Structure-from-motion without correspondence from tomographic projections by Bayesian inversion theory

In conventional tomography, the interior of an object is reconstructed from tomographic projections such as X-ray or transmission electron microscope images. All the current reconstruction methods assume that projection geometry of the imaging device is either known or solved in advance by using e.g., fiducial or nonfiducial feature points in the images. In this paper, we propose a novel approach where the imaging geometry is solved simultaneously with the volume reconstruction problem while no correspondence information is needed. Our approach is a direct application of Bayesian inversion theory and produces the maximum likelihood or maximum a posteriori estimates for the motion parameters under the selected noise and prior distributions. In this paper, the method is implemented for a two-dimensional model problem with one-dimensional affine projection data. The performance of the method is tested with simulated and measured X-ray projection data.     

Characterization of oligo- and polysialic acids by MALDI-TOF-MS

Oligo- and polysialic acids (oligo/polySia) are characterized by a high diversity in nature due to the different types of sialic acids linked to each other and glycosidic linkages involved. Considering the methods that are presently available for analysis of oligo/polySia chains, only fluorometric anion-exchange high-performance liquid chromatography (HPLC) analysis, fluorometric C7/C9 detection, and western blotting are applicable to small amounts of material. Here we describe an alternative technique using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry after on-target lactonization to characterize different sialic acid polymers. The MS-based method allows a rapid, highly sensitive, and unambiguous identification of native as well as fluorescently labeled sialic acid polymers without the need of standard substances due to exact mass determination. PolySia chains with at least 100 sialic moieties are easily detectable, and in addition, potential modifications of hydroxyl groups by, for instance, acetyl residues can be precisely registered. Based on different lactonization characteristics, alpha2-8- and alpha2-9-linked oligo/polySia can be distinguished. Furthermore, this method can be combined with fluorometric derivatization and HPLC separation.     

Above 16% efficient sequentially grown Cu(In,Ga)(Se,S)2‐based solar cells with atomic layer deposited Zn(O,S) buffers

We report the development of Cd‐free buffers by atomic layer deposition for chalcopyrite‐based solar cells. Zn(O,S) buffer layers were prepared by atomic layer deposition on sequentially grown Cu(In,Ga)(Se,S)₂ absorbers from Bosch Solar CISTech GmbH. An externally certified efficiency of 16.1% together with an open circuit voltage of 612 mV were achieved on laboratory scale devices. Stability tests show that the behavior of the ALD‐Zn(O,S)‐buffered devices can be characterized as stable only showing a minor drift of the open circuit voltage and the fill factor. Copyright © 2015 John Wiley & Sons, Ltd.     

Characterisation of kinematic hardening and yield surface evolution from uniaxial to biaxial tension with continuous strain path change

With respect to multistage forming processes the material behaviour and the history of the strain path during the process is of special interest for the improvement of the numerical prediction of forming processes. While different researchers investigated the Bauschinger effect during a load reversal and biaxial loading with pre-strained specimens, in this paper the yield locus evolution in the first quadrant of the principles stress space under biaxial loading of a modified cruciform specimen without test interruption is presented. The movement of the yield surface centre caused by kinematic hardening is approximated by an alternative approach based on experimental results.     

Controlling a supplier’s subcontracting decisions through contractual enforcement or economic incentives

Suppliers often subcontract part of their workload to other suppliers, and manufacturers might suffer severe consequences if they do not anticipate their suppliers’ incentives to subcontract. In this paper, we study the case where a manufacturer outsources two tasks to a top-tier supplier. The manufacturer must decide whether it should design a contract that enforces that the different tasks are completed by the appropriate suppliers, and when it is preferable to use economic incentives to manipulate the top-tier supplier’s subcontracting behaviour. We find that when the cost difference between suppliers of different tiers is small and the correlation between the risks associated with the two tasks is minimal, the manufacturer can benefit from designing a contract that ensures the preferred subcontracting behaviour, if the cost of enforcing such a contract is not too high. However, when such enforcement cost is substantial, the manufacturer might be better off manipulating the top-tier supplier’s economic incentives.     

A flexible costing system for flexible manufacturing systems using activity based costing

Flexible manufacturing systems (FMSs) are designed to integrate the flexibility of job shops and the efficiency of mass production systems. Product costing methods have to adapt to this new technological environment. On one hand, the high production overhead cost of these systems requires a special attention to overhead allocation. On the other hand, the constantly changing setup configuration and production plans require a constant recalculation of overhead allocation and an a priori estimation of the expected production cost. This paper introduces the concept of flexible costing in FMSs, and proposes a method that modifies the overhead allocation based on the results of the production plan and on the simulated performance of the process. This approach is illustrated with some numerical examples.     

A heuristic based on Vogel's approximation method for sequencing mixed-model assembly lines

Sequencing mixed-model assembly lines is a well researched topic in the literature. However, many methods that have been developed to solve this problem fail to cope with either the large size or the specific characteristics of real-life problems. In this paper, a heuristic is proposed that is derived from Vogel's approximation method for transportation planning. The heuristic is able to handle large and supposedly difficult problem instances. Sophisticated test scenarios considering real-life aspects were generated to evaluate the performance of the heuristic for realistic problem instances. It is shown that the proposed heuristic significantly outperforms priority rule-based methods and requires only reasonable computational effort.     

Effect of glass fillers in Cu2ZnNb2O8 ceramics for advanced microwave applications

The effect of glass addition on sintering temperature and microwave dielectric properties of Cu₂ZnNb₂O₈ (CZN) is investigated for possible low temperature co-fired ceramic (LTCC) application. The CZN ceramic was prepared by the solid-state ceramic route. The phase formation, microstructure and elemental composition of the ceramics were studied using X-Ray Diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy and Energy Dispersive Analysis. The CZN sintered at 975 °C/4 h has ?_r = 15.2, tan δ = 0.0007 (at 5.1 GHz) and τ_f of −98 ppm °C⁻¹ and CTE = 1.9 ppm °C⁻¹. The addition of LBS and LMZBS glasses lowered the sintering temperature of CZN to below the melting point of silver. The 1 wt% LBS added CZN sintered at 935 °C/4 h had ?_r = 14.7, tan δ = 0.001 (at 5.1 GHz), τ_f = −19 ppm °C⁻¹ and CTE = −0.6 ppm °C⁻¹. The addition of 0.7 wt% LMZBS to CZN and sintered at 935 °C/4 h had ?_r = 14.8, tan δ = 0.002 (at 5.1 GHz), τ_f = −39 ppm °C⁻¹ and CTE = −0.9 ppm °C⁻¹.