Detection of Low Frequency Signals using Interferometric Fiber Sensors based on Phase Generated Carrier Demodulation Technique

Wang Yong-jiao,Wang Chuan,Yuan Yin-quan,Liang Lei 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.2

A fiber-optic sensor is a sensor with high sensitivity, and signal detection technology is one of its key technologies. Phase generated carrier demodulation technology is a homodyne demodulation method widely used for interference fiber-optic sensors. Research reveals that the amplitude of the interference signal and the modulation depth will affect the result of demodulation. The distortion of the demodulated signal can be reduced by the elimination of the effects of the interference signal amplitude and modulation depth. A phase generated carrier demodulation method for interference fiber-optic sensors is proposed to detect weak ELF signals. Theoretical analysis and simulation have been implemented on the demodulation of weak ELF signals using low-level sub-mixer carrier. The results indicate that in the demodulation of weak ELF signals, DC drift occurs in the DCM approach, while the Arctangent approach does not have this problem. Then, an optical fiber sensing system for ELF signals is established based on optical fiber interferometer, indicating the Arctangent approach is able to demodulate the VLF signals accurately.

Distributed Adaptive Fault-tolerant Control for Heterogeneous Nonlinear Multi-agent Systems with Actuator Faults

Quan-Yong Fan,Chao Deng,Xin Wang,Cai-Cheng Wang 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.2

This paper investigates the fuzzy cooperative reliable output regulation (CROR) problem for heterogeneous nonlinear multi-agent systems (MASs) with actuator faults under directed network topology. Compared with the existing CROR results, this paper considers more general heterogeneous nonlinear MASs with actuator faults under directed network topology. To identity the dynamic matrix of the exosystem for each subsystem, distributed finite-time estimators are firstly designed. Then, a novel hierarchical mechanism is introduced for the MASs network such that each subsystem knows its layer in the network. By using the introduced hierarchical variables in the hierarchical mechanism, distributed finite-time observers are proposed to estimate the state of the exosystem. Based on the proposed finite-time observers, a new decentralized fuzzy resilient controller is proposed. It is proved that the developed method can be used to solve the considered problem. Finally, a simulation example is provided to show the effectiveness of the developed method.

Member capacity-based progressive collapse analysis of transmission towers under wind load

Yong-Quan Li,Yong Chen,Guohui Shen,Wenjuan Lou,Weijian Zhao,Hao Wang 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.33 No.4

The wind-induced collapse of transmission towers has raised many concerns. Progressive collapse analysis is recognized as a promising method for the assessment of the collapse-resistant capacity of the transmission tower. The finite element model of an actual transmission tower is firstly built for the analysis, in which the dynamic behavior of the member in failure is taken into account to be in accord with the actual tower collapse. The analysis considering the main design load cases is conducted in advance to determine the case under which the tower has the potential to collapse. The incremental dynamic analysis in association with the explicit time integration algorithm is employed to perform a progressive collapse analysis, where the wind loads are simulated by using the linear filtering method, and the developed failure criterion with axial force and bending moment involved is based on the stability bearing capacity of the members. It is found the tower collapse begins with the horizontal bracing member near the waist. Then, the adjacent members, including the leg members, fail sequentially, and the tower collapses eventually with a shear-type failure. The demand to capacity ratio (DCR) in terms of bearing capacity of the member is defined to quantify the structural behavior, the location of the member that has the potential to fail, and when the initial failure occurs are thereby identified. It is concluded that compared to the member capacity-based analysis, the ultimate strain-based analysis, which is most likely to be an inelastic dynamic analysis permitting a large deformation, may overestimate the bearing capacity of the structure in wind-induced collapse.

Cooperative Control Feedback: On Backoff Misbehavior of CSMA/CA MAC in Channel-Hopping Cognitive Radio Networks

Quan Liu,Yong Lu,Gang Hu,Shaohe Lv,Xiaodong Wang,Xingming Zhou 한국통신학회 2018 Journal of communications and networks Vol.20 No.6

Due to dynamic channel availability in cognitive radionetworks (CRNs), rendezvous problem is known as the mostchallenging issue in the design of media access control (MAC)protocol, which is a key step for secondary users (SUs) to startcommunication. With the concept of blind rendezvous, numerouschannel-hopping sequence (CHS) based rendezvous schemeshave been proposed to solve this problem in these years. Currently,little attention is paid to the design of a carrier sensing multipleaccess/collision avoidance (CSMA/CA) MAC based on theserendezvous schemes and also the rendezvous de-synchronizationproblem brought by multiple rendezvous networking paradigminto MAC design. To this end, we propose a cooperative channelhoppingbased CSMA/CA MAC (named CoCH-CSMA/CA MAC)which works on the top of existing CHS based rendezvous schemes. Resulting from the rendezvous de-synchronization problem, a newtype of collision, named false collision, is identified. As a SU cannotdiscern the false collision by itself, we design a cooperative controlfeedback scheme which employs correlation-based signal detectionto reduce the coordination overhead of cooperation and helps SUsto avoid backoff misbehavior. Moreover, we analyze the behavior ofour MAC protocol and its advantage. Extensive simulations provethat the cooperative control feedback scheme can effectively alleviatethe impact of rendezvous de-synchronization problem on backoffmisbehavior and improve network performance.

Common Model EMI Prediction in Motor Drive System for Electric Vehicle Application

Yong-Ming Yang,He-Meng Peng,Quan-Di Wang 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.1

Common mode (CM) conducted interference are predicted and compared with experiments in a motor drive system of Electric vehicles in this study. The prediction model considers each part as an equivalent circuit model which is represented by lumped parameters and proposes the parameter extraction method. For the modeling of the inverter, a concentrated and equivalent method is used to process synthetically the CM interference source and the stray capacitance. For the parameter extraction in the power line model, a computation method that combines analytical method and finite element method is used. The modeling of the motor is based on measured date of the impedance and vector fitting technique. It is shown that the parasitic currents and interference voltage in the system can be simulated in the different parts of the prediction model in the conducted frequency range (150 kHz-30 MHz). Experiments have successfully confirmed that the approach is effective.

A joint probability distribution model of directional extreme wind speeds based on the t-Copula function

Quan, Yong,Wang, Jingcheng,Gu, Ming Techno-Press 2017 Wind and Structures, An International Journal (WAS Vol.25 No.3

The probabilistic information of directional extreme wind speeds is important for precisely estimating the design wind loads on structures. A new joint probability distribution model of directional extreme wind speeds is established based on observed wind-speed data using multivariate extreme value theory with the t-Copula function in the present study. At first, the theoretical deficiencies of the Gaussian-Copula and Gumbel-Copula models proposed by previous researchers for the joint probability distribution of directional extreme wind speeds are analysed. Then, the t-Copula model is adopted to solve this deficiency. Next, these three types of Copula models are discussed and evaluated with Spearman's rho, the parametric bootstrap test and the selection criteria based on the empirical Copula. Finally, the extreme wind speeds for a given return period are predicted by the t-Copula model with observed wind-speed records from several areas and the influence of dependence among directional extreme wind speeds on the predicted results is discussed.

Fangchinoline Inhibits Cell Proliferation Via Akt/GSK-3beta/cyclin D1 Signaling and Induces Apoptosis in MDA-MB-231 Breast Cancer Cells

Wang, Chang-Dong,Yuan, Cheng-Fu,Bu, You-Quan,Wu, Xiang-Mei,Wan, Jin-Yuan,Zhang, Li,Hu, Ning,Liu, Xian-Jun,Zu, Yong,Liu, Ge-Li,Song, Fang-Zhou Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.2

Fangchinoline (Fan) inhibits cell proliferation and induces apoptosis in several cancer cell lines. The effects of Fan on cell growth and proliferation in breast cancer cells remain to be elucidated. Here, we show that Fan inhibited cell proliferation in the MDA-MB-231 breast cancer cell line through suppression of the AKT/Gsk-3beta/cyclin D1 signaling pathway. Furthermore, Fan induced apoptosis by increasing the expression of Bax (relative to Bcl-2), active caspase 3 and cytochrome-c. Fan significantly inhibited cell proliferation of MDA-MB-231 cells in a concentration and time dependent manner as determined by MTT assay. Flow cytometry analysis demonstrated that Fan treatment of MDA-MB-231 cells resulted in cell cycle arrest at the G1 phase, which correlated with apparent downregulation of both mRNA and protein levels of both PCNA and cyclin D1. Further analysis demonstrated that Fan decreased the phosphorylation of AKT and GSK-3beta. In addition, Fan up-regulated active caspase3, cytochrome-c protein levels and the ratio of Bax/Bcl-2, accompanied by apoptosis. Taken together, these results suggest that Fan is a potential natural product for the treatment of breast cancer.

Susceptibility Loci Associations with Prostate Cancer Risk in Northern Chinese Men

Wang, Na-Na,Xu, Yong,Yang, Kuo,Wei, Dong,Zhang, Yao-Guang,Liu, Ming,Shi, Xiao-Hong,Liang, Si-Ying,Sun, Liang,Zhu, Xiao-Quan,Yang, Yi-Ge,Tang, Lei,Zhao, Cheng-Xiao,Wang, Xin,Chen, Xin,Hui, Juan,Zhang, Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.5

Background: KLK3 gene products, like human prostate-specific antigen (PSA), are important biomarkers in the clinical diagnosis of prostate cancer (PCa). G protein-coupled receptor RFX6, C2orf43 and FOXP4 signaling plays important roles in the development of PCa. However, associations of these genes with PCa in northern Chinese men remain to be detailed. This study aimed to investigate their impact on occurrence and level of malignancy. Methods: All subjects were from Beijing and Tianjin, including 266 cases with prostate cancer and 288 normal individuals as controls. We evaluated associations between clinical covariates (age at diagnosis, prostate specific antigen, Gleason score, tumor stage and aggressive) and 6 candidate PCa risk loci, genotyped by PCR- high resolution melting curve and sequencing methods. Results: Case-control analysis of allelic frequency of PCa associated with PCa showed that one of the 6 candidate risk loci, rs339331 in the RFX6 gene, was associated with reduced risk of prostate cancer (odds ratio (OR) = 0.73, 95% confidence interval (CI) =0.57-0.94, P = 0.013) in northern Chinese men. In addition, subjects with CX (CC+TC) genotypes had a decreased risk for prostrate cancer compared to those carrying the TT homozygote (OR =0.64, 95% CI = 0.45- 0.90, P = 0.008). The TT genotype of 13q22 (rs9600079, T) was associated with tumor stage (P=0.044, OR=2.34, 95% CI=0.94-5.87). Other SNPs were not significantly associated with clinical covariates in prostate cancer (P > 0.05). Conclusions. rs339331 in the RFX6 gene may be associated with prostate cancer as a susceptibility locus in northern Chinese men.

Improved first-order method for estimating extreme wind pressure considering directionality for non-typhoon climates

Jingcheng Wang,Yong Quan,Ming Gu 한국풍공학회 2020 Wind and Structures, An International Journal (WAS Vol.31 No.5

The first-order method for estimating the extreme wind pressure on building envelopes with consideration of the directionality of wind speed and wind pressure is improved to enhance its computational efficiency. In this improved method, the result is obtained directly from the empirical distribution of a random selection of annual maximum wind pressure samples generated by a Monte Carlo method, rather than from the previously utilized extreme wind pressure probability distribution. A discussion of the relationship between the first- and full-order methods indicates that when extreme wind pressures in a non-typhoon climate with a high return period are estimated with consideration of directionality, using the relatively simple first-order method instead of the computationally intensive full-order method is reasonable. The validation of this reasonableness is equivalent to validating two assumptions to improve its computational efficiency: 1) The result obtained by the full-order method is conservative when the extreme wind pressure events among different sectors are independent. 2) The result obtained by the first-order method for a high return period is not significantly affected when the extreme wind speeds among the different sectors are assumed to be independent. These two assumptions are validated by examples in different regions and theoretical derivation.

Diagnostic Significance of Combined Detection of Epstein-Barr Virus Antibodies, VCA/IgA, EA/IgA, Rta/IgG and EBNA1/IgA for Nasopharyngeal Carcinoma

Cai, Yong-Lin,Li, Jun,Lu, Ai-Ying,Zheng, Yu-Ming,Zhong, Wei-Ming,Wang, Wei,Gao, Jian-Quan,Zeng, Hong,Cheng, Ji-Ru,Tang, Min-Zhong Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.5

The objective of this study was to investigate the diagnostic significance of EBV antibody combined detection for nasopharyngeal carcinoma (NPC) in a high incidence region of southern China. Two hundred and eleven untreated NPC patients, 203 non-NPC ENT patients, and 210 healthy controls were recruited for the study. The titers of VCA/IgA and EA/IgA were assessed by immunoenzyme assay, and the levels of Rta/IgG and EBNA1/IgA were determined by enzyme-linked immunosorbent assay. The levels of VCA/IgA, EA/IgA, Rta/IgG and EBNA1/IgA demonstrated no association with gender or age (p>0.05). The receiver operating characteristic curve and the area under the curve were used to evaluate the diagnostic value. The sensitivity of VCA/IgA (98.1%) and the specificity of EA/IgA (98.5%) were the highest. When a logistic regression model was used to combine the results from multiple antibodies to increase the accuracy, the combination of VCA/IgA+Rta/IgG, whose area under the curve was 0.99, had the highest diagnostic efficiency, and its sensitivity, specificity and Youden index were 94.8%, 98.0% and 0.93 respectively. The data suggest that the combination of VCA/IgA+Rta/IgG may be most suitable for NPC serodiagnosis.