Human Perception of Audio Deepfakes

The recent emergence of deepfakes has brought manipulated and generated content to the forefront of machine learning research. Automatic detection of deepfakes has seen many new machine learning techniques, however, human detection capabilities are far less explored. In this paper, we present results from comparing the abilities of humans and machines for detecting audio deepfakes used to imitate someone's voice. For this, we use a web-based application framework formulated as a game. Participants were asked to distinguish between real and fake audio samples. In our experiment, 472 unique users competed against a state-of-the-art AI deepfake detection algorithm for 14912 total of rounds of the game. We find that humans and deepfake detection algorithms share similar strengths and weaknesses, both struggling to detect certain types of attacks. This is in contrast to the superhuman performance of AI in many application areas such as object detection or face recognition. Concerning human success factors, we find that IT professionals have no advantage over non-professionals but native speakers have an advantage over non-native speakers. Additionally, we find that older participants tend to be more susceptible than younger ones. These insights may be helpful when designing future cybersecurity training for humans as well as developing better detection algorithms.Comment: Published at ACM Multimedia 2022 Workshop DDAM First International Workshop on Deepfake Detection for Audio Multimedia at ACM Multimedia 202

Remote sensing and simulation modelling as tools for improving nitrogen efficiency for winter oilseed rape (Brassica napus L.)

Winter oilseed rape (OSR) became more and more important during the last decades due to its profitability, the potential to grow OSR as a renewable resource for biofuel production and its beneficial value as preceding crop. Its high fertilizer requirements and its low nitrogen efficiency enhance the risk of N losses from soil-crop system to the environment by leaching during winter rainfall. Site specific fertilization is one approach to improve N efficiency for OSR. Therefore, high resoluted spatial and time concerning information about current crop parameters like biomass and N uptake as well as information about yield potential is necessary. Two approaches were developed to realize these requirements. First, site specific differences of crop development should become measurable in realtime and for a large scale. Second, time courses of biomass production and N uptake should be comprehended by model simulation. Subsequently, appropriate fertilizer algorithms should be implemented for the derivation of fertilizer recommendations. Furthermore, the applicability of these approaches on field scale must be investigated in the course of additional studies. The first objective of this thesis was the establishment of a non-destructive, remote sensing based method to achieve information on site specific variability of above ground biomass and crop uptake of OSR during the growth period by measuring canopy reflectance in order to save intensive destructive measurements in the fields. A systematic analysis of hyperspectral reflectance measurements by testing all possible waveband combinations enabled to derive new vegetation indices. These indices were successfully used to estimate crop canopy parameters like the green area index (GAI), shoot dry matter (DMshoot) and nitrogen in the shoot (Nshoot) during the vegetation period and their prediction power exceeded commonly used indices in terms of r2 and RMSE. Particularly, combinations of near-infrared wavebands 740 nm and 780 nm served best to estimate GAI and DMshoot and Nshoot. Regarding calibration and validation, the indices showed stable results. Using these indices enables to identify small differences between crop canopy parameters in realtime and for large areas. These information can be used to initialize and parameterize a crop growth model for OSR. A further objective of this thesis was the development of a growth model to predict plant parameters like biomass and canopy N in the time course, to derive the amount of fertilizer demand. The presented crop growth model follows a dynamic, empirical approach for predicting dry matter production based on the concept of light use efficiency (LUE) for vegetative growth from emergence to flowering. Data gave evidence that LUE before winter was not constant but depended on radiation intensity. Therefore, it was calculated according to a linear regression function for this specific period. Furthermore, the model calculates dry matter partitioning into leaf and stem fraction according to an allometric approach. For the calculation of nitrogen uptake, nitrogen concentration had to be determined. For leaves, it was set to be constant, whereas stem nitrogen concentration depended on stem dry matter according to an exponential dilution curve. Nitrogen uptake for the shoot was obtained by adding leaf and stem nitrogen uptake. Additionally, the model calculated dry matter losses during winter, which were calculated according to temperatures below 0 °C. Taking these losses into account, enabled for a continuously prediction of dry matter from emergence to flowering without interruption. The variable LUE approach before winter improved dry matter predictions compared to calculations with an optimized, constant LUE. The model could reproduce the dynamic of dry matter losses during winter. Only few data sets were available for calibration and validation, so that parameterization was not robust regarding standard errors for optimized parameters. Prediction for validation data set revealed high differences concerning quality, indicating that additional data set are needed for improving parameterization and prediction of the crop growth model. Because crop growth differs for different developmental stages, another object of this study was the development of a phenological model. Knowledge about time and duration of growth stages can also be used for a growth specific crop management like N fertilization. The presented phenological model based on BRASNAP-PH, which was developed for north-west Europe. Because BRASNAP-PH predicts only four main developmental stages, modifications were conducted, to predict highly resoluted developmental stages according to BBCH. Vernalization and photoperiod were the most important factors besides temperature to estimate leaf development, whereas temperature was determinant during all phases of development. The modified model was calibrated and validated on a large data set throughout Germany. Optimized parameter values and corresponding standard errors for calibration and cross calibration gave advice for a robust parameterization. Validation and cross validation let to a root mean square error (RMSE) of 3.11 and 3.25 BBCH stages, respectively, for the whole developmental phase. The presented results of this thesis can contribute to improve N efficiency for OSR in terms of a site specific fertilization implementing fertilizer algorithms to the growth model. Therefore, an accurate, adjusted, site specific N fertilization recommendation should be derived from information of current crop status and of yield potential. Since the site specific fertilization deals only with one aspect for improving N efficiency for OSR, other approaches must be developed and investigated. Especially approaches concerning production management and crop rotations reveal promising for improvement

Studienreformen - Impulse für eine neue Lehr-Lernkultur

Im Folgenden soll aufgezeigt werden, dass Hochschuldidaktik sich im Verlauf der Hochschulreformdebatte der 70er Jahre zunehmend als Wissenschaftsbereich etablierte und schließlich im Rahmen von Bologna grundsätzlich neuen Aufwind bekommen hat und so die Chance erhält, die Forderungen aus dem "shift from teaching to learning" tatsächlich umgesetzt hat

III Congreso Panamericano de Ciencias de la Comunicación - Integración comercial o Diálogo Cultural ante el desafío de la sociedad de la información

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EVENTOS RURAIS

O cone sul da América Latina é uma região estratégica para a agropecuária, um dos pilares da economia brasileira e dos países vizinhos, que podem enfrentar os mesmos desafios de produção. Este trabalho é resultado de um breve levantamento dos eventos realizados pela Empresa Brasileira da Pesquisa Agropecuária (Embrapa), do Brasil, e pelo Instituto Nacional de Tecnologia Agropecuária (INTA), da Argentina, buscando uma aproximação inicial para entender como tais organizações se relacionam com os sujeitos do setor. O número expressivo de eventos promovidos por ambas as instituições evidencia o caráter estratégico conferido a esse recurso pelo setor agropecuário

EVENTOS RURAIS

O cone sul da América Latina é uma região estratégica para a agropecuária, um dos pilares da economia brasileira e dos países vizinhos, que podem enfrentar os mesmos desafios de produção. Este trabalho é resultado de um breve levantamento dos eventos realizados pela Empresa Brasileira da Pesquisa Agropecuária (Embrapa), do Brasil, e pelo Instituto Nacional de Tecnologia Agropecuária (INTA), da Argentina, buscando uma aproximação inicial para entender como tais organizações se relacionam com os sujeitos do setor. O número expressivo de eventos promovidos por ambas as instituições evidencia o caráter estratégico conferido a esse recurso pelo setor agropecuário

TELENOVELA E ETNICIDADE NEGRA: ESTUDOS DE RECEPÇÃO NO QUILOMBO URBANO DA FAMÍLIA SILVA

O artigo é fruto de reflexões iniciais, surgidas a partir de entradas em campo da pesquisa empírica no primeiro quilombo urbano brasileiro, o da Família Silva. O objetivo da discussão é compreender a relação desses sujeitos com os meios de comunicação de massa, principalmente as telenovelas, verificando suas apropriações e percepções sobre personagens negros presentes neste produto televisivo.RESÚMEN: El artículo es resultado de una reflexión preliminar, que surge de las entradas en el campo de la investigación empírica en el primer quilombo urbano brasileño, la Familia Silva. El propósito del debate es entender la relación de estas personas con los medios de comunicación, especialmente las telenovelas brasileñas, revisando sus créditos y percepciones acerca de los personajes negros presentes en este producto televisivo.PALABRAS CLAVE: Recepción, Mediaciones culturales; Telenovela brasileña; Representación; Etnia negra. ABSTRACT: The article is the result of initial reflections, arising from entries in the field of empirical research in the first quilombo urban Brazil, the Silva Family. The purpose of discussion is to understand the relationship of these subjects with the mass media, especially Brazilian telenovelas, checking its appropriations and perceptions about black characters present in this television product.KEY WORDS: Reception; Cultural Mediations; Brazilian telenovela; Representation; Ethnicity black