Cascaded 3D Full-body Pose Regression from Single Depth Image at 100 FPS

There are increasing real-time live applications in virtual reality, where it plays an important role in capturing and retargetting 3D human pose. But it is still challenging to estimate accurate 3D pose from consumer imaging devices such as depth camera. This paper presents a novel cascaded 3D full-body pose regression method to estimate accurate pose from a single depth image at 100 fps. The key idea is to train cascaded regressors based on Gradient Boosting algorithm from pre-recorded human motion capture database. By incorporating hierarchical kinematics model of human pose into the learning procedure, we can directly estimate accurate 3D joint angles instead of joint positions. The biggest advantage of this model is that the bone length can be preserved during the whole 3D pose estimation procedure, which leads to more effective features and higher pose estimation accuracy. Our method can be used as an initialization procedure when combining with tracking methods. We demonstrate the power of our method on a wide range of synthesized human motion data from CMU mocap database, Human3.6M dataset and real human movements data captured in real time. In our comparison against previous 3D pose estimation methods and commercial system such as Kinect 2017, we achieve the state-of-the-art accuracy

DeepLOB: Deep Convolutional Neural Networks for Limit Order Books

We develop a large-scale deep learning model to predict price movements from limit order book (LOB) data of cash equities. The architecture utilises convolutional filters to capture the spatial structure of the limit order books as well as LSTM modules to capture longer time dependencies. The proposed network outperforms all existing state-of-the-art algorithms on the benchmark LOB dataset [1]. In a more realistic setting, we test our model by using one year market quotes from the London Stock Exchange and the model delivers a remarkably stable out-of-sample prediction accuracy for a variety of instruments. Importantly, our model translates well to instruments which were not part of the training set, indicating the model's ability to extract universal features. In order to better understand these features and to go beyond a "black box" model, we perform a sensitivity analysis to understand the rationale behind the model predictions and reveal the components of LOBs that are most relevant. The ability to extract robust features which translate well to other instruments is an important property of our model which has many other applications.Comment: 12 pages, 9 figure

A Simulation Study on Cooperation Behavior Using NetLogo Software Considering Resource Re-Allocation

On the study of cooperation behavior, agent-based simulation possesses the advantage of being capable to build a more detailed model and perform more elaborated analysis. Macroscopic characteristics of the system can be revealed by the combined behaviors of microscopic units in the system using an agent-based simulation model. Based on previous works, this paper proposes a cooperation behavior simulation model using NetLogo software. A third-party supervisor who re-allocates resources among participants in the system is added to the simulation model. Results show that adding the re-allocator in the system expands the survival space for cooperators and increases system robustness

Subsonic flows with a contact discontinuity in a two-dimensional finitely long curved nozzle

This paper concerns the structural stability of subsonic flows with a contact discontinuity in a two-dimensional finitely long slightly curved nozzle. We establish the existence and uniqueness of subsonic flows with a contact discontinuity by prescribing the entropy function, the Bernoulli quantity and the horizontal mass flux distribution at the entrance and the flow angle at the exit. The problem can be formulated as a free boundary problem for the hyperbolic-elliptic coupled system. To deal with the free boundary value problem, the Lagrangian transformation is employed to straighten the contact discontinuity. The Euler system is reduced to a nonlinear second-order equation for the stream function. Inspired by \cite{CXZ22}, we use the implicit function theorem to locate the contact discontinuity. We also need to develop an iteration scheme to solve a nonlinear elliptic boundary value problem with nonlinear boundary conditions in a weighted H\"{o}lder space

Fast Evaluation of Generalized Todd Polynomials: Applications to MacMahon's Partition Analysis and Integer Programming

The Todd polynomials $td_k=td_k(b_1,b_2,\dots,b_m)$ are defined by their generating functions $$\sum_{k\ge 0} td_k s^k = \prod_{i=1}^m \frac{b_i s}{e^{b_i s}-1}.$$ It appears as a basic block in Todd class of a toric variety, which is important in the theory of lattice polytopes and in number theory. We find generalized Todd polynomials arise naturally in MacMahon's partition analysis, especially in Erhart series computation.We give fast evaluation of generalized Todd polynomials for numerical $b_i$'s. In order to do so, we develop fast operations in the quotient ring $\mathbb{Z}_p[[x]]$ modulo $s^d$ for large prime $p$. As applications, i) we recompute the Ehrhart series of magic squares of order 6, which was first solved by the first named author. The running time is reduced from 70 days to about 1 day; ii) we give a polynomial time algorithm for Integer Linear Programming when the dimension is fixed, with a good performance.Comment: 2 table