SoC balancing method for energy storage systems in DC microgrids using simplified droop control

Qi, Nan,Fang, Wei,Wang, Wei,Liu, Xiaodong,Liu, Sucheng The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.8

DC microgrids adopt energy storage units to maintain the dynamic power balance between distributed power systems and the load. For DC microgrids in small-scale applications including residential microgrids, to ensure the coordination of the state of charge (SoC) and load current sharing among each of the energy storage units, an improved SoC-balanced control method without interconnection communication is proposed in this paper. The proposed method applies an adaptive droop control expression with a specific SoC-function to regulate its reference voltage in both the charging and discharging processes of the energy storage units. Thus, the balance of the SoC and the load current is achieved autonomously. This method can reduce the bus voltage deviation and weaken the impact of the output current on the bus voltage variation, especially for low-voltage DC microgrids. Moreover, the sampling of the output current is avoided, and both the cost and complexity of controller design are significantly reduced. In addition, a function curves analysis method is proposed to analyze the speed of the SoC balancing and the DC bus voltage deviation, which gives instruction in the choice of the adjustment factor in the adaptive droop equation. A mathematical description of the operating process and a small signal model of the proposed method are established to evaluate the system feasibility and stability. A laboratory-scale DC microgrid is built to verify the proposed method. Finally, simulation and experimental results are presented.

Energy-efficient full-duplex UAV relaying networks: Trajectory design for channel-model-free scenarios

Qi, Nan,Wang, Wei,Ye, Diliao,Wang, Mei,Tsiftsis, Theodoros A.,Yao, Rugui Electronics and Telecommunications Research Instit 2021 ETRI Journal Vol.43 No.3

In this paper, we propose an energy-efficient unmanned aerial vehicle (UAV) relaying network. In this network, the channels between UAVs and ground transceivers are model-free. A UAV acting as a flying relay explores better channels to assist in efficient data delivery between two ground nodes. The full-duplex relaying mode is applied for potential energy efficiency (EE) improvements. With the genetic algorithm, we manage to optimize the UAV trajectory for any arbitrary radio map scenario. Numerical results demonstrate that compared to other schemes (eg, fixed trajectory/speed policies), the proposed algorithm performs better in terms of EE. Additionally, the impact of self-interference on average EE is also investigated.

이가원의 절구시(絶句詩)를 논함

순친안 ( Sun Qinan ) 연민학회 2016 연민학지 Vol.25 No.-

본고에서는 이가원의 絶句詩에 대해 집중적으로 분석하였다. 우선, 오언절구와 칠언절구의 소재와 내용에 대한 상세한 고찰을 진행하고, 아울러 분류 귀납하였다. 다음으로, 절구의 예술적 성취를 고찰하였다. 이가원의 칠언절구는 감정이 진솔하 고, 의미심장하며, 句法이 다변적이며, 오언절구는 시어는 짧으나 감성이 솔직하며, 때론 의론을 겸하고 있다. 마지막으로, 이가원 절구시의 예술적 원천의 형성 원인에 대해 분석하였다. This paper is to discuss the writings of quatrain of Li Jiayuan. It first focuses on the themes of Li`s quatrains with an effort to categorize them. Then the paper holds that li`s seven-character-quatrain features sincere emotions, deep implication and flexible syntactical structure, meanwhile Li`s five-character-quatrain boasts strait emotions and intellectual comments. Finally the paper reveals the artistic origin of Li`s quatrain writings.

Managing human capital for innovative activities in Indonesian herbal medicine firms

Erman Aminullah,Wati Hermawati,Trina Fizzanty,Qinan M. B. Soesanto 기술경영경제학회 2017 ASIAN JOURNAL OF TECHNOLOGY INNOVATION Vol.25 No.2

This paper attempts to explain human capital enhancement (HCE)practices in upgrading human skills, knowledge and ability,specifically (i) how firms’ internal upgrading mechanisms areimplemented and (ii) how firms enhance human capital throughinteractions with external parties. Through case studies ofIndonesian herbal medicine firms, this study reveals that HCE forinnovative activities in herbal medicine firms occurred throughinnovative learning – by using and interacting. Companies showlearning by using traditional herbal ingredients to redesigninnovative products; managing continuously internal learning byinteracting across functional teams to create new, innovativeproducts; and managing external learning by interacting withexternal parties in the search for new, innovative products. Theeffective use of internal and external sources of innovation iscoordinated by, respectively, top management direction inside thecompany without research and development (R&D); managers ofcross-functional teams within the company with in-house R&Dactivities; and top-level management meetings within thecompany with limited R&D activities.

Sparstolonin B suppresses lipopolysaccharide-induced inflammation in human umbilical vein endothelial cells

Qiaoli Liang,Fang Yu,Xiaodong Cui,Jin-ao Duan,Qinan Wu,Prakash Nagarkatti,Daping Fan 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.7

Sparstolonin B (SsnB) is an isocoumarin compoundisolated from the tubers of both Sparganium stoloniferumand Scirpus yagara. We previously demonstratedthat SsnB blocked the Toll-like receptor (TLR) 2- andTLR4-triggered inflammatory signaling in macrophages byinhibiting the recruitment of MyD88 to the TIR domains ofTLR2 and TLR4. The present study was designed toexamine the effects of SsnB on vascular inflammatoryresponses in human umbilical vein endothelial cells (HUVECs)challenged by lipopolysaccharide (LPS, a TLR4ligand). We found that SsnB dose-dependently attenuatedthe LPS-induced expression of interleukin (IL)-1b andmonocyte chemoattractant protein 1 both at the transcriptionand translation levels in HUVEC. LPS-inducedendothelial cell adhesion molecules, intercellular adhesionmolecular-1 and vascular cell adhesion molecule-1expressions were also reduced by treatment with SsnB. Inaddition, co-incubation with SsnB attenuated THP-1monocyte adhesion to LPS-activated HUVECs. Furthermore,SsnB efficiently suppressed LPS-induced phosphorylationof extracellular -signal-regulated kinase (Erk1/2)and Akt in HUVECs. These findings show that SsnB cansuppress endothelial cell inflammation, suggesting thatSsnB might be suitable for development as a therapeuticagent for inflammatory cardiovascular disease.

Comparison of Fecal Microbiota of Mongolian and Thoroughbred Horses by High-throughput Sequencing of the V4 Region of the 16S rRNA Gene

Zhao, Yiping,Li, Bei,Bai, Dongyi,Huang, Jinlong,Shiraigo, Wunierfu,Yang, Lihua,Zhao, Qinan,Ren, Xiujuan,Wu, Jing,Bao, Wuyundalai,Dugarjaviin, Manglai Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.9

The hindgut of horses is an anaerobic fermentative chamber for a complex and dynamic microbial population, which plays a critical role in health and energy requirements. Research on the gut microbiota of Mongolian horses has not been reported until now as far as we know. Mongolian horse is a major local breed in China. We performed high-throughput sequencing of the 16S rRNA genes V4 hypervariable regions from gut fecal material to characterize the gut microbiota of Mongolian horses and compare them to the microbiota in Thoroughbred horses. Fourteen Mongolian and 19 Thoroughbred horses were used in the study. A total of 593,678 sequence reads were obtained from 33 samples analyzed, which were found to belong to 16 phyla and 75 genera. The bacterial community compositions were similar for the two breeds. Firmicutes (56% in Mongolian horses and 53% in Thoroughbred horses) and Bacteroidetes (33% and 32% respectively) were the most abundant and predominant phyla followed by Spirochaete, Verrucomicrobia, Proteobacteria, and Fibrobacteres. Of these 16 phyla, five (Synergistetes, Planctomycetes, Proteobacteria, TM7, and Chloroflexi) were significantly different (p<0.05) between the two breeds. At the genus level, Treponema was the most abundant genus (43% in Mongolian horses vs 29% in Thoroughbred horses), followed by Ruminococcus, Roseburia, Pseudobutyrivibrio, and Anaeroplasma, which were detected in higher distribution proportion in Mongolian horses than in Thoroughbred horses. In contrast, Oscillibacter, Fibrobacter, Methanocorpusculum, and Succinivibrio levels were lower in Mongolian horses. Among 75 genera, 30 genera were significantly different (p<0.05) between the two breeds. We found that the environment was one of very important factors that influenced horse gut microbiota. These findings provide novel information about the gut microbiota of Mongolian horses and a foundation for future investigations of gut bacterial factors that may influence the development and progression of gastrointestinal disease in horses.