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The aim of this paper is to present basic hardware components of a Flexible Assembly System (FAS) and investigate possible faults, classify the errors and implement real diagnosis. The mentioned system offers professional training according to the industrial reality, simulating a real assembly process and including different technologies from Industry 4.0. This equipment consists of an automated flexible assembly cell with five different stages: assembly, handling, quality inspection, transfer and warehouse. The pneumatic system repeats the identical programmed sequence during it operation. The data was collected when the pneumatic system worked perfectly and had some generated faults including empty magazine, zero vacuum, inappropriate material, no pressure, closed manual pressure valve, missing drilling stroke, poorly located material, not vacuuming the material and low air pressure. The faults are simulated according to developed algorithms in this investigation. The case study with fuzzy logic is used to develop a new sequence for one pneumatic module diagnosis. The analysis of the simulated faults is discussed and the obtained results can be applied in the similar pneumatic systems in industry.

* The Workshop program of the Twenty-First National Conference on Artificial Intelligence was held July 16-17, 2006 in Boston, Massachusetts. The program was chaired by Joyce Chai and Keith Decker. […]

Improving the quality and reliability of machines is a necessary condition for the development of mechanical engineering. Most often, the main reason for the failure of machines is the wear of working parts. The reliability of the machines is ensured primarily by achieving high-quality materials of the working parts with the required level of mechanical properties.The short service life of parts reduces the economic efficiency of many machines and industrial equipment and results in irretrievable metal losses.Under conditions of wear that are not associated with large impact loads, white wear-resistant cast irons, which wear resistance is 5-10 times greater than structural steels, have shown themselves well.Grinding and the main processes of non-ferrous and ferrous metal ore-dressing, as well as coal, mining and chemical raw materials are associated with the need to process large volumes of ore slurry (pulps). For the implementation of complex dressing technological schemes at modern factories and the removal of refuse materials, centrifugal sand and soil pumps are widely used, the service life of which is limited. Impellers, bends, and sealing elements are the first to break down, resulting in significant repair costs and reduced productivity due to forced downtime [1-3].To replace worn out parts, it is necessary to remove the pumps from the operation, or install redundant pumps for the main technological stages, which takes up to 20-25 % of the productive time. If we take into account the fact that due to the wear of these parts, the pumps have lower productivity, then the total losses on a national scale are enormous.The low durability of the cast working parts of the pumps is related to the fact that the properties of used alloys do not always correspond to the operating conditions. But even parts made of the same cast iron composition and working under the same conditions have a different service life. This is due to the fact that changes in the concentrations of alloying elements within the grade composition strongly affect their properties [4-6].

The results of the study of the cooling rate effect on the structure and properties of castings for parts of equipment made of complex alloyed manganese cast iron, which operate under conditions of abrasive and impact-abrasive wear, are presented. The properties and characteristics of microstructures of samples from the investigated cast iron composition for different cooling rates are given: relative and impact-abrasive wear resistance, hardness, volume fraction of the carbide phase, and the average size of carbides. It is shown that the cooling rate (as well as the chemical composition of cast iron) is a determining factor in the primary microstructure formation that affects the properties of castings.

Non-metallic impurities in continuous cast billets are evaluated by a growth rate of edge point impurities. The first part of our research was devoted to a relationship between the growth rate of edge point impurities and other macrostructure defects. A correlation-regression analysis of steel macrostructure quality showed the relationship between the rate of edge point impurities and segregation cracks in general, as well as corner streaks. The second part of our research indicated that impurities in billets from conventional carbon steel were crucially influenced by a method of pouring steel from a tundish into a mould. By transferring from open stream casting to shrouded casting, the quantity of non-metallic impurities in billets decreases by 7 times. In case of open stream casting, prevailing inclusions are oxides resulting from secondary oxidation, while the growth rate of edge point impurities in billets increases with an increased content of sulphur and phosphorus in steel, and decreases with an increased manganese/sulphur ratio. In case of shrouded casting, non-metallic impurities are limited to casting temperature and speed: steel overheating in the tundish above the liquidus temperature and withdrawal speed of billets. Less non-metallic impurities in case of the shrouded casting are contributed by steel overheating in the tundish above the liquidus temperature over 30oС and withdrawal speed, not exceeding 2.5 m/min.

Purpose Metamaterials have been utilised in several exciting configurations such as tuneable reflectors, reconfigurable absorbers, and programmable modulators, triggering intense research efforts. Among them, the ability to steer the radiation pattern of a single antenna component by employing a metamaterial-based superstrate is considered crucial for the development of advanced beam forming applications. The purpose of this paper is to introduce an adjustable omega-inspired metamaterial module to facilitate the design of beam steering implementations, involving beam forming capabilities, as well.Design/methodology/approach A variable capacitive diode is properly positioned at the novel omega element, hence advancing the controllability of its electromagnetic performance and circumventing the requirement of extra bias networks. When an array of these particles is placed in front of an antenna, several negative refractive index profiles can be realised, allowing the manipulation of the beam direction. Furthermore, a pyramidal horn antenna, loaded with this complex medium superstrate, is thoroughly investigated in terms of programmable beam steering and beam forming attributes. Several numerical data derived via the finite element method unveil the merits of the featured configuration.Findings The proposed structure allows programmability of the electromagnetic behaviour, but also circumvents the necessity of complicated bias networks, while minimising interference. The numerical assessment of a standard gain pyramidal horn antenna, associated to the featured metamaterial superstrate, sufficiently proves the controllable beam steering and beam forming attributes. Several parametric studies clarify the principal characteristics of the proposed setup, facilitating the design of high-end systems.Originality/value Development of tuneable metamaterial, which utilises variable capacitive diodes to enable controllability. Incorporation of reconfigurable metamaterials into antenna technology. Design of a pyramidal horn antenna, loaded with a complex medium superstrate exhibiting programmable beam steering and beam forming attributes. The proposed device circumvents the necessity of complicated bias networks, while minimising interference. [ABSTRACT FROM AUTHOR]

At the present time, various types of autonomous mobile robots have found their place in many applications related with surveillance, transportation, inspection, and other problems. The trajectory tracking problem stands along with this growth. In real world, uncertainty and fuzziness of information cause additional difficulties. Hence, deterministic models insufficient usually are, one possible way to overcome the problem is to resort to the use of type-2 fuzzy systems. In this paper an adaptive tuned interval type-2 Takagi-Sugeno fuzzy-neural PID controller for compensation of friction and disturbance effects during the trajectory tracking control of a non-holonomic mobile robot is proposed. The parameters of the adaptive controller are updated according the introduced on-line learning algorithm. Preformed simulation experiments demonstrate the effect of the developed control algorithm on the trajectory tracking performance of a mobile robot.

This paper describes the development of a novel state-space model predictive controller. The proposed modelling structure used to capture and predict the nonlinear process dynamics lies on the concept for a neo-fuzzy neuron, deployed in state-space. The introduced approach represents a set of simple fuzzy inferences along the temporal behaviour of each input node, whose dynamics is expressed as a singleton function. The learning algorithm for the proposed modelling structure is realized as a gradient descent procedure. On the basis of the obtained neo-fuzzy state-space model, a fuzzy predictor for the purpose of predictive control is developed. The achieved predictions are used to optimize the future system response by implementing a quadratic programming optimization procedure along the stated controller horizons. The potentials of the proposed approach are studied by simulation experiments to modelling and control of a nonlinear drying plant.

This paper presents the electromagnetic traction characteristics of the vibration isolator rigidity compensator. When defining power, positioning characteristics against each axis should be taken into account. The equation was derived to describe the characteristics of each axis based on rigidity.

The sensitivity of the optical clocks to thermal radiation is shown in the research. The paper gives a brief overview of the optical clocks shift resonance reasons. The ways to investigate and decrease the thermal radiation impact on 87Sr optical clocks are found.

This paper deals with the research aimed at the efficiency upgrading techniques of start-up process of the diesel engines of shunt locomotives. The application features are indicated and methods of reliable start of the diesel engines with using of the supercapacitors are developed. The issues of reliability and lifetime of the supercapacitors stacks in start-up systems improvement are considered. The mathematical and simulation modelsare developed, changing of current - and speed-time curve charts are also presented.

In this paper device for vibroisolation with Neodimium-Iron-Boron (NdFeB) supermagnets is presented. The use of the supermagnets allows developing device for vibroisolation with less size in comparison with present vibroisolators.

Accuracy in design of steel and composite bridges against fatigue is strongly connected with the distinct features of regional traffic. However, the approach followed by Eurocode 1 (EN1991-2) barely differs among European countries as far as fatigue load models are concerned. The recommended fatigue load model in Eurocode is FLM3. It is easy to use, but it has to be calibrated for each region where it is applied if major differences in traffic composition exist (especially regarding the distribution of heavy vehicles, the traffic volume and the vehicle types). This paper takes into account the particular aspects of Finnish traffic through extensive recorded traffic data covering the whole Finnish road network. It examines and evaluates the influence of essential factors, through the available data, in fatigue design. Results of the study for steel and composite bridges, according to EN1993-2 and EN1994-2, respectively, are summarized in simple rules, additional to the basis of Eurocode 1, at the Finnish National Annex of EN1991-2, so that the level of safety is assured against the actual Finnish traffic conditions. Besides the locally oriented nature of the composed criteria, this attempt to quantify and build-in the codes fatigue's primary features could also be used as an initial guideline for future attempts for any road network.

AbstractSeit dem Erscheinen des zusammenfassenden Bandes Mezolit SSSR“ wurden einige hundert neue mesolithische Fundstellen entdeckt und einige Dutzend davon, darunter 15 bedeutende Feuchtbodenfundstellen, ausgegraben. Neues Material und die kritische Analyse der alten Kollektionen erlauben es, die bestehenden Vorstellungen über das Mesolithikum der Wolga-Oka-Region erheblich zu überarbeiten und zu vervollständigen. Mit Hilfe von naturwissenschaftlichen Methoden konnte eine groβe Menge Daten zur natürlichen Umgebung und zur Wirtschaft des mesolithischen Menschen gesammelt werden. Der Artikel analysiert kurz vier kulturelle Traditionen des späten und finalen Paläolithikums, auf deren Grundlage sich die mesolithischen Kulturen der Region – die Ienevo-, die Butovo- und die Resseta-Kultur – herausbildeten. Es wird eine kurze Zusammenfassung der abgesicherten mesolithischen Fundstellen und der Entwicklungsgeschichte der Kulturen der Region gegeben. Kurz werden ebenso die Grundfragen der Wirtschaft der mesolithischen Bevölkerung des Wolga-Oka-Einzugsgebiets berührt.Depuis la parution du volume de synthèse Mezolit SSSR“, on a découvert plusieurs centaines de nouveaux sites mésolithiques, dont 15 sites importants en zone humide furent fouillés. Le nouveau matériel et l’examen critique des anciennes collections permettent de revoir et de compléter considérablement nos idées du Mésolithique dans la région de Volga-Oka. Grâce aux méthodes scientifiques, on a pu réunir une grande quantité de données sur le milieu naturel et l’économie des hommes du Mésolithique. Cet article analyse brièvement quatre traditions culturelles épipaléolithiques d’où naîtront les cultures mésolithiques de la région, celles de Ienevo, de Butovo et de Resseta. Il livre également un aperçu des sites mésolithiques sûrs et de l’évolution des cultures de la région, et aborde brièvement les questions économiques fondamentales de la population mésolithique du bassin de Volga-Oka.Since the publication of the collection “Mezolit SSSR”, several hundred new Mesolithic sites have been discovered and a few dozen of them excavated, including 15 significant wetland sites. New material and a critical analysis of the old collections allow for present notions of the Mesolithic Age in the Volga-Oka region to be revised and updated. Using scientific methods, a great amount of data has been compiled on the natural environment and economy of the Mesolithic people. The article briefly examines four cultural traditions of the late and final Paleolithic Age, from which the Mesolithic cultures of the region – the Ienevo, Butovo and Resseta cultures – emerged. It also provides a summary of the protected Mesolithic sites and the evolution of the region’s cultures. Basic questions on the economy of the Mesolithic peoples of the Volga-Oka region are looked at in brief.

The nonlinear optical properties of one-dimensional all-solid-state photonic-crystal microcavities (MCs) are experimentally studied by second-harmonic generation (SHG) spectroscopy in both the frequency and the wave-vector domains. The studied single and coupled MCs are formed by the alternating of mesoporous silicon layers of different porosities. When the fundamental radiation is in resonance with the MC mode the second-harmonic intensity is enhanced by a factor of approximately 10^2. The resonant SHG response is compared with the off-resonance response, as the fundamental wavelength is outside the photonic bandgap. The splitting of the modes of two identical coupled MCs is observed in the wave-vector domain spectrum of enhanced SHG. The SHG enhancement is attributed to the combined effects of the spatial localization of the fundamental field in the MC spacer and the fulfillment of the phase-matching conditions. The confinement of the resonant fundamental field is probed directly at the MC cleavage by a scanning near-field optical microscope. The role of the phase matching that is associated with the giant effective dispersion in the spectral vicinity of the MC mode is deduced from a comparison with the SHG peaks at both edges of the photonic bandgap.

Evolutionary relationships among 116 representatives (80 genera) ofApiaceae (Umbelliferae) subfam.Apioideae were investigated by comparative sequencing of the two internal transcribed spacers of the 18S–26S nuclear ribosomal DNA repeat. The resultant phylogenies, inferred using maximum parsimony and neighbor-joining methods, clarified the relationships of several genera whose phylogenetic placements have heretofore been problematic. Comparisons between the phylogenies inferred and the distribution of several phytochemical (coumarins, flavonoids, and phenylpropenes) and morphological (stomates, pollen, and cotyledonary shape) characters were also made, revealing that many of these characters (like those morphological and anatomical characters of the fruit) are highly homoplastic. It is not surprising then that systems of classification ofApioideae based on these characters, particularly with regard to tribal and subtribal designations and relationships, are unsatisfactory. The results of recent serological investigations of the subfamily support several relationships proposed herein using molecular data.

Navigation and collision avoidance are major areas of research in mobile robotics that involve varying degrees of uncertainty. In this paper, a new approach is proposed for navigation and control of a wheeled mobile robot in a partially known environment. A collision-free path is calculated using an efficient neural motion planner. An additional fuzzy logic based navigation strategy is developed to adjust the moving information in the cases when the mobile robot encounters unexpected obstacles. The output of the navigation level is transformed into a time indexed data sequence which is fed into a tracking controller that takes into account the complete dynamics of the mobile base. The locomotion control structure is based on the integration of a kinematic controller and an adaptive fuzzy-net torque controller.

A complete motion planning and control procedure for mobile robot is presented. A collision-free path is calculated using a neural-net motion planner. The output of the planner is then transformed into a time indexed data sequence which is fed into a tracking controller that takes into account the complete dynamics of the mobile base. A locomotion control structure based on the integration of a kinematic controller and an adaptive fuzzy-net torque controller is proposed. An evolutionary feedback-error-learning method for automatic elicitation of knowledge in the form of fuzzy if-then rules is developed. The results of the simulations show the effectiveness of the proposed approach.

The effect of 5 silatranes RSi(OCH2CH2)3N, where R = C2HsO; C6H5; ClCH2and RSi[OCH(CH3)CH2]3N, where R = C6H5, ClCH2and tetraethoxysilane were studied on the growth, photosynthetic oxygen evolution and dark respiration of the marine centric diatom Cyclotella cryptica. Both silica-free and Si(OH)4supplemented media were used. Only 1-ethoxy- silatrane was hydrolyzed by the diatom, giving sufficient quantities of Si(OH)4to maintain growth without exogenous Si(OH)4. In this case the diatoms multiplied by a factor of 18 within 48 h. With silica in the medium, 1-phenylsilatrane, 1-phenyl-3,7,10-trimethylsilatrane, 1-chlormethylsilatrane and 1-chlorm ethyl-3,7,10-trimethylsilatrane exhibited only slightly inhibitory activity. In contrast, however, tetraethoxysilane (5 · 10-4mol/1) inhibited growth almost completely. Respiration was unaffected by all the silatranes tested, but net photosynthetic oxygen evolution was reduced by approx. 50% by 1-chlormethylsilatrane and 1-chlormethyl- 3,7,10-trimethylsilatrane and almost completely by 1-phenylsilatrane and 1-phenyl-3,7,10-tri- methylsilatrane. In the absence of silica as nutrient in the medium, the silatranes hardly affected dark respiration within 24 h. Conversely, the same samples showed no photosynthetic oxygen evolution after 24 h, and 24 h later again a negative O2balance was produced in the light. Different silatranes produced significant differences in the final oxygen balance.

SnCl4Complexes with methylaryl ethers and their 35Cl NQR spectra have been obtained. All these complexes, except SnCl4· 1,2-(CH3O)2C6H4, have a trigonal-bipyramidal structure. The latter compound has an essentially distorted octahedral structure. One of the ligand oxygen atoms takes part in the formation of the SnCl4complex with 1,3-, 1,4-(CH3O)2C6H4and RNO2. These complexes have a trigonal-bipyramidal structure too.

The intramolecular cyclization of NH and N-alkyl quaternary salts of 2-quinoxaline-2-carboxaldehyde hydrazones affords pyrazolo[3,4-b]quinoxalines in good yields.

In order to understand the role of the 3′‐terminal untranslated region (3′‐UTR) of alfalfa mosaic virus (A1MV) RNA 4 in viral RNA translation we have constructed the RNA derivatives differing in the length of their 3′‐terminal portions and expressed them in a wheat germ extract. The result shows that the removal of the 3′‐UTR from A1MV RNA 4 causes a lagged RNA translation in the cell‐free system as compared with the translation of the full length RNA 4, thus suggesting the involvement of the 3′‐UTR in the translation initiation pathway.