bluuebunny/crossref_metadata_2025 huggingface dataset:
Constrained tolerance rough set in incomplete information systems
Authors: Wan Renxia , Miao Duoqian , Pedrycz Witold
Published: April 2021

The tolerance rough set is developed as one of the outstanding extensions of the Pawlak's rough set model under incomplete information, and the limited tolerance relation is developed to overcome the problem that objects leniently satisfy the tolerance relation. However, the classification based on the limited tolerance relationship cannot reflect the matching degree of uncertain information of objects. In this article, we explore the influence of null values in an incomplete system, and propose the constrained tolerance relation based on the matching degree of uncertain information of objects. The proposed rough set based on the constrained tolerance relation can provide a more detailed structure of an object class through threshold. Proofs and example analyses further show the rationality and superiority of the proposed model.
Content‐based image retrieval using Gaussian–Hermite moments and firefly and grey wolf optimization
Authors: Tadepalli Yasasvy , Kollati Meenakshi , Kuraparthi Swaraja , Kora Padmavathi , Budati Anil Kumar , Kala Pampana Lakshmi
Published: April 2021

Rapid growth in the transfer of multimedia information over the Internet requires algorithms to retrieve a queried image from large image database repositories. The proposed content‐based image retrieval (CBIR) uses Gaussian–Hermite moments as the low‐level features. Later these features are compressed with principal component analysis. The compressed feature set is multiplied with the weight matrix array, which has the same size as the feature vector. Hybrid firefly and grey wolf optimization (FAGWO) is used to prevent the premature convergence of optimization in the firefly algorithm. The retrieval of images in CBIR is carried out in an OpenCV python environment with K‐nearest neighbours and random forest algorithm classifiers. The fitness function for FAGWO is the accuracy of the classifier. The FAGWO algorithm derives the optimum weights from a randomly generated initial population. When these optimized weights are applied, the proposed algorithm shows better precision/recall and efficiency than other techniques such as exact legendre moments, Region‐based image retrieval, K‐means clustering ​and Color descriptor wavelet‐based texture descriptor retrieval technique. In terms of optimization, hybrid FAGWO outperformed various optimization techniques (when used alone) like Particle Swarm Optmization, Genetic Algorithm, Grey‐Wolf Optimization and FireFly algorithm.
Cyber‐physical component ranking for risk sensitivity analysis using betweenness centrality
Authors: Umunnakwe Amarachi , Sahu Abhijeet , Narimani Mohammad Rasoul , Davis Katherine , Zonouz Saman
Published: April 2021

This article proposes a model for critical component ranking in power system risk analysis using a proposed cyber‐physical betweenness centrality (CPBC) index. Risk assessment, as part of the contingency analysis, is a critical activity that can identify and evaluate component outages that lead to system vulnerability, aiding operators to improve resilience. A power system cyber‐physical risk assessment model is proposed that calculates and offers an efficient protection strategy to the system operator based on component vulnerability to adversaries and the impact of compromised assets on the system operation. We present the CPBC index, which traverses generated attack graphs to rank components according to their importance in reducing adversary impact on the power system. The CPBC extends upon betweenness centrality and integrates into analysis, the services and security cost of communications between system components, as well as the likelihood of component exploitation as an adversary medium to the target relays. The proposed model recommends actions, taking into account the interconnections between cyber and physical components as well as cyber‐induced Common Vulnerabilities and Exposure scores associated with these connections, thus protecting critical components. The proposed model is implemented on the Cyber‐Physical Situational Awareness 8‐substation and extended IEEE 300‐bus cyber‐physical power system models, and results are presented on the impacts of the proposed component ranking model on the security‐aware operation of the power system.
H∞ containment control with time‐varying delays and communicate noise under semi‐Markov switching topologies
Authors: Ru Xinfeng , Wu Mengjie , Liu Weifeng , Ge Quanbo , Peng Zhangming
Published: April 2021

This article focuses on H

∞
containment control and the communication network topologies that are driven by a semi‐Markov chain. Moreover, the communication channels between agents exist time‐varying delays and noise. Firstly, the authors extend the Markov switching topologies to semi‐Markov switching topologies. Because the transition rate of the semi‐Markov switching topology is time‐varying and depends on the sojourn time, the analysis of containment control under semi‐Markov switching topology becomes more challenging. Secondly, a control protocol with time‐varying delays is adopted. The error function is derived by the property of graph theory, convex hull and communication noise. Hence, the problem of H

∞
containment control is transformed into the stability problem of the semi‐Markov jump system. To avoid the zero initial condition in the traditional H

∞
control approach, a novel performance function is constructed with the initial condition considered. Finally, simulation experiments are provided to verify the effectiveness of the proposed algorithm.
A polarisation‐analysing CMOS image sensor for sensitive polarisation modulation detection
Authors: Okada R. , Sasagawa K. , Haruta M. , Takehara H. , Tashiro H. , Ohta J.
Published: April 2021

In this study, a polarisation‐analysing CMOS image sensor is fabricated for sensitive polarisation modulation detection. Although the image sensor with on‐pixel polarisers can image the incident polarisation collectively, its sensitivity to a weak polarisation change is not high. With the proposed method, an external polariser is used to enhance the polarisation modulation sensitivity with a polarisation image sensor. The performance of this highly sensitive polarisation image sensor and imaging experiments are evaluated using a flow channel.
A method for fault recognition in the last three rounds of Advanced Encryption Standard
Authors: Jiang Huilong , Zhu Xiang , Pang Jinfeng , Liu Zhipeng , Han Jianwei , Li Yue
Published: April 2021

A large number of studies are there for Advanced Encryption Standard (AES) fault attack analysis, but less for fault recognition. This paper presents a recognition method for single‐byte fault which is induced in the last three rounds of AES. Studying the differential characteristics of Sbox, the single byte fault induced in ninth round or tenth round will be identified respectively with 9.3 and 9.1 ciphertexts. For the fault induced in eighth round, the fault value can be obtained with 188.5 ciphertexts by analyzing the differential features of two Sboxes and MixColumns. As an auxiliary means for fault attacks, this method is used to realize the byte or bit level physical positioning of confidential data in the encryption chip, which is beneficial to reduce the blindness of the attacker's experiments and obtain the sensitive area of fault attack.
E‐band InAs quantum dot laser on InGaAs metamorphic buffer layer with filter layer
Authors: Kwoen J. , Zhan W. , Arakawa Y.
Published: April 2021

InAs quantum dots (QDs) are receiving attention as next‐generation E‐band light source that offers high‐temperature operation and temperature insensitive operation. However, high‐density crystal defects occur at the interface between the InGaAs buffer layer and GaAs, resulting in reduced device performance and shortened lifetime. Here, E‐band QD lasers are demonstrated on InGaAs buffer layer, which suppressed the spread of dislocation by introducing a high‐temperature annealing and a strained layer superlattice filter. In the device, the peak wavelength at room temperature is measured to be 1427 nm and the threshold current density was 440 A/cm2. This result indicates that E‐band QD laser structures on low threading dislocation density are promising for the realisation of high‐performance E‐band lasers.
Improved hybrid scheduling design of partitioned processing and network communication in distributed integrated modular avionics systems
Authors: Zhou Xuan , He Feng , Li Ershuai , Liu Jianhua , Xiong Huagang
Published: April 2021

Traditional hybrid scheduling method of partitioned processing and network communication restricts the schedulability of distributed integrated modular avionics (DIMA) systems according to strict constraints. This paper loosens these constraints by introducing harmonic partitions, converts the hybrid scheduling design into a nonlinear optimization problem, and proposes an improved method based on the tabu search metaheuristic. Comparative experiments demonstrate that this method adapts to a larger‐scale system including 50 partitions and 1000 messages and guarantees lower processing‐level end‐to‐end delay with an average optimization of 48%.
Convolutional neural network‐based power system frequency security assessment
Authors: Wang Changjiang , Li Benxin , Liu Chunxiao , Li Peng
Published: April 2021

Weak inertia characteristics of power systems with high penetrations of renewables have become a prominent problem for frequency security. To solve this problem, a convolutional neural network (CNN)‐based deep learning approach is applied to realize rapid frequency security assessment (FSA). First, the time series frequency security feature is autonomously mined from the wide‐area measurement data to serve as the input data. By doing so, the complex construction process of frequency security feature quantity is avoided. A deep learning structure is then used to establish a non‐linear mapping relationship between time series features and frequency security indicators to realize end‐to‐end power system frequency security prediction. Next, the evaluation accuracy of the proposed approach is optimized by tuning the key parameters in the CNN‐based evaluation model. Through data measurement error analysis and a wind penetration sensitivity study, the anti‐interference performance of the proposed evaluation model is demonstrated. Finally, the effectiveness of the CNN‐based FSA is verified by case studies of a modified 16‐machine 68‐node system and the China Southern Power Grid.
Life cycle cost assessment method considering multiple factors for economic evaluation of cable line steel brackets
Authors: Zhang Yujiao , Wang Zhenliang , Zhu Yanyan , Huang Xiongfeng , Wang Yaxin
Published: April 2021

In China, the bracket of underground high voltage cable transmission line is mainly made of various carbon steels. However, no unified standard exists for type selection of cable brackets in practice. Here, a selection method of the bracket based on life cycle cost assessment is proposed from the viewpoint of technical economy, in which the size of brackets, steel grade, carbon steel corrosion and eddy current loss are considered as influencing factors to the costs. Stress performance analysis under identical pole arm stress constraints is employed to determine the size and grade of carbon steel which influences the initial cost. And 3D coupled electromagnetic fluid‐dynamical and thermal finite‐element analysis is applied to calculate the eddy current loss of cable brackets which influences the operation cost. Meanwhile, multi‐physics coupling analysis and experiment are conducted to prove the correctness of loss simulation calculation. Tafel curve measured by electrochemical corrosion experiment is used to obtain the corrosion rate of carbon steel which influences the maintenance cost by affecting service life of brackets. A case study is demonstrated, and the results show that the channel steel type is the most economical for the commendatory and the proposed method is effective.
Hybrid flexible arc suppression device based on soft grid connection strategy for MV distribution systems
Authors: Zheng Ze‐Yin , Guo Mou‐Fa , Jin Tao , Liu Jian‐Hong
Published: April 2021

As an essential apparatus in resonance grounding systems, the arc suppression coil is widely used in rejecting the single‐line‐to‐ground (SLG) fault of distribution networks. However, the resistive ground‐fault current cannot be compensated by an arc suppression coil (ASC). As a novel active arc suppression device, the hybrid flexible arc suppression device (HFASD) composed of ASC and flexible arc suppression device (FASD) can eliminate the capacitive component of ground‐fault current and the resistive component of ground‐fault current. After the SLG fault occurs, the FASD from stand‐alone mode to grid‐connected mode may lead to switching transients, affecting the stability of distribution networks. The soft grid connection (SGC) strategy can achieve low or without transient response during the grid synchronization of FASD to the grid. Thus, the HFASD based on SGC strategy and segmented proportional‐integral‐differential (SPID) and second‐order generalized integrator phase‐locked loop (SOGI‐PLL) control method is proposed for rejecting the current and voltage overshoot responses during the process of grid synchronization of FASD in this paper. Simulation and experimental results verify the effectiveness of the proposed method, and the benefit of the proposed method is indicated in comparison with the non‐SGC (NSGC) strategy.
Partial discharge detection and identification at low air pressure in noisy environment
Authors: Nasr Esfahani Ali , Shahabi Saeed , Kordi Behzad
Published: April 2021

Increasing demand for electric power in more electric aircraft requires a higher operating voltage for the power system that leads to higher electric stress on the insulation system. Operating at high altitudes where the electrical strength of air is weakened exposes the insulation system to even higher levels of electrical stress. As such, the probability of partial discharges (PD), which result in insulation degradation and failure, is higher. The presence of switching circuits in the power distribution system of the more electric aircraft is capable of producing high levels of noise. This noise in combination with the background noise and parasitic impedances will cause high amplitude ringing in the measured partial discharge signal waveform. Here, a method based on the combination of the wavelet and energy techniques is employed to detect PD pulses in a noisy environment under the low air pressure condition. To verify the technique, a laboratory setup consisting of two separate PD sources mounted in low air pressure (33 kPa) chamber is developed where sine and square waveforms are used as the applied voltage. The obtained results demonstrate that the proposed approach offers low computational complexity, high performance in PD phase localization, and robustness in a noisy environment.
Insulation structure design and electric field simulation of 500 kV isolation energy supply transformer for HVDC breaker
Authors: Zhang Sheng , Fan Yadong , Lei Qingquan , Wang Jianguo , Liu Yuan , Zhan Ting
Published: April 2021

The high‐voltage isolated energy supply transformer (HIET) is the key component of the HVDC breaker, which is used for energy transmission and the potential isolation. There is a lack of research results that can meet engineering applications at home and abroad. The design of a 500 kV HIET with dry‐type insulation is proposed, using 10 cascade connected 50 kV sub‐transformers (STs), which uses silicon rubber suitable for DC voltage as the main insulation material. High‐voltage (HV) winding of ST adopts double‐shielding structure of coil semi‐conductive shielding and inner semi‐conductive shielding to improve electric field distribution. The simulation analysis of an electric field at different insulation thicknesses and temperatures shows that the electric field decreases with an increase in thickness of insulation. When the thickness is greater than 25 mm, the electric field reduction effect is significantly weakened. The electric field is closely related to temperature, when at 20°C, the electric field between double‐shielding is relatively uniform. When at 70°C, the inner shielding electric field is much higher than coil shielding, and undergoes obvious reversal. In addition, the 500 kV HIET's electric field has been analysed. The 50 0kV HIET prototype has been manufactured and passed the type test, and successfully applied to the 500 kV Zhangbei DC grid project.
Multilook phase difference distribution for slightly rough boundary layered ground
Authors: Afifi Saddek , Dusséaux Richard
Published: April 2021

The authors derive the distribution of the phase difference between two multilook scattering signals for a multilayer stack with randomly rough surfaces under a plane wave excitation. First, for infinite slightly rough surfaces described by Gaussian centred stochastic processes, the authors show that the underlying complex scattering signals follow a Gaussian joint distribution. Also, it is demonstrated that this property is within the scope of the first‐order perturbation theory. Secondly, the authors use this joint probability law to derive the closed‐form expression for the probability density function of the phase difference. The theoretical formula is verified by comparison with Monte‐Carlo simulations.
Wideband circularly polarised antenna array with isoflux pattern
Authors: Zeng Fanchao , Zhang Zhi‐Ya , Feng Yang , Zuo Shaoli , Zhang Chengbin , Wang Li
Published: April 2021

The authors present a wideband circularly polarised antenna array consisting of a 10‐element ellipse dipole antenna and a feed network. A metal pillar is vertically loaded at the end of each ellipse dipole arm to extend the current path, thereby reducing the lateral dimension of the antenna element. For uniform coverage over the Earth's surface, antenna with an isoflux pattern is required due to its uniform power density over a wide coverage area. To obtain wideband and isoflux characteristics, the amplitude and phase distributions along the network are optimised by applying the hybrid of the genetic algorithm and particle swarm optimisation. Particularly, the feed network with broadband phase shifting performance is designed to attain a broad bandwidth requirement. The proposed antenna can achieve excellent impedance matching and axial ratio characteristics from 1.1 to 1.6 GHz. In addition, the isoflux radiation pattern is obtained with the beamwidth of ±21° where the gain is higher than 0 dBi in the elevation plane (xoz‐Plane). The realised gain is better than 10.2 dBi and the side lobes are below −14.2dB across the operating frequency. Finally, the antenna array is manufactured and measured, and good agreement is achieved between the simulation and measurement results.
Planar wide‐angle and polarisation‐insensitive ultrathin frequency selective surface patch absorber design analysis and implementation
Authors: Abdalla Yasmine , Hammad Hany
Published: April 2021

Single‐layer ultrathin absorber patch elements are analysed under normal and oblique incidence. A compensation technique for impedance variation with an angle of incidence (θ) is proposed. An equivalent‐circuit model is formulated that provides a realisation for the absorption response (in terms of resonance frequency and absorption ratio) of non‐complicated rectangular patch absorbers using simple equations. The design methodology proposed is based on using multiple subcells of simple patches to add another degree of freedom for the design equations and keep the ultrathin planar feature. Previously reported techniques realising a wide angle of incidence are applied for fair comparison with the proposed methodology. The developed structure features angular stability, polarisation insensitivity, and a planar non‐complicated configuration compared with that of structures reported in literature. Moreover, a prototype is fabricated and measured to validate the proposed approach.
Meander‐line‐loaded circularly polarized square‐slot antenna with inverted‐L‐shaped feed line for C‐band applications
Authors: Midya Manas , Ghosh Anumoy , Mitra Monojit
Published: April 2021

A compact broadband circularly polarized square‐slot antenna based on an offset‐fed inverted‐L‐shaped microstrip feed line is proposed. A rectangular slot beneath the feed line and an inverted‐L‐shaped grounded strip on the left bottom corner of the wide square slot produce dual‐wideband circular polarization (CP) coverage in a compact size. Meander lines with a square slot loaded at the right bottom corner of the ground plane result in broadband CP through overlapping of the dual‐wideband axial ratio (AR) bandwidths. The magnitude and phase differences between two field components can be controlled effectively with proper tuning of the square slot dimensions (4.5 × 4.5 mm2), which is helpful for broadening AR bandwidth over the C‐band by minimizing AR values (≤3 dB). The overall dimensions of the prototype are only 26 × 26 × 1.6 mm3. The antenna prototype has been validated experimentally. The measured results indicate an impedance bandwidth of 104% (3.56–11.22 GHz) and a 3 dB AR bandwidth of 76% (3.90–8.72 GHz). A peak gain of 3.4–4.42 dBi is achieved within the AR bandwidth. The proposed antenna is suitable for CP applications in the C‐band.
Performance enhancement of optical camera communication system using optical camera communication coding and region‐of‐interest detection
Authors: Nguyen Duy Thong , Park Youngil
Published: April 2021

Optical camera communication (OCC) is considered an important transmission scheme in implementing indoor navigation, beacons, and other Internet of Things applications. One of the disadvantages of OCC, however, is that transmission is successful only if the line‐of‐sight requirement is satisfied between transmitting LED lamps and receiving image sensors. Any obstacle between them or movement of the receiver direction causes a reduction in the light signal and leads to a burst error, and its compensation is not easy. A low‐density parity check (LDPC) code is employed in the OCC to overcome burst error. To improve the performance further, a region of interest area detection is proposed that utilizes only the centre part of an image frame for LDPC decoding rather than using the whole area measurement. The LDPC codes are tested using an appropriate OCC packet structure, and its performance is compared with that of polar codes. The experimental results indicate that LDPC coding is more suitable in OCC systems. It is found that the proposed LDPC coding scheme not only recovers the data from burst errors but also enhances the transmission distance. In particular, soft‐decision LDPC decoding shows more resistance to burst errors and bit loss.
A soft switching four‐phase converter with ultra‐high step down conversion ratio and automatic uniform current sharing
Authors: Asghari Amin
Published: April 2021

This paper introduces a new high step down four‐phase converter with soft switching and automatic uniform current sharing. The phase number of the introduced topology can be expanded. In this converter, the main switches are turned on under zero voltage zero current switching condition and turned off under zero voltage switching. Also, the auxiliary switches and diodes operate respectively under zero voltage switching and zero current switching conditions. In the proposed architecture, the duty cycle is extended and the semiconductors voltage stress is reduced by applying series capacitors and coupled inductors. The leakage energy associated with the coupled inductors is absorbed and the reverse recovery losses of diodes are eliminated. Uniform current sharing between four phases is achieved without any extra current sharing control circuit. Furthermore, by utilizing the interleaved method, the current stress and the output current ripple are reduced. This converter provides above advantages while its input and output grounds are connected. As a result, the introduced topology can provide high step down conversions at high frequencies. The converter operation and its characteristics are analysed in detail. The accuracy of the theoretical analysis is verified by a laboratory prototype.
A new characteristic peaks group judgement method for the accurate measurement of time‐of‐flight in the ultrasonic gas flowmeter
Authors: Zheng Dandan , Mao Yang , Yang Zhibin
Published: April 2021

As a typical method for calculating time‐of‐flight (TOF), the double‐threshold method is widely applied in many time‐difference‐based ultrasonic gas flowmeters. However, the cycle‐skip phenomenon caused by noises and various flowrate often affects the accuracy and reliability of flowmeters. Based on traditional double‐threshold method and other improved double‐threshold methods, a new characteristic peaks group judgement method is proposed for calculating TOF in this work. In this method, the peak's characteristics of the received signal are used to find the feature point which is stable in different flowrates. Then, based on the feature point, zero‐crossing detection is executed for calculating TOF. In order to evaluate the new method, it is compared with traditional double‐threshold method and the similarity judgment‐based double‐threshold method through offline tests on both simulated signals and real‐flow signals. Results show that the proposed method can effectively eliminate the cycle‐skip phenomenon and has higher precision and reliability than other methods. Furthermore, a digital signal‐processing‐based ultrasonic gas flowmeter with this method was implemented. Three calibration experiments were carried out on a gas flow standard device. The calibration results show that the flowmeter can achieve accuracy of class 1 in a wide velocity range from 1  to 35 m/s.
Effects of noise and time delay on E2F's expression level in a bistable Rb‐E2F gene’s regulatory network
Authors: Kirunda John Billy , Yang Lijian , Lu Lulu , Jia Ya
Published: April 2021

The bistable Rb‐E2F gene regulatory network plays a central role in regulating cellular proliferation‐quiescence transition. Based on Gillespie's chemical Langevin method, the stochastic bistable Rb‐E2F gene’s regulatory network with time delays is proposed. It is found that under the moderate intensity of internal noise, delay in the Cyclin E synthesis rate can greatly increase the average concentration value of E2F. When the delay is considered in both E2F‐related positive feedback loops, within a specific range of delay (3‐13), the average expression of E2F is significantly increased. Also, this range is in the scope with that experimentally given by Dong et al. [65]. By analysing the quasi‐potential curves at different delay times, simulation results show that delay regulates the dynamic behaviour of the system in the following way: small delay stabilises the bistable system; the medium delay is conducive to a high steady‐state, making the system fluctuate near the high steady‐state; large delay induces approximately periodic transitions between high and low steady‐state. Therefore, by regulating noise and time delay, the cell itself can control the expression level of E2F to respond to different situations. These findings may provide an explanation of some experimental result intricacies related to the cell cycle.
Influence of dry run speed on the cleaning of compressor blade
Authors: Tang Jie , Gao Dianrong , Wang Liwen , Zeng Jie
Published: April 2021

To optimize the on‐line cleaning process parameters of aero‐engines, the influence of the engine's dry run Speed on the cleaning flow field was analysed. Through the reverse modelling and numerical simulation of the CFM56‐7B compressor, the changes of static pressure, velocity and vorticity of the cleaning flow field under different dry run speeds were analysed. The results showed that the static pressure and speed of the cleaning flow field increased linearly with the increase of the dry run speed; the vortex of the cleaning flow field decreases with the increase of the speed, but the increase of the speed was beneficial to the cleaning of the compressor. Through the aero‐engines online cleaning test, comparing the recovery of EGTM at different speeds, when the engine dry run speed was 323 r/min, a better cleaning effect and higher economic benefits can be obtained. The research can provide a theory for engine online cleaning.
Carrier frequency offsets problem in recent DST‐SC‐FDMA system: Investigation and compensation
Authors: Al‐kamali Faisal S. , Al‐Soufy Khaled A.
Published: April 2021

Carrier frequency offset (CFO) is a challenging problem in the uplink of the single‐carrier frequency division multiple access (SC‐FDMA) system. CFOs effect on the orthogonality between subcarriers and cause inter‐carrier interference (ICI) and multiple access interference (MAI). This paper, analyzes the impact of the CFOs on the performance of the Discrete Sine Transform (DST) SC‐FDMA (DST‐SC‐FDMA) system and investigates with different wireless channels, different modulation schemes and different subcarriers mapping schemes. Furthermore, an efficient equalization and CFOs compensation scheme is proposed to enhance the performance of the DST‐ SC‐FDMA system and transmit images efficiently over DST‐ SC‐FDMA system. The proposed scheme combines the minimum mean square error (MMSE) equalizer and the parallel interference cancellation (PIC). The combined method is referred to as MMSE+PIC. The results show that CFOs degrades the DST‐FDMA performance. The obtained results show a noticeable performance improvement of the proposed MMSE‐PIC scheme over the conventional MMSE equalizer. Moreover, it is found that it is possible to efficiently transmit wireless image using the proposed MMSE+PIC scheme,
Clustered star formation toward Berkeley 87/ON2
Authors: de la Fuente Diego , Román-Zúñiga Carlos G. , Jiménez-Bailón Elena , Alves João , Garcia Miriam , Venus Sean
Published: April 2021

Context. Disentangling line-of-sight alignments of young stellar populations is crucial for observational studies of star-forming complexes. This task is particularly problematic in a Cygnus-X subregion where several components, located at different distances, overlap: the Berkeley 87 young massive cluster, the poorly known [DB2001] Cl05 embedded cluster, and the ON2 star-forming complex, which in turn is composed of several H II regions.

Aims. We provide a methodology for building an exhaustive census of young objects that can consistently treat large differences in extinction and distance.

Methods. OMEGA2000 near-infrared observations of the Berkeley 87/ON2 field were merged with archival data from Gaia, Chandra, Spitzer, and Herschel and with cross-identifications from the literature. To address the incompleteness effects and selection biases that arise from the line-of-sight overlap, we adapted existing methods for extinction estimation and young object classification. We also defined the intrinsic reddening index, Rint, a new tool for separating intrinsically red sources from those whose infrared color excess is caused by extinction. Finally, we introduce a new method for finding young stellar objects based on Rint.

Results. We find 571 objects whose classification is related to recent or ongoing star formation. Together with other point sources with individual estimates of distance or extinction, we compile a catalog of 3005 objects to be used for further membership work. A new distance for Berkeley 87, (1673 ± 17) pc, is estimated as a median of 13 spectroscopic members with accurate Gaia EDR3 parallaxes.

Conclusions. The flexibility of our approach, especially regarding the Rint definition, allows overcoming photometric biases caused by large variations in extinction and distance in order to obtain homogeneous catalogs of young sources. The multiwavelength census that results from applying our methods to the Berkeley 87/ON2 field will serve as a basis for disentangling the overlapped populations.
Study of the impact of the food biopolymer system on the clinical-biochemical status of white inbred mice in the invivo experiment
Authors: Alekseeva Tatyana , Korystin Mihail , Klimova Ekaterina , Kalgina Yuliya , Vitruk Lidiya , Malakova Lyudmila
Published: April 2021

Studies have been conducted on the effect of the food biopolymer composition on the clinical-biochemical status of white inbred mice. The experiment showed that the development of laboratory animals was carried out without abnormalities with the complete safety of all individuals. Clinical-biochemical dynamics, glucose monitoring and the results of experiments in the exchange of macro and microelements of plasma of mouse blood indicated the normal flow of metabolic processes. In addition, the animals that consumed food additives had a higher rate of absorption of feed carbohydrates and a predominance of osteosynthesis processes in animal bone tissue. The studies conducted allow us to conclude that enrichment and trace elements increase the availability of trace elements, as well as activate the formation and strengthening of the bone tissue of the body.
Recipe modeling and the study of the chemical composition of functional fish culinary products
Authors: Kutina Olga , Korotkyh Irina
Published: April 2021

The biochemical composition of the new fish culinary product is considered. The results make it possible to attribute the product to functional products. Compositions with a given set of nutritional value indicators were simulated by optimizing multicomponent formulations. Products are characterized by preset properties: functionality, balance of amino acid, mineral and vitamin compositions, high organoleptic characteristics due to the inclusion of original plant materials (spinach, green peas, cauliflower, eggplant, etc.) and individual methods for their preliminary preparation. The technology and the recipe are protected by a patent [1], technical standards [2], have been tested in production conditions. Product samples participated in the nomination “Innovative Product” at the international exhibition of food products, beverages and raw materials for their production PRODEXPO in 2015-2018. Development “Fish loaf” received a silver medal in 2015.
The use of bio-efficient plant materials to optimize the fatty acid composition of poultry terrins
Authors: Popova Nadezhda , Pisklyukova Yuliya , Orlova Viktoriya
Published: April 2021

The development of functional products characterized by high biological efficiency is an urgent task. The article presents the results of the development of balanced-fatty acid terrins from poultry meat. To increase the biological effectiveness of chopped products, raw materials containing omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) were selected. Based on the analysis of the chemical composition of the raw material kit, the intervals for the Introduction of ingredients containing biologically effective components are calculated. Their optimum amount has been experimentally established. The resulting innovative products are characterized by a balanced composition in terms of content and ratio of omega-3 and omega-6 PUFAs. In addition, the value of the indicator of biological value has increased. Developed poultry terrins can be recommended both for a wide range of consumers, and for use in diet (including low-carb diets), baby food. The developed terrines will expand the range of chopped poultry products of functional orientation.
Assessment of the marketing and innovative potential of synbiotic products with herbal biocorrector
Authors: Rodionova Natalya , Rodionov Alexander , Shchetilina Irina , Manukowskaya Marina , Rusanova Mariya , Razinkova Tatyana
Published: April 2021

The article presents the results of studies of the relationship of potential consumers to new synbiotic products with predictably formed functional, prebiotic properties and biological activity. The assessment of the prospects of including the developed bioactive synbiotic products in the recipes of dishes of public catering enterprises and giving them functional properties is given. The main socio-demographic characteristics and preferences of consumers in relation to synbiotic products with compositions of bioactive plant components have been identified. The trends of needs change, their duality, dilemmas, reality and problems of the main drivers relevant to the modern consumer, price expectations, preferred options for introducing bioactive synbiotic products into the diet are revealed. The study allows us to draw a conclusion about the need to take into account when developing new technologies and reflect in the information and advertising materials the identified consumer expectations regarding the taste, usefulness, safety, convenience and authenticity of new products, including synbiotic with plant-based biological active components, and their Introduction into food recipes is a promising direction for the development of enterprises of the HoReCa segment. The results of the study, carried out with a focus on enterprises in the public catering sector, seem relevant, since the use of synbiotic products with herbal biological components is an expansion of opportunities for food and bio-technologies, public catering organizations with justified socio-economic effect.
Study of organoleptic and technological properties of minced meat products with addition of mushroom powder
Authors: Stepanova Tetiana , Akrashie Naaja A.
Published: April 2021

The authors propose a new type of minced meat products with the addition of dry mushrooms in powder form. It provides high protein content and good taste of finished products. The article presents the results of experimental studies on the enrichment of minced meat products with mushroom powder. Tasting analysis showed that the best organoleptic indicators have samples of culinary products with the content of enriched mushroom powder in 10%. A further increase above 15% adversely affects the organoleptic characteristics of the finished culinary products. Adding of mushroom powder to the amount of minced meat products allowed to improve consumer properties, reduce calorie content, as well as produce functional products.
Purification of water and fertile soil with bentonite-like clays of the Belgorod Region
Authors: Vezentsev Alexandr , Volovicheva Natalia , Korolkova Svetlana , Peristaya Lidiia , Milyutin Vitaliy , Korolkov Igor
Published: April 2021

This paper presents the results of a comparative assessment of the effectiveness of sorption purification of aquatic medium and fertile soils using native forms of bentonite clays of deposits in the Belgorod region (Russia) from heavy metal ions (Cu2+, Fe3+, Cr3+, Pb2+) and radionuclides (137Cs, 85Sr, 233U и 239Pu). It was revealed that during the sorption of heavy metal ions (Cu2+, Fe3+ и Cr3+) from model water systems, the most absorbing activity is shown by the natural clays of the Polyana and Nelidovka deposits, which have almost the same ability to absorb heavy metal ions. The purification efficiency of the model aqueous solutions from these cations taken at an initial concentration of 0.1 mmol/l reaches 95%. It was established that the natural clay of the Polyana deposit is also an effective sorbent for the purification of solutions from cesium radionuclides. In terms of sorption ability, the studied sample is 5 times superior to natural clinoptilolite, which is most often used to purify solutions from radiocesium.. It was revealed that with an increase in the amount of added sorbents, the detoxification effect is increased, that is, the content of heavy metals in the green mass decreases.
Impact of working conditions on the health of pharmacy workers
Authors: Filina Irina , Nikishina Svetlana , Snimshchikova Irina , Kulakova Anastasiia , Ovchinnikova Anastasiia , Leonidov Ilya
Published: April 2021

The analysis revealed factors that have an adverse effect on human health: artificial lighting (I =0.72); standing activity (I=0.63); monotonous movements (I =0.56); prolonged work at the computer (I =0.55). It was found that many pharmacy workers have chronic diseases: vascular pathology (29.4%), musculoskeletal pathology (28.4%), gastrointestinal tract pathology (27.5%); visual impairment (27.5%). It was found that 20.6% of pharmacy employees do not have breaks for rest and meal; 13.7% do not have the opportunity to take warm food at work; 35.3% have the biggest meal of the day in the evening. In the workplace, a set of factors that have an adverse effect on the health of pharmaceutical professionals has been identified; many workers have work-related chronic diseases; most pharmacists experience discomfort after work; some employers violate labour legislation by not providing specialists with breaks for rest and meal.
Low homology between 2019-nCoV Orf8 protein and its SARS-CoV counterparts questions their identical function
Authors: Iatsenko Viktoria , Boyarshin Konstantin , Bespalova Olga , Klyueva Violetta , Kurkina Yuliya , Batlutskaya Irina
Published: April 2021

SARS-CoV accessory protein Orf8b is involved in suppressing interferon-mediated immune response of the infected cell and this might lead to supposition that the corresponding protein 2019-nCoV Orf8 shares the same role. But the tertiary structures of these proteins are still unknown, and the primary structures demonstrate very low homology and different calculating parameters. This time they both are affected by stabilizing selection and in natural viral populations do not tend to be deleted. The question whether in this case very different proteins could share the same function rises from the present data.
The productivity of boars when introduced to the feed sprouted grains
Authors: Kovrigin Aleksandr , Pokhodnya Grigorii , Yastrebova Olga , Breslavets Yuriy
Published: April 2021

Recipes were developed for compound feeds for boars with replacement of 5% and 10% of natural barley grain with sprouted grain. The use of experimental feeds allowed to increase the volume of boar ejaculate-by 25.5% and 31.9%; sperm concentration-by 18.4 and 20.1%; sperm survival-by 7.7 and 9.2 hours; sperm resistance by 27.0 and 27.8%. The fertilization rate of sows increased by 3.0 and 6.3%, multiplicity-by 3.1 and 4.2%, large-scale fertility remained at the control level. The cost of compound feed increases with the Introduction of sprouted grain, but this increase is economically justified, since the productivity of animals increases. The cost of a dose of sperm from boars is reduced by 2.8 and 3.2 rubles, the number of farrowed sows increases in the experimental groups by 51.8 and 71.4%, respectively, and the cost of one Piglet is lower by 12.4 - 17.5 rubles or 8.6 - 12.6%..
Stochastic analysis of COVID-19 by a SEIR model with Lévy noise
Authors: Ding Yamin , Fu Yuxuan , Kang Yanmei
Published: April 2021

We propose a Lévy noise-driven susceptible-exposed-infected-recovered model incorporating media coverage to analyze the outbreak of COVID-19. We conduct a theoretical analysis of the stochastic model by the suitable Lyapunov function, including the existence and uniqueness of the positive solution, the dynamic properties around the disease-free equilibrium and the endemic equilibrium; we deduce a stochastic basic reproduction number R0s for the extinction of disease, that is, if R0s≤1, the disease will go to extinction. Particularly, we fit the data from Brazil to predict the trend of the epidemic. Our main findings include the following: (i) stochastic perturbation may affect the dynamic behavior of the disease, and larger noise will be more beneficial to control its spread; (ii) strengthening social isolation, increasing the cure rate and media coverage can effectively control the spread of disease. Our results support the feasible ways of containing the outbreak of the epidemic.
Characterization of MIPS in a suspension of repulsive active Brownian particles through dynamical features
Authors: Martin-Roca José , Martinez Raul , Alexander Lachlan C. , Diez Angel Luis , Aarts Dirk G. A. L. , Alarcon Francisco , Ramírez Jorge , Valeriani Chantal
Published: April 2021

We study a two-dimensional system composed by Active Brownian Particles (ABPs), focusing on the onset of Motility Induced Phase Separation (MIPS), by means of molecular dynamics simulations. For a pure hard-disk system with no translational diffusion, the phase diagram would be completely determined by their density and Péclet number. In our model, two additional effects are present: translational noise and the overlap of particles; we study the effects of both in the phase space. As we show, the second effect can be mitigated if we use, instead of the standard Weeks–Chandler–Andersen potential, a stiffer potential: the pseudo-hard sphere potential. Moreover, in determining the boundary of our phase space, we explore different approaches to detect MIPS and conclude that observing dynamical features, via the non-Gaussian parameter, is more efficient than observing structural ones, such as through the local density distribution function. We also demonstrate that the Vogel–Fulcher equation successfully reproduces the decay of the diffusion as a function of density, with the exception of very high densities. Thus, in this regard, the ABP system behaves similar to a fragile glass.
Informing NMR experiments with molecular dynamics simulations to characterize the dominant activated state of the KcsA ion channel
Authors: Pérez-Conesa Sergio , Keeler Eric G. , Zhang Dongyu , Delemotte Lucie , McDermott Ann E.
Published: April 2021

As the first potassium channel with an x-ray structure determined, and given its homology to eukaryotic channels, the pH-gated prokaryotic channel KcsA has been extensively studied. Nevertheless, questions related, in particular, to the allosteric coupling between its gates remain open. The many currently available x-ray crystallography structures appear to correspond to various stages of activation and inactivation, offering insights into the molecular basis of these mechanisms. Since these studies have required mutations, complexation with antibodies, and substitution of detergents in place of lipids, examining the channel under more native conditions is desirable. Solid-state nuclear magnetic resonance (SSNMR) can be used to study the wild-type protein under activating conditions (low pH), at room temperature, and in bacteriomimetic liposomes. In this work, we sought to structurally assign the activated state present in SSNMR experiments. We used a combination of molecular dynamics (MD) simulations, chemical shift prediction algorithms, and Bayesian inference techniques to determine which of the most plausible x-ray structures resolved to date best represents the activated state captured in SSNMR. We first identified specific nuclei with simulated NMR chemical shifts that differed significantly when comparing partially open vs fully open ensembles from MD simulations. The simulated NMR chemical shifts for those specific nuclei were then compared to experimental ones, revealing that the simulation of the partially open state was in good agreement with the SSNMR data. Nuclei that discriminate effectively between partially and fully open states belong to residues spread over the sequence and provide a molecular level description of the conformational change.