Semi-Automated Extraction of Rivers from Digital Imagery

The manual production of vector maps from digital imagery can be a time consuming and costly process. Developing tools to automate this task for specific features, such as roads, has become an important research topic. The purpose of this paper was to present a technique for the semi-automatic extraction of multiple pixel width river features appearing in high resolution satellite imagery. This was accomplished using a two stage, multi-resolution procedure. Initial river extraction was performed on low resolution (SPOT multi-spectral, 20 m) imagery. The results from this low resolution extraction were then refined on higher resolution (KFA1000, panchromatic, 5 m) imagery to produce a detailed outline of the channel banks. To perform low resolution extraction a cost surface was generated to represent the combined local evidence of the presence of a river feature. The local evidence of a river was evaluated based on the results of a number of simple operators. Then, with user specified start and end points for the network, rivers were extracted by performing a least cost path search across this surface using the A* algorithm. The low resolution results were transferred to the high resolution imagery as closed contours which provided an estimate of the channel banks. These contours were then fit to the channel banks using the dynamic contours (or snakes) technique.     

Functionalized Graphdiyne Nanowires: On‐Surface Synthesis and Assessment of Band Structure,Flexibility, and Information Storage Potential

Carbon nanomaterials exhibit extraordinary mechanical and electronic properties desirable for future technologies. Beyond the popular sp²‐scaffolds, there is growing interest in their graphdiyne‐related counterparts incorporating both sp² and sp bonding in a regular scheme. Herein, we introduce carbonitrile‐functionalized graphdiyne nanowires, as a novel conjugated, one‐dimensional (1D) carbon nanomaterial systematically combining the virtues of covalent coupling and supramolecular concepts that are fabricated by on‐surface synthesis. Specifically, a terphenylene backbone is extended with reactive terminal alkyne and polar carbonitrile (CN) moieties providing the required functionalities. It is demonstrated that the CN functionalization enables highly selective alkyne homocoupling forming polymer strands and gives rise to mutual lateral attraction entailing room‐temperature stable double‐stranded assemblies. By exploiting the templating effect of the vicinal Ag(455) surface, 40 nm long semiconducting nanowires are obtained and the first experimental assessment of their electronic band structure is achieved by angle‐resolved photoemission spectroscopy indicating an effective mass below 0.1m₀ for the top of the highest occupied band. Via molecular manipulation it is showcased that the novel oligomer exhibits extreme mechanical flexibility and opens unexplored ways of information encoding in clearly distinguishable CN‐phenyl trans–cis species. Thus, conformational data storage with density of 0.36 bit nm^?2 and temperature stability beyond 150 K comes in reach.     

An Application Platform for the Development and Experimental Validation of Mobile Robots for Health Care Purposes

This paper describes an Application Platform for the development and testing of mobile robot units. Within this platform, various applications addressing different aspects of robot development are composed into an experimental environment. The Application Platform comprises modules such as a Neural Networks Simulator, a simulation and off-line programming system, optical sensor components, a rapid prototyping system, and an experimental workcell. Each of these modules is described in detail including its integration with the other modules. In conclusion, the potential use of this platform for health care tasks is indicated.     

Highly Dynamic Four-Quadrant AC Motor Drive with Improved Power Factor and On-Line Optimized Pulse Pattern with PROMC

The power factor and the waveforms of the currents of voltage source inverters can be improved essentially when two-pulse inverters are used?one at the line side and the other at the machine side. Both inverters are controlled by similar current vector controllers. The reference value of the stator current can be calculated by field-oriented control or by decoupling, for example. The reference value of the line current is derived from the actual state of the mains and the machine. Furthermore, on-line optimization of the pulse pattern by programmable read-only memory control (PROMC) is used.     

A Bayesian approach to information fusion for evaluating the measurement uncertainty

The Bayesian approach to uncertainty evaluation is a classical example of the fusion of information from different sources. Basically, it is founded on both the knowledge about the measurement process and the influencing quantities and parameters. The knowledge about the measurement process is primarily represented by the so-called model equation, which forms the basic relationship for the fusion of all involved quantities. The knowledge about the influencing quantities and parameters is expressed by their degree of belief, i.e. appropriate probability density functions that usually are obtained by utilizing the principle of maximum information entropy and the Bayes theorem. Practically, the Bayesian approach to uncertainty evaluation is put into effect by employing numerical integration techniques, preferably Monte-Carlo methods. Compared to the ISO-GUM procedure, the Bayesian approach does not have any restrictions with respect to nonlinearities and calculation of confidence intervals.     

Managing architectural decision models with dependency relations, integrity constraints, and production rules

Software architects consider capturing and sharing architectural decisions increasingly important; many tacit dependencies exist in this architectural knowledge. Architectural decision modeling makes these dependencies explicit and serves as a foundation for knowledge management tools. In practice, however, text templates and informal rich pictures rather than models are used to capture the knowledge; a formal definition of model entities and their relations is missing in the current state of the art. In this paper, we propose such a formal definition of architectural decision models as directed acyclic graphs with several types of nodes and edges. In our models, architectural decision topic groups, issues, alternatives, and outcomes form trees of nodes connected by edges expressing containment and refinement, decomposition, and triggers dependencies, as well as logical relations such as (in)compatibility of alternatives. The formalization can be used to verify integrity constraints and to organize the decision making process; production rules and dependency patterns can be defined. A reusable architectural decision model supporting service-oriented architecture design demonstrates how we use these concepts. We also present tool support and give a quantitative evaluation.     

AspectC++: An integrated approach for static and dynamic adaptation of system software

Modern computer systems require an enormous amount of flexibility. This is especially the case in low-level system software, from embedded devices to networking services. From literature and practice, various approaches to modularize and integrate adaptations have been investigated. However, most of this work is implemented with dynamic languages that offer extensive run-time support and enable easy integration of such approaches. System software is written in languages like C or C++ in order to minimize utilization of system resources and maximize efficiency. While for these languages highly optimized and reliable compilers are available, the support for static and dynamic adaptation is rather limited. In order to overcome these limitations, we present an adaptation approach that is based on a sophisticated combination of static and dynamic aspect weaving for aspects written in AspectC++. This facilitates the incremental evolution and deployment of system software that has to be “always on”. We demonstrate the feasibility of our approach and its applicability to two pieces of system software, namely the Squid web proxy and the eCos operating system, which is used in the domain of resource-constrained deeply embedded systems.     

Observable Behavior of Dynamic Systems: Component Reasoning for Concurrent Objects

Current object-oriented approaches to distributed programs may be criticized in several respects. First, method calls are generally synchronous, which leads to much waiting in distributed and unstable networks. Second, the common model of thread concurrency makes reasoning about program behavior very challenging. Models based on concurrent objects communicating by asynchronous method calls, have been proposed to combine object orientation and distribution in a more satisfactory way. In this paper, a high-level language and proof system are developed for such a model, emphasizing simplicity and modularity. In particular, the proof system is used to derive external specifications of observable behavior for objects, encapsulating their state. A simple and compositional proof system is paramount to allow verification of real programs. The proposed proof rules are derived from the Hoare rules of a standard sequential language by a semantic encoding preserving soundness and relative completeness. Thus, the paper demonstrates that these models not only address the first criticism above, but also the second.     

Age-dependent gene expression profile and protein expression in a transgenic rat model of Huntington's disease

Polyglutamine‐induced changes in gene expression have been demonstrated by using several mouse models of Huntington's disease (HD), which express extreme numbers of CAG repeats. We have recently developed a transgenic rat model of HD carrying a truncated huntingtin fragment with 51 CAG repeats, which is in the range seen in adult HD patients. For further evaluation, we have performed microarray analyses on whole brains of transgenic rats at 3 and 12 months of age and correlated it with protein expression by Western blot analysis. We found that genes functionally associated with gene expression and behavior were differently regulated already at 3 months of age, whereas at 12 months of age especially genes related to neurological diseases and cell‐to‐cell signaling and interaction were dysregulated. A detailed analysis of canonical pathways revealed that at 3 months of age genes in calcium signaling and synaptic long term potentation pathways were altered, while at 12 months of age, additionally, expression level of many genes implicated in Huntington's disease signaling, were changed.     

Johnny: An Autonomous Service Robot for Domestic Environments

In this article we describe the architecture, algorithms and real-world benchmarks performed by Johnny Jackanapes, an autonomous service robot for domestic environments. Johnny serves as a research and development platform to explore, develop and integrate capabilities required for real-world domestic service applications. We present a control architecture which allows to cope with various and changing domestic service robot tasks. A software architecture supporting the rapid integration of functionality into a complete system is as well presented. Further, we describe novel and robust algorithms centered around multi-modal human robot interaction, semantic scene understanding and SLAM. Evaluation of the complete system has been performed during the last years in the RoboCup@Home competition where Johnnys outstanding performance led to successful participation. The results and lessons learned of these benchmarks are explained in more detail.