Okinawa Prefecture
U.S. to send long-range surveillance drones to Japan amid Taiwan tensions
The U.S. military will deploy several long-range surveillance drones to Okinawa Prefecture, near Japan's far-flung southwestern islands area near Taiwan, as the allies seek to counter China's ramped-up drone presence in the same area. Defense Minister Gen Nakatani said Tuesday that the U.S. MQ-4C Triton drones will be sent to the U.S. air base in Kadena, on Okinawa's main island, in the coming weeks. "This deployment is expected to enhance the Japan-U.S. alliance's intelligence-gathering capabilities and, by extension, the alliance's deterrence and response capabilities," Nakatani told a news conference.
On the Role of Priors in Bayesian Causal Learning
Geiger, Bernhard C., Kern, Roman
--In this work, we investigate causal learning of independent causal mechanisms from a Bayesian perspective. Confirming previous claims from the literature, we show in a didactically accessible manner that unlabeled data (i.e., cause realizations) do not improve the estimation of the parameters defining the mechanism. Furthermore, we observe the importance of choosing an appropriate prior for the cause and mechanism parameters, respectively. Specifically, we show that a factorized prior results in a factorized posterior, which resonates with Janz-ing and Sch olkopf's definition of independent causal mechanisms via the Kolmogorov complexity of the involved distributions and with the concept of parameter independence of Heckerman et al. Impact Statement --Learning the effect from a given cause is an important problem in many engineering disciplines, specifically in the field of surrogate modeling, which aims to reduce the computational cost of numerical simulations. Causal learning, however, cannot make use of unlabeled data - i.e., cause realizations - if the mechanism that produces the effect is independent from the cause. In this work, we recover this well-known fact from a Bayesian perspective.
I-trustworthy Models. A framework for trustworthiness evaluation of probabilistic classifiers
Vashistha, Ritwik, Farahi, Arya
As probabilistic models continue to permeate various facets of our society and contribute to scientific advancements, it becomes a necessity to go beyond traditional metrics such as predictive accuracy and error rates and assess their trustworthiness. Grounded in the competence-based theory of trust, this work formalizes I-trustworthy framework -- a novel framework for assessing the trustworthiness of probabilistic classifiers for inference tasks by linking local calibration to trustworthiness. To assess I-trustworthiness, we use the local calibration error (LCE) and develop a method of hypothesis-testing. This method utilizes a kernel-based test statistic, Kernel Local Calibration Error (KLCE), to test local calibration of a probabilistic classifier. This study provides theoretical guarantees by offering convergence bounds for an unbiased estimator of KLCE. Additionally, we present a diagnostic tool designed to identify and measure biases in cases of miscalibration. The effectiveness of the proposed test statistic is demonstrated through its application to both simulated and real-world datasets. Finally, LCE of related recalibration methods is studied, and we provide evidence of insufficiency of existing methods to achieve I-trustworthiness.
Adaptive Refinement Protocols for Distributed Distribution Estimation under $\ell^p$-Losses
Yuan, Deheng, Guo, Tao, Huang, Zhongyi
Consider the communication-constrained estimation of discrete distributions under $\ell^p$ losses, where each distributed terminal holds multiple independent samples and uses limited number of bits to describe the samples. We obtain the minimax optimal rates of the problem in most parameter regimes. An elbow effect of the optimal rates at $p=2$ is clearly identified. To show the optimal rates, we first design estimation protocols to achieve them. The key ingredient of these protocols is to introduce adaptive refinement mechanisms, which first generate rough estimate by partial information and then establish refined estimate in subsequent steps guided by the rough estimate. The protocols leverage successive refinement, sample compression, thresholding and random hashing methods to achieve the optimal rates in different parameter regimes. The optimality of the protocols is shown by deriving compatible minimax lower bounds.
Okinawa's Ishigaki uses drone for first time during marine survey around Senkakus
The city government of Ishigaki, Okinawa Prefecture, has conducted its third marine survey around the Japanese-administered Senkaku Islands, with Jiji Press and other reporters allowed to board its survey ship. During the survey, which lasted from Thursday to Saturday, Chinese coast guard vessels entered Japanese waters around the islands and attempted to interfere with the city's ship, but Japan Coast Guard vessels blocked the move. The city survey ship's journey to the area was the first since January last year. The latest survey was joined by Ishigaki Mayor Yoshitaka Nakayama and some lawmakers, including former Defense Minister Tomomi Inada. The Japanese government did not allow the survey participants to land on the islands.
Okinawa meat shop uses tech to improves efficiency and raise wages
In a factory run by Nakamatsu Meat, a small "meat shop in town" with a 42-year history in Uruma, Okinawa Prefecture, a part-time employee speaks into a small monitor: "Alexa, I made five cases of ham and cheese sandwiches." Alexa, an artificial-intelligence powered voice assistant from Amazon, then turns the report into data that is compiled in the firm's computer. "At first, workers were a little shy about talking to a machine," said Kazumi Nakamoto, the company's executive director. "But now they are used to it, and they even say'Alexa, good morning.'"
Normalising Flow-based Differentiable Particle Filters
Recently, there has been a surge of interest in incorporating neural networks into particle filters, e.g. differentiable particle filters, to perform joint sequential state estimation and model learning for non-linear non-Gaussian state-space models in complex environments. Existing differentiable particle filters are mostly constructed with vanilla neural networks that do not allow density estimation. As a result, they are either restricted to a bootstrap particle filtering framework or employ predefined distribution families (e.g. Gaussian distributions), limiting their performance in more complex real-world scenarios. In this paper we present a differentiable particle filtering framework that uses (conditional) normalising flows to build its dynamic model, proposal distribution, and measurement model. This not only enables valid probability densities but also allows the proposed method to adaptively learn these modules in a flexible way, without being restricted to predefined distribution families. We derive the theoretical properties of the proposed filters and evaluate the proposed normalising flow-based differentiable particle filters' performance through a series of numerical experiments.
Score-based Causal Representation Learning: Linear and General Transformations
Varıcı, Burak, Acartürk, Emre, Shanmugam, Karthikeyan, Kumar, Abhishek, Tajer, Ali
This paper addresses intervention-based causal representation learning (CRL) under a general nonparametric latent causal model and an unknown transformation that maps the latent variables to the observed variables. Linear and general transformations are investigated. The paper addresses both the \emph{identifiability} and \emph{achievability} aspects. Identifiability refers to determining algorithm-agnostic conditions that ensure recovering the true latent causal variables and the latent causal graph underlying them. Achievability refers to the algorithmic aspects and addresses designing algorithms that achieve identifiability guarantees. By drawing novel connections between \emph{score functions} (i.e., the gradients of the logarithm of density functions) and CRL, this paper designs a \emph{score-based class of algorithms} that ensures both identifiability and achievability. First, the paper focuses on \emph{linear} transformations and shows that one stochastic hard intervention per node suffices to guarantee identifiability. It also provides partial identifiability guarantees for soft interventions, including identifiability up to ancestors for general causal models and perfect latent graph recovery for sufficiently non-linear causal models. Secondly, it focuses on \emph{general} transformations and shows that two stochastic hard interventions per node suffice for identifiability. Notably, one does \emph{not} need to know which pair of interventional environments have the same node intervened.
Stochastic Bayesian Optimization with Unknown Continuous Context Distribution via Kernel Density Estimation
Huang, Xiaobin, Song, Lei, Xue, Ke, Qian, Chao
Bayesian optimization (BO) is a sample-efficient method and has been widely used for optimizing expensive black-box functions. Recently, there has been a considerable interest in BO literature in optimizing functions that are affected by context variable in the environment, which is uncontrollable by decision makers. In this paper, we focus on the optimization of functions' expectations over continuous context variable, subject to an unknown distribution. To address this problem, we propose two algorithms that employ kernel density estimation to learn the probability density function (PDF) of continuous context variable online. The first algorithm is simpler, which directly optimizes the expectation under the estimated PDF. Considering that the estimated PDF may have high estimation error when the true distribution is complicated, we further propose the second algorithm that optimizes the distributionally robust objective. Theoretical results demonstrate that both algorithms have sub-linear Bayesian cumulative regret on the expectation objective. Furthermore, we conduct numerical experiments to empirically demonstrate the effectiveness of our algorithms.
An overview of differentiable particle filters for data-adaptive sequential Bayesian inference
By approximating posterior distributions with weighted samples, particle filters (PFs) provide an efficient mechanism for solving non-linear sequential state estimation problems. While the effectiveness of particle filters has been recognised in various applications, their performance relies on the knowledge of dynamic models and measurement models, as well as the construction of effective proposal distributions. An emerging trend involves constructing components of particle filters using neural networks and optimising them by gradient descent, and such data-adaptive particle filtering approaches are often called differentiable particle filters. Due to the expressiveness of neural networks, differentiable particle filters are a promising computational tool for performing inference on sequential data in complex, high-dimensional tasks, such as vision-based robot localisation. In this paper, we review recent advances in differentiable particle filters and their applications. We place special emphasis on different design choices for key components of differentiable particle filters, including dynamic models, measurement models, proposal distributions, optimisation objectives, and differentiable resampling techniques.