bluuebunny/crossref_metadata_2025_split huggingface dataset:
Does exercise therapy improve patient-reported outcomes in rheumatoid arthritis? A systematic review and meta-analysis for the update of the 2020 JCR guidelines for the management of rheumatoid arthritis
Authors: Sobue Yasumori , Kojima Toshihisa , Ito Hiromu , Nishida Keiichiro , Matsushita Isao , Kaneko Yuko , Kishimoto Mitsumasa , Kohno Masataka , Sugihara Takahiko , Seto Yohei , Tanaka Eiichi , Nakayama Takeo , Hirata Shintaro , Murashima Atsuko , Morinobu Akio , Mori Masaaki , Kojima Masayo , Kawahito Yutaka , Harigai Masayoshi 
Published: February 2021

Abstract

Objectives
This study aimed to evaluate the impact of exercise therapy on patient-reported outcomes (PROs) in rheumatoid arthritis (RA) as part of the process of updating the 2020 Japanese guidelines for the management of RA according to the Grading of Recommendations, Assessment, Development, and Evaluation system.

Methods
We searched PubMed, Japana Centra Revuo Medicina Web, and the Cochrane Library (from 2009 to 2018) to identify articles that evaluated PROs of exercise therapy and RA disease activity.

Results
A total of 662 articles were identified, including nine RCTs, and meta-analyses were performed on six RCTs on systemic exercise therapy and three RCTs on upper extremity exercise therapy. Analyzed exercise therapies were diverse, differing in target population, intervention method, and duration. Significant improvements were observed in the Health Assessment Questionnaire Disability Index (mean difference −0.35, 95% confidence interval (CI): −0.60 to −0.10), pain (standardized mean difference −2.04, 95% CI: −3.77 to −0.32), and SF-36. For upper extremity exercise therapy, significant improvements in PROs (Disabilities of the Arm, Shoulder, and Hand Questionnaire, Michigan Hand Outcome Questionnaire) were observed.

Conclusion
Exercise therapy in RA treatment improves patient subjective assessment of pain, physical function, and quality of life.
The heat distribution in a logarithm potential
Authors: Paraguassú Pedro V , Morgado Welles A M 
Published: February 2021

Abstract
All statistical information about heat can be obtained with the probability distribution of the heat functional. This paper derives analytically the expression for the distribution of the heat, through path integral, for a diffusive system in a logarithm potential. We apply the found distribution to the first passage problem and find unexpected results for the reversibility of the distribution, giving a fluctuation theorem under specific conditions of the strength parameters.
A Novel Method for Parameter Identification of Fuel Cell Equivalent Circuit Model
Authors: Jin Zhihan , Su Jianhui , Shi Yong , Wang Haining , Chen Yonghui 
Published: February 2021

Abstract
In order to monitor the running state of fuel cell and prolong its service life, fault diagnosis technology has been widely researched. The fuel cell equivalent circuit model (ECM) can easily characterize the water content and membrane drying of the cells which has attracted the attention of scholars. Usually ECM is obtained by electrochemical impedance spectroscopy (EIS), and uses an electronic load for impedance excitation test, then achieves parameter identification through algorithms for fault diagnosis. This paper proposes a novel fuel cell ECM model parameter identification method by constructing a new combined network that the fuel cell ECM is included. It doesn’t require an electronic load to provide an excitation, meanwhile it relies on the DC/DC converter’s input voltage and inductor current, without voltage and current sensors on the fuel cell side. It uses the least square method to identify this new combined network’s parameter. This method reduces the cost of system components and achieves a good test performance.
Analysis Of Typical Power Grid Blackout Accidents And Suggestions For Countermeasures
Authors: Yi ZHANG , Feng ZHANG , Youchun LI , Lv TANG , Xuehu PENG , Jianguo MO 
Published: February 2021

Abstract
The prevention and control of power grid blackout has become an important research content of the modern power industry and government departments. This paper collects and compares 160 influential international large-area blackouts since 1960, summarizes and analyzes the main causes, common problems and developing Process. Combined with the operation of China's power grid, the main risk sources of large-scale blackouts and the recovery process are summarized. Based on the lessons of international blackout accidents, some specific suggestions and countermeasures are put forward from four aspects, such as strengthening risk management and operation control of large power grid, which can provide useful reference for the safe operation of large power grids above provincial level.
PSCAD-MATLAB Coupled Simulation Method for Power Flow Optimization using Continuous Reactive Power Controllable Device
Authors: Yang Fan , Chen Kai , Qian Shaofeng , Zhan JiangYang , Yu Rui , Song Pan 
Published: February 2021

Abstract
With the integration of distributed generation (DG), micro-grids and are becoming attractive. Power flow studies are very important in the planning or expansion of power systems. The paper proposed a novel method that incorporates MATLAB and PSCAD to study the optimal control of the reactive control algorithm to reduce the power loss in the transmission lines. The proposed strategy is easy to implement and effective in solving the dynamic power flow problems. The results can apply to control the continuous reactive power controllable device and show that the power loss can be greatly reduced.
Research on commutation identity between matrix converter and three-level inverter
Authors: Cai Wei , Sun Junzhong , Wang Zongliang 
Published: February 2021

Abstract
The commutation strategy is the important content of matrix converter industrial application, for it not only affects the converter safe operation, but also is closely related to the input and output performance. In this paper, the matrix converter and the three-level inverter are compared on the perspective of three-level, the relationship between them is studied, and the logical correspondence of switch tubes in two topologies is established. By analyzing the switching sequence of the three-level inverter and equivalent the clamping diode, the two-step voltage-controlled commutation strategy is obtained, which proves the equivalence between the matrix converter and three-level inverter.
Analysis of Condensation Problem in High Voltage Switchgear and Design of Anti-condensation System
Authors: Jinlei Hu , Yangyang Li , Junju Lai , Wei Wang , Fan Yang , Yuhang Liu , Yao Zhao 
Published: February 2021

Abstract
The southern region is hot, rainy and humid, and the switchgear is prone to moisture and condensation during long-term operation in this environment, causing partial discharge and other failures. To solve the problem that the switchgear is prone to condensation, this paper studies the conditions for the condensation phenomenon and analyses the condensation temperature calculation curve based on the air temperature and relative humidity in the cabinet. Then a three-dimensional model of the switchgear was established, and the thermal-electric coupling finite element simulation was performed to obtain the spatial temperature distribution of the switchgear under long-term operation and different humidity states. The simulation results are combined with the condensation temperature calculation curve to study the condensation situation of the switchgear under different conditions and the parts prone to condensation. Finally, according to the analysis results, a moisture-proof and anti-condensation control and early-warning system based on optical fiber temperature and humidity sensor is provided to detect the data in the cabinet and conduct comprehensive research and judgment, which provides theoretical basis for anti-condensation and intelligent operation and maintenance of switch cabinet.
Adsorption behavior of Cu-doped ZIF-67 for decomposition gases of organic insulator: A first-principles study
Authors: Li Song , Wei Xiao , Zhu Shiping , Zhou Qu , Gui Yingang 
Published: February 2021

Abstract
In order to detect the decomposition gas of organic insulator in gas insulated switchgear, Cu doped ZIF-67 material was proposed. In this paper, the gas adsorption process was analyzed by the first principle. The calculation indexes include density of States (DOS), adsorption energy (Eads
), charge transfer quantity (Qt
), Charge density difference (CDD), electron localization function (ELF), the highest occupied molecular orbitals (HOMO) and the lowest unoccupied molecular orbital (LUMO). The results show that the adsorption capacity of Cu-ZIF-67 for CO and CO2 is better than that of CF4 in the single gas adsorption calculation. The adsorption energies of three single gases are -1.306eV, -1.597eV and -0.991eV, respectively. Therefore, this study provides excellent gas sensing materials and scientific theoretical calculation for selective detection and gas adsorption of decomposition gas.
IGBT Failure mechanism and boundary analysis under large current and high temperature turn-off
Authors: Ma Xiao , Huang Yongle , Luo Yifei 
Published: February 2021

Abstract
Considering overload working conditions in electromagnetic emission, the paper presents a simulation of IGBT turn-off under large current and high temperature. Numerous simulation result is received under a specific test circuit. Boundary conditions for temperature, current and starry inductance are obtained under a set of temperature criterion. Further analysis proves that after temperature reaches the criterion, high current density path swiftly extends from local area to a vertical current path throughout the cells. This method for IGBT theoretical boundary is useful for similar projects or working conditions.
STFT Analysis of Broadband Oscillation in VSC-HVDC Connected to Offshore Wind Farms
Authors: Bo Xin , Wang Linyuan , Gao Lei , Zhang Huiyuan 
Published: February 2021

Abstract
The transmission technology of offshore windfarms (OWFs) through VSC-HVDC system is developing rapidly. The impact factor of broadband oscillation is complex, it often occurs in VSC-HVDC and direct drive permanent magnet synchronous generator (DDPMSG). In this paper, based on short time fourier transform (STFT), factors that cause broadband oscillation are studied. Firstly, the primary structure of DDPMSG and VSC-HVDC is established. Then the correctness of small signal method (SSM) is verified. Based on eigenvalue analysis, instability caused by controlling parameter is analysed. Finally, time-frequency characteristic of oscillation waveforms in PSCAD is extracted using STFT, asynchronous characteristics of broadband oscillation is verified. It is of guiding significance, for the developing technology of offshore wind farm integrated into grid through VSC-HVDC system.
Research on the wettability of pulse electrochemical machining GCr12 substrates
Authors: Tian Kun , Xu Jinkai , Ren Wanfei , Sun Xiaoqing , Liu Zheming , Yu Huadong 
Published: February 2021

Abstract
Based on mold steel (GCr12), the relationship between pulse electrochemical machining (PECM) parameters and surface for wetting characteristics was explored. The groove structure with the depth of 0.5mm has been machined on the surface of the steel casting GCr12 by impulse electrochemical machine. Under the best processing parameters, the hydrophobic angle can reach 161.8°. The microstructure, elementary composition, and wettability of the sample were characterized and analyzed by scanning electron microscope (SEM), ultra-depth-of-field microscope, EDS energy spectrum, and contact angle measuring instrument. Single factor experiments are used to explore the influence of pulse electrochemical machining voltage and pulse time on the surface wettability of mold steel (GCr12).
Research on 220kV Substation Main Electrical Connection Optimization Based on Life Cycle Cost Theory
Authors: Zeng Wenhui , Liu Xiaoyu , Wang Hanyu , Li Chunmei , Sun Xu , Zhang Zhirong 
Published: February 2021

Abstract
As a key link of power transmission, substation main wiring plays an important role in improving the reliability of power supply in the grid. At present, the design of substation main wiring mainly is made with reference to the typical design schemes. However, due to the continuous development of load and the reliability requirements, the traditional wiring scheme may not fully meet the actual operation requirements. In response to this problem, a new main wiring idea is proposed, 3/2 circuit breaker wiring is added to the conventional double bus wiring scheme to form a mixed wiring scheme. The reliability of each scheme is calculated and analyzed. A certain 220kV substation with heavy load in Chengdu is taken as an example, the loss of social output value is considered, the comprehensive economy of the whole life cycle of the substation construction is calculated and compared, and finally the conclusion is drawn that the reliability and economy of the proposed scheme are the best.
Research on hot spot temperature monitoring technology of transformer winding
Authors: Jia Danping , Huangfu Liying 
Published: February 2021

Abstract
A temperature monitoring system based on fiber grating is designed to realize real-time measurement of the hot spot temperature of transformer windings. This paper introduces the principle of fiber grating temperature measurement, and use the Maxwell and Fluent modules in ANSYS to simulate and analyze the electromagnetic field-fluid field-temperature field of the transformer to obtain specific information about hot spots so that the fiber grating can be placed reasonably. Through the fiber grating wavelength demodulation system based on volume phase grating, the center wavelength value of the grating is obtained, and the quantitative relationship between the center wavelength and temperature is found, which proves the feasibility of the system.
An Improved Varied Virtual-space-vector Modulation for Neutral-point-clamped Three-level Inverter
Authors: Zhou Guanqing , Zhang Guorong , Wang Chunpeng , Gao Kai 
Published: February 2021

Abstract
The problem of neutral-point potential balance is always an inherent problem of three-level inverters. In this paper, an improved varied virtual-space-vector modulation method is proposed to improve the neutral point potential balance capability of three-level inverters. Firstly, the virtual medium vector is redefined, and the distribution coefficient k is introduced to control the amount of charge flowing out of the neutral point. Secondly, based on the principle of compensating the maximum charge in a switching period, the appropriate composite voltage vector is selected to improve the dynamic response of neutral point balance control. The simulation results show that the method can accurately control the neutral point potential balance in the full power factor range, and the dynamic and static performance of this method is excellent.
Research on structure design of thermocouple junction for spacecraft thermal vacuum tests
Authors: Liu Jiabin , Zhang Yu , Wu Bin , Yang Xiaoyuan , Xu Xincheng , Liu Zhe 
Published: February 2021

Abstract
This paper investigates the structure design problem for the thermocouple junction in spacecraft thermal vacuum tests. Due to the different configurations during the tests, the length and the number of thermocouples are always different, which would lead to certain cost. As a result, a novel thermocouple integrated junction structure is developed and the thermocouple wire can be re-used. The experiment demonstrates that the proposed design method can save the spacecraft thermal vacuum test cost and considerably improve the test efficiency.
Summary of Gridding-based Planning Method for Electric Energy Substitution Supporting Network
Authors: Li Yaxin , Yang Jie , Fang Rengcun , Xu Hanping , Yang Ruixi , Zhang Dongyin 
Published: February 2021

Abstract
Electric energy substitution technology is of great significance for optimizing the final energy consumption structure, promoting energy conservation and emission reduction, and preventing air pollution. This paper aims to review the current research status of electric energy substitution technology and related fields, summarize the planning methods of electric energy substitution supporting network, and provide reliable network support for large-scale promotion of electric energy substitution. Firstly, the connotation, strategic significance and characteristics of electric energy substitution technology are summarized, and the basic structure of electric energy substitution technology is proposed. Then, the characteristics of network planning and gridding planning ideas are integrated into the gridding planning framework under the background of electric energy substitution is proposed. Finally, the development challenges of gridding planning methods in the current electric energy substitution background in terms of technology, mechanism and infrastructure are summarized, and looking forward to the development direction of the electric energy replacement supporting network plan under the background of the 14th Five-Year Plan and the new round of power system reform.
Power Loss Investigation of Si-SiC Hybrid Switches in a Modular Multilevel Converter System
Authors: Mao Hua , Jiang Huaping , Hu Jiayu , Qiu Guanqun , Ran Li , Wu Yuping , Qin Han , Yang Minxiang 
Published: February 2021

Abstract
To reduce the power loss in a modular multilevel converter (MMC), hybrid switches with different combinations of Si-IGBT, SiC-MOSFET, Si-FRD and SiC-SBD in parallel or anti-parallel are comparatively investigated. By comparing the power losses in MMC submodule (SM) bridge arm switching devices, one bridge arm of a SM is replaced with a different switch configuration, while the other remains in the conventional Si-IGBT and FRD configuration. Itot
− Esw
and I - V curves are obtained for four switch configurations through SIMETRIX, and brought to SIMULINK simulation over longer time scales to account for the variable switch operating condition. Along with the simulation and experimental results, the loss differences under different switch configurations are verified, obtaining the optimal switch configuration at last, which is instructive for the selection of MMC SM in the future.
Research on power Trade Arrangement and Risk Management in South and Southeast Asia
Authors: Liu Xiang-rui , Liu Shuan-quan , Chen Qing-gui , Zhang Mao-lin , Mou Chun-feng , He Pei-shan 
Published: February 2021

Abstract
In recent years, with the continuous growth of economy in South and Southeast Asia, the demand for energy and electricity is also increasing. In terms of power supply and demand, there are complementarities, among which international power trade can realize the optimal allocation of resources among countries and achieve the goal of mutual benefit and win-win results. Now parts of South Asia, southeast Asia within the scope of power trade between overall is still sporadic, and belongs to the power flow on the basis of bilateral one-way trade, electricity trade amount and scale are small, the current trade arrangements to see also is not very perfect, also can't fully meet the needs of the development of South Asia power trade further in southeast Asia. Therefore, it is necessary to study the power trade arrangement in South Asia and Southeast Asia. At the same time, closely related to trade arrangements is the issue of risk, because many risks are often caused by unreasonable trade arrangements. Due to the differences of power construction status and national level among countries in South Asia and Southeast Asia, there are many risks in carrying out power trade, such as political system, environment and economy. Therefore, this paper studies the risk management of power trade in South Asia and Southeast Asia, in order to clearly understand the risks, and take corresponding countermeasures to solve them timely and properly, so as to realize the ultimate goal of power trade in the sub-region smoothly.
Sensorless control of SMPMSM drive system integrated the differential algebra with the algebraic parameter identification
Authors: Xu Ben , Li Hongmei , Yang Liguo , Wang Xianling , Wang jinyu 
Published: February 2021

Abstract
The differential algebraic sensorless control has the technical features of clear concept and low calculation amount. However, this method is particularly sensitive to motor parameters. Therefore, a differential algebraic sensorless control strategy combined with algebraic parameter identification is proposed and applied to surface mounted permanent magnet synchronous motor (SMPMSM) drive system in this paper. Without the signal injection, the proposed method can promptly and accurately realize the online simultaneous identification of stator resistance and inductance based on the different torque conditions of system, and then the motor parameters used in the differential algebraic sensorless control are updated in time. In addition, the tracking differentiator is designed to accurately obtain the first-order differential of the stator current signal with noises for rotor position estimation. Finally, the effectiveness of the proposed sensorless control method is validated by the simulation results.
Research on Pneumatic Muscle Position Control Based on Adaptive Backstepping Sliding Mode
Authors: Jia Danping , Cao Zhi 
Published: February 2021

Abstract
Aiming at the nonlinearity and uncertainty of pneumatic muscles, an adaptive backstepping sliding mode control method is proposed. Using the three-element model of pneumatic muscles, an adaptive backstepping sliding mode controller for pneumatic muscles is designed, which is proved by Lyapunov theory. For the stability of the system, a simulation test platform is built in MATLAB. The simulation results show that the designed controller has fast convergence speed and strong robustness.
Planning method for charging piles of intelligent networked electric vehicles in consideration of charging safety
Authors: Li Lei , Liu Weidong , Li Dan , Li Xiaohui , Liu Xiaochen , Hou Yucheng , Zhang Yajian , Yang Ting 
Published: February 2021

Abstract
As the number of electric vehicles in cities increases, the charging demand has surged. Optimizing deployment planning of electric vehicle charging piles is of great significance to safe charging. Based on the analysis of the factors affecting the planning of electric vehicle charging piles and the spatial distribution characteristics of electric vehicles, this paper proposes a new planning method for urban intelligent networked electric vehicle charging piles that takes into account the charging safety. Using the point clustering algorithm, the optimal division of the urban electric vehicle service range is calculated, and then the central point selection algorithm is employed to allocate the optimal site. Taking the actual electric vehicle charging pile planning in one of the central cities as the experimental example, and comparing with tow of existing charging pile planning methods, the calculation results show that the method proposed in this paper has better planning effects and obtains more reasonable service regional division, balanced services amount, and shorter charging path distance, thus ensuring the safety of charging pile operation and service capabilities.