170 research outputs found
Diagnosis and Treatment of Unbalance about Power Plant Rotating Auxiliary Equipment
This paper introduces the characteristics of unbalanced fault and the handling method of rigid rotor unbalanced fault, and expounds the handling process of large fan unbalanced fault through two balancing cases, which can be used for reference to the fault analysis and handling of the unbalanced fault of power plant rotating auxiliary equipment
A Comprehensive Survey on Orbital Edge Computing: Systems, Applications, and Algorithms
The number of satellites, especially those operating in low-earth orbit
(LEO), is exploding in recent years. Additionally, the use of COTS hardware
into those satellites enables a new paradigm of computing: orbital edge
computing (OEC). OEC entails more technically advanced steps compared to
single-satellite computing. This feature allows for vast design spaces with
multiple parameters, rendering several novel approaches feasible. The mobility
of LEO satellites in the network and limited resources of communication,
computation, and storage make it challenging to design an appropriate
scheduling algorithm for specific tasks in comparison to traditional
ground-based edge computing. This article comprehensively surveys the
significant areas of focus in orbital edge computing, which include protocol
optimization, mobility management, and resource allocation. This article
provides the first comprehensive survey of OEC. Previous survey papers have
only concentrated on ground-based edge computing or the integration of space
and ground technologies. This article presents a review of recent research from
2000 to 2023 on orbital edge computing that covers network design, computation
offloading, resource allocation, performance analysis, and optimization.
Moreover, having discussed several related works, both technological challenges
and future directions are highlighted in the field.Comment: 18 pages, 9 figures and 5 table
A Radiation Viewpoint of Reconfigurable Reflectarray Elements: Performance Limit, Evaluation Criterion and Design Process
Reconfigurable reflectarray antennas (RRAs) have rapidly developed with
various prototypes proposed in recent literatures. However, designing wideband,
multiband, or high-frequency RRAs faces great challenges, especially the
lengthy simulation time due to the lack of systematic design guidance. The
current scattering viewpoint of the RRA element, which couples antenna
structures and switches during the design process, fails to address these
issues. Here, we propose a novel radiation viewpoint to model, evaluate, and
design RRA elements. Using this viewpoint, the design goal is to match the
element impedance to a characteristic impedance pre-calculated by switch
parameters, allowing various impedance matching techniques developed in
classical antennas to be applied in RRA element design. Furthermore, the
theoretical performance limit can be pre-determined at given switch parameters
before designing specific structures, and the constant loss curve is suggested
as an intuitive tool to evaluate element performance in the Smith chart. The
proposed method is validated by a practical 1-bit RRA element with degraded
switch parameters. Then, a 1-bit RRA element with wideband performance is
successfully designed using the proposed design process. The proposed method
provides a novel perspective of RRA elements, and offers a systematic and
effective guidance for designing wideband, multiband, and high-frequency RRAs.Comment: Accepted by IEEE Transactions on Antennas and Propagatio
CAMKs support development of acute myeloid leukemia.
BACKGROUND: We recently identified the human leukocyte immunoglobulin-like receptor B2 (LILRB2) and its mouse ortholog-paired Ig-like receptor (PirB) as receptors for several angiopoietin-like proteins (Angptls). We also demonstrated that PirB is important for the development of acute myeloid leukemia (AML), but exactly how an inhibitory receptor such as PirB can support cancer development is intriguing. RESULTS: Here, we showed that the activation of Ca (2+)/calmodulin-dependent protein kinases (CAMKs) is coupled with PirB signaling in AML cells. High expression of CAMKs is associated with a poor overall survival probability in patients with AML. Knockdown of CAMKI or CAMKIV decreased human acute leukemia development in vitro and in vivo. Mouse AML cells that are defective in PirB signaling had decreased activation of CAMKs, and the forced expression of CAMK partially rescued the PirB-defective phenotype in the MLL-AF9 AML mouse model. The inhibition of CAMK kinase activity or deletion of CAMKIV significantly slowed AML development and decreased the AML stem cell activity. We also found that CAMKIV acts through the phosphorylation of one of its well-known target (CREB) in AML cells. CONCLUSION: CAMKs are essential for the growth of human and mouse AML. The inhibition of CAMK signaling may become an effective strategy for treating leukemia
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