279 research outputs found
Linear Convergence of Adaptively Iterative Thresholding Algorithms for Compressed Sensing
This paper studies the convergence of the adaptively iterative thresholding
(AIT) algorithm for compressed sensing. We first introduce a generalized
restricted isometry property (gRIP). Then we prove that the AIT algorithm
converges to the original sparse solution at a linear rate under a certain gRIP
condition in the noise free case. While in the noisy case, its convergence rate
is also linear until attaining a certain error bound. Moreover, as by-products,
we also provide some sufficient conditions for the convergence of the AIT
algorithm based on the two well-known properties, i.e., the coherence property
and the restricted isometry property (RIP), respectively. It should be pointed
out that such two properties are special cases of gRIP. The solid improvements
on the theoretical results are demonstrated and compared with the known
results. Finally, we provide a series of simulations to verify the correctness
of the theoretical assertions as well as the effectiveness of the AIT
algorithm.Comment: 15 pages, 5 figure
Fast time-stepping discontinuous Galerkin method for the subdiffusion equation
The nonlocality of the fractional operator causes numerical difficulties for
long time computation of the time-fractional evolution equations. This paper
develops a high-order fast time-stepping discontinuous Galerkin finite element
method for the time-fractional diffusion equations, which saves storage and
computational time. The optimal error estimate of the current time-stepping discontinuous Galerkin
method is rigorous proved, where denotes the number of time intervals,
is the degree of polynomial approximation on each time subinterval, is the
maximum space step, , is the order of finite element space, and
can be arbitrarily small. Numerical simulations verify the
theoretical analysis.Comment: 21 pages, 1 figure,4 table
Exploiting Visual Semantic Reasoning for Video-Text Retrieval
Video retrieval is a challenging research topic bridging the vision and
language areas and has attracted broad attention in recent years. Previous
works have been devoted to representing videos by directly encoding from
frame-level features. In fact, videos consist of various and abundant semantic
relations to which existing methods pay less attention. To address this issue,
we propose a Visual Semantic Enhanced Reasoning Network (ViSERN) to exploit
reasoning between frame regions. Specifically, we consider frame regions as
vertices and construct a fully-connected semantic correlation graph. Then, we
perform reasoning by novel random walk rule-based graph convolutional networks
to generate region features involved with semantic relations. With the benefit
of reasoning, semantic interactions between regions are considered, while the
impact of redundancy is suppressed. Finally, the region features are aggregated
to form frame-level features for further encoding to measure video-text
similarity. Extensive experiments on two public benchmark datasets validate the
effectiveness of our method by achieving state-of-the-art performance due to
the powerful semantic reasoning.Comment: Accepted by IJCAI 2020. SOLE copyright holder is IJCAI (International
Joint Conferences on Artificial Intelligence), all rights reserved.
http://static.ijcai.org/2020-accepted_papers.htm
Peran Daya Dukung Wilayah Terhadap Pengembangan USAha Peternakan Sapi Madura
Research conducted on the island of Madura. The aim of the research was analyzed the area-based development of beef cattle in Madura island. Primary research data was sourced from statistics in the Madura district in figures. Data was analyzed using Location Quotient (LQ) method. Data procesing conducted whith spreadsheet from Excel on Microsoft Windows 7. The results showed that the basis for the development of Madura cattle each regency were Pamekasan (sub-district Larangan, Pasean, Batumamar, Palengan, Proppo, Tlanakan, and Pegantenan), Sumenep (sub-district Gayam, Nonggunong and Batuputih), Bangkalan (subdistrict Kokop, Geger, Galis, Tanah Merah, and Blega) and Bangkalan (sub-district Ketapang, Sokobanah, Kedungdung, Sampang, Banyuates, Robatal, and Omben. Conclusion of the research was the development of Madura cattle concentrated in the base region of Madura cattle
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Cyclodepsipeptide Toxin Promotes the Degradation of Hsp90 Client Proteins through Chaperone-Mediated Autophagy
Promoting the degradation of Hsp90 client proteins by inhibiting Hsp90, an important protein chaperone, has been shown to be a promising new anticancer strategy. In this study, we show that an oxazoline analogue of apratoxin A (oz-apraA), a cyclodepsipeptide isolated from a marine cyanobacterium, promotes the degradation of Hsp90 clients through chaperone-mediated autophagy (CMA). We identify a KFERQ-like motif as a conserved pentapeptide sequence in the kinase domain of epidermal growth factor receptor (EGFR) necessary for recognition as a CMA substrate. Mutation of this motif prevents EGFR degradation by CMA and promotes the degradation of EGFR through the proteasomal pathway in oz-apraA–treated cells. Oz-apraA binds to Hsc70/Hsp70. We propose that apratoxin A inhibits Hsp90 function by stabilizing the interaction of Hsp90 client proteins with Hsc70/Hsp70 and thus prevents their interactions with Hsp90. Our study provides the first examples for the ability of CMA to mediate degradation of membrane receptors and cross talks of CMA and proteasomal degradation mechanisms
Process, microstructure and mechanical properties
Funding Information:
This work was supported by National Natural Science Foundation of China (Grant No. 51875168/52002112 ), Natural Science Foundation of Hebei Province (Grant No. E2019208089 ) and “Three-Three-Three Talent Project” Foundation of Hebei Province ( C20221022 ). Sichuan Province Science Funding for Distinguished Young Scholars ( 3NSFJQ0064 ). JPO acknowledges funding by national funds from FCT – Fundação para a Ciência e a Tecnologia, I.P., in the scope of the projects LA/P/0037/2020. Science and Technology Research Project of Colleges and Universities in Hebei Province (Grant No. BJK2022020 ).
Publisher Copyright:
© 2023 The AuthorsAiming to decouple the inherent relationship between mass transfer and heat transfer in traditional arc-based directed energy deposition, a novel heterogeneous multi-wire indirect arc directed energy deposition (DED) has been developed for in-situ synthesis of Al-Zn-Mg-Cu alloy components. Multi-wires (Al-Cu and Al-Mg) with a bypassing Zn wire have been used to replace the traditional homogeneous twin-wires. The process, microstructure and mechanical properties of the deposited Al-Zn-Mg-Cu alloy components obtained by multi-wire indirect arc DED were investigated. The results indicate that the wire feeding speed, current and angle between the two wires have a significant influence on the multi-wire indirect arc DED process. When the current was 200 A, the different wire feeding speeds could be used for both wires and the angle between them was 90°. The resulting indirect arc presented a ‘heart’ shape and allowed to obtain an Al-5.7Zn-3.4Mg-1.6Cu (wt%) alloy with a high deposition rate of 5.1 kg/h. The Al-5.7Zn-3.4Mg-1.6Cu alloy is mainly composed of α-Al, S (Al2CuMg), η (Mg (Al, Zn, Cu)2) and η′ phases. The composition and phases are in accordance with the 7xxx series aluminum alloys. The microstructure is dominated by columnar and equiaxed grains, and it has obvious periodic distribution along the building direction, which is related to the process thermal cycle. Fine second phases η′ are observed to precipitate during the manufacturing process. Furthermore, the average hardness, ultimate tensile strength and elongation of the fabricated material are 98.6 HV, 243.9 MPa and 5.9%, respectively. These mechanical properties are higher than those of as-cast 7050 aluminum alloy, thus showing the potential of this new process variant to fabricate high strength Al alloys in the as-deposited state. The fracture morphology exhibit features mainly associated to a ductile-like fracture, accompanied by some transgranular and partial cleavage fracture characteristics. This novel multi-wire indirect arc DED provides a new choice for arc-based directed energy deposition of Al-Zn-Mg-Cu alloys and shows great potential for the in-situ synthesis of other high-performance alloys.publishersversionpublishe
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