Properties of functions generalized convex with respect to a WT-system

AbstractContinuity and convergence properties of functions, generalized convex with respect to a continuous weak Tchebysheff system, are investigated. It is shown that, under certain non-degeneracy assumptions on the weak Tchebysheff system, every function in its generalized convex cone is continuous, and pointwise convergent sequences of generalized convex functions are uniformly convergent on compact subsets of the domain. Further, it is proved that, with respect to a continuous Tchebysheff system, Lp-convergence to a continuous function, pointwise convergence and uniform convergence of a sequence of generalized convex functions are equivalent on compact subsets of the domain

Home range and habitat use by Kemp's Ridley turtles in West-Central Florida

The Kemp's ridley turtle (Lepidochelys kempii) is an endangered species whose recovery depends in part on the identification and protection of required habitats. We used radio and sonic telemetry on subadult Kemp's ridley turtles to investigate home-range size and habitat use in the coastal waters of west-central Florida from 1994 to 1996. We tracked 9 turtles during May-August up to 70 days after release and fou.ld they occupied 5-30 km2 foraging ranges. Compositional analyses indicated that turtles used rock outcroppings in their foraging ranges at a significantly higher proportion than expected. based on availability within the study area. Additionally. turtles used live bottom (e.g .• sessile invertebrates) and green macroalgae habitats significantly more than seagrass habitat. Similar studies are needed through'mt the Kemp's ridley turtles' range to investigate regional and stage-specific differences in habitat use. which can then be used to conserve important foraging areas

Hybrid Beam-Steering OFDM-MIMO Radar: High 3-D Resolution With Reduced Channel Count

We report on the realization of a multichannel imaging radar that achieves uniform 2-D cross-range resolution by means of a linear array of a special form of leaky-wave antennas. The presented aperture concept enables a tradeoff between the available range resolution and a reduction in the number of channels required for a given angular resolution. The antenna front end is integrated within a multichannel radar based on stepped-carrier orthogonal frequency-division modulation, and the advantages and challenges specific to this combination are analyzed with respect to signal processing and a newly developed calibration routine. The system concept is fully implemented and verified in the form of a mobile demonstrator capable of soft real-time 3-D processing. By combining radio frequency (RF) components operating in the W-band (85-105 GHz) with the presented aperture, a 3-D resolution of less than 1.5° x 1.5° x 15 cm is demonstrated using only eight transmitters and eight receivers

Biopolitical Marketing and Technologies of Enclosure

Recently, there has been a lot of talk about consumer empowerment through new information and communication technologies. Corporate captains of marketing, Wired Magazine’s neo-libertarian techno-utopians, marketing consultants of the digital economy and many marketing academics agree that we all have more choices, more information, more entertainment, more transparency, and lower prices thanks to Amazon, Facebook, Youtube, and all the rest. We are liberated from the burdens of material ownership, free to access digital objects and services in ways that satisfy our needs in highly targeted and efficient ways. The empowerment through technology chorus is so loud and cohesive that we generally take the message for granted. And in some limited respect, consumers may feel empowered when shopping on Amazon.com or in the malls with their iPhones on hand. But let us be very clear about the idea of empowerment that is promoted by the cheerleaders of what Jodi Dean (2005) calls communicative capitalism. Real empowerment, so much should be clear, will never be “granted” to consumers by those in economic (and thus political) power. In the final analysis – and putting aside for a moment the fact that even empowered consumers are still interpellated first and foremost as subjects of consumption – the ideal of the empowered consumer (rational, enlightened, informed, restrained, un-manipulable) is completely antithetical to the needs of capital and the marketing regime within consumer capitalism. Therefore, any call for actual consumer empowerment would automatically be a radical demand and an insurgent claim aimed at undermining and replacing capital’s power to dominate the consumer totally. In the end, it is important to recognize that any technology employed by marketing today becomes a technology of enclosure (even if never completely successful), which permits empowerment only in a version sanction by capital. That is why marketing (and capital more generally [see Lazzarato, 2004]) today is biopolitical. It wants to govern life completely while appearing to not govern at all. In this chapter we argue that new technologies in contemporary marketing management are best thought of as technologies of enclosure. On the one hand, marketing encloses the subject as individualized and individuated consumer. On the other, marketing aims to enclose (ie., capture, make proprietary, appropriate) what is common or collectively produced or cherished by individuals as inalienable expressions of personal identity and agency. At the same time that marketing encloses, it operates ideologically, although not in the classical Marxist sense of creating a false consciousness. Rather, the challenge for marketers is to enclose and capture the subject and the common while appearing not to do any of these things. By accepting as non-ideological terms such as choice, identity, fulfillment, empowerment, enrichment, collaboration, creativity and so on, marketers and consumers alike choose to believe, just as anyone sensible would believe, that new techniques and technologies of enclosure are really just good marketing practice aimed at value creation and delivery, not customer domination and exploitation. We should remember that an atmosphere of distrust has accompanied the development of marketing from the beginning and marketers have long been suspected of being professional manipulators, devising salacious techniques and technologies with which to incite, manipulate and exploit consumer desire and anxiety. As Packard put it fifty years ago, “[T]hese depth manipulators are in their operations beneath the surface of conscious life, starting to acquire a power of persuasion that is becoming a matter of justifiable public scrutiny and concern” (1957, pp. 9-10). More recent popular indictments of marketing include Adam Curtis’s documentaries on The Century of the Self, Naomi Klein’s No Logo (2000), and the BBC series The Men Who Makes Us Spend (presented by Jacques Peretti). Criticism of marketers is compounded by widespread consumer cynicism regarding the genuineness of marketing messages (see Gabriel and Lang, 1995). Interestingly, the emerging generation of online marketers– typically referred to as digital or social media marketers – see marketing’s crisis of legitimacy directly tied to what it considers the corporate, top-down marketing methods devised in the 1970s and 1980s and designed to discipline and control consumers. For a new generation of tech-savvy marketers, imbued with a solid dose of techno-libertarian ideals of independence and a frontier mentality that rejects top-down authority and bureaucracy in favor of self-organizing systems, radical autonomy and freely collaborative networks, a dramatic shift in mindset was needed in the age of participatory media and Big Data. In a radical turn propagated, for example, by prominent social media marketing experts like Solis (2010) and Stratten (2010), marketing has to be ‘un’-done. The term ‘un-marketing’ rises to prominence in the consulting literature and offers a reframing of marketing that rejects corporate-controlled top-down techniques, and favours horizontal, collaborative, and participatory customer engagement (Kutcher, 2010, Stratten, 2010, 2014). In this context, the idea of online customer communities gains popularity because it provides a fantasy of restructuring marketplace relations according to principles of co-creation, sovereignty, equality, and sharing. More recently, what we call Big Data marketing is framed according to similar registers where data magnetizes consumers and marketers to a shared ethos of the “opt-in” economy (Godin, 1999). Big Data marketers – at least in the version propagated by Google’s Hal Varian, for example – pose innocuously enough as personal recommendation and consulting agents for consumers who in return for giving up personal information receive ever more relevant, valuable, and desired information, goods and services (Zuboff, 2015). Who would not like such a deal that appears to be based on liberal ideals of good intentions on all sides and the equal distribution of costs and benefits, even as companies manage communities and customer data not on behalf of consumers but on behalf of corporate profit. In sum, new marketing technologies – from blogs to communities to surveillance-based collaborative filtering and recommender systems – no matter how invasive, ever-present and insidious, have been framed by technology-driven marketers as democratizing and equalizing forces reshaping the contemporary marketplace in favor of the consumer. Customer and brand communities are happy places of collaboration and collective value creation governed by an ethos of mutual respect, sharing and dispersed control. Big Data Marketing, which aspires to intensifying consumer surveillance and control (Zuboff, 2015), is often presented as part of the contemporary ethos of collaborative ‘in-this-together-ness’ and collective support structures between companies and consumers. Marketers are asked to employ Big Data to better understand, assist, support and connect with customers; the technology magnetizing both exchange parties to a fantasy of better products, better choices, better experiences, better prices, better service and generally happier lives. To live in a world where companies strain to innovate and please consumers, all we need to do in return is give companies complete access to our personal information. Such a request makes sense to a generation of marketing professionals and consumers that have grown up with Google, Facebook and Amazon tracking its every move. In the next section we explore critically new marketing technologies such as online customer communities and Big Data, and possession of digital objects as consumer lock in. .We suggest that these technologies are technologies of Biopolitical Marketing. They aspire to enclose all forms of life for profit. We suggest that marketing innovation is now structured according to the imperative of biopolitical marketing: the making, valorizing and enclosing of all forms and expressions of life

50 Years of Test (Un)fairness: Lessons for Machine Learning

Quantitative definitions of what is unfair and what is fair have been introduced in multiple disciplines for well over 50 years, including in education, hiring, and machine learning. We trace how the notion of fairness has been defined within the testing communities of education and hiring over the past half century, exploring the cultural and social context in which different fairness definitions have emerged. In some cases, earlier definitions of fairness are similar or identical to definitions of fairness in current machine learning research, and foreshadow current formal work. In other cases, insights into what fairness means and how to measure it have largely gone overlooked. We compare past and current notions of fairness along several dimensions, including the fairness criteria, the focus of the criteria (e.g., a test, a model, or its use), the relationship of fairness to individuals, groups, and subgroups, and the mathematical method for measuring fairness (e.g., classification, regression). This work points the way towards future research and measurement of (un)fairness that builds from our modern understanding of fairness while incorporating insights from the past.Comment: FAT* '19: Conference on Fairness, Accountability, and Transparency (FAT* '19), January 29--31, 2019, Atlanta, GA, US

Symmetric Strategy Improvement

Symmetry is inherent in the definition of most of the two-player zero-sum games, including parity, mean-payoff, and discounted-payoff games. It is therefore quite surprising that no symmetric analysis techniques for these games exist. We develop a novel symmetric strategy improvement algorithm where, in each iteration, the strategies of both players are improved simultaneously. We show that symmetric strategy improvement defies Friedmann's traps, which shook the belief in the potential of classic strategy improvement to be polynomial

Unravelling the conductance path through single-porphyrin junctions

Porphyrin derivatives are key components in natural machinery enabling us to store sunlight as chemical energy. In spite of their prominent role in cascades separating electrical charges and their potential as sensitizers in molecular devices, reports concerning their electronic transport characteristics are inconsistent. Here we report a systematic investigation of electronic transport paths through single porphyrin junctions. The transport through seven structurally related porphyrin derivatives was repeatedly measured in an automatized mechanically controlled break-junction set-up and the recorded data were analyzed by an unsupervised clustering algorithm. The correlation between the appearances of similar clusters in particular sub-sets of the porphyrins with a common structural motif allowed us to assign the corresponding current path. The small series of model porphyrins allowed us to identify and distinguish three different electronic paths covering more than four orders of magnitude in conductance

How universal is the one-particle Green's function of a Luttinger liquid?

The one-particle Green's function of the Tomonaga-Luttinger model for one-dimensional interacting Fermions is discussed. Far away from the origin of the plane of space-time coordinates the function falls off like a power law. The exponent depends on the direction within the plane. For a certain form of the interaction potential or within an approximated cut-off procedure the different exponents only depend on the strength of the interaction at zero momentum and can be expressed in terms of the Luttinger liquid parameters $K_{\rho}$ and $K_{\sigma}$ of the model at hand. For a more general interaction and directions which are determined by the charge velocity $v_{\rho}$ and spin velocity $v_{\sigma}$ the exponents also depend on the smoothness of the interaction at zero momentum and the asymptotic behavior of the Green's function is not given by the Luttinger liquid parameters alone. This shows that the physics of large space-time distances in Luttinger liquids is less universal than is widely believed.Comment: 5 pages with 2 figure

Surface characterization and surface electronic structure of organic quasi-one-dimensional charge transfer salts

We have thoroughly characterized the surfaces of the organic charge-transfer salts TTF-TCNQ and (TMTSF)2PF6 which are generally acknowledged as prototypical examples of one-dimensional conductors. In particular x-ray induced photoemission spectroscopy turns out to be a valuable non-destructive diagnostic tool. We show that the observation of generic one-dimensional signatures in photoemission spectra of the valence band close to the Fermi level can be strongly affected by surface effects. Especially, great care must be exercised taking evidence for an unusual one-dimensional many-body state exclusively from the observation of a pseudogap.Comment: 11 pages, 12 figures, v2: minor changes in text and figure labellin