Asymmetrical SPWM‑based control scheme for BESS‑integrated UPQC with hybrid connected configuration

Zhenqiang Zhang,Jianjun Zhao,Shen Liu,Hongbo Wang,Nan Wang,Peng Zhang,Yue Yu,Peng Xu 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.10

The unified power quality conditioner (UPQC) integrated with the battery energy storage system not only mitigates the power quality problems on the grid side and load side but also supplies active power to the load or the grid. The wide voltage variation of the battery and the high efficiency of the whole system can be achieved with the hybrid connected configuration, i.e., the battery is connected simultaneously to the series and shunt converters of the UPQC directly and indirectly through the dc–dc converter. However, the control and modulation strategies are the major challenges for this configuration. This study proposes a control scheme based on asymmetrical sinusoidal pulse width modulation (SPWM) to realize high-efficiency active power delivery, thereby addressing the issue above. The mechanism of the modulation scheme to regulate active power is revealed, and the voltage variation of the battery is considered. The modified SPWM strategy features easy implementation and a low computation burden. The effectiveness of the system with the proposed control and modulation schemes is verified by both simulation and experimental results.

Attention and Working Memory Task-Load Dependent Activation Increase with Deactivation Decrease after Caffeine Ingestion

Peng, Wei,Zhang, Jian,Chang, Da,Shen, Zhuo-Wen,Shang, Yuanqi,Song, Donghui,Ge, Qiu,Weng, Xuchu,Wang, Ze Korean Society of Magnetic Resonance in Medicine 2017 Investigative Magnetic Resonance Imaging Vol.21 No.4

Purpose: Caffeine is the most widely consumed psychostimulant. It is often adopted as a tool to modulate brain activations in fMRI studies. However, its pharmaceutical effect on task-induced deactivation has not been fully examined in fMRI. Therefore, the purpose of this study was to examine the effect of caffeine on both activation and deactivation under sustained attention. Materials and Methods: Task fMRI was acquired from 26 caffeine naive healthy volunteers before and after taking caffeine pill (200 mg). Results: Statistical analysis showed an increase in cognition-load dependent task activation but a decrease in load dependent de-activation after caffeine ingestion. Increase of attention and memory task activation and its load-dependence suggest a beneficial effect of caffeine on the brain even though it has no overt behavior improvement. The reduction of deactivation by caffeine and its load-dependence indicate reduced facilitation from task-negative networks. Conclusion: Caffeine affects brain activity in a load-dependent manner accompanied by a disassociation between task-positive network and task-negative network.

LES of wind environments in urban residential areas based on an inflow turbulence generating approach

Shen, Lian,Han, Yan,Cai, C.S.,Dong, Guochao,Zhang, Jianren,Hu, Peng Techno-Press 2017 Wind and Structures, An International Journal (WAS Vol.24 No.1

Wind environment in urban residential areas is an important index to consider when evaluating the living environment. However, due to the complexity of the flow field in residential areas, it is difficult to specify the correct inflow boundary conditions in the large eddy simulation (LES). In this paper, the weighted amplitude wave superposition (WAWS) is adopted to simulate the fluctuating velocity data, which satisfies the desired target wind field. The fluctuating velocity data are given to the inlet boundary of the LES by developing an UDF script, which is implemented into the FLUENT. Then, two numerical models - the empty numerical wind tunnel model and the numerical wind tunnel model with spires and roughness elements are established based on the wind tunnel experiment to verify the present method. Finally, the turbulence generation approach presented in this paper is used to carry out a numerical simulation on the wind environment in an urban residential area in Lisbon. The computational results are compared with the wind tunnel experimental data, showing that the numerical results in the LES have a good agreement with the experimental results, and the simulated flow field with the inlet fluctuations can generate a reasonable turbulent wind field. It also shows that strong wind velocities and turbulent kinetic energy occur at the passageways, which may affect the comfort of people in the residential neighborhood, and the small wind velocities and vortexes appear at the leeward corners of buildings, which may affect the spreading of the pollutants.

Hepatic Resection Provides Survival Benefit for Selected Intermediate-Stage (BCLC-B) Hepatocellular Carcinoma Patients

Zhang Zhaohui,Shen Shunli,Chen Bin,Li Shaoqiang,Hua Yunpeng,Kuang Ming,Liang Lijian,Peng Bao Gang 대한암학회 2019 Cancer Research and Treatment Vol.51 No.1

Purpose The intermediate stage of hepatocellular carcinoma (HCC) (Barcelona Clinic Liver Cancer [BCLC] B) comprises a highly heterogeneous population, and the treatment strategy is still controversial. Because of the heterogeneity, a subclassification of intermediate-stage HCCs was put forward by Bolondi according to the ‘beyond Milan and within up-to-7’ criteria and Child-Pugh score. In this study, we aim to analyze the prognosis of BCLC-B stage HCC patients who received hepatic resection according to the Bolondi’s subclassification. Materials and Methods One thousand and one hundred three patients diagnosed with HCC and treated with hepatic resection were enrolled in our hospital between 2006 and 2012. According to Bolondi’s subclassification, the BCLC-B patients were divided into four groups. Recurrence-free survival (RFS) and overall survival (OS) were analyzed. Results According to Bolondi’s subclassification, the BCLC-B patients were divided into four groups: B1 (n=41, 18.7%), B2 (n=160, 73.1%), B3 (n=11, 5.0%), and B4 (n=7, 3.2%). Significant difference was observed between B1 and other groups (B1 vs. B2, p=0.022; B1 vs. B3, p < 0.001; B1 vs. B4, p < 0.001), but no difference for B2 vs. B4 (p=0.542) and B3 vs. B4 (p=0.542). In addition, no significant differences were observed between BCLC-A and BCLCB1 group for both RFS (p=0.087) and OS (p=0.643). In multivariate analysis, BCLC-B subclassification was not a risk factor for both OS (p=0.263) and RFS (p=0.892). Conclusion In our study, HCC patients at B1 stage were benefited from hepatic resection and had similar survival to BCLC-A stage patients. Our study provided rationality of hepatic resection for selected BCLC-B stage HCC patients instead of routine transarterial chemoembolization.

Increased Cognition Connectivity Network in Major Depression Disorder: A fMRI Study

Ting Shen,Cao Li,Biao Wang,Wei-min Yang,Chen Zhang,Zhiguo Wu,Mei-hui Qiu,Jun Liu,Yi-feng Xu,Dai-hui Peng 대한신경정신의학회 2015 PSYCHIATRY INVESTIGATION Vol.12 No.2

ObjectiveaaEvidence of the brain network involved in cognitive dysfunction has been inconsistent for major depressive disorder (MDD), especially during early stage of MDD. This study seeks to examine abnormal cognition connectivity network (CCN) in MDD within the whole brain. MethodsaaSixteen patients with MDD and 16 health controls were scanned during resting-state using 3.0 T functional magnetic resonance imaging (fMRI). All patients were first episode without any history of antidepressant treatment. Both the left and right dorsolateral prefrontal cortex (DLPFC) were used as individual seeds to identify CCN by the seed-target correlation analysis. Two sample t test was used to calculate between-group differences in CCN using fisher z-transformed correlation maps. ResultsaaThe CCN was constructed by bilateral seed DLPFC in two groups separately. Depressed subjects exhibited significantly increased functional connectivity (FC) by left DLPFC in one cluster, overlapping middle frontal gyrus, BA7, BA43, precuneus, BA6, BA40, superior temporal gyrus, BA22, inferior parietal lobule, precentral gyrus, BA4 and cingulate gyrus in left cerebrum. Health controls did not show any cluster with significantly greater FC compared to depressed subjects in left DLPFC network. There was no significant difference of FC in right DLPFC network between depressed subjects and the health controls. ConclusionaaThere are differences in CCN during early stage of MDD, as identified by increased FCs among part of frontal gyrus, parietal cortex, cingulate cortex, and BA43, BA22, BA4 with left DLPFC. These brain areas might be involved in the underlying mechanisms of cognitive dysfunction in MDD.

LES of wind environments in urban residential areas based on an inflow turbulence generating approach

Lian Shen,Yan Han,C.S. Cai,Guochao Dong,Jianren Zhang,Peng Hu 한국풍공학회 2017 Wind and Structures, An International Journal (WAS Vol.24 No.1

Wind environment in urban residential areas is an important index to consider when evaluating the living environment. However, due to the complexity of the flow field in residential areas, it is difficult to specify the correct inflow boundary conditions in the large eddy simulation (LES). In this paper, the weighted amplitude wave superposition (WAWS) is adopted to simulate the fluctuating velocity data, which satisfies the desired target wind field. The fluctuating velocity data are given to the inlet boundary of the LES by developing an UDF script, which is implemented into the FLUENT. Then, two numerical models - the empty numerical wind tunnel model and the numerical wind tunnel model with spires and roughness elements are established based on the wind tunnel experiment to verify the present method. Finally, the turbulence generation approach presented in this paper is used to carry out a numerical simulation on the wind environment in an urban residential area in Lisbon. The computational results are compared with the wind tunnel experimental data, showing that the numerical results in the LES have a good agreement with the experimental results, and the simulated flow field with the inlet fluctuations can generate a reasonable turbulent wind field. It also shows that strong wind velocities and turbulent kinetic energy occur at the passageways, which may affect the comfort of people in the residential neighborhood, and the small wind velocities and vortexes appear at the leeward corners of buildings, which may affect the spreading of the pollutants.

Comparative Analysis of the Genomes of Bombyx mandarina and Bombyx mori Nucleopolyhedroviruses

Yi-Peng Xu,Zheng-Pei Ye,Chang-Ying Niu,Yan-Yuan Bao,Wen-Bing Wang,Wei-De Shen,Chuan-Xi Zhang 한국미생물학회 2010 The journal of microbiology Vol.48 No.1

The Bombyx mandarina nucleopolyhedrovirus (BomaNPV) S1 strain can infect the silkworm, Bombyx mori,but is significantly less virulent than B. mori nucleopolyhedrovirus (BmNPV) T3 strain. The complete nucleotide sequence of the S1 strain of BomaNPV was determined and compared with the BmNPV T3 strain. The circular, double stranded DNA genome of the S1 strain was 126,770 nucleotides long (GenBank accession no. FJ882854), with a G+C content of 40.23%. The genome contained 133 potential ORFs. Most of the putative proteins were more than 96% identical to homologs in the BmNPV T3 strain, except for bro-a, lef-12,bro-c, and bro-d. Compared with the BmNPV T3 strain, however, this genome did not encode the bro-b and bro-e genes. In addition, hr1 lacked two repeat units, while hr2L, hr2R, hr3, hr4L, hr4R, and hr5 were similar to the corresponding hrs in the T3 strain. The sequence strongly suggested that BomaNPV and BmNPV are variants with each other, and supported the idea that baculovirus strain heterogeneity may often be caused by variation in the hrs and bro genes.

Dynamic Control Allocation Algorithm for a Class of Distributed Control Systems

Dengfeng Zhang,Shen-Peng Zhang,Zhi-Quan Wang,Baochun Lu 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.2

The control allocation algorithm is developed for a class of distributed control systems with hierarchical structure and similar models of the subsystems, to solve the real-time cooperative control taking the dynamics and possible variations of subsystems into consideration. The augmented state-space model of the subsystems is first established for the control allocation. Based on robust control theory, the constrained and convex optimization is then developed with LMIs form to design the gain matrix of the dynamic control allocation. Furthermore, the closed-loop stability of the distributed control system is analyzed on the basis of stable upper-level main control law. Finally, simulations on the four-corner leveling control system of an advanced hydraulic press demonstrate the effectiveness of the proposed control allocation algorithm.

Abnormal Crowd Motion Behaviour Detection based on SIFT Flow

Dongping Zhang,Kaihang Xu,Huailiang Peng,Ye Shen 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.1

This paper focuses on the detection of the abnormal motion behaviour recognition of the crowd, and proposes an innovation method which is consist of three steps, i.e. SIFT flow + weighted orientation histogram + Hidden Markov Model(HMM). Analogous to optical flow, which is used to get the motion information of the pixels from two adjacent frames, SIFT flow is of higher precision. Next, we build up a a weighted orientation histogram as a statistical measurement for the SIFT flow features from the first step. Finally, the derived histogram is taken as the input for HMM in preparation for the detection of abnormal crowd motion. Experimental results show that compared to the existing method, our proposed one can detect the abnormal motion behaviour more effectively.

Attention and Working Memory Task- Load Dependent Activation Increase with Deactivation Decrease after Caffeine Ingestion

Wei Peng,Jian Zhang,Da Chang,Zhuo-Wen Shen,Yuanqi Shang,Donghui Song,Qiu Ge,Xuchu Weng,Ze Wang 대한자기공명의과학회 2017 Investigative Magnetic Resonance Imaging Vol.21 No.4

Purpose: Caffeine is the most widely consumed psychostimulant. It is often adopted as a tool to modulate brain activations in fMRI studies. However, its pharmaceutical effect on task-induced deactivation has not been fully examined in fMRI. Therefore, the purpose of this study was to examine the effect of caffeine on both activation and deactivation under sustained attention. Materials and Methods: Task fMRI was acquired from 26 caffeine naive healthy volunteers before and after taking caffeine pill (200 mg). Results: Statistical analysis showed an increase in cognition-load dependent task activation but a decrease in load dependent de-activation after caffeine ingestion. Increase of attention and memory task activation and its load-dependence suggest a beneficial effect of caffeine on the brain even though it has no overt behavior improvement. The reduction of deactivation by caffeine and its load-dependence indicate reduced facilitation from task-negative networks. Conclusion: Caffeine affects brain activity in a load-dependent manner accompanied by a disassociation between task-positive network and task-negative network.