4,573 research outputs found

    A stroll in the energy landscape

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    We review recent results on the potential energy landscape (PES) of model liquids. The role of saddle-points in the PES in connecting dynamics to statics is investigated, confirming that a change between minima-dominated and saddle-dominated regions of the PES explored in equilibrium happens around the Mode Coupling Temperature. The structure of the low-energy saddles in the basins is found to be simple and hierarchically organized; the presence of saddles nearby in energy to the local minima indicates that, at non-cryogenic temperatures, entropic bottlenecks limit the dynamics.Comment: 8th International Workshop on Disordered Systems, Andalo (Trento), Italy, 12-15 March 200

    SAFE: Self-Attentive Function Embeddings for Binary Similarity

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    The binary similarity problem consists in determining if two functions are similar by only considering their compiled form. Advanced techniques for binary similarity recently gained momentum as they can be applied in several fields, such as copyright disputes, malware analysis, vulnerability detection, etc., and thus have an immediate practical impact. Current solutions compare functions by first transforming their binary code in multi-dimensional vector representations (embeddings), and then comparing vectors through simple and efficient geometric operations. However, embeddings are usually derived from binary code using manual feature extraction, that may fail in considering important function characteristics, or may consider features that are not important for the binary similarity problem. In this paper we propose SAFE, a novel architecture for the embedding of functions based on a self-attentive neural network. SAFE works directly on disassembled binary functions, does not require manual feature extraction, is computationally more efficient than existing solutions (i.e., it does not incur in the computational overhead of building or manipulating control flow graphs), and is more general as it works on stripped binaries and on multiple architectures. We report the results from a quantitative and qualitative analysis that show how SAFE provides a noticeable performance improvement with respect to previous solutions. Furthermore, we show how clusters of our embedding vectors are closely related to the semantic of the implemented algorithms, paving the way for further interesting applications (e.g. semantic-based binary function search).Comment: Published in International Conference on Detection of Intrusions and Malware, and Vulnerability Assessment (DIMVA) 201

    Determinación de una alternativa costo-efectiva de floculación para cultivos de la microalga chlorella en el Caribe colombiano

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    Esta investigación consiguió determinar una alternativa de floculación de microalgas, comunes en el Caribe colombiano, que no altera ni la vitalidad de las células, ni la composición química de su biomasa, minimiza la energía requerida para la remoción de agua durante la cosecha y permite emplear la biomasa en diferentes aplicaciones. Se adelantó una metodología en tres etapas: una no experimental, una experimental de tamizado y la última, experimental de optimización. Se probaron, en una cepa de Chlorella sp. recogida en aguas de la Región Caribe colombiana, cinco de los métodos más usados por los investigadores para promover la floculación de las algas: electrofloculación, adición de hidróxido de sodio, adición de otra cepa de alga, adición de floculante y adición de coagulante. La primera de las técnicas intentadas, la electrofloculación, se descartó desde la etapa no experimental por los bajos resultados obtenidos con la cepa de interés; las otras cuatro se probaron en la primera etapa experimental y se encontró un efecto más importante en dos de ellas: la adición de hidróxido de sodio y la de coagulante. Estas dos fueron probadas durante la segunda etapa experimental. Se apreció que, para la cepa probada, la adición de pequeñas concentraciones (alrededor de 1,2 mg por litro de cultivo) del coagulante permitió alcanzar efectividades másicas de cerca de 32 (el volumen de cultivo a tratar para un secado adicional se reduce a menos de la treintava parte). Los otros métodos empleados alcanzaron, por si solos, efectividades másicas máximas de 1,2 para la adición de hidróxido de sodio; 1,03 para la adición de la cepa Scenedesmus almeriensis y 1,06 para la adición del floculante Actipol. Aún cuando todas las pruebas realizadas siguieron un protocolo idéntico y, por consiguiente, dieron lugar a consumos de energía idénticos; al considerar los distintos consumos energéticos

    Adversarial Attacks against Binary Similarity Systems

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    In recent years, binary analysis gained traction as a fundamental approach to inspect software and guarantee its security. Due to the exponential increase of devices running software, much research is now moving towards new autonomous solutions based on deep learning models, as they have been showing state-of-the-art performances in solving binary analysis problems. One of the hot topics in this context is binary similarity, which consists in determining if two functions in assembly code are compiled from the same source code. However, it is unclear how deep learning models for binary similarity behave in an adversarial context. In this paper, we study the resilience of binary similarity models against adversarial examples, showing that they are susceptible to both targeted and untargeted attacks (w.r.t. similarity goals) performed by black-box and white-box attackers. In more detail, we extensively test three current state-of-the-art solutions for binary similarity against two black-box greedy attacks, including a new technique that we call Spatial Greedy, and one white-box attack in which we repurpose a gradient-guided strategy used in attacks to image classifiers

    Function Representations for Binary Similarity

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    The binary similarity problem consists in determining if two functions are similar considering only their compiled form. Advanced techniques for binary similarity recently gained momentum as they can be applied in several fields, such as copyright disputes, malware analysis, vulnerability detection, etc. In this paper we describe SAFE, a novel architecture for function representation based on a self-attentive neural network. SAFE works directly on disassembled binary functions, does not require manual feature extraction, is computationally more efficient than existing solutions, and is more general as it works on stripped binaries and on multiple architectures. Results from our experimental evaluation show how SAFE provides a performance improvement with respect to previoussolutions. Furthermore, we show how SAFE can be used in widely different use cases, thus providing a general solution for several application scenarios

    Observational evidence of intensified nocturnal urban heat island during heatwaves in European cities

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    A heatwave (HW) is a large-scale meteorological event characterised by persistent and extremely high-temperature condition. At the local scale, the urban heat island (UHI) is another thermal-related phenomenon defined as an urban area warmer than its surrounding regions due to different surfaces’ capabilities to absorb and store heat. However, the assessment about the effect produced on UHI by HW events is not homogeneous. Indeed, regarding the capability of HWs to influence the urban-rural temperature difference, several studies report different conclusions describing both an exacerbation and a reduction of UHI during HW events. In this context, the present study analyses in situ long records of temperature measurements (20 years) to provide observational shreds of evidence of UHI modification under HW conditions. We examine data from the European Climate Assessment & Dataset and World Meteorological Organization computing the UHI index (UHII) to quantify the UHI effect intensity in 37 European cities during the last 20 summers. The results show an UHII intensification for 28 of the 32 cities affected by positive UHI during extremely high temperatures at night, while substantial variations are not observed during the daytime. The time evolution of UHI during a HW highlights that a more significant and persistent urban-rural temperature gradient explains the UHI intensification. Finally, the relationship between the large and local-scale temperature phenomena reveals that continental high-temperature periods are often associated with prominent temperature differences between small-scale urban and rural environments, assessing the impact of large-scale features on thermal stress at the local scale

    A novel integrated industrial approach with cobots in the age of industry 4.0 through conversational interaction and computer vision

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    From robots that replace workers to robots that serve as helpful colleagues, the field of robotic automation is experiencing a new trend that represents a huge challenge for component manufacturers. The contribution starts from an innovative vision that sees an ever closer collaboration between Cobot, able to do a specific physical job with precision, the AI world, able to analyze information and support the decision-making process, and the man able to have a strategic vision of the future
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