Multi-UAV collaborative path planning in dynamic environments requires fast path response and strict demand that all UAVs reach the same target at the same time. However, the vast majority of existing methods fail to consider the scenario of multi-UAV coordinated arrival. Moreover, current methods often use only local avoidance and global re-planning, leading to high computation, slow response, and poor scalability for multi-UAV cooperation. To solve the above problems, in this paper, we introduce a database-oriented algorithm PC-DPRRT*, which integrates precomputed deviation paths and reverse graph optimization as the core solution. First, the DPRRT* recreates the 3D airspace into cubic airblocks, which serve as spatio-temporal indexes. Secondly, we compute an initial obstacle-avoidance path using the PC-DPRRT* algorithm for each UAV, and then improve Yen's K-shortest path algorithm to pre-compute multiple conflictfree deviation paths from each air cell to the destination. This effectively avoids the path search cost of subsequent global planning. Finally, a heuristic artificial potential field algorithm is proposed to handle local dynamic obstacle avoidance for UAVs, guiding conflict paths toward neighboring cubic airblocks. Then, in conflict-free cubic, quick path switching is achieved with the stored pre-computed deviation paths. This strategy reintegrates UAVs more quickly encountering obstacles into the mission planning, avoiding global re-planning. Experiments in simulated dynamic battlefield scenarios show that the PCDPRRT* algorithm is an order of magnitude faster than existing methods and exhibits better scalability in scenarios with larger numbers of UAVs.

Training Deep Learning (DL) model requires multiple resource types, including CPUs, GPUs, storage IO, and network IO. Advancements in DL have produced a wide spectrum of models that have diverse usage patterns on different resource types. Existing DL schedulers focus on only GPU allocation, while missing the opportunity of packing jobs along multiple resource types.

Deep learning (DL) is moving its step into a growing number of mobile software applications. These software applications, named as DL based mobile applications (abbreviated as mobile DL apps) integrate DL models trained using large-scale data with DL programs. A DL program encodes the structure of a desirable DL model and the process by which the model is trained using training data. Due to the increasing dependency of current mobile apps on DL, software engineering (SE) for mobile DL apps has become important. However, existing efforts in SE research community mainly focus on the development of DL models and extensively analyze faults in DL programs. In contrast, faults related to the deployment of DL models on mobile devices (named as deployment faults of mobile DL apps) have not been well studied. Since mobile DL apps have been used by billions of end users daily for various purposes including for safety-critical scenarios, characterizing their deployment faults is of enormous importance. To fill in the knowledge gap, this paper presents the first comprehensive study to date on the deployment faults of mobile DL apps. We identify 304 real deployment faults from Stack Overflow and GitHub, two commonly used data sources for studying software faults. Based on the identified faults, we construct a fine-granularity taxonomy consisting of 23 categories regarding to fault symptoms and distill common fix strategies for different fault symptoms. Furthermore, we suggest actionable implications and research avenues that can potentially facilitate the deployment of DL models on mobile devices.

Deep learning (DL) becomes increasingly pervasive, being used in a wide range of software applications. These software applications, named as DL based software (in short as DL software), integrate DL models trained using a large data corpus with DL programs written based on DL frameworks such as TensorFlow and Keras. A DL program encodes the network structure of a desirable DL model and the process by which the model is trained using the training data. To help developers of DL software meet the new challenges posed by DL, enormous research efforts in software engineering have been devoted. Existing studies focus on the development of DL software and extensively analyze faults in DL programs. However, the deployment of DL software has not been comprehensively studied. To fill this knowledge gap, this paper presents a comprehensive study on understanding challenges in deploying DL software. We mine and analyze 3,023 relevant posts from Stack Overflow, a popular Q&A website for developers, and show the increasing popularity and high difficulty of DL software deployment among developers. We build a taxonomy of specific challenges encountered by developers in the process of DL software deployment through manual inspection of 769 sampled posts and report a series of actionable implications for researchers, developers, and DL framework vendors.

To bridge the knowledge gap between research and practice, we present the first empirical study on 16,500 the most popular Android apps, demystifying how smartphone apps exploit deep learning in the wild. To this end, we build a new static tool that dissects apps and analyzes their deep learning functions. Our study answers threefold questions: what are the early adopter apps of deep learning, what do they use deep learning for, and how do their deep learning models look like. Our study has strong implications for app developers, smartphone vendors, and deep learning R&D. On one hand, our findings paint a promising picture of deep learning for smartphones, showing the prosperity of mobile deep learning frameworks as well as the prosperity of apps building their cores atop deep learning. On the other hand, our findings urge optimizations on deep learning models deployed on smartphones, protection of these models, and validation of research ideas on these models.