The influence of leader-keyman relations on combat crew effectiveness.

The relation between the leader's interpersonal attitudes and the effectiveness of military combat crews is investigated. Two types of leader attitudes are considered: a generalized attitude toward co-workers, derived by asking the S to predict personality test responses of most and least preferred co-workers; and, the leader's sociometric preference for a particular co-worker. Studies with B-29 bomber crews and Army tank crews indicate that psychological distance between accepted leaders and their keymen is related to effective teamwork. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of Wheel Surface Conditions on the Casting of Amorphous Metal Ribbons

The wetting of the liquid metal on the casting wheel surface is important in the continuous casting of amorphous metal ribbons. The wetting characteristics are substantially revealed by the wetting pattern on the wheel-side surface of the ribbon, which consists of areas of air pockets and areas of direct contact between metal and wheel. Experimental results will be presented regarding the effects of the condition of the casting wheel surface on the wetting pattern and the related interfacial phenomena such as the ribbon surface smoothness, the heat transfer at metal-wheel interface, and the separation of ribbon from the wheel. In particular, the mechanism of formation of the periodic ribbon surface defect known as “fish scale” and the elimination of this defect by changing the condition of the casting wheel surface will be discussed.     

Pose Estimation in Conformal Geometric Algebra Part I: The Stratification of Mathematical Spaces

2D-3D pose estimation means to estimate the relative position and orientation of a 3D object with respect to a reference camera system. This work has its main focus on the theoretical foundations of the 2D-3D pose estimation problem: We discuss the involved mathematical spaces and their interaction within higher order entities. To cope with the pose problem (how to compare 2D projective image features with 3D Euclidean object features), the principle we propose is to reconstruct image features (e.g. points or lines) to one dimensional higher entities (e.g. 3D projection rays or 3D reconstructed planes) and express constraints in the 3D space. It turns out that the stratification hierarchy [11] introduced by Faugeras is involved in the scenario. But since the stratification hierarchy is based on pure point concepts a new algebraic embedding is required when dealing with higher order entities. The conformal geometric algebra (CGA) [24] is well suited to solve this problem, since it subsumes the involved mathematical spaces. Operators are defined to switch entities between the algebras of the conformal space and its Euclidean and projective subspaces. This leads to another interpretation of the stratification hierarchy, which is not restricted to be based solely on point concepts. This work summarizes the theoretical foundations needed to deal with the pose problem. Therefore it contains mainly basics of Euclidean, projective and conformal geometry. Since especially conformal geometry is not well known in computer science, we recapitulate the mathematical concepts in some detail. We believe that this geometric model is useful also for many other computer vision tasks and has been ignored so far. Applications of these foundations are presented in Part II [36].Bodo Rosenhahn gained his diploma degree in Computer Science in 1999. Since then he has been pursuing his Ph.D. at the Cognitive Systems Group, Institute of Computer Science, Christian-Albrechts University Kiel, Germany. He is working on geometric applications of Clifford algebras in computer vision.Prof. Dr. Gerald Sommer received a diploma degree in physics from the Friedrich-Schiller-Universität Jena, Germany, in 1969, a Ph.D. degree in physics from the same university in 1975, and a habilitation degree in engineering from the Technical University Ilmenau, Germany, in 1988. Since 1993 he is leading the research group Cognitive Systems at the Christian-Albrechts-Universität Kiel, Germany. Currently he is also the scientific coordinator of the VISATEC project.     

Nutrient Composition of Larval Nectar Secretions from Three Species of Myrmecophilous Butterflies

A comparative chemical analysis of the larval nectar secretions and hemolymph from three unspecifically and facultatively ant-attended lycaenid species (Polyommatus coridon, P. icarus, and Zizeeria knysna) was performed by using high-performance liquid chromatography techniques. Sucrose was the main sugar component in all three species. In half of the samples of P. coridon, it was accompanied by glucose, whereas other sugars occurred only rarely. In P. icarus and Z. knysna, melezitose was the second-most important component, followed by fructose and glucose. Total sugar contents were 43.6 ± 14.8 g/l (mean ± SD) for P. coridon, 74.2 g/l for P. icarus, and 68.3 ± 22.6 g/l for Z. knysna. Up to 14 different identified amino acids were found in P. coridon nectar, with a total content of 9.7 ± 3.4 g/l. Leucine was always the major component (contributing 50% of overall amino acid content). Other important amino acids were tyrosine, proline, arginine, and phenylalanine. P. icarus nectar contained up to six amino acids with a total content of 1.2 g/l, dominated by tyrosine and phenylalanine. Z. knysna nectar contained alanine and proline, with only 0.3 ± 0.17 g/l total content. In the hemolymph of all species, up to 16 different amino acids occurred relatively regularly, with histidine dominating, followed by serine and proline. The amino acid pattern in hemolymph was considerably different from that of the nectar secretions. Larval diet weakly influenced P. coridon nectar sugars, and with a semisynthetic diet, a more homogeneous amino acid pattern was detected. Comparison with reports from other lycaenid species shows that secretions rich in amino acids are related to intimate, often obligate ant associations, whereas facultative, unspecific myrmecophiles rely on carbohydrates.     

Adaptive multivlevel methods in three space dimensions

We consider the approximate solution of self-adjoint elliptic problems in three space dimensions by piecewise linear finite elements with respect to a highly non-uniform tetrahedral mesh which is generated adaptively. The arising linear systems are solved iteratively by the conjugate gradient method provided with a multilevel preconditioner. Here, the accuracy of the iterative solution is coupled with the discretization error. As the performance of hierarchical bases preconditioners deteriorates in three space dimensions, the BPX preconditioner is used, taking special care of an efficient implementation. Reliable a posteriori estimates for the discretization error are derived from a local comparison with the approximation resulting from piecewise quadratic elements. To illustrate the theoretical results, we consider a familiar model problem involving reentrant corners and a real-life problem arising from hyperthermia, a recent clinical method for cancer therapy.     

Nanodroplet‐Containing Polymers for Efficient Low‐Power Light Upconversion

Sensitized triplet–triplet‐annihilation‐based photon upconversion (TTA‐UC) permits the conversion of light into radiation of higher energy and involves a sequence of photophysical processes between two dyes. In contrast to other upconversion schemes, TTA‐UC allows the frequency shifting of low‐intensity light, which makes it particularly suitable for solar‐energy harvesting technologies. High upconversion yields can be observed for low viscosity solutions of dyes; but, in solid materials, which are better suited for integration in devices, the process is usually less efficient. Here, it is shown that this problem can be solved by using transparent nanodroplet‐containing polymers that consist of a continuous polymer matrix and a dispersed liquid phase containing the upconverting dyes. These materials can be accessed by a simple one‐step procedure that involves the free‐radical polymerization of a microemulsion of hydrophilic monomers, a lipophilic solvent, the upconverting dyes, and a surfactant. Several glassy and rubbery materials are explored and a range of dyes that enable TTA‐UC in different spectral regions are utilized. The materials display upconversion efficiencies of up to ≈15%, approaching the performance of optimized oxygen‐free reference solutions. The data suggest that the matrix not only serves as mechanically coherent carrier for the upconverting liquid phase, but also provides good protection from atmospheric oxygen.