11,873 research outputs found
Learning the dynamics and time-recursive boundary detection of deformable objects
We propose a principled framework for recursively segmenting deformable objects across a sequence
of frames. We demonstrate the usefulness of this method on left ventricular segmentation across a cardiac
cycle. The approach involves a technique for learning the system dynamics together with methods of
particle-based smoothing as well as non-parametric belief propagation on a loopy graphical model capturing
the temporal periodicity of the heart. The dynamic system state is a low-dimensional representation
of the boundary, and the boundary estimation involves incorporating curve evolution into recursive state
estimation. By formulating the problem as one of state estimation, the segmentation at each particular
time is based not only on the data observed at that instant, but also on predictions based on past and future
boundary estimates. Although the paper focuses on left ventricle segmentation, the method generalizes
to temporally segmenting any deformable object
Rules-based international order and US Indo-Pacific strategy: what does it mean for China's BRI?
The third decade of the 21st century has witnessed more tensions, instabilities, and new alliances in the Indo-Pacific/Asia-Pacific region due to intensifying rivalry and strategic competition between the US Indo-Pacific Strategy (IPS) and China's Belt and Road Initiative (BRI), two grand strategies of the US and China respectively. This article aims to assess the Rules-Based International Order (RBIO) and comprehend Biden's IPS, particularly exploring how the Indo-Pacific Economic Framework (IPEF) may impact China's BRI. This paper argues that RBIO is debatable and not universal. It is also argued that while the IPEF unveiled by President Biden represents a strategically important step forward, a long-term US genuine commitment to its implementation to counter China's BRI is essential. The methodology of this research is primarily based on secondary literature and official documents. This study concludes that although China is reluctant to pay too much attention to the US IPEF in its official statements, China is concerned about this economic initiative. The paper also concludes that because of the intense US-China rivalry, new alliances will emerge in the region leading to a new cold war or new world order
Breast Pump for Low-Resource Settings
ME450 Capstone Design and Manufacturing Experience: Winter 2015Exclusive breastfeeding for the first six months of life is highly recommended by the United Nations Children’s Fund (UNICEF) and World Health Organization (WHO) based on its extraordinary range of benefits to both mothers and children. However, only 15% of infants aged 0 to 6 months in some least developed countries such as Nigeria and only 38% of infants worldwide are exclusively breastfed. The low breastfeeding rates are due in large part to a mother’s need to return to work, where mothers have no access to breastfeeding or expressing breast milk at work. Existing commercial grade and personal-use breast pumps are cost prohibitive and difficult to maintain for mothers in low-resource settings where clean water is a challenge and electricity is not available. Therefore, the team designed and prototyped a cheap, easy to clean, and easy to maintain breast pump for working mothers in low-resource settings.http://deepblue.lib.umich.edu/bitstream/2027.42/111327/1/09_Report.pd
A Hybrid Mechanism Forming a 2:1 Librating-Circulating Resonant Configuration in the Planetary System
A diversity of resonance configurations may be formed under different
migration of two giant planets. And the researchers show that the HD 128311 and
HD 73526 planetary systems are involved in a 2:1 mean motion resonance but not
in apsidal corotation, because one of the resonance argument circulates over
the dynamical evolution. In this paper, we investigate potential mechanisms to
form the 2:1 librating-circulating resonance configuration.
In the late stage of planetary formation, scattering or colliding among
planetesimals and planetary embryos can frequently occur. Hence, in our model,
we consider a planetary configuration of two giants together with few
terrestrial planets. We find that both colliding or scattering events at very
early stage of dynamical evolution can influence the configurations trapped
into resonance. A planet-planet scattering of a moderate terrestrial planet, or
multiple scattering of smaller planets in a crowded planetary system can change
the resonant configuration. In addition, collision or merging can alter the
masses and location of the giant planets, which also play an important role in
shaping the resonant configuration during the dynamical evolution. In this
sense, the librating-circulating resonance configuration is more likely to form
by a hybrid mechanism of scattering and collision.Comment: 8 pages, 5 figures, 2 Tables, accepted for publication in MNRA
SIVALHIPPUS PTYCHODUS AND SIVALHIPPUS PLATYODUS (PERISSODACTYLA, MAMMALIA) FROM THE LATE MIOCENE OF CHINA
Herein, the authors report on skulls, mandibles and postcranial specimens of two species of Chinese Sivalhippus, S. ptychodus and S. platyodus. We frame our description and analyses within the context of newly described characters of the cheek teeth of Hippotherium from the Pannonian C of the Vienna Basin, the oldest and most primitive Old World hipparions. Our report includes original skull, mandibular and limited postcranial material of Sivalhippus ptychodus and skulls and dentitions of Sivalhippus platyodus from the Paleontological Museum of Uppsala (PMU, Uppsala, Sweden), the American Museum of Natural History (AMNH, New York, USA) and the Licent Collection in Tianjin Natural History Museum (Tianjin, China). The skull, maxillary and mandibular material we attribute to Sivalhippus ptychodus and Sivalhippus platyodus exhibit some primitive features for Old World hipparions and synapamorphies of the face and dentition that unite it with the Sivalhippus clade. Our analysis shows that S. ptychodus and S. platyodus differ significantly from the Cormohipparion occidentale – Hippotherium primigenium clade. Species belonging to the Sivalhippus clade are found in IndoPakistan (S. nagriensis, S. theobaldi, S. perimensis and S. anwari), Libya and Kenya (S. turkanensis) and Uganda (S. macrodon). We hypothesize that the Sivalhippus clade originated in South Asia where it is earliest represented by Sivalhipus nagriensis, ca. 10.4 Ma and underwent range extension into Africa and China circa 9-7 Ma
Temporal Changes in the Observed Relationship between Cloud Cover and Surface Air Temperature
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