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91.
This research analyzes network effects in technology acceptance. The hypothesis is that the size of the user network affects technology acceptance. Even today, empirical measurement of network effects is challenging and there is a lack of experimental evidence. In order to investigate and measure the relationship between network size (number of adopters) and user acceptance, technology acceptance research needs to broaden its scope and approaches. To overcome this limitation we reproduce a particular type of technology acceptance process in a laboratory experiment, controlling for user network size and testing its influence on user perceptions and, ultimately, on acceptance decisions. We measured user perceptions and analyzed the data using consolidated and tested technology acceptance models. The results confirm our hypothesis, showing a significant effect of user network size on user perceptions. Finally, we discuss the theoretical and managerial implications of our approach and findings.  相似文献   
92.
Cultural heritage sites and artefacts get a significant added value from high-resolution 3D models. These models are increasingly available due to improvements in technology and to higher integration of survey techniques such as laser scanning and photogrammetry. In this paper we present a case study on the development of a web-based application for user access and interactive exploration of three-dimensional models by providing integrated geometrical and non-geometrical information into an intuitive interface. The main feature of this interactive system is to provide the user with a completely new visit experience based on a free interactive exploration interface of the object (i.e., not constrained by any predefined pathway) and on the opportunity to get more detailed information on specific parts of interest. A parallel aim achieved was to use, in data processing and in the architecture, open source tools and free software, thus providing full transparency on adopted methodology and data processing methods, and a cost effective solution both for server and client. Furthermore, the aspect of data size has been considered using a segmentation and simplification scheme and server-side data management to keep transmission size to a minimum, thus improving access speed.  相似文献   
93.
The cross-linking processes of three drying oils (poppy, linseed, walnut), a class of organic compounds very important in the field of artworks, were studied by means of 1H-NMR spectroscopy, following the change of the protons signals when oils are heated at 60 °C in the presence of air or nitrogen gas. This preliminary information is particularly important to identify the presence of drying oils within a solid painting film. We demonstrated that it was possible to study these films by swollen-state NMR, an innovative spectroscopy method that can directly analyze very small semisolid samples instead of solutions. The main advantages of this method are the short time of analysis, the possibility to analyze samples without any preliminary treatment, and the small quantity of the sample required. Therefore, swollen-state NMR technique was used to characterize three real painting films: in this way, we succeeded in recognizing in real paintings specimens the presence of drying oils employed as binders, avoiding any interferences due to other organic compounds acting as binding agents, like waxes or egg-yolk media.  相似文献   
94.
Microrheometry is very important for exploring rheological behaviours of several systems when conventional techniques fail. Microrheometrical measurements are usually carried out in microfluidic devices made of Poly(dimethylsiloxane) (PDMS). Although PDMS is a very cheap material, it is also very easy to deform. In particular, a liquid flowing in a PDMS device, in some circumstances, can effectively deform the microchannel, thus altering the flow conditions. The measure of the fluid relaxation time might be performed through viscoelasticity induced particle migration in microfluidics devices. If the channel walls are deformed by the flow, the resulting measured value of the relaxation time could be not reliable. In this work, we study the effect of channel deformation on particle migration in square-shaped microchannel. Experiments are carried out in several PolyEthylene Oxyde solutions flowing in two devices made of PDMS and Poly(methylmethacrylate) (PMMA). The relevance of wall rigidity on particle migration is investigated, and the corresponding importance of wall rigidity on the determination of the relaxation time of the suspending liquid is examined.  相似文献   
95.
Research in Higher Education - We test for the signaling hypothesis versus the human capital theory using the Wiles test in a country which has experienced a dramatic increase in the supply of...  相似文献   
96.
Motion capture through inertial sensors is becoming popular, but its accuracy to describe kinematics during changes in walking speed is unknown. The aim of this study was to determine the accuracy of trunk speed extracted using an inertial motion system compared to a gold standard optical motion system, during steady walking and stationary periods. Eleven participants walked on pre-established paths marked on the floor. Between each lap, a 1-second stationary transition period at the initial position was included prior to the next lap. Resultant trunk speed during the walking and transition periods were extracted from an inertial (240 Hz sampling rate) and an optical system (120 Hz sampling rate) to calculate the agreement (Pearson’s correlation coefficient) and relative root mean square errors between both systems. The agreement for the resultant trunk speed between the inertial system and the optical system was strong (0.67 < r ≤ 0.9) for both walking and transition periods. Moreover, relative root mean square error during the transition periods was greater in comparison to the walking periods (>40% across all paths). It was concluded that trunk speed extracted from inertial systems have fair accuracy during walking, but the accuracy was reduced in the transition periods.  相似文献   
97.
98.
The electrical resistivity tomography (ERT) represents one of the widely used geophysical techniques for the exploration of the subsurface. In the last few years, this method has been demonstrated to be an efficient reconnaissance tool not only for monitoring degradation status of walls and foundations of historical buildings, but also for imaging the spatial distribution of injected mortar, commonly employed for consolidation purposes. A 3D resistivity tomography survey was carried out on four selected wall portions of the historical church of Montepetriolo, Perugia, Central Italy. The obtained 3D resistivity distribution models before and after grouting provided suggestive images of the internal structure of the studied walls. Moreover, the spatial distribution of the zones being filled with mortar was determined quantitatively by scaling the post- to the preinjection resistivity values. Using a well known correlation between resistivity and porosity, established in the geophysical community, a further step towards a more quantitative assessment was attempted to indirectly determine the unit volumes of the injected mortar The obtained results were satisfactory and in some cases almost similar to the yard data. Furthermore, two flat-jack tests confirmed the local increment of the mechanical resistance of the studied left front (2) and right lateral (3) wall portions.  相似文献   
99.
Active participation in the information society requires the ability to find some order in the chaotic nature of the Web and not to get lost within the endemic presence of inaccurate, misleading, biased and false information. This article presents an approach to Information Problem Solving (IPS) – that is, finding, understanding and assessing information on the Web – and discusses a study carried out in an Italian secondary school, using an experimental and a control group. The study aimed at exploring how to best foster IPS skills, and observing whether and how IPS activities could promote the development of more general learning dispositions and competences. After a period of training with IPS activities, the experimental group showed different dispositions towards learning from a text and engaging with open-ended questions. Despite serious limitations in the depth of analysis, most students were able to reach acceptable solutions; at the same time, they felt empowered and developed an embryonic critical attitude on which it might be possible to build further.  相似文献   
100.
This article aims to investigate how university students perform agency in an online course and whether the collaborative nature of the course affects such expression. A total of 11 online web forums involving 18 students (N = 745 posts in total) were qualitatively analysed through the use of a codebook composed of five categories (individual, interpersonal, epistemic, transformative and collective) and several sub-categories purposely developed for the sake of this research. The results show that each category follows a specific path, although two events – the re-mixing of the groups and the assumption of the peer-tutor role – particularly affected the evolution of trends. Although this study needs further development, the authors believe that an in-depth understanding of the nature of agency, including how to analyse it as well as empower it when implementing blended educational activities, engages relevant theoretical and pedagogical issues.  相似文献   
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