969 research outputs found
GelSlim: A High-Resolution, Compact, Robust, and Calibrated Tactile-sensing Finger
This work describes the development of a high-resolution tactile-sensing
finger for robot grasping. This finger, inspired by previous GelSight sensing
techniques, features an integration that is slimmer, more robust, and with more
homogeneous output than previous vision-based tactile sensors. To achieve a
compact integration, we redesign the optical path from illumination source to
camera by combining light guides and an arrangement of mirror reflections. We
parameterize the optical path with geometric design variables and describe the
tradeoffs between the finger thickness, the depth of field of the camera, and
the size of the tactile sensing area. The sensor sustains the wear from
continuous use -- and abuse -- in grasping tasks by combining tougher materials
for the compliant soft gel, a textured fabric skin, a structurally rigid body,
and a calibration process that maintains homogeneous illumination and contrast
of the tactile images during use. Finally, we evaluate the sensor's durability
along four metrics that track the signal quality during more than 3000 grasping
experiments.Comment: RA-L Pre-print. 8 page
Gate defined quantum dot realized in a single crystalline InSb nanosheet
Single crystalline InSb nanosheet is an emerging planar semiconductor
material with potential applications in electronics, infrared optoelectronics,
spintronics and topological quantum computing. Here we report on realization of
a quantum dot device from a single crystalline InSb nanosheet grown by
molecular-beam epitaxy. The device is fabricated from the nanosheet on a
Si/SiO2 substrate and the quantum dot confinement is achieved by top gate
technique. Transport measurements show a series of Coulomb diamonds,
demonstrating that the quantum dot is well defined and highly tunable. Tunable,
gate-defined, planar InSb quantum dots offer a renewed platform for developing
semiconductor-based quantum computation technology.Comment: 12 pages, 4 figure
Energy-Water Balance and Ecosystem Response to Climate Change in Southwest China
It is important to highlight energy-water balance and ecosystem response to climate changes. The change of water-energy balance and ecosystem due to climate change will affect the regional ecological and human living significantly, especially in Southwest China which is an ecologically fragile area. This chapter presents the retrieval methodology of parameters (reconstruction of vegetation index, land cover semi-automatic classification, a time series reconstruction of land surface temperature based on Kalman filter and precipitation interpolation based on thin plate smoothing splines), time-series analysis methodology (land cover change, vegetation succession and drought index) and correlate analysis methodology (correlation coefficient and principal component analysis). Then, based on the above method, remote sensing data were integrated, a time series analysis on a 30-year data was used to illustrate the water-energy balance and ecosystem variability in Southwest China. The result showed that energy-water balance and ecosystem (ecosystem structures, vegetation and droughts) have severe response to climate change
PASS-JOIN: A Partition-based Method for Similarity Joins
As an essential operation in data cleaning, the similarity join has attracted
considerable attention from the database community. In this paper, we study
string similarity joins with edit-distance constraints, which find similar
string pairs from two large sets of strings whose edit distance is within a
given threshold. Existing algorithms are efficient either for short strings or
for long strings, and there is no algorithm that can efficiently and adaptively
support both short strings and long strings. To address this problem, we
propose a partition-based method called Pass-Join. Pass-Join partitions a
string into a set of segments and creates inverted indices for the segments.
Then for each string, Pass-Join selects some of its substrings and uses the
selected substrings to find candidate pairs using the inverted indices. We
devise efficient techniques to select the substrings and prove that our method
can minimize the number of selected substrings. We develop novel pruning
techniques to efficiently verify the candidate pairs. Experimental results show
that our algorithms are efficient for both short strings and long strings, and
outperform state-of-the-art methods on real datasets.Comment: VLDB201
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