bluuebunny/crossref_metadata_2025 huggingface dataset:
Finite element analysis on buckling behaviour of integrated wing spar
Authors: Elumalai E. S. , Asokan R. , Vasanth Naidu Adduru Veda Sai , Arunkumar K. , Seralathan S.
Published: October 2024

With advancement in manufacturing processes like 3D printing, it is easy to manufacture the components. This study focuses on the numerical simulation of an aircraft wing and spar as an integral component. The study examines the buckling behaviour of the integrated wing spar, a critical load carrying member in the wing. The spar is connected to the wing so that the buckling analysis can be performed on the wing as well. CATIA software is used to design the integrated wing spar model as well as the conventional wing spar model, and ANSYS software is used to perform FEA analysis for both the wing spars. Under different loading circumstances, the structural performance of both the wing spars is compared. Buckling occurs in both the spars. But the stress acting on the conventional spar is 280MPa whereas, the stress acting the integrated wing spar is 348MPa which is comparatively higher by 13.5%. Based on the buckling stress, strain, weight savings and cost, the results reveal that the integrated wing spar design is better than the conventional wing spar design.
An investigation into process parameters optimization for ultimate tensile strength of friction stir welded Al-10Mg-8Ce-3.5Si joint: Numerical and Design of Experiments approach
Authors: Duncan Agweu Remmy , Suresh Udayagiri , Sai Mukthinuthalapati Satya , Udayakiran M , Pittala Raj Kumar , Yelamasetti Balram , Abhishek D
Published: October 2024

The Friction stir welding (FSW) process has become a popular method of joining metals, due to its clean and efficient nature of producing welds. The input process parameters such as tool rotation speed, tool feed and tool pin shape are the deciding parameters to get an optimum output quality characteristic such as ultimate tensile stress (UTS) of the weld joint. In this study, earlier published experimental results were used to find out optimum process parameters for UTS by applying Taguchi full factorial design technique and numerical analysis using Abaqus. A governing equation which can easily determine and maximize the UTS of the weld joint is generated. The ANOVA of means and Signal to Noise ratios for UTS were used to assess the influence of each process parameter on the output UTS. The main effect plots of the ANOVA results demonstrated that the tool rotation speed at level 1 or 800 rpm, tool feed at level 3 or 20 mm/ min and tool pin shape at level 1 or triangular cross section gave the optimum results for the output UTS. The percentage contribution of each process parameter on the UTS were investigated. Optimized process parameters to get the highest UTS were suggested.
Application of Taguchi-Grey approach for wire electro discharge machining of aluminium alloy
Authors: Thejasree P , Manikandan N , Raghurami Reddy D , Kumar Jyothula Sunil , Kumar Peyyala Pramod
Published: October 2024

AA 7075 has been recognized as a highly suitable material for numerous applications in engineering due to its exceptional characteristics, including enhanced ductility and decreased susceptibility to fatigue. It is widely used in the aerospace industry and shows promise for several other technical applications. Its exceptional corrosion resistance makes it the favoured choice for many applications. Producing complex-shaped components using traditional machining methods is difficult. Various advanced machining techniques have been developed to prevent such difficulties. Wire Electrical Discharge Machining (WEDM) is a distinct technique that belongs to the broader classification of Electrical Discharge Machining (EDM). This study utilizes Taguchi’s methods to investigate the Wire Electrical Discharge Machining (WEDM) of AA 7075 aluminum alloy. This study utilizes a natural dielectric medium in order to reduce the negative impacts on the environment. The investigation includes a wide range of performance indicators, including material removal rate, surface roughness, and tolerance errors. ANOVA is a statistical method used to assess the importance of process factors. The outcomes of this investigation are much helpful for the manufacturers to make the quality parts precisely.
Examination of the Impact of suitable Process Parameters on the Cold Extrusion of AA5754
Authors: Harika Chowdary M , Gowthami K , Nayeem Shaik , Nirmala Devi E. , Ananda Rao G
Published: October 2024

High strength and exceptional non-corrosive properties make aluminum alloy AA5754 ideal for use in vehicle cages, aerospace, and marine applications. The purpose of this work is to assess how process parameters affect the cold extrusion of grade 5754 aluminum alloy. For the investigation, process variables like changing force, die angles, and lubricants are taken into account. Solid Works is used to develop and model the die, while EN13 steel is the material used in its manufacture. To determine how process parameters affect cold extrusion, full factorial layout of experiments is taken into consideration. The Universal Testing Machine is utilized for conducting experimental experiments on cold extrusion. Testing is done on the material’s hardness, tensile strength, and surface roughness following cold extrusion. Results-based suggestions for suitable applications are made.
Microstructure analysis of SS316L using Selective Laser Melting
Authors: Prathyusha Chityala , Jani S P , Uppalapati Sudhakar , Raghavulu K. V , Lakshmi Kala K. , Ahilan C. , Kumar Ashish , Chandrashekar Rakesh , Vemanaboina Harinadh
Published: October 2024

Additive manufacturing has emerged as a prominent and expanding domain in materials engineering, driven by a rising need for customized, highly accurate, and readily available production. Applying the selective laser melting (SLM) technique further is delayed by the layer-by-layer melting and solidification of the metal powder. The impeller constructions were extracted from a substrate, with the bending curvature as an indicator of the stress level. This research aims to analyze the quality of impeller components, surface roughness, and microstructural features of components made for the SS316L. The microstructure examinations show the part is free from the surface and internal defects are verified.
Numerical Analysis of the Structure of an Aluminium Alloy Piston: A Comprehensive Study
Authors: Ganapathi R , Omprakash B , Lava Kumar P , Pittala Raj Kumar , Yelamasetti Balram , Abhishek D
Published: October 2024

In this research, our focus centers on investigating the stress distribution across various piston materials employed in internal combustion (IC) engines. Recognizing the pivotal role of the piston as a critical and intricate component within the engine, its sustained optimal condition is imperative to ensure the engine’s proper functionality. Mechanical stress emerges as a primary factor leading to piston failure. Consequently, our study delves into the analysis of mechanical stress exhibited by different piston materials, aiming to gain insights into their performance under various conditions. The exploration of stress distribution across diverse materials contributes valuable information for enhancing the durability and reliability of pistons, thereby advancing the overall efficiency and longevity of IC engines.
A study on friction stir welding with dissimilar aluminium alloys using various tool profiles
Authors: Sukesh O.P. , Menachery Nice , Abin C.T. , Deepanraj B.
Published: October 2024

The advantages of Friction Stir Welding (FSW) over conventional fusion welding processes have led to its increased attention in joining aluminum alloys. This study investigated the effects of varying welding parameters, including rotational speed, traverse feed rate, and pin profile, on the quality and mechanical properties of FSW joints between AA2024 and AA6061 alloys. The experimental work involved conducting FSW experiments using a pin tool with different profiles, such as cylindrical and hexagonal designs. Additionally, rotational speeds and traverse feed rates were varied to evaluate their impact on the weld quality and performance. The welding process was performed on plates of AA2024 and AA6061 alloys, and the resulting joints were examined. This study provided valuable insights into the friction stir welding of AA2024 and AA6061 alloys, highlighting the significance of welding parameters on weld quality and mechanical properties. The results could aid in the development of optimized welding conditions for specific applications, promoting the wider adoption of FSW in the automotive, aerospace, and other industries requiring high performance aluminum joints.
Machine Learning Advancements in Machining Processes: A Comprehensive Review for Manufacturing Optimization
Authors: Suthahar P , Palanikumar K , Ponshanmugakumar A , Anbuchezhiyan G.
Published: October 2024

Machine learning (ML), a subset of AI, allows computer programs to autonomously learn from data. This self-learning process, also known as “self-learning,” has witnessed significant advancements, particularly in Deep Learning (DL) techniques, applied in strategy games and autonomous vehicles. ML’s potential in various industries, including operation management, is evident, with studies indicating its pivotal role in transitioning production systems to Industry 4.0 standards. Despite its prevalence in multinational corporations, industrial applications of ML remain limited. This study project aims to illuminate both the benefits and challenges of employing ML algorithms in operation management, facilitating easy adoption by professionals. By organizing pre-2000 articles based on relevant algorithms and application areas, along with keyword analysis to identify popular research domains, the project aims to address growing interest and publication trends. Notably, unsupervised and deep learning methods have garnered significant attention in recent years, reflecting a rising interest in addressing issues such as bug detection and output planning in operation management. As such, ML is poised to play a crucial role across various facets of operation management in the coming years.
Research on new structure of high voltage 4H-SiC power UMOSFET devices
Authors: Xu Binyi , Zhao Yuhao , Wei Yuan , Hu Kaifu , Zhang Xiaodong , Shen Chong
Published: October 2024

In this article, we investigate a novel optimized 4H-SiC U-shaped groove gate MOSFET (UMOSFET) structure, which is characterized by improving the gate to a stepped gate structure, adding an n-type wrapped p+region at the bottom of the gate, and finally adding an unevenly distributed superjunction p/n structure at the bottom. We improve the problem of the gate oxygen electric field at the corner by using a stepped gate structure. Next, we design an n-type doping encapsulation (nw) region that wraps around the p+gate oxygen protection zone with a higher concentration than the drift zone to reduce the conduction resistance. Finally, a super junction structure was designed to reduce conduction resistance and increase breakdown voltage. After testing, the performance of the breakdown voltage has been improved by 54% compared to the initial structure.
Electric vehicle charging station siting planning model considering distribution grids
Authors: Yan Chunwang , Liu Na
Published: October 2024

The widespread adoption of electric vehicles will present a novel challenge to distribution network planning, necessitating the establishment of new standards. Improving the electric vehicle charging infrastructure is pivotal for the advancement of electric vehicles. In this paper, the construction principles of charging station siting are first proposed to consider the influence of the distribution network. When building a multi-faceted planning model for electric vehicle charging networks, we holistically consider various costs including the construction and operational expenses incurred by charging station operators, as well as the yearly cost to EV users related to their charging journey times, queuing for charging, and the combined annual expense of both charging duration and electricity prices. Moreover, we integrate critical constraints like service demand and travel distances into the model’s design parameters. Ultimately, the paper considers the construction of a mathematical model for distribution network planning, incorporating charging stations. The objective of this model is to minimize the overall investment and operational costs associated with new lines and electric vehicle charging stations within the distribution network.
An 8~18 GHz 6-bit phase shifter with balance-compensated balun
Authors: Shangguan Yiping , Quan Haiyang , Wen Wu , Liang Yishu
Published: October 2024

This paper presents a 6-bit wideband, low error, digitally controlled active phase shifter operating from 8 to 18 GHz. The phase shifter consists of three modules, namely input transformer balun, quadrature signal generator, and vector modulator, using 0.18μm SiGe BiCMOS process. The transformer balun is designed with a center tap with a capacitive compensation circuit, the quadrature signal generator circuit features a two-stage resistive-capacitive (R-C) based polyphase filter (PPF) structure, and the vector modulator module utilizes an adjustable current array structure to enable quadrant selection and gain adjustability. The post-simulation results of the phase shifter indicate that the RMS phase error is below 2°, the RMS amplitude error is under 0.5 dB, the gain ranges from -0.5 to 1.8 dB, and the input return loss is less than -10 dB across the 8 to 18 GHz operating range.
Filtering coupler with tight coupling based on trans-directional coupler
Authors: Cao Yuan , Gu Xinyue , Yin Songfeng , Hu Xiao
Published: October 2024

In the text, a filtering trans-directional coupler is designed. This structure consists of three coupled lines, resonant circuits, and a trans-directional coupler. The filtering function is achieved through three coupling lines, and resonant circuits play a role in eliminating resonance points. A 3-dB filtering coupler with tight coupling characteristics is designed. When S11<-10 dB, the relative bandwidth in simulation can reach 48.59% (2.15 GHz ∼ 3.53 GHz). Moreover, the filtering trans-directional coupler has the characteristic of a wide stopband. Under the standards of |S11| and |S21| less than -10 dB, the cutoff frequency of the upper stopband is 7.23 GHz.
Improve PMSM parameter identification of model reference adaptive system
Authors: Lei Ke , Tan Bo , Luo Shichao , Qiao Hao
Published: October 2024

To overcome the issue of under-rank in the mathematical PMSM in parameter identification, the reference model and adjustable model of PMSM are established, according to Popov’s stability theorem (Popov), the adaptive law is established to assure the system stability during online recognition, and the stator inductance is first identified by using the recursive least squares method, and then the identified inductance value is substituted into the stator resistor and flux fluxe are distinguishd in the established adaptive laws. It overcomes the issue of underranking the mathematical equation of the motor and realizes step-by-step identification. This study is a PMSM identification method depending on improved model reference adaptive (MRAS). The simulation consequence indicate that the methods of research has fast recognition rpm, high recognition degree and fast motor speed response, and has certain practicality.
SOC estimation of adaptive untraceable Kalman filtered lithium batteries based on fractional order modeling
Authors: Miao Henggang , Zhou Guangxu , Lao Kaiyue , Zhu Yunhai
Published: October 2024

Since the description of the chemical reactions inside the battery of the traditional integer-order circuit model is not comprehensive, in order to estimate the battery state of charge (SOC) more accurately, this paper first establishes a fractional-order model and selects an adaptive genetic algorithm (AGA) when identifying the parameters of the circuit model. Then, for the problem that the estimation of battery state of charge by the Traceless Kalman Filter (UKF) algorithm will be inaccurate under complex working conditions and noise uncertainty, a fractional-order adaptive untraceable Kalman filtering (AUKF) algorithm with adaptive adjustment of noise and measurement covariance is proposed. Finally, it is proved that the combination of fractional order modeling and adaptive unscented Kalman filter algorithm can improve the accuracy and anti-interference ability of SOC estimation.
Optimization voltage-dependent current order limiter parameters for improving the voltage stability of multi-DC receiving-end power grid
Authors: Zhang Yijing , Shi Yanqiang , Liu Jiachen , Huang Minjie , Luo Heyu , Liu Xiaolong
Published: October 2024

Power grids with multi-DC high voltage direct current (HVDC) commonly face challenges such as inadequate voltage support, exacerbated interactions between AC and DC, and complex and variable operation modes. Severe AC faults in these grids can easily trigger consecutive failures in DC commutation, potentially leading to a collapse in the voltage across the entire network. This study introduces a synchronized optimization technique aimed at improving voltage stability within receiving-end power systems by adjusting the parameters of the Voltage Dependent Current Order Limiter (VDCOL). Firstly, principles for adjusting VDCOL parameters are proposed grounded on voltage instability mode. Derived from the sorting outcomes of the multi-infeed short-circuit ratio, parameters of VDCOL are adjusted to ultimately suppress commutation failures and enhance the capability of receiving-end power grids to accept external power. Finally, the simulation result verifies that optimizing VDCOL parameters according to the proposed method significantly increases the capability of receiving-end power grids to accept external power.
Research on energy routing optimization of medical bracelet network for home care temperature measurement
Authors: Wang Long , Tang Zhenghua
Published: October 2024

In this paper, a new algorithm imitates the behavior of ants to find the optimal path. Considering the node energy, communication distance, packet size, and network topology, the data transmission path is dynamically adjusted to achieve the balance of network energy consumption and maximum utilization.
Study on temperature characteristics of inter-turn short circuit in oil-immersed self-cooling transformer windings
Authors: Fang Zhen , Liu Li-Qiang
Published: October 2024

According to the physical characteristics of the short turn of the transformer winding, the possibility of judging the position of the inter-turn short circuit by the axial temperature characteristics of fault winding is discussed. Initially, employing multiphysics simulation techniques, a coupled electromagnetic-thermal multiphysics model of the ONAN transformer is established to simulate the three-dimensional temperature distribution under different load impedances, fault severities, and short-circuit positions. Subsequently, a comparative analysis is conducted on the temperature distribution characteristics of windings or axial oil passages under normal and various inter-turn short-circuit fault conditions. Through this investigation, it is proposed to utilize temperatures at five equidistant points distributed axially inside faulty windings as characteristic monitoring quantities. This proposal can be used as the basis for the research of subsequent shorted winding turn position positioning algorithms.
Improved differential protection scheme based on the statistical distribution of differential current sampling points for the main transformer in wind farms
Authors: Song Xupeng , Liu Zhisheng , Yang Yang
Published: October 2024

During the fault ride-through process in wind farms based on doubly-fed induction generators (DFIGs), there is a frequency deviation phenomenon in the short-circuit current provided by the wind farm, which can cause errors in phasor extraction based on the Fourier algorithm, and the second harmonic restraint criterion may operate incorrectly. As a result, the differential protection remains locked for an extended period, leading to a decrease in the performance of the traditional differential protection. To address this issue, an improved differential protection scheme based on the time domain and frequency domain in DFIG-based wind farms is introduced. The method is based on the longitudinal statistical distribution of pre-processed differential current sampling points combined with ratio differential elements to form an improved differential protection scheme. Simulation results show that the proposed protection scheme quickly and accurately identifies magnetizing currents and internal transformer faults, and performs well in cases of external faults accompanied by current transformer (CT) saturation and CT measurement error.
Research on output voltage control of DAB converter based on SMC-ESO
Authors: Zhang Sining , Wang Xiaosong , Wang Dazhi , Qiao Fengpu
Published: October 2024

This article addresses the limitations of collecting disturbance load current information to regulate output voltage in practical applications and proposes a sliding mode control based on an extended state observer. The extended state observer is used to accurately estimate disturbance load current, thereby reducing the number of current sensors and achieving effective control of output voltage without relying on real-time load current information. Finally, a corresponding model was built in the MATLAB/Simulink environment and simulation experiments were conducted.
Active-reactive power coordinated optimization of distribution network considering reactive power compensation of EV charging station
Authors: Zhang Yuanbo , Li Tao , Sun Yue , Yang Chao
Published: October 2024

With the increasing number of electric vehicles (EVs) integrated into the distribution network (DN) year by year, the uncertainty of EV charging has exacerbated voltage fluctuations in the DN, affecting DN’s safe and stable operation. Therefore, this paper proposes a DN active-reactive power coordinated optimization method that combines the voltage regulation capability of EV charging piles with real-time reactive power regulation devices. Firstly, a generative adversarial network (GAN) based on Wasserstein distance and gradient penalty is used to generate typical EV charging scenarios to address the uncertainty of EV charging load. Secondly, the impact of EV uncertainty on the stability of the DN operation is analyzed, and a DN active-reactive power coordination model considering the reactive power compensation of EV charging stations is constructed. Finally, simulation analysis is conducted on the IEEE33-node distribution system to validate the model’s effectiveness.
Electromagnetic reverberation characteristic of chamber in high intensity radiation field test
Authors: Zuo Chang , Si Xiaoliang , Huang Yeyuan , Duan Zemin
Published: October 2024

This paper studies the electromagnetic reverberation characteristics of the cabin in high-intensity radiation field tests. Referring to the design requirements of the reverberation chamber, a simplified model of the cabin with an mode stirrer is established. Based on the joint simulation method, field strength sampling was conducted at different stirring positions, and the cabin reverberation characteristics under external electromagnetic wave irradiation were analyzed according to the requirements of field uniformity and statistical characteristic. The feasibility of creating a good reverberant field environment in the cabin for statistical testing was verified.
Research on the gate reliability of HZO FeFETs with different interface layers
Authors: Liu Xing
Published: October 2024

The gate reliability of Hf0.5Zr0.5O2 (HZO) ferroelectric field-effect transistors (FeFETs) with varying interface layers was investigated in this paper, specifically SiO2 and Y2O3. By employing voltage-ramp and time-dependent dielectric breakdown (TDDB) tests, along with an analysis of different gate dimensions, we provide insights into the impact of interface layer composition and device geometry on FeFET performance and reliability in this study. The research aims to enhance device longevity and efficiency by understanding and optimizing the interface layer’s dielectric properties, addressing the critical challenge of gate dielectric failure, and guiding future design strategies for improved ferroelectric memory devices.
Battery SOC estimation based on UHIF algorithm for third-order circuit models
Authors: Lao Kaiyue , Zhou Guangxu , Miao Henggang , Zhu Yunhai
Published: October 2024

With the rapid development of electric vehicles, the accurate estimation of power battery SOC becomes particularly important. Since the noise chance distribution of the power battery is unknown under different cases of operating currents, this paper analyzes the above problem, relies on the third-order equivalent circuit model, uses the forgetting factor recursive least squares (FFRLS) for parameter identification, and proposes a third-order circuit model-based traceless H-infinity estimation algorithm (3RC Unscented H-Infinity, 3RC-UHIF), whose main framework is the H-infinity filtering algorithm introduced for the problem that the noise assumption of the UKF algorithm must be white noise. The non-Gaussian noise is filtered by minimizing the cost function, and the a priori state estimates of the expectation and error covariance matrices are rewritten in third-order form to improve the estimation accuracy.
A demand response scheduling method of distribution network based on shock load screening and prediction
Authors: Zhang Binfan , Zhao Shengnan , Yan Peicheng , Cheng Xingong
Published: October 2024

With the increasing power load, the power supply pressure of the distribution network increases, among which the impact load has the characteristics of large instantaneous power and fast power growth, which makes the distribution network face problems such as insufficient capacity and short-term supply and demand imbalance. The load interlock method has been used in the past to cope with the impact load of the distribution network. Still, this method forcibly schedules the user load, affects the user’s power consumption experience, and makes it difficult to ensure sufficient dispatch. To solve this problem, this paper adopts a distribution network demand response scheduling based on impact load screening and prediction. By applying the outlier anomaly detection algorithm, the impact load is screened from numerous loads. Then, the required impact load is determined according to the maximum amount of allowable dispatch in the distribution network lines and the location of the grid load nodes. Then, a demand response resource scheduling model that considers shock load is established. This method solves the problem of insufficient capacity caused by shock load, avoids the cost caused by power network expansion, and gives economic compensation to users through demand response, achieving a win-win situation.
Lossless congestion control based on priority scheduling in named data networking
Authors: Diao Wenlan , An Jianping , Li Tong , Wang Xiaotian , Liu Zhoujie , Li Zhenghan
Published: October 2024

The LEO satellite network is an important component of the next-generation (6G) communication network, carrying a large amount of data exchange, which poses challenges to congestion control. The Named Data Networking (NDN) with the characteristics of in-network cache and content multicast can save the traffic consumed by data distribution. However, due to issues such as long control loops, packet loss, and lack of quality of service support, the existing congestion control methods in NDN cannot be applied to the LEO satellite networks. In this paper, we propose an easily deployable congestion control method: NDN Data Forwarding Control (NDFC). We improve the backhaul forwarding of data packets. According to the occupancy of the output queue in each interface, the data packet can be injected into the queue from the content store (CS), avoiding congestion and achieving packet loss-free forwarding. Besides, we design a forwarding dispatch table and priority-based scheduling to support the rapid transmission of data packets with high priority and the fair transmission of data packets with the same priority. The NDFC method has been evaluated and the simulation results show that compared with the practical congestion control scheme (PCON), the NDFC mechanism stabilizes high throughput, reduces the completion time of high-priority data flows by 50%, and evenly allocates bandwidth for data flows with the same priority.
Audio completion method based on tensor analysis
Authors: Zhu Lin , Yang Lidong
Published: October 2024

The audio signal may be damaged or lost in the process of acquisition and transmission, resulting in poor quality of the received audio signal and affecting subsequent processing. The completion algorithm can be used to recover the audio with some loss. In this paper, the tensor ring decomposition is introduced into the recovery algorithm to recover the audio. The audio signal is pre-processed, then it is transformed from the time domain to the frequency domain. The MEL frequency spectrum diagram of the audio signal is obtained after MEL scale transformation, and a third-order tensor is constructed. Then, the audio signal is recovered by the recovery algorithm, and the results are compared. The results show that the recovery algorithm based on tensor analysis has a better audio recovery effect than the traditional matrix completion method.
Fast mapping algorithm with optimized placement selection for CGRA
Authors: He Tengyuan , Lu Weijun , Li Pengju
Published: October 2024

In the field of parallel computing, Coarse-Grained Reconfigurable Architecture (CGRA) is a promising technique for processing parallel applications. Application kernels are mapped on CGRA through the calculation of mapping algorithms. This paper presents a Fast Mapping Algorithm with Optimized Placement Selection for mapping application kernels on CGRAs. The mapping algorithm incorporates heuristic optimizations for processing element (PE) selection based on Hycube Mapping Algorithm and reduces the redundant extra calculation procedures to achieve fast DFG mapping. In algorithm tests from CGRA-Bench, the proposed algorithm demonstrates an average 70.83% reduction in mapping computation time compared with Hycube Mapping Algorithm. Moreover, the quality of mapping results, as measured by the initiation interval (II), remains largely consistent with Hycube Mapping Algorithm, thereby significantly reducing computation time and improving the mapping efficiency.
Novel Cascaded PV System with Common Mode Leakage Current Suppression
Authors: Cai Xiaopeng , Li Zichao , Wang Yizhou , Zhang Ruizhi , Han Jing
Published: October 2024

The problem of large common mode leakage current (CMLC) in cascaded H4 transformerless PV systems is investigated. Firstly, the reasons for the large CMLC of the cascaded system are analyzed, the common mode equivalent circuit is established, based on which the cascaded iH6 PV system is proposed, and the mechanism by which the cascaded iH6 system is able to effectively suppress the CMLC is analyzed and explained. Finally, the system is verified by simulation in Matlab/Simulink.
A clustering algorithm for multidimensional time series devices based on feature extraction
Authors: Li Lei , Zhang Yong , Zheng Yiming , An Gaoxiang , Guo Feng , You Ziyi
Published: October 2024

With the increasing number and types of data center equipment, the use of centralized monitoring has some disadvantages, such as network bandwidth limit and excessive data processing pressure of the monitoring server. The equipment grouping according to the running status and trend of the equipment can meet the dynamic changes of the equipment, and the equipment with similar running status is divided into groups for monitoring, which greatly improves the sensitivity of fault detection. Therefore, this paper designs a multidimensional time series device clustering algorithm based on feature extraction. First, a feature extraction algorithm of time series fluctuations based on correlation measure is designed to extract the subject running trend of monitoring data, reduce the dimension of time series data, and improve the accuracy of clustering. Second, a multidimensional time-series clustering algorithm based on Fuzzy C mean is designed to obtain the optimal clustering results. The experimental simulation results show that the proposed algorithm improves the clustering effect and can more accurately cluster the devices with similar running characteristics into one group for monitoring.
Gray mapping method of QAM constellation for trellis shaping
Authors: Wang Yuanming , Li Yuanjie , Dong Chao , Niu Kai
Published: October 2024

A novel method to construct quadrature amplitude modulation (QAM) constellation for trellis shaping is proposed. To overcome the non-gray mapping of set-partitioning constellation used in trellis shaping, we proposed a Gray mapping constellation. This constellation can get the same shaping gain as the set-partitioning constellation while the demodulation bit error ratio (BER) performance is better than the latter, which makes the trellis shaping connect with the forward error correction (FEC) code to form an FEC-shaping concatenation system to improve the error correction performance. For 64-QAM and 256-QAM, based on the BER results, the system can get 0.5-0.8 dB gain with the non-shaping system at BER 10−3.
NASA’s aerospace data relay satellite system development and its implications
Authors: Li Qiang , Wang Hongfeng , Liu Wenwen , Lv Lihong
Published: October 2024

The research, development, and application of the Tracking and Data Relay Satellite System (TDRSS) have greatly improved the TT&C coverage of low-orbit spacecraft and the real-time data transmission capability, but as the number of low-orbit spacecraft grows larger and larger, it is difficult for TDRSS to provide data relay services for all low-orbit spacecraft. For this reason, the National Aeronautics and Space Administration (NASA) of the United States is exploring new data relay services through commercial communications satellite systems and has selected six companies to carry out demonstration and verification tests. China’s low-orbit satellite system is developing vigorously with more and more satellites, and there is also the problem of a shortage of resources for TDRSS and TT&C stations. By sorting out the procurement of NASA’s commercial data relay service, differentiating between the task characteristics, diverting business, and enhancing the commercial spaceflight capability, this paper provides a reference for the expansion of China’s data relay service.
A radar emitter individual identification method based on maximum entropy spectrum estimation
Authors: Guo Linyu , Yang Xinquan , Wen Wei
Published: October 2024

Radar emitter individual identification is an important research topic in modern electronic intelligence and electronic support systems. Based on the analysis of the individual characteristics of the radar emitter, this paper proposes a radar emitter individual recognition algorithm based on the maximum entropy spectrum estimation feature of the pulse envelope. The method is characterized by the maximum entropy spectrum estimation of pulse envelope and combined with long short-term memory (LSTM) to complete the identification of radar emitter individuals. Compared with the traditional methods based on local features, the entropy sequence used in this paper can be regarded as a global estimation, so the features have better robustness. The simulation results show that when the transmitter transmits the same single-tone signal, the recognition accuracy is close to 82 % when the signal-to-noise ratio is 0 dB. When the signal-to-noise ratio is 5 dB, the recognition accuracy can reach 94 %, and at 10 dB, the recognition accuracy is close to 99 %. Under the condition that three radiation sources randomly send signals of nine different modulation types, the recognition accuracy reaches 80 % when the signal-to-noise ratio is 0 dB. When the signal-to-noise ratio is 5 dB, the recognition accuracy is improved to 90 %. When the signal-to-noise ratio is 10 dB, the recognition accuracy reaches 97 %. This conclusion proves that the signal type has little effect on the recognition accuracy, and the method has high accuracy and good robustness.
A fast synthetic aperture radar echo simulation technique based on ray tracing
Authors: Xi Zhan , Guo Lixin
Published: October 2024

For high-resolution Synthetic Aperture Radar (SAR) echo simulation in complex and large-scale scenes, this paper presents a combined approach that integrates ray tracing with the Modified Electric Current Algorithm (MECA). This method leverages the powerful parallel computing capabilities of graphics processing units (GPUs) to rapidly calculate the full-polarization scene echoes. Additionally, the Distance-Doppler Algorithm (RDA) is employed to process the echo data for imaging. Simulation results demonstrate that the simulation accurately captures the electromagnetic scattering characteristics of complex scenes, thereby validating the correctness of this algorithm.
Design of a dual-mode communication module for electricity information collection
Authors: Li Luqi , Li Yongjie , Lu Jizhao , Zhu Rui
Published: October 2024

At present, the growing scale of power users is getting faster and faster, resulting in meter reading management becoming more and more onerous, and manual meter reading is easy to cause various errors. The intelligent automatic meter reading system using Sub-GHz and HPLC dual-mode can avoid the problems existing in the traditional meter reading. Based on Sub-GHz and HPLC dual-mode communication modules, wired channels and wireless channels are combined to improve communication stability and reliability, and improve the success rate of power information collection in the station area.
MIDI I/O
Authors: Edstrom Brent
Published: October 2024

This chapter expounds on the extent of MIDI I/O. Musical Instrument Digital Interface (MIDI) refers to a digital communications language that enables computers, keyboards, synthesizers, and other devices to transmit performance information as a series of bytes. The chapter then provides an overview of the code and circuitry that are required to transmit and receive messages via USB and five-pin UART connections. Teensy microcontrollers are fantastic tools for working with MIDI as they can handle multi-port USB and UART input and output, and some Teensy devices can even function as USB MIDI hosts. The chapter explains that connecting components opens the door to unique and expressive interactive instruments.
Interactive MIDI Arpeggiator
Authors: Edstrom Brent
Published: October 2024

This chapter examines the key concept of Interactive MIDI Arpeggiator (IMA) project. It explains that the project demonstrates several concepts including memory buffers, MIDI I/O, and clock synchronization. Additionally, the IMA project also demonstrates the creative potential of microcontroller technology, where unique interactive playback algorithms are only limited by imagination. The chapter notes that the arpeggiator consists of four pairs of buttons that control pattern selection, rate, note duration, and note repetitions. It highlights that the IMA provides a convenient way to develop customized arpeggiation patterns beyond the limited number of patterns available in a typical digital audio workstation.
An exponential stochastic Runge–Kutta type method of order up to 1.5 for SPDEs of Nemytskii-type
Authors: von Hallern Claudine , Missfeldt Ricarda , Rössler Andreas
Published: October 2024

For the approximation of solutions for stochastic partial differential equations, numerical methods that obtain a high order of convergence and at the same time involve reasonable computational cost are of particular interest. We therefore propose a new numerical method of exponential stochastic Runge–Kutta type that allows for convergence with a temporal order of up to $\frac{3}/{2}$ and that can be combined with several spatial discretizations. The developed family of derivative-free schemes is tailored to stochastic partial differential equations of Nemytskii-type, i.e., with pointwise multiplicative noise operators. We prove the strong convergence of these schemes in the root mean-square sense and present some numerical examples that reveal the theoretical results.
A Right to Solidarity. World Ordering from the Margins through International Law?
Authors: Haaf Johannes , Anderl Felix
Published: October 2024

In 2005, the United Nations (UN) created the Independent Expert on Human Rights and International Solidarity. The mandate holder works toward the establishment and promotion of the human right to solidarity. Usually, a right is regarded as something that people demand, and solidarity is something that people give regardless of legal obligations. Codifying solidarity in international law therefore seems paradoxical. Yet, as we show in this article, the initiative, driven by the G77, stands in a long tradition of attempts to transform the international order into a more just and equitable structure. We highlight its function as a possible means of world ordering from the margins. Through the voting power of a coalition of discontents—against the consistent resistance of Organisation for Economic Co-operation and Development countries—in the General Assembly/the Human Rights Council, the mandate holder can use their marginal position in the UN bureaucracy to update discourses about a just international order by altering legal discourses in pursuit of the right to solidarity.
The role of a specialized urethral catheter in early detection of intra-abdominal hypertension: a case report
Authors: Halalmeh Dia R , Aftab Neha , Hussein Mohamed , Ansari Yusuf , White Hutton , Jenkins Phillip , Mercer Leo , Beer Patrick , Sachwani-Daswani Gul
Published: October 2024

Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) impact morbidity and mortality in burn patients, exacerbated by extensive fluid resuscitation required for more than 20% of total body surface area burns. We report a case of a 28-year-old male with severe burns and a TBSA of 49% who presented after a fire incident. The trauma team managed the patient’s fluid resuscitation, followed by early burn debridement. A TraumaGuard catheter was used for continuous intra-abdominal pressure (IAP) monitoring. On the second day of admission, a critical IAP of 20 mm Hg was detected, indicative of impending ACS. Immediate intervention with cistracurium and increased sedation reduced the IAP to 9 mm Hg, preventing the progression to ACS. This case demonstrates the importance of routine IAP monitoring in severely burned patients to prevent ACS. Early identification and management of elevated IAP can avert the progression to ACS and reduce the need for more invasive interventions.
KS02.5.A THE ONCOMETABOLITE D-2-HYDROXYGLUTARATE PROMOTES DNA HYPERMETHYLATION AT LINEAGE-SPECIFIC ENHANCERS CONTROLLING MICROGLIAL ACTIVATION IN IDH-MUTATED GLIOMAS
Authors: Laurenge A , Pugliese P , Mathon B , Richard Q , Jouannet S , Hayat Y , Scuderi S , Marijon P , Labreche K , Alentorn A , Verreault M , Idbaih A , Birzu C , Huillard E , Pottier N , Desmons A , Fayache I , Kaas G A , Kingsley P J , Marnett L J , Duplus E , El-Habr E , Salas L A , Mokhtari K , Tran S , Suvà M L , Iavarone A , Ceccarelli M , Touat M , Bielle F , Mallat M , Sanson M , Castro-Vega L
Published: October 2024

BACKGROUND

Resident microglia are highly plastic myeloid cells. Their phenotype and immune response are determined by the microenvironment composition. Although microglial cells are highly abundant in IDH-mutated (IDHm) gliomas, how this particular environment modulates the transcriptional programs and cell states of these cells remain largely uncharacterized. Herein we investigated whether and how D-2HG, the oncometabolite produced by the IDH mutation and released into the tumor microenvironment, impinges upon the phenotypic and functional properties of resident microglia.

MATERIAL AND METHODS

We analyzed bulk DNA methylome (Methylation EPIC array) and transcriptome of CD11b+magnetic-purified fractions from IDHm (n= 25) and IDH-wildtype (n=11) gliomas, as well from normal brain tissues (n=6). To determine direct effects of D-2-hydroxyglutarate (D-2HG), the oncometabolite produced by IDHm glioma cells, we optimized human primary microglial cultures obtained from glioma or drug-resistant epilepsy surgery. Microglia exposed to 5mM D-2HG or vehicle for 14 days were analyzed with DNA methylome (LC-MS/MS, EPIC arrays and single-base resolution approaches) and transcriptome (RNA-seq). Using snRNA-seq, we analyzed microglial transcriptome from a paired sample of one IDHm glioma patient before and after treatment with the IDH-inhibitor vorasidenib, which is known to deplete tumor D-2HG levels.

RESULTS

We uncovered that CD11b+ myeloid cells in human IDHm gliomas exhibit DNA hypermethylation predominantly at enhancer elements. Hypermethylation was linked to decreased expression of genes involved in inflammatory responses and glycolytic metabolism, as well as inactivation of transcription factors that regulate microglial responses to environmental stimuli. Prolonged exposure of human primary microglia to D-2HG inhibited TET-mediated 5mC oxidation, resulting in a reduced accumulation of global 5hmC levels. We observed high 5mC/5hmC ratios particularly at lineage-specific enhancers. Consistent with the remodeled enhancer landscape, D-2HG-treated microglia showed reduced proinflammatory capacity and enhanced oxidative phosphorylation. Conversely, depletion of D-2HG levels following vorasidenib treatment in an IDHm glioma patient was associated with overexpression of genes related to microglial activation.

CONCLUSION

Our findings provide a mechanistic rationale for the hyporesponsive state of microglia in IDHm gliomas and support the hypothesis that oncometabolites such as D-2HG may disrupt the function of immune cells residing in the tumor microenvironment.