Investigation of image enhancement techniques for the development of a self-contained airborne radar navigation system

This study was devoted to an investigation of the feasibility of applying advanced image processing techniques to enhance radar image characteristics that are pertinent to the pilot's navigation and guidance task. Millimeter (95 GHz) wave radar images for the overwater (i.e., offshore oil rigs) and overland (Heliport) scenario were used as a data base. The purpose of the study was to determine the applicability of image enhancement and scene analysis algorithms to detect and improve target characteristics (i.e., manmade objects such as buildings, parking lots, cars, roads, helicopters, towers, landing pads, etc.) that would be helpful to the pilot in determining his own position/orientation with respect to the outside world and assist him in the navigation task. Results of this study show that significant improvements in the raw radar image may be obtained using two dimensional image processing algorithms. In the overwater case, it is possible to remove the ocean clutter by thresholding the image data, and furthermore to extract the target boundary as well as the tower and catwalk locations using noise cleaning (e.g., median filter) and edge detection (e.g., Sobel operator) algorithms

Sensitivity analysis of helicopter IMC decelerating steep approach and landing performance to navigation system parameters

Results of a study to investigate, by means of a computer simulation, the performance sensitivity of helicopter IMC DSAL operations as a function of navigation system parameters are presented. A mathematical model representing generically a navigation system is formulated. The scenario simulated consists of a straight in helicopter approach to landing along a 6 deg glideslope. The deceleration magnitude chosen is 03g. The navigation model parameters are varied and the statistics of the total system errors (TSE) computed. These statistics are used to determine the critical navigation system parameters that affect the performance of the closed-loop navigation, guidance and control system of a UH-1H helicopter

VTOL shipboard letdown guidance system analysis

Alternative letdown guidance strategies are examined for landing of a VTOL aircraft onboard a small aviation ship under adverse environmental conditions. Off line computer simulation of shipboard landing task is utilized for assessing the relative merits of the proposed guidance schemes. The touchdown performance of a nominal constant rate of descent (CROD) letdown strategy serves as a benchmark for ranking the performance of the alternative letdown schemes. Analysis of ship motion time histories indicates the existence of an alternating sequence of quiescent and rough motions called lulls and swells. A real time algorithms lull/swell classification based upon ship motion pattern features is developed. The classification algorithm is used to command a go/no go signal to indicate the initiation and termination of an acceptable landing window. Simulation results show that such a go/no go pattern based letdown guidance strategy improves touchdown performance

If We Were Birds

Book Under ReviewShields, Erin. 2011. If We Were Birds. Toronto, ON: Playwrights Canada Press.

Bioconversion of D-glucose into D-glucosone by immobilized glucose 2-oxidase from Coriolus versicolorat moderate pressures

The immobilized glucose 2-oxidase (pyranose oxidase, pyranose:oxygen-2-oxidoreductase, EC 1.1.3.10) from Coriolus versicolor was used to convert D-glucose into D-glucosone at moderate pressures, up to 150 bar, with compressed air in a modified commercial batch reactor. Several parameters affecting biocatalysis at moderate pressures were investigated as follows: pressure, different forms of immobilized biocatalysts, glucose concentration, pH, temperature and the presence of catalase. Glucose 2-oxidase (GOX2) was purified by immobilized metal affinity chromatography on epoxy-activated Sepharose 6B-IDA-Cu(II) column at pH 6.0. Purified enzyme and catalase were immobilized into a polyethersulfone (PES) membrane in the presence of glutaraldehyde and gelatin. Enhancement of the bioconversion of D-glucose was done by the pressure since an increase in the pressure with compressed air increases the conversion rates. The optimum temperature and pH for bioconversion of D-glucose were found to be 62 degrees C and pH 6.0, respectively and the activation energy (E(a)) was 28.01 kJ mol(-1). The apparent kinetic constants (V(max)' K(m)', K(cat)' and K(cat)/K(m)') for this bioconversion were 2.27 U mg(-1) protein, 11.15 mM, 8.33 s(-1) and 747.38 s(-1) M(-1), respectively. The immobilized biomass of C. versicolor as well as crude extract containing GOX2 activity were also useful for bioconversion of D-glucose at 65 bar with a yield of 69.9 +/- 3.8% and 91.3 +/- 1.2%, respectively. The immobilized enzyme was apparently stable for several months without any significant loss of enzyme activity. On the other hand, this immobilized enzyme was also stable at moderate pressures, since such pressures did not affect significantly the enzyme activity. (C) 2010 Elsevier Ltd. All rights reserved

Droplet Interferometry: A Schlick Way to Consider Interfacial Energetics

We verify the use of an evaporating sessile water droplet as a source of dynamic interference fringes in a Fizeau-like interferometer. Experimentally-obtained interference patterns are compared with those produced by a geometrical optics-based computational model to demonstrate the potential for classical optical theory to enhance the analysis of interfacial energetics. A detailed description of the process taken to optimize fringe visibility is presented, and a comparison is made between various droplet substrates. Silicon-based substrates appear to be superior than glass-based substrates in their ability to image a clear dynamic interference pattern

Rappertk: a versatile engine for discrete restraint-based conformational sampling of macromolecules

Background: Macromolecular structures are modeled by conformational optimization within experimental and knowledge-based restraints. Discrete restraint-based sampling generates high-quality structures within these restraints and facilitates further refinement in a continuous all-atom energy landscape. This approach has been used successfully for protein loop modeling, comparative modeling and electron density fitting in X-ray crystallography.|Results: Here we present a software toolkit (Rappertk) which generalizes discrete restraint-based sampling for use in structural biology. Modular design and multi-layered architecture enables Rappertk to sample conformations of any macromolecule at many levels of detail and within a variety of experimental restraints. Performance against a C-alpha-tracing benchmark shows that the efficiency has not suffered despite the overhead required by this flexibility. We demonstrate the toolkit's capabilities by building high-quality beta-sheets and by introducing restraint-driven sampling. RNA sampling is demonstrated by rebuilding a protein-RNA interface. Ability to construct arbitrary ligands is used in sampling protein- ligand interfaces within electron density. Finally, secondary structure and shape information derived from EM are combined to generate multiple conformations of a protein consistent with the observed density.|Conclusion: Through its modular design and ease of use, Rappertk enables exploration of a wide variety of interesting avenues in structural biology. This toolkit, with illustrative examples, is freely available to academic users from http://www-cryst.bioc.cam.ac.uk/similar to swanand/mysite/rtk/index.html

The Anatomy of a Weight Recidivism and Revision Bariatric Surgical Clinic

Abstract. Weight recidivism in bariatric surgery failure is multifactorial. It ranges from inappropriate patient selection for primary surgery to technical/anatomic issues related to the original surgery. Most bariatric surgeons and centers focus on primary bariatric surgery while weight recidivism and its complications are very much secondary concerns. Methods. We report on our initial experience having established a dedicated weight recidivism and revisional bariatric surgery clinic. A single surgeon, dedicated nursing, dieticians, and psychologist developed care maps, goals of care, nonsurgical candidate rules, and discharge planning strategies. Results. A single year audit (2012) of clinical activity revealed 137 patients, with a mean age 49 ± 10.1 years (6 years older on average than in our primary clinic), 75% of whom were women with BMI 47 ± 11.5. Over three quarters had undergone a vertical band gastroplasty while 15% had had a laparoscopic adjustable gastric band. Only 27% of those attending clinic required further surgery. As for primary surgery, the role of the obesity expert clinical psychologist was a key component to achieving successful revision outcomes. Conclusion. With an exponential rise in obesity and a concomitant major increase in bariatric surgery, an inevitable increase in revisional surgery is becoming a reality. Anticipating this increase in activity, Alberta Health Services, Alberta, Canada, has established a unique and dedicated clinic whose early results are promising

Volume 4: Cosmopolitanisms in Muslim Contexts : Perspectives from the Past

Cosmopolitanism is a key concept in social and political thought, standing in opposition to closed human group ideologies such as tribalism, nationalism and fundamentalism. Much recent discussion of this concept has been situated within Western self-perceptions, with little inclusion of information from Muslim contexts. This volume redresses the balance by focusing attention on instances in world history when cosmopolitan ideas and actions pervaded specific Muslim societies and cultures, exploring the tensions between regional cultures, isolated enclaves and modern nation-states. Models are chosen from four geographic areas: The Swahili coast, the Ottoman empire/Turkey, Iran and Indo-Pakistan.https://ecommons.aku.edu/uk_ismc_series_emc/1005/thumbnail.jp

Volume 1: The Challenge of Pluralism : Paradigms from Muslim Contexts

The volume discusses notions of pluralism and its specific relevance to Muslim societies. Current popular and academic discussions tend to make certain assumptions regarding Islam and its lack of compatibility with notions of pluralism. Some notable liberal thinkers have even argued that pluralism itself is inherently antithetical to Islam. These assumptions are challenged by discussing the broad spectrum of relevance and application of the notion of pluralism to modern day societies, examining securalism, multiculturalism, democracy, globalisation and the pivotal role of civil society.https://ecommons.aku.edu/uk_ismc_series_emc/1004/thumbnail.jp