Effect of post-annealing conditions on electrical and optical properties of AZO thin film on flexible PET substrates

Wenhao YAO,Kun LIU,Shulei CHEN,Xiaojie LIU,Dongyang WANG,Yingchao NING,Dechun BA,Guangyu DU,Yaoshuai BA 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

Probabilistic Evaluation of Progressive Collapse Resistance of Truss String Structures Considering Structural Uncertainties

Wenhao Liu,Bin Zeng,Zhen Zhou,Yifan Zheng 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.5

Truss string structures (TSSs) are often prone to the risk of progressive collapse owing to critical member failures in accidental events. Moreover, the randomness of material properties, cross-sectional dimensions, and construction errors can inevitably lead to fluctuations in the collapse resistance of structures. Thus, to avoid catastrophic collapse of TSSs, it is essential to investigate the resistance to progressive collapse of TSSs considering structural uncertainties. In this study, three limit states of TSSs under key member failures are defined. In addition, a probabilistic evaluation methodology for the progressive collapse resistance of single TSSs considering structural uncertainties is proposed and extended to spatial TSSs. The analysis reveals that the external load of single or spatial TSSs reaching different limit states due to cable failure is less than that of the failure of the bottom chord of the support. Furthermore, the fragility analysis shows that the progressive collapse resistance of TSSs exposed to the failure of the bottom chord of the support is greater than that of cable failure, the cable failure should be given more attention than the failure of the bottom chord of the support in the structural design and post-maintenance of TSSs. The sensitivity analysis indicates that the performance of single TSSs against progressive collapse is more sensitive to the variability of random parameters. In addition, the spatial effect can considerably enhance the performance of TSSs against progressive collapse when the bottom chord of the support fails, whereas the improvement is marginal when the cable fails.

Damage Mechanism of Broad-narrow Joint of CRTSII Slab Track under Temperature Rise

Xiaokai Liu,Wenhao Zhang,Jieling Xiao,Xueyi Liu,Wei Li 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.5

There is two typical damage pattern at broad-narrow joint of CRTSII slab track breakage of narrow joint and fracture at junction between broad joint and narrow joint. This paper aims to study the damage mechanism and develop of broad-narrow joint of CRTSII slab track and put forward the methods to reduce the damage. Based on damaged plasticity model for concrete and cohesive zone model, the damage mechanism and development process of broad-narrow joint are analyzed in this study. The unequal width of broad joint and narrow joint, different concrete strength between broad-narrow joints and slab and slab integrity reducing due to the interface are the main reason for the typical damage. It is suggested to set the same width of broad joint and narrow joint, set the same strength of broad-narrow joint and slab and enhance the integrity of the slab by chipping or adding adhesives, among which the former two methods are more effective. Breakage of narrow joint is a gradual compression damage due to the lower concrete strength than slab. Fracture at the junction between narrow joint and broad joint is a mutational tension damage due to the unequal width of broad joint and narrow joint. The temperature gradient has significant effect on the compression damage, but small to the tension damage, it has the risk of complete destruction under extreme conditions.

Polyethyleneimine-functionalized phenolphthalein-based cardo poly (ether ether ketone) membrane for CO2 separation

Yunwu Yu,Junhai Wang,Yan Wang,Wenhao Pan,Changwei Liu,Peng Liu,Lianjie Liang,Changwei Xu,Yunxue Liu 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.83 No.-

Phenolphthalein-based cardo poly(ether ether ketone) (PEEKWC)/polyethyleneimine (PEI) crosslinkingmembranes were prepared by solution casting followed by solution reaction at room temperature. Theeffects of reaction time and PEI content on the membrane structure and gas separation performanceswere investigated. Light transmittance measure and AFM evidenced the relationship between themicrophase separation in PEEKWC-PEI membranes and reaction time. The CO2 permeability increasedwith the PEI content, while the N2 and CH4 permeability remained nearly constant. This result indicatedthat only CO2 was transported by the solution–diffusion mechanism and also that PEI exhibited a positivecontribution as afixed carrier for CO2 facilitated transport. Meanwhile the PEEKWC-PEI crosslinkingmembranes showed higher selectivities than the pure PEEKWC membrane. The highest CO2/N2 and CO2/CH4 selectivities were about 131 and 122 increasing from 33 and 30, respectively. The crosslinkingstructure of membranes improved the CO2 permeability stability.

Nitrate control strategies in an activated sludge wastewater treatment process

Wenhao Shen,Erpan Tao,Xiaoquan Chen,Dawei Liu,류홍빈 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.3

We studied nitrate control strategies in an activated sludge wastewater treatment process (WWTP) basedon the activated sludge model. Two control strategies, back propagation for proportional-integral-derivative (BP-PID)and adaptive-network based fuzzy inference systems (ANFIS), are applied in the WWTP. The simulation results showthat the simple local constant setpoint control has poor control effects on the nitrate concentration control. However,the ANFIS (4*1) controller, which considers not only the local constant setpoint control of the nitrate concentration,but also three important indices in the effluent--ammonia concentration, total suspended sludge concentration and totalnitrogen concentration--demonstrates good control performance. The results also prove that ANFIS (4*1) controllerhas better control performance than that of the controllers PI, BP-PID and ANFIS (2*1), and that the ANFIS (4*1)controller is effective in improving the effluent quality and maintaining the stability of the effluent quality.

Adaptive Application Component Mapping for Parallel Computation Offloading in Variable Environments

( Wenhao Fan ),( Yuan`an Liu ),( Bihua Tang ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.11

Distinguished with traditional strategies which offload an application`s computation to a single server, parallel computation offloading can promote the performance by simultaneously delivering the computation to multiple computing resources around the mobile terminal. However, due to the variability of communication and computation environments, static application component multi-partitioning algorithms are difficult to maintain the optimality of their solutions in time-varying scenarios, whereas, over-frequent algorithm executions triggered by changes of environments may bring excessive algorithm costs. To this end, an adaptive application component mapping algorithm for parallel computation offloading in variable environments is proposed in this paper, which aims at minimizing computation costs and inter-resource communication costs. It can provide the terminal a suitable solution for the current environment with a low incremental algorithm cost. We represent the application component multi-partitioning problem as a graph mapping model, then convert it into a pathfinding problem. A genetic algorithm enhanced by an elite-based immigrants mechanism is designed to obtain the solution adaptively, which can dynamically adjust the precision of the solution and boost the searching speed as transmission and processing speeds change. Simulation results demonstrate that our algorithm can promote the performance efficiently, and it is superior to the traditional approaches under variable environments to a large extent.

A New Triterpenoid Saponin from Pulsatilla cernua

Wenhao Fan,Yongnan Xu,Jianyu Liu,Yixia Gong,Jing Ma,Nan Zhou 한국생약학회 2013 Natural Product Sciences Vol.19 No.2

A new oleanane-type triterpenoid saponin together with six known saponins were isolated from the roots of Pulsatilla cernua. Their structures were elucidated on the basis of spectroscopic data, including 2D NMR spectra and chemical evidence. Compounds 1 and 6 are reported from this genus for the first time.

Application Multi-partitioning for Offloading Computation to Multiple Computing Resources around Mobile Terminals

Wenhao Fan,Bihua Tang,Yuan’an Liu 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.6

Different with traditional approaches that offload computation to a single remote server, the performance of an application can be further enhanced by simultaneously distributing its computing tasks to multiple computing resources around the mobile terminal. How to effectively multiply partition application components is critical for parallel computation offloading. In this paper, an application multi-partitioning scheme is proposed, which optimally offloads application's components to surrounding resources. A graph mapping model is converted and set up to represent components and resources as undirected graphs, and the A* algorithm is employed to efficiently search the optimal mapping from component graph to resource graph, which minimizes computing costs and inter-resource communication costs. Simulation results demonstrate that the performance can be efficiently promoted by our algorithm, which outperforms the traditional approaches to a large degree.

An API Calls Monitoring-based Method for Effectively Detecting Malicious Repackaged Applications

Wenhao Fan,Yuan’an Liu,Bihua Tang 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.8

The number of mobile applications on Android platform has largely increased in recent years. The security problems, as one of the outcomes induced by the popularity of Android, become more and more critical. Malicious repackaged applications (MRAs) perform malicious behaviors through malware developers embedding malicious codes into the benign origin applications (BOAs), which threat the security of users’ finance and privacy. In this paper, a method based on API calls monitoring is proposed to effectively detect MRAs. We discuss the characteristics of behaviors and analyze the differences in API calls between MRAs and their BOAs. A MRA detection model is established, which builds up the super-sphere for each BOA via a SVDD algorithm. The model can detect the abnormal behaviors of MRAs which deviate the normal behaviors of corresponding BOAs. Experiments are carried out on imitated and real MRAs, where the results demonstrate the effectiveness of our method for detecting the singly and multiply contaminated BOAs.

Energy Efficient Traffic Allocation for Resource-constrained Multi-homed WSN Gateway

Wenhao Fan,Bihua Tang,Yuan’an Liu 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.10

WSN (Wireless Sensor Network) gateway acts as a bridge between WSN and external networks. Currently, rapid growing demands from various IoTs (Internet of Things) applications are posing critical challenges to the data transmission capability of such gateway. As a promising solution, multi-homed WSN gateway, which is equipped with multiple network interfaces, can obtain enhanced parallel data transmission by jointly utilizing multiple RATs (Radio Access Technologies). However, the multi-homed gateway is a resource-constrained device, so it’s crucial to guarantee the efficiency for both data throughput and resource consumption. Delay and buffer size, simulation results validate that the proposed algorithm can allocate To this end, an energy efficient traffic allocation algorithm for resource-constrained multi-homed WSN gateway is proposed in this paper, which aims at minimizing the gateway's power consumption while guaranteeing the transmission the traffic optimally for the gateway with different constraints and configurations, and it can significantly promote the gateway's energy efficiency in comparison to the traditional method.