Supercomputing for Digitized 3D Models of Cultural Heritage

Three-dimensional digital data capture techniques such as laser scanning hold great promise for preserving and studying cultural heritage objects. However, the immense size of many scanned datasets and the computationally demanding nature of geometric processing algorithms can overwhelm traditional desktop computing environments. To overcome this bottleneck, we will investigate the application of high performance supercomputing resources for processing and analyzing scanned 3D models of cultural heritage. We will develop new algorithms and software to utilize supercomputers for humanities scholarship, including methods for converting raw scan point cloud data to finished 3D surface models, and for automated re-assembly of fragmented archaeological artifacts. We will begin to apply these techniques to large raw scan datasets that we have previously acquired, including notable artistic statuary, important archaeological artifacts, and historical architectural sites

A portable MBE system for in situ X-Ray investigations at synchrotron beamlines

A portable synchrotron MBE system is designed and applied for in situ investigations. The growth chamber is equipped with all the standard MBE components such as effusion cells with shutters, main shutter, cooling shroud, manipulator, RHEED setup and pressure gauges. The characteristic feature of the system is the beryllium windows which are used for in situ x-ray measurements. An UHV sample transfer case allows in-vacuo transfer of samples prepared elsewhere. We describe the system design and demonstrate it's performance by investigating the annealing process of buried InGaAs self organized quantum dots

Eddy Current System for Material Inspection and Flaw Visualization

Eddy current methods have been successfully used in a variety of non-destructive evaluation applications including detection of cracks, measurements of material thickness, determining metal thinning due to corrosion, measurements of coating thickness, determining electrical conductivity, identification of materials, and detection of corrosion in heat exchanger tubes. This paper describes the development of an eddy current prototype that combines positional and eddy-current data to produce a C-scan of tested material. The preliminary system consists of an eddy current probe, a position tracking mechanism, and basic data visualization capability. Initial test results of the prototype are presented in this paper

Development of rear-end collision avoidance in automobiles

The goal of this work is to develop a Rear-End Collision Avoidance System for automobiles. In order to develop the Rear-end Collision Avoidance System, it is stated that the most important difference from the old practice is the fact that new design approach attempts to completely avoid collision instead of minimizing the damage by over-designing cars. Rear-end collisions are the third highest cause of multiple vehicle fatalities in the U.S. Their cause seems to be a result of poor driver awareness and communication. For example, car brake lights illuminate exactly the same whether the car is slowing, stopping or the driver is simply resting his foot on the pedal. In the development of Rear-End Collision Avoidance System (RECAS), a thorough review of hardware, software, driver/human factors, and current rear-end collision avoidance systems are included. Key sensor technologies are identified and reviewed in an attempt to ease the design effort. The characteristics and capabilities of alternative and emerging sensor technologies are also described and their performance compared. In designing a RECAS the first component is to monitor the distance and speed of the car ahead. If an unsafe condition is detected a warning is issued and the vehicle is decelerated (if necessary). The second component in the design effort utilizes the illumination of independent segments of brake lights corresponding to the stopping condition of the car. This communicates the stopping intensity to the following driver. The RECAS is designed the using the LabVIEW software. The simulation is designed to meet several criteria: System warnings should result in a minimum load on driver attention, and the system should also perform well in a variety of driving conditions. In order to illustrate and test the proposed RECAS methods, a Java program has been developed. This simulation animates a multi-car, multi-lane highway environment where car speeds are assigned randomly, and the proposed RECAS approaches demonstrate rear-end collision avoidance successfully. The Java simulation is an applet, which is easily accessible through the World Wide Web and also can be tested for different angles of the sensor

Reactive Metal-Organic Interfaces Studied with Adsorption Calorimetry and Photoelectron Spectroscopy

This doctoral thesis presents investigations on the reactive interactions between Ca and oligomeric organic thin films with X-ray photoelectron spectroscopy (XPS), adsorption microcalorimetry, and scanning transmission electron microscopy (STEM). By combining X-ray photoelectron spectroscopy (XPS) and adsorption microcalorimetry, it is concluded that Ca exhibits a rather different growth behavior on oligomeric organic thin films compared with their polymeric homologs: the diffusion of Ca atoms into the oligomeric organic thin films is generally stronger than into the comparable polymeric thin films, resulting in thicker reaction zones. These effects can be observed in the Ca/α-sexithiophene (Ca/6T) system at room temperature, where a thick reaction zone (ca. 30 nm) with a constant composition of the reacted and unreacted sulfur species is present. This finding is possibly due to steric hindrance effects in the reaction zone. Such hindrance effects are presumably the result of massive backbone structural modifications, which are introduced by ring opening reactions at the thiophene units of 6T, subsequently followed by CaS cluster formation. The initially measured adsorption enthalpy of Ca on 6T (275 kJ/mol) is discussed in the context of previous calculations and measurements on similar systems. In contrast to expectation, the initial value for the measured adsorption enthalpy remains independent of coverage up to 4 monolayers of Ca (1 monolayers corresponding to 7.4×1018 atoms/m2). This indicates a continuous exposure of yet unreacted sulfur to Ca from the gas phase up to this point, resulting in the formation of an extended reaction zone. Based on literature data, one would expect that a closed metallic Ca layer would form on top of the 6T film significantly below the observed threshold of 4 monolayers, quenching the reaction between Ca and 6T at an earlier stage during the Ca deposition. In order to improve the existing adsorption microcalorimeter setup, a reliable and multifunctional data acquisition system is built with the LabVIEW programming environment. To accommodate the pendulum style movement of the calorimeter's chopper for Ca pulse generation, synchronized timing of the desktop data acquisition program and step motor’s internal control program is realized through the calibrated compensations and the employment of pulse pair as the unit experimental step. Possible solutions for the balance between the ease of programming and runtime reliability are proposed together with the ideas for code efficiency improvement. As for the hardware development of the calorimeter, a possible transition from the PVDF film detector to the LiTaO3 single crystalline detector is also proposed, with a prototype detector being designed and manufactured

Scalable Parallel Optimization of Digital Signal Processing in the Fourier Domain

The aim of the research presented in this thesis is to study different approaches to the parallel optimization of digital signal processing algorithms and optical coherence tomography methods. The parallel approaches are based on multithreading for multi-core and many-core architectures. The thesis follows the process of designing and implementing the parallel algorithms and programs and their integration into optical coherence tomography systems. Evaluations of the performance and the scalability of the proposed parallel solutions are presented. The digital signal processing considered in this thesis is divided into two groups. The first one includes generally employed algorithms operating with digital signals in Fourier domain. Those include forward and inverse Fourier transform, cross-correlation, convolution and others. The second group involves optical coherence tomography methods, which incorporate the aforementioned algorithms. These methods are used to generate cross-sectional, en-face and confocal images. Identifying the optimal parallel approaches to these methods allows improvements in the generated imagery in terms of performance and content. The proposed parallel accelerations lead to the generation of comprehensive imagery in real-time. Providing detailed visual information in real-time improves the utilization of the optical coherence tomography systems, especially in areas such as ophthalmology

A comparison of terrestrial laser scanning and structure-from-motion photogrammetry as methods for digital outcrop acquisition

Terrestrial laser scanning (TLS) has been used extensively in Earth Science for acquisition of digital outcrop data over the past decade. Structure-from-­motion (SfM) photogrammetry has recently emerged as an alternative and competing technology. The real-world performance of these technologies for ground-based digital outcrop acquisition is assessed using outcrops from North East England and the United Arab Emirates. Both TLS and SfM are via­ble methods, although no single technology is universally best suited to all situations. There are a range of practical considerations and operating conditions where each method has clear advantages. In comparison to TLS, SfM benefits from being lighter, more compact, cheaper, more easily replaced and repaired, with lower power requirements. TLS in comparison to SfM provides intrinsically validated data and more robust data acquisition in a wide range of operating conditions. Data post-processing is also swifter. The SfM data sets were found to contain systematic inaccuracies when compared to their TLS counterparts. These inaccuracies are related to the triangulation approach of the SfM, which is distinct from the time-of-flight principle employed by TLS. An elaborate approach is required for SfM to produce comparable results to TLS under most circumstances