Transformer-based approach for Ethereum Price Prediction Using Crosscurrency correlation and Sentiment Analysis

The research delves into the capabilities of a transformer-based neural network for Ethereum cryptocurrency price forecasting. The experiment runs around the hypothesis that cryptocurrency prices are strongly correlated with other cryptocurrencies and the sentiments around the cryptocurrency. The model employs a transformer architecture for several setups from single-feature scenarios to complex configurations incorporating volume, sentiment, and correlated cryptocurrency prices. Despite a smaller dataset and less complex architecture, the transformer model surpasses ANN and MLP counterparts on some parameters. The conclusion presents a hypothesis on the illusion of causality in cryptocurrency price movements driven by sentiments.

BrainVoxGen: Deep learning framework for synthesis of Ultrasound to MRI

The study presents a deep learning framework aimed at synthesizing 3D MRI volumes from three-dimensional ultrasound images of the brain utilizing the Pix2Pix GAN model. The process involves inputting a 3D volume of ultrasounds into a UNET generator and patch discriminator, generating a corresponding 3D volume of MRI. Model performance was evaluated using losses on the discriminator and generator applied to a dataset of 3D ultrasound and MRI images. The results indicate that the synthesized MRI images exhibit some similarity to the expected outcomes. Despite challenges related to dataset size, computational resources, and technical complexities, the method successfully generated MRI volume with a satisfactory similarity score meant to serve as a baseline for further research. It underscores the potential of deep learning-based volume synthesis techniques for ultrasound to MRI conversion, showcasing their viability for medical applications. Further refinement and exploration are warranted for enhanced clinical relevance.

Systematic Review of Techniques in Brain Image Synthesis using Deep Learning

This review paper delves into the present state of medical imaging, with a specific focus on the use of deep learning techniques for brain image synthesis. The need for medical image synthesis to improve diagnostic accuracy and decrease invasiveness in medical procedures is emphasized, along with the role of deep learning in enabling these advancements. The paper examines various methods and techniques for brain image synthesis, including 2D to 3D constructions, MRI synthesis, and the use of transformers. It also addresses limitations and challenges faced in these methods, such as obtaining well-curated training data and addressing brain ultrasound issues. The review concludes by exploring the future potential of this field and the opportunities for further advancements in medical imaging using deep learning techniques. The significance of transformers and their potential to revolutionize the medical imaging field is highlighted. Additionally, the paper discusses the potential solutions to the shortcomings and limitations faced in this field. The review provides researchers with an updated reference on the present state of the field and aims to inspire further research and bridge the gap between the present state of medical imaging and the future possibilities offered by deep learning techniques.

Multi-Shooting Differential Dynamic Programming for Hybrid Systems using Analytical Derivatives

Differential Dynamic Programming (DDP) is a popular technique used to generate motion for dynamic-legged robots in the recent past. However, in most cases, only the first-order partial derivatives of the underlying dynamics are used, resulting in the iLQR approach. Neglecting the second-order terms often slows down the convergence rate compared to full DDP. Multi-Shooting is another popular technique to improve robustness, especially if the dynamics are highly non-linear. In this work, we consider Multi-Shooting DDP for trajectory optimization of a bounding gait for a simplified quadruped model. As the main contribution, we develop Second-Order analytical partial derivatives of the rigid-body contact dynamics, extending our previous results for fixed/floating base models with multi-DoF joints. Finally, we show the benefits of a novel Quasi-Newton method for approximating second-order derivatives of the dynamics, leading to order-of-magnitude speedups in the convergence compared to the full DDP method.

On Second-Order Derivatives of Rigid-Body Dynamics: Theory & Implementation

Model-based control for robots has increasingly been dependent on optimization-based methods like Differential Dynamic Programming and iterative LQR (iLQR). These methods can form the basis of Model-Predictive Control (MPC), which is commonly used for controlling legged robots. Computing the partial derivatives of the dynamics is often the most expensive part of these algorithms, regardless of whether analytical methods, Finite Difference, Automatic Differentiation (AD), or Chain-Rule accumulation is used. Since the second-order derivatives of dynamics result in tensor computations, they are often ignored, leading to the use of iLQR, instead of the full second-order DDP method. In this paper, we present analytical methods to compute the second-order derivatives of inverse and forward dynamics for open-chain rigid-body systems with multi-DoF joints and fixed/floating bases. An extensive comparison of accuracy and run-time performance with AD and other methods is provided, including the consideration of code-generation techniques in C/C++ to speed up the computations. For the 36 DoF ATLAS humanoid, the second-order Inverse, and the Forward dynamics derivatives take approx 200 mu s, and approx 2.1 ms respectively, resulting in a 3x speedup over the AD approach.

Closed-Form Second-Order Partial Derivatives of Rigid-Body Inverse Dynamics

Optimization-based control methods for robots often rely on first-order dynamics approximation methods like in iLQR. Using second-order approximations of the dynamics is expensive due to the costly second-order partial derivatives of dynamics with respect to the state and control. Current approaches for calculating these derivatives typically use automatic differentiation (AD) and chain-rule accumulation or finite-difference. In this paper, for the first time, we present closed-form analytical second-order partial derivatives of inverse dynamics for rigid-body systems with floating base and multi-DoF joints. A new extension of spatial vector algebra is proposed that enables the analysis. A recursive $\mathcal{O}(Nd^2)$ algorithm is also provided where $N$ is the number of bodies and $d$ is the depth of the kinematic tree. A comparison with AD in CasADi shows speedups of 1.5-3$\times$ for serial kinematic trees with $N> 5$, and a C++ implementation shows runtimes of $\approx$400$\mu s$ for a quadruped.

Details of Second-Order Partial Derivatives of Rigid-Body Inverse Dynamics

This document provides full details of second-order partial derivatives of rigid-body inverse dynamics. Several properties and identities using an extension of Spatial Vector Algebra for tensorial use are listed, along with their detailed derivations. Using those, the expressions for second-order derivatives are derived step-by-step in detail. The expressions build upon previous work by the authors on first-order partial derivatives of inverse dynamics.

Multi-Attributed and Structured Text-to-Face Synthesis

Generative Adversarial Networks (GANs) have revolutionized image synthesis through many applications like face generation, photograph editing, and image super-resolution. Image synthesis using GANs has predominantly been uni-modal, with few approaches that can synthesize images from text or other data modes. Text-to-image synthesis, especially text-to-face synthesis, has promising use cases of robust face-generation from eye witness accounts and augmentation of the reading experience with visual cues. However, only a couple of datasets provide consolidated face data and textual descriptions for text-to-face synthesis. Moreover, these textual annotations are less extensive and descriptive, which reduces the diversity of faces generated from it. This paper empirically proves that increasing the number of facial attributes in each textual description helps GANs generate more diverse and real-looking faces. To prove this, we propose a new methodology that focuses on using structured textual descriptions. We also consolidate a Multi-Attributed and Structured Text-to-face (MAST) dataset consisting of high-quality images with structured textual annotations and make it available to researchers to experiment and build upon. Lastly, we report benchmark Frechet's Inception Distance (FID), Facial Semantic Similarity (FSS), and Facial Semantic Distance (FSD) scores for the MAST dataset.

Fair Decision-Making for Food Inspections

We revisit the application of predictive models by the Chicago Department of Public Health to schedule restaurant inspections and prioritize the detection of critical violations of the food code. Performing the first analysis from the perspective of fairness to the population served by the restaurants, we find that the model treats inspections unequally based on the sanitarian who conducted the inspection and that in turn there are both geographic and demographic disparities in the benefits of the model. We examine both approaches to use the original model in a fairer way and ways to train the model to achieve fairness and find more success with the former class of approaches. The challenges from this application point to important directions for future work around fairness with collective entities rather than individuals, the use of critical violations as a proxy, and the disconnect between fair classification and fairness in the dynamic scheduling system.

Efficient Analytical Derivatives of Rigid-Body Dynamics using Spatial Vector Algebra

Optimization algorithms are increasingly important for the control of rigid-body systems. An essential requirement for these algorithms is the availability of accurate partial derivatives of the equations of motion with respect to the state and control variables. State of the art methods for calculating the derivatives use analytical differentiation methods based on the chain rule, and although these methods are an improvement over finite-difference in terms of accuracy, they are not always the most efficient. In this paper, we present an analytical method for calculating the first-order partial derivatives of rigid-body dynamics. The method uses Featherstone's spatial vector algebra and is presented in a recursive form similar to the Recursive-Newton Euler Algorithm (RNEA). Several dynamics identities and computational options are exploited for efficiency. The algorithms are bench-marked against competing approaches in Fortran and C++. Timing results are presented for kinematic trees with up to 500 links. As an example, the 100 link case leads to a 7x speedup over our Fortran implementation of the existing state-of-the-art method. Preliminary comparison of compute timings for the partial derivatives of inverse dynamics in C++ are also shown versus the existing Pinocchio framework. A speedup of 1.6x is reported for the 36-dof ATLAS humanoid using the new algorithm proposed in this paper.