Last-Mile Delivery Methods in E-Commerce : Does Perceived Sustainability Matter for Consumer Acceptance and Usage ?

Sustainability has gained significant importance in e-commerce, as it impacts both consumer behavior and company success. This paper contributes to the literature on sustainability in ecommerce by studying the perceived sustainability of three common last-mile delivery methods (home delivery, parcel lockers, and click and collect) and other drivers of consumers’ acceptance of each delivery method (perceived costs, convenience). Based on a review of the relevant literature, a conceptual model integrating key determinants of consumers’ attitudes to delivery methods and their intention to use them is derived and tested using a sample of 536 German online buyers. The results demonstrate that perceived ease of use and perceived usefulness increase the acceptance of the delivery methods, whereas perceived costs constrain it. The findings reveal significant influences of perceived sustainability on the acceptance of the delivery methods, which vary between its three components (environmental, economic, and social) and regarding the delivery method. Retailers and collaborating parcel delivery services are advised to continue making last-mile delivery methods more convenient. However, they are also advised to implement standards in terms of environmental and social sustainability and inform customers about their efforts regarding sustainable last-mile delivery to build a competitive advantage in omni-channel retailing

Dynamic Magnetography of Solar Flaring Loops

We develop a practical forward fitting method based on the SIMPLEX algorithm with shaking, which allows the derivation of the magnetic field and other parameters along a solar flaring loop using microwave imaging spectroscopy of gyrosynchrotron emission. We illustrate the method using a model loop with spatially varying magnetic field, filled with uniform ambient density and an evenly distributed fast electron population with an isotropic, power-law energy distribution.Comment: ApJ Letters, in pres

Hierarchical Salient Object Detection for Assisted Grasping

Visual scene decomposition into semantic entities is one of the major challenges when creating a reliable object grasping system. Recently, we introduced a bottom-up hierarchical clustering approach which is able to segment objects and parts in a scene. In this paper, we introduce a transform from such a segmentation into a corresponding, hierarchical saliency function. In comprehensive experiments we demonstrate its ability to detect salient objects in a scene. Furthermore, this hierarchical saliency defines a most salient corresponding region (scale) for every point in an image. Based on this, an easy-to-use pick and place manipulation system was developed and tested exemplarily.Comment: Accepted for ICRA 201

Development of a monthly to seasonal forecast framework tailored to inland waterway transport in central Europe

Traditionally, navigation-related forecasts in central Europe cover short- to medium-range lead times linked to the travel times of vessels to pass the main waterway bottlenecks leaving the loading ports. Without doubt, this aspect is still essential for navigational users, but in light of the growing political intention to use the free capacity of the inland waterway transport in Europe, additional lead time supporting strategic decisions is more and more in demand. However, no such predictions offering extended lead times of several weeks up to several months currently exist for considerable parts of the European waterway network. This paper describes the set-up of a monthly to seasonal forecasting system for the German stretches of the international waterways of the Rhine, Danube and Elbe rivers. Two competitive forecast approaches have been implemented: the dynamical set-up forces a hydrological model with post-processed outputs from ECMWF general circulation model System 4, whereas the statistical approach is based on the empirical relationship ("teleconnection") of global oceanic, climate and regional hydro-meteorological data with river flows. The performance of both forecast methods is evaluated in relation to the climatological forecast (ensemble of historical streamflow) and the well-known ensemble streamflow prediction approach (ESP, ensemble based on historical meteorology) using common performance indicators (correlation coefficient; mean absolute error, skill score; mean squared error, skill score; and continuous ranked probability, skill score) and an impact-based evaluation quantifying the potential economic gain. The following four key findings result from this study: (1) as former studies for other regions of central Europe indicate, the accuracy and/or skill of the meteorological forcing used has a larger effect than the quality of initial hydrological conditions for relevant stations along the German waterways. (2) Despite the predictive limitations on longer lead times in central Europe, this study reveals the existence of a valuable predictability of streamflow on monthly up to seasonal timescales along the Rhine, upper Danube and Elbe waterways, and the Elbe achieves the highest skill and economic value. (3) The more physically based and the statistical approach are able to improve the predictive skills and economic value compared to climatology and the ESP approach. The specific forecast skill highly depends on the forecast location, the lead time and the season. (4) Currently, the statistical approach seems to be most skilful for the three waterways investigated. The lagged relationship between the monthly and/or seasonal streamflow and the climatic and/or oceanic variables vary between 1 month (e.g. local precipitation, temperature and soil moisture) up to 6 months (e.g. sea surface temperature). Besides focusing on improving the forecast methodology, especially by combining the individual approaches, the focus is on developing useful forecast products on monthly to seasonal timescales for waterway transport and to operationalize the related forecasting service

We Could, but Should We? Ethical Considerations for Providing Access to GeoCities and Other Historical Digital Collections

We live in an era in which the ways that we can make sense of our past are evolving as more artifacts from that past become digital. At the same time, the responsibilities of traditional gatekeepers who have negotiated the ethics of historical data collection and use, such as librarians and archivists, are increasingly being sidelined by the system builders who decide whether and how to provide access to historical digital collections, often without sufficient reflection on the ethical issues at hand. It is our aim to better prepare system builders to grapple with these issues. This paper focuses discussions around one such digital collection from the dawn of the web, asking what sorts of analyses can and should be conducted on archival copies of the GeoCities web hosting platform that dates to 1994.This research was supported by the Natural Sciences and Engineering Research Council of Canada, the Social Sciences and Humanities Research Council of Canada, the US National Science Foundation (grants 1618695 and 1704369), the Andrew W. Mellon Foundation, Start Smart Labs, and Compute Canada

The Change of Motives to Become and to be a Party Member. An Empirical Analysis of the German Party Membership Studies 1998, 2009 and 2017

In this paper, the thesis is put forward that selective outcome incentives for party membership gain relevance over time. Two possible mechanisms are identified as the cause of this increase in importance: a supply-side mechanism based on processes of societal change that took place through generational succession and a demand-side mechanism focusing on shifts in the self-image and organizational structure of political parties. The supply-side mechanism should lead to changes in the motives of potential members, whereas the demand-side mechanism alters the incentives potential and current members are exposed to. The empirical analyses are based on the German Party Membership Studies of 1998, 2009 and 2017. These three studies are nationwide representative surveys of the members of the following six parties: Christian Democratic Union (CDU), Christian Social Union (CSU), Social Democratic Party of Germany (SPD), Free Democratic Party (FDP), Alliance90/The Greens (Bündnis90/Die Grünen), and The Left (Die Linke). Within the German Party Membership Studies, both the motives for joining the party and the current membership motives are surveyed. Empirically, it is shown that there is indeed an increase in the importance of selective outcome membership motives over the period under study. The mechanisms behind this increase in importance are investigated using multivariate Age-Period-Cohort (APC) models based on the cumulated data of the German Party Membership Studies. These analyses are based on a total of nearly 30,000 cases. The results of the APC analyses are largely consistent with the supply-side explanation of the increased importance of selective outcome motives for party entry and membership. The demand-side explanation is only partially confirmed.In diesem Beitrag wird die These aufgestellt, dass selektive ergebnisbezogene Anreize für die Parteimitgliedschaft im Laufe der Zeit an Bedeutung gewinnen. Als Ursache für diesen Bedeutungszuwachs werden zwei mögliche Mechanismen identifiziert: ein angebotsseitiger Mechanismus, der auf gesellschaftlichen Veränderungsprozessen im Zuge der Generationensukzession beruht, und ein nachfrageseitiger Mechanismus, der sich auf Veränderungen im Selbstverständnis und in der Organisationsstruktur der politischen Parteien bezieht. Der angebotsseitige Mechanismus sollte zu Veränderungen in den Motiven potenzieller Mitglieder führen, während der nachfrageseitige Mechanismus die Anreize verändert, denen potenzielle und aktuelle Mitglieder ausgesetzt sind. Die empirischen Analysen basieren auf den Deutschen Parteimitgliederstudien von 1998, 2009 und 2017. Bei diesen drei Studien handelt es sich um bundesweite repräsentative Befragungen der Mitglieder der folgenden sechs Parteien: Christlich Demokratische Union (CDU), Christlich Soziale Union (CSU), Sozialdemokratische Partei Deutschlands (SPD), Freie Demokratische Partei (FDP), Bündnis90/Die Grünen und Die Linke. Im Rahmen der Deutschen Parteimitgliederstudien werden sowohl die Motive für den Parteieintritt als auch die aktuellen Mitgliedschaftsmotive erhoben. Empirisch zeigt sich, dass die Bedeutung selektiver ergebnisbezogener Motive für die Mitgliedschaft im Untersuchungszeitraum tatsächlich zunimmt. Die Mechanismen, die hinter diesem Bedeutungszuwachs stehen, werden mit Hilfe von multivariaten Alters-Perioden-Kohorten (APK)-Modellen auf der Basis der kumulierten Daten der Deutschen Parteimitgliederstudien untersucht. Diese Analysen beruhen auf insgesamt fast 30.000 Fällen. Die Ergebnisse der APK-Analysen sind weitgehend konsistent mit der angebotsseitigen Erklärung der gestiegenen Bedeutung selektiver ergebnisbezogener Motive für den Parteieintritt und die Mitgliedschaft. Die nachfrageseitige Erklärung wird nur teilweise bestätigt

Changes in the genetic structure of an invasive earthworm species (Lumbricus terrestris, Lumbricidae) along an urban – rural gradient in North America

European earthworms were introduced to North America by European settlers about 400 years ago. Human-mediated introductions significantly contributed to the spread of European species, which commonly are used as fishing bait and are often disposed deliberately in the wild. We investigated the genetic structure of Lumbricus terrestris in a 100km range south of Calgary, Canada, an area that likely was devoid of this species two decades ago. Genetic relationships among populations, gene flow, and migration events among populations were investigated using seven microsatellite markers and the mitochondrial 16S rDNA gene. Earthworms were collected at different distances from the city and included fishing baits from three different bait distributors. The results suggest that field populations in Alberta established rather recently and that bait and field individuals in the study area have a common origin. Genetic variance within populations decreased outside of the urban area, and the most distant populations likely originated from a single introduction event. The results emphasise the utility of molecular tools to understand the spatial extent and connectivity of populations of exotic species, in particular soil-dwelling species, that invade native ecosystems and to obtain information on the origin of populations. Such information is crucial for developing management and prevention strategies to limit and control establishment of non-native earthworms in North America.Peer reviewe

Radio Spectral Evolution of an X-ray Poor Impulsive Solar Flare: Implications for Plasma Heating and Electron Acceleration

We present radio and X-ray observations of an impulsive solar flare that was moderately intense in microwaves, yet showed very meager EUV and X-ray emission. The flare occurred on 2001 Oct 24 and was well-observed at radio wavelengths by the Nobeyama Radioheliograph (NoRH), the Nobeyama Radio Polarimeters (NoRP), and by the Owens Valley Solar Array (OVSA). It was also observed in EUV and X-ray wavelength bands by the TRACE, GOES, and Yohkoh satellites. We find that the impulsive onset of the radio emission is progressively delayed with increasing frequency relative to the onset of hard X-ray emission. In contrast, the time of flux density maximum is progressively delayed with decreasing frequency. The decay phase is independent of radio frequency. The simple source morphology and the excellent spectral coverage at radio wavelengths allowed us to employ a nonlinear chi-squared minimization scheme to fit the time series of radio spectra to a source model that accounts for the observed radio emission in terms of gyrosynchrotron radiation from MeV-energy electrons in a relatively dense thermal plasma. We discuss plasma heating and electron acceleration in view of the parametric trends implied by the model fitting. We suggest that stochastic acceleration likely plays a role in accelerating the radio-emitting electrons.Comment: 22 pages, 10 figure

Competitive Accretion in Sheet Geometry and the Stellar IMF

We report a set of numerical experiments aimed at addressing the applicability of competitive accretion to explain the high-mass end of the stellar initial mass function in a sheet geometry with shallow gravitational potential, in contrast to most previous simulations which have assumed formation in a cluster gravitational potential. Our flat cloud geometry is motivated by models of molecular cloud formation due to large-scale flows in the interstellar medium. The experiments consisted of SPH simulations of gas accretion onto sink particles formed rapidly from Jeans-unstable dense clumps placed randomly in the finite sheet. These simplifications allow us to study accretion with a minimum of free parameters, and to develop better statistics on the resulting mass spectra. We considered both clumps of equal mass and gaussian distributions of masses, and either uniform or spatially-varying gas densities. In all cases, the sink mass function develops a power law tail at high masses, with $dN/dlog M \propto M^{-\Gamma}$. The accretion rates of individual sinks follow $\dot{M} \propto M^2$ at high masses; this results in a continual flattening of the slope of the mass function towards an asymptotic form $\Gamma \sim 1$ (where the Salpeter slope is $\Gamma = 1.35$). The asymptotic limit is most rapidly reached when starting from a relatively broad distribution of initial sink masses. In general the resulting upper mass slope is correlated with the maximum sink mass; higher sink masses are found in simulations with flatter upper mass slopes. Although these simulations are of a highly idealized situation, the results suggest that competitive accretion may be relevant in a wider variety of environments than previously considered, and in particular that the upper mass distribution may generally evolve towards a limiting value of $\Gamma \sim 1$.Comment: 20 pages, 12 figure