Applying Evolutionary Algorithms Successfully: A Guide Gained from Real-world Applications

Metaheuristics (MHs) in general and Evolutionary Algorithms (EAs) in particular are well known tools for successful optimization of difficult problems. But when is their application meaningful and how does one approach such a project as a novice? How do you avoid beginner\u27s mistakes or use the design possibilities of a metaheuristic search as efficiently as possible? This paper tries to give answers to these questions based on 30 years of research and application of the Evolutionary Algorithm GLEAM and its memetic extension HyGLEAM. Most of the experience gathered and discussed here can also be applied to the use of other metaheuristics such as ant algorithms or particle swarm optimization. This paper addresses users with basic knowledge of MHs in general and EAs in particular who want to apply them in an optimization project. For this purpose, a number of questions that arise in the course of such a project are addressed. At the end, some non-technical project management issues are discussed, whose importance for project success is often underestimated

Stability of a trapped atom clock on a chip

We present a compact atomic clock interrogating ultracold 87Rb magnetically trapped on an atom chip. Very long coherence times sustained by spin self-rephasing allow us to interrogate the atomic transition with 85% contrast at 5 s Ramsey time. The clock exhibits a fractional frequency stability of $5.8\times 10^{-13}$ at 1 s and is likely to integrate into the $1\times10^{-15}$ range in less than a day. A detailed analysis of 7 noise sources explains the measured frequency stability. Fluctuations in the atom temperature (0.4 nK shot-to-shot) and in the offset magnetic field ($5\times10^{-6}$ relative fluctuations shot-to-shot) are the main noise sources together with the local oscillator, which is degraded by the 30% duty cycle. The analysis suggests technical improvements to be implemented in a future second generation set-up. The results demonstrate the remarkable degree of technical control that can be reached in an atom chip experiment.Comment: 12 pages, 11 figure

Spin waves and Collisional Frequency Shifts of a Trapped-Atom Clock

We excite spin-waves with spatially inhomogeneous pulses and study the resulting frequency shifts of a chip-scale atomic clock of trapped $^{87}$Rb. The density-dependent frequency shifts of the hyperfine transition simulate the s-wave collisional frequency shifts of fermions, including those of optical lattice clocks. As the spin polarizations oscillate in the trap, the frequency shift reverses and it depends on the area of the second Ramsey pulse, exhibiting a predicted beyond mean-field frequency shift. Numerical and analytic models illustrate the observed behaviors.Comment: Will appear soon in Physical Review Letters - Typos correcte

Einfluss des Aktivitätsverhaltens auf die Ausdauerleistungsfähigkeit von Nachwuchsfußballspielern

Zweck: Absicht der Studie war es, ein Aktivitätsprofil von Elite-Nachwuchsfußballspielern während der Wettkampfperiode zu erstellen. Außerdem wurde in dieser Studie getestet, wie sich das Aktivitätsverhalten auf die Ausdauerleistungsfähigkeit dieser Athleten auswirkt. Ferner war es Ziel dieser Untersuchung, einen möglichen Zusammenhang zwischen subjektivem Belastungsempfinden und objektiv gemessenen Parametern bei körperlichen Aktivitäten zu prüfen. Methode: 15 Spieler der U-14 Mannschaft (Saison 2011/12) des SK Rapid Wien trugen während Wachzeiten an sieben aneinander folgenden Tagen an der rechten Hüftseite einen Actigraph GT1M Akzelerometer, sowie einen Suunto Smartbelt Herzfrequenz-sensor am Ansatz der Brustmuskulatur. Das subjektive Belastungsempfinden bei Ver-eins- und schulsportlichen Aktivitäten wurde mitttels OMNI Scale erhoben. Zur Beurtei-lung der Ausdauerleistungsfähigkeit wurde ein 20-m-Shuttle Run-Test absolviert. Die Einteilung der Aktivitätsmessung erfolgte in die fünf Bereiche Gesamt, Verein, Schule, Schulsport und Freizeit. Ergebnisse: Ein signifikanter (p<0,05) Unterschied aller Akzelerometer-Kenngrößen zeigte sich beim Vergleich zwischen Schultag mit Schulsport und Schultag ohne Schul-sport festgestellt werden. Des Weiteren konnte ein signifikanter (p<0,01) Unterschied bei der Intensität zwischen schulsportlichen und Vereinsaktivitäten (Trainings + Match) so-wohl bei den objektiv gemessenen Parametern, als auch beim subjektiven Belastungs-empfinden festgestellt werden. Die Akzelerometer-Kenngrößen im Bereich Verein unter-schieden sich signifikant (p<0,01) von den Werten in der Schule und der Freizeit. Weder zwischen dem wöchentlichen Aktivitätsverhalten und der Ausdauerleistungsfähigkeit, noch zwischen subjektiven Belastungsempfinden und Akzelerometer-Kenngrößen war ein signifikanter (p<0,05) Zusammenhang vorhanden. Fazit: In dieser Untersuchung hat sich die Akzelerometrie als eine geeignete Methode zur Erstellung eines Aktivitätsprofils erwiesen. Für die Beurteilung des subjektive Belas-tungsempfindens und der Ausdauerleistungsfähigkeit ist das verwendete Verfahren kein geeigneter Prädiktor.Purpose: The study aims to evaluate physical activity (PA) patterns of adolescent elite soccer players during season. The main objective of the study was to examine the effect of PA habits on aerobic capacity. Furthermore, the study tried to determine whether a link between the rating of perceived exertion (RPE) and objective measures can be found. Methods: 15 members of Rapid Wien´s under 14 youth soccer team (season 2011/12) participated in this study. During waking hours, players wore a hip-mounted Actigraph GT1M accelerometer and a chest-worn Suunto Smartbelt heart rate monitor within seven consecutive days. The rating of perceived exertion was measured with children´s OMNI Scale and was assessed in Physical Education (PE) as well as in training sessions and during a match. In order to assess aerobic capacity, a 20-m shuttle run was conducted. PA was classified into five fields: total, club, school, PE and leisure time. Results: Accelerometry measures differed significantly between schooldays including PE lessons and school days without PE lessons (p<0,05). The difference between PE and club sessions (training sessions + match) was significant (p<0,01) in objectively measured accelerometry data as well as in RPE. Accelerometry-derived values in club sessions differed significantly (p<0,01) to PE and leisure time values. No relationship has been found between PA and aerobic capacity. There was no significant association (p<0,05) between RPE and objectively measured accelerometry data. Conclusion: Accelerometry is an appropriate method for measuring PA patterns in young soccer athletes. However, accelerometry is not recommended as a method for predicting perceived exertion. There is no relationship between accelerometry data and aerobic capacity

GLEAM - General Learning Evolutionary Algorithm and Method : ein Evolutionärer Algorithmus und seine Anwendungen

Nach einer grundlegenden Einführung wird der Evolutionäre Algorithmus GLEAM ausführlich vorgestellt. Das breite Anwendungspotential dieses Optimierungs- und Planungsverfahrens wird durch eine Reihe von Anwendungsbeispielen aus den Bereichen Robotik, Scheduling, Bauindustrie und Designoptimierung unterstrichen. Dabei werden auch Weiterentwicklungen behandelt, die Heuristiken und lokale Suche in das evolutionäre Verfahren integrieren, so dass ein hybrider oder memetischer Algorithmus entsteht

Data processing of high-rate low-voltage distribution grid recordings for smart grid monitoring and analysis

Power networks will change from a rigid hierarchic architecture to dynamic interconnected smart grids. In traditional power grids, the frequency is the controlled quantity to maintain supply and load power balance. Thereby, high rotating mass inertia ensures for stability. In the future, system stability will have to rely more on real-time measurements and sophisticated control, especially when integrating fluctuating renewable power sources or high-load consumers like electrical vehicles to the low-voltage distribution grid. In the present contribution, we describe a data processing network for the in-house developed low-voltage, high-rate measurement devices called electrical data recorder (EDR). These capture units are capable of sending the full high-rate acquisition data for permanent storage in a large-scale database. The EDR network is specifically designed to serve for reliable and secured transport of large data, live performance monitoring, and deep data mining. We integrate dedicated different interfaces for statistical evaluation, big data queries, comparative analysis, and data integrity tests in order to provide a wide range of useful post-processing methods for smart grid analysis. We implemented the developed EDR network architecture for high-rate measurement data processing and management at different locations in the power grid of our Institute. The system runs stable and successfully collects data since several years. The results of the implemented evaluation functionalities show the feasibility of the implemented methods for signal processing, in view of enhanced smart grid operation. © 2015, Maaß et al.; licensee Springer

Impact of prior JAK-inhibitor therapy with ruxolitinib on outcome after allogeneic hematopoietic stem cell transplantation for myelofibrosis: a study of the CMWP of EBMT.

JAK1/2 inhibitor ruxolitinib (RUX) is approved in patients with myelofibrosis but the impact of pretreatment with RUX on outcome after allogeneic hematopoietic stem cell transplantation (HSCT) remains to be determined. We evaluated the impact of RUX on outcome in 551 myelofibrosis patients who received HSCT without (n = 274) or with (n = 277) RUX pretreatment. The overall leukocyte engraftment on day 45 was 92% and significantly higher in RUX responsive patients than those who had no or lost response to RUX (94% vs. 85%, p = 0.05). The 1-year non-relapse mortality was 22% without significant difference between the arms. In a multivariate analysis (MVA) RUX pretreated patients with ongoing spleen response at transplant had a significantly lower risk of relapse (8.1% vs. 19.1%; p = 0.04)] and better 2-year event-free survival (68.9% vs. 53.7%; p = 0.02) in comparison to patients without RUX pretreatment. For overall survival the only significant factors were age > 58 years (p = 0.03) and HLA mismatch donor (p = 0.001). RUX prior to HSCT did not negatively impact outcome after transplantation and patients with ongoing spleen response at time of transplantation had best outcome

EVOLUTIONARY DESIGN OPTIMIZATION OF A MICROOPTICAL COLLIMATION SYSTEM

The production of specimen for microsystems or microcomponents is both, time and material-consuming. In a traditional design process the number of possible variations which can be considered is very limited. Thus, in microsystem technology computer-based design techniques become more and more important- similar to the development of microelectronics. The computer aided development and optimization is based on simulation models. This paper presents the concept of a partially automated design optimization as an application of our evolutionary optimization environment. A 2-lens-system being part of a heterodyne receiver, a microoptical communication module, has to be optimized to be as insensitive to fabrication tolerances as possible while still maintaining optimal properties of the collimation system. The optimization results obtained are compared to a hillclimbing strategy with respect to both, convergence reliability and convergence velocity