Kostenmodellierung mit SystemC/System-AMS

In diesem Beitrag wird eine Methode zur Beschreibung von Kostenfaktoren und deren Verknüpfung über Hierarchiegrenzen hinweg dargestellt. Sie eignet sich sowohl für rein digitale Systeme mit Softwareanteilen als auch für gemischt analog/digitale Systeme. Damit ist sie im Hardware-Software Codesign und im Analog-Digital Codesign zum Vergleich verschiedener Systemkompositionen anwendbar. Die Implementierung mit C++ ermöglicht neben einer Nutzung mit digitalem SystemC auch den Einsatz mit der analogen SystemC-Erweiterung SystemC-AMS und vereinfacht die Nutzung gegenüber einer vorhandenen VHDL-Implementierung. Als Anwendungsbeispiel fungieren Komponenten eines Systems zur Inertialnavigation

The simulation of terahertz waves transmission in the arc plasma

The diagnostic of high-density hot plasma is a challenging task due to its high temperature and electron density. Arc plasma is one of the typical hot density plasmas, and its diagnosis is the key to develop its new applications. In this paper, the temperature and density distributions of welding plasmas with different discharge currents are numerically simulated based on a Tungsten Inert Gas Arc Welding model, and the electron density distributions are calculated. Then propagation properties of broadband terahertz (THz) waves in the modeling arc jets are calculated by the finite difference time domain method. These results not only provide a preliminary theoretical guidance for in-depth understanding the problems of blackout in re-entry communication, but also develop a new idea for the terahertz diagnostic of plasma with high density

Slack and Innovation in Africa: A Curve Linear Relationship

In this study, we undertake the financial slack and innovation intensity linkage across industries in Africa.  We reported empirical evidence based on the data of 923 non-financial firms in 10 African countries. The industry-level robust regression result shows that the association between financial slack and innovation intensity varied across industries because of the heterogeneous nature R&D spending and financial slack accumulation of firms in different industries. That is, both a U-shape and an inverted U-shape relationship between slack and innovation intensity are confirmed. We finally discussed results and policy implications in detail. Keywords: Africa, Financial Slack, Innovation intensity, R&D investmen

Nanocomposite electret with surface potential self-recovery from water dipping for environmentally stable energy harvesting

Due to their high charge densities, electret materials have gained extensive attention in recent years for their abilities to harvest mechanical energy. However, the environmental stability of electret materials is still a major concern for real applications. Here, we report a thin-film nanocomposite electret material (NCEM) that exhibits immediate and effective self-recovery of the surface potential after water dipping. The NCEM is composed of a polytetrafluoroethylene (PTFE) film, a nanocomposite film with PTFE nanoparticles as the nanofiller and polydimethylsiloxane (PDMS) as the matrix. The surface potential of the NCEM resulting from corona charging could be stably maintained with very little decay of 2% after 25 days. More importantly, the surface potential exhibited quick self-recovery to 75% and 90% of its initial value after 10 min and 60 min, respectively, when the NCEM was removed from water. A 70% self-recovery was still observed even when the NCEM was dipped in water for 200 cycles. When used in electret nanogenerators (ENGs), the electric output recovered to 90% even when the ENG experienced water dipping. Therefore, this work presents a key step towards developing high-performance and environmentally stable energy harvesting nanogenerators that can survive harsh conditions for real applications

On modeling and measuring viscoelasticity with dynamic Atomic Force Microscopy

The interaction between a rapidly oscillating atomic force microscope tip and a soft material surface is described using both elastic and viscous forces with a moving surface model. We derive the simplest form of this model, motivating it as a way to capture the impact dynamics of the tip and sample with an interaction consisting of two components: interfacial or surface force, and bulk or volumetric force. Analytic solutions to the piece-wise linear model identify characteristic time constants, providing a physical explanation of the hysteresis observed in the measured dynamic force quadrature curves. Numerical simulation is used to fit the model to experimental data and excellent agreement is found with a variety of different samples. The model parameters form a dimensionless impact-rheology factor, giving a quantitative physical number to characterize a viscoelastic surface that does not depend on the tip shape or cantilever frequency.Comment: 13 pages, 7 figure

The Effects of Low and High Levels of Sadness on Scope of Attention: An ERP Study

Sadness has inconsistent effects on the scope of attention. These differing effects may be attributed to different levels of sadness induced in different experiments. Low levels of sadness can expand the scope of attention, but high levels can narrow it. In this study, we recruited 42 college students and induced different levels of sadness in them by having them view sad images continuously, and then we assigned them Navon’s letter task. The results showed that among participants with local-processing bias, those at lower levels of sadness were slower to identify small letters than were those at high levels of sadness and control condition (watching neutral images). Event-related potential (ERP) results showed that low-sadness participants put more attention resources toward processing large letters (global stimuli). They showed increased amplitude of the P1 component compared with high-sadness participants and participants at control condition. These results suggested that different levels of sadness had different effects on attention scope: low levels of sadness extended the scope but as sadness increased, this extension disappeared. This influence pattern mainly occurred in the early stages of visual processing

Modeling and Measuring Viscoelasticity with Dynamic Atomic Force Microscopy

The interaction between a rapidly oscillating atomic-force-microscope tip and a soft-material surface is described with use of both elastic and viscous forces in a moving-surface model. We present the simplest form of this model, motivating our derivation with the models ability to capture the impact dynamics of the tip and sample with an interaction consisting of two components: interfacial or surface force, and bulk or volumetric force. Analytic solutions to the piecewise linear model identify characteristic time constants, providing a physical explanation for the hysteresis observed in the measured dynamic-force-quadrature curves. Numerical simulation is used to fit the model to experimental data, and excellent agreement is found with a variety of different samples. The model parameters form a dimensionless impact-rheology factor, giving a quantitative physical number to characterize a viscoelastic surface that does not depend on the tip shape or cantilever frequency

High-density molecular characterization and association mapping in Ethiopian durum wheat landraces reveals high diversity and potential for wheat breeding

Durum wheat (Triticum turgidum subsp. durum) is a key crop worldwide, yet its improvement and adaptation to emerging environmental threats is made difficult by the limited amount of allelic variation included in its elite pool. New allelic diversity may provide novel loci to international crop breeding through quantitative trait loci (QTL) mapping in unexplored material. Here we report the extensive molecular and phenotypic characterization of hundreds of Ethiopian durum wheat landraces and several Ethiopian improved lines. We test 81,587 markers scoring 30,155 single nucleotide polymorphisms and use them to survey the diversity, structure, and genome-specific variation in the panel. We show the uniqueness of Ethiopian germplasm using a siding collection of Mediterranean durum wheat accessions. We phenotype the Ethiopian panel for ten agronomic traits in two highly diversified Ethiopian environments for two consecutive years, and use this information to conduct a genome wide association study. We identify several loci underpinning agronomic traits of interest, both confirming loci already reported and describing new promising genomic regions. These loci may be efficiently targeted with molecular markers already available to conduct marker-assisted selection in Ethiopian and international wheat. We show that Ethiopian durum wheat represents an important and mostly unexplored source of durum wheat diversity. The panel analyzed in this study allows the accumulation of QTL mapping experiments, providing the initial step for a quantitative, methodical exploitation of untapped diversity in producing a better wheat