5,118 research outputs found
Towards Efficient Data Valuation Based on the Shapley Value
"How much is my data worth?" is an increasingly common question posed by
organizations and individuals alike. An answer to this question could allow,
for instance, fairly distributing profits among multiple data contributors and
determining prospective compensation when data breaches happen. In this paper,
we study the problem of data valuation by utilizing the Shapley value, a
popular notion of value which originated in coopoerative game theory. The
Shapley value defines a unique payoff scheme that satisfies many desiderata for
the notion of data value. However, the Shapley value often requires exponential
time to compute. To meet this challenge, we propose a repertoire of efficient
algorithms for approximating the Shapley value. We also demonstrate the value
of each training instance for various benchmark datasets
and meson exclusive decay in QCD factorization
Belle has observed surprisingly copious production of in
meson decay , of which the rate is comparable to that of
. We study this puzzling process in the QCD factorization
approach with the effect of S-D mixing considered. We find that the soft
scattering effects in the spectator interactions play an essential role. With a
proper parametrization for the higher twist soft end-point singularities
associated with kaon, and with the S-D mixing angle , the
calculated decay rates can be close to the data. Implications of these soft
spectator effects to other charmonium production in exclusive decays are
also emphasized.Comment: journal versio
Double-loop sliding mode control of reentry hypersonic vehicle with RCS
In order to solve the problem of insufficient aerodynamic moment caused by thin air in the re-entry stage of hypersonic vehicle, this paper establishes an attitude angle model of hypersonic vehicle with reaction control system (RCS), and derives its affine linear model to decoupled the internal and external loop. According to the dead zone and saturation characteristics of RCS thruster, a control method to convert continuous moment into discrete switching instruction using pulse width modulation (PWM) is proposed. Since the number of thrusters is usually redundant, the installation matrix of thrusters in the body coordinate is established, and the command moment is coordinately distributed to the individual thrusters. Then a double-loop sliding mode controller (DSMC) is designed to achieve attitude stability and trajectory tracking. Finally, the simulation results show that DSMC has higher maneuverability, fewer thruster switches and stronger robustness to interference
Simultaneous determination of ten compounds in two main medicinal plant parts of Tibetan herb, Pterocephalus hookeri (CB Clarke) Höeck, by ultra-high performance liquid chromatography-photodiode array
Purpose: To develop an ultra-high performance liquid chromatography (UPLC) - photodiode array (PDA) method to compare the chemical composition of two different medicinal components of Pterocephalus hookeri.Methods: Samples were chromatographically separated in succession using Waters Acquity UPLCR BEH C18 column (2.1 × 100 mm, 1.7 μm) and gradient elution (0.2 % phosphoric acid aqueous -acetonitrile). Using partial least squares discriminant analysis and one-way analysis of variance, attempts were made to distinguish different medicinal parts of P. hookeri.Results: Regression equation for 10 compounds showed good linear regression (R2 > 0.9994). The relative standard deviations of precision, stability, repeatability and recovery were under 5 %. Compared with the aerial plant part, the root had significantly higher levels of sylvestroside I (p < 0.01), cantleyoside (p < 0.001), dipsanosides B (p < 0.01) and dipsanosides A (p < 0.01), but significantly lower levels of loganic acid (p < 0.001), chlorogenic acid (p < 0.01), and isochlorogenic acid (p < 0.01). There were no significant differences between loganin, sweroside and isochlorogenic acid C.Conclusion: The described method is simple, accurate and reproducible, and can be used for the simultaneous determination of 10 major compounds of P. hookeri. The results demonstrate that there is variation in the chemical composition of the aerialpart and root of P. hookeri and that loganic acid and cantleyoside are the primary chemical biomarkers.Keywords: Tibetan medicine, Pterocephalus hookeri, Medicinal parts, Loganic acid and Cantleyoside, UPLC-PD
Effective and Efficient Federated Tree Learning on Hybrid Data
Federated learning has emerged as a promising distributed learning paradigm
that facilitates collaborative learning among multiple parties without
transferring raw data. However, most existing federated learning studies focus
on either horizontal or vertical data settings, where the data of different
parties are assumed to be from the same feature or sample space. In practice, a
common scenario is the hybrid data setting, where data from different parties
may differ both in the features and samples. To address this, we propose
HybridTree, a novel federated learning approach that enables federated tree
learning on hybrid data. We observe the existence of consistent split rules in
trees. With the help of these split rules, we theoretically show that the
knowledge of parties can be incorporated into the lower layers of a tree. Based
on our theoretical analysis, we propose a layer-level solution that does not
need frequent communication traffic to train a tree. Our experiments
demonstrate that HybridTree can achieve comparable accuracy to the centralized
setting with low computational and communication overhead. HybridTree can
achieve up to 8 times speedup compared with the other baselines
Subgroup analyses from a phase 3, open-label, randomized study of eribulin mesylate versus capecitabine in pretreated patients with advanced or metastatic breast cancer
Purpose and methods: Our secondary analyses compared survival with eribulin versus capecitabine in various patient subgroups from a phase 3, open-label, randomized study. Eligible women aged ≥18 years with advanced/metastatic breast cancer and ≤3 prior chemotherapies (≤2 for advanced/metastatic disease), including an anthracycline and taxane, were randomized 1:1 to intravenous eribulin mesylate 1.4 mg/m² on days 1 and 8 or twice-daily oral capecitabine 1250 mg/m² on days 1–14 (21-day cycles). Results: In the intent-to-treat population (eribulin 554 and capecitabine 548), overall survival appeared longer with eribulin than capecitabine in various subgroups, including patients with human epidermal growth factor receptor 2-negative (15.9 versus 13.5 months, respectively), estrogen receptor-negative (14.4 versus 10.5 months, respectively), and triple-negative (14.4 versus 9.4 months, respectively) disease. Progression-free survival was similar between the treatment arms. Conclusions: Patients with advanced/metastatic breast cancer and human epidermal growth factor receptor 2-, estrogen receptor-, or triple-negative disease may gain particular benefit from eribulin as first-, second-, and third-line chemotherapies
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