Stability and performance of intersecting aircraft flows under decentralized conflict resolution

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2000.Includes bibliographical references (p. 84-88).by Zhi-Hong Mao.S.M

Wireless Power Transfer for Miniature Implantable Biomedical Devices

Miniature implantable electronic devices play increasing roles in modern medicine. In order to implement these devices successfully, the wireless power transfer (WPT) technology is often utilized because it provides an alternative to the battery as the energy source; reduces the size of implant substantially; allows the implant to be placed in a restricted space within the body; reduces both medical cost and chances of complications; and eliminates repeated surgeries for battery replacements. In this work, we present our recent studies on WPT for miniature implants. First, a new implantable coil with a double helix winding is developed which adapts to tubularly shaped organs within the human body, such as blood vessels and nerves. This coil can be made in the planar form and then wrapped around the tubular organ, greatly simplifying the surgical procedure for device implantation. Second, in order to support a variety of experiments (e.g., drug evaluation) using a rodent animal model, we present a special WPT transceiver system with a relatively large power transmitter and a miniature implantable power receiver. We present a multi-coil design that allows steady power transfer from the floor of an animal cage to the bodies of a group of free-moving laboratory rodents

Sampling Through the Lens of Sequential Decision Making

Sampling is ubiquitous in machine learning methodologies. Due to the growth of large datasets and model complexity, we want to learn and adapt the sampling process while training a representation. Towards achieving this grand goal, a variety of sampling techniques have been proposed. However, most of them either use a fixed sampling scheme or adjust the sampling scheme based on simple heuristics. They cannot choose the best sample for model training in different stages. Inspired by "Think, Fast and Slow" (System 1 and System 2) in cognitive science, we propose a reward-guided sampling strategy called Adaptive Sample with Reward (ASR) to tackle this challenge. To the best of our knowledge, this is the first work utilizing reinforcement learning (RL) to address the sampling problem in representation learning. Our approach optimally adjusts the sampling process to achieve optimal performance. We explore geographical relationships among samples by distance-based sampling to maximize overall cumulative reward. We apply ASR to the long-standing sampling problems in similarity-based loss functions. Empirical results in information retrieval and clustering demonstrate ASR's superb performance across different datasets. We also discuss an engrossing phenomenon which we name as "ASR gravity well" in experiments

4,4′-(Anthracene-9,10-di­yl)dibenzoic acid dimethyl­formamide disolvate

In the title compound, C28H18O4·2C3H7NO, the dihedral angle between the benzene rings and the anthracene system is 74.05 (12)°. A crystallographic inversion centre is located in the middle of the anthracene unit. The dimethyl­formamide solvent mol­ecules are partially disordered over two positions of approximately equal occupancy [0.529 (6):0.471 (6)]. Inter­molecular O—H⋯O hydrogen bonds with the major occupancy formamide O atom as acceptor result in the formation of 2:1 solvate–complex aggregates, which are alternately linked to shorter solvate units via weak inter­molecular C—H⋯O contacts generated from the rotational disorder of the formamide O atom (minor occupancy component). Weak C—H⋯π inter­actions between the solvent mol­ecules as the donor and the outer anthracene rings support these contacts in the crystal structure for both disorder components

Effects of different starch sources on Bacillus spp. in intestinal tract and expression of intestinal development related genes of weanling piglets

The study was conducted to evaluate the effects of different starch sources on Bacillus spp. in intestinal tract and expression of intestinal development related genes of weanling piglets. Twenty-eight PIC male piglets were divided into four homogeneous groups according to initial body weight (similar birth and parity, weaned at 21 ± 1.5 days). Diets for the four treatments consisted of corn starch, wheat starch, tapioca starch and pea starch with the determined ratio for amylose to amylopectin of 0.21, 0.24, 0.12 and 0.52 respectively. Real-time quantitative polymerase chain reaction was applied to: (1) detect genomic DNA of Bacillus and to quantify the number of Bacillus in the intestinal tract chyme of piglets with the primers and probe which designed based on the 16S rRNA sequences of maximum species of Bacillus on GenBank; (2) measure the mRNA level of glucagon-like peptide 2 (GLP-2), insulin-like growth factors 1 (IGF-1) and epidermal growth factor (EGF) in duodenum, jejunum and ileum. Results showed that the number of Baciilus and the percentage based on all bacteria in the whole intestinal content of piglets fed pea starch was highest in all groups (P < 0.05). There was no significant differance on copy numbers for all bacteria and Bacillus in the whole intestinal tract of piglets between the corn starch group and wheat starch group (P > 0.05). In addition, the expression level of GLP-2, IGF-1 mRNA in jejunum and ileum of pea starch treatment (the high amylose/amylopectin ratio) were increased while the tapioca starch decreased their mRNA level significantly compared to other three treatments (P < 0.05). There was no significant difference for the mRNA level of EGF in each group. The present study revealed that high amylose/amylopectin ratio of starches significantly enhanced the numbers of Bacillus in all segments of intestine and the mRNA level of intestinal development related genes

Interplay between Chiral Charge Density Wave and Superconductivity in Kagome Superconductors: A Self-consistent Theoretical Analysis

Inspired by the recent discovery of a successive evolutions of electronically ordered states, we present a self-consistent theoretical analysis that treats the interactions responsible for the chiral charge order and superconductivity on an equal footing. It is revealed that the self-consistent theory captures the essential features of the successive temperature evolutions of the electronic states from the high-temperature ``triple-$Q$" $2\times 2$ charge-density-wave state to the nematic charge-density-wave phase, and finally to the low-temperature superconducting state coexisting with the nematic charge density wave. We provide a comprehensive explanation for the temperature evolutions of the charge ordered states and discuss the consequences of the intertwining of the superconductivity with the nematic charge density wave. Our findings not only account for the successive temperature evolutions of the ordered electronic states discovered in experiments but also provide a natural explanation for the two-fold rotational symmetry observed in both the charge-density-wave and superconducting states. Moreover, the intertwining of the superconductivity with the nematic charge density wave order may also be an advisable candidate to reconcile the divergent or seemingly contradictory experimental outcomes regarding the superconducting properties

cis-4-(Tosyl­oxymeth­yl)cyclo­hexa­ne­carboxylic acid

The title compound, C15H20O5S, is an inter­mediate in the synthesis of novel amino­carboxylic acid derivatives. The cyclo­hexane ring exhibits a chair conformation. In the crystal structure, adjacent mol­ecules form dimers via O—H⋯O hydrogen bonds