3D Reconstruction of Building Rooftop and Power Line Models in Right-of-Ways Using Airborne LiDAR Data

The research objectives aimed to achieve thorough the thesis are to develop methods for reconstructing models of building and PL objects of interest in the power line (PL) corridor area from airborne LiDAR data. For this, it is mainly concerned with the model selection problem for which model is more optimal in representing the given data set. This means that the parametric relations and geometry of object shapes are unknowns and optimally determined by the verification of hypothetical models. Therefore, the proposed method achieves high adaptability to the complex geometric forms of building and PL objects. For the building modeling, the method of implicit geometric regularization is proposed to rectify noisy building outline vectors which are due to noisy data. A cost function for the regularization process is designed based on Minimum Description Length (MDL) theory, which favours smaller deviation between a model and observation as well as orthogonal and parallel properties between polylines. Next, a new approach, called Piecewise Model Growing (PMG), is proposed for 3D PL model reconstruction using a catenary curve model. It piece-wisely grows to capture all PL points of interest and thus produces a full PL 3D model. However, the proposed method is limited to the PL scene complexity, which causes PL modeling errors such as partial, under- and over-modeling errors. To correct the incompletion of PL models, the inner and across span analysis are carried out, which leads to replace erroneous PL segments by precise PL models. The inner span analysis is performed based on the MDL theory to correct under- and over-modeling errors. The across span analysis is subsequently carried out to correct partial-modeling errors by finding start and end positions of PLs which denotes Point Of Attachment (POA). As a result, this thesis addresses not only geometrically describing building and PL objects but also dealing with noisy data which causes the incompletion of models. In the practical aspects, the results of building and PL modeling should be essential to effectively analyze a PL scene and quickly alleviate the potentially hazardous scenarios jeopardizing the PL system

FM airborne passive radar

The airborne application of Passive Bistatic Radar (PBR) is the latest evolution of the now established international interest in passive radar techniques. An airborne passive system is cheaper to construct, easier to cool, lighter and requires less power than a traditional active radar system. These properties make it ideal for installation on an Unmanned Aerial Vehicle (UAV), especially for the next generation of Low Observable (LO) UAVs, complementing the platforms LO design with an inherently Low Probability of Intercept (LPI) air-to-air and air-to-ground sensing capability. A comprehensive literature review identified a lack of practical and theoretical research in airborne passive bistatic radar and a quantitative model was designed in order to un- derstand the theoretical performance achievable using a hypothetical system and FM as the illuminator of opportunity. The results demonstrated a useable surveillance volume, assuming conservative estimates for the receiver parameters and allowed the scoping and specification of an airborne demonstrator system. The demonstrator system was subsequently designed and constructed and flown on airborne experiments to collect data for both air-to-air and air-to-ground operation analysis. Subsequent processing demonstrated the successful detection of air targets which correlated with the actual aircraft positions as recorded by a Mode-S/ADS-B receiver. This is the first time this has been conclusively demonstrated in the literature. Doppler Beam Sharpening was used to create a coarse resolution image allowing the normalised bistatic clutter RCS of the stationary surface clutter to be analysed. This is the first time this technique has been applied to an airborne passive system and has yielded the first quantitive values of normalised bistatic clutter RCS at VHF. This successful demonstration of airborne passive radar techniques provides the proof of concept and identifies the key research areas that need to be addressed in order to fully develop this technology

Achieving the Shared Economic Growth

After critically reviewing the literature on the institutional approaches for the shared growth, this paper briefly presents a General Theory of Economic Development (GTED) as basis for the discussion of shared growth. The GTED argues that Economic Discrimination (ED) by Markets, Corporations and Government is a necessary condition for shared economic development while Egalitarianism by any of them is a sufficient condition for economic stagnation. ED means treating the different differently while Egalitarianism is antithesis to ED. This paper also presents a new empirical framework for analysing growth and productivity implied by the GTED, and provides the empirical results that a 1 percent increase of per capita corporate asset brings about a 0.4 percent increase in per capita income and a decrease of income GIN1 coefficient by 0.015, supporting "the corporate-led shared growth hypothesis" of the GTED. Finally, the paper discusses the dramatic experiences of the rise. and fall of Korea's economic development and the stagnated Pakistani experience over the last 60 years, implying that the growth stagnation has been due to the anti-corporate policy led by the egalitarianism. JEL Classification: B, B5, D21, D23, 01, 043, P14 Keywords: General Theory of Economic Development, Shared Growth, Economic Discrimination (ED), Egalitarianism, Corporate-led Shared Growth, ED Policy Paradig

Reversible control of spin-polarized supercurrents in ferromagnetic Josephson junctions.

Magnetic inhomogeneity at a superconductor (S)-ferromagnet (F) interface converts spin-singlet Cooper pairs into spin-one triplet pairs. These pairs are immune to the pair-breaking exchange field in F and support a long-range proximity effect. Although recent experiments have confirmed the existence of spin-polarized triplet supercurrents in S-F-S Josephson junctions, reversible control of the supercurrent has been impossible because of the robust preconfigured nature of the inhomogeneity. Here, we use a barrier comprising three F layers whose relative magnetic orientation, and hence the interfacial inhomogeneity, can be controlled by small magnetic fields; we show that this enables full control of the triplet supercurrent and, by using finite element micromagnetic simulations, we can directly relate the experimental data to the theoretical models which provide a general framework to understand the role played by magnetic states in long-range supercurrent modulation.This is the author's accepted manuscript. It will be under embargo until the 26th of February 2015. The final version is published by NPG in Nature Communications here: http://www.nature.com/ncomms/2014/140826/ncomms5771/full/ncomms5771.html

Large Superconducting Spin Valve Effect and Ultrasmall Exchange Splitting in Epitaxial Rare-Earth-Niobium Trilayers.

Epitaxial Ho/Nb/Ho and Dy/Nb/Dy superconducting spin valves show a reversible change in the zero-field critical temperature (ΔT(c0)) of ∼400  mK and an infinite magnetoresistance on changing the relative magnetization of the Ho or Dy layers. Unlike transition-metal superconducting spin valves, which show much smaller ΔT(c0) values, our results can be quantitatively modeled. However, the fits require an extraordinarily low induced exchange splitting which is dramatically lower than known values for rare-earth Fermi-level electrons, implying that new models for the magnetic proximity effect may be required.This work is partially supported by ERC AiG “Superspin”. Yuanzhou Gu acknowledges financial support from King’s College, Cambridge.This is the accepted manuscript of a paper published in Physical Review Letters (Phys. Rev. Lett. 115, 067201). The final version is available at http://dx.doi.org/10.1103/PhysRevLett.115.06720

Cryo-electron microscopy of Weibel-Palade Bodies in human endothelial cells

Weibel-Palade bodies (WPBs) are a secretory storage organelle found in endothelial cells. Their primary cargo is the large haemostatic protein von Willebrand factor (VWF), however there are many other minor components, both in the membrane and lumen of the WPB. VWF is stored in long helical tubules which define the ‘rod-like’ shape of the WPBs. WPBs are released in response to raised intracellular Ca²⁺ or cAMP levels, secreting the VWF content. Upon exocytosis, the environment of the VWF changes from acidic to neutral pH, causing the tubules of VWF to unfurl into strings. The expansion of the VWF tubules into strings exposes binding and cleavage sites, turning VWF into its haemostatically active form. As tubules transform into strings, the overall shape of the WPB changes, first becoming round before releasing its contents. Imaging at the periphery of frozen-hydrated, whole human umbilical vein endothelial cells (HUVECs) by cryo-electron microscopy (cryo-EM) and cryo-electron tomography has been used to study WPBs within their native environment. The structure of WPBs within HUVECs both unstimulated and stimulated to release WPBs with raised intracellular Ca²⁺ has been examined. This has enabled imaging of both rod-shaped and rounded WPBs. Round WPBs in HUVECs exposed to hypotonic shock and within human heart microvasculature endothelial cells (HHMECs) have also been imaged. A subset of the WPBs imaged within endothelial cells contain an internal vesicle within them. Light microscopy studies have shown a vesicle with corresponding characteristics is enriched for the membrane protein CD63, a known constituent of WPBs. Finally, a technique for chemically fixing cells for light microscopy studies prior to plunge-freezing is shown, with subsequent correlative light and electron microscopy experiments looking at CD63-enriched vesicles within WPBs. The quality of preservation for cryo-EM experiments, including tomography and image processing for correlative microscopy is discussed