Control Allocation for Double-ended Ferries with Full-scale Experimental Results

International Journal of Control, Automation and Systems - A novel control allocation algorithm for double-ended ferries with symmetrical thruster configuration is proposed. The allocation problem...     

Remote mobile manipulation with the centauro robot: Full‐body telepresence and autonomous operator assistance

Solving mobile manipulation tasks in inaccessible and dangerous environments is an important application of robots to support humans. Example domains are construction and maintenance of manned and unmanned stations on the moon and other planets. Suitable platforms require flexible and robust hardware, a locomotion approach that allows for navigating a wide variety of terrains, dexterous manipulation capabilities, and respective user interfaces. We present the CENTAURO system which has been designed for these requirements and consists of the Centauro robot and a set of advanced operator interfaces with complementary strength enabling the system to solve a wide range of realistic mobile manipulation tasks. The robot possesses a centaur‐like body plan and is driven by torque‐controlled compliant actuators. Four articulated legs ending in steerable wheels allow for omnidirectional driving as well as for making steps. An anthropomorphic upper body with two arms ending in five‐finger hands enables human‐like manipulation. The robot perceives its environment through a suite of multimodal sensors. The resulting platform complexity goes beyond the complexity of most known systems which puts the focus on a suitable operator interface. An operator can control the robot through a telepresence suit, which allows for flexibly solving a large variety of mobile manipulation tasks. Locomotion and manipulation functionalities on different levels of autonomy support the operation. The proposed user interfaces enable solving a wide variety of tasks without previous task‐specific training. The integrated system is evaluated in numerous teleoperated experiments that are described along with lessons learned.     

Methane Oxidation Over Pd Supported on Ceria–Alumina Under Rich/Lean Cycling Conditions

Catalysts with highly dispersed palladium on alumina, alumina doped with 20 wt% ceria and ceria have been prepared, characterized and examined for net-lean methane oxidation. In particular, the activity and selectivity were investigated during rich/lean cycling of the feed. The ceria content is found to influence both the general and the instantaneous activity responses. The results indicate that the active phase of palladium changes between reduced and oxidised Pd during the rich/lean cycling, and that the process is influenced by the presence of ceria.     

Mechanical Properties of Two Plain-Woven Chemical Vapor Infiltrated Silicon Carbide-Matrix Composites

The elastic and inelastic properties of a chemical vapor infiltrated (CVI) SiC matrix reinforced with either plain-woven carbon fibers (C/SiC) or SiC fibers (SiC/SiC) have been investigated. It has been investigated whether the mechanics of a plain weave can be described using the theory of a cross-ply laminate, because it enables a simple mechanics approach to the nonlinear mechanical behavior. The influences of interphase, fiber anisotropy, and porosity are included. The approach results in a reduction of the composite system to a fiber/matrix system with an interface. The tensile behavior is described by five damage stages. C/SiC can be modeled using one damage stage and a constant damage parameter. The tensile behavior of SiC/SiC undergoes four damage stages. Stiffness reduction due to transverse cracks in the transverse bundles is very different from cross-ply behavior. Compressive failure is initiated by interlaminar cracks between the fiber bundles. The crack path is dictated by the bundle waviness. For SiC/SiC, the compressive behavior is mostly linear to failure. C/SiC exhibits initial nonlinear behavior because of residual crack openings. Above the point where the cracks close, the compressive behavior is linear. Global compressive failure is characterized by a major crack oriented at a certain angle to the axial loading. In shear, the matrix cracks orientate in the principal tensile stress direction (i.e., 45° to the fiber direction) with very high crack densities before failure, but only SiC/SiC shows significant degradation in shear modulus. Hysteresis is observed during unloading/reloading sequences and increasing permanent strain.     

Assessing the value of patent portfolios: an international country comparison

Patent counts have been extensionally used to measure the innovative capacities of countries. However, since economic values of patents may differ, simple patent counts may give misleading rankings, if the patents of one country are on average more valuable than those of another. In the literature several methods have been proposed, which shall adjust for these differences. However, often these do not possess a solid economic micro-foundation and therefore are often ad-hoc and arbitrary procedures. In this paper, we intend to present an adjustment method that is based on the analysis of renewal decisions. The method builds on the theoretical model used in Schankerman and Pakes (1986) and Besson (2008) but goes beyond both approaches in that it recovers the important long tail of the value distribution. It also transfers Besson’s (2008) econometric methodology (applicable to the organisational structures of the US Patent and Trademark Office) also to the European Patent Office which is necessary, since each application here may split up into several national patent documents. The analysis is performed for 22 countries. Exemplarily, we find that in the cohort of 1986 patent applications, Danish patents are about 60% more valuable than the average patent. German patents are a bit below average. Japanese patents are of least value. In the cohort of 1996, Danish patents lose some of their lead but are still more valuable than the average. While German are a bit above average, Japanese patents even fall further behind (possibly due to the economic downturn in since the mid of 1990ies).     

The determinants of {alpha}-amylase pH-activity profiles

The glycosyl hydrolases present a large family of enzymes thatare of great significance for industry. Consequently, thereis considerable interest in engineering the enzymes in thisfamily for optimal performance under a range of very diverseconditions. Until recently, tailoring glycosyl hydrolases forspecific industrial processes mainly involved stability engineering,but lately there has also been considerable interest in engineeringtheir pH–activity profiles. We mutated four neutral residues(N190, F290, N326 and Q360) in the chimeric Bacillus Ba2     

Effects of hot spices on energy intake,appetite and sensory specific desires in humans

This study investigated the effect of hot spices on energy intake and appetite. Forty participants received five meals of fixed portion sizes, served with or without five hot spices followed by a buffet. Spices were used in doses perceived as moderately hot, ensuring that the meals were palatable. Food intake (kJ), appetite and liking (before, during, after the meal and after the buffet), mood (before, after the meal and after the buffet) and desire to eat sweet, sour, fatty, salty, bitter and hot foods (after the meal and after the buffet) were measured on 9-point scales. Hot spices did not affect energy intake (p > 0.05). Desire for sweet foods was increased by chili (0.6 point, p < 0.05) whereas desire to eat salty foods was decreased by mustard (1 point, p < 0.01), suggesting that hot spices can induce changes in sensory specific desires. Liking of the meals tended to increase during the buffet when compared to the relatively constant liking of the fixed starter meals, suggesting that traditional sensory specific satiety does not play a large role in determining eating behaviour with complex meals.     

Investigation of MBH4–VCl2, M = Li,Na or K

Systematic investigations of MBH₄−VCl₂, M = Li, Na, or K, 2:1 or 3:1, samples prepared by mechano-chemistry and different milling time in order to gain insight in the phase stability and search for novel borohydrides. The samples were investigated using powder X-ray diffraction and Raman spectroscopy. Subsequently, the samples were exposed to heat treatment and investigated by in-situ synchrotron radiation powder X-ray diffraction (SR-PXD). These studies reveal formation of numerous compounds during decomposition of the samples, which contrasts with previous investigations. In several cases the formed compounds were in a less well-crystalline state, which did not allow identification. One of the unidentified compounds was observed both in the LiBH₄−VCl₂ and NaBH₄−VCl₂ systems and appeared to decompose at T ∼ 190 °C and is assumed to be a new vanadium borohydride. Crystalline Li₂VCl₄ was observed, but a major fraction of the decomposition products appeared to be amorphous. The KBH₄−VCl₂ system revealed formation of well-crystalline solid solutions of K(BH₄)_1−xCl_x.