bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatio‐temporal expand‐and‐squeeze networks for crowd flow prediction in metropolis
Authors: Yang Bing , Kang Yan , Li Hao , Zhang Yachuan , Yang Yan , Zhang Lan
Published: January 2020

The use of deep learning methods to predict traffic flow in transportation systems has become a hot research project. The existing predictive model method faces problems such as long calculation time and difficult data pre‐processing, especially for the prediction effect of high traffic area. In this study, the authors propose a novel framework ST‐ESNet, spatio‐temporal expand‐and‐squeeze networks, that designs several effective strategies for considering the complexity, non‐linearity and uncertainty of traffic flow, and better captures traffic flow characteristics to adapt to the dynamic characteristics of traffic trajectory, traffic duration and traffic flow. Specially, we use extend‐and‐squeeze process rather than squeeze‐and‐extend process during the normal residual unit to capture farther spatial dependence among regions. Specifically, inverted residual and deformed convolution structures are utilised in the expanding process, and the convolution with stride 2 is utilised in the squeeze process. Furthermore, image feature scaling is used in each residual unit to obtain more fine‐grained surface information, which improves the ability of the model to capture dynamic spatial dependence features. Finally, they use stochastic weight averaging to obtain an integration model. In summary, they propose a new predictive model ST‐ESNet. The experimental results show that the authors’ proposed network model has better prediction performance compared with the state‐of‐the‐art model.
Innovative complete solution for health safety of children unintentionally forgotten in a car: a smart Arduino‐based system with user app for remote control
Authors: Visconti Paolo , de Fazio Roberto , Costantini Paolo , Miccoli Simone , Cafagna Donato
Published: January 2020

This study describes an innovative complete car control system against children abandonment in unattended vehicles. Even if systems of this kind are already available in the automotive market, other solutions are currently object of intense researches by several important Research and Development centres or under patent procedure. In this study, a description of the technologies already adopted in the currently used car control systems and in those that are in research and testing phase too is provided. Then, it will be introduced to the proposed control system, which enables to improve all the described systems by providing innovative technologies and functionalities. The proposed system implements a microwave motion sensor, two infrared sensors, a carbon dioxide sensor, a temperature/humidity sensor, a vocal detector and a micro‐camera. These acquisition devices are connected to a microcontroller board that is able to combine all acquired data for detecting the alarm scenario and consequently acting some warning procedures: alarm short message service transmission with vehicle Global Positioning System position, vehicle's horn activation and/or car windows lowering. Thanks to such a wide set of sensors, the system can correlate the acquired information in order to ensure a good detection capability in every condition in which it can operate.
Field‐circuit simulation of electromagnetic interference and optimisation design in vehicle navigation system
Authors: Yang Hui , Xiao Xia , Song Hang
Published: January 2020

With the rapid development of the vehicle navigation system (VNS), the functions of VNS are improved, while the design becomes very complicated. The conventional field‐circuit simulation method is not precise enough to evaluate the VNS design. It is difficult to ensure that the electromagnetic compatibility index of VNS meets the GMW 3097 standard, resulting in electromagnetic interference (EMI) testing in an absorber lined shielded enclosure (ALSE). If the VNS does not comply with the GMW 3097 standard, it needs to be debugged repeatedly in the expensive ALSE. Therefore, a more accurate simulation method is highly desired, which can be used for improving the designed system to avoid using the expensive ALSE solution. In this study, an advanced field‐circuit simulation method utilising actual parameters of the working printed circuit board is proposed to improve the simulation accuracy. The system is debugged by the proposed simulation method. Meanwhile, the optimisation method is proposed to enhance the EMI performance. Finally, by suppressing noise on the transmission path, the emission level of the VNS at 1.6 GHz is reduced from 5.9 dBμV to below−4 dBμV, which is ∼8 dBμV lower than the GMW 3097 standard.
Using RBF neural networks to identify relationship between development of oil prices in world market and value of Chinese currency
Authors: Horák Jakub , Vrbka Jaromír , Krulický Tomáš
Published: January 2020

The objective of the contribution is to identify a possible relationship between the development of the price of Brent oil (Brent in USD/barrel) and the CNY / USD Exchange rate by means of artificial neural networks. Understanding future fluctuation characteristics and the trend in oil prices is the basis for a deep understanding of systemic mechanisms and trends in related research areas. However, given the complexities of oil prices, it is very difficult to obtain accurate forecasts. Within the experiment, a total of 50,000 artificial RBF neural networks were generated. Was found the CNY / USD price will play a significant role in creating China's real product. Given that it was already proven that the CNY / USD exchange depends on Brent in USD / barrel, it is important to focus the further research on finding out the time lag with which the price of Brent in USD / barrel is actually reflected in the price of CNY / USD.
The Ukraine and EU trade balance: prediction via various models of time series
Authors: Matskul Valerii , Okara Diana , Podvalna Nataliia
Published: January 2020

This article is the first to study, simulate and forecast the monthly dynamics of the trade balance between Ukraine and the European Union for the period from 2005 to 2019. In the presented work, three types of models were used for modeling and forecasting: Automated Neural Networks, additive models ARIMA *ARIMAS (Autoregressive integrated moving average with season component) and Holts model with a damped trend.

When modeling using the Automated Neural Networks module, various ensembles of networks and neuron activation functions in hidden layers were used. It turned out that Automated Neural Networks have poor prognostic ability (as in the case considered by us, when modeling insufficiently long series of dynamics). Therefore, when modeling and forecasting the dynamics of the Ukraine-EU trade balance, classical (so-called Box-Jenkins) time series models were used. In this case, the time series is divided into several components (in our case, terms): the main trend is the trend, the seasonal component and the random component (the so-called white noise). By smoothing the initial series, a trend was found, and an analysis of the autocorrelation functions revealed a one-year seasonality. Eliminating the trend and the seasonal component, we obtained a random component, which has a Gaussian distribution. This made it possible to apply first the ARIMA* ARIMAS additive model, and then the Holt model of exponential smoothing with a damped trend. Adequate models of Ukraine-EU trade balance dynamics have been obtained, according to which the forecast has been made. A comparative analysis of the models used. The best model was chosen for forecasting, which allowed to get a good forecast (in comparison with actual data).
Machine learning forecasting of USA and PRC balance of trade in context of mutual sanctions
Authors: Rowland Zuzana , Vrbka Jaromír , Vochozka Marek
Published: January 2020

The USA decided to regulate the trade more by imposing tariffs on specific types of traded goods. It is therefore more interesting to find out whether the current technologies based on artificial intelligence with time series influenced by extraordinary factors such as the trade war between two powers are able to work. The objective of the contribution is to examine and subsequently equalize two time series – the USA import from the PRC and the USA export to the PRC. The dataset shows the course of the time series at monthly intervals between January 2000 and July 2019. 10,000 multilayer perceptron networks (MLP) are generated, out of which 5 with the best characteristics are retained. It has been proved that multilayer perceptron networks are a suitable tool for forecasting the development of the time series if there are no sudden fluctuations. Mutual sanctions of both states did not affect the result of machine learning forecasting.
Human Resource Management in SMEs in the Czech Republic – Specifics and Key Requirements
Authors: Caha Zdeněk , Urban Jan
Published: January 2020

A frequent problem regarding human resources management in SMEs is that established rules are not followed. This is because managers either do not fully understand the rules or the importance thereof, or because of a lack of professional support or rigorous control by a human resources department. Another reason is that not all SMEs have personnel specialists or HR managers at their disposal, as a consequence of which the control and advisory role falls under the responsibility of line management. The solution to this conundrum may be the adoption of a personnel manual, a document that summarises best practice regarding human resources management based on the experience of professionally managed and financially prosperous small companies. This can be understood to represent a user-friendly methodological guide for the successful implementation of personnel management activities in SMEs by line managers, a guide which includes clearly defined methodological, control and advisory tasks and functions.
Condition Factor Analysis in the Region of South Bohemia
Authors: Pártlová Petra
Published: January 2020

Socio-economic transformation in many post-communist states has influenced the dynamic process in such states with the differentiation trends. Such process often causes disparities in different regions, creates relations and ties, often contradictory, and spatial socio-economic polarization in the regions. The above-mentioned processes and their impacts are demonstrated on the example of the South Bohemian region, in particular the LAG territory. Using the methods of correlation analysis, the author demonstrates the conditionality of the indicators in the area of interest. Different links and relations of socio-economic, infrastructural and natural factors to the emergence of disparities in different LAGs are analyzed. The most important factors of the emerging disparities within the region and the LAGs include the relations between the progressiveness of the economic structure and population density and between the demographic structure of the region and the infrastructure, as revealed by the analysis.
Urinary ethyl glucuronide (uEtG) as a marker for alcohol consumption in liver transplant candidates: a real-world cohort
Authors: Vollmar Johanna , Stern Franziska , Lackner Karl , Mildenberger Philipp , Greif-Higer Gertrud , Mittler Jens , Darstein Felix , Foerster Friedrich , Grimm Daniel , Marquardt Jens Uwe , Schattenberg Joern , Woerns Marcus Alexander , Lang Hauke , Galle Peter Robert , Zimmermann Tim
Published: January 2020

Background In order to reduce alcohol relapse after liver transplantation (LT), the German national guidelines for waiting-list maintenance and organ allocation demand a minimum 6-month period of alcohol abstinence pre-LT, confirmed by measuring urinary ethyl glucuronide (uEtG).

Methods Between January 2015 and June 2016, uEtG was measured at least once in 339 cirrhotic patients with an indication for LT at the University Medical Center Mainz. uEtG was measured with an enzyme-linked immunosorbent assay (ELISA) screening test (cutoff value: 500 µg/L). For uEtG values ≥ 500 µg/L, liquid chromatography–mass spectrometry (LC-MS/MS) was performed as a confirmatory assay. Data were collected prospectively in a transplant database.

Results Of the 339 potential liver transplant candidates, uEtG was negative in 86.4 %. Most patients were male (64.3 %), with an average age of 56.42 ± 10.1 years. In the multivariate analysis, mean corpuscular volume (p = 0.001), urinary creatinine (p = 0.001), gamma-glutamyl transferase (p = 0.001), and hemoglobin (p = 0.003) were significantly associated with a positive uEtG test result. The sensitivity of the ELISA screening test was 100 % for uEtG values > 2000 µg/L, as confirmed by LC-MS/MS.

Conclusion uEtG is an effective parameter to reveal alcohol consumption by patients on the waiting list for LT. The sensitivity of the ELISA is excellent for uEtG values > 2000 µg/L, for which LC-MS/MS confirmation could be omitted.
Die Bedeutung der „Big Five“-Persönlichkeitsmerkmale für die subjektive Gesundheit und Lebenszufriedenheit im Jugendalter: Ergebnisse des Nationalen Bildungspanels (NEPS)
Authors: Heilmann Kristina , Hinrichs Richard , Herke Max , Richter Matthias , Rathmann Katharina
Published: January 2020

Ziel der Studie Die Studie untersucht erstmals die Assoziation zwischen den „Big Five“-Persönlichkeitsmerkmalen und der selbstberichteten Gesundheit sowie der Lebenszufriedenheit Heranwachsender in Deutschland.

Methodik Datenbasis bildet das Nationale Bildungspanel (NEPS), Startkohorte 3 (Welle 3, 2012). Die Stichprobe umfasst (n=5440) Heranwachsende der siebten Klassen in Regelschulen. Als Persönlichkeitsmerkmale werden die „Big Five“ (BFI-10) herangezogen: Extraversion, Verträglichkeit, Gewissenhaftigkeit, Neurotizismus und Offenheit. Die statistische Analyse erfolgt bivariat und in binär-logistischen Mehrebenenmodellen unter Berücksichtigung der Clusterung der Heranwachsenden in Schulklassen und Schulen.

Ergebnisse Heranwachsende mit ausgeprägtem Neurotizismus haben ein höheres Risiko einer schlechten Gesundheitseinschätzung (OR: 1,33) sowie niedrigen Lebenszufriedenheit (OR: 1,46). Hingegen weisen Heranwachsende mit hohen Werten in Gewissenhaftigkeit ein verringertes Risiko einer schlechten Gesundheitseinschätzung (OR: 0,72) und geringen Lebenszufriedenheit (OR: 0,59) auf. Hohe Werte in Extraversion (OR: 0,78) und Verträglichkeit (OR: 0,72) sind ebenfalls mit einer höheren Lebenszufriedenheit, nicht jedoch mit einer besseren Gesundheit assoziiert. Das Merkmal Offenheit steht weder mit der selbstberichteten Gesundheit noch mit der Lebenszufriedenheit von Heranwachsenden in Zusammenhang.

Schlussfolgerung Die Ergebnisse legen nahe, dass bestimmte Persönlichkeitsmerkmale wichtige Indikatoren sowohl für die Gesundheit als auch die Lebenszufriedenheit von Heranwachsenden im frühen Jugendalter darstellen können. Es bedarf jedoch weiterer Studien, die die Zusammenhänge und ihre Verallgemeinerbarkeit auf andere Altersgruppen prüfen. Der Rolle von Persönlichkeitsmerkmalen für die Gesundheit und die Lebenszufriedenheit Heranwachsender wurde in Deutschland bislang nur wenig Beachtung geschenkt und sollte in zukünftigen Analysen Berücksichtigung finden.
Validated HPLC Method for Quantification of a Novel Trk Inhibitor, Larotrectinib in Mice Plasma: Application to a Pharmacokinetic Study
Authors: Tripathy Harsha K. , Nair Manju S.V. , Zakkula Ashok , Bestha Ram Murthi , Dittakavi Sreekanth , Mullangi Ramesh
Published: January 2020

Larotrectinib, is an orally active novel small molecule approved for the treatment of solid tumors in pediatrics and adult patients. It acts by inhibiting tropomyosin receptor kinase. In this paper, we report the development and validation of a high-performance liquid chromatography (HPLC) method for the quantitation of larotrectinib in mice plasma as per the FDA regulatory guideline. Plasma samples processing was accomplished through simple protein precipitation using acetonitrile enriched with internal standard (IS, enasidenib). The chromatographic analysis was performed using a gradient mobile phase comprising 10 mM ammonium acetate and acetonitrile at a flow-rate of 0.8 mL/min on an X-Terra Phenyl column. The UV detection wave length was set at λmax 262 nm. Larotrectinib and the IS eluted at 3.85 and 6.60 min, respectively with a total run time of 8.0 min. The calibration curve was linear over a concentration range of 0.20–5.00 μg/mL (r2=≥0.992). The intra- and inter-day precision and accuracy results were within the acceptable limits. Results of stability studies indicated that larotrectinib was stable on bench-top, in auto-sampler, up to three freeze/thaw cycles and long-term storage at −80°C. The validated HPLC method was successfully applied to a pharmacokinetic study in mice.
Monozentrische Erfahrungen mit stereotaktischer Bestrahlung (SBRT) beim fortgeschrittenen hepatozellulären Karzinom im Stadium BCLC-C
Authors: Czauderna Carolin , Stockinger Marcus , Ebersberger Anne , Schmidberger Heinz , Müller Lukas , Kloeckner Roman , Düber Christoph , Weinmann Arndt , Galle Peter R. , Marquardt Jens U.
Published: January 2020

Hepatozelluläre Karzinome (HCC) sind durch eine schlechte Prognose und limitierte Behandlungsoptionen in fortgeschrittenen Stadien gekennzeichnet. Die Behandlung erfordert daher interdisziplinäre Diskussion und multimodale Therapiekonzepte. Neben etablierten lokoregionalen sowie systemischen Therapieansätzen gewinnt die stereotaktische Bestrahlung (SBRT, stereotactic body radiation therapy) zunehmend an Bedeutung. Ergebnisse früher klinischer Studien weisen auf hohe lokale Kontrollraten bei einem akzeptablen Toxizitätsprofil hin. In der vorliegenden Arbeit beschreiben wir die monozentrischen Erfahrungen zur SBRT bei fortgeschrittener HCC-Erkrankung (BCLC-C) in einem universitären Tumorzentrum.

Insgesamt zehn Patienten mit insgesamt 16 SBRT Behandlungen wurden in die Fallsammlung aufgenommen und retrospektiv ausgewertet. Alle Patienten wiesen ein fortgeschrittenes Stadium mit vaskulärer Invasion und/oder Metastasen unter erhaltener Leberfunktion auf. Zwei Patienten wurden ausschließlich mittels SBRT, zwei nach TACE und sechs Patienten zusätzlich mit einer Systemtherapie behandelt. Bestrahlt wurden in den meisten Fällen intrahepatische Herde (n = 7), darüber hinaus Tumorthrombosen und Lymphknoten- sowie Knochenmetastasen. Bestrahlt wurde in einer, drei und fünf Fraktionen zu Gesamtdosen von durchschnittlich 38 Gy. Wir beobachteten ein gutes Ansprechen der bestrahlten Läsionen (73 % nach drei Monaten; 66 % nach sechs Monaten) bei insgesamt guter Verträglichkeit der SBRT. Auch in der Kombination mit lokoregionalen Verfahren bzw. Systemtherapien kam es zu keinen schwerwiegenden Komplikationen.

Zusammenfassend stützen unsere Erfahrungen die Ergebnisse der frühen klinischen Studien und deuten auf eine sichere Anwendung der SBRT mit einer guten lokalen Kontrolle auch bei fortgeschrittener HCC-Erkrankung mit erhaltener Leberfunktion hin.
Diagnostic performance of different cholangioscopes in patients with biliary strictures: a systematic review
Authors: Kulpatcharapong Santi , Pittayanon Rapat , J. Kerr Stephen , Rerknimitr Rungsun
Published: January 2020

Background Cholangioscopy provides direct intraductual imaging, which can enhance diagnostic efficacy during endoscopic retrograde cholangiopancreatography in patients with biliary strictures. This study aimed to review the diagnostic yield of different cholangioscopes for the diagnosis of malignant biliary stricture (MBS).

Methods A comprehensive literature review was performed. Full papers of prospective studies using any type of peroral cholangioscope (POC) were included without language restriction. The primary outcomes were sensitivity, specificity, and accuracy of various POCs to diagnose MBS.

Results Data from 20 published articles, involving 1141 patients, were extracted. Overall sensitivities of POCs for diagnosing MBS were higher for the diagnosis made under visual impression compared with those from cholangioscopy-guided biopsy (67 % – 100 % vs. 38 % – 100 %), whereas the overall specificities were generally high and comparable (73 % – 100 % vs. 75 % – 100 %). Newer video cholangioscopes (digital single-operator POC [digital SOC], direct POC) with the exception of video dual-operator mother – baby POC (video DOC), provided better sensitivity of cholangioscopy-guided biopsy compared with fiberoptic scopes (digital SOC 80 % – 85 %, direct POC 80 % – 100 %, video DOC 38 % – 100 %, and fiberoptic SOC 49 % – 100 %, respectively). Among these video cholangioscopes, the digital SOC provided the highest technical success rate, at 100 %.

Conclusions POCs enhanced the diagnostic yield for diagnosis of MBS. Compared with fiberoptic POCs that only provide good image impression, the digital SOC and direct POC were good at both image impression and cholangioscopy-guided biopsy to diagnose MBS. To ensure high technical success for MBS diagnosis, the digital SOC is a good option.
Peripheral Nerve Schwannomas: A Literature Review
Authors: Magalhães Marcelo José Silva , Pereira Douglas Vitor Maia , Oliva Henrique Nunes Pereira , Durães Dayane Tabatha Santos , Caiado Fernanda Leal , Araújo Grazielle Mendes , Freitas Junior Enilton Teixeira
Published: January 2020

Introduction Schwannomas are benign tumors originating from the cells, which wrap around axons that are usually encapsulated and solitary. These tumors usually lead to little or no symptomatology. They are usually the most common peripheral nerve tumors in adults, with their highest incidence between the third and fifth decades of life.

Objective To perform a review about schwannoma of the peripheral nerves, presenting its definition, epidemiology, diagnosis, symptomatology and treatment.

Methodology This is a descriptive work, based on a review of articles available in the PubMed database with the descriptors schwannoma and peripheral nerves.

Results and Discussion Only papers published between 1981 and 2019, describing studies in humans, and that were available as full articles were selected. A total of 391 articles were included; after reading the titles, we noted that 67 articles fit the topic of the present study. Among the articles selected for reading, 33 fit the objectives of the present work, and were considered for the writing of the present article.

Conclusion Schwannomas are benign myelin sheath tumors that develop with local symptomatology or asymptomatic and present a good surgical prognosis with generally reduced rates of surgical complications.
Pediatric Shock: An Uncommon and Underrecognized Etiology
Authors: Derespina Kim R. , Kaushik Shubhi , Medar Shivanand S.
Published: January 2020

Kawasaki disease, also known as mucocutaneous lymph node syndrome, is a well-known disease entity. Kawasaki shock syndrome (KSS), on the other hand, is less well recognized and has been reported in small single-center international studies and case reports. We report a case in the United States of an 11-year-old male with multiorgan failure and shock, presumed to be secondary to toxic shock but later diagnosed with KSS, an underrecognized entity in the US and review the literature. KSS should be considered in a critically ill child with unexplained shock.
Influence of copper dopants on the photoluminescence of single CdTe quantum dots
Authors: Szymura M. , Kłopotowski Ł. , Wojnar P. , Baranowski P. , Fronc K. , Rodek A. , Kazimierczuk T. , Kossut J.
Published: January 2020

We report on a magnetoluminescence study of epitaxially grown single CdTe quantum dots doped with small amounts of copper (of the order of 0.1 at. %) embedded in a ZnTe semiconducting matrix. The survey of tens of quantum dots did not reveal the presence of a dot containing one Cu ion in a +2 oxidation state with a localized spin 1/2. Instead, more complicated patterns of emission lines were detected. This fact leads us to a conclusion that Cu impurities are in a Cu+ spinless state and are subject to trigonal strain. Such an assumption gives (as our model calculations show) a qualitative agreement with an observed decrease of the excitonic g-factors and the values of the circular polarization degree as compared to those values in CdTe quantum dots without copper impurities. To further improve the agreement, we propose that the quantum dot formation in the Stranski-Krastanov mode is perturbed by the presence of copper, which results in a slight tilt of the dot quantization axis away from the [100] growth direction.
Attraction between trapped ions and beams of electrons
Authors: Kłosowski Łukasz , Piwiński Mariusz
Published: January 2020

The attraction between 100 and 160 eV electron beams and a cloud of trapped calcium ions was observed experimentally. To explain the effect, analytical and numerical models were proposed. They are based on the well-known, classical, Rutherford scattering model. The experimental results and theoretical predictions are in very good agreement. The observed effect is important for studying propagation of electrons through plasmas.
Resting state structure of the hyperdepolarization activated two-pore channel 3
Authors: Dickinson Miles Sasha , Myasnikov Alexander , Eriksen Jacob , Poweleit Nicole , Stroud Robert M.
Published: January 2020

Voltage-gated ion channels endow membranes with excitability and the means to propagate action potentials that form the basis of all neuronal signaling. We determined the structure of a voltage-gated sodium channel, two-pore channel 3 (TPC3), which generates ultralong action potentials. TPC3 is distinguished by activation only at extreme membrane depolarization (V
50
∼ +75 mV), in contrast to other TPCs and Na
V
channels that activate between −20 and 0 mV. We present electrophysiological evidence that TPC3 voltage activation depends only on voltage sensing domain 2 (VSD2) and that each of the three gating arginines in VSD2 reduces the activation threshold. The structure presents a chemical basis for sodium selectivity, and a constricted gate suggests a closed pore consistent with extreme voltage dependence. The structure, confirmed by our electrophysiology, illustrates the configuration of a bona fide resting state voltage sensor, observed without the need for any inhibitory ligand, and independent of any chemical or mutagenic alteration.
Influence of Stipa ichu on the thermal and mechanical properties of adobe as a biocomposite material
Authors: Piñas J M , Lira L , Horn M , Solis J L , Gómez M M
Published: January 2020

A millenary building material that has been used in many cultures is “adobe”. In the Peruvian Andean regions during the winter, the temperature decreases drastically (+5 to -15°C), affecting the health of people of vulnerable age, agriculture and bovine livestock. Bioclimatic techniques must be considered to provide a comfortable thermal environment in the interior of housing. Furthermore, knowing the thermal conductivity of the elements that compose the houses allows us to perform thermal exchange simulations before construction is developed. Specifically, in this investigation, the thermal conductivity of adobe with and without Stipa ichu was measured as 0.371 W/m K and 0.349 W/m K, respectively, considering the norm ASTM C177 for that purpose. The mechanical behavior is as important as the thermal properties, and a value of 2.41 N/mm2 was obtained for unit compression. Additionally, scanning electron microscopy (SEM) mages of adobe samples were evaluated to investigate the internal composition, and X-ray diffraction (XRD) was used to determine the type of clay present. According to these results, our adobe has favorable thermal and mechanical performance.
Tribological properties and wear resistance of the metal deposited by chromium flux-cored wire with carbide-boride alloying
Authors: Eremin E N , Losev A S , Borodikhin S A , Ponomarev I A
Published: January 2020

The wear resistance and the tribotechnical properties of chromium steel of the Fe-C-Cr-B system deposited by flux-cored wire with boron carbide alloyed were investigated. It is shown that this steel has high wear resistance. The average values of the mass wear of the deposited metal is 0.0028 g/m, and the linear values are 0.00723 mm/m. The average value of the friction moment was 21.82 N·m, and the coefficient of friction was 0.412. The hardness of such a metal reaches a maximum value of 58 HRC. The microhardness of structural objects for the matrix is 499-603 HV, for hardening phases is 859-924 HV. The metal structure is a martensitic matrix with a large number of reinforcing phases, formed on the basis of type carboboride (Cr, Fe)7(CB)3. It is shown that the mechanism of metal wear is associated with its high hardness due to the dispersed hardening by particles of compounds, which are effective obstacles to dislocation slip under conditions of plastic deformation of the surface during wear and a decrease in the role of the abrasive component of wear.
Minimizing information security risks based on security threat modeling
Authors: Barankova I I , Mikhailova U V , Afanaseva M V
Published: January 2020

The well-elaborated models of information security threats (IST) allow for the optimal development of a protection plan. This plan will be based on current threats and will consider effective countermeasures that increase the level of information security (IS). The threat model is described using different automation methodologies of this process. It is also possible to visualize the structure of complex objects and processes them from the required angle and with sufficient granularity. Constructing various threat implementations as trees or attack graphs (AG) is one of the relevant directions in assessing the level of IS. The creation of a software application for automation and formalization of assessing the information security process of IS assets, and the localization of bottlenecks in the IS protection, is dealt with in the article. A distinctive feature of the application is the use of the Federal Service for Technology and Export Control of Russia (FSTEC of Russia) threat data bank for modeling the attack tree. The developed software application allows you to reduce time, simplify the process of assessing the security of an IS, and also visualizes the threat modeling process. The scope of the developed software product may be small and medium-sized businesses, as well as state-owned enterprises.
Applying intelligent systems of speech recognition for optimizing the algorithm of noise reduction in audio records
Authors: Ivanov A V , Fazluktinov P S , Kolesnev V A
Published: January 2020

The effectiveness of applying intelligent systems for speech recognition in speech intelligibility estimation is considered. The experiment with employing adaptive filtering to reduce ambient noise in audio records for further analysis of speech intelligibility with applying intelligent systems for speech recognition. Analysis of intelligibility with applying computer speech recognition is found to provide the intelligibility level close to a subjective method and differ not more than 6% averagely. The architecture of a Web service for automated noise reduction in audio records and automatised analysis of intelligibility for each result is designed. The recommendations on applying the obtained results to improve the speech security level and noise reduction are given.
About the methods of forming a test signal in the instrumental evaluation of speaker clearance
Authors: Trushin V A , Khitsenko V E
Published: January 2020

This work presents the analysis of the possibility of creating a speech-like test signal for formant methods of assessing speech intelligibility based on the tables of syllables and words, random selection of speech elements from the database, the synthesis of sound files. Experimental research of the synthesized speech spectra, as well as its probability density, has been carried out. It is shown that the spectral and statistical characteristics of the synthesized speech-like test signals of the three voices of “speech choir” type coincide with the similar characteristics of real speech signals. Articulation tests of speech intelligibility by using synthesized speech-like interference with different signal-to-noise ratios showed the possibility of reducing the integral level of interference by 12 ÷ 15 dB in comparison with noise-like interference. There is discussed the direction of further research of improving the efficiency of generation of speech-like interference.
Research and selection of methods for operational control of diffusion coefficient in block products made of capillary-porous materials
Authors: Belyaev V P , Varepo L G , Belyaev P S
Published: January 2020

For studies of heat and mass transfer in porous media, operational pulse methods are becoming increasingly common. Unlike most known methods, they eliminate the need for destruction of controlled products for preparing special samples of a given configuration. The metrological analysis of the methods providing the possibility of measuring the diffusion coefficient of polar solvents in block products made of porous materials without their destruction is performed. The areas of their preferred use are justified in the context of ensuring acceptable accuracy, in the presence of pronounced anisotropy of properties including.
New matrix for geometrical product specifications on coordinate basis
Authors: Glukhov V I , Varepo L G , Shalay V V , Grinevich V A
Published: January 2020

This study is devoted to the recent problem of quality assurance of technical products in the design process. However, it is impossible to solve this problem by using international standards ISO and geometrical product specifications developed by ISO technical Committee ISO/TC 213. They lack a reference system of geometrical characteristics, i.e. the coordinate systems of the products are not applied. On the other hand, the technical committee ISO/TC 184 – "Industrial automation systems and integration" introduced in their standards coordinate systems for the design of machine tools with numerical control, which made parts of products, 40 years ago, since neither design nor manufacture, nor the development of control programs or the control of parts after processing can be without coordinate systems. At the beginning of the XXI century, the same technical committee developed a series of international standards for the implementation of electronic geometrical 3D models of products, in the structure of which coordinate systems were introduced. Consequently, the coordinate system of products should be introduced in the standards for geometrical specifications ISO-GPS. With that study purpose, a new matrix of common GPS standards of a higher level on a coordinate basis was recommended.
Regular linear surfaces in architecture and construction
Authors: Korotkiy V A , Usmanova E A
Published: January 2020

Linear surfaces are widely used in engineering, architecture and construction, which is explained by their simplicity and adaptability. The linear surface is formed by the movement of a straight line sliding along curvilinear guides. The shape of the guides is determined by the architect-designer and depends on the geometric boundary conditions. At the same time, the surface must meet certain aesthetic criteria. As a result, the shape of the curved guides may be overly complex, and the designed surface becomes irregular, that is, it does not have an exact analytical description. For visualization of the irregular surface, two-dimensional spline approximation methods (Koons surface, Bezier, NURBS surfaces) are used. The technology for making such a surface is, as a rule, extremely complicated. The article proposes a simplified graphical algorithm for constructing a regular linear surface, given by flat guides of arbitrary shape. The algorithm is based on approximation of the guide lines by arcs of curves of the second order. To build a linear surface that passes through given guides, the method of dividing the chords into proportional parts is used. In the general case, a proportional or projective correspondence is established between the points of the chords. The points of division are transferred to curvilinear guides by the method of central or parallel projection, after which the corresponding points are connected by segments of straight lines. In addition to general surfaces, the article considers oblique transition surfaces and wedge-shaped surfaces. The surface of an oblique transition rests on arcs of circles of the same radius. The wedge-shaped surface contains one or two rectilinear guides. The use of such surfaces in the practice of architectural and construction design allows to create a variety of forms while ensuring good technological conditions for the manufacture of the supporting framework of the designed surface.
Construction of a discrete planar contour by fractional rational Bezier curves of second order
Authors: Panchuk K L , Myasoedova T M , Odinets M N
Published: January 2020

A solution to the problem of formation of a smooth closed curve given an array of points is proposed. For the curve, a spline consisting of fractional rational Bezier curves of second order is taken. It is shown that upon appropriate reparametrization, the standard form of representation of this Bezier curve can be reduced to a more simple form. This form is convenient in construction of a closed spline from said segments, which are connected in the process of formation according to the second order of smoothness. Depending on the calculated value of control parameter in the proposed form of representation of fractional rational Bezier curve, it is possible to construct a closed spline of segments of certain curves of second order.
Early detection of the beginning of a gradual change in properties insulating materials
Authors: Pavlov V I , Gribkov A N , Selivanova Z M , Belousov O A , Belyaev M P , Nagornova I V
Published: January 2020

Procedure of early detection of a gradual change in insulating materials properties (disorder) is developed on the basis of thermal conductivity degradation under the hostility exposure. In the procedure of Bayesian statement development for early detection of a gradual disorder beside the initial data in which the disorder is searching it is proposed to use the additional information from indicators indirectly proofing a possible disorder. The simulated results showed that the value of delay in the detection of gradual change beginning of thermal conductivity in various insulating materials is reduced by an average of 20% in comparison with the existing procedures. The worked out procedure is meant for implementation in information-measuring systems of materials properties and process characteristics control.
Improving the accuracy of geometric model to the mark out networks for high-rise buildings
Authors: Shekhovtsov G A , Zhilina N D , Pavlov A S , Raskatkina O V
Published: January 2020

This article describes the various options for using angular and linear-angular triangulation to create the mark out networks on the floors for high-rise buildings construction. A polynomial addition of geometric data is proposed to obtain an estimate of accuracy. The method for estimating the accuracy of geometric constructions using gradients of directions, angles and distances is considered. The numerical example shows the simplicity and high efficiency of this method. The calculations were performed using spreadsheets.
Approximation of distribution law of experimental test data to assess reliability of information-measuring and control systems
Authors: Zyryanov Yu T , Ryazanov I G , Naumova A Yu , Muromtsev D Yu , Chernyshov N G , Trapeznikov E V
Published: January 2020

Methods of approximation for the distribution law of experimental data find wide application in problems of reliability assessment in tests of both hardware and software of software modules of information-measuring and control systems (SM IMCS). Thus, the main task is to solve the problem of increasing the accuracy of the approximation and simplify experimental data processing. In this paper various modification types of Pearson distribution for data taking both positive and negative values, and for data taking only positive values are considered. The described modifications allow one to solve a range of problems related to the existing distributions, as well as to improve the simplicity of the approximation procedure. Pearson logarithmic distributions are proposed for experimental data that take only positive values.
Deformation of flexible gear of harmonic drive
Authors: Baris A V , Vanag Yu V
Published: January 2020

Harmonic drives have high load capacity, kinematic accuracy, and small weight and dimensions’ parameters, compared to other transmissions. Due to the variable stiffness in the areas of the teeth and tooth sockets, the toothed rim of the harmonic drive during bending takes the shape of a polyhedron. This effect most strongly appears when the gear ratio is less than 60. For this reason the geometric synthesis of harmonic drives with gear ratios of less than 60 is an important task. In this paper, the law of deformation of the flexible gear is given by harmonic oscillations of the inner angles of the polygon. The dependences which allow the teeth of a rigid gear to be profiled, taking into account the effect of the “polyhedron” of the toothed rim of the flexible gear are obtained. The proposed dependences are the basis of the geometric synthesis of harmonic drive elements.
Survivability assessment of damaged rod-type vibration systems
Authors: Filippova Yu F , Doronin S V
Published: January 2020

From the point of view of dynamics, structural damage manifests as a decrease of stiffness of the material of structural elements or a decrease of their masses (removal from the system due to destruction). The effect of damage on the behavior of vibration systems consists in redistribution of stiffnesses and masses and manifests as a change in natural frequencies and vibration modes. The survivability of damaged vibration systems is viewed as the sensitivity of their natural frequencies and vibration modes to various types of damage. The survivability analysis technology consists in a multivariate modal analysis of the structure with variation in its damage. The article considers the results of numerical simulation of frequencies and modes of natural vibrations of a high-pressure xenon tank mounted on the hull’s primary structure after various types of damage to the latter. The tank is a part of the electric propulsion engine of a spacecraft. The results allow assessment of the sensitivity of dynamic characteristics of the tank to damage to the primary structure.
Mathematical model of the working process of the road sweeping machine as a complex dynamic system
Authors: Korytov M S , Shcherbakov V S , Titenko V V , Ignatov S D , Tsekhosh S I
Published: January 2020

The article is devoted to the urgent problem of improving the roadway cleaning efficiency. To achieve maximum cleaning efficiency, an optimal pressing force of the brush equipment to the surface being cleaned should be provided. A schematic diagram of a sweeping machine working process as a complex dynamic system was constructed including a basic machine, brush and running equipment, a hydraulic drive, a road surface, as well as a microrelief control device reflecting the effect of the microrelief on the vertical coordinate of the working equipment. A mathematical model of the working process of a sweeping machine is presented. The simulation was carried out using the MATLAB software, Simulink extension. As a result, the dependences of the vertical coordinates and the pressing force of the brush equipment were established. In most cases, the brush positioning control is provided by a standard hydraulic drive; however, when the dimensions of a pothole are large enough, the standard hydraulic pump does not guarantee the required speed of the control device so that the deviations of the vertical coordinate could be compensated. To improve the speed of the brush positioning control device, the standard hydraulic pump was supplemented with an additional pump switching on only at particular periods of time.
Hydroelastic Response of an End Wall Interacting with a Vibrating Stamp via a Viscous Liquid Layer
Authors: Popov V S , Popova A A , Christoforova A V
Published: January 2020

The mathematical modelling of a vibrating stamp interaction with a flexible restrained end wall (bellows) of a narrow channel via a viscous incompressible fluid is carried out. The narrow channel formed by two parallel walls and filled with a viscous liquid is investigated. The liquid motion in the channel is considered as a laminar one. The bottom channel wall is absolutely rigid, and the top one is the absolutely rigid vibrating stamp. At the right edge of the channel, the end wall with flexible restraint (bellows) is installed, and at the left one, there is a free liquid flow. The problem of longitudinal hydroelastic vibrations of the channel end wall is formulated and solved analytically. The distribution laws of velocities and pressure in the fluid layer along the channel are found. The motion law of the channel end wall is determined. The amplitude frequency and phase frequency responses of the end wall for steady-state harmonic oscillations are constructed. The mathematical modelling has shown the possibility of damping the channel end wall (bellows) vibrations by changing the distance between the channel walls or by changing the liquid viscosity in the channel.
The influence of the vertical cantledge mass on the vibratory drum vibrations during the material compaction
Authors: Tarasov V N , Boyarkina I V , Boyarkin G N , Serebrennikov V S
Published: January 2020

The road roller vibratory drum is considered as a three-mass vibration system consisting of the eccentric weight mass m
1, vibratory drum mass m
2, additional mass m
3, which is transmitted to the vibratory drum axis through the roller frame. Differential equations of vertical vibrations were formulated, they were solved, analytical expressions were obtained of the amplitude A
1 of the vibrator drum vertical vibrations and of the amplitude A
2 of the additional mass m
3 vibrations, rigidly connected with the road roller frame. The dependences of the vertical vibration amplitudes A
1 and A
2 on the vibration frequency, mass ratio (m
1 + m
2) and m
3, stiffness factors and viscous friction factors of the soil and rubber-metal shock absorbers have been established. The additional mass m
3 is considered as an additional shock absorber that protects the roller frame from vibration. The differential equation of the additional mass m
3 vertical vibrations has been obtained, which are excited by the harmonic inertia force. The analytical dependence conclusion for the determination of the dynamic factor Kd
as the ratio of the dynamic and static vibration amplitudes of the additional mass m
3 of the vibratory drum have been specified. The specified dependence of the driving force transfer factor K determination on mass m
3 to the roller frame has been obtained. The diagrams of the dependence of Kd
and K factors on the frequency ratio of forced and natural vibrations of the mass m
3 are constructed.
Prediction of cracks growth in the main pipeline based on the elastoplastic model
Authors: Vansovich K A , Aistov I P , Beselia D S , Nakhlestkin A A
Published: January 2020

A method is proposed for predicting the growth of surface cracks in the wall of a main pipeline under the action of exploitative forces. An elastoplastic model for the growth of surface cracks under biaxial loading is described using steel 20 as an example. Using the ANSYS program, a crack growth modeling algorithm has been developed which takes into account residual stresses. The forms and magnitudes of crack opening for variable cycles of pipeline loading are determined. The influence of the stress state before the crack tip at variable loads on the growth rate of cracks has been established. The effect of overload cycles on crack growth is researched. A method for predicting the development of cracks according to the internal diagnostics of the pipeline and monitoring their loading is described.