ of generating functionals for sets of symmetric n-point functions is investigated. It contains a twosided ideal $\text{T}$ of functionals which vanish on mass-shell. Since scattering processes are described by on-mass-shell values of these functionals, it is proposed to formulate the physical conditions of unitarity, relativity and causality (locality) in terms of elements of the algebra $\text{U}\text{′ =}\text{F}\text{/}\text{T}$ of equivalence classes modulo $\text{T}$. In Part I the extended form of the unitarity and relativity condition is discussed. An example of the algebra of coherent functionals is considered. The causality condition will be treated in the second part of this paper.     

Molecular structure calculations applied to solid state polymer physics: Part I

This review focuses upon the applications of molecular structure calculations to determine the three-dimensional physicochemical features of polymeric solids. In some cases, the structure calculations are used to evaluate expressions arising from specific models or theories. As such, molecular structure calculations are auxillary aides in the illumination of the solid-state properties of polymers.     

Computational complexity of the landscape: Part I

We study the computational complexity of the physical problem of finding vacua of string theory which agree with data, such as the cosmological constant, and show that such problems are typically NP hard. In particular, we prove that in the Bousso-Polchinski model, the problem is NP complete. We discuss the issues this raises and the possibility that, even if we were to find compelling evidence that some vacuum of string theory describes our universe, we might never be able to find that vacuum explicitly. In a companion paper, we apply this point of view to the question of how early cosmology might select a vacuum.     

Microwave cavity perturbation technique: Part I: Principles

This report reviews the analysis used to extract the complex conductivity of a compound from a microwave cavity perturbation measurement. We intend to present a generalized treatment valid for any spheroidally shaped sample of arbitrary conductivity which is placed at either the electric or magnetic field antinode of the cavity. To begin with, we establish the relationship between the measured parameters and the conductivity for a spherical sample. Next, we extend these results to the case of spheroids; and for the first time, we cover all different configurations that one can possibly use to study an arbitrary conducting sample inside a cavity: in particular, all possible orientations of the sample with respect to the applied field are solved.     

Interaction-induced magnetoresistance: from the diffusive to the ballistic regime

We study interaction-induced quantum correction deltasigma(alphabeta) to the conductivity tensor of electrons in two dimensions for arbitrary Ttau, where T is the temperature and tau the transport mean free time. A general formula is derived, expressing deltasigma(alphabeta) in terms of classical propagators ("ballistic diffusons"). The formalism is used to calculate the interaction contribution to the magnetoresistance in a classically strong transverse field and smooth disorder in the whole range of temperatures from the diffusive (Ttau<1) to the ballistic (Ttau greater, similar 1) regime.