Time-Series Forecasting based on Cumulative Data (TSFCD) is a crucial problem in decision-making across various industrial scenarios. However, existing time-series forecasting methods often overlook two important characteristics of cumulative data, namely monotonicity and irregularity, which limit their practical applicability. To address this limitation, we propose a principled approach called Monotonic neural Ordinary Differential Equation (MODE) within the framework of neural ordinary differential equations. By leveraging MODE, we are able to effectively capture and represent the monotonicity and irregularity in practical cumulative data. Through extensive experiments conducted in a bonus allocation scenario, we demonstrate that MODE outperforms state-of-the-art methods, showcasing its ability to handle both monotonicity and irregularity in cumulative data and delivering superior forecasting performance.

Detecting and diagnosing anomalies in observational data plays a crucial role in various real-world applications, such as e-commerce applet maintenance. Unsupervised machine learning techniques are typically employed for anomaly detection and diagnosis due to their convenience and independence from labeled data. Density estimation (DE), as one of the most widely used unsupervised machine learning techniques for anomaly detection, can be categorized into kernel density estimation (KDE)-based methods and normalizing flow (NF)-based methods. While KDE-based methods offer fast computation speed, they often ignore the complex manifold structure present in observational data. On the other hand, NF-based methods address the manifold issue but suffer from longer computation times. In this study, we propose a novel DE-based anomaly detection & diagnosis method using Stein Variational Gradient Descent (SVGD), aiming to leverage the strengths of KDE and NF approaches. Firstly, we rigorously derive the DE capability of SVGD through mathematical analysis. Subsequently, we demonstrate the ability of the SVGD method to perform anomaly diagnosis based on input feature attribution. Finally, to validate the effectiveness of our approach, we conduct experiments using synthetic, benchmark, and industrial datasets. The results demonstrate the superior performance and practical applicability of our proposed method.

By using directional sensor nodes such as cameras, wireless multimedia sensor networks are typically used in traffic monitoring, target tracking and other fields. However, most sensor nodes powered by batteries are strictly limited in energy and cannot achieve long-term frontal tracking and monitoring of moving objects. To solve these problems, a model of directed sensor nodes with solar energy harvesting is introduced in this paper, where the energy of such nodes is no longer limited to batteries and the directed sensing area enables better frontal tracking. On this basis, we propose a distributed algorithm for directional task assignment called EN-DADA. EN-DADA is a task assignment algorithm with energy harvesting and orientation awareness, including a task classification phase and node bidding phase. The task is first classified to determine the candidate node set that can execute the task, and then the task assignment is determined according to the monitoring income of each node in the candidate node set. Experimental results show that the proposed task assignment algorithm has advantages in terms of task revenue and network lifetime when using the same energy harvesting model.

Abstract Today, a directional wireless multimedia sensor network is a popular environment for solving the task assignment problem. Achieving long‐term frontal monitoring of moving objects is a crucial challenge for scholars in this field. Utilizing directional sensors equipped with energy harvesting is an effective technique to enhance network performance. In this way, the energy of nodes is no longer limited to batteries and can result in better frontal monitoring. In this method, each sensor categorizes tasks based on its own energy, allowing the determination of task execution nodes through bidding. The present study proposes a distributed algorithm for directional task assignment, EN‐DADA, based on energy harvesting. The task was first classified to determine the candidate node set that could execute the task, and then the task assignment was determined according to the monitoring income of each node in the candidate node set. The comparative analysis confirmed that the proposed method had advantages in terms of task revenue and network lifetime when using the same energy harvesting model.