Entwurf einer Patternbeschreibungssprache für die Informationsextraktion in der Dokumentanalyse

Dokumentanalyse befaßt sich mit der Extraktion von relevanten Informationen aus Dokumenten, die in Papierform vorliegen. Um die gewünschten Informationen in einem Text zu finden, können verschiedene Techniken angewendet werden. Sie reichen von einfachen Suchverfahren hin zum Versuch des vollständigen Parsens eines Textes. Häufig stammen diese Techniken aus dem Bereich der NLP, wo sie zur Verarbeitung von elektronischen Texten eingesetzt werden. Unabhängig von der eingesetzten Technik benötigt man jedoch immer eine Sprache, mit der die Syntax und die Semantik der gesuchten Informationen beschrieben werden können. In diesem Dokument wird eine solche Sprache vorgestellt, die insbesondere den Erfordernissen der Dokumentanalyse Rechnung trägt, aber allerdings auch für die Verarbeitung elektronischer Texte genutzt werden kann. Derzeit wird die Sprache zur Informationsextraktion in und zur Klassifikation von deutschen Geschäftsbriefen eingesetzt

Die Römer im Hessischen Ried : Archäologie einer Kulturlandschaft über fünf Jahrhunderte

Das Hessische Ried war nur dünn besiedelt, als die Römer kurz vor der Zeitenwende die Garnisonsstadt Mogontiacum/Mainz gründeten. Gelegen im rechtsrheinischen Vorfeld der neuen Metropole, profitierte das Ried von der Wirtschaftskraft der dort stationierten Legionen, denen es als Nutzland und Manövergebiet diente. Vollständig erschlossen wurde das Gebiet aber erst durch die zivile Besiedlungsphase im frühen zweiten Jahrhundert n. Chr. mit der Gründung von Dörfern und zahlreichen Gutshöfen. Nach zwischenzeitlichem Rückgang der Besiedlung erlebte das Ried im vierten Jahrhundert eine neue Blütezeit. Das Institut für Archäologische Wissenschaften hat die Entwicklung dieser Region bis um 500 n. Chr. in einem mehrjährigen Projekt rekonstruiert. Nach dem rheinischen Kohleabbaugebiet ist das Hessische Ried die am intensivsten erforschte Landschaft im römischen Deutschland

Real-time inference of word relevance from electroencephalogram and eye gaze

Objective. Brain-computer interfaces can potentially map the subjective relevance of the visual surroundings, based on neural activity and eye movements, in order to infer the interest of a person in real-time. Approach. Readers looked for words belonging to one out of five semantic categories, while a stream of words passed at different locations on the screen. It was estimated in real-time which words and thus which semantic category interested each reader based on the electroencephalogram (EEG) and the eye gaze. Main results. Words that were subjectively relevant could be decoded online from the signals. The estimation resulted in an average rank of 1.62 for the category of interest among the five categories after a hundred words had been read. Significance. It was demonstrated that the interest of a reader can be inferred online from EEG and eye tracking signals, which can potentially be used in novel types of adaptive software, which enrich the interaction by adding implicit information about the interest of the user to the explicit interaction. The study is characterised by the following novelties. Interpretation with respect to the word meaning was necessary in contrast to the usual practice in brain-computer interfacing where stimulus recognition is sufficient. The typical counting task was avoided because it would not be sensible for implicit relevance detection. Several words were displayed at the same time, in contrast to the typical sequences of single stimuli. Neural activity was related with eye tracking to the words, which were scanned without restrictions on the eye movements.EC/FP7/611570/EU/Symbiotic Mind Computer Interaction for Information Seeking/MindSe

Classification of Eye Fixation Related Potentials for Variable Stimulus Saliency

Objective: Electroencephalography (EEG) and eye tracking can possibly provide information about which items displayed on the screen are relevant for a person. Exploiting this implicit information promises to enhance various software applications. The specific problem addressed by the present study is that items shown in real applications are typically diverse. Accordingly, the saliency of information, which allows to discriminate between relevant and irrelevant items, varies. As a consequence, recognition can happen in foveal or in peripheral vision, i.e., either before or after the saccade to the item. Accordingly, neural processes related to recognition are expected to occur with a variable latency with respect to the eye movements. The aim was to investigate if relevance estimation based on EEG and eye tracking data is possible despite of the aforementioned variability. Approach:Sixteen subjects performed a search task where the target saliency was varied while the EEG was recorded and the unrestrained eye movements were tracked. Based on the acquired data, it was estimated which of the items displayed were targets and which were distractors in the search task. Results: Target prediction was possible also when the stimulus saliencies were mixed. Information contained in EEG and eye tracking data was found to be complementary and neural signals were captured despite of the unrestricted eye movements. The classification algorithm was able to cope with the experimentally induced variable timing of neural activity related to target recognition. Significance: It was demonstrated how EEG and eye tracking data can provide implicit information about the relevance of items on the screen for potential use in online applications.EC/FP7/611570/EU/Symbiotic Mind Computer Interaction for Information Seeking/MindSeeBMBF, 01GQ0850, Bernstein Fokus Neurotechnologie - Nichtinvasive Neurotechnologie für Mensch-Maschine Interaktio

Isabelle/PIDE as Platform for Educational Tools

The Isabelle/PIDE platform addresses the question whether proof assistants of the LCF family are suitable as technological basis for educational tools. The traditionally strong logical foundations of systems like HOL, Coq, or Isabelle have so far been counter-balanced by somewhat inaccessible interaction via the TTY (or minor variations like the well-known Proof General / Emacs interface). Thus the fundamental question of math education tools with fully-formal background theories has often been answered negatively due to accidental weaknesses of existing proof engines. The idea of "PIDE" (which means "Prover IDE") is to integrate existing provers like Isabelle into a larger environment, that facilitates access by end-users and other tools. We use Scala to expose the proof engine in ML to the JVM world, where many user-interfaces, editor frameworks, and educational tools already exist. This shall ultimately lead to combined mathematical assistants, where the logical engine is in the background, without obstructing the view on applications of formal methods, formalized mathematics, and math education in particular.Comment: In Proceedings THedu'11, arXiv:1202.453

Semiconductor Laser Linewidth Theory Revisited

More and more applications require semiconductor lasers distinguished not only by large modulation bandwidths or high output powers, but also by small spectral linewidths. The theoretical understanding of the root causes limiting the linewidth is therefore of great practical relevance. In this paper, we derive a general expression for the calculation of the spectral linewidth step by step in a self-contained manner. We build on the linewidth theory developed in the 1980s and 1990s but look from a modern perspective, in the sense that we choose as our starting points the time-dependent coupled-wave equations for the forward and backward propagating fields and an expansion of the fields in terms of the stationary longitudinal modes of the open cavity. As a result, we obtain rather general expressions for the longitudinal excess factor of spontaneous emission ($K$-factor) and the effective $\alpha$-factor including the effects of nonlinear gain (gain compression) and refractive index (Kerr effect), gain dispersion and longitudinal spatial hole burning in multi-section cavity structures. The effect of linewidth narrowing due to feedback from an external cavity often described by the so-called chirp reduction factor is also automatically included. We propose a new analytical formula for the dependence of the spontaneous emission on the carrier density avoiding the use of the population inversion factor. The presented theoretical framework is applied to a numerical study of a two-section distributed Bragg reflector laser.Comment: semiconductor laser, spectral linewidth, coupled-wave equations, traveling wave model, noise, Langevin equations, Henry factor, Petermann factor, chirp reduction factor, population inversion facto

Semiconductor laser linewidth theory revisited

More and more applications require semiconductor lasers distinguished not only by large modulation bandwidths or high output powers, but also by small spectral linewidths. The theoretical understanding of the root causes limiting the linewidth is therefore of great practical relevance. In this paper, we derive a general expression for the calculation of the spectral linewidth step by step in a self-contained manner. We build on the linewidth theory developed in the 1980s and 1990s but look from a modern perspective, in the sense that we choose as our starting points the time-dependent coupled-wave equations for the forward and backward propagating fields and an expansion of the fields in terms of the stationary longitudinal modes of the open cavity. As a result, we obtain rather general expressions for the longitudinal excess factor of spontaneous emission (K-factor) and the effective Alpha-factor including the effects of nonlinear gain (gain compression) and refractive index (Kerr effect), gain dispersion and longitudinal spatial hole burning in multi-section cavity structures. The effect of linewidth narrowing due to feedback from an external cavity often described by the so-called chirp reduction factor is also automatically included. We propose a new analytical formula for the dependence of the spontaneous emission on the carrier density avoiding the use of the population inversion factor. The presented theoretical framework is applied to a numerical study of a two-section distributed Bragg reflector laser

A Primer for Pediatric Emergency Front-of-the-Neck Access

"Cannot intubate, cannot oxygenate" situations in healthy children are uncommon but are often associated with poor outcomes. Clinical assessment, anticipatory planning, and the use of algorithms can lessen the likelihood of untoward outcomes, but the common final pathway of many algorithms for a difficult pediatric airway involves obtaining emergency tracheal access. The airway practitioner must have the know-how and training needed to invasively secure the airway when confronted with this rare but potentially devastating emergency. We provide practitioners with an overview of pediatric emergency front-of-the-neck access strategies and a structure for their management

WCET Analysis: The Annotation Language Challenge

Worst-case execution time (WCET) analysis is indispensable for the successful design and development of systems, which, in addition to their functional constraints, have to satisfy hard real-time constraints. The expressiveness and usability of annotation languages, which are used by algorithms and tools for WCET analysis in order to separate feasible from infeasible program paths, have a crucial impact on the precision and performance of these algorithms and tools. In this paper, we thus propose to complement the WCET tool challenge, which has recently successfully been launched, by a second closely related challenge: the WCET annotation language challenge. We believe that contributions towards mastering this challenge will be essential for the next major step of advancing the field of WCET analysis

Implicit relevance feedback from electroencephalography and eye tracking in image search

Objective. Methods from brain–computer interfacing (BCI) open a direct access to the mental processes of computer users, which offers particular benefits in comparison to standard methods for inferring user-related information. The signals can be recorded unobtrusively in the background, which circumvents the time-consuming and distracting need for the users to give explicit feedback to questions concerning the individual interest. The obtained implicit information makes it possible to create dynamic user interest profiles in real-time, that can be taken into account by novel types of adaptive, personalised software. In the present study, the potential of implicit relevance feedback from electroencephalography (EEG) and eye tracking was explored with a demonstrator application that simulated an image search engine. Approach. The participants of the study queried for ambiguous search terms, having in mind one of the two possible interpretations of the respective term. Subsequently, they viewed different images arranged in a grid that were related to the query. The ambiguity of the underspecified search term was resolved with implicit information present in the recorded signals. For this purpose, feature vectors were extracted from the signals and used by multivariate classifiers that estimated the intended interpretation of the ambiguous query. Main result. The intended interpretation was inferred correctly from a combination of EEG and eye tracking signals in 86% of the cases on average. Information provided by the two measurement modalities turned out to be complementary. Significance. It was demonstrated that BCI methods can extract implicit user-related information in a setting of human-computer interaction. Novelties of the study are the implicit online feedback from EEG and eye tracking, the approximation to a realistic use case in a simulation, and the presentation of a large set of photographies that had to be interpreted with respect to the content.EC/FP7/611570/EU/Symbiotic Mind Computer Interaction for Information Seeking/MindSeeBMBF, 01GQ0850, Bernstein Fokus Neurotechnologie - Nichtinvasive Neurotechnologie für Mensch-Maschine Interaktio