This paper proposes a new dynamic driving risk potential field model under the connected and automated vehicles environment that fully considers the dynamic effect of the vehicle's acceleration and ...steering angle. The statistical analysis of the model's parameter reveals that acceleration and steering angle will directly affect the distribution of the driving risk potential field and that this strong correlation should not be ignored if one is interested in the vehicle's microscopic motion behavior. We further develop a driving risk potential field-based car-following model (DRPFM) to remedy the failure of acceleration consideration under the conventional environment, whose parameters are calibrated by filtered I-80 NGSIM data with frequent traf?c oscillations. Simulation results indicate that our proposed DRPFM model is proved to be a good description of car-following behavior and outperforms two classical car-following models (Optimal Velocity Model and Intelligent Driver Model) in frequent oscillation phases due to our consideration of potential acceleration data acquisition in real-time under the CAVs environment. In addition, this DRPFM model is applied to deduce the safety conditions for vehicle lane-changing. The analysis results prove that this model can reasonably explain the influencing factors between driver types and lane-changing safety conditions in practice.
Summary
Mode identification in civil engineering uses ambient excitation response, where the excitation is assumed to be stationary white noise. However, practical engineering conditions cannot ...satisfy this assumption of ideal excitation. This paper proposes an innovative method based on eigensystem realization algorithm and a proposed virtual frequency response function. The formulation of the virtual frequency response function is derived from the ratio of the cross‐power and autopower spectral density functions of the measurement signals. The impulse responses are calculated by inverse Fourier transform of the product of the virtual frequency response function and the frequency response function of the reference point. After obtaining impulse responses, eigensystem realization algorithm is then performed to identify structural modes. The proposed virtual frequency response function and eigensystem realization algorithm are validated by a numerical example. The results show that the virtual frequency response function and eigensystem realization algorithm can give much a better impulse response than natural excitation technique and identify more precise mode parameters. Finally, the proposed method is applied to a practical engineering bridge, where the results by the virtual frequency response function and eigensystem realization algorithm can also give better results than those given by natural excitation technique and eigensystem realization algorithm.
To tackle performance issues stemming from assembly errors in practical fuel cell applications, a criss-crossed matching design for anode and cathode bipolar plates (BPP) is proposed. The ...effectiveness of the proposed design is assessed by joint simulations of finite element analysis (FEA) and computational fluid dynamics (CFD). Concurrently, the orthogonal experimental method is utilized to investigate the performance of the criss-crossed matching design at various operating conditions. The results show that the GDL deformation rate of the criss-crossed matching design with error in practical assembly is merely 4.8%, significantly lower than the 19.9% observed in the aligned matching design. Furthermore, the criss-crossed design performance could be improved by 5.9% compared to the aligned matching design in practical assembly with error. The criss-crossed matching design consistently outperforms the aligned matching design at various operating conditions. Notably, the highest performance growth rate, observed in high stoichiometric ratio and high humidity, reaches 12.38%.
•A criss-crossed matching design of the bipolar plate is proposed.•Criss-crossed design performance is seldomly impacted by assembly errors.•Criss-crossed matching design increases performance by 5.9% over aligned design.•Criss-crossed matching design works well in various conditions.
Background: Combined therapy with tyrosine kinase inhibitors (TKIs) and anti-PD-1 antibodies has shown high tumor response rates for patients with unresectable hepatocellular carcinoma (HCC). ...However, using this treatment strategy to convert initially unresectable HCC to resectable HCC was not reported. Methods: Consecutive patients with unresectable HCC who received first-line therapy with combined TKI/anti-PD-1 antibodies were analyzed. Tumor response and resectability were evaluated via imaging every 2 months (±2 weeks) using RECIST v1.1. Resectability criteria were (1) R0 resection could be achieved with sufficient remnant liver volume and function; (2) intrahepatic lesions were evaluated as partial responses or stable disease for at least 2 months; (3) no severe or persistent adverse effects occurred; and (4) hepatectomy was not contraindicated. Results: Sixty-three consecutive patients were enrolled. Of them, 10 (15.9%) underwent R0 resection in 3.2 months (range: 2.4–8.3 months) after the initiation of combination therapy. At baseline, these 10 patients had a median largest tumor diameter of 9.3 cm, 7 had Barcelona Clinic Liver Cancer stage C (vascular invasion) disease, 2 had stage B, and 1 had stage A. Before surgery, 6 patients were evaluated as a partial response, 3 stable disease, and 1 partial response in the intrahepatic lesion but a new metastatic lesion in the right adrenal gland. Six patients (60%) achieved a pathological complete response. One patient died from immune-related adverse effects 2.4 months after hepatectomy. After a median follow-up of 11.2 months (range: 7.8–15.9 months) for other 9 patients, 8 survived without disease recurrence, and 1 experienced tumor recurrence. Conclusions: Combination of TKI/anti-PD-1 antibodies is a feasible conversion therapy for patients with unresectable HCC to become resectable. This study represents the largest patient cohort on downstaging role of combinational systemic therapy on TKI and PD-1 antibody for HCC.
Modal identification is based on modal superposition theory. For structures with proportional damping, the structural responses are recognized as real modal shapes multiplied by real modal ...coordinates. However, it is not true because the actual modal shapes should be complex even though they can be normalized to real ones. If the modal shapes are recognized as real ones, the modal superposition theory cannot reflect the actual modal parameters. This paper proposes an innovative method to identify complex frequencies for a structure with proportional damping using the identified real modal shapes, where the complex modal shapes are considered. The proportional damping is ideal but always assumed in practical engineering. The characteristic of the proposed method is that the complex property of frequencies is considered along with modal identification process. First, the reason why the complex modal shapes are hidden is revealed. When the real modal shapes are obtained, the Hilbert transform of analytical responses is used to estimate complex coordinates. Then, formulas to identify the complex frequencies are derived. The k‐means clustering method is employed. Finally, the proposed method is used in a numerical example and a practical bridge example. The results show that the proposed method can estimate the complex frequencies effectively, and can be used in practical engineering.
A collaborative design method for multi-types of graphite end plates geometric parameters, membrane electrolyte assembly physical parameters, and operating parameters, was novelly developed to break ...bounds of parameter types for design stage and operational stage matching in fuel cells. A multi-step design method, assisted by a surrogate-assisted hierarchical particle swarm optimization algorithm, was used for the optimal design of multi-type parameters. During this multi-step design process, the initial experiments are implemented following the design of experiments, and further experiments are adaptively carried out under the guidance of the layered optimization method. Experimental evidence of cell performance response to the coupled effects of multi-parameters was firstly provided and discussed in details. The collaborative design of multi-type parameters realized using the proposed multi-step design method was proven to improve the energy conversion efficiency by 10.9%. Different performance requirements, from single to multiple objectives in various types of fuel cells, were also shown to be fulfilled using this collaborative design method.
•Collaborative design of multi-type parameters in fuel cell systems is realized.•A multi-step design method is proposed to break bounds of parameter types.•Design and operational stage matching contributes to energy conversion efficiency improvement.•The design of multi-type parameters can be flexible and adapt to different performance requirements and fuel cells.
•Non-uniform cross-sectional designs are systematically investigated.•Converging design enhances both in- and through-plane methanol transportations.•Converging design is numerically proven to ...enhance power generation to 12%.•Efficacy of non-uniform design is clarified at various experimental conditions.•Optimal application conditions of converging design have also been determined.
Non-uniform cross-sectional designs of serpentine channel in direct methanol fuel cells are systematically studied in the present work. A parametric design is proposed to describe and classify channel geometries whose effects on cell performance are numerically and experimentally analyzed. Numerical results show that the non-uniform converging designs are beneficial for both in- and through-plane methanol transportations, and thus to enhance the peak power generation performance as much as 12% at high-current-density operations. Effectiveness of non-uniform designs for power generation enhancements is also validated by experimental studies which consider various operating conditions, and significant enhancement of power generation (18.4%) is noticed by the usage of non-uniform converging design. Optimal application conditions for the non-uniform converging designs are determined to be the high-current-density operations with high temperatures.
Background
Combined treatment with tyrosine kinase inhibitors (TKI) plus anti-PD-1 antibodies showed high anti-tumor efficacy and made conversion resection possible for patients with unresectable ...hepatocellular carcinoma (HCC). However, long-term survival has not been reported.
Methods
A cohort of consecutive patients who received combined TKI/anti-PD-1 antibodies as first-line treatment for initially unresectable HCC at the authors’ hospital between August 2018 and September 2020 was eligible for this study. Patients who were responding to systemic therapy and met the criteria for hepatectomy underwent liver resection with curative intention. The study also investigated the association of clinical factors with successful conversion resection and postoperative recurrence.
Results
The study enrolled 101 patients including 24 patients (23.8 %) who underwent R0 resection a median of 3.9 months (interquartile range: 2.5–5.9 months) after initiation of systemic therapy. Patients with an Eastern cooperative oncology group performance status of 0, fewer intrahepatic tumors, or a radiographic response to systemic therapy were more likely to be able to receive curative resection. After a median follow-up period of 21.5 months, hepatectomy was independently associated with a favorable overall survival (hazard ratio HR, 0.050; 95 % confidence interval CI, 0.007–0.365;
P
= 0.003). For the 24 patients who underwent surgery, the 12-month recurrence-free survival and overall survival rates were respectively 75% and 95.8%. Achieving a pathologic complete response (
n
= 10) to systemic therapy was associated with a favorable recurrence-free survival after resection, with a trend toward significance (HR, 0.345; 95% CI, 0.067–1.785;
P
= 0.187).
Conclusions
Selected patients with initially unresectable HCC can undergo hepatectomy after systemic therapy with combined TKI/anti-PD-1 antibodies. In this study, conversion resection was associated with a favorable prognosis.
Severe asthma is the main reason for death and disability caused by asthma. However, effective biomarkers for severe asthma have not been identified. Here, we aimed to identify potential biomarkers ...in severe asthma. We identified 202 differentially expressed genes (DEGs) between severe asthma and mild-moderate asthma after integrating the results from GSE69683 and GSE27011 datasets. The enrichment analysis indicated that 202 DEGs were associated with metabolism- and immune-related processes. 10 hub genes were identified by Cytoscape and five of these genes' AUC (area under the curve) values were greater than 0.6 in GSE69683. The AUC value reached to 0.701 when combined SEC61A1 and ALDH18A1 expression. The expression of the five hub genes was verified in an external dataset. The network analysis revealed that transcription factor (TF) WT1, ZEB1, RERE, FOSL1, and miR-20a may be involved in the development of asthma. In addition, we found cyclosporine and acetaminophen could interact with these hub genes and may be negatively associated with most of the five hub genes according to previous reports. Overall, key genes were identified between mild-moderate and severe asthmatics, which contributed to the understanding of the development of asthma.
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