Producing Scheduling that Causes Concurrent Programs to Fail

A noise maker is a tool that seeds a concurrent program with conditional synchronization primitives (such as yield()) for the purpose of increasing the likelihood that a bug manifest itself. This work explores the theory and practice of choosing where in the program to induce such thread switches at runtime. We introduce a novel fault model that classifies locations as .good., .neutral., or .bad,. based on the effect of a thread switch at the location. Using the model we explore the terms in which efficient search for real-life concurrent bugs can be carried out. We accordingly justify the use of probabilistic algorithms for this search and gain a deeper insight of the work done so far on noise-making. We validate our approach by experimenting with a set of programs taken from publicly available multi-threaded benchmark. Our empirical evidence demonstrates that real-life behavior is similar to what our model predicts

An Outbreak of Q fever in a prison in Italy

We observed an outbreak of Q fever in a prison population. Overall, 65 of the 600 prison inmates developed the disease. The location of the prison cells had no apparent effect on the risk of infection. The outbreak was probably due to exposure to dust contaminated by a passing flock of sheep, which at the time of the outbreak was engaged in lambing. These findings highlight the possible emergence of Q fever in settings and populations not normally thought of as being at risk of exposure to the infection

Arabic Vowels Acoustic Characterization

International audienceA sentence is constructed using basic word units. Each word is composed of syllables and each syllable being composed of phonemes, which in turn, can be classified as vowels or consonants. Vowels may occupy the center or nucleus of a syllable, as opposed to consonants, which occur in marginal positions in a syllable (onsets and codas).Vowels appear early in speech development and are central to understanding the acoustic properties of speech. The aim of this work is to enrich the automatic speech recognition system, by the classification of Arabic vowels based on normalized energy in the formant frequency bands

Dynamic Race Prediction in Linear Time

Writing reliable concurrent software remains a huge challenge for today's programmers. Programmers rarely reason about their code by explicitly considering different possible inter-leavings of its execution. We consider the problem of detecting data races from individual executions in a sound manner. The classical approach to solving this problem has been to use Lamport's happens-before (HB) relation. Until now HB remains the only approach that runs in linear time. Previous efforts in improving over HB such as causally-precedes (CP) and maximal causal models fall short due to the fact that they are not implementable efficiently and hence have to compromise on their race detecting ability by limiting their techniques to bounded sized fragments of the execution. We present a new relation weak-causally-precedes (WCP) that is provably better than CP in terms of being able to detect more races, while still remaining sound. Moreover it admits a linear time algorithm which works on the entire execution without having to fragment it.Comment: 22 pages, 8 figures, 1 algorithm, 1 tabl

Brain tumor classification in magnetic resonance imaging images using convolutional neural network

Deep learning (DL) is a subfield of artificial intelligence (AI) used in several sectors, such as cybersecurity, finance, marketing, automated vehicles, and medicine. Due to the advancement of computer performance, DL has become very successful. In recent years, it has processed large amounts of data, and achieved good results, especially in image analysis such as segmentation and classification. Manual evaluation of tumors, based on medical images, requires expensive human labor and can easily lead to misdiagnosis of tumors. Researchers are interested in using DL algorithms for automatic tumor diagnosis. convolutional neural network (CNN) is one such algorithm. It is suitable for medical image classification tasks. In this paper, we will focus on the development of four sequential CNN models to classify brain tumors in magnetic resonance imaging (MRI) images. We followed two steps, the first being data preprocessing and the second being automatic classification of preprocessed images using CNN. The experiments were conducted on a dataset of 3,000 MRI images, divided into two classes: tumor and normal. We obtained a good accuracy of 98,27%, which outperforms other existing models