Active damping strategy with differential feedback of grid‑side inductor voltage for LCL‑filtered grid‑connected inverters

Mingming Li,Hua F. Xiao,Ming Cheng 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.2

Active damping (AD) methods with extra feedback provide a high rejection of the resonance peak caused by LCL-filters, and have the advantages of simple implementation and strong robustness. Among them, capacitor current proportional-feedback AD has been proved to be effective and robust with only a proportional calculation. However, a large capacitive current pulsation restricts the detection accuracy. Based on a theoretical derivation, the same damping effect but with a better rejection of grid harmonic can be obtained by grid-side inductor voltage differential-feedback AD. However, the measured inductor voltage usually contains a parasitic resistance voltage that is difficult to separated, and it deteriorates the performance of LCL-filters. To solve this problem, a differential-negative proportional method based on the vector relationship between the voltages of the grid-side inductor and its parasitic resistance is proposed in this paper. In addition, the influence of control delays is considered and a solution is given. Experimental results based on a 3 kW LCL-type grid-connected inverter prototype are provided to verify the effectiveness of the proposed method.

山东省跨境电商物流发展的影响因素研究

程文思(Wensi Cheng),陈,明明(Mingming Chen) 동북아경상학회 2021 동북아경상연구 Vol.2 No.1

在全球经济一体化和移动信息的推动下,山东省作为中国对外贸易的重要省份,跨境电商行业快速向前发展。跨境物流作为跨境电商的中间环节,对跨境电商的发展起着重要作用。然而现阶段山东省跨境物流方面仍存在着基础配套设施不够完善、物流配送缓慢,现代化程度低、缺乏专业人才等问题,因此跨境电商物流发展的影响因素值得进行深入研究。本文利用Eviews数据分析软件,首先分析山东省跨境电商物流的现状;其次通过钻石模型对山东省跨境物流的影响因素进行分析;最后选取出口额、港口货物吞吐量、货运周转量、人民币汇率四个影响因素,建立多元线性回归模型进行分析研究。研究结果表明出口额和港口货物吞吐量对山东省跨境物流的影响最为显著,呈正相关的关系,人民币汇率对跨境物流的影响呈负相关的关系。并通过研究结果提出了关于提高山东省跨境物流发展的建设性建议,这对于山东省跨境物流发展的理论研究及政策实施都具有一定的意义,本文对其它省份跨境物流的发展提供借鉴。 Purpose - The purpose of this paper is to explore the influencing factors of the development of cross-border logistics in Shandong Province. As an intermediate link of cross-border e-commerce, cross-border logistics plays an important role in the development of cross-border e-commerce. However, at this stage, there are still some problems in the cross-border logistics of Shandong Province, such as imperfect infrastructure, slow logistics distribution, low degree of modernization, lack of professionals and so on. Therefore, the influencing factors of cross-border e-commerce logistics development are worthy of in-depth study. Design/Methodology/Approach - Based on international trade, this paper first analyzes the development status of cross-border logistics in Shandong Province, and then analyzes the influencing factors of cross-border logistics in Shandong Province through diamond model; Finally, the paper selects four influencing factors of export volume, port cargo throughput, freight turnover and RMB exchange rate, and establishes a multiple linear regression model by using Eviews data analysis software. The results show that export volume and port cargo throughput have the most significant impact on cross-border logistics in Shandong Province, which is positively correlated, while RMB exchange rate has a negative impact on cross-border logistics. Therefore, we put forward three suggestions. Findings - This paper studies improve infrastructure, develop advanced production factors, improve cross-border e-commerce logistics service level, and cultivate professionals. Research Implications - In the management of this paper, this study has significance for the theoretical research and policy implementation of cross-border logistics development in Shandong Province. This paper provides reference for the development of cross-border logistics in other provinces

EMOJIS AND BRAND SELF-REPRESENTATION: A TEXT ANALYTICS APPROACH

Xiaowei Wang,,Mingming Cheng,Shanshi Li,Ruochen Jiang 글로벌지식마케팅경영학회 2020 Global Marketing Conference Vol.2020 No.11

AN AUTOMATIC VIDEO ANALYTICS APPROACH TO EXAMINE THE EFFECTS OF VIDEO CONTENT FEATURES ON AUDIENCE ENGAGEMENT

Jingjie Zhu,Mingming Cheng,Ying Wang,Jie Tan 글로벌지식마케팅경영학회 2023 Global Marketing Conference Vol.2023 No.07

While there is an increasing number of studies highlighting the power of videos in influencing audience attitudes and behavior, academic research in tourism is largely behind due to the methodological challenges of analyzing unstructured video data. This study adopts an automatic video analytics approach to examine the relationship between content features of pro-environmental videos and audience engagement in tourism. Artificial intelligence was used to extract video content features by detecting scenes and shots as well as labels (e.g., trees). Our findings suggest that there exists an inverted U-shape relationship between video informativeness and audience engagement. This study makes significant theoretical and methodological contributions to extant tourism literature by theoretically explaining and empirically testing how video content features influence audience engagement in pro-environmental video communications in tourism.

UNDERSTANDING CONSUMER ACCEPTANCE AND REJECTION OF INAUTHENTIC RETAIL ESTABLISHMENTS

Mark S. Rosenbaum,Ipkin Anthony Wong,Mingming (Jake) Cheng 글로벌지식마케팅경영학회 2014 Global Marketing Conference Vol.2014 No.1

This study examines an unexplored area in services-namely, the existence of inauthentic retail establishments. These fake establishments, which mimic the service and product offerings of genuine establishments, such as Starbucks, McDonald’s, 7-Eleven, Apple, and others, prevail across Southeast Asia, primarily in China, Vietnam, and Cambodia. By employing grounded theory methodology, this study offers an original framework that illustrates why consumers accept and patronize both authentic and inauthentic retail establishments. The model shows that many consumers are satisfied with inauthentic retail establishments, and that some inauthentic retailers are building a loyal customer following. Thus, service organizations should respond to these inauthentic companies by viewing them as potential partners for innovation and expansion, rather than as future parties for costly litigation. That is, the authors suggests that authentic retail organizations should target their inauthentic competitors as possible joint venture partners, especially because these competitors have the ability to mimic authentic operations by operating counterfeit schemes.

UNDERSTANDING CONSUMER ACCEPTANCE AND REJECTION OF INAUTHENTIC RETAIL ESTABLISHMENTS

Mark S. Rosenbaum,Ipkin Anthony Wong,Mingming (Jake) Cheng 글로벌지식마케팅경영학회 2014 Global Marketing Conference Vol.2014 No.7

This study examines an unexplored area in services—namely, the existence of inauthentic retail establishments. These fake establishments, which mimic the service and product offerings of genuine establishments, such as Starbucks, McDonald’s, 7-Eleven, Apple, and others, prevail across Southeast Asia, primarily in China, Vietnam, and Cambodia. By employing grounded theory methodology, this study offers an original framework that illustrates why consumers accept and patronize both authentic and inauthentic retail establishments. The model shows that many consumers are satisfied with inauthentic retail establishments, and that some inauthentic retailers are building a loyal customer following. Thus, service organizations should respond to these inauthentic companies by viewing them as potential partners for innovation and expansion, rather than as future parties for costly litigation. That is, the authors suggests that authentic retail organizations should target their inauthentic competitors as possible joint venture partners, especially because these competitors have the ability to mimic authentic operations by operating counterfeit schemes.

LncRNA PVT1 influences breast cancer cells glycolysis through sponging miR-145-5p

Qu Huan,Li Xingxing,Chen Fei,Zhang Min,Lu Xun,Gu Yun,Lv Mingming,Lu Cheng 한국유전학회 2023 Genes & Genomics Vol.45 No.5

Background Long-non-coding RNA PVT1 (lncRNA PVT1) can be used as an oncogenic regulatory non-coding RNA (ncRNA) for many cancers. However, its function and mechanism in breast cancer (BRCA) are still not clearly elucidated. Objective We attempt to explain the mechanism of PVT1’s role in breast cancer from different perspectives. Methods We analyzed the expression of PVT1 and its correlation with the breast cancer related clinical data in the The Cancer Genome Atlas (TCGA) database. We used PVT1 overexpression and knockdown lentivirus to infect breast cancer MDA-MB-231 cell line for cell function verification, in vitro using CCK-8 to measure proliferation, flow cytometry to measure apoptosis, transwell test to measure invasion and migration ability, detecting cell extracellular acidification rate (ECAR) to assess glycolysis metabolism and explore the biological functions of PVT1 in breast cancer cells. Transcriptome sequencing was used to analyze the changes of related genes in cells after overexpression of PVT1. In vivo we used a xenograft model to study the effect of PVT1 on breast cancer. Results PVT1 was up-regulated in breast cancer tissues and was positively correlated with the clinical stage of breast cancer patients. Overexpression of PVT1 in vitro promoted cell proliferation, migration and invasion, and promoted tumor growth in vivo. Knockdown of PVT1 led to the opposite biological consequence. Further bioinformatics analysis showed that PVT1 changes the glycolysis metabolism of tumors through regulation of glycolysis-related genes. In addition, the expression of miR-145-5p is negatively correlated with PVT1. We consider the possibility of PVT1 promoting cell proliferation and metastasis by regulating the aerobic glucose metabolism in breast cancer cells through sponging the miR-145-5p. Conclusion Our results reveal a potential pathway for competing endogenous RNA to regulate breast cancer glucose metabolism. PVT1 regulates glycolysis related genes expression by competitively binding to endogenous miR-145-5p in breast cancer cells to change the metabolic phenotype. This may Provide new ideas for precise molecular therapy targets for breast cancer.