Revisiting Machine Learning based Test Case Prioritization for Continuous Integration

To alleviate the cost of regression testing in continuous integration (CI), a large number of machine learning-based (ML-based) test case prioritization techniques have been proposed. However, it is yet unknown how they perform under the same experimental setup, because they are evaluated on different datasets with different metrics. To bridge this gap, we conduct the first comprehensive study on these ML-based techniques in this paper. We investigate the performance of 11 representative ML-based prioritization techniques for CI on 11 open-source subjects and obtain a series of findings. For example, the performance of the techniques changes across CI cycles, mainly resulting from the changing amount of training data, instead of code evolution and test removal/addition. Based on the findings, we give some actionable suggestions on enhancing the effectiveness of ML-based techniques, e.g., pretraining a prioritization technique with cross-subject data to get it thoroughly trained and then finetuning it with within-subject data dramatically improves its performance. In particular, the pretrained MART achieves state-of-the-art performance, producing the optimal sequence on 80% subjects, while the existing best technique, the original MART, only produces the optimal sequence on 50% subjects.Comment: This paper has been accepted by ICSME 202

Deep intelligence as a service: A real-time scheduling perspective

This thesis presents a new type of cloud service, called {\em deep intelligence as a service\/}, that is expected to become increasingly common in the near future to support emerging "smart" embedded applications. This work offers a real-time scheduling model motivated by the special needs of embedded applications that use this service. A simple run-time scheduler is proposed for the server and prove an approximation bound in terms of application-perceived service utility. The service is implemented on representative device hardware and tested with a machine vision application illustrating the advantages of our scheme. The work is motivated by the proliferation of increasingly ubiquitous but resource-constrained embedded devices (often referred to as the Internet of Things -- IoT -- devices) and the growing desire to endow them with advanced interaction capabilities, such as voice recognition or machine vision. The trend suggests that machine intelligence will be increasingly offloaded to cloud or edge services that will offer advanced capabilities to the otherwise simple devices. New services will feature farms of complex trainable (or pre-trained) classifiers that client-side applications can send data to in order to gain certain types of advanced functionality, such as face recognition, voice command recognition, gesture recognition, or other. These new services will revolutionize human interaction with their physical environment, but may impose interesting real-time scheduling challenges in order to maintain responsiveness while maximizing service quality. This work includes challenges, designs for an efficient real-time scheduling algorithm for the new machine intelligence service, and evaluation on an implemented prototype

High-speed integrated lithium niobate low-index rib loaded waveguide modulator without direct lithium niobate etching

Integrated thin film lithium niobate (TFLN) modulators are emerging as an appealing choice for fiber-optic communications, data centers, and microwave photonics due to their high modulation speed and low driving voltage. The key step in fabricating integrated TFLN modulators is the high-quality etching of TFLN, which typically requires long-term fabrication process iteration and specialized equipment. Here we present an integrated TFLN modulator by incorporating low-index rib loaded waveguides onto TFLN without direct etching of TFLN. Based on our systematic investigation into the theory and design methodology of this design, we experimentally demonstrated a 1.3 cm-long Mach-Zender modulator, featuring a 3-dB bandwidth of 59 GHz and a half-wave voltage of 1.96 V. Our design significantly simplifies the fabrication process of integrated TFLN modulators and in turn opens up new avenues for the mass production of high-performance TFLN modulators at low cost

Research on the application status and countermeasures of traditional architectural elements in architectural environment design

Traditional architectural elements carry our excellent traditional culture, contain rich connotation, and are the valuable wealth of modern architectural environment design research and reference. However, the application of traditional architectural elements in the architectural environment design has some problems, such as homogenization and does not reflect the connotation of traditional architectural elements. The effective integration of traditional architectural elements and architectural environment design is of great significance to the development, inheritance of traditional architectural elements and the development of architectural environment design engineering. On the basis of understanding the design characteristics of the architectural environment art, this paper analyzes the current situation of the traditional architectural elements in the architectural environment design, and puts forward the countermeasures to effectively integrate the traditional architectural elements and the architectural environment design. In order to combine the traditional architectural elements with the development needs and use functions of architectural environment design in the new era, enrich the connotation of architecture and improve the artistic aesthetic level of architectural environment design

Reverse Diffusion Monte Carlo

We propose a Monte Carlo sampler from the reverse diffusion process. Unlike the practice of diffusion models, where the intermediary updates -- the score functions -- are learned with a neural network, we transform the score matching problem into a mean estimation one. By estimating the means of the regularized posterior distributions, we derive a novel Monte Carlo sampling algorithm called reverse diffusion Monte Carlo (rdMC), which is distinct from the Markov chain Monte Carlo (MCMC) methods. We determine the sample size from the error tolerance and the properties of the posterior distribution to yield an algorithm that can approximately sample the target distribution with any desired accuracy. Additionally, we demonstrate and prove under suitable conditions that sampling with rdMC can be significantly faster than that with MCMC. For multi-modal target distributions such as those in Gaussian mixture models, rdMC greatly improves over the Langevin-style MCMC sampling methods both theoretically and in practice. The proposed rdMC method offers a new perspective and solution beyond classical MCMC algorithms for the challenging complex distributions.Comment: 44 pages, 16 figures, ICLR 202

Learning Raw Image Denoising with Bayer Pattern Unification and Bayer Preserving Augmentation

In this paper, we present new data pre-processing and augmentation techniques for DNN-based raw image denoising. Compared with traditional RGB image denoising, performing this task on direct camera sensor readings presents new challenges such as how to effectively handle various Bayer patterns from different data sources, and subsequently how to perform valid data augmentation with raw images. To address the first problem, we propose a Bayer pattern unification (BayerUnify) method to unify different Bayer patterns. This allows us to fully utilize a heterogeneous dataset to train a single denoising model instead of training one model for each pattern. Furthermore, while it is essential to augment the dataset to improve model generalization and performance, we discovered that it is error-prone to modify raw images by adapting augmentation methods designed for RGB images. Towards this end, we present a Bayer preserving augmentation (BayerAug) method as an effective approach for raw image augmentation. Combining these data processing technqiues with a modified U-Net, our method achieves a PSNR of 52.11 and a SSIM of 0.9969 in NTIRE 2019 Real Image Denoising Challenge, demonstrating the state-of-the-art performance. Our code is available at https://github.com/Jiaming-Liu/BayerUnifyAug.Comment: Accepted by CVPRW 201