Non-uniform Weighted Vibration Target Positioning Algorithm Based on Sensor Reliability

Yanli Chu,Yuyao He,Junfeng Chen,Qiwu Wu 한국정보처리학회 2023 Journal of information processing systems Vol.19 No.4

In the positioning algorithm of two-dimensional planar sensor array, the estimation error of time difference-ofarrival(TDOA) algorithm is difficult to avoid. Thus, how to achieve accurate positioning is a key problem ofthe positioning technology based on planar array. In this paper, a method of sensor reliability discrimination isproposed, which is the foundation for selecting positioning sensors with small error and excellent performance,simplifying algorithm, and improving positioning accuracy. Then, a positioning model is established. Theestimation characteristics of the least square method are fully utilized to calculate and fuse the positioningresults, and the non-uniform weighting method is used to correct the weighting factors. It effectively handlesthe decreased positioning accuracy due to measurement errors, and ensures that the algorithm performance isimproved significantly. Finally, the characteristics of the improved algorithm are compared with those of otheralgorithms. The experiment data demonstrate that the algorithm is better than the standard least square methodand can improve the positioning accuracy effectively, which is suitable for vibration detection with large noiseinterference.

Remarks on asymptotic behavior of weighted quadratic variation of subfractional Brownian motion

Junfeng Liu,Litan Yan 한국통계학회 2012 Journal of the Korean Statistical Society Vol.41 No.2

The present note is devoted to prove, by means of Malliavin calculus, the convergence in L2 of some properly renormalized weighted quadratic variation of sub-fractional Brownian motion SH with parameter H < 1/4.

Lightweight corundum-mullite refractories: I, Effects of pore characteristics and phase compositions on the slag resistance of porous corundum-mullite aggregates

Wen Yan,Xiaoli Lin,Junfeng Chen,Qingjie Chen,Nan Li 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.3

Corrosion of five corundum-mullite aggregates with the same chemical composition and the different pore characteristics andphase compositions by the blast furnace slag were conducted using the static crucible test. Effects of pore characteristics andphase compositions on the slag resistance of the aggregates were investigated through X-ray diffractometer (XRD), scanningelectron microscopy (SEM), mercury porosimetry measurement and FactSage® software, etc. It is found that the porecharacteristics and phase compositions strongly affect the slag resistance of the aggregates. With an increase in apparentporosities (1.4-41.6%), the slag penetration and corrosion resistances of aggregates decrease evidently. When the apparentporosities are in the range of 41.6-44.8%, the pore size plays more important role in the penetration resistance than theviscosity of the slag penetrated; the pore size of 2.74 µm can greatly inhibit the slag penetration. Under the conditions of largedifference in the apparent porosities, the phase compositions have little effect on the corrosion resistance; whereas, when theapparent porosities are similar, the higher the corundum content, the higher the corrosion resistance is.

Lightweight corundum-mullite refractories: II, Effects of porous aggregates on the slag resistances of corundum-mullite refractories

Wen Yan,Qingjie Chen,Xiaoli Lin,Junfeng Chen,Nan Li 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.4

Corrosion of five corundum-mullite refractories with the different porous aggregates and the same matrix by the blast furnaceslag was conducted using the static crucible test. Effects of properties of corundum-mullite aggregates on the slag resistanceof refractories were investigated through X-ray diffractometer (XRD), scanning electron microscopy (SEM), and mercuryporosimetry measurement, etc. It is found that the porous corundum-mullite aggregates have different slag absorbing capacity,which affects the composition of the corroded aggregates and matrices at slag/refractory interface, and thus affects the slagcorrosion and penetration resistances. Comparing with the dense corundum-mullite refractory, the porous corundum-mulliteaggregate with 31.6% apparent porosity (AP) substituting the dense aggregates in the refractories does not make the slagresistance degenerate and reduces the bulk density by 16.7 wt%; whereas, when the APs of aggregates increase to 41.6-44.8%,the slag resistance sharply deceases. It is a successful case that the developed lightweight refractory with high slag resistancehas a potential application for working lining of high-temperature furnace.

Hardware Implementation of Two-level Scheduling Algorithm in μC/OS-II

Guangwu Zhang,Yan Li,Yidong Chen,Huaiguo Dong,Huanhuan Chi,Min Shi,Junfeng Gao 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.4

Aiming at the problem that μC/OS-II does not support round-robin scheduling of the same priority task, a two-level hybrid task scheduling strategy was proposed. In the first level, by putting the task priority as criterion for task scheduling, a preemptive scheduling of different priority task was implemented. And in the second level, adopting time slice circulars scheduling strategy, round-robin scheduling of same priority task was implemented. The waiting list of tasks was designed by on-chip registers of FPGA and the ready list of tasks was designed by RAM of FPGA, and to implement time slice circulars scheduling, hardware circuit for finding successor of task was designed. The system adopted VHDL, and simulated by the software ISE10.1. The simulation results show that the hardware implementation of the system is well-worked.

Aerodynamic modeling for streamlined box girders using nonlinear differential equations and validation in actively generated turbulence

Lin Zhao,Shengyuan Liu,Junfeng Yan,Yao-Jun Ge 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.33 No.1

In classical buffeting analysis theory, aerodynamic forces are usually expressed by a linear quasi-steady formula, and they are improved by aerodynamic admittances suitable for streamlined bridge girders. Recent studies have shown that admittances change obviously with incoming flow characteristics and aerodynamic nonlinearity, such as the frequency multiplication phenomenon, and motion-induced amplitude-related aerodynamic effects cannot be ignored in some cases. To address these problems, a nonlinear condensed subsystem equation (NCSE) suitable for wind-induced aerodynamic force modeling is established in the time domain. It characterizes aerodynamic nonlinearity with series of nonlinear differential equations and data-driven parameters. The proposed framework can be used for complex aerodynamic re-illustration related to the strong nonlinearity of streamlined box girders. To validate the precision and feasibility of the framework, sectional model experiments performed on a streamlined box girder were carried out in an active turbulence generated wind tunnel in which an adjustable array of multiple fans was assisted by actively controlled vibrating wings for a 2D turbulence condition. The case study shows that the NCSE model can be used to predict nonlinear aerodynamic forces in the time and frequency domains, even under complex stochastic flow conditions. The proposed method provides an alternative way to predict possible aerodynamics based on the condition of incoming flow with sufficient accuracy, and it can illustrate multifrequency components of aerodynamic forces.

Harmonic Structure Features for Robust Speaker Diarization

Yu Zhou,Hongbin Suo,Junfeng Li,Yonghong Yan 한국전자통신연구원 2012 ETRI Journal Vol.34 No.4

In this paper, we present a new approach for speaker diarization. First, we use the prosodic information calculated on the original speech to resynthesize the new speech data utilizing the spectrum modeling technique. The resynthesized data is modeled with sinusoids based on pitch, vibration amplitude, and phase bias. Then, we use the resynthesized speech data to extract cepstral features and integrate them with the cepstral features from original speech for speaker diarization. At last, we show how the two streams of cepstral features can be combined to improve the robustness of speaker diarization. Experiments carried out on the standardized datasets (the US National Institute of Standards and Technology Rich Transcription 04-S multiple distant microphone conditions) show a significant improvement in diarization error rate compared to the system based on only the feature stream from original speech.

Association between perioperative glucocorticoids and cancer metastasis and survival in patients undergoing radical cystectomy for urothelial carcinoma of the bladder: A single-center retrospective study

Shiyu Mao,Yuan Wu,Ruiliang Wang,Yadong Guo,Jing Yuan,Wentao Zhang,Junfeng Zhang,Yang Yan,Xudong Yao 대한비뇨의학회 2020 Investigative and Clinical Urology Vol.61 No.4

Purpose: Perioperative glucocorticoids have the potential to increase the risk of tumor metastasis. However, the relationship between perioperative glucocorticoids and oncologic outcomes remains controversial. The present study was undertaken to evaluate the association of perioperative glucocorticoids with clinicopathologic outcomes following radical cystectomy (RC). Materials and Methods: We screened and included 185 patients who underwent radical surgery for bladder cancer in our center between 2009 and 2018. The Kaplan–Meier method was applied, and a log-rank test was used to estimate differences in metastasis-free survival (MFS) and overall survival (OS) between the groups. Multivariate Cox proportional hazards regression models were used to analyze any association of glucocorticoids with clinical outcomes. Results: A total of 76 (41.1%) patients received perioperative glucocorticoids. Median postoperative follow-up was 2.0 years. Kaplan–Meier survival curve indicated that the glucocorticoids group was significantly associated with increased distant MFS (p=0.008) but not with OS. In the multivariate analysis, no significant differences were observed for MFS between the groups. Interestingly, when the variable of blood transfusion was excluded from the multivariate analysis model, we found that patients receiving glucocorticoids were independently associated with worse MFS (hazard ratio, 1.790; p=0.030). Furthermore, the partial correlation analysis showed a significant positive correlation between perioperative glucocorticoids and blood transfusion (r=0.604, p<0.001). In the nontransfusion subgroup, propensity score matching showed that patients receiving glucocorticoids had a higher risk of distant metastasis. Conclusions: Perioperative glucocorticoids were associated with a higher rate of distant metastasis in patients undergoing RC for bladder cancer.

Fisetin Inhibits Cell Proliferation and Induces Apoptosis via JAK/STAT3 Signaling Pathways in Human Thyroid TPC 1 Cancer Cells

Ying Liang,Deyu Kong,Yi Zhang,Siqi Li,Yan Li,Anuradha Ramamoorthy,Junfeng Ma 한국생물공학회 2020 Biotechnology and Bioprocess Engineering Vol.25 No.2

Thyroid cancer is the most important malignant tumor reported in human populations where, its treatment remains undeveloped. Fisetin, a plant flavonoid exhibits several pharmacological properties like antioxidant, antiinflammatory, and anticancer function. In the existing study, we assessed fisetin mediated cytotoxic effects and action potential of fisetin on cell proliferation in TPC-1 human cancer cells. Also, examined the apoptosis in TPC-1 cells by reactive oxygen species (ROS) generation, the mitochondrial membrane potential (MMP) and apoptotic morphological changes through AO/EtBr staining. Additionally, we analyzed the effects of fisetin through ELISA analysis to evaluate the caspases expression and studied JAK 1 and STAT3 signaling molecule in TPC1 cells. Our results demonstrated that fisetin stimulated apoptosis, which confirmed through reduced cell viability, improved ROS generation, altered MMP and cell cycle phases in TPC-1 cells. Further, the fisetin up-regulated the expression of caspase (3, 8, and 9) expressions in TPC-1 cells. Also, we observed the fisetin down-regulated the JAK 1 and STAT3 expression in TPC1 cells. Thus, the fisetin induced apoptosis in TPC-1 cells by the induction of oxidative damage and enhanced caspases expression by down-regulating JAK 1 and STAT3 signaling molecules. Hence, the fisetin would be considered as a beneficial therapeutic agent for the thyroid cancer treatment.