Embedding impedance of a millimeter wave Schottky mixer: Scaled model measurements and computer simulations

1983 ◽  
Vol 4 (4) ◽  
pp. 609-628 ◽  
Author(s):  
Arto O. Lehto ◽  
Antti V. R�is�nen
Keyword(s):  
Millimeter Wave ◽  
Computer Simulations ◽  
Scaled Model ◽  
Embedding Impedance

Development of a Scaled Vehicle Model for Dynamics Testing

2021 ◽  
Author(s):  
R.R. Hewavithana ◽  
◽  
J.P.L. Ravihara ◽  
K.K.S. Wishwajith ◽  
U.L.S. Perera ◽  
...  
Keyword(s):  
Computer Simulations ◽  
Simulation Models ◽  
Autonomous Driving ◽  
Aggressive Driving ◽  
Scaled Model ◽  
State Behaviour ◽  
Dynamic Similitude ◽  
Scaled Models ◽  
Vehicle Testing ◽  
Future Work

The interest in using scaled models for dynamics testing of prototype vehicles is growing due to the high demand for autonomous driving. In the early design phases, vehicle testing is done using computer simulations. Even though computer simulations are proven to be extremely helpful in designing prototypes, simulation models need to be validated using realworld testing. There are high costs involved in vehicle testing and it’s dangerous to conduct aggressive driving manoeuvres with real drivers. As a solution, researchers have used scaled models. To validate the computer simulations, researchers matched the scaled model test data with full-size vehicle prototypes considering the dynamic similitude. However, previous work was limited to the analysis of the steady-state behaviour of vehicles. To accurately predict the behaviour, the transientstate response must be tested as well. Therefore, this paper outlines the precursory work of a scaled model with the ability to test both states during vehicle manoeuvres. This paper is structured as follows. Section II presents related work. Section III elaborates on the mathematical modelling and present the results of the computer simulations. Section IV presents the scaled model which will be developed. Section V concludes the findings, and present the future work of research.

scholarly journals The concept and methodical assumptions for the development of dynamically scaled aircraft model (passenger aircraft)

2019 ◽  
Vol 304 ◽  
pp. 02010
Author(s):  
Aleksander Olejnik ◽  
Stanisław Kachel ◽  
Robert Rogólski ◽  
Jarosław Milczarczyk
Keyword(s):  
Structural Properties ◽  
Computer Simulations ◽  
Complete Information ◽  
Scaled Model ◽  
Scale Factors ◽  
University Of Technology ◽  
Numerous Data ◽  
Passenger Aircraft ◽  
Scaled Models ◽  
The Military

The article describes the concept of scaled model and its application in the process of real aircraft prototyping. Computer simulations of aerodynamic flows are commonly used in the design of aircraft. Numerous data on the characteristics of an airplane can be obtained using tunnel tests of geometry scaled models. To get complete information in extreme or unstable conditions, dynamically scaled models are tested. The scaled model is reduced model of the real airplane which has specific qualities similar to real aircraft qualities and these relations are strictly defined with characteristic similarity numbers (factors). The paper presents methodology for determining scale factors in relation to geometric, aerodynamic and structural properties (mass, stiffness) of the aircraft. The methodology was presented on the example of passenger aircraft (Tu-154M) model developed in Faculty of Mechatronics and Aerospace of the Military University of Technology (FMA MUT Warsaw, PL).

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

Multislice calculations for quasi-periodic and non-periodic objects

1990 ◽  
Vol 48 (4) ◽  
pp. 138-139
Author(s):  
R. Herrera ◽  
A. Gómez
Keyword(s):  
Electron Diffraction ◽  
Computer Simulations ◽  
Periodic Table ◽  
Amorphous Materials ◽  
Space Group ◽  
Essential Step ◽  
Shape Effects ◽  
Atomic Scattering ◽  
Diffraction Patterns ◽  
Periodic Continuation

Computer simulations of electron diffraction patterns and images are an essential step in the process of structure and/or defect elucidation. So far most programs are designed to deal specifically with crystals, requiring frequently the space group as imput parameter. In such programs the deviations from perfect periodicity are dealt with by means of “periodic continuation”.However, for many applications involving amorphous materials, quasiperiodic materials or simply crystals with defects (including finite shape effects) it is convenient to have an algorithm capable of handling non-periodicity. Our program “HeGo” is an implementation of the well known multislice equations in which no periodicity assumption is made whatsoever. The salient features of our implementation are: 1) We made Gaussian fits to the atomic scattering factors for electrons covering the whole periodic table and the ranges [0-2]Å−1 and [2-6]Å−1.

Computer simulations for the TEM bend contour technique

1996 ◽  
Vol 54 ◽  
pp. 134-135
Author(s):  
Vladimir Yu. Kolosov ◽  
Anders R. Thölén
Keyword(s):  
Computer Simulations ◽  
Real Space ◽  
Advantages And Disadvantages ◽  
Short Overview ◽  
Diffraction Contrast ◽  
Beam Method ◽  
Convergent Beam ◽  
Contour Technique

In this paper we give a short overview of two TEM applications utilizing the extinction bend contour technique (BC) giving the advantages and disadvantages; especially we consider two areas in which the BC technique remains unique. Special attention is given to an approach including computer simulations of TEM micrographs.BC patterns are often observed in TEM studies but are rarely exploited in a serious way. However, this type of diffraction contrast was one of the first to be used for analysis of imperfections in crystalline foils, but since then only some groups have utilized the BC technique. The most extensive studies were performed by Steeds, Eades and colleagues. They were the first to demonstrate the unique possibilities of the BC method and named it real space crystallography, which developed later into the somewhat similar but more powerful convergent beam method. Maybe, due to the difficulties in analysis, BCs have seldom been used in TEM, and then mainly to visualize different imperfections and transformations.

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