47 research outputs found
Quantum Gaussian process regression
In this paper, a quantum algorithm based on gaussian process regression model
is proposed. The proposed quantum algorithm consists of three sub-algorithms.
One is the first quantum subalgorithm to efficiently generate mean predictor.
The improved HHL algorithm is proposed to obtain the sign of outcomes.
Therefore, the terrible situation that results is ambiguous in terms of
original HHL algorithm is avoided, which makes whole algorithm more clear and
exact. The other is to product covariance predictor with same method. Thirdly,
the squared exponential covariance matrices are prepared that annihilation
operator and generation operator are simulated by the unitary linear
decomposition Hamiltonian simulation and kernel function vectors is generated
with blocking coding techniques on covariance matrices. In addition, it is
shown that the proposed quantum gaussian process regression algorithm can
achieve quadratic faster over the classical counterpart
M2GRL: A Multi-task Multi-view Graph Representation Learning Framework for Web-scale Recommender Systems
Combining graph representation learning with multi-view data (side
information) for recommendation is a trend in industry. Most existing methods
can be categorized as \emph{multi-view representation fusion}; they first build
one graph and then integrate multi-view data into a single compact
representation for each node in the graph. However, these methods are raising
concerns in both engineering and algorithm aspects: 1) multi-view data are
abundant and informative in industry and may exceed the capacity of one single
vector, and 2) inductive bias may be introduced as multi-view data are often
from different distributions. In this paper, we use a \emph{multi-view
representation alignment} approach to address this issue. Particularly, we
propose a multi-task multi-view graph representation learning framework (M2GRL)
to learn node representations from multi-view graphs for web-scale recommender
systems. M2GRL constructs one graph for each single-view data, learns multiple
separate representations from multiple graphs, and performs alignment to model
cross-view relations. M2GRL chooses a multi-task learning paradigm to learn
intra-view representations and cross-view relations jointly. Besides, M2GRL
applies homoscedastic uncertainty to adaptively tune the loss weights of tasks
during training. We deploy M2GRL at Taobao and train it on 57 billion examples.
According to offline metrics and online A/B tests, M2GRL significantly
outperforms other state-of-the-art algorithms. Further exploration on diversity
recommendation in Taobao shows the effectiveness of utilizing multiple
representations produced by \method{}, which we argue is a promising direction
for various industrial recommendation tasks of different focus.Comment: Accepted by KDD 2020 ads track as an oral paper. Code
address:https://github.com/99731/M2GR
The Quality and Outcomes of Care Provided to Patients with Cirrhosis by Advanced Practice Providers
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153696/1/hep30695.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153696/2/hep30695_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153696/3/hep30695-sup-0001-TableS1-S6.pd
Explainable recommender with geometric information bottleneck
Explainable recommender systems can explain their recommendation decisions, enhancing user trust in the systems. Most explainable recommender systems either rely on human-annotated rationales to train models for explanation generation or leverage the attention mechanism to extract important text spans from reviews as explanations. The extracted rationales are often confined to an individual review and may fail to identify the implicit features beyond the review text. To avoid the expensive human annotation process and to generate explanations beyond individual reviews, we propose to incorporate a geometric prior learnt from user-item interactions into a variational network which infers latent factors from user-item reviews. The latent factors from an individual user-item pair can be used for both recommendation and explanation generation, which naturally inherit the global characteristics encoded in the prior knowledge. Experimental results on three e-commerce datasets show that our model significantly improves the interpretability of a variational recommender using the Wasserstein distance while achieving performance comparable to existing content-based recommender systems in terms of recommendation behaviours
Simulation and analysis of microring electric field sensor based on a lithium niobate-on-insulator
With the increasing sensitivity and accuracy of contemporary high-performance electronic information systems to electromagnetic energy, they are also very vulnerable to be damaged by high-energy electromagnetic fields. In this work, an all-dielectric electromagnetic field sensor is proposed based on a microring resonator structure. The sensor is designed to work at 35 GHz RF field using a lithium niobate-on-insulator (LNOI) material system. The 2.5-D variational finite difference time domain (varFDTD) and finite difference eigenmode (FDE) methods are utilized to analyze the single-mode condition, bending loss, as well as the transmission loss to achieve optimized waveguide dimensions. In order to obtain higher sensitivity, the quality factor (Q-factor) of the microring resonator is optimized to be 106 with the total ring circumference of 3766.59 μm. The lithium niobate layer is adopted in z-cut direction to utilize TM mode in the proposed all-dielectric electric field sensor, and with the help of the periodically poled lithium niobate (PPLN) technology, the electro-optic (EO) tunability of the device is enhanced to 48 pm·μm/V
Tunable electromagnetically induced transparent window of terahertz metamaterials and Its sensing performance
The electromagnetically induced transparency effect of terahertz metamaterials exhibits excellent modulation and sensing properties, and it is critical to investigate the modulation effect of the transparent window by optimizing structural parameters. In this work, a unilateral symmetrical metamaterial structure based on the cut-wire resonator and the U-shaped split ring resonator is demonstrated to achieve electromagnetically induced transparency-like (EIT-like) effect. Based on the symmetrical structure, by changing the structural parameters of the split ring, an asymmetric structure metamaterial is also studied to obtain better tuning and sensing characteristics. The parameters for controlling the transparent window of the metamaterial are investigated in both passive and active modulation modes. In addition, the metamaterial structure based on the cut-wire resonator, unilateral symmetric and asymmetric configurations are investigated for high performance refractive index sensing purposes, and it is found that the first two metamaterial structures can achieve sensitivity responses of 63.6 GHz/RIU and 84.4 GHz/RIU, respectively, while the asymmetric metamaterial is up to 102.3 GHz/RIU. The high sensitivity frequency response of the proposed metamaterial structures makes them good candidates for various chemical and biomedical sensing applications