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In order to reduce energy consumption of homes, it is important to make transparent which devices consume how much energy. However, power consumption is often only monitored aggregated at the house energy meter. Disaggregating this power consumption into the contributions of individual devices can be achieved using Machine Learning. Our work aims at making state of the art disaggregation algorithms accessibe for users of the open source home automation platform Home Assistant.
Purpose
To design and evaluate a modular transceiver coil array with 32 independent channels for cardiac MRI at 7.0T.
Methods
The modular coil array comprises eight independent building blocks, each containing four transceiver loop elements. Numerical simulations were used for B1+ field homogenization and radiofrequency (RF) safety validation. RF characteristics were examined in a phantom study. The array's suitability for accelerated high spatial resolution two-dimensional (2D) FLASH CINE imaging of the heart was examined in a volunteer study.
Results
Transmission field adjustments and RF characteristics were found to be suitable for the volunteer study. The signal-to-noise intrinsic to 7.0T together with the coil performance afforded a spatial resolution of 1.1 × 1.1 × 2.5 mm3 for 2D CINE FLASH MRI, which is by a factor of 6 superior to standardized CINE protocols used in clinical practice at 1.5T. The 32-channel transceiver array supports one-dimensional acceleration factors of up to R = 4 without impairing image quality significantly.
Conclusion
The modular 32-channel transceiver cardiac array supports accelerated and high spatial resolution cardiac MRI. The array is compatible with multichannel transmission and provides a technological basis for future clinical assessment of parallel transmission techniques at 7.0T.
Cardiac MR (CMR) at ultrahigh (≥7.0 T) fields is regarded as one of the most challenging MRI applications. At 7.0 T image quality is not always exclusively defined by signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Detrimental effects bear the potential to spoil the signal-to-noise (SNR) and contrast-to-noise (CNR) benefits of cardiac MR (CMR) at 7.0 T. B₁⁺-inhomogeneities and signal voids represent the main challenges. Various pioneering coil concepts have been proposed to tackle these issues, enabling cardiac MRI at 7.0 T. This includes a trend towards an ever larger number of transmit and receive channels. This approach affords multi-dimensional B₁⁺ modulations to improve B₁⁺ shimming performance and to enhance RF efficiency. Also, parallel imaging benefits from a high number of receive channels enabling two-dimensional acceleration. Realizing the limitations of existing coil designs tailored for UHF CMR and recognizing the opportunities of a many element TX/RX channel architecture this work proposes a modular, two dimensional 32-channel transmit and receive array using loop elements and examines its efficacy for enhanced B¹+ homogeneity and improved parallel imaging performance.
Today, the assembly of laser systems requires a large share of manual operations due to its complexity regarding the optimal alignment of optics. Although the feasibility of automated alignment of laser optics has been shown in research labs, the development effort for the automation of assembly does not meet economic requirements – especially for low-volume laser production. This paper presents a model-based and sensor-integrated assembly execution approach for flexible assembly cells consisting of a macro-positioner covering a large workspace and a compact micromanipulator with camera attached to the positioner. In order to make full use of available models from computer-aided design (CAD) and optical simulation, sensor systems at different levels of accuracy are used for matching perceived information with model data. This approach is named "chain of refined perception", and it allows for automated planning of complex assembly tasks along all major phases of assembly such as collision-free path planning, part feeding, and active and passive alignment. The focus of the paper is put on the in-process image-based metrology and information extraction used for identifying and calibrating local coordinate systems as well as the exploitation of that information for a part feeding process for micro-optics. Results will be presented regarding the processes of automated calibration of the robot camera as well as the local coordinate systems of part feeding area and robot base.
Akzeptorionen in BaTiO3 und SrTiO3 und ihre Auswirkungen auf die Eigenschaften von Titanatkeramiken
(1980)
Photoabsorption of alloys of Al with transition metals V, Fe, Ni and Cu and Pr near the Al L₂,₃-edge
(1974)
The onset of Al 2p transitions of VAl₃, FeAl, NiAl, NiAl₃, CuAl₂, PrAl₂ and the disordered alloys V-Al (16 at % Al, 28%, 41%), Fe-Al (11%) is shifted up to 1.1 eV. New pronounced structure develops close to the onset which for NiAl agrees with a density of states calculation by Connolly and Johnson.
Optical constants from the far infrared to the X-ray region: Mg, Al, Cu, Ag, Au, Bi, C, and Al₂O₃
(1975)
The absorption coefficient of VAI3, FeAI, NiAI, NiAl2, CuAI2, PrAl2, and of disordered V–AI (16 at% AI, 28%, 41%) and Fe–AI (11%) alloys has been measured in the region of the M₂,₃ absorption of the transition metals and the Labsorption of AI. The strong changes of the AI spectrum in the region of the 100 eV maximum upon alloying are explained as another evidence of the EXAFS (extended X-ray absorption fine structure) nature of these structures. The broad, prominent absorption peaks from the 3p excitations in V and Fe and from the 4d excitations in Pr are influenced only little on allyoing and thus appear to be of atomic origin. The fine structure at the onset of the Pr 4d transitions is identical in the metal and the alloy but differs from that of Pr oxide. The only M₂,₃ edge which is detectably shifted is that of Ni (up to 2.1 eV), whereas the onset of the AI L₂,₃ edge is shifted in all the alloys (up to 1.1 eV). The shifts are interpreted in accordance with X-ray fluorescence and nuclear resonance measurements as changes of the density of states in the valence band of the alloys.
BaTiO3 dotiert mit 3d-Ionen: Valenzen, Leerstellen und ihre Auswirkungen. Hagemann, H. J.; Ihrig, H.
(1980)
Grain boundary and surface segragation of Ba-Ti-O-Phases in rutile. O´Bryan, H. M.; Hagemann, H. J.
(1987)
IT-Sicherheit im Automobil
(2014)
Media Delivery Based on Service Aware Transport Overlay Networks / Kampmann, Markus ; Hartung, Frank
(2007)
Phase Repeatable Synthesizers as a New Harmonic Phase Standard for Nonlinear Network Analysis
(2018)
This paper introduces a new maritime search and rescue system based on S-band illumination harmonic radar (HR). Passive and active tags have been developed and tested while attached to life jackets and a small boat. In this demonstration test carried out on the Baltic Sea, the system was able to detect and range the active tags up to a distance of 5800 m using an illumination signal transmit-power of 100 W. Special attention is given to the development, performance, and conceptual differences between passive and active tags used in the system. Guidelines for achieving a high HR dynamic range, including a system components description, are given and a comparison with other HR systems is performed. System integration with a commercial maritime X-band navigation radar is shown to demonstrate a solution for rapid search and rescue response and quick localization.
Prozessorientierte Messung der Customer Experience am Beispiel der Telekommunikationsindustrie
(2018)
Hohe Wettbewerbsintensität und gestiegene Kundenanforderungen erfordern bei Telekommunikationsunternehmen eine aktive Gestaltung der Customer Experience (CX). Ein wichtiger Aspekt dabei ist die CX-Messung. Traditionelle Zufriedenheitsmessungen sind oft nicht ausreichend, um die Kundenerfahrung in komplexen Prozessen vollständig zu erfassen. Daher wird in diesem Kapitel eine prozessübergreifende Referenzlösung zur CX-Messung am Beispiel der Telekommunikationsindustrie vorgeschlagen. Ausgangspunkt ist ein industriespezifisches Prozessmodell, das sich an dem Referenzmodell eTOM orientiert. Dieses wird um Messpunkte erweitert, die Schwachstellen in Bezug auf die CX identifizieren. Für die erkannten Schwachstellen werden über eine Referenzmatrix mögliche Auslöser abgeleitet und anhand von typischen Geschäftsfallmengen bewertet. Somit ist eine direkte Zuordnung und Erfolgsmessung konkreter Maßnahmen zur Behebung der Schwachstellen möglich. Die so entwickelte Referenzlösung wurde im Projekt K1 bei der Deutschen Telekom erfolgreich umgesetzt. Details zur Umsetzung werden als Fallstudien dargestellt.
Das Ziel des INTERREG-Projektes „SHAREuregio“ (FKZ: 34.EFRE-0300134)
ist es, grenzüberschreitende Mobilität in der Euregio Rhein-Maas-Nord zu
ermöglichen und zu fördern. Dazu soll ein elektromobiles Car- und Bikesharing-
System entwickelt und in der Stadt Mönchengladbach, im Kreis Viersen
sowie in den Gemeinden Roermond und Venlo (beide NL) zusammen mit den
Partnern Wirtschaftsförderung Mönchengladbach, Wirtschaftsförderung für den
Kreis Viersen, NEW AG, Goodmoovs (NL), Greenflux (NL) und der FH Aachen
implementiert werden. Zunächst richtet sich das Angebot, bestehend aus 40
Elektroautos und 40 Elektrofahrrädern, an Unternehmen und wird nach einer
Erprobungsphase, mit einer größeren Anzahl an Fahrzeugen, auch für Privatpersonen
verfügbar gemacht werden. Die Fahrzeuge stehen bei den jeweiligen
Anwendungspartnern in Deutschland und den Niederlanden.
Im Rahmen dieses Projektes hat die FH Aachen „FlexSHARE“ entwickelt
– ein methodisches Framework zur innovativen Gestaltung urbaner Sharing-
Angebote. Das Framework ermöglicht es, anhand von messbaren Kenngrößen,
bedarfsgerechte und auf die Region abgestimmte Sharing-Systeme zu entwickeln.
This study demonstrates the feasibility of applying free-breathing, cardiac-gated, susceptibility-weighted fast spin-echo imaging together with black blood preparation and navigator-gated respiratory motion compensation for anatomically accurate T₂ mapping of the heart. First, T₂ maps are presented for oil phantoms without and with respiratory motion emulation (T₂ = (22.1 ± 1.7) ms at 1.5 T and T₂ = (22.65 ± 0.89) ms at 3.0 T). T₂ relaxometry of a ferrofluid revealed relaxivities of R2 = (477.9 ± 17) mM⁻¹s⁻¹ and R2 = (449.6 ± 13) mM⁻¹s⁻¹ for UFLARE and multiecho gradient-echo imaging at 1.5 T. For inferoseptal myocardial regions mean T₂ values of 29.9 ± 6.6 ms (1.5 T) and 22.3 ± 4.8 ms (3.0 T) were estimated. For posterior myocardial areas close to the vena cava T₂-values of 24.0 ± 6.4 ms (1.5 T) and 15.4 ± 1.8 ms (3.0 T) were observed. The merits and limitations of the proposed approach are discussed and its implications for cardiac and vascular T₂-mapping are considered.
Mikrowellentechnik
(2014)
Praezise Streuparametermessungen sind der Schluessel zur Modellierung elektrischer Schaltungen
(1997)
Dieses Lehr- und Fachbuch vermittelt anschaulich die Grundlagen der HF-Technik, gibt konkrete Beschreibungen für den Entwurf von linearen Komponenten aus Bauteilen wie auch Leitungen für High-Speed- und HF-Schaltungen. Dem Leser wird vermittelt, wie Bauteile modelliert und Schaltungen synthetisiert und optimiert werden. Mit Hilfe frei verfügbarer Simulationssoftware können GHz-Schaltungen selbst entwickelt werden. Viele Übungsbeispiele ermöglichen die Eigenkontrolle des Wissensstandes. Weiterhin werden komplexe nichtlineare Komponenten wie Hochfrequenzmischer, Oszillatoren und Synthesegeneratoren in ihrer Funktionalität dargestellt. Die neuen Mixed-Mode-Streuparameter sowie deren Leitungs- und Schaltungstechnik für Anwendungen der schnellen Digital- und der modernen HF-Technik sind ausführlich beschrieben. Es wird auf Systeme für folgende Bereiche eingegangen: Streuparametermesstechnik, verschiedene Funktechniken, UHF-RFID und Lokalisierung- und Ortung. Dem Leser wird somit ermöglicht, komplexe GHz-Schaltungen insbesondere mit Halbleiter-, SMD- und LTCC-Schaltungen zu entwickeln.
Calibration of a Network Analyzer Without a Thru Connection for Nonlinear and Multiport Measurements
(2008)
Calibration procedures with series impedances and unknown lines simplify on-wafer measurements
(1999)
Upcoming gasoline engines should run with a larger number of fuels beginning from petrol over methanol up to gas by a wide range of compression ratios and a homogeneous charge. In this article, the microwave (MW) spark plug, based on a high-speed frequency hopping system, is introduced as a solution, which can support a nitrogen compression ratio up to 1:39 in a chamber and more. First, an overview of the high-speed frequency hopping MW ignition and operation system as well as the large number of applications are presented. Both gives an understanding of this new base technology for MW plasma generation. Focus of the theoretical part is the explanation of the internal construction of the spark plug, on the achievable of the high voltage generation as well as the high efficiency to hold the plasma. In detail, the development process starting with circuit simulations and ending with the numerical multiphysics field simulations is described. The concept is evaluated with a reference prototype covering the frequency range between 2.40 and 2.48 GHz and working over a large power range from 20 to 200 W. A larger number of different measurements starting by vector hot-S11 measurements and ending by combined working scenarios out of hot temperature, high pressure and charge motion are winding up the article. The limits for the successful pressure tests were given by the pressure chamber. Pressures ranged from 1 to 39 bar and charge motion up to 25 m/s as well as temperatures from 30◦ to 125◦.