Distributed Extended Object Tracking Using Coupled Velocity Model from WLS Perspective

This study proposes a coupled velocity model (CVM) that establishes the relation between the orientation and velocity using their correlation, avoiding that the existing extended object tracking (EOT) models treat them as two independent quantities. As a result, CVM detects the mismatch between the prior dynamic model and actual motion pattern to correct the filtering gain, and simultaneously becomes a nonlinear and state-coupled model with multiplicative noise. The study considers CVM to design a feasible distributed weighted least squares (WLS) filter. The WLS criterion requires a linear state-space model containing only additive noise about the estimated state. To meet the requirement, we derive such two separate pseudo-linearized models by using the first-order Taylor series expansion. The separation is merely in form, and the estimates of interested states are embedded as parameters into each other's model, which implies that their interdependency is still preserved in the iterative operation of two linear filters. With the two models, we first propose a centralized WLS filter by converting the measurements from all nodes into a summation form. Then, a distributed consensus scheme, which directly performs an inner iteration on the priors across different nodes, is proposed to incorporate the cross-covariances between nodes. Under the consensus scheme, a distributed WLS filter over a realistic network with ``naive'' node is developed by proper weighting of the priors and measurements. Finally, the performance of proposed filters in terms of accuracy, robustness, and consistency is testified under different prior situations.Comment: Corrected Versio

Kinematics and stiffness of a planar tensegrity parallel mechanism

In this work, the kinematics and stiffness of a planar tensegrity parallel mechanism are investigated. The analytical solutions to the forward and reverse kinematics were found using an energy method. The singular configurations and workspaces were detailed. Afterwards, the stiffness of the mechanism was analyzed. It is demonstrated that the stiffness is at a local maximum when the mechanism is in stable equilibrium and at a local minimum when the mechanism is in unstable equilibrium. The stiffness distributions are approximately symmetric about a certain line inside the actuator and Cartesian workspaces. Large values of the actuator length should be selected for high stiffness applications. The singular configurations, workspaces and stiffness variations inside the actuator and Cartesian workspaces lay a foundation for the use of the mechanism

Compulsive eating of binge- like eating prone rats under conditioned fear and exploration of the neural mechanism with c-fos expression

Le trouble de l'hyperphagie boulimique (THB) est un trouble de l'alimentation défini de manière autonome dans la 5e édition du Manuel diagnostique et statistique des troubles mentaux (DSM-5) en mai 2013. Le THB est caractérisé par des épisodes d'ingestion d'une quantité anormalement élevée de nourriture dans une courte période de temps sans comportements compensatoires tels que des vomissements auto-induits. La prévalence du THB a augmenté très rapidement en raison de la grande disponibilité d'aliments riches en calories et du stress croissant dans la vie moderne. Malheureusement, l'étiologie du THB est encore mal comprise et les traitements cliniques actuels du THB sont principalement limités à la thérapie cognitive comportementale, dont le pronostic est également assez limité. Afin d'étudier le THB, notre laboratoire a précédemment développé un modèle de THB chez le rat en utilisant une combinaison de stress causé par des chocs électriques aux pattes et d'un accès intermittent d'une heure à une solution de sucrose à 10%. Dans notre modèle de rat THB, les rats sujets à la frénésie alimentaire (BEP; de l'anglais binge-eating prone) ont consommé plus de sucrose que les rats résistants à la frénésie alimentaire (BER, de l'anglais binge-eating resistant) à la fois dans des conditions normales et ces rats ont augmenté davantage leur consommation après avoir vécu le stress. Nous avons également observé une alimentation compulsive dans les rats BEP avec notre test modifié de boîte claire / sombre. Une alimentation compulsive est la caractéristique la plus obstinée du THB. Mon projet de thèse se concentre sur l'observation de l'alimentation compulsive dans le modèle de THB chez le rat avec un test concurrentiel, dans lequel les comportements d'alimentation et d'immobilité ont été surveillés en présence d'un stimulus auditif conditionné de manière aversive. Les rats BEP ont montré une consommation persistante élevée de sucrose et ont montré une réponse inhibée à la peur induite en situation stressante en comparaison aux rats BER, indiquant respectivement un déficit de dévaluation de l'appétence et une réponse anxiolytique plus forte au sucrose. Après l'observation de l'alimentation compulsive dans nos rats BEP, nous avons analysé les activités cérébrales de ces rats avec l'hybridation in situ de l'ARNm c-fos. Nous avons trouvé que, dans les rats BEP, le sucrose réduisait l'activité c-fos du noyau paraventriculaire de l'hypothalamus, tout en augmentant l'activité dans la zone hypothalamique latérale face au stimulus conditionné aversif. La résistance à la dévaluation de l'appétence de la nourriture pourrait être le résultat d'un recrutement atténué de la réponse iii du cortex préfrontal médian et d'une réponse persistante du noyau accumbens à la consommation de sucrose. Ces résultats suggèrent que le système de récompense a pris le dessus sur les systèmes homéostatiques et répondant au stress. Étonnamment, l'apport de sucrose sous la peur conditionnée n'a pas inhibé l'activité de l'amygdale centrale, mais l'a plutôt activée à la place. Cette étude a exploré le mécanisme de l'alimentation compulsive dans un modèle de THB et a fourni certaines cibles cérébrales, telles que le noyau accumbens, pour de futures recherches thérapeutiquesThe binge eating disorder (BED) is an eating disorder that was defined in the 5th edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in May 2013. The BED is characterized by episodes of ingestion of abnormally large amounts of food in a short period of time without compensative behaviors such as self-induced vomiting. The prevalence of the BED is on the rise due to the availability of high-calorie food and the stressors of modern life. Unfortunately, the etiology of the BED is still poorly understood, and current clinical treatments of the BED are mostly limited to cognitive behavioral therapy, of which the prognosis is also quite limited. In order to study the BED, our lab previously developed a rat model of the BED with combination of foot-shock stress and intermittent 1 h access to a 10% sucrose solution. In our BED rat model, the binge-like eating prone rats (BEPs) consumed more sucrose than the binge-like eating resistant rats (BERs) in normal conditions and consumed more sucrose in response to stress. We also observed compulsive eating in the BEPs with our modified light/dark box test. Compulsive eating is the most obstinate feature of the BED. My PhD project focuses on the observation of compulsive eating in the BED rat model with a conflicting test, in which the feeding and freezing behaviors were monitored in the presence of an aversively conditioned auditory stimulus. The BEPs showed persistently high sucrose intake and inhibited fear response under stress when comparted with BERs, respectively indicating a deficiency in palatability devaluation and stronger anxiolytic response to sucrose. After the observation of compulsive eating in the BEPs, we further analyzed the brain activities of the BEPs and BERs by analyzing the expression of c-fos mRNA using in situ hybridization. In the BEPs, we found that sucrose reduced c-fos expression in the paraventricular nucleus of the hypothalamus (PVN) in response to an aversively conditioned stimulus (CS), but enhanced activities in the lateral hypothalamic area (LHA) in response to the CS. The resistance to devaluating the palatable food could be a result of attenuated recruitment of the medial prefrontal cortex (mPFC) and persistent nucleus accumbens (Acb) response to the sucrose intake. These findings suggest that the rewarding system overrode the homeostatic and the stress-responding systems. Surprisingly, the sucrose intake under fear conditions did not inhibit the activity of the central amygdala, but further activated it instead. Current study explored the mechanism of compulsive eating in the BED, and suggests that the mPFC and Acb should be examined for further therapeutic

Fundamental Studies of the Structure-Property Correlations of Na-ion and K-ion Storage in Non-Graphitic Carbon

Grid-scale energy storage systems are urgently needed to increase the flexibility and rigidity of the grid for modern society and take full advantage of the renewable green energy resources such as solar energy and wind energy. Na-ion batteries (NIBs) and K-ion batteries (KIBs) have been emerged as one of the most promising solutions for grid-scale energy storage systems. Unfortunately, graphite, which is the commercialized anode in LIBs, does not show meaningful capacity in NIBs, and it shows poor cycling performance in KIBs. Non-graphitic carbon materials have been shown promising electrochemical performance in NIBs and KIBs. However, due to the structural complexity of non-graphitic carbon, the structure-property correlations of non-graphitic carbon anodes for Na-ion and K-ion storage are still not well established. Therefore, in this thesis, I focus on understanding the structure-property correlations of Na-ion and K-ion storage in non-graphitic carbon and improving the Na-ion and K-ion storage performance of non-graphitic carbon anodes. There had been reports regarding the structure-property correlations of hard carbon anodes in NIBs, where discrepancies still exist. In addition, the capacity of hard carbon anodes in NIBs rarely reaches values beyond 300 mAh/g. Herein, in this thesis, we first applied POx doping on hard carbon to tune its structure, which increases its reversible capacity from 283 to 359 mAh/g. We observe the interlayer d-spacing of the turbostratic nanodomains is expanded and the defect concentration of the doped hard carbon is increased. The structural changes of hard carbon lead to enhanced plateau and slope capacity. Our study demonstrates that Na-ion storage in hard carbon heavily depends on carbon local structures, where such structures, despite being disordered, can be tuned toward unusually high capacities. Even though our above-mentioned results agree well with our early proposed model, the structure-property correlations of Na-ion storage in hard carbon is still not solidified. Furthermore, how defects affect the slope capacity and what types of defects are beneficial for the slope capacity is still not clear. Therefore, in our following work, we synthesized a series of well-controlled heteroatom doped hard carbons, namely, P-, S- and B-doped hard carbon, and non-doped hard carbon where they show consistently low surface area. We then comprehensively characterized these hard carbons’ structural features and electrochemical performance which allows us to reveal the mechanism of Na-ion storage in hard carbon. Our combined experimental studies and first principles calculations reveal that it is the Na-ion-defect binding that corresponds to the slope capacity, while the Na intercalation between graphenic layers is responsible for the low-potential plateau capacity. In addition, our computational results also revealed that too strong binding between Na-ion and defects will lead to irreversibility. The new understanding provides a new set of design principles to optimize hard carbon anode for Na-ion storage. In a recent work, guided by our proposed design principles, we synthesized a highly defective hard carbon by microwave heating a low-temperature (650˚C) pre-annealed hard carbon. After a brief microwave treatment, i.e., for 6 seconds, the reversible capacity of the hard carbon was increased from 204 to 308 mAh/g. The microwaved carbon retains a high extent of structural defects after microwaving the low-temperature annealed hard carbon. Such a defective structure exhibits a much higher slope capacity than conventional hard carbon with less low-potential plateau capacity which can reduce the safety concerns. The microwave heating of carbon represents a new direction for tuning structures of hard carbon. The rate capability of hard carbon has long been underestimated in prior studies that used carbon/Na two-electrode half-cells. Through a three-electrode cell setup, we discover that it is the overpotential of the sodium counter electrode that drives the half-cells to the lower cutoff potential prematurely during hard carbon sodiation, particularly at high current rates, which prevents the hard carbon anode from being fully sodiated. Hard carbon demonstrates a much better rate-capability in this three-electrode setup. In the last part of this thesis, we studied soft carbon as anode for K-ion storage. In this work, we synthesized a series of soft carbons (SCs) by the pyrolysis of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) at different temperatures. By using polyacrylic acid as the binder, SC obtained at 700˚C (SC700) shows the highest capacity of 354 mAh/g which is the highest capacity of non-graphitic carbons reported so far by accounting the potential between 0-2 V. More importantly, SC700 shows a better cycling stability than SCs obtained at higher temperature, where it is still worse than the cycling performance of hard carbons. Via combined experimental and computational studies, we generate mechanistic insights about the structure-property correlations of K-ion storage in soft carbons