A computational method to track the evolution of business models in the Digital Economy

Companies within the Digital Economy are evolving their business models as they take advantage of the opportunities afforded by emerging digital technologies. There is a need to develop methods that will allow researchers and policy makers to understand the existence of, and relationships between, the different business models within the Digital Economy and track their evolution. Such methods could also help quantify the size and growth of the Digital Economy. This paper presents a computational method, which utilizes machine learning and web scraping, to identify new business models, and a taxonomy of organisations, through the analysis of a firm’s webpage. The work seeks to provide an autonomous tool that provides regular output tracking trends in the number of firms in a market, their business model and changes in activity from product to service over time. This information would provide valuable and actionable insight for researchers, firms and markets

Siphonaptera from mammals in Alaska. Supplement IV. Revised check list for southeastern Alaska

The annotated check list grew to 15 taxa with the addition of <i>Opisodasys vesperalis</i> (Jordan) and <i>Chaetopsylla setosa</i> Rothschild, both new for Alaska: <i>Tarsopsylla octodecimdentata coloradensis</i> (Baker), new for southeastern Alaska; and an <i>Oropsylla</i> sp. Nine species of wild mammals and the domestic cat are reported as hosts of fleas in southeastern Alaska for the first time, increasing the total number of mammalian hosts to 25 identified species. Seventy new records for 10 islands and the mainland are combined with published records in a distribution table. Morphological variations in the posterior margin of sternum VII of females of <i>Monopsyllus ciliatus protinus</i> (Jordan) and distinguishing characters of three other taxa are illustrated

Assessing the impact of digital innovations in the London transportation network

Findings suggest that the digital innovations introduced by Uber disrupted the market and changed the nature of how people interact with the wider transportation system. Uber has made it easier for individuals to move around the city, filling a gap in the existing transportation system. Uber have rapidly achieved a leading position in the private hire taxi service across the city. Regulation for Black Cabs needs to change if they are to compete and remain a service in the broader customer market

CONVERSION ATTRIBUTION BASED ON VIEWABLE IMPRESSIONS

Viewable View Through Conversion (vVTC) are introduced in this publication. vVTC is a way to attribute view-through conversion events back to the impressions that deserve credit for them. vVTC may measure viewability for each impression and attribute conversions to impressions based in part on the measured viewability of each impression. In some implementations, vVTC considers only viewable impressions for attribution

Design to Delivery of Additively Manufactured Propulsion Systems for the SWARM-EX Mission

Recent progress in miniaturized spacecraft propulsion technology has allowed for the development of complex, multi-vehicle missions which enable the cost-effective realization of science goals that would previously have been prohibitively expensive. The upcoming NSF-funded Space Weather Atmospheric Reconfigurable Multiscale EXperiment (SWARM-EX) mission leverages these swarm techniques to demonstrate novel autonomous formation flying capabilities while characterizing the spatial and temporal variability of ion-neutral interactions in the Equatorial Ionization Anomaly and Equatorial Thermospheric Anomaly. SWARM-EX will fly a trio of 3U CubeSats in a variety of relative orbits with along-track separations ranging from 3 km to 1300 km. To achieve the required orbital variability, the mission uses a novel hybrid approach of differential drag and an onboard cold gas propulsion system. Mission requirements necessitate a propulsion system that provides each spacecraft with 15 m/s of ∆V and a maximum thrust greater than 5 mN in a volume of roughly 0.7U (7 cm x 10 cm x 10 cm). Unlike many other CubeSat-scale cold gas propulsion systems which are used to provide attitude control and perform reaction wheel desaturation burns, the primary objective of the SWARM-EX propulsion system (SEPS) is to provide ∆V during maneuvers. The Georgia Institute of Technology Space Systems Design Laboratory (SSDL) is conducting the design, assembly, and testing of three identical SEPS. By leveraging additive manufacturing technology, the propellant tanks, nozzle, and tubing are combined into a single structure that efficiently utilizes the allocated volume. The propulsion system uses two-phase R-236fa refrigerant as a propellant, which allows for the storage of the majority of propellant mass as a liquid to maximize volumetric efficiency. The final design allows for 17 m/s of total ∆V per spacecraft and a measured maximum thrust of approximately 35 mN for short pulse lengths at room temperature. Each individual propulsion system has a volume under 0.5U (489 cm3), making them among the smallest formation-flying CubeSat-scale propulsion systems developed thus far. Owing to their two-phase propellant storage and single nozzle, the SEPS have a high impulse density (total impulse provided per unit of system volume) of 176 N-s/L. Additionally, process improvements to mitigate known failure modes such as propellant leaks and foreign object debris are implemented. This paper describes the entire design-to-delivery life cycle of the SWARM-EX propulsion units, including pertinent mission requirements, propulsion system design methodologies, assembly, and testing. Major lessons learned for future small satellite propulsive endeavors are also detailed