A magneto-sensitive skin for robots in space

The development of a robot arm proximity sensing skin that can sense intruding objects is described. The purpose of the sensor would be to prevent the robot from colliding with objects in space including human beings. Eventually a tri-mode system in envisioned including proximity, tactile, and thermal. To date the primary emphasis was on the proximity sensor which evolved from one based on magneto-inductive principles to the current design which is based on a capacitive-reflector system. The capacitive sensing element, backed by a reflector driven at the same voltage and in phase with the sensor, is used to reflect field lines away from the grounded robot toward the intruding object. This results in an increased sensing range of up to 12 in. with the reflector on compared with only 1 in. with it off. It is believed that this design advances the state-of-the-art in capacitive sensor performance

Magneto-inductive skin sensor for robot collision avoidance: A new development

Safety is a primary concern for robots operating in space. The tri-mode sensor addresses that concern by employing a collision avoidance/management skin around the robot arms. This rf-based skin sensor is at present a dual mode (proximity and tactile). The third mode, pyroelectric, will complement the other two. The proximity mode permits the robot to sense an intruding object, to range the object, and to detect the edges of the object. The tactile mode permits the robot to sense when it has contacted an object, where on the arm it has made contact, and provides a three-dimensional image of the shape of the contact impression. The pyroelectric mode will be added to permit the robot arm to detect the proximity of a hot object and to add sensing redundancy to the two other modes. The rf-modes of the sensing skin are presented. These modes employ a highly efficient magnetic material (amorphous metal) in a sensing technique. This results in a flexible sensor array which uses a primarily inductive configuration to permit both capacitive and magnetoinductive sensing of object; thus optimizing performance in both proximity and tactile modes with the same sensing skin. The fundamental operating principles, design particulars, and theoretical models are provided to aid in the description and understanding of this sensor. Test results are also given

Geometric Network Creation Games

Network Creation Games are a well-known approach for explaining and analyzing the structure, quality and dynamics of real-world networks like the Internet and other infrastructure networks which evolved via the interaction of selfish agents without a central authority. In these games selfish agents which correspond to nodes in a network strategically buy incident edges to improve their centrality. However, past research on these games has only considered the creation of networks with unit-weight edges. In practice, e.g. when constructing a fiber-optic network, the choice of which nodes to connect and also the induced price for a link crucially depends on the distance between the involved nodes and such settings can be modeled via edge-weighted graphs. We incorporate arbitrary edge weights by generalizing the well-known model by Fabrikant et al.[PODC'03] to edge-weighted host graphs and focus on the geometric setting where the weights are induced by the distances in some metric space. In stark contrast to the state-of-the-art for the unit-weight version, where the Price of Anarchy is conjectured to be constant and where resolving this is a major open problem, we prove a tight non-constant bound on the Price of Anarchy for the metric version and a slightly weaker upper bound for the non-metric case. Moreover, we analyze the existence of equilibria, the computational hardness and the game dynamics for several natural metrics. The model we propose can be seen as the game-theoretic analogue of a variant of the classical Network Design Problem. Thus, low-cost equilibria of our game correspond to decentralized and stable approximations of the optimum network design.Comment: Accepted at 31st ACM Symposium on Parallelism in Algorithms and Architectures (SPAA '19). 33 pages, 11 figure

Data analysis and summary for surfactant-polymer flooding based on oil field projects and laboratory data

Enhanced oil recovery screening is considered as an important first step towards evaluating a potential EOR technique for a candidate reservoir. A vast amount of research is continuously been conducted in EOR. Therefore, it is imperative to update the screening criteria regularly. This study involves updating the screening criteria for surfactant polymer flooding for field projects dataset and laboratory dataset. Many of the screening criteria for surfactant-polymer flooding in the literature were achieved on the basis of data collected from the EOR surveys published biennially in Oil & Gas Journals. However, these datasets contain problems like missing data and inconsistent data. Data quality has not been addressed in the previous works in the literature on screening criteria. The objective of this study was to update achieve a range for 42 surfactant-polymer projects after the data. Another comprehensive work of this study was to establish a range for laboratory dataset consisting of 200 experiments. Box-plots and Cross-plots were used to study the dataset for special cases or inconsistent data. Histograms and box-plots were used to exhibit the distribution of each parameter and present the range of the dataset. Eventually, the ranges for field projects were compared with the screening criteria previously published in the literature. Also, the developed screening criteria for laboratory work were compared with the developed screening criteria for oilfield projects --Abstract, page iii

Effect of epidural analgesia on the duration of labour and pains: a comparative study

Background: Epidural analgesia is regional anaesthesia that blocks pain in a particular region of the body. The use of Epidural Analgesia (EA) in labor is widespread in modern labor ward practice, and its benefits in terms of pain relief are well-recognized. Objective of this study was to study the effect of epidural analgesia on the duration of labour and pains.Methods: The present study was conducted on 60 women in the department of obstetrics and gynecology at Topiwala National Medical College, Mumbai during a period from October 2014 to January 2017. The women requesting EA were assigned as the study group (Group A - 30 cases) and women not receiving EA were included in the control group (Group B - 30 cases).Results: The duration of active phase of first and second stage of labour was found to be prolonged in patients who received EA as compared to control group. An increase in number of caesarean sections and requirement of oxytocin augmentation was found to be more in Group A as compared to Group B. There was no statistically significant difference in Apgar score of newborns at 1 min and 5 min in both the groups. The patients demanding epidural drug had better pain relief during labour. In Group A, 17% of patients and in Group B, 7% of patients had nausea and vomiting. Other side effects were minimal.Conclusions: Epidural analgesia is not a totally free of disadvantages, it is the most effective mode of pain relief available compared with other techniques. The addition of patient-controlled epidural analgesia and innovations using new technologies enhance patient satisfaction

Regulation of u-PAR gene expression by H2A.Z is modulated by the MEK–ERK/AP-1 pathway

The urokinase receptor (u-PAR) which is largely regulated at the transcriptional level has been implicated in tumor progression. In this study, we explored the epigenetic regulation of u-PAR and showed that the histone variant H2A.Z negatively regulates its expression in multiple cell lines. Chromatin immunoprecipitation assays revealed that H2A.Z was enriched at previously characterized u-PAR-regulatory regions (promoter and a downstream enhancer) and dissociates upon activation of gene expression by phorbol ester (PMA). Using specific chemical and dominant negative expression constructs, we show that the MEK–ERK signaling pathway terminating at AP-1 transcription factors intersects with the epigenetic control of u-PAR expression by H2A.Z. Furthermore, we demonstrate that two other AP-1 targets (MMP9 gene and miR-21 microRNA) are also H2A.Z regulated. In conclusion, our work demonstrates that (i) the expression of two genes and a microRNA all implicated in tumor progression are directly regulated by H2A.Z and (ii) MEK–ERK signaling terminating at AP-1 intersects with the epigenetic control of target gene expression by H2A.Z