Temporal effects in trend prediction: identifying the most popular nodes in the future

Prediction is an important problem in different science domains. In this paper, we focus on trend prediction in complex networks, i.e. to identify the most popular nodes in the future. Due to the preferential attachment mechanism in real systems, nodes' recent degree and cumulative degree have been successfully applied to design trend prediction methods. Here we took into account more detailed information about the network evolution and proposed a temporal-based predictor (TBP). The TBP predicts the future trend by the node strength in the weighted network with the link weight equal to its exponential aging. Three data sets with time information are used to test the performance of the new method. We find that TBP have high general accuracy in predicting the future most popular nodes. More importantly, it can identify many potential objects with low popularity in the past but high popularity in the future. The effect of the decay speed in the exponential aging on the results is discussed in detail

Non-transferable unidirectional proxy re-encryption scheme for secure social cloud storage sharing

(c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.Proxy re-encryption (PRE), introduced by Blaze et al. in 1998, allows a semi-trusted proxy with the re-encryption key to translatea ciphertext under the delegator into another ciphertext, which can be decrypted by the delegatee. In this process, the proxy is required to know nothing about the plaintext. Many PRE schemes have been proposed so far, however until now almost all the unidirectional PRE schemes suffer from the transferable property. That is, if the proxy and a set of delegatees collude, they can re-delegate the delegator's decryption rights to the other ones, while the delegator has no agreement on this. Thus designing non-transferable unidirectional PRE scheme is an important open research problem in the field. In this paper, we tackle this open problem by using the composite order bilinear pairing. Concretely, we design a non-transferable unidirectional PRE scheme based on Hohenberger et al.'s unidirectional PRE scheme. Furthermore, we discuss our scheme's application to secure cloud storage, especially for sharing private multimedia content for social cloud storage users.Peer ReviewedPostprint (author's final draft

Beyond Routine: Symbolic Adoption, Extended Use, and Emergent Use of Complex Information Systems in the Mandatory Organizational Context

Organizational investments in complex information systems (CIS) have reached a record high. However, the underutilization of these expensive CIS prevents organizations from achieving the advertised return on investment. This study attempts to address this issue from the perspective of extended use and emergent use. Extended use concerns using more of the technology features, while emergent use concerns applying the technology in a novel manner to support task performance. To study uses that surpass routine use, a special focus is placed on the motivational factor that drives these behaviors. Drawing upon the insights from information system (IS) infusion, the IS continuance model, and the symbolic adoption theory, this paper proposes a research model for understanding extended and emergent use in mandatory organizational contexts. The model was examined in two large manufacturing firms that had implemented CIS for at least two years. The results suggest that perceived usefulness, satisfaction, and symbolic adoption influence extended use, and that perceived usefulness, symbolic adoption, and extended use affect emergent use. More importantly, the concept of symbolic adoption offers a theoretical explanation for extended and emergent use from the motivational point of view. Implications for theory and practice are also discussed

Explaining Employees Extended Use of Complex Information Systems

Investments in complex information systems by organizations reached a record high of U.S.$26.7 billion in 2004. Yet, organizations seldom use these systems to the fullest extent and attain the expected return on investment. This paper addresses the issue of system underutilization by investigating Extended Use, which refers to using more system features to support one\u27s tasks. Extended Use was examined in the nomological networks of the IS Continuance (ISC) Model and Technology Acceptance Model (TAM). A field survey was conducted in a large manufacturing firm that had successfully implemented a popular enterprise resource planning solution for more than 2 years. All paths in both ISC and TAM were statistically significant. A synthesized model was later proposed and examined in a post hoc analysis. The results indicate that the synthesized model, as compared to ISC and TAM, explained slightly higher variances in Extended Use, Perceived Usefulness (PU), and Satisfaction. Specifically, both Perceived Ease of Use (PEOU) and PU both affected Extended Use. Interestingly, Satisfaction has no direct impact on Extended Use in the presence of PU and PEOU. In contrast to most technology acceptance research, PEOU has a stronger behavioral impact than that of PU. This research provides a framework that explains Extended Use and is one of the few studies that investigates IS use behavior that exceeds simple, shallow, and routine use

Effect of electroosmotic flow on brine imbibition in porous media

AbstractBased on Darcy's Law and the Helmholta-Smoluchowski equation, an imbibition velocity formula for the water phase with an electric field was deduced, showing that the imbibition velocity with an electric field is to various extents not only related to the rock permeability and characteristic length, the fluid viscosity, the oil-water interface tension and the gravity of the imbibing brine, but also to the fluid dielectric permittivity, zeta potential, applied electric field direction, and strength. Imbibition experiments with electric fields that are different in direction and strength were conducted, showing that application of a positive electric field enhances the imbibition velocity and increases the imbibition recovery ratio, while application of a negative electric field reduces the imbibition velocity and decreases the imbibition recovery ratio. The imbibition recovery ratio with a positive electric field increases with the strength of the electric field, and the imbibition recovery ratio with a negative electric field is lower than that without an electric field