Wireless charging system for unmanned aerial vehicles using lightweight and compact receiver modules

Yuhong Tian,Zhenjie Li,Hao Liu,Yiqi Liu,Mingfei Ban,Junyuan Zheng 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.4

This paper proposes a wireless charging system (WCS) for unmanned aerial vehicles (UAVs) that features a lightweight andcompact receiver module and constant current/constant voltage (CC/CV) charging. Optimizing the LCC-none compensation topology reduces the weight and volume of the receiver module mainly by avoiding the secondary-side resonant capacitors. In addition, high system performance similar to that of the LCC-S compensation topology is achieved. A magnetic coupler with dual power transfer channels is designed using the specific structure of the UAV. The reasonable charging zone is determined by optimizing the magnetic coupler parameters. Besides, a primary-side PI-controlled Buck converter is used to realize CC/CV charging with a high system efficiency under a suitable misalignment range to avoid the secondary-side circuit and control complexity. Finally, both simulation and experimental results verify the feasibility of the designed WCS. The total weight of the receiver coil is only 54 g. During 5 A CC charging, the tested maximum output power and system efficiency values are 90 W and 87.2%, respectively.

A Survey of Security and Privacy Challenges in Cloud Computing: Solutions and Future Directions

Liu, Yuhong,Sun, Yan Lindsay,Ryoo, Jungwoo,Rizvi, Syed,Vasilakos, Athanasios V. Korean Institute of Information Scientists and Eng 2015 Journal of Computing Science and Engineering Vol.9 No.3

While cloud computing is gaining popularity, diverse security and privacy issues are emerging that hinder the rapid adoption of this new computing paradigm. And the development of defensive solutions is lagging behind. To ensure a secure and trustworthy cloud environment it is essential to identify the limitations of existing solutions and envision directions for future research. In this paper, we have surveyed critical security and privacy challenges in cloud computing, categorized diverse existing solutions, compared their strengths and limitations, and envisioned future research directions.

A Survey of Security and Privacy Challenges in Cloud Computing

Yuhong Liu,Yan (Lindsay) Sun,Jungwoo Ryoo,Syed Rizvi,Athanasios V. Vasilakos 한국정보과학회 2015 Journal of Computing Science and Engineering Vol.9 No.3

While cloud computing is gaining popularity, diverse security and privacy issues are emerging that hinder the rapid adoption of this new computing paradigm. And the development of defensive solutions is lagging behind. To ensure a secure and trustworthy cloud environment it is essential to identify the limitations of existing solutions and envision directions for future research. In this paper, we have surveyed critical security and privacy challenges in cloud computing, categorized diverse existing solutions, compared their strengths and limitations, and envisioned future research directions.

Integrated Solution for Timely Delivery of Customer Change Requests : A Case Study of Using DevOps Approach

Yuhong Liu,Chengbo Li,Wei Liu 보안공학연구지원센터(IJUNESST) 2014 International Journal of u- and e- Service, Scienc Vol.7 No.2

Influence of the camber trailing-edge wings on the motion performance of underwater gliders

Liu Yuhong,Xu Shixun,Tian Shan,Lan Shiquan,Deng Shihan,Liu Shuhe,Feng Dengxue 대한조선학회 2022 International Journal of Naval Architecture and Oc Vol.14 No.1

Wings are the main source of lift for Underwater Gliders (UGs) and play a decisive role in their motion performance. The wings of UGs are generally rectangular and symmetrical airfoils. In this study, a mini- UG with flexible camber trailing-edge wings was proposed and developed to investigate the influence of the trailing edge of the wings on the motion performance of UGs. Flexible deformation of the trailing edge was realized using a steer-by-wire actuator. The test results showed that the trailing edge of the wing could realize maximum upward/downward sloping angles of þ16/16. By combining computational fluid dynamics simulations and tank experiments, this study obtained the glide efficiency (in liftdrag ratio) and stable margins of a mini-UG with variable camber trailing-edge wings. The results showed that the angles of attack corresponding to the minimum lift-to-drag ratio were all negative in cases of downward sloping and positive in cases of upward sloping. Moreover, the suitable camber of the trailing edge, that is, downward-sloping trailing edge on descending glides and upward-sloping trailing edge on ascending glides, can not only greatly improve glide efficiency but also benefit flight stability. Tank experiments showed that the lift-to-drag ratio of the mini-UG with appropriate variable camber trailing-edge wings can be increased by at least 25% compared to those with a symmetrical airfoil.

Prospects and challenges of epigenomics in crop improvement

Huang Yuhong,Liu Yang,Liu Chang,Birchler James A.,Han Fangpu 한국유전학회 2022 Genes & Genomics Vol.44 No.3

Background: The advent of high-throughput epigenome mapping techniques has ushered in a new era of multiomics with powerful tools now available to map and record genomic output at different levels. Integrating the different components of the epigenome from these multiomics measures allows investigations of cis-regulatory elements on a genome-scale. Mapping of chromatin state, chromatin accessibility dynamics, and higher-order chromatin structure enables a new level of understanding of cell fate determination, identity and function in normal growth and development, disease resistance, and yield. Objective: In this paper, the recent advances in epigenomics research of rice, maize, and wheat are reviewed, and the development trends of epigenomics of major crops in the coming years are projected. Methods: We highlight the role of epigenomics in regulating growth and development and identifying potential distal cis-regulatory elements in three major crops, and discuss the prospects and challenges for new epigenetics-mediated breeding technologies in crop improvement. Conclusion: In this review, we summarize and analyze recent epigenomic advances in three major crops epigenomics and discuss possibilities and challenges for future research in the field.

Anti‑misalignment capability optimization for laminated magnetic couplers in wireless charging systems using balanced particle swarm optimization method

Hao Liu,Zhenjie Li,Yuhong Tian,Yiqi Liu,Wenlong Song 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.2

To desensitize wireless charging systems (WCSs) to misalignment and to achieve a stable output voltage without using additional control methods, a laminated magnetic coupler (LMC) optimized by the balanced particle swarm optimization (BPSO) method is proposed to improve the performance of WCSs. First, the output characteristics of the LCC-S compensated WCS are analyzed to illustrate the working principle of the LMC. Next, the misalignment characteristics of the LMC, which employs the magnetic integration technique and coil self-decoupling method, are analyzed. Then, the operating principle of the BPSO method is analyzed and used to optimize the LMC in terms of the mutual inductance and anti-misalignment range. Finally, experimental results indicate that the optimized LMC achieves high-efficiency constant voltage charging within a reasonable horizontal misalignment range. When compared to commonly used methods (such as the exhaustive method) for optimizing magnetic couplers, the BPSO method avoids complex algorithms and a heavy computation burden.

Extracellular Vesicles Carrying RUNX3 Promote Differentiation of Dental Pulp Stem Cells

Chi Yuhong,Liu Tingzhong,Jin Qingsong,Liu Hao 한국조직공학과 재생의학회 2024 조직공학과 재생의학 Vol.21 No.1

Background: This study aims to clarify the mechanism underlying dental pulp cells-extracellular vesicles (DPC–EVs) carrying runt-related transcription factor 3 (RUNX3) in mediating odontogenic differentiation of dental pulp stem cells (DPSCs) with the involvement of miR-30a-5p-regulated NOTCH1. Methods: Extracellular vesicles (EVs) were isolated from human DPSCs, and identified using transmission electron microscopy, and nanoparticle tracking analysis. PBS, EVs, or EV inhibitor GW4869 was added to DPSCs for co-culture, whilst odontogenic differentiation was assessed in terms of ratio of mineralized nodules and expression odontoblast differentiation markers. Dual luciferase reporter gene assay and chromatin immunoprecipitation for binding relation among RUNX3, miR-30a-5p and NOTCH1were employed to evaluate their roles in odontogenic differentiation was determined. Animal experiment was established to confirm the effect of DPC-EVs-loaded RUNX3 on dental pulp. Results: In vitro finding demonstrated that EVs delivered RUNX3 to DPSCs, thereby activated miR-30a-5p expression and inhibited NOTCH1 expression, which was reversed by addition of GW4869. RUNX3 upregulation promoted miR-30a-5p while miR-30a-5p targeted and inhibited NOTCH1. Silencing of RUNX3 in EVs decreased expression of those differentiation markers, downregulated miR-30a-5p and upregulated NOTCH1. Conclusion: DPSC-EVs can carry RUNX3 to the DPSCs, promote the transcription of miR-30a-5p, and then inhibit the expression of NOTCH1, and finally promote the odontogenic differentiation of DPSCs. Background: This study aims to clarify the mechanism underlying dental pulp cells-extracellular vesicles (DPC–EVs) carrying runt-related transcription factor 3 (RUNX3) in mediating odontogenic differentiation of dental pulp stem cells (DPSCs) with the involvement of miR-30a-5p-regulated NOTCH1. Methods: Extracellular vesicles (EVs) were isolated from human DPSCs, and identified using transmission electron microscopy, and nanoparticle tracking analysis. PBS, EVs, or EV inhibitor GW4869 was added to DPSCs for co-culture, whilst odontogenic differentiation was assessed in terms of ratio of mineralized nodules and expression odontoblast differentiation markers. Dual luciferase reporter gene assay and chromatin immunoprecipitation for binding relation among RUNX3, miR-30a-5p and NOTCH1were employed to evaluate their roles in odontogenic differentiation was determined. Animal experiment was established to confirm the effect of DPC-EVs-loaded RUNX3 on dental pulp. Results: In vitro finding demonstrated that EVs delivered RUNX3 to DPSCs, thereby activated miR-30a-5p expression and inhibited NOTCH1 expression, which was reversed by addition of GW4869. RUNX3 upregulation promoted miR-30a-5p while miR-30a-5p targeted and inhibited NOTCH1. Silencing of RUNX3 in EVs decreased expression of those differentiation markers, downregulated miR-30a-5p and upregulated NOTCH1. Conclusion: DPSC-EVs can carry RUNX3 to the DPSCs, promote the transcription of miR-30a-5p, and then inhibit the expression of NOTCH1, and finally promote the odontogenic differentiation of DPSCs.

Influence of spent ginger yeast cultures on the production performance, egg quality, serum composition, and intestinal microbiota of laying hens

Liu Junhan,Jin Yuhong,Yang Junhua 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.8

Objective: Spent ginger is a byproduct of juice extraction from the rhizome of ginger (Zingiber officinale). Despite its nutritional value, it is difficult to preserve or further process and thus is often wasted. This study uses spent ginger as a substrate for fermentation and cultivates spent ginger yeast cultures (SGYCs) that are then added to the feed of laying hens. The effects of SGYCs on production performance, egg quality, serum composition, and intestinal microbiota of laying hens were investigated. Methods: Eighty 60-week-old Hy-Line Brown hens were separated into 5 experimental groups with 4 replicates per group (4 hens per cage, 4 cages per replicate). The control group was fed a basal diet while experimental groups were also given SGYCs at the levels of 5, 10, 20, and 40 g/kg for 6 weeks. Results: The addition of SGYCs significantly increased the laying rate and nutrient digestibility, decreased feed conversion ratio, and enhanced the color of egg yolks (p<0.05). No changes were observed in activity levels of alanine aminotransferase and aspartate aminotransferase in the serum (p>0.05), but the activities of superoxide dismutase, glutathione peroxidase, and peroxidase all significantly increased, and contents of malondialdehyde were significantly reduced (p<0.05). In addition, changes in the relative abundance of Firmicutes and Bacteroidetes might be the main factor contributing to the significant increase in the apparent digestibility of crude protein and crude fat in laying hens (p<0.05). Conclusion: The current evidence shows that dietary supplementation of SGYCs to the feed of laying hens can improve laying rates, enhance antioxidative defenses, and influence dominant intestinal bacteria. Objective: Spent ginger is a byproduct of juice extraction from the rhizome of ginger (<i>Zingiber officinale</i>). Despite its nutritional value, it is difficult to preserve or further process and thus is often wasted. This study uses spent ginger as a substrate for fermentation and cultivates spent ginger yeast cultures (SGYCs) that are then added to the feed of laying hens. The effects of SGYCs on production performance, egg quality, serum composition, and intestinal microbiota of laying hens were investigated.Methods: Eighty 60-week-old Hy-Line Brown hens were separated into 5 experimental groups with 4 replicates per group (4 hens per cage, 4 cages per replicate). The control group was fed a basal diet while experimental groups were also given SGYCs at the levels of 5, 10, 20, and 40 g/kg for 6 weeks.Results: The addition of SGYCs significantly increased the laying rate and nutrient digestibility, decreased feed conversion ratio, and enhanced the color of egg yolks (p<0.05). No changes were observed in activity levels of alanine aminotransferase and aspartate aminotransferase in the serum (p>0.05), but the activities of superoxide dismutase, glutathione peroxidase, and peroxidase all significantly increased, and contents of malondialdehyde were significantly reduced (p<0.05). In addition, changes in the relative abundance of Firmicutes and Bacteroidetes might be the main factor contributing to the significant increase in the apparent digestibility of crude protein and crude fat in laying hens (p<0.05).Conclusion: The current evidence shows that dietary supplementation of SGYCs to the feed of laying hens can improve laying rates, enhance antioxidative defenses, and influence dominant intestinal bacteria.

Serviceability assessment of subway induced vibration of a frame structure using FEM

Yuhong Ling,Jingxin Gu,T.Y. Yang,Rui Liu,Yeming Huang 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.71 No.2

It is necessary to predict subway induced vibration if a new subway is to be built. To obtain the vibration responsereliably, a three-dimensional (3D) FEM model, consisting of the tunnel, the soil, the subway load and the building above, isestablished in MIDAS GTS NX. For this study, it is a six-story frame structure built above line 3 of Guangzhou metro. The entiremodeling process is described in detail, including the simplification of the carriage load and the determination of model parameters. Vibration measurements have been performed on the site of the building and the model is verified with the collected data. Thepredicted and measured vibration response are used together to assess vibration level due to the subway traffic in the building. TheNo.1 building can meet work and residence comfort requirement. This study demonstrates the applicability of the numerical traintunnel-soil-structure model for the serviceability assessment of subway induced vibration and aims to provide practical referencesfor engineering applications.