Recent Progress in Tungsten Oxides based Memristors and their Neuromorphological Applications

Bo Qu,Adnan Younis,Dewei Chu 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.6

The advance in conventional silicon based semiconductor industry is nowbecoming indeterminacy as it still along the road of Moore’s Law and concomitantproblems associated with it are the emergence of a number of practical issues suchas short channel effect. In terms of memory applications, it is generally believedthat transistors based memory devices will approach to their scaling limits up to2018. Therefore, one of the most prominent challenges today in semiconductorindustry is the need of a new memory technology which is able to combine the bestcharacterises of current devices. The resistive switching memories which areregarded as “memristors” thus gain great attentions thanks to their specificnonlinear electrical properties. More importantly, their behaviour resembles withthe transmission characteristic of synapse in biology. Therefore, the research ofsynapses biomimetic devices based on memristor will certainly bring a greatresearch prospect in studying synapse emulation as well as building artificialneural networks. Tungsten oxides (WOx) exhibits many essential characteristics asa great candidate for memristive devices including: accredited endurance (over 105cycles), stoichiometric flexibility, complimentary metal-oxide-semiconductor(CMOS) process compatibility and configurable properties including non-volatilerectification, memorization and learning functions. Herein, recent progress onTungsten oxide based materials and its associating memory devices had beenreviewed. The possible implementation of this material as a bio-inspired artificialsynapse is also highlighted. The penultimate section summaries the currentresearch progress for tungsten oxide based biological synapses and end up withseveral proposals that have been suggested for possible future developments.

Control Strategies for a High-Performance 2x27 MVA Machine Test Bench with Multilevel IGCT Converters

Bo Qu,Jingkui Shi,Hongwu She,Jie Shen,Stefan Schroeder,Zhuohui Tan,Kunlun Chen,Jianmei Zhang,Yulong Li,Fan Zhang,Richard Zhang 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

In this paper, control strategies of a 22 MW / 27 MVA machine test bench using pumpback topology are introduced. The current loop design at extremely low pulse ratios (e.g. 600 Hz carrier frequency / 80 Hz load frequency) is developed. The system stability and dynamic response are analyzed. The challenges for high-power machine control with a sine filter and a transformer connected between the voltage-source-inverter and the machine are listed and solutions are given. Afterwards, some specific test modes are introduced as well. Finally, the control strategy is validated with the motor test at the customer site.

Development of Characteristics Measurement System for the Micro-Wall of Flexible Joints

Da Qu,Fei Ding,Jia-Dai Xue,Bo Wang 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.11

Characteristics of the micro-wall of flexible joints seriously impact the performance of gyro. Hence, measurements of these characteristics become very important. The present study carries out a system to measure the characteristics, including the stiffness and thickness, of the micro-wall of flexible joints. The force sensor deemed as a core component is mainly expounded in the paper. It is developed based on the principle of resistance strain gauge and good performance is shown on measuring the stiffness and the thickness. The measurement accuracy is calculated though repeated experiments and measurement theory and results are elaborated. The measurement results help to reveal the rule of structural design so as to enhance the performance of gyro. Finally, some improvements of this measurement system are proposed for further applications.

최적화된 신경망 기반 무선 센서 노드위치 알고리즘 제안

관보(Bo Guan),쥐훙샹(Hongxiang Qu),양펑지옌(Fengjian Yang),리홍량(Hongliang Li),정양권(Yang-Kwon Jeong) 한국전자통신학회 2022 한국전자통신학회 논문지 Vol.17 No.6

본 연구는 RSSI의 거리측정 방법이 외부 환경에 의해 쉽게 영향을 받아 위치 오차가 크다는 결점을 도출하였고 이 3차원 배치 환경에서 RSSI의 거리측정 노드에서 측정한 거리값을 최적화하는 문제에 대해 향상된 CA-PSO 알고리즘을 개선한 CA-PSO-BP 알고리즘을 제안하였다. 제안된 알고리즘은 3차원 무선센서네트워크(WSN) 공간에서 인식할 수 없는 노드를 설정할 수 있도록 하였다. 또한, CA-PSO를 BP 신경망에 응용하므로, 학습을 통해 BP 네트워크의 학습시간 단축과 알고리즘의 수렴 속도를 제고 할 수 있었다. 본 연구에서 제안한 알고리즘을 통해 네트워크의 위치의 정밀도를 현저(15%)하게 높일 수 있다는 것을 증명하였고 유의미한 결과를 얻을 수 있었다. This study leads to the shortcoming that the RSSI distance measurement method is easily affected by the external environment and the position error is large, leading to the problem of optimizing the distance values measured by the RSSI distance measurement nodes in this three-dimensional configuration environment. We proposed the CA-PSO-BP algorithm, which is an improved version of the CA-PSO algorithm. The proposed algorithm allows setting unknown nodes in WSN 3D space. In addition, since CA-PSO was applied to the BP neural network, it was possible to shorten the learning time of the BP network and improve the convergence speed of the algorithm through learning.Through the algorithm proposed in this study, it was proved that the precision of the network location can be increased significantly (15%), and significant results were obtained.

Effects of Selenium, Copper and Magnesium on Antioxidant Enzymes and Lipid Peroxidation in Bovine Fluorosis

Han, Bo,Yoon, Soonseek,Su, Jingliang,Han, H.R.,Wang, Mei,Qu, Weijie,Zhong, Daibin Asian Australasian Association of Animal Productio 2004 Animal Bioscience Vol.17 No.12

The antioxidant enzymes, lipid peroxidation and free radicals assessment were made of the effects of selenium, copper and magnesium on bovine endemic fluorosis under high fluoride, low selenium and low copper productive conditions. Thirty-two beef cattle were selected from high fluoride area, and randomly divided into four groups with eight cattle each as follows: (1) high fluoride control group (HFC); (2) supplemented group with 0.25 mg/kg selenium (HFSe); (3) supplemented group with 15 mg/kg copper (HFCu) and (4) supplemented group with 0.25 mg/kg selenium+15 mg/kg copper+1 mg/kg magnesium (HFSeCuMg) per day for 83 days. Moreover, eight beef cattle were selected from non-high fluoride area as normal control group. Blood samples were collected from cattle on 0 d, 30 d and 83 d respectively, to analyze the enzyme activities and concentration of GSH-px, CAT, SOD, MDA and free radicals. The results showed that the contents of free radicals and MDA in HFC group were significantly higher, and the whole blood GSH-px, CAT, erythrocyte SOD activities were lower than the normal control group. Free radicals, metabolic imbalance and antioxidant disorder therefore, play an important role in fluorosis. However, GSH-px, CAT and SOD activities in HFSe group and HFSeCuMg group at 30 d and 83 d were markedly higher than the same groups at the 0 d and the HFC group at the same time. Likewise, there was a corresponding reduction in the contents of free radicals and MDA. These findings indicated that supplementation with selenium, copper and magnesium elevated high fluoride bovine antioxidant enzymes, and decreased MDA and free radicals contents. But, the activities of supplementation selenium group did not increase until day 83. These results demonstrated that fluorosis was associated with lower serum Se and Cu levels than in the control, and it was therefore concluded that fluorosis is associated with decreased serum levels of these minerals. Long-term high fluoride intake under productive condition enhances oxidative stress in the blood, thereby disturbing the antioxidant defense of cattle. Increased oxidative stress could be one of the mediating factors in the pathogenesis of toxic manifestations of fluoride. It is benefical for high fluoride cattle supplemented with proper selenium, copper and magnesium to increase fluoride excretion and obtain the protective impact of the activity of oxidative enzymes, and to decrease lipid peroxidation and free radicals contents.

Effect of Low Ambient Temperature on the Concentration of Free Radicals Related to Ascites in Broiler Chickens

Han, Bo,Yoon, Soon-Seek,Han, Hong-Ryul,Qu, Wei-jie,Nigussie, Fikru Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.8

A flock of Arbor Acres chickens were reared in cages and provided with high energy pelleted feed. At 14 d of age, a total of 350 birds were separated into 3 groups randomly as follows: 100 birds were exposed to ambient temperature of 20$^{\circ}C$ as a control group, 150 birds were exposed to lower ambient temperature of 11$^{\circ}C$ to induce ascites (group I), and another group of 100 birds were exposed to lower ambient temperature of 11$^{\circ}C$ and fed diet containing 1% L-arginine for ascitic prophylactic treatment (group II). Blood and tissue samples (lung and liver) were collected from chickens at 3, 4, 5, 6 and 7 wk of age subsequently, to analyze the concentration and activities of free radicals, mononaldehyde (MDA), superoxide dismutase (SOD), Nitric Oxide (NO) and Nitric oxide synthase (NOS). The results showed that the prevalence of ascites in the control, group I and group II was 3%, 9.33% and 3% respectively (p<0.01). The concentration of free radicals in the lungs of 3 wks old preascitic broilers in group I was significantly higher than in the corresponding control group (p<0.05). The concentrations of free radicals in lung and liver in the 7 wk period, and that of NO and SOD in the plasma were significantly lower in group I than in the control group (p<0.01). However, the accumulated MDA contents in group I were higher than in the control group and group II (p<0.05), respectively. In the same way, the activity of NOS in group II was higher than both group I and control group (p<0.01) during the 7 wk period. There was no significant difference between SOD activities of group II and the control group (p>0.05), and also insignificant difference between NOS in group I and the control group (p>0.05). The results of this study indicate that there was a significant decrease in the concentration of MDA in group II. On the other hand, the concentration of free radicals decreased and MDA concentration increased in group I during the 7 wk period. The reduction in concentration of MDA in group II, following arginine supplementation may be associated with the scavenging activity of NO.

Enhanced proton conductivity of sulfonated poly(ether ether ketone) membranes at elevated temperature by incorporating (3-aminopropyl)triethoxysilane-grafted graphene oxide

Shuguo Qu,Chenchen Zhang,Minhui Li,Yan Zhang,Lunbo Chen,Yushuai Yang,Bo Kang,Yiwei Wang,Jihai Duan,Weiwen Wang 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.12

Making inexpensive proton exchange membrane with high proton conductivity for the proton exchange membrane fuel cell (PEMFC) is still a challenging problem. Graphene oxide (GO) nanoparticles grafted with (3-aminopropyl) triethoxy silane (APTES) were prepared and then incorporated into sulfonated poly(ether ether ketone) (SPEEK) matrix by solution casting to make the composite proton exchange membrane. The obtained nanoparticles and composite membranes were characterized by XRD, FT-IR, Raman, TGA, SEM, and UTM. GO treated with the silane coupling agent improved the dispersion stability and compatibility of GO in SPEEK, which decreased the agglomeration of GO nanoparticles in the SPEEK membrane. The prepared nanocomposite membranes exhibited better water retention properties and proton conductivity. The proton conductivity of the SPEEK membrane with 2wt% amine functionalized GO (AGO) reached 11.32mS/cm at 120oC, which was 2.45-times higher than that of the pristine SPEEK membrane. The reason was that AGO nanoparticles disperse uniformly in the SPEEK membranes, which provides new channels for proton transfer. The potential application of this composite membrane in the PEMFC was indicated.

Peroxisome Proliferator-Activated Receptor α Facilitates Osteogenic Differentiation in MC3T3-E1 Cells via the Sirtuin 1-Dependent Signaling Pathway

Kai Gong,Bo Qu,Cairu Wang,Jingsong Zhou,Dongfa Liao,Wei Zheng,Xianming Pan 한국분자세포생물학회 2017 Molecules and cells Vol.40 No.6

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease characterized by lack of insulin and high glucose levels. T2DM can cause bone loss and fracture, thus leading to diabetic osteoporosis. Promoting osteogenic differentiation of osteoblasts may effectively treat diabetic osteoporosis. We previously reported that Sirtuin 1 (Sirt1), a NAD+-dependent deacetylase, promotes osteogenic differentiation through downregulation of peroxisome proliferator-activated receptor (PPAR) γ. We also found that miR-132 regulates osteogenic differentiation by downregulating Sirt1 in a PPAR /δ-dependent manner. The ligand-activated transcription factor, PPAR , is another isotype of the peroxisome proliferator-activated receptor family that helps maintain bone homeostasis and promot bone formation. Whether the regulatory role of PPAR in osteogenic differentiation is mediated via Sirt1 remains unclear. In the present study, we aimed to de-termine this role and the underlying mechanism by using high glucose (HG) and free fatty acids (FFA) to mimic T2DM in MC3T3-E1 cells. The results showed that HG-FFA significantly inhibited expression of PPAR , Sirt1 and osteogenic differentiation, but these effects were markedly reversed by PPAR overexpression. Moreover, siSirt1 attenuated the positive effects of PPAR on osteogenic differentiation, suggesting that PPAR promotes osteogenic differentiation in a Sirt1-dependent manner. Luciferase activity assay confirmed interactions between PPAR and Sirt1. These findings indicate that PPAR promotes osteogenic differentiation via the Sirt1-dependent signaling pathway.

Paper Defects Recognition Based on Deformable Convolution

Yun-hui Qu,Wei Tang,Bo Feng 한국펄프·종이공학회 2022 펄프.종이기술 Vol.54 No.2

Paper Defects Classification Based on VGG16 and Transfer Learning

Yun-hui Qu,Wei Tang,Bo Feng 한국펄프·종이공학회 2021 펄프.종이기술 Vol.53 No.2