21 research outputs found
In-Hand Manipulation of Unknown Objects with Tactile Sensing for Insertion
In this paper, we present a method to manipulate unknown objects in-hand
using tactile sensing without relying on a known object model. In many cases,
vision-only approaches may not be feasible; for example, due to occlusion in
cluttered spaces. We address this limitation by introducing a method to
reorient unknown objects using tactile sensing. It incrementally builds a
probabilistic estimate of the object shape and pose during task-driven
manipulation. Our approach uses Bayesian optimization to balance exploration of
the global object shape with efficient task completion. To demonstrate the
effectiveness of our method, we apply it to a simulated Tactile-Enabled Roller
Grasper, a gripper that rolls objects in hand while collecting tactile data. We
evaluate our method on an insertion task with randomly generated objects and
find that it reliably reorients objects while significantly reducing the
exploration time
Dysregulation of PRMT5 in chronic lymphocytic leukemia promotes progression with high risk of Richter's transformation
: Richter's Transformation (RT) is a poorly understood and fatal progression of chronic lymphocytic leukemia (CLL) manifesting histologically as diffuse large B-cell lymphoma. Protein arginine methyltransferase 5 (PRMT5) is implicated in lymphomagenesis, but its role in CLL or RT progression is unknown. We demonstrate herein that tumors uniformly overexpress PRMT5 in patients with progression to RT. Furthermore, mice with B-specific overexpression of hPRMT5 develop a B-lymphoid expansion with increased risk of death, and Eµ-PRMT5/TCL1 double transgenic mice develop a highly aggressive disease with transformation that histologically resembles RT; where large-scale transcriptional profiling identifies oncogenic pathways mediating PRMT5-driven disease progression. Lastly, we report the development of a SAM-competitive PRMT5 inhibitor, PRT382, with exclusive selectivity and optimal in vitro and in vivo activity compared to available PRMT5 inhibitors. Taken together, the discovery that PRMT5 drives oncogenic pathways promoting RT provides a compelling rationale for clinical investigation of PRMT5 inhibitors such as PRT382 in aggressive CLL/RT cases
Robust aperiodic-disturbance rejection in an uncertain modified repetitive-control system
This paper concerns the problem of designing an EID-based robust output-feedback modified repetitive-control system (ROFMRCS) that provides satisfactory aperiodic-disturbance rejection performance for a class of plants with time-varying structured uncertainties. An equivalent-input-disturbance (EID) estimator is added to the ROFMRCS that estimates the influences of all types of disturbances and compensates them. A continuous-discrete two-dimensional model is built to describe the EID-based ROFMRCS that accurately presents the features of repetitive control, thereby enabling the control and learning actions to be preferentially adjusted. A robust stability condition for the closed-loop system is given in terms of a linear matrix inequality. It yields the parameters of the repetitive controller, the output-feedback controller, and the EID-estimator. Finally, a numerical example demonstrates the validity of the method
Efficient and continuous near-duplicate video detection
Online video steam data is surging to an unprecedented level. Massive video publishing and sharing impose heavy demands on continuous video near-duplicate detection for many novel video applications. This paper presents an accurate and accelerated system for video near-duplicate detection over continuous video streams. We propose to transform a high-dimensional video stream into a one-dimensional Video Trend Stream (VTS) tomonitor the continuous luminance changes of consecutive frames, based on which video similarity is derived. In order to do fast comparison and effective early pruning, a compact auxiliary signature named CutSig is proposed to approximate the video structure. CutSig explores cut distribution feature of the video structure and contributes to filter candidates quickly. To scan along a video stream in a rapid way, shot cuts with local maximum AI (average information) in a query video are used as reference cuts, and a skipping approach based on reference cut alignment is embedded for efficient acceleration. Extensive experimental results on detecting diverse near-duplicates in real video streams show the effectiveness and efficiency of our method. © 2010 IEEE
The Glutamate Receptor Plays a Role in Defense against Botrytis cinerea through Electrical Signaling in Tomato
Plant glutamate-like receptor genes (GLRs) are homologous to mammalian ionotropic glutamate receptors genes (iGluRs). Although GLRs have been implicated in plant defenses to biotic stress, the relationship between GLR-mediated plant immunity against fungal pathogens and electrical signals remains poorly understood. Here, we found that pretreatment with a GLR inhibitor, 6,7-dinitriquinoxaline-2,3-dione (DNQX), increased the susceptibility of tomato plants to the necrotrophic fungal pathogen Botrytis cinerea. Assessment of the glr3.3, glr3.5 and glr3.3/glr3.5 double-mutants upon B. cinerea infection showed that tomato GLR3.3 and GLR3.5 are essential for plant immunity against B. cinerea, wherein GLR3.3 plays the main role. Analysis of the membrane potential changes induced by glutamate (Glu) or glycine (Gly) revealed that amplitude was significantly reduced by knocking out GLR3.3 in tomato. While treatment with Glu or Gly significantly increased immunity against B. cinerea in wild-type plants, this effect was significantly attenuated in glr3.3 mutants. Thus, our data demonstrate that GLR3.3- and GLR3.5-mediated plant immunity against B. cinerea is associated with electrical signals in tomato plants
Automatic and Precise Localization and Cortical Labeling of Subdural and Depth Intracranial Electrodes
Object: Subdural or deep intracerebral electrodes are essential in order to precisely localize epileptic zone in patients with medically intractable epilepsy. Precise localization of the implanted electrodes is critical to clinical diagnosing and treatment as well as for scientific studies. In this study, we sought to automatically and precisely extract intracranial electrodes using pre-operative MRI and post-operative CT images.</p
Scanning optical microscopy for porosity quantification of additively manufactured components
Electron beam melting (EBM) is a representative powder-bed fusion additive manufacturing technology, which is suitable for producing near-net-shape metallic components with complex geometries and near-full densities. However, various types of pores are usually present in the additively manufactured components. These pores may affect mechanical properties, particularly the fatigue properties. Therefore, inspection of size, quantity and distribution of pores is critical for the process control and assessment of additively manufactured components. Here, we propose a method to quantify the pore size distribution and porosity of additively manufactured components by utilizing scanning optical microscopy. The advantages and limitations of the developed method are discussed based on the comparison study between Archimedes method, conventional optical microscopy and x-ray computed tomography. It is revealed that the new method exhibits the advantages of high precision (∼ 1.75 μm), more information, high repeatability and low time consumption (20 min/per sample). This provides a new metrology for measurement of not only pores but also micro-cracks, which are the common defects in additively manufactured components.ASTAR (Agency for Sci., Tech. and Research, S’pore