Handel und Marketing in virtuellen Welten

Seit der Entstehung des Internets wurde es für die Kommunikation und Interaktion genutzt. Kurze Zeit später wurde mit Möglichkeiten experimentiert. durch die mehrere Benutzer gleichzeitig in der Lage waren zu kommunizieren und interagieren. Dabei entstanden einfache Umgebungen. die sowohl wissenschaftlichen Zwecken dienten, als auch für die Unterhaltung genutzt wurden. Mit zunehmender Verbreitung des Internets und den immer besser werdenden Möglichkeiten zur grafischen Darstellung, entstanden virtuelle Welten, welche sich bis heute großer Beliebtheit erfreuen. Diese Welten erfuhren in den letzten Jahren erhöhte Aufmerksamkeit, so dass ein regelrechter Hype um diese und das Web 2.0 entstand. Infolgedessen begannen einige Firmen, dies als Präsentationsplattform auszubauen, um interaktiv mit potenziellen Kunden in Verbindung zu treten. Hierbei ist die Verwendung dieser Plattformen recht unterschiedlich und reicht von Marketing, virtuellen Konferenzen, Prototyping und bis zur virtuellen Kaufabwicklung. In dieser Arbeit erfolgt neben einer eingehenden Betrachtung von Grundlagen des Marketings ebenso eine Einführung in die virtuellen Welten anhand von ausgewählten Beispielen. Dabei sollten auch Unterschiede zwischen den virtuellen Welten aufgezeigt werden, vor allem was ihre Möglichkeiten zur Interaktion und Präsentation betrifft, und ihren Geschäftsmodellen. Dann sollte anhand von bestehenden Beispielen gezeigt werden, wie Unternehmen die Möglichkeiten von virtuellen Welten bereits nutzen und wie diskutiert wird, inwiefern die Unternehmen auf diesem Wege erfolgreich sind.Weiters sollte erläutert werden, welche konkreten Ziele Unternehmen in den virtuellen Welten verfolgen, wie sie bei der Verfolgung dieser Ziele vorgehen und welche Vorteile sich durch den Einsatz von virtuellen Welten als Medium ergeben.Since the formation of the internet it has been used for interaction and communication. A short time thereafter, people began to experiment with the possibility of letting multiple users interact and communicate. As a result simple, enviroments were developed that could be used for scientific purposes or for entertainment. With propagation of the internet technology and increasing graphical computation power, virtual worlds began to form, which enjoyed great popularity. These worlds experienced rising attention during the last years and a hype started around these and the Web 2.0. As a result, corporations have started to use this new media as a means of presentation to get into interactive contact with potential customers. These corporations have used the virtual worlds in various forms, ranging from marketing efforts, virtual conferences, prototyping to virtual shopping. In this thesis it should be explained on the basis of scientific material, how corporations should represent themselves and the means, which virtual worlds offer. Therefore a comparison should be made between the most prevalent virtual worlds, the focus of which shall be on the business model of the virtual worlds and their possibilities for interaction and representation. Further, it shall be demonstrated how corporations are already taking advantage of these possibilities and it shall be discussed if and how much their efforts pay off

Global patterns of shallow groundwater temperatures

Only meters below our feet, shallow aquifers serve as sustainable energy source and provide freshwater storage and ecological habitats. All of these aspects are crucially impacted by the thermal regime of the subsurface. Due to the limited accessibility of aquifers however, temperature measurements are scarce. Most commonly, shallow groundwater temperatures are approximated by adding an offset to annual mean surface air temperatures. Yet, the value of this offset is not well defined, often arbitrarily set, and rarely validated. Here, we propose the usage of satellite-derived land surface temperatures instead of surface air temperatures. 2 548 measurement points in 29 countries are compiled, revealing characteristic trends in the offset between shallow groundwater temperatures and land surface temperatures. Here it is shown that evapotranspiration and snow cover impact on this offset globally, through latent heat flow and insulation. Considering these two processes only, global shallow groundwater temperatures are estimated in a resolution of approximately 1 km × 1 km. When comparing these estimated groundwater temperatures with measured ones a coefficient of determination of 0.95 and a root mean square error of 1.4 K is found

The evolution of the geothermal potential of a subsurface urban heat island

Meeting the rising energy demands of cities is a global challenge. Exploitation of the additional heat in the subsurface associated with the subsurface urban heat island (SUHI) has been proposed to address the heating demands. For the sustainable use of this heat it is crucial to understand how SUHIs evolve. To date, there have been no comprehensive studies showing how temperature anomalies beneath cities change over time scales of decades. Here, we reveal the long-term increase of temperatures in the groundwater beneath Cologne, Germany from 1973 to 2020. The rise in groundwater temperature trails atmospheric temperature rise in the rural areas and exceeds the rise in atmospheric temperature in the urban center. However, the amount of heat that is currently stored each year in the thin shallow aquifer reaches only 1% of the annual heating demand. The majority of the anthropogenic heat passes by the vertical extent of the aquifer or is discharged by the adjacent river. Overall the geothermal resource of the urban ground remains largely underused and heat extraction as well as combined heating and cooling could substantially raise the geothermal potential to supply the city\u27s demand

ThreatCrawl: A BERT-based Focused Crawler for the Cybersecurity Domain

Publicly available information contains valuable information for Cyber Threat Intelligence (CTI). This can be used to prevent attacks that have already taken place on other systems. Ideally, only the initial attack succeeds and all subsequent ones are detected and stopped. But while there are different standards to exchange this information, a lot of it is shared in articles or blog posts in non-standardized ways. Manually scanning through multiple online portals and news pages to discover new threats and extracting them is a time-consuming task. To automize parts of this scanning process, multiple papers propose extractors that use Natural Language Processing (NLP) to extract Indicators of Compromise (IOCs) from documents. However, while this already solves the problem of extracting the information out of documents, the search for these documents is rarely considered. In this paper, a new focused crawler is proposed called ThreatCrawl, which uses Bidirectional Encoder Representations from Transformers (BERT)-based models to classify documents and adapt its crawling path dynamically. While ThreatCrawl has difficulties to classify the specific type of Open Source Intelligence (OSINT) named in texts, e.g., IOC content, it can successfully find relevant documents and modify its path accordingly. It yields harvest rates of up to 52%, which are, to the best of our knowledge, better than the current state of the art.Comment: 11 pages, 9 figures, 5 table

Meeting the demand: geothermal heat supply rates for an urban quarter in Germany

Abstract Thermal energy for space heating and for domestic hot water use represents about a third of the overall energy demand in Germany. An alternative to non-renewable energy-based heat supply is the implementation of closed and open shallow geothermal systems, such as horizontal ground source heat pump systems, vertical ground source heat pump (vGSHP) systems and groundwater heat pump systems. Based on existing regulations and local hydrogeological conditions, the optimal site-specific system for heat supply has to be identified. In the presented technical feasibility study, various analytical solutions are tested for an urban quarter before and after building refurbishment. Geothermal heat supply rates are evaluated by providing information on the optimal system and the specific shortcomings. Our results show that standard vGSHP systems are even applicable in older and non-refurbished residential areas with a high heat demand using a borehole heat exchanger with a length of 100 m or in conjunction with multiple boreholes. After refurbishment, all studied shallow geothermal systems are able to cover the lowered heat demand. The presented analysis also demonstrates that ideally, various technological variants of geothermal systems should be evaluated for finding the optimal solution for existing, refurbished and newly developed residential areas

Pricing high-dimensional Bermudan options with hierarchical tensor formats

An efficient compression technique based on hierarchical tensors for popular option pricing methods is presented. It is shown that the "curse of dimensionality" can be alleviated for the computation of Bermudan option prices with the Monte Carlo least-squares approach as well as the dual martingale method, both using high-dimensional tensorized polynomial expansions. This discretization allows for a simple and computationally cheap evaluation of conditional expectations. Complexity estimates are provided as well as a description of the optimization procedures in the tensor train format. Numerical experiments illustrate the favourable accuracy of the proposed methods. The dynamical programming method yields results comparable to recent Neural Network based methods.Comment: 26 pages, 3 figures, 5 tables, added affiliations and update acknowledgement

Recent trends of groundwater temperatures in Austria

Climate change is one of if not the most pressing challenge modern society faces. Increasing temperatures are observed all over the planet and the impact of climate change on the hydrogeological cycle has long been shown. However, so far we have insufficient knowledge on the influence of atmospheric warming on shallow groundwater temperatures. While some studies analyse the implication climate change has for selected wells, large-scale studies are so far lacking. Here we focus on the combined impact of climate change in the atmosphere and local hydrogeological conditions on groundwater temperatures in 227 wells in Austria, which have in part been observed since 1964. A linear analysis finds a temperature change of +0.7±0.8K in the years from 1994 to 2013. In the same timeframe surface air temperatures in Austria increased by 0.5±0.3K, displaying a much smaller variety. However, most of the extreme changes in groundwater temperatures can be linked to local hydrogeological conditions. Correlation between groundwater temperatures and nearby surface air temperatures was additionally analysed. They vary greatly, with correlation coefficients of −0.3 in central Linz to 0.8 outside of Graz. In contrast, the correlation of nationwide groundwater temperatures and surface air temperatures is high, with a correlation coefficient of 0.83. All of these findings indicate that while atmospheric climate change can be observed in nationwide groundwater temperatures, individual wells are often primarily dominated by local hydrogeological conditions. In addition to the linear temperature trend, a step-wise model was also applied that identifies climate regime shifts, which were observed globally in the late 70s, 80s, and 90s. Hinting again at the influence of local conditions, at most 22% of all wells show these climate regime shifts. However, we were able to identify an additional shift in 2007, which was observed by 37% of all wells. Overall, the step-wise representation provides a slightly more accurate picture of observed temperatures than the linear trend

Observed groundwater temperature response to recent climate change

Climate change is known to have a considerable influence on many components of the hydrological cycle. Yet, the implications for groundwater temperature, as an important driver for groundwater quality, thermal use and storage, are not yet comprehensively understood. Furthermore, few studies have examined the implications of climate-change-induced groundwater temperature rise for groundwater-dependent ecosystems. Here, we examine the coupling of atmospheric and groundwater warming by employing stochastic and deterministic models. Firstly, several decades of temperature time series are statistically analyzed with regard to climate regime shifts (CRSs) in the long-term mean. The observed increases in shallow groundwater temperatures can be associated with preceding positive shifts in regional surface air temperatures, which are in turn linked to global air temperature changes. The temperature data are also analyzed with an analytical solution to the conduction–advection heat transfer equation to investigate how subsurface heat transfer processes control the propagation of the surface temperature signals into the subsurface. In three of the four monitoring wells, the predicted groundwater temperature increases driven by the regime shifts at the surface boundary condition generally concur with the observed groundwater temperature trends. Due to complex interactions at the ground surface and the heat capacity of the unsaturated zone, the thermal signals from distinct changes in air temperature are damped and delayed in the subsurface, causing a more gradual increase in groundwater temperatures. These signals can have a significant impact on large-scale groundwater temperatures in shallow and economically important aquifers. These findings demonstrate that shallow groundwater temperatures have responded rapidly to recent climate change and thus provide insight into the vulnerability of aquifers and groundwater-dependent ecosystems to future climate change