L imited version, time-locked, and hybrid are three software free trial strategies employed by software firms to exploit increased installed base and/or reduction of consumers' uncertainty about software quality. We develop an analytical model to examine these three software free trial strategies. We find that the hybrid strategy weakly dominates the limited and time-locked versions, and the intensity of the network effects is a key factor determining which strategy is optimal.

Summary The monitoring and localization of defects and wire breaking of bridge cable are vital to the safe operation of the whole bridge. In this work, an innovative monitoring method that uses waveguides to draw out the steel wires at the end of the cable is proposed. This monitoring method can effectively capture the acoustic emission (AE) signal produced by defects and wire breaking of the cable. The transverse position of the wire breaking can also be accurately located so as to provide basis for the decision making of maintenance department. The pencil‐lead breaks (PLB) test method is utilized to investigate the influence of the transition modes between the waveguide and the sensor and the connection modes between the waveguide and the cone on the AE signal. The PLB test and tensile test method are utilized to examine the AE signal characteristics of different sensors at the end of steel wires. Results showed that the cone transition between the waveguide and the sensor and the welding connection between waveguide and cone exhibit the minimum effect on AE waveform and parameters, such as amplitude, compared with that of the reference sensor without waveguide. In the tensile test, the transverse position of the wire breaking cannot be identified by analyzing the AE signals collected by each senor when the wire breaks, whereas it can be identified in the process of defects before the wire breaks.

This research aims to identify price determinants for sharing economy-based accommodation services and to further use the identified price determinants to predict accommodation prices. A dataset drawn from Airbnb.com, was collected for analysis. We identify price determinants from five categories. The top five price determinants are identified as room type, city, distance to tourist attractions, number of pictures posted, and number of amenities provided. More importantly, we find that interaction effects between variables can also significantly influence price. Finally, a series of price prediction models are built based on the identified price determinants.

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Acoustic emission testing of semirigid base specimens subjected to uniaxial compression was performed by a mechanical testing machine and AE system to find the AE criterion of the uniaxial compressive failure process of the semirigid base of dense skeleton types. AE counts, cumulative AE energy, andb-value were discussed. Results indicated that the AE parameters could reflect the failure process of semirigid bases of dense skeleton types. The failure process mainly underwent three stages that were divided based on AE parameters into initial stage of development, stable growth stage, and unstable stage. The knees of the AE parameter curve were at 25% and 85% of the ultimate load. The variation of theb-value could indicate the stress and be a precursor to the failure of the specimens. In general terms, ab-value greater than 3.5 indicates that specimens are at the initial stage of development. Ab-value between 1 and 2 indicates that the specimens are at the stable growth stage. If theb-value seems to fluctuate and increase, the specimens are at the unstable stage. Moreover, the AE parameters indicated that attaching sensors to the waist of specimens was superior to that at other locations of a specimen.