On Smartphone Indispensability: A Country-level Exploratory Study

To understand a pervasive but seldom examined phenomenon that people become heavily dependent on their smartphone, this exploratory study introduces a new concept, smartphone indispensability, defined as the intensive psychological dependency on smartphones due to the absolute necessary and primary role of smartphones in ones’ daily life. Observing that the smartphone indispensability is heterogeneously distributed across country, we argue that this heterogeneity results from a particular country-specific variable, national happiness. By integrating public and proprietary data on global smartphone usage and country characteristics, we use country- and time-fixed effects model and instrumental variable analysis to empirically explore the causal effect of national happiness on the average smartphone indispensability of the population in a country. We also investigate the effect of national happiness on mobile consumption and the mediating role of smartphone indispensability in this relationship. Potential theoretical, managerial and political implications are discussed

Research on the Application of VIC-3D Technology in Civil Engineering

Digital image correlation method has been widely used in various research fields of civil engineering since it was proposed, because of its convenient and simple, full-field measurement, good environmental adaptability and other characteristics. It has become an important measurement method in various research fields. The CCD camera is used to match the position of the same pixel in the two speckle images before and after the surface deformation of the specimen to obtain the displacement vector of the pixel, and record the change of the speckle characteristics of the specimen surface. Combined with computer vision and digital image processing technology, the physical quantities such as the morphology, displacement and strain of the object surface can be accurately measured. Therefore, this paper introduces the application of VIC-3D technology in civil engineering in detail.

Emergence, Evolution and Scaling of Online Social Networks

This work was partially supported by AFOSR under Grant No. FA9550-10-1-0083, NSF under Grant No. CDI-1026710, NSF of China under Grants Nos. 61473060 and 11275003, and NBRPC under Grant No. 2010CB731403. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD