FOUGERE: User-Centric Location Privacy in Mobile Crowdsourcing Apps

International audienceMobile crowdsourcing is being increasingly used by industrial and research communities to build realistic datasets. By leveraging the capabilities of mobile devices, mobile crowdsourcing apps can be used to track participants' activity and to collect insightful reports from the environment (e.g., air quality, network quality). However, most of existing crowdsourced datasets systematically tag data samples with time and location stamps, which may inevitably lead to user privacy leaks by discarding sensitive information. This paper addresses this critical limitation of the state of the art by proposing a software library that improves user privacy without compromising the overall quality of the crowdsourced datasets. We propose a decentralized approach, named Fougere, to convey data samples from user devices to third-party servers. By introducing an a priori data anonymization process, we show that Fougere defeats state-of-the-art location-based privacy attacks with little impact on the quality of crowd-sourced datasets

A contabilidade gerencial e os métodos multicriteriais

Os métodos multicritérios agregam um valor significativo à informação contábil, na medida em que não somente permitem a abordagem de problemas considerados complexos e, por isto mesmo, não tratáveis pelos procedimentos intuitivo-empíricos usuais, mas também conferem, ao processo de tomada de decisão uma clareza e conseqüente transparência não disponíveis quando esses procedimentos, ou outros métodos de natureza monocritério, são utilizados. Discorre-se acerca dos métodos multicriteriais de apoio à tomada de decisão, citando conceitos e referências históricas, abordando medidas subjetivas e seu uso pela contabilidade gerencial, apresentando os principais métodos multi-atributos de apoio à tomada de decisão e alguns casos de aplicação na área contábil.Multicriterion methods aggregate a significant value to accounting information, since they do not only allow for the treatment of problems that are considered complex and that, therefore, cannot be treated by the usual intuitive-empirical procedures, but also provide the decision-making process with a level of clearness and, consequently, transparency that is not available when these procedures or other monocriterion methods are used. This article deals with the multicriterion methods that support decisionmaking, quoting concepts and historical references, discussing subjective measures and their use in management accounting and presenting the main multi-attribute methods used in support of decision-making and some examples of their application in the accounting area

The Effects of Incongruent Feedback on Bimanual Task Performance

Previous studies analyzing the effects of incongruent visual and haptic feedback have found differences in the perceived stiffness of an object depending on what modality was delayed. These studies required only unilateral performance of the individual and did not measure functional task completion. Our study evaluated the effects of incongruent visual and haptic feedback during a bimanual pick and place task within a virtual environment using two Phantom Omnis. Subjects were asked to place three different colored spheres into matching colored baskets under various testing conditions. The testing conditions included various temporal delays in either the haptic feedback, visual feedback or both feedback modalities simultaneously. The amount of time required to complete the task as well as the number of spheres broken were recorded for each trial. The results show that delays in either or both of the feedback modalities had a negative effect on the subject\u27s ability to complete the task. The most detrimental effects on task performance were observed when both feedback modalities were simultaneously delayed 133 ms for both the completion time and number of broken spheres

Synthesis and Reactivity of Precolibactin 886

The clb gene cluster encodes the biosynthesis of metabolites known as precolibactins and colibactins. The clb pathway is found in gut commensal E. coli, and clb metabolites are thought to initiate colorectal cancer via DNA cross-linking. Precolibactin 886 (1) is one of the most complex isolated clb metabolites; it contains a 15-atom macrocycle and an unusual 5-hydroxy-3-oxazoline ring. Here we report confirmation of the structural assignment via a biomimetic synthesis of precolibactin 886 (1) proceeding through the amino alcohol 9. Double oxidation of 9 afforded the unstable α-ketoimine 2 which underwent macrocyclization to precolibactin 886 (1) upon HPLC purification (3% from 9). Studies of the putative precolibactin 886 (1) biosynthetic precursor 2, the model α-ketoimine 25, and the α-dicarbonyl 26 revealed that these compounds are susceptible to nucleophilic rupture of the C36–C37 bond. Moreover, cleavage of 2 produces other known clb metabolites or biosynthetic intermediates. This unexpected reactivity explains the difficulties in isolating full clb metabolites and accounts for the structure of a recently identified colibactin–adenine adduct. The colibactin peptidase ClbP deacylates synthetic precolibactin 886 (1) to form a non-genotoxic pyridone, suggesting precolibactin 886 (1) lies off-path of the major biosynthetic route.</div

Estudo de caso aplicando modelo para identificação de potenciais geradores de intangíveis

Relata estudo de caso em que foi aplicado o modelo Mapa para Identificação de Potenciais Geradores de Intangíveis. Após mencionar resumidamente a ferramenta utilizada, apresentam-se os procedimentos seguidos para implementar tal modelo numa empresa industrial, evidenciando os passos seguidos, as análises realizadas, os resultados alcançados e as limitações inerentes.This article reports on a case study which applied the model called Map for the Identification of Potential Intangible Asset Generators. After a summarized description of the applied tool, we present the procedures followed to implement such a model in an industrial company, disclosing the steps that were taken, the analyses carried out, obtained results and inherent limitations

Análise de rentabilidade dos segmentos de mercado de empresa distribuidora de mercadorias

O artigo apresenta possíveis aplicações do conceito de margem de contribuição para avaliação de desempenho de segmentos comerciais, voltando-se mais especificamente para empresas que operam no ramo de distribuição de mercadorias. São comentadas e exemplificadas situações em que a margem de contribuição pode servir como ferramenta de apoio aos gestores da área de vendas para averiguar a rentabilidade de produtos, linhas de mercadorias, territórios de venda, canais de distribuição, clientes e vendedores. Por último enfatiza-se o aspecto da projeção de resultados operacionais com base na contribuição total e seus benefícios.The article presents possible applications of the contribution margin concept for the performance evaluation of commercial segments, more specifically oriented towards goods distribution companies. We comment on and give examples of situations in which the contribution margin can serve as a tool to support managers from the sales area to verify the profitability of products, product lines, sales regions, distribution channels, clients and salespersons. Finally, we emphasize the aspect of operational result projection on the basis of the total contribution and its benefits