14 research outputs found

    Rear-end collision escape algorithm for intelligent vehicles supported by vehicular communication

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    To reduce rear-end collision risks and improve traffic safety, a novel rear-end collision escape algorithm is proposed for intelligent vehicles supported by vehicular communication. Numerous research has been carried out on rear-end collision avoidance. Most of these studies focused on maintaining a safe front clearance of a vehicle while only few considered the vehicle’s rear clearance. However, an intelligent vehicle may be collided by a following vehicle due to wrong manoeuvres of an unskilled driver of the following vehicle. Hence, it is essential for an intelligent vehicle to maintain a safe rear clearance when there is potential for a rear-end collision caused by a following vehicle. In this study, a rear-end collision escape algorithm is proposed to prevent rear-end collisions by a following vehicle considering both straight and curved roads. A trajectory planning method is designed according to the motions of the considered intelligent vehicle and the corresponding adjacent vehicles. The successive linearization and the Model Predictive Control (MPC) algorithms are used to design a motion controller in the proposed algorithm. Simulations were performed to demonstrate the effectiveness of the proposed algorithm. The results show that the proposed algorithm is effective in preventing rear-end collisions caused by a following vehicle. First published online 18 January 202

    Extraction of phosphorus from metallurgical grade silicon using a combined process of Si-Al-Ca solvent refining and CaO-CaF 2 slag treatment

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    Abstract(#br)A combined purification process of Si-Al-Ca solvent refining and CaO-CaF 2 slag treatment was investigated with a focus on removing phosphorus (P) from metallurgical-grade Si (MG-Si). The primary precipitates in the slag-treated Si-Al-Ca alloy are CaAl 2 Si 2 and CaSi 2 , and these precipitates can be eliminated via leaching with HCl + CH 3 COOH and HCl + HF in sequence. Compared to MG-Si, a higher extraction efficiency of P was achieved with Si-Al-Ca alloy after CaO-CaF 2 slag treatment. Influences of alloy composition, slag components, and operation parameter on the P removal efficiency were studied systematically. The optimal dephosphorization efficiency reached 98.6% when the 70%Si-Al-Ca alloy was treated with 20%CaO–80%CaF 2 slag twice. Furthermore, the mechanism of P removal using the combined process was studied. The results indicate that the Si-Al-Ca solvent refining causes the segregation coefficient of P to be lower, thus facilitating its mass transfer in slag treatment. A large amount of P was reduced and then diffused to the slag phase in the slag experiment. Residual P in the slag-treated alloy was trapped by the CaAl 2 Si 2 phase and was then removed via acid leaching

    Competitive Coexistence in a Two-Strain Epidemic Model with a Periodic Infection Rate

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    In this article, we study the global dynamical behavior of a two-strain SIS model with a periodic infection rate. The positivity and boundedness of solutions are established, and the competitive exclusion conditions are given for the model. The conditions for the global stability of the disease-free equilibrium and persistence of the model are obtained. The conditions of coexistence in this model are also found. Finally, the conditions of uniqueness of the solution are proved

    Trajectory planning algorithm for merging control of heterogeneous vehicular platoon on curve road

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    The main goal of this study is to propose a trajectory planning algorithm for the merging control of heterogeneous vehicular platoons. Merging control is essential for the application of vehicular platoons, by which vehicles can be coordinated to form a platoon in a lane. While most previous researches on merging control only considered the operation on straight roads and ramps. Few studies have investigated the merging operation on curve roads, which may hinder the application of platoons on general traffic environment. In this study, a trajectory planning algorithm is proposed for the merging control of heterogeneous vehicular platoons on curve roads with constant radius. The proposed algorithm consists of two stages for the operation of merging: the first stage is to align the vehicles in each lane to form a structure with a certain clearance; the second stage is to conduct a lane changing manoeuvre for each merging vehicle to form a platoon in a lane. In the proposed algorithm, the dynamic limits of speed and acceleration are considered. The distance of each vehicle can be guaranteed to avoid undesired collisions. Two simulations are carefully conducted for the merging control of heterogeneous vehicular platoons on a curve road to demonstrate the effectiveness of the proposed algorithm. The results of simulations indicate that the proposed algorithm is capable of the merging control of platoons on a curve road

    Virtual Belt Algorithm for the Management of Isolated Autonomous Intersection

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    To enhance traffic efficiency, in this paper, a novel virtual belt algorithm is proposed for the management of an isolated autonomous intersection. The proposed virtual belt algorithm consists of an offline algorithm and an online algorithm. Using the offline algorithm, the considered intersection can be modeled as several virtual belts. The online algorithm is designed for the real-time application of the virtual belt algorithm. Compared with the related algorithms, the main advantage of the proposed algorithm is that, there are several candidate trajectories for each approaching vehicle. Thus, there are more opportunities for an approaching vehicle to obtain a permission to pass an intersection, which is effective to improve traffic efficiency. The proposed algorithm is validated using numerical simulations conducted by Matlab and VISSIM. The simulation results show that the proposed algorithm is effective for autonomous intersection management

    UC-BSCs Exosomes Regulate Th17/Treg Balance in Patients with Systemic Lupus Erythematosus via miR-19b/KLF13

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    Umbilical cord blood mesenchymal stem cells (UC-BSCs) are cells with low immunogenicity and differentiation potential, and the transfer of exosomes carried by UC-BSCs can regulate innate and adaptive immunity and affect immune homeostasis. This is an area of focus for autoimmune illnesses such as systemic lupus erythematosus (SLE). The target of this research was to investigate the immunomodulatory effect of exosomes produced from mesenchymal stem cells on SLE and its mechanism. After isolation of peripheral blood mononuclear cells (PBMC) from the SLE group and healthy group and treatment of SLE-derived PBMCs with UC-BSC-derived exosomes, the mRNA levels of corresponding factors in cells under different treatments were determined by RT-PCR, Th17/Treg content was analyzed by FCM (flow cytometry), and the targeted binding of microRNA-19b (miR-19b) to KLF13 was identified by in vitro experiments and bioinformatics analysis. The findings demonstrated that PBMC cells from SLE patients had higher proportions of Th17 subsets than the control group, whereas Treg subgroups with lower percentages were discovered. miR-19b’s expression level was markedly reduced, which was inversely associated to the concentration of KLF13. In vitro experiments show that UC-BSC-derived exosome treatment can target KLF13 expression by increasing the miR-19b level, thereby regulating Th17/Treg balance and inhibiting the expression of inflammatory factors. According to the study’s findings, SLE patients have dysregulated expression of the genes miR-19b and KLF13, and UC-BSC exosomes could regulate Th17/Treg cell balance and inflammatory factor expression in SLE patients through miR-19b/KLF13

    Exploring the landscape, hot topics, and trends of bariatric metabolic surgery with machine learning and bibliometric analysis

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    Background: This study aimed to analyze the landscape of publications on bariatric metabolic surgery through machine learning and help experts and scholars from various disciplines better understand bariatric metabolic surgery’s hot topics and trends. Methods: In January 2021, publications indexed in PubMed under the Medical Subject Headings (MeSH) term ‘Bariatric Surgery’ from 1946 to 2020 were downloaded. Python was used to extract publication dates, abstracts, and research topics from the metadata of publications for bibliometric evaluation. Descriptive statistical analysis, social network analysis (SNA), and topic modeling with latent Dirichlet allocation (LDA) were used to reveal bariatric metabolic surgery publication growth trends, landscape, and research topics. Results: A total of 21,798 records of bariatric metabolic surgery–related literature data were collected from PubMed. The number of publications indexed to bariatric metabolic surgery had expanded rapidly. Obesity Surgery and Surgery for Obesity and Related Diseases are currently the most published journals in bariatric metabolic surgery. The bariatric metabolic surgery research mainly included five topics: bariatric surgery intervention, clinical case management, basic research, body contour, and surgical risk study. Conclusion: Despite a rapid increase in bariatric metabolic surgery–related publications, few studies were still on quality of life, psychological status, and long-term follow-up. In addition, basic research has gradually increased, but the mechanism of bariatric metabolic surgery remains to be further studied. It is predicted that the above research fields may become potential hot topics in the future

    Table_4_Identification of a novel variant in N-cadherin associated with dilated cardiomyopathy.DOCX

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    BackgroundDilated cardiomyopathy (DCM), which is a major cause of heart failure, is a primary cardiac muscle disease with high morbidity and mortality rates. DCM is a genetically heritable disease and more than 10 gene ontologies have been implicated in DCM. CDH2 encodes N-cadherin and belongs to a superfamily of transmembrane proteins that mediate cell–cell adhesion in a calcium-dependent manner. Deficiency of CDH2 is associated with arrhythmogenic right ventricular cardiomyopathy (OMIM: 618920) and agenesis of the corpus callosum, cardiac, ocular, and genital syndrome (OMIM: 618929). However, there have been no reports of isolated DCM associated with CDH2 deficiency.MethodsWe performed whole exome sequencing in a 12-year-old girl with non-syndromic DCM and her unaffected parents. Variants in both known DCM-related genes and novel candidate genes were analyzed and pathogenicity confirmation experiments were performed.ResultsNo pathogenic/likely pathogenic variant in known DCM-related genes was identified in the patient. We found a de novo variant in a candidate gene CDH2 in the patient, namely, c.474G>C/p.Lys158Asn (NM_001792.5). This variant has not been reported in the ClinVar or Human Gene Mutation Database (HGMD). CDH2 p.Lys158Asn was found in the conserved domain of N-cadherin, which is associated with the hydrolysis of the precursor segment and interference with adhesiveness. Furthermore, we tested the expression and efficiency of cell–cell adhesion while overexpressing the CDH2 Lys158Asn mutant and two previously reported variants in CDH2 as positive controls. The adhesion efficiency was considerably reduced in the presence of the mutated CDH2 protein compared with wild-type CDH2 protein, which suggested that the mutated CDH2 protein's adhesion capacity was impaired. The variant was probably pathogenic after integrating clinical manifestations, genetic analysis, and functional tests.ConclusionWe identified a CDH2 variant in DCM. We observed a new clinical symptom associated with N-cadherin deficiency and broadened the genetic spectra of DCM.</p
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