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45 results on '"Huang, Junchang"'

4. Spatiotemporal variation characteristics analysis of infrastructure iron stock in China based on nighttime light data

Author

Huang Junchang, Yue Shuaijun, Ji Guangxing, Cheng Mingyue, Ma Hengyun, and Hua Xuanke

Subjects
night lighting, iron stock, china, infrastructure, Geology, QE1-996.5
Abstract

Iron is one of the most important basic materials in infrastructure development, spatial and temporal variation characteristics analysis of infrastructure iron stocks is conducive to revealing its distribution and change patterns from different scales, which can provide a scientific basis for sustainable urban development and iron resource management in China. In this article, we first calculated provincial infrastructure iron stock data from 2000 to 2020. Then, fitting equations between nighttime lighting data and infrastructure iron stock are constructed to simulate the spatial distribution of China’s infrastructure iron stock at 500 m resolution from 2000 to 2020. Finally, the spatial and temporal dynamics of China’s infrastructure iron stock is analyzed from four scales: national, regional, provincial, and urban agglomeration. The results show as follows: (1) China’s infrastructure iron stock grew at an average annual rate of 26.42% from 2000 to 2020, with China’s infrastructure iron stock increasing 6.28 times over the 21 years. Construction facilities are the most important part of the infrastructure iron stock, and its share is still increasing. (2) On a regional scale, the high-growth type of infrastructure iron stock is mainly distributed in the eastern region, while the no-obvious-growth type is mainly distributed in the western region. The high grade of infrastructure iron stock is mainly distributed in the eastern region, while the low grade is mainly distributed in the western region. (3) On a provincial scale, the highest share of no-obvious-growth type of infrastructure iron stock is in Xinjiang. The highest proportion of infrastructure iron stock of high-growth type is in Jiangsu. The highest proportion of low-grade infrastructure iron stock is in Xinjiang. The highest proportion of infrastructure iron stock of high grade is in Beijing. (4) In terms of urban agglomerations, the high-growth type of infrastructure iron stock is mainly located in Shanghai–Nanjing–Hangzhou, while the no-obvious-growth type is mainly located in the Middle south of Liaoning. The high-grade infrastructure iron stock is mainly distributed in Shanghai–Nanjing–Hangzhou, while the low grade is mainly distributed in Sichuan–Chongqing.

Published
2023
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5. Research and Test of the Error Self-monitoring Merging Unit

Author

Wang, Chengnan, Hu, Haoliang, Li, Dong, Huang, Junchang, Li, Xiaofei, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, He, Jinghan, editor, Li, Yaohua, editor, Yang, Qingxin, editor, and Liang, Xidong, editor

Published
2022
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6. Research on the Scheme and Experiment of Quantum-Voltage-Based Verification Device for the Transformer Calibrator

Author

Wu, Ruoyu, Hu, Haoliang, Li, Dong, Nie, Qi, Huang, Junchang, Li, Xiaofei, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, He, Jinghan, editor, Li, Yaohua, editor, Yang, Qingxin, editor, and Liang, Xidong, editor

Published
2022
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12. Deterioration identification method of key optical devices of fiber optical current transformer based on neural network.

Author

Zhang, Min, Guo, Xianshan, Chen, Zhengguang, Zhou, Feng, Hu, Haoliang, Huang, Junchang, Xiao, Hao, Liu, Dongwei, Li, Jianguang, Wang, Qianglong, and Deng, Xing

Subjects
CURRENT transformers (Instrument transformer), OPTICAL devices, PROBLEM solving
Abstract

Optical fiber current transformers (FOCTs) are affected by various external factors, resulting in the deterioration or even failure of devices, causing changes in critical state quantities, and reducing the accuracy and reliability of products. To solve this problem, based on the neural network algorithm, this paper starts from the four deterioration characteristics of FOCT SLD junction temperature, SLD output optical power, phase modulator half‐wave voltage, and optical fiber sensing ring temperature, and identifies the deterioration of key optical components of FOCT, which provides a basic model and data support for the online monitoring and early warning to improving the stability and reliability of FOCT in long‐term operation. [ABSTRACT FROM AUTHOR]

Published
2024
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22. Assessing the Impact of Vegetation Variation, Climate and Human Factors on the Streamflow Variation of Yarlung Zangbo River with the Corrected Budyko Equation.

Author

Ji, Guangxing, Yue, Shuaijun, Zhang, Jincai, Huang, Junchang, Guo, Yulong, and Chen, Weiqiang

Subjects
STREAMFLOW, WATER management, FUNCTIONAL equations, RESTORATION ecology, VEGETATION dynamics, HEURISTIC algorithms, WATERSHEDS
Abstract

The Yarlung Zangbo River (YZR) is the largest river on the Qinghai Tibet Plateau, and changes in its meteorology, hydrology and vegetation will have a significant impact on the ecological environment of the basin. In order to deepen our understanding of the relationship of climate–vegetation–hydrological processes in YZR, the purpose of this study is to explore how vegetation growth in the YZR affects its runoff changes. We first identified the abrupt year of discharge in the YZR using a heuristic segmentation algorithm and cumulative anomaly mutation test approach. After that, the functional equation for NDVI and the Budyko parameter (n) was computed. Finally, the NDVI was introduced into the Budyko equation to evaluate the impact of vegetation changes on the streamflow in the YZR. Results showed that: (1) NDVI and discharge in the YZR both presented an increasing trend, and the mutation year of annual runoff in Nuxia station occurred in 1997. (2) n had a significant negative correlation with NDVI in the YZR (p < 0.01). (3) The contributions of Pr, ET0, NDVI, and n on streamflow change in the S2 period (1998–2015) were 5.26%, 1.14%, 43.04%, and 50.06%. The results of this study can provide scientific guidance and support for the evaluation of the effects of ecological restoration measures, as well as the management and planning of water resources in the YZR. [ABSTRACT FROM AUTHOR]

Published
2023
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33. Design and development of an improved calibrator for the DC electronic transformer in HVDC system

Author

Huang Junchang, Qi Nie, Han Liu, Feng Zhou, Yefeng Yu, and Dong Li

Subjects
Synchronization (alternating current), Sampling (signal processing), Computer science, Direct current, Calibration, Electronic engineering, Transmission system, Accuracy class, Multimeter, Transformer (machine learning model)
Abstract

The direct current (DC) electronic transformer is widely used in high-voltage DC (HVDC) transmission systems as primary equipment, and its steady-state accuracy is necessary to be calibrated for safe and reliable operation of the electrical power system. Usually, the method of calibration is to compare the outputs of the standard transformer and the test object with the same source, and the high-precision digital multimeter (DMM) is used to convert the analog output into digital form with the synchronous pulse per second (PPS) triggering. The DMM acquires a series of data after each trigger firstly, then the sampling data are transmitted to the host computer, thus the sampling is noncontinuous. Besides, the DMM can’t ensure the precise synchronization of sampling only based on the PPS. These factors affect the calibration result. Therefore, a control scheme of continuous and synchronous sampling for the DMM is proposed, and an improved DC electronic transformer calibrator is designed and developed. The test results under laboratory conditions show that the DC steady-state accuracy of the calibrator can reach up to 0.05 accuracy class.

Published
2021

34. Design and application of a calibrator suitable for direct current transformer of Zhangbei VSC-HVDC Project

Author

Zhao Lin, Nie Qi, Gao Shuai, Zhang Shuo, Huang Junchang, and Xu Zhanhe

Subjects
Signal processing, Software, Transmission (telecommunications), Sampling (signal processing), business.industry, Computer science, Electronic engineering, Calibration, business, Signal, Current transformer, Transformer (machine learning model)
Abstract

DC transformer is the core equipment to provide control, protection and measurement signal in DC transmission project, its reliable work directly affects the safety and stability of the system. In order to develop a calibrator for DC transformer of Zhangbei VSC-HVDC Project, this paper studies a precise synchronous verification scheme and a high-speed FT3 message reception and analysis scheme through the analysis of non synchronous verification and secondary signal processing, which meets the needs of FT3 message analysis under different sampling rates during field verification of transformer, and is suitable for Zhangbei VSC-HVDC Project equipment In this paper, the hardware and software structure of the calibrator system are also studied, and the error calibration test of the calibrator is carried out. Finally, the calibrator is applied in a converter station of Zhangbei VSC-HVDC Project.

Published
2021

41. Progress of the RF Negative Ion Source Research at HUST

Author

Chen, DeZhi, Fan, Mingwu, Huang, Jiang, Huang, Junchang, Li, Dong, Li, Xiaofei, Liu, Dawei, Liu, Kaifeng, Wang, Chenre, Yue, HaiKun, Zhang, Zhe, and Zhou, Chi

Subjects
T01 Proton and Ion Sources, 03 Particle Sources and Alternative Acceleration Techniques, Accelerator Physics
Abstract

To promote the research and talent cultivation for ITER negative ion sources, Huazhong University of Science and Technology (HUST) has started to develop an experimental facility since 2011 under the support of Ministry of Science and Technology of China. As the first stage, we are building a radio frequency (RF) driver which will produce the plasma for yielding negative ions in the next stage. A deal of experimental research has been carried out on the setup., Proceedings of the 5th Int. Particle Accelerator Conf., IPAC2014, Dresden, Germany

Published
2014
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45. [The effect of dexamethasone in different application on treatment of sudden sensorineural hearing loss].

Author

Huang J and Ren Z

Subjects
Humans, Retrospective Studies, Treatment Outcome, Anti-Inflammatory Agents administration & dosage, Dexamethasone administration & dosage, Hearing Loss, Sensorineural drug therapy, Hearing Loss, Sudden drug therapy
Abstract

Objective: To investigate the effect of dexamethasone through different methods of administration in treatment of sudden sensorineural hearing loss., Method: One hundred cases of sudden sensorineural hearing loss were retrospectively studied, in which patients were divided into 2 groups as A and B. The cases were treated with dexamethasone intravenous injection in A group and intratympanic application in B group., Result: The total effective rate was 66.00% in A group and 68.00% in B group. The difference between the total effective rate in group A and B did not reach significance in statistics (P > 0.05)., Conclusion: The effect of dexamethasone intravenous injection and intratympanic application on treatment of sudden sensorineural hearing loss has no difference.

Published
2012

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