A New Approach to Distributed Control for Multi-agent Systems Based on Approximate Upper and Lower Bounds

Fangfang Zhang,Jinfeng Gao,Huanshui Zhang,Cheng Tan,Wei Wang 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.6

In this paper, the distributed control of the LQR problem for continuous-time multi-agent systems isconsidered. Based on the centralized optimal control, we prove that the solution of the algebraic Riccati equationis the maximal solution of the algebraic Riccati inequality. The algebraic relations of the solutions of the algebraicRiccati equations for different weighted matrices are shown and two distributed controllers are designed: the fullydistributed one and the interconnected distributed one. They can provide an upper bounds and a lower bounds ofthe centralized optimal cost function. The optimal closed-loop feedback control systems for the two distributedcontrollers are also asymptotically stable. Some examples are given to show the correctness of the proposed results.

Distributed Suboptimal Controller Synthesis for Multi-agent Systems

Fangfang Zhang,Wei Wang,Huan-Shui Zhang 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.3

In this paper, the distributed suboptimal LQR control problem for discrete-time multi-agent systems is considered. The distributed controllers that each subsystem can sense and/or exchange information with only a subset of its neighbors are designed, which are based on the topological structure of the system. Using the “averaged” optimization approach, the suboptimal feedback gain matrices are presented and the distributed suboptimal controllers are obtained. Under mild conditions, the asymptotical convergence of the modified Riccati equation is proved. Accordingly, the infinite-time distributed suboptimal controllers are presented. Examples are given to show the efficiency of the proposed results.

ROCK1 induces dopaminergic nerve cell apoptosis via the activation of Drp1-mediated aberrant mitochondrial fission in Parkinson’s disease

Qian Zhang,Changpeng Hu,Jingbin Huang,Wuyi Liu,Wenjing Lai,Faning Leng,Qin Tang,Yali Liu,Qing Wang,Min Zhou,Fangfang Sheng,Guobing Li,Rong Zhang 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Dopamine deficiency is mainly caused by apoptosis of dopaminergic nerve cells in the substantia nigra of themidbrain and the striatum and is an important pathologic basis of Parkinson’s disease (PD). Recent research has shownthat dynamin-related protein 1 (Drp1)-mediated aberrant mitochondrial fission plays a crucial role in dopaminergicnerve cell apoptosis. However, the upstream regulatory mechanism remains unclear. Our study showed that Drp1knockdown inhibited aberrant mitochondrial fission and apoptosis. Importantly, we found that ROCK1 was activated inan MPP+-induced PD cell model and that ROCK1 knockdown and the specific ROCK1 activation inhibitor Y-27632blocked Drp1-mediated aberrant mitochondrial fission and apoptosis of dopaminergic nerve cells by suppressing Drp1dephosphorylation/activation. Our in vivo study confirmed that Y-27632 significantly improved symptoms in a PDmouse model by inhibiting Drp1-mediated aberrant mitochondrial fission and apoptosis. Collectively, our findingssuggest an important molecular mechanism of PD pathogenesis involving ROCK1-regulated dopaminergic nerve cellapoptosis via the activation of Drp1-induced aberrant mitochondrial fission.

UWB Radar Imaging of Multiple Targets through Multi-Layer Walls

Huamei Zhang,Yerong Zhang,Fangfang Wang 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.8

In the practical application of Ultra Wideband (UWB) through-wall radar imaging, the walls that are generally encountered consist of multiple layers, and there may be multiple targets, which presents challenges for the imaging algorithm. In this study, both the back-projection (BP) algorithm, which is a time-domain algorithm, and the phase-shift migration (PSM) algorithm, which is a frequency-domain algorithm, are used to locate two targets behind a two-layer wall. The image quality, the azimuth and range resolutions, the image entropy and the processing time of the two algorithms are compared. The simulation results demonstrate that the BP algorithm produces better image quality and that the PSM algorithm is faster. The effect of the sampling interval on the image entropy and processing time is discussed. In addition, the feasibility and the validity of the two algorithms are tested under noisy conditions. The results show that the two algorithms are robust, regardless of the presence of noise.

Definitive extended field intensity-modulated radiotherapy and concurrent cisplatin chemosensitization in the treatment of IB2-IIIB cervical cancer

Guangyu Zhang,Fangfang He,Chunli Fu,Youzhong Zhang,Qiuan Yang,Jianbo Wang,Yufeng Cheng 대한부인종양학회 2014 Journal of Gynecologic Oncology Vol.25 No.1

Objective: To assess the toxicity of delivering extended field intensity-modulated radiotherapy (EF-IMRT) and concurrent cisplatin chemotherapy for locally advanced cervical carcinoma. Methods: Forty-five patients who underwent EF-IMRT and concurrent cisplatin chemotherapy for the treatment of stage IB2 to IIIB cervical cancer were retrospectively reviewed. The clinical target volume included all areas of gross and potentially microscopic disease and regional lymph node regions. All patients underwent high-dose-rate brachytherapy. The acute and late toxicity were scored using the Common Terminology Criteria for Adverse Events and the Radiation Therapy Oncology Group late radiation morbidity scoring criteria, respectively. Results: The median follow-up was 28 months (range, 5 to 62 months). Forty-two patients had a complete response, and three had a persistent disease. Of those 42 patients, 15 patients (35.7%) had recurrence. The regions of recurrence were in-field in 2 patients and out-field in 13 patients. Acute grade ≥3 gastrointestinal, genitourinary and hematologic toxicity occurred in 3, 1, and 9 patients, respectively. Three patients (6.7%) suffered from late grade 3 toxicities. Seven patients experienced ovarian transposition, 5 of those patients (71%) maintained ovarian function. Thirty-eight patients (84.4%) were alive at the last follow-up. Conclusion: Concurrent cisplatin chemotherapy with EF-IMRT was safe. The acute and late toxicities are acceptable. EF-IMRT provides an opportunity to preserve endocrine function for patients with ovarian transposition.

Porous WO₃ monolith-based photoanodes for high-efficient photoelectrochemical water splitting

Wang, Yina,Zhang, Fangfang,Zhao, Guoyan,Zhao, Yingao,Ren, Yangyang,Zhang, Huijun,Zhang, Linyu,Du, Jimin,Han, Yumin,Kang, Dae Joon Elsevier 2019 CERAMICS INTERNATIONAL Vol.45 No.6

<P><B>Abstract</B></P> <P>We report a successful fabrication of low-cost, high-efficient, structurally-rigid, porous WO<SUB>3</SUB> photoelectrochemical (PEC) catalysts using polystyrene as the template by a sol-gel method and a high-temperature annealing treatment. The scanning electron microscopy and Brunauer-Emmett-Teller surface analysis results indicate that such WO<SUB>3</SUB> monoliths possess a porous structure and a large specific surface area, which can supply lots of photogenerated charge transfer pathways as well as more surface PEC active sites. Compared with a commercially available WO<SUB>3</SUB>, our highly porous WO<SUB>3</SUB> PEC catalysts show an excellent PEC water splitting activity. Particularly, the porous WO<SUB>3</SUB> photoanodes calcinated in the presence of oxygen atmosphere at 450 °C for 7 h show the best PEC performance exhibiting the photocurrent density of 0.97 mA/cm<SUP>2</SUP> at 1.23 V versus reversible the hydrogen electrode and the incident photon-to-current conversion efficiency up to 48.9% at 420 nm in 0.5 M Na<SUB>2</SUB>SO<SUB>4</SUB> electrolyte under AM 1.5 G irradiation. Such excellent PEC performance is due to the high porosity of the WO<SUB>3</SUB>, promoting the fast transfer and the separation rate of photogenerated carriers during the PEC water splitting process.</P>

Antiviral effects of Bovine antimicrobial peptide against TGEV in vivo and in vitro

Xiuli Liang,Xiaojun Zhang,Kaiqi Lian,Xiuhua Tian,Mingliang Zhang,Shiqiong Wang,Cheng Chen,Cunxi Nie,Yun Pan,Fangfang Han,Zhanyong Wei,Wen-Ju Zhang 대한수의학회 2020 Journal of Veterinary Science Vol.21 No.5

Background: In suckling piglets, transmissible gastroenteritis virus (TGEV) causes lethal diarrhea accompanied by high infection and mortality rates, leading to considerable economic losses. This study explored methods of preventing or inhibiting their production. Bovine antimicrobial peptide-13 (APB-13) has antibacterial, antiviral, and immune functions. Objectives: This study analyzed the efficacy of APB-13 against TGEV through in vivo and in vitro experiments. Methods: The effects of APB-13 toxicity and virus inhibition rate on swine testicular (ST) cells were detected using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT). The impact of APB-13 on virus replication was examined through the 50% tissue culture infective dose (TCID50). The mRNA and protein levels were investigated by real-time quantitative polymerase chain reaction and western blot (WB). Tissue sections were used to detect intestinal morphological development. Results: The safe and effective concentration range of APB-13 on ST cells ranged from 0 to 62.5 μg/mL, and the highest viral inhibitory rate of APB-13 was 74.1%. The log10TCID50 of 62.5 μg/mL APB-13 was 3.63 lower than that of the virus control. The mRNA and protein expression at 62.5 μg/mL APB-13 was significantly lower than that of the virus control at 24 hpi. Piglets in the APB-13 group showed significantly lower viral shedding than that in the virus control group, and the pathological tissue sections of the jejunum morphology revealed significant differences between the groups. Conclusions: APB-13 exhibited good antiviral effects on TGEV in vivo and in vitro.

Histone demethylase KDM4A plays an oncogenic role in nasopharyngeal carcinoma by promoting cell migration and invasion

Zhao Jingyi,Li Bingyan,Ren Yongxia,Liang Tiansong,Wang Juan,Zhai Suna,Zhang Xiqian,Zhou Pengcheng,Zhang Xiangxian,Pan Yuanyuan,Gao Fangfang,Zhang Sulan,Li Liming,Yang Yongqiang,Deng Xiaoyu,Li Xiaole,C 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

Compelling evidence has indicated the vital role of lysine-specific demethylase 4 A (KDM4A), hypoxia-inducible factor-1α (HIF1α) and the mechanistic target of rapamycin (mTOR) signaling pathway in nasopharyngeal carcinoma (NPC). Therefore, we aimed to investigate whether KDM4A affects NPC progression by regulating the HIF1α/DDIT4/mTOR signaling pathway. First, NPC and adjacent tissue samples were collected, and KDM4A protein expression was examined by immunohistochemistry. Then, the interactions among KDM4A, HIF1α and DDIT4 were assessed. Gain- and loss-of-function approaches were used to alter KDM4A, HIF1α and DDIT4 expression in NPC cells. The mechanism of KDM4A in NPC was evaluated both in vivo and in vitro via RT-qPCR, Western blot analysis, MTT assay, Transwell assay, flow cytometry and tumor formation experiments. KDM4A, HIF1α, and DDIT4 were highly expressed in NPC tissues and cells. Mechanistically, KDM4A inhibited the enrichment of histone H3 lysine 9 trimethylation (H3K9me3) in the HIF1α promoter region and thus inhibited the methylation of HIF1α to promote HIF1α expression, thus upregulating DDIT4 and activating the mTOR signaling pathway. Overexpression of KDM4A, HIF1α, or DDIT4 or activation of the mTOR signaling pathway promoted SUNE1 cell proliferation, migration, and invasion but inhibited apoptosis. KDM4A silencing blocked the mTOR signaling pathway by inhibiting the HIF1α/DDIT4 axis to inhibit the growth of SUNE1 cells in vivo. Collectively, KDM4A silencing could inhibit NPC progression by blocking the activation of the HIF1α/DDIT4/mTOR signaling pathway by increasing H3K9me3, highlighting a promising therapeutic target for NPC.

ZnO/TiO2 core–shell heterojunction for CdS and PbS quantum dot-cosensitized solar cells

Fangfang Gao,Qian Chen,Xiaoshan Zhang,Huan Wang,Tianjiao Huang,Liya Zhou 한국물리학회 2018 Current Applied Physics Vol.18 No.5

ZnO nanorods (NRs) with regular morphology were prepared through hydrothermal method, and the TiO2 shell was assembled onto the surface of ZnO NRs by spin coating to the ZnO/TiO2 core–shell heterojunction. CdS and PbS quantum dots (QDs) were used to cosensitize the ZnO/TiO2 nanostructure by direct adsorption (DA) and successive ionic layer adsorption and reaction, respectively. SEM, TEM, and HRTEM images show that the samples possessed a rough surface and four lattice fringes indicating the successful synthesis of the ZnO/TiO2/ CdS/PbS composite structure. The ZnO/TiO2(10T)/CdS/PbS sample showed a high absorption intensity at a broad range of wavelength to visible light region. The ZnO/TiO2(10T)/CdS/PbS photoelectrode with QDSSCs showed the highest IPCE of 36.04% and photoelectric efficiency (η) of 1.59%; these values increased by approximately 550% and 150% compared with those of unsensitized ZnO (0.29%) and ZnO/TiO2(10T) (1.04%) and about 146% and 120% compared with those of ZnO/TiO2(10T)/CdS and ZnO/TiO2(10T)/PbS, respectively. The fill factor was 0.36, and the photocurrent density (Jsc) and open circuit voltage (Voc) reached the maximum values of 9.73 mA cm−2 and 0.46 V, respectively.

A Study on Group Buying of O2O Mode using Generalized Stochastic Petri Nets

Fangfang Hou,Shuyun Zhang,Yue Wang 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.3

This paper proposes a Group Buying model (paid in advance) of online-to-offline mode using Generalized Stochastic Petri Nets. As the time cost of consumers is getting higher and higher, time efficiency is getting much more important in all aspects of life, especially in catering industry, and one way that can lead to direct communication between store owners and consumers is Group Buying of online-to-offline mode, the center of which is the brand building and service efficiency. Although researches based on both users’ and sellers’ perspective about online buying are very rich, these findings are not entirely applicable for this new e-commerce model, and most of current research on online-to-offline mode use qualitative methods. More importantly, few researchers have concerned about the efficiency of Group Buying process and come up with related solutions to improve it. By constructing a business model of GB and conducting time efficiency and performance analysis on it, we find that the key transitions of the system only take up less than half of the time before the whole process has been completed. And when we shorten the feedback process, the percentage of finishing consumption in physical store in the whole Group Buying model can be improved by 14.5%. Thus, we suggest that suppliers and sellers should be more focused and efficient in encouraging customers review timely as well as giving consumers feedback as soon as possible, since consumer comments are proved to be significantly important for the retailers. Besides, site operators and store sellers can also use other ways like WeChat and microblogging to promote their site linkages and gain more market share.