Zero-Crossing Analysis and Information Divergence of Lévy Walks for Real-Time Feature Extraction

2016 ◽  
Vol 7 (4) ◽  
pp. 41-59
Author(s):  
Jesus David Terrazas Gonzalez ◽  
Witold Kinsner

A method, based on the Smirnov transform, for generating synthetic data with the statistical properties of Lévy-walks is presented. This method can be utilized for generating arbitrary prescribed probability density functions (pdf). A cybersecurity engineering problem associated with Internet traffic is addressed. The synthetic Lévy-walks process is intertwined with sections of distinct characteristics creating a composite signal that is analyzed through zero-crossing rate (ZCR) within a varying-size window to identify sections. The advantages of the ZCR computation directly in the time-domain are appealing for real-time implementations. Moreover, the characterization of the degree of closeness, via the Kullback-Leibler divergence (KLD), among the pdfs of arbitrary processes (focusing on Lévy walks) and model pdfs is presented. The results obtained from the KLD experiments provide a categorical determination of the closeness degree. These results, a remarkable achievement in this research, are also promising to be used as features for classification of complex signals in real-time.

Author(s):  
Jesus David Terrazas Gonzalez ◽  
Witold Kinsner

A comparison between the probability similarities of a Distributed Denial-of-Service (DDoS) dataset and Lévy walks is presented. This effort validates Lévy walks as a model resembling DDoS probability features. In addition, a method, based on the Smirnov transform, for generating synthetic data with the statistical properties of Lévy-walks is demonstrated. The Smirnov transform is used to address a cybersecurity problem associated with the Internet-of-things (IoT). The synthetic Lévy-walk is merged with sections of distinct signals (uniform noise, Gaussian noise, and an ordinary sinusoid). Zero-crossing rate (ZCR) within a varying-size window is utilized to analyze both the composite signal and the DDoS dataset. ZCR identifies all the distinct sections in the composite signal and successfully detects the occurrence of the cyberattack. The ZCR value increases as the signal under analysis becomes more complex and produces steadier values as the varying window size increases. The ZCR computation directly in the time-domain is its most notorious advantage for real-time implementations.


Author(s):  
Jesus David Terrazas Gonzalez ◽  
Witold Kinsner

A comparison between the probability similarities of a Distributed Denial-of-Service (DDoS) dataset and Lévy walks is presented. This effort validates Lévy walks as a model resembling DDoS probability features. In addition, a method, based on the Smirnov transform, for generating synthetic data with the statistical properties of Lévy-walks is demonstrated. The Smirnov transform is used to address a cybersecurity problem associated with the Internet-of-things (IoT). The synthetic Lévy-walk is merged with sections of distinct signals (uniform noise, Gaussian noise, and an ordinary sinusoid). Zero-crossing rate (ZCR) within a varying-size window is utilized to analyze both the composite signal and the DDoS dataset. ZCR identifies all the distinct sections in the composite signal and successfully detects the occurrence of the cyberattack. The ZCR value increases as the signal under analysis becomes more complex and produces steadier values as the varying window size increases. The ZCR computation directly in the time-domain is its most notorious advantage for real-time implementations.


2016 ◽  
Vol 4 (2) ◽  
pp. SF137-SF149 ◽  
Author(s):  
Junsheng Hou ◽  
Burkay Donderici ◽  
David Torres

Multicomponent induction (MCI) logging is able to provide a wealth of measurements at multiple subarrays and frequencies that can be used to evaluate complex subsurface formations. Real-time and postprocessing inversion methods have been introduced by various researchers for determining formation resistivity anisotropy (horizontal and vertical resistivity or conductivity), dip, and dip azimuth/strike using MCI measurements. The majority of these methods are based on single-frequency information. We have developed an enhanced real-time method and relevant workflow for determining formation resistivity anisotropy, dip, and dip azimuth using multifrequency MCI information. This enhanced method can be used to improve accuracy in formation evaluation applications, such as reservoir identification, hydrocarbon/water saturation calculation, and geologic and structural interpretation. Enhancements over the present single-frequency data processing include: (1) optimal harmonization of multiple single-frequency inverted logs, (2) robust determination of dip and dip azimuth angle for low-resistivity anisotropy ratios, (3) practical data-quality evaluation that takes into account the effects of formation resistivity, anisotropy ratio, and dip parameters, and (4) a new integrated workflow that can be used to determine formation anisotropy, true dip, and dip azimuth by integrating processed relative dip and azimuth and borehole directional logging data. Finally, all of these data process enhancements have been validated with synthetic data and field log data.


INFO ARTHA ◽  
2017 ◽  
Vol 1 (1) ◽  
pp. 17-34
Author(s):  
Fadlil Usman

Probity audit is an independence assessment activity to ensure the goods/services procurement processes have been implemented consistently appropriate with the principle of upholding integrity, uprightness, honesty and fulfill certain occur legislation aimed for improving the accountability for the use of public sector fund. Probity audit is done in real time simultaneously with the goods/services procurement process. This study aims to evaluate the suitability of the implementation of probity audit conducted by BPKP Headquarter as agency that initiated the implementation of probity audit in Indonesia compared with the Probity audit Guidelines for Procurement of Goods/Services as criteria. The results of this study indicate that the implementation of probity audit conducted by BPKP Headquarter has been implemented adequately, but there are activities that do not fit the criteria, especially in the activities of the determination of the scope of the audit, the preparation of working papers and the follow-up monitoring of the audit results. Probity audit merupakan kegiatan penilaian (independen) untuk memastikan bahwa proses pengadaan barang/jasa telah dilaksanakan secara konsisten sesuai dengan prinsip penegakan integritas, kebenaran, kejujuran dan memenuhi ketentuan perundangan yang berlaku yang bertujuan meningkatkan akuntabilitas penggunaan dana sektor publik. Probity audit dilakukan secara real time yaitu bersamaan dengan pelaksanaan pengadaan barang/jasa. Penelitian ini bertujuan untuk melakukan evaluasi kesesuaian pelaksanaan probity audit yang dilakukan oleh BPKP Pusat selaku instansi yang menginisiasi pelaksanaan probity audit di Indonesia dibandingkan dengan kriteria berupa Pedoman Probity audit Pengadaan Barang/Jasa Pemerintah. Hasil dari penelitian ini menunjukkan bahwa pelaksanaan probity audit yang dilakukan oleh BPKP Pusat sudah dilaksanakan secara memadai, namun masih terdapat hal yang belum sesuai dengan kriteria terutama dalam kegiatan penentuan ruang lingkup audit, penyusunan kertas kerja dan pemantauan terhadap tindak lanjut hasil audit.


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