Die Crowd-Community als Lieferant auf der letzten Meile?

In der Last-Mile-Logistik werden zunehmend neue Trends diskutiert. Dazu zählen automatisierte Fahrzeuge, Drohnen oder auch emissionsfreie Zustellungen unter Einsatz von E-Fahrzeugen und (Lasten-)Rädern. Aber auch Crowd Delivery (oder auch Crowd Logistics) wird als neue Form der (urbanen) Logistik gehandelt (Botsman 2014, Kunze 2016). Crowd Delivery beschreibt unter anderem das Mitbringen (z. B. von Paketen oder Gegenstände aus Geschäften) durch Privatpersonen, die ohnehin gerade unterwegs sind, sich in dem Geschäft aufhalten oder sich als Bote etwas dazu verdienen möchten. Dadurch sollen Wege eingespart, Ressourcen geschont und Städte verkehrlich entlastet werden. Doch wie kommt man zu einer lokalen “Liefer-Crowd-Community” und wie lassen sich Personen dazu motivieren? Innerhalb eines Feldtests am Grazer Fesch’Markt soll aufgezeigt werden, wie eine Crowd-Community rekrutiert, aufgebaut und auf ihre Funktions- und Motivationslogiken beim „Mitnehmen” getestet werden kann. Es wird dabei bewusst auf Geldleistungen verzichtet, um die intrinsischen Motive wie Spaß und Neugier auf ihre Anreizwirkung auszuprobieren. Die Annahmme war unter anderem, dass bei dem Fesch’Markt mit 140 Ausstellern und etwa 10.000 Besuchern eine ausreichende Nutzerfrequenz sowie ein junges, Rad-affines Publikum vorzufinden ist

WHO IS KEY...? - CHARACTERIZING VALUE ADDING USERS IN ENTERPRISE SOCIAL NETWORKS

Whereas the use of Enterprise Social Networks (ESN) is a pervasive topic in research and practice, both parties are still struggling to come to a better understanding of the role and impact of ESN in and on knowledge-intensive corporate work. As a part of this phenomenon, employees who communicate their knowledge in ESN helping other users to do their daily work play a decisive role. We need to come to a better understanding of the role and behaviour of such valu adding users. This is a prerequisite, for example, for understanding knowledge support hubs or for enabling more effective internal information and knowledge sharing. Against this background, we investigate the structural characteristics of valu adding users in ESN using qualitative text analysis and Social Network Analysis. Based on a large scale dataset of a global consulting company using the ESN Yammer.com we analyse the social relationships of valu adding users. We confirm their significant position and draw conclusions for research and practice

A Review of Information Systems Research on Online Social Networks

Over the last decade, online social networks have evolved into a global mainstream medium with increasing social, organizational, and economic impact. This paper provides a structured overview of Information Systems research on this outstanding techno-social phenomenon of the 21st century via a structured literature review. Based on our search in information systems journals and conference proceedings that resulted in 510 papers, we carve out and assess the knowledge and the research fields that have been predominantly addressed and impacted by the information systems research community so far. Moreover, we identify research gaps that future research should address. We analyze how the academic discussion on online social networks developed in the information systems literature over time, which publication outlets are most receptive to research on online social networks, which research areas have already been covered by information systems research on online social networks, and what potential future research areas exist that have not been covered by information systems research yet. We hope that our results will stimulate and guide future research in this field

Determination of the effective detector area of an energy-dispersive X-ray spectrometer at the scanning electron microscope using experimental and theoretical X-ray emission yields

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.A method is proposed to determine the effective detector area for energy-dispersive X-ray spectrometers (EDS). Nowadays, detectors are available for a wide range of nominal areas ranging from 10 up to 150 mm2. However, it remains in most cases unknown whether this nominal area coincides with the “net active sensor area” that should be given according to the related standard ISO 15632, or with any other area of the detector device. Moreover, the specific geometry of EDS installation may further reduce a given detector area. The proposed method can be applied to most scanning electron microscope/EDS configurations. The basic idea consists in a comparison of the measured count rate with the count rate resulting from known X-ray yields of copper, titanium, or silicon. The method was successfully tested on three detectors with known effective area and applied further to seven spectrometers from different manufacturers. In most cases the method gave an effective area smaller than the area given in the detector description

Swiss Corporate Sustainability Survey 2012 : Nachhaltigkeit in Schweizer Unternehmen

StudieDas Thema Nachhaltigkeit ist viel diskutiert und immer wieder Gegenstand von Untersuchungen. Der Erkenntnisgewinn der bereits existierenden Studien liegt grösstenteils in der Bedeutung von Nachhaltigkeit für Konsumenten, deren Kaufverhalten oder deren Verständnis des Begriffs Nachhaltigkeit. Wo aber steht der Werkplatz Schweiz bezüglich Nachhaltigkeit? Welche Herausforderungen sehen Unternehmen und wie wird Nachhaltigkeit in der Praxis umgesetzt? Die Studie "Swiss Corporate Sustainability Survey 2012" gibt Antwort auf diese und andere Fragen

Learning optimal environments using projected stochastic gradient ascent

In this work, we propose a new methodology for jointly sizing a dynamical system and designing its control law. First, the problem is formalized by considering parametrized reinforcement learning environments and parametrized policies. The objective of the optimization problem is to jointly find a control policy and an environment over the joint hypothesis space of parameters such that the sum of rewards gathered by the policy in this environment is maximal. The optimization problem is then addressed by generalizing the direct policy search algorithms to an algorithm we call Direct Environment Search with (projected stochastic) Gradient Ascent (DESGA). We illustrate the performance of DESGA on two benchmarks. First, we consider a parametrized space of Mass-Spring-Damper (MSD) environments and control policies. Then, we use our algorithm for optimizing the size of the components and the operation of a small-scale autonomous energy system, i.e. a solar off-grid microgrid, composed of photovoltaic panels, batteries, etc. On both benchmarks, we compare the results of the execution of DESGA with a theoretical upper-bound on the expected return. Furthermore, the performance of DESGA is compared to an alternative algorithm. The latter performs a grid discretization of the environment's hypothesis space and applies the REINFORCE algorithm to identify pairs of environments and policies resulting in a high expected return. The choice of this algorithm is also discussed and motivated. On both benchmarks, we show that DESGA and the alternative algorithm result in a set of parameters for which the expected return is nearly equal to its theoretical upper-bound. Nevertheless, the execution of DESGA is much less computationally costly

Runaway electron generation during tokamak start-up

Tokamak start-up is characterized by low electron densities and strong electric fields, in order to quickly raise the plasma current and temperature, allowing the plasma to fully ionize and magnetic flux surfaces to form. Such conditions are ideal for the formation of superthermal electrons, which may reduce the efficiency of ohmic heating and prevent the formation of a healthy thermal fusion plasma. This is of particular concern in ITER where engineering limitations put restrictions on the allowable electric fields and limit the prefill densities during start-up. In this study, we present a new 0D burn-through simulation tool called STREAM (STart-up Runaway Electron Analysis Model), which self-consistently evolves the plasma density, temperature and electric field, while accounting for the generation and loss of relativistic runaway electrons. After verifying the burn-through model, we investigate conditions under which runaway electrons can form during tokamak start-up as well as their effects on the plasma initiation. We find that Dreicer generation plays a crucial role in determining whether a discharge becomes runaway-dominated or not, and that a large number of runaway electrons could limit the ohmic heating of the plasma, thus preventing successful burn-through or further ramp-up of the plasma current. The runaway generation can be suppressed by raising the density via gas fuelling, but only if done sufficiently early. Otherwise a large runaway seed may have already been built up, which can avalanche even at relatively low electric fields and high densities

Refreshing medical students' intravenous-cannulation skills: a blinded observer three-arm randomised comparison of mental imagery, part-task trainer simulation and written instructions.

INTRODUCTION Intravenous cannulation is a core competence in medicine, but is considered challenging to learn. This study investigates the effectiveness of three educational strategies used to refresh the intravenous cannulation skills of first-year medical students: mental imagery, part-task trainer simulation and written instructions. MATERIALS AND METHODS In this single-centre randomised controlled trial, first-year medical students were assigned to one of three different refresher tutorials on intravenous cannulation. Six months after their compulsory 4 hour instructor-led intravenous-cannulation course, each student was randomised to a 6 min self-learning tutorial: a mental imagery audioguide session, hands-on intravenous cannulation on a part-task trainer or reading written instructions.Immediately after the refresher tutorials, trained evaluators who were blinded to the randomised group assessed the students' performance. Each evaluator completed a 15-item standardised checklist in an Objective Structured Clinical Examination (OSCE) station for intravenous cannulation. We performed a descriptive analysis of the data and a one-way analysis of variance. Additionally, we investigated the influence of previous intravenous cannulation experience on the total OSCE score. RESULTS AND DISCUSSION On analysing the 309 students' results, we did not find differences in the total rating of the performance (in percentage) between the three groups at the OSCE station (mental imagery group: 72.0%±17.9%; part-task trainer group: 74.4%±15.6%; written instructions group: 69.9%±16.6%, p=0.158). Multiple linear regression showed a small but statistically significant effect of students' previous intravenous cannulation experience on OSCE performance. With the same outcome, written instructions and mental imagery had a better return on effort, compared with resource-intensive hands-on training with part-task trainers. CONCLUSION A single, short refresher seems to have a limited effect on intravenous-cannulation skills in first-year medical students. Less resource-intensive interventions, such as written instructions or mental imagery, are effective compared with hands-on part-task trainer simulation for refreshing this simple but important skill. TRIAL REGISTRATION NUMBER AEARCTR-0008043