bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inertial Measurement Unit based Human Action Recognition for Soft-Robotic Exoskeleton
Authors: Kuschan Jan , Burgdorff Moritz , Filaretov Hristo , Krüger Jörg 
Published: May 2021

Abstract
Absence from work caused by overloading the musculoskeletal system lowers the life quality of the worker and gains unnecessary costs for both the employer and the health system. Exoskeletons can present a solution. Typically, such systems struggle with stiffness and discomfort and primarily a lack of battery lifetime. Soft-robotic exoskeletons offer a possibility to overcome these problems by increasing the system flexibility, not limiting the supported DoF and being actuator and joint together. Since soft-robotic exoskeletons can be designed only using power when supporting the wearer, it is possible to increase the battery lifetime by only acting on those actions for which the wearer needs support. Dealing with controls for soft-robotic exoskeleton one major difficulty is to find a compromise between saving energy and supporting the wearer. Having an action-depending control can reduce the supported actions to cover only relevant ones and increase the lifetime of the battery. The system conditions are to detect the user actions in real-time and distinguish between actions which require support and those which do not. We contribute an analysis and modification of human action recognition (HAR) benchmark algorithms from activities of the daily living, transferred them onto industrial use cases containing short and mid-term action and reduce the models to be compatible using embedded computers for real-time recognition on soft exoskeletons. We identified the most common challenges for inertial measurement units based HAR and compare the best-performing algorithms using a newly recorded data set overhead car assembly for industrial relevance. As a benchmark data set we focused on the “Opportunity” data set. By introducing orientation estimation, we were able to increase the F1 scores by up to 0.04. With an overall F1 score without a Null-class of up to 0.883, we were able to lay the foundation to use HAR for action dependent force support.
Laboratory stand for multi-axis control of stepper drives via EtherCAT fieldbus
Authors: Paprocki Marcin , Erwinski Krystian 
Published: May 2021

Abstract
In this paper a laboratory stand is presented that was developed for a multi-axis machine stepper drive control system. Each stepper drive utilizes an EtherCAT communication module based on a development board with software developed by the authors. The modules are used to exchange process data with a higher level controller. The EtherCAT communication standard is described including it’s utilization for stepper drive control. A functional description of the developed communication module is also presented. The aim of the Laboratory stand is to conduct research of cyclic communication (1 milisecond or less) and synchronization between multiple drive slave devices and a supervisory controller. The main focus of the presented results was to determine EtherCAT communication cycle jitter on the developed modules. The main aim of the research was to verify whether the data exchange via EtherCAT bus has an impact on the synchronous operation of the multi-axis system.
Universal identification and control of industrial manufacturing equipment as a service
Authors: Tessaro V. , Vick A. , Krüger J. 
Published: May 2021

Abstract
Rapid prototyping as well as retrofitting and digitization of legacy manufacturing equipment often needs design and application of closed loop controllers. The analysis and modeling for such systems like energy-conversion or material transport devices is labor-intensive and needs process understanding. This paper presents a universal approach of identification and closed loop control of arbitrary linear systems delivered through web services using OPC UA as a standardized industrial communication interface. The identification service was used to model the dynamics of a 6-DOF industrial robot and a laboratory-scale water plant containing two separately controllable pumps. The control service successfully controlled the robot’s linearizable axes and the water plant’s pumps by using their respective identified state-space models. To evaluate the performance of the controllers in terms of stability, accuracy, and time response, target trajectories and disturbances like signal noise and latency in communication were introduced. Simulation and laboratory experiments show promising results for control of diverse systems with varying time-constants and imply broad applicability. So, this paper brings a guideline to efficiently implement model predictive control in manufacturing.
Complex use of smart grid technology in railway traction networks
Authors: Kryukov A V , Cherepanov A V , Lyubchenko I A 
Published: May 2021

Abstract
The goal is to develop a methodology for modeling electric power supply systems for railways equipped with a complex of devices implemented using smart grid technologies. The results obtained showed that a reliable and high-quality electric power supply for traction of trains and non-traction consumers could be implemented on the basis of the integrated use of Smart Grid active elements, such as a phase converter, an active harmonic conditioner, a controlled reactive power source and a distributed generation plant. On the basis of computer simulation, it has been established that in the absence of reactive power sources, noticeable voltage fluctuations are observed on the 10 kV buses of a non-traction consumer. The asymmetry approaches the limit of normally permissible values; turning off the active filter leads to an increase in the total voltage harmonic distortion up to 16%; in the presence of the whole complex of active devices, high quality of electricity is achieved. The phase number converter is robust and has low sensitivity to parameter setting errors; voltage deviations caused by a limited range of changes in reactive power in its source are short-term and do not exceed values acceptable for practice. Thus, on the basis of Smart Grid technologies, it is possible to implement the connection of distributed generation plants directly to the traction network using a device for transducing the number of phases, formed according to the inverted Steinmetz’s circuit. Elimination of harmonic distortions created by rectifier electric locomotives is carried out by means of an active conditioner of higher harmonics. A controlled reactive power source can be used to maintain voltage levels.
Improving the efficiency of the railway electric power system
Authors: Alekseeva T L , Ryabchyonok N L , Astrakhancev L A , Mihalchuk N L , Tikhomirov V A 
Published: May 2021

Abstract
The railway productivity can be increased by increasing the efficiency of the electric power system, the main elements of which are traction substations, overhead contact systems and electric locomotives. The paper analyzes the technical infrastructure of the electric power system of the railway and evaluates the energy efficiency of the equipment. To assess the energy efficiency of the system elements, the revised law of conservation of energy in the electromagnetic field, spectral analysis of electrical quantities and mathematical computer modeling of electromagnetic processes in the system are used. The proposed energy characteristics of the elements of the electric power system made it possible to determine the reasons that hinder the further development of the throughput and carrying capacity of the railway. In order to eliminate the negative impact of inductive resistance of the system elements on the energy indicators of the traction supply and the AC electric rolling stock, the feasibility of the use of high voltage DC electric traction has been proved. Through the complete and continuous use of the voltage of the electricity system for electric traction, it is possible to ensure movement in the intersubstation zone of three linked multiple trains instead of one and increase the speed of trains by 20%. Using high-voltage direct current, the efficiency of electric traction of trains can be in-creased by 7% compared to electric traction of trains using alternating current by reducing the current by 40% in the overhead contact system.
Modeling a boiler unit in the automation systems of transport infrastructure
Authors: Kutsy N N , Podkorytov A A 
Published: May 2021

Abstract
The goal is to develop a model that takes into account the dynamics of the operation of the combustion device of the boiler unit. The article discusses the application of the technique of D.Zh. Box and G. Jenkins to identify the steam production process. A boiler unit used in transport infrastructure automation systems was chosen as the object of research. The boiler unit is a dynamic stochastic object with uncontrolled disturbing influences. Using statistical methods, a mathematical model has been obtained that can be used to predict and regulate the operating modes of the boiler unit.
Evaluation of central tendency measures in relation to the parameters of contact network feeders controlled by relay protection
Authors: Trifonov R S , Yakovlev D A , Filippov S A , Solovyeva O A 
Published: May 2021

Abstract
The paper considers the importance of possible input values of standby stages of remote protection of contact network feeders from the point of view of their influence on the reliability of protection. The measures of the central tendency of parameters controlled by relay protection of contact network feeders were evaluated based on the theory of statistics, using the example of the Trans-Baikal Railway for 2018-2019. In total, 14 parameters were measured according to GOST 32144-2013. Electric power. Electromagnetic compatibility of technical facilities. Standards for the quality of electric energy in general-purpose power supply systems, in 2020 on the feeder of the contact network of the Sokhondo traction substation of the Trans-Baikal Railway against 88965290 obtained values, which made it possible to select significant values from all possible parameters on the basis of mathematical analysis. Statistical data on the following parameters were considered and analyzed: effective voltage value, effective current, peak voltage amplitude factor, peak current amplitude factor, harmonic voltage distortion factor, harmonic current distortion factor, phase shift factor, load resistance, angle between the first voltage harmonic on substation buses and feeder current. The reasonable selection of significant parameters proposed by the authors allows improving the operation of standby stages of remote protections of contact system feeders in heavy traffic conditions and increasing their selectivity.
Stress-strain state of the “wheel-rail” system under different movement conditions
Authors: Ovchinnikov D V , Koven’kin D A 
Published: May 2021

Abstract
A mathematical model of wheel-rail interaction for unworn profiles in the final-element modeling environment under different movement conditions, i.e. with the addition of additional torque and frictional forces, has been developed and tested in the article. Thus, the movement of rolling stock in the mode of braking (related to all cars and locomotives) and gaining traction (related to locomotives) is simulated. A significant influence of friction forces in the contact zone and additional torque on the stress-strain state during the interaction of the wheel and the rail are shown. The data obtained are additional refinements of one of the important factors in testing the durability of the material from which the rails are made – the loading of the samples and load application frequency. The work also approximated the results to maximize compressing and stretching stresses on the rail surface not only in a few variants of the studied original data. With the help of approximation, it is possible to study the stress state of the “wheel – rail” system at any point in a given range of vertical forces and additional torque.
Modelling the efficiency of infrastructure repair based on the risk process
Authors: Krakovsky Y M , Hoang N A , Ivanyo Ya M 
Published: May 2021

Abstract
To improve the efficiency of railway infrastructure repairs, it is proposed to introduce an insurance fund, which performs two functions: it accumulates payments with different frequency and cost for performing different types of repair work; it pays for these works as necessary. To mathematically describe the state of the insurance fund, it is suggested that the risk process of a special kind be used. This approach made it possible to introduce indicators of repairs in the form of resource-cost and financial risks, considering the possibility of non-performance of repairs due to lack of funds. To study these indicators, a modeling program has been created in the MATLAB environment, based on the event-driven approach. Experiments with the modelling program led to the conclusion that, in terms of a minimum_of risk values, preference should be given to the option when the shares and frequency of payments should depend on the type of repair work and initial data.
A method for regulating modes of motion of a wheeled vehicle with installed thermal and reactive energy converters
Authors: Kim V A , Sazonov I S , Bilyk O V , Moiseev E A 
Published: May 2021

Abstract
Understanding the interaction between an elastic tire and a bearing surface is important not only for studying motion of wheeled vehicles, their controllability and running smoothness, but also necessary for creating systems for car motion automatic control. At the same time, the interaction forces between wheels and the bearing surface attract special attention since they have a decisive effect on vehicle’s controllability and stability. Indeed, all effects, including aerodynamic ones, are reflected in forces and moments arising in the wheel/bearing surface contact area, which, in turn, determine car motion parameters. Consequently, in creating a control system for vehicle motion, the primary task is to establish patterns of changes in force factors depending on characteristics of the bearing surface and parameters of the operator’s control in order to develop a criterion for controlling signal formation. The analysis of experimental and theoretical studies of wheel rolling showed that all research results are reduced to establishing patterns of change in force factors (indirect parameters) in the wheel/bearing surface contact patch depending on the parameters that indirectly characterize the kinematic parameters. Meanwhile, establishing a regular pattern of changes in force factors in the wheel/bearing surface interface is the most important task in developing a criterion for the formation of control signals for active safety systems based on force analysis. The paper presents a method for increasing vehicle’s traction and braking dynamics by partially converting thermal energy of the car into reactive tractive force (air propeller, gas turbine).
Influence of spatial arrangement of wires on electromagnetic ecology near high-voltage power transmission lines at railway station
Authors: Buyakova N V , Kryukov A V , Seredkin D A , Thao Le Van , Suslov K V 
Published: May 2021

Abstract
Based on computer modeling, we have considered the effect of a spatial arrangement of wires on electromagnetic pollution of environment on high-voltage electric transmission lines. This pollution is determined based on voltages of electric and magnetic fields. We have considered two variants of the arrangement of wires on power towers. The first version provides for the location of wires in a vertical plane and the second variant provides for the location of the wire at corners of a triangle. Three modes of the high-voltage power line operation were considered: 1) normal with a load at the receiving end of the power line 120 + j90 MVA; 2) break of the phase A wire at the starting end of the power line; 3) two-phase short circuit. The simulation result in the Fazonord software package showed that the spatial arrangement of the wires significantly affects the maximum amplitudes of the electric and magnetic fields at a normalized height of 1.8 m. Moreover, the nature of dependence of the voltage on the x-axis coordinates directed perpendicular to the path of the analyzed power transmission section changes. The results of the simulation showed that under symmetrical load for a power line with a triangular arrangement of wires, the maximum value of the amplitude of the electric field show insignificant increase in comparison with high-voltage power lines with vertically arranged wires. The same indicator for the magnetic field shows increase of one and a half time.
Development of the automatic control system of the blower motors of the diesel electric locomotive
Authors: Konovalova T G , Izotova I I , Astashkov N P , Olentsevich A A 
Published: May 2021

Abstract
The main tasks of the railway industry are focused on reducing the costs associated with the operation and repair of technological equipment. It is possible to solve them by the development of technical means that optimally take into account the natural and climatic, geographical and technical operating conditions. In these operating conditions, the development of locomotive traction involves the modernization of the existing fleet of traction rolling stock, improvement of the locomotives produced, the development of a paradigm-shifting platform of lines of innovative locomotives, the replacement of equipment by more reliable and modern one, and the automation of processes. Automation makes it easier to control the locomotive, reduce the risk of errors and ensure the most rational equipment operation modes. It was found that the damage to the electric parts of the electric motors accounted for more than 70 percent of the total number of faults. The purpose of this article is to develop a technical solution, the use of which will minimize the number of failures of auxiliary machines and locomotive equipment of this series. To implement this, it considers the main design features of electric motors, their connection diagram and the presence of protection elements to determine the trouble spots and justify the proposed technical solution.
Uncertainty quantification by ensemble learning for computational optical form measurements
Authors: Hoffmann Lara , Fortmeier Ines , Elster Clemens 
Published: May 2021

Abstract
Uncertainty quantification by ensemble learning is explored in terms of an application known from the field of computational optical form measurements. The application requires solving a large-scale, nonlinear inverse problem. Ensemble learning is used to extend the scope of a recently developed deep learning approach for this problem in order to provide an uncertainty quantification of the solution to the inverse problem predicted by the deep learning method. By systematically inserting out-of-distribution errors as well as noisy data, the reliability of the developed uncertainty quantification is explored. Results are encouraging and the proposed application exemplifies the ability of ensemble methods to make trustworthy predictions on the basis of high-dimensional data in a real-world context.
Likelihood-based tests for detecting circadian rhythmicity and differential circadian patterns in transcriptomic applications
Authors: Ding Haocheng , Meng Lingsong , Liu Andrew C , Gumz Michelle L , Bryant Andrew J , Mcclung Colleen A , Tseng George C , Esser Karyn A , Huo Zhiguang 
Published: May 2021

AbstractCircadian rhythmicity in transcriptomic profiles has been shown in many physiological processes, and the disruption of circadian patterns has been found to associate with several diseases. In this paper, we developed a series of likelihood-based methods to detect (i) circadian rhythmicity (denoted as LR_rhythmicity) and (ii) differential circadian patterns comparing two experimental conditions (denoted as LR_diff). In terms of circadian rhythmicity detection, we demonstrated that our proposed LR_rhythmicity could better control the type I error rate compared to existing methods under a wide variety of simulation settings. In terms of differential circadian patterns, we developed methods in detecting differential amplitude, differential phase, differential basal level and differential fit, which also successfully controlled the type I error rate. In addition, we demonstrated that the proposed LR_diff could achieve higher statistical power in detecting differential fit, compared to existing methods. The superior performance of LR_rhythmicity and LR_diff was demonstrated in four real data applications, including a brain aging data (gene expression microarray data of human postmortem brain), a time-restricted feeding data (RNA sequencing data of human skeletal muscles) and a scRNAseq data (single cell RNA sequencing data of mouse suprachiasmatic nucleus). An R package for our methods is publicly available on GitHub https://github.com/diffCircadian/diffCircadian.
DOP28 Medical and Surgical Outcomes in Isolated Internal Penetrating Crohn’s Disease: A Multi-Centre Experience
Authors: Sebepos-Rogers G , Fragkos K , Shakweh E , Shah K , Lake L , Balarajah S , Chung Y , McGuire J , Al-Shakarchi N , Khetan T , Bottle J , Anandarajah C , Meade S , David L , Hicks L , Kok K , Joshi N , Samaan M , Patel K , Mehta S 
Published: May 2021

Abstract

Background
Isolated internal penetrating Crohn’s diseases (IIPCD) is the second most common fistulating phenotype yet remains poorly characterised in therapeutic trials. This study assessed long-term outcomes of IIPCD.

Methods
We performed a retrospective study on data collected from 6 IBD referral centres, screening imaging reports between January 2016 and April 2019, excluding perianal or enterocutaneous fistulation, resulting in 121 patients with IIPCD. Management was classified as no intervention, medical (new/optimised) or surgical. The primary endpoint was complete resolution (CR) of fistula at next two imaging reassessments, paired with symptom and nutrition status, as previously defined(Samimi et al., 2010). Secondary endpoint was combined CR and partial resolution (PR). Statistics: Fisher’s exact, Kaplan-Meier method (SPSS v.27).

Results
Of patients at IIPCD diagnosis, 21% had previous IBD-related surgery, 21% were on a current biologic, 41% immunomodulator and 41% no treatment. Fistulae were majority enteroenteric (55%) and enterocolonic (48%), minority genitourinary (7.4%), with median disease duration at IIPCD diagnosis of 64 months.
Outcomes of 118 patients with ≥1 interval imaging were analysed. Initial management was: 25.4% (n=30) no intervention, 49.2% (n=59) medical, 25.4% (n=30) surgical. Of fistula characteristics, only abscess predicted surgery over medical management (OR 5.30, 95% CI 1.60–15.48 p=0.0061), Figure 1.
At first reassessment, CR and PR for the three management cohorts was 13.3%, 12.1%, 66.7% and 20.0%, 46.6%, 26.7%, respectively. The cumulative probability of CR was significantly greater for surgery compared with no intervention and medical management (log-rank p&lt;0.001), Figure 2, and sustained when excluding pre-existing biologic (log-rank p=0.007), Figure 3, or previous surgery history (log-rank p&lt;0.001).
As observed management was then adjusted, cohorts were re-stratified: 13.5% (n=16) no intervention only, 45.8% (n=54) any medical but no surgery, 40.7% (n=48) any surgery. At second reassessment, again surgery significantly predicted CR over other management (log-rank p&lt;0.001), Figure 4, but this was lost using the less strict outcome of combined CR and PR (log-rank p=0.447). No baseline variables were predictive of CR by each management. 27.6% (16/58) and 6.7% (2/30) of initial medical and no intervention cohorts had subsequent surgery (median interval 6.7 and 50.1 months) but there was no significant difference in peri-operative parenteral nutrition or post-operative intra-abdominal septic complication rates between earlier or later surgery.

Conclusion
In this cohort, surgery increases the probability of resolution of IIPCD with medical therapy including biologics offering limited temporising effect.