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Open access

Bartłomiej Borkowski and Marek Pluta

Abstract

Currently used procedures in room acoustics measurements are not automated. Particularly in medium-sized and large areas they require a lot of time and intensive labour which directly translates into an increase in the measurement cost. Introduction of an automated system would increase efficiency of the measurements, and therefore could present both practical and scientific benefit. The paper presents initial feasibility study for designing a system that permits the measurement of selected acoustic parameters for any choice of three-dimensional grid of measurement points throughout the volume of the room. The system will utilize an autonomous probe attached to a blimp, and will be able to measure and analyze acoustic characteristics of the rooms. The article discusses the initial choices of the system elements, starting from the general idea, through the mechanical design and control procedures, the software that controls positioning and flying of the probe, up to the automation of the measurement procedure and its possible impact on the acoustic field.

Open access

Stanisław Adamczak, Jerzy Bochnia and Bożena Kaczmarska

Abstract

The aim of this study was to estimate the measurement uncertainty for a material produced by additive manufacturing. The material investigated was FullCure 720 photocured resin, which was applied to fabricate tensile specimens with a Connex 350 3D printer based on PolyJet technology. The tensile strength of the specimens established through static tensile testing was used to determine the measurement uncertainty. There is a need for extensive research into the performance of model materials obtained via 3D printing as they have not been studied sufficiently like metal alloys or plastics, the most common structural materials. In this analysis, the measurement uncertainty was estimated using a larger number of samples than usual, i.e., thirty instead of typical ten. The results can be very useful to engineers who design models and finished products using this material. The investigations also show how wide the scatter of results is.

Open access

E. Sysoev, R. Kulikov, I. Vykhristyuk and Yu. Chugui

Abstract

In scanning interferometry of longitudinal shift, an uncertainty of required phase shift performance leads to a measurement error. Such uncertainty can be caused by external factors (vibrations, air turbulence in measuring area etc.) as well as inaccuracy of the scanning system. The method for calculating the phase shift between interferograms, which allows reducing the measurement error, is proposed. The results of numerical and full scale experiments are presented.

Open access

Aleksandrs Gasparjans, Aleksandrs Terebkovs and Anastasia Zhiravetska

Abstract

A method of technical diagnostics of ship diesel engine – generator installation – is proposed. Spectral-power diagnostic parameters of the synchronous generator voltage and currents are used. The electric machine in this case is the multipurpose sensor of diagnostic parameters. A judgment on the quality of the operational processes in diesel engine cylinders and its technical condition is possible on the basis of these parameters. This method is applicable to piston compressor installations with electric drive. On the basis of such parameters as rotating torque, angular speed and angular acceleration it is possible to estimate the quality of the operating process in the cylinders of a diesel engine, the condition of its cylinder-piston group and the crank gear mechanism. The investigation was realized on the basis of a diesel-generator with linear load. The generator operation was considered for the case of constant RL load. Together with the above mentioned, the condition of bearings of synchronous machines, uniformity of the air gap, windings of the electric machine were estimated during the experiments as well. The frequency spectrum of the stator current of the generator was researched and analyzed. In this case the synchronous machine is becoming a rather exact multipurpose diagnostic sensor. The signal of non-uniformity in the operation process of diesel engine cylinders and its technical condition is the increasing of the amplitudes of typical frequencies.

Open access

Jozef Gnap, Dominika Rovňaníková and Marek Jaśkiewicz

Abstract

The introduction of this article outlines the terms and conditions of food control in the Slovak Republic and the institutions that provide it. This section also provides the comparison of inspection results in selected periods. The second part of the paper describes the measurement of the regional transport of perishable food products. The measurement compares all permitted temperature tolerances and is subsequently evaluated. The results of the measurements are also compared with the analysis of the number of checks carried out.

Open access

Petr Kašpar, Pavel Ripka and Jan Vyhnánek

Abstract

We describe D-permeameter originally designed by Trnka and later improved by Fajt and Kaspar and we analyze its precision for the measurement of different soft magnetic materials. The device measures DC hysteresis loops using compensation method, so that H and B can be calculated from the magnetization and compensation currents. The differences from results obtained by other standard methods are below 2%.

Open access

Jana Hornungová

Abstract

The main aim of this paper is to provide a framework of concepts and models from the area of performance measurement. Due to the fact that the business environment is con-stantly changing, changes also occur in the trends relating to performance. Traditional financial performance measures have been highly criticized and the need identified to integrate non-financial perspectives, such as level of innovation, degree of motivation, intellectual capital and other criteria. Intellectual capital is often a crucial factor in the creation of value in a company. This paper provides a literature review supplemented by the author’s research in the field of performance. The article shows that the performance appraisal system is currently focused on several areas that could affect the performance of the company, which is also part of the overall performance of the economy in the form of GDP growth. Based on the research, it can be said that, for the sample tracked, the selection of performance evaluation system does not depend on the legal form of the business.

Open access

Wojciech Pachelski, Małgorzata Paśnicka, Karolina Szafranek and Agnieszka Zwirowicz-Rutkowska

Geokinematics in GGOS - Different Relations and Dependences

The paper presents the preliminary results of the analysis of fundamental dependencies between different geodetic concepts related to the one of the GGOS (Global Geodetic Observation System) pillars called Geometry and Kinematics. These relationships are described using UML (Unified Modelling Language) - one of the graphical notations that can be used for information modelling. Concepts are represented as classes with their names, attributes, and different kinds of links between them. The main purpose of this paper is to introduce the full description of connections between all GGOS components.

Open access

Michal Činák, Alexander Schrek and Peter Žitňanský

Plastic Strain Measurments of Deep Drawn Part by Means of Photogrammetry

Local strain is often evaluated by means of the deformation pattern of circles as they change, during the forming process, into ellipses. The surface with such deformed pattern is then evaluated by an optical measurement system. Automated optic evaluation requires high-priced equipment and thus, at the Institute of Technologies and materials, we have developed manual methods for strain evaluation. The digital photography method is effective but restricted only to planar strain areas. Multiple image stereo photogrammetry enables us to digitalize the surface of the part into a three-dimensional form, including the real texture colour of deformation pattern. Strain measurements of individual ellipse elements are executed exclusively on the virtual threedimensional model, without any restriction by the shape geometry of the surface.

Open access

Emil Škultéty, Elena Pivarčiová and Ladislav Karrach

Abstract

One of the most frequently measured quantity is temperature, which is also one of the most important physical quantities. Temperature has influence on the almost all states and processes in the nature as well as in technique. A wide range of temperature sensors is currently available on the market. They use different measurement principles and exist in many designs. According to the location of the sensing element in the measured environment, they are divided into two main groups: contact and non-contact. Further, we can divide the temperature sensors according to the physical principle on which they work. The article deals with the analysis and comparison of selected Arduino-compatible contact temperature sensors. The temperature measurement of machine functional nodes and its diagnostics are part of maintenance and engineering diagnostics. At present, NC and CNC machine diagnostics are an important trend in machine condition monitoring and machine status prediction to maintain production quality. Machine status monitoring allows reducing of machine service costs as well as maintaining the high production quality.