Maitenance management and the production company management

A systematic and processional attitude to the maintenance management, as processional technical activities, has to be followed by firms and production companies for their organization processes including the maintenance. Then, an excellent level can be achieved according to the theory of vitality. In practice, it means that the maintenance is controlled in right way and the principles of the vitality theory have to be applied into the maintenance management. Application principles of the vitality theory in the management for maintenance management as a processional technical activity

Methodology devising for bucket-wheel excavator surveying by laser scanning method to determine its main geometrical parameters

The application of laser scanning techniques to bucket-wheel excavator surveying seeks primarily to determine the machines’ key geometric parameters and to establish realistic mathematical descriptions of their movement dynamics in 3D space. The data will be used to visualize excavator movement and to control the coal extraction process in real time. The measurements take place at Doly Nástup Opencast Coal Mine, Tušimice, North-Bohemian Lignite Coal Field, Czech Republic. GNSS technology and inclinometric measurements are used to calculate 3D positions of the bucket-wheel excavators. The data is transferred to the research team workplace and stored in a database. KVAS software is used to visualise the bucket-wheel excavators and their 3D movements in real time

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Teplota ložisek točivých strojů jako důsledek vibrací

The article deals with the analysis of influence of vibration on temperature of sliding bearings. In this work, attention is paid to the basic principles of diagnostic measurements, such as methods of vibrodiagnostics and thermography used in the case of sliding bearings. The final part is elaborated on the basis of information from practice. Description of the measurement, data analysis and final interpretation of dependence of vibration on temperature are presented.Článek se zabývá analýzou vlivu vibrací na teplotě kluzných ložisek. V této práci se věnuji základním principům diagnostických měření, jako jsou metody vibrodiagnostiky a termografie praktikované na kluzná ložiska. Závěrečná část je zpracována na základě informací z praxe. Popis měření, analýza dat a závěrečné vyhodnocení závislosti vibrací na teplotě

Zjišťování tvrdých poloh v nadloží hnědouhelných lomů

PrezenčníNeuvedenoNeuveden

Hodnocení efektivnosti dobývacího procesu kolesových rypadel s využitím vrtného monitoringu

Import 20/04/2006Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Fakulta strojn

Zvýšení účinnosti pohonů pásových dopravníků keramickým obložením hnacích bubnů

In any point of the belt contact with the drum a relative speed compensation takes place that is carried out by a slippage even when the relevant contact spots are fairly clean and dry. This leads to heat generation that is being absorbed by both materials involved – by the belt as well as by the drum. Unlike the belt, the drum lagging would increase its temperature up to a certain limit that depends on number of factors. When the lagging surface temperature is reaching appx. 60°C some structural changes in the lagging material take place and further rise of temperature can create a risk of belt inflammation and destruction of the driving unit. This can be avoided by lagging the drum with new materials that eliminate any friction on the contact surfaces and that are heat resistant.V každém bodě styku pásu s bubnem dochází k vzájemnému vyrovnání rychlostí, které je realizováno prokluzem a to i při relativně suchých a čistých stykových plochách. To vede k vývinu tepla absorbovaného oběma prvky – pásem i bubnem. Na rozdíl od pásu dochází na bubnu k růstu teploty až do určité ustálené meze, která závisí na řadě faktorů. Při překročení teploty povrchu bubnu cca 60°C již dochází k strukturálním změnám v materiálu obložení bubnu a při dalším růstu teploty k nebezpečí zapálení pásu a destrukci pohonné jednotky. Tomu lze zabránit obložením bubnu novými materiály, které na stykových plochách vylučují tření a jsou tepelně odolné

Drilling Process Control Using theCriterion of Specific Energy

Optimalization effort of exploitation processes follows from requirements of minimisation of operating costs and maximisation of efficiency. The article describes theoretical analysis and operational verification of minimisations criterion of specific volume energy for drilling operations. It was verified that specific volume energy sensibly reacts on change of rock type or on change of rock properties respectively thus it is able to coordinate or optimise drilling process