Batch-Oriented Setting Time Optimisation in an Aerodynamic Feeding System

The change of conditions for production companies in high-wage countries is characterized by the globalization of competition and the transition of a supplier´s to a buyer´s market. The companies need to face the challenges of reacting flexibly to these changes. Due to the significant and increasing degree of automation, assembly has become the most expensive production process. Regarding the reduction of production cost, assembly consequently offers a considerable rationalizing potential. Therefore, an aerodynamic feeding system has been developed at the Institute of Production Systems and Logistics (IFA), Leibniz Universitaet Hannover. This system has been enabled to adjust itself by using a genetic algorithm. The longer this genetic algorithm is executed the better is the feeding quality. In this paper, the relation between the system´s setting time and the feeding quality is observed and a function which enables the user to achieve the minimum of the total feeding time is presented

A vector equilibrium problem for the two-matrix model in the quartic/quadratic case

We consider the two sequences of biorthogonal polynomials (p_{k,n})_k and (q_{k,n})_k related to the Hermitian two-matrix model with potentials V(x) = x^2/2 and W(y) = y^4/4 + ty^2. From an asymptotic analysis of the coefficients in the recurrence relation satisfied by these polynomials, we obtain the limiting distribution of the zeros of the polynomials p_{n,n} as n tends to infinity. The limiting zero distribution is characterized as the first measure of the minimizer in a vector equilibrium problem involving three measures which for the case t=0 reduces to the vector equilibrium problem that was given recently by two of us. A novel feature is that for t < 0 an external field is active on the third measure which introduces a new type of critical behavior for a certain negative value of t. We also prove a general result about the interlacing of zeros of biorthogonal polynomials.Comment: 60 pages, 9 figure

Identification of Influencing Variables of Demand-oriented Measures for Volume Flexibility

Abstract The appropriate response to fluctuating demand situations is a major challenge manufacturing companies currently have to face these days. In particular, the selection of appropriate measures to adapt the production system efficiently is difficult. In order to handle an expected demand fluctuation, the goal is to reply the question about the optimal adjustment time of production systems in combination with measures of capacity synchronization. By the identification of influencing variables this optimum can be found for individual measures as well as for measure combinations. With the help of dynamic capacity envelopes, a pragmatic visualization is provided as well

To know or not to know: archiving and the under-appreciated historical value of data

Surplus goods, produced by a community, allow individuals to dedicate their efforts to abstract problems, while enjoying the benefits of support from the community. In return, the community benefits from the intellectual work, say, efficiently producing goods or profound medical aid. In further elevating quality of life, we need to understand nature and biology on the most detailed level. Inevitably, research costs are increasing along with the need for more scientists to specialize their efforts. As a result, a vast amount of data and information is generated that needs to be archived and made openly accessible with the permission to re-use and re-distribute. With economies undergoing crises and prosperity in an almost cyclic manner, it seems that funding for science and technology follows a similar pattern. Another aspect to the problem of the loss of data is the human propensity, at the level of each individual researcher, to passively discard data in the course of daily life and through a career. In a typical laboratory, significant amounts of information is still stored on disks in file cabinets or on isolated computers, and is lost when a research group disbands. Being conscientious to one's data, to see that it reaches a place in which it can persist beyond the lifespan of any one individual requires responsibility on the part of its creator

Metrical Diophantine approximation for quaternions

Analogues of the classical theorems of Khintchine, Jarnik and Jarnik-Besicovitch in the metrical theory of Diophantine approximation are established for quaternions by applying results on the measure of general `lim sup' sets.Comment: 30 pages. Some minor improvement

Explanatory models in the processing of science text: The role of prior knowledge activation through small-group discussion

Two experiments assessed effects of activation of prior knowledge through small-group discussion. Subjects were given a description of natural phenomena and were asked to elaborate on possible explanations for them. In Experiment 1, small groups of subjects were presented with a problem describing the behavior of a blood cell in pure water and in a salt solution. No additional text was studied. The experimental subjects produced more than twice as many propositions about osmosis (i.e. the biological process explaining the blood cell's behavior) as a control group produced. Experiment 2 investigated effects of problem analysis on subsequent text processing for subjects with imprecise prior knowledge (novices) and subjects with precise knowledge (experts). Recall of the text showed considerable facilitative effects of problem analysis. Results are explained in terms of faster accessibility of prior knowledge and better integration of new information into explanatory models that may exist before, or are actively constructed during, problem analysis

Basalt-trachybasalt samples in Gale Crater, Mars

The ChemCam instrument on the Mars Science Laboratory (MSL) rover, Curiosity, observed numerous igneous float rocks and conglomerate clasts, reported previously. A new statistical analysis of single-laser-shot spectra of igneous targets observed by ChemCam shows a strong peak at ~55 wt% SiO2 and 6 wt% total alkalis, with a minor secondary maximum at 47–51 wt% SiO2 and lower alkali content. The centers of these distributions, together with the rock textures, indicate that many of the ChemCam igneous targets are trachybasalts, Mg#=27 but with a secondary concentration of basaltic material,with a focus of compositions around Mg#=54. We suggest that all of these igneous rocks resulted from low-pressure, olivine-dominated fractionation of Adirondack (MER) class-type basalt compositions. This magmatism has subalkaline, tholeiitic affinities. The similarity of the basalt endmember to much of the Gale sediment compositions in the first 1000 sols of the MSL mission suggests that this type of Fe-rich, relatively low-Mg#, olivine tholeiite is the dominant constituent of the Gale catchment that is the source material for the fine-grained sediments in Gale. The similarity to many Gusev igneous compositions suggests that it is a major constituent of ancient Martian magmas, and distinct from the shergottite parental melts thought to be associated with Tharsis and the Northern Lowlands. The Gale Crater catchment sampled a mixture of this tholeiitic basalt along with alkaline igneous material, together giving some analogies to terrestrial intraplate magmatic provinces

Observation of enhanced chiral asymmetries in the inner-shell photoionization of uniaxially oriented methyloxirane enantiomers

Most large molecules are chiral in their structure: they exist as two enantiomers, which are mirror images of each other. Whereas the rovibronic sublevels of two enantiomers are almost identical, it turns out that the photoelectric effect is sensitive to the absolute configuration of the ionized enantiomer - an effect termed Photoelectron Circular Dichroism (PECD). Our comprehensive study demonstrates that the origin of PECD can be found in the molecular frame electron emission pattern connecting PECD to other fundamental photophysical effects as the circular dichroism in angular distributions (CDAD). Accordingly, orienting a chiral molecule in space enhances the PECD by a factor of about 10

Sex-Specific Hip Movement Is Correlated With Pelvis and Upper Body Rotation During Running

There is a sex bias for common overuse running injuries that are associated with sex-specific hip kinematics. Gait retraining programs aimed at altering hip kinematics may be more efficient if they incorporated an understanding of how hip kinematics are correlated with the movement of the remaining body segments. We applied a principal component analysis to structure the whole-body running kinematics of 23 runners (12 ♀) into k = 12 principal movements (PMk), describing correlated patterns of upper and lower body movements. We compared the time-dependent movement amplitudes with respect to each PMk between males and females using a waveform analysis and interpreted our findings according to stick figure animations. The movement amplitudes of two PMs (PM6 and PM8) showed statistically significant effects of “sex,” which were independent of running speed. According to PM8, females showed more hip adduction, which correlated with increased transverse rotation of the pelvis and upper body compared to men. We propose that increased hip adduction and upper body rotation in female runners may be a strategy to compensate for a less efficient arm and upper body swing compared to men. Gait interventions aimed at reducing hip adduction and running-related injuries in female runners should consider instructions for both upper and lower body to maximize training efficacy

Vision enhancement for maritime search and rescue operations at night and bad weather conditions

During search and rescue operations (SAR) at night and bad weather conditions, the detection of persons in water represents a major challenge. When conventional searchlights are used, the backscattering from rain and fog decreases the detection range. For these conditions, the transportable angegated viewing system (TRAGVIS) was developed, aiming to reduce the effect of backscatter, in particular from close ranges (up to several hundred meters). After data acquisition, image post processing techniques were applied. The objective of the study presented here is to enchance the vision of the image for better object recognition by the operator. In addition automatic object detection methods were tested