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Open access

Dániel Kiss and Anna Lovrics

Abstract

In this paper, we introduce a three-dimensional lattice-based computational model in which every lattice point can be occupied by an agent of various types (e.g. cancer cell, blood vessel cell or extracellular matrix). The behavior of agents can be associated to different chemical compounds that obey mass-transfer laws such as diffusion and decay in the surrounding environment. Furthermore, agents are also able to produce and consume chemical compounds. After a detailed description, the capabilities of the model are demonstrated by presenting and discussing a simulation of a biological experiment available in the literature.

Open access

Zhanna Mingaleva, Nataliy Shaidurova and Vanessa Prajová

Abstract

The challenges and achievements of technological upgrading are traditionally discussed in the context of the of high-tech production. However, such areas as agriculture and food production demand no less modern scientific and technological achievements. The challenges of appropriate feeding the population remain relevant. The article focuses on the examinations of issues related to the possibilities of involving modern technological achievements for the development of Russian agriculture. The main scientific methods of research were bibliographic analysis, statistical and factor analysis, comparative analysis, methods of analogies. The factual basis for the research was the official data of the Federal State Statistic Service (Rosstat), the data of technoparks in Russia, the results of modern scientific research of foreign and Russian scientists. A conclusion on the feasibility of involving the scientific and productive capacity of Russian technology parks for technological upgrading of agriculture in Russia is based on the analysis of the activities of the organizations in the country's science and technology sector, first and foremost technoparks.

Open access

Pavol Ťavoda, Ján Kováč and Zygmunt Ł Łukaszczyk

Abstract

The article deals with the research of operational reliability of forest felling machines with the method FMEA (Failure Mode and Effect Analysis) and its implementation for observed machines in the organization. Forwarders 810D by John Deere were chosen for this research. The research was realized in real operational conditions. Application of the FMEA method allows flexibility in case of unexpected situations and optimization of human potential abilities. FMEA tool is a tool preventing outages operational reliability and preventive tool for ensuring the maintenance of facilities. This paper explores and verifies the operational reliability theory in practical real-world conditions, resulting in a reduction in operating (variable) costs, minimization of failures and readiness and increased performance of observed machines.

Open access

Ladislav Karrach and Elena Pivarčiová

Abstract

The paper deals with the possibilities of using Data Matrix codes in production engineering. We designed and tested the computationally efficient method for locating the Data Matrix code in the images. The location search procedure consists of identification of candidate regions using image binarization, then joining adjacent points into continuous regions and also examining outer boundaries of the regions. Afterwards we verify the presence of the Finder Pattern (as two perpendicular line segments) and Timing Pattern (as alternating sequence of black and white modules) in these candidate regions. Such procedure is invariant to shift rotation and scale change of Data Matrix codes. The method we have proposed has been verified on a set of real industrial images and compared to other commercial algorithms. We are also convinced that such technique is also suitable for real-time processing and has achieved better results than comparable commercial algorithms.

Open access

Ján Turis, Pavel Beňo and Witold Biały

Abstract

The article deals with the experimental detection of the tribotechnical parameters for two different types of sliding bearings which are intended for operation without an additional lubrication due to the increasing requirements in ecology and environment. The dominant tribotechnical parameters of the self-lubricating bearing are the coefficient of friction and temperature. To determine these parameters, an experimental method was applied in this paper. The introductory part deals with materials of self-lubricating sliding bearings, their properties and usage. The experimental part consists of the evaluation of friction characteristics and geometric change of a surface after sliding pairs were being worn. Experimental examined sliding pairs comprise a sliding bearing and the shaft. The aim of this research was to determine the effect of radial force on tribotechnical parameters in order to predict the behavior of examined sliding bearings in real operating conditions.

Open access

Samir Bouzoualegh, El-Hadi Guechi and Ridha Kelaiaia

Abstract

This paper presents a model predictive control (MPC) for a differential-drive mobile robot (DDMR) based on the dynamic model. The robot’s mathematical model is nonlinear, which is why an input–output linearization technique is used, and, based on the obtained linear model, an MPC was developed. The predictive control law gains were acquired by minimizing a quadratic criterion. In addition, to enable better tuning of the obtained predictive controller gains, torques and settling time graphs were used. To show the efficiency of the proposed approach, some simulation results are provided.

Open access

Abdesselam Debbah and Hamid Kherfane

Abstract

In gas turbine process, the axial compressor is subjected to aerodynamic instabilities because of rotating stall and surge associated with bifurcation nonlinear behaviour. This paper presents a Genetic Algorithm and Particle Swarm Optimization (GA/PSO) of robust sliding mode controller in order to deal with this transaction between compressor characteristics, uncertainties and bifurcation behaviour. Firstly, robust theory based equivalent sliding mode control is developed via linear matrix inequality approach to achieve a robust sliding surface, then the GA/PSO optimization is introduced to find the optimal switching controller parameters with the aim of driving the variable speed axial compressor (VSAC) to the optimal operating point with minimum control effort. Since the impossibility of finding the model uncertainties and system characteristics, the adaptive design widely considered to be the most used strategy to deal with these problems. Simulation tests were conducted to confirm the effectiveness of the proposed controllers.

Open access

Miroslava Ťavodová, Daniela Kalincová and Ivana Slováková

Abstract

In this paper we discuss the possibility of increasing service life of tools used in forestry for mulching of undesirable forest growths. In a heterogeneous working environment in which they are operated, such tools are subjected to constant abrasion and impact loading. There are several ways how to extend their service life and operational fitness. One of these is hard surface treatment, or hard surfacing of their functional surfaces. In our experiment, we chose suitable hard surfacing materials and applied these on the sample materials using the MMA and MAG welding. The hard surface was applied in an one layer. Subsequently, we performed hardness tests, microscopic analysis of the structure of the basic material and the hard surface and evaluation of the fusion penetration of the base material with the hard surfacing weld. Fusion is crucial as it determines the cohesiveness of the weld and base materials and thus also the actual extension of the service life of the tools.

Open access

Tanyana Nikolaevna Ivanova, Aleksandr Ivanovich Korshunov and Vladimir Pavlovich Koretckiy

Abstract

Cost-efficient, enabling technologies for keeping and increasing the reservoir recovery rate of oil-formations with high water cut of produced fluids and exhausted resource are really essential. One of the easiest but short-term ways to increase oil production and incomes at development of oil deposits is cost of development and capital cost reduction. Therefore, optimal choice and proper feasibility study on the facilities for multilayer oil fields development, especially at the late stage of reservoir working, is a crucial issue for now-day oil industry. Currently, the main oil pools do not reach the design point of coefficient of oil recovery. The basic feature of the late stage of reservoir working is the progressing man-made impact on productive reservoir because of water injection increasing for maintaining reservoir pressure. Hence cost-efficient, enabling technologies for keeping and increasing the reservoir recovery rate of oil-formations with high water cut of produced fluids and exhausted resource are really essential. To address the above concerns the dual completion petroleum production engineering was proposed. The intensity of dual completion of formation with of different permeability is determined by rational choice of each of them. The neglect of this principle results a disproportionately rate of highly permeable formations development for the time. In effect the permeability of the formations or their flow rate is decreasing. The problem is aggravated by lack of awareness of mechanics of layers' mutual interference in producers and injectors. Dual completion experience in Russian has shown, that success and efficiency of the technology in many respects depend on engineering support. One of the sufficient criteria for the choice of operational objects should be maximal involvement of oil-saturated layers by oil displacement from seams over the economic life of well producing oil. If it is about getting high rate of oil recovery for irregular formations there is no alternative to dual completion and production. The recommended dual completion petroleum production technology enables development several formations by single well at the time. The dual completion petroleum production technology has been more important than ever because it is right not only for formations but for thin layers with undeveloped remaining reserves.