Pixel-Level Clustering Network for Unsupervised Image Segmentation

While image segmentation is crucial in various computer vision applications, such as autonomous driving, grasping, and robot navigation, annotating all objects at the pixel-level for training is nearly impossible. Therefore, the study of unsupervised image segmentation methods is essential. In this paper, we present a pixel-level clustering framework for segmenting images into regions without using ground truth annotations. The proposed framework includes feature embedding modules with an attention mechanism, a feature statistics computing module, image reconstruction, and superpixel segmentation to achieve accurate unsupervised segmentation. Additionally, we propose a training strategy that utilizes intra-consistency within each superpixel, inter-similarity/dissimilarity between neighboring superpixels, and structural similarity between images. To avoid potential over-segmentation caused by superpixel-based losses, we also propose a post-processing method. Furthermore, we present an extension of the proposed method for unsupervised semantic segmentation. We conducted experiments on three publicly available datasets (Berkeley segmentation dataset, PASCAL VOC 2012 dataset, and COCO-Stuff dataset) to demonstrate the effectiveness of the proposed framework. The experimental results show that the proposed framework outperforms previous state-of-the-art methods.Comment: 13 page

Évaluation des charges de fatigue des haubans des ponts haubanés sous l'action du vent et des véhicules

L'effet de la rotation aux ancrages est connu comme la principale raison engendrant la fatigue des haubans. Malgré la grande variation de cet effet d'un hauban à l'autre, tous les haubans des ponts haubanés sont généralement conçus par une même règle proposée dans plusieurs normes et recommandations. Cette règle semble excessive pour le cas des haubans dont l'effet de la rotation n'est pas important (tablier très rigide, espacement des haubans petit, etc.), mais probablement pas suffisamment sécuritaire pour le cas des haubans dont cet effet devient critique (tablier très flexible, grand espacement des haubans, haubans très longs, etc.). Afin d'optimiser la conception des ponts haubanés, il est donc intéressant d'estimer la demande de la fatigue qui consiste elle-même à estimer la demande de rotation aux ancrages des haubans. Ce document présente un projet de recherche visant à évaluer la rotation aux ancrages des haubans sous les charges de trafic et de vent. Un indice d'amplification de fatigue qui relie la rigidité du tablier, l'espacement des haubans et leur rigidité verticale à l'amplitude de rotation aux ancrages bas des haubans sous les charges routières est développé. En se basant sur des calculs analytiques et numériques (méthode des éléments finis), des équations sont proposées pour prédire l'amplitude de rotation aux ancrages bas des haubans sous charge de fatigue. Il est démontré que la contrainte axiale maximale due aux charges d'exploitation n'est pas directement liée à la rotation aux ancrages bas des haubans. En combinant avec un autre indice, \Omega, il est possible de relier la contrainte axiale maximale dans le hauban et l'amplitude de rotation à son ancrage bas. Afin d'évaluer la rotation des haubans sous les charges de vent, des essais en soufflerie ont d'abord été réalisés pour évaluer les coefficients aérodynamiques d'un cylindre incliné (représentant un hauban) dans un écoulement. Le cylindre a été positionné à différents angles d'inclinaisons, par rapport à la verticale et l'horizontal, relatifs au vent. Deux balances dynamiques à trois composantes ont été conçues pour mesurer les forces aérodynamiques. Les trois coefficients des forces aérodynamiques sont normalisés en se basant sur la vitesse de l'écoulement. Les résultats montrent que le coefficient de traînée et la résultante du coefficient de portance ainsi que celui de côté peuvent être exprimés par une fonction empirique en fonction de l'angle d'incidence. Le coefficient de portance et celui de côté restent cependant des fonctions d'angles vertical et horizontal, et ne peuvent pas s'exprimer en fonction de l'angle d'incidence. Il a été observé expérimentalement que le principe d'indépendance devient inexact pour les angles d'incidence supérieurs à 40◦. Les résultats expérimentaux ont ensuite été appliqués pour déterminer les charges de vent sur les haubans. La rotation aux ancrages des haubans due aux charges de vent comprend deux parties: l'une est due à la variation de la vitesse moyenne du vent et l'autre, à ses fluctuations. L'effet de la variation de la vitesse moyenne a été déterminée par des analyses statiques non-linéaires des haubans sous charges de vent moyen correspondant aux moyennes horaires de vitesse de vent extraite à partir des données enregistrées à une station météorologique. L'effet des fluctuations du vent a été déterminée par des analyses dynamiques linéaires des haubans en utilisant la méthode spectrale. Seulement la fluctuation longitudinale de la vitesse du vent a été considérée dans cette étude. Ces rotations ont enfin été comparées à la rotation des haubans sous les charges routières. Les résultats de cette étude permettent de constater la sensibilité des haubans à chaque source de fatigue

Entrepreneurial Finance: Insights from English Language Training Market in Vietnam

Entrepreneurship plays an indispensable role in the economic development and poverty reduction of emerging economies like Vietnam. The rapid development of technologies during the Fourth Industrial Revolution (Industry 4.0) has a significant impact on business in every field, especially in the innovation-focused area of entrepreneurship. However, the topic of entrepreneurial activities with technology applications in Vietnam is under-researched. In addition, the body of literature regarding entrepreneurial finance tends to focus on advanced economies, while mostly neglecting the contextual differences in developing nations. Therefore, this research contributes to these topics by investigating the main characteristics of a high potential market for entrepreneurs in Vietnam, which is the English language training market (ELTM). It also aims at indicating the impacts of technology on the entrepreneurial firms within this market, with an emphasis on financing sources. To answer the research questions, this study employs a qualitative analysis and conducts 12 in-depth, semi-structured interviews with entrepreneurs and researchers in the field. The key findings in our study highlight the main contributing factors to the growth of the market, both universally and context-specific for a developing nation like Vietnam. It also lists the leaders in each market segment and the industry’s potential profit margin. The results also show that most entrepreneurs in the ELTM utilized private sources of finance rather than external ones, such as bank loans. It again confirms the idea from previous works that even with the rapid development of the economic and technological landscape, entrepreneurial activities in general barely benefit from additional sources of funding. However, it also points out the distinct characteristics of the ELTM that may influence these financing issues; for example, English training services usually collect revenues from customers before delivering their classes. This is of advantage for entrepreneurs in this area and helps significantly reduce the financial barriers. These findings, which are among the first attempts to contribute to a better understanding of entrepreneurial opportunities in the Industry 4.0 in Vietnam, provide valuable insights for policymakers and entrepreneurs, as well as investors

Calculation of nonlinear vibrations of piecewise-linear systems using the shooting method

In this paper, an explicit formulation of the shooting scheme for computation of multiple periodic attractors of a harmonically excited oscillator which is asymmetric with both stiffness and viscous damping piecewise linearities is derived. The numerical simulation by the shooting method is compared with that by the incremental harmonic balance method (IHB method), which shows that the shooting method is in many respects distinctively advantageous over the incremental harmonic balance method

Federated Few-shot Learning for Cough Classification with Edge Devices

Automatically classifying cough sounds is one of the most critical tasks for the diagnosis and treatment of respiratory diseases. However, collecting a huge amount of labeled cough dataset is challenging mainly due to high laborious expenses, data scarcity, and privacy concerns. In this work, our aim is to develop a framework that can effectively perform cough classification even in situations when enormous cough data is not available, while also addressing privacy concerns. Specifically, we formulate a new problem to tackle these challenges and adopt few-shot learning and federated learning to design a novel framework, termed F2LCough, for solving the newly formulated problem. We illustrate the superiority of our method compared with other approaches on COVID-19 Thermal Face & Cough dataset, in which F2LCough achieves an average F1-Score of 86%. Our results show the feasibility of few-shot learning combined with federated learning to build a classification model of cough sounds. This new methodology is able to classify cough sounds in data-scarce situations and maintain privacy properties. The outcomes of this work can be a fundamental framework for building support systems for the detection and diagnosis of cough-related diseases.Comment: 21 pages, 5 figure

STEM education and outcomes in Vietnam: Views from the social gap and gender issues

United Nations’ Sustainable Development Goals 4 Quality Education has highlighted major challenges for all nations to ensure inclusive and equitable quality access to education, facilities for children, and young adults. The SDG4 is even more important for developing nations as receiving proper education or vocational training, especially in science and technology, means a foundational step in improving other aspects of their citizens’ lives. However, the extant scientific literature about STEM education still lacks focus on developing countries, even more so in the rural area. Using a dataset of 4967 observations of junior high school students from a rural area in a transition economy, the article employs the Bayesian approach to identify the interaction between gender, socioeconomic status, and students’ STEM academic achievements. The results report gender has little association with STEM academic achievements; however, female students (αa_Sex[2] = 2.83) appear to have achieved better results than their male counterparts (αa_Sex[1] = 2.68). Families with better economic status, parents with a high level of education (βb(EduMot) = 0.07), or non-manual jobs (αa_SexPJ[4] = 3.25) are found to be correlated with better study results. On the contrary, students with zero (βb(OnlyChi) = -0.14) or more than two siblings (βb(NumberofChi) = -0.01) are correlated with lower study results compared to those with only one sibling. These results imply the importance of providing women with opportunities for better education. Policymakers should also consider maintaining family size so the parents can provide their resources to each child equally

Cultural evolution in Vietnam’s early 20th century: a Bayesian networks analysis of Franco-Chinese house designs

The study of cultural evolution has taken on an increasingly interdisciplinary and diverse approach in explicating phenomena of cultural transmission and adoptions. Inspired by this computational movement, this study uses Bayesian networks analysis, combining both the frequentist and the Hamiltonian Markov chain Monte Carlo (MCMC) approach, to investigate the highly representative elements in the cultural evolution of a Vietnamese city’s architecture in the early 20th century. With a focus on the façade design of 68 old houses in Hanoi’s Old Quarter (based on 78 data lines extracted from 248 photos), the study argues that it is plausible to look at the aesthetics, architecture, and designs of the house façade to find traces of cultural evolution in Vietnam, which went through more than six decades of French colonization and centuries of sociocultural influence from China. The in-depth technical analysis, though refuting the presumed model on the probabilistic dependency among the variables, yields several results, the most notable of which is the strong influence of Buddhism over the decorations of the house façade. Particularly, in the top 5 networks with the best Bayesian Information Criterion (BIC) scores and p\u3c0.05, the variable for decorations (DC) always has a direct probabilistic dependency on the variable B for Buddhism. The paper then checks the robustness of these models using Hamiltonian MCMC method and find the posterior distributions of the models’ coefficients all satisfy the technical requirement. Finally, this study suggests integrating Bayesian statistics in the social sciences in general and for the study of cultural evolution and architectural transformation in particular

Conservation, Exploitation And Use Of The Ginger Family (Zingiberaceae) At The National Genebank In Vietnam

There are 741 accessions in the ginger family such as turmeric, ginger, galangal, and pinecone ginger collections conserved at Plant Resources Center, Vietnam. These collections were highly diverse in the number of accessions and species composition. The results of the Zingiberaceae exploitation shown the G10 ginger variety plants reached around 63.7 - 77.5 cm in height, 400 - 500 g/clumps in fresh weight, 25 - 27 tonnes/ha in fresh yield. The G10 ginger variety contained 4.37% oil, 1.2 mg/kg Zn and 9.31 mg/100g Vitamin C. This G10 ginger variety resistance to leaf spot and green aphids. In addition, the N8 turmeric variety plants reached 130 - 170 cm in height; 880 - 1000 g/clumps in fresh weight and 35 tonnes/ha in yield, curcumin content 6.2 - 6.6%, essential oil contents 2.5 - 2.7%. This turmeric resistance to heat stress, leaf spot, and green aphids. The conserved root and tuber crops at PRC are very diverse both of the amount of sample in collections and species. Conservation and evaluation on root and tuber crops reviewed the promising G10 ginger and N8 turmeric varieties had high yield, good oil content to release for production

A study on multi-criteria decision-making in powder mixed electric discharge machining cylindrical shaped parts

In life as well as in engineering, many times, it is necessary to choose the best option among many different options. That will be more difficult when the criteria given for the selection contradict each other. For example, when external cylindrical grinding, the minimum surface roughness requirement necessitates a small depth of cut and feed rate. The material removal rate will be reduced in this case, and this requirement will conflict with the maximum material removal rate requirement. To solve the above problem, a very useful tool is multi-criteria decision-making (MCDM). In this paper, for the first time, MCDM results for powder mixed discharge machining (PMEDM) cylindrical parts of SKD11 tool steel with copper electrodes have been presented. In this work, eighteen experiments with the L18 (16×53) design using the Taguchi method were conducted. Six main input process parameters include the powder concentration, the pulse current, the servo voltage, the pulse on time, and the pulse off time. To select an alternative that simultaneously ensures two criteria including minimum surface roughness (RS) and maximum material removal speed (MRS), four different MCDM methods including MAIRCA (Multi-Attributive Ideal-Real Comparative Analysis), MARCOS (Measurement of Alternatives and Ranking according to Compromise Solution), TOPSIS (Technique for order of preference by similarity to ideal solution), and EAMR (Area-based Method of Ranking) and two methods of criteria weight calculation including MEREC (Method based on the Removal Effects of Criteria) and Entropy methods were selected. The results of MCDM when PMEDM SKD11 tool steel cylindrical parts with two methods for weight determination and four methods for solving MCDM problem were evaluated. In addition, the best alternative to ensure simultaneous minimum RS and maximum MRS was proposed