Coreness of Cooperative Games with Truncated Submodular Profit Functions

Coreness represents solution concepts related to core in cooperative games, which captures the stability of players. Motivated by the scale effect in social networks, economics and other scenario, we study the coreness of cooperative game with truncated submodular profit functions. Specifically, the profit function $f(\cdot)$ is defined by a truncation of a submodular function $\sigma(\cdot)$: $f(\cdot)=\sigma(\cdot)$ if $\sigma(\cdot)\geq\eta$ and $f(\cdot)=0$ otherwise, where $\eta$ is a given threshold. In this paper, we study the core and three core-related concepts of truncated submodular profit cooperative game. We first prove that whether core is empty can be decided in polynomial time and an allocation in core also can be found in polynomial time when core is not empty. When core is empty, we show hardness results and approximation algorithms for computing other core-related concepts including relative least-core value, absolute least-core value and least average dissatisfaction value

The diffusion of mobile social networking: Further study

In a recent study, Scaglione et al. (2015) analyzed the diffusion of mobile social networking in four G7 countries. Using Bass’s model and Bemmaor’s Gamma/Shifted Gompertz (G/SG) model, they found evidence of a left skew in the right-censored distributions of the times to adoption in three countries out of four. However, this conclusion relied on the skewness parameter of Bemmaor’s model. We reanalyze the data, making use of three special cases of the G/SG as well as the full version. Extending the data set to six countries, we show that (i) fitting the four models to the data does not allow us to discriminate between models, but (ii) forecasting the subsequent adoptions provides a strong support of right skewness in the data set: each country (except France) shows a substantial mass of later adopters of mobile social networking following an initial embrace of the access

Modelling internet diffusion across tourism sectors

This study investigates the Bass Diffusion model. Bass’ parameters of innovation (p) and imitation (q) help explain adoption, and the ratio of these parameters sheds insights on critical mass. This study compares the parameters p and q across 13 internet diffusion datasets in five tourism sectors across international, European and five national datasets. Information and communication technologies (ICTs) play an increasing role with tourists and tourism organisations. The data contain destination management organisations (Switzerland, Austria and Germany), tour operators (European and Swiss), accommodation providers (international chain hotels, Malaysian hotels, Swiss affiliated hotels and Swiss guest houses) and Swiss cable cars. This study also uses the Gamma/Shifted Gompertz model to incorporate heterogeneous adoption. Across the same datasets, tourism organisations showed heterogeneous adoption tendencies and the influence of critical mass. This exploratory research illustrates the usefulness of Bass’ parameters both as a foundation and to measure critical mass