scholarly journals ConFuzz: Coverage-Guided Property Fuzzing for Event-Driven Programs

2021 ◽  
pp. 127-144
Author(s):  
Sumit Padhiyar ◽  
K. C. Sivaramakrishnan
Keyword(s):  
Experimental Results ◽  
Concurrent Programs ◽  
Concurrent Schedules ◽  
Concurrency Bugs ◽  
Concurrent Program ◽  
Novel Technique ◽  
Event Driven ◽  
Bug Finding ◽  
High Level ◽  
Concurrency Bug

AbstractBug-free concurrent programs are hard to write due to non-determinism arising out of concurrency and program inputs. Since concurrency bugs typically manifest under specific inputs and thread schedules, conventional testing methodologies for concurrent programs like stress testing and random testing, which explore random schedules, have a strong chance of missing buggy schedules.In this paper, we introduce a novel technique that combines property-based testing with mutation-based, grey box fuzzer, applied to event-driven OCaml programs. We have implemented this technique in , a directed concurrency bug-finding tool for event-driven OCaml programs. Using , programmers specify high-level program properties as assertions in the concurrent program. uses the popular greybox fuzzer AFL to generate inputs as well as concurrent schedules to maximise the likelihood of finding new schedules and paths in the program so as to make the assertion fail. does not require any modification to the concurrent program, which is free to perform arbitrary I/O operations. Our experimental results show that is easy-to-use, effective, detects concurrency bugs faster than Node.Fz - a random fuzzer for event-driven JavaScript programs, and is able to reproduce known concurrency bugs in widely used OCaml libraries.

Platform Independent Analysis of Probabilities on Multithreaded Programs

2013 ◽  
Vol 1 (3) ◽  
pp. 48-65
Author(s):  
Yuting Chen
Keyword(s):  
Operating System ◽  
Static Analysis ◽  
Main Idea ◽  
Experimental Results ◽  
Machine To Machine ◽  
Concurrent Program ◽  
Acceptable Accuracy ◽  
Multithreaded Programs ◽  
Independent Analysis ◽  
And Performance

A concurrent program is intuitively associated with probability: the executions of the program can produce nondeterministic execution program paths due to the interleavings of threads, whereas some paths can always be executed more frequently than the others. An exploration of the probabilities on the execution paths is expected to provide engineers or compilers with support in helping, either at coding phase or at compile time, to optimize some hottest paths. However, it is not easy to take a static analysis of the probabilities on a concurrent program in that the scheduling of threads of a concurrent program usually depends on the operating system and hardware (e.g., processor) on which the program is executed, which may be vary from machine to machine. In this paper the authors propose a platform independent approach, called ProbPP, to analyzing probabilities on the execution paths of the multithreaded programs. The main idea of ProbPP is to calculate the probabilities on the basis of two kinds of probabilities: Primitive Dependent Probabilities (PDPs) representing the control dependent probabilities among the program statements and Thread Execution Probabilities (TEPs) representing the probabilities of threads being scheduled to execute. The authors have also conducted two preliminary experiments to evaluate the effectiveness and performance of ProbPP, and the experimental results show that ProbPP can provide engineers with acceptable accuracy.

scholarly journals Multi-Sensor Fusion for Aerial Robots in Industrial GNSS-Denied Environments

2021 ◽  
Vol 11 (9) ◽  
pp. 3921
Author(s):  
Paloma Carrasco ◽  
Francisco Cuesta ◽  
Rafael Caballero ◽  
Francisco J. Perez-Grau ◽  
Antidio Viguria
Keyword(s):  
Sensor Fusion ◽  
Computational Efficiency ◽  
Probabilistic Approach ◽  
Laser Scanner ◽  
Industrial Applications ◽  
Experimental Results ◽  
Added Value ◽  
Aerial Robots ◽  
3D Localization ◽  
High Level

The use of unmanned aerial robots has increased exponentially in recent years, and the relevance of industrial applications in environments with degraded satellite signals is rising. This article presents a solution for the 3D localization of aerial robots in such environments. In order to truly use these versatile platforms for added-value cases in these scenarios, a high level of reliability is required. Hence, the proposed solution is based on a probabilistic approach that makes use of a 3D laser scanner, radio sensors, a previously built map of the environment and input odometry, to obtain pose estimations that are computed onboard the aerial platform. Experimental results show the feasibility of the approach in terms of accuracy, robustness and computational efficiency.

scholarly journals Towards High-Level Intrinsic Exploration in Reinforcement Learning

2020 ◽  
Author(s):  
Nicolas Bougie ◽  
Ryutaro Ichise
Keyword(s):  
Reinforcement Learning ◽  
Time Horizon ◽  
State Of The Art ◽  
Experimental Results ◽  
Prior Work ◽  
Extrinsic Rewards ◽  
Intrinsic Reward ◽  
Long Time ◽  
End To End ◽  
High Level

Deep reinforcement learning (DRL) methods traditionally struggle with tasks where environment rewards are sparse or delayed, which entails that exploration remains one of the key challenges of DRL. Instead of solely relying on extrinsic rewards, many state-of-the-art methods use intrinsic curiosity as exploration signal. While they hold promise of better local exploration, discovering global exploration strategies is beyond the reach of current methods. We propose a novel end-to-end intrinsic reward formulation that introduces high-level exploration in reinforcement learning. Our curiosity signal is driven by a fast reward that deals with local exploration and a slow reward that incentivizes long-time horizon exploration strategies. We formulate curiosity as the error in an agent’s ability to reconstruct the observations given their contexts. Experimental results show that this high-level exploration enables our agents to outperform prior work in several Atari games.

Influence of the Laminate Configurations of Transparent Armor on its Ballistic Protection

2014 ◽  
Vol 608 ◽  
pp. 253-258 ◽  
Author(s):  
Priawthida Jantharat ◽  
Ryan C. McCuiston ◽  
Chaiwut Gamonpilas ◽  
Sujarinee Kochawattana
Keyword(s):  
Experimental Results ◽  
Front Face ◽  
Light Weight ◽  
Ballistic Performance ◽  
User Requirement ◽  
Element Analysis ◽  
Minimum Requirement ◽  
National Institute Of Justice ◽  
Ballistic Protection ◽  
High Level

The ballistic performance of transparent armors has been continuously developed for an application on security purposes. Generally, ballistic performance of the laminated glass increases with its thickness and weight while the user requirement prefers high level of ballistic protection with thin and light weight body. In this study, fabrication of light weight glass-PVB transparent armors with the level-3 protection according to the National Institute of Justice (NIJ) standard was attempted. The ballistic performances of various configurations of glass-PVB laminates were determined against 7.62 mm ammunitions. Results from fragmentation analysis indicated the influence of glass-sheet-arrangement in the armor structures on the ballistic damages. The minimum requirement on the thickness of front-face layer was also discussed. To verify the experimental results, finite element analysis was performed on all laminated systems. It was found that the results from computational analysis were in reasonable agreement with the experimental results.

REACHABILITY TESTING: AN APPROACH TO TESTING CONCURRENT SOFTWARE

1995 ◽  
Vol 05 (04) ◽  
pp. 493-510 ◽  
Author(s):  
GWAN-HWAN HWANG ◽  
KUO-CHUNG TAI ◽  
TING-LU HUANG
Keyword(s):  
Empirical Studies ◽  
Concurrent Programs ◽  
Concurrent Software ◽  
Sequential Programs ◽  
Concurrent Program ◽  
Testing Approach ◽  
Reachability Testing ◽  
Deterministic Behavior

Concurrent programs are more difficult to test than sequential programs because of non-deterministic behavior. An execution of a concurrent program non-deterministically exercises a sequence of synchronization events called a synchronization sequence (or SYN-sequence). Non-deterministic testing of a concurrent program P is to execute P with a given input many times in order to exercise distinct SYN-sequences. In this paper, we present a new testing approach called reachability testing. If every execution of P with input X terminates, reachability testing of P with input X derives and executes all possible SYN-sequences of P with input X. We show how to perform reachability testing of concurrent programs using read and write operations. Also, we present results of empirical studies comparing reachability and non-deterministic testing. Our results indicate that reachability testing has advantages over non-deterministic testing.

A Visual Saliency Detection Approach by Fusing Low-Level Priors With High-Level Priors

2019 ◽  
Vol 9 (3) ◽  
pp. 23-37
Author(s):  
Monika Singh ◽  
Anand Singh Singh Jalal ◽  
Ruchira Manke ◽  
Aamir Khan
Keyword(s):  
Minimum Distance ◽  
Saliency Detection ◽  
Visual Saliency ◽  
Research Area ◽  
Experimental Results ◽  
Low Level ◽  
Detection Approach ◽  
Art Methods ◽  
High Level ◽  
Visual Saliency Detection

Saliency detection has always been a challenging and interesting research area for researchers. The existing methodologies either focus on foreground regions or background regions of an image by computing low-level features. However, considering only low-level features did not produce worthy results. In this paper, low-level features, which are extracted using super pixels, are embodied with high-level priors. The background features are assumed as the low-level prior due to the similarity in the background areas and boundary of an image which are interconnected and have minimum distance in between them. High-level priors such as location, color, and semantic prior are incorporated with low-level prior to spotlight the salient area in the image. The experimental results illustrate that the proposed approach outperform the sate-of-the-art methods.

scholarly journals Remote Speckle-Based Measurements of Backward Brillouin Acoustic Vibrations in Optical Fibers

2020 ◽  
Vol 10 (2) ◽  
pp. 664
Author(s):  
Sagie Asraf ◽  
Benjamin Lengenfelder ◽  
Michael Schmidt ◽  
Zeev Zalevsky
Keyword(s):  
Spatial Resolution ◽  
Optical Fibers ◽  
Experimental Results ◽  
Limiting Factors ◽  
Acoustic Vibrations ◽  
Frequency Measurements ◽  
Novel Technique ◽  
Temporal Tracking ◽  
Speckle Patterns ◽  
Pump Waves

We propose a novel technique for measurements of Brillouin acoustic vibrations based on temporal tracking of back-reflected speckle patterns. The proposed method holds the potential to enhance some of the limiting factors in Brillouin frequency measurements while yielding increased spatial resolution and shorter scanning times of the inspected fiber. Experimental results show the capabilities of the proposed method are presented, using a two pump-waves configuration.

The addition of methanol to Criegee intermediates

2019 ◽  
Vol 21 (32) ◽  
pp. 17760-17771 ◽  
Author(s):  
Gustavo J. R. Aroeira ◽  
Adam S. Abbott ◽  
Sarah N. Elliott ◽  
Justin M. Turney ◽  
Henry F. Schaefer
Keyword(s):  
Ab Initio ◽  
Rate Constants ◽  
Experimental Results ◽  
Kinetic Rate ◽  
Criegee Intermediates ◽  
Kinetic Rate Constants ◽  
High Level

High level ab initio methods are employed to study the addition of methanol to the simplest Criegee intermediates and its methylated analogue. Kinetic rate constants over a range of temperatures are computed and compared to experimental results.

scholarly journals Critical Temperature Prediction of Superconductors Based on Atomic Vectors and Deep Learning

Symmetry ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 262 ◽  
Author(s):  
Shaobo Li ◽  
Yabo Dan ◽  
Xiang Li ◽  
Tiantian Hu ◽  
Rongzhi Dong ◽  
...  
Keyword(s):  
Neural Network ◽  
Critical Temperature ◽  
Short Term Memory ◽  
Inorganic Compounds ◽  
Machine Learning Algorithms ◽  
Experimental Results ◽  
Network Algorithms ◽  
Characterization Methods ◽  
High Level ◽  
Value Decomposition

In this paper, a hybrid neural network (HNN) that combines a convolutional neural network (CNN) and long short-term memory neural network (LSTM) is proposed to extract the high-level characteristics of materials for critical temperature (Tc) prediction of superconductors. Firstly, by obtaining 73,452 inorganic compounds from the Materials Project (MP) database and building an atomic environment matrix, we obtained a vector representation (atomic vector) of 87 atoms by singular value decomposition (SVD) of the atomic environment matrix. Then, the obtained atom vector was used to implement the coded representation of the superconductors in the order of the atoms in the chemical formula of the superconductor. The experimental results of the HNN model trained with 12,413 superconductors were compared with three benchmark neural network algorithms and multiple machine learning algorithms using two commonly used material characterization methods. The experimental results show that the HNN method proposed in this paper can effectively extract the characteristic relationships between the atoms of superconductors, and it has high accuracy in predicting the Tc.

scholarly journals Concurrency Bug Avoiding Based on Optimized Software Transactional Memory

2019 ◽  
Vol 2019 ◽  
pp. 1-19
Author(s):  
Z. Yu ◽  
Y. Zuo ◽  
W. C. Xiong
Keyword(s):  
Transactional Memory ◽  
File Systems ◽  
Software Transactional Memory ◽  
Concurrency Bugs ◽  
Multithreaded Programs ◽  
In The Wild ◽  
Human Cost ◽  
Data Races ◽  
Virtual File Systems ◽  
Concurrency Bug

Software transactional memory is an effective mechanism to avoid concurrency bugs in multithreaded programs. However, two problems hinder the adoption of such traditional systems in the wild world: high human cost for equipping programs with transaction functionality and low compatibility with I/O calls and conditional variables. This paper presents Convoider to solve these problems. By intercepting interthread operations and designating code among them as transactions in each thread, Convoider automatically transactionalizes target programs without any source code modification and recompiling. By saving/restoring stack frames and CPU registers on beginning/aborting a transaction, Convoider makes execution flow revocable. By turning threads into processes, leveraging virtual memory protection and customizing memory allocation/deallocation, Convoider makes memory manipulations revocable. By maintaining virtual file systems and redirecting I/O operations onto them, Convoider makes I/O effects revocable. By converting lock/unlock operations to no-ops, customizing signal/wait operations on condition variables, and committing memory changes transactionally, Convoider makes deadlocks, data races, and atomicity violations impossible. Experimental results show that Convoider succeeds in transparently transactionalizing twelve real-world applications with averagely incurring only 28% runtime overhead and perfectly avoid 94% of thirty-one concurrency bugs used in our experiments. This study can help efficiently transactionalize legacy multithreaded applications and effectively improve the runtime reliability of them.

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