This study aims to propose an integrated model of smartphone adoption that incorporates social influences (SIs), perceived technicality, as well as hedonic and utilitarian attitudes into the technology acceptance model. The proposed model was empirically evaluated by using survey data collected from 239 Korean college students to investigate their perception and attitudes toward smartphone adoption intention. Our results show that users' attitudes and their adoption intention are highly influenced by SI and positive self-image. This implies that a smartphone is a symbolic product that can signal affiliation and enhance the users' status in a group. The results also indicate that hedonic enjoyment is equally important as utilitarian usefulness in predicting the adoption intention, and the two variables mediate the relationships between SI, positive self-image, perceived technicality, and the intention to use. Consequently, the results reveal that smartphones are convergent media that can be viewed as both task-oriented and entertainment-oriented devices.

We performed equilibrium and nonequilibrium molecular dynamics simulation to study electro-osmotic flows inside charged nanochannels with different types of surface roughness. We modeled surface roughness as a sequence of two-dimensional subnanoscale grooves and ridges (step function-type roughness) along the flow direction. The amplitude, spatial period, and symmetry of surface roughness were varied. The amplitude of surface roughness was on the order of the Debye length. The walls have uniform negative charges at the interface with fluids. We included only positive ions (counterions) for simplicity of computation. For the smooth wall, we compared our molecular dynamics simulation results to the well-known Poisson-Boltzmann theory. The density profiles of water molecules showed "layering" near the wall. For the rough walls, the density profiles measured from the wall are similar to those for the smooth wall except near where the steps are located. Because of the layering of water molecules and the finite size effect of ions and the walls, the ionic distribution departs from the Boltzmann distribution. To further understand the structure of water molecules and ions, we computed the polarization density. Near the wall, its z component dominates the other components, indicating the preferred orientation ("ordering") of water molecules. Especially, inside the groove for the rough walls, its maximum is 10% higher (stronger ordering) than for the smooth wall. The dielectric constant, computed with a Clausius-Mosotti-type equation, confirmed the ordering near the wall and the enhanced ordering inside the groove. The residence time and the diffusion coefficient, computed using the velocity autocorrelation function, showed that the diffusion of water and ions along the direction normal to the wall is significantly reduced near the wall and further decreases inside the groove. Along the flow direction, the diffusion of water and ions inside the groove is significantly lowered while it is similar to the bulk value elsewhere. We performed nonequilibrium molecular dynamics simulation to compute electro-osmotic velocities and flow rates. The velocity profiles correspond to those for overlapped electric double layers. For the rough walls, velocity inside the groove is close to zero, meaning that the channel height is effectively reduced. The flow rate was found to decrease as the period of surface roughness decreases or the amplitude of surface roughness increases. We defined the zeta potential as the electrostatic potential at the location of a slip plane. We computed the electrostatic potential with the ionic distribution and the dielectric constant both from our molecular dynamics simulation. We estimated the slip plane from the velocity profile. The zeta potential showed the same trend as the flow rate: it decreases with an increasing amplitude and a decreasing period of surface roughness.

This study examines smartphone adoption behavior among American college students by combining all components of innovation diffusion theory (IDT), the technology acceptance model (TAM), the value-based adoption model (VAM), and the social influence (SI) model. Data indicate that the smartphone adoption rates are beyond the early majority and are now approaching the late majority. The findings of analysis of variance tests revealed that all variables of TAM, VAM, and SI varied across the adopter groups: The current adopter's mean values of the variables were the highest, followed by those of potential and nonadoption groups. Multinomial logistic regression (MLR) analyses revealed that perceived value and affiliation mainly determine the different perceptions of adoption groups. Smartphone adoption, however, was relatively unaffected by perceived ease of use and perceived usefulness. Perceived popularity, perceived price, and ethnicity played a role in distinctive determinants between current adopters and nonadopters. The results imply that adopters perceive smartphones as not only a worthwhile device in which to invest money but also a symbolic device to signal their affiliation and timely technology adoption. Another intriguing finding is the differences of interest in contents between current adopters and nonadopters. Social interactions via social networking services, acquisition for lifestyle, information seeking, and entertainment via gaming were the main applications of interest. IntroductionIn recent years the use of smartphones has become more widespread and continues to grow significantly. Despite the lack of a standard definition, the term smartphone generally refers to a mobile phone offering some computer-like functionalities, including Internet access. Because of these advanced functionalities, smartphones have been rapidly replacing traditional cellular phones since 2007, when Apple launched the first iPhone. As of February 2012, 46% of the American adult population owned a smartphone (Pew Internet, 2012). In particular, the smartphone adoption rate of American young adults whose ages range from 18 to 24 is 67%, which is much higher than the average rates for other generations. The rapid penetration rate raises the question of why the growth rate of smartphone adoption has been so high and what features draw people to the new mobile device. Thus, because nearly half of American adults now use a smartphone, a study is needed to examine what factors have accelerated smartphone adoption among college students.Despite the quick penetration of smartphones into daily use, studies on smartphone adoption are lacking. One reason may lie in the conventional assumption that the smartphone adoption process is not very different from the adoption process of other personal information devices, such as personal digital assistants, the Internet, and mobile phones. This assumption, however, should be reconsidered in the case of smartphone adoption. According to data released by the Nielson Company (2011), women are ...

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We propose a new type of micro/nano fluidic mixer based on non-equilibrium electrokinetics and demonstrate its mixing performance. We fabricate the device with two-step reactive ion etching, one for nanochannels and one for microchannels. Mixing is achieved by strong vortex structures formed near the micro/nano channel interface. We expect the proposed device to be beneficial in the development of micro total analysis systems, since it is simple in its design with minimal fabrication complications.