4 research outputs found

    Efficient Underground Object Detection for Ground Penetrating Radar Signals

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    Ground penetrating radar (GPR) is one of the common sensor system for underground inspection. GPR emits electromagnetic waves which can pass through objects. The reflecting waves are recorded and digitised, and then, the B-scan images are formed. According to the properties of scanning object, GPR creates higher or lower intensity values on the object regions. Thus, these changes in signal represent the properties of scanning object. This paper proposes a 3-step method to detect and discriminate landmines: n-row average-subtraction (NRAS); Min-max normalisation; and image scaling. Proposed method has been tested using 3 common algorithms from the literature. According to the results, it has increased object detection ratio and positive object discrimination (POD) significantly. For artificial neural networks (ANN), POD has increased from 77.4 per cent to 87.7 per cent. And, it has increased from 37.8 per cent to 80.2 per cent, for support vector machines (SVM)

    HyperGI: Automated Detection and Repair of Information Flow Leakage

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    Maintaining confidential information control in soft-ware is a persistent security problem where failure means secrets can be revealed via program behaviors. Information flow control techniques traditionally have been based on static or symbolic analyses — limited in scalability and specialized to particular languages. When programs do leak secrets there are no approaches to automatically repair them unless the leak causes a functional test to fail. We present our vision for HyperGI, a genetic improvement framework that detects, localizes and repairs information leakage. Key elements of HyperGI include (1) the use of two orthogonal test suites, (2) a dynamic leak detection approach which estimates and localizes potential leaks, and (3) a repair component that produces a candidate patch using genetic improvement. We demonstrate the successful use of HyperGI on several programs with no failing functional test cases. We manually examine the resulting patches and identify trade-offs and future directions for fully realizing our vision

    Keeping Secrets: Multi-objective Genetic Improvement for Detecting and Reducing Information Leakage

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    Information leaks in software can unintentionally reveal private data, yet they are hard to detect and fix. Although several methods have been proposed to detect leakage, such as static verificationbased approaches, they require specialist knowledge, and are timeconsuming. Recently, HyperGI introduced a dynamic, hypertestbased approach that detects and produces potential fixes for information leakage. Its fitness function tries to balance information leakage and program correctness, but as the authors of that work point out, there may be a tradeoff between keeping program semantics and reducing information leakage. In this work we ask if it is possible to automatically detect and repair information leakage in more realistic programs without requiring specialist knowledge. Our approach, called LeakReducer explicitly encodes the tradeoff between program correctness and information leakage as a multi-objective optimisation problem. We apply LeakReducer to a set of leaky programs including the well known Heartbleed bug. It is comparable with HyperGI on their toy applications. In addition, we demonstrate it can find and reduce leakage in real applications and we see diverse solutions on our Pareto front. Upon investigation we find that having a Pareto front helps with some types of information leakage, but not all
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