Analysis of hurricane directionality effects using event-based simulation

Huang, Zhigang,Rosowsky, David V. Techno-Press 2000 Wind and Structures, An International Journal (WAS Vol.3 No.3

This paper presents an approach for evaluating directionality effects for both wind speeds and wind loads in hurricane-prone regions. The focus of this study is on directional wind loads on low-rise structures. Using event-based simulation, hurricane directionality effects are determined for an open-terrain condition at various locations in the southeastern United States. The wind speed (or wind load) directionality factor, defined as the ratio of the N-year mean recurrence interval (MRI) wind speed (or wind load) in each direction to the non-directional N-year MRI wind speed (or wind load), is less than one but increases toward unity with increasing MRI. Thus, the degree of conservatism that results from neglecting directionality effects decreases with increasing MRI. It may be desirable to account for local exposure effects (siting effects such as shielding, orientation, etc.) in design. To account for these effects in a directionality adjustment, the factor described above for open terrain would need to be transformed to other terrains/exposures. A "local" directionality factor, therefore, must effectively combine these two adjustments (event directionality and siting or local exposure directionality). By also considering the direction-specific aerodynamic coefficient, a direction-dependent wind load can be evaluated. While the data necessary to make predictions of directional wind loads may not routinely be available in the case of low-rise structures, the concept is discussed and illustrated in this paper.

Roof failure of shallow tunnel based on simplified stochastic medium theory

Huang, Xiaolin,Zhou, Zhigang,Yang, X.L. Techno-Press 2018 Geomechanics & engineering Vol.14 No.6

The failure mechanism of tunnel roof is investigated with upper bound theorem of limit analysis. The stochastic settlement and nonlinear failure criterion are considered in the present analysis. For the collapse of tunnel roof, the surface settlement is estimated by the simplified stochastic medium theory. The failure curve expressions of collapse blocks in homogeneous and in layered soils are derived, and the effects of material parameters on the potential range of failure mechanisms are discussed. The results show that the material parameters of initial cohesion, nonlinear coefficient and unit weight have significant influences on the potential range of collapse block in homogeneous media. The proportion of collapse block increases as the initial cohesion increases, while decreases as the nonlinear coefficient and the unit weight increase. The ground surface settlement increases with the tunnel radius increasing, while the possible collapse proportion decreases with increase of the tunnel radius. In layered stratum, the study is investigated to analyze the effects of material parameters of different layered media on the proportion of possible collapse block.

Research on Relay Selection Technology Based on Regular Hexagon Region Segmentation in C-V2X

Zhigang Li,Xinan Yue,Xin Wang,Baozhu Li,Daoying Huang 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.9

Traffic safety and congestion are becoming more and more serious, especially the frequent occurrence of traffic accidents, which have caused great casualties and economic losses. Cellular Vehicle to Everything (C-V2X) can assist in safe driving and improve traffic efficiency through real-time information sharing and communication between vehicles. All vehicles communicate directly with Base Stations (BS), which will increase the base station load. And when the communicating vehicles are too far apart, too fast or there are obstacles in the communication path, the communication link can be unstable or even interrupted. Therefore, choosing an effective and reliable multi-hop relay-assisted Vehicle to Vehicle (V2V) communication can not only reduce the base station load and improve the system throughput but also expand the base station coverage and improve the communication quality of edge vehicles. Therefore, a communication area division scheme based on regular hexagon segmentation technology is proposed, a relay-assisted V2V communication mechanism is designed for the divided communication areas, and an efficient communication link is constructed by selecting the best relay node. Simulation results show that the scheme can improve the throughput of the system by nearly 55% and enhance the robustness of the V2V communication link.

Temporal and Spatial Traffic Analysis Based on Human Mobility for Energy Efficient Cellular Network

( Zhigang Li ),( Xin Wang ),( Junsong Zhang ),( Wei Huang ),( Ye Tian ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.1

With the drastic growth of Information and Communication Technology (ICT) industry, global energy consumption is exponentially increased by mobile communications. The huge energy consumption and increased environmental awareness have triggered great interests on the research of dynamic distribution of cell user and traffic, and then designing the energy efficient cellular network. In this paper, we explore the temporal and spatial characteristics of human mobility and traffic distribution using real data set. The analysis results of cell traffic illustrate the tidal effect in temporal and spatial dimensions and obvious periodic characteristics which can be used to design Base Station (BS) dynamic with sleeping or shut-down strategy. At the same time, we designed a new Cell Zooming and BS cooperation mode. Through simulation experiments, we found that running in this mode can save about 35% of energy consumption and guarantee the required quality of service.

Blockchain and central bank digital currency

Tao Zhang,Zhigang Huang 한국통신학회 2022 ICT Express Vol.8 No.2

With the development of blockchain and digital currencies, central banks all over the world are accelerating the process of CBDC development. However, it is still controversial on adoption of blockchain in CBDC design. In the paper, we analyze both functional and non-functional requirements of CBDC design, and make a literature review on blockchain based CBDC schemes. Analysis findings show that permissioned blockchain are more suitable for CBDC than permissionless blockchain. Besides, there are some challenges in blockchain based CBDC, such as performance, scalability, and cross-chain interoperability. Our analysis is timely and can provide guidelines for blockchain based CBDC design.

Reliable H∞ Filter Design for a Class of Mixed-Delay Markovian Jump Systems with Stochastic Nonlinearities and Multiplicative Noises via Delay-Partitioning Method

Shiping Wen,Zhigang Zeng,Tingwen Huang 제어·로봇·시스템학회 2012 International Journal of Control, Automation, and Vol.10 No.4

This paper is concerned with the problem of reliable H∞ filter design for a class of mixed-delay Markovian jump systems with stochastic nonlinearities and multiplicative noises. The mixed delays comprise both discrete time-varying delay and distributed delay. The stochastic nonlinearities in the form of statistical means cover several well-studied nonlinear functions. And the multiplicative disturbances are in the form of a scalar Gaussian white noise with unit variance. Furthermore, the failures of sensors are quantified by a variable varying in a given interval. A filter is designed to guarantee that the dynamics of the estimation error is asymptotically mean-square stable. Sufficient conditions for the existence of such a filter are obtained by using a new Lyapunov-Krasovskii functional and delay-partitioning method. Then a linear matrix inequality (LMI) approach for designing such a reliable H∞ filter is presented. Finally, the effectiveness of the proposed approach is demonstrated by a numerical example.

Electrochemical properties of Bi-Ni and Bi-Ni-Mn composite-coated electrolytic manganese dioxide

Xiaofeng Li,Zhigang Huang,Tongchi Xia,Huichao Dong,Yanghua Song 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.6

The Bi-Ni and Bi-Ni-Mn composite is separately coated on the surface of commercial electrolytic manganesedioxide (EMD) by using a simple chemical precipitation/oxidation method. The results of X-ray diffractionshow that a structure of γ-MnO2 is kept for all the coated EMD, but the intensity of their diffraction peaks is lower thanuncoated one. Both the Bi0.5-Ni0.5 and Bi0.35-Ni0.35-Mn0.3 composite benefits the discharge capacity and high-power performanceof the EMD electrodes. On the other hand, the results of scanning electron microscopy and energy dispersivespectroscopy confirm the more uniform distribution of the Bi0.15-Ni0.55-Mn0.3 composite on the surface of EMD thanthe Bi0.5-Ni0.5 one, thereby resulting in better cyclability of the electrodes. After 50 cycles at a 1C rate, the capacity retentionrate of the Bi0.15-Ni0.55-Mn0.3 composite-coated electrode reaches to 80%, which is far larger than the un-coated(49%) and the Bi0.5-Ni0.5 composite-coated (63%) one.

Drug-loaded microbubble delivery system to enhance PD-L1 blockade immunotherapy with remodeling immune microenvironment

Zheng Jun,Huang Ju,Zhang Liang,Wang Mengna,Xu Lihong,Dou Xiaoyun,Leng Xiaojing,Fang Mingxiao,Sun Yang,Wang Zhigang 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Although programmed cell death protein 1 (PD-1)/ programmed cell death-ligand protein 1 (PD-L1) checkpoint blockade immunotherapy demonstrates great promise in cancer treatment, poor infiltration of T cells resulted from tumor immunosuppressive microenvironment (TIME) and insufficient accumulation of anti-PD-L1 (αPD-L1) in tumor sites diminish the immune response. Herein, we reported a drug-loaded microbubble delivery system to overcome these obstacles and enhance PD-L1 blockade immunotherapy.Docetaxel (DTX) and imiquimod (R837)-loaded microbubbles (RD@MBs) were synthesized via a typical rotary evaporation method combined with mechanical oscillation. The targeted release of drugs was achieved by using the directional "bursting" capability of ultrasound-targeted microbubble destruction (UTMD) technology. The antitumor immune response by RD@MBs combining αPD-L1 were evaluated on 4T1 and CT26 tumor models.The dying tumor cells induced by DTX release tumor-associated antigens (TAAs), together with R837, promoted the activation, proliferation and recruitment of T cells. Besides, UTMD technology and DTX enhanced the accumulation of αPD-L1 in tumor sites. Moreover, RD@MBs remolded TIME, including the polarization of M2-phenotype tumor-associated macrophages (TAMs) to M1-phenotype, and reduction of myeloid-derived suppressor cells (MDSCs). The RD@MBs + αPD-L1 synergistic therapy not only effectively inhibited the growth of primary tumors, but also significantly inhibited the mimic distant tumors as well as lung metastases.PD-L1 blockade immunotherapy was enhanced by RD@MBs delivery system.

FPoR: Fair proof-of-reputation consensus for blockchain

Tao Zhang,Zhigang Huang 한국통신학회 2023 ICT Express Vol.9 No.1

Current consensus protocols for permissionless blockchain cannot balance security, performance and centralization issues. In the paper, we present a reputation based consensus, FPoR, which combines reputation, committee based consensus, PBFT, reward and penalization mechanisms. FPoR can balance scalability, security and decentralization, and promote fairness, increase participation and strengthen security. Experiment results show that FPoR is with high performance and scalability, which can be used for permissionless blockchain. FPoR can also be extended to permissioned blockchain applications.

Acaricidal activity and structure-activity relationships of Spiro- Butyrolactone derivatives against Tetranychus cinnabarinus

Shaoyong Ke,Ting Ke,Zhigang Zhang,Liqiao Shi,Daye Huang,Kaimei Wang,Ziwen Yang,Nina Yang 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.3

The phytophagous mite is highly polyphagous and widespread in warmer regions and greenhouses around the world, and so the focus of novel acaricides is shifting towards more effective, ecofriendly new chemical entity with unique modes of action. In this study, eighteen spirobutyrolactones derived from natural tetronic acid have been synthesized and their acaricidal activities against Tetranychus cinnabarinus were investigated by slide-dip method. The results of preliminary bioassay indicate that some of these compounds exhibited promising acaricidal activities, especially, compounds 6 and 18 show significant activities against T. cinnabarinus than the commercial spirodiclofen 1 (27.37% mortality), and which present 58.55% and 82.24% mortality at tested dose, respectively. The relationship between structure and acaricidal activity was also discussed based on the experimental data, and which indicate that the compounds (16, 17 and 18) with non-substituted phenyl ring (R1=H) show obviously better activities. Especially, we also can find that substituted benzoyl unit will help to increase the activity than substituted phenylacetyl group.