Evaluation of high frequency vibrator response

Accurate analysis of the motion of a commercial high frequency hydraulic vibrator commonly used for near-surface applications demonstrated that the rigid body assumption of the weighted-sum approximation is not valid throughout the vibrator's operational frequencies. This study reveals significant response variability across the baseplate, which is dependent on accelerometer position with respect to radial position and internal baseplate structure. Consequently, the baseplate cannot be considered a point source of propagation, which complicates optimizing source operations to increase data fidelity. In an effort to optimize the source signature approximation to increase data fidelity, simultaneous acquisition of baseplate acceleration and pressure beneath the baseplate provided a means to directly compare the response of strategically placed accelerometers to the true ground force. This study concludes that the most representative approximation occurs when multiple accelerometers are positioned on the baseplate to average the baseplate motion. In addition, this study found that the IVI Minivib I is incapable of providing measurable seismic energy at frequencies over 200 Hz due to opposing baseplate and reaction mass phase. Based on this observation, it is clear the design of the baseplate needs to be modified by adding extra weight and rigidity to the driven structure. Increasing rigidity of the baseplate will reduce source generated harmonic distortion caused by baseplate flexure resulting in a more uniform response across the baseplate and a more accurate ground force approximation. Additionally, the opposing phase relationship between the baseplate and the reaction mass could be remediated by increasing the baseplate weight resulting in an increase in energy above 200 Hz

Langzeitverhalten von weichballistischen Materialien

Dieser Aufsatz befasst sich mit dem Langzeitverhalten ballistischer Materialien. Vorrangig soll die Frage geklärt werden, ob ballistisches Material qualitätsmindernde Erscheinungen im Schutzverhalten aufweist, die mit dem fortschreitenden Alter des Materials einhergehen. Um diese Frage zu klären, wurden anhand zahlreicher Beschussversuche an polizeilichen Schutzwesten statistisch verlässliche Daten gesammelt und anschließend unter verschiedenen Blickwinkeln ausgewertet. Zusätzlich wurden verschiedene Laborversuche am Aramid-Gewebe durchgeführt.This publication deals with the long-term behavior of ballistic material. It aims to answer the question, whether ballistic material shows significant signs of a deterioration that comes with preceding age. To answer that question numerous shooting tests with bulletproof vests were made to collect statistically reliable Data. The data was then evaluated under different point of views. Additionally various laboratory experiments were performed with Aramid fibre

Ermittlung des Energiebedarfs zur Bewegung von Fahrzeugen in mikroskopischen Verkehrssimulationen

Die Integration von Modellen für Fahrzeuge mit alternativen Antrieben in Verkehrssimulationen erfordert eine genauere Betrachtung der Energieflüsse in den einzelnen Fahrzeugen. Diese Arbeit betrachtet den Energiebedarf für die Bewegung von Fahrzeugen und evaluiert vorhandene klassische Modelle zur Abstraktion der physikalischen Einflüsse. Aufgrund der fehlenden Einstimmigkeit der Autoren bei der Beschreibung solcher Modelle in der Literatur wird letztlich der Ansatz verfolgt, ein entsprechendes Modell von der physikalischen Basis ausgehend neu zu entwickeln. Zusätzlich dazu wird festgestellt, dass die Beschränkungen der geläufigen Verkehrssimulationsumgebungen einen signifikanten Einfluss auf die Berechenbarkeit einzelner Komponenten derartiger Modelle haben. Das geschaffene Modell wird anschließend in verschiedenen Varianten in einem Vergleich mit einem weit verbreiteten Modell evaluiert. Zu guter Letzt muss konstatiert werden, dass eine Erhöhung der Realitätsnähe der Simulation – insbesondere im situativen Bereich – erreicht werden konnte, für wesentliche Verbesserungen jedoch eine Beseitigung bestehender Restriktionen der Simulationsumgebungen erforderlich wäre.The integration of models for alternative fuel vehicles in traffic simulation requires a closer examination of the energy flows in the individual vehicles. This work considers the energy required for the movement of vehicles and evaluates existing classical models for the abstraction of the physical influences. Due to the lack of unanimity of the authors in the discribing of such models in the literature, the approach ultimately pursued requires redeveloping an appropriate model of the physical basis as a starting point. Additionally, it has been established that the restrictions of the common traffic simulation environments have a significant impact on the computability of individual components of such models. The created model is then evaluated in different variants in comparison with a widely used model. Finally, it is notable that increasing simulation realism could be achieved, however, for in order to see substantial improvements, the elimination of certain restrictions of current simulation environments would be required

Sicherheit von Unternehmensdaten auf Mobilen Endgeräten

Mobile Endgeräte werden mit zunehmender Tendenz in unternehmensweite Anwendungen integriert. Damit stellt sich verstärkt die Frage nach der Sicherheit der sich auf den Geräten befindlichen Unternehmensdaten. Dieser Beitrag analysiert die wesentlichen Szenarien, die zum Verlust bzw. Missbrauch von auf mobilen Endgeräten gespeicherten Daten führen, und diskutiert Ansätze zur Sicherung dieser Daten. Insbesondere werden dabei Schutzmechanismen gegen den Verlust des mobilen Endgerätes, gegen den reinen Datenverlust und Mechanismen gegen das Abhören der Datenübertragung erörtert. Dabei werden sowohl allgemeingültige Prinzipien als auch endgerätspezifische Merkmale betrachtet.Mobile devices are increasingly integrated in enterprise applications. As a consequence this intensifies the concern about the stored enterprise data. This paper analyses the most relevant scenarios leading to the loss or the abuse of data stored on mobile devices and shows approaches how to increase data security, detailing about preventive measures in the case of device loss, securing against direct data loss as well as actions to increase data transmission security. The results incorporate commonly usable principles and device specific characteristics

miRTRAP, a computational method for the systematic identification of miRNAs from high throughput sequencing data

A novel method for prediction of miRs from deep sequencing data. Its utility is demonstrated when applied to Ciona data

Schutzverhalten von weichballistischem ultrahochmolekularem Polyethylen

Diese Publikation befasst sich mit dem Langzeitverhalten der Schutzeigenschaften von weichballistischem ultra-hochmolekularem Polyethylen. Vorrangig soll die Frage geklärt werden, ob dieses Material qualitätsmindernde Erscheinungen im Schutzverhalten aufweist, die mit seinem fortschreitenden Alter einhergehen. Um diese Frage zu klären, wurden anhand zahlreicher Beschussversuche an polizeilichen Schutzwesten und Prüfmustern statistisch verlässliche Daten gesammelt und anschließend unter verschiedenen Blickwinkeln ausgewertet. Ein wesentliches Ergebnis der Untersuchungen ist, dass sich die Schutzeigenschaften von weichballistischem ultra-hochmolekularem Polyethylen zumindest über einen Zeitraum von 30 Jahren nicht nennenswert ändern.This publication deals with the long-term behavior of the ballistic protection of ultra high molecular weight polyethylene. It aims to answer the question, whether ballistic material shows significant signs of a deterioration that comes with preceding age. To answer that question numerous shooting tests with bulletproof vests and test samples were made to collect statistically reliable data. The data then have been evaluated from different point of views. An essential result of the tests is that no appreciable deterioration of the ballistic protection can be recognized with preceding age up to 30 years

Advanced Debris Analysis Techniques Enabled by Rich Persistent Datasets

Recent events in Geosynchronous Earth Orbit (GEO), including two probable breakup events in summer 2017, illustrate the potential risks of hazardous debris on orbit. Historically, distinguishing among the many types of negative events that may befall a satellite on orbit (and which may all be grouped together under the category of anomalies) has been challenging, due to a lack of observation data of sufficient volume and quality to support analyses capable of disambiguating these occurrences. As a result, there is limited opportunity to examine these incidents and extract lessons that may support future space traffic management objectives. However, the events of summer 2017 provided extensive data to multiple observers, including the ExoAnalytic Global Telescope Network (EGTN). The significant volume of collected imagery and derived products can be used to interrogate the events in depth and potentially to ascertain future methods of mitigating the relevant risks. In both cases, staring sensors were pointed at the objects, and thousands of frames were collected during the immediate period surrounding the two very different events. Because the sensors used were persistent, there was a stream of relevant data bracketing the time of interest. Because the data collection architecture used captures and stores raw imagery at large scales, the data stream was rich enough to support primary analysis of astrometric and photometric data as well as secondary analysis of the child objects, including attempts to account for impact and kinetic energy conserved through the event. Additionally, because the sensors were elements of a global network, there was an existing detailed pattern of life for the objects, and data from before the breakup was available for comparison, and deviations were notable on an almost real-time basis. Taken together, these facts show the importance of a robust persistent SSA sensor network, and how to utilize the data to develop advanced alerts for other satellites operating nearby. This paper describes the data collected, explains the analyses performed and others that may be possible with additional advancement, and uses the two events as case studies for the future

Classification of Human Retinal Microaneurysms Using Adaptive Optics Scanning Light Ophthalmoscope Fluorescein Angiography

Purpose. Microaneurysms (MAs) are considered a hallmark of retinal vascular disease, yet what little is known about them is mostly based upon histology, not clinical observation. Here, we use the recently developed adaptive optics scanning light ophthalmoscope (AOSLO) fluorescein angiography (FA) to image human MAs in vivo and to expand on previously described MA morphologic classification schemes. Methods. Patients with vascular retinopathies (diabetic, hypertensive, and branch and central retinal vein occlusion) were imaged with reflectance AOSLO and AOSLO FA. Ninety-three MAs, from 14 eyes, were imaged and classified according to appearance into six morphologic groups: focal bulge, saccular, fusiform, mixed, pedunculated, and irregular. The MA perimeter, area, and feret maximum and minimum were correlated to morphology and retinal pathology. Select MAs were imaged longitudinally in two eyes. Results. Adaptive optics scanning light ophthalmoscope fluorescein angiography imaging revealed microscopic features of MAs not appreciated on conventional images. Saccular MAs were most prevalent (47%). No association was found between the type of retinal pathology and MA morphology (P = 0.44). Pedunculated and irregular MAs were among the largest MAs with average areas of 4188 and 4116 μm2, respectively. Focal hypofluorescent regions were noted in 30% of MAs and were more likely to be associated with larger MAs (3086 vs. 1448 μm2, P = 0.0001). Conclusions. Retinal MAs can be classified in vivo into six different morphologic types, according to the geometry of their two-dimensional (2D) en face view. Adaptive optics scanning light ophthalmoscope fluorescein angiography imaging of MAs offers the possibility of studying microvascular change on a histologic scale, which may help our understanding of disease progression and treatment response

An Empirical Test of New Developments in Coalition Theory for the Design of International Environmental Agreements

We consider new developments in coalition theory for the design of international environmental agreements (IEAs). Applying an empirical model on climate change that comprises benefit and cost estimates from abatement for 12 world regions, we analyze how the design of an agreement affects the success of self-enforcing IEAs. We analyze single versus multiple coalitions, open versus exclusive membership with majority and unanimity voting, and no transfers versus transfers with four different transfer schemes

Models of the cardiac L-type calcium current: A quantitative review

The L-type calcium current (ICaL) plays a critical role in cardiac electrophysiology, and models of ICaL are vital tools to predict arrhythmogenicity of drugs and mutations. Five decades of measuring and modeling ICaL have resulted in several competing theories (encoded in mathematical equations). However, the introduction of new models has not typically been accompanied by a data-driven critical comparison with previous work, so that it is unclear which model is best suited for any particular application. In this review, we describe and compare 73 published mammalian ICaL models and use simulated experiments to show that there is a large variability in their predictions, which is not substantially diminished when grouping by species or other categories. We provide model code for 60 models, list major data sources, and discuss experimental and modeling work that will be required to reduce this huge list of competing theories and ultimately develop a community consensus model of ICaL. // This article is categorized under: Cardiovascular Diseases > Computational Models Cardiovascular Diseases > Molecular and Cellular Physiolog