3,323 research outputs found
MU-MIMO Communications with MIMO Radar: From Co-existence to Joint Transmission
Beamforming techniques are proposed for a joint multi-input-multi-output
(MIMO) radar-communication (RadCom) system, where a single device acts both as
a radar and a communication base station (BS) by simultaneously communicating
with downlink users and detecting radar targets. Two operational options are
considered, where we first split the antennas into two groups, one for radar
and the other for communication. Under this deployment, the radar signal is
designed to fall into the null-space of the downlink channel. The communication
beamformer is optimized such that the beampattern obtained matches the radar's
beampattern while satisfying the communication performance requirements. To
reduce the optimizations' constraints, we consider a second operational option,
where all the antennas transmit a joint waveform that is shared by both radar
and communications. In this case, we formulate an appropriate probing
beampattern, while guaranteeing the performance of the downlink communications.
By incorporating the SINR constraints into objective functions as penalty
terms, we further simplify the original beamforming designs to weighted
optimizations, and solve them by efficient manifold algorithms. Numerical
results show that the shared deployment outperforms the separated case
significantly, and the proposed weighted optimizations achieve a similar
performance to the original optimizations, despite their significantly lower
computational complexity.Comment: 15 pages, 15 figures. This work has been submitted to the IEEE for
possible publication. Copyright may be transferred without notice, after
which this version may no longer be accessibl
Early Detection and Diagnosis of Chronic Kidney and Breast Cancer Using Multi-level Machine Learning: A Hybrid Prediction Model
In this study, a multilevel machine learning approach is proposed for the early detection and diagnosis of chronic kidney disease (CKD) and breast cancer. The proposed hybrid prediction model uses a combination of supervised and unsupervised machine learning techniques, including Long Short-Term Memory (LSTM) and random forest algorithms, to improve the early detection and diagnosis of these diseases. The model also includes a feature selection process to extract the most relevant features from the data. The performance of the proposed model was evaluated on a dataset of patient information and compared with other machine learning models and traditional diagnostic methods. The results show that the proposed model outperforms traditional diagnostic methods and other machine learning models in terms of accuracy, sensitivity, and specificity in the early detection and diagnosis of CKD and breast cancer. The proposed multilevel machine learning approach provides an effective way to improve the early detection and diagnosis of CKD and breast cancer and has the potential to be used in clinical practice to improve patient outcomes
Integrability of SLE via conformal welding of random surfaces
We demonstrate how to obtain integrable results for the Schramm-Loewner
evolution (SLE) from Liouville conformal field theory (LCFT) and the
mating-of-trees framework for Liouville quantum gravity (LQG). In particular,
we prove an exact formula for the law of a conformal derivative of a classical
variant of SLE called . Moreover, we prove
that the SLE loop measure constructed by Zhan (2020) arises naturally from the
conformal welding of two quantum disks in LQG. Our proofs are built on two
connections between SLE, LCFT, and mating-of-trees. Firstly, LCFT and
mating-of-trees provide equivalent but complementary methods to describe
natural random surfaces in LQG. We extend earlier equivalence results in two
directions, namely by allowing fewer marked points and more generic
singularities. Secondly, the conformal welding of these random surfaces
produces SLE curves as their interfaces. In particular, we rely on the
conformal welding results proved in our companion paper [AHS20]. Our paper is
an essential part of a program proving integrability results for SLE, LCFT, and
mating-of-trees based on these two connections.Comment: 57 pages, 4 figure
Nothing but Being There Matters: Expectancy-Value Motivation Between U.S. and Chinese Middle School Students
Current literature theorizes that culture-induced expectancy beliefs and values in learning may engage learners of varied cultures in differentiated motivational processes. The purpose of the study was to determine the extent to which U.S. and Chinese middle school students differed in expectancy-value motivation in physical education. Middle school students from the U.S. (n = 813, 14 schools) and China (n = 806, 8 schools) provided data on expectancy-value motivation in physical education. A MANOVA with country as the independent factor and grade level as covariate revealed that the U.S. students held higher expectancy beliefs (p =.001, η2=.62), while the Chinese students showed stronger appreciation for the attainment (p =.001, η2=.33) and utility values (p =.001, η2=.35). The students from both countries equally appreciated the intrinsic value (p =.45). A canonical correlation analysis demonstrated that the expectancy-value motivation declined with age/grade increase at the same pace regardless of culture. These findings clarify for us the cultural influence or non-cultural influence on the expectancy-value motivation in middle school students. They inform us about the potential to develop intrinsic-value based across-cultural motivation strategies as well as the cultural sensitivity of applying motivation strategies focusing on expectancy of success, attainment value, and utility value
The Impact of Rural Pensions in China on Labor Migration
We study the impact of China’s new rural pension program on promoting migration of labor by applying a regression discontinuity analysis to this new pension program. The results reveal a perceptible difference in labor migration among adult children whose parents are just above and below the age of pension eligibility: The adult children with a parent just attaining the pension-eligible age are more likely to be labor migrants compared with those with a parent just below the pension-eligible age. We also find that with a pension-eligible parent, the adult children are more likely to have off-farm jobs. These abrupt changes in household behavior at the cutoff suggest that these households are credit constrained. In addition, we find that the pension’s effect on migration is greater among adult children with a parent in poor health; pension-eligible elderly report that they are more likely to use inpatient services when needed and less likely to rely on adult children for care when they are ill. These results suggest that (expectations regarding) providing care for elderly parents has constrained labor migration from China\u27s rural areas to some extent, and that the new rural pension program has helped to relax this constraint
Quantum triangles and imaginary geometry flow lines
We define a three-parameter family of random surfaces in Liouville quantum
gravity (LQG) which can be viewed as the quantum version of triangles. These
quantum triangles are natural in two senses. First, by our definition they
produce the boundary three-point correlation functions of Liouville conformal
field theory on the disk. Second, it turns out that the laws of the triangles
bounded by flow lines in imaginary geometry coupled with LQG are given by these
quantum triangles. In this paper we demonstrate the second point for boundary
flow lines on a quantum disk. Our method has the potential to prove general
conformal welding results with quantum triangles glued in an arbitrary way.
Quantum triangles play a basic role in understanding the integrability of SLE
and LQG via conformal welding. In this paper, we deduce integrability results
for chordal SLE with three force points, using the conformal welding of a
quantum triangle and a two-pointed quantum disk. In a subsequent work we will
explore their applications to the mating-of-trees framework of LQG, including
the exact evaluation of the expected proportion of inversions in skew Brownian
permutons.Comment: 52 pages, 20 figure
FZZ formula of boundary Liouville CFT via conformal welding
Liouville Conformal Field Theory (LCFT) on the disk describes the conformal
factor of the quantum disk, which is the natural random surface in Liouville
quantum gravity with disk topology. Fateev, Zamolodchikov and Zamolodchikov
(2000) proposed an explicit expression, the so-called the FZZ formula, for the
one-point bulk structure constant for LCFT on the disk. In this paper we give a
proof of the FZZ formula in the probabilistic framework of LCFT, which
represents the first step towards rigorously solving boundary LCFT using
conformal bootstrap. In contrast to previous works, our proof is based on
conformal welding of quantum disks and the mating-of-trees theory for Liouville
quantum gravity. As a byproduct of our proof, we also obtain the exact value of
the variance for the Brownian motion in the mating-of-trees theory. Our paper
is an essential part of an ongoing program proving integrability results for
Schramm-Loewner evolutions, LCFT, and in the mating-of-trees theory.Comment: 50 pages, 4 figure
A coupled chlorinase-fluorinase system with high efficiency of trans-halogenation and a shared substrate tolerance
Enzymatic trans-halogenation enables radiolabeling under mild and aqueous conditions, but rapid reactions are desired. We discovered two new S-adenosyl-L-methionine (SAM)-dependent chlorinases from soil bacteria and developed a coupled chlorinase-fluorinase system for highly improved trans-halogenation reactions. The chlorinase was for the first time demonstrated to tolerate the modification at the C-2 position of the adenine ring and act cooperatively with the fluorinase to accelerate the trans-halogenation of 5’-chlorodeoxy-2-ethynyladenosine (5’-ClDEA) to 5’-fluorodeoxy-2-ethynyladenosine (5’-FDEA). The acetylene group will enable the linkage with an azide tethered peptide via a “click” reaction. The coupled chlorinase-fluorinase system offers the prospect of developing rapid radiolabeling protocols under mild and aqueous conditions.
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Derivation of all structure constants for boundary Liouville CFT
We prove that the probabilistic definition of the most general boundary
three-point and bulk-boundary structure constants in Liouville conformal field
theory (LCFT) agree respectively with the formula proposed by Ponsot-Techsner
(2002) and by Hosomichi (2001). These formulas also respectively describe the
fusion kernel and modular kernel of the Virasoro conformal blocks, which are
important functions in various contexts of mathematical physics. As an
intermediate step, we obtain the formula for the boundary reflection
coefficient of LCFT proposed by Fateev-Zamolodchikov-Zamolodchikov (2000). Our
proof relies on the boundary Belavin-Polyakov-Zamolodchikov differential
equation recently proved by the first named author, a conformal welding result
proved by Wu (2023), and an integrable input from the mating-of-trees theory
for Liouville quantum gravity (LQG). Our results supply all the structure
constants needed to perform the conformal bootstrap for boundary LCFT. They
also yield exact descriptions for the joint law of the area and boundary
lengths of basic LQG surfaces, including quantum triangles and two-pointed
quantum disks.Comment: 64 page
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