5702445
The role of moderating factors in user technology acceptance
Along with increasing investments in new technologies, user technology acceptance becomes a frequently studied topic in the information systems discipline. The last two decades have seen user acceptance models being proposed, tested, refined, extended and unified. These models have contributed to our understanding of user technology acceptance factors and their relationships. Yet they have also presented two limitations: the relatively low explanatory power and inconsistent influences of the factors across studies. Several researchers have recently started to examine the potential moderating effects that may overcome these limitations. However, studies in this direction are far from being conclusive. This study attempts to provide a systematic analysis of the explanatory and situational limitations of existing technology acceptance studies. Ten moderating factors are identified and categorized into three groups: organizational factors, technological factors and individual factors. An integrative model is subsequently established, followed by corresponding propositions pertaining to the moderating factors.
13409963
Affective Quality and Cognitive Absorption: Extending Technology Acceptance Research
Agarwal and Karahanna (2000) suggested that holistic user experiences with IT contribute to users’ evaluation of and reaction to using the technology. They proposed and empirically tested a construct named cognitive absorption that has preceding effects on important user technology acceptance constructs. We propose that an important antecedent of cognitive absorption is perceived affective quality (PAQ) of the target IT. Such perception is a user’s impression on the IT itself prior to any other cognitive appraisal and evaluation on the consequences or potential interactions with the IT. Rooted in psychological work on affect and cognition, we develop a theoretical model that depicts the causal relationships among PAQ, cognitive absorption, cognitive beliefs, and IT use intention. A field study was conducted to validate this model. Our results indicate that PAQ is a strong antecedent to cognitive absorption, explaining 39% variances in it, and has direct impacts on cognitive beliefs.
22897954
A methodological analysis of user technology acceptance
The majority of research on user technology acceptance, e.g. technology acceptance model, focuses on individual users' beliefs, attitudes, and behavioral intentions toward technology use. In this paper, we attempt to examine prior research on user technology acceptance from a methodological angle by borrowing Markus and Robey's research framework (1988). We find that prior studies usually take technology imperative perspective, use variance theories, and emphasize the micro level of analysis. Therefore, we propose an "emergent perspective - process theories - mixed level of analysis" approach to analyze user technology acceptance. From this perspective, a new model is proposed and several propositions are derived and discussed. This paper draws on several prior theories and models, such as the technology acceptance model, computer self-efficacy and the task-technology fit model, but reassembles them in a novel way. The paper concludes with the research and practical implications.
16767252
Constant quality rate allocation for FGS coding using composite R-D analysis
In this correspondence, we propose a constant quality rate allocation algorithm for fine granularity scalability (FGS) coded videos. The rate allocation problem is formulated as a constrained minimization of quality fluctuation. The minimization is solved using a composite rate distortion (R-D) analysis. For a set of video frames, a composite R-D curve is first computed and then used for computing the optimal rate allocation. This algorithm is efficient because it is neither iterative nor recursive. After the composite R-D curve is computed, it can be used for optimal rate allocation of any rate budget. Moreover, the composite R-D curve can be updated efficiently over sliding windows. Experimental results have shown both the effectiveness and the efficiency of the proposed algorithm.
8069730
Development and validation of COMPASS force field parameters for molecules with aliphatic azide chains
To establish force-field-based (molecular) modeling capability that will accurately predict condensed-phase thermophysical properties for materials containing aliphatic azide chains, potential parameters for atom types unique to such chains have been developed and added to the COMPASS force field. The development effort identified the need to define four new atom types: one for each of the three azide nitrogen atoms and one for the carbon atom bonded to the azide. Calculations performed with the expanded force field yield (gas-phase) molecular structures and vibrational frequencies for hydrazoic acid, azidomethane, and the anti and gauche forms of azidoethane in good agreement with values determined experimentally and/or through computational quantum mechanics. Liquid densities calculated via molecular dynamics (MD) simulations were also in good agreement with published values for 13 of 15 training set compounds, the exceptions being hydrazoic acid and azidomethane. Of the 13 compounds whose densities are well simulated, nine have experimentally determined heats of vaporization reported in the open literature, and in all of these cases, MD simulated values for this property are in reasonable agreement with the published values. Simulations with the force field also yielded reasonable density estimates for a series of 2-azidoethanamines that have been synthesized and tested for use as hydrazine-alternative fuels.
10091977
Urea: An ab initio and force field study of the gas and solid phases
We have studied the gaseous and solid phases of urea using both quantum mechanics calculation and force field simulation methods. Our ab initio calculations confirmed experimental observations that urea structure is planar in the crystal, but nonplanar in the gas phase. Based on electron structure analysis, we suggest that the significant difference between these two structures in different environments can be qualitatively explained by two resonance structures. The planar structure is more polarized than the nonplanar one, and the former is stabilized in the solid phases due to strong electrostatic interactions. We found classical force field method is incapable to represent such strong polarization effect. Using molecular dynamics simulations with a force field optimized for condensed phases, we calculated the crystalline structures of urea in the temperature range of 12 to 293 K. The densities as well as cell parameters are within 2% deviation from the experimental data in the temperature range.