Dynamical ionization ignition of clusters in intense and short laser pulses

The electron dynamics of rare gas clusters in laser fields is investigated quantum mechanically by means of time-dependent density functional theory. The mechanism of early inner and outer ionization is revealed. The formation of an electron wave packet inside the cluster shortly after the first removal of a small amount of electron density is observed. By collisions with the cluster boundary the wave packet oscillation is driven into resonance with the laser field, hence leading to higher absorption of laser energy. Inner ionization is increased because the electric field of the bouncing electron wave packet adds up constructively to the laser field. The fastest electrons in the wave packet escape from the cluster as a whole so that outer ionization is increased as well.Comment: 8 pages, revtex4, PDF-file with high resolution figures is available from http://mitarbeiter.mbi-berlin.de/bauer/publist.html, publication no. 24. Accepted for publication in Phys. Rev.

Swarm-Like Distributed Algorithm for Scheduling a Microservice-Based Application to the Cloud Servers

Introduction of virtualization containers and container orchestrators fundamentally changed the landscape of cloud application development. Containers provide an ideal way for practical implementation of microservice-based architecture, which allows for repeatable, generic patterns that make the development of reliable, distributed applications more approachable and efficient. Orchestrators allow for shifting the accidental complexity from inside of an application into the automated cloud infrastructure. Existing container orchestrators are centralized systems that schedule containers to the cloud servers only at their startup. In this paper, we propose a swarm-like distributed cloud management system that uses live migration of containers to dynamically reassign application components to the different servers. It is based on the idea of “pheromone” robots. An additional mobile agent process is placed inside each application container to control the migration process. The number of parallel container migrations needed to reach an optimal state of the cloud is obtained using models, experiments, and simulations. We show that in the most common scenarios the proposed swarm-like algorithm performs better than existing systems, and due to its architecture it is also more scalable and resilient to container death. It also adapts to the influx of containers and addition of new servers to the cloud automatically

The application of conceptnet for knowledge management of texts in the Polish and English languages

In the paper, the possibility of ConceptNet application for knowledge management of texts in the Polish and English language is discussed. ConceptNet is a freely-available semantic network, designed to help computers understand the meanings of words that people use, it contains concepts from many languages. The semantics of ConceptNet is presented in the context of the semantics of the EuroVoc which is based on the SKOS standard. Indexing tool, created by authors, based on ConceptNet is briefly described. Tests of texts indexing with the use of papers in Polish and English language were performed. Results are analyzed and evaluated. At the end, some conclusions about the quality of results are formulated

Time Complexity of an Distributed Algorithm for Load Balancing of Microservice-oriented Applications in the Cloud

Microservice architecture is a relatively new cloud application design pattern. Each microservice has a single responsibility in terms of functional requirement, and that can be managed independently from other microservices. This is done using automated cloud orchestration systems. In this paper we analyze the time complexity of an simple swarm-like decentralized load balancing algorithm for microservices running inside OpenVZ virtualization containers. We show that it can offer performance improvements with respect to the existing centralized container orchestration systems

Using the Hotspot function of the Xerte tool for developing interactive presentations

Due to dynamic development of e-learning tools, which are available on the commercial and non-commercial market, e-learning is today a common and valued form of supporting the learning process. To achieve some cognitive objectives, for example to visualize the structures or patterns, it is very effective to use techniques like interactive presentations. A particularly useful function of the presentation enforcing student's interest is the Hot Spot. This activity is available within a non-commercial tool environment - Xerte. The present publication focuses on the benefits and educational opportunities of this environment. In particular, the authors share their experiences of the Hot Spot activity creation in three different variants. The publication describes, in a comprehensive and detailed way, the creation of Hotspots, saving presentations in SCORM format as well publishing presentations on e-learning platform Moodle