To provide real-time map information, roadside units (RSUs) near vehicles cache 3D map tiles to reduce transmission delays and alleviate backhaul congestion. Unfortunately, traditional cache problems primarily focus on maximizing the cache hit rate (i.e., popularity) while often neglecting other criteria, thus suppressing caching efficiency. For instance, the priority of each map tile may vary for different vehicles based on their route plans and current positions. Additionally, caching a greater number of small-scale map tiles with broader coverage helps serve more vehicles’ requests and reduce cache misses. However, these tiles may only be sufficient for vehicles that can tolerate lower detail levels, as they provide less information than large-scale tiles. Furthermore, ensuring the freshness of cached map tiles is essential for maintaining driving safety. To address the interplay among popularity, priority, map scale, and information freshness in online map caching, this paper formulates an online optimization problem and proposes a novel online algorithm called ADAM, which integrates mixed-integer linear programming (MILP) with deep reinforcement learning. The ADAM predicts future total costs to support caching decisions by leveraging an ingeniously designed MILP that emulates the behavior of a neural network. Finally, simulation results manifest that the proposed ADAM outperforms existing methods by an average of 50%.

A built-in self-test (BIST) architecture is proposed for voltage-controlled oscillators (VCO) operating at multi- gigahertz frequencies. By utilizing a frequency divider and a frequency-to-voltage converter (FVC), the output frequency and tuning range of the VCO can be extracted without external test instruments. The proposed BIST module is integrated with a wideband VCO as the DUT in a 0.18-mum CMOS process for demonstration. Within the tuning range of the VCO from 4.4 to 5.5 GHz, a frequency extraction error less than plusmn0.4% is achieved. The active area and the power consumption of the BIST module are 0.038 mm2and 11 mW, respectively.

A generic embedded device (GED) that can be installed to various kinds of information equipment, such as manufacturing equipment, portal servers, automatic guided vehicles, etc., is successfully developed In this work. GED is equipped with an embedded real-time operating system and several software modules to retrieve, collect, and manage equipment data. In particular, the communication management module of GED can transmit and receive data to/from remote clients via both wired and wireless networks. Moreover, GED has an object-oriented application interface that flexibly enables GED to add-in or update any customized application. Three typical communication mechanisms, namely the standard processes of exception notification, periodic inspection, and data inquiry are built in GED. As such, GED is able to handle a variety of customized applications, such as monitoring, detection, diagnostics, and prognostics of various kinds of information equipment. We believe that GED possesses the potentiality of information acquisition and transmission so that it can assist all kinds of information equipment to reach the goal of equipment-to-system (E2S) communication and facilitate the maintenance tasks.