Distributed Model Predictive Control for Heterogeneous Vehicle Platoon with Inter-Vehicular Spacing Constraints

This paper proposes a distributed control scheme for a platoon of heterogeneous vehicles based on the mechanism of model predictive control (MPC). The platoon composes of a group of vehicles interacting with each other via inter-vehicular spacing constraints, to avoid collision and reduce communication latency, and aims to make multiple vehicles driving on the same lane safely with a close range and the same velocity. Each vehicle is subject to both state constraints and input constraints, communicates only with neighboring vehicles, and may not know a priori desired setpoint. We divide the computation of control inputs into several local optimization problems based on each vehicle’s local information. To compute the control input of each vehicle based on local information, a distributed computing method must be adopted and thus the coupled constraint is required to be decoupled. This is achieved by introducing the reference state trajectories from neighboring vehicles for each vehicle and by employing the interactive structure of computing local problems of vehicles with odd indices and even indices. It is shown that the feasibility of MPC optimization problems is achieved at all time steps based on tailored terminal inequality constraints, and the asymptotic stability of each vehicle to the desired trajectory is guaranteed even under a single iteration between vehicles at each time. Finally, a comparison simulation is conducted to demonstrate the effectiveness of the proposed distributed MPC method for heterogeneous vehicle control with respect to normal and extreme scenarios

Triangle Counting Rule: An Approach to Forecast the Magnetic Properties of Benzenoid Polycyclic Hydrocarbons

Open-shell benzenoid polycyclic hydrocarbons (BPHs) are promising materials for future quantum applications. However, the search and realization of open-shell BPHs with desired properties is a challenging task due to the gigantic chemical space of BPHs, requiring new strategies for both theoretical understanding and experimental advancement. In this work, by building a structure database of BPHs through graphical enumeration, performing data-driven analysis, and combining tight-binding and mean-field Hubbard calculations, we discovered that the number of the internal vertices of the BPH graphs is closely correlated to their open-shell characters. We further established a series of simple rules, the triangle counting rule (TCR), to predict the magnetic ground state of BPHs. These findings not only provide a database of open-shell BPHs, but also extend the well-known Lieb's theorem and Ovchinnikov's rule and provide a straightforward method for designing open-shell carbon nanostructures. These insights may aid in the exploration of emerging quantum phases and the development of magnetic carbon materials for technology applications.Comment: 6 pages, 4 figure

Long-term effects of total vs. partial pancreatectomy among patients with pancreatic cancer: a population-based study

Background: Total pancreatectomy (TP) for pancreatic cancer (PC) has been limited historically for fear of elevated perioperative morbidity and mortality. With advances in perioperative care, TP may be an alternative option to partial pancreatectomy (PP). Limited evidence clarified the indication for these two procedures in PC patients, especially in patients with different tumor staging and location. Thus, this study aims to compare the outcomes after TP and PP for PCs of different T stages and locations. Methods: The study identified 14,456 PC patients with potentially curable primary tumor (T1???3) who received TP or PP from the Surveillance, Epidemiology, and End Results (SEER) database during 2000 to 2016. Detailed clinical and tumor covariates were all collected. Overall survival (OS) and cancer-specific survival (CSS) were the primary endpoints of interest in this study. OS and CSS were compared between patients after TP and PP using log-rank analysis. Results: For all patients, except for tumor location, TP group was comparable to the PP group. OS and CSS of the TP group were worse than of the PP group (median OS: 19 vs. 20 months, P=0.0058; median CSS: 24 vs. 26 months, P=0.00098, respectively). In stratifying analyses, TP was significantly related to worse OS and CSS than PP in pancreatic head and neck cancer patients with T2-stage tumors (median OS: 18 vs. 19 months, P=0.0016; median CSS: 22 vs. 24 months, P=0.00055, respectively), whereas for patients with T1-or T3-stage pancreatic head and neck cancer as well as T1-to T3-stage pancreatic body and tail cancer or overlapping location cancer, OS and CSS of the two groups were similar (all P>0.05). Conclusions: Compared with PP, TP offered worse prognosis in pancreatic head and neck cancer patients with T2-stage tumors, furthermore, TP and PP achieved comparable prognosis in patients with T1-or T3-stage pancreatic head and neck cancer as well as T1-to T3-stage pancreatic body and tail cancer or overlapping location cancer

A Recombination Hotspot in a Schizophrenia-Associated Region of GABRB2

Background: Schizophrenia is a major disorder with complex genetic mechanisms. Earlier, population genetic studies revealed the occurrence of strong positive selection in the GABRB2 gene encoding the β2 subunit of GABAA receptors, within a segment of 3,551 bp harboring twenty-nine single nucleotide polymorphisms (SNPs) and containing schizophrenia-associated SNPs and haplotypes. Methodology/Principal Findings:In the present study, the possible occurrence of recombination in this 'S1-S29' segment was assessed. The occurrence of hotspot recombination was indicated by high resolution recombination rate estimation, haplotype diversity, abundance of rare haplotypes, recurrent mutations and torsos in haplotype networks, and experimental haplotyping of somatic and sperm DNA. The sub-segment distribution of relative recombination strength, measured by the ratio of haplotype diversity (Hd) over mutation rate (θ), was indicative of a human specific Alu-Yi6 insertion serving as a central recombining sequence facilitating homologous recombination. Local anomalous DNA conformation attributable to the Alu-Yi6 element, as suggested by enhanced DNase I sensitivity and obstruction to DNA sequencing, could be a contributing factor of the increased sequence diversity. Linkage disequilibrium (LD) analysis yielded prominent low LD points that supported ongoing recombination. LD contrast revealed significant dissimilarity between control and schizophrenic cohorts. Among the large array of inferred haplotypes, H26 and H73 were identified to be protective, and H19 and H81 risk-conferring, toward the development of schizophrenia. Conclusions/Significance: The co-occurrence of hotspot recombination and positive selection in the S1-S29 segment of GABRB2 has provided a plausible contribution to the molecular genetics mechanisms for schizophrenia. The present findings therefore suggest that genome regions characterized by the co-occurrence of positive selection and hotspot recombination, two interacting factors both affecting genetic diversity, merit close scrutiny with respect to the etiology of common complex disorders. © 2010 Ng et al

Tribocorrosion Failure Mechanism of TiN/SiOx Duplex Coating Deposited on AISI304 Stainless Steel

TiN/SiOx duplex coatings were synthesized on AISI304 stainless steel by plasma immersion ion implantation and deposition (PIIID) followed by radio frequency magnetron sputtering (RFMS). The microstructure and tribocorrosion failure behaviors of the duplex coatings were investigated by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, reciprocating-sliding tribometer, and electrochemical tests. The as-deposited duplex coating had a two-layered columnar growth structure consisting of face-centered cubic TiN and amorphous SiOx. Sliding tests showed that the TiN interlayer had good adhesion with the substrate, but the SiOx layer suffered from severe delamination failure. Friction force induced a number of micro-cracks in the coating, which provided channels for the diffusion of NaCl solution. The tribocorrosion test showed that the duplex coating exhibited a lower wear-performance in NaCl solution than in ambient atmosphere. Multi-scale chloride ion corrosion occurred simultaneously and substantially degraded the bonding strength of the columnar crystals or neighboring layers. Force-corrosion synergy damage eventually led to multi-degradation failure of the duplex coating. The presented results provide a comprehensive understanding of the tribocorrosion failure mechanism in coatings with duplex architecture

Detecting abnormal patterns of daily activities for the elderly living alone

International audienceIn order to reduce the potential risks associated with physically and cognitively impaired ability of the elderly living alone, in this work, we develop an automated method that is able to detect abnormal patterns of the elderly's entering and exiting behaviors collected from simple sensors equipped in home-based setting. With spatiotemporal data left by the elderly when they carrying out daily activities, a Markov Chains Model (MCM) based method is proposed to classify abnormal sequences via analyzing the probability distribution of the spatiotemporal activity data. The experimental evaluation conducted on a 128-day activity data of an elderly user shows a high detection ratio of 92.80% for individual activity and of 92.539% for the sequence consisting of a series of activitie

pi-pi interaction between fluorinated reduced graphene oxide and acridizinium ionic liquid: Synthesis and anti-corrosion application

Graphene has long been considered a superlative protection material due to its extraordinary characteristics and properties. However, its high electrical conductivity can facilitate the electrochemical corrosion of metal, which strongly limits its anti-corrosion applications. Here, we developed a facile fluorination strategy to suppress the corrosion promotion activity of graphene. Fluorinated reduced graphene oxide (FrGO) exhibited low electrical conductivity (3.643 x 10(-13) S/cm), which proved unable to trigger micro-galvanic corrosion. Furthermore, acridizinium ionic liquid (IL) [MAc]Br was non-covalently grafted on FrGO to achieve the well dispersion in the polymer matrix. Results revealed that FrGO-IL nanohybrid can be stably dispersed in the epoxy resin. Electrochemical impedance spectroscopy revealed that incorporating a small percentage of FrGO-IL into waterborne epoxy matrix effectively improved the corrosion resistance performance of the coating by exerting the superior shielding effect and inhibiting the ability for micro-galvanic corrosion. Moreover, local electrochemical and scratching tests further confirmed that FrGO-IL significantly reinforced the corrosion protection capability of waterborne epoxy coating because the well-dispersed nanohybrid enhanced the integrity of the composite coating, effectively utilizing the labyrinth effect. Our finding could inspire the development of new graphene-based materials with superior protection properties for metal materials. (C) 2019 Elsevier Ltd. All rights reserved

Micro- to Nanoscale Morphologies and Chemical Components of Soils Investigated by SEM-EDS for Forensic Science

As a kind of microscale physical evidence, soil can provide significant assistance to forensic science. In this study, soil samples that were collected from eighteen different regions of Shandong Province, China, were examined by scanning electron microscope-energy dispersive spectrometer (SEM-EDS). The homogeneities and diameters of the samples were evaluated by SEM which has been applied to observe objects at nanoscale. The soil from Jiaxiang, a city in Eastern Shandong Province, showed the maximal particle diameter and the sample from Liaocheng, another Eastern city in Shandong Province, showed the best homogeneity. The mass fraction and molar percentages of nine inorganic elements in all samples were analyzed by EDS. Oxygen and silicon showed the highest content in all of these samples. However, different samples exhibited their own characteristic elements, which can help to discriminate them from other samples. In this regard, SEM-EDS-based homogeneity and element analysis might be used as a fast and reliable technique for the soil criminological analysis in Shandong Province