Management science in the era of smart consumer products: challenges and research perspectives

Smart products not only provide novel functionalities, but also may establish new business models, markets, or distribution channels, strengthen relationships with consumers, and/or add smart remote services. While many technical obstacles of such products have already been overcome, the broad market dissemination of smart products still poses some vital managerial challenges for decision makers. In this paper, we outline the technical potential and future trends of smart consumer products, discuss economic challenges in four scopes, namely, preference-based new product development, market analysis, supply chain design, and industry development, and, in particular, we highlight research perspectives for management science in this promising field.     

Imaging of the structure of the argon and neon dimer, trimer, and tetramer

We Coulomb explode argon and neon dimers, trimers, and tetramers by multiple ionization in an ultrashort 800 nm laser pulse. By measuring all momentum vectors of the singly charged ions in coincidence, we determine the ground state nuclear wave function of the dimer, trimer, and tetramer. Furthermore we retrieve the bond angles of the trimer in position space by applying a classical numerical simulation. For the argon and neon trimer, we find a structure close to the equilateral triangle. The width of the distribution around the equilateral triangle is considerably wider for neon than for argon.     

Tellurophenes with delocalized π-systems and their extended valence adducts

The π-conjugated 2,5-substituted tellurophene compounds 2,5-bis(2-(9,9-dihexylfluorene))tellurophene (1) and 2,5-diphenyltellurophene (3) were synthesized through ring closing reactions of 1,4-substituted butadiyne. The oxidative addition of Br(2) to tellurophene compounds 1 and 3 was studied through absorption spectroscopy, NMR, electrochemistry, X-ray crystallography, and density functional theory (DFT) calculations. When Br(2) adds to the tellurium center the absorption spectrum shifts to a lower energy. From electrochemistry and DFT calculations we show that this is caused by lowering the lowest unoccupied orbital. The highest occupied orbital is also lowered, but to a lesser extent. This shift in absorption spectrum and lowering of the oxidation potential can provide a method to modify tellurophene containing materials. The two-electron oxidative addition is promising for catalyzing energy storage reactions.     

Coulomb asymmetry in strong field multielectron ionization of diatomic molecules

We measure the angular distribution of an electron emitted by a strong elliptically polarized two-color laser field from exploding doubly charged molecular nitrogen. This angular distribution is vastly different for emission of the electron from the up-field core of the molecule as compared to that from the down-field core. The emission from the down-field core leads to a slight rotation with respect to the internuclear axis in the direction expected by the Coulomb effect of the remaining ion, while, for the emission from the up-field core, this direction is inversed. Our semiclassical simulations suggest that this unexpected angular distribution is caused by an initial longitudinal momentum of the electron freed by over-the-barrier ionization above the inner barrier in the molecule. The initial kinetic energy is in the range of the potential energy of the Stark-shifted orbital above the barrier.     

Spatial imaging of the H2(+) vibrational wave function at the quantum limit

We experimentally obtained a direct image of the nuclear wave functions of H(2)(+) by dissociating the molecule via electron attachment and determining the vibrational state using the cold target recoil ion momentum spectroscopy technique. Our experiment visualizes the nodal structure of different vibrational states. We compare our results to the widely used reflection approximation and to quantum simulations and discuss the limits of position measurements in molecules imposed by the uncertainty principle.     

Stable irregular dynamics in complex neural networks

Irregular dynamics in multidimensional systems is commonly associated with chaos. For infinitely large sparse networks of spiking neurons, mean field theory shows that a balanced state of highly irregular activity arises under various conditions. Here we analytically investigate the microscopic irregular dynamics in finite networks of arbitrary connectivity, keeping track of all individual spike times. For delayed, purely inhibitory interactions we demonstrate that any irregular dynamics that characterizes the balanced state is not chaotic but rather stable and convergent towards periodic orbits. These results highlight that chaotic and stable dynamics may be equally irregular.     

Mathematikgeschichte für Lehrer – Gründe und Beispiele

Zusammenfassung. Die folgenden überlegungen beinhalten ein Pl?doyer für die verbindliche Einführung einer Vorlesung über Mathematikgeschichte in die Lehrerbildung. Es wird dargestellt, warum eine solche Veranstaltung n?tig und wünschenswert ist. Dann wird an Beispielen gezeigt, was Inhalte und Botschaft sein k?nnten. In einem dritten Schritt wird eine p?dagogische Konzeption für die Einbeziehung historischer Inhalte in den Mathematikunterricht skizziert. Eingegangen am 15.5.1995 / Angenommen am 30.10.1995     

Light-polarization and intensity dependence of higher-order nonlinearities in excitonic FWM signals

A theory-experiment comparison for the intensity and polarization dependence of spectrally resolved transient four-wave-mixing signals is presented for a ZnSe single quantum well. Results for high intensities deviate from a simple model based on the optical Bloch equations for a five-level system whereas a microscopic theory for coherent excitonic and biexcitonic nonlinearities shows excellent agreement.Received: 8 July 2004, Published online: 14 December 2004PACS: 71.35.-y Excitons and related phenomena - 78.47. + p Time-resolved optical spectroscopies and other ultrafast optical measurements in condensed matter     

Efficient approximations of univariate nonlinearities for linear planning models

Univariate nonlinearities occur either if the variables or parameters of a planning model are nonlinear functions of time, or if linear functions of time are multiplied by each other. Moreover, cost functions or revenue functions consist in most cases of univariate nonlinear terms. These nonlinearities are approximated by several types of piecewise-linear functions either particularly or simultaneously. In the case of linearizing nonlinearities in the decision variables it should be mentioned that the results of the approximation can only be used for linear models, if the convexity of the set of feasible solutions is guaranteed. Since the approximating procedure is based on variable nodes, the fit may be improved by optimizing the positions of these nodes. Therefore, this approach yields a far better fit than an approximation on the basis of equidistant and fixed nodes. As the number of variables and restrictions in linearized models increases according to the number of approximating intervals, the number of nodes determines substantially the size of a LP-model and therefore the expenses of a planning approach. Using the procedure described here, the number of approximating intervals will be minimal at a given goodness of fit and the model's size may be effectively reduced. On the other hand, for a certain number of intervals the most efficient approximation is found.