270 research outputs found
A Reputation-Based Approach to Self-Adaptive Service Selection
Service-orientation provides concepts and tools for flexible composition and management of largescale distributed software applications. The automated run-time management of such loosely coupled software systems, however, poses still major challenges and is therefore an active research area, including the use of novel computing paradigms. In this context, the dynamic and adaptive selection of best possible service providers is an important task, which can be addressed by an appropriate middleware layer that allows considering different service quality aspects when managing the adaptive execution of distributed service workflows dynamically. In such an approach, service consumers are enabled to delegate the adaptive selection of service providers at run-time to the execution infrastructure. The selection criteria used are based on the cost of a service provision and the continuous, dynamic evaluation of reputations of providers, i.e. maintained track records of meeting the respective service commitments. This paper discusses the design and operating principle of such an automatic service selection middleware extension. Its ability to balance different quality criteria for service selection, such as service cost vs. the reliability of provision, is empirically evaluated based on a multi-agent platform approach
Systematically Engineering Self-Organizing Systems: The SodekoVS Approach
Self-organizing systems promise new software quality attributes that
are very hard to obtain using standard software engineering approaches. In accordance
with the visions of e.g. autonomic computing and organic computing,
self-organizing systems promote self-adaptability as one major property helping to
realize software that can manage itself at runtime. In this respect, self-adaptability
can be seen as a necessary foundation for realizing e.g. self* properties such as self-configuration or self-protection. However, the systematic development of systems
exhibiting such properties challenges current development practices. The SodekoVS
project addresses the challenge to purposefully engineer adaptivity by proposing a
new approach that considers the system architecture as well as the software development
methodology as integral intertwined aspects for system construction. Following
the proposed process, self-organizing dynamics, inspired by biological, physical
and social systems, can be integrated into applications by composing modules
that distribute feedback control structures among system entities. These compositions
support hierarchical as well as completely decentralized solutions without a
single point of failure. This novel development conception is supported by a reference
architecture, a tailored programming model as well as a library of ready to use
self-organizing patterns. The key challenges, recent research activities, application
scenarios as well as intermediate results are discussed
Non-Regulated Emissions and PN of Two Passenger Cars with Diesel-Butanol Blends
Biofuels represent one of the alternatives to obtain the CO2-neutral propulsion of IC-engines. Butanol, which can be produced from biomass, is considered and was investigated in the last years due to the very advantageous characteristics of this alternative fuel. Butanol can be easily and irreversibly blended both with light (gasoline) and heavier (Diesel) fuels. Comparing with ethanol it has the advantages of: higher calorific value, lower hygroscopicity and lower corrosivity. It can replace the aviation fuels. This paper presents the emission results obtained on two Diesel passenger cars with different technology (Euro2 and Euro6c) and with addition of Butanol to Diesel fuel, as a part of the research project DiBut (Diesel and Butanol). Interesting results are given about some non-legislated (non-regulated) components, Acetaldehyde (MeCHO) and Formaldehyde (HCHO) and about the PN-emissions with/without DPF
Ancestral and derived attributes of the dlx gene repertoire, cluster structure and expression patterns in an African cichlid fish
<p>Abstract</p> <p>Background</p> <p>Cichlid fishes have undergone rapid, expansive evolutionary radiations that are manifested in the diversification of their trophic morphologies, tooth patterning and coloration. Understanding the molecular mechanisms that underlie the cichlids' unique patterns of evolution requires a thorough examination of genes that pattern the neural crest, from which these diverse phenotypes are derived. Among those genes, the homeobox-containing <it>Dlx </it>gene family is of particular interest since it is involved in the patterning of the brain, jaws and teeth.</p> <p>Results</p> <p>In this study, we characterized the <it>dlx </it>genes of an African cichlid fish, <it>Astatotilapia burtoni</it>, to provide a baseline to later allow cross-species comparison within Cichlidae. We identified seven <it>dlx </it>paralogs (<it>dlx1a</it>, <it>-2a</it>, <it>-4a</it>, <it>-3b</it>, <it>-4b</it>, <it>-5a </it>and <it>-6a</it>), whose orthologies were validated with molecular phylogenetic trees. The intergenic regions of three <it>dlx </it>gene clusters (<it>dlx1a-2a</it>, <it>dlx3b-4b</it>, and <it>dlx5a-6a</it>) were amplified with long PCR. Intensive cross-species comparison revealed a number of conserved non-coding elements (CNEs) that are shared with other percomorph fishes. This analysis highlighted additional lineage-specific gains/losses of CNEs in different teleost fish lineages and a novel CNE that had previously not been identified. Our gene expression analyses revealed overlapping but distinct expression of <it>dlx </it>orthologs in the developing brain and pharyngeal arches. Notably, four of the seven <it>A. burtoni dlx </it>genes, <it>dlx2a</it>, <it>dlx3b</it>, <it>dlx4a </it>and <it>dlx5a</it>, were expressed in the developing pharyngeal teeth.</p> <p>Conclusion</p> <p>This comparative study of the <it>dlx </it>genes of <it>A. burtoni </it>has deepened our knowledge of the diversity of the <it>Dlx </it>gene family, in terms of gene repertoire, expression patterns and non-coding elements. We have identified possible cichlid lineage-specific changes, including losses of a subset of <it>dlx </it>expression domains in the pharyngeal teeth, which will be the targets of future functional studies.</p
Numerical simulation of individual coil placement -- A proof-of-concept study for the prediction of recurrence after aneurysm coiling
Rupture of intracranial aneurysms results in severe subarachnoidal
hemorrhage, which is associated with high morbidity and mortality.
Neurointerventional occlusion of the aneurysm through coiling has evolved to a
therapeutical standard. The choice of the specific coil has an important
influence on secondary regrowth requiring retreatment. Aneurysm occlusion was
simulated either through virtual implantation of a preshaped 3D coil or with a
porous media approach. In this study, we used a recently developed numerical
approach to simulate aneurysm shapes in specific challenging aneurysm anatomies
and correlated these with aneurysm recurrence 6 months after treatment. The
simulation showed a great variety of coil shapes depending on the variability
in possible microcatheter positions. Aneurysms with a later recurrence showed a
tendency for more successful coiling attempts. Results revealed further trends
suggesting lower simulated packing densities in aneurysms with reoccurrence.
Simulated packing densities did not correlate with those calculated by
conventional software, indicating the potential for our approach to offer
additional predictive value. Our study, therefore, pioneers a comprehensive
numerical model for simulating aneurysm coiling, providing insights into
individualized treatment strategies and outcome prediction. Future directions
involve expanding the model's capabilities to simulate intraprocedural outcomes
and long-term predictions, aiming to refine occlusion quality criteria and
validate prediction parameters in larger patient cohorts. This simulation
framework holds promise for enhancing clinical decision-making and optimizing
patient outcomes in endovascular aneurysm treatment.Comment: 13 pages, 4 figure
Separating Agent-Functioning and Inter-Agent Coordination by Activated Modules: The DECOMAS Architecture
The embedding of self-organizing inter-agent processes in distributed
software applications enables the decentralized coordination system elements,
solely based on concerted, localized interactions. The separation and
encapsulation of the activities that are conceptually related to the
coordination, is a crucial concern for systematic development practices in
order to prepare the reuse and systematic integration of coordination processes
in software systems. Here, we discuss a programming model that is based on the
externalization of processes prescriptions and their embedding in Multi-Agent
Systems (MAS). One fundamental design concern for a corresponding execution
middleware is the minimal-invasive augmentation of the activities that affect
coordination. This design challenge is approached by the activation of agent
modules. Modules are converted to software elements that reason about and
modify their host agent. We discuss and formalize this extension within the
context of a generic coordination architecture and exemplify the proposed
programming model with the decentralized management of (web) service
infrastructures
The IMO Reference Data Model: One Solution Fits Most!
In 2019, the International Maritime Organization (IMO) made it mandatory to support the electronic clearance of ships entering foreign ports. In preparation, the IMO Facilitation Committee started to develop a reference data model to harmonise the most important standards for ship clearance. The first version was published in 2020. The model is already extending into other areas of ship-port data exchanges and it is now increasingly seen as a tool to coordinate development of new electronic data exchange standards for ship operations. The lack of such coordination has, up until now, been a significant problem—much better coordination is essential in the relatively small and highly international market that shipping represents.acceptedVersio
The Analgesic Effect of the Mitochondria-Targeted Antioxidant SkQ1 in Pancreatic Inflammation
Background. Chronic pancreatitis is one of the main risk factors for pancreatic cancer. In acute and chronic pancreatitis, oxidative stress is thought to play a key role. In this respect, the recently described mitochondria-targeted antioxidant SkQ1 effectively scavenges reactive oxygen species at nanomolar concentrations. Therefore, we aimed to characterize the influence of SkQ1 on tissue injury and pain in acute and chronic pancreatitis. Methods. Both acute and chronic pancreatitis were induced in C57BL/6 mice by intraperitoneal cerulein injections and treatment with SkQ1 was carried out by peroral applications. Hyperalgesia was assessed by behavioral observation and measurement of abdominal mechanical sensitivity. Blood serum and pancreatic tissue were harvested for analysis of lipase and histology. Results. SkQ1 did not influence pain, serological, or histological parameters of tissue injury in acute pancreatitis. In chronic pancreatitis, a highly significant reduction of pain-related behavior (p < 0.0001) was evident, but histological grading revealed increased tissue injury in SkQ1-treated animals (p = 0.03). Conclusion. After SkQ1 treatment, tissue injury is not ameliorated in acute pancreatitis and increased in chronic pancreatitis. However, we show an analgesic effect in chronic pancreatitis. Further studies will need to elucidate the risks and benefits of mitochondria-targeted antioxidants as an analgesic
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