Pilot, Rollout and Monte Carlo Tree Search Methods for Job Shop Scheduling

Greedy heuristics may be attuned by looking ahead for each possible choice, in an approach called the rollout or Pilot method. These methods may be seen as meta-heuristics that can enhance (any) heuristic solution, by repetitively modifying a master solution: similarly to what is done in game tree search, better choices are identified using lookahead, based on solutions obtained by repeatedly using a greedy heuristic. This paper first illustrates how the Pilot method improves upon some simple well known dispatch heuristics for the job-shop scheduling problem. The Pilot method is then shown to be a special case of the more recent Monte Carlo Tree Search (MCTS) methods: Unlike the Pilot method, MCTS methods use random completion of partial solutions to identify promising branches of the tree. The Pilot method and a simple version of MCTS, using the $\varepsilon$-greedy exploration paradigms, are then compared within the same framework, consisting of 300 scheduling problems of varying sizes with fixed-budget of rollouts. Results demonstrate that MCTS reaches better or same results as the Pilot methods in this context.Comment: Learning and Intelligent OptimizatioN (LION'6) 7219 (2012

Synthese von kompatiblen Soluten mit ectoinanaloger Struktur und Charakterisierung des protektiven Effektes auf biochemische Modellsysteme und Escherichia coli

Synthese von kompatiblen Soluten mit ectoinanaloger Struktur und Charakterisierung des protektiven Effektes auf biochemische Modellsysteme und Escherichia Coli. Halophile Bakterien schützen ihre Zellen durch kompatible Solute gegen die unwirtlichen Bedingungen in salzhaltigen Gewässern. Eines der am häufigsten vorkommenden Solute ist Ectoin. Im Labor hat es seine stabilisierende Wirkung auf einzelne Zellstrukturen vielfältig unter Beweis gestellt und heutzutage kommt es unter Anderem in Hautcremes, als Feuchtespender und Aktivator der zelleigenen Reparaturmechanismen, vor. Im Rahmen dieser Arbeit wurden kompatible Solute synthetisiert, deren Strukur dem natürlichen Schutzstoff Ectoin ähneln. Ferner wurden die Solute sowie ihre Wechselwirkungen mit Wasser und Zellstrukturen untersucht um auf molekularer Ebene einen Einblick in die Funktionsweise zu erhalten. Auf dieser Basis können neue industrielle Anwendungen für die Solute entwickelt werden

Oxygen Diffusion in Tissue Preparations with Michaelis-Menten Kinetics

A model is introduced for the oxygen consumption in thin vital tissue preparation. The steady uptake kinetics is modelled by a MichaelisMenten form and for this case it proved that the resulting boundary value problem admits a unique solution for those parameter ranges typical of related physiological experiments. This solution is compared with Otto Warburg's hyperoxia model and with a hypoxia model. Useful and easily computed approximations are derived for the minimum oxygen supply across the tissue and some numerical solutions of the governing equations are discussed

Volumetric Segmentation of Cell Cycle Markers in Confocal Images Using Machine Learning and Deep Learning

© Copyright © 2020 Khan, Voß, Pound and French. Understanding plant growth processes is important for many aspects of biology and food security. Automating the observations of plant development—a process referred to as plant phenotyping—is increasingly important in the plant sciences, and is often a bottleneck. Automated tools are required to analyze the data in microscopy images depicting plant growth, either locating or counting regions of cellular features in images. In this paper, we present to the plant community an introduction to and exploration of two machine learning approaches to address the problem of marker localization in confocal microscopy. First, a comparative study is conducted on the classification accuracy of common conventional machine learning algorithms, as a means to highlight challenges with these methods. Second, a 3D (volumetric) deep learning approach is developed and presented, including consideration of appropriate loss functions and training data. A qualitative and quantitative analysis of all the results produced is performed. Evaluation of all approaches is performed on an unseen time-series sequence comprising several individual 3D volumes, capturing plant growth. The comparative analysis shows that the deep learning approach produces more accurate and robust results than traditional machine learning. To accompany the paper, we are releasing the 4D point annotation tool used to generate the annotations, in the form of a plugin for the popular ImageJ (FIJI) software. Network models and example datasets will also be available online

Austausch fossiler Energieträger untereinander : Zusammenfassung der Ergebnisse des Studienkomplexes A.3

Ziel der Arbeiten des Studienkomplexes A.3 ist es, die technisch-wirtschaftlichen Möglichkeiten der Minderung energiebedingter klimarelevanter Spurengase, insbesondere von CO2 durch eine Substitution zwischen den fossilen Energieträgern für die Bundesrepublik Deutschland für verschiedene Zeitpunkte (1987, 2005, 2050) aufzuzeigen. Dabei ist auch darzustellen, inwieweit eine verstärkte Nutzung kohlenstoffarmer fossiler Energieträger in den nächsten Dekaden einen Zeitgewinn für die Realisierung einer klimaverträglichen Energieversorgung ermöglicht. Die Minderungspotentiale klimarelevanter Spurengase sind dabei vor dem Hintergrund der langfristigen Verfügbarkeit von Kohle, Mineralöl und Erdgas zu beurteilen

MNEs and flexible working practices in Mauritius

We compare how far companies based in Africa, India and the 'global North' operating in Mauritius adopt high-trust flexible working practices, and how these are linked to different clusters of wider labour management practice. Using comprehensive firm-level data collected in late 2011, we find that African/Indian company practices are closer to those of indigenous firms than to those of Northern companies. The different company groups operate in quite different ways but regional MNEs operate in a similar way to indigenous companies. We therefore conclude that Rugman and Verbeke’s ‘regionalization’ theory also applies to the HR field. We further find that both a relatively strategic approach to HRM and measures to develop employer-employee interdependence are, respectively, linked directly and indirectly to flexible working incidence

How do older people discuss their own sexuality? A systematic review of qualitative research studies

This study captured older people’s attitudes and concerns about sex and sexuality in later life by synthesising qualitative research published on this issue. The systematic review was conducted between November 2015 and June 2016 based on a pre-determined protocol. Key words were used to ensure a precise search strategy. Empirically based, qualitative literature from 18 databases was found. Twenty studies met the inclusion criteria. Thomas and Harden’s thematic synthesis was used to generate ‘analytical themes’ which summarise this body of literature. Three main themes were identified: (a) social legitimacy for sexuality in later life; (b) health, not age, is what truly impacts sexuality, and (c) the hegemony of penetrative sex. The themes illustrate the complex and delicate relation between ageing and sexuality. Older adults facing health issues that affect sexual function adopt broader definitions of sexuality and sexual activit