bluuebunny/crossref_metadata_2025 huggingface dataset:
Speech and Music Therapy in the Treatment of Childhood Apraxia of Speech: An Introduction and a Case Study
Authors: van Tellingen Mirjam , Hurkmans Joost , Terband Hayo , van de Zande Anne Marie , Maassen Ben , Jonkers Roel
Published: August 2023

Purpose:

Speech–Music Therapy for Aphasia (SMTA), a method that combines speech therapy and music therapy, is introduced as a treatment method for childhood apraxia of speech (CAS). SMTA will be evaluated in a proof-of-principle study. The first case study is presented herein.

Method:

SMTA was evaluated in a study with a single-subject experimental design comparing 10 weeks of treatment with 2 months of no treatment. The research protocol included a pretest, baseline phase, treatment phase, posttest, no-treatment phase, and follow-up test. The participant was a boy with CAS aged 5;8 (years;months). Outcome measures were selected to reflect both intelligibility in daily communication as well as features of CAS and speech motor planning and programming.

Results:

Results on the Intelligibility in Context Scale–Dutch (ICS-Dutch) and in the analysis of a spontaneous speech sample suggest generalization of treatment effects. Improvements were found in measures that reflect complex speech motor skills, that is, the production of consonant clusters and consistency.

Conclusions:

This case study showed that speech production of the participant improved after treatment with SMTA. Although intelligibility as measured with the ICS-Dutch improved over the study period, objectifying changes at the level of intelligibility in daily communication proved to be difficult. Additional measures may be necessary to gain more insight into treatment effects at this level.

Overall, the results of this first case study provide sufficient support and important leads for further evaluation of SMTA in the treatment of CAS in a proof-of-principle study.
Double input DC-DC converter for highly flexible and reliable Battery Storage Systems
Authors: Benevieri Alessandro , Carbone Lorenzo , Cosso Simone , Marchesoni Mario , Passalacqua Massimiliano , Vaccaro Luis
Published: August 2023

Battery storage systems are fundamental in UPS applications. UPSs are exploited when high reliability is required. A DC-DC converter is typically used to interface the battery to the inverter to match the different voltage levels. In normal operation, the battery of the UPS is not used and it intervenes only during grid blackout. However, the battery is subjected to deterioration and UPS intervention could fail. In medium and high power UPS, more battery modules are connected in series. If one battery is damaged, all the series is affected. To prevent this issue, a new double-input DC-DC converter is presented in this paper. The two DC sources can be controlled separately, resulting in a system reliability improvement. In addition, the damaged battery is not bypassed; hence the overall system performance can be maximized, since the deteriorated battery can provide energy at a limited rate. Additionally, the proposed converter allows batteries based on different technologies to be mixed together, achieving the best performances from each technology.
Study on an adaptive multi-model predictive controller for the thermal management of a SOFC-GT hybrid system
Authors: Chen Jinwei , Hu Zhenchao , Zhang Huisheng
Published: August 2023

A SOFC temperature control system based on adaptive multimodel predictive control (MMPC) method is designed for a solid oxide fuel cell-gas turbine (SOFC-GT) hybrid system with anode and cathode ejectors. Two multi-input and multi-output MPCs (under 100% and 90% load) are designed to control the anode and cathode inlet temperatures. The accuracy of the identified linear models are both more than 95%. The control performance of the designed MMPC is compared with a single MPC and traditional PI. The comparison results demonstrate that the proposed MMPC is most effective and competitive in SOFC thermal management. During the load following, the controller overshoot is less than 1.19K. The settling time is about 2000s, and the integral of time-weighted absolute error is less than 472.
Performance assessment of a reversible Tesla machine
Authors: Tiwari Ravi Nath , Traverso Alberto , Reggio Federico
Published: August 2023

It is well known that bladeless or Tesla turbomachinery, which was invented by Nikola Tesla in 1913, has several distinct features, such as reversibility of operation, which includes expander as well as compressor operation, just by reversing the rotational speed, provided that the statoric channels are purposely designed. Despite their potential application to a variety of fields, such as energy harvesting, automotive, light aircraft, and food processing, especially for low volumetric flows, Tesla machines have not found yet a specific market niche. In fact, at small size, it is estimated that the Tesla machinery does not change performance significantly, while conventional bladed machines are subject to significant efficiency reduction because of mechanical tolerances, thus matching the Tesla relatively low performance. Therefore, Tesla machines can become the fluid machinery of choice for small-size applications, thanks to their competitive performance at that size, simple construction, and reversible operation. A key objective of this paper is to numerically study Tesla devices in both expander and compressor modes with air as the working fluid. As a consequence of the high losses due to rotor and stator interactions, statorless (volute) configurations are investigated here, showing superior performance in both direct and indirect modes of operation. With reference to a laboratory prototype under construction, this paper presents the numerical design results, which predict the peak isentropic efficiencies of 63.5% and 57.5%, for the expander and compressor mode of operation, respectively. Actual prototype is expected to match those performance, apart from leakage and ventilation losses, not included in the numerical analysis.
Mathematical modeling of a three-component system to investigate the formation and characteristics of glass
Authors: Sidikova Taxira , Mirsaatov Ravshanbek , Mansurova Mavjuda
Published: August 2023

The article investigates glass formation and its properties in a three-component system using mathematical modeling. The authors have applied the method of mathematical planning to increase the efficiency of research and to establish the dependences of glass properties on the composition. The authors propose a mathematical model of structure relaxation and two-dimensional stress field in grade glass products, considering the temperature dependencies of glass viscosity of a given chemical composition.
Analysis of the information verification model in non-financial reporting of oil and gas companies
Authors: Kolosova Olga , Leonova Olesy , Bogataya Irina , Bulyga Roman , Evstafyeva Elena , Lavrov Denis
Published: August 2023

The article is aimed at investigating the current practice of verifying information in non-financial statements of oil and gas sector companies. The study is based on the analysis of the current regulatory framework for confirming “(certification)” of non-financial reporting, which is structured into two blocks: regulatory documents that define the requirements for the disclosure of information in non-financial reporting, applied at the international and national levels, and regulatory documents that define the requirements for the verification of non-financial reporting at the international and national levels. A comparative analysis of the main standards and recommendations used for disclosure of information in ESG reporting is carried out. Regulatory acts containing general requirements for disclosure of information about the activities of PJSC oil and gas complex in the Russian Federation are considered. The systematization of Russian regulations in the field of disclosure of information on sustainable development and ESG factors and structural elements of the annual report is carried out and the characteristics of the main regulations for conducting an independent audit of non-financial reporting are given. In the course of the study, a matrix of categories was developed that ensure the reliability of public reporting. The features of the verification practice of Russian oil and gas companies that are system-forming are considered. An overview of Russian companies disclosing non-financial information in accordance with GRI, SASB, TCFD and CDP standards is presented. Based on the conducted research, it is concluded that the current regulatory framework in the field of confirmation (assurance) of non-financial reporting requires improvement of the terminology and differentiation of the concepts of “verification”, “assurance”, “confirmation”, “audit”, in order to develop the practice of business audit of the XXI century. The study can be useful for managers and decision makers aimed at implementing the Concept of Sustainable Development and achieving Sustainable Development Goals.
Analysis of the effectiveness of energy strategies
Authors: Guliyev Igbal , Ruzakova Valeriya , Kuzmina Margarita
Published: August 2023

The article examines the effectiveness of national strategic energy planning within the context of countries’ adaptation to the global energy transition. The authors study the national energy strategies of the world’s 20 largest economies, with a particular focus on the technological aspects of adaptation to the global energy transition, and give analysis of their correspondence with the actual national performance.
Application of heat pumps in the food industry: purification plant
Authors: Martyanov Andrey , Zimina Yuliya , Antipin Dmitry
Published: August 2023

Furnaces and thermal chambers are created with specific guidelines in mind. These guidelines include using energy in an efficient manner, arranging products closer together to increase productivity, ensuring the direction of air flow is precise, having accurate control over temperature and humidity, making sure the equipment is reliable and convenient to use, and ensuring that any gaseous waste emissions fall within acceptable levels set by regulations. Also, a clear advantage of a heat pump is the possibility of using it at high power enterprises, where it is difficult to use water as a heating coolant. Heat pumps are also able to reduce the risk of bacterial growth, as they can maintain a safe and consistent temperature throughout the entire process. Heat pump processing is an effective and efficient method for meat products because it can achieve a high level of product uniformity with minimal product degradation.
Mathematical modeling formation of wole drainage under soil deformations
Authors: Juraev F.U. , Shodiev Sh.B. , Khamroev G.F. , Juraev J.T. , Khamroev I.F.
Published: August 2023

In agriculture, the processing of land plots from underground is one of the modern problems. To solve this problem, new scientific and technical approaches to agricultural technology are required. This article presents data on the formation of mole drainage during washing of saline soils. The newly created technical device has a thick-walled conical-cylindrical shape. Here it is experimentally analyzed that the soil is deformed and does not lose its stability. Experimental data were obtained by numerical element and coordinate methods. It is compared with the results of a numerical solution obtained on the basis of an exact circuit of the device. The study of nonlinear processes of compression and supercritical deformation of the soil forming the mole drainage due to soil pressure is a complex and important scientific and technical problem.The discrepancy between the results of field and computational experiments, as well as the characteristics of the accepted mathematical model and the method of their solution, associated with the rough discretization of the original problem, are characterized by external pressure forces. Therefore, experimental and theoretical studies evaluating the accuracy of methods for numerical analysis of nonlinear problems of soil deformation during the formation of mole drainage under various types of pressure and loads, as well as the study of the influence of initial deficiencies on the results of solutions, are considered relevant issues. In this article, mathematical models were created for the relationships between deformations, stresses and coordinates of the solution of the above problems, as well as their numerical solutions were considered.
Comparative analysis of experimental data clustering in MATLAB and Python environment
Authors: Seroklinov Gennady , Goonko Andrew
Published: August 2023

The paper compares normalization and clustering methods for processing experimental data in the MATLAB package and a Python program using the scikit-learn library. Recommendations on further application of Python programs and selection of normalization and clustering methods are provided. The choice of clustering methods for further research is discussed.
Model for monitoring the psychological safety of young people based on automated analysis of queries in search engines
Authors: Uglova Anna , Nizomutdinov Boris
Published: August 2023

The paper considers the method of parsing and processing information in combination with classical psychological science. The result of the synthesis of the two directions was a predictive model of the mood and psychological state of city residents. The analysis of information about self-destructive practices and the need for psychological assistance based on search engine statistics is one of the most objective analysis tools, since it allows you to evaluate large amounts of information without the influence of social desirability and socio-cultural stereotypes about psychological assistance. The study showed that the analysis of queries in a search engine can serve as an important source of information about psychological security, self-destructive practices and the dynamics of demand for the services of specialists in helping professions. The results of the work can be used to visualize and track the seasonal dynamics of requests for psychological help and monitoring the quality of life of the population. In the course of the work, 30 topics in the field of psychology were analyzed, a database and a predictive model of the psychological state of urban residents based on big data from search engines were developed.
Institutional modeling and management of the firm’s ecosystem
Authors: Popov Evgeny , Simonova Victoria , Chelak Igor , Khusainova Marina
Published: August 2023

By the early 20s of this century, it became clear that the network paradigm of inter-firm relations does not describe the entire landscape of business interactions. The introduction of digital technologies stimulated business development taking into account not only economic partners, consumers, suppliers and competitors, but also taking into account the influence of public organizations, authorities and social media. The paradigm of ecosystem analysis of the economy began to develop, the first works of which appeared at the end of the twentieth century. The purpose of this study is to develop an institutional model and principles for managing the firm’s ecosystem. The theoretical basis of the research is the authors’ model of the potential of digitalization of the company’s ecosystem. The article analyzes and criticizes previous studies, which demonstrated the relevance of formulating the problem of developing the formalized potential of digitalization of the firm’s ecosystem. Based on the authors’ development on the representation of ecosystem actors in the form of stakeholders, the main components of the external space of the company are identified: stakeholders, company resources and end-to-end digital technologies. The main factors forming the potential of digitalization of the company’s ecosystem are highlighted. Ecosystem stakeholders are divided into representatives of business, government, consumers, education and science, and mass media. The company’s resources are material, labor, financial and information resources. Digital technologies: artificial intelligence, additive technologies, blockchain, the Internet of Things, robotics, social networks, virtual reality. Various directions of application of the formalized potential of digitalization of the company’s ecosystem are presented: the possibility of assessing the use of potential in various directions; assessment of the impact of various components of the firm’s ecosystem on the development of its other elements; development of a general analytical model of potential; assessment of threshold values of factors for the development of the potential of digitalization of the firm’s ecosystem; a tool for developing a strategy for the firm’s ecosystem.
An ontological model for planning urban areas with a given level of economic efficiency
Authors: Salnikov Viktor , Pridvizhkin Stanislav , Fedorov Arsenii , Reznikov Vladimir
Published: August 2023

The paper presents an ontological model for planning urban areas with a given level of economic efficiency, the use of which can provide optimal configurations of future neighbourhoods for all participants in their construction and operation. The implementation of intelligent systems based on the algorithms of the proposed model can provide optimal configurations of future neighborhoods for all parties involved in their construction and operation
Environmental marketing: harnessing consumer influence to save the environment in sustainable development
Authors: Kulikova Elena
Published: August 2023

This article explores the potential of environmental marketing as a means to promote sustainable consumption and contribute to the preservation of the environment. By analyzing the relevance of this approach, examining the existing literature, and presenting a new study, we aim to provide valuable insights into the effectiveness of environmental marketing strategies. We will discuss the implications of our results and suggest possible avenues for further research, ultimately offering a comprehensive understanding of how environmental marketing can contribute to a more sustainable future for both businesses and consumers.
Methodical aspects of assessing the impact of industrial plants on air pollution
Authors: Datciuk T. , Ulyasheva V. , Pukhal V. , Leonteva U.
Published: August 2023

The article suggests that besides the established maximum permissible emissions of enterprises, which characterize air pollution from organized sources, emissions from “low” and unorganized sources, consider industrial sites as area sources. The authors propose a sequence of measures to reduce the impact of industrial sites as additional sources of pollution on the example of the aluminum production plant.
Osteopathie beim Kaninchen: Tipps und Tricks für eine
erfolgreiche Behandlung
Authors: Louis Anne Lisa , Röhrmann Nicole
Published: August 2023

Kaninchen gehören sicherlich (noch) nicht zum Standardklientel
osteopathisch arbeitender Tierärztinnen und Tierärzte. Diese
Tierarten erfreuen sich einer ungebrochenen Beliebtheit bei Tierhaltern und sind
in vielen Familien längst zum Familienmitglied avanciert. Dieser Artikel
präsentiert verschiedene Indikationen für eine osteopathische
Behandlung von Heimtieren und einige Anregungen und Ideen zum
bestmöglichen Gelingen der Behandlung. Drei Fallberichte zeigen auf,
dass eine osteopathische Behandlung durchaus möglich ist und die
konventionelle Therapie unterstützen kann.
Recover all coefficients in second-order hyperbolic equations from finite sets of boundary measurements
*
Authors: Liu Shitao , Pierrottet Antonio , Scruggs Scott
Published: August 2023

We consider the inverse hyperbolic problem of recovering all spatial dependent coefficients, which are the wave speed, the damping coefficient, potential coefficient and gradient coefficient, in a second-order hyperbolic equation defined on an open bounded domain with smooth enough boundary. We show that by appropriately selecting finite pairs of initial conditions we can uniquely and Lipschitz stably recover all those coefficients from the corresponding boundary measurements of their solutions. The proofs are based on Carleman estimate, continuous observability inequality and regularity theory for general second-order hyperbolic equations.
Coexistence of spin liquid state and magnetic correlations in 3d-5d based triangular-lattice antiferromagnet Sr3CuIr2O9
Authors: Gondh Shobha , Kumar Kranti , Saravanan M P , Pramanik A K
Published: August 2023

Here, we report detailed lattice structure, magnetization (dc and ac) and specific heat measurements on a 3d-5d based new triple-perovskite material Sr3CuIr2O9. The Sr/Cu forms a layered structure of triangular-lattice while the Ir forms Ir2O9 dimers which lie in chain as well as simultaneously makes layered triangular-lattice with neighboring atoms. Due to random site-sharing with Sr2+, the Cu2+ (3d
9, spin-1/2) forms a diluted magnetic lattice, thus giving a disordered in-plane exchange interaction. Opposed to conventional

J

e
f
f

model, the Ir5+ (5d
4,

J

e
f
f

= 0) is believed to be magnetic here which participates both in-chain and in-plane magnetic interactions. This complex lattice structure driven competing exchange interaction leads the ground state to a gapless quantum-spin-liquid state which coexists with (weak) ferromagnetic spin correlations. While underling the importance of spin state (spin-1/2), we believe that the combined effect of lattice structure, geometric frustration, spin–orbit coupling and spin state has given rise this interesting ground state in this material.
A multi-frequency and multi-mode metasurface energy harvester for RF energy harvesting
Authors: Huang Xiaojun , Wang Kun , Sun Cuizhen , Li Chuan , Zhang Jianchen , Li Shouqing
Published: August 2023

Metasurface energy harvesters (MEHs) lessen the dependence of wireless communication devices on batteries or other external power sources by capturing untapped electromagnetic energy in the surroundings. In this paper, we propose a multi-frequency and multi-mode microwave metasurface for efficient radio frequency (RF) and microwave energy harvesting. The MEH is comprised of a sub-wavelength resonant ring array, which can harvest RF energy in both Wi-Fi and 5 GHz bands. A feeding network is designed to integrate the TE and TM wave energy collected by the MEH into two separate networks that each gather AC energy and deliver them to the resistive loads. In terms of the simulation’s results, the efficiency of energy harvesting at frequencies of 2.4 GHz, 3.1 GHz, as well as 3.6 GHz is 91.3%, 88.9%, and 73.9%, specifically. We manufactured a 6 × 6 array sample and conducted experiments utilizing a microwave anechoic chamber. The simulation results and results from experiments were approximately identical. The proposed design has potential applications in various fields, such as efficient wireless energy harvesting systems, self-powered devices, which has a significant potential on the environment and the energy sector by reducing carbon emissions and reducing reliance on non-renewable energy sources.
A flexible metamaterial absorber with temperature-insensitive design at microwave frequencies
Authors: Li Kai , Lu Haipeng , Bi Mei , Qi Lun , Weng Xiaolong
Published: August 2023

Developing a metamaterial absorber (MA) with both flexibility and temperature insensitivity continues to be a challenge in the field of radar stealth. In this paper, we propose a compensation method for designing flexible and temperature-insensitive MA. This method is revealed through the relationship between the square resistance of the resistive film, the permittivity of the substrate, and the temperature. Importantly, the compensation method is applicable to both the MA in the plane state and the bending state. By utilizing the benefits of the compensation mechanism and the flexible designability of the bilayer cross-shaped structure, the flexible MA proposed in this paper can achieve temperature-insensitive absorption across a broad frequency range. Experimental results indicate that the absorption peaks achieve an absorptivity greater than 90% within the frequency of 7.2–9.4 GHz, exhibiting excellent temperature stability from 25 °C to 300 °C. In comparison to previous studies on flexible MAs, this design offers a distinct advantage in high-temperature environments and provides valuable guidelines for the design of integrated multi-functional absorbers in practical applications.
Improved two-mode dynamic model for external-cavity quantum cascade lasers under strong optical feedback
Authors: Yousefvand Hossein Reza
Published: August 2023

In this paper, we propose an improved model for describing the dynamical behavior and mode selection mechanism of an external-cavity quantum-cascade laser (EC-QCL) when subject to strong optical feedback. Theoretical analysis including the dynamical effective reflectivity model, two-mode rate-equation model and Lang-Kobayashi equations are employed to carry out the laser output characteristics under the multiple feedback effects. A main aspect of the model is that the excess mirror loss caused by the EC effective reflectivity is incorporated into the laser dynamical equations as a nonlinear dynamical variable. Because of accounting the multiple round-trip feedback terms in the EC effective reflectivity, the analysis is valid for the arbitrary feedback regimes from weak to strong levels. Besides the stationary characteristics, the model accurately predicts the dynamical competition between the fundamental laser-cavity mode and the desired EC mode that reflected strongly by external diffraction grating. The results are in well agreement with theoretical and experimental data reported earlier for the EC-QCLs.
Performance of hollow hyperbolic sinusoidal Gaussian beam in weak turbulent optical communication links
Authors: Secilmis Gamze Nur , Bayraktar Mert , Elmabruk Kholoud
Published: August 2023

The performance of hollow hyperbolic sinusoidal Gaussian beam (HHsGB) propagating in weak turbulent optical communication link is examined by analysing the beam scintillation indices. System parameters’ effect on point-like and aperture-averaged scintillation index values is investigated. The obtained results show that HHsGBs with small source sizes improve the link performance by reducing the scintillation level. In communication systems with a big receiver aperture radius, HHsGBs with high orders significantly minimize the scintillation level. Thus, the provided results will have significant potential in improving free-space optical communication performance in a wide range of applications.
Research on Aircraft Wheel Hub Pose Detection Method Based on Machine Vision
Authors: Ren Wenbo , Zhu Yiwen , Zhang Ning
Published: August 2023

In order to achieve the action of lifting and clamping the aircraft wheel by the wheel holding device, machine vision is innovatively introduced to detect the position and pose of the wheel hub during the wheel holding process. The overall process design was systematically carried out, and an industrial camera was selected and calibrated. Then, the generalized Hough transform was used to extract the target from the processed image, and its center position was calculated. Based on the data of the number and position of the target’s center, it was determined whether the wheel hub was intact. If it was incomplete, more photos were taken. If the number of targets met the standard and the wheel hub was intact, the PnP pose calculation algorithm was adopted to calculate the position and pose of the wheel hub. The results showed that the calculated position and pose met the requirements proposed by the project design.
Detection of Agricultural Pests Based on YOLO
Authors: Luo Yingjie , Ni Lei , Cai Fangkai , Wang Daming , Luo Yang , Li Xiaoyu , Fu Ning , Tang Jiangwen , Xue Liang
Published: August 2023

Focus on the problem of the species pests are difficult to identify in agricultural production an application based on the YOLO algorithm is presented. The algorithm extracts features fastly and complete detection task simultaneously. Through collecting agricultural pests, the algorithm establishes a data-set build target object detection model and train them, the problem of difficulties in identifying agricultural pest species and locating them has been solved. The result shows that the mAP’value of YOLO algorithm is 92.42%, the prediction precision is 96.8%. The algorithm has a high recognition rate, and identify the species of pests fastly and accurately, it can meet the detection and identification requirements.
Study on Facial Recognition Method Based on YOLOv5
Authors: Xu Wenjin , Li Bo , Du Yonghui , Dong Shaokang
Published: August 2023

This study focuses on the facial recognition algorithm. To address limitations of facial recognition, this paper proposes a deep learning method called YOLOv5-Attention for facial feature extraction, recognition. The algorithm in the article is designed based on YOLOv5 and incorporates an attention mechanism module to enhance the expression ability of the model’s eyebrow features and improve its overall performance. The experimental results demonstrate that the algorithm proposed in this paper achieves a harmonic mean of 94% for eyebrow recognition accuracy. This highlights the effectiveness and reliability of the algorithm, which can be applied to eyebrow recognition and dramatic character facial recognition, as well as the research of general facial recognition.
Object Detection Based on Fusion of Visible and Infrared Images
Authors: Yongshi Ye , Haoyu Ma , Tashi Nima , Xinting Liu , Yuchen Yuan , Zihang Shang
Published: August 2023

In consideration of the complementary characteristics between visible light and infrared images, this paper proposes a novel method for object detection based on the fusion of these two types of images, thereby enhancing detection accuracy even under harsh environmental conditions. Specifically, we employ an improved AE network, which encodes and decodes the visible light and infrared images into dual-scale image decomposition. By reconstructing the original images with the decoder, we highlight the details of the fused image. Yolov5 network is then constructed based on this fused image, and its parameters are adjusted accordingly to achieve accurate detection of objects. Due to the complementary information features that are missing between the two image types, our method effectively enhances the precision of object detection.
Typical Fault Characteristics Analysis of Distribution Network
Authors: Yu Xiaoxi , Huang Jianqiong , Zhou Bin , Zahir Muhammad Zeeshan
Published: August 2023

China has built the largest power network in the world, forming a pattern of “nationwide interconnection, sending power from west to east, mutual supply between south and north.” As the user-oriented terminal power network, the safe operation of distribution network is the basis of power system stability. However, the distribution network system is huge, widely distributed and prone to failure. In order to quickly and accurately judge the fault category, improve the efficiency of fault location and reduce the non-fault outage area after the fault occurs in the distribution network system. Four typical faults of distribution network, namely single-phase grounding fault, phase-to-phase short circuit fault, ferromagnetic resonance and magnetizing inrush current, are studied in this paper, their fault characteristics are analyzed, and fault simulation analysis is carried out by MATLAB. Finally, the theoretical analysis results are verified by the actual on-site fault recording data, which proves the scientific and feasibility of the theoretical analysis.
An Intelligent Optimization Method for Wireless Communication Network Resources Based on Reinforcement Learning
Authors: Tian Di
Published: August 2023

The scarcity of spectrum resources is becoming increasingly severe, and the traditional static spectrum allocation method leads to low spectrum utilization. To address these issues, this article introduces reinforcement learning (RL) into wireless communication systems and proposes an optimization method for wireless resource allocation in deep Q networks (DQN). This paper uses the deep reinforcement learning (DRL) method to model the selection process of cluster heads and relay nodes as a Markov decision process, and then uses DQN to establish a cluster head and relay node selection mechanism aimed at maximizing the life cycle of wireless sensor network (WSN). Experimental results show that compared with the existing algorithms, the proposed algorithm effectively reduces the energy consumption of the network and extends the life cycle of WSN. Ultimately, it is possible to reconfigure relevant spectrum resources to obtain available spectrum resources, and idle spectrum resources can be discovered at any time.
Named Entity Recognition of Electronic Medical Records based on BERT-BiLSTM-Biaffine Model
Authors: Wang Peng , Gu Jinguang
Published: August 2023

In the case of the specific task of identifying named entities within electronic medical record, it is hard to determine the boundary of nested entities, and existing NER systems have insufficient decoding performance. Based on the pre training model BERT, this paper introduces a novel network structure called Biaffine Layer using a bidirectional LSTM layer. The network uses a dual affine attention mechanism for semantic information learning, which can better interact with the semantic information of entity heads and entity tails, thereby achieving better recognition results for entities. Due to the sparsity of named entity datasets and the uneven distribution of entity categories, traditional binary cross entropy loss functions require multiple rounds of training to decode entities. In this paper, we have modified the binary cross entropy loss function to make the proposed model faster decode the entities that need to be identified. The model performs well, according to the experimental findings. The approach suggested in this paper offers a fresh approach to the NER issue raised by electronic medical records, and it is anticipated to considerably boost the effectiveness and caliber of clinical medical research.
Research on Resource Allocation Strategies for Wireless Powered Sensor Network
Authors: Yuan Lina , Huang Mingjuan , Wen Xianli , Wang Rong
Published: August 2023

Wireless powered sensor network (WPSN) solves the problem of difficult battery replacement of sensor nodes in some environments. The unreasonable distribution of network resources in the energy transmission environment will lead to a sharp decline in the energy collected by sensor nodes, reduce the network life, and cause resource waste. In this paper, by introducing hybrid relay nodes to transmit energy to passive terminals and forward terminal information, the distance between passive terminals and final receiving nodes of information is reduced, and the contradiction between passive terminals’ data transmission requirements and “double path loss” of radio frequency energy transmission in WPSN is alleviated. At the same time, in the relay-powered WPSN, the life span of the relay node is equal to the life span of the whole network. This paper studies the energy efficiency transmission scheme of the relay node to maximize the energy utilization efficiency of the relay node and improve the life span of the WPSN.
Temperature drop for CO2 gas flowing through multilayer micro-pin fin arrays
Authors: Hua Chaoyue , Weng Jiahua , Yan Jia’ning , Cui Xiaoyu
Published: August 2023

A reasonable theoretical calculation model is established, and an appropriate correlation formula is selected to calculate the flow and heat transfer of CO2 gas flowing through micro-pin fin arrays in a micro-cooler respectively under different working conditions. The inlet pressure of CO2 gas is 1.0 MPa, 1.5 MPa, and 2.0 MPa respectively, and the inlet temperature is 12 °C and 16 °C respectively. The results show that the cold end temperature of the gas decreases with the increase of CO2 gas inlet pressure and the decrease of inlet temperature, and the lowest temperature reaches -29.93 °C. The calculated results have the same trend as the experimental data, and the calculated values are consistent with the experimentally measured values, which demonstrates the calculation model’s logic.
Power quality transient disturbances detection system based on db5 wavelet
Authors: Liu Dongmei , Zhu Weiyuan , Wang Yanhui , Chang Ziyi , Xie Kaikai , Wang Shun
Published: August 2023

To improve the real-time and accuracy of transient disturbance localization in the power grid, this paper designs an FPGA-based transient disturbance detection system based on the good time-frequency local analysis capability, multi-resolution analysis characteristics of wavelet decomposition, and the selection of db5 (Daubechies 5) wavelets. The system acquires the original disturbance signal through an external high-speed AD/DA board, implements the wavelet transform algorithm by the EP4CE10F17C8 FPGA, and then feeds back to the high-speed AD/DA board to output the location of the singularities in the high-frequency detail signal that corresponds to the start and end moments of the disturbance. Simulation and actual test results together show that the system can accurately and quickly locate the start and end moments of typical single disturbances such as voltage sag and short interruption, with a measurement deviation of within 3ms, meeting the real-time requirements.
DC negative corona discharge characteristics of the needle-plate electrode under different air pressures
Authors: Lv Duo , Zhou Yang , Liu Jiqiu , Li Feng , He Wangling , Wang Yanzhao , Wan Baoquan , Gan Zheyuan , Wei Hongyu
Published: August 2023

Because of the low normal atmospheric pressure and frequent, more severe corona discharges in high-altitude regions. The electromagnetic environment problems caused by the corona discharge restrict the line design in high-altitude areas. The variance in the law of negative DC corona characteristics under different air pressure conditions is derived using an artificial climate tank with adjustable air pressure. The characteristics of the negative DC needle-plate corona discharge were measured experimentally. The negative DC corona discharge pulses at 89.4 kPa–56.04 kPa were obtained, and the characteristics of the current pulses were statistically examined. The study of the mechanism of the DC corona discharge can benefit from the research findings as essential reference data.
Sinusoidal Frequency Estimator by Using Interpolation of Four DTFT Spectral Lines
Authors: Bai Yuchan , Liu Jinyu , Wu Huihao , Fan Lei , Li Renqing , Xing Jun
Published: August 2023

This paper proposes a sinusoid frequency estimator by interpolating four Discrete Time Fourier Transform (DTFT) samples. Firstly, Discrete Fourier Transform (DFT) is performed on the received sinusoid. Then we find the positional information of the maximal DFT bin and obtain the coarse estimation results. Next, the proposed method uses four symmetrical DTFT samples on both sides of the maximal DFT bin to interpolate the signal frequency and obtain accurate estimation results. Simulation experiment results illustrate that the proposed method’s accuracy is higher than that of the competitive methods. When the signal-to-noise ratio (SNR) increases from 0dB to 90dB, the presented estimator performs better than the competitive methods.
Voltage Regulating Strategy of a New LCC/S+L Inductive Power Transfer System
Authors: Liao Hongbin , Wang Wei , Zhang Weige , Du Xiaogong , Yu Qingsong , Wang Lifeng
Published: August 2023

In the voltage control of the inductive power transfer (IPT) system, a cascaded DC-DC converter is normally adopted which reduces the power density. However, the wireless communication between the transmitter and the receiver may lead to a delay of control as well as communication instability. This paper proposes a new LCC/S+L resonance topology for the IPT system, which can realize single-stage voltage regulation on the receiving side with both buck and boost capability. Based on the fundamental wave analysis method, this paper analyzes the working principle of LCC/S+L resonant topology. Then the control strategy of the phase shift angle between bridges and within bridges is obtained by the voltage of both ends of the series inductor and the load voltage vector. It is verified by simulation that the proposed new resonance topology and control strategy can achieve output voltage regulation of 300-500 V with a constant 375 V input DC voltage.
Short-circuit Fault Detection in Low-voltage DC Microgrids Based on Improved Current Change Rate
Authors: Huiyin Cai , Zhenyu Li
Published: August 2023

Along with the explosion of new energy sources, DC microgrid has obvious advantages as well as better development paths, but reliable fault detection is still one of the key issues to be solved for DC microgrid. The fault current characteristics are analyzed by a fault RLC equivalent circuit, and the characteristics at different fault location points are further analyzed on the independent DC microgrid model composed of a PV generation unit, an energy storage unit, and a load unit. A fault detection method based on the improved current change rate is proposed by combining the current abrupt change direction. A DC microgrid model with a bus voltage of 400 V is built and simulated in Matlab/Simulink. The simulation results show that the proposed method can detect and isolate bus and unit short-circuit faults in less than 2 ms, ensuring the proper operation of the whole system, which has a certain reference significance for fault protection of low-voltage DC microgrids at independent operation sites.
Estimation of Electricity Supply and Demand under Dual Carbon Goals: A Chance-constrained Linear Programming Model
Authors: Yang Xuan , Zhou Ruoxin , Tang Fei , Yan Zhouzhou , Wei Xiaoqing
Published: August 2023

Implementing the green and low-carbon development strategy has become a global consensus with the increased severity of global environmental problems. In 2020, Chinese President Xi Jinping put forward China’s carbon peak and carbon neutrality goals (i.e., dual carbon goals), which is a guideline for the development of Chinese power systems. Thus, a supply and demand estimation system that includes dual carbon indicators and considers the long-term supply capacity is needed. To address these gaps, this study put forward an estimation model and provided the solutions. First, a supply and demand estimation indicator system is established to meet the dual carbon goals. Second, with minimizing cost being the main objective and several constraints, a chance-constrained linear programming model is used to estimate the supply and demand of electricity in 2030, 2040, and 2050. Finally, with model relaxation, we obtained the estimation results with Matlab-Cplex, which verified the efficiency and validity of the proposed model.
Evaluation of the Influence of Thermal State and Mechanical State of Overhead Conductors on Power Flow
Authors: Sun Rongfu , Wang Jingran , Ding Ran , Geng Yan , Qiu Wei , Pei Yuting , Zhao Leiqing , Yao Yiming
Published: August 2023

Overhead conductors’ thermal and mechanical states are the critical factors to determine their safe operation and have an impact on the power flow calculation. The thermal and mechanical state parameters of overhead conductors change the resistance parameters of the line on the one hand and change the line parameters through the tensile action of force on the line on the other hand. The parameters of the line are closely related to the power flow calculation of the power system. Based on two kinds of influence mechanisms and regional power systems, this paper quantitatively analyzes the influence of thermal state and mechanical state on power flow under light load and heavy load.
The Improved Control Method of Parallel Microgrid Inverters
Authors: Wang Liwei , Miao Hong
Published: August 2023

The parallel of inverters is inevitable in the operation of distributed generation with a Microgrid. However, due to the difference in line impedance between each parallel inverter and the public AC bus in the microgrid, the m available control method is insufficient to overcome the disadvantages such as unbalancing distribution of power, large circulating current, and poor dynamic characteristics, etc., especially when the line impedance difference is large. To conquer the above problems, the paper proposed an improved droop control strategy, in which a differential module is adapted to the droop control to improve the dynamic response. Further, a modified adaptive virtual resistance is proposed, so that the system can maintain high response speed, high stability, and robustness. These can effectively benefit power sharing and circulation suppression of parallel inverters while ensuring excellent dynamic characteristics of the system. Finally, the effectiveness of the improved control method is verified by the simulation results.
Online parameter identification of permanent magnet synchronous motor based on recursive least squares algorithm
Authors: Lv Sixun
Published: August 2023

In order to solve the problem of variable parameters in the system when the PMSM works, this project intends to use the recursive algorithm in the steady state of alpha-beta. This project identifies the two parameters as the fixed values of two parameters at the same time, so as to reduce the number of parameters to be estimated and avoid the problem of under-classification. The proposed method is studied experimentally on the 2 kW PMSM experimental platform. Simulation results show that this method can quickly and accurately realize the online identification of parameters in the PMSM system.
Thrust Pointing Adjustment of Electric Propulsion System
Authors: Li Zongliang , Zhao Jingchao , Peng Zheng , Song Fei , Li Zhong , Liu Yizhuo
Published: August 2023

The satellite uses an electric propulsion system (EPS) to complete the north-south station-keeping (NSSK) work. Due to the change of satellite centroid position during the whole life period, electric propulsion thrust pointing adjustment is required to minimize the deviation between the thrust vector and the satellite centroid, to avoid the additional interference torque and the decrease of the position protection efficiency of the EPS. In this paper, the electric propulsion thrust pointing adjustment method is designed, the mathematical model of the pointing adjustment angle is established, the conformity of the thrust pointing adjustment during the whole life of the spacecraft is analyzed, and the ground integration test verification and the on-orbit electric propulsion thrust pointing adjustment verification are completed. The analysis and verification data show that the adjustment range and accuracy of the EPS can meet the requirements of the NSSK mission.
Aeroacoustics Analysis of Propeller Blades
Authors: Zhang Yifei , Zhao Longzhi , Zhao Tianming , Liu Lu , Xu Lijun
Published: August 2023

Under rapid development, drone propellers are facing two essential problems: noise emission and aerodynamic efficiency. In this work, the aeroacoustics characteristics of two propellers were experimentally and numerically investigated. Both propellers have exactly the same design points, and MTprop-1678 has a thinner blade and larger chord than MTprop-1688. Results showed that the broadband noise of 1678 significantly rose due to a larger Reynolds number, and the total noise was larger. The study shows that reducing the Reynolds number might be a good idea for propellers’ noise reduction.