291 research outputs found
-Regression in the Arbitrary Partition Model of Communication
We consider the randomized communication complexity of the distributed
-regression problem in the coordinator model, for . In this
problem, there is a coordinator and servers. The -th server receives
and and the coordinator would like to find a -approximate
solution to . Here
for convenience. This model, where the data is
additively shared across servers, is commonly referred to as the arbitrary
partition model.
We obtain significantly improved bounds for this problem. For , i.e.,
least squares regression, we give the first optimal bound of
bits.
For ,we obtain an upper bound. Notably, for sufficiently large,
our leading order term only depends linearly on rather than
quadratically. We also show communication lower bounds of for and for . Our bounds considerably improve previous bounds due to (Woodruff et al.
COLT, 2013) and (Vempala et al., SODA, 2020)
Synthesis of Fe-MCM-41 Using Iron Ore Tailings as the Silicon and Iron Source
Highly ordered Fe-MCM-41 molecular sieve was successfully synthesized by using n-hexadecyl-trimethyl ammonium bromide (CTAB) as the template and the iron ore tailings (IOTs) as the silicon and iron source. X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), diffuse reflectance UV-visible spectroscopy, 29Si magic-angle spinning (MAS) nuclear magnetic resonance (NMR), and nitrogen adsorption/desorption were used to characterize the samples. The results showed that the mesoporous materials had highly ordered 2-dimensional hexagonal structure. The synthesized sample had high surface area, and part of iron atoms is retained in the framework with formation of tetrahedron after removal of the template by calcinations. The results obtained in the present work demonstrate the feasibility of employing iron ore tailings as a potential source of silicon and iron to produce Fe-MCM-41 mesoporous materials
Joint Beamforming Design for RIS-Assisted Integrated Sensing and Communication Systems
Integrated sensing and communication (ISAC) has been envisioned as a
promising technology to tackle the spectrum congestion problem for future
networks. In this correspondence, we investigate to deploy a reconfigurable
intelligent surface (RIS) in an ISAC system for achieving better performance.
In particular, a multi-antenna base station (BS) simultaneously serves multiple
single-antenna users with the assistance of a RIS and detects potential
targets. The active beamforming of the BS and the passive beamforming of the
RIS are jointly optimized to maximize the achievable sum-rate of the
communication users while satisfying the constraint of beampattern similarity
for radar sensing, the restriction of the RIS, and the transmit power budget.
An efficient alternating algorithm based on the fractional programming (FP),
majorization-minimization (MM), and manifold optimization methods is developed
to convert the resulting non-convex optimization problem into two solvable
sub-problems and iteratively solve them. Simulation studies illustrate the
advancement of deploying RIS in ISAC systems and the effectiveness of the
proposed algorithm.Comment: Accepted by IEEE TV
Cells derived from iPSC can be immunogenic — Yes or No?
The induced pluripotent stem cells (iPSCs), derived by ectopic expression of reprogramming factors in somatic cells, can potentially provide unlimited autologous cells for regenerative medicine. In theory, the autologous cells derived from patient iPSCs should be immune tolerant by the host without any immune rejections. However, our recent studies have found that even syngeneic iPSC-derived cells can be immunogenic in syngeneic hosts by using a teratoma transplantation model (Nature 474:212–215, 2011). Recently two research groups differentiated the iPSCs into different germ layers or cells, transplanted those cells to the syngeneic hosts, and evaluated the immunogenicity of those cells. Both of the two studies support our conclusions that some certain but not all tissues derived from iPSCs can be immunogenic, although they claimed either “negligible” or “lack of” immunogenicity in iPSC derivatives (Nature 494:100–104, 2013; Cell Stem Cell 12:407–412, 2013). To test the immunogenicity of clinically valuable cells differentiated from human iPSCs are emergently required for translation of iPSC technology to clinics
Business Process Text Sketch Automation Generation Using Large Language Model
Business Process Management (BPM) is gaining increasing attention as it has
the potential to cut costs while boosting output and quality. Business process
document generation is a crucial stage in BPM. However, due to a shortage of
datasets, data-driven deep learning techniques struggle to deliver the expected
results. We propose an approach to transform Conditional Process Trees (CPTs)
into Business Process Text Sketches (BPTSs) using Large Language Models (LLMs).
The traditional prompting approach (Few-shot In-Context Learning) tries to get
the correct answer in one go, and it can find the pattern of transforming
simple CPTs into BPTSs, but for close-domain and CPTs with complex hierarchy,
the traditional prompts perform weakly and with low correctness. We suggest
using this technique to break down a difficult CPT into a number of basic CPTs
and then solve each one in turn, drawing inspiration from the
divide-and-conquer strategy. We chose 100 process trees with depths ranging
from 2 to 5 at random, as well as CPTs with many nodes, many degrees of
selection, and cyclic nesting. Experiments show that our method can achieve a
correct rate of 93.42%, which is 45.17% better than traditional prompting
methods. Our proposed method provides a solution for business process document
generation in the absence of datasets, and secondly, it becomes potentially
possible to provide a large number of datasets for the process model extraction
(PME) domain.Comment: 10 pages, 7 figure
Streaming quantum state purification
Quantum state purification is the task of recovering a nearly pure copy of an
unknown pure quantum state using multiple noisy copies of the state. This basic
task has applications to quantum communication over noisy channels and quantum
computation with imperfect devices, but has only been studied previously for
the case of qubits. We derive an efficient purification procedure based on the
swap test for qudits of any dimension, starting with any initial error
parameter. Treating the initial error parameter and the dimension as constants,
we show that our procedure has sample complexity asymptotically optimal in the
final error parameter. Our protocol has a simple recursive structure that can
be applied when the states are provided one at a time in a streaming fashion,
requiring only a small quantum memory to implement
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