Regularized Dual Averaging Image Reconstruction for Full-Wave Ultrasound Computed Tomography

Ultrasound computed tomography (USCT) holds great promise for breast cancer screening. Waveform inversion-based image reconstruction methods account for higher order diffraction effects and can produce high-resolution USCT images, but are computationally demanding. Recently, a source encoding technique was combined with stochastic gradient descent to greatly reduce image reconstruction times. However, this method bundles the stochastic data fidelity term with the deterministic regularization term. This limitation can be overcome by replacing stochastic gradient descent (SGD) with a structured optimization method, such as the regularized dual averaging (RDA) method, that exploits knowledge of the composition of the cost function. In this work, the dual averaging method is combined with source encoding techniques to improve the effectiveness of regularization while maintaining the reduced reconstruction times afforded by source encoding. It is demonstrated that each iteration can be decomposed into a gradient descent step based on the data fidelity term and a proximal update step corresponding to the regularization term. Furthermore, the regularization term is never explicitly differentiated, allowing non-smooth regularization penalties to be naturally incorporated. The wave equation is solved by use of a time-domain method. The effectiveness of this approach is demonstrated through computer-simulation and experimental studies. The results suggest that the dual averaging method can produce images with less noise and comparable resolution to those obtained by use of stochastic gradient descent

Maximizing ROMI of DMOs: Enabled Through Tourism Investment Framework and Agile Marketing

As most Destination Marketing Organizations (DMOs) are faced with stiffening competition and depleting resources, it requires an agile and reinstituted approach towards the allocation and usage of marketing resources. This paper explores an always-on approach towards destination marketing strategy formulation and execution, leveraging data created through digitalization in the tourism ecosystem. In terms of strategy formulation, the conceptual framework brings together the potential of source markets, the destination’s ability to win, along with the available resources and targets, to dynamically allocate resources to theoretically maximize return on marketing investment (ROMI). For implementation, data-streams are leveraged to allocate marketing budgets to appropriate channels, thereby maximizing the ROMI. The framework is delivered through a data-driven, dynamic model for resource allocation. The model leverages meta-analyses on existing data streams and transactional information created through digitalization in tourism (i.e., internet-of-things or smart tourism), thereby minimizing the costs related to incremental quantitative or qualitative research

Attosekunden-zeitaufgelöste Streaking-Spektroskopie an dem Schichtkristall Bi2Te3 und an den unterschiedlichen Oberflächen des nicht-zentrosymmetrischen Schichtkristalls BiTeCl

Neb S. Attosekunden-zeitaufgelöste Streaking-Spektroskopie an dem Schichtkristall Bi2Te3 und an den unterschiedlichen Oberflächen des nicht-zentrosymmetrischen Schichtkristalls BiTeCl. Bielefeld: Universität Bielefeld; 2018

Methodik zur automatischen Generierung von Montagesequenzen aus einem 3D-Modell

Im Rahmen dieser Arbeit wurde untersucht, wie Montageplaner/-innen schon frühzeitig bei der Planung von Montagesequenzen unterstützt werden können. Hierzu wurde geprüft, wie montagerelevante Informationen aus einem 3D-Modell extrahiert werden können. Anschließend wurde ein Vorgehen entwickelt, um aus diesen Informationen automatisiert Montagesequenzen zu generieren. Hierzu wurden zwei Kernfragen geklärt: Welche Montageinformationen können automatisiert aus 3D-Modellen extrahiert werden und wie können aus diesen Informationen automatisiert Montagesequenzen generiert werden? Mithilfe eines Zugriffs auf das CAD-System wurden alle relevanten Informationen direkt aus dem 3D-Modell extrahiert. Durch einen neuartigen Ansatz konnten vielfältige und detaillierte Montageinformationen in Form von Features gewonnen und analysiert werden. Diese wurden dazu eingesetzt, die Montagesequenzen hinsichtlich Kriterien, wie die Baugruppenstabilität oder Werkzeugwechsel, zu optimieren. Nach der Generierung der optimierten Montagesequenzen wurde das 3D-Modell nochmals herangezogen, um die einzelnen Montageschritte auch in Form einer automatisch generierten Montageanleitung zu visualisieren. Validiert wurde die Arbeit in einem dreistufigen Verfahren anhand realer Baugruppen. Hierzu wurden Expertenmeinungen herangezogen und reale Produkte untersucht. Das Resultat sind optimierte, ausführbare Montagesequenzen, die vollkommen automatisch aus dem 3D-Modell generiert werden konnten. Somit wird ein neuartiges Vorgehen zur Generierung von Montagesequenzen aufgrund detaillierter Kriterien, weit über den Stand der Technik hinaus, vorgestellt.This work investigated how assembly planners can be supported in the planning of assembly sequences at an early stage. For this purpose, it was examined how assembly-relevant information can be extracted from a 3D model. Subsequently, a procedure was developed to automatically generate assembly sequences from this information. To this end, two key questions were clarified: What assembly information can be automatically extracted from 3D models and how can assembly sequences be automatically generated from this information? By accessing the CAD system, all relevant information was extracted directly from the 3D model. Using a novel approach, a wide range of detailed features could be obtained and analyzed. These were used to optimize the assembly sequences with regard to criteria such as assembly stability or tool changes. After generating optimized assembly sequences, the 3D model was used again to visualize the individual assembly steps in the form of automatically generated assembly instructions. The work was validated in a three-stage process using real assemblies. For this purpose, expert interviews were executed and real products were examined. The result are optimized, executable assembly sequences that could be generated completely automatically from the 3D model. Thus, a novel procedure for the generation of assembly sequences using the most comprehensive criteria, far beyond the state of the art, could be presented

Bedeutung von SWEET-Genen für den pflanzlichen Zuckerexport in einer Ektomykorrhizasymbiose

In mutualsitic interactions between fungi and plants, such as ectomycorrhiza, the fungus contributes nutrition and obtains plant derived carbohydrates as a response. The carbohydrate transport in ectomycorrhized roots is not yet fully understood and requires additional investigations. However prerequisites for such analysis are transgenic plants. Poplar is a well established model for investigation of ectomycorrhizal symbiosis. As the generation of transgenic poplar plants is a highly time consuming process and can take up to one year a new A. rhizogenes- based transformation protocol was developed in the present thesis. Furthermore, the role of the recently discovered SWEET-proteins in the carbohydrate transport in ectomycorrhiza was investigated. Ectomycorrhiza regulated SWEET proteins were localized in the plasma membrane of Nicotiana benthamiana leaves determining their role in the carbohydrate supply of the fungal partner in ectomycorrhiza. Additionally a promoter analysis of one of the mycorrhiza-induced SWEET genes, PtSWEET 1.c, was performed and two regulatory regions could be identified. However, an ectomycorrhiza specific regulation of the promoter reporter constructs was not observed

Smart Airport App

We are going to make an app that can be used by people traveling through or from ORD airport (Chicago), which will provide live time update for security check line (in terms of time), change of gate for the flight and whether or not the flight is on time. The reason for developing this application is to simplify and improve the passenger’s overall airport experience in order to make it more enjoyable, informative, and time efficient while decreasing the current negative mentality towards traveling. Resources needed to create the prototype would include softwares that help in creating wireframes of the applications like Balsamiq and app developing softwares like Android studio and Xcode. The anticipated beneficiaries of this project would be the consumers that are being provided a smoother airport experience, as well as the airport operators who will be able to provide a better service to the customers with the data collected. An expected result of this app is that fewer passengers will miss their flights; by focusing on waiting times, flight schedules, flight locations, and other airport operations, it can be assumed that users of this app will have more control in the travel process and therefore will make educated decisions based on real time data to make their flight on time. The constraints for this app will be that it is only available on Android-OS compatible phones. Only O’Hare International Airport in Chicago, Illinois will be functional at the time of app release while the team learns about the learning capabilities of the ap

Redox Modulation at Work: Natural Phytoprotective Polysulfanes From Alliums Based on Redox-Active Sulfur

Purpose of review: This article provides a brief overview of natural phytoprotective products of allium with a special focus on the therapeutic potential of diallyl polysulfanes from garlic, their molecular targets and their fate in the living organisms. A comprehensive overview of antimicrobial and anticancer properties of published literature is presented for the reader to understand the effective concentrations of polysulfanes and their sensitivity towards different human pathogenic microbes, fungi, and cancer cell lines. Recent findings: The article finds polysulfanes potentials as new generation novel antibiotics and chemo preventive agent. The effective dose rates of polysulfanes for antimicrobial properties are in the range of 0.5–40 mg/L and for anticancer 20–100 μM. The molecular targets for these redox modulators are mainly cellular thiols as well as inhibition and/or activation of certain cellular proteins in cancer cell lines. Summary: Antimicrobial and anticancer activities of polysulfanes published in the literature indicate that with further development, they could be promising candidates for cancer prevention due to their selectivity towards abnormal cells