The 10 most recently published documents
The task-based view of web search implies that retrieval should take the user perspective into account. Going beyond merely retrieving the most relevant result set for the current query, the retrieval system should aim to surface results that are actually useful to the task that motivated the query.
This dissertation explores how retrieval systems can better understand and support their users’ tasks from three main angles: First, we study and quantify search engine user behavior during complex writing tasks, and how task success and behavior are associated in such settings. Second, we investigate search engine queries formulated as questions, and explore patterns in a large query log that may help search engines to better support this increasingly prevalent interaction pattern. Third, we propose a novel approach to reranking the search result lists produced by web search engines, taking into account retrieval axioms that formally specify properties of a good ranking.
Diese Arbeit beschäftigt sich mit der Nutzung von Worteinbettungen in der automatischen Analyse von argumentativen Texten. Die Arbeit diskutiert wichtige Einstellungen des Einbettungsverfahren sowie diverse Anwendungsmethoden der eingebetteten Wortvektoren für drei Aufgaben der automatischen argumentativen Analyse: Textsegmentierung, Argumentativitäts-Klassifikation und Relationenfindung. Meine Experimente auf zwei Standard-Argumentationsdatensätzen zeigen die folgenden Haupterkenntnisse: Bei der Textsegmentierung konnten keine Verbesserungen erzielt werden, während in der Argumentativitäts-Klassifikation und der Relationenfindung sich kleine Erfolge gezeigt haben und weitere bestimmte Forschungsthesen bewahrheitet werden konnten. In der Diskussion wird darauf eingegangen, warum bei der einfachen Worteinbettung in der argumentativen Analyse sich kaum nutzbare Ergebnisse erzielen lassen konnten, diese sich aber in Zukunft durch erweiterte Worteinbettungsverfahren verbessern können.
The need for finding persuasive arguments can arise in a variety of domains such as politics, finance, marketing or personal entertainment. In these domains, there is a demand to make decisions by oneself or to convince somebody about a specific topic. To obtain a conclusion, one has to search thoroughly different sources in literature and on the web to compare various arguments. Voice interfaces, in form of smartphone applications or smart speakers, present the user with natural conversations in a comfortable way to make search requests in contrast to a traditional search interface with keyboard and display. Benefits and obstacles of such a new interface are analyzed by conducting two studies. The first one consists of a survey for analyzing the target group with questions about situations, motivations, and possible demanding features. The latter one is a wizard-of-oz experiment to investigate possible queries on how a user formulates requests to such a novel system. The results indicate that a search interface with conversational abilities can build a helpful assistant, but to satisfy the demands of a broader audience some additional information retrieval and visualization features need to be implemented.
Jazzforschung heute
(2019)
Die internationale Jazzforschung hat sich in den vergangenen Jahrzehnten zahlreiche neue Fragestellungen und Forschungsansätze erschlossen. So sind etwa die globalen Dimensionen des Jazz, die Rolle von Frauen im Jazz oder seine mannigfaltigen kulturellen Bedeutungen in Geschichte und Gegenwart ins Zentrum der Forschung gerückt. Die dreizehn Beiträge des Tagungsbandes widmen sich Themen, Methoden und Desideraten der gegenwärtigen wissenschaftlichen Auseinandersetzung mit dem Jazz. Zudem werden Perspektiven des künstlerischen Forschens im Jazz und der Ausbildung von Jazzmusikern und -forschern diskutiert.
This research seeks to make an exploratory study of the strategies used by the creators of monuments, memorials, and commemorative places located in the public spaces that use sound as one of the primary raw material in their design. The term acoustic monu-memorials was coined in this research to encircle these structures and places. In order to achieve the goal of this research, it was necessary to compile a number of samples, primarily after the digital recording era of captured sound around 1971 to the present. The compilation was relevant because such a compendium was not found in the literature, and to the author's knowledge, a comprehensive investigation of the strategies used in planning acoustic monu-memorials in the urban spaces does not exist.
The method used to create such compendium was to send a question to people with different background identities, such as visual and sound artists, musicians, art curators, and heritage scholars among others. This question produced a selection of 51 examples of acoustic monu-memorials located in public spaces. Subsequently, the examples were classified into four major categories according to their form and nature. Additionally, two examples from the main categories were chosen as case studies: The Sinti and Roma Memorial in Berlin, Germany and the Niche monument in Cali, Colombia. These study cases were presented, described, and analysed in detail as they represent the type of what could be defined as an acoustic monu-memorial in general.
Lynch’s (1960) five elements that help individuals build the image of the city were transferred and used as a tool to help to build this image into acoustic terms. A thorough analysis of the acquired data yielded found the strategies used by the designers to shape, modify, transform, and structure public space. These strategies are entitled Sound Spaces. Moreover, a list entitled Urban Acoustic Commemoration Code was compiled. This list of suggestions addresses urban planners, architects, artists, designers, and general public interested in the aspects involved when creating acoustic commemoration phenomena in public spaces.
Am Beispiel der Elektrifizierung zweier Großstädte an der Westküste Südamerikas zeigt die Arbeit den globalen Einfluss deutscher Industrie- und Finanzakteure auf technische, städtebauliche und gesellschaftlich-kulturelle Entwicklungen zur Blütezeit des europäischen Imperialismus auf. Damit werden die Regionalgeschichten der chilenischen Hauptstadtregion und der Elektropolis Berlin zu einer Globalgeschichte miteinander verknüpft. Ein Hauptaugenmerk der Analyse liegt dabei auf den weltweiten Akteursnetzwerken und Machtverhältnissen sowie dem kulturellen Erbe und seiner gegenwärtigen Interpretation.
Components of structural glazing have to meet different requirements and resist various impacts, depending on the field of application. Within an international research project of the EU innovation program Horizon 2020, special glass panes with a fluid circulating in capillaries are developed exploiting solar energy. Major influences to this glazing are UV irradiation and the fluidic contact, effecting the mechanical and optical durability of the bonding material within the glass setup. Regarding to visual requirements, acrylate adhesives and EVA films are analyzed as possible bonding materials by destructive and non-destructive testing methods. Two types of specimen are presented for obtaining the mechanical behavior and the surface appearances of the bonding material.
Wireless sensor networks have attracted great attention for applications in structural health monitoring due to their ease of use, flexibility of deployment, and cost-effectiveness. This paper presents a software framework for WiFi-based wireless sensor networks composed of low-cost mass market single-board computers. A number of specific system-level software components were developed to enable robust data acquisition, data processing, sensor network communication, and timing with a focus on structural health monitoring (SHM) applications. The framework was validated on Raspberry Pi computers, and its performance was studied in detail. The paper presents several characteristics of the measurement quality such as sampling accuracy and time synchronization and discusses the specific limitations of the system. The implementation includes a complementary smartphone application that is utilized for data acquisition, visualization, and analysis. A prototypical implementation further demonstrates the feasibility of integrating smartphones as data acquisition nodes into the network, utilizing their internal sensors. The measurement system was employed in several monitoring campaigns, three of which are documented in detail. The suitability of the system is evaluated based on comparisons of target quantities with reference measurements. The results indicate that the presented system can robustly achieve a measurement performance commensurate with that required in many typical SHM tasks such as modal identification. As such, it represents a cost-effective alternative to more traditional monitoring solutions.
The p-Laplace equation is a nonlinear generalization of the well-known Laplace equation. It is often used as a model problem for special types of nonlinearities, and therefore it can be seen as a bridge between very general nonlinear equations and the linear Laplace equation, too. It appears in many problems for instance in the theory of non-Newtonian fluids and fluid dynamics or in rockfill dam problems, as well as in special problems of image restoration and image processing.
The aim of this thesis is to solve the p-Laplace equation for 1 < p < 2, as well as for 2 < p < 3 and to find strong solutions in the framework of Clifford analysis. The idea is to apply a hypercomplex integral operator and special function theoretic methods to transform the p-Laplace equation into a p-Dirac equation. We consider boundary value problems for the p-Laplace equation and transfer them to boundary value problems for a p-Dirac equation. These equations will be solved iteratively by applying Banach’s fixed-point principle. Applying operator-theoretical methods for the p-Dirac equation, the existence and uniqueness of solutions in certain Sobolev spaces will be proved.
In addition, using a finite difference approach on a uniform lattice in the plane, the fundamental solution of the Cauchy-Riemann operator and its adjoint based on the fundamental solution of the Laplacian will be calculated. Besides, we define gener- alized discrete Teodorescu transform operators, which are right-inverse to the discrete Cauchy-Riemann operator and its adjoint in the plane. Furthermore, a new formula for generalized discrete boundary operators (analogues of the Cauchy integral operator) will be considered. Based on these operators a new version of discrete Borel-Pompeiu formula is formulated and proved.
This is the basis for an operator calculus that will be applied to the numerical solution of the p-Dirac equation. Finally, numerical results will be presented showing advantages and problems of this approach.