Search results

The purpose of this paper is to analyze and compare the costs of price and income subsidies when the food security policy targets the urban poor. The result may help policymakers choose a desired subsidy scheme to ensure food security for the urban poor facing food price surge.

The analysis consists of three parts: constructing an empirical model on provincial panel data in 1993‐2009 estimating the impact of grain price on food security among urban residents by different income level; evaluating the potential costs of shifting to income subsidy aiming to maintain the real income levels of the low income, lowest income or the poor residents if grain price increases by 20 percent; and comparing with the cost of price subsidy to achieve the same policy goal.

The paper finds that, food price surge will hurt the urban poor much more seriously than the high income population; the rich residents may receive more benefit from price subsidy; and income subsidy has obviously a cost advantage while the targeted people benefit more.

The obvious value of the paper is to show that income subsidy is much more desired than price subsidy, if the policy goal is to help the poor during food price surge.

This paper aims to prepare Poly(Styrene-Butyl acrylate-Methacrylic acid) @Poly Gallic acid-Fe³⁺ photonic crystal composite inks [P(St-BA-MAA)@PGA-Fe³⁺ PCCI, @ means the PGA-Fe³⁺ is loaded on the microspheres] and construct noniridescent structural colors on fabric substrates, with the goal of improving the visibility of structural colors.

P(St-BA-MAA)@PGA-Fe³⁺ PCCI were prepared by coating P(St-BA-MAA) microspheres with a metal-polyphenol network formed by gallic acid (GA, C₇H₆O₅) and Fe³⁺. The assembly effects of the inks were explored under different conditions, including pH, temperature, concentration and surface tension. The optimal self-assembly conditions of the inks were determined using the controlled variable method.

The results demonstrated the successful preparation of P(St-BA-MAA)@PGA-Fe³⁺ PCCI. The metal polyphenol network film composed of GA and Fe³⁺ was successfully coated on the surface of P(St-BA-MAA) seed microspheres. The assembly mechanism of the inks was investigated, indicating that at a diethylene glycol (DEG, C₄H₁₀O₃) concentration of 0.3 wt% and pH of 7, bright noniridescent structural colors could be formed on fabric surfaces after self-assembly by PCCI at 60 °C for 10 min. Furthermore, the mechanical fastness of the structural colors was enhanced due to the adherence of the soft shell composed of P(St-BA-MAA) and GA.

Utilizing a cost-effective approach and a diverse array of readily available raw materials, we have successfully prepared P(St-BA-MAA)@PGA-Fe³⁺ PCCI, which boasts superior performance and offers fabrics a range of unique coloring styles. This innovation paves the way for potential applications of structural colors in practical production, thereby broadening their realm of utility.

This study aims to reveal the room-temperature effect of a superconducting gravimeter prototype, which will guide its subsequent optimization to improve its gravimetric measurement accuracy.

Without leveling, the prototype output signal, tilt data and room temperature were measured under steady operating conditions. After analyzing the correlations of the three data sets, the residuals of the prototype’s output signal were compensated using the tilt data and the geodynamic effects (ocean tide loading, atmospheric loading and the gravitational effect of polar motion) were then corrected.

The remaining residuals after correction may be caused by small tilt variations that are due to the sensor chamber temperature and radiation shield temperature changes. These small tilt variations were submerged in the tilt signal noise. Although the peak-to-peak noise of the tiltmeter does not exceed 15 µrad, it can still produce gravimetric deviations above 60 µGal when the prototype is significantly tilted.

This study analyzes in detail the room-temperature effect of a superconducting gravimeter prototype, introduces the tilt effect of the relative gravimeters to compensate for the gravimetric deviations and emphasizes that the improvement of fine leveling and the accuracy of the tiltmeter are key requirements for the prototype to perform high-accuracy gravity measurement tasks.

This paper aims to present a longitudinal and visualising study using bibliometric approaches to depict the emerging trends and research hotspots within the mobile information system domain.

Publications included in the Web of Science (WoS) database for 2001–2021 are reviewed and analysed on various aspects through coauthorship, cocitation and co-occurrence analysis. The analyses are conducted using VOSViewer, a scientific visualisation software program.

Academic publications related to mobile information systems fluctuated at a low level during the initial part of the 21st century and have grown rapidly in number in the past decade. The USA and China are the leading contributors to these publications and hold dominant positions in the obtained collaboration network. Computer science, engineering and telecommunications are the top three research areas in which mainstream mobile information system research occurs. Moreover, medical informatics and health-care science services have gradually become new research hotspots.

This study provides a systematic and holistic account of the developmental landscape of the mobile information system domain. This study provides a good basis for analysing the evolution of research in mobile information systems and may serve as a potential foundation for future research.

Compared to the occurrence of conflict in general teams in organizations, conflict occurrence in entrepreneurial teams is more prevalent and intense. However, previous studies have found inconsistent relationships between entrepreneurial team conflict and performance, and the mechanisms underlying this relationship remain in the “black box.” Drawing on the motivated information processing in groups theory, this study aims to investigate how and when entrepreneurial team conflict influences entrepreneurial performance.

The authors collected survey data from 190 entrepreneurs across 58 entrepreneurial teams in China. The hypothesized relationships were examined through path analysis using the Mplus7.0 program.

Entrepreneurial team relationship conflict is negatively related to entrepreneurial performance mediated through team behavioral integration. Conversely, there exists a curvilinear (U-shaped) relationship between entrepreneurial team task conflict and entrepreneurial performance, also mediated through team behavioral integration. Furthermore, the curvilinear relationship between entrepreneurial team task conflict and team behavioral integration is strengthened by team contractual governance, whereas the relationship between entrepreneurial team relationship conflict and team behavioral integration is not moderated by team contractual governance.

This study contributes to a deeper understanding of the relationship between entrepreneurial team conflict and performance by identifying the mediating mechanism and boundary condition. The finding of a U-shaped relationship between entrepreneurial team task conflict and entrepreneurial performance underscores the uniqueness of the entrepreneurial team context, offering new empirical insights for future conflict research.

Recently, the double joint photographic experts group (JPEG) compression detection tasks have been paid much more attention in the field of Web image forensics. Although there are several useful methods proposed for double JPEG compression detection when the quantization matrices are different in the primary and secondary compression processes, it is still a difficult problem when the quantization matrices are the same. Moreover, those methods for the different or the same quantization matrices are implemented in independent ways. The paper aims to build a new unified framework for detecting the doubly JPEG compression.

First, the Y channel of JPEG images is cut into 8 × 8 nonoverlapping blocks, and two groups of features that characterize the artifacts caused by doubly JPEG compression with the same and the different quantization matrices are extracted on those blocks. Then, the Riemannian manifold learning is applied for dimensionality reduction while preserving the local intrinsic structure of the features. Finally, a deep stack autoencoder network with seven layers is designed to detect the doubly JPEG compression.

Experimental results with different quality factors have shown that the proposed approach performs much better than the state-of-the-art approaches.

To verify the integrity and authenticity of Web images, the research of double JPEG compression detection is increasingly paid more attentions.

This paper aims to propose a unified framework to detect the double JPEG compression in the scenario whether the quantization matrix is different or not, which means this approach can be applied in more practical Web forensics tasks.

As to different angles of attack and nonlinear problems caused by high temperatures in coexisting hypersonic aircraft, people mainly rely on fluid software for research but lack analysis of flow mechanisms. Owing to computational difficulties, few people use numerical algorithms to combine them for discussion. Hence, this study aims to make a deep inquiry into the laminar flow and heat transfer of compressible Newtonian fluid in hypersonic aircraft with small attack angles.

In this paper, on the basis of mass, momentum and energy conservation laws, the governing equations of the hypersonic boundary layer are established. Viscosity, specific heat capacity and thermal conductivity are considered nonlinear functions concerning temperature. In virtue of the MacCormack finite difference method, the stationary numerical solutions are solved directly, and the validity of the algorithm is verified.

The results demonstrate that at Mach number 5, compared to the 0° attack angle, the maximum temperature near-wall at the 3° attack angle increases by about 25%. An enjoyable phenomenon is discovered, where the position corresponding to the maximum wall shear force shifts back as the attack angle and Mach number increase. The relationship between the near-wall maximum temperature versus attack angle and Mach number is fitted through numerical calculation results.

Empirical formulas can be used to estimate heat transfer characteristics at small attack angles, which will guide the design of aircraft thermal protection systems.

Recent years have witnessed the rapid development of massive open online courses (MOOCs). With more and more courses being produced by instructors and being participated by learners all over the world, unprecedented massive educational resources are aggregated. The educational resources include videos, subtitles, lecture notes, quizzes, etc., on the teaching side, and forum contents, Wiki, log of learning behavior, log of homework, etc., on the learning side. However, the data are both unstructured and diverse. To facilitate knowledge management and mining on MOOCs, extracting keywords from the resources is important. This paper aims to adapt the state-of-the-art techniques to MOOC settings and evaluate the effectiveness on real data. In terms of practice, this paper also tries to answer the questions for the first time that to what extend can the MOOC resources support keyword extraction models, and how many human efforts are required to make the models work well.

Based on which side generates the data, i.e instructors or learners, the data are classified to teaching resources and learning resources, respectively. The approach used on teaching resources is based on machine learning models with labels, while the approach used on learning resources is based on graph model without labels.

From the teaching resources, the methods used by the authors can accurately extract keywords with only 10 per cent labeled data. The authors find a characteristic of the data that the resources of various forms, e.g. subtitles and PPTs, should be separately considered because they have the different model ability. From the learning resources, the keywords extracted from MOOC forums are not as domain-specific as those extracted from teaching resources, but they can reflect the topics which are lively discussed in forums. Then instructors can get feedback from the indication. The authors implement two applications with the extracted keywords: generating concept map and generating learning path. The visual demos show they have the potential to improve learning efficiency when they are integrated into a real MOOC platform.

Conducting keyword extraction on MOOC resources is quite difficult because teaching resources are hard to be obtained due to copyrights. Also, getting labeled data is tough because usually expertise of the corresponding domain is required.

The experiment results support that MOOC resources are good enough for building models of keyword extraction, and an acceptable balance between human efforts and model accuracy can be achieved.

This paper presents a pioneer study on keyword extraction on MOOC resources and obtains some new findings.

This study, based on construal level theory, aims to examine the influential mechanism of leader empowerment behaviour on employee creativity. Specifically, it examines the mediating role of cognitive flexibility between leader empowerment behaviour and employee creativity, along with the moderating effect of consideration of future consequences (CFC) on this linkage.

A two time-point survey study (n = 214) was conducted to collect information from leaders and employees in terms of mutual evaluation in several Chinese industries. To effectively avoid common source bias, this survey was conducted through pairing leaders and employees. During the survey, the supervisors and subordinates were double-blinded. Correlation analysis and hierarchical regression analysis were used to test the research hypotheses.

Firstly, leader empowerment behaviour can significantly predict employee creativity. Second, cognitive flexibility plays a partial mediating role in the linkage between leader empowerment behaviour and employee creativity. Thirdly, CFC moderates the relationship between leadership empowerment behaviour and cognitive flexibility. The mediating role of cognitive flexibility underlies the overall moderating effect of CFC on the relationship between leader empowerment behaviour and employee creativity.

We used construal level theory to explain the influence of the mechanism of leader empowerment behaviour on employee creativity. In this manner, this study bridges the gap between theory and practice, as well as enriching the research on leader empowerment behaviour and employee creativity, especially in the Chinese context. Moreover, our study has several practical managerial implications, based on the importance of employee creativity. It inspires the implementation of leader empowerment behaviour, cultivation of employee creativity and introduction of several procedures.

This paper discusses the influential mechanism of leader empowerment behaviour on employee creativity from a new perspective and explains the process of encouraging employee creativity through information-processing methods. It mainly highlights the application of construal level theory to discuss employee creativity and develops a new research frame for employee creativity. Leaders can raise employee creativity through leader empowerment behaviour.

Some indirect evidence indicates that leadership may affect work-related flow, a core concept in positive psychology. However, the exact process of how this relationship takes place is still unknown. Based on the nature of leader-member exchange (LMX), the purpose of this paper is to hypothesize a moderated mediation model of the LMX-flow relationship in which psychological empowerment is the mediator while emotional intelligence (EI) is the moderator.

Two samples are utilized in the study. One sample (n=219) is from the service industry representing a high emotional labor job, and the other sample (n=208) is from the manufacturing industry representing a low emotional labor job.

In both the samples, psychological empowerment mediates the positive relationship between LMX and work-related flow. However, the moderated mediation effect of EI is supported only in the service sample but not in the manufacturing sample.

Leader plays an important role in facilitating subordinates’ flow experience by enhancing psychological empowerment. For the high emotional labor job, employees with high EI are better able to transfer leader’s support into flow experience.

The paper, as the first study to connect LMX with flow concept, advances the study of positive psychology in workplace context, especially the leadership field. By proposing a mediating mechanism and outlining EI as a moderator, the study explains how LMX relates to flow experience at work.