004 Datenverarbeitung; Informatik
Das Erkennen von Personen auf Fotos und in Videos geschieht in aktuellen Klassifizierungsverfahren durch die Zuordnung eines Köperteils zu jedem Pixel. Anschließend werden die gefundenen Körperteile zu Skeletten zusammengefasst. Im Falle mehrerer abgebildeter Personen ergibt sich das Problem der Zuordnung der Körperteile zu den verschiedenen Skeletten. Es wurde in dieser Arbeit ein auf dem Suurballe-Algorithmus basierendes graphentheoretisches Verfahren entwickelt, das diese Aufgabe löst. Aufbauend auf im Wesentlichen abstandsabhängigen Kantengewichten wird eine k-kürzeste-disjunkte-Wege-Suche durchgeführt. Unter Einbezug von möglicherweise fehlenden Körperteilen durch Unsichtbar-Knoten und automatisches Aussortieren zu viel gefundener Körperteile werden so die k-optimalen Skelette gefunden. Die Methode wurde an idealisierten computergenerierten Bildern mit einer Trefferquote von 100 % gefundener Personen getestet. Ein Test mit realen Bilddaten lieferte eine Trefferquote von 71,7 %.
In recent years, 3D movies and streaming films have become increasingly popular. Even mobile devices, such as mobile phones and tablet computers, are becoming more popular, more powerful and have better multimedia capabilities. Nevertheless, compact mobile devices to broadcast live 3D videos in real time are barely available. In this article, we provide a modular and mobile solution that allows 3D video streaming in real time at 25 frames per second and with a resolution of 1280 × 720 pixels (720p). As operating system, we use standard hardware components combined with Android. Furthermore, we will describe the restraints of the development, and how they were solved.
This paper introduces procedures, which facilitate the development of as well as the linking between modular data processing processes into different and versatile system solutions. Based on the concept of data flow diagrams (Yourdon 1989), processes and data flows are used. With the ability of a process to harness any amount of in- and outputs with different sources and destinations, it is possible to model any conceivable data processing problem. By aggregating a diagram as a new process, it becomes possible to outsource partial process chains to different abstraction levels. As a result, even very complex solutions can be modeled and explained in a clear way. The introduced uniform termination flow while traversing the graph creates a good readability, which also makes it possible to quickly detect weaknesses. Moreover, this solution is comprehensive and advances the cooperation in teams and development.
A domain specific language for the automatic generation of parsers classes for text protocols
(2014)
ABNF is a language for the definition of the formal syntax of technical specifications and is widely used for the definition of textual protocol messages of many internet protocols. The automatic generation of parser classes for ABNF specifications is currently very limited, because ABNF only defines the transfer syntax of the text messages and does not define names for the set of production rules. The lack of name definitions within ABNF rules does not allow to automatically generate expressiveness and meaningful program code for ABNF specifications. In this paper we present X-ABNF, which is a domain-specific language (DSL) for the definition of name-bindings for ABNF rules. The name-bindings with X-ABNF facilitates to generate a concise and meaningful code for an ABNF specification. Additionally, we show that the name-binding can also be used for language extensions through macro programming to dynamically access ABNF encoded text data within source code. We have used Xtext and Xtend for the implementation of the language grammar of ABNF and X-ABNF, which provide good tool support and code generation capabilities.
Dieser Beitrag präsentiert einen Lösungsvorschlag zur Erkennung von Bewegungs- und Ausbreitungsprofilen anhand von Sensordaten im Gebäudemanagement. Dazu wird zunächst ein Szenario definiert, auf dessen Basis ein Ansatz vorgestellt wird, der auf der Integration von Ereignissen über der Zeit und dem Ort basiert. Anschließend wird auf Informationen eingegangen, welche für eine Auswertung bereit stehen müssen. Zum Schluss wird die umgesetzte Lösung zur Implementierung des Ansatzes auf Basis des Complex Event Processing vorgestellt.
A metamodel-based ASN.1 editor and compiler for the implementation of communication protocols
(2013)
In the software industry many metamodel-based tools and approaches have been developed to support the creation of programming and especially domain specific languages (DSL). An example of these tools is eclipse Xtext, which has gained much popularity in the model-driven software engineering (MDSE) community. In this article we investigate whether Xtext and related metamodel-based approaches can also be used to implement the ASN.1 specification that was standardized by the ITU-T. The metamodel-based approach for the implementation of the ASN.1 specification allows to treat ASN.1 documents as software models, so that these ASN.1 models can be interrelated with other models (e.g. state machines). Our results show that relatively little efforts are required to create a basic implementation of this standard with good tool support. However, some details of the implementation are quite difficult to realize because they touch the limits of feasibility. This concerns in particular the parser generator and the complex metamodel.