▶ This study applied the combination of a topic modeling algorithm and a path-finding algorithm to mine research topics of scientists based on their publications and identified their semantic ...associations based on coauthorship networks and author citation networks. ▶ This paper was able to address the collaboration patterns and citation patters at the topic level rather than at the domain/disciplinary level.
Scientific collaboration and endorsement are well-established research topics which utilize three kinds of methods: survey/questionnaire, bibliometrics, and complex network analysis. This paper combines topic modeling and path-finding algorithms to determine whether productive authors tend to collaborate with or cite researchers with the same or different interests, and whether highly cited authors tend to collaborate with or cite each other. Taking information retrieval as a test field, the results show that productive authors tend to directly coauthor with and closely cite colleagues sharing the same research interests; they do not generally collaborate directly with colleagues having different research topics, but instead directly or indirectly cite them; and highly cited authors do not generally coauthor with each other, but closely cite each other.
Citation analysis does not generally take the quality of citations into account: all citations are weighted equally irrespective of source. However, a scholar may be highly cited but not highly ...regarded: popularity and prestige are not identical measures of esteem. In this study we define popularity as the number of times an author is cited and prestige as the number of times an author is cited by
highly cited papers. Information retrieval (IR) is the test field. We compare the 40 leading researchers in terms of their popularity and prestige over time. Some authors are ranked high on prestige but not on popularity, while others are ranked high on popularity but not on prestige. We also relate measures of popularity and prestige to date of Ph.D. award, number of key publications, organizational affiliation, receipt of prizes/honors, and gender.
•Revised title, introduction, literature review and hypotheses development to better describe our research focus.•Emphasizing our theoretical contribution to social media clearly.•Adding more ...discussion about why we choose DOUYU as our research case.•Revising conclusion part by discussing the theoretical contributions and managerial implications respectively.•Modifying typos and grammar errors. Also, polishing the entire paper.
A novel function of live streaming is that viewers can send paid gifts to broadcasters. In addition, viewers can engage with broadcasters by sending danmaku, a type of comment scrolled across the screen in real time. This paper investigates the role of viewers’ social interaction in paid gifting on live streaming platforms. We argue that viewer-viewer interaction can prompt paid gifting by affecting viewers’ arousal level through stimuli extracted from danmaku. Types of danmaku-related stimuli are presence of others, social competition, and emotional stimuli. Specifically, presence of others is measured by total number of words; social competition by debate level; and emotional stimuli by similarity of danmaku, number of excitement-related words, and number of emoji. Using data from a major live streaming platform in China, empirical results show that except for number of emoji, the other four variables positively affect paid gifting.
This research is motivated by discovering and underpinning genetic causes for the progression of a bilateral eye disease, age-related macular degeneration (AMD), of which the primary outcomes, ...progression times to late-AMD, are bivariate and interval-censored due to intermittent assessment times. We propose a novel class of copula-based semiparametric transformation models for bivariate data under general interval censoring, which includes the case 1 interval censoring (current status data) and case 2 interval censoring. Specifically, the joint likelihood is modeled through a two-parameter Archimedean copula, which can flexibly characterize the dependence between the two margins in both tails. The marginal distributions are modeled through semiparametric transformation models using sieves, with the proportional hazards or odds model being a special case. We develop a computationally efficient sieve maximum likelihood estimation procedure for the unknown parameters, together with a generalized score test for the regression parameter(s). For the proposed sieve estimators of finite-dimensional parameters, we establish their asymptotic normality and efficiency. Extensive simulations are conducted to evaluate the performance of the proposed method in finite samples. Finally, we apply our method to a genome-wide analysis of AMD progression using the Age-Related Eye Disease Study data, to successfully identify novel risk variants associated with the disease progression. We also produce predicted joint and conditional progression-free probabilities, for patients with different genetic characteristics.
The modern intelligent transportation system brings not only new opportunities for vehicular Internet of Things (IoT) services but also new challenges for vehicular ad-hoc networks (VANETs). Apart ...from enhanced network performance, a practical and reliable security scheme is needed to handle the trust management while preserving user privacy at the same time. The emerging 5G mobile communication system is viewed as a prominent technology for ultra-reliable, low-latency wireless communication services. Furthermore, incorporating software-defined network (SDN) architecture into the 5G-VANET enables global information gathering and network control. Hence, real-time IoT services on transportation monitoring and reporting can be well supported. Both pave the way for an innovative vehicular security scheme. This paper investigates the security and privacy issue in the transportation system and the vehicular IoT environment in SDN-enabled 5G-VANET. Due to the decentralized and immutable characteristics of blockchain, a blockchain-based security framework is designed to support the vehicular IoT services, i.e., real-time cloud-based video report and trust management on vehicular messages. This paper explicitly illustrates the SDN-enabled 5G-VANET model and the scheduling procedures of the blockchain-based framework. The numerical simulation results also show that malicious vehicular nodes or messages can be well detected while the overhead and impact on the network performance are acceptable for large-scale scenarios. Through case studies and theoretical analysis, we demonstrate our design substantially guarantees a secure and trustworthy vehicular IoT environment with user privacy preserved.
Purpose
To determine if magnetic resonance imaging (MRI) histogram analyses can help predict response to chemotherapy in patients with colorectal hepatic metastases by using response evaluation ...criteria in solid tumours (RECIST1.1) as the reference standard.
Materials and methods
Standard MRI including diffusion-weighted imaging (b=0, 500 s/mm
2
) was performed before chemotherapy in 53 patients with colorectal hepatic metastases. Histograms were performed for apparent diffusion coefficient (ADC) maps, arterial, and portal venous phase images; thereafter, mean, percentiles (1st, 10th, 50th, 90th, 99th), skewness, kurtosis, and variance were generated. Quantitative histogram parameters were compared between responders (partial and complete response, n=15) and non-responders (progressive and stable disease, n=38). Receiver operator characteristics (ROC) analyses were further analyzed for the significant parameters.
Results
The mean, 1st percentile, 10th percentile, 50th percentile, 90th percentile, 99th percentile of the ADC maps were significantly lower in responding group than that in non-responding group (
p
=0.000–0.002) with area under the ROC curve (AUCs) of 0.76–0.82. The histogram parameters of arterial and portal venous phase showed no significant difference (
p
>0.05) between the two groups.
Conclusion
Histogram-derived parameters for ADC maps seem to be a promising tool for predicting response to chemotherapy in patients with colorectal hepatic metastases.
Key Points
•
ADC histogram analyses can potentially predict chemotherapy response in colorectal liver metastases.
•
Lower histogram-derived parameters (mean, percentiles) for ADC tend to have good response.
•
MR enhancement histogram analyses are not reliable to predict response.
In this paper; the surface plasmon resonance (SPR) sensor with a porous silica film was studied. The effect of the thickness and porosity of the porous silica film on the performance of the sensor ...was analyzed. The results indicated that the figure of merit (FOM) of an SPR sensor can be enhanced by using a porous silica film with a low-refractive-index. Particularly; the FOM of an SPR sensor with 40 nm thick 90% porosity porous silica film; whose refractive index is 1.04 was improved by 311% when compared with that of a traditional SPR sensor. Furthermore; it was found that the decrease in the refractive index or the increase in the thickness of the low-refractive-index porous silica film can enlarge the FOM enhancement. It is believed that the proposed SPR sensor with a low-refractive-index porous silica film will be helpful for high-performance SPR sensors development.
Cancer is a leading cause of death among people living with HIV/AIDS (PLWHA). We conducted a systematic review and meta-analysis to evaluate prevalence of cancer risk factors among Chinese PLWHA ...based on 102 articles. Random effects meta-analysis was used to calculate the summary prevalence estimate (sPrev) and 95% confidence interval (CI) for each cancer risk factor by demographic group. Overall, the sPrev for each risk factor among Chinese PLWHA was: 41.1% (95% CI: 35.3-46.9%) for current smoking; 30.3% (95% CI: 23.3-37.4%) for current alcohol consumption; 24.4% (95% CI: 14.7-30.2%) for overweight and obesity; 12.5% (95% CI: 10.6-14.3%) for hepatitis B virus infection; 29.1% (95% CI: 23.6-34.5%) for hepatitis C virus infection; 33.9% (95% CI: 24.3-43.5%) for high-risk human papillomavirus infection from cervical samples and 78.6% (95% CI: 69.4-87.7%) from anal samples; 2.7% (95% CI: 0.7-4.7%) for Epstein-Barr virus (EBV) immunoglobulin M (IgM) positivity, 94.7% (95% CI: 90.7-98.8%) for EBV IgG positivity and 25.6% (95% CI: 12.4-38.8%) for EBV DNA positivity; 14.9% (95% CI: 12.4-17.4%) for human herpes virus 8 infection. The prevalence of major cancer risk factors was high among PLWHA in China, suggesting an urgent need for interventions to reduce cancer risk in this high-risk group.
Traditional citation analysis has been widely applied to detect patterns of scientific collaboration, map the landscapes of scholarly disciplines, assess the impact of research outputs, and observe ...knowledge transfer across domains. It is, however, limited, as it assumes all citations are of similar value and weights each equally. Content‐based citation analysis (CCA) addresses a citation's value by interpreting each one based on its context at both the syntactic and semantic levels. This paper provides a comprehensive overview of CAA research in terms of its theoretical foundations, methodical approaches, and example applications. In addition, we highlight how increased computational capabilities and publicly available full‐text resources have opened this area of research to vast possibilities, which enable deeper citation analysis, more accurate citation prediction, and increased knowledge discovery.
Greenhouses constitute a proven solution for coping with environmental degradation and for increasing both the quantity and quality of agricultural products. Appropriate carbon dioxide (CO2) control ...not only improves crop yield and quality but also reduces the carbon footprint of greenhouses. However, CO2 enrichment control in greenhouses is a dynamic, interactive and time-delayed process. In practice, optimal CO2 concentrations in the greenhouse are difficult to maintain because CO2 is confounded with temperature, humidity, light intensity, etc.; therefore, ambient CO2 concentrations in greenhouses are often suboptimal or excessive. This paper is a review of the current theoretical and applied studies of CO2 enrichment in greenhouses and discusses the advantages and limitations of various methods. The major points addressed are as follows: 1) the five sources of CO2 enrichment in greenhouses; 2) the monitoring and data processing of CO2 concentrations; and 3) the various methods for controlling automatic CO2 enrichment. This paper discusses new challenges and perspectives and suggests future studies and methods for a greenhouse CO2 enrichment system. A new symbiotic greenhouse system requiring sensible CO2 balance is also presented.
•Different sources of carbon dioxide (CO2) for greenhouse enrichment are discussed.•Control strategies for greenhouse CO2 enrichment are reviewed.•Research Challenges of CO2 control in the greenhouse are presented.•A new symbiosis greenhouse system requiring sensible CO2 balance is described.
PDF
