Global Constructive Optimization of Vascular Systems

*† ‡ § An efficient and high-fidelity design approach is proposed by combining global and local optimization methods for wing planform and surface design. For enhanced design results, aerodynamic shape optimization process is carried out via 2-stage with different optimization strategy. In the first stage, global optimization techniques are applied to planform design with a few geometric design variables. In the second stage, local optimization techniques are used for wing surface design with a lot of design variables to maintain a sufficient design space with high DOF (Degree of Freedom) geometric change. For global optimization, meta-modeling techniques such as RS (Response Surface) and Kriging methods are used in conjunction with Genetic Algorithm (GA). For local optimization, a discrete adjoint variable method is used. By the successive combination of global and local optimization techniques, drag minimization is performed for a multi-body aircraft configuration while maintaining the baseline lift and the wing weight at the same time. Through the design process, performances of the test models are remarkably improved in comparison with the single stage design approach. The capability of proposed design framework including wing planform design variables can be evaluated by the drag decomposition method which can provide improvement of induced drag and wave drag, respectively.

Preliminary values for the resolutions of various figures of merit have been deduced by the SOFIA TwinMUSIC [1] for the spectra of isotopes obtained from the fission of U. The energy-loss resolution was measured to be σΔE E = 0.34% with P25 gas (Fig. 1). This leads to a charge resolution of σZ1,2 = 0.23± 0.01 for the measurements in 1 2 of the TwinMUSIC and σZ1+2 = 0.31±0.02 for the sum of both. The steep falloff of Δt,10−90% ≈ 150ps of the drift times close to the cathode measured for single anodes yields a corresponding resolution of the straight-line fit to a track through the active volume of σdt,fit = (268± 40)ps (Fig. 2). For the electrical field settings applied the measured drift velocity is well reproduced by Magboltz simulations. After fine adjustment of the drift-times with the help of an adjacent MWPC, a position resolution for the single anode of σx,PB = (28±11)μm and σx,FF = (47±13)μm for the primary beam and fission fragments, respectively, can be deduced (Fig. 3). Consequently, the angular distribution of the fragments of ≈ 40mrad could be measured with a precision of σΘ,FF = (0.13± 0.10)mrad by eventwise tracking. The analysis of the data is still ongoing, further refinements on the achieved resolutions are to be expected. Isotopic mass yields have been be deduced and published elsewhere [2]. Changes in the design of the TwinMUSIC detector system are ongoing and will allow for an even better charge, position and angular resolution. We are aiming for a full 3D tracking operation with rates of 1 − 2 MHz with a non-triggered DAQ. The potential of a low-pressure operation (0.2 − 0.3atm) and the application of other, ’faster’ gas mixtures will be tested too. The next physics run is already scheduled 2014 at CaveC looking into more details of the isotopic mass distributions. In the far future, a more complete set of measurements will be performed in the context of RB (Reaction studies with Relativistic Radioactive Beams) at the FAIR (Facility for Antiproton and Ion Research) project at GSI/Darmstadt. Dedicated detector developments will be performed for those endeavors which foster similar developments e.g. for the instrumentation of the SuperFRS.

Reproduction couleur par trames irrégulières et semi-régulières

Electronic Blood Vessel

OF THE DISSERTATION Adaptive OFDM Radar for Target Detection and Tracking by Satyabrata Sen Doctor of Philosophy in Electrical Engineering Washington University in St. Louis, December 2010 Research Advisor: Dr. Arye Nehorai We develop algorithms to detect and track targets by employing a wideband orthogonal frequency division multiplexing (OFDM) radar signal. The frequency diversity of the OFDM signal improves the sensing performance since the scattering centers of a target resonate variably at different frequencies. In addition, being a wideband signal, OFDM improves the range resolution and provides spectral efficiency. We first design the spectrum of the OFDM signal to improve the radar’s wideband ambiguity function. Our designed waveform enhances the range resolution and motivates us to use adaptive OFDM waveform in specific problems, such as the detection and tracking of targets. We develop methods for detecting a moving target in the presence of multipath, which exist, for example, in urban environments. We exploit the multipath reflections by utilizing different Doppler shifts. We analytically evaluate the asymptotic performance of the detector and adaptively design the OFDM waveform, by maximizing the noncentrality-parameter expression, to further improve the detection performance. ii Next, we transform the detection problem into the task of a sparse-signal estimation by making use of the sparsity of multiple paths. We propose an efficient sparse-recovery algorithm by employing a collection of multiple small Dantzig selectors, and analytically compute the reconstruction performance in terms of the `1-constrained minimal singular value. We solve a constrained multi-objective optimization algorithm to design the OFDM waveform and infer that the resultant signal-energy distribution is in proportion to the distribution of the target energy across different subcarriers. Then, we develop tracking methods for both a single and multiple targets. We propose a tracking method for a low-grazing angle target by realistically modeling different physical and statistical effects, such as the meteorological conditions in the troposphere, curved surface of the earth, and roughness of the sea-surface. To further enhance the tracking performance, we integrate a maximum mutual information based waveform design technique into the tracker. To track multiple targets, we exploit the inherent sparsity on the delay-Doppler plane to develop an computationally efficient procedure. For computational efficiency, we use more prior information to dynamically partition a small portion of the delay-Doppler plane. We utilize the block-sparsity property to propose a block version of the CoSaMP algorithm in the tracking filter.

Water changes information in the hydrological system, in time and space, as an environmental issue takes heed of managers and decision makers in watershed management and river engineering, which can be addressed by using spatially distributed modeling. In this study simulation of water balance components in Taleghan mountainous watershed is performed using the spatially distributed hydrological model, WetSpa. This area is located on southern hillside of the eastern north part of Alborz Mountain range in Iran with mean annual precipitation of 591 mm, mean slope of 40.48%, and mean elevation of 2750 m. The model implementation is based on 85 m and daily spatial and temporal resolution, respectively. By applying the spatial parameters derived from three base digital maps and daily time series data as model inputs, peak discharges and flow hydrographs are predicted at any point of stream network and spatial distribution of water balance components and hydrologic characteristics are simulated. The simulated and observed hydrographs are compared using statistical and visual methods. The results revealed a very good agreement between simulated and observed data. Considering evaluation model outputs, accuracy of 83.5% based on the Nash-Sutcliffe efficiency criterion and the Aggregated Measure of 85.6% indicate very good performance of model and well reproduction of stream flow. The Nash-Sutcliffe criterion for the model validation period is 77%. Estimation of runoff 73.5% comparing 74.9% observed runoff indicates the model efficiency and capability in simulation of watershed runoff and the other water balance components.

Three methods are analyzed for the design of ocean observing systems to monitor the meridional overturning circulation (MOC) in the North Atlantic. Specifically, a continuous monitoring array to monitor the MOC at 1000 m at different latitudes is “deployed” into a numerical model. The authors compare array design methods guided by (i) physical intuition (heuristic array design), (ii) sequential optimization, and (iii) global optimization. The global optimization technique can recover the true global solution for the analyzed array design, while gradient-based optimization would be prone to misconverge. Both global optimization and heuristic array design yield considerably improved results over sequential array design. Global optimization always outperforms the heuristic array design in terms of minimizing the root-mean-square error. However, whether the results are physically meaningful is not guaranteed; the apparent success might merely represent a solution in which misfits compensate for each other accidentally. Testing the solution gained from global optimization in an independent dataset can provide crucial information about the solution’s robustness.

Global Optimization (GO) is an area of applied mathemetics that has been active for many years. A large variety of GO algorithms have been constructed in an effort to find a solution to the general GO problem. Some of these have proved to be successful on certain classes of problems. However no general deterministic algorithm exists that can locate the global optimum for every multidimensional problem. Traditionally in the lens design discipline the search for an optimum solution in the design space has been done by optimization methods. The conventional design methods are in principle local search methods and do not pmvide any global information on the design space. As the available computer power increases GO tools can be used also in optical design. A two phase search algorithm based on global optimization techniques is described. In a first phase using a coarse sampling approach the program finds the favorable regions that correspond to potentially promising configurations. In a second phase conventional optimization routines are used to find the best solutions in eh region. Then an optimum solution is determined according to the application at hand. The pro algorithm is analyzed and compared to more conventional design approaches. A further refmement of the algorithm excludes from the systematic search some unfavorable configuration regions through the use of a simple expert system. Search times are further reduced through parallel-processing methods. We believe this approach to lens design represents new initiative towards the determination of the optimum solution in any lens design problem. 1.

Planets are assembled from the gas, dust, and ice in the accretion disks that encircle young stars. Ices of chemical compounds with low condensation temperatures ( This thesis addresses two fundamental questions concerning the nature of volatiles in planet-forming disks: (1) how are volatiles distributed throughout a disk, and (2) how can we use volatiles to probe planet-forming processes in disks? We tackle the first question in two complementary ways. We have developed a novel super-resolution method to constrain the radial distribution of volatiles throughout a disk by combining multi-wavelength spectra. Thanks to the ordered velocity and temperature profiles in disks, we find that detailed constraints can be derived even with spatially and spectrally unresolved data -- provided a wide range of energy levels are sampled. We also employ high-spatial resolution interferometric images at (sub)mm frequencies using the Atacama Large Millimeter Array (ALMA) to directly measure the radial distribution of volatiles. For the second question, we combine volatile gas emission measurements with those of the dust continuum emission or extinction to understand dust growth mechanisms in disks and disk instabilities at planet-forming distances from the central star. Our observations and models support the idea that the water vapor can be concentrated in regions near its condensation front at certain evolutionary stages in the lifetime of protoplanetary disks, and that fast pebble growth is likely to occur near the condensation fronts of various volatile species.

For the measurements of size and circularity distributions of sawing slurries with microscopy (where the slurry is diluted in a liquid) we investigated the time dependent and concentration dependent agglomeration behaviour of slurry particles. We developed a preparation method that avoids the agglomeration of particles before and during the measurement. Because laser diffraction is one of the most widespread methods which are used to characterise the size distributions of slurry particles we compared the measurement results of different laser diffractometers. For characterising slurries we suggest a couple of measurement categories one of which is the ratio of half width to the modal value, which describes the narrowness of silicon carbide particles. Light microscopy is able to measure both size and circularity distributions of slurry grains. Because this method fails to measure small slurry particles we started to develop a new method that overcomes the resolution limitation of light microscopy by combining scanning electron microscopy and pattern recognition. Results are presented concerning an adapted preparation of the slurry.

Even though breast cancer is a cancer with relatively easy early diagnostic and has an appropriate treatment, it has high mortality rates in Brazil. This is in part because the disease is diagnosed only in advanced stages, but also because the whole information contained in the mammograms is not used by physicians and radiologists. There are many parameters to be considered in assessing the quality of a mammogram image. Among these parameters are contrast, spatial resolution, the signal-to-noise ratio, and the efficiency of the applied dose. Even with the improvement of the quality of radiographs, many structures, such as small microcalcifications, are not always identified by radiologists in the images. To determine the lowest detectable structures in digital mammograms, we made a numerical analysis of a few digital mammography using simulators, determining the spatial and intensity resolutions, and studying the noise and its distribution. With this, we could determine the detection levels, quantifying the probability that any point is due to statistical noise or a real change in breast density. This is the first step towards early detection of microcalcifications. In our work, it was possible to detect even the smallest microcalcifications of the simulator, 0.18 mm in diameter, with false alarm probability smaller than 1/1000.

DATASET: Alpha version 2010 and 2015 estimates of numbers of people per grid square, with national totals adjusted to match UN population division estimates (http://esa.un.org/wpp/) and remaining unadjusted. REGION: Asia SPATIAL RESOLUTION: 0.000833333 decimal degrees (approx 100m at the equator) PROJECTION: Geographic, WGS84 UNITS: Estimated persons per grid square MAPPING APPROACH: Land cover based, as described in: Gaughan AE, Stevens FR, Linard C, Jia P and Tatem AJ, 2013, High resolution population distribution maps for Southeast Asia in 2010 and 2015, PLoS ONE, 8(2): e55882 FORMAT: Geotiff (zipped using 7-zip (open access tool): www.7-zip.org) FILENAMES: Example - VNM_popmap10adj_v2.tif = Vietnam (VNM) population count map for 2010 (popmap10) adjusted to match UN national estimates (adj), version 2 (v2). DATE OF PRODUCTION: January 2013

In this paper shape control optimization of piezoelectric bimorph is done by piezo response function (PRF) and global optimization technique. PRF is used to formulate the optimization problem and global optimization algorithm is used to minimize the error between the target and the achieved shape. The performance of four global optimization techniques, simulated annealing (SA), genetic algorithm, particle swarm optimization and teacher learning based optimization are compared for the shape control of piezoelectric bimorph. 28 piezoelectric actuators are used in the piezoelectric bimorph to generate the sinusoidal profile, elliptical profile and arbitrary deformation profile by the external load. PRF is calculated by solving finite element model of piezoelectric bimorph and, optimization of electric potential with safety limit is done to achieve the target profiles by using all the aforementioned optimization techniques. SA gives best value of the objective function. At optimum electrode potential, the target and, achieved sinusoidal, elliptical and arbitrary deformation profiles obtained by SA at 5 × 107 computation, matches closely with root mean square (RMS) errors of 0.72, 12.18 and 28.86 nm, respectively. Subsequently, a robust and fully reproducible method for the shape control of piezo actuated deformable mirrors and smart structures is developed.

A search for “virtual museum” on the web returns a variety of fundamentally different websites. From sites that host photo collections to those with “interactive” QuickTime tours, the common thread with current online virtual museums is that they use a form of innovative digital media to present content. The Virtual Hampson Museum Project is a next generation virtual museum that provides high-resolution, 3-dimensional data of scanned artifacts from the Native American collections at the Hampson Archeological Museum State Park in Wilson, Arkansas. The Virtual Hampson Museum Project uses close range 3D laser scanning to document and digitally archive over 500 artifacts from the collections in Wilson. While the collections at Hampson are known by most in the archeological community, they are not widely known to the public. Visitors to the online museum can view the artifacts in full 3D within their browser window using tools available in Adobe Reader. Additional high and low resolution versions of the artifacts are available for download in a number of common 3D formats (VRML/X3D, OBJ and PDF). Interested researchers, and others, can use a free software package that permits very detailed analysis to be conducted on one’s own computer. They can perform a range of measurements, create cross-sections and do comparative analyses of the artifacts. Under Creative Commons license, the 3D objects can be reused in other visualizations and 3D contexts. This paper will present the challenges in compiling, distributing, and presenting a large number of 3D datasets in an online environment. By combining 3D laser scanning for digital artifact curation and the internet as a distribution platform, the Virtual Hampson Museum Project goes beyond typical online virtual museums and provides accurate 3D data of museum artifacts for public viewing and use and provides users the necessary tools to explore, view, and even analyze the Virtual Hampson collection.

In addition to meteorological inputs, land use and emission factor database are also required for simulation of the Biogenic Emission Inventory System (BEIS). The resolution of land use database in the Taiwan BEIS (TBEIS) can be up to 1 km^2 and this database consists of vegetation species and their spatial distribution in Taiwan with a total land area of approx 36000 km^2. The previous Taiwanese land use database was established in 1995, but since then Taiwan has gone through cultural, ecological and seismic changes for more than a decade. As a result, the area and distribution of current land use types needed revision. To complete this revision accurately, recent satellite remote sensing data were used in this research. In the updated land use database, the new forested area had increased by 2400 km^2, grass land had increased by 1790 km^2, paddy fields had increased by 2,100 km^2 and dry agriculture land had decreased by 1830 km^2. There was a net increase of 4460 km^2 in vegetation area, which equates to about 16% of the total vegetation land area of Taiwan. Simulation of the TBEIS-2 rendered to an increase of 28,000 ton/yr in total BVOCs (6.6%), in which other VOCs (OVOC) increased by 17,000 ton/yr (12.1%) and isoprene increased by 10,000 ton/yr (7.9%). The biogenic emissions obtained by the use of TBEIS-2 with the new land use database are utilized to simulate air quality by the Taiwan Air Quality Monitoring (TAQM). Results indicated that concentrations of ozone and other photochemical pollutants raised in some areas of Taiwan. In the simulation conducted in May 2003, the greatest ozone concentration difference occurred in southern Taiwan and central Taiwan with an increase of 3 ~ 7 ppb in these districts.