Siemens (Czechia)

BACKGROUND: Analysis of ciliary function for assessment of patients suspected of primary ciliary dyskinesia (PCD) and for research studies of respiratory and ependymal cilia requires assessment of both ciliary beat pattern and beat frequency. While direct measurement of beat frequency from high-speed video recordings is the most accurate and reproducible technique it is extremely time consuming. The aim of this study was to develop a freely available automated method of ciliary beat frequency analysis from digital video (AVI) files that runs on open-source software (ImageJ) coupled to Microsoft Excel, and to validate this by comparison to the direct measuring high-speed video recordings of respiratory and ependymal cilia. These models allowed comparison to cilia beating between 3 and 52 Hz. METHODS: Digital video files of motile ciliated ependymal (frequency range 34 to 52 Hz) and respiratory epithelial cells (frequency 3 to 18 Hz) were captured using a high-speed digital video recorder. To cover the range above between 18 and 37 Hz the frequency of ependymal cilia were slowed by the addition of the pneumococcal toxin pneumolysin. Measurements made directly by timing a given number of individual ciliary beat cycles were compared with those obtained using the automated ciliaFA system. RESULTS: The overall mean difference (± SD) between the ciliaFA and direct measurement high-speed digital imaging methods was -0.05 ± 1.25 Hz, the correlation coefficient was shown to be 0.991 and the Bland-Altman limits of agreement were from -1.99 to 1.49 Hz for respiratory and from -2.55 to 3.25 Hz for ependymal cilia. CONCLUSIONS: A plugin for ImageJ was developed that extracts pixel intensities and performs fast Fourier transformation (FFT) using Microsoft Excel. The ciliaFA software allowed automated, high throughput measurement of respiratory and ependymal ciliary beat frequency (range 3 to 52 Hz) and avoids operator error due to selection bias. We have included free access to the ciliaFA plugin and installation instructions in Additional file 1 accompanying this manuscript that other researchers may use.

Protein-protein interactions are central to most biological processes and represent a large and important class of targets for human therapeutics. Small molecules containing peptide substituents may mimic regions of interacting proteins and inhibit their interactions. We set out to develop efficient methods to screen for similarities between known peptide structures within proteins and small molecules. We developed a method to rank peptide-compound similarities, that is restricted to small linear motifs in proteins, and to compounds containing amino acid substituents. Application to a search of the PubChem database (5.4 million compounds) using all short motifs on accessible surface areas in a nonredundant set of 11 488 peptides from the protein structure database PDB demonstrated the feasibility of the method for high throughput comparisons and the availability of compounds with comparable substituents: over 6 million compound-peptide pairs shared at least three amino acid substituents, approximately 100 000 of which had an rmsd score of less than 1 A. A Z-score function was developed that compares matches of a compound to different instances of the peptide motif in PDB, providing an appropriate scoring function for comparison among peptide-compound similarities involving different numbers of atoms (while simultaneously enriching for similarities that are likely to be more specific for the protein of interest). We applied the method to searches of known short protein motifs against the National Cancer Institute Developmental Therapeutic Program compound database, identifying a known true positive.

Nowadays, the power electronics converter design is challenged with a request of high efficiency and compactness for various applications. To tackle this, the research community and the industry have almost fully exploited the silicon technology, leading to the development of new power transistors. The Gallium-Nitride (GaN) HEMTs can be promising power devices to replace the traditional power devices. Therefore, the performances of GaN-based converters should be assessed to validate the effectiveness in terms of efficiency and power density. Moreover, among the available converter topologies, the performance of the three-level Neutral Point Clamped (NPC) family can be enhanced with the GaN HEMTs. In light of the above, in this paper, the performance of a GaN-based three-level Active NPC (3L-ANPC) converter is evaluated in terms of power losses, volume impact of passive components, and output distortions. Simulations and experiments have been performed.

Nowadays, it is very desirable to obtain the low cost polymeric material with the best material properties. For the best modification of the commodity and construction polymeric materials it is firstly necessary to know the basic material properties. In this study the bending and Charpy impact test specimens were fabricated via a professional FDM 3D printer Fortus 900mc, from company Stratasys, processing ABS-M30 in three build orientation XY, XZ-H and XZ-V. The 3D printed test specimens were examined to compare the effect of layer thickness and building orientation. Tensile test machine Zwick 1456 and impact pendulum Zwick HIT50P were used for bending and Charpy impact tests. Optical microscopy was utilized to perform fractography on impact test specimens to explore the effect of the layer thickness and building orientation on the fracture surface morphology of the failed specimens. This study demonstrates the need for material testing for specific processing as additive manufacturing technologies.

We present a system for IP based networks which allows policy based handover between different access network technologies. The policy rules for selection of the access network are provided by the network/service provider. An interface selection subsystem on the mobile terminal triggers the handover according to these policy rules, and a service subsystem initiates adaptation of the media streams to match the network resource availability. We provide performance measurements to analyze the handover behaviour of our system during a running video session. These measurements show that with the proper interworking between interface selection in the mobile terminal and media adaptation in the video server, an almost seamless policy based handover between heterogeneous wireless networks is possible.

The energy efficiency of machines is nowadays an intensively studied problem. The efficiency of the induction motor is dominantly influenced by the rotor’s and stator winding’s temperature. The main goal of the research presented in this paper is to develop a methodology based on Computational Fluid Dynamics (CFD) analysis of internal and external aerodynamics, which is necessary for the optimisation of cooling of the induction motors. In this paper, the theoretical, as well as the numerical study of the internal and external aerodynamics of the induction motor, is described and verified by the experimental measurements. In the CFD-based numerical study, the Reynolds-averaged Navier–Stokes (RANS) turbulence modelling approach was applied to the flow field simulations inside and outside the induction motor. The complexity of the solved problem is increased not only by the geometric asymmetry but also by the flow’s asymmetric character caused by the fan’s rotation to cool the motor casing. This increases demand, especially on computational resources, as it is impossible to create a simplified numerical model incorporating symmetry. The volume flow of the cooling air and velocity between ribs was measured for the experimental study. Comparing the results of the Computational Fluid Dynamics (CFD) simulations and data obtained from the experimental measurement, we concluded that the results of CFD simulations are in good relationship with the results of experimental measurement and analytical approximations. An experimentally validated CFD model of the induction motor, the so-called digital twin, will be in the future used for virtual optimisation of the new designs concerning minimising losses and maximising efficiency, respectively.

This paper indicates the importance and advantages of the application of hybrid models in the control of water supply systems. A range of possibilities provided by this scientific approach is presented in the practical examples related to the fault diagnostics and fault-tolerant control in the pumping station (PS) control systems. It is presented that continuous monitoring and recording of the data of the pumping stations operation processes (electrical parameters such as electrical power, pressure or flow in the pipelines, water levels in the tanks, changes in various discrete states, etc.) could represent a significant resource that can be used to develop various hybrid models using the appropriate “data-driven” techniques. During this process, data are transformed into information, and thereafter, information into knowledge. Based on this knowledge, the control of PS operation can be significantly improved and a significant increase in the user’s satisfaction can be achieved while the maintenance and operation costs can be reduced.

Protein-protein interactions are fundamental in mediating biological processes including metabolism, cell growth, and signaling. To be able to selectively inhibit or induce protein activity or complex formation is a key feature in controlling disease. For those situations in which protein-protein interactions derive substantial affinity from short linear peptide sequences, or motifs, we can develop search algorithms for peptidomimetic compounds that resemble the short peptide's structure but are not compromised by poor pharmacological properties. SAAMCO is a Web service ( http://bioware.ucd.ie/ approximately saamco) that facilitates the screening of motifs with known structures against bioactive compound databases. It is built on an algorithm that defines compound similarity based on the presence of appropriate amino acid side chain fragments and a favorable Root Mean Squared Deviation (RMSD) between compound and motif structure. The methodology is efficient as the available compound databases are preprocessed and fast regular expression searches filter potential matches before time-intensive 3D superposition is performed. The required input information is minimal, and the compound databases have been selected to maximize the availability of information on biological activity. "Hits" are accompanied with a visualization window and links to source database entries. Motif matching can be defined on partial or full similarity which will increase or reduce respectively the number of potential mimetic compounds. The Web server provides the functionality for rapid screening of known or putative interaction motifs against prepared compound libraries using a novel search algorithm. The tabulated results can be analyzed by linking to appropriate databases and by visualization.

Separate flow friction formulations for laminar and turbulent regimes of flow through pipes are in common use in engineering practice. However, variation of different parameters in a system of conduits during conveying of fluids can cause changes in flow pattern from laminar to fully turbulent and vice versa. Because of that, it is useful to unify formulations for laminar and turbulent hydraulic regimes in one single coherent equation. In addition to a physical interpretation of hydraulic friction, this communication gives a short overview of already available Darcy’s flow friction formulations for both laminar and turbulent flow and additionally includes two simple completely new approximations based on symbolic regression.

The article deals with the influence of the shape Boucherot's cage on induction motor parameters, which are mainly values of starting torque, breakdown torque, but also power factor, efficiency and starting current. Torque curve of induction motor with Boucherot's cage is characterized by a high value of starting torque with a relatively low starting current. The waveform of the resulting torque characteristics is the sum of characteristic of outer cage and characteristic of the inner cage. These partial waveforms are given by their impedances which are given by active part - so by cross-section of rotor slot, and by reactive part - so by self-inductance respectively reactance which is associated the depth of rotor slot, the width of the rotor tooth, width and height of bar etc. The principle of calculating the reactance and resistance of the machine is given in the article and also to analyze the equivalent circuit according to the choices we derive formulas for equations required torques. We are finding the optimum of shape of rotor slot for the maximum size of the relative starting torque and minimum size of relative starting current while maintaining favorable power factor and efficiency the motor.

A full‐wave numerical scheme of polarisability (polarisability) tensors evaluation is presented. The method accepts highly conducting bodies of arbitrary shape and explicitly accounts for the radiation as well as ohmic losses. The method is verified on canonical bodies with known polarisability tensors, such as a sphere and a cube, as well as on realistic scatterers. The theoretical developments are followed by a freely available code whose sole user input is the triangular mesh covering the surface of the body under consideration.

To obtain the deeper knowledge about the mechanical behaviour of 3D printed polymeric materials it is necessary to study the material properties from the beginning to the end. The commonly processed polymeric materials (via injection moulding etc.) are already deeply studied and evaluated, but 3D printed specimens in the various orientation build are not yet. In this study the tensile impact test specimens were fabricated via a desktop material extrusion 3D printer Zortrax M200 processing ABS and HIPS in build orientation XY. The 3D printed tensile impact test specimens were examined to compare the effect of layer thickness. Impact pendulum Zwick HIT50P was used for tensile impact tests according to ISO 8256 standard. Optical microscopy was utilized to perform fractography on impact test specimens to explore the effect of the layer thickness on the fracture surface morphology of the failed specimens. This study demonstrates the need for material testing for specific processing as additive manufacturing technologies.

This letter summarizes and proves the concept of bounded-input bounded-state (BIBS) stability for weight convergence of a broad family of in-parameter-linear nonlinear neural architectures (IPLNAs) as it generally applies to a broad family of incremental gradient learning algorithms. A practical BIBS convergence condition results from the derived proofs for every individual learning point or batches for real-time applications.

The primary objective of the research presented in this paper was to design a methodology for analyzing the thermal field of an induction motor that would be of higher fidelity but less time- and cost-consuming and that would deal with air-cooled induction motors of all sizes. The complexity of the simulation is increased by the geometric asymmetry and by the asymmetric character of flow cooling the motor casing caused by the fan’s rotation. This increases demand, especially on computational resources, as creating a simplified numerical model using symmetry boundary conditions is impossible. The new methodology uses the existing findings from many partial articles and literature, which are modified into more accurate relationships suitable for predicting the external thermal field of induction motors. That way, we do not have to solve the thermal field by the conjugate heat transfer method, and it is possible to assess temperature gradients over the entire range. Furthermore, a new relationship between shear strain rate and thermal contact conductivity has been discovered that allows solving heat transfer of fluid adjacent to the internal walls of an induction motor at any location. That approach has not yet been published in the literature, so it can be considered a new method to simplify heat transfer simulation. An experimentally validated new methodology of the induction motor was performed. The so-called digital twin will be used for the virtual optimization of the new designs concerning minimizing losses and maximizing efficiency.

Nowadays, a large amount of experimental and predicted data about the 3D structure of organic molecules and biomolecules is available. Advanced computational methods and high performance computers allow us to obtain large sets of descriptors that can be used to estimate physicochemical properties. It is often of interest to study the correlations between descriptors and properties using multilinear regression and to design, parameterize, and test different QSPR (Quantitative Structure Property Relationship) models. We developed a modular and easily extensible program, called QSPR Designer, which can read or calculate structural properties of atoms and bonds, employ them as QSPR descriptors, and evaluate correlations between the descriptors and the examined physicochemical property of a molecule. Furthermore, the software allows us to effectively design and parameterize QSPR models, calculate physicochemical properties via the models, test the quality of the models, and provide graphs and tables summarizing the results. The performance of the software is demonstrated by a case study on the prediction of pKa. The pKa is of fundamental relevance for chemical, biological and pharmaceutical research, because many important physicochemical properties are pKa dependent. Unfortunately, pKa is also one of the most challenging properties to calculate [1]. Atomic charges have proven very successful descriptors for the prediction of pKa [2]. Charges can be calculated using a variety of methods (HF, MP2, functionals, etc.), population analyses (Mulliken, ESP, NPA, etc.) and basis sets. Consequently, the procedure of charge calculation strongly influences their correlation with pKa [3]. Using the QSPR Designer, we have successfully designed, evaluated, and compared 75 different QSPR models for the prediction of pKa from charges. Our best model predicted the pKa for 143 phenols with a correlation coefficient 0.969, RMSE (root mean square error) 0.416 and the average pKa error 0.329.

The article presents evaluation of indirect torque measurement accuracy of converter-fed induction motors. The low-power (5.5 kW) motor supplied by Siemens SINAMICS S120 frequency converters was used to perform the measurement. The converter was set up to vector control method, also the effects of speed sensor presence or absence were compared. The dynamometer test bench with gauge strain measurement of force (torque) to produce the load torque was used. It allows us to evaluate the whole working area of tested drive. The results show that the relative accuracy of torque value is acceptable for specific industrial applications and therefore it allows to cut down expenses for direct torque measurement device. The results presented in the article enlarges our measurement database focused on industrial frequency converter performance.

This paper summarizes the technical approach of losses resolution in the Induction Motor (IM) supplied by Pulse Width Modulation (PWM) of the nonharmonic deform converter voltage. The main aim is to get the total motor losses which can be separated on the fundamental harmonic component of supply voltage and higher order harmonic components represented by harmonic losses. This analysis is directly provided from measured waveform of input/output quantities such as voltage, current, torque and speed. The 55 kW/4 p motor is supplied by the converter with chosen switching frequency 2, 4 and 8 kHz with fundamental frequency 50 Hz. Further, the results are compared with other measurements on the same motor provided with sinus source which replaces the real grid (DOL – direct on line).

This article investigates an unconventional approach to solving the control of lateral displacement for railway bogie wheelsets using recurrent higher order neural units (HONUs). Although studies addressing control of independently rotating wheelsets have shown promising results, they are rarely applied by railway manufacturers. Research and developments in modern bogie design are trending toward active yaw control design as an extension to conventional wheelsets mechanics, particularly for higher speeds. We investigate a model-reference architecture for active control via setpoint tracking of lateral displacement. Then, a new HONU sliding mode architecture is derived to solve convergence for zero lateral displacements in higher running speeds which is a more profoundly complex issue in maintaining minimal hunting motion. Starting from the property of nonlinear polynomial architecture of HONUs with in-parameter linearity, we derive a time-variant state-space representation via nonlinear identical decomposition. Then, an input-to-state stability (ISS) approach is applied to prove the local asymptotic convergence of the applied algorithm in each state point and the bounded-input-bounded-state stability of the entire nonlinear adaptive control loop. Using ISS theory, we also prove the global asymptotic stability of the HONU sliding mode controller for the actively controlled wheelset system. The techniques are validated by simulations and a real roller rig system.

This paper deals with the design of low voltage reluctance synchronous rotor with barriers for water pump applications. The design of reluctance synchronous motor (RSM) rotor is carried out as a replacement of existing permanent magnet rotor in stator with concentrated three phase winding. The main aim is to decrease manufacturing price of the water pump motor, which can be used in heating systems or vehicles. The several designs of barriers RSM rotor are studied and the best is selected and manufactured. The analysis based on Finite Element Method (FEM) is used for design and optimization process. The characteristics of designed RSM are presented. The experimental verification is carried out on the prototype of the barriers RSM rotor.

This paper deals with design, simulation, analysis and experimental verification of low voltage synchronous motor for water pump. The design of RSM rotor is carried out on the base of existing stator with concentrating winding as a replacement of original rotor with permanent magnets (PM - ferrites). The new reluctance rotor has been designed to achieve comparable parameters in comparison with PM rotor. FEM analysis has been taken into account during design process and RSM rotor optimization. The best rotor construction has been chosen, the steady state and transients have been simulated and the rotor prototype was manufactured. The experimental verifications were carried out for synchronous inductances in d and q axis and for transient ones.