Impact of technological trends on city planning

Thesis (M.C.P.) Massachusetts Institute of Technology. Dept. of Architecture and City Planning, 1947.Bibliography: leaves 154-160.by Roger Willcox.M.C.P

Bayesian optimization with a finite budget: An approximate dynamic programming approach

We consider the problem of optimizing an expensive objective function when a finite budget of total evaluations is prescribed. In that context, the optimal solution strategy for Bayesian optimization can be formulated as a dynamic programming instance. This results in a complex problem with uncountable, dimension-increasing state space and an uncountable control space. We show how to approximate the solution of this dynamic programming problem using rollout, and propose rollout heuristics specifically designed for the Bayesian optimization setting. We present numerical experiments showing that the resulting algorithm for optimization with a finite budget outperforms several popular Bayesian optimization algorithms

Advances in Bayesian Optimization with Applications in Aerospace Engineering

Optimization requires the quantities of interest that define objective functions and constraints to be evaluated a large number of times. In aerospace engineering, these quantities of interest can be expensive to compute (e.g., numerically solving a set of partial differential equations), leading to a challenging optimization problem. Bayesian optimization (BO) is a class of algorithms for the global optimization of expensive-to-evaluate functions. BO leverages all past evaluations available to construct a surrogate model. This surrogate model is then used to select the next design to evaluate. This paper reviews two recent advances in BO that tackle the challenges of optimizing expensive functions and thus can enrich the optimization toolbox of the aerospace engineer. The first method addresses optimization problems subject to inequality constraints where a finite budget of evaluations is available, a common situation when dealing with expensive models (e.g., a limited time to conduct the optimization study or limited access to a supercomputer). This challenge is addressed via a lookahead BO algorithm that plans the sequence of designs to evaluate in order to maximize the improvement achieved, not only at the next iteration, but once the total budget is consumed. The second method demonstrates how sensitivity information, such as gradients computed with adjoint methods, can be incorporated into a BO algorithm. This algorithm exploits sensitivity information in two ways: first, to enhance the surrogate model, and second, to improve the selection of the next design to evaluate by accounting for future gradient evaluations. The benefits of the two methods are demonstrated on aerospace examples

Pre-agricultural plant management in the uplands of the central Zagros: the archaeobotanical evidence from Sheikh-e Abad

Prior to the emergence of agriculture in southwest Asia, sedentarising human communities were experimenting with a diverse range of wild plant species over a prolonged period. In some cases, this involved the cultivation of species that would go on to be domesticated and form the foundation of future agricultural economies. However, many forms of plant use did not follow this trajectory, and in multiple places farming was only taken up later as an established ‘package’. In this paper, we present new archaeobotanical evidence from the Early Neolithic site of Sheikh-e Abad in the central Zagros of western Iran. Sheikh-e Abad is unique in being the only settlement known to date within southwest Asia that lies at an altitude above 1000m and which has occupation spanning the agricultural transition. Thus, it provides a rare opportunity to examine pre-agricultural plant management strategies in an upland zone. Our analyses of the plant remains from Sheikh-e Abad suggest that from its earliest occupation inhabitants were unconsciously ‘auditioning’ a suite of locally available wild grasses which ultimately were never domesticated. We discuss the possible reasons for this from a socio-ecological perspective, considering both the biology and ecology of the plant species in question, as well as the ways in which they were potentially managed

An Evaluation of Limited Equity Housing Cooperatives in the United States

Limited equity cooperatives (LECs) are evaluated within the following framework: 1) the effect of resident participation on operating costs, 2) the disutility of time and effort that members devote to co-op activities, 3) the intangible benefits of co-op living, 4) the degree of subsidization, and 5) the financial viability of LECs. As a result of information gathered from interviews of field practitioners and academic experts, the authors\u27 personal experiences, and a review of the literature, LECs are seen as an effective way of providing home-ownership opportunities for low-income families the United States

An Evaluation of Limited equity Housing Cooperatives in the United States

Limited equity cooperatives (LECs) are evaluated within the following framework: 1) the effect of resident participation on operating costs, 2) the disutility of time and effort that members devote to co-op activities, 3) the intangible benefits of co-op living, 4) the degree of subsidization, and 5) the financial viability of LECs. As a result of information gathered from interviews of field practitioners and academic experts, the authors' personal experiences, and a review of the literature, LECs are seen as an effective way of providing home-ownership opportunities for low-income families the United States.

Isolation, biochemical characterization and anti-adhesion property of mucin from the Blue Blubber Jellyfish (Catostylus mosaicus)

Mucins are large glycoproteins that have been identified as the main component of various biological gels and lubricants. Their compositions contribute to the viscoelastic properties of mucus secretions. Gel-forming mucins have now been identified in a variety of organisms from marine molluscs to humans and are thought to cover and protect epithelial cells from attachment and entry of pathogens. We employed a new approach using a combination of tryptic digestion and the fractionation by hydrophobic interaction chromatography to enable the isolation and purification of mucins from the Blue Blubber jellyfish, Catostylus mosaicus. The purified proteins were stained with Alcian blue indicating extensive glycosylation. Amino acid composition analysis of the purified protein found that it was enriched for Ala, Glu, Thr, Pro and Val residues (together constituting ~93 mole % of the protein), which is typical for mucins. Consistent with this, monosaccharide composition analysis revealed extensive O-linked oligosaccharides with N-acetylgalactosamine (GalNAc), galactose (Gal) and N-acetylglucosamine (GlcNAc) as major monosaccharide constituents. The purified C. mosaicus mucins inhibited the attachment of an ocular Pseudomonas aeruginosa (PA) isolate (Paer6294) to human corneal epithelial (HCE) cells grown in vitro.10 page(s

Rapid quantification of free cholesterol in tears using direct insertion/electron ionization-mass spectrometry

Purpose - To establish a simple and rapid analytical method, based on direct insertion/electron ionization-mass spectrometry (DI/EI-MS), for measuring free cholesterol in tears from humans and rabbits. Methods - A stable-isotope dilution protocol employing DI/EI-MS in selected ion monitoring mode was developed and validated. It was used to quantify the free cholesterol content in human and rabbit tear extracts. Tears were collected from adult humans (n = 15) and rabbits (n = 10) and lipids extracted. Results - Screening, full-scan (m/z 40-600) DI/EI-MS analysis of crude tear extracts showed that diagnostic ions located in the mass range m/z 350 to 400 were those derived from free cholesterol, with no contribution from cholesterol esters. DI/EI-MS data acquired using selected ion monitoring (SIM) were analyzed for the abundance ratios of diagnostic ions with their stable isotope-labeled analogues arising from the D6-cholesterol internal standard. Standard curves of good linearity were produced and an on-probe limit of detection of 3 ng (at 3:1 signal to noise) and limit of quantification of 8 ng (at 10:1 signal to noise). The concentration of free cholesterol in human tears was 15 ± 6 μg/g, which was higher than in rabbit tears (10 ± 5 μg/g). Conclusions - A stable-isotope dilution DI/EI-SIM method for free cholesterol quantification without prior chromatographic separation was established. Using this method demonstrated that humans have higher free cholesterol levels in their tears than rabbits. This is in agreement with previous reports. This paper provides a rapid and reliable method to measure free cholesterol in small-volume clinical samples