75 research outputs found

    A geographical analysis of trafficking on a popular darknet market

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    © 2017 Elsevier B.V. Cryptomarkets are online marketplaces, located on the darknet, that facilitate the trading of a variety of illegal goods, mostly drugs. While the literature essentially focus on drugs, various other goods and products related to financial or identity fraud, firearms, counterfeit goods, as well as doping products are also offered on these marketplaces. Through the analysis of relevant data collected on a popular marketplace in 2014–2015, Evolution, this research provides an analysis of the structure of trafficking (types and proportions of products, number of vendors and shipping countries). It also aims at highlighting geographical patterns in the trafficking of these products (e.g. trafficking flows, specialisation of vendors and assessment of their role in the distribution chain). The analysis of the flow of goods between countries emphasises the role of specific countries in the international and domestic trafficking, potentially informing law enforcement agencies to target domestic mails or international posts from specific countries. The research also highlights the large proportion of licit and illicit drug listings and vendors on Evolution, followed by various fraud issues (in particular, financial fraud), the sharing of knowledge (tutorials) and finally goods, currencies and precious metals (principally luxury goods). Looking at the shipping country, there seems to be a clear division between digital and physical products, with more specific information for physical goods. This reveals that the spatial analysis of trafficking is particularly meaningful in the case of physical products (such as illicit drugs) and to a lesser extent for digital products. Finally, the geographical analysis reveals that spatial patterns on Evolution tend to reflect the structure of the traditional illicit market. However, regarding illicit drugs, country-specificity has been observed and are presented in this article

    Screening of gunshot residues using desorption electrospray ionisation-mass spectrometry (DESI-MS)

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    Several studies have indicated that there are potential environmental sources of particles resembling inorganic primer found in gunshot residues (GSR); as a consequence examiners are reluctant to unambiguously assign the origin of inorganic particles. If organic gunshot residues (OGSR) were found in combination with inorganic particles, the possibility of environmental sources could be potentially eliminated, thereby significantly enhancing the strength of the evidence.Methods have been previously described whereby GSR specimens can be analysed for the presence of OGSR or inorganic GRS (IGSR). However, no methods have been reported that allow the analysis of both OGSR and IGSR on the same specimen.Described in this article is a direct method using desorption electrospray ionisation-mass spectrometry (DESI-MS) for the detection of methyl centralite (MC), ethyl centralite (EC) and diphenylamine (DPA) on adhesive tape GSR stubs typically used for scanning electron microscopy-energy-dispersive X-ray (SEM-EDX) analysis. The optimisation of numerous parameters was conducted using an experimental design. The results indicate that direct analysis of these organic components of GSR is possible although some limitations were also identified.This initial investigation has also indicated that subjecting stubs to DESI analysis does not interfere with subsequent SEM-EDX analysis of primer residues; therefore the technique described herein allows a comprehensive examination of GSR that would be highly probative in the event that both OGSR and IGSR are detected in the same specimen. © 2011 Elsevier Ireland Ltd

    Um método prático para a definição dos ajustes de relés baseados em medidas de freqüência usados para detecção de ilhamento de geração distribuída

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    Antes de se proceder com a instalação de geração distribuída em redes de distribuição de energia elétrica, engenheiros de proteção devem projetar e parametrizar sistemas de proteção de forma eficiente para desconectar os geradores distribuídos dentro de um tempo pré-determinado, no caso de ocorrência de situações de ilhamento. Tanto o projeto quanto a avaliação de sistemas de proteção anti-ilhamento confiáveis exigem um estudo detalhado envolvendo numerosas simulações dinâmicas, as quais podem demandar muito tempo por parte dos especialistas de proteção. Este artigo tem por objetivo propor um conjunto de fórmulas para reduzir esse número de simulações dinâmicas. Tais fórmulas são capazes de determinar diretamente o comportamento dinâmico dos dispositivos anti-ilhamento mais empregados em geradores síncronos distribuídos: os relés baseados em medidas de freqüência. Elas são obtidas da solução analítica da equação de oscilação da máquina síncrona, juntamente com a solução das equações dos relés. Além disso, as curvas que relacionam o tempo de detecção com o desbalanço de potência ativa, conhecidas como curvas de desempenho, são empregadas para avaliar a exatidão das fórmulas. Tais curvas são obtidas tanto por simulação dinâmica quanto pelas fórmulas propostas, assim uma comparação abrangente pode ser realizada. Os dispositivos de proteção contra ilhamentos analisados neste trabalho são o relé de sub/sobre freqüência, o relé de taxa de variação de freqüência (em inglês, ROCOF relay - Rate Of Change Of Frequency relay) e o relé de deslocamento de fase ou "salto de vetor" (em inglês Vector Surge, Vector Shift ou Voltage Jump relay).Prior to the installation of distributed generation in distribution networks, protection engineers must design and adjust efficiently protection systems to disconnect all distributed generators within acceptable time frame in case of islanding occurrences. Designing and evaluating reliable protection systems require numerous repeated dynamic simulations, which may be very time consuming. This paper aims to reduce the number of simulations necessary to design anti-islanding protection of distributed generators by proposing a set of formulas that determine directly the dynamic behavior of the most employed anti-islanding devices in synchronous-based distributed generation: frequency-based relays. Such formulas are derived from the solution of the synchronous machine and relays equations. Moreover, the detection time versus active power imbalance curves, known as performance curves, are employed to evaluate the accuracy level of these formulas. These curves are obtained by non-linear dynamic simulations as well as by the proposed formulas, thus a thorough comparison can be done. The frequency-based relays analyzed are: under and over-frequency relays, rate of change of frequency relays (ROCOF relays) and vector surge or vector jump relays (VS relays).Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    The use of wastewater analysis in forensic intelligence: drug consumption comparison between Sydney and different European cities

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    © 2019, © 2019 The Author(s). Published by Taylor & Francis Group on behalf of the Academy of Forensic Science. Wastewater analysis offers objective and complementary information to illicit drug agencies by monitoring patterns of illicit drug consumption. In this study, wastewater samples from three different wastewater treatment plants in Sydney, Australia were collected in March 2016. Ten targeted drugs were analysed and temporal and geographical analyses were performed to obtain a better understanding of the type and amount of illicit drugs consumed in Sydney in comparison with similar studies conducted around Australia and in Europe. Among the targeted drugs, methamphetamine was consumed the most, followed by cocaine and 3,4-methylenedioxymethamphetamine (MDMA). Weekly patterns were observed where a peak during the weekend was present. The geographical analysis showed differences between the regions targeted. This observation may be related to socio-demographic aspects. The comparison of our study to other data sources from Australia showed a high consumption of methamphetamine in Sydney and Western Australia. The comparison between Sydney and different European cities revealed a difference in consumption, which is in line with traditional market indicators. The information obtained through wastewater analysis provides complementary information regarding illicit drug consumption, the size, and the evolution of the illicit drug market. This, ultimately, will assist authorities in making informed decisions

    Forensic intelligence framework. Part II: study of the main generic building blocks and challenges through the examples of illicit drugs and false identity documents monitoring

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    The development of forensic intelligence relies on the expression of suitable models that better represent the contribution of forensic intelligence in relation to the criminal justice system, policing and security. Such models assist in comparing and evaluating methods and new technologies, provide transparency and foster the development of new applications. Interestingly, strong similarities between two separate projects focusing on specific forensic science areas were recently observed. These observations have led to the induction of a general model (Part I) that could guide the use of any forensic science case data in an intelligence perspective. The present article builds upon this general approach by focusing on decisional and organisational issues. The article investigates the comparison process and evaluation system that lay at the heart of the forensic intelligence framework, advocating scientific decision criteria and a structured but flexible and dynamic architecture. These building blocks are crucial and clearly lay within the expertise of forensic scientists. However, it is only part of the problem. Forensic intelligence includes other blocks with their respective interactions, decision points and tensions (e.g. regarding how to guide detection and how to integrate forensic information with other information). Formalising these blocks identifies many questions and potential answers. Addressing these questions is essential for the progress of the discipline. Such a process requires clarifying the role and place of the forensic scientist within the whole process and their relationship to other stakeholders

    Forensic Science: Current State and Perspective by a Group of Early Career Researchers

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    © 2016, Springer Science+Business Media Dordrecht. Forensic science and its influence on policing and the criminal justice system have increased since the beginning of the twentieth century. While the philosophies of the forensic science pioneers remain the pillar of modern practice, rapid advances in technology and the underpinning sciences have seen an explosion in the number of disciplines and tools. Consequently, the way in which we exploit and interpret the remnant of criminal activity are adapting to this changing environment. In order to best exploit the trace, an interdisciplinary approach to both research and investigation is required. In this paper, nine postdoctoral research fellows from a multidisciplinary team discuss their vision for the future of forensic science at the crime scene, in the laboratory and beyond. This paper does not pretend to be exhaustive of all fields of forensic science, but describes a portion of the postdoctoral fellows’ interests and skills

    Dataset of coded handwriting features for use in statistical modelling

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    © 2017 The Authors The data presented here is related to the article titled, “Using handwriting to infer a writer's country of origin for forensic intelligence purposes” (Agius et al., 2017) [1]. This article reports original writer, spatial and construction characteristic data for thirty-seven English Australian1 writers and thirty-seven Vietnamese writers. All of these characteristics were coded and recorded in Microsoft Excel 2013 (version 15.31). The construction characteristics coded were only extracted from seven characters, which were: ‘g’ ‘h’ ‘th’ ‘M’ ‘0’ ‘7’ and ‘9’. The coded format of the writer, spatial and construction characteristics is made available in this Data in Brief in order to allow others to perform statistical analyses and modelling to investigate whether there is a relationship between the handwriting features and the nationality of the writer, and whether the two nationalities can be differentiated. Furthermore, to employ mathematical techniques that are capable of characterising the extracted features from each participant

    Applications of Direct Injection Soft Chemical Ionisation-Mass Spectrometry for the Detection of Pre-blast Smokeless Powder Organic Additives

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    Analysis of smokeless powders is of interest from forensics and security perspectives. This article reports the detection of smokeless powder organic additives (in their pre-detonation condition), namely the stabiliser diphenylamine and its derivatives 2-nitrodiphenylamine and 4-nitrodiphenylamine, and the additives (used both as stabilisers and plasticisers) methyl centralite and ethyl centralite, by means of swab sampling followed by thermal desorption and direct injection soft chemical ionisation-mass spectrometry. Investigations on the product ions resulting from the reactions of the reagent ions H3O+ and O2+ with additives as a function of reduced electric field are reported. The method was comprehensively evaluated in terms of linearity, sensitivity and precision. For H3O+, the limits of detection (LoD) are in the range of 41-88 pg of additive, for which the accuracy varied between 1.5 and 3.2%, precision varied between 3.7 and 7.3% and linearity showed R20.9991. For O2+, LoD are in the range of 72 to 1.4 ng, with an accuracy of between 2.8 and 4.9% and a precision between 4.5 and 8.6% and R20.9914. The validated methodology was applied to the analysis of commercial pre-blast gun powders from different manufacturers.(VLID)4826148Accepted versio

    Increased throughput and ultra-high mass resolution in DESI FT-ICR MS imaging through new-generation external data acquisition system and advanced data processing approaches

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    Desorption electrospray ionisation-mass spectrometry imaging (DESI-MSI) is a powerful imaging technique for the analysis of complex surfaces. However, the often highly complex nature of biological samples is particularly challenging for MSI approaches, as options to appropriately address mass spectral complexity are limited. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) offers superior mass accuracy and mass resolving power, but its moderate throughput inhibits broader application. Here we demonstrate the dramatic gains in mass resolution and/or throughput of DESI-MSI on an FT-ICR MS by developing and implementing a sophisticated data acquisition and data processing pipeline. The presented pipeline integrates, for the first time, parallel ion accumulation and detection, post-processing absorption mode Fourier transform and pixel-by-pixel internal re-calibration. To achieve that, first, we developed and coupled an external high-performance data acquisition system to an FT-ICR MS instrument to record the time-domain signals (transients) in parallel with the instrument’s built-in electronics. The recorded transients were then processed by the in-house developed computationally-efficient data processing and data analysis software. Importantly, the described pipeline is shown to be applicable even to extremely large, up to 1 TB, imaging datasets. Overall, this approach provides improved analytical figures of merits such as: (i) enhanced mass resolution at no cost in experimental time; and (ii) up to 4-fold higher throughput while maintaining a constant mass resolution. Using this approach, we not only demonstrate the record 1 million mass resolution for lipid imaging from brain tissue, but explicitly demonstrate such mass resolution is required to resolve the complexity of the lipidome
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