State‐of‐the‐Art in GPU‐Based Large‐Scale Volume Visualization

This survey gives an overview of the current state of the art in GPU techniques for interactive large‐scale volume visualization. Modern techniques in this field have brought about a sea change in how interactive visualization and analysis of giga‐, tera‐ and petabytes of volume data can be enabled on GPUs. In addition to combining the parallel processing power of GPUs with out‐of‐core methods and data streaming, a major enabler for interactivity is making both the computational and the visualization effort proportional to the amount and resolution of data that is actually visible on screen, i.e. ‘output‐sensitive’ algorithms and system designs. This leads to recent output‐sensitive approaches that are ‘ray‐guided’, ‘visualization‐driven’ or ‘display‐aware’. In this survey, we focus on these characteristics and propose a new categorization of GPU‐based large‐scale volume visualization techniques based on the notions of actual output‐resolution visibility and the current working set of volume bricks—the current subset of data that is minimally required to produce an output image of the desired display resolution. Furthermore, we discuss the differences and similarities of different rendering and data traversal strategies in volume rendering by putting them into a common context—the notion of address translation. For our purposes here, we view parallel (distributed) visualization using clusters as an orthogonal set of techniques that we do not discuss in detail but that can be used in conjunction with what we present in this survey.     

Evolution strategies with cumulative step length adaptation on the noisy parabolic ridge

This paper presents an analysis of the performance of the (μ/μ,λ)-ES with isotropically distributed mutations and cumulative step length adaptation on the noisy parabolic ridge. Several forms of dependency of the noise strength on the distance from the ridge axis are considered. Closed form expressions are derived that describe the mutation strength and the progress rate of the strategy in high-dimensional search spaces. It is seen that as for the sphere model, larger levels of noise present lead to cumulative step length adaptation generating increasingly inadequate mutation strengths, and that the problem can be ameliorated to some degree by working with larger populations.     

Optimum tracking with evolution strategies

Evolutionary algorithms are frequently applied to dynamic optimization problems in which the objective varies with time. It is desirable to gain an improved understanding of the influence of different genetic operators and of the parameters of a strategy on its tracking performance. An approach that has proven useful in the past is to mathematically analyze the strategy's behavior in simple, idealized environments. The present paper investigates the performance of a multiparent evolution strategy that employs cumulative step length adaptation for an optimization task in which the target moves linearly with uniform speed. Scaling laws that quite accurately describe the behavior of the strategy and that greatly contribute to its understanding are derived. It is shown that in contrast to previously obtained results for a randomly moving target, cumulative step length adaptation fails to achieve optimal step lengths if the target moves in a linear fashion. Implications for the choice of population size parameters are discussed.     

Direct magnetic problem solved by quaternion analog of 3-D Cauchy-Riemann system

Contents By applying the quaternion variant of the Cauchy integral formula the general solution of the direct magnetic problem is derived. The applicability of the method presented here is shown by investigating and calculating the outer field of a analytically magnetized sphere.

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Die Lösung der direkten Aufgabe der Magnetik mit Hilfe des Quaternionen Analogons des 3-D Cauchy-Riemann Systems

Übersicht Die allgemeine Lösung der direkten Aufgabe der Magnetik wird mit Hilfe der Quaternionenvariante des Cauchy-Integrals abgeleitet. Die Anwendbarkeit der vorgestellten, Methode wird am Beispiel des berechneten äußeren magnetischen Feldes einer analytisch magnetisierten Kugel untersucht.

     

Correction to: Reliable benchmarking: requirements and solutions

International Journal on Software Tools for Technology Transfer - The article Reliable benchmarking: requirements and solutions.     

Erprobungsmethodik für zyklisch überelastisch beanspruchte Bauteile unter Torsion – Bauschinger‐Kenngrößen für 54SiCr6

Power transmission contains several torsion‐stressed parts. Especially shafts and springs are numerous considered. Helical springs as a special type of springs are mainly stressed by torsion load. During operation the spring's load is basically elastic. In some cases, like overload or machine disaster, the load exceeds the spring's yield stress. For a single event the deformations can be calculated easily by using flow charts. However in other cases the spring will be stressed several times with alternating plastic load. Therefore the calculation will not be as easy as in the single load case. Especially the hardening and softening mechanisms have major influence on material behavior. For high strength steel this material behavior is not fully investigated right now. Present article shows a way how to investigate several important Bauschinger parameters based on plastic torsion load for the high strength steel 54SiCr6. Finally it can be shown that 54SiCr6 is influenced by the Bauschinger effect. On the other hand the needed material characteristic can be investigated by the shown methodology. Based on the identified data, analytical and numerical calculation of alternating plastic torsion load can be done.     

Studies on the potential risk of liquid metal assisted cracking (LMAC) in normal‐temperature and high‐temperature hot‐dip galvanizing of high strength bolts of dimensions greater M24

Liquid metal assisted cracking (LMAC) mainly occurs due to an unfavorable interaction of three factors: a susceptible material condition, presence of a liquid metal and sufficient tensile stress. Hot‐dip galvanizing of high‐strength bolts induces high thermal loads in bolts made of tempered steel in the presence of a zinc melt and thus, provides the boundary conditions for the above mentioned critical factors to interact. The focus of this study is on investigating thermally‐induced stresses in large diameter bolts and their impact on the formation of liquid metal assisted cracking (LMAC). In order to calculate the thermal loads in hot‐dip galvanizing, simulations were carried out regarding the thermo‐mechanical behavior of bolts during the hot‐dip galvanizing process. The simulations illustrate that cracks are most likely to occur in the first thread turn. This prediction is confirmed by experimental observations.     

Synthesen und Eigenschaften Mono- und diphenylsubstituierter Monothio-β-dicarbonylverbindungen und ihrer Nickel(II)chelate

Syntheses and Properties of Mono- and Disubstituted Monothio-β-dicarbonyl Compounds and their Nickel(II) chelates Reaction of phenylacetaldehyde with phosphorous oxichloride and dimethylformamide yielded 3-chloro-2-phenyl-propenal, which was converted into 2-phenyl-monothiomalonic dialdehyde 2 by treating with sodium sulfide nonahydrate. Furthermore the reactions of other mono- and diphenylsubstituted monothio-β-dicarbonyl compounds with aniline on the one side and nickel(II)acetate on the other side have been studied. It was shown, that compounds 1–6 react in different way with aniline yielding either sulfur free products or in case of 1 and 4 enaminothioketones, which are of interest as building blocks for syntheses. In contrast to this the nickel complexes of 1–6 indicates an one another similar, typical chelate structure, which have been elucidated by u.v.-vis-, i.r.- and x-ray photoelectron spectroscopy.