Probabilistic Multilevel Clustering via Composite Transportation Distance

We propose a novel probabilistic approach to multilevel clustering problems based on composite transportation distance, which is a variant of transportation distance where the underlying metric is Kullback-Leibler divergence. Our method involves solving a joint optimization problem over spaces of probability measures to simultaneously discover grouping structures within groups and among groups. By exploiting the connection of our method to the problem of finding composite transportation barycenters, we develop fast and efficient optimization algorithms even for potentially large-scale multilevel datasets. Finally, we present experimental results with both synthetic and real data to demonstrate the efficiency and scalability of the proposed approach.Comment: 25 pages, 3 figure

An open database of productivity in Vietnam's social sciences and humanities for public use

This study presents a description of an open database on scientific output of Vietnamese researchers in social sciences and humanities, one that corrects for the shortcomings in current research publication databases such as data duplication, slow update, and a substantial cost of doing science. Here, using scientists’ self-reports, open online sources and cross-checking with Scopus database, we introduce a manual system and its semi-automated version of the database on the profiles of 657 Vietnamese researchers in social sciences and humanities who have published in Scopus-indexed journals from 2008 to 2018. The final system also records 973 foreign co-authors, 1,289 papers, and 789 affiliations. The data collection method, highly applicable for other sources, could be replicated in other developing countries while its content be used in cross-section, multivariate, and network data analyses. The open database is expected to help Vietnam revamp its research capacity and meet the public demand for greater transparency in science management

Improving Bayesian statistics understanding in the age of Big Data with the bayesvl R package

The exponential growth of social data both in volume and complexity has increasingly exposed many of the shortcomings of the conventional frequentist approach to statistics. The scientific community has called for careful usage of the approach and its inference. Meanwhile, the alternative method, Bayesian statistics, still faces considerable barriers toward a more widespread application. The bayesvl R package is an open program, designed for implementing Bayesian modeling and analysis using the Stan language’s no-U-turn (NUTS) sampler. The package combines the ability to construct Bayesian network models using directed acyclic graphs (DAGs), the Markov chain Monte Carlo (MCMC) simulation technique, and the graphic capability of the ggplot2 package. As a result, it can improve the user experience and intuitive understanding when constructing and analyzing Bayesian network models. A case example is offered to illustrate the usefulness of the package for Big Data analytics and cognitive computing

Does diversification affect the quality of loan portfolio?Panel Granger-causality evidence from US banks

This paper investigates the direction of causality between bank business model and the quality of loan portfolio using a large sample of US banks. We employ the panel causality testing approach, developed by Dumitrescu and Hurlin (2012), and new technique of optimal lag selection of Hans et al (2017). Empirical results show that there is evidence of two-way causality between diversification and non-performing loans

CURRENT SITUATION AND SOLUTIONS DEVELOPING TEAM OF THE LECTURES IN VIETNAM CURRENT EDUCATION INSTITUTIONS

In the context that the fundamental and comprehensive reform of higher education in Vietnam is being promoted, it is becoming increasingly urgent to set requirements for innovation and to develop the team of lecturers, especially when the goal of education is the formation of personality and the development of personal capabilities for learners. With the identification of the teaching staff as the decisive factor for the success of the educational innovation process, the article summarizes and analyzes the current situation of the team of lecturers in higher education institutions in Vietnam today. On that basis, some basic solutions are proposed to develop the teaching staff to meet the tasks in the coming time. Article visualizations

Scrambling for higher metrics in the Journal Impact Factor bubble period: a real-world problem in science management and its implications

Universities and funders in many countries have been using Journal Impact Factor (JIF) as an indicator for research and grant assessment despite its controversial nature as a statistical representation of scientific quality. This study investigates how the changes of JIF over the years can affect its role in research evaluation and science management by using JIF data from annual Journal Citation Reports (JCR) to illustrate the changes. The descriptive statistics find out an increase in the median JIF for the top 50 journals in the JCR, from 29.300 in 2017 to 33.162 in 2019. Moreover, on average, elite journal families have up to 27 journals in the top 50. In the group of journals with a JIF of lower than 1, the proportion has shrunk by 14.53% in the 2015–2019 period. The findings suggest a potential ‘JIF bubble period’ that science policymaker, university, public fund managers, and other stakeholders should pay more attention to JIF as a criterion for quality assessment to ensure more efficient science management

DETERMINATION OF VARIABLE LAW OF THE TURBULENT DIFFUSION PARAMETERS WITH TIME INTERVAL IN THE AIR ENVIRONMENT IN VIETNAM

Joint Research on Environmental Science and Technology for the Eart

Assessment of the “Rule of Thirds” Inter-Occlusal Distance Ratio of Angle Class I and II Occlusions: An In Vivo Study

When treatment planning an increase in VDO a dental articulator is used to orient the maxillary and mandibular casts in centric occlusion. The incisal pin can be raised to increase the proposed VDO. This results in more inter-occlusal distance between the anterior teeth than the posterior because of the “arc of closure”. Several studies have mentioned this variation in inter-occlusal distance in the posterior teeth compared to the anterior teeth, specifically at the molar region and central incisors. Rebibo et al, proposed a “Rule of Thirds” explaining that for the same vertical variation, molar height, incisal edge and anterior pin are proportional. The “Rule of Thirds” states that for a 3mm increase at the incisal pin, we obtain a 2mm increase at the incisors and 1mm increase between molars.” The purpose of this in vivo study was to: 1. Evaluate the validity of the “Rule of Thirds” for facebow-mounted casts on a dental articulator. 2. Assess differences between Angle Class I and II occlusions. The null hypothesis was there would be no statistically significant difference in the findings of this study and previous studies regarding the “Rule of Thirds”, and there would be no statistically significant difference in the “Rule of Thirds” between Angle Class I and II occlusions. Thirty participants were selected and impressions of the maxillary and mandibular arches were made with irreversible hydrocolloid. A facebow record was made and casts were mounted in centric relation on a SAM 3 dental articulator. The interocclusal distance at the second molar was set at 1mm, and measurements at the central incisors, and incisal pin were recorded for data analysis. Within the limitation of this in vivo study, the following conclusions can be drawn: 1. There was no significant difference between the findings of this study and previous studies regarding the “Rule of Thirds”. 2. There was no significant difference in the incisal vertical point, incisal horizontal point, and incisal pin point, between Angle Class I and II occlusions. 3. The inter-occlusal distance ratio of the second molar to the vertical overlap of the central incisor and incisal pin was approximately 1:1.8:2.9 on the SAM 3 articulator. 4. The inter-occlusal distance ratio of the second molar to the horizontal overlap of the central incisor was approximately 1:0.8