631 research outputs found
Mutation analysis of the WNT4 gene in Han Chinese women with premature ovarian failure
BACKGROUND: The WNT4 gene plays an important role in female sex determination and differentiation. It also contributes to maintaining of the ovaries and the survival of follicles. METHODS: We sequenced the coding region and splice sites of WNT4 in 145 Han Chinese women with premature ovarian failure (POF) and 200 healthy controls. RESULTS: Only one novel variation, in Exon 2 (195C > T), was detected among the women with POF. However, this synonymous variation did not result in a change in amino acid sequence (65 Asp > Asp). No further variants were found in any of the samples. CONCLUSION: Although we cannot provide any evidence that it is a possible disease-causing gene, this study is the first attempt to investigate the possible role of WNT4 in Han Chinese women with POF
From Speech to Data: Unraveling Google's Use of Voice Data for User Profiling
Smart home voice assistants enable users to conveniently interact with IoT
devices and perform Internet searches; however, they also collect the voice
input that can carry sensitive personal information about users. Previous
papers investigated how information inferred from the contents of users' voice
commands are shared or leaked for tracking and advertising purposes. In this
paper, we systematically evaluate how voice itself is used for user profiling
in the Google ecosystem. To do so, we simulate various user personas by
engaging with specific categories of websites. We then use \textit{neutral
voice commands}, which we define as voice commands that neither reveal personal
interests nor require Google smart speakers to use the search APIs, to interact
with these speakers. We also explore the effects of the non-neutral voice
commands for user profiling. Notably, we employ voices that typically would not
match the predefined personas. We then iteratively improve our experiments
based on observations of profile changes to better simulate real-world user
interactions with smart speakers. We find that Google uses these voice
recordings for user profiling, and in some cases, up to 5 out of the 8
categories reported by Google for customizing advertisements are altered
following the collection of the voice commands.Comment: 11 pages, 1 figure, 7 table
An Early Diagnosis of Oral Cancer based on Three-Dimensional Convolutional Neural Networks
Three-dimensional convolutional neural networks (3DCNNs), a rapidly evolving modality of deep learning, has gained popularity in many fields. For oral cancers, CT images are traditionally processed using two-dimensional input, without considering information between lesion slices. In this paper, we established a 3DCNNs-based image processing algorithm for the early diagnosis of oral cancers, which was compared with a 2DCNNs-based algorithm. The 3D and 2D CNNs were constructed using the same hierarchical structure to profile oral tumors as benign or malignant. Our results showed that 3DCNNs with dynamic characteristics of the enhancement rate image performed better than 2DCNNS with single enhancement sequence for the discrimination of oral cancer lesions. Our data indicate that spatial features and spatial dynamics extracted from 3DCNNs may inform future design of CT-assisted diagnosis system
Quantization of the minimal nilpotent orbits and the quantum Hikita conjecture
We show that the specialized quantum D-module of the equivariant quantum
cohomology ring of the minimal resolution of an ADE singularity is isomorphic
to the D-module of graded traces on the minimal nilpotent orbit in the Lie
algebra of the same type. This generalizes a recent result of Shlykov [Hikita
conjecture for the minimal nilpotent orbit, to appear in Proc. AMS,
https://doi.org/10.1090/proc/15281] and hence verifies in this case the quantum
version of Hikita's conjecture, proposed by Kamnitzer, McBreen and Proudfoot
[The quantum Hikita conjecture, Advances in Mathematics 390 (2021) 107947]. We
also show analogous isomorphisms for singularities of BCFG type
Serviceability behaviour of ultra-high performance fibre-reinforced concrete composite slabs
This thesis presents a comprehensive study of composite slabs comprised of a steel profiled deck and ultra-high-performance fibre-reinforced concrete (UHPFRC). The study begins by examining the local bond properties of composite slabs at the contact surface, investigating the impact of concrete mix designs and profiled deck rib openings on the longitudinal bond behaviour. Subsequently, an experimental study is conducted to analyse the behaviour of simply-supported and continuous composite slabs with varying fibre content, focusing on flexural behaviour, load-slip performance and cracking resistance at both the serviceability and ultimate limit states. These experimental results are then used to validate a new numerical model that allows for changing fibre contents and time-dependent behaviour as well as the partial interaction (PI) behaviour between concrete and steel components (for both internal reinforcements and profiled deck). This numerical model is a displacement-based approach that models the serviceability flexural behaviour of simply-supported composite slabs. Finally, based on the same theory as numerical model, an analytical solution which considers non-linear shrinkage strains is developed to provide a quick and rational solution for predicting the load-deflection behaviour of composite slabs at the serviceability limit state. In the first chapter, the characteristics of UHPFRC and the significant benefits of its application as part of steel concrete composites are introduced. The current studies that investigate the behaviour of steel concrete composite structures in experimental and numerical studies and approaches used to evaluate the performance of composites are summarised. Learning from these studies, research gaps and significances of these studies covered in this thesis are identified. The second chapter focuses on the study of local bond properties conducting by a new single-lap test apparatus. This new test apparatus is designed to avoid material pre-failure (such as buckling of profiled deck and concrete crushing) and reduce the friction impact from additional clamping force. Six trial tests are conducted to study the impact of various bonded length and then the shortest one is selected for the following 48 tests to study bond behaviour of steel concrete composites in terms of two different steel decks (dove-tailed and trapezoidal types), varying fibre contents and the presence/absence of coarse aggregate in concrete mixing. This interfacial bond-slip property is important because longitudinal shear transfer dominates the behaviour of composites such as ultimate capacity and flexural stiffness. The third chapter reports on an experimental investigation aimed at quantifying the benefits of application of UHPFRC to composite slabs with profiled steel decks. Steel concrete composites comprising of steel fibre reinforced concrete (SFRC) and high strength concrete (HSC) have been extensively investigated in the previous studies while the application of UHPFRC as potential substitute because of its high compressive strength and ductility, tensile strain-hardening behaviour and superior post-crack characteristics as one component of composite structures have not been given enough attention. This experimental study focuses on the performance of six simply-supported composite slabs and three continuous composite slabs with fibre content of 0%, 1% and 2%. These tests aims to evaluate the influence of fibre content on the behaviour of composite slabs in terms of deformation, stiffness, crack control and moment redistribution. Furthermore, a rotational displacement-based numerical model is proposed to evaluate the behaviour of composite slab in serviceability with considering long-term effects. The development of this unified approach is necessary because there are numerous combinations for fibre contents and fibre types in cementitious matrix when designing a composite slab. Therefore, a general and applicable model for predicting behaviour of different composite slab designs is required. This model only requires fundamental material properties obtained from small scale tests instead of full-scale slabs loading test results which provides a financial benefit. With application of PI theory in a tension stiffening analysis to determine relative slip between concrete and steel components (local behaviour) and in a mechanics segmental analysis to determine moment/rotation/strain (M//ɛ) properties (global behaviour) for the non-debonded and debonded region, this model predicts crack behaviour, longitudinal slip and flexural performance of profiled slab at the serviceability limit state. This numerical model is validated by comparing with a total of six simply-supported experimental test results with applying their corresponding tested material properties as shown in Chapter 3. Finally, on the basis of numerical model, in order to allow for realistic nonlinear shrinkage strains and relative slip occurring between concrete and steel decking, a closed-form analytical solution is developed to estimate the load-deflection behaviour of composites slab at the serviceability limit state up until the formation of macro-cracking. In this approach, two loading configurations are considered, a central point load and uniform distributed load (UDL), and their corresponding elemental curvature expressions in segmental analysis are demonstrated separately. To simplify the process, all the material properties are assumed to be linear-elastic while concrete tensile strain-stress relationship is bi-linear. This approach is validated by comparing with numerical model results. Therefore, this analytical solutions can be used as design guideline for evaluating the load-deflection performance of profiled slabs in serviceability behaviour.Thesis (Ph.D.) -- University of Adelaide, School of Architecture and Civil Engineering, 202
SpringGrasp: Synthesizing Compliant, Dexterous Grasps under Shape Uncertainty
Generating stable and robust grasps on arbitrary objects is critical for
dexterous robotic hands, marking a significant step towards advanced dexterous
manipulation. Previous studies have mostly focused on improving differentiable
grasping metrics with the assumption of precisely known object geometry.
However, shape uncertainty is ubiquitous due to noisy and partial shape
observations, which introduce challenges in grasp planning. We propose,
SpringGrasp planner, a planner that considers uncertain observations of the
object surface for synthesizing compliant dexterous grasps. A compliant
dexterous grasp could minimize the effect of unexpected contact with the
object, leading to more stable grasp with shape-uncertain objects. We introduce
an analytical and differentiable metric, SpringGrasp metric, that evaluates the
dynamic behavior of the entire compliant grasping process. Planning with
SpringGrasp planner, our method achieves a grasp success rate of 89% from two
viewpoints and 84% from a single viewpoints in experiment with a real robot on
14 common objects. Compared with a force-closure based planner, our method
achieves at least 18% higher grasp success rate
Real-time Model Predictive Control and System Identification Using Differentiable Physics Simulation
Developing robot controllers in a simulated environment is advantageous but
transferring the controllers to the target environment presents challenges,
often referred to as the "sim-to-real gap". We present a method for continuous
improvement of modeling and control after deploying the robot to a
dynamically-changing target environment. We develop a differentiable physics
simulation framework that performs online system identification and optimal
control simultaneously, using the incoming observations from the target
environment in real time. To ensure robust system identification against noisy
observations, we devise an algorithm to assess the confidence of our estimated
parameters, using numerical analysis of the dynamic equations. To ensure
real-time optimal control, we adaptively schedule the optimization window in
the future so that the optimized actions can be replenished faster than they
are consumed, while staying as up-to-date with new sensor information as
possible. The constant re-planning based on a constantly improved model allows
the robot to swiftly adapt to the changing environment and utilize real-world
data in the most sample-efficient way. Thanks to a fast differentiable physics
simulator, the optimization for both system identification and control can be
solved efficiently for robots operating in real time. We demonstrate our method
on a set of examples in simulation and show that our results are favorable
compared to baseline methods
One-Shot Transfer of Long-Horizon Extrinsic Manipulation Through Contact Retargeting
Extrinsic manipulation, the use of environment contacts to achieve
manipulation objectives, enables strategies that are otherwise impossible with
a parallel jaw gripper. However, orchestrating a long-horizon sequence of
contact interactions between the robot, object, and environment is notoriously
challenging due to the scene diversity, large action space, and difficult
contact dynamics. We observe that most extrinsic manipulation are combinations
of short-horizon primitives, each of which depend strongly on initializing from
a desirable contact configuration to succeed. Therefore, we propose to
generalize one extrinsic manipulation trajectory to diverse objects and
environments by retargeting contact requirements. We prepare a single library
of robust short-horizon, goal-conditioned primitive policies, and design a
framework to compose state constraints stemming from contacts specifications of
each primitive. Given a test scene and a single demo prescribing the primitive
sequence, our method enforces the state constraints on the test scene and find
intermediate goal states using inverse kinematics. The goals are then tracked
by the primitive policies. Using a 7+1 DoF robotic arm-gripper system, we
achieved an overall success rate of 80.5% on hardware over 4 long-horizon
extrinsic manipulation tasks, each with up to 4 primitives. Our experiments
cover 10 objects and 6 environment configurations. We further show empirically
that our method admits a wide range of demonstrations, and that contact
retargeting is indeed the key to successfully combining primitives for
long-horizon extrinsic manipulation. Code and additional details are available
at stanford-tml.github.io/extrinsic-manipulation.Comment: 8 pages, 6 figure
Crystal structure and morphology of CeO₂ doped stabilized zirconia ceramics under high-frequency microwave field sintering
AbstractUnder high-frequency microwave irradiation, zirconia ceramics were prepared by sintering nano-CeO₂ (Ce = 7 mol%) doped zirconia powder. The different effects of temperature environment on the phase structure transformation, surface functional groups, microstructure, growth process, and density of doped zirconia were analyzed, and the optimized microwave sintering process for zirconia was determined. The experimental results reveal that the tetragonal phase of zirconia is positively correlated with the temperature when the temperature reaches about 1100 °C in the studied range. The reason is that the grain grows with the increase of sintering temperature, and the surface energy of grain decreases, which leads to the fluctuation of tetragonal phase content. The density of zirconia reaches 98.03% at 1300 °C, and the growth activation energy is 27.40 kJ/mol. There is no abnormal growth of zirconia particles, and the phase transition temperature decreases, which is attributed to the efficient heating of microwave and the incorporation of nano-ceria stabilizer.Abstract
Under high-frequency microwave irradiation, zirconia ceramics were prepared by sintering nano-CeO₂ (Ce = 7 mol%) doped zirconia powder. The different effects of temperature environment on the phase structure transformation, surface functional groups, microstructure, growth process, and density of doped zirconia were analyzed, and the optimized microwave sintering process for zirconia was determined. The experimental results reveal that the tetragonal phase of zirconia is positively correlated with the temperature when the temperature reaches about 1100 °C in the studied range. The reason is that the grain grows with the increase of sintering temperature, and the surface energy of grain decreases, which leads to the fluctuation of tetragonal phase content. The density of zirconia reaches 98.03% at 1300 °C, and the growth activation energy is 27.40 kJ/mol. There is no abnormal growth of zirconia particles, and the phase transition temperature decreases, which is attributed to the efficient heating of microwave and the incorporation of nano-ceria stabilizer
Source Localization for Cross Network Information Diffusion
Source localization aims to locate information diffusion sources only given
the diffusion observation, which has attracted extensive attention in the past
few years. Existing methods are mostly tailored for single networks and may not
be generalized to handle more complex networks like cross-networks.
Cross-network is defined as two interconnected networks, where one network's
functionality depends on the other. Source localization on cross-networks
entails locating diffusion sources on the source network by only giving the
diffused observation in the target network. The task is challenging due to
challenges including: 1) diffusion sources distribution modeling; 2) jointly
considering both static and dynamic node features; and 3) heterogeneous
diffusion patterns learning. In this work, we propose a novel method, namely
CNSL, to handle the three primary challenges. Specifically, we propose to learn
the distribution of diffusion sources through Bayesian inference and leverage
disentangled encoders to separately learn static and dynamic node features. The
learning objective is coupled with the cross-network information propagation
estimation model to make the inference of diffusion sources considering the
overall diffusion process. Additionally, we also provide two novel
cross-network datasets collected by ourselves. Extensive experiments are
conducted on both datasets to demonstrate the effectiveness of \textit{CNSL} in
handling the source localization on cross-networks.Comment: Code and data are available at: https://github.com/tanmoysr/CNSL
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