Knitwear customisation as repeated redesign

Producing large numbers of garment variants will only be economically viable if it requires very little human effort. But garment customisation cannot always be fully automated. Applying grading rules maintain the same details but sometimes achieves a different overall effect; but the customer expects the same overall effect and is less concerned about details. Choosing between alternative customisations requires a human designer's trained perceptual judgement. Therefore a viable mass customisation support system must support the repeated redesign of a garment by combining automatic design with fast human editing. Evaluating and modifying the suggestions of others is a natural and efficient activity for designers. This paper describes two prototype automatic design systems exploring techniques that could be used for mass customisation of knitted garments – in which the shape and patterns are indivisibly linked. An early pattern placing system that automatically altered both shape and pattern parameters in a variety of alternative ways. A shape design system that generates technically correct and consistent garment shapes from a set of measurements and a verbal description; it works independently of sizes, recalculating the shape for each new set of measurements. Starting from the system's suggestions, designers can very quickly tweak the new design to fulfil their aesthetic intentions

Optimal Taxation in a Simple Model of Human Capital Accumulation

This paper studies optimal taxation in dynamic economies with a simple form of human capital accumulation as considered in Bull (1993). We show that in a Ramsey equilibrium along any balanced growth path, the taxes on wage income and (physical) capital income must be zero. Under the assumption on preferences of Bull (1993), we extend his result by showing that along a balanced growth all optimal taxes are necessarily zero.

References to past designs

Designing by adaptation is almost invariably a dominantambiguity feature of designing, and references to past designs are ubiquitous in design discourse. Object references serve as indices into designers' stocks of design concepts, in which memories for concrete embodiments and exemplars are tightly bound to solution principles. Thinking and talking by reference to past designs serves as a way to reduce the overwhelming complexity of complex design tasks by enabling designers to use parsimonious mental representations to which details can be added as needed. However object references can be ambiguous, and import more of the past design than is intended or may be desirable

A large energy-gap oxide topological insulator based on the superconductor BaBiO3

Mixed-valent perovskite oxides based on BaBiO3 (BBO) are, like cuperates, well-known high-Tc superconductors. Recent ab inito calculations have assigned the high-Tc superconductivity to a correlation-enhanced electron--phonon coupling mechanism, stimulating the prediction and synthesis of new superconductor candidates among mixed-valent thallium perovskites. Existing superconductivity has meant that research has mainly focused on hole-doped compounds, leaving electron-doped compounds relatively unexplored. Here we demonstrate through ab inito calculations that BBO emerges as a topological insulator (TI) in the electron-doped region, where the spin-orbit coupling (SOC) effect is significant. BBO exhibits the largest topological energy gap of 0.7 eV among currently known TI materials, inside which Dirac-type topological surface states (TSSs) exit. As the first oxide TI, BBO is naturally stable against surface oxidization and degrading, different from chalcoginide TIs. An extra advantage of BBO lies in its ability to serve an interface between the TSSs and the superconductor for the realization of Majorana Fermions

Sampling Sup-Normalized Spectral Functions for Brown-Resnick Processes

Sup-normalized spectral functions form building blocks of max-stable and Pareto processes and therefore play an important role in modeling spatial extremes. For one of the most popular examples, the Brown-Resnick process, simulation is not straightforward. In this paper, we generalize two approaches for simulation via Markov Chain Monte Carlo methods and rejection sampling by introducing new classes of proposal densities. In both cases, we provide an optimal choice of the proposal density with respect to sampling efficiency. The performance of the procedures is demonstrated in an example.Comment: 11 pages, 2 figure

Ambiguity is a double-edged sword: similarity references in communication

Designers often explain new concepts and new ideas by reference to existing designs. This is parsimonious, as it only requires a pointer to the referent and a description of the modifications. Such descriptions can be extremely powerful, expressing the entire context of a design or a process in a few words. However similarity assertions are inherently ambiguous, because they depend not only on the chosen description but also on the intention behind the similarity comparison. In this paper we attempt to analyse the effect that the ambiguity of similarity references has on communication and idea generation in design. The reinterpretation of a similarity assertion can be extremely creative, where ambiguity allows for new interpretations of a problem. At the same time, it can make accurate communication extremely difficult because every assertion can be interpreted differently unless the context is fully shared

Regional Origins of Employment Volatility: Evidence from German States

Openness for trade can have positive welfare effects in terms of higher growth. But increased openness may also increase uncertainty through a higher volatility of employment. We use regional data from Germany to test whether openness for trade has an impact on volatility. We find a downward trend in the unconditional volatility of employment, which has been interrupted by the re-unification period. Patterns are similar to those for output volatility. The conditional volatility of employment, measuring idiosyncratic developments across states, in contrast, has remained fairly unchanged. In contrast to evidence for the US, we do not find evidence for a significant link between employment volatility and trade openness.employment volatility, trade openness, regional labour markets

Mobility and Cooperation: On the Run

In public goods experiments where subjects may change groups, we observe a continual flight of the more cooperative subjects away from the less cooperative ones. The less cooperative subjects attempt to enter cooperative groups in order to free-ride on their contributions. Lorsque les sujets peuvent changer de groupes dans les expériences sur les contributions volontaires aux biens publics, nous observons que les sujets plus coopératifs délaissent les sujets moins coopératifs. De plus, ces derniers essaient de joindre les groupes coopératifs pour profiter comme resquilleurs de leurs contributions.Public goods, Tiebout hypothesis, migration, experimental economics, Biens publics, hypothèse de Tiebout, migration, économie expérimentale

Mean-field optimal control and optimality conditions in the space of probability measures

We derive a framework to compute optimal controls for problems with states in the space of probability measures. Since many optimal control problems constrained by a system of ordinary differential equations (ODE) modelling interacting particles converge to optimal control problems constrained by a partial differential equation (PDE) in the mean-field limit, it is interesting to have a calculus directly on the mesoscopic level of probability measures which allows us to derive the corresponding first-order optimality system. In addition to this new calculus, we provide relations for the resulting system to the first-order optimality system derived on the particle level, and the first-order optimality system based on $L^2$-calculus under additional regularity assumptions. We further justify the use of the $L^2$-adjoint in numerical simulations by establishing a link between the adjoint in the space of probability measures and the adjoint corresponding to $L^2$-calculus. Moreover, we prove a convergence rate for the convergence of the optimal controls corresponding to the particle formulation to the optimal controls of the mean-field problem as the number of particles tends to infinity