FrameProv: Towards End-To-End Video Provenance

Video feeds are often deliberately used as evidence, as in the case of CCTV footage; but more often than not, the existence of footage of a supposed event is perceived as proof of fact in the eyes of the public at large. This reliance represents a societal vulnerability given the existence of easy-to-use editing tools and means to fabricate entire video feeds using machine learning. And, as the recent barrage of fake news and fake porn videos have shown, this isn't merely an academic concern, it is actively been exploited. I posit that this exploitation is only going to get more insidious. In this position paper, I introduce a long term project that aims to mitigate some of the most egregious forms of manipulation by embedding trustworthy components in the video transmission chain. Unlike earlier works, I am not aiming to do tamper detection or other forms of forensics -- approaches I think are bound to fail in the face of the reality of necessary editing and compression -- instead, the aim here is to provide a way for the video publisher to prove the integrity of the video feed as well as make explicit any edits they may have performed. To do this, I present a novel data structure, a video-edit specification language and supporting infrastructure that provides end-to-end video provenance, from the camera sensor to the viewer. I have implemented a prototype of this system and am in talks with journalists and video editors to discuss the best ways forward with introducing this idea to the mainstream

Economic Lives of Artists : Studies into Careers and the Labour Market in the Cultural Sector

The economic aspects of the lives of artists already puzzled classical economists such as Adam Smith and Alfred Marshall. Their theories provide the background for this book, which presents a number of empirical studies into careers and the labour market in the cultural sector. Leitmotivs are two modern theories in Cultural Economics: work-preference, which focuses on the overriding preference of artists to work in their own occupation in spite of the low earnings and winner-take-all or superstar theory, which aims to explain the extremely skewed income distribution in the arts. These theories are studied in detail in five chapters that cover diverse topics such as the relation between wages and labour supply among artists; the impact of the extensive system of grants and subsidies of the Dutch government for the careers of visual artists; the earnings and artistic achievements of a cohort of graduates from arts education during the first years of their career; the exhibitions of visual artists in museums, galleries and other locations and the determinants of the prices of works of visual art in Dutch modern art gallerie

3D Arrangements of Encapsulated Fluorescent Quantum Dots

Nanomaterials have attracted considerable attention during the past decades due to their unique and fascinating properties. However, this class of materials is not an invention of modern age. People have been using nanomaterials for centuries, although unwittingly. Probably the most famous example for the usage of nanomaterials in ancient times is the Lycurgus Cup, a Roman glass cage cup created in the 4th century which changes the colour of its glass from green to ruby depending on the illumination conditions. The foundation for the development of the field of nanotechnology was laid by the speech of Feynman “There is plenty of room at the bottom” in 1959, in which he spoke about the principles of miniaturisation as low as to the atomic level. Today, modern nanotechnology made it its business to purposefully develop and synthesise nanomaterials as well as to face their applications in various fields, such as microelectronics, catalysis or biomedicine. However, the term “nanomaterials” does not solely involve the nanoparticulate units itself, but also their arrangement into two- or three-dimensional structures. Thereby, the maintenance of the nanoscale properties is one of the main challenges. This task was focussed by this work implied the preparation and macroscale arrangement of fluorescent QDs while preserving their optical properties. The main achievement of this work was the development of a novel aerogel material with non-quenching PL behaviour by using silica coated QDs as nanoparticulate building units. In comparison to other monolithic silica-QD structures or aerogels from pure QDs, a defined and controllable distance between the fluorescent QDs is provided in these structures by the silica shell. The spacing was shown to efficiently disable energy transfers so that no spectral shifts, lifetime shortening or PL QY losses are observed during the colloid to gel transition. The silica shell, established by a standard reverse microemulsion approach, was found to exhibit a certain porosity, which was proven by gas adsorption measurements. Existing cavities in the micro- and mesoporous range were found to allow small species such as metal ions to pass through the shell and interact with the QD core causing a detectable change of the PL intensity, which makes these materials suitable for future sensing applications. The gel preparation was based on a metal ion assisted complexation approach, which requires tetrazole functionalisation of the nanoparticulate building units. A major development in this work that permitted this gelation approach for silica-QDs was the development of a novel tetrazole-silane ligand. TMSPAMTz was specifically designed to bind to the silica surface of silica-QDs in aqueous solution and was prepared by a covalent coupling of an alkyl chained silane with a 5-subsituted tetrazole ring. Network formation is subsequently achieved by the interconnection of negatively charged tetrazole rings with metal ions, which allows for a broad spectrum of aerogel materials from different NP species as well as their mixtures as long as tetrazole capping is provided. Considering this diversity and the disabling of energy transfers, straightforward colour tuning was demonstrated herein by mixing differently emitting silica-QD species which gives great prospects for lighting applications. Furthermore, the possibility of plasmon enhanced emission was presented for mixed Au NP/silica-QD gels. With respect to future sensing applications, thin porous films from silica-QDs gels were prepared, which showed a promising concentration dependant PL quenching for the model analyst hydrogen peroxide. However, the film reproducibility of the applied drop-cast coating method was insufficient. As a suggestion to this, a LbL method was presented, wherein a gel is subsequently grown with the metal ion assisted complexation approach. In addition to the tetrazole ligands on the NP surface, tetrazole-silane ligands were used in this approach to functionalise the glass substrate surface. By this, homogeneous gel films of distinct thickness can be grown while the use of organic polymers can be completely avoided. Besides the preparation of NP assemblies, standard Cd-based QD materials as well as Au NPs of different sizes and shape, recent progresses in the synthesis of InP-based QDs were presented in this work. A thorough investigation and understanding of the growth influencing parameters allowed for the establishment of preparation routes for In(Zn)P/GaP/ZnS core/shell/shell QDs with emission wavelengths tuneable within a large range from 500 to 650 nm, narrow peak widths of 45 to 70 nm and PL QYs up to 60%. Successful incorporation of these QDs into salt matrices was further demonstrated. The resulting composite materials are very photostable and suitable as colour conversion materials for solid state lighting, as was clearly pointed out by a self-prepared WLED that met the standard commercial LEDs

The Influence of Transient Perturbations on Landscape Evolution: Exploring Gully and Post-Wildfire Erosion

The power of water shapes landscapes, redistributes sediment on the earths surface, and creates natural hazards that have an enormous impact on the natural and built environment. In quasi-equilibrium landscapes, slope angles balance water erosion and sedimentation processes. However, after major disturbances such as wildfire or drought rapid landscape evolution can result, causing massive landscape reorganization. How do these disturbances propagate through a landscape? What is the imbalance in sediment mass conservation that creates catastrophic erosion or deposition? These questions are dependent on how landscapes respond to transient perturbations, and they are important for understanding both long-term landscape evolution and short-term hazards. In this research I focus on two transient deviations that interrupt landscape steady-state equilibrium: gully and post-wildfire erosion. To understand gully erosion I relied on a natural laboratory in a semi-arid grassland. I instrumented a watershed with rain gages, soil-moisture sensors, a flume to measure water discharge, and time-lapse cameras. This instrumentation allowed me to track the hydrologic drivers of erosion. I measured the short-term erosion response in gullies with repeat terrestrial LiDAR surveys on a sub- annual basis. Combining LiDAR data with field hydrology data, I found that most erosion occurs during times of high soil moisture, which are present during summer thunderstorms and winter snowmelt. To put this erosion into a long-term context, I used optically stimulated luminescence dating to identify past episodes of gully erosion and deposition. Additionally, I studied the landscape response following a wildfire by using terrestrial LiDAR to map evolving erosion patterns over a period of two years following a wildfire. To date, it has been difficult to assess which morphologic units on a landscape are most susceptible to erosion after wildfire, but this approach made it possible to document where erosion occurred in a catchment after a wildfire. I found that although deep erosion within channels is visible to any observer, the majority of eroded sediment comes from shallow hillslope erosion. Additionally, I showed that the first summer thunderstorms after a wildfire created the most geomorphic change, because of an abundance of available sediment. Over time, subsequent storms of a similar magnitude generated less erosion because available sediment on the landscape decreased. Therefore, this work identified patterns that would be difficult to assess without high-precision equipment

Snitches get stitches: On the difficulty of whistleblowing

One of the most critical security protocol problems for humans is when you are betraying a trust, perhaps for some higher purpose, and the world can turn against you if you're caught. In this short paper, we report on efforts to enable whistleblowers to leak sensitive documents to journalists more safely. Following a survey of cases where whistleblowers were discovered due to operational or technological issues, we propose a game-theoretic model capturing the power dynamics involved in whistleblowing. We find that the whistleblower is often at the mercy of motivations and abilities of others. We identify specific areas where technology may be used to mitigate the whistleblower's risk. However we warn against technical solutionism: the main constraints are often institutional.Thales e-Securit

Interpersonal Antecedents to Selective Disclosure of Lesbian and Gay Identities at Work

Lesbian, gay, and bisexual (LGB) employees' sexual identitymay be considered a concealable stigmatised identity. Disclosing it to others at work could potentially lead to discrimination and rejection, hence threatening their inclusion. Therefore, they may hide their sexual identity instead, which may then come at the cost of, e.g., guilt for not living authentically. However, disclosure is a continuum - rather than a dichotomy - meaning that LGB workers may decide to disclose selectively, i.e., telling some, but not all co‐workers. Most literature on disclosure focuses on the interplay between intrapersonal (e.g., psychological) and contextual (e.g., organisational) characteristics, thereby somewhat overlooking the role of interpersonal (e.g., relational) characteristics. In this article, we present findings from semi‐structured, in‐depth interviews with nine Dutch lesbian and gay employees, conducted in early 2020, to gain a better understanding of interpersonal antecedents to disclosure decisions at work. Through our thematic analysis, we find that LGB workers may adopt a proactive or reactive approach to disclosure, which relates to the salience of their sexual identity at work (high/low) and their concern for anticipated acceptance. Other themes facilitating disclosure include an affective dimension, being in a relationship, and associating with the employee resource group. We demonstrate the importance of studying disclosure at the interpersonal level and reflect on how our findings relate to literature on disclosure, authenticity, belonging, and social inclusion of LGB individuals at work

Stille Reserve in Deutschland: Gemeinsamkeiten und Unterschiede zweier Konzepte; Ergebnisse für das Jahr 2019

Die Stille Reserve ist eine bedeutende Größe in der Arbeitsmarktberichterstattung, die sich nicht unmittelbar beobachten lässt. Es existieren unterschiedliche Konzepte bezüglich Definition, Datengewinnung und Blickwinkel auf den Arbeitsmarkt, mit denen eine Stille Reserve ermittelt wird. Der vorliegende Beitrag vergleicht die Schätzung der Stillen Reserve beim Statistischen Bundesamt (StBA) mit der beim Institut für Arbeitsmarkt- und Berufsforschung (IAB). Das Statistische Bundesamt schätzt sie aus einer mikroökonomischen Perspektive heraus und schließt aus Angaben von Befragten des Mikrozensus beziehungsweise der darin integrierten Arbeitskräfteerhebung auf die Zugehörigkeit zur Stillen Reserve. Zur Anwendung kommt dabei das Labour-Force-Konzept der Internationalen Arbeitsorganisation. Danach gehören zur Stillen Reserve zum einen Personen, die aktiv eine Arbeit suchen, für eine solche aber kurzfristig nicht zur Verfügung stehen und zum anderen Personen, die aktuell keine Arbeit suchen, aber grundsätzlich gerne arbeiten würden und dafür auch verfügbar sind. Das Institut für Arbeitsmarkt- und Berufsforschung schätzt die Stille Reserve aus einer makroökonomischen Perspektive unmittelbar aufgrund der jeweiligen Arbeitsmarktlage. In einem regressionsanalytischen Modell wird zuerst die Abhängigkeit einer langen Zeitreihe der Erwerbsquoten von der Arbeitsmarktlage geschätzt. Dabei ist die Datengrundlage der Erwerbsquoten zum einen der Mikrozensus, während die Lage des Arbeitsmarktes unter anderem über Quoten von registrierten Arbeitslosen der Bundesagentur für Arbeit abgebildet wird. Darüber hinaus wird ein sogenannter "Vollbeschäftigungswert" für diese Arbeitslosenquoten ermittelt und die Stille Reserve als Folge der Anspannung am Arbeitsmarkt interpretiert, das heißt, je mehr die Vollbeschäftigungsarbeitslosigkeit vom tatsächlichen Wert abweicht, umso höher ist die Stille Reserve. Hinsichtlich der Ergebnisse zur Stillen Reserve war die vom Institut für Arbeitsmarkt- und Berufsforschung geschätzte Stille Reserve in früheren Jahren immer etwas umfangreicher als die des Statistischen Bundesamtes. Die Differenzen sanken jedoch, bis schließlich für 2019 beide Ergebnisse mit jeweils knapp 900.000 Personen nahezu gleichauf lagen.The hidden labour force (also known as hidden unemployment) is an important issue in labour market reporting that cannot be observed directly. There are different concepts regarding definition, data collection and the perspective on the labour market with which a hidden labour force is estimated. This article compares the estimation approach at the Federal Statistical Office (StBA) with that at the Institute for Employment Research (IAB). The Federal Statistical Office applies a microeconomic perspective and derives the hidden labour force from information provided by respondents to the microcensus and the labour force survey (which is integrated in the microcensus in Germany). The labour force concept of the International Labour Organization is thereby applied. Consequently, the hidden labour force includes, on the one hand, people who are actively looking for work but are not available for it in the short term and, on the other hand, people who are not currently looking for work, but would like to work in principle and are available for work. The Institute for Employment Research estimates the hidden labour force from a macroeconomic perspective directly based on the actual labour market situation. As a first step the dependence of a long time series of labour force participation rates on the labour market situation is estimated using a regression model. The data basis for the labour force participation rates is, on the one hand, the microcensus, while the labour market situation is represented, amongst others, by rates of registered unemployed from the Federal Employment Agency. Secondly, a so-called "full employment level" for these unemployment rates is estimated and the hidden labour force is interpreted as a consequence of the tightening of the labour market, i.e. the more the full-employment unemployment rate deviates from the actual value, the higher the hidden labour force. With regard to the results on the hidden labour force, in earlier years, the estimation of the Institute for Employment Research was always somewhat more extensive than that of the Federal Statistical Office. However, the differences decreased until finally, for 2019, both results were almost equal at just under 900,000 persons each