Machine learning and Design of Experiments: Alternative approaches or complementary methodologies for quality improvement?

Machine Learning (ML), or the ability of self-learning computer algorithms to autonomously structure and interpret data, is a methodological approach to solve complicated optimization problems based on abundant data. ML is recently gaining momentum as algorithmic applications, computing potency, and available data sets increased manifold over the past two decades, providing an information-rich environment in which human reasoning can partially be replaced by computer reasoning. In this paper, we want to assess the implications of ML for Design of Experiments (DoE), a statistical methodology widely used in Quality Management for quantifying effects and interactions of factors with influence on the production quality or the process yield. We specifically want to assess the future role and importance of DoE: Will it remain unaltered by ML, will it be made obsolete, or will it be reinforced? With this, we want to contribute to the discussion of the future use of traditional Quality Management methodologies in production, as our ML assessment can in principle be applied to other statistical methodologies as well. While we are convinced that ML will heavily impact the field of Quality Management and its predominant set of statistical methodologies, we find reason to expect that this impact will be a mutual one. As this is the first paper addressing the joint force potential of the two methodologies ML and DoE, we expect a range of follow-up papers being written on the subject and a spark in specialized applications addressing DoE's ML-enhanced vital functionality for process improvements.     

Assessment of residential battery storage systems and operation strategies considering battery aging

With the increasing popularity of combining residential photovoltaic systems with battery storages, research, industry, and customers look for ways to determine if such an investment is economically profitable. Simulation programs may serve to predict the profitability and lifetime of the system. In this paper, we use techno-economic analysis with a specific account of battery degradation to determine profitability and lifetime of a residential photovoltaic (PV) battery system under different energy management and tariff regimes. This work presents two case studies: the first being a techno-economic comparison for a residential PV-battery system in New South Wales, Australia and Germany, and the second analyzing the profitability and degradation impact of three different operation strategies for a battery storage in Australia. The results reveal that site-specific conditions (i.e., geographical and energy-economic constraints) may have a significant impact on the ideal system configuration and ultimately the anticipated battery lifetime. Furthermore, statistical analysis of different storage operation strategies applied to various prosumer load and generation profiles reveals the effects of storage dispatch strategies on battery aging.     

ITER safety and licensing update

Safety files were submitted by the ITER Organization to the French nuclear safety authorities in March 2010 as a part of the licensing process. These included the preliminary safety report (RPrS) which presents the extensive safety analyses performed for ITER. The report has been the subject of examination by the authorities and their advisors, and discussions with them have been held on many topics. In the light of this process, this paper discusses some of the topics that remain prominent in the safety analysis of ITER. In particular, the provision of the two safety functions, confinement of radioactive material and limitation of exposure to radiation, is explained and some of the potential challenges to them are identified. Amongst these are the risks of fire and explosion, and external events such as earthquake and loss of all electric power. Provisions in the ITER design, together with the characteristics of fusion, ensure that a very good safety performance will be achieved.     

A coupled CFD-population balance approach for nanoparticle synthesis in turbulent reacting flows

This paper investigates the first part of a two-stage methodology for the detailed fully coupled modelling of nanoparticle formation in turbulent reacting flows. We use a projected fields (PF) method to approximate the joint composition probability density function (PDF) transport equation that describes the evolution of the nanoparticles. The method combines detailed chemistry and the method of moments with interpolative closure (MoMIC) population balance model in a commercial computational fluid dynamics (CFD) code. We show details of the implementation and present an extensive set of numerical experiments and validation. We consider the example of the chloride process for the industrial synthesis of titania. We show good agreement with experimental data and present fully coupled detailed chemistry CFD simulations of nanoparticle formation in a representative ‘slot’ reactor geometry. The simulations show that inception occurs in a mixing zone near the reactor inlets. Most of the nanoparticle mass is due to surface growth downstream of the mixing zone with a narrower size distribution occurring in the regions of higher surface growth. The predicted temperature and particle properties are compared to a perfect mixing case. The implications for the second part of the methodology, where it is proposed to post-process the data using a more detailed particle model, are discussed critically.     

CrasyDSE: A framework for solving Dyson–Schwinger equations

Dyson–Schwinger equations are important tools for non-perturbative analyses of quantum field theories. For example, they are very useful for investigations in quantum chromodynamics and related theories. However, sometimes progress is impeded by the complexity of the equations. Thus automating parts of the calculations will certainly be helpful in future investigations. In this article we present a framework for such an automation based on a C++ code that can deal with a large number of Green functions. Since also the creation of the expressions for the integrals of the Dyson–Schwinger equations needs to be automated, we defer this task to a Mathematica notebook. We illustrate the complete workflow with an example from Yang–Mills theory coupled to a fundamental scalar field that has been investigated recently. As a second example we calculate the propagators of pure Yang–Mills theory. Our code can serve as a basis for many further investigations where the equations are too complicated to tackle by hand. It also can easily be combined with DoFun, a program for the derivation of Dyson–Schwinger equations.¹Program summaryProgram title: CrasyDSECatalogue identifier: AEMY _v1_0Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEMY_v1_0.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 49030No. of bytes in distributed program, including test data, etc.: 303958Distribution format: tar.gzProgramming language: Mathematica 8 and higher, C++.Computer: All on which Mathematica and C++ are available.Operating system: All on which Mathematica and C++ are available (Windows, Unix, Mac OS).Classification: 11.1, 11.4, 11.5, 11.6.Nature of problem: Solve (large) systems of Dyson–Schwinger equations numerically.Solution method: Create C++ functions in Mathematica to be used for the numeric code in C++. This code uses structures to handle large numbers of Green functions.Unusual features: Provides a tool to convert Mathematica expressions into C++ expressions including conversion of function names.Running time: Depending on the complexity of the investigated system solving the equations numerically can take seconds on a desktop PC to hours on a cluster.     

Plasma modification and deposition on inner tube faces by pulsed DC discharges

The modification of inner surfaces of tubes becomes increasingly important in many fluid transport applications. However, long tubes require special plasma techniques for a surface functionalization on the nanometer scale without damaging the bulk. This work focuses on pulsed DC glow discharges in inert argon, reactive oxygen, nitrogen and air plasma as well as polymerizing acetylene plasma revealing strong influences to the wetting behavior by the total duration of the plasma discharge time (plasma on-time). While the investigated polymers polyamide, polycarbonate, polyethylene terephtalate, and thermoplastic polyurethane react very differently on the inert and reactive etching (activation) plasma, the deposition of plasma polymer films (polymer-like carbon with decreasing cross-linking at lower plasma intensity and >50% hydrogen content) suppresses all substrate influences.     

Aqueous nanogels modified with cyclodextrin

In this work, the incorporation of reactive cyclodextrins (CDs) in aqueous nanogels based on poly(N-vinylcaprolactam) (VCL) is studied by surfactant-free precipitation polymerization process. α-, β-, γ-CDs were functionalized with acrylic groups and the average amount of vinyl bonds per CD molecule was adjusted to 2, 4, or 6. The increase of the CD concentration in the reaction mixture led to the reduction of the final hydrodynamic radius of nanogels from 227 nm to 62 nm. The increase of the vinyl groups number per CD molecule induced formation of smaller nanogels (R_h = 22.5 nm) and considerable increase of the crosslinking degree. Obtained cyclodextrin-modified nanogels show temperature sensitivity in aqueous medium with a volume transition point around 30 °C. The complexation properties of CDs incorporated in nanogel networks were proved by titration with phenolphthalein.     

Europeanizing planning education and the enduring power of national institutions

It is widely observed that planning education in Europe is affected increasingly by various forces of Europeanisation and internationalization. While these trends are not regarded uncritically, very often commentators treat them as inexorable, or it is assumed that individual universities have considerable agency in how they respond. However, closer attention to the literature on Europeanisation shows that nation-states significantly mediate these processes. This is the focus of this paper, which draws on a case study of the creation of an integrated multi-country Masters programme in spatial planning. The analysis shows that national institutions still exert significant force, at least on the structure of the degree programmes that can be created, which universities seeking to Europeanize have to negotiate.     

Electrochemistry with alkyl-linked oligothiophenes

Two pairs of β,β′-didodecyl substituted quinquethiophenes linked via a tri- (3) and tetramethylene spacer (4) at their α-positions have been synthesized and their electrochemical behavior investigated with cyclic voltammetry in solution and in solid films. Both compounds can be charged to a tetracation in two two-electron transfer steps, which are reversible at room temperature but become partially irreversible at low temperatures. Concentration and scan rate dependent measurements support an intramolecular coupling of the oligothiophene units preferentially next to their bridging site with σ-bond formation. In solution no electropolymerization can be observed. In the solid state upon oxidation intermolecular coupling of the oligothiophene segments takes place. Conductance measurements confirm the voltammetric findings. Obviously, the mechanism of conductance is based on hopping processes within mixed valence states.