61 research outputs found
Deep Landscape Forecasting for Real-time Bidding Advertising
The emergence of real-time auction in online advertising has drawn huge
attention of modeling the market competition, i.e., bid landscape forecasting.
The problem is formulated as to forecast the probability distribution of market
price for each ad auction. With the consideration of the censorship issue which
is caused by the second-price auction mechanism, many researchers have devoted
their efforts on bid landscape forecasting by incorporating survival analysis
from medical research field. However, most existing solutions mainly focus on
either counting-based statistics of the segmented sample clusters, or learning
a parameterized model based on some heuristic assumptions of distribution
forms. Moreover, they neither consider the sequential patterns of the feature
over the price space. In order to capture more sophisticated yet flexible
patterns at fine-grained level of the data, we propose a Deep Landscape
Forecasting (DLF) model which combines deep learning for probability
distribution forecasting and survival analysis for censorship handling.
Specifically, we utilize a recurrent neural network to flexibly model the
conditional winning probability w.r.t. each bid price. Then we conduct the bid
landscape forecasting through probability chain rule with strict mathematical
derivations. And, in an end-to-end manner, we optimize the model by minimizing
two negative likelihood losses with comprehensive motivations. Without any
specific assumption for the distribution form of bid landscape, our model shows
great advantages over previous works on fitting various sophisticated market
price distributions. In the experiments over two large-scale real-world
datasets, our model significantly outperforms the state-of-the-art solutions
under various metrics.Comment: KDD 2019. The reproducible code and dataset link is
https://github.com/rk2900/DL
Nematic crossover in BaFeAs under uniaxial stress
Raman scattering can detect spontaneous point-group symmetry breaking without
resorting to single-domain samples. Here we use this technique to study
, the parent compound of the "122" Fe-based
superconductors. We show that an applied compression along the Fe-Fe direction,
which is commonly used to produce untwinned orthorhombic samples, changes the
structural phase transition at temperature into a crossover
that spans a considerable temperature range above . Even in
crystals that are not subject to any applied force, a distribution of
substantial residual stress remains, which may explain phenomena that are
seemingly indicative of symmetry breaking above . Our results
are consistent with an onset of spontaneous nematicity only below
.Comment: 4 pages, 4 figure
Lifelong Sequential Modeling with Personalized Memorization for User Response Prediction
User response prediction, which models the user preference w.r.t. the
presented items, plays a key role in online services. With two-decade rapid
development, nowadays the cumulated user behavior sequences on mature Internet
service platforms have become extremely long since the user's first
registration. Each user not only has intrinsic tastes, but also keeps changing
her personal interests during lifetime. Hence, it is challenging to handle such
lifelong sequential modeling for each individual user. Existing methodologies
for sequential modeling are only capable of dealing with relatively recent user
behaviors, which leaves huge space for modeling long-term especially lifelong
sequential patterns to facilitate user modeling. Moreover, one user's behavior
may be accounted for various previous behaviors within her whole online
activity history, i.e., long-term dependency with multi-scale sequential
patterns. In order to tackle these challenges, in this paper, we propose a
Hierarchical Periodic Memory Network for lifelong sequential modeling with
personalized memorization of sequential patterns for each user. The model also
adopts a hierarchical and periodical updating mechanism to capture multi-scale
sequential patterns of user interests while supporting the evolving user
behavior logs. The experimental results over three large-scale real-world
datasets have demonstrated the advantages of our proposed model with
significant improvement in user response prediction performance against the
state-of-the-arts.Comment: SIGIR 2019. Reproducible codes and datasets:
https://github.com/alimamarankgroup/HPM
Design and development of a ceiling-mounted workshop measurement positioning system for large-scale metrology
This paper presents a new ceiling-mounted workshop Measurement Positioning System (C-wMPS) compensating for many deficiencies shown by conventional metrology systems, especially on the possibility of task-oriented designing for coverage ability, measurement accuracy and efficiency. A hybrid calibration system consisting of a high-precision coordinate control field and standard lengths is developed and implemented for the C-wMPS, which can be designed concretely to provide both traceability and the ability of local accuracy enhancement. Layout optimization using a genetic algorithm based on grids is applied to design an appropriate layout of the system, therefore promotes the system’s performance and reduce cost. An experiment carried out at the Guidance, Navigation and Control laboratory (GNC lab, 40×30×12m) validates the prominent characteristic of C-wMPS and the fitness of the new calibration system and layout optimization method.<br/
OmniObject3D: Large-Vocabulary 3D Object Dataset for Realistic Perception, Reconstruction and Generation
Recent advances in modeling 3D objects mostly rely on synthetic datasets due
to the lack of large-scale realscanned 3D databases. To facilitate the
development of 3D perception, reconstruction, and generation in the real world,
we propose OmniObject3D, a large vocabulary 3D object dataset with massive
high-quality real-scanned 3D objects. OmniObject3D has several appealing
properties: 1) Large Vocabulary: It comprises 6,000 scanned objects in 190
daily categories, sharing common classes with popular 2D datasets (e.g.,
ImageNet and LVIS), benefiting the pursuit of generalizable 3D representations.
2) Rich Annotations: Each 3D object is captured with both 2D and 3D sensors,
providing textured meshes, point clouds, multiview rendered images, and
multiple real-captured videos. 3) Realistic Scans: The professional scanners
support highquality object scans with precise shapes and realistic appearances.
With the vast exploration space offered by OmniObject3D, we carefully set up
four evaluation tracks: a) robust 3D perception, b) novel-view synthesis, c)
neural surface reconstruction, and d) 3D object generation. Extensive studies
are performed on these four benchmarks, revealing new observations, challenges,
and opportunities for future research in realistic 3D vision.Comment: Project page: https://omniobject3d.github.io
Tetraploidy in Citrus wilsonii Enhances Drought Tolerance via Synergistic Regulation of Photosynthesis, Phosphorylation, and Hormonal Changes
Polyploidy varieties have been reported to exhibit higher stress tolerance relative to their diploid relatives, however, the underlying molecular and physiological mechanisms remain poorly understood. In this study, a batch of autotetraploid Citrus wilsonii were identified from a natural seedling population, and these tetraploid seedlings exhibited greater tolerance to drought stress than their diploids siblings. A global transcriptome analysis revealed that a large number of genes involved in photosynthesis response were enriched in tetraploids under drought stress, which was consistent with the changes in photosynthetic indices including Pn, gs, Tr, Ci, and chlorophyll contents. Compared with diploids, phosphorylation was also modified in the tetraploids after drought stress, as detected through tandem mass tag (TMT)-labeled proteomics. Additionally, tetraploids prioritized the regulation of plant hormone signal transduction at the transcriptional level after drought stress, which was also demonstrated by increased levels of IAA, ABA, and SA and reduced levels of GA3 and JA. Collectively, our results confirmed that the synergistic regulation of photosynthesis response, phosphorylation modification and plant hormone signaling resulted in drought tolerance of autotetraploid C. wilsonii germplasm
Translation and initial psychometric evaluation of the Chinese version of the partners in health scale.
All Published work is licensed under a Creative Commons Attribution 4.0 International LicenseThis study aimed to translate the Partner in Health (PIH) scale (12 items) into the mandarin Chinese language and investigate the psychometric properties of the Chinese version PIH scale in patients with chronic diseases in primary care settings in Changsha, China. The instrument was translated according to the Sousa guideline including the following steps: Forward translation, back translation, expert panel evaluation and pilot study, with achievement of consensus at each step. Psychometric properties of the Chinese version PIH were assessed in a random sample of 300 community-dwelling patients with chronic diseases in Changsha, China. These properties included content validity, internal consistency, test-retest reliability and structural validity. Survey response rate was 93.7%. The results showed that the Chinese PIH scale had satisfactory reliability and validity. The test-retest reliability was 0.832 and the Cronbach’s coefficient was 0.865. The content validity rate (S-CVI/Ave) was 0.965. The correlation between the Patient Activation Measure (PAM) and the PIH was 0.505 (p<0.001). Results of the confirmatory factor analysis suggest that the PIH scale consisted of four factors: knowledge, partnership, management and coping. The Chinese PIH scale yields high reliability and validity. It can be used as a generic self-rated tool to assess self-management of patients with chronic diseases in China
Strain-induced enhancement of in infinite-layer PrSrNiO films
The mechanism of unconventional superconductivity in correlated materials
remains a great challenge in condensed matter physics. The recent discovery of
superconductivity in infinite-layer nickelates, as analog to high-Tc cuprates,
has opened a new route to tackle this challenge. By growing 8 nm Pr0.8Sr0.2NiO2
films on the (LaAlO3)0.3(Sr2AlTaO6)0.7 substrate, we successfully raise the
transition temperature Tc from 9 K in the widely studied SrTiO3-substrated
nickelates into 15 K. By combining x-ray absorption spectroscopy with the
first-principles and many-body simulations, we find a positive correlation
between Tc and the pre-edge peak intensity, which can be attributed to the
hybridization between Ni and O orbitals induced by the strain. Our result
suggests that structural engineering can further enhance unconventional
superconductivity, and the charge-transfer property plays a crucial role in the
pairing strength.Comment: 8 pages, 4 figure
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