Reducing the time complexity of the derandomized evolution strategy with covariance matrix adaptation (CMA-ES)

This paper presents a novel evolutionary optimization strategy based on the derandomized evolution strategy with covariance matrix adaptation (CMA-ES). This new approach is intended to reduce the number of generations required for convergence to the optimum. Reducing the number of generations, i.e., the time complexity of the algorithm, is important if a large population size is desired: (1) to reduce the effect of noise; (2) to improve global search properties; and (3) to implement the algorithm on (highly) parallel machines. Our method results in a highly parallel algorithm which scales favorably with large numbers of processors. This is accomplished by efficiently incorporating the available information from a large population, thus significantly reducing the number of generations needed to adapt the covariance matrix. The original version of the CMA-ES was designed to reliably adapt the covariance matrix in small populations but it cannot exploit large populations efficiently. Our modifications scale up the efficiency to population sizes of up to 10n, where n is the problem dimension. This method has been applied to a large number of test problems, demonstrating that in many cases the CMA-ES can be advanced from quadratic to linear time complexity.     

STLlint: lifting static checking from languages to libraries

Traditional static checking centers around finding bugs in programs by isolating cases where the language has been used incorrectly. These language‐based checkers do not understand the semantics of software libraries, and therefore cannot be used to detect errors in the use of libraries. In this paper, we introduce STLlint, a program analysis we have implemented for the C++ Standard Template Library and similar, generic software libraries, and we present the general approach that underlies STLlint. We show that static checking of library semantics differs greatly from checking of language semantics, requiring new representations of program behavior and new algorithms. Major challenges include checking the use of generic algorithms, loop analysis for interfaces, and organizing behavioral specifications for extensibility. Copyright © 2005 John Wiley & Sons, Ltd.     

Molmassebestimmung an Polyamiden und Reaktionsprodukten aus ε–Caprolactam und Phenylglycidether

Molar Mass Determination on Polyamides and on Reaction Products from ε-Caprolactam and Phenyl Glycidyl Ether Terminal groups (-NH₂, -COOH, -OH (-OH from termination reaction with epoxides)) of aliphatic oligo- and polyamides were titrated to determine the corresponding molar masses. ε-Caprolactam terminal groups were hydrolyzed to form -COOH permitting subsequent titration. The same samples were measured by using capillary viscometry, vapour pressure osmometry and size exclusion chromatography. It was shown that the molar masses obtained depend on the reaction process of the polyamide formation (anionic process with Na-caprolactam as initiator and activated anionic process with Na-caprolactam/N-acetylcaprolactam as initiator) and on the analytical method used. Molar masses from titration of terminal groups correspond to molar masses from capillary viscometry in sulfuric acid as solvent.     

Effects of Calcination Temperature and A/B Ratio on the Dielectric Properties of (Ba,Ca)(Ti,Zr,Mn)O3 for Multilayer Ceramic Capacitors with Nickel Electrodes

The electrical performance of multilayer ceramic capacitors (MLCCs) with Ni inner electrodes, made from (Ba,Ca)(Ti,Zr,Mn)O₃ (BCTZM), is closely related to the calcination temperature and the A/B ratio of the powder. For materials showing A/B = 1.000, the lifetime, the breakdown voltage, and the RC increase with higher calcination temperatures. No significant effect of the calcination temperature on RC and lifetime was found for materials showing A/B = 0.991. The isoelectric point of BCTZM is shifted toward higher pH values when the calcination temperature is decreased. The above results are attributed to the colloidal stability of aqueous BCTZM suspensions and the resulting green density of powder compacts.     

Modular Manufacturing Platform for Continuous Synthesis and Analysis of Versatile Nanomaterials

Nanoparticular materials have a great potential in various fields including technical and biomedical applications; to meet the specific requirements, a good control over the particle characteristics is mandatory. Addressing this, a modular system for the automated and continuous synthesis, workup, and analysis of a broad range of nanoparticles was developed. Application examples of inorganic (silica) and organic (polymersomes, niosomes) nanoparticles demonstrate the versatility of the production platform. Modules for downstream processing via a falling‐film microreactor or tangential flow filtration are presented. The hydrodynamic size as a key parameter is acquired in real time, with an inline dynamic light scattering device. All modules are controlled and operated by a process control system.     

On the use of the partitioning approach to derive Environmental Quality Standards (EQS) for persistent organic pollutants (POPs) in sediments: a review of existing data

A review of experimental data has been performed to study the relationships between the concentration in water, pore water and sediments for different families of organic contaminants. The objective was to determine whether it is possible to set EQS for sediments from EQS defined for surface waters in the Daughter Directive of the European Parliament (COM (2006) 397). The analysis of experimental data showed that even though in some specific cases there is a coupling between water column and sediments, this coupling is rather the exception. Therefore it is not recommendable to use water column data to assess the chemical quality status of sediments and it is necessary to measure in both media. At the moment EQS have been defined for the water column and will assess only the compliance with good chemical status of surface waters. Since the sediment toxicity depends on the dissolved pore water concentration, the EQS developed for water could be applied to pore water (interstitial water); hence, there would be no need of developing another set of EQS. The partitioning approach has been proposed as a solution to calculate sediment EQS from water EQS, but the partitioning coefficient strongly depends on sediment characteristics and its use introduces an important uncertainty in the definition of sediment EQS. Therefore, the direct measurement of pore water concentration is regarded as a better option.