An Anti-Overvoltage Strategy for Electrolytic Capacitorless IPMSM Drives Using Power Controller

Dawei Ding,Haiming Hu,Gaolin Wang,Guoqiang Zhang,Dianguo Xu,Frede Blaabjerg 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Three-phase input diode rectifier interior permanent magnet synchronous motor (IPMSM) drives with small-volume film capacitors have many merits, such as high reliability, low cost and high power density. However, in regenerative braking, the DC-link voltage becomes harder to be controlled than the traditional topology due to the application of slim film capacitors. In this paper, an anti-overvoltage strategy is proposed by controlling the electrical power of the motor directly. The q-axis current boundary is determined by the proposed power controller. Compared with the conventional method of voltage controller, the proposed method is more suitable for electrolytic capacitorless drives.

대형구조물의 구조해석 정밀도 향상을 위한 용접부 모델링 기법

다웨이진(Dawei Jin),박상후(Sang Hu Park) 대한기계학회 2012 大韓機械學會論文集A Vol.36 No.10

용접은 대형구조물을 제작할 때 영구적 접합을 위해서 많이 사용하는 공정이다. 용접부는 용융부, 부분용융부, 열영향부로 나누어지며 각각의 영역들은 다른 재료물성을 가지게 된다. 또한 용접부는 용접비드 형상에 따라 기계적 신뢰성이 많이 차이 난다. 따라서 정밀한 구조해석을 수행하기 위해서는 이러한 국부적인 용접부의 특성을 잘 고려해야 한다. 본 연구에서는 이러한 용접부의 효과적인 모델링 방법에 대하여 제안하고자 한다. 특히 하중을 받는 구조물에 잘 일어나는 세 가지 변형모드(인장모드, 굽힘모드, T-굽힘모드)에 대하여 용접부를 정밀하게 모델링하는 방법을 제안하였다. 대형구조물의 구조해석을 통하여 제안된 모델링 방법이 변형, 응력분포 등을 좀 더 정밀하게 묘사해 줌을 해석적으로 확인하였다. Welding is a well-developed, widely used process for permanently joining metal components. However, the mechanical reliability of welded parts still offers room for improvement. A weld region consists of a fusion zone, a partially melted zone, and a heat-affected zone, and each zone has different material properties. In addition, the geometrical shape of a weld bead or fillet influences the mechanical reliability. A precise structural analysis must consider how a local welded region influences the mechanical behavior of the entire structure. This study focuses on an effective modeling scheme for the weld region. It relies on experimental and numerical methods to determine the proper correlation based on experimental results and to propose a modeling scheme for welded parts.

Preparation and Investigation of Ulex Europaeus Agglutinin IConjugated Liposomes as Potential Oral Vaccine Carriers

KeXin Li,DaWei Chen,XiuLi Zhao,HaiYang Hu,ChunRong Yang,DaHai Pang 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.11

We prepared and optimized Ulex europaeus agglutinin I (UEAI)-modified Bovine serum albumin (BSA)-encapsulating liposomes (UEAI-LIP) as oral vaccine carriers and examined the feasibility of inducing systemic and mucosal immune responses by oral administration of UEAILIP. The prepared systems were characterized in vitro for their average size, zeta potential,encapsulation efficiency (EE%) and conjugation efficiency (CE%). In vitro release studies indicated that the presence of UEAI around the optimized liposomes was able to prevent a burst release of loaded BSA and provide sustained release of the encapsulated protein. In vivo immune-stimulating results in KM mice showed that BSA given intramuscularly generated systemic response only but both systemic and mucosal immune responses could be induced simultaneously in the groups in which BSA-loaded liposomes (LIP) and UEAI-LIP were administered intragastrically. Furthermore, the modification of UEAI on the surface of liposomes could further enhance the IgA and IgG levels obviously. In conclusion, this study demonstrated the high potential of lectin-modified liposomes containing the antigen as carriers for oral vaccine.

The Two Echelon Open Vehicle Routing Problem: Optimization of Crowdshipping Based Parcel Delivery

Xue Wu,Dawei Hu,Bingshan Ma,Ruisen Jiang 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.9

Crowdshipping is a revolutionary concept of the sharing economy. In this study, two carriers are used to perform the following expedition: the truck starts from the depot to complete part of the deliveries, shares part of the load with the crowdshipper at the relay point, and the private driver selected as the crowdshipper continues from that point onward. This study proposes the two-echelon open vehicle routing problem with crowdshipping (2EOVRP-CS) and formulates a mathematical model to determine the crowdshipper, parcel relay location, truck route, and crowdsource route. A tangible nested genetic algorithm (NGA) is proposed, and its efficiency is demonstrated by comparison with CPLEX and genetic algorithm (GA). A real case study is investigated in Xi'an city to test the applicability of the proposed model. The results show that using crowdshipping instead of truck delivery alone can save approximately 14% of the total cost and 26% of truck vehicle miles traveled (VMT). Moreover, several sensitivity analyses are performed. The results show that crowdshipping is sensitive to the detour limit and the time value of carriers. For the detour limit, after the acceptable detour distance increases by 8%, the total cost can be reduced by up to 5.94%.

A study of deterioration of reinforced concrete beams under various forms of simulated acid rain attack in the laboratory

Fan, Yingfang,Hu, Zhiqiang,Luan, Haiyang,Wang, Dawei,Chen, An Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.1

This paper studies the behaviour of deteriorated reinforced concrete (RC) beams attacked by various forms of simulated acid rain. An artificial rainfall simulator was firstly designed and evaluated. Eleven RC beams ($120mm{\times}200mm{\times}1800mm$) were then constructed in the laboratory. Among them, one was acting as a reference beam and the others were subjected to three accelerated corrosion methods, including immersion, wetting-drying, and artificial rainfall methods, to simulate the attack of real acid rain. Acid solutions with pH levels of 1.5 and 2.5 were considered. Next, ultrasonic, scanning electron microscopy (SEM), dynamic, and three-point bending tests were performed to investigate the mechanical properties of concrete and flexural behaviour of the RC beams. It can be concluded that the designed artificial simulator can be effectively used to simulate the real acid rainfall. Both the immersion and wetting-drying methods magnify the effects of the real acid rainfall on the RC beams.

Application of unascertained measurement to the performance evaluation of enterprise managers

Wang Baosen,Hu Dawei 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

Management performance of enterprise uncertain and complicated, with is affected by many factors, so management performance of enterprise could not be evaluated correctly with any single factor, Based on the analysis of the influencing factors of the analysis of the influencing factors of the performance evaluation of enterprise managers, this establishes a comprehensive evaluation model of multi-level unascertained measurement to evaluate the performance of enterprise managers. In the evaluating process, for the second-rate indicators we use information entropy to determine their weights, and for the first-rate indicators we use the Analytic Hierarchy Process to determine their weights, realizing the combination of quantitative and qualitative analysis, achieving the unascertained comprehensive evaluation results of performance of enterprise managers. Then we take an example to analyze and explain the model. This provides a scientific basis and theory for evaluating correctly the performance of enterprise managers and establishing effective incentive-mechanism.

The Location Routing Problem of the Car-Sharing System with Autonomous Electric Vehicles

Bingshan Ma,Dawei Hu,Xue Wu 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.8

Car-sharing, electrification, and autonomous driving are greatly revolutionizing the future of the transportation system. This study proposes a location routing problem for the car-sharing system with autonomous electric vehicles to determine optimal station location and vehicle routing, where each station is both a depot and a charging station. A mathematical model is formulated and then extended to three variants, while simultaneously considering different recharging and service options. The proposed mixed-integer nonlinear models are separately solved by general algebraic modeling system (GAMS) and genetic algorithm (GA), and the efficiency of the GA is demonstrated. The comparative experimental results of instances are presented, and the benefits of allowing partial recharge are obtained. More significant savings in cost can be achieved if partial service is simultaneously allowed. Furthermore, the trade-off between the operator’s interests and the interests of users, as well as the operator’s immediate profits and future profits, are explored through sensitivity analysis.

A study of deterioration of reinforced concrete beams under various forms of simulated acid rain attack in the laboratory

Yingfang Fan,Zhiqiang Hu,Haiyang Luan,Dawei Wang,An Chen 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.1

This paper studies the behaviour of deteriorated reinforced concrete (RC) beams attacked by various forms of simulated acid rain. An artificial rainfall simulator was firstly designed and evaluated. Eleven RC beams (120 mm×200 mm×1800 mm) were then constructed in the laboratory. Among them, one was acting as a reference beam and the others were subjected to three accelerated corrosion methods, including immersion, wetting-drying, and artificial rainfall methods, to simulate the attack of real acid rain. Acid solutions with pH levels of 1.5 and 2.5 were considered. Next, ultrasonic, scanning electron microscopy (SEM), dynamic, and three-point bending tests were performed to investigate the mechanical properties of concrete and flexural behaviour of the RC beams. It can be concluded that the designed artificial simulator can be effectively used to simulate the real acid rainfall. Both the immersion and wetting-drying methods magnify the effects of the real acid rainfall on the RC beams.

A Ghost-Imaging System Based on a Microfluidic Chip

Kaimin Wang,Xiaoxuan Han,Hualong Ye,Zhaorui Wang,Leihong Zhang,Jiafeng Hu,Meiyong Xu,Xiangjun Xin,Dawei Zhang 한국광학회 2021 Current Optics and Photonics Vol.5 No.2

Microfluidic chip technology is a research focus in biology, chemistry, and medicine, for example. However, microfluidic chips are rarely applied in imaging, especially in ghost imaging. Thus in this work we propose a ghost-imaging system, in which we deploy a novel microfluidic chip modulator (MCM) constructed of double-layer zigzag micro pipelines. While in traditional situations a spatial light modulator (SLM) and supporting computers are required, we can get rid of active modulation devices and computers with this proposed scheme. The corresponding simulation analysis verifies good feasibility of the scheme, which can ensure the quality of data transmission and achieve convenient, fast ghost imaging passively.

Targeted Editing of Myostatin Gene in Sheep by Transcription Activator-like Effector Nucleases

Zhao, Xinxia,Ni, Wei,Chen, Chuangfu,Sai, Wujiafu,Qiao, Jun,Sheng, Jingliang,Zhang, Hui,Li, Guozhong,Wang, Dawei,Hu, Shengwei Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.3

Myostatin (MSTN) is a secreted growth factor expressed in skeletal muscle and adipose tissue that negatively regulates skeletal muscle mass. Gene knockout of MSTN can result in increasing muscle mass in sheep. The objectives were to investigate whether myostatin gene can be edited in sheep by transcription activator-like effector nucleases (TALENs) in tandem with single-stranded DNA oligonucleotides (ssODNs). We designed a pair of TALENs to target a highly conserved sequence in the coding region of the sheep MSTN gene. The activity of the TALENs was verified by using luciferase single-strand annealing reporter assay in HEK 293T cell line. Co-transfection of TALENs and ssODNs oligonucleotides induced precise gene editing of myostatin gene in sheep primary fibroblasts. MSTN gene-edited cells were successfully used as nuclear donors for generating cloned embryos. TALENs combined with ssDNA oligonucleotides provide a useful approach for precise gene modification in livestock animals.