Learning of grasp selection based on shape-templates

The ability to grasp unknown objects still remains an unsolved problem in the robotics community. One of the challenges is to choose an appropriate grasp configuration, i.e., the 6D pose of the hand relative to the object and its finger configuration. In this paper, we introduce an algorithm that is based on the assumption that similarly shaped objects can be grasped in a similar way. It is able to synthesize good grasp poses for unknown objects by finding the best matching object shape templates associated with previously demonstrated grasps. The grasp selection algorithm is able to improve over time by using the information of previous grasp attempts to adapt the ranking of the templates to new situations. We tested our approach on two different platforms, the Willow Garage PR2 and the Barrett WAM robot, which have very different hand kinematics. Furthermore, we compared our algorithm with other grasp planners and demonstrated its superior performance. The results presented in this paper show that the algorithm is able to find good grasp configurations for a large set of unknown objects from a relatively small set of demonstrations, and does improve its performance over time.     

Spiropyran, chromene and spirooxazine, mélange á trois: Molecular logic systems through selective and reversible deactivation of photochromism mediated by CO2 gas

We report a new expanded molecular logic system based upon combinations of spiropyrans, spirooxazines and chromenes, whereby the photochromism of some molecules can be selectively preserved while reversibly deactivating the photochromism of others. The non-photochromic molecules can be reversibly activated by CO₂ gas. It was found that the photochromic effect of spiropyrans, in general, and one spirooxazine (with a hydroxyl group on the naphtho-ring) could be reversibly deactivated by DBU, while a chromene and an unsubstituted spirooxazine remained photochromic in the system under the same conditions. The presence of protic solvent was necessary for the deactivation of some of these photochromic molecules and hence it was used as an additional sensitizer in the system. This afforded the expansion of stimuli for molecular logic operations and allowed combinations of the benign stimuli of UV, visible light, CO₂, and CO₂ depleted with protic and aprotic solvents. This effect provided the mechanism for molecular logic systems that do not suffer from the usual problems of dilution effects and hence become truly reversible. This is highly significant when designing molecular switches to perform logic operations.     

Localization of trehalose in partially hydrated DOPC bilayers: insights into cryoprotective mechanisms

Trehalose, a natural disaccharide with bioprotective properties, is widely recognized for its ability to preserve biological membranes during freezing and dehydration events. Despite debate over the molecular mechanisms by which this is achieved, and that different mechanisms imply quite different distributions of trehalose molecules with respect to the bilayer, there are no direct experimental data describing the location of trehalose within lipid bilayer membrane systems during dehydration. Here, we use neutron membrane diffraction to conclusively show that the trehalose distribution in a dioleoylphosphatidylcholine (DOPC) system follows a Gaussian profile centred in the water layer between bilayers. The absence of any preference for localizing near the lipid headgroups of the bilayers indicates that the bioprotective effects of trehalose at physiologically relevant concentrations are the result of non-specific mechanisms that do not rely on direct interactions with the lipid headgroups.     

Voice Data Entry (VDE) training and Implementation Strategies

Current effort at Kennedy Space Center (KSC) involves implementation of voice data entry in the thermal Tile Processing System (TPS). Large amounts of data collection and recording along with the advancement in voice recognition and speech synthesis justified the introduction of a voice data entry system in support of TPS.

This paper presents a training and an implementation strategies for the VDE System in TPS at KSC. Training Strategies are tailored to different levels of the target population with varying objectives for the training sessions. Training scenarios and training manuals are designed to support the objectives of each session. A unique feature of the VDE is the fact that the “system” also needs to be trained for specific users.

Implementation strategy calls for parallel implementation for the current manual system over a period of four consecutive missions. This would be followed by gradual phasing out of the current manual system and phasing in of the VDE system over a span of three missions.

The methodologies used and the developed strategies can be used for the introduction of new technologies in general, and that related to voice and speech recognition in particular.     

Conceptual framework for decentralized green water‐infrastructure systems

We present a model for a decentralized green water‐infrastructure system (DGWIS) based on a new conceptual framework that optimises the use of captured rainwater, recycled wastewater and renewable energy resources. DGWIS is designed for building‐scale localised water supply systems that utilise rainwater and greywater and incorporate advanced small‐scale water treatment systems and renewable local energy sources such as solar and wind. Several constraints are considered: (i) available renewable energy; (ii) greywater production rate; (iii) potential captured rainwater; (iv) water demand; (v) water storage volumes required to accommodate greywater, harvested rainwater and separate water/energy supplies from the city and (vi) water treatment capacities. The proposed DGWIS optimisation framework demonstrates proof‐of‐concept and provides a solid foundation for an innovative paradigm shift towards water and energy sustainability.     

Investigating Morphology and Stability of Fac‐tris (2‐phenylpyridyl)iridium(III) Films for OLEDs

Stable film morphology is critical for long‐term high performance organic light‐emitting diodes (OLEDs). Neutron reflectometry (NR) is used to study the out‐of‐plane structure of blended thin films and multilayer structures comprising evaporated small molecules. It is found that as‐prepared blended films of fac‐tris(2‐phenylpyridyl)iridium(III) [Ir(ppy)₃] in 4,4′‐bis(N‐carbazolyl)biphenyl (CBP) are uniformly mixed, but the occurrence of phase separation upon thermal annealing is dependent on the blend ratio. Films comprised of the ratio of 6 wt% of Ir(ppy)₃ in CBP typically used in OLEDs are found to phase separate with moderate heating while a higher weight percent mixture (12 wt%) is found to be stable. Furthermore, it is found that thermal annealing of a multilayer film comprised of typical layers found in efficient devices ([tris(4‐carbazoyl‐9‐ylphenyl)amine (TCTA)/Ir(ppy)₃:CBP/bathocuproine (BCP)]) causes the BCP layer to become mixed with the emissive blend layer, whereas the TCTA interface remains unchanged. This significant structural change causes no appreciable difference in the photo­luminescence of the stack although such a change would have a dramatic effect on the charge transport through the device, leading to changes in performance. These results demonstrate the effect of thermal stress on the delicate interplay between the chemical composition and morphology of OLED films.     

A Simple Glycolipid Mimic of the Phosphatidylinositol Mannoside Core from Mycobacterium tuberculosis Inhibits Macrophage Cytokine Production

Glycolipids from Mycobacterium tuberculosis have a profound impact on the innate immune response of the host. Macrophage‐inducible C‐type lectin (Mincle) is a pattern‐recognition receptor that has been shown to bind trehalose dimycolate (TDM) from the mycobacterium and instigate intracellular signalling in the immune cell. There are structural similarities between the structures of TDM and phosphatidyl inositol mannoside (PIM). We thus hypothesized that these latter structures might also modulate an immune response in a similar manner. To test this, we synthesized a series of new mannose derivatives modified with fatty esters at the 6‐position and assessed the release of inflammatory cytokines in human U937 macrophages under the induction of lipopolysaccharides (LPS) after glycolipid treatment. The results showed that the amount of two major cytokines—tumour necrosis factor (TNF)‐α and interleukin (IL)‐6—released from LPS‐stimulated U937 cells decreased significantly when compared to a control upon treatment with the prepared glycolipids, thus indicating a reduction in cytokine production by the macrophages.     

Automatic detection of Moroccan coastal upwelling zones using sea surface temperature images

An efficient unsupervised method is developed for automatic segmentation of the area covered by upwelling waters in the coastal ocean of Morocco using the Sea Surface Temperature (SST) satellite images. The proposed approach first uses the two popular unsupervised clustering techniques, k-means and fuzzy c-means (FCM), to provide different possible classifications to each SST image. Then several cluster validity indices are combined in order to determine the optimal number of clusters, followed by a cluster fusion scheme, which merges consecutive clusters to produce a first segmentation of upwelling area. The region-growing algorithm is then used to filter noisy residuals and to extract the final upwelling region. The performance of our algorithm is compared to a popular algorithm used to detect upwelling regions and is validated by an oceanographer over a database of 92 SST images covering each week of the years 2006 and 2007. The results show that our proposed method outperforms the latter algorithm, in terms of segmentation accuracy and computational efficiency.     

High sodium continuous veno‐venous hemodialysis with regional citrate anticoagulation and online dialysate generation in patients with acute liver failure and cerebral edema

Introduction: Acute liver failure is associated with a high mortality rate. Induction of plasma hypertonicity with mannitol or hypertonic saline remains the cornerstone in the management of resultant cerebral edema. Significant disadvantages of this approach include poor or unpredictable control of serum sodium concentration and volume expansion, among others. Methods: We used high sodium continuous veno‐venous hemodialysis with regional citrate anticoagulation and online dialysate generation to accurately control the serum sodium in eleven patients with acute liver failure, renal failure, and cerebral edema. We used a Fresenius 2008 K/K2 machine in hemodialysis mode to deliver a blood flow of 60 ml/minute and dialysate flow of 400 ml/minute. Our previously published protocol results in complete removal of infused citrate by the dialyzer. On‐line clearance calculations were used to model the time required to reach the target serum sodium. Findings: All patients achieved serum sodium within 2 mEq/L of target without fluctuations or rebound. Nine patients survived without requiring liver transplantation and two died despite reaching the prescribed serum sodium target. We did not encounter any citrate toxicity. Discussion: We describe a novel approach for delivering continuous osmotherapy to patients with acute liver failure, renal failure, and cerebral edema. In comparison to standard therapy, the described modality enables precise titration of serum sodium without undesirable fluctuations in extracellular fluid volume. A particular advantage is zero delivery of citrate to this vulnerable group of patients with acute liver failure.     

A strategy for grasping unknown objects based on co-planarity and colour information

In this work, we describe and evaluate a grasping mechanism that does not make use of any specific object prior knowledge. The mechanism makes use of second-order relations between visually extracted multi-modal 3D features provided by an early cognitive vision system. More specifically, the algorithm is based on two relations covering geometric information in terms of a co-planarity constraint as well as appearance based information in terms of co-occurrence of colour properties. We show that our algorithm, although making use of such rather simple constraints, is able to grasp objects with a reasonable success rate in rather complex environments (i.e., cluttered scenes with multiple objects).Moreover, we have embedded the algorithm within a cognitive system that allows for autonomous exploration and learning in different contexts. First, the system is able to perform long action sequences which, although the grasping attempts not being always successful, can recover from mistakes and more importantly, is able to evaluate the success of the grasps autonomously by haptic feedback (i.e., by a force torque sensor at the wrist and proprioceptive information about the distance of the gripper after a gasping attempt). Such labelled data is then used for improving the initially hard-wired algorithm by learning. Moreover, the grasping behaviour has been used in a cognitive system to trigger higher level processes such as object learning and learning of object specific grasping.