Modeling the systematic behavior at the micro and nano length scales

The assessment of the systematic behavior based on frequentist statistics was analyzed in the context of micro/nano metrology. The proposed method is in agreement with the well-known GUM recommendations. The investigation assessed three different case studies with definition of model equations and establishment of the traceability. The systematic behavior was modeled in Sq roughness parameters and step height measurements obtained from different types of optical microscopes, and in comparison with a calibrated contact instrument. The sequence of case studies demonstrated the applicability of the method to micrographs when their elements are averaged. Moreover, a number of influence factors, which are typical causes of inaccuracy at the micro and nano length scales, were analyzed in relation to the correction of the systematic behavior, viz. the amount of repeated measurements, the time sequence of the acquired micrographs and the instrument-operator chain. The possibility of applying the method individually to the elements of the micrographs was instead proven not convenient and too onerous for the industry. Eventually, the method was also examined against the framework of the metrological characteristics defined in ISO 25178-600 with hints on possible future developments.

Forecasting FOMC Forecasts

(Hendry 1980, p. 403) The three golden rules of econometrics are “test, test, and test”. The current paper applies that approach to model the forecasts of the Federal Open Market Committee over 1992–2019 and to forecast those forecasts themselves. Monetary policy is forward-looking, and as part of the FOMC’s effort toward transparency, the FOMC publishes its (forward-looking) economic projections. The overall views on the economy of the FOMC participants–as characterized by the median of their projections for inflation, unemployment, and the Fed’s policy rate–are themselves predictable by information publicly available at the time of the FOMC’s meeting. Their projections also communicate systematic behavior on the part of the FOMC’s participants.

Behavior change through wearables: the interplay between self-leadership and IT-based leadership

Physical inactivity is a global public health problem that poses health risks to individuals and imposes financial burdens on already strained healthcare systems. Wearables that promote regular physical activity and a healthy diet bear great potential to meet these challenges and are increasingly integrated into the healthcare system. However, extant research shows ambivalent results regarding the effectiveness of wearables in improving users’ health behavior. Specifically important is understanding users’ systematic behavior change through wearables. Constructive digitalization of the healthcare system requires a deeper understanding of why some users change their behavior and others do not. Based on self-leadership theory and our analysis of narrative interviews with 50 long-term wearable users, we identify four wearable use patterns that bring about different behavioral outcomes: following, ignoring, combining, and self-leading. Our study contributes to self-leadership theory and research on individual health information systems and has practical implications for wearable and healthcare providers.

Temporal Characteristics of Debris Flow Surges

Debris flow is one of the most destructive geomorphological events in mountainous watersheds, which usually appears in the form of successive surge waves as observed all over the world. In particular, debris flows in the Jiangjia Gully in southwest China have displayed a great variety of surge phenomena; each debris flow event contains tens or hundreds of separate surges originating from different sources. Therefore, the surge sequence of an event must encode the information of debris flow developing. The unmanned aerial vehicle photos provide an overview of debris flow sources, showing the different potentials of the debris flow and surge sequences present various patterns responding to the rainfall events. Then the variety of rainfalls and material sources determine the diversity of surge sequence. Using time series analysis to the surge discharge sequences, we calculate the Hurst exponent, the autocorrelation function, and the power spectrum exponent and find that all the sequences commonly share the property of long-term memory and these parameters are correlated in an exponential form, with values depending on rainfall patterns. Moreover, all events show a gross trend of discharge decay, despite the local rainfall process, which implies the intrinsic nature of the surge sequence as a systematic behavior of watershed. It is expected that these findings are heuristic for establishing mechanisms of debris flow initiation and evolution in a watershed.

Characterization of sand and sand–binder systems from the foundry industry with electrical impedance spectroscopy

The global economy consumes an estimated 4×1010 t of sand per year, with only 2×1010 t of sand being reproduced by natural sedimentation (Götze and Göbbels, 2017; Peduzzi, 2014). Among other things, sand is also used as a basic material for the production of molds and cores in the foundry industry. The consumption and the economic as well as ecological savings' potential in this area of application can be appreciated by way of an example: the environmental certificate of a single, albeit big German foundry (5160 employees) can be consulted, which states that 39 820 t of sand for casting molds had to be purchased in 2017 (Denes, 2018). In order to avoid having to dispose of the used sand in landfills and to reduce the use of new sand, it is therefore advantageous to renew the used sand in a so-called regeneration process and reuse it as a substitute for new sand in the production of molds and cores. It would be very advantageous if the condition of molding materials (sand–binder systems) in regenerator units could be monitored in real time because of the economic and ecological advantages of a monitored and optimized regeneration process. This work presents the results of investigations in this direction. The objects of investigation in this work are typical molding materials in the foundry industry, e.g., quartz sand, chromite sand, and bentonite as a binder, which are measured impedimetrically with the help of a plate capacitor measuring cell which is connected to an LCR meter (Agilent E4980A). The impedance of the filled capacitor is measured in a frequency range from 1.2 kHz to 1 MHz, containing 123 frequency points. The aim of this research is to work out if the mentioned substances can be measured with the presented measuring method and classified on the basis of impedance characteristics and thus whether impedance spectroscopy can be considered for process monitoring in the molding industry. It is shown that the condition monitoring can possibly be based on impedance spectroscopy because the resulting curves are characteristic of the material used. New and used sands as well as two-component mixtures of sands and binders showed a systematic behavior, which allows the sand or the composition of the mixture to be identified (classified) in the future. The examination of the scatter of the measurement results shows that the impedance data obtained with this method can be measured reproducibly. A descriptive model for multi-component systems is developed in order to be able to interpret the impedance scatter results and their representation in Nyquist plots. From this model, the filling density of the measurement cell and the density of conduction paths can be extracted as essential influence quantities.

Shape Anisotropic Magnetic Thrombolytic Actuators: Synthesis and Systematic Behavior Study

Thrombosis-related diseases are undoubtedly the deadliest disorders. Numerous attempts were made during the last decades to reduce the overall death rate and severe complications caused by treatment delays. Significant progress...

Computational Thinking in Educational Digital Games

In our age, computational thinking is a required skill for the 21st century that guides individuals' systematic behavior towards resolving the problems they face. Today, it could be argued that one of the tools that could be used with the students to achieve this skill is the educational digital games. Literature review revealed no measurement tools that scrutinize the readiness levels of educational digital games for the students to achieve computational thinking skills. Thus, the present study aimed to develop a checklist to determine the competency of educational digital games in promoting the achievement of computational thinking skills determined by ISTE and CSTA (2011) by the students. It was considered that the developed measurement tool would facilitate the assessment of educational digital games for achievement of computational thinking skills and guide the designers. At the end of the study, recommendations for future research and applications are presented.

Study of CaF2- Doped PbTe Thin Films Grown by Molecular Beam Epitaxy

We present here a study on the electrical and structural properties of p-type PbTe films doped with CaF2. The layers were grown by molecular beam epitaxy on freshly cleaved (111) BaF2 substrates. The doping level was monitored by the CaF2 solid source cell temperature (TCaF2), which varied from 500 to 1150 °C. The films with low doping level, TCaF2 ≤ 1010 °C, exhibited flat surfaces with crystalline quality close to the undoped PbTe sample. In contrast, samples with high levels of doping (TCaF2 > 1010 °C) presented CaF2 agglomerates on the surface and a worse crystal quality. The hole density at 77 K versus TCaF2 oscillated between 1.3 × 1017 and 3.6 × 1017 cm-3 and did not exhibit a systematic behavior as the fluoride supply is raised. The results indicate that CaF2 is not an effective p-type dopant for PbTe, due to the abscence of a resonant level close to the valence band or to compensation of extrinsic dopant levels.

VIX VERSUS VXX: A JOINT ANALYTICAL FRAMEWORK

We propose a framework for modeling in a consistent manner the VIX index and the VXX, an exchange-traded note written on the VIX. Our study enables to link the properties of VXX to those of the VIX in a tractable way. In particular, we quantify the systematic loss observed empirically for VXX when the VIX futures term-structure is in contango and we derive option prices, implied volatilities and skews of VXX from those of VIX in infinitesimal developments. We also perform a calibration on real data which highlights the flexibility of our model in fitting the futures and the vanilla options market of VIX and VXX. Our framework can be used to model other exchange-traded notes on the VIX as well as any market where exchange-traded notes have been introduced on a reference index, hence providing tools to better anticipate and quantify systematic behavior of an exchange-traded note with respect to the underlying index.