Model Predictive Control for Autonomous Driving Based on Time Scaled Collision Cone

In this paper, we present a Model Predictive Control (MPC) framework based on path velocity decomposition paradigm for autonomous driving. The optimization underlying the MPC has a two layer structure wherein first, an appropriate path is computed for the vehicle followed by the computation of optimal forward velocity along it. The very nature of the proposed path velocity decomposition allows for seamless compatibility between the two layers of the optimization. A key feature of the proposed work is that it offloads most of the responsibility of collision avoidance to velocity optimization layer for which computationally efficient formulations can be derived. In particular, we extend our previously developed concept of time scaled collision cone (TSCC) constraints and formulate the forward velocity optimization layer as a convex quadratic programming problem. We perform validation on autonomous driving scenarios wherein proposed MPC repeatedly solves both the optimization layers in receding horizon manner to compute lane change, overtaking and merging maneuvers among multiple dynamic obstacles.Comment: 6 page

In vitro antimitotic activity and in silico study of some 6-fluoro-triazolo-benzothiazole analogues

In this work, nine 6-fluoro-triazolo-benzothiazole derivatives were prepared and evaluated for in vitro antimitotic activity. In addition, in silico study was also done using tubulin protein (PDB: 6QQN) by molecular docking method. Results revealed that TZ2 and TZ9 were the most active compounds with antimitotic action opposing the standard drug, aspirin. Results of molecular docking exhibited the inhibitory potential of triazolo-benzothiazole against tubulin protein. The mitotic study indicates the efficacy of triazolo-benzothiazole analogues in inhibiting the proliferation of cancer cells either by promoting microtubule formation or affecting microtubules, thereby preventing microtubule breakdown

Fast Adaptation of Manipulator Trajectories to Task Perturbation by Differentiating through the Optimal Solution

Joint space trajectory optimization under end-effector task constraints leads to a challenging non-convex problem. Thus, a real-time adaptation of prior computed trajectories to perturbation in task constraints often becomes intractable. Existing works use the so-called warm-starting of trajectory optimization to improve computational performance. We present a fundamentally different approach that relies on deriving analytical gradients of the optimal solution with respect to the task constraint parameters. This gradient map characterizes the direction in which the prior computed joint trajectories need to be deformed to comply with the new task constraints. Subsequently, we develop an iterative line-search algorithm for computing the scale of deformation. Our algorithm provides near real-time adaptation of joint trajectories for a diverse class of task perturbations, such as (i) changes in initial and final joint configurations of end-effector orientation-constrained trajectories and (ii) changes in end-effector goal or way-points under end-effector orientation constraints. We relate each of these examples to real-world applications ranging from learning from demonstration to obstacle avoidance. We also show that our algorithm produces trajectories with quality similar to what one would obtain by solving the trajectory optimization from scratch with warm-start initialization. Most importantly, however, our algorithm achieves a worst-case speed-up of 160x over the latter approach

An in vitro study to compare antibacterial efficacy of cinnamon extract, neem extract and sodium hypochlorite as root canal irrigants

Background: E. faecalis is the predominant micro-organism recovered from root canal of the teeth where previous endodontic treatment has failed. Thorough debridement and complete elimination of micro-organisms are objectives of an effective endodontic treatment. For many years, intracanal irrigants have been used as an adjunct to enhance antimicrobial effect of cleaning and shaping in endodontics. Aim: The aim of the study is to compare the antibacterial effectiveness between cinnamon extract as irrigant with neem extract irrigant and sodium hypochlorite against E. fecalis. Methodology: The present study is a randomized controlled in vitro study conducted on 90 extracted permanent single rooted teeth. The teeth were divided into three groups- Group 1 was irrigated with cinnamon extract, Group 2 was irrigated with neem extract irrigant and Group 3 with 3% sodium hypochlorite. The colonies in the reduction of E. feacalis was noted as CFU values per ml. Wilcoxon signed ranked test was used to compare in between the three groups. Mann- Whitney's test was used for inter group comparison between the three groups.&nbsp

Stereoselective Access to the Core Structure of Macroline-Type Indole Alkaloids: Total Synthesis of Macroline and Alstomicine

Rapid synthesis of the pentacyclic core structure of macroline-type indole alkaloids, and its application in the total synthesis of macroline and alstomicine is described. The core structure was accomplished in a highly stereocontrolled manner via two key steps, Ireland–Claisen rearrangement and Pictet–Spengler cyclization, commencing from a readily available starting material l-tryptophan, which obviated the need of a particular chiral source as an external catalyst, reagent, or internal auxiliary