User Privacy Awareness, Incentive and Data Supply Chain Pricing Strategy

In recent years, the collection, mining, and utilization of data have become a new profit growth point for enterprises, and these events have also accelerated the pace of enterprises to collect users’ data. However, the relevance of personal data privacy and the frequent occurrence of data leakage events have increased users’ privacy awareness. The purpose of our study is to enhance the effective flow of data while protecting users’ data privacy. The data supply chain consists of the end user, data provider, and service provider, and involves the flow of the value-added process of data. Our study focuses on the pricing strategy of data products considering data incentive and data protection levels. We propose three models—centralized pricing, decentralized pricing, and revenue-sharing pricing—and solve them, and then we analyze the impact of users’ privacy awareness on data incentives, protection, and pricing of data products in the three models. We also analyze which pricing method works best for participants

Dietary Vegetable Powders Modulate Immune Homeostasis and Intestinal Microbiota in Mice

As the largest immune organ of the human body, the intestine also plays a vital role in nutrient digestion and absorption. Some vegetables are considered to have improvement effects on the intestine. This experiment explored the effects of freeze-dried asparagus, broccoli and cabbage powder on the intestinal immune homeostasis and microflora of mice. Thirty-two mice were divided into four groups (n = 8), including control group (fed normal diet), asparagus group (fed normal diet with 5% asparagus power), broccoli group (fed normal diet with 5% broccoli power) and cabbage group (fed normal diet with 5% cabbage power). The experiment lasted 21 days. The results showed that the serum immunoglobulin concentration (IgA and IgM) and intestinal cytokine content (like IFN-γ and TNF-α) were increased after vegetable powder supplement. The experiment also detected that vegetable powder supplementation changed intestinal flora and their metabolites (short-chain fatty acid), which showed that the abundance of Lachnospiraceae and Bacteroides were decreased, while the abundance of Firmicutes and Lactobacillus as well as propionic acid and butyric acid contents were increased. Together, these vegetable powders, especially cabbage, changed the intestinal immune response and microbial activity of mice

Determination of inner pressure for fluid inclusions by Raman spectroscopy and its application

Using a Diamond Anvil Cell combined with micro Raman spectroscopy, the quantitative relations among Raman shifts, pressure and temperature were obtained for the vibration of O–H in H2O–NaCl, C–O in CO32−, S–O in SO42− and C–H in n-heptane-cyclohexane. Based on the quantitative relationships obtained, it is possible to determine the inner pressure for single fluid inclusions and to further determine the isochore of the systems. It is not only helpful to obtain the forming temperatures and pressures of the enclosing minerals, but also to be able to provide information concerning the chemical compositions of the fluid inclusions

Role of Nitrogen on the Mechanical Properties of the Novel Carbon Nitride Nanothreads

Carbon nanothread (C-NTH) is a new ultrathin one-dimensional sp3 carbon nanostructure, which exhibits promising applications in novel carbon nanofibers and nanocomposites. Recently, researchers have successfully developed a new alternative structure - ultrathin carbon nitride nanothread (CN-NTH). In this work, we investigate the mechanical properties of CN-NTHs through large-scale molecular dynamics simulations. Comparing with their C-NTH counterparts, CN-NTHs are found to exhibit a higher tensile and bending stiffness. In particular, because of the bond redistribution, the CN-NTHs in the polymer I group and tube (3,0) group are found to possess a higher failure strain than their C-NTH counterparts. However, the CN-NTH in the polytwistane group has a smaller failure strain compared with the pristine C-NTH. According to the atomic configurations, the presence of nitrogen atoms always leads to stress/strain concentrations for the nanothreads under tensile deformation. This study provides a comprehensive understanding of the mechanical properties of CN-NTHs, which should shed light on their potential applications such as fibers or reinforcements for nanocomposites.</p

An E-learning Ecosystem Based on Cloud Computing Infrastructure

Recently the research community has believed that an e-learning ecosystem is the next generation e-learning. However, the current models of e-learning ecosystems lack the support of underlying infrastructures, which can dynamically allocate the required computation and storage resources for e-learning ecosystems. Cloud computing is a promising infrastructure which provides computation and storage resources as services. Hence, this paper introduces Cloud computing into an e-learning ecosystem as its infrastructure. In this paper, an e-learning ecosystem based on Cloud computing infrastructure is presented. Cloud computing infrastructure and related mechanisms allow for the stability, equilibrium, efficient resource use, and sustainability of an e-learning ecosystem

Modeling User Psychological Experience and Case Study in Online E-learning

In the post WWW era, the research of e-learning focuses on facilitating intelligent and proactive services for learners. The quality of user experience determines whether e-learning services would be accepted by learners. However, many researchers traditionally focus on the effectiveness of computer systems or the accuracy of algorithms themselves rather than on user-centric psychological experience. How to model and evaluate user experience taking into account user psychological and cognitive properties are challenging research topics. There are some traditional methods typically proposed to evaluate users’ psychological experience, such as interview, questionnaire etc. They are qualitative and easy to conduct but need more time and resource. And they are liable to subjective views. Based on user web log data, the current paper presents a quantitative approach of modeling user psychological experience in the context of intelligent e-learning. The properties and elements, which affect user experience, are analyzed and quantified. The holistic user experience is quantified through the fusion of analytic hierarchy process (AHP) and Delphi methods. A case study, at a university in China, is conducted for diagnosing whether the result of the proposed approach can be uniform with user subjective experience, and indicates that the proposed approach is effective and complements existing user experience research in intelligent e-learning

Mechanical Properties of a Single-Layer Diamane under Tension and Bending

Based on atomistic simulations, we investigated the mechanical properties of a single-layer diamond - diamane under tensile and bending deformation. It is found that the layer stacking sequence exerts ignorable influence on the mechanical properties of diamane. Specifically, a similar Young's modulus is found along the zigzag and armchair directions, whereas a much larger fracture strain/strength is observed along the zigzag direction. Atomic configurations reveal that the fracture of diamane is dominated by the crack propagation along zigzag directions, which is independent of the tensile directions. Moreover, Young's modulus and the fracture strain/strength are found to decrease when the temperature increases, and the relationship between the fracture strain/strength and temperature can be well described by the kinetic fracture theory. It is additionally found that diamane possesses a high bending stiffness (around 3600 eV Å). These findings establish a fundamental understanding of the mechanical behavior of diamane, which should benefit its usage in advanced nanodevices. </p

Analysis of the vibrational characteristics of diamane nanosheet based on the Kirchhoff plate model and atomistic simulations

Single layer diamond—diamane, has been reported with excellent mechanical properties. In this work, molecular dynamics (MD) simulation and Kirchhoff plate model are utilized to investigate the vibrational characteristics of diamane sheets. The mechanical parameters of diamane sheets, including bending stiffness, Young’s modulus, Poisson’s ratio and coefficient of thermal expansion, are calibrated by using MD simulations. The natural frequencies and corresponding modal shapes of the diamane sheets predicted by the Kirchhoff plate model agree well with that obtained from the MD simulations. It is found that the edges exert marginal effect on the modal shapes when free boundary conditions are applied. Additionally, the Kirchhoff plate model considering the thermal expansion provides reasonable prediction for the natural frequencies of the diamane sheets with all boundary clamped under varying temperatures. This study offers valuable insights into the vibrational properties of diamane sheets, from both a simulation and theoretical standpoint. The findings would be beneficial for the design of nanoscale mechanical resonators utilizing these novel carbon materials.</p

How Gaseous Environment Influences a Carbon Nanotube-Based Mechanical Resonator

Nanoscale mechanical resonator-based nanoelectromechanical systems have been reported with ultrahigh sensitivity, which are normally acquired from an ultravacuum environment at cryostat temperature. To facilitate their practical applications for gas sensing or bio-detection, it is critical to understand how the fluid (gas or liquid) environment will impact the resonance behaviors of the nanoresonator. This work reports a first-time comprehensive investigation on the influence of the N2 gaseous environment on the resonance properties of carbon nanotube (CNT)-based mechanical resonator, through a combination of grand canonical Monte Carlo and large-scale molecular dynamics simulations. It is shown that the gaseous environment exerts a significant effect on the resonance properties of the CNT resonator through a dynamic desorption and readsorption process. Under the temperature of 100 K and the pressure of 1 bar, the displacement amplitude of the CNT resonator is found to experience a sharp reduction of about 82% within the first 90 ps vibration in the N2 gaseous environment. Further, a large initial excitation is found to result in smaller adsorption and a reduced damping effect. For instance, when the excitation velocity amplitude increases from 2 to 8 Å/ps, the damping ratio shows more than 40% reduction. It is found that higher pressure leads to a smaller resonance frequency and enhanced damping effect, while higher temperature induces an increase in the resonance frequency but a decrease in the damping ratio. This work shows that the gaseous environment has a marked impact on the vibrational properties of nanoresonators, which should shed light on the application of mechanical nanoresonators in a fluid environment.</p