AiMT Volume 3 (2008), Issue 2

RESEARCH OF BRAKE FLUIDS VISCOSITY PROPERTIES

Š. Čorňák, J. Skolil

Four samples of the top SYNTOL HD 265 PLUS brake fluid with 0.2 %, 1.7 % , 3.6 % and 5.9 % by weight water content were prepared in the laboratory. Ubbelohde viscosimeter was used for the determination of the brake fluid kinematic viscosity. The results have proved that the change of brake fluid viscosity is affected not only by temperature but by water content, too.

Keywords: Brake fluids, ethylene glycol, polyglycols, boiling point, viscosity, Ubbelohde viscosimeter

Page: 5 - 10

DETERMINATION OF BLACK POWDER BURNING RATE

P. Konečný, Z. Křižan

The paper is focused on a method of experimental black powder burning law finding. This method issues from records acquired during black powder charge burning tests in closed vessel (ballistic bomb). Evaluation of data sets brings courses of parameters needed for calculation of instantaneous values of black powder burning rate. The burning law is then given as spare regression function of experimental data.

Keywords: Black powder, burning law, internal ballistics

Page: 11 - 18

THE 3-CLASS CLASSIFIER OF FREQUENCY SHIFT KEYING AND PHASE SHIFT KEYING SIGNALS BASED ON KARHUNEN-LOEVE TRANSFORM

M. Richterová, D. Juráček, A. Mazálek

This paper describes the use of Karhunen-Loeve transform (KLT) for the modulation recognition in HF and VHF bands. The input real signal is pre-processed and converted to the "phase image". The KLT is applied and the dimensionality reduction is implemented and the classifier recognized the signal. The method clustering analysis was chosen by acclamation for 3-class recognition of 2-FSK, 4-FSK and PSK signals. The 3-class minimum-distance classifier of modulation was created in the programme Matlab. The tests of designed algorithm were implemented on real signal patterns.

Keywords: modulation recognition, orthogonal transforms, Karhnunen-Loeve transform, modulation classifiers, digital modulation, signal processing

Page: 19 - 24

DETECTION AND TRACKING OF WARM AREAS ON WATER VAPOUR 6.2 M SATELLITE IMAGES

J. Novotný

The paper was focused on verification of relation between potential vorticity anomalies and occurrence of intensive convection via detection of warm areas on satellite WV pictures in the spectral channel of 6.2 ?m. In contrast to other papers, however, the dependence was not tested on selected situations but on a common four-month series of data. Within processing three basic methods of detection were checked. The procedure of the most successful option was tracked.

Keywords: Potential vorticity anomaly, WV satellite imagery, dry intrusion

Page: 25 - 36

DAMAGE OF COMBAT AIRCRAFT AIRFRAME BY PROJECTILES OF CALIBER 7.62 AND 12.7 MM

M. Petrásek, V. Tříska

This contribution solves the issues of primary damage of aircraft skin. The emphasis is laid on determination of mutual relationship between the extent of damage caused by small caliber projectiles and various factors, which influence the extent of such damage. Based on the experimental data, the theoretical conclusions are modified for the given type of material into a form, which can be used for automated estimation of aircraft vulnerability.

Keywords: Airframe damage, vulnerability estimation, small caliber projectile

Page: 37 - 46

EFFECT OF INERTIA FORCES ON FUNCTION OF AUTOMATIC WEAPON

S. Procházka, M. Novák

Inertia forces affect on the automatic weapon during firing. Inertia forces can cause a malfunction of the automatic weapon or can help important moving parts of the automatic weapon. Article deals with a new math's model describe a resistive force of the human body during working forces of the automatic weapon. Math's results are verified by an experiment.

Keywords: Automatic weapons, inertia forces, main function element, nonlinear biomechanics models

Page: 47 - 54

SEISMIC SENSOR USING PIEZO-FILM

J. Čechák

The presented paper focuses on the possibilities of technical methods designed to detect a trespasser under the ground, and in general on the possibilities of detection a trespasser behind an obstruction. The paper analyses method of detection of a trespasser that were practically verified by the author of the paper. The first part of the paper discusses the characteristics and use of piezoelectric films that could be used as a replacement for the traditional geophone for detection of underground mining operation. It also provides a block connection diagram of the measuring chain and photos of the practical implementation of the sensor. The paper is supplemented with illustrative photos and results of numeric processing of signals in the form of graphs and courses.

Keywords: Seismic detection, Unattended ground sensor, Piezo-film sensor

Page: 55 - 65

MAXIMUM LIKELIHOOD ESTIMATION OF A NEUTRON SPECTRUM AND ASSOCIATED UNCERTAINTIES

J. Cvachovec, F. Cvachovec

This article discusses several methods for computing neutron (resp. gamma) spectrum from experimental data. In addition to basic description, we also outline the possibilities of propagation of uncertainty. In detail we describe the Maximum Likelihood Estimation, which we have applied to computing neutron and gamma spectra from experimental data. Moreover, we have found a procedure to determine the uncertainty of the resulting spectrum.

Keywords: Unfolding, maximum likelihood estimation, uncertainty propagation

Page: 67 - 79

PREDICTION OF ICE FORMATION ON EARTH'S SURFACE

K. Dejmal, V. Répal

"The Road meteorology" is a branch of an applied meteorology, which deals with the meteorological elements and phenomena in the light of their influence over running of communication namely the major roads and motorways on a given territory. Road meteorology tries to solve the theoretic problems pair with the meteorological support of the road maintenance.

Keywords: Icing, prediction, road meteorology, criteria of successfulness

Page: 81 - 86

INFLUENCE OF AXIAL CLEARANCE BETWEEN BOTTOM OF CARTRIDGE CASE AND FRONT SURFACE OF BREECH TO PRIMARY LOAD OF GUN

Z. Krist

The article deals with influence of breech clearance to primary loading of gun breech. Theoretical solution was verified by experiment.

Keywords: Force to breech, breech clearance

Page: 87 - 94